Design methods of planar six-bar mechanism in servo applications

Abstract

ABSTRACT Aiming at improving the reliability of the hydraulic servo actuator constructed using a nozzle-flapper servo valve, the design of a servo actuator with a combination of electro-hydraulic and mechanical manipulations is proposed. This solution enables the system to be switched to a mechanical operation pattern in the event of failure of the electro-hydraulic servo valve, which results in a loss of control. A 2-degrees of freedom planar six-bar lower-pair mechanism is proposed to achieve mechanically operated hydraulic servo-driven actions in a switched pattern. The dimensional synthesis of the mechanism is completed by applying the adaptive particle swarm optimization (APSO), and optimized numerical solutions are obtained. The virtual prototype of the mechanism is designed, and the kinematic properties of the output link along with the sinusoidal motion of the given input links are assessed using the mathematical software ADAMS. The simulation results show that the optimally designed planar six-bar mechanism has small geometric errors, thus verifying that APSO can be satisfactorily applied in dimensional synthesis.