Browse Topic: Passive suspension systems

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Experimental Assessment of a Controlled Slippage Magnetorheological Automotive Active Suspension for Ride Comfort10-06-04-00248/23/2022
Active suspensions can alter the dynamic behavior of a vehicle in real time to respond optimally to any given operating scenario. Today’s active suspension technologies such as hydraulics, rotary electromagnetics, and linear electromagnetics do offer performance gains but these gains are outweighed by important disadvantages including high power consumption, low quality of force, and high costs and weights. Controlled slippage magnetorheological (MR) actuators are an emerging alternative actuation technology that is light, compact, power dense, and produces a high-quality force, making it ideal for active suspension applications. This article conducts an in-depth experimental assessment of the potential of MR actuators to increase vehicle ride comfort quality when used as active suspensions. Four high power MR actuators are installed on a BMW 330Ci and tests are performed on a closed road. Results show that with an impedance controller, comfort is increased by 67% at 65 km/h and by 61% at 80 km/h. These results compare favorably with the best-in-class electromagnetic active suspension technologies reported to date and suggest that MR actuators are promising for automotive active suspensions.
Turcotte, Jérôme, East, William, Plante, Jean-Sébastien
Vibration Control of Semi-Active Vehicle Suspension System Incorporating MR Damper Using Fuzzy Self-Tuning PID Approach2020-01-10824/14/2020
In this paper, a nonlinear semi-active vehicle suspension system using MR fluid dampers is investigated to enhance ride comfort and vehicle stability. Fuzzy logic and fuzzy self-tuning PID control techniques are applied as system controllers to compute desired front and rear damping forces in conjunction with a Signum function method damper controller to assess force track-ability of system controllers. The suggested fuzzy self-tuning PID operates fuzzy system as a PID gains tuner to mitigate the vehicle vibration levels and achieve excellent performance related to ride comfort and vehicle stability. The equations of motion of four-degrees-of-freedom semi-active half-vehicle suspension system incorporating MR dampers are derived and simulated using Matlab/Simulink software. Control performance criteria including bounce and pitch motions are evaluated in both time and frequency domains in order to quantify the effectiveness of proposed system controllers under bump and random road disturbances. Fuzzy self-tuning PID controller gives a better force tracking than fuzzy logic. The performance of both controlled semi-active suspension systems using MR dampers is compared with MR passive and conventional passive to show the efficiency of the proposed controlled suspension systems. The simulation results prove that the semi-active MR suspension system controlled using fuzzy self-tuning PID controller can offer significant improvements of ride comfort and vehicle stability among all investigated systems.
Gad, Ahmed Shehata, Oraby, W., Metered, H.
Multi-Mode Controller Design for Active Seat Suspension with Energy-Harvesting2020-01-10834/14/2020
In this paper, a multi-mode active seat suspension with a single actuator is proposed and built. A one-DOF seat suspension system is modelled based on a quarter car model of commercial vehicle with an actuator which is comprised of a DC motor and a gear reducer. Aiming at improving ride comfort and reducing energy consumption, a multi-mode controller is established. According to the seat vertical acceleration and suspension dynamic travel signals, control strategies switch between three modes: active drive mode, energy harvesting mode and plug breaking mode. In active drive mode, the DC motor works in driving state and its output torque which calculated by LQR algorithm is controlled by a current-loop controller; In energy harvesting mode, the DC motor works in generator state by which induced current can charge the power source, in this mode, the DC motor is considered as a damper which damping coefficient is decided by the charging current and controlled by Skyhook algorithm; In plug breaking mode, the DC motor works in the plug breaking state and its inverse voltage reaches to maximum to stop the suspension movement quickly. Simulations are carried out with random road and triangle block as the road excitation. The simulation results show that the multi-mode control strategy improves the ride comfort a lot compared with passive seat suspension, which effectively reduces energy consumption compared with fully active control strategy meanwhile.
Zhang, Zhenrui, Zhang, Yunqing, Xu, Peijun
The Effect of Friction on Ride Comfort Simulation and Suspension Optimization2020-01-07654/14/2020
The design of suspension affects the vehicle dynamics such as ride comfort and handling stability. Nonlinear characteristics and friction are important characteristics of suspension system, and the influence on vehicle dynamic performance cannot be ignored. Based on the seven-degree-of-freedom vehicle vibration nonlinear model with friction, the vibration response process of the vehicle and the influence of suspension friction on vehicle ride comfort and suspension action process were studied. The results show that friction will significantly affects the simulation of ride comfort and coincide with the function of the shock absorber. The suspension shock absorbers of vehicles were optimized with and without suspension friction. The results showed that the suspension tended to choose softer shock absorbers when there was friction. However, both of the two optimizations are able to improve the ride comfort of vehicles, and the simulation results were similar. At the same time, it was found that the better the dynamic performance of the vehicle model, the greater the influence of suspension friction on the simulation results of ride comfort.
Xuwang, Wang, Chen, Xiaoyu, Xu, Peijun, Zhang, Yunqing
Behavioral Study on Passenger and Driver Dynamics Utilizing 14-DOF Half Car Active Suspension System2020-01-10064/14/2020
The main aim of the current research work is to investigate the behavior of passenger and driver biomechanics when the vehicle is excited under road irregularities. For this purpose, a 14-degrees of freedom (DOF) human-vehicle-road model was proposed. In addition to that, the ride comfort of the occupant with the aid of active suspension and its influence on other performance indices like suspension working space and road holding were also investigated. Besides sprung mass acceleration, the ride comfort was evaluated with pitching acceleration and occupant’s head acceleration representation. Active suspension based on Proportional Integral Derivative (PID) controller with hydraulic actuator was implemented. Then, the parameters of the PID controller are optimally tuned by adopting genetic algorithm (GA) with the assist of integral time absolute error (ITAE) method. The objective function was obtained by combining the ITAE of tire deflection, suspension deflection and sprung mass motion. Various road profiles such as single bump and random profile were generated and tested on the proposed controller vehicle model to guarantee the robustness. Numerical examples were presented under frequency and time domains to clearly demonstrate the effectiveness of the proposed GAPID-based active suspension system over the passive system. Furthermore, the Seat-To-Head transmissibility ratio (STH) for driver and passenger was established to comprehend the behavior.
Anandan, Arivazhagan, K, Arunachalam
Second-Order Sliding Mode Controller for Performance Analysis of Quarter Car Magnetorheological Suspension System2020-01-10054/14/2020
To achieve the simultaneous improvement in ride comfort of the passenger as well as the stability of the vehicle, a second-order sliding mode controller is proposed in this study. Super twisting algorithm attenuates the chattering effect present in the conventional sliding mode controller without affecting the stability of the system. The Lyapunov stability analysis is carried out to verify the stability of the controller. The effectiveness of the designed super twisting algorithm used second-order sliding mode controller is validated in a semiactive quarter car suspension with seat model. Modified Bouc-wen magnetorheological (MR) damper model is used as a semiactive damper and the voltage that has to be supplied to the magnetorheological damper is controlled by a super twisting algorithm and sliding mode controller. Continuous modulation filtering algorithm is adopted to convert the force signal of a controller into the equivalent voltage input to the MR damper. The entire system is modelled in Matlab/Simulink software and the simulations are carried out based on random road disturbances. The results show that there is a significant improvement in the second-order sliding mode controller semiactive MR suspension system compared with an uncontrolled passive suspension system. The robustness of the system is verified by analyzing it with mass uncertainties. Selected second-order sliding mode controller is validated by comparing it with a conventional sliding mode controller. The results depict a significant improvement in the performance of suspension system because of the application of the super twisting algorithm, second-order sliding mode controller.
Soosairaj, Arockia Suthan, K, Arunachalam
Minimizing Power Consumption of Fully Active Vehicle Suspension System Using Combined Multi-Objective Particle Swarm Optimization2019-01-50777/16/2019
This paper introduces an optimum design for a feedback controller of a fully active vehicle suspension system using the combined multi-objective particle swarm optimization (CMOPSO) in order to minimize the actuator power consumption while enhancing the ride comfort. The proposed CMOPSO algorithm aims to minimize both the vertical body acceleration and the actuator power consumption by searching about the optimum feedback controller gains. A mathematical model and the equations of motion of the quarter-car active suspension system are considered and simulated using Matlab/Simulink software. The proposed active suspension is compared with both active suspension system controlled using the linear quadratic regulator (LQR) and the passive suspension systems. Suspension performance is evaluated in time and frequency domains to verify the success of the proposed control technique. The simulated results reveal that the proposed controller using CMOPSO grants a significant enhancement of ride comfort and road holding, and reduction of actuator power consumption.
Elsawaf, Ahmed, Metered, H., Abdelhamid, A.
A Novel Three Steps Composited Parameter Matching Method of an Electromagnetic Regenerative Suspension System2019-01-01734/2/2019
The electromagnetic regenerative suspension has attracted much attention recently due to its potential to improve ride comfort and handling stability, at the same time recover kinetic energy which is typically dissipated in traditional shock absorbers. The key components of a ball-screw regenerative suspension system are a motor, a ball screw and a nut. For this kind of regenerative suspension, its damping character is determined by the motor's torque-speed capacity, which is different from the damping character of the traditional shock absorber. Therefore, it is necessary to establish a systematic approach for the parameter matching of ball-screw regenerative suspension, so that the damping character provided by it can ensure ride comfort and handling stability. In this paper, a 2-DOF quarter vehicle simulation model with regenerative suspension is constructed. The effects of the inertia force on ride comfort and handling stability are analyzed. A novel three steps composited matching method is proposed to determine the non-linear damping character of the ball-screw electromagnetic regenerative suspension. In this composited method, a genetic algorithm is adopted to calculate the optimal damping coefficient within its linear range, probability statistics is applied to determine the constant damping force provided by the motor over constant damping range, and the decreasing damping force range is determined by the motor speed ratio. Through the above three steps, system parameters including the motor rated power and the lead of ball screw are determined. The effectiveness of the systematic parameter selection approach is validated through simulation.
Cui, Dandan, Yongchang, Du
Vibration Control of an Active Seat Suspension System Integrated Pregnant Woman Body Model2019-01-01724/2/2019
Proportional-integral-derivative (PID) controller is effective, popular and cost effective for a lot of scientific and engineering applications. In this paper, PID and fuzzy-self-tuning PID (FSTPID) controllers are applied to improve the performance of an active seat suspension system to enhance the pregnant woman comfort. The equations of motion of thirteen-degrees-of-freedom (13-DOF) active seat suspension system incorporating pregnant woman body model are derived and simulated. PID gains are tuned and estimated using genetic algorithm (GA) to formulate GA PID controller. In FSTPID, fuzzy logic technique is used to tune PID controller gains by selecting appropriate fuzzy rules using Matlab/Simulink software. Both controlled active seat suspension systems are compared with a passive seat suspension. Suspension performance is evaluated under bump and random road excitations in order to verify the success of the proposed controllers. Theoretical results reveal that the proposed controllers using GA PID and FSTPID grant a significant enhancement of the pregnant woman comfort and her fetus.
Ali, Shaimaa A., Metered, H., Bassiuny, A. M, Abdel-Ghany, AM
A Study of Triple Skyhook Control for Semi-Active Suspension System2019-01-01684/2/2019
The research described in this paper focused on improving occupant ride comfort and road holding by suppressing sprung and unsprung vibration using a semi-active suspension system. It has been reported that occupants tend to perceive vertical vibrations in a frequency range between 4 and 8 Hz as uncomfortable (described below as the “mid-frequency range”). Previous research into semi-active suspension system has focused on reducing vibration in this mid-frequency range, as well as close to the sprung resonance frequency of between 1 and 2 Hz. Skyhook damper (SH) control is a typical ride comfort control used to damp vibration close to the sprung resonance frequency. However, since SH control is not capable of damping vibration in the mid-frequency range, the shock absorbers are configured with a lower damping factor. This helps to achieve a good balance between reducing vibration close to the sprung mass resonance and in the mid-frequency range. In contrast, it has the trade-off effect of increasing unsprung vibration. The triple skyhook (tSH) control, which suspends the vehicle using three virtual elements (i.e., springs, dampers, and inerters), has been proposed to help resolve these issues. This control is capable of reducing sprung vibration over a wide range without altering the suspension characteristics. Furthermore, this control only uses information from sprung mass sensors, and can be configured using simple control laws. The purpose of this research is to simultaneously satisfy requirements for both ride comfort and road holding by applying tSH control to a vehicle with a semi-active suspension system. This was accomplished by driving a test vehicle over an irregular road surface, and analyzing the vehicle roll, pitch, and heave, as well as the unsprung vibration frequency. As a result, this research confirmed that the proposed control improves ride comfort by reducing sprung vibration over a wide frequency range. In addition, by suppressing deterioration in unsprung vibration, the control improves the road-holding performance compared to the conventional SH control.
Shimoya, Naoto, Katsuyama, Etsuo
Model Reference Control for Active Suspension System2019-01-01654/2/2019
The objective of this study is to develop a Model Reference Control (MRC) strategy for active suspension System. The MRC strategy employs both the suspension look-ahead preview and wheelbase preview concepts, and the methodology of the MRC based on the ideal hybrid skyhook-groundhook concept. The study performed using a 13 degree-of-freedom (DoF) vehicle vertical dynamics model including the active suspension actuators masses. The engine mass, driver seat and anti-roll bar are considered in the model. The MRC strategy uses eight Proportional-Integral-Derivative (PID) controllers for both body and wheel control. A gradient-based optimization algorithm is applied to obtain the controller parameters using a cost function including both ride comfort and road holding performance. Comparison between the active suspension system provided with proposed MRC strategy, the ideal hybrid skyhook-groundhook suspension system, and the passive suspension system in terms of ride comfort and road holding is performed. The obtained results showed that, the proposed MRC strategy with the PID controllers are able to track the performance of the ideal hybrid skyhook-groundhook system, and provided significant improvements in both ride comfort and road holding.
Kaldas, Mina M.S., Soliman, Aref M.A., Abdallah, Sayed A., Amien, Fomel F.
Application of a Preview Control with an MR Damper Model Using Genetic Algorithm in Semi-Active Automobile Suspension2019-01-50062/5/2019
A non-linear mathematical model of a semi-active (2DOF) vehicle suspension using a magnetorheological (MR) damper with information concerning the road profile ahead of the vehicle is proposed in this paper. The semi-active vibration control system using an MR damper consists of two nested controllers: a system controller and a damper controller. The fuzzy logic technique is used to design the system controller based on both the dynamic responses of the suspension and the Padé approximation algorithm method of a preview control to evaluate the desired damping force. In addition, look-ahead preview of the excitations resulting from road irregularities is used to quickly mitigate the effect of the control system time delay on the damper response. Adaptive neuro-fuzzy inference system (ANFIS) inverse model without preview, ANFIS inverse model with preview, and ANFIS inverse model with preview and optimization strategies are used to design the damper controller to evaluate different values of the command voltage based on the tracking of a desired damping force to compare which of them gave the best behavior of the MR damper. Each one of these strategies is used in conjunction with the system controller to evaluate the effectiveness of a damper controller design on semi-active control. Control performance criteria are evaluated in the time and frequency domains in order to quantify the suspension effectiveness under bump and random road disturbance. The simulation results prove that the proposed strategy of the ANFIS inverse model with preview and optimization on MR damper produces a smoother and lower input voltage to the MR damper coil, ensuring extended damper life and lower power requirement, respectively. The compared results reveal that although the ANFIS inverse model with preview and optimization is able to improve ride comfort and vehicle stability over other mentioned strategies for semi-active suspension system or even passive suspension system.
Shehata Gad, Ahmed, El-Zoghby, Helmy, Oraby, Walid, Mohamed El-Demerdash, Samir
Improving Vehicle Rollover Resistance Using Fuzzy PID Controller of Active Anti-Roll Bar System06-12-01-000312/20/2018
The active anti-roll bar (AARB) system in vehicles has recently become one of the research hotspots in the field of vehicle technology to improve the vehicle’s active safety. In most off-road vehicles, high ground clearance is required while keeping all wheels in contact with the ground in order to improve traction and maintain load distribution among the wheels. A problem however arises in some types of the off-road vehicles when the vehicle is operated at high speeds on smooth roads. In such condition, the combination of the vehicle’s center of gravity position, large suspension stroke, and soft spring construction creates a stability problem, which could make the vehicle liable to rollover. This article analyzes a comparison of stability performance between passive and active anti-roll bar systems to improve rolling resistance. For active systems, two control strategies will be investigated. The conventional Proportional Integral Derivative (PID) controller is firstly investigated and taken as a reference. Then a modified Proportional Integral Derivative (PID) controller with fuzzy technology is developed and compared to the reference one. A full-car model of 14-degrees of freedom (DOF) associated with the Pacejka tire model is used for the analysis and the simulation of the rollover prevention. The performances of the control strategies are compared and simulated using the MATLAB/Simulink program through a series of stability tests prepared by the National Highway Traffic Safety.
Khalil, Mohamed Mostafa, Atia, Mostafa R.A.
Influence of Intelligent Active Suspension System Controller Design Techniques on Vehicle Braking Characteristics10-03-01-000312/4/2018
This article presents a comprehensive investigation for the interaction between vehicle ride vibration control and braking control using two degrees of freedom (2DOF) quarter vehicle model. A typical limited bandwidth active suspension system with nonlinear spring and damping characteristics of practical hydraulic and pneumatic components is controlled to regulate both suspension and tire forces and therefore provide the optimum ride comfort and braking performance of an anti-lock braking system (ABS). In order to design a suitable controller for this nonlinear integrated system, various control techniques are followed including state feedback tuned using Linear Quadratic Regulator (LQR), state feedback tuned using Genetic Algorithm (GA), Proportional Integral (PI) tuned genetically, and Fuzzy Logic Control (FLC). The ABS control system is designed to limit skid ratio below threshold of 15%. Several simulations are carried out in MATLAB environment to assess the benefits of the designed integrated controller including vehicle body vertical acceleration, dynamic tire load, stopping time, and distance. Furthermore, the proposed control techniques have been examined in terms of robustness, disturbance rejection, and noise attenuation. The obtained results revealed that the nonlinear assumptions of hydraulic and pneumatic suspension system components are notably influenced by the braking performance in terms of stopping time and distance which has successfully justified the aimed research topic. The effectiveness and robustness of the proposed controllers are discussed based on the simulation results which confirmed their significant improvements in both braking and ride characteristics.
Onsy, Ahmed Mahmoud, Sharaf, Alhossein Mostafa, Ashrey, Mahmoud Mohamed, Eldemerdash, Samir Mohamed
PSO-Fuzzy Gain Scheduling of PID Controllers for a Nonlinear Half-Vehicle Suspension System06-12-01-000111/19/2018
The present article addresses the gain scheduling of proportional-integral-differential (PID) controllers using fuzzy set theory coupled with a metaheuristic optimization technique to control the vehicle nonlinear suspension system. The nonlinearities of the vehicle suspension system are due to the asymmetric piecewise dampers, quadratic tire stiffness, and the cubical spring stiffness. Conventional PID controller suffers from the low performance subject to modeling nonlinearities, while fuzzy logic controller (FLC), as a universal approximator, has the capacity to deal with the nonlinear, stochastic, and complex models. However, finding the optimal Mamdani FLC rules is still a challenging task in addition to a proper architecture of the membership functions (MFs). As a remedy to this drawback, particle swarm optimization (PSO) technique is employed in this article to improve the efficiency of the FLC-based PID controllers. The proposed nonlinear controller is suggestive of the decreased overshoot and reduced settling time for the heave and pitch motions of the half-vehicle model. The satisfactory performance of the controller, when tires are subject to random excitations, to reduce the peak magnitude is observable in a relatively less computational time.
Taghavifar, Hamid, Li, Bin
Numerical study on suspension parameters optimization for bus traveling on poor road condition2018-36-00629/3/2018
This paper uses a multi-objective approach in order to optimize the suspension parameters of a bus traveling on poorly maintained runways. The objective functions chosen are the minimization of loads acting on the track and the RMS accelerations on the seat of three strategically positioned passengers on the bus. The numerical model of the bus has 13 degrees of freedom, including lateral dynamics, and the optimization is performed at a traveling speed of 40 km/h in a Double Lane Change (DLC) maneuver. The track is generated according to ISO 8606: 1995, described as class E. The model provides correlations between the sidetracks, and the dynamic interaction between the pavement and the tire is considered using the well-known model of Pacejka. Finally, the equations are solved in the time domain by the nonlinear Newmark method. The numerical model is coupled to a multi-objective optimization algorithm based on the Quantum Particle Swarm Optimization (MOQPSO) and to the well-known Non-dominated Sorting Genetic Algorithm (NSGA-II) algorithm. Comparisons between the algorithms and a mono-objective approach are performed in order to verify the quality of the obtained results, as well as their performance. As general conclusion, it is verified that the new parameters generated by the optimization produce lower vibrations when compared to those obtained by using the nominal values. Thus, the resulting Pareto Front can be used to choose the most suitable components for the minimization of passenger’s acceleration and applied tire loads, remaining to a specialist the choice of the most convenient solution from the Pareto Front.
Gomes, Herbert Martins, Grotti, Ewerton, Backes, Artur Dieguez, Freitas Awruch, Marcos Daniel de
Active SARIB: a New Generation of Suspension for HelicoptersF-0074-2018-127565/14/2018
ABSTRACT The main objective of this paper is to present a new generation of active vibration system for helicopters developed by Airbus Helicopters. The design of this system is the result of an analysis performed through numerical simulations to select the most promising strategy of vibrations mitigation. Different solutions have been compared: classic active vibration control with force generators on the cabin floor, passive suspension based on DAVI system and an innovative active version of a suspension called SARIB®. The reduction of vibratory loads in the vicinity of the rotor pylon with active means appears as the most efficient solution. A development of the active suspension has so been undertaken. The principle of the system is presented firstly in an academic way. Then higher fidelity models are set up to design in details the system and to size it. The active suspension has been manufactured and it has been evaluated through lab test on a full scale mock-up. The test results indicate excellent level of attenuation and they validate the interest and feasibility of the concept.
Cranga, Paul, Jouve, Jérémy, Skladanek, Yan
Suspension Systems: Some New Analytical Formulas for Describing the Dynamic Behavior2018-01-05544/3/2018
The paper presents some new and unreferenced analytical formulae describing the dynamic behaviour of the suspension system of road or off-road vehicles. The quarter car model (2 degrees of freedom) is considered, the suspension can be either passive or active. Passive suspensions can be simplified as the spring-damper combination or the spring-damper combination with an additional in series spring (representing, e.g., the rubber bushing at the top of a McPherson strut or the rubber bushing at the end joints of the damper). The mathematical system is linear and the excitation is given by a random stationary and ergodic process. The standard deviations in analytical form are given referring to, respectively, the vehicle body acceleration, the relative displacement between sprung and unsprung mass, and the force at the ground. The so called invariant points of the frequency response functions are derived for both active and passive suspension. Unreferenced sub-invariant points are derived which give hints on the performance of suspension systems. The analytical expressions of the Pareto-optimal solutions for selecting proper suspension parameters and the preferred performance are given, when possible, in analytical form. Analytical formulae are useful to understand qualitatively the behaviour of suspension systems. Despite their simplicity, they appear to be useful during testing.
Mastinu, Giampiero, Gobbi, Massimiliano, Yang, Liunan, Ramakrishnan, Kesavan, Ballo, Federico
Study on Fuzzy Control of MR into Semi - Active Suspension2018-01-05614/3/2018
Suspension has a great influence on vehicle ride comfort and handling stability. How to improve the suspension performance has received more and more attention. To improve vehicle ride comfort, the magnetorheological damper (MRD) semi-active suspension is studied in this paper. Firstly, the dynamic calibration experiment of MRD was carried out so that the mechanical property curves was obtained. According to the experimental results, the Bouc-Wen model of MRD was identified and validated by Simulink Design Optimization. Secondly, The 1/4 of the vehicle vibration model can construct and calculate the vibration differential equations. The suspension of the simulation model can be constructed by the use of Matlab/Simulink software. Based on the established model, we can do an in-depth research on the active suspension control strategies under different road conditions and make related control strategies use the transfer function method. Then, taking the strong nonlinear of MRD itself into account, the fuzzy control algorithm is used to design the semi-active controller, which is realized by the single-chip microcomputer. Finally, in the Simulink, the magneto-rheological semi-active suspension is simulated and analyzed. We do the research on simulation of active suspension fuzzy control and get the simulation results for different road excitation and speeds. Simulation and experimental results show that the fuzzy control of the semi-active suspension can effectively improve the overall performance of the vehicle suspension. Compared with the passive suspension, the overall performance of the MRD semi-active suspension under the random pavement excitation is obviously improved. It provides the theoretical basis and numerical reference for the experimental study of the semi-active suspension.
Long, Haiyang
Simulation Research of a Hydraulic Interconnected Suspension Based on a Hydraulic Energy Regenerative Shock Absorber2018-01-05824/3/2018
The current paper proposes a hydraulic interconnected suspension system (HIS) based on a hydraulic energy-regenerative shock absorber (HESA) comparatively with the passive suspensions. The structure and working principles of the HIS system are introduced in order to investigate the damping performance and energy regeneration characteristics of the proposed system. Then, the dynamic characteristics of the HIS-HESA system have been investigated based on a 4-DOF longitudinal half vehicle model. In the simulation, two different road inputs were used in the dynamic characterization of the HIS-HESA; the warp sinusoidal excitation, and the random road signal. In addition, a comparative analysis was provided for the dynamic responses of the half vehicle model for both the HIS-HESA and the conventional suspension. Furthermore, a parametric analysis of the HIS-HESA has been carried out highlining the key parameters that have a remarkable effect on the HIS-HESA performance. The dynamic performance evaluation includes both of the body acceleration and the pitch angle as the main analysis criteria of the vehicle dynamic performance. The results showed that the vehicle with the HIS-HESA system has good anti-pitch performance and excellent ride performance against the traditional suspensions. Moreover, the HIS-HESA suspension system can regenerate some of the dissipated power due to the damping process.
Zou, Junyi, Guo, Xuexun, Xu, Lin, Abdelkareem, Mohamed A. A., Gong, Bian, Zhang, Jie, Tan, Gangfeng
Vibration Control of Active Vehicle Suspension System Using Optimized Fuzzy-PID2018-01-14024/3/2018
In this paper, a fuzzy-PID controller is applied in a half vehicle active suspension system to enhance vibration levels of vehicle chassis and passenger seat. The fuzzy-PID controller consists of fuzzy and PID connecting in a series manner, the fuzzy output is considered as the PID input. Genetic Algorithm (GA) is selected to tune controller parameters to obtain optimal values that minimize the objective function. The equations of motion of five-degrees-of-freedom active half-vehicle suspension system are derived and simulated using Matlab/Simulink software. Double bumps and random road excitations are used to study the performance of suspension systems including bounce and pitch motion. The performance of the active suspension system using optimized fuzzy-PID controller is compared with conventional passive to show the efficiency of the proposed active suspension system. The simulation results prove that the active suspension system controlled using the optimized fuzzy-PID controller can offer significant improvements of ride comfort and vehicle stability.
El-taweel, H., Abd elhafiz, Mohamed M., Metered, H.
Multi-Objective Optimization to Improve SUV Ride Performances Using MSC.ADAMS and Mode Frontier2018-01-05754/3/2018
Ride is an important attribute which must be accounted in the passenger segment vehicles. Excessive H point acceleration, Steering wheel acceleration, Pitch acceleration can reduce the comfort of the driver and the passengers during high frequency and low frequency rough road events. Excessive Understeer gradient, roll gradient, roll acceleration and Sprung mass lift could affect the Vehicle driver interaction during Steady state cornering, Braking and Step steer events. The concept architecture of the vehicle plays an important role in how comfort the vehicle will be. This paper discusses how to improve SUV ride performances by keeping handling performance attributes same or better than base vehicle. Multi Objective Optimization was carried out by keeping spring, bushing and damper characteristic as the design variables to avoid new system or component development time and cost. The first step in this process is DOE (Design of Experiments method) which allows to select critical or highly influence input variables and to understand the effect of input variables on output performances. The consequent Optimization leads to select the optimum from various conflicting solutions.
Lenka, Visweswara Rao, Anthonysamy, Baskar, Londhe, Abhijit, Hatekar, Harshad
Energy-Harvesting Potential and Vehicle Dynamics Conflict Analysis under Harmonic and Random Road Excitations2018-01-05684/3/2018
Energy has the worldwide concern since the World War. Recently, the energy harvesting technology has got more attraction in different fields and applications. Hence, in a world where energy becomes rare and expensive, even the small quantities are worth to be harvested where it can be exploited in different applications. Vehicle suspension is one of the vibration power dissipation sources in which the undesired vibration is dissipated into heat waste. Accordingly, the principal motivation of this study is exploitation the conflict between the potentially harvested power and vehicle dynamics in automotive suspension system induced by road irregularity. Therefore, in terms of RMS conflict diagrams, the conflict between the potential power and vehicle dynamics are sufficiently and comprehensively defined considering a vehicle speed of 20 m/s. The conflict analysis includes ride comfort (body acceleration), road handling (dynamic tire force) and potentially harvested power considering the influence of sprung and unsprung masses, stiffness rate, damping coefficient, tire stiffness, speed and road roughness. In this manner, a quarter suspension mathematical model is developed and built in Matlab/Simulink interface and uneven road profile is modeled for different road classes according to the ISO standard. Besides, a parametric analysis study is adopted to investigate the influence of the model parameters on the potentially harvested power. Then, the amount of the potential harvested power is quantified and presented for different driving conditions. The results are of interest for the researchers and vehicle manufacturers for further considerations during design and test preparation in the generative vehicle suspensions.
Abdelkareem, Mohamed A. A., Xu, Lin, Zou, Junyi, Ali, Mohamed Kamal Ahmed, Essa, F. A., Elagouz, Ahmed, Hassan, Mohamed A.
On Enhanced Fuzzy Sliding-Mode Controller and Its Chattering Suppression for Vehicle Semi-Active Suspension System2018-01-14034/3/2018
This paper aims to present an enhanced fuzzy sliding-mode control scheme with variable rate reaching law for semi-active vehicle suspension systems, which can reduce chattering phenomena in high frequency compared with the sliding-mode controller with traditional exponent reaching law. First, an ideal-skyhook damping suspension system is taken as reference model; then the new control law is synthesized by employing the fuzzy logic control while considering the sliding-mode reaching segment characteristics, which can dynamically change the reaching rate to suppress chattering in closed-loop control systems; finally, simulation analysis is conducted under both random road and bump road surface, the results verified the effectiveness and feasibility of the proposed control scheme.
Pang, Hui, Yang, Junjie, Liang, Jun, Xu, Zeren
Optimized Proportional Integral Derivative Controller of Vehicle Active Suspension System Using Genetic Algorithm2018-01-13994/3/2018
Proportional integral derivative (PID) control method is an effective, easy in implementation and famous control technique applied in several engineering systems. Also, Genetic Algorithm (GA) is a suitable approach for optimum searching problems in science, industrial and engineering applications. This paper presents the usage of GA for determining the optimal PID controller gains and their implementation in the active quarter-vehicle suspension system to achieve good ride comfort and vehicle stability levels. The GA is applied to solve a combined multi-objective (CMO) problem to tune PID controller gains of vehicle active suspension system for the first time. The active vehicle suspension system is modeled mathematically as a two degree-of-freedom mechanical system and simulated using Matlab/Simulink software. The performance of the proposed suspension system controlled using the optimized PID GA is compared to both controlled system using the classical PID (C PID) controller and the passive suspension systems. Systems performance criteria are evaluated in both time and frequency domains, in order to quantify the success of the proposed suspension system. The theoretical results reveal that the proposed optimized PID GA controller of the active vehicle suspension provides a vital enhancement of ride comfort and vehicle stability levels.
Metered, H., Abbas, W., Emam, A. S.
Active Suspension Control of Electric Vehicle Driven by Switched Reluctance Motor Based on Vibration Absorbing Structure2018-01-14014/3/2018
Active suspension control for in-wheel switched reluctance motor (SRM) driven electric vehicle with dynamic vibration absorber (DVA) based on robust H∞ control method is presented. The mounting of the electric drives on the wheels, known as in-wheel motor (IWM), results in an increase in the unsprung mass of the vehicle and a significant drop in the suspension ride performance and road holding stability. Structures with suspended shaftless direct drive motors have the potential to improve the road holding capability and ride performance. The quarter car active suspension model equipped with in-wheel SRM is established, in which the SRM stator serves as a dynamic vibration absorber. The in-wheel SRM is modelled using an analytical Fourier fitting method. The SRM airgap eccentricity is influenced by the road excitation and becomes time-varying such that a residual unbalanced radial force is induced. This is one of the major causes of SRM vibration. Current chopping control (CCC) and pulse width modulation control (PWM) are adapted to suppress motor vibration. Moreover, a robust H∞ controller is developed for the active suspension with DVA to further enhance vehicle ride performance. A comparison of passive suspension with conventional SRM, passive suspension with DVA, active suspension with DVA on vehicle suspension and SRM dynamic responses are presented. Simulation results under bump road excitation and random road excitation demonstrate the effectiveness of DVA structure active suspension system with proposed control method in enhancing suspension and motor performance.
Shao, Xinxin, Naghdy, Fazel, Du, Haiping
Suspension Parameters Estimation of a RWD Vehicle2017-36-038211/7/2017
In this work, an inverse problem approach is employed to estimate the suspension parameters of a light vehicle based on field tests. The modeling process of a rear-wheel drive (RWD) vehicle is depicted. The model considers only the vertical dynamics of the vehicle. The experimental data were measured by sensors installed on the vehicle during specific road tests in a proving ground. The inverse problem is solved by using the Particle Swarm Optimization (PSO), minimizing the quadratic error between experimental data and numerical results of the vehicle simulation. Accuracy, computational time, efficiency and efficacy of the model were compared regarding the behavior of the performance responses of the vehicle measured on the road tests. Throughout this process, the vehicle model was validated to be used in future studies of vehicle dynamics.
Campos, Caroline Goulart, de Oliveira, André Noronha, Peralta, Alejandro Oscar, Neto, Ricardo Teixeira da Costa, Caldeira, Aldélio Bueno
Development of Full Air Pneumatic Suspension Type for Commercial Vehicles2017-01-14903/28/2017
The air suspension development and its applications have becoming increasingly relevant for commercial vehicles to provide dynamic ride comfort to driver and reduce the load impact onto driver and or cargo. This paper shows the analysis and application of an air suspension system for commercial tractor vehicles and its dynamic influence. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladed. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. During the development quality tools were used, considering the possible failure modes and effects to guide the design changes in order to achieve the desired behavior, as well as virtual simulation tools (Adams) and rig test validations. Using data acquisition and vehicle test analysis, the improved dynamic results proposed were validated and considered as the final design solution.
Iombriller, Silvia Faria
Optimization of Damper Top Mount Characteristics for Semi-Active Suspension System2017-01-04123/28/2017
Semi-active suspension offers variety of damping force range which demands greater need to optimize the top mount to ensure multiple objectives of ride comfort, harshness and safety can be achieved. For this purpose, this paper proposes a numerical optimization procedure for improving the harshness performance of the vehicle through the adjustment of the damper top mount characteristics of the semi-active suspension system. The proposed optimization process employs a frequency dependent combined objective function based on ride comfort and harshness evaluation. A detailed and accurate damper top mount mathematical model is implemented inside a validated full vehicle model to provide a realistic simulation environment for the optimization study. The semi-active suspension system employs a Rule-Optimized Fuzzy-Logic controller. The ride comfort and harshness of the full vehicle are evaluated by analyzing the body acceleration in different frequency ranges. The dynamic stiffness of the damper top mount is used to describe the optimum damper top mount characteristics for different optimization case studies. The results show that, the proposed optimization routine enables - compensation of the harshness degradation in the semi-active suspension system by adjusting the characteristics of the damper top mount.
Çalışkan, Kemal, Henze, Roman, Küçükay, Ferit, Kaldas, Mina M.S.
Study on Controller of Electronically Controlled Air Suspension for Bus2016-01-80339/27/2016
According to the vehicle’s driving conditions, electronically controlled air suspension (ECAS) systems can actively adjust the height of vehicle body, so that better ride comfort and handling stability will be achieved, which can’t be realized by traditional passive suspension. This paper presents a design and implementation of ECAS controller for vehicle. The controller is aimed at adjusting the static and dynamic height of the vehicle. To exactly track the height of the vehicle and satisfy the control demand of air suspension, a height sensor decoding circuit based on the inductance sensor is designed. Based on it, a new height control algorithm is adopted to achieve rapid and precise control of vehicle height. To verify the function of the designed controller and the proposed height control algorithm, an air spring loading test bench and an ECU-in-loop simulation test bench are respectively established.
Chen, Guoying
Development of Pneumatic Suspension Type Full Air for Commercial Vehicles2016-36-00695/11/2016
The air suspension development and application has becoming increasingly applied also in commercial vehicles, offering to the driver more dynamic comfort as well as contributing to the reduction of impact loads on highways. Through this project pursuit show the analysis and application of an air suspension system for commercial tractor vehicles application. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension′s stiffness under different conditions of usage, laden and unladen. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain the vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. For entire development were also used quality tools, considering the possible failure modes and effects as well as virtual simulation tools (Adams) and bench validations. Through data acquisition and vehicular analysis, the better dynamic results proposed was validated and considered the final design solution.
Silva, Misael Neris da, Belli, Milton Monteverde, Iombriller, Silvia Faria, Knoll, Paulo Henrique, Conde, Ramon, Netto, Robson, Carraro, Eduardo
Improvement of Vehicle Ride Comfort Using Control Strategies for the Switchable Damper Suspension System2016-01-04414/5/2016
An active suspension system has better performance than a passive suspension. However, it requires a significant amount of energy and is constructed from high cost components. To solve the problem of the power required, a switchable damper suspension system has been studied. In this paper, control strategies for the switchable damper suspension system and passive are compared in terms of their relative ride performance capabilities. Practical limitations involving switching time delay and threshold delay values are modeled and their effect on the ride performance are evaluated. The four setting switchable damper is compared with the two and three setting switchable dampers. The control strategies are used to maintain suspension working space level within design limit and to minimize body acceleration level. The results showed that the four setting switchable damper gives better ride improvements compared with the two and three setting switchable dampers.
Soliman, Aref M. A.
Simulation Analysis on Controllability of Hydraulic Electrical Energy Regenerative Semi-Active Suspension2016-01-04434/5/2016
A vehicular hydraulic electrical energy regenerative semi-active suspension(HEERSS) was presented, and its working principle and performance were analyzed. Firstly, configuration and working principle of the HEERSS were described; Secondly, kinetic equation of HEERSS was deduced, and a skyhook controller was designed for HEERSS. The traditional skyhook control strategy should be changed for the characteristic of HEERSS, because the damping force during extension stroke could be controlled, but not in compression stroke. Thirdly, the performance of HEERSS was compared with passive suspension(PS), traditional semi-active suspension(TSS). The simulation results indicated that the performance of HEERSS would be compromise between TSS and PS, but the HEERSS could harvest vibration energy which was advanced than TSS and PS.
Zhang, Han, Li, Gang, Wang, Yu, Gu, Yuchuan, Wang, Xiang, Guo, Xuexun
Design and Control of a Novel Geared Electromagnetic Active Suspension2016-01-15544/5/2016
A novel geared electromagnetic active suspension is proposed in this paper. A pushing rod and a rocker are introduced to transfer the suspension vertical motion to the rotational motion of the motor. Comparing with the common ball-screw active suspension, it presents advantages of simple structure, easy manufacturing and module design. As the state variables of the suspension system cannot be all obtained for the sake of cost, taking the suspension deflection as the measurement, an output feedback LQR optimal controller is adopted, and it is concluded that the system can be stable with damping. Considering the nonlinearity of equivalent stiffness and unsprung mass caused by the system structure, parameter perturbation ranges are concluded through dynamic analysis, and robust H∞ control algorithm is proposed to realize the multi-objective optimization. The performance comparisons of both controllers mentioned above are carried out in the ADAMS/MATLAB co-simulation to reflect the influence of the nonlinearity of real time in practice. The results conclude that, in real system containing nonlinearity and parameter perturbations, the robust H∞ controller performs better in robustness of improving the ride comfort and handling stability.
Gu, Cheng, Chen, Xinbo, Yin, Jun
Research on Inerter-Spring-Damper Semi-Active Suspension with Robust Control2016-01-04284/5/2016
For coordinating the ride comfort and driving safety, the “inerter-spring-damper” (ISD) system is proposed in this paper, and the “spring-adjustable damper” is adapted to connect with ISD in series, then, a new type of semi-active suspension system is established. In order to verify the system rationality, the ISD semi-active suspension model and robust controller model are established respectively in the AMESim and MATLAB/Simulink environment, which is based on two degrees of freedom suspension model. Then, the co-simulation of ISD semi-active suspension with robust control is analyzed. Compared with the conventional ISD suspension, the results show that, the ISD semi-active suspension with robust control can significantly reduce the body vertical vibration, restrain tire resonance and enhance the tire grounding, that is, this system can coordinate the conflicts between vehicle ride comfort and driving safety.
Wang, Ruochen, Ding, Renkai, Ye, Qing
Performance Analysis of the Rule-Optimized Fuzzy-Logic Controller for Semi-Active Suspension2016-01-04444/5/2016
This paper presents a performance analysis study for the Rule-Optimized controller of a semi-active suspension system. The Rule-Optimized controller is based on a Fuzzy Logic control scheme which offers new opportunities in the improvement of vehicle ride performance. An eleven degree of freedom full vehicle ride dynamics model is developed and validated through laboratory tests performed on a hydraulic four-poster shaker. An optimization process is applied to obtain the optimum Fuzzy Logic membership functions and the optimum rule-base of the semi-active suspension controller. The global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle is determined through discrete optimization with Genetic Algorithm (GA). The performance analysis of the controller is performed by evaluating the Rule-Optimized controller performance under different driving conditions; including different road profiles, different vehicle speeds and different vehicle loadings. The results show that, the Fuzzy-Logic based Rule-Optimized controller for semi-active suspension provides significant improvements in both ride comfort and road holding performance of the vehicle under different operating conditions.
Çalışkan, Kemal, Kaldas, Mina M.S., Henze, Roman, Küçükay, Ferit
Implementation of Fuzzy Logic Control in Semiactive Suspension for a Vehicle Using MATLAB SIMULINK2016-28-00352/1/2016
The design of the conventional passive suspension has always been a compromise between vehicle handling and comfort, which led to the development of the modern active and semi active suspension systems. Amongst these, semi-active suspension has been focus of research in recent years owing to its lesser complexity and less power consumption as compared to active suspension. Semi active suspension uses real time variation in damping coefficient which can be achieved by using various control strategies. It is observed from available literature that Skyhook (for better ride comfort), Groundhook (for better vehicle handling) and Hybrid are most widely used strategies. These strategies use ‘On-Off’ control strategy (i.e. two preset values of damping co-efficient) but a better control over damping coefficients can be achieved using Continuous Control strategy. This paper aims to implement Continuous control strategy using Fuzzy logic for the semi active suspension. For the analysis, Two degree of freedom Quarter car model is used which is excited by three road profiles namely Bump, Sine Wave and Swept Sine wave. Comparison is done on the basis of vehicle parameters: Body displacement, Wheel displacement, Suspension working space and Dynamic tire deflection. Also frequency response of system is analysed using Fast Fourier Transform. Simulation is done using MATLAB SIMULINK and results of ‘Continuous control strategy’ are compared with the results of ‘On-Off control strategy’ and ‘Passive suspension’. Continuous control strategy using Fuzzy Logic control was found to provide better overall performance with 22.1% reduction in body displacement, 11.66% reduction in dynamic tire deflection and 31.77% reduction in suspension working space. Also Fuzzy logic control retained its stability over whole frequency range.
Rasal, Shraddhesh, Jaganmohan, Jayanth, Agashe, Sohan, Wani, Kiran P
Research and Verification on Ideal Stiffness Characteristic Curve of Suspension Coil Springs2015-01-13284/14/2015
Taking a domestic brand car as example, this paper is about how to find out a three-point nonlinear stiffness characteristic curve which can meet the requirements of variable stiffness and three-load condition. The new coil spring gives the passive suspension a lot of improvements in riding and safety, changing the nonlinear stiffness characteristic from weak to strong. This paper summarizes the optimization design method for the rear suspension coil spring, which includes the fitting of ideal stiffness characteristic curve, quantitative method for figuring out how the change of vehicle load influences the load on rear suspension axle, the design method of variable stiffness coil spring which corresponds to the change of vehicle load. A new kind of modified ideal point solution for building the objective function was also put forward. Using the kits Fminimax, Fmincon in Matlab as optimization tools, finally verify the validity of optimization result through the four post testing module in ADAMS/Car.
Gao, Da-Wei, Huang, Xing-Xing, Xu, Jun, Zheng, Song-Lin
Ride Comfort Performance Investigation for Compressed Natural Gas Fuelled Car2015-01-06114/14/2015
This paper presents experimental and theoretical investigations for ride comfort performance of compressed natural gas fuelled car. A compressed natural gas and gasoline fuel are used to run the engine car and its effect on the vehicle ride comfort is evaluated. The ride comfort performance in terms of experimental Root Mean Square (RMS) values of the vertical acceleration at near driver's feet on the floor, on the front and back seat for the same passenger car fuelled by gasoline and natural gas is evaluated. Furthermore, seven degrees of freedom vehicle mathematical model is developed, and validated through laboratory tests. The validation process is performed by comparing the predicted RMS values of the vertical accelerations with the measured RMS values. Furthermore, the optimum values of vehicle suspension parameters are obtained through the validated vehicle model. The experimental results showed that the car fuelled by compressed natural gas gives a significant improvement in the ride comfort compared with the same car fuelled by gasoline. The best ride comfort is found on the back seat. The experimental results of the vehicle using the compressed natural gas and the theoretical results obtained indicate that the mathematical model produces optimistic results for the vertical direction of body accelerations. The predicted results show optimum values of vehicle suspension system elements.
Soliman, Aref M. A., Kaldas, Mina M.S.
A Comparison of the Performance and Power Requirements for Various Active Suspensions with Gain Scheduling Strategies2015-01-06164/14/2015
In this paper, passive and various types of intelligent vehicle suspension systems are compared in terms of their relative ride performance capabilities and power requirements. These systems are active, two and three setting switchable dampers suspension systems. The control gains of the intelligent systems are obtained using optimal control theory and gain scheduling strategy (GS) is used for the system behaviour. In the first strategy (GS) used, gains are selected based on suspension working space. While, the other strategy (GS), gains are selected based on body acceleration. These strategies are used to maintain suspension working space and dynamic tyre deflection levels within design limits and to minimise body acceleration level. The mean power consumed in rolling resistance and the mean power dissipation within the suspensions is evaluated. The results showed that the active with gain scheduling strategy gives better ride improvements compared with the active system in terms of body acceleration. Also, the results are presented the potential benefits of the switchable damper with gain scheduling strategy. The mean power demand and dissipation within the suspensions are evaluated. The percentages of power dissipation with the passive, setting switchable damper and active suspension systems relative to the power losses in rolling, resistance are discussed,
Soliman, Aref M.A.
A Comparative Study of Lumped Parameter Models for Assessing the Performance of Vehicle Suspension Systems2015-01-06204/14/2015
Idealized mathematical models, also known as lumped parameter models (LPMs), are widely used in analyzing vehicles for ride comfort and driving attributes. However, the limitations of some of these LPMs are sometimes not apparent and a rigorous comparative study of common LPMs is necessary in ascertaining their suitability for various dynamic situations. In the present study, the mathematical descriptions of three common LPMs, viz. quarter, half and full car models, are systematically presented and solved for the appropriate response parameters such as body acceleration, body displacement, and, pitch and roll angles using representative passive suspension system properties. By carrying out a comparison of the three stated LPMs for hump-type road profiles, important quantitative insights, not previously reported in the literature, are generated into their behaviors so that their applications can be judicious and efficient.
Mahala, Manoj, Deb, Anindya, Chou, Clifford
Tyre Load Analysis of Hydro-Pneumatic Interconnected Suspension with Zero Warp Suspension Stiffness2015-01-06304/14/2015
The purpose of this paper is to present a concept of Hydro-Pneumatic Interconnected Suspension (HPIS) and investigate the unique property of the zero warp suspension stiffness. Due to the decoupling of warp mode from other modes, the road holding ability of the vehicle is maximized meanwhile the roll stability and ride comfort can be tuned independently and optimally without compromise. Ride comfort can be improved with reduced bounce stiffness and the progressive air spring rate can reduce the requirement of suspension deflection space. The roll stability can also be improved by increased roll stiffness. Vehicle suspension system modelling and modal analysis are carried out and compared with conventional suspension. The frequency response of tyres' dynamic load reveals that the proposed zero-warp-stiffness suspension enables the free articulation of front and rear axles at low frequency. The wheel load transfer is significantly reduced when travelling on uneven off-road surface at low speed, hence the handling/traction performance are greatly improved and twisting load on vehicle body/frame can be reduced.
Xu, Guangzhong, Zhang, Nong, Roser, Holger, Ruan, Jiageng
Triple-Control-Mode for Semi-Active Suspension System2015-01-06214/14/2015
There is an increasing customer demand for adjustable chassis control features which enable adaption of the vehicle comfort and driving characteristics to the customer requirements. One of the most promising vehicle control systems which can be used to change the vehicle characteristics during the drive is the semi-active suspension system. This paper presents a Rule-Optimized Fuzzy Logic controller for semi-active suspension systems which can continuously adjust itself not only according to the road conditions but also to the driver requirements. The proposed controller offers three different control modes (Comfort, Normal and Sport) which can be switched by the driver during driving. The Comfort Mode minimizes the accelerations imposed on the driver and passengers by using a softer damping. On the other hand, the increased damping in Sport Mode provides better road holding capability, which is critical for sporty handling. The Normal Mode is adjusted to provide an overall balance between the vehicle ride comfort and road holding. The controller synthesis is performed by using an eleven degree of freedom full vehicle ride dynamics simulation model which is validated through laboratory tests performed on a hydraulic four-poster shaker. A unique optimization process is employed for obtaining the optimum Fuzzy Logic membership functions and the optimum rule-base of the proposed semi-active suspension controller. Discrete optimization is performed with Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle. A comparison between the three control modes in terms of ride comfort and road holding is performed. The results show that, the proposed control modes provide three different vehicle characteristics to the driver. In addition to this, all three control modes are superior to the optimal passive suspension in terms of both ride comfort and road holding.
Kaldas, Mina M.S., Çalışkan, Kemal, Henze, Roman, Küçükay, Ferit
Road Profile Estimation for Active Suspension Applications2015-01-06514/14/2015
The road profile has been shown to have significant effects on various vehicle conditions including ride, handling, fatigue or even energy efficiency; as a result it has become a variable of interest in the design and control of numerous vehicle parts. In this study, an integrated state estimation algorithm is proposed that can provide continuous information on road elevation and profile variations, primarily to be used in active suspension controls. A novel tire instrumentation technology (smart tire) is adopted together with a sensor couple of wheel attached accelerometer and suspension deflection sensor as observer inputs. The algorithm utilizes an adaptive Kalman filter (AKF) structure that provides the sprung and unsprung mass displacements to a sliding-mode differentiator, which then yields to the estimation of road elevations and the corresponding road profile along with the quarter car states. The proposed method is tested through numerical analysis under MATLAB/Simulink environment using a multi-body vehicle model from CarSim software and road profile samples from the Federal Highway Administration's Long Term Pavement Performance (LTPP) database.
Arat, Mustafa Ali, Taheri, Saied, Holweg, Edward
Vibration Control of MR-Damped Vehicle Suspension System Using PID Controller Tuned by Particle Swarm Optimization2015-01-06224/14/2015
Proportional integral derivative (PID) control technique is the most common control algorithm applied in various engineering applications. Also, particle swarm optimization (PSO) is extensively applied in various optimization problems. This paper introduces an investigation into the use of a PSO algorithm to tune the PID controller for a semi-active vehicle suspension system incorporating magnetorheological (MR) damper to improve the ride comfort and vehicle stability. The proposed suspension system consists of a system controller that determine the desired damping force using a PID controller tuned using PSO, and a continuous state damper controller that estimate the command voltage that is required to track the desired damping force. The PSO technique is applied to solve the nonlinear optimization problem to find the PID controller gains by identifying the optimal problem solution through cooperation and competition among the individuals of a swarm. A mathematical model of a two degree-of-freedom MR-damped vehicle suspension system is derived and simulated using Matlab/Simulink software. The proposed PSO PID controlled suspension is compared to both the conventional PID controller and the passive suspension systems. System performance criteria are evaluated in both time and frequency domains, in order to quantify the success of the proposed suspension system. The simulated results reflect that the proposed PSO PID controller of the MR-damped vehicle suspension offers a significant improvement in ride comfort and vehicle stability.
Metered, H., Elsawaf, A., Vampola, T., Sika, Z.
Attitude Control Using Stability Augmentation System for a Military Vehicle Using Active Damper2015-26-01811/14/2015
This study is made on a simplified pitch model of an armored fighting vehicle. Jerks and angular acceleration inside the vehicle compartment Affects accurate firing attack and reduced fatigue to the occupants in Vehicle. The Stability Augmentation Technique can enhance the stability and ride comfort of the vehicle platform from road and firing disturbance. The force requirement for stabilizing the platform is calculated from the displacement of vehicle body in terms of pitch angle and Heave displacement with respect to the equilibrium position, the equivalent force at suspension mounting points required to stabilize the platform is calculated using a force transformation technique. The required force is given by an active Damper for stabilization, within the limit of damper capacity. From simulation conducted and comparison with passive suspension it is perceived that the Stability of vehicle platform is increased together with a reduced VDV (Vibration Dose Value) and rms acceleration at Centre of gravity of the Vehicle Platform.
Trikande, Mukund, Muralidharan, Sujithkumar, Jagirdar, Vinit
Preview Enhanced Rule-Optimized Fuzzy Logic Damper Controller2014-01-08684/1/2014
New developments in road profile measurement systems and in semi-active damper technology promote the application of preview control strategies to vehicle suspension systems. This paper details a new semi-active suspension control approach in which a rule-optimized Fuzzy Logic controller is enhanced through preview capability. The proposed approach utilizes an optimization process for obtaining the optimum membership functions and the optimum rule-base of the preview enhanced Fuzzy Logic controller. The preview enhanced Fuzzy Logic controller uses the feedforward road input information and the feedback vehicle state information as the controller inputs. An eleven degree of freedom full vehicle model, which is validated through laboratory tests performed on a hydraulic four-poster shaker, is used for the controller synthesis. The cost function including both ride comfort and road holding performance of the full vehicle is minimized through a discrete optimization process utilizing Genetic Algorithm (GA). The preview distance is also considered as a design parameter during the optimization process. The performance of the preview enhanced rule-optimized Fuzzy Logic controller is evaluated by using a measured stochastic road profile as vehicle model input. The results demonstrate the potential of the preview enhanced controller in improving all aspects of system performance compared to the rule-optimized Fuzzy Logic controller without preview.
Kaldas, Mina, Caliskan, Kemal, Henze, Roman, Küçükay, Ferit
Influence of Active Suspension Preview Control on Vehicle Ride and Braking Performance2014-01-08624/1/2014
The integrated control between the vehicle chassis subsystems (suspension, brake, and steering) became one of the most important aspects for current developments to improve the dynamics of the vehicles. Therefore, the aim of this study is to investigate the influence of the preview control of the active suspension on the vehicle ride and braking performance. The vehicle performance was examined theoretically using a longitudinal half vehicle model with four degrees of freedom considering the rotational motion of the tires. The active suspension system model, tire-road interface model and braking system model are included in the vehicle model. In order to study the influence of the preview control on the vehicle ride and braking performance, an active suspension system control algorithm employing the lock-ahead preview information and the wheel-base time delay based on the optimal control theory is derived. On the other hand, the ABS control algorithm is designed based on the slip-control strategy. The vehicle ride performance is evaluated in terms of discomfort and road holding, while the braking distance and time is considered as evaluation criteria for the vehicle brake performance. The results are generated in the time domain to simulate the vehicle response during braking, while wheels are subjected to vertical road input. Comparisons between passive and active suspension systems in terms of ride and braking performance are discussed as well as correlated and uncorrelated active suspension systems. The improvement of the preview control of the active suspension system on the ride and braking performance is shown.
Kaldas, Mina M.S., Soliman, Aref M.A.
Characteristic Analysis of Roll and Pitch Independently Controlled Hydraulically Interconnected Suspension2014-01-08704/1/2014
This paper presents the modeling and characteristic analysis of roll-plane and pitch-plane combined Hydraulically Interconnected Suspension (HIS) system. Vehicle dynamic analysis is carried out with four different configurations for comparison. They are: 1) vehicle with spring-damper only, 2) vehicle with roll-plane HIS, 3) vehicle with pitch-plane HIS and 4) vehicle with roll and pitch combined HIS. The modal analysis shows the unique modes-decoupling property of HIS system. The roll-plane HIS increases roll stiffness only without affecting other modes, and similarly pitch-plane HIS increases the pitch stiffness only with minimum influence on other modes. When roll and pitch plane HIS are integrated, the vehicle ride comfort and handling stability can be improved simultaneously without compromise. A detailed analysis and discussion of the results are provided to conclude the paper.
Xu, Guangzhong, Zhang, Nong
Design, Fabrication and Testing of a Regenerative Strut2014-01-19384/1/2014
The fuel prices are increasing every day and so are the pollution caused by vehicles using fossil fuels. Moreover, in a car with an internal combustion engine, we get on average 25% efficiency, the other 75% is wasted, mostly through friction and heat. One important loss is the dissipation of vibration energy by shock absorbers in the vehicle suspension under the excitation of road irregularity and vehicle acceleration or deceleration. In this paper we design, manufacture and test a regenerative coil-over strut that is compact, simple in design and more economical. Since our strut is a modification of an existing strut design, it would be much more feasible to implement. We tested our prototype strut using a TATA Indica car under city road conditions. The damping characteristics and output voltage of the strut were recorded and compared with a normal coil over strut. Based on the test data, it was found that the strut was able to recover about 8-10 watts of electricity at 20kmph.
Nandakumar, Pragadish
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