Compound Mechanism Analysis of Backlash and Friction Nonlinearity in Full-Closed-Loop Servo Drive System

The loop controller of double position fully closed makes the AC servo drive system acquire a very high position accuracy and speed following which is hard to be achieved for time-varying parameters, load disturbance, AC motors and severely nonlinear controlled objects. For the system, the dynamic nature can be ensured by the inner position loop adopting PI regulation of half closed loop structure, while the stability and the immunity can be achieved by closed loop structures with the rings outside adopting dual-mode fuzzy control. This article analyzes the cause of positioning errors for servo motor and semi-closed loop structure. The article also explains how to design a two position closed-loop servo system based on fuzzy control by adopting the AC servo motor drive, the motor shaft back-end incremental photoelectric encoder to form the inner position loop and using the motion control card, the inner ring of servo system and the work platform of grating ruler to make up the outer position loop. Based on double position loop composed of three-dimensional laser processing gear, the accuracy of the three-axis linkage workbench position control and the speed following can be ensured, thus meeting the requirement of the laser subsurface engraving machine for high speed and high precision motion.

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Intelligent Permanent Magnet Motor-Based Servo Drive System Used for Automated Tuning of Piano

Energies ◽

10.3390/en14206627 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6627

Author(s):

Ying Zhou ◽

Zuyu Wu ◽

Yutong Wu

Keyword(s):

Permanent Magnet ◽

Closed Loop ◽

Permanent Magnet Synchronous Motor ◽

Synchronous Motor ◽

Drive System ◽

Servo Drive ◽

Speed Regulation ◽

Control Scheme ◽

Position Regulation ◽

Servo Drive System

This paper presents an intelligent permanent magnet synchronous motor-based servo drive system used in automated piano tuning applications. The permanent magnet synchronous motor-based drives are able to improve the accuracy of the piano tuning process in comparison with the traditional direct-current motor-based and step motor-based servo drives. To explain the techniques, firstly, the structure and principles of the automated piano tuning devices with a surface-mounted permanent magnet synchronous motor-based drive system integrated are introduced, illustrating that it is feasible to implement the proposed piano tuning strategy. Secondly, the piano tuning devices have two functions: low-speed rotation and position holding. To ensure that the surface-mounted permanent magnet synchronous motor can rotate stably over the low-speed range with strong anti-interference capacity, a double closed-loop speed-regulation-based control scheme is employed. And to ensure high position control performance, a fuzzy-adaptive triple closed-loop position-regulation-based control scheme is employed. It terms of the control schemes, it deserves to be mentioned that main contributions include, firstly, the parameters of the proportional integral controllers in the double closed-loop speed-regulation structure is tuned relying on both stability and bandwidth analyses. Then, a fuzzy-adaptive proportional integral controller is specially-designed for the triple closed-loop position-regulation to adapt to the piano tuning applications. Simulation is conducted on a 20 rpm three-phase permanent magnet synchronous motor servo drive-based piano tuning system to validate the proposed piano tuning method and to verify the proposed control techniques.

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