Dynamic behaviors of an integrated crawler mobile parallel robot in obstacle-crossing

A crawler mobile parallel robot equipped with swing arms has been proposed to improve the parallel robot’s limited workspace and poor mobility. The robot’s obstacle performance in the condition of step-climbing, gap-crossing, and hill-climbing was investigated through multi-body system simulation. The flexible body finite segment model method is used to model the crawler to simulate the dynamic behaviors. The results show that the motion of the parallel manipulator along the modified path is stable and continuous. The maximum step height for the robot in the forward and backward step-climbing is 170 and 160 mm, respectively. The maximum gap widths in the forward and backward gap-crossing are 420 and 615 mm, respectively. The maximum slope gradient is 20° in the hill-climbing. In the three circumstances of obstacle-crossing, with the increase in step height, gap width, and slope gradient, the crawler slip rate increases with a more significant fluctuation, resulting in a greater force and impact on the crawler. Compared with the forward step-climbing and gap-crossing, the robot moves more smoothly with less impact in backward conditions. The initial speed is critical to improving the forward gap-crossing and hill-climbing movement. The integrated crawler mobile parallel robot has the advantages of simple structure and excellent obstacle-crossing performance.