An Original System for Controlling the Speed of Movement of Pneumatic Drives in Rehabilitation Devices

Abstract

The aim of the article is to present an original method of speed control and simultaneous stroke of the piston rods of two pneumatic cylinders using potentiometric position transducers, pneumatic solenoid valves, properly scaled throttle-check valves, solenoid valves and a microcontroller with power modules for solenoid valves. Initial experimental studies of the control system for simultaneous displacement of two piston rods of pneumatic actuators were carried out. The purpose of the research was to obtain the characteristics of the displacement of the extension of two pneumatic drives. The obtained results were analyzed. The results of the measurements confirmed the possibility of applying the presented control to rehabilitation devices for passive exercises of the lower extremities. The advantage of the proposed control system is its reaction speed, which is a response to changes in operating conditions of a given actuator, such as: external disturbances, own resistance of the controlled device, frictional resistance or movement caused by the patient exercising on the rehabilitation device moved by these actuators.