ABSTRACT
This paper presents a new technique of actuating a parallel platform manipulator using
shape memory alloy (SMA). This is a type of smart materials that can attain a high
strength-to-weight ratio, which makes them ideal for miniature application. The work is
divided into two main parts; developing a new SMA actuator and then incorporating the
actuator in building the parallel manipulator prototype. The SMA used in this study is a
commercial NiTi wire. The SMA wire provides an actuating force that produces a large
bending and end displacement. A 3-UPU (Universal-Prismatic-Universal) parallel
manipulator using linear SMA actuators was developed. The manipulator consists of a
fixed platform, a moving platform and three SMA actuators. The manipulator workspace
was specified based on the restrictions due to actuator strokes and joint angle limits.
System identification techniques were used to model both heating and cooling processes.
An ON/OFF control was performed and the results showed closeness in simulation and
experimental results. This study showed that shape memory alloy actuated beam can
successfully be used to provide linear displacement. The built prototype indicates the
feasibility of using SMA actuators in parallel manipulators.