Multi-Axis SMA Actuator Array for Driving Anthropomorphic Robot Hand

A novel multi-axis Shape Memory Alloy (SMA) array actuator has been developed for driving five-fingered anthropomorphic robot hand. The new actuator array uses Segmented Binary Control (SBC), which controls the SMA wires segment by segment in a digital manner. Normally, SMA wires are hard to control and require nonlinear controllers to control each wire. SBC simplifies the control of SMA wire but increases the complexity of the design and the number of control loops. A multi-axis segmentation theory has been developed to reduce the design complexity and the number of control loops by reducing the number of segments. Segmentation architecture of an actuator array is designed for five-fingered robotic hand that performs fourteen different postures. The segmentation architecture is implemented with ten SMA wires sandwiched between a layer of thermoelectric modules embedded on a printed circuit board and a layer of acrylic substrate board with grooves. Initial results of the segmented binary controlled SMA wire are verified with minimum segment architecture of a single axis.