Opto-Fluidic Robot Control System

Abstract

Intending to explore the possibility of an optical control robot without interposing any electrical signal, a pneumatic control robot arm controlled with a new differential optofl uidic interface was developed. The interface employs opposed light absorbing nozzle walls in a laminar proportional fluid amplifier. The fluidic output signal of the interface was amplified by a three-stage proportional amplifier gain block. Robot arm has two members and two joints moved by pneumatic rotary actuators. Two membrane type booster amplifiers with two staged nozzle-flapper valves were used to amplify the power of the output signals of the gain block so far as enough to drive the rotary actuator. PID control was applied to the robot arm system and the feasibility of the optical control was proved.

Development of the Pneumatic Servo Control System

“…The characteristics of using digital valves and control methods are very important, in the article both of the static and dynamic characteristics with different affecting parameters and the developed M-D-PWM control method are studied and measured in the test stand. Since 1984, the optical pneumatic control devices have been developed [6] [7]. The differential output pressures of the optical pneumatic control device is direct proportional to the differential intensity of light signal.…”

“…The optical fl uidic control device had been applied to control the pneumatic robot arm successfully by Yamamoto,K. [7].…”

Characteristic of Opto-fluidic Control System

“…There are two conversion methods, one is the combination of a laminar proportional amplifier (LPA, Fig. 1) and a photo-acoustic cell as the control port of the LPA [1,2], the other is the temperature control of the power jet's boundary layer in which light is focused onto the base plate of the LPA [3,4,5] and light through optical fi ber illuminates the light absorbing side walls of the LPA supply nozzle [6,7,8].…”

“…The opto-fluidic control system using photo-acoustic cell was used to control thrust vector of the jet propulsion for missile [3]. The opto-fluidic control system using light absorbing side walls of the LPA supply nozzle illuminated by the light through the optical fibers could drive pneumatic rotary actuators rotating the joints of robot arm by using a booster amplifier as a power amplifier [7,8,9]. The mechanism of the interface utilizing the temperature control of jet's boundary layer has not been clarified experimentally and analytically.…”