Hybrid Position And Force Adaptive Control For Rigid Manipulators

Position/force control problem of rigid manipulators is the most interesting topic in thefield of manipulators, precise trajectory and force tracking control both in theory andengineering has very important value and significance. This paper makes a thoroughtheoretical study on the position/force control problem of rigid manipulators, the reasonablecontrol schemes are put forward and the system numerical simulations are completed, whichwould be useful for the future research.This paper takes a two-link revolute manipulator as an example, the mathematical modelof the manipulator is established, which includes kinematic model, dynamic model and motormodel. Lagrange method is used to establish the dynamic equation. Choosing the independentjoint variables to reduce the order of dynamic model for constrained manipulators and a newdynamic model that only contains independent joint variables and contact force variable isderived.This paper discusses the trajectory tracking control of manipulators, a controller isdesigned based on computed torque algorithm, because of the poor robustness of thecomputed torque algorithm for the model parameters, another controller is designed based onadaptive algorithm to solve this problem, the system’s stability is analyzed in detail combinedwith Barbalat lemma, the simulation results show the proposed controllers are valid.This paper discusses the position/force control of statically constrained manipulators, arobust adaptive controller based on backstepping method is proposed, and the controller isdecomposed into two parts including a dynamic controller and a motor controller, whichmakes it easy to design, and robust control is adopted to achieve the robustness for the motorparameter uncertainties, the system’s stability is analyzed in detail combined with Barbalat lemma, the simulation results show the proposed controller is valid.This paper also discusses the position/force control of rheonomically constrainedmanipulators, a hybrid position and force controller is proposed based on a modifiedjoint-space orthogonalization method, the speed signal is decomposed into two parts,respectively mapped to the tangent space and normal space of the contact point, so itdecouples position/velocity signals and force signal, and the adaptive algorithm is used toenhance the robustness of the controller, the system’s stability is analyzed in detail combinedwith Barbalat lemma, the simulation results show the proposed controller is valid.