In a method suggested by M.Vukobratovic and M.Kircanski [1982] the energy of the system was proposed as an excellent method for path planning. Using the techniques of optimization for energy the best path is found. This is done by calculating the dynamics at certain points in space, and then using the dynamic programming technique (of operations research) to find the best path. This technique runs a few minutes on a PDP11/70. The end effector is ignored in this method as negligible. This method is only intended to smooth paths, so that the stresses on the load and manipulator are decreased. The information provided on this method was not very complete.