This work presents an integrated pressure-tracking controller for a novel electro-hydraulic brake(EHB) system considering friction and hydraulic disturbances. To this end, a mathematical model of an EHB system, consis...This work presents an integrated pressure-tracking controller for a novel electro-hydraulic brake(EHB) system considering friction and hydraulic disturbances. To this end, a mathematical model of an EHB system, consisting of actuator and hydraulic sub-systems, is derived for describing the fundamental dynamics of the system and designing the controller. Due to sensor inaccuracy and measurement noise, a Kalman filter is constructed to estimate push rod stroke for generating desired master cylinder pressure. To improve pressure-tracking accuracy, a linear friction model is generated by linearizing the nonlinear Tustin friction model, and the unmodeled friction disturbances are assumed unknown but bounded. A sliding mode controller is designed for compensating friction disturbances, and the stability of the controller is investigated using the Lyapunov method. The performance of the proposed integrated controller is evaluated with a hardware-in-the-loop(HIL) test platform equipped with the EHB prototype. The test results demonstrate that the EHB system with the proposed integrated controller not only achieves good pressure-tracking performance, but also maintains robustness to friction disturbances.展开更多
Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) fimction. When the ABS control is terminated, th...Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) fimction. When the ABS control is terminated, the motor regenerative braking is readmitted. Aiming at avoiding permanent cycles from hydraulic anti-lock braking to motor regenerative braking, a novel electro-mechanical hybrid anti-lock braking system using fuzzy logic is designed. Different from the traditional single control structure, this system has a two-layered hierarchical structure, The first layer is responsible for harmonious adjustment or interaction between regenerative system and anti-lock braking system. The second layer is responsible for braking torque distribution and adjustment. The closed-loop simulation model is built. Control strategy and method for coordination between regenerative and anti-lock braking are developed. Simulation braking on low adhesion-coefficient roads with fuzzy logic control and real vehicle braking field test are presented. The results from simulating analysis and experiment show braking performance of the vehicle is perfect, harmonious coordination between regenerative and anti-lock braking function, significant amount of braking energy can be recovered and the proposed control strategy and method are effective.展开更多
A blend braking system of heavy vehicle was proposed.The main control part of the system is the electro hydraulic proportional servo valve.A nonlinear model of brake cylinder controlled by the valve was deduced throug...A blend braking system of heavy vehicle was proposed.The main control part of the system is the electro hydraulic proportional servo valve.A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature.The transfer function of the system was also proposed,and the hydraulic inherent frequency and the PID closed-loop system feature were calculated.The simulated result is consistent with those tested in the bench and on the site with 50 t heavy vehicle.The experimental result shows that the control method has quick response and high precision.展开更多
This paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system( DEHB) to replace the traditional automobile braking system. The a...This paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system( DEHB) to replace the traditional automobile braking system. The actuator of this system is driven by an electrical motor instead of the conventional vacuum booster to make the brake pressure be linearity controlled quickly. Therefore,the system has the advantages of quick response speed,good control performance and simple structure. Firstly,an overview of the actuator and the whole DEHB system is shown. Secondly,the possibility of this new kind of actuator working for the system is ensured based on some braking theories. Thirdly,the appropriate dynamic simulations are done to get some results to show the relations of different parameters and the effect of braking. Eventually,the proper parameters are determined to build a test bench which shows that DEHB system can achieve the maximum pressure of 13 MPa within 100 ms after parametric optimization,and meanwhile,the actuator is able to reduce pressure quickly after maintaining high pressure. All of the bench test results can meet with the design requirements and real demand of vehicle and this actuator may improve vehicle braking effect in the future. Besides,this actuator can be widely applied to the regenerative braking system because of its linear braking performance.展开更多
基金Projects(51405008,51175015)supported by the National Natural Science Foundation of ChinaProject(2012AA110904)supported by the National High Technology Research and Development Program of China
文摘This work presents an integrated pressure-tracking controller for a novel electro-hydraulic brake(EHB) system considering friction and hydraulic disturbances. To this end, a mathematical model of an EHB system, consisting of actuator and hydraulic sub-systems, is derived for describing the fundamental dynamics of the system and designing the controller. Due to sensor inaccuracy and measurement noise, a Kalman filter is constructed to estimate push rod stroke for generating desired master cylinder pressure. To improve pressure-tracking accuracy, a linear friction model is generated by linearizing the nonlinear Tustin friction model, and the unmodeled friction disturbances are assumed unknown but bounded. A sliding mode controller is designed for compensating friction disturbances, and the stability of the controller is investigated using the Lyapunov method. The performance of the proposed integrated controller is evaluated with a hardware-in-the-loop(HIL) test platform equipped with the EHB prototype. The test results demonstrate that the EHB system with the proposed integrated controller not only achieves good pressure-tracking performance, but also maintains robustness to friction disturbances.
基金supported by National Development and Reform Commission of China (Grant No. 2005934)
文摘Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) fimction. When the ABS control is terminated, the motor regenerative braking is readmitted. Aiming at avoiding permanent cycles from hydraulic anti-lock braking to motor regenerative braking, a novel electro-mechanical hybrid anti-lock braking system using fuzzy logic is designed. Different from the traditional single control structure, this system has a two-layered hierarchical structure, The first layer is responsible for harmonious adjustment or interaction between regenerative system and anti-lock braking system. The second layer is responsible for braking torque distribution and adjustment. The closed-loop simulation model is built. Control strategy and method for coordination between regenerative and anti-lock braking are developed. Simulation braking on low adhesion-coefficient roads with fuzzy logic control and real vehicle braking field test are presented. The results from simulating analysis and experiment show braking performance of the vehicle is perfect, harmonious coordination between regenerative and anti-lock braking function, significant amount of braking energy can be recovered and the proposed control strategy and method are effective.
文摘A blend braking system of heavy vehicle was proposed.The main control part of the system is the electro hydraulic proportional servo valve.A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature.The transfer function of the system was also proposed,and the hydraulic inherent frequency and the PID closed-loop system feature were calculated.The simulated result is consistent with those tested in the bench and on the site with 50 t heavy vehicle.The experimental result shows that the control method has quick response and high precision.
基金Sponsored by the National High Technology R&D Program of China(Grant No.2012AA111204 and 2012AA110903)National Key Basic Research Program of China(Grant No.2011CB711205)Free Research Project of State Key Laboratory of Automotive Safety and Energy(Grant No.zz2011-052)
文摘This paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system( DEHB) to replace the traditional automobile braking system. The actuator of this system is driven by an electrical motor instead of the conventional vacuum booster to make the brake pressure be linearity controlled quickly. Therefore,the system has the advantages of quick response speed,good control performance and simple structure. Firstly,an overview of the actuator and the whole DEHB system is shown. Secondly,the possibility of this new kind of actuator working for the system is ensured based on some braking theories. Thirdly,the appropriate dynamic simulations are done to get some results to show the relations of different parameters and the effect of braking. Eventually,the proper parameters are determined to build a test bench which shows that DEHB system can achieve the maximum pressure of 13 MPa within 100 ms after parametric optimization,and meanwhile,the actuator is able to reduce pressure quickly after maintaining high pressure. All of the bench test results can meet with the design requirements and real demand of vehicle and this actuator may improve vehicle braking effect in the future. Besides,this actuator can be widely applied to the regenerative braking system because of its linear braking performance.