Control Of Kangaroo-like One-Legged Hopping Robots

This paper aims to the control research of the under actuated kangaroo-like one-legged hopping robot.The design of a global stabilization control law to this system is so difficult that there is still no general method. In this case, the local control law of the kangaroo-like one-legged hopping robot is proposed. First, by using the local feedback linearization method at the equilibrium point of the stand phase, an approximate model is acquired and which can be proved to be controllable. Then, a linear quadratic optimal control law is designed and simulated; also the affect of weighing function is illustrated. On this base, a more robust variable structure control method is ac vanced. According to the variable structure control method using local linearization Lyap inov function, the particular steps of the sliding mode switch function of the linearization me del is presented, and the stability of the variable structure control law is validated by simulation.Kangaroo-like one-legged hopping robot is a very complex under actuated nonlinear system, of which the global control law design need refer to the control design ideas of a simpler under actuated inertia wheel pendulum system. With the knowledge of differential geometry, a nonlinear system can be transformed to a linearization system by the Precise Linearization Theorem. By the theorie of precise linearization and differential flatness, the transformed system can be proved to be a differential flatness system, and the smooth output function of the inertia wheel pendulum is acquired. A method of transforming the under actuated system into the linear system by the Precise Linearization Theorem is proposed, as well as the design of LQR control law and sliding mode variable structure control law with the Ackermann's Formula Method, which are applicable in the domain of state variables. Moreover, the detailed steps of solving switch function by the Ackermann Formula are presented. The stability of the control law designed is validated by simulation, of which the results are analyzed. On the basis of these studies, In erted pendulum system is as the object to the research, whose foregoing control laws are ver fied by simulation experiments. In the conclusion, the differences of the two control law design methods are analyzed; the simulation experiments results are given analysis and compar son. The valuable conclusions about the methods of the nonlinear system, whose state variabl es are in a certain state space, being transformed into a linear system are also included.