Research On High Speed And High Precision Positioning Method For Permanent Magnet AC Position Servo System

With the development of micro-power electronics technology,Internet industry and artificial intelligence,industrial robots are widely used in automobile manufacturing,national defense,military,transportation,construction and other fields.PMSM has become the preferred driving equipment for industrial robots because of its fast response,high precision and high efficiency.And each joint of each industrial robot needs a special permanent magnet AC servo system,so its performance plays a key role in the control system of the industrial robot.t present,most permanent magnet AC servo systems adopt PID control.Although this control method has simple structure,high reliability and easy digital implementation,it is vulnerable to parameter changes and external disturbances.The working conditions of industrial robots are quite special,especially for the objects which are mainly used for position control,such as relocation and welding.They have the characteristics of time-varying load,time-varying inertia,frequent start-stop and so on.The servo system matched with joint drive is provided with higher response,higher precision,stronger anti-interference ability and higher overload energy.High-end performance requirements of force and higher speed range,but the existing domestic general servo system can not meet the above requirements.And high response and high precision are usually needed to meet at the same time.Therefore,this paper focuses on how to improve the positioning speed and accuracy of permanent magnet AC servo system.Firstly,the research background and significance of the subject and the control methods of high-precision positioning and high-speed positioning at home and abroad are described.Secondly,in order to improve the positioning accuracy of position servo system,an improved sliding mode observer based on load moment identification and a feedforward compensation algorithm are proposed.To improve the positioning speed of position servo system,based on the previous algorithm,an improved sliding mode controller is proposed.In order to achieve the final high-speed and high-precision drive,a dual sliding mode variable structure integrated control method based on load moment identification and compensation algorithm and position-speed integrated control method is proposed.Then,in order to verify the effectiveness of the proposed method in improving positioning accuracy and positioning speed of position servo system,a motor test platform consisting of a special motor drive test platform,a control system based on Dspace and a speed servo system based on MATLAB/Simlink is built.Finally,based on the experimental platform of the design,the experimental test is carried out.The experiment can be divided into three parts: first,the estimation performance comparison test of the improved and traditional load torque identification Sliding mode Observer is carried out,and the dynamic performance test of constant speed constant load,constant speed variable load and speed servo system is carried out respectively,and the experimental results show that The proposed improved load torque identification sliding mode observer can effectively identify the load torque in the real-time positioning process,and the identification accuracy is obviously high,the speed servo system can obviously shorten the recovery time of the system when the sudden and raid load is carried out,and secondly,the performance comparison test between the position current two ring system and the traditional three-ring system is performed.The experimental results show that the two-ring system designed by the scheme of position speed integrated sliding mode controller is significantly faster than the traditional position speed current three-ring system,and thirdly,the performance test of the integrated system of double sliding mode variable structure control is carried out,and the results show that The integrated position speed integrated sliding mode controller and load torque identification sliding mode Observer and Feedforward algorithm system can shorten the recovery time when the load is increased,and thus improve the positioning accuracy,therefore,the positioning system using the method proposed in this paper has the advantages of high precision and high speed positioning at the same time,which is more suitable for application in the driving situation of point control.