Opto-Mechanical Smart Actuator

A proportionally controlled all optical actuator system has been assembled. The optically controlled actuator system had no electronic components and performed direct optical-to-mechanical signal conversion in combination with an optical position feedback sensor to demonstrate the viability of opto-mechanical closed loop control. The actuator system operated by transmitting an optical command signal, 10 mW maximum, to the opto-fluidic interface (OFI) which converted the signal to a differential pneumatic pressure proportional to the input intensity. The OFI output was amplified 275 times by a fluidic amplifier composed of six laminar proportional amplifiers (LPAs) to obtain an eight psi maximum output signal. The amplifier output drove a double acting pneumatic actuator in a direction dependent upon the sign of the amplifier's differential output. The actuator position feedback loop closure was achieved by summing the OFI optical command signal with a variable optical attenuator which subtracted power from the OFI input as a function of actuator position. System equilibrium occur when a 5 mW reference OFI input signal was present, thus a change in the command signal moved the actuator until the reference OFI input was re-established.