It has been experimentally verified that the jerk of the desired traje
ctory adversely affects the performance of the tracking control algori
thms for robotic manipulators. In this paper, we investigate the reaso
ns behind this effect, and state the trajectory planning problem as an
optimization problem that minimizes a norm of joint jerk over a presp
ecified Cartesian space trajectory. The necessary conditions are deriv
ed and a numerical algorithm is presented.