Decoupling control of nonholonomic mobile manipulators based on differential geometry

The differential geometry method was applied to coordinated control of a nonholonomic mobile manipulator (NMM) system to solve the problems of local linearization and approximate linearization caused by using conventional linearization methods. The differential geometry method can realize the decoupling control of multi-input multi-output nonlinearization in a NMM system by diffeomorphism and nonlinear feedback, and transform accurately a multivariate, strong-coupling and nonlinear system into a linear-decoupled system. An affine nonlinear system was built up according to the state equations of the NMM system, and the decoupled conditions were validated. The linear-decoupled system of the NMM was obtained by the differential geometry method, and the PD trajectory tracking controller was designed for the linear-decoupled subsystem. The simulation results show the controller has the better tracking effect, and the linear system decoupled by differential geometry method has its validity.