In this paper,a kind of lateral stability control strategy is put forward about the four wheel independent drive electric vehicle.The design of control system adopts hierarchical structure.Unlike the previous control ...In this paper,a kind of lateral stability control strategy is put forward about the four wheel independent drive electric vehicle.The design of control system adopts hierarchical structure.Unlike the previous control strategy,this paper introduces a method which is the combination of sliding mode control and optimal allocation algorithm.According to the driver’s operation commands(steering angle and speed),the steady state responses of the sideslip angle and yaw rate are obtained.Based on this,the reference model is built.Upper controller adopts the sliding mode control principle to obtain the desired yawing moment demand.Lower controller is designed to satisfy the desired yawing moment demand by optimal allocation of the tire longitudinal forces.Firstly,the optimization goal is built to minimize the actuator cost.Secondly,the weighted least-square method is used to design the tire longitudinal forces optimization distribution strategy under the constraint conditions of actuator and the friction oval.Beyond that,when the optimal allocation algorithm is not applied,a method of axial load ratio distribution is adopted.Finally,Car Sim associated with Simulink simulation experiments are designed under the conditions of different velocities and different pavements.The simulation results show that the control strategy designed in this paper has a good following effect comparing with the reference model and the sideslip angle is controlled within a small rang at the same time.Beyond that,based on the optimal distribution mode,the electromagnetic torque phase of each wheel can follow the trend of the vertical force of the tire,which shows the effectiveness of the optimal distribution algorithm.展开更多
With the worsening of energy crisis and environmental pollution,electric vehicles with four in?wheel motors have been paid more and more attention. The main research subject is how to reasonably distribute the driving...With the worsening of energy crisis and environmental pollution,electric vehicles with four in?wheel motors have been paid more and more attention. The main research subject is how to reasonably distribute the driving torque of each wheel. Considering the longitudinal motion,lateral motion,yaw movement and rotation of the four wheels,the tire model and the seven DOF dynamic model of the vehicle are established in this paper. Then,the torque distribution method is proposed based on road adhesion margin,which can be divided into anti ? slip control layer and torque distribution layer. The anti?slip control layer is built based on sliding mode variable structure control,whose main function is to avoid the excessive slip of wheels caused by road conditions. The torque distribution layer is responsible for selecting the torque distribution method based on road adhesion margin. The simulation results show that the proposed torque distribution method can ensure the vehicle quickly adapt to current road adhesion conditions,and improve the handling stability and dynamic performance of the vehicle in the driving process.展开更多
A differential steering system is presented for electric vehicle with motorized wheels and a dynamic model of three-freedom car is built.Based on these models,the quantitative expressions of the road feel,sensitivity,...A differential steering system is presented for electric vehicle with motorized wheels and a dynamic model of three-freedom car is built.Based on these models,the quantitative expressions of the road feel,sensitivity,and operation stability of the steering are derived.Then,according to the features of multi-constrained optimization of multi-objective function,a multi-island genetic algorithm(MIGA)is designed.Taking the road feel and the sensitivity of the steering as optimization objectives and the operation stability of the steering as a constraint,the system parameters are optimized.The simulation results show that the system optimized with MIGA can improve the steering road feel,and guarantee the operation stability and steering sensibility.展开更多
This paper describes in detail three kinds of typical compound braking strategy of wheel motor drive electric vehicle and summarizes the current commonly used strategies based on the three typical strategies developed...This paper describes in detail three kinds of typical compound braking strategy of wheel motor drive electric vehicle and summarizes the current commonly used strategies based on the three typical strategies developed. In the end, a new compound braking strategy is proposed;that is, we take braking mode classify, ECE regulations and SOC value of the battery as an important reference of braking force that joins the motor braking force, as well as we join the different identification models;according to the different braking modes, the purpose is that we can apply the different braking program.展开更多
As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic p...As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic principles of nose wheel steering system and the design technique of mechanotronics,an all-electric aircraft nose wheel steering system,composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire with both steering and anti-shimmy functions is designed to meet the demand for operation control in the nose wheel steering system.Then,based on the LMS-AMESim software,the simulation model of the system is established to simulate the dynamics for the verification of its steering function.The simulation results indicate that the nose wheel steering system is reasonable,and can meet the requirements of the general project.Furthermore,the prototypes of the steering mechanism and control system are studied to validate the design,and the steering test bench is prepared to test the designed system.The test results,such as steer angle,rotate speed of motor are analyzed in details and compared with the theoretical results.The analysis and comparison results show that the design is reasonable and the property of the prototype can achieve the design objectives.展开更多
Due to quick response and large quantity of electric motor torque,the traction wheels of battery electric vehicle are easy to slip during the initial phase of starting.In this paper,a sliding mode control approach of ...Due to quick response and large quantity of electric motor torque,the traction wheels of battery electric vehicle are easy to slip during the initial phase of starting.In this paper,a sliding mode control approach of acceleration slip regulation is designed to prevent the slip of the traction wheels.The wheel slip ratio is used as the state variable for the formulation of system dynamics model.The fuzzy algorithm is utilized to adjust the switch function of sliding mode controller.After stability and robustness analysis,the sliding mode control law is transferred into C code and downloaded into vehicle control unit,which is validated under wet and dry road conditions.The experimental results with a small overshoot and a quick response during starting indicate that the sliding mode controller has good control efect on the slip ratio regulation.This article proposes an acceleration slip regulation method that improves the safety during acceleration for battery electric vehicle.展开更多
由于动车组车轮受加工装配及工况载荷等不确定因素的影响,车轮退化过程复杂,存在显著的个体差异及多个性能退化特征量,且多个退化特征量间相互耦合,仅考虑单个性能特征量难以全面反映其退化过程。因此,以轮缘和轮径作为车轮退化特征量,...由于动车组车轮受加工装配及工况载荷等不确定因素的影响,车轮退化过程复杂,存在显著的个体差异及多个性能退化特征量,且多个退化特征量间相互耦合,仅考虑单个性能特征量难以全面反映其退化过程。因此,以轮缘和轮径作为车轮退化特征量,通过随机化尺度参数表征车轮个体差异,采用Gamma过程和Copula函数建立二元相关退化模型,并根据赤池信息准则(Akaike Information Criterion, AIC)筛选Copula函数,得到可靠度解析式。基于某型动车组车轮实测磨耗数据,对车轮进行可靠性分析,同时通过车辆动力学模型进行仿真验证。结果显示:考虑二元相关时的可靠性结果比仅考虑一元退化更贴近车辆实际运行情况;根据动力学仿真结果体现了考虑个体差异的必要性,表明所提模型能够更准确地表征车轮退化过程,可为可靠性分析以及维修决策优化提供理论支撑。展开更多
为进一步提高制动能量回收率,考虑不同工况下驾驶员不同制动意图所需的制动效果,提出了一种四驱电动汽车制动控制策略。首先,针对常规制动工况,基于常规制动意图识别,从制动能量回收率、稳定性和安全性角度分别设计控制策略;其次,针对...为进一步提高制动能量回收率,考虑不同工况下驾驶员不同制动意图所需的制动效果,提出了一种四驱电动汽车制动控制策略。首先,针对常规制动工况,基于常规制动意图识别,从制动能量回收率、稳定性和安全性角度分别设计控制策略;其次,针对滑行工况下的不同滑行制动意图,判断电机制动力是否介入及何时介入,并根据驾驶员所需的滑行距离计算电机制动力的大小;然后,由台架试验获得前后电机外特性并建立前后电机最优利用效率模型;最后,利用Carsim和Simulink进行了联合仿真分析。仿真结果表明,在新欧洲驾驶循环(New European Driving Cycle,NEDC)工况下,与并联控制策略相比,能量回收率提升了13.64百分点;在滑行工况下可有效识别驾驶员需求滑行距离,提升了整车滑行经济性。展开更多
为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter...为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter,ARMAX-KF)与速度补偿的拖拉机无前轮传感器转角估计方法。首先,利用Hammerstein非线性系统对拖拉机的转向系统建模,并采用递归最小二乘法(Recursive least squares method,RLS)将其辨识为ARMAX模型;其次,对后轮轴中心接地点速度进行杆臂误差补偿;最后,提出了ARMAX-KF方法,利用卡尔曼滤波器的校正特性,以拖拉机的运动学转角作为观测值,修正ARMAX模型预测的转角速度积分值,从而估计拖拉机的前轮转角。在速度杆臂补偿测量方法试验验证中,补偿后运动学转角平均绝对误差为1.110°,标准差为1.727°,相比补偿前分别减少61.13%和31.55%;在动态转角试验中,ARMAX模型预测的转角速度标准差为2.439(°)/s,相比采用固定传动比方法误差减少56.58%;采用基于ARMAX-KF的前轮转角估计绝对平均误差为0.649°,标准差为0.371°,相比采用固定传动比和卡尔曼滤波器的方法分别减少56.9%和78.82%;在直线导航跟踪试验中,采用基于ARMAX-KF的前轮转角估计标准差为0.649°,本文提出的方法提高了转角估计精度和农机导航作业质量。展开更多
基金supported by the National Nature Science Foundation(U1664263)National Key R&D Program of China(2016YFB0101102)。
文摘In this paper,a kind of lateral stability control strategy is put forward about the four wheel independent drive electric vehicle.The design of control system adopts hierarchical structure.Unlike the previous control strategy,this paper introduces a method which is the combination of sliding mode control and optimal allocation algorithm.According to the driver’s operation commands(steering angle and speed),the steady state responses of the sideslip angle and yaw rate are obtained.Based on this,the reference model is built.Upper controller adopts the sliding mode control principle to obtain the desired yawing moment demand.Lower controller is designed to satisfy the desired yawing moment demand by optimal allocation of the tire longitudinal forces.Firstly,the optimization goal is built to minimize the actuator cost.Secondly,the weighted least-square method is used to design the tire longitudinal forces optimization distribution strategy under the constraint conditions of actuator and the friction oval.Beyond that,when the optimal allocation algorithm is not applied,a method of axial load ratio distribution is adopted.Finally,Car Sim associated with Simulink simulation experiments are designed under the conditions of different velocities and different pavements.The simulation results show that the control strategy designed in this paper has a good following effect comparing with the reference model and the sideslip angle is controlled within a small rang at the same time.Beyond that,based on the optimal distribution mode,the electromagnetic torque phase of each wheel can follow the trend of the vertical force of the tire,which shows the effectiveness of the optimal distribution algorithm.
基金supported by the Natural Science Foundation of Jiangsu Province(No. BK20151472)the Research Project of Key Laboratory of Advanced Manufacture Technology for Automobile Parts(Chongqing University of Technology) , Ministry of Education (No. 2015KLMT04)
文摘With the worsening of energy crisis and environmental pollution,electric vehicles with four in?wheel motors have been paid more and more attention. The main research subject is how to reasonably distribute the driving torque of each wheel. Considering the longitudinal motion,lateral motion,yaw movement and rotation of the four wheels,the tire model and the seven DOF dynamic model of the vehicle are established in this paper. Then,the torque distribution method is proposed based on road adhesion margin,which can be divided into anti ? slip control layer and torque distribution layer. The anti?slip control layer is built based on sliding mode variable structure control,whose main function is to avoid the excessive slip of wheels caused by road conditions. The torque distribution layer is responsible for selecting the torque distribution method based on road adhesion margin. The simulation results show that the proposed torque distribution method can ensure the vehicle quickly adapt to current road adhesion conditions,and improve the handling stability and dynamic performance of the vehicle in the driving process.
基金Supported by the National Natural Science Foundation of China(51375007,51205191)the Visiting Scholar Foundation of the State Key Lab of Mechanical Transmission in Chongqing University+1 种基金the Funds from the Postgraduate Creative Base in Nanjing University of Aeronautics and Astronauticsthe Research Funding of Nanjing University of Aeronautics and Astronautics(NS2013015)
文摘A differential steering system is presented for electric vehicle with motorized wheels and a dynamic model of three-freedom car is built.Based on these models,the quantitative expressions of the road feel,sensitivity,and operation stability of the steering are derived.Then,according to the features of multi-constrained optimization of multi-objective function,a multi-island genetic algorithm(MIGA)is designed.Taking the road feel and the sensitivity of the steering as optimization objectives and the operation stability of the steering as a constraint,the system parameters are optimized.The simulation results show that the system optimized with MIGA can improve the steering road feel,and guarantee the operation stability and steering sensibility.
文摘This paper describes in detail three kinds of typical compound braking strategy of wheel motor drive electric vehicle and summarizes the current commonly used strategies based on the three typical strategies developed. In the end, a new compound braking strategy is proposed;that is, we take braking mode classify, ECE regulations and SOC value of the battery as an important reference of braking force that joins the motor braking force, as well as we join the different identification models;according to the different braking modes, the purpose is that we can apply the different braking program.
基金supported partly by the Aeronautical Science Foundation of China(No.20142852025)
文摘As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic principles of nose wheel steering system and the design technique of mechanotronics,an all-electric aircraft nose wheel steering system,composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire with both steering and anti-shimmy functions is designed to meet the demand for operation control in the nose wheel steering system.Then,based on the LMS-AMESim software,the simulation model of the system is established to simulate the dynamics for the verification of its steering function.The simulation results indicate that the nose wheel steering system is reasonable,and can meet the requirements of the general project.Furthermore,the prototypes of the steering mechanism and control system are studied to validate the design,and the steering test bench is prepared to test the designed system.The test results,such as steer angle,rotate speed of motor are analyzed in details and compared with the theoretical results.The analysis and comparison results show that the design is reasonable and the property of the prototype can achieve the design objectives.
基金Supported by Key Research and Development Program of Jiangsu Province of China(Grant No.BE2021006-2)University Synergy Innovation Program of Anhui Province of China(Grant No.GXXT-2020-076)Innovation Project of New Energy Vehicle and Intelligent Connected Vehicle of Anhui Province of China,and Foundation of State Key Laboratory of Automotive Simulation and Control of China(Grant No.20201107).
文摘Due to quick response and large quantity of electric motor torque,the traction wheels of battery electric vehicle are easy to slip during the initial phase of starting.In this paper,a sliding mode control approach of acceleration slip regulation is designed to prevent the slip of the traction wheels.The wheel slip ratio is used as the state variable for the formulation of system dynamics model.The fuzzy algorithm is utilized to adjust the switch function of sliding mode controller.After stability and robustness analysis,the sliding mode control law is transferred into C code and downloaded into vehicle control unit,which is validated under wet and dry road conditions.The experimental results with a small overshoot and a quick response during starting indicate that the sliding mode controller has good control efect on the slip ratio regulation.This article proposes an acceleration slip regulation method that improves the safety during acceleration for battery electric vehicle.
文摘由于动车组车轮受加工装配及工况载荷等不确定因素的影响,车轮退化过程复杂,存在显著的个体差异及多个性能退化特征量,且多个退化特征量间相互耦合,仅考虑单个性能特征量难以全面反映其退化过程。因此,以轮缘和轮径作为车轮退化特征量,通过随机化尺度参数表征车轮个体差异,采用Gamma过程和Copula函数建立二元相关退化模型,并根据赤池信息准则(Akaike Information Criterion, AIC)筛选Copula函数,得到可靠度解析式。基于某型动车组车轮实测磨耗数据,对车轮进行可靠性分析,同时通过车辆动力学模型进行仿真验证。结果显示:考虑二元相关时的可靠性结果比仅考虑一元退化更贴近车辆实际运行情况;根据动力学仿真结果体现了考虑个体差异的必要性,表明所提模型能够更准确地表征车轮退化过程,可为可靠性分析以及维修决策优化提供理论支撑。
文摘为进一步提高制动能量回收率,考虑不同工况下驾驶员不同制动意图所需的制动效果,提出了一种四驱电动汽车制动控制策略。首先,针对常规制动工况,基于常规制动意图识别,从制动能量回收率、稳定性和安全性角度分别设计控制策略;其次,针对滑行工况下的不同滑行制动意图,判断电机制动力是否介入及何时介入,并根据驾驶员所需的滑行距离计算电机制动力的大小;然后,由台架试验获得前后电机外特性并建立前后电机最优利用效率模型;最后,利用Carsim和Simulink进行了联合仿真分析。仿真结果表明,在新欧洲驾驶循环(New European Driving Cycle,NEDC)工况下,与并联控制策略相比,能量回收率提升了13.64百分点;在滑行工况下可有效识别驾驶员需求滑行距离,提升了整车滑行经济性。
文摘为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter,ARMAX-KF)与速度补偿的拖拉机无前轮传感器转角估计方法。首先,利用Hammerstein非线性系统对拖拉机的转向系统建模,并采用递归最小二乘法(Recursive least squares method,RLS)将其辨识为ARMAX模型;其次,对后轮轴中心接地点速度进行杆臂误差补偿;最后,提出了ARMAX-KF方法,利用卡尔曼滤波器的校正特性,以拖拉机的运动学转角作为观测值,修正ARMAX模型预测的转角速度积分值,从而估计拖拉机的前轮转角。在速度杆臂补偿测量方法试验验证中,补偿后运动学转角平均绝对误差为1.110°,标准差为1.727°,相比补偿前分别减少61.13%和31.55%;在动态转角试验中,ARMAX模型预测的转角速度标准差为2.439(°)/s,相比采用固定传动比方法误差减少56.58%;采用基于ARMAX-KF的前轮转角估计绝对平均误差为0.649°,标准差为0.371°,相比采用固定传动比和卡尔曼滤波器的方法分别减少56.9%和78.82%;在直线导航跟踪试验中,采用基于ARMAX-KF的前轮转角估计标准差为0.649°,本文提出的方法提高了转角估计精度和农机导航作业质量。