线性参变过驱动系统鲁棒控制分配策略

针对一类具有不确定时变参量的线性参变(linear parameter-varying,LPV)过驱动系统的控制分配问题,考虑系统的不确定参量扰动和执行器物理约束,利用伪控指令分配误差和控制量误差的1--范数,建立了含有时变不确定因子的控制分配优化模型.根据鲁棒优化思想,采用矢量变换技术处理时变不确定因子,得到了一种基于有约束锥二次凸优化模型的鲁棒控制分配算法,实现对LPV过驱动系统伪控指令的在线优化分配.最后,对某4轮电动汽车时变二自由度转向过驱动控制系统的对比仿真实验表明,相比常规4WS和伪逆控制分配方法,本文的鲁棒控制分配算法有效地降低了系统参变量不确定扰动的影响,得到更合理的控制分配解,有效改善了车辆的操纵稳定性.

Robust control allocation strategy for linear parameter-varying over-actuated systems

Abstract: The control allocation problem is studied for a class of linear parameter-varying (LPV) over-actuated systems with uncertain time-varying parameters in this paper. In view of the uncertain parameter perturbations and actuators physical constraints, a control allocation optimization model with time-varying uncertainties is established based on the 1-norms of allocation error of pseudo-control command and the control input error. According to the principle of robust optimization, the robust control allocation algorithm based on constrained second-order cone programming model is developed by using vector transforms technology to deal with time-varying uncertainties. The online optimal allocation of pseudo-control command is thus realized for LPV over-actuated systems. Finally, the comparative simulations are executed for the steering over-actuated control system with time varying 2-DOF of a four-wheel electric-vehicle. The simulative results indicated that the proposed robust control allocation algorithm can effectively reduce the influence of parametric uncertainties on the system, compared with the conventional 4WS and pseudo-inverse control allocation methods. The more reasonable control allocation solution is obtained, and the vehicle handling stability is improved.