Hybrid impedance control of robotic manipulators

The inclusion of force information in the control of robots increases their adaptability to uncertain environments, such as are found in deburring, grinding, and assembly tasks. The authors present a foundation for force control strategies, in view of the fact that the type of control strategy that is employed depends fundamentally on the characteristics of the environment. A general control approach is introduced, called hybrid impedance control which in its simplest forms reduces the operational space control of O. Khatib and J. Burdick (1986), or to N. Hogan´s (1985) impedance control. The control law is formulated in a general enough fashion, however, to allow for higher order controllers