非平稳随机循环工况下离合器接合过程的鲁棒控制

Robust Control of Clutch Engagement Process under Non-Stationary Random Cyclic Conditions

针对离合器接合过程存在的非线性、外界干扰和参数不确定等因素带来的接合品质问题,提出了一种离合器接合过程的鲁棒控制方法。首先,以某5t装载机V型工况重载后退换挡离合器接合过程为研究对象,在构建以冲击度和滑磨功为性能评价指标的多目标泛函基础上,依据Pontryagin极值原理和终端约束,求解干扰矩阵中包含参数化非平稳随机项的泛函极值,获得了其时变最优控制律和权值组合下的扭矩最优轨迹。其次,通过变量转换,将时变扭矩最优轨迹转化为非线性离合器液压执行机构参数摄动下的压力跟踪轨迹。最后,采用自适应滑模控制策略以提高系统的跟踪精度和鲁棒性能,并利用Lyapunov理论对其闭环系统的稳定性进行了分析。数值仿真结果表明:该方法能有效地降低冲击度和减少滑磨功,实现了在0.7%误差范围内的最优控制轨迹跟踪。所提出的非平稳随机循环工况下离合器接合过程时变扭矩轨迹优化及其跟踪鲁棒控制的方法,对解决同类问题具有一定的工程借鉴价值。

A robust control method for clutch engagement process is proposed for the engagement quality problem caused by the nonlinearity,external disturbance and parameter uncertainty in the clutch engagement process.Firstly,taking the clutch engagement process in the heavy-duty reverse shifting of a 5-ton loader in V-type working condition as the research object,a multi-objective functional with performance evaluation based on jerk and friction work is established.According to the Pontryagin’s maximum principle and terminal constraints,after solving the functional extremum of the parameterized non-stationary random terms in the disturbance matrix,the optimal trajectory of the torque under the time-varying optimal control law and weight combination is obtained.Secondly,through the variable transformation,the time-varying torque optimal trajectory is transformed into the pressure tracking trajectory of the nonlinear clutch hydraulic actuator with parameter perturbation.Finally,the adaptive sliding mode control(ASMC)strategy is adopted to improve the tracking accuracy and robust performance of the system,and the stability of the closed-loop system is analyzed by Lyapunov stability theory.Numerical simulation results show that the proposed method can effectively reduce the jerk and the friction work,achieve the optimal control trajectory tracking within 0.7%error.