为了克服控制系统中摩擦等随机扰动的影响,研究了扰动信号模型,给出其随机游走的状态空间模型,设计了有限拍扰动观测器和状态反馈加积分控制两种扰动补偿方案对扰动进行了补偿。通过对这两种方案的对比,证明了二者的等价性。仿真结果表明了这两种方案均能够实现一拍补偿。如果使二者的特征方程也相等,则这两个等价系统的扰动响应也完全相同,但从实际控制系统考虑,由于控制输入信号受限,用扰动观测器进行扰动补偿的效果更佳。以球一杆控制系统为例,给出了以上两种方案的设计过程,并进行了实验验证。
In order to compensate the effect of stochastic disturbances in control systems, the state-space model of disturbance signal is established first. It is a random walk model. With this model in consideration, two compensation systems are proposed and and a state-feedback system with integral control. designed: a system with finite-step disturbance observer By comparison with these systems, the equivalence between them is proved. The simulation shows that they can compensate the disturbance in one step. And if the characteristic equations are equal, the disturbance responses of the systems are also identical. But because the control input is limited in practice, the system with disturbance observer is preferable. A ball- and-beam system is used as an example to illustrate the compensation design and the result is proved by experiment.