汽车电动制动助力器电机控制算法研究
Research on Motor Control Algorithm of Automotive Electric Brake Booster

电动制动助力器是现代汽车的关键难点技术之一，直接关系到整车系统功能的实现，对电机控制策略的研究极为关键，目前该技术主要由国外公司掌控，自主研究该技术已成为整车厂迫切任务之一。首先，分析对比了电动制动助力器的工作机理，并将PMSM与BLDC做了对比，明确了选择矢量控制策略作为助力电机控制的主要原因。其次，分析了矢量控制策略的特点及对其控制逻辑进行了项目详细描述，对其核心部分的坐标变换和SVPWM算法进行了公式推导和数学建模，在理论上论证了该套逻辑的可行性，建立了8种开关状态与相电压和线电压的对应关系，以扇区描述了电压空间矢量图。接着，通过MATLAB/Simulink搭建了矢量控制策略的仿真模型，并将位置、速度、扭矩作为目标输入，从里到外分别以PI控制器控制电流环，速度环及位置环。最后，以仿真模型验证了电流环、速度和和位置环，其控制精度分别为99%、96%和99%，系统延迟均控制在0.02秒以内，电机幅值波动也较少，均在合理范围以内，从而验证了该仿真模型的正确性和有效性。
Electric brake booster is one of the key and difficult technologies of modern vehicles, which is directly related to the realization of vehicle system functions. The research on motor control strategy becomes very critical. At present, this technology is mainly controlled by foreign companies and research on this technology has become one of the urgent tasks of OEMs. First of all, the working mechanism of the electric brake booster is analyzed and compared, the PMSM and BLDC are compared, and the main reason for choosing the vector control strategy as the power motor control is clarified. Second, analyzing the characteristics of the vector control strategy and its control logic is described in detail, the project of the core part of the coordinate transformation and the SVPWM algorithm formula derivation and mathematical modeling, demonstrates the feasibility of this set of logic in theory, set up eight kinds of switch state, the corresponding relationship between phase voltage and line voltage sector which is used to describe the voltage space vector diagram. Then, the simulation model of vector control strategy is built by MATLAB/Simulink, and the position, speed and torque are taken as the target input, and the current loop, speed loop and position loop are respectively controlled by PI controller from inside to outside. Finally, the simulation model is used to verify the current loop, speed loop and position loop, and the control accuracy is 99%, 96% and 99%, respectively. The system delay is controlled within 0.02 seconds, and the amplitude fluctuation of the motor is less, which is within a reasonable range, thus proving the correctness and effectiveness of the simulation model.