A sliding mode and synergetic control approaches applied to Permanent Magnet Synchronous Motor

This paper presents a novel nonlinear speed control for a permanent magnet synchronous motor (PMSM) using the synergetic approach to control theory (SACT) and sliding mode control (SMC).The traditional proportion integral derivative (PID) control is widely used in the permanent magnet synchronous motor (PMSM) speed control system because of its simple control method, but it is difficult to meet the high precision control requirements. Recent research has reported that the PMSM is being increasingly used in high-performance applications, such as robots and industrial machines, which require speed controllers that provide not only accuracy and high performance, but also flexibility and efficiency in the design process and implementation. It has also been reported that the best approach to achieve high-performance in a PMSM drive is to consider the whole nonlinear motor dynamics in the controller synthesis. Many control schemes using varied nonlinear strategies have been presented; however, most of them are very complex to design and implement, even when they show good performance. We propose a nonlinear control scheme based on the SMC-SACT, which allows the designer to generate the required control laws by following a direct method. This paper proposes a new motor speed control approach based on methods of synergetic control thory, which combines the traditional speed closed-loop control and synergetic control. Then, an sliding-mode disturbance observer is proposed to estimate lumped uncertainties directly, to compensate strong disturbances and achieve high servo precisions. Simulation and experimental results both show the validity of the proposed control approach. (paper)