线性参变过驱动系统鲁棒控制分配策略
Robust control allocation strategy for linear parameter-varying over-actuated systems

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.
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.