Study On Passivity Control Of Underactuated Snake Robots

With the development of bionics, a new force of the bionic robots suddenly rises, in which the snake robot is the most remarkable. The national and foreign experts have studied the snake robots earlier than the others, so that the theory and technique about snake robots is more perfectible and many have been put into practice. The snake robot can be applied in a widest area, such as more impediment, concavo-convex terrains, narrowness space to martial scout, examine and repair pipeline, recon in ruins etc. independent works in such unknown environments, especially play a important role in the star explore. Just because of the complexity and uncertainty of the working environment, parts of the snake robot often be invalidated, in which the actuators have the most possibility. But because of the particularity of the working environment, it is impossible to replace or maintain timely the destroyed parts and it must work and deal with some problem. Furthermore the energy consumed can be decreased, improve the agility. So the study of the underactuated snake robots has the more practical application. The national and foreign experts process many theory problems and plames, which mostly aim at the snake robot having wheels in the belly. The relatively contents about the underactuated snake robots haven't been reported. This thesis mainly studies the snake robot closer to the real snake by getting rid of wheels. Modeling the robot dynamicsâ… , which regard the absolute angles of every link and the head coordinates as the variables and decoupled by coordinate transformation. Introducing the dynamicsâ…¡, which regard the absolute angles of every link and the coordinates of the center of gravity. Introducing the serpenoid curve detailed and designing two joint angles tracking controller by the passivity control technique. Illuminating the serpenoid motion of the snake robot and the validity of the controller by simulation. Finally studying the motion characteristic of the four-link snake robot, which is underactuated in the last joint by simulation and analyzed the effect of the three parameters to the motion. And proving the small time local controllability of the three-link snake robot, which is underactuated in the last joint. The configuration and position of the snake robot in any time can be get by the dynamicsâ… , which recuperates the lack of the dynamicsâ…¡. The provement of the local controllability of the robot underactuated in the last joint established the basement of the design of the angles controller in the...