考虑摩擦特性的稳定平台变结构控制研究

Variable Structure Control Based on Stabilized Platform Considering Friction Characteristic

对于单轴稳定平台,载体的运动主要是通过反电动势和摩擦力矩耦合给平台的。鉴于复杂非线性的摩擦力矩耦合不能简单用线性模型代替的情况,研究了稳定平台的摩擦特性。指出了相关参考文献中描述的摩擦模型存在的问题,建立了更贴近实际情况的摩擦模型,并将其加入到稳定平台系统模型中。为了减少载体运动对平台稳定的干扰,设计了滑模变结构控制器。但一般的变结构控制需要的信息多从而会导致系统结构的复杂化,故对其进行了简化。仿真结果表明,变结构控制器控制效果优于传统的超前滞后控制。通过仿真证实了使用摩擦模型可以有效判断控制器控制效果的好坏,对控制器的设计和选择有一定的指导意义。

Aiming at a single axis stabilized platform, the movement of carrier is coupled to the platform by the opposing electromotive force and the friction moment. In view of the fact that linear model can not simply replace non-linear coupling of friction moment, the friction characteristic of platform is studied. The shortage of friction model in the correlated references is indicated. A more actual friction model is built and added into the system model. To reduce the interference of carrier movement, a sliding mode variable structure controller （VSC） is designed. But the system structure would become complicated because of needing more messages in common VSC. For that, VSC is simplified. The simulation results illustrate that VSC＇ s control effect is better than classical lead - lag control＇ s. Besides, simulation shows that the friction model in this paper can effectively judge the control effect of controllers. The friction model has a certain value for the design and choice of the controller.