Comments on "Adaptive controller designs for robot manipulator systems using Lyapunov direct method"

The commenters state that for the above-named work (ibid., vol. AC-30, pp. 1229-1233. Dec. 1985) the type of design presented has been shown to be useful in the adaptive control of a linear system. However, the extension to the nonlinear case presented in the paper is incomplete since the time varying nature of the control law feedback gains is not taken into account.