带宽化扰动观测复合滑模的闭链机构协调控制

Bandwidth parameterized disturbance observer composite sliding mode coordination control for closed chain mechanisms

针对闭链机构关节协调控制问题,在耦合空间中提出了一种带宽化扰动观测器复合等速趋近律的滑模控制方法.扰动观测器保留扩张状态观测器的计算结构,使用观测误差的比例、积分、微分(P, I, D)估计扰动;它与滑模控制复合,不但放宽了滑模切换增益的边界条件,而且消除了抖振.使用等速趋近律,切换增益可根据执行器饱和限制条件计算获得,其他控制参数结合带宽参数化法整定.仿真和实验表明,带宽化扰动观测器复合滑模控制,可以在系统限制允许的范围内有效解决闭链机构协调控制问题,且具有参数物理意义明确,易整定的优点.

To solve the control problem of joint coordination for closed chain mechanisms, the bandwidth-parameterized disturbance observer composite sliding mode control on constant rate reaching law is proposed in the coupling space. The disturbance observer(DOB) retains the computational structure of the extended state observer(ESO) and estimates the disturbance with the combinations of proportional, integral and differential of the observation error of ESO. The combinations with the proposed DOB and sliding mode control(SMC) not only relax the boundary condition of the SMC’s switching gain, but also eliminate the chattering of SMC. The switching gain of SMC can be calculated according to the saturation limitation of the actuator, and the other control parameters can be tuned with bandwidth parameterization method. The simulations and experiments illustrate that the composite control scheme can effectively solve the problem of coordinated control to closed chain mechanism within the system limitation by clear parameter physical meanings and easy adjustments.