A Micro Biped Wall-Climbing Robot Actuated By Shape Memory Alloy

It is the trend that robots become more and more miniature with the development of science technology. Miniature robots are widely used in military department and civilian industries because they are hard to be discovered and capable of precise operation in the narrow working space that general mechanical system can not enter. As a special kind of miniature robots, Micro Wall-climbing Robots, which can collect a variety of information and operate intelligently in complex3-D environment, such as on the vertical or inverted wall, is drawing more and more attention.This paper is an exploratory study of micro biped wall-climbing robot actuators. Now days, the mostly researches of bipedal climbing robots are based on motor drive system at home and abroad. In this paper, the robot is driven by the new smart materials shape memory alloy (SMA), which can reduce the weight, simplify the structure and improve the security during the robot working on the wall. Firstly, the paper introduces the nicer characteristics of SMA materials, shape memory effect, and the working principle of the SMA actuator with different structures. And the appropriate SMA spring, drive architecture and drive mode are designed to meet the requirements of the robot. Meanwhile, the mathematical model of SMA spring is established. The simulation results show that the established mathematical model of SMA is effective.Secondly, the structure of biped wall-climbing robot is designed based on solidworks, including the rotating joint institutions and the adsorption institutions. Then it analyzes the robot kinematics, and the robot’s gait motion planning.Thirdly, the control system with hardware and software is presented, which is controlled by the fuzzy control strategy. The DSP microcomputer generates control signals and collects signals for the robot, at the same time basic external circuit and drive heating control circuit are designed.Finally, according to motion gait programming, experiments with a variety of actions are carried out to verify the robot’s athletic performance. The results show that the SMA actuator can meet the requirements to achieve several basic movements of the biped wall climbing robot. The robot is able to wriggle with19mm/min speed and flip with66mm/min.