Biologically inspired control laws for trajectory formation and generating motor command in multi-joint manipulator movement

Biological experiment results said that a trajectory of the reaching arm movement is roughly straight path in unconstrained point-to-point movement. Many manipulator control methods have been achieved by defining an energy or potential index such as minimum-jerk or mean squared residual. However, in almost all the cases, the potential or energy like approaches have some disadvantages especially for controlling dynamical system, since the energy index is constructed in order to treat an equilibrium state, not dynamical one. On the other hand, an actual manipulator movement is commonly a dynamical control task. To overcome this problem, we introduce the dynamical properties into a stable index. In this paper, we propose a new type of the motor controlling method of a multi-joint manipulator based on the biological experiment results by defining a new type of stable index. In addition, we show the way to control any kind of multi-joint manipulator by using one simple principle, even under external perturbations like the gravity effect simultaneously.