基于状态估计的轮毂电机驱动控制策略研究

Drive Control Strategy of In-wheel Motor Based on State Estimation

为克服轮毂电机响应慢,控制精度和抗干扰性差的难题,本文在滑模控制(Sliding mode control,SMC)的基础上,开发基于转速和角度在线状态估计的超螺旋滑模(Super-twisting sliding mode control,STSMC)轮毂电机转速转矩联合控制策略。采用单移线工况,轮毂电机汽车匀速换变道时分别对各轮毂电机进行转速控制,满足阿克曼转向要求,变道后采用正弦过渡方法对各轮毂电机进行转矩控制,电机快速平滑输出期望转矩,车辆直线加速。为防止转速和角度传感器误差或者损坏,轮毂电机控制中采用最大相关熵平方根广义高阶容积卡尔曼算法(Maximum correlation entropy square root generalized high-order cubature Kalman filter,MCSRGHCKF)对转速和转子角度进行无传感器估计,实验测试得到转子角度估计误差为-0.05 rad,转速误差为0.3 r/min,满足电机控制要求。从电机启动到匀速运行阶段采用STSMC算法控制,转速超调量为6.33%,最大输出转矩为0.35 N·m,响应时间为0.22 s,稳态转速脉动为±0.5 r/min,转矩脉动为±0.01 N·m,相比PID和SMC算法,控制效果更佳。在转速切换转矩控制,转矩可按照正弦函数平滑过渡,最大超调仅为2.86%,电机运行平稳。

To overcome the challenges of slow response,poor control accuracy,and poor anti-interference performance of in-wheel motor,a super-twisting sliding mode control(STSMC)in-wheel motor speed and torque joint control strategy was developed based on online state estimation of speed and angle,which was based on the sliding mode control(SMC).Under the single-lane change condition,the speed of each in-wheel motor was controlled when the vehicle changed lanes at a constant speed,meeting the Ackermann steering requirements.After lane changing,the torque of each in-wheel motor was controlled by using a sinusoidal transition method,allowing the motor to quickly and smoothly output the desired torque and accelerate the vehicle in a straight line.To prevent errors or damage of the speed and angle sensors,the maximum correlation entropy square root generalized high-order cubature Kalman filter(MCSRGHCKF)was used for sensorless estimation of the speed and rotor angle.Based on experimental testing,the rotor angle estimation error was-0.05 rad,and speed error was 0.3 r/min,both of which met the motor control requirements.From the start of the motor to the uniform speed operation stage,the STSMC algorithm was used for control,with speed overshoot of 6.33%,maximum output torque of 0.35 N·m,response time of 0.22 s,steady-state speed ripple of±0.5 r/min,and torque ripple of±0.01 N·m.Compared with PID and SMC algorithms,the control effect was better.In the speed switching torque control,the torque can smoothly transition according to the sine function,with maximum overshoot of only 2.86%,and the motor ran smoothly.