The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Shi Guo-biao - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Steer-by-Wire System's Steering Ratio Using Genetic Algorithm
Computer Simulation, 2008Co-Authors: Shi Guo-biaoAbstract:Steer-by-Wire system cuts off the mechanical link between Steering wheel and steered wheels,so it can change Steering Ratio according to vehicle state to improve vehicle handling and stability.First,a driver-vehicle-road close loop dynamics model of Steer-by-Wire system including road model,driver model and two degree of freedom full vehicle model is built.Then the open loop total variance including trace error total variance,direction error total variance and driver Steering load is researched.Finally the Steering Ratios under different velocities are optimized with open loop total variance as fitness function using genetic algorithm.Results show that the optimized Steering Ratios can make the open loop total variance significantly smaller,improve lane trace performance and direction stability performance,and lower driver's Steering load thus improving vehicle handling and stability.
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Research on Active Steering Control Strategy of Steer-by-Wire System
Computer Simulation, 2008Co-Authors: Shi Guo-biaoAbstract:Steer-By-Wire (SBW) system eliminates the mechanical connections between Steering wheel and turning wheels so it can perform active Steering control to enhance handling and stabilities and active safety. SBW system’s variable Steering Ratio is designed and front wheel angles are actively controlled by making desired yaw rate of front wheel SBW trace yaw rate of Four-Wheel-Steering whose steady slip angles are zero. Performance analysis is done by indexes including time domain response ,Steering gain and open-loop total variation .Results show that when adopting prescribed active Steering,the steady slip angles are decreased greatly, open-loop total variation is decreased greatly, and handling stabilities are enhanced.
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Research on Steering Control Strategy of Four-Wheel-Steer-by-Wire System
Computer Simulation, 2008Co-Authors: Shi Guo-biaoAbstract:To control automobile's steady slip angle and keep constant Steering gain at the same time,rear wheel Steering control strategy and front wheel Steering control strategy are researched.Firstly,full vehicle two degree of freedom models of Four-Wheel-Steer-by-Wire are built.Then two types of Rear-Wheel angle control strategies based on zero steady slip angle are achieved,i.e.proportional with Front-Wheel angle type and yaw rate feedback type,of which the former doesn't change system poles while the latter does.Then their front wheels Steering Ratio formulas are acquired based on Steering gain not changing with velocity.Simulations show that the Front-Wheel Steering control strategy can keep constant Steering gain and decrease driver workload and improve the handling,and the Rear-Wheel Steering control strategy can achieve zero steady slip angle and control vehicle attitude,thus improving the handling and stabilities.
Changfu Zong - One of the best experts on this subject based on the ideXlab platform.
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Study on Control Strategy of Steer-by-Wire Vehicle with Joystick
Advanced Materials Research, 2013Co-Authors: Chang Liu, Hongyu Zheng, Changfu ZongAbstract:This study aims the development of a control strategy of steer-by-wire automotive with joystick. This control strategy makes driver able to change or maintain the Steering angle of road wheels of the vehicle by joystick, provides feedback force to the driver and offers variable Steering Ratio, variable force feedback and proper damping. The control strategy was mathematically modeled and implemented using the simulation tool Matlab/Simulink and tested to inspect its effectiveness. The result of the test proves the control strategy is effective and the performance of a joystick Steering system can be comparable to a traditional Steering wheel by applying this control strategy, indicating potential possibility of joystick-steered automotive.
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Research on Variable Steering Ratio of Vehicle Steer-by-Wire System Based on Joystick
Applied Mechanics and Materials, 2013Co-Authors: Hongyu Zheng, Bing Yu Wang, Changfu ZongAbstract:In the steer by wire system of vehicle, a joystick can instead of the Steering wheel. A control algorithm based on variable Steering Ratio is developed on the basis of vehicle speed and joystick Steering angle. By verifying the control algorithm with the vehicle model from CarSim, it shows that this proposed algorithm can effective carry out Steering intention of drivers, which enhance the steer comfort in low speed driving and steer handling in high speed driving and effectively improve the vehicle maneuverability.
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Investigations on control algorithm of steady-state cornering and control strategy for dynamical correction in a steer-by-wire system
Journal of Zhejiang University-SCIENCE A, 2009Co-Authors: Changfu Zong, Lei LiuAbstract:To improve the handling performance of a steer-by-wire (SBW) vehicle, a series of control logics are proposed. Firstly, an algorithm for enhancing the maneuvering in steady-state cornering is presented. On this basis, two categories of control strategies are used to dynamically correct and compensate the transient state Steering responses and vehicle behaviors. Simulator tests including subjective evaluations and virtual field tests are both conducted to make comprehensive investigations on the series of control logics. The subjective evaluations demonstrate that the SBW vehicle with a specifically selected value of Steering sensitivity tends to be more desirable for driving than a conventional one in which a fixed Steering Ratio exists. The virtual field tests indicate that the control strategies for dynamical correction and compensation could effectively improve the handling performances of an SBW vehicle by reducing the work load of drivers, enhancing the track-holding performance, and improving Steering response properties.
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Investigations on cornering control algorithm design and road feeling optimization for a Steer-By-Wire vehicle
2009 International Conference on Mechatronics and Automation, 2009Co-Authors: Changfu ZongAbstract:To improve the handling performance of a Steer-By-Wire (SBW) vehicle, a series of cornering control algorithms are proposed in this paper. Firstly, an algorithm for enhancing the maneuvering in steady-state cornering is presented. Subjective evaluations are then carried based on a driving simulator to demonstrate its superiority against a conventional vehicle with a fixed Steering Ratio. On this basis, two categories of control algorithms for dynamically correcting and compensating the transient state cornering responses of vehicles are added on. Simulator tests again are conducted to make comprehensive investigations. Test results indicate that the control algorithms for transient state cornering could effectively improve the handling performances of a SBW vehicle, in terms of reducing the work load of drivers, enhancing the track-holding ability and improving Steering response properties. Thirdly, optimization approaches on road feeling have been devised and simulated based on a modified Steering effort preference function of Chinese drivers. Test results revealed have declared its validation.
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Research on Steer-by-Wire System With Ideal Steering Ratio and 4WS
Design Engineering Parts A and B, 2005Co-Authors: Changfu Zong, Li Mai, Zhenhai GaoAbstract:This paper has studied the variable Steering Ratio for Steering-by-wire (SBW) based on the 29 DOF vehicle dynamic model, which kept the Steering gain of vehicle constant. And the Steering Ratio varied with the vehicle velocity and hand wheel angles. We have proposed three control strategies for SBW including front wheel control, yaw rate feedback control and yaw rate & acceleRation feedback control. We compared these three control methods by simulation and simulator tests. We have researched the forward and feedback control methods in the four wheels (4WS) for SBW system. And compared with 2WS for SBW and the classical 4WS. The results indicated that 4WS for SBW could improve the vehicle handling.Copyright © 2005 by ASME
Kamal Youcef-toumi - One of the best experts on this subject based on the ideXlab platform.
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Powered Two-Wheeled Vehicles Steering Behavior Study: Vision-Based Approach
2018Co-Authors: Pierre-marie Damon, Hicham Hadj-abdelkader, Hichem Arioui, Kamal Youcef-toumiAbstract:This paper presents a vision-based approach to prevent dangerous Steering situations when riding a motorcycle in turn. In other words, the proposed algorithm is capable of detecting under, neutral or over-Steering behavior using only a conventional camera and an inertial measurement unit. The inverse perspective mapping technique is used to reconstruct a bird-eye-view of the road image. Then, filters are applied to keep only the road markers which are, afterwards, approximated with the well-known clothoid model. That allows to predict the road geometry such that the curvature ahead of the motorcycle. Finally, from the predicted road curvature, the measures of the Euler angles and the vehicle speed, the proposed algorithm is able to characterize the Steering behavior. To that end, we propose to estimate the Steering Ratio and we introduce new pertinent indicators such that the vehicle relative position dynamics to the road. The method is validated on the advanced simulator BikeSim during a steady turn.
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ICARCV - Powered Two-Wheeled Vehicles Steering Behavior Study: Vision-Based Approach
2018 15th International Conference on Control Automation Robotics and Vision (ICARCV), 2018Co-Authors: Pierre-marie Damon, Hicham Hadj-abdelkader, Hichem Arioui, Kamal Youcef-toumiAbstract:This paper presents a vision-based approach to prevent dangerous Steering situations when riding a motorcycle in turns. The proposed algorithm is capable of detecting under, neutral or over-Steering behavior using only a conventional camera and an inertial measurement unit. The inverse perspective mapping technique is used to reconstruct a bird-eye-view of the road image. Then, filters are applied to keep only the road markers which are, afterwards, approximated with the well-known clothoid model. This allows the prediction of the road geometry such as the curvature ahead of the motorcycle. Finally, from the predicted road curvature, the measurements of the Euler angles and the vehicle speed, the proposed algorithm is able to characterize the Steering behavior. To that end, we propose to estimate the Steering Ratio and we introduce new pertinent indicators such as the vehicle relative position dynamics to the road. The method is validated using the advanced simulator BikeSim during a steady turn.
Hongyu Zheng - One of the best experts on this subject based on the ideXlab platform.
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Design of a variable Steering Ratio for steer-by-wire vehicle with a joystick:
Advances in Mechanical Engineering, 2017Co-Authors: Hongyu ZhengAbstract:Steer-by-wire system has replaced the conventional mechanical linkages with electronic actuators. In this article, a joystick is utilized to substitute the conventional Steering wheel and study the variable Steering Ratio design methods in this new human–machine interface. With this structure of steer-by-wire system, the Steering angle and torque Ratio can be designed flexibly. A dynamic model of joystick of steer-by-wire system is built based on bilateral control scheme. Through comparing the vehicle Steering performance of joystick with Steering wheel, three conventional Steering Ratio design methods are studied that are speed-dependent, speed- and angle-dependent and constant yaw rate gain. The drawbacks are analysed by three kinds of conventional Steering Ratio, and a novel variable yaw rate gain Steering Ratio design method is investigated. A driving simulator is used to verify and compare these Steering Ratio design methods. The computer simulation and experimental test results demonstrate that the ...
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Variable Steering Ratio Design for Vehicle Steer-by-wire with Joystick Based on Variable Yaw Rate Gain
Journal of Mechanical Engineering, 2014Co-Authors: Hongyu ZhengAbstract:A joystick is utilized to substitute the conventional Steering wheel with typical vehicle steer-by-wire(SBW) system and studied the variable Steering Ratio design method in this novel control structure.A 2-DOF dynamic reference model of vehicle is established and focused on the vehicle Steering performance of drivers control joystick.The drawbacks are analyzed that traditional ideal Steering Ratio of constant yaw rate gain of SBW system with Steering wheel is applied to joystick.The velocity factor and angle factor are presented to design variable Steering Ratio that keep the vehicle yaw rate gain linear variation.In addition,the vehicle model and Steering Ratio design method are computed and analyzed by using the software of Matlab/Simulink.A fixed driving simulator is used to verify variable Steering Ratio design method.The test results show that the proposed method can improve vehicle handling stability and comfort,which can effectively carry out Steering intention of drivers that the joystick is better than the Steering wheel in the lane tracking performance.
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Research on Variable Steering Ratio of Vehicle Steer-by-Wire System Based on Joystick
Applied Mechanics and Materials, 2013Co-Authors: Hongyu Zheng, Bing Yu Wang, Changfu ZongAbstract:In the steer by wire system of vehicle, a joystick can instead of the Steering wheel. A control algorithm based on variable Steering Ratio is developed on the basis of vehicle speed and joystick Steering angle. By verifying the control algorithm with the vehicle model from CarSim, it shows that this proposed algorithm can effective carry out Steering intention of drivers, which enhance the steer comfort in low speed driving and steer handling in high speed driving and effectively improve the vehicle maneuverability.
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Study on Control Strategy of Steer-by-Wire Vehicle with Joystick
Advanced Materials Research, 2013Co-Authors: Chang Liu, Hongyu Zheng, Changfu ZongAbstract:This study aims the development of a control strategy of steer-by-wire automotive with joystick. This control strategy makes driver able to change or maintain the Steering angle of road wheels of the vehicle by joystick, provides feedback force to the driver and offers variable Steering Ratio, variable force feedback and proper damping. The control strategy was mathematically modeled and implemented using the simulation tool Matlab/Simulink and tested to inspect its effectiveness. The result of the test proves the control strategy is effective and the performance of a joystick Steering system can be comparable to a traditional Steering wheel by applying this control strategy, indicating potential possibility of joystick-steered automotive.
Chang Liu - One of the best experts on this subject based on the ideXlab platform.
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Human-Centered Feed-Forward Control of a Vehicle Steering System Based on a Driver's Path-Following Characteristics
IEEE Transactions on Intelligent Transportation Systems, 2017Co-Authors: Wenshuo Wang, Chang LiuAbstract:To improve vehicle path-following performance and to reduce driver workload, a human-centered feed-forward control (HCFC) system for a vehicle Steering system is proposed. To be specific, a novel dynamic control strategy for the Steering Ratio of vehicle Steering systems that treats vehicle speed, lateral deviation, yaw error, and Steering angle as the inputs and a driver's expected Steering Ratio as the output is developed. To determine the parameters of the proposed dynamic control strategy, drivers are classified into three types according to the level of sensitivity to errors, i.e., low, middle, and high. The proposed HCFC system offers a human-centered Steering system (HCSS) with a tunable Steering gain, which can assist drivers in tracking a given path with smaller Steering wheel angles and change rate of the angle by adaptively adjusting Steering Ratio according to driver's path-following characteristics, reducing the driver's workload. A series of experiments of tracking the centerline of double lane change (DLC) are conducted in CarSim and three different types of drivers are subsequently selected to test in a portable driving simulator under a fixed-speed condition. The simulation and experiment results show that the proposed HCSS with the dynamic control strategy, as compared with the classical control strategy of Steering Ratio, can improve task performance by about 7% and reduce the driver's physical workload and mental workload by about 35% and 50%, respectively, when following the given path.
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Study on Control Strategy of Steer-by-Wire Vehicle with Joystick
Advanced Materials Research, 2013Co-Authors: Chang Liu, Hongyu Zheng, Changfu ZongAbstract:This study aims the development of a control strategy of steer-by-wire automotive with joystick. This control strategy makes driver able to change or maintain the Steering angle of road wheels of the vehicle by joystick, provides feedback force to the driver and offers variable Steering Ratio, variable force feedback and proper damping. The control strategy was mathematically modeled and implemented using the simulation tool Matlab/Simulink and tested to inspect its effectiveness. The result of the test proves the control strategy is effective and the performance of a joystick Steering system can be comparable to a traditional Steering wheel by applying this control strategy, indicating potential possibility of joystick-steered automotive.
