中文摘要：

为了提高有刷直流电机低速控制的精确性,设计了基于扰动补偿的有刷直流电机转速自适应滑模控制器。首先,针对转速模型中摩擦力在转速快速变化过程中体现的快变特性和在线估计困难的特点,采用Stribeck稳态摩擦力模型,通过离线辨识模型参数的方式计算摩擦力;其次,针对负载扭矩等扰动的慢变特性,设计了扰动观测器对其进行在线估计,并证明了估计误差的有限时间收敛性及有界性;最后,设计了自适应滑模控制器对扰动进行补偿和误差反馈校正,进而实现精确的转速跟踪控制,并在Lyapunov稳定性框架下证明了闭环系统的稳定性。该控制器的开关增益仅与扰动观测器估计误差的上界相关,避免了一般滑模控制方法采用高增益来提高控制精度的问题,从而能够大大减小系统输入抖振现象,有利于工程实现。所提方法的稳态误差分别为PI、传统滑模控制器稳态误差的46%、63%,响应时间在0.15s以内,远小于PI、传统滑模控制器的响应时间,通过正弦参考信号跟踪实验,验证了所提方法在瞬态工况下具有很好的控制效果。实验结果表明,所设计的控制器能有效抑制摩擦力及负载扰动对电机控制带来的影响,能显著改善电机控制的稳态和瞬态性能,并且该方法能大大减小控制输入的抖振问题。

英文摘要：

To improve the control accuracy of brushed DC motor at low speeds, a novel control system using disturbance observer and sliding mode control is developed. It aims at compensating the nonlinear friction and load disturbances. First, since the friction changes fast with the variation of motor speed, it is very difficult to estimate it online. Therefore, the Stribeek friction model is used for computing the friction, and the parameters of this model are identified offline. Then, a disturbance observer is designed for estimating the model errors and load disturbances. It is proved that the estimated errors can converge to a prescribed range after a finite time. Finally, the estimated errors are taken as the amplitude bounded disturbance inputs, and an adaptive slide mode controller is designed to guarantee the robustness of this system. The switching gain estimated by the adaptive technique is just related to the upper bounds of the estimated errors,therefore, the demand of high-gain feedback for high accuracy is avoided since the switching gain is reduced with this method. The designed controller is evaluated through experimental tests. Compared with the PI and traditional slide-mode control methods, the steady-state output error of this controller is reduced to 46% and 63% of the two methods＇ errors, respectively; its response time is 0.15 s, and the input chattering is also reduced. It shows that the designed controller could effectively suppress the effects of the friction and load disturbances on the control over the brushed DC motor.