A 20 degree of the freedom model of the micro-suspended monorail is established to analyze a new type of the vehicle system named micro-suspended monorail.The formula of the tire is established by using the magic form...A 20 degree of the freedom model of the micro-suspended monorail is established to analyze a new type of the vehicle system named micro-suspended monorail.The formula of the tire is established by using the magic formula.Through the modal analysis of the vehicle,the modes of the vehicle are obtained,and resonance has little effect on the vehicle.When the vehicle moves in a right turn curve,it yaws in the clockwise direction.Under the action of the guidewheel(stable wheel)force,the front bogie yaws clockwise but the rear one yaws counterclockwise.Moreover,the two bogies and the car body roll during the curve passing process of the vehicle.When the vehicle speed is high enough,the left drive wheel will derail and the anti-overturning moments are provided by the stable wheels.Then,the car body yaws in the counterclockwise direction when it moves out of the curve.In the simulation of the vehicle passing the curve,the clearance between the guide wheel and rail surface will lead to a fatal impact on the bogie.At the same time,the dynamic response of the vehicle under the crosswind is tested.The vehicle will not overturn due to the crosswind.Finally,the collision of adjacent vehicles is analyzed.The results show that there is an intermittent collision force between two vehicles due to the vehicle's non synchronous pitch motion.展开更多
Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented ...Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented via support vector machines （SVMs）. The feasibility of applying SVMs to steady-state tyre modelling is investigated by comparison with three-layer backpropagation （BP） neural network at pure slip and combined slip. The results indicate SVMs outperform the BP neural network in modelling the tyre characteristics with better generalization performance. The SVMsqyre is implemented in 8-DOF vehicle model for vehicle dynamics simulation by means of the PAC 2002 Magic Formula as reference. The SVMs-tyre can be a competitive and accurate method to model a tyre for vehicle dynamics simuLation.展开更多
The magic formula(MF)tire model is a semi-empirical tire model that can precisely simulate tire behavior.The heuristic optimization algorithm is typically used for parameter identification of the MF tire model.To avoi...The magic formula(MF)tire model is a semi-empirical tire model that can precisely simulate tire behavior.The heuristic optimization algorithm is typically used for parameter identification of the MF tire model.To avoid the defect of the traditional heuristic optimization algorithm that can easily fall into the local optimum,a parameter identification method based on the Fibonacci tree optimization(FTO)algorithm is proposed,which is used to identify the parameters of the MF tire model.The proposed method establishes the basic structure of the Fibonacci tree alternately through global and local searches and completes optimization accordingly.The global search rule in the original FTO was modified to improve its efficiency.The results of independent repeated experiments on two typical multimodal function optimizations and the parameter identification results showed that FTO was not sensitive to the initial values.In addition,it had a better global optimization performance than genetic algorithm(GA)and particle swarm optimization(PSO).The root mean square error values optimized with FTO were 5.09%,10.22%,and 3.98%less than the GA,and 6.04%,4.47%,and 16.42%less than the PSO in pure lateral and longitudinal forces,and pure aligning torque parameter identification.The parameter identification method based on FTO was found to be effective.展开更多
鉴于魔术公式轮胎模型能够较准确地描述轮胎特性,为获取跨座式单轨走行轮胎的魔术公式轮胎模型,采用Tire Data Fitting Tool模块和遗传算法相结合的方法进行魔术公式参数辨识。利用Tire Data Fitting Tool模块辨识出粗糙参数,再利用遗...鉴于魔术公式轮胎模型能够较准确地描述轮胎特性,为获取跨座式单轨走行轮胎的魔术公式轮胎模型,采用Tire Data Fitting Tool模块和遗传算法相结合的方法进行魔术公式参数辨识。利用Tire Data Fitting Tool模块辨识出粗糙参数,再利用遗传算法辨识出精确参数。基于参数辨识获得的魔术公式轮胎模型计算出的轮胎力结果与仿真数据相关性好。研究成果为跨座式单轨车辆动力学分析提供了有效的轮胎模型。展开更多
基金The National Key Research and Development Program of China(No.2018YFB1201702)the Program of State Key Laboratory of Traction Power(No.2018TPL_T11)the Fundamental Research Funds for the Central Universities(No.2682017CX009).
文摘A 20 degree of the freedom model of the micro-suspended monorail is established to analyze a new type of the vehicle system named micro-suspended monorail.The formula of the tire is established by using the magic formula.Through the modal analysis of the vehicle,the modes of the vehicle are obtained,and resonance has little effect on the vehicle.When the vehicle moves in a right turn curve,it yaws in the clockwise direction.Under the action of the guidewheel(stable wheel)force,the front bogie yaws clockwise but the rear one yaws counterclockwise.Moreover,the two bogies and the car body roll during the curve passing process of the vehicle.When the vehicle speed is high enough,the left drive wheel will derail and the anti-overturning moments are provided by the stable wheels.Then,the car body yaws in the counterclockwise direction when it moves out of the curve.In the simulation of the vehicle passing the curve,the clearance between the guide wheel and rail surface will lead to a fatal impact on the bogie.At the same time,the dynamic response of the vehicle under the crosswind is tested.The vehicle will not overturn due to the crosswind.Finally,the collision of adjacent vehicles is analyzed.The results show that there is an intermittent collision force between two vehicles due to the vehicle's non synchronous pitch motion.
基金This project is supported by Shanghai Automobile Industry Corporation Technology Foundation, China(No.0224).
文摘Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented via support vector machines （SVMs）. The feasibility of applying SVMs to steady-state tyre modelling is investigated by comparison with three-layer backpropagation （BP） neural network at pure slip and combined slip. The results indicate SVMs outperform the BP neural network in modelling the tyre characteristics with better generalization performance. The SVMsqyre is implemented in 8-DOF vehicle model for vehicle dynamics simulation by means of the PAC 2002 Magic Formula as reference. The SVMs-tyre can be a competitive and accurate method to model a tyre for vehicle dynamics simuLation.
基金the National Natural Science Foundation of China(No.11672127)the Army Research and Technology Project(No.AQA19001)the Fundamental Research Funds for the Central Universities(No.NP2020407)。
文摘The magic formula(MF)tire model is a semi-empirical tire model that can precisely simulate tire behavior.The heuristic optimization algorithm is typically used for parameter identification of the MF tire model.To avoid the defect of the traditional heuristic optimization algorithm that can easily fall into the local optimum,a parameter identification method based on the Fibonacci tree optimization(FTO)algorithm is proposed,which is used to identify the parameters of the MF tire model.The proposed method establishes the basic structure of the Fibonacci tree alternately through global and local searches and completes optimization accordingly.The global search rule in the original FTO was modified to improve its efficiency.The results of independent repeated experiments on two typical multimodal function optimizations and the parameter identification results showed that FTO was not sensitive to the initial values.In addition,it had a better global optimization performance than genetic algorithm(GA)and particle swarm optimization(PSO).The root mean square error values optimized with FTO were 5.09%,10.22%,and 3.98%less than the GA,and 6.04%,4.47%,and 16.42%less than the PSO in pure lateral and longitudinal forces,and pure aligning torque parameter identification.The parameter identification method based on FTO was found to be effective.
文摘鉴于魔术公式轮胎模型能够较准确地描述轮胎特性,为获取跨座式单轨走行轮胎的魔术公式轮胎模型,采用Tire Data Fitting Tool模块和遗传算法相结合的方法进行魔术公式参数辨识。利用Tire Data Fitting Tool模块辨识出粗糙参数,再利用遗传算法辨识出精确参数。基于参数辨识获得的魔术公式轮胎模型计算出的轮胎力结果与仿真数据相关性好。研究成果为跨座式单轨车辆动力学分析提供了有效的轮胎模型。
