COMPARISONS OF POSITION CONTROL OF VALVE-CONTROLLED AND PUMP-CONTROLLED FOLDING MACHINES

Control units of electro-hydraulic double-axial folding machine can be classified as throttling type (valve-controlled) and volumetric type (pump-controlled). This paper focuses to compare their control performances. Valve-controlled folding machine (VCFM) has higher supply pressure, different circuit resistance between subsystems. Pump-controlled folding machine (PCFM) has variable working pressure and circuit resistance is slightly different. The folding machine is a coupled system and has significant structural interaction. This paper proposes coupled adaptive self-organizing sliding-mode fuzzy controllers to improve folding machine's level control performance. It found higher supply pressure of VCFM cause faster transient response, larger maximum overshoot via a variety of coupled intensity synchronous level control experiments. Experimental results indicate that their transient and steady state responses are similar, but pump-controlled folding machine has better level control accuracy than valve-controlled folding machine.