Reliability Analysis of Continuum Robot Actuated by Shape Memory Alloy (SMA)

As one of the intelligent materials, shape memory alloy (SMA) has the characteristics of light weight, strong driving force and large shape variable. When SMA is used as the actuating device of continuum robot, it can effectively reduce the overall weight and structure volume, and expand the use of the continuum robot. Reliability analysis refers to the quantitative analysis and evaluation of equipment performance with statistical methods, and the establishment of effective analysis methods is the key to reliability analysis. However, reliability analysis of continuum robot driven by SMA is rarely reported. In this paper, Weibull distribution is used for reliability analysis, which is excellent for complex model processing. Firstly, the performance of the SMA wire and the model of the continuum robot are studied, and the selection of the reliability model is analyzed. Then, the experiments of SMA applied load and SMA joint model are carried out, and the experimental phenomena of both are statistically analyzed. Finally, based on the experimental model, the Weibull distribution is established to predict the robot reliability. The experimental results show that the method combining Weibull distribution with SMA-actuation continuum robot is easy to realize and ensures high reliability.