| Shape memory alloys are a class of materials capable of producing a significant force or displacement in response to a thermal control input. Combined with their light weight, the large strains and forces available make shape memory alloys attractive for robotic applications where thermally-activated devices are practical. Unfortunately, shape memory alloys are highly non-linear devices, exhibiting a significant and complex hysteresis in their strain-temperature characteristics. While models of this non-linear characteristic have been developed, no attempt has been made in the literature to analyse the stability of a closed-loop feedback control system involving a shape memory actuator. In this research, the physical phenomena inherent to shape memory alloys are investigated. The dynamic behaviour of shape memory alloys is examined. A new model for the non-linear shape memory behaviour is developed that overcomes some of the shortcomings of earlier models found in the literature. Using this model, the L... |
