| With the development of robot technology, it evolved from the teaching robots tointelligent robots which are able to perceive and judge. Many important technicaldifficulties are overcame, but many technical problems are still to be solved. One of thecontradictions is the certain flexibility needed when the working robot contacts with aparticular environment. However, certain stiffness is required by the robot in theposition servo control and certain rigidity is in mechanical mechanism as well. To solvethis problem, many people want the robot to have the ability to obedience when it is incontact with the environment, such as the human. It is also known as compliance control.For compliance control, a variety of methods are proposed by many scholars andresearchers. Impedance control and hybrid force/position control are applicated much.In this paper, the impedance control is studied systematically in a6-DOF robot arm.Firstly, the basic principles of impedance control and the research status at home andabroad are summarized. Secondly, mathematical model of a dexterous arm is established,and its kinematics and dynamics models are analyzed. Fuzzy impedance control basedon fuzzy PD controller is designed based on the classical theory of fuzzy control. Then,a dual fuzzy control structure is formed and its validity and superiority are verified bysimulation analysis. Finally, the basic principles of adaptive neural fuzzy control(ANFIS) are studied. Fuzzy rules of the impedance controller are optimized by ANFIS.A number of simulation results show that better force and position control effect ofdexterous arm in free space and constraint space are achieved by proposed dual-fuzzycontrol. |
