数控机床直线伺服系统混合LQ-H_∞控制器设计

Mixed LQ-H∞ Controller Design for Linear Servo System of Numerically Controlled Machine Tool

文章基于永磁直线同步电机系统提出了一种将线性二次型最优控制同H∞鲁棒控制相结合的鲁棒跟踪控制策略,文中的控制器由两部分组成,H∞鲁棒反馈控制器和线性二次型最优控制器,前者作为抗扰调节器,后者作为跟随调节器。这种控制策略的优点在于,它既能利用H∞控制方法保证系统的鲁棒性能,克服系统中存在的模型不确定性与外部干扰对系统性能的影响,又能够利用线性二次型最优控制器的线性反馈控制策略保证系统的跟踪性能。仿真结果表明,该方案在保证对系统参数变化和阻力扰动具有很强的鲁棒性的同时,又改善了伺服系统跟踪的快速性、精确性。

A mixed control strategy for the aim of robust tracking control by combine the Linear Quadric （LQ） optimal control method and robust H∞ control method is proposed in this thesis on the basis of Permanent Magnet Linear Synchronous Motor. The controller is made of two parts, which are named of robust H∞ feedback controller and LQ optimal controller respectively. The former is used as the regulator for depressing disturbances, and the later is the regulator for tracking. The advantage of this control strategy is that, on the one hand it is used to assure the system performance of robustness by overcoming the modeling uncertainties and disturbances from outside space, on the other hand the linear feedback structure of the LQ controller is used to guarantee the tracking performance. The emulation results indicated that the scheme used is able to assure the robustness to parameter changes and disturbances of the system, while improving the tracking rapidity and precision.