液壓-雙壓電混合系統力量控制之研究

Abstract

本論文旨在發展液壓-雙壓電混合系統之力量控制研究，結合液壓伺服系統與雙壓電致動器構成基本的液壓-雙壓電混合架構，由於液壓伺服系統具有高響應與高出力的特性，而壓電致動器具高響應、中出力及精密定位能力，故結合液壓伺服系統與雙壓電伺服系統所發展出的混合力量控制系統，是針對系統達到高精度力量控制之目標。力量控制係以伺服液壓缸進行力量響應的粗控制，再以雙壓電致動器進行力量響應的精密補償，因此形成了二進一出之控制系統架構。但由於堆疊式壓電致動器無法承受大拉力及扭力，本論文提出創新之精密力量控制系統，運動時本系統壓電致動器都只有承受壓的力量，不會因過大之拉力而造成斷裂。而液壓伺服力量控制及雙壓電伺服精密力量控制，本文以具自調式模糊滑動補償之適應性模糊控制(Adaptive fuzzy controller with self-tuning fuzzy sliding-mode compensation)進行控制器設計，以實驗驗證及實現高精度之液壓-雙壓電混合系統之力量控制，來克服液壓系統不確定性、時變性和環境變動等高度非線性的問題。本文首先利用數值分析軟體Matlab/Simulink進行開迴路系統的建立和閉迴路系統的模擬，以驗證控制器的可行性，最終以實驗實現。實驗證實此控制器在本系統之液壓力控制的穩態誤差可達到3％，而液壓-雙壓電混合系統力控制的穩態誤差可達到力量感測器（Loadcell）最小解析度5N內，且有效縮短力控制系統響應的上升時間並減低力控制響應的最大超越量，充分展現液壓-雙壓電混合系統力控制性能較液壓系統力控制具更高性能的特性。

The purpose of this thesis is to develop a hydraulic-dual piezoelectric hybrid force control system, in which the variable rotational speed hydraulic pump driving hydraulic cylinders combines dual-piezoelectric actuators force system. Due to the structure limit of the stack type piezoelectric actuator, the piezoelectric actuator allows big compression forces, but small tension forces and torque. The dual- piezoelectric force system developed in this paper makes the two piezoelectric actuators having only compression force for applying in bi-directional high loading condition. The hydraulic servo system serves to control force in coarse range and the dual-piezoelectric force control system works in fine range to reach control force accuracy. The control system contains dual-input and single output. For that, adaptive fuzzy controller with self-tuning fuzzy slide-mode compensation (AFT-STFSMC) is used to design the hydraulic force controller and the dual-piezoelectric force controller. To solve the coupling interaction between the two subsystems, a decoupling controller is added. The simulation and experiment results show that the proposed hydraulic-dual piezoelectric system can achieve 5 N accuracy with the steady state error within 0.7％ of the output. The hydraulic-dual piezoelectric hybrid force control system can perform better than the hydraulic system force control, both in transient response and steady-state error.