Comments On “Impedance Control With Adaptation For Robotic Manipulations”

This comment points out an error in the adaptive impedance control approach for robotic manipulators given in the short paper by Lu and Meng. In that work, the authors assert that their adaptive impedance control scheme can compensate for uncertainty in the force measurements; however, we show that it is possible for the uncertainty in the force measurements to cause the parameter estimates to go unbounded. To remedy this possible instability problem, we suggest an additional auxiliary controller. © 1991 IEE