Browse Topic: Traction control

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Series Fuzzy PID with Anti-windup Controller for Intelligent Vehicle2020-01-01134/14/2020
A series fuzzy PID controller with anti-windup scope (SFPCA) is proposed in this paper to address saturation nonlinear problem and control disturbance caused by uncertainty of actuator model. In order to achieve novel dynamic and steady-state performance, the fuzzy controller and PID controller are fused into series, which realizes excellent dynamic performance of fast response and low overshoot like pure fuzzy controller at the initial response stage, and the excellent steady-state performance of stable and no static difference like PID control at the later response stage. The Hurwitz low is employed to configure PID parameters and 49 rules are designed for fuzzy controller. Since the input of the actuator could not be infinite, the actuator being saturated for a long time could reduce the stability of system and, even lead to irreversible damage. Moreover, after exiting the saturation state, it is difficult to quickly recover to the fast and stable response state of the original system. Therefore, an anti-windup scope is meticulously developed to limit the system input to a reasonable range under the saturation state, and, in the unsaturated state, the original Fuzzy PID control is restored. In order to verify the performance of the algorithm, four comparison algorithms were adopted, including pure PD, pure PID, pure Fuzzy and series Fuzzy PID controller (SFPC), and two typical commands like step and sine are employed as desired signals. The experimental results show that the SFPCA has more excellent dynamic and steady performance than pure PD, pure PID, pure Fuzzy and series Fuzzy PID controller (SFPC).
Luo, Chao
Requirements for Road Weather ApplicationsJ2945/3_202003 (Historical)3/24/2020
Inclement weather can have a significant impact on surface transportation systems. It can result in hazardous conditions for travelers due to poor visibility, or wet or icy roadways. Weather applications have the potential to provide additional data to surface transportation infrastructure owners and operators, allowing them to better assess the impacts of the weather environment on or around the roadway and to better manage the surface transportation system. Such weather applications can: Collect road weather data from connected vehicles and mobile devices, increasing the number of data sources available. Provide road weather related traveler information to travelers via connected vehicles and devices, such as when and where a hazardous condition exists. Provide the ability to manage road weather response on specific roadways. This SAE Standard specifies interface requirements between vehicles and infrastructure for weather applications, including detailed systems engineering documentation (needs and requirements mapped to appropriate message exchanges). The purpose of this SAE Standard is to enable interoperability supporting these weather applications over a communications technology agnostic interface.
Infrastructure Applications Technical Committee
Autonomy's ‘Pirouetting’ Future20AVEP01_061/1/2020
Protean Electric's novel 360-degree steering and in-wheel drive systems add new potential for urban mobility. Designing and engineering a 360-degree steering capability for a production electric autonomous road vehicle's four wheels is no mean achievement. But Protean Electric also combines this pirouetting capability with an in-wheel electric motor, “innovative” suspension and pneumatic ride height control into an all-in-one package. Its adroit wheel-at-each-corner module, called Protean360+, is designed initially for next-generation urban mobility pods. But it could also be applied to a wide variety of other autonomous vehicles. Development of the 360-degree capability began in early 2018. It is the latest element to be added to the company's ProteanDrive in-wheel system, on which work started more than a 10 years ago to specifically meet emerging needs for radical new urban vehicle technology combined with autonomous transport visions. These include autonomous passenger cars, light-duty commercial vehicles and other future mobility solutions.
Birch, Stuart
Holistic hydraulic designs add more sensors, controls19TOFHP08_078/1/2019
Hydraulic system developers are moving on many different fronts as they strive to improve performance and efficiency. A full-system approach that includes more sensors and advanced controls is helping design teams reduce component counts without sacrificing performance. The multifaceted design challenges of today's equipment are forcing engineers to take a broad view of the vehicle and its systems in order to get the most from valves, electronics, pumps and other equipment. Customer expectations and regulatory requirements are both rising, forcing engineers and planners to examine every element of a design.
Costlow, Terry
Development and Control of Four-Wheel Independent Driving and Modular Steering Electric Vehicles for Improved Maneuverability Limits2019-01-04594/2/2019
Electric vehicles are capable of more flexible drivetrain configurations, such that driving dynamics of each wheel could be controlled independently to increase its stability and maneuverability bounds. We hereby propose a configuration consisting of four wheel independent driving and front and rear axle modular steering. The vehicle implements drive-by-wire technology, which means the control program running on vehicle control computer will have direct control authority of the vehicle under normal driving conditions, based on inputs of higher level systems such as human drivers and autonomous driving programs. Both the torque allocation on four wheels and the steering allocation on axles are completely independent on the mechanical hardware level, thus the vehicle is able to harness adverse contact conditions with confidence. A slip-aware model-free control method for torque allocation and steering is proposed and inspected in the paper, with digital model of a modified SUV simulated for validation, and the vehicle responses with and without such controller are compared to elaborate its strengths. Such control method has more safety margin under close-to-limits driving conditions with presence of tire slip. The control method along with drive-by-wire features also enhance driving safety by correcting excessive inputs by human drivers. Additionally, a comprehensive index reflecting the stability and maneuverability of the vehicle is also introduced and based on which a model-based controller is designed and compared.
Yang, Haoguang, Liu, Chen, Shi, Jiongming, Zheng, Gangtie
Influence Mechanism of Electromechanical Parameters on Transient Vibration of Electric Wheel System2019-01-04624/2/2019
Electric wheel systems of in-wheel motor driven vehicles consist of the motor controller, in-wheel motor and tire-suspension assembly. The coupling between the electromagnetic excitation and elastic structure gives rise to electromechanical dynamic issues. As for the structural layout of the electric wheel system, the driving motor is directly connected to the wheel without torsion dampers or transmission in the driveline, thus making the electric wheel structure a weak damping system. Moreover, the driving torque of electric wheel can change rapidly in various conditions of vehicle. As a result, the transient vibration problem becomes one of the key electromechanical dynamic issues in the electric wheel system. To investigate this problem, the electromechanical coupling model of the electric wheel system is established first. Then the transient responses of the electric wheel under abrupt changes of the driving torque are simulated. The results indicate that the tire mainly suffers from longitudinal shocks in the anti-phase rotational mode at 95 Hz and vibration in the in-phase rotational mode at 44Hz successively, while the motor vibrates in the in-phase rotational mode at 44Hz. As the electric wheel system is electromechanically coupled, the influence mechanism and rules of electromechanical parameters on the transient vibration are studied. The results show that the permanent magnet flux linkage increases damping ratio of the in-phase rotational mode in virtue of the electromagnetic stiffness and damping, thus further weakening transient vibration of motor. The anti-phase rotational mode is sensitive to tire’s stiffness. It is effective to optimize tire’s shock by adjusting tire’s stiffness. This paper reveals the electromechanical coupling mechanism of the electric wheel system, and provides reference for parameter design from the perspective of improvement in dynamic characteristics.
Feng, Zhaoyang, Zuo, Shuguang, Mao, Yu
Investigation of Cabin Noise while Accelerating on Low Mu Track through Simulation Approach Using Full Vehicle ADAMS/Car Model2019-26-01791/9/2019
Cabin noise is a significant product quality criteria which enables the customers for product differentiation. There are various sources of cabin noise such as wind, structures(panels), engine, suspension, tire and roads. During product development phase, extensive tests has been conducted to improve vehicle dynamics behavior on various climatic conditions. One such test is accelerating vehicle on low mu or icy surface. While performing acceleration manoeuvre (tractions) on a low mu tracks, Cabin noise with source identified from front underbody & low tractive torque build up is reported. This undesirable behavior may occur due to following reason (1) Excitation of coupled modes between suspension and powertrain which induces torque fluctuation. (2) Transmissibility of various subsystem can be the reason for above problem statement. (3) Poorly chosen tire compounds and design leads to fluctuation in torque. A detailed simulation based study using ADAMS/CAR has been performed to assess the contribution of various full vehicle sub-systems, primarily suspension & powertrain sub-system towards the said problem statement. The dynamic interaction between road, suspension, powertrain and BIW has been is the focus of study both in time and frequency domain. This simulation helped understand the factor effects and contribution levels and correlates well with the subjective feel observed on the physical vehicle on low-mu track. This model has been further used to provide design recommendation on the compliance parameters to overcome the issue at hand. Test has been conducted with recommended tire grip properties and suspension bushing parameters which lead to reduction in cabin noise
Singh, Vivek, Prasad, Tej, Srivastava, Harshit
Movement Prediction Hypotheses for Pedestrians and Trajectory Planning for Cooperative Driving Systems12-02-01-000212/19/2018
It is a challenge to find a safe trajectory for automated vehicles in urban environments with pedestrians. The prediction of future movements with 100% certainty is impossible, if the intention is unknown. A Gaussian process approach is used to formulate future movement hypotheses of the pedestrian based on historical movements. A mixed integer linear programming (MILP) optimization approach is used for the trajectory planning of the vehicle. The collision probability between the ego-vehicle and pedestrian is used as constraints in the optimization. This approach is useful for cooperative vehicle systems, with historical movement data in a fixed urban environment (e.g., intersection) and the premise that pedestrians follow typical movement data.
Hartmann, Michael, Stolz, Michael, Watzenig, Daniel
All-Wheel Drive Systems ClassificationJ1952_201804 (Current)4/18/2018
In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III).
Drivetrain Standards Committee
An Analysis of EDR Data in Kawasaki Ninja ZX-6R and ZX-10R Motorcycles Equipped with ABS (KIBS) and Traction Control (KTRC)2018-01-14434/3/2018
Electronic control units (ECU) from Kawasaki Ninja ZX-6R and ZX-10R motorcycles were tested in order to examine the capabilities and behavior of the event data recorders (EDR). All relevant hexadecimal data was downloaded from the ECU and translated using known and historically proven applications. The hexadecimal translations were then confirmed using data acquisition systems as well as the Kawasaki Diagnostic Software (KDS)1. Numerous tests were performed to establish the algorithms which cause the EDR to record data. Issues of sensor and power loss were analyzed and discussed. Additionally, data sets were studied that involved maximum deceleration from ABS brakes. Similarly, data sets that involved traction control intervention were studied and analyzed. It was determined that the EDR recording ‘trigger’ was caused by the activation of the tip-over sensor, which in turn shuts the engine off. However, specific conditions must be met with regards to the rear wheel rotation prior to engine shut-down. An EDR event was only recorded if the motorcycle was commanded to shut-down by the tip-over sensor, and either had rear wheel movement at the time of shut-down or the rear wheel experienced a certain amount of deceleration in the several seconds prior to shut-down. The ‘time zero’ data element was synchronous with the tip-over commanded shut-down signal. Various data elements were stored at either 10 Hz or 2 Hz for a total of 8 seconds of data prior to the commanded engine shut-down. It was determined that ABS and traction control intervention at the rear wheel could still create a sudden deceleration significant enough to trigger an EDR event after tip-over.
Fatzinger, Edward, Landerville, Jon
Automotive Stability Enhancement SystemsJ2564_201711 (Current)11/14/2017
The purpose of this SAE Information Report is to describe currently known automotive active stability enhancement systems, as well as identify common names which can be used to refer to the various systems and common features and functions of the various systems. The primary systems discussed are: a ABS - Antilock Brake Systems b TCS - Traction Control Systems c ESC - Electronic Stability Control The document is technical in nature and attempts to remain neutral regarding unique features that individual system or vehicle manufacturers may provide.
Vehicle Dynamics Standards Committee
Proposal for Improving the Performance of Longitudinal Acceleration of a Land Vehicle2017-36-038111/7/2017
The present study introduces a proposal to improve the longitudinal performance of a land vehicle through the adoption of an unusual traction control system. The system is capable of improving the transfer of engine power to the ground and reduces the complexity of the task being performed by the driver. High-performance vehicles are able to achieve high levels of longitudinal acceleration and, sometimes, the power excess leads to the spinoff of the drive wheels, which decrease the ability of the tires to generate force, and consequently the vehicle acceleration. The proposed system acts in addition with the motor control, through the derivation of the motor speed signal, and its control by comparison with a predefined value. The control can delay or even suppress the ignition of the engine. Thus, the rate at which the engine gains speed, and consequently, the rate at which the vehicle accelerates, is limited. The benefits of the system are the low cost and the ease of application in a modern vehicle.
de Lima, Bruno Silva, de Oliveira, Rafael Megale, de Oliveira Moraes, Luiz Fernando, Araújo, Gustavo Abreu, de Almeida Carvalho, Gabriel Mendes
THE NAVIGATOR17AUTP10_0710/1/2017
Time for standard naming of safety features Smart cruise control. Intelligent cruise control. Adaptive cruise control. Radar speed control. As The Bard wrote so long ago, “A rose by any other name would smell as sweet.” Sadly that tale did not end well for the protagonists. In today's world of increasingly sophisticated active safety systems, engineers and consumers alike are being bombarded by more and more brand-specific labels for essentially the same technology. Unfortunately, imprecise branding driven more by marketers than technologists threatens to put us all at risk.
Abuelsamid, Sam
Performance Comparison between ABS 4S/4M and ABS 4S/3M2017-36-00015/24/2017
After the anti-skid brake system (ABS) introduction, mandatory for all vehicles in the Brazilian market, manufacturers have given increasing attention to optimized systems which meet legal and safety requirements. For commercial vehicles, an alternative for the ABS, which presents feasibility, is the configuration 4S/3M (4 wheel-speed sensors and 3 modulator valves) in substitution to the configuration 4S/4M. In other words, application of just one modulator valve to control the brakes of the same axle, front or rear, instead of independent control per each brake of the vehicle. The aim of this paper is to present a performance comparison between a brake system fitted with ABS configuration 4S/3M and an ABS configuration 4S/4M. To this end, both configurations were tested on the same vehicle application in accordance with the Brazilian legislation, CONTRAN 519/15. In addition, a test on which the vehicle was prepared with an unusual load distribution was performed in order to verify if the proposed system would be capable to keep its performance. A discussion regarding feasibility of ABS 4S/3M on 6x2 or 6x4 trucks is also presented.
de Souza, Luís Fernando Nuss, de Oliveira, Antônio Carlos, Vetter, Narã Vieira
Mechatronics Based Accident Alarming System with Automatic Roadblock Prevention System2017-01-17283/28/2017
In any unlikely event of accidents or vehicle breakdown, there is accumulation of traffic which results in road-blockage and causes in convenience to other vehicles. If this happens in remote areas, the accidents victims are left unattended and there is delay in providing emergency services. In case of traffic, it obstructs the entry of ambulance and rescue team which results in death of passengers. To prevent this mishap, a mechatronics based road block avoidance and accident alarming system is designed which is automated by the use of sensors. The road-block is detected with the help sensors located at regular intervals on road. This input is given to a Local Control Unit (LCU) which is integrated on every road. Several such LCUs are connected to a Main Control Unit (MCU) which is located at the nearest police station. A single MCU covers the area administered by that police station. Additional CCTV cameras are present to give graphical view of accident. The MCU alerts the Traffic department, nearest Hospital and currently running ambulances for initiation of emergency services. There is also a group of small modular retractable robots which blocks the nearest entrance of the road to prevent further traffic accumulation. This paper shows the technology behind the this concept and its implementation
Singh, Nitin, Sharma, Aayoush, Shah, Sameer, Gardampaali, Balakumar
Improvement of Lap-Time of a Rear Wheel Drive Electric Racing Vehicle by a Novel Motor Torque Control Strategy2017-01-05093/28/2017
This paper presents a novel strategy for the control of the motor torques of a rear wheel drive electric vehicle with the objective of improving the lap time of the vehicle around a racetrack. The control strategy is based upon increasing the size of the friction circle by implementing torque vectoring and tire slip control. A two-level nested control strategy is used for the motor torque control. While the outer level is responsible for computing the desired corrective torque vectoring yaw moment, the inner level controls the motor torques to realize the desired corrective torque vectoring yaw moment while simultaneously controlling the wheel longitudinal slip. The performance of the developed controller is analyzed by simulating laps around a racetrack with a non-linear multi-body vehicle model and a professional human racing driver controller setting. The advantage of the developed control strategy is studied by looking qualitatively and quantitatively at the sectors of the track where the controlled vehicle gains lap time. Simulation results indicate improvement in the vehicle controllability due to oversteer control and in the racetrack lap time due to better utilization of the available tire grip.
Ghosh, Jyotishman, Tonoli, Andrea, Amati, Nicola
Design of an Integrated Yaw-Roll Moment and Active Front Steering Controller using Fuzzy Logic Control2017-01-15693/28/2017
This paper presents an advanced control system, which integrates three fuzzy logic controllers namely; Direct Yaw-moment Control (DYC), Active Roll-moment Control (ARC) and Active Front Steering (AFS) to enhance vehicle cornering and overturning stability. Based on a well-developed and validated fourteen degree of freedom (DOF) full vehicle model with non-linear tire characteristics, a reference 3-DOF yaw-roll plane vehicle model is introduced to control yaw rate, sideslip angle, and roll angle of the vehicle body. The control actions of both direct yaw and active roll moments are performed by generating differential braking moments across the front wheels, while the control action of the active steering is performed by modifying the steering wheel angle. Different standard cornering tests are conducted in MATLAB / Simulink environment such as J-turn, fishhook and lane change maneuvers. The simulation results show a substantial improvement in vehicle stability by employing the proposed integrated controller compared to that of the individual controllers and the conventional vehicle without control.
Elhefnawy, Amro, sharaf, Alhossein, Ragheb, Hossam, Hegazy, Shawky
Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System2017-01-15653/28/2017
A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system. A sliding mode variable structure vehicle dynamics stability controller based on hierarchical control framework is built in MATLAB/Simulink. The I-EHB actuator model and vehicle dynamic model with 15 degrees of freedom are built in simulation package AMESim through a parameterized and modularized method. Simulations are conducted via co-simulation platform using MATLAB/Simulink and AMESim under scenarios of the typical braking and NHTSA FMVSS 126 standard-Sine With Dwell. Simulation results show that hydraulic braking forces are coordinated well during typical braking process, verifying the feasibility and effectiveness of the models built and the control strategy proposed. Under Sine With Dwell maneuver, compared with the base systems equipped without/with the conventional ESP, the proposed stability control system has a good improvement on the vehicle dynamics.
He, Xiangkun, Yang, Kaiming, Ji, Xuewu, Liu, Yahui, Deng, Weiwen
Using Generic Tyre Parameters for Low Friction Surfaces in Full Vehicle Simulations2017-01-15063/28/2017
An intervention of vehicle stability control systems is more likely on slippery surfaces, e.g. when the road is covered with snow or ice. Contrary to testing on dry asphalt, testing on such surfaces is restricted by weather and proving grounds. Another drawback in testing is the reproducibility of measurements, since the surface condition changes during the tests, and the vehicle reaction is more sensitive on slippery surface. For that, simulation enables a good pre-assessment of the control systems independent from testing conditions. Essential for this is a good knowledge about the contact between vehicle and road, meaning a good tyre model and a reasonable set of tyre model parameters. However, the low friction surface has a high variation in the friction coefficient. For instance, the available lateral acceleration on scraped ice could vary between 0.2 and 0.4 g within a day. These facts lead to the idea of using generic tyre parameters that vary in a certain range. Benefit would be the robust testing of the stability control systems. Generic tyre parameters could also cover a high variety of available tyres on the market. Furthermore the model can be used to evaluate changing surface conditions. The extreme case of this situation are then the µ-slip manoeuvres, e.g. braking with asphalt on one lane and snow or ice on the other side.
Wiessalla, Johannes, Mao, Yiqin, Esser, Frank
Reliability Testing of High-Power DevicesTBMG-263342/1/2017
Before a new high-power semiconductor device can be used for industrial applications, it must be thoroughly tested to determine if it will survive environmental stresses and continue to meet specifications. This is especially true for the latest wide-bandgap semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) to ensure they can withstand high voltage and temperatures.
Analysis of Low-Cost MEMS Accelerometer and Gyroscope Characteristics for Stochastic Sensor Simulation within Motorcycle Models2016-32-002711/8/2016
Vehicle dynamics control (VDC) for motorcycles had a fast growth during the last 10 years. The available technologies comprise curve-safe ABS and traction control (TC) systems, anti-wheelie control, right up to comprehensive motorcycle stability systems including even more control functions. VDC systems rely on real-time information about the current motorcycle dynamic state. Thus motorcycles are equipped with additional sensor units, namely MEMS inertial measurement devices, capable of gathering accelerations and angular rates. The application of model-based estimation theory enables the determination of the necessary information about the in-plane and out-of-plane motion, e.g. the motorcycle lean angle. Since VDC systems include safety critical control functions, the validation within simulations including sensor characteristics is mandatory. The MEMS accelerometer and gyroscope features include low-cost and small footprint, however there are considerable stochastic sensor errors to cope with. In this study the characteristic of different MEMS sensors and their noise models are investigated. The sensor noise terms are identified by analyzing measurement data using the Allan variance method. Different sensors are compared and the stochastic noise coefficients are quantified. The sensor noises are modeled with according random processes defined by linear time-invariant systems and white-noise inputs. As a result, the obtained stochastic sensor models can be used for model-based estimation and control algorithm design, as well as verification within simulation environments.
Winkler, Alexander, Grabmair, Gernot
Aerodynamic Forces Impact on Vehicle Braking Longitudinal Dynamics with a Sliding Mode Controller2016-01-04604/5/2016
The control of automotive braking systems performance and wheel slip is a challenging problem due to the nonlinear of the braking process, vehicle body dynamics during braking and the tire-road interaction. When the wheel slip is not between the optimal limits during braking, the desired tire-friction force cannot be achieved, which influences the braking distance, the loss in steerability and maneuverability of the vehicle. A simple and at the same time realistic vehicle longitudinal braking model is essential for such challenging problem. In this paper, a new longitudinal rolling/braking lumped-vehicle model that takes vehicle aerodynamic forces in consideration is presented. The proposed model takes the rolling resistance force, the braking force and the aerodynamic lift and drag forces in consideration and investigates their impact on the vehicle longitudinal dynamics especially vehicle braking distance and time. An anti- lock sliding-mode controller is designed to provide wheel slip control during vehicle motion. This type of controller is chosen due to its expected robustness against varying road friction coefficient. The controllers provide an optimal braking torque control which minimize the braking distance by maintaining a desired slip ratio corresponding to the road condition. Based on this optimal braking control method, the impact of the vehicle aerodynamic forces (lift and drag) are investigated and presented.
Haggag, Salem A., Mansouri, Abraham
Performance Analyses of Driver-Vehicle-Steer-By-Wire Systems Considering Driver Neuromuscular Dynamics2016-01-04564/5/2016
One main objective is to find out how these parameters interact and optimal driver control gain and driver preview time are obtained. Some steps further, neuromuscular dynamics is considered and the system becomes different from the simplified driver-vehicle system studied before. New optimal driver control gain and driver preview time could be obtained for both tensed and relaxed muscle state. Final step aims at analysing the full system considering driver, neuromuscular, steer-by-wire and vehicle models. The steer-by-wire system could potentially have a significant influence on the vehicle when the driver is at impaired state, which could be represented by setting higher response delay time or smaller preview time. Vehicle's stability and active safety could also be improved by introducing the steer-by-wire system. Optimal driver control gains and driver preview times from all these three models would be compared and contrasted in order to examine the effects of neuromuscular dynamics and steer-by-wire system at different situations.
Zhang, Zhaozhong, Cao, Dongpu
Co-Simulation Research of Integrated Electro-Hydraulic Braking System2016-01-16474/5/2016
A program of integrated electro-hydraulic braking system is proposed, and its structural composition and working principle are analyzed. According to the structural and mechanical characteristics of all key components, through some reasonable assumptions and simplifications, a motor, a brake master cylinder, four brake wheel cylinders, solenoid valves and an ESP (Electronic Stability Program) algorithm model is set up and simulations of typical braking conditions are carried out based on the Matlab/Simulink. Finally, after the assembly of each sub-model is complete and combining a vehicle which is set up in CarSim software environment, simulation tests and comprehensive performance analysis of the active safety stability control for a vehicle in double lane change and single lane change situations are carried out respectively. According to the dynamic characteristic curves of system, the effects of different structural and control parameters on braking performance are analyzed. To improve overall braking performance, the results would help to match and optimize system parameters, and provide reference data for further clarifying ideas and goals of parameters optimization. The vehicle control results show that the proposed integrated electrohydraulic braking system has characteristics of a simple structure, very low cost, a good controllability, could be easily integrated with ABS (Anti-lock Braking System), TCS (Traction Control System), ESP and other intelligent electronic control braking functions, and has more extensive application value.
Li, Jing, Yang, Xiong, Miao, Hui, Shi, Zheng Tang
Development of an Electronically Controlled Brake System for Fuel-efficient Vehicles2016-01-16644/5/2016
To solve various environmental problems, fuel-efficient vehicles that reduce CO2 emissions as well as exhaust gas emissions have been developed. In such vehicles, a regenerative brake is used to further reduce fuel consumption. Because the market size for such vehicles is expanding, a brake system is required that can be used in a wide range of vehicles extending from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs). In addition, issues such as deceleration fluctuation and brake pedal fluctuation arise because the regenerative brake force is dependent on the vehicle speed. This paper presents a brake system configuration and its element technologies that can replace existing brake systems in different vehicles ranging from ICEVs to EVs. The proposed system can realize a regenerative cooperative brake not only by replacing the brake booster unit but also without replacing the modulator. The advantages of this system are the maximization of regenerative efficiency, assurance of system reliability, and better brake feel.
Masuda, Yoshio, Yamasoe, Yosuke, Kuki, Yosuke, Okano, Takahiro, Uchida, Kiyoyuki
Investigations of Power Distribution in Transmissions of Heavy Trucks2016-01-11004/5/2016
The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity (it is defined as the distance traveled divided by the time elapsed), and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-toweight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution between the drive wheels of the multipurpose wheeled vehicles: disabling of drive axles, blocking of cross-axle and inter-axle differentials, a slowdown of slipping wheels. It was revealed that the transmission of a promising multipurpose wheeled vehicle has to be modernized in the following ways: 1) all-wheel drive with the rational value of the gear ratio of inter-axle differential; 2) realization of the possibility of periodic shutdown of the drive axles when road conditions are good, or turning on the additional driving axles of the trailer when the road conditions require significant drive forces and torques; 3) providing of limited excess capacity of power unit by reducing the fuel supply or applying braking torque to the slipping wheels; 4) providing of rigid kinematic connection in the movement process with compensation of the kinematic mismatch by adjusting of air pressure in the tires. At present, the effectiveness of the proposed methods of power distribution has been investigated in different extent. Thus, there arises the problem of the complex evaluation of the effectiveness of methods of the power distribution between the drive wheels of the multi-purpose wheeled vehicle. This investigation is devoted to this problem.
Keller, Andrei, Aliukov, Sergei, Anchukov, Vladislav, Ushnurcev, Stanislav
Power Distribution in Transmissions of Multi-Wheeled Vehicles2016-01-11034/5/2016
The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity (it is defined as the distance traveled divided by the time elapsed), and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution between the drive wheels of the multipurpose wheeled vehicles: disabling of drive axles, blocking of cross-axle and inter-axle differentials, a slowdown of slipping wheels. It was revealed that the transmission of a promising multipurpose wheeled vehicle has to be modernized in the following ways: 1) all-wheel drive with the rational value of the gear ratio of inter-axle differential; 2) realization of the possibility of periodic shutdown of the drive axles when road conditions are good, or turning on the additional driving axles of the trailer when the road conditions require significant drive forces and torques; 3) providing of limited excess capacity of power unit by reducing the fuel supply or applying braking torque to the slipping wheels; 4) providing of rigid kinematic connection in the movement process with compensation of the kinematic mismatch by adjusting of air pressure in the tires. At present, the effectiveness of the proposed methods of power distribution has been investigated in different extent. Thus, there arises the problem of the complex evaluation of the effectiveness of methods of the power distribution between the drive wheels of the multi-purpose wheeled vehicle. This investigation is devoted to this problem.
Keller, Andrei, Alyukov, Sergei Viktorovich
Semi-Autonomous Longitudinal Guidance for Pedestrian Protection in Electric Vehicles by Means of Optimal Control2016-01-01634/5/2016
This paper proposes a framework for semi-autonomous longitudinal guidance for electric vehicles. To lower the risk for pedestrian collisions in urban areas, a velocity trajectory which is given by the driver is optimized with respect to safety aspects with the help of Nonlinear Model Predictive Control (NMPC). Safety aspects, such as speed limits and pedestrians on the roadway, are considered as velocity and spatial constraints within prediction horizon in NMPC formulation. A slack variable is introduced to enable overshooting of velocity constraints in situations with low risk potential to rise driver acceptance. By changing the weight of slack variable, the control authority can be shifted continuously from driver to automation. Within this work, a prototypical real-time implementation of the longitudinal guidance system is presented and the potential of the approach is demonstrated in human-in-the-loop test drives in the Stuttgart Driving Simulator.
Rothermel, Thomas, Pitz, Jürgen, Reuss, Hans-Christian
Function-Based Architecture Design for Next-Generation Automotive Brake Controls2016-01-04674/5/2016
This paper presents a unified novel function-based brake control architecture, which is designed based on a top-down approach with functional abstraction and modularity. The proposed control architecture includes a commands interpreter module, including a driver commands interpreter to interpret driver intention, and a command integration to integrate the driver intention with senor-guided active driving command, state observers for estimation of vehicle sideslip, vehicle speed, tire lateral and longitudinal slips, tire-road friction coefficient, etc., a commands integrated control allocation module which aims to generate braking force and yaw moment commands and provide optimal distribution among four wheels without body instability and wheel lock or slip, a low-level control module includes four wheel pressure control modules, each of which regulates wheel pressure by fast and accurate tracking commanded wheel pressure. For electric vehicles, a distribution module considered regenerative braking will also be added into the architecture (low-level control). Then, based on the above novel control architecture and simulation platform, some extensive simulations have been conducted, which demonstrate the validity and effectiveness of the proposed concept and method.
Liu, Haizhen, Deng, Weiwen, He, Rui, Wu, Jian, Zhu, Bing
Vehicle Side Slip and Roll Angle Estimation2016-01-16544/5/2016
Vehicle dynamics estimation has been the subject of study for some years now. If on-board vehicle control systems can be provided with information such as side slip angle, lateral force etc. then stability of the vehicle can be improved. To estimate these dynamic variables different observers have been used e.g., sliding mode, fuzzy logic, neural networks etc. In this article the authors propose an extended Kalman filter to estimate vehicle side slip angle. Roll angle is estimated using vertical loads as input. First, a linear Kalman filter is used to filter out the vertical forces and estimate roll angle. This information is then used to estimate the vehicle side slip angle. To take into account the nonlinearities concerning lateral vehicle dynamics, Pacejka magic formula is used to model lateral forces. Estimated results are then compared with simulations, showing good accuracy.
Syed, Umair Hussain, Vigliani, Alessandro
Development of a Motorcycle Frame with Low Stiffness in the Side Direction for Racing2015-32-083911/17/2015
In motorcycle race represented by MotoGP, the motorcycle bank angle in turning state reaches approximately 60 degrees. In such a large bank angle, it is important that response of the motorcycle for the road surface displacement input is relaxed by designing the frame with low stiffness in the side direction to secure the speed on cornering. On the other hand, strong frame stiffness of longitudinal direction is required with a proper frame displacement to resist large force by the rapid deceleration. As seen above, regarding stiffness of longitudinal and side direction of the frame of motorcycle, one should be high, and the other should be low. However, in general, the ratio estimated by stiffness of side direction per that of longitudinal direction is approximately constant with existing frame. This means that if the frame stiffness of side direction is lowered, that of the longitudinal would also be lowered accordingly. Thus, it is difficult to design the frame of which stiffness of longitudinal direction is strengthened while that of side direction is kept lowered. An object of this study is the development of the frame with different longitudinal and side stiffness ratio unlike the current longitudinal and side stiffness ratio. The frame developed from this study is adopted in our MotoGP machine and contributes to secure high speed on cornering.
Kawata, Koichiro
Effectiveness of Methods of Power Distribution in Transmissions of All-Wheel-Drive Trucks2015-01-27329/29/2015
The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity, and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution among drive wheels of the multi-purpose wheeled vehicles. It was revealed that the transmission of a promising multipurpose wheeled vehicle has to be modernized in the following ways: 1) all-wheel drive with the rational value of the gear ratio of inter-axle differential; 2) realization of the possibility of periodic shutdown of the drive axles when road conditions are good, or turning on the additional driving axles of the trailer when the road conditions require significant drive forces and torques; 3) providing of limited excess capacity of power unit by reducing the fuel supply or applying braking torque to the slipping wheels; 4) providing of rigid kinematic connection in the movement process with compensation of the kinematic mismatch by adjusting of air pressure in the tires. At present, the effectiveness of the proposed methods of power distribution has been investigated in different extent. Thus, there arises the problem of the complex evaluation of the effectiveness of methods of the power distribution between the drive wheels of the multi-purpose wheeled vehicle. This investigation is devoted to this problem.
Keller, Andrei, Aliukov, Sergei
Rational Criteria for Power Distribution in All-wheel-drive Trucks2015-01-27869/29/2015
The problem of the theory of power transmission to wheels of a vehicle, as part of the theory of cars, has always been in the center of attention of specialists. With the improvement of designs of a vehicle there was a need of thorough scientific review of theoretical and experimental aspects of creating and applying of mechanical, hydrostatic, electrical, and combined transmissions. This has always remained one of the most important questions of the rational allocation of power among drive wheels. In the present paper, it has been done study of different methods of power distribution among the drive wheels of an all-wheel-drive truck, namely: method of partial solution; method of introducing a rigid kinematic connection; method of periodical action; and method of limit of excessive action. Assessment how these methods influence on the performance characteristics of a multi-purpose vehicle has been done. For implementation of the method of partial solution it has been developed method of measuring of rational gear ratio of center differential providing the required level of performance of the all-wheel drive truck. For implementation of the method of periodical action the appropriateness of switching off some of the driving axles is justified. Assessment of the effectiveness of the method of limit of excessive action by applying a braking torque to the slipping wheels has showed that the degree of braking is limited, on the one hand, by exception of slipping of the wheels on the surface with worse traction, and, on the other hand, by providing sustainable drive of the all-wheel-drive truck. Using the method of limit of excessive action by controlling engine torque with simultaneous introduction of rigid kinematic connection is the best way to increase the mobility of all-wheel-drive trucks in conditions of compacted and loose soils. The made studies that are described in this paper will help designers to find the best way for design a system of power distribution in transmissions of all-wheel-drive trucks.
Keller, Andrei, Aliukov, Sergei Viktorovich
Based on the Unscented Kalman Filter to Estimate the State of Four-Wheel-Independent Electric Vehicle with X-by-Wire2015-01-27319/29/2015
As a new form of electric vehicle, Four-wheel-independent electric vehicle with X-By-Wire (XBW) inherits all the advantages of in-wheel motor drive electric vehicles. The vehicle steering system is liberated from traditional mechanical steering mechanism and forms an advanced vehicle with all- wheel independent driving, braking and steering. Compared with conventional vehicles, it has more controllable degrees of freedom. The design of the integrated vehicle dynamics control systems helps to achieve the steering, driving and braking coordinated control and improves the vehicle's handling stability. In order to solve the problem of lacking of vehicle state information in the integrated control, some methods are used to estimate the vehicle state of four-wheel-independent electric vehicles with XBW. In order to improve the estimation accuracy, unscented Kalman filter (UKF) is used to estimate the vehicle state variables in this paper. At the same time, simulations in several typical working conditions have been carried out based on the simulation models of four-wheel- independent electric vehicle with XBW, which are established by CarSim and Simulink together. The simulation results show that: Unscented Kalman Filter can achieve a high-precision in the estimation of vehicle state.
Gu, Xingjian, Chen, Guoying, Zong, Changfu
Model Based Design for Automobile External Lighting Systems2015-36-03749/22/2015
Model-Based Design (MBD) has been widely used for automotive embedded software design. Automobile manufacturers and suppliers have often underlined the importance of an unified approach for electrical and electronic (E/E) system design. In this scenario, MBD can provide a mutual benefit for stakeholders due to the share of information, workflow, and tool-chain. In this paper, we highlight MBD application for automotive Exterior Lighting System (ELS) design. In fact, ELS is an event-driven control system typically needed for car lighting and signalization, in particular at night. Furthermore, this system is mandatory for every road vehicle according to current Brazilian laws and legislation. Also, it provides safety drive preventing car accidents and pedestrian injury. In this context, we present how to boost ELS design using MBD concepts. ELS was developed in three MBD workflow (Model-In-the-Loop, Software-In-the-Loop, and Processor-In-the-Loop), from supplier’s viewpoint. The results highlight how MBD can provide better system design leading to significant automotive embedded software quality improvement. Function’s integration and software architecture is an ongoing research project and it will be considered in future work. The paper is organized as follow. Second section presents a brief literature review of the research domain. Third section shows MBD workflows for ELS design. Last section highlights concluding remarking and future work.
Neme, João Henrique, Santos, Max Mauro Dias, Teixeira, Evandro Leonardo Silva
Comparative Analysis of Methods of Power Distribution in Mechanical Transmissions and Evaluation of their Effectiveness2015-01-10974/14/2015
The main indicators for mobility of a multipurpose wheeled vehicle (MWV) are the maximum and average technical velocity, and they are mainly determined by power-to-weight ratio and parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multipurpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and tire traction, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution between the drive wheels of the multipurpose wheeled vehicles: disabling of drive axles, blocking of cross-axle and inter-axle differentials, a slowdown of slipping wheels. It was revealed that the transmission of a promising MWV has to be modernized in the following ways: 1) all-wheel drive with the rational value of the gear ratio of inter-axle differential (by a “rational gear ratio” here and further in this paper we mean the selection of the gear ratio by fitting a number of teeth of gears in inter-axle differential); 2) realization of the possibility of periodic shutdown of the drive axles when road conditions are good, or turning on the additional driving axles of the trailer when the road conditions require significant drive forces and torques; 3) providing of limited excess capacity of power unit by reducing the fuel supply or applying braking torque to the slipping wheels; 4) providing of rigid kinematic connection in the movement process with compensation of the kinematic mismatch by adjusting of air pressure in the tires. At present, the effectiveness of the proposed methods of power distribution has been investigated in different extent. Thus, there arises the problem of the complex evaluation of the effectiveness of methods of the power distribution between the drive wheels of the multi-purpose wheeled vehicle. This investigation is devoted to this problem.
Keller, Andrei, Murog, Igor, Aliukov, Sergei
FE-Based Tire Loading Estimation for Developing Strain-Based Intelligent Tire System2015-01-06274/14/2015
The development of intelligent tire technology from concept to application covers multi-disciplinary fields. During the course of development, the computational method can play a significant role in understanding tire behavior, assisting in the design of the intelligent tire prototype system and in developing tire parameters estimation algorithm, etc. In this paper, a finite element tire model was adopted for developing a strain-based intelligent tire system. The finite element tire model was created considering the tire's composite structure and nonlinear properties of its constituent materials, and the FE model was also validated by physical tests. The FE model is used to study tire strain characteristics by steady state simulation for straight line rolling, traction and braking, as well as cornering. Tire loading conditions were estimated by feature extraction and data fitting. This process forms the fundamentals for identifying tire loadings from strain information at potential sensor locations. Finally, the pros and cons of applying finite element tire model in developing tire loading estimation algorithm are discussed. A perspective of the role of FE-based method in developing strain-based intelligent tire system is proposed.
Yang, Xiaoguang, Olatunbosun, Oluremi, Garcia-Pozuelo, Daniel, Bolarinwa, Emmanuel
Development of Three-Motor Electric Vehicle “EMIRAI 2 xEV”2015-01-15974/14/2015
Mitsubishi Electric has developed a concept car “EMIRAI 2 xEV” that features an electric vehicle (EV) powertrain for safe, comfortable, eco-friendly driving experiences in the future. The vehicle was exhibited during the 2013 Tokyo Motor Show and the 2014 Automotive Engineering Exposition. The xEV is a four-wheel-drive EV with three motors: a water-cooled front motor and two air-cooled rear motors with integrated inverters. The rear wheels can be driven independently. The degrees of freedom of the actuation can realize improved maneuverability and safety. The vehicle is also equipped with an onboard charger with a built-in step down DC/DC converter, an EV control unit, a battery management unit, and electric power steering. All of the instruments are developed by Mitsubishi Electric. Motion control systems for the xEV have been developed based on our proprietary motor control technology. In particular, this paper shows the design of three controllers: the high-precision traction control, the smooth G control, and the speed control. The effectiveness of the controllers is verified in simulations and driving experiments.
Yokoyama, Kazuto, Iezawa, Masahiro, Tanaka, Hideyuki, Enoki, Keiichi
Integrated Longitudinal Vehicle Dynamics Control with Tire/Road Friction Estimation2015-01-06454/14/2015
The longitudinal dynamics control is an essential task of vehicle dynamics control. In present, it is usually applied by adjusting the slip ratio of driving wheels to achieve satisfactory performances both in stability and accelerating ability. In order to improve its performances, the coordination of different subsystems such as engine, transmission and braking system has to be considered. In addition, the proposed algorithms usually adopt the threshold methods based on less road condition information for simpleness and quick response, which cannot achieve optimal performance on various road conditions. In this paper, an integrated longitudinal vehicle dynamics control algorithm with tire/road friction estimation was proposed. First, a road identification algorithm was designed to estimate tire forces of driving wheels and the friction coefficient by the method of Kalman Filter and Recursive Least Squares (RLS). Then, a rule based integrated control algorithm which coordinate the engine torque control, brake pressure control and transmission shifting control was built to improve the vehicle driving performance. During the longitudinal dynamics control procedure, the transmission shifting control algorithm firstly decided whether the vehicle starting up at the 1st or the 2nd gear based on the road condition. Then, the engine torque control algorithm was applied to adjust the slip ratio of driving wheels. Its process was divided into three phases. In each phase, different control rules with integration of engine torque and brake torque were set by the combined feed forward and feedback methods to meet with requirements of accuracy, rapidity and stability. The brake pressure was determined by method of sliding mode control (SMC) for its rapid adjustment characteristic, in the meanwhile, it was also an important component to be considered in engine torque feedback control. Finally, the algorithm was verified by using Matlab/Simulink and CarSim co-simulation, the results show that the proposed control algorithm could regulate slip ratios of driving wheels fast and accurately, and the vehicle driving performance could be improved effectively.
Zhao, Jian, Zhang, Jin, Zhu, Bing
Synthesis of a Hybrid-Observer-Based Active Controller for Compensating Powetrain Backlash Nonlinearity of an Electric Vehicle during Regenerative Braking2015-01-12254/14/2015
Regenerative braking provided by an electric powertrain is far different from conventional friction braking with respect to the system dynamics. During regenerative decelerations, the nonlinear powertrain backlash would excite driveline oscillations, deteriorating vehicle drivability and blended brake performance. Therefore, backlash compensation is worthwhile researching for an advanced powertrain control of electrified vehicles during regenerative deceleration. In this study, a nonlinear powertrain of an electric passenger car equipped with a central motor is modeled using hybrid system approach. The effect of powertrain backlash gap on vehicle drivability during regenerative deceleration is analyzed. To further improve an electric vehicle's drivability and blended braking performance, an active control algorithm with a hierarchical architecture is studied for powertrain backlash compensation. Since the backlash in driveline is unable to be measured by a sensor, a high-level hybrid observer for backlash identification is designed at first. Then, based on the observation of the backlash traverse, a low-level switching-based active controller for powertrain backlash compensation is synthesized. The proposed control algorithm is simulated and compared with a non-active baseline strategy under regeneration deceleration. The simulation results show that the nonlinear powertrain backlash is well compensated by the developed active control algorithm, and the vehicle drivability and blended braking performance are also significantly enhanced.
Lv, Chen, Zhang, Junzhi, Li, Yutong, Yuan, Ye
Structural Testing of Passenger Car and Truck Disc BrakesJ1713_201411 (Current)11/15/2014
This SAE Recommended Practices specifies a procedure for determining structural strength and fatigue life of disc-brake caliper assemblies which are satisfactory for vehicle usage. It is applicable to new caliper assemblies which are employed in passenger car and truck brake systems utilizing hydraulic brake fluids. Brake design and vehicle performance requirements are not included. Specification limits are left to the discretion of the responsible manufacturer. This procedure was developed for base brake operation and does not consider some unusual effects of ABS (Anti-Lock-Brake System) or Traction Control systems which may have a significant effect on the caliper. Careful analysis of the particular type ABS and/or Traction Control should be made and additional tests may be required which are not included in this document.
Hydraulic Brake Components Standards Committee
Objective Driveability Development of Motorcycles with AVL-DRIVE2014-32-002011/11/2014
Originally developed for the automotive market, a fully automatic real-time measurement tool AVL-DRIVE is commercially available for analyzing and scoring vehicle drive quality, also known as “Driveability”. This system from AVL uses its own transducers, calibrated to the sensitivity and response of the human body to measure the forces felt by the driver, such as acceleration, shock, surging, vibration, noise, etc. Simultaneously, the vehicle operating conditions are measured, (throttle grip angle, engine speed, gear, vehicle speed, temperature, etc.). Because the software is pre-programmed with the scores from a multitude of different vehicles in each vehicle class via neural networks and fuzzy logic formula, a quality score with reference to similar competitor vehicles is instantly given. This tool is already successfully implemented in the market for years to investigate such driveability parameters for passenger cars. Due to the fact that electronic systems more and more find their way into the 2-wheeler applications, motorcycle manufacturers are facing a lot of challenges and these are increasing from year to year. Increasing power, with the goal to reduce fuel consumption is just one of the targets OEMs have to deal with. Beside that engines with different calibration versions to fit into various motorcycle classes are brought into the market and need to be objectively judged to fulfil the demands of the different motorcycle applications. At the moment the main point of interests are: drive by wire traction control, ABS different driving modes (throttle/ignition maps) electronic suspension automatic and semiautomatic transmissions Some of these development areas are new for motorcycle manufacturers, but they have to deal with it to stay competitive. On top of these points all of them have to come together to the attribute: “FUN TO DRIVE”. This paper describes the process of adding the capability to assess these tasks in the AVL driveability measurement tool and gives examples how the tool supports the increasing effort in such calibration tasks for motorcycles. The objective driveability tool AVL-DRIVE is providing a lot of experiences on the tasks listed above, based on mature and proven automotive background. Beside the shown examples using this real time driveability assessment tool for more efficient new technology development, the paper summarizes the benefits for motorcycle manufacturers all around the world.
Falk, Patrick, Hubmann, Christian
Effect of Direct Yaw Moment Control Based on Steering Angle Velocity and Camber Angle Control2014-01-23869/30/2014
It has been reported that steering systems with derivative terms have a heightened lateral acceleration and yaw rate response in the normal driving range. However, in ranges where the lateral acceleration is high, the cornering force of the front wheels decreases and hence becomes less effective. Therefore, we applied traction control for the inner and outer wheels based on the steering angle velocity to improve the steering effectiveness at high lateral accelerations. An experiment using a driving simulator showed that the vehicle's yaw rate response improved for a double lane change to avoid a hazard; this improves hazard avoidance performance. Regarding improved vehicle control in the cornering margins, traction control for the inner and outer wheels is being developed further, and much research and development has been reported. However, in the total skid margin, where few margin remains in the forward and reverse drive forces on the tires, spinout is unavoidable. Therefore, we applied tire camber angle control to improve vehicle maneuverability in the total skid margin. An experiment using a driving simulator has confirmed that the vehicle's lateral acceleration at the turning limit can be improved by controlling the camber angle. Because of this, camber angle control promises to be more effective than traction control for the inner and outer wheels. By applying this type of steering control, it is possible to increase maneuverability and stability in the cornering margins.
Yoshino, Takahiko, Nozaki, Hiromichi
Friction Coefficient Mapping during Brake Interventions2014-01-24969/28/2014
This paper comprises obtaining friction coefficient (μ) measure by extracting surface and texture information using sensors during brake interventions. A primary estimate of friction coefficient has been obtained using wheel and vehicle signals. The estimates have been compared and combined to obtain a more accurate measure of friction coefficient. Finally, a suitable interpolation technique is used to obtain a μ-grid around the vehicle. The grid is graphically realized with the aid of visualization techniques using vehicle traces. This type of surface characterization usually enables brake distance optimization and effective countermeasures pertaining to a standard ESP system.
Venkata Padmanabhan, Adarsh, Ravichandran, Hariram, Pappala, Lokendra Pavan Kumar, Shenoy, Shreyas
Professional Driving Simulator to Design First-Time-Right Race Cars2014-01-00994/1/2014
Professional driving simulators can be successfully exploited to shorten the traditional design-prototype testing-production process relative to a new race car. Consider as a real example the Dallara 2014 Super Formula (“SF”) race car; built in 2013 at the Dallara factory in Varano de' Melegari, Parma, Italy and scheduled to race in Japan in 2014. Professional race drivers from the SF series have already been conducting multiple test sessions with the Dallara Simulator (Dec 2012), working together with vehicle dynamicists, aerodynamicists, designers, structural engineers and engine manufacturers, in an effort to evaluate and validate kinematics, steering geometry, aerodynamics, packaging, cooling, engine performance, as well as monocoque stiffness and minor installation details, even before the design had started. Multiple on track test sessions (Jul-Sep 2013), conducted with the real prototypes, have impressed both drivers and their respective engineers and engine representatives. The real car was found to be close in performance and feeling with respect to the virtual car developed on the simulator. This experience is a remarkable example worth sharing to the SAE community. It illustrates an innovative way for Motor Racing engineers to shorten the design-to-track development time.
Toso, Andrea, Moroni, Alessandro
Steer Assistance Control for Improved Vehicle Response2014-01-01094/1/2014
Advanced research in ABS (Anti-lock Braking System), traction control, electronic LSD's (Limited Slip Differential) and electrical powertrains have led to an architecture development which can be used to provide a controlled yaw moment to stabilize a vehicle. A steer assistance mechanism that uses the same architecture and aims at improving the vehicle response to the driver steering inputs is proposed. In this paper a feed-forward approach where the steering wheel angle is used as the main input is developed. An optimal control system is designed to improve vehicle response to steering input while minimizing the H2 performance of the body slip angle. The control strategy developed was simulated on a 14 DOF full vehicle model to analyze the response and handling performance.
Vaddi, Prashanth KR., Vinjamuri, Sandeep, Cheruvu, Kumar
Hybrid Cars Setting New Challenges for Optimized Power Semiconductors2014-01-02424/1/2014
The electrification of the powertrain is still one of the main challenges and innovation drivers for modern cars. With the introduction of the Toyota Prius, launched in Japan in 1997 the first commercially available hybrid car in mass production, the development continued towards the BMW i3 launched in July 2013. One main component for all kind of hybrid cars is still the power semiconductor, which is used for DC/DC converters and for the inverter to drive the electric motor for the traction control. What makes the selection of the right power semiconductor complex, is the variety of different voltage levels within the car (from standard 12V board net, the new 48V board net all the way up to 400V and above) plus different requirements in terms of switching and conduction performance, or accordingly power losses. The selection of device by application and voltage will be discussed in this paper. By comparing and contrasting the technology differences of MOSFETs and IGBTs, a recommendation for the ideal power device for different applications will be given. Typical trade off diagrams including switching frequency and breakdown voltage will help the designer to select the right device at a glance.
Puerschel, Marco, Kiep, Andreas
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.
Regenerative Braking Control Algorithm for an Electrified Vehicle Equipped with a By-Wire Brake System2014-01-17914/1/2014
Regenerative braking, which can effectively improve vehicle's fuel economy by recuperating the kinetic energy during deceleration processes, has been applied in various types of electrified vehicle as one of its key technologies. To achieve high regeneration efficiency and also guarantee vehicle's brake safety, the regenerative brake should be coordinated with the mechanical brake. Therefore, the regenerative braking control performance can be significantly affected by the structure of mechanical braking system and the brake blending control strategy. By-wire brake system, which mechanically decouples the brake pedal from the hydraulic brake circuits, can make the braking force modulation more flexible. Moreover, its inherent characteristic of ‘pedal-decouple’ makes it well suited for the implementation in the cooperative regenerative braking control of electrified vehicles. With the aims of regeneration efficiency and braking performance, a regenerative braking control algorithm for electrified vehicles equipped with a brake-by-wire system is researched in this paper. The layout of the adopted brake-by-wire system is introduced. The proposed regenerative braking control algorithm is illustrated. To validate the control performance of the algorithm, hardware-in-the-loop simulations are carried out. The simulation results show that, based on brake-by-wire system, the proposed control algorithm, coordinating regenerative brake and hydraulic brake well, can further improving the regeneration efficiency of electrified vehicle and guarantee the braking performance in the meantime.
Lv, Chen, Zhang, Junzhi, Li, Yutong, Yuan, Ye
A Comparison of Fuel-Cut Ageing during Retardation and Fuel-Cut during Acceleration2014-01-15044/1/2014
The effect of various fuel-cut agings, on a Volvo Cars 4-cylinder gasoline engine, with bimetallic three-way catalysts (TWCs) was examined. Deactivation during retardation fuel-cut (low load) and acceleration fuel-cut (high load, e.g. gearshift or traction control) was compared to aging at λ=1. Three-way catalysts were aged on an engine bench comparing two fuel-cut strategies and their impact on of the life and performance of the catalysts. In greater detail, the catalytic activity, stability and selectivity were studied. Furthermore, the catalysts were thoroughly analyzed using light-off and oxygen storage capacity measurements. The emission conversion as a function of various lambda values and loads was also determined. Fresh and 40-hour aged samples showed that the acceleration fuel-cut was the strategy that had the highest contribution towards the total deactivation of the catalyst system. Also, the retardation fuel-cut was found to be detrimental to the catalyst system but not to the same extent as an acceleration fuel-cut. During the aging procedure, exotherms were observed at the fuel-cut and the intensity of these exotherms was increasing with the length of aging time. The growing exotherms could be explained by the decomposition of HC into C and H2 and their subsequent oxidation at lean conditions. Also, the fuel-cut-off temperature measurements demonstrated that the magnitude of those exotherms was related to the total number as opposed to the total length of the fuel-cut.
Fathali, Anna, Laurell, Mats, Ekström, Fredrik B., Kristoffersson, Annika, Andersson, Bengt, Olsson, Louise
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