Browse Topic: Steer-by-wire

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Directional Vehicle Control by Steering the Third Axle to Provide Redundancy for Steer-by-Wire Systems and Highly Autonomous Vehicles02-13-03-00159/25/2020
A way of providing steering redundancy for highly autonomous vehicles or vehicles equipped with steer-by-wire systems by steering the rear axle for directional control of the vehicle has been previously proposed. In this study, we further investigate and improve on that concept and validate it through simulation and experimental testing on a vehicle. Consequently, we show that in the case of failure of primary front axle steering system, the vehicle controller steering command (in the case of autonomous driving) or the driver’s steering command (in the case of a steer-by-wire system) can be mathematically manipulated to generate a steering input at the rear axle, which results in the same yaw rate response as if the vehicle was steered from the front, and thus providing a way to control the vehicle should a failure occur in the primary steering system.
Nhila, Amine, Williams, Dan E.
Steering Control of the Off-Highway Vehicles2019-26-01081/9/2019
Steering is integral system of any vehicle to achieve direction control. With driver’s inputs, as steering wheel is turned, the steering mechanism is operated to turn the road wheels to route the vehicle on desired path. This Paper studies the different steering architectures and the learning is applied to improve the off-highway vehicles’ steering control. Off-Highway vehicles have traditionally been using Hydrostatic Power Steering (HPS) mechanism with no feedback controls. This mechanism consists of inherent limitations to vehicle efficiency, reliability and control preciseness. In this paper, HPS is modeled using 1D simulation tools from the system parameters and derived equations. The results are plotted and discussed to acknowledge the merits and demerits of existing system which helped in proposing the alternate steering solution. Different steering architectures are evaluated and trade-off study performed to choose the Electro-Hydraulic Power Steering (EHPS) architecture. The mathematical equations behind the Electro-Hydraulic steering system are derived and couple of control strategies (like PID controller and state-feedback controller) are applied to minimize the error between commanded and actual road wheel angle. Non-linear system is simulated using different software and PID controller gains are tuned to achieve desired response. Linearized state space system is modeled to obtain the state-feedback control to operate electro-hydraulic steering valve. In the end, event triggered control is discussed to operate the steering system at desired threshold for potential energy saving.
Joshi, Bharat, Sukumar, Srikant, Jawale, Vinit, Patil, Ojas
Control of Steer by Wire System for Reference Steering Wheel Torque Tracking and Return-Ability2018-01-05664/3/2018
This paper proposes a torque tracking algorithm via steer by wire to achieve the target steering feel and proposed a modified friction model to obtain return-ability. A three dimensional reference steering wheel torque map is designed using the measurement data of the steering characteristics of the target vehicle at a transition test and a weave test. In order to track the reference steering wheel torque, a sliding mode control is used in the tracking algorithm. In addition, to achieve return-ability, the modified friction model for steer by wire is used instead of the friction model defined in the reference steering wheel torque map. The modified friction model is composed of various models according to the angular velocity. The angular velocity and the angular acceleration used in the control algorithm are estimated using a kalman filter. A motor is used as the actuators to generate the targeted steering feel and the torque angle sensor (TAS) is used to measure the steering wheel torque and the steering wheel angle. Using the computer simulations, the return-ability of the proposed controller was evaluated with the return test and the tracking performance of the proposed controller was evaluated with the weave test and transition test. By using this proposed control algorithm in steer by wire system, the steering feel close to that of a conventional motor driven steer system has been successful obtained and return-ability has been achieved.
Lee, Jaepoong, kyongsu, Yi, Kim, Kwangil, Lee, Byungrim, Lee, Dongpil, Jang, Bongchoon, Chang, Sehyun
Studies on Steering Feeling Feedback System Based on Nonlinear Vehicle Model2017-01-14943/28/2017
The steer-by-wire system has been widely studied due to many advantages such as good controllability. In the system, the steering column is cancelled and the driver can't feel the feedback torque (also called steering feeling) coming from the ground. Therefore a steering feeling feedback system is needed. In this paper, we propose a simple method to calculate desired feedback torque based on a nonlinear 2DOF vehicle model. The vehicle model contains the nonlinearity of tire. So that the proposed method is also appropriate for big acceleration conditions. Besides that, the properties of steering system such as friction and stiffness are also taken into consideration. As for conventional steering system, driver can only feel part of the feedback torque due to the power assist system. In order to provide steering feeling similar to conventional steering system, a weighting function is proposed to compensate the influence of power assist system. At the last part of this paper, real vehicle experiments are conducted to validate the proposed method. In comparison with the test data, the steering feeling feedback algorithm can calculate desired feedback torque precisely.
Tao, Weinan, Gao, Bingzhao, Chu, Hongqing, Tian, Mengjian, Chen, Hong
Robust Control of a Four-Wheel-Independent-Steering Electric Vehicle for Path Tracking2017-01-15843/28/2017
Compared with the traditional front-wheel- steering (FWS) vehicles, four-wheel-independent-steering (4WIS) vehicles have better handing stability and path-tracking performance. In view of this, a novel 4WIS electric vehicle (EV) with steer-by-wire (SBW) system is proposed in this paper. As to the 4WIS EV, a linear quadratic regulator (LQR) optimal controller is designed to make the vehicle track the target path based on the linear dynamic model. Taking the effect of uncertainties in vehicle parameters into consideration, a robust controller utilizing μ synthesis approach is designed and the controller order reduction is implemented based on Hankel-Norm approximation. In order to evaluate the performance of the designed controllers, numerical simulations of two maneuvers are carried out using the nonlinear vehicle model with 9 degrees of freedom (DOF) in MATLAB/Simulink. Simulation results show that the robust controller is superior to the LQR optimal controller in tracking accuracy in terms of the nominal vehicle model. Furthermore, the robust controller can make the vehicle track the target path well under the circumstances of different vehicle velocities and road friction coefficients, which indicates the robust controller has strong robust stability and good robust performance against parametric perturbations.
Hang, Peng, Chen, Xinbo, Luo, Fengmei, Fang, Shude
A Steer-by-Wire System that Enables Remote and Autonomous Operation2014-01-24049/30/2014
Original equipment manufacturers and their customers are demanding more efficient, lighter, smaller, safer, and smarter systems across the entire product line. In the realm of automotive, agricultural, construction, and earth-moving equipment industries, an additional highly desired feature that has been steadily trending is the capability to offer remote and autonomous operation. With the previous requirements in mind, the authors have proposed and validated a new electrohydraulic steering technology that offers energy efficiency improvement, increased productivity, enhanced safety, and adaptability to operating conditions. In this paper, the authors investigate the new steering technology's capacity to support remote operation and demonstrate it on a compact wheel loader, which can be remotely controlled without an operator present behind the steering wheel. This result establishes the new steer-by-wire technology's capability to enable full autonomous operation as well.
Daher, Naseem A., Ivantysynova, Monika
The Resistance Loading System of Electronic Control Steering System Performance Test Bench2014-01-02304/1/2014
Nowadays, electric control steering system has been a main tendency. It consists of Electric Power Steering (EPS) system, Steer by Wire (SBW) system and Active Front Steering (AFS) system. EPS is more widely applied and its technology is more developed. By 2010, the cars equipped with EPS have reached almost 30%. This paper describes one integrated test bench which can test and verify electric control steering system. The main target of the paper is to design and set up a resistance loading system for the test bench referred. The paper takes EPS as a prototype to verify the designed resistance loading system. If the resistance loading system provides a precise simulated torque for the bench, the results of tests will be more approximate with vehicle tests and the acquired data will be reliable for electric control steering system's design and improvement. The linear electric cylinder applied in the loading system is used to provide simulated torque for the bench. The linear electric cylinder is combined with a kind of software independently designed. The linear electric cylinder's control method is stress control and its control principle is PID. The control program of the cylinder has been programmed in the master computer. If you want to change the control program or just modify somewhere, you amend parameters related.
Yu, Lijiao, Zheng, Hongyu, Zong, Changfu
The Design of Electrically Controlled Steering System Hardware-In-the-Loop Test Bench2014-01-02434/1/2014
Nowadays, conventional steering system cannot meet consumers' requirements as their environmental awareness increasing. Electrically controlled steering system can solve this problem well [1] [2]. Electrically controlled steering system has been not only applied widely in automobile steering technique but also becomes an important section of automobile integrated chassis control technology. It is necessary for vehicles to test their every component repeatedly before every component assembled. So a test bench becomes an essential part for vehicle products' design and improvement. The electrically controlled steering system consists of Electric Power Steering system (EPS), Active Front Steering (AFS) and Steer by Wire (SBW). The similarity among them is containing pinion-and-rack mechanical structure, so it is viable to design a test bench suitable for these three systems. This paper takes EPS as a prototype to verify the design's availability. The designed test bench is also used to detect and verify the electrically controlled steering system's performance at the same time. The steering system's performance is mainly about vehicle's stability and safety. A test bench is expected to provide techniques for electrically controlled steering system's extensive use. Combining with the steering system's working principle, the paper drafts performance test methods to verify the designed test bench able to test EPS prototype performance correctly or not. If this bench is able to test the prototype performance exactly, it is also effective to test the other electrically controlled steering system.
Yu, Lijiao, Zheng, Hongyu, Zong, Changfu
A New Control Strategy for Electric Power Steering on Low Friction Roads2014-01-00834/1/2014
In vehicles equipped with conventional Electric Power Steering (EPS) systems, the steering effort felt by the driver can be unreasonably low when driving on slippery roads. This may lead inexperienced drivers to steer more than what is required in a turn and risk losing control of the vehicle. Thus, it is sensible for tire-road friction to be accounted for in the design of future EPS systems. This paper describes the design of an auxiliary EPS controller that manipulates torque delivery of current EPS systems by supplying its motor with a compensation current controlled by a fuzzy logic algorithm that considers tire-road friction among other factors. Moreover, a steering system model, a nonlinear vehicle dynamics model and a Dugoff tire model are developed in MATLAB/Simulink. Physical testing is conducted to validate the virtual model and confirm that steering torque decreases considerably on low friction roads. Finally, simulation results show that the new EPS assist control strategy successfully increases steering effort under slippery conditions without compromising ease of steering, while ensuring that road feel also increases with decreasing in road friction and/or increasing vehicle speed as an additional safety measure.
Fan, Lu, Zhou, Bing, Zheng, Harry
Variable Yaw Rate Gain for Vehicle Steer-by-wire with Joystick2013-01-04134/8/2013
Steering-By-Wire (SBW) system has advantages of advanced vehicle control system, which has no mechanical linkage to control the steering wheel and front wheels. It is possible to control the steering wheel actuator and front wheels actuator steering independently. The goal of this paper is to use a joystick to substitute the conventional steering wheel with typical vehicle SBW system and to study a variable steering ratio design method. A 2-DOF vehicle dynamic reference model is built and focused on the vehicle steering performance of drivers control joystick. By verifying the results with a hardware-in-the-loop simulation test bench, it shows this proposed strategy can improve vehicle maneuverability and comfort.
Zheng, Hongyu, Zong, Changfu
A Control Allocation Algorithm for Improving the Fail-Safe Performance of an Electric Vehicle Brake System2013-01-01874/8/2013
The ample electrical power supply makes brake-by-wire technology more suitable for application in electric vehicles than in conventional vehicles. The fail-safe performance of a brake-by-wire system is a key factor regarding its application on production vehicles. A new control allocation algorithm for improving the fail-safe performance of an electric vehicle brake system is proposed. The electric vehicle is equipped with a four-wheel independent brake-by-wire and steer-by-wire system. The main objective of the algorithm is to maintain the vehicle braking performance as close to the desired level as possible by reallocating the control inputs to the actuators in cases of partial or full failure of the brake-by-wire system. The control algorithm is developed using a two degrees of freedom vehicle model. A pseudo control vector is calculated by a sliding mode controller to minimize the difference between the desired and actual vehicle motions. A pseudo-inverse controller then allocates the control inputs according to the pseudo control vector and the failure mode which is assumed to have been determined by some diagnostic algorithms. The control algorithm is evaluated in Matlab/Simulink. Cases of the brake-by-wire system's partial failure and full failure are all covered while performing the simulations. In cases of partial failure, the control algorithm reallocates the braking forces to the failure-free wheels and corrects the steering angles of the four wheels to compensate the yaw moment generated by the possible asymmetric braking. In the case of full failure, the wheels on each of the two axles are steered in opposite directions to generate braking forces. Simulation results show that the algorithm works effectively to ensure safe braking in case of brake system failures.
Feng, Chong, Ding, Nenggen, He, Yongling, Xu, Guoyan, Gao, Feng
Bilateral Control Method of Torque Drive/Angle Feedback Used for Steer-by-Wire System2012-01-07924/16/2012
Steer-by-Wire system is capable of improving the performance of vehicle handling and stability, and assisting driving. It becomes a key technique to control front wheel angle and simulate the steering resistance delivered to the driver because of removing mechanical linkages between the steering wheel and the front wheels. This paper proposes a bilateral control method of steering wheel torque drive/pinion angle feedback, which is disaccustomed of controlling steering wheel block and steering actuator as master-slave plants. The pinion angle, steering wheel angle and its torque signals are used in the control logic without estimating or measuring the tire/road force. Simulations and vehicle experiments proceeded with this proposed method and the results confirmed that it achieves the bilateral control of the position and torque between the two plants. Meanwhile, the characteristics of the steering and returning dynamics obtained are very similar to conventional mechanical steering systems.
Wang, Xiang, Zong, Changfu, Xing, Haitao, Hu, Rufei, xie, Xujun
Understeer Concepts with Extensions to Four-Wheel Steer, Active Steer, and Time Transients2012-01-02454/16/2012
An overview of existing and alternative forms of vehicle understeer/oversteer expressions is presented. New forms are derived consistent with conceptual extensions to the configurations of the vehicle's steering system, the driving mode - steady-state or transient, and the responses - path curvature or yaw velocity. Derivation of all understeer expressions is presented with a consistent use of the Ackermann reference case and the related “Ackermann vehicle” construct. The vehicle is otherwise represented in a traditional manner as a bicycle model operating in the linear range consistent with small angle approximations. The vehicle's steering system is assumed to be more generally configured with four-wheel steer and active or steer-by-wire actuation at both axles. The actuation is assumed to allow the introduction of significant speed sensitivity to the effective overall steering ratios. Discussion is devoted to the significance of this speed sensitivity on test results and the determination of the mean reference steer angles. Expressions for understeer gradient associated with this generally configured vehicle are simplified for the more familiar case of a front-wheel steer vehicle with a passive steering system having a fixed overall steering ratio. The driving mode can be either steady-state, as is traditionally assumed, or transient. The transients are assumed to be the result of steering transients or speed changes. Understeer expressions are presented using traditional variables, included reference steer angle and included Ackermann steer angle, and less frequently used variables, axle reference sideslip angles and cornering compliances. Context is given with a brief history of the development of understeer concepts, both traditional steady-state and transient, and usage of the terms “understeer” and “oversteer”.
Topping, Richard
Software Function Allocation and Configuration of an AUTOSAR-Compliant System2012-01-00024/16/2012
The software part of an automotive embedded system continues to increase significantly. It enables the development of new functionalities and it may improve the quality and comfort of driver assistance functions. However, the design of such functions becomes a complex task involving networked ECUs (Electronic Control Unit), several sensors/actuators and a set of embedded networks. The introduction of Model-Based Development (MBD) in the automotive field promised to improve the development process by allowing continuity between requirements definition, system design and the distributed system implementation. Further, the definition of AUTOSAR consortium standardized the design of such automotive embedded system by allowing the portability of software functions on the hardware architecture and their reuse. It defines a set of rules and interfaces to design, interconnect, deploy and configure a set of application software components (SWCs). However, designing an embedded system according to AUTOSAR standard necessitates the configuration of thousands of parameters and requires several software allocation decisions. Each decision may influence the system performance and also the development cost. This architectural complexity leads to a large design decision space which is difficult to be explored without using an analytical method or a design tool. For example, mapping software components (SWCs) to ECUs may affect the system performance. Actually, this phase of configuration and software allocation is performed manually using engineering and system architect knowledge. AUTOSAR provide a methodology for the software development of an Electricals/Electronics (E/E) system. However, this method doesn't guide the designer to deploy and bring a high-level software function onto a set of SWCs and then SWCs to ECUs. In this paper we present a model-based methodology to optimize software allocation and component configuration of an AUTOSAR system. This methodology relies on a multi-objective evolutionary algorithm which is characterized by its composability and speed performance. This algorithm is combined with a model-based system analysis engine permitting to evaluate system performance objectives. The objectives considered here are the CPU load, network load and functions response times.
Daghsen, Ahmed, Chaaban, Khaled, Saudrais, Sébastien, Shawky, M. M.
Safety steps up11OFHD1215_0112/15/2011
Electronic controls let suppliers improve safety without sacrificing reliability. Safety has become a major factor in design programs as regulators and customers alike call for more safeguards. Electronic controls are letting design engineers add features without lowering reliability, reducing the amount of downtime caused by accidents. Over the past few years, safety has become an important selling point throughout the transportation industry. As microprocessors increased their computing power while costs drop, engineers have deployed these chips in many ways to safeguard operators, equipment, and the surrounding environment.
Costlow, Terry
Steer-by-Wire Systems with Integrated Torque Feedback Improve Steering Performance and Reduce CostTBMG-106706/1/2011
Hydraulic steering systems have long dominated the industrial utility vehicle market because of their familiarity both to vehicle designers and operators. More recently, a trend has been seen towards the use of electronic steer-by-wire systems that provide greater design flexibility by enabling software to customize the connection between the steering wheel and steering mechanism. Several suppliers offer integrated steer-by-wire systems targeting the industrial utility vehicle market. A key differentiating factor is the method used to provide torque feedback to give the operator a heightened sense of vehicle control. The latest generation of integrated steer-by-wire systems consumes less power, is less expensive, and offers the ability to be programmed to provide a wide range of value-added features.
Integrated Control of Active Steering and Electronic Differentials in Four Wheel Drive Vehicles2009-01-04464/20/2009
In this paper the integrated control of front and rear active differentials with active front steering is investigated in order to improve dynamics, stability and to reduce the drawbacks of mechanical self-locking differentials. The proposed integrated centralized control feeds back both the yaw rate and the wheel speed measurements to the control inputs which are the front wheel steering angle and the torque transferred by the electronic differentials between the left and the right wheels of both vehicle's axles. The control of the electronic differentials is not only aimed at keeping the wheel speed differences at desired values but it is also integrated with the active steering control (a PI action from the yaw rate error) to produce a yaw moment (also depending on the yaw rate error) which improves handling and stability. Several simulations are carried out on a CarSim small SUV model to explore the robustness with respect to unmodelled dynamics such as pitch, roll and nonlinear combined lateral and longitudinal tire forces. In response to sudden direction changes the simulations show reduced oscillations, robustness and enlarged bandwidth for the yaw rate tracking dynamics while new stable maneuvers are allowed especially in critical conditions such as μ-split braking.
Marino, Riccardo, Scalzi, Stefano
BEI Duncan’s Steer-by-Wire Technology Improves Fuel Efficiency for AGCO Challenger® TractorTBMG-96674/1/2009
Off-highway tractors slog through mud, muck, and other rough terrain on a daily basis. Achieving high reliability and performance in spite of these harsh conditions requires technology at its best. To improve fuel efficiency and reliability while decreasing manufacturing costs, the AGCO Challenger® track tractor went through a major redesign from the ground up.
Optimum Design of a Steer by Wire System using Systematic System Engineering Approach2008-01-14524/14/2008
A systematic system engineering methodology to design and analyze a Steer by Wire (SBW) system optimizes the system performance. The proposed system engineering approach along with dynamic system analysis leads to a robust, reliable and efficient SBW system design. This approach assures a concrete definition by considering possible use cases, regulatory restrictions, user's expectation and constraints from stake holders. The further decomposition of definitions to design and analysis is derived from all these inputs. Performance of the system is evaluated by defining measure of effectiveness and use cases. The dynamic analysis is performed using SysML methodology.
Rath, Manaswini, Kelly, Morrel, Kober, Kurt, Gulati, Anand
Vehicle Steer-by-Wire System Control2006-01-11754/3/2006
This paper describes a method for controlling a vehicle steer-by-wire system. It gives a novel control structure for the steer-by-wire system to implement steering functions and to improve the vehicle handling performance. The paper focuses on the implementation of various steering functions by applying control design methods. Some vehicle test results are included.
Yao, Yixin
Controllability of Active Steering System Hazards: From Standards to Driving Tests2006-01-06004/3/2006
When developing new automotive systems a great deal of the development effort is devoted to ensure a sufficient functional safety of the system. A question that arises during early risk analyses of such a system is that of the controllability of possible system hazards. While this question is answered in early stages very often using worst-case risk graphs, the question comes back later in a much more precise way: in case of active steering systems component failures would produce a deviation between desired and actual road wheel position, the deviation can be measured in terms of amplitude and/or time. The central question is how much deviation can be controlled by the driver? Note, that there will always be a certain, even small, deviation between desired and actual road wheel position since the steering systems controller contains feedback control algorithms aiming at minimising the regulation error but not actually making it disappear totally. The contribution reviews the different notions of controllability used in safety standards such as MISRA Guidelines, IEC61508 [1], DIN V 19250 [6] and DS 00-55 [3]. The role of the operator/driver as a potential source of failure or as a safety measure is touched as well. Goal of this paper is to bridge the gap between safety standards and driving tests, recently applied during development of electronically controlled steering systems.
Reinelt, Wolfgang, Lundquist, Christian
Improvement of Vehicle Lateral Dynamics by Active Front Steering Control2004-01-20815/4/2004
In this work, the active front steering control is studied using linear three degrees of freedom handling model incorporating the driver’s operation model and vehicle suspension derivatives. The active steering control strategy is based on the optimal control theory. In this design, the active front steering angle is determined based on minimizing all model state variables and full state feedback gains. The results are generated when the model is excited by random wind excitation, which was modeled as quasi-static approach with statistical properties taken from previous work, and presented in frequency domain as power spectral density as well as root mean square values in tables. Significant improvements are achieved for the vehicle handling characteristics using active front steering control in comparison with active four wheel steering and conventional two wheel steering.
Oraby, W. A. H., El-Demerdash, S. M., Selim, A. M., Faizz, A., Crolla, D. A.
A Control System Methodology for Steer by Wire Systems2004-01-11063/8/2004
Steer by Wire systems provide many benefits in terms of functionality, and at the same time present significant challenges too. Chief among them is to make sure that an acceptable steering feel is achieved. Various aspects of this subjective attribute will be defined mathematically. A control system that is architected specifically to meet these challenges is presented. Furthermore, the design is made such that it would be robust to tire and loading variations. Supporting vehicle data and model results are shown as needed.
Amberkar, Sanket, Bolourchi, Farhad, Demerly, Jon, Millsap, Scott
Sensor for Modern Steering Assist Systems2004-01-17733/8/2004
A torque sensor is presented in this paper that is designed for application on electric power steering systems. The sensor is based on a novel magnetic principle where the magnetic flux path is modified by a torsion bar which is placed in the steering shaft. A multipole magnetic ring is placed on one side of the torsion bar (e.g. input shaft) and two soft magnetic stators on the other side (e.g. output shaft). The magnetic field strength between these two stators is a direct measure of the steering torque angle and is detected by a standard Hall effect magnetic field sensor. This magnetic field signal is nearly constant along the circumference and therefore the magnetic filed sensor can be mounted stationary with respect to the rotating steering shaft. Two linear Hall sensors are used to detect the magnetic field strength for the purpose of redundancy. This novel non-contact technology allows a simple and robust design. The functional principle and the design will be presented as well as 3D magnetic field simulations enabling an optimization of the magnetic circuit.
Jerems, F, Rachui, D., Fröhlich, E., Proft, M.
The Application of Tolerance Rings to Provide Shock Overload Protection in EPAS Systems2004-01-10993/8/2004
Tolerance Rings have traditionally been used to compensate for component tolerances or differential thermal expansion effects but developments in Tolerance Ring technology are enabling them to be more widely used as simple, low cost, non-destructive overload protection devices. By following suitable design principles, detailed in this paper, tolerance rings can be designed to operate as shock overload protection devices within existing component space envelopes whilst also allowing reduction in design strength of other components in the drive system. The factors to be considered in selecting between various alternative tolerance ring positions within the EPAS electric drive train are explained. The effects of mating component and tolerance ring variation on the performance of the overall system are detailed. Examples of the use of Tolerance Rings in production EPAS systems are outlined.
Smith, James W.
Design of Controller for Fundamental Steer-by-wire system2003-28-00138/22/2003
An overview of today's automotive industry reminds us about an ever-increasing demand for passenger comfort, safety and zero emissions vehicles. Drivers are also seeking improvements in the handling stability at high vehicle speeds. Electronically controlled steering systems have made their mark in the power assisted steering systems. The next generation of power steering system is the STEER BY WIRE System that is made of completely electronically controlled electrical components in place of mechanical and hydraulic parts. This project is an attempt to design and develop a first generation control system that is compatible with any steering system of car and passenger transport vehicle with slight changes in the basic configuration. Electronic control improves the power saving effectiveness and increases the steering performance. As this system needs no drive from the engine it can be fitted in an electric vehicle also. The directional control of DC servomotor is done using two DPST relays. The Programmable Logic Controller (PLC) is used for control logic programming using C.
Arasan, Santhosh T., Midhun, V.S., Subburaj, V., Jawahar, P.Mannar
Automotive Engineering International 2002-08-01AUTOAUG028/1/2002
Then there were two Prevailing sentiment in the Japanese media, and to some extent among the public, is that there are two truly indigenous automobile manufacturers in Japan: the Toyota group of companies and Honda. Others have entrenched themselves in global alliances for much-needed infusions of foreign capital. Cars and light trucks merge As light-vehicle segments blur in function and utlility, Japanese manufacturers are placing body design emphasis on optimum space utilization and crash safety. Chassis trends Technologies in development by Japanese companies include lane keeping, steer by wire, and dynamic stability via hybrid-electric drive. Engines and electric motors The Japanese industry is pursuing a high-tech mix of internal combustion engines, hybrid IC/electric powertrains, and fuel cells. Proof of performance As advanced powertrain technologies such as cylinder deactivation, hybrid-electric drivelines, and fuel-cell propulsion become more prevalent, independent service providers and OEMs are positioning themselves to support these trends through greater testing and engineering service capabilities. Steel rules the body panel kingdom The predominant choice for the armor of mass-produced cars and trucks, steel is not going unchallenged at a time when weight reduction is more important than ever. Testing and engineering resources Independent service providers are continually expanding their portfolio of technical capabilities to meet the testing and engineering needs of automotive OEMs and suppliers. AEI editors review some of the latest service and technologies being offered to the industry.
Embedded Real Time Operating Systems and the OSEK Standard2000-01-03823/6/2000
In recent years the growth of distributed architectures in automotive electronics has been well documented. It is not uncommon for advanced vehicles to contain more than 70 individual Electronic Control Units (ECU's). The use of embedded processors to gain enhancements in comfort and safety, as well as to achieve legislative requirements, has meant that the software content in vehicles has now become a significant part of the system design. This paper looks at some of the issues for the designer of embedded automotive systems and looks at the OSEK/VDX 1 standard (Open systems and the corresponding interfaces for automotive electronics) as a way of providing a framework for addressing them.
Brook, David
Future Electrical Steering Systems: Realizations with Safety Requirements2000-01-08223/6/2000
Additional future requirements for automobiles such as improved vehicle dynamics control, enhanced comfort, increased safety and compact packaging are met by modern electrical steering systems. Based on these requirements the new functionality is realized by various additional electrical components for measuring, signal processing and actuator control. However, the reliability of these new systems has to meet the standard of today's automotive steering products. To achieve the demands of the respective components (e.g. sensors, bus systems, electronic control units, power units, actuators) the systems have to be fault-tolerant and/or fail-silent. The realization of the derived safety structures requires both expertise and experience in design and mass production of safety relevant electrical systems. Beside system safety and system availability the redundant electrical systems also have to meet economic and market requirements. Within this scope the paper discusses three different realizations of electrical steering systems 1 Electrical power steering system (mechanical system with electrical boosting) 2 Steer-by-wire system with hydraulic back-up and 3 Full steer-by-wire system The paper presents solutions for these systems and discusses the various advantages and disadvantages, respectively. Furthermore strategies for failure detection, failure localization and failure treatment are presented. Finally the various specifications for the components used are discussed.
Harter, Werner, Pfeiffer, Wolfgang, Dominke, Peter, Ruck, Gerhard, Blessing, Peter
Electric Power Steering - The First Step on the Way to “Steer by Wire”1999-01-04013/1/1999
The automotive industry is facing a revolution in steering technology. For many years powersteering technology was focussed on hydraulic systems. These systems have achieved a remarkable performance in regard to ride and handling, cost and comfort. At the moment the situation is changing dramatically. A lot of car manufacturers mainly in Europe and Asia are switching to electric power steering because of several advantages e.g. concerning fuel consumption and logistics. This paper will discuss the demands for EPS systems of the second generation. A technical approach is described, as well as measurements showing several benefits in regard to vehicle dynamics. The general introduction of EPS systems also has restarted the discussion about „Steer by Wire”. This technology confronts the industry with even higher challenges. The additional requirements - mainly for maintaining safety - are highlighted and the chances and risks are discussed. In summary: EPS systems are competitive right now. Based on this technology the future of „Steer by Wire” may come soon.
Peter, Dominke, Gerhard, Ruck
Active Suspension and Rear Wheel Steering Make Powerful Research and Development Tools9302663/1/1993
Experience has shown that a vehicle equipped with Active suspension and rear wheel steering can be a very powerful tool for research into vehicle dynamics. Passive or “adaptiveu vehicle suspension systems can be emulated. This has considerable potential for shortening vehicle development times. Active systems provide the ability to separate dynamic modes from one another. This enables detailed examination of each effect without the cross coupling normally experienced with passive vehicles. The driver is an important part of the dynamic loop and ultimately it is he/she who must be able to control the vehicle with confidence, precision, and minimum fatigue. An Active vehicle is a powerful way to investigate the feedback and cues needed by the driver, and to produce objective requirements to achieve them. Thus armed, vehicle design, computer simulation and development functions can be more effective in getting better products more quickly to the market.
Hurdwell, Richard, Pilling, Michael J.
Advanced Commercial Vehicle Steering Systems, Variants and Development Trends91268711/1/1991
Better cost effectiveness, further improvement in ease of steering as well as energy advantages, with the safety standard as high as ever: these are the principal targets characterizing current and future developments in the field of steering systems for commercial vehicles. The relevant major development areas refer to single-circuit and dual-circuit steering systems with additional functions such as influencing by parameters. Steering systems for rear axles are another key development area.
Hughes, Robert A., Elser, Dieter
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