基于Lipschitz观测器的新型离合器执行机构控制算法

在并联混动车辆中,为实现在系统反馈状态下,通过控制膜片弹簧离合器分离轴承位置对摩擦转矩高质量的伺服控制,同时避免对有噪声执行机构位置信号进行微分来获取速度,设计了基于状态观测器的新型位置控制算法,弥补了速度传感器的缺失.分析了膜片弹簧、波形弹簧及分离指弹性特性对分离轴承端载荷的影响,导出了执行机构非线性状态方程,以此设计前馈补偿器,同时将Lipschitz非线性状态观测理论用于观测执行机构位置、电机转速及分离轴承作用力.仿真结果初步验证了上述控制算法的可行性及观测器良好的鲁棒性,即:若观测器中蜗轮蜗杆效率与实际值存在偏差,对位置及转速的观测存在稳态误差,前者可忽略,后者不超过可接受的10 r/min;位置信号中噪声几乎完整地出现在对自身及作用力观测值中,但不影响转速;从动盘磨损后,对位置及转速观测效果较好,但对作用力的观测存在稳态误差,幅值不超过25 N. 

A Novel Clutch Actuator Control Algorithm Based on Lipschitz Observer

For parallel hybrid vehicles, a nonlinear observer based novel position servo control algorithm was designed without the need of speed sensors. This algorithm, according to the feedback of system states, can implement high-quality servo control of friction torque through the position control of release bearing in diaphragm spring clutch. It can also obtain actuator moving velocity without differentiating position signal with noise. Based on the elastic properties of diaphragm spring, wave spring and release finger, release bearing side load feature were analyzed, nonlinear actuator state space equations were derived in order to design feedforward compensation. Meanwhile, Lipschitz nonlinear observer theory was applied to observe actuator position, motor speed and release bearing force. Simulation results demonstrate that the control algorithm is feasible and has satisfactory observation robustness: In the presence of deviation between the worm gear efficiency and actual one, although there are steady errors in position and speed observation, the former error is negligible, and the latter is no more than 10 r/min, both of which are acceptable;Noise is visible in the observed values of position and force observations, but does not affect speed observation;When the driven plate is worn, although position and speed observations are still desirable, there is steady error in force observation, which is no more than 25 N.