【作者】 林文尧；

【导师】 吴斌；

【作者基本信息】 北京工业大学 ， 热能工程， 2011， 硕士

【摘要】 离合器的接合控制是AMT研究的重点和难点。离合器接合过程有两个评价指标:即冲击度和滑磨功,这两个指标是相互矛盾的。为了协调这两个控制指标,实现车辆平稳起步,本文应用基于模型的控制方法,对AMT自动离合器的接合过程进行了研究,主要内容包括:按照车辆传动系统的结构,建立了系统动力学方程。为了便于分析离合器的接合控制,对系统动力学方程进行了等效简化。然后针对本文所用的AMT实验台建立了离合器接合过程中滑磨阶段和同步阶段的动力学方程,并计算了其等效摩擦半径和允许的最大接合速度。通过仿真分析,证明系统动力学模型是正确的。基于模型的控制策略需要确定传动系统的转动惯量、刚度和阻尼等参数。从AMT实验台架上采集发动机的输出扭矩、离合器输出轴上的扭矩、发动机飞轮的转速、离合器的转速和等效负载的转速等信号,经过数据处理后做为模型的输入和输出。AMT在二档时分别应用最小二乘法和遗传算法做参数辨识分析,并与AMT在一档的情况下进行对比验证,证明了参数辨识结果是准确可靠的。根据参数辨识的结果设计了离合器接合的控制策略。按照冲击度与滑磨功的设计要求分析了阶段模糊控制、基于离合器转速控制、基于发动机恒转速控制和扭矩匹配控制的原理及优缺点,并在MATLAB/Simulink环境下建立了控制模型。最后确定了基于发动机恒转速模型和扭矩匹配模型相接合的控制方法。在上述理论分析的基础上,设计了基于Freescale MC9S12DT128单片机和dSPACE的离合器接合电子控制系统。其中MC9S12DT128单片机用于采集AMT测试台架的各传感器信号、给离合器的电动执行器输出控制信号,同时也将采集得到的相关信号经CAN总线发送给dSPACE;dSPACE根据各传感器的输出信号对离合器及换档进行快速原型控制计算,并将计算的结果经CAN总线发送给MC9S12DT128单片机,以实现对离合器接合的实时控制。在此基础之上,采用发动机恒转速和扭矩匹配的控制策略,在AMT实验台架上进行了基于模型的离合器接合综控制实验。实验结果表明:在不同控制目标下,基于模型的控制方法均能满足实验控制要求。更多还原

【Abstract】 The engagement control of clutch is the key problem in the research of AMT. There are two evaluation indicators,namely jerk and friction work,and they are conflicting. In order to harmonize the two evaluation indicators each other, this paper is focused on the model-based control in the engagement process of AMT automatic clutch, mainly include:According to the structure of AMT transmission, the dynamic equations of the vehicle were established and simplified. Moreover, the dynamic equations of the experiment bench were established in slipping and synchronous stages. The friction radius and the maximum engagement speed of clutch were calculated. The friction torque was tested on the bench. It was testified the correction and feasibility of dynamic model by the simulation model.The simulation model was constructed to identify the parameters, such as inertia, stiffness and damping coefficient. The signals were tested from AMT experiment bench, including the output torque of engine, the friction torque, the engine speed, the clutch speed and the equivalent load speed. The signals were preprocessed as input and output of the simulation model. Then, the least square method and genetic algorithm were used to identify the parameters for AMT in second gear and verify in first gear.The control strategy was designed after parameter identification. According to the jerk and friction work in different stages, Four methods were designed, namely, fuzzy control, clutch speed model control, engine constant speed control and torque matching control. The control models were designed based on MATLAB/Simulink. According to jerk and friction work, both engine constant speed model and torque matching model were determined to take experiment.According to the above analysis, the electronic control system for clutch engagement was designed based on Freescale MC9S12DT128 MCU and dSPACE. The MC9S12DT128 MCU was to collect the signals from each sensor on the AMT test bench as well as outputing the control signals to the actuator of the clutch. And at the same time, it also sent the signals that collect to the dSPACE by CAN bus. Then, according to the output signals of each sensor, the dSPACE made the rapid prototyping calculate about the clutch engagement and the gear shift. The results sent to the MC9S12DT128 MCU by CAN bus. The engine constant speed model and torque matching model were used to control clutch engagement on the bench. The test results showed that: the model-based control strategy could ensure smooth and fast start of vehicle under various conditions.更多还原