Auto-sensing antagonistic shape memory alloy actuated manipulator

This paper investigates and realizes the self sensing tracking control of a manipulator using antagonistic shape memory alloy actuators. Antagonistic shape memory alloy actuators use opposing force to create systems capable of producing alternative tracking paths and two-way mechanical work is done in an efficient way. A PID based control scheme is designed and implemented experimentally using self sensing property. The use of self sensing completely removes the complexity and cost introduced by additional sensors. Experimental results show that a shape memory alloy actuated manipulator in combination with the controller can track input trajectory signal with a wide dynamic range of frequency up to 1.8 Hz and ± 1.1 % accuracy is achieved.