The minimum-time control of robot arms has usually been implemented as a two-task procedure, where the appropriate trajectory planning is performed off-line, and then tracking is carried out on-line to achieve the desired motion. However, such an approach is unacceptable whenever the motion is dependent on the on-board sensory equipment operated during the application. In the paper, an on-line trajectory generator is described in which the history of motion is planned and executed in real time. The computational complexities of the minimum-time requirements of the motion have been reduced significantly by distributing the proposed algorithm on a multiprocessor system. The practical implementation of the distributed system on a T800 transputer network shows its efficiency in accomplishing the required task. Real-time simulation results are reported for a PUMA 560 robot manipulator.