Application of Self-optimization Closed-Loop Input-shaping with Parameter of Chaotic Particle Swarm in Coaxial Drive Printing System

Abstract

Based on the issue of torsional vibration, this article analyzes the structure of the drive part of coaxial drive printing system, constructs its mathematic model, and explores the mechanism of generation of torsional vibration of press-that is the coupling of inherent frequency between input signal and machine drive system which leads to torsional vibration. In view of this, it adopts the closed loop input-shaping based on chaotic particle swarm to restrain the torsional vibration. In the algorithm, it firstly finds out the optimal control structure by the transfer function based on the structure of three kinds of closed-loop input-shaping and secondly adopts the approach of chaotic particle swarm optimization to make off-line optimization of parameter of input-shaping. Such kind of approach avoids the prematurity phenomenon existing in traditional particle swarm optimization to some extent. Besides, it enlarges the scope of parameter selection. Finally, it achieves the onetime collection of vibration signal and off-line optimization by the transfer function. This approach can not only avoid system oscillation caused by online optimization but also solve the problem of low precision of pure offline modeling optimization. Meanwhile, it builds multi-mass experimental platforms as well as makes a contrast with site collected signal. The data shows that experimental platform proves the system oscillation caused by low frequency vibration point of the drive system of press. It carries out experimental verification by simulation platform and it proves that chaotic particle swarm optimization has fewer iterations and quick convergence compared with traditional particle swarm optimization in the first place. Secondly, after adding chaotic particle swarm optimization, compared with traditional PID control, the closed-loop input-shaping has simple parameter adjustment and obvious effect of vibration restraint. After adopting ITSE evaluation function to evaluate the inhibitory effect, it is found that the vibration damps by 54.4% compared with the fact without adding input-shaping.