纯电动客车整车控制系统容错控制策略研究

发布时间：2019-03-30 16:47

【摘要】：随着高校和车企对纯电动汽车研发的日益深入,纯电动汽车各方面性能得到不断完善,其系统的复杂程度随之增加,导致各电控系统的传感器、执行机构和控制单元等出现故障的可能性增大。这对车辆的安全可靠性提出了更高的要求。如何降低故障发生的频率、提高故障诊断准确性并及时进行可靠的容错处理已成为纯电动汽车研究的关键问题。本课题来源于吉林省高新电动汽车有限公司与吉林大学合作研发项目,通过制定合理的容错控制策略,完善整车驱动控制策略,提高车辆的行驶安全性和可靠性。主要研究内容如下:1)纯电动客车典型故障机理分析。本文分别从加速踏板传感器、动力电池组和电机驱动系统三方面分析了纯电动客车可能存在的故障及其原因和影响,并结合实际情况,选取加速踏板传感器和动力电池组作为故障诊断对象。2)故障诊断与容错控制策略的制定。首先本文提取了加速踏板传感器故障信号特征,提出了基于逻辑门限值的故障诊断方法,并加入故障确认模块,减少误诊率。对加速踏板传感器故障信号的容错控制采用信号值动态替换的方法,实现了故障发生前后信号的平稳过渡,确保了整车的行驶可靠性。其次,本文通过实验得到环境温度和充放电倍率与电池可用容量的关系,在实车运行中对划分行驶模式的SOC值进行修正,完善驱动控制策略。最后,针对电机的过载故障采取输出扭矩上限限制进行过载时间管理的策略,对电机欠压、过温、过流等故障以温度为观测量,分别采取降温处理、限制输出功率等策略。3)模型搭建及离线仿真。本文在MATLAB/Simulink下搭建了故障诊断及容错控制策略模型,在CRUISE下搭建了整车动力学模型,对制定的容错控制策略进行了联合仿真,仿真结果表明故障诊断策略能够很好的识别发生的故障,并且加入容错控制策略后,整车行驶的可靠性得以提高。4)容错控制的硬件在环试验。本文基于课题组前期的整车控制策略硬件在环测试平台,搭建整车动力学模型,修改功能测试接口定义,并编写故障诊断与容错控制策略程序,对提出的容错控制策略进行试验,试验结果表明,在误差允许范围内,故障诊断能够很好的检测出发生的故障,制定的容错控制策略能够合理有效的对故障信号进行处理,验证了容错控制策略的可行性。
[Abstract]:With the deepening of the research and development of pure electric vehicles in universities and automobile enterprises, all aspects of the performance of pure electric vehicles have been constantly improved, and the complexity of the system has increased, leading to the sensors of each electronic control system. The possibility of failure of actuator and control unit is increased. This puts forward higher requirements for the safety and reliability of vehicles. How to reduce the frequency of fault occurrence, improve the accuracy of fault diagnosis and carry out reliable fault-tolerant processing in time have become the key problems in the research of pure electric vehicle. This project comes from the project of cooperation between Jilin province high-tech electric vehicle co., Ltd and Jilin university. Through making reasonable fault-tolerant control strategy and perfecting the driving control strategy of the whole vehicle, the driving safety and reliability of the vehicle can be improved. The main research contents are as follows: 1) Analysis of typical fault mechanism of pure electric bus. In this paper, the possible faults, causes and effects of pure electric bus are analyzed from three aspects: acceleration pedal sensor, power battery pack and motor drive system, and combined with the actual situation. The acceleration pedal sensor and power battery pack are selected as fault diagnosis objects. 2) Fault diagnosis and fault-tolerant control strategy formulation. Firstly, the fault signal characteristics of acceleration pedal sensor are extracted, and a fault diagnosis method based on logical threshold value is proposed, and a fault confirmation module is added to reduce the misdiagnosis rate. The fault tolerant control of the fault signal of the acceleration pedal sensor adopts the method of dynamic replacement of the signal value, which realizes the smooth transition of the signal before and after the failure, and ensures the driving reliability of the whole vehicle. Secondly, the relationship between the environment temperature, charge-discharge rate and the usable capacity of the battery is obtained through the experiment. In the real vehicle operation, the SOC value of dividing the driving mode is modified to perfect the driving control strategy. Finally, aiming at the overload fault of motor, the strategy of overloading time management is adopted to limit the upper limit of output torque. The faults such as under-voltage, over-temperature and over-current of motor are measured according to temperature, and the cooling treatment is adopted respectively. Strategies such as limiting output power. 3) Modeling and off-line simulation. In this paper, the fault diagnosis and fault-tolerant control strategy model is built under MATLAB/Simulink, the vehicle dynamics model is built under CRUISE, and the fault-tolerant control strategy is simulated jointly. The simulation results show that the fault diagnosis strategy can identify the faults well, and the reliability of the vehicle can be improved by adding the fault-tolerant control strategy. 4) the hardware-in-loop test of fault-tolerant control is carried out. Based on the hardware-in-the-loop test platform of the whole vehicle control strategy, this paper builds the vehicle dynamics model, modifies the function test interface definition, and compiles the fault diagnosis and fault-tolerant control strategy program. The test results of the proposed fault-tolerant control strategy show that the fault diagnosis can detect the fault within the allowable range of the error, and the fault-tolerant control strategy can deal with the fault signal reasonably and effectively. The feasibility of fault-tolerant control strategy is verified.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.72

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