Design of Dual-Axial Electro-Hydraulic Servo Pump-Controlled Folding Machine

Electro-hydraulic servo control systems can be classified as throttling type and volumetric type system. The throttling type system is controlled by servo-valve and has faster response and higher accuracy, however, its noise is higher and energy efficiency is lower. On the contrary, the volumetric type system is pump-controlled. It has the advantage of higher energy efficiency and larger steady-state stiffness. However, its response is sluggish. In this paper a dual-axial electro-hydraulic servo pump-controlled folding machine (PCFM) is designed and manufactured, in order to meet the requirements of energy saving. Coupled Adaptive Self-Organizing Sliding-Mode Fuzzy Controller (CASOSMFC) is used as the controller of PCFM, which is composed of sliding-mode fuzzy controllers (SMFC), self-organizing learning mechanisms, adaptive laws and level-modify mechanism. The SMFC reduce 2-dimensional fuzzy rules into 1-dimensional. Self-learning mechanism can modify fuzzy rules online improve time response. Adaptation gain can adjust the defuzzification proportional factor on-line to improve the control response. Level-modify mechanisms are setup for the synchronous control function. Experiment result shows that the rising time of PCFM is a little bit slower than that of the electro-hydraulic servo valve-controlled folding machine (VCFM). However, it has better synchronicity and is energy saving, so, PCFM is an option to replace VCFM.