Trajectory formation of arm movement by a single particle approximation strategy inspired from biological reaching movement

It is clear that many creatures including human being and macaque have dealt with multi joint arm movement by taking a special control strategy from many biological experiments. These studies said that when moving the hand between pairs of targets, subjects tended to generate roughly straight hand trajectories with single-peaked, bell-shaped speed profiles. For explaining this experimental result, many of movement control strategies have been proposed so far, though, there are many of the problems for resolving multi-joint arm control. Kawato said that the major problem is collected into "two ill-posed" problems. First is the way of selecting a single trajectory from the possible movement. Second is the control problem for realizing the planned trajectory by deciding each of the joint torque and for reaching the whole actuator system to an objective position. First of all, we argue that what advantage a creature gets by taking a bell-shaped speed profiles control strategy form the viewpoint of simple single particle movement experiments and discuss the way of realizing the control procedure. In this paper, we proposed a new control strategy which the speed profiles of the end-effector is modified as the bell-shaped form actively. We regard the end-effector of a multi joint system as a kind of single particle system in this method. By the subsumption, the control problem of the multi-joint system movement can be simplified. And we will show that the proposed strategy accomplish the control of a two-link arm reaching movement, and after that, realize a standing up movement of human model by constructing four link systems which use the physical parameter of human being.