Jurnal Mekanikal, Jilid II, 1996 \ ACTIVE FORCE CONTROL APPLIED TO A RIGID ROBOT ARM Musa Mailah Department of Applied Mechanics Faculty of Mechanical Engineering Universiti Teknologi Malaysia J RHewit Sheik Meeran Department of APEME University of Dundee, United Kingdom ABSTRACT The paper presents the implementation of Active Force Control (AFC) strategy to control a rigid robot arm. The robustness and effectiveness of AFC as 'disturbance rejector' is demonstrated through a simulation study using MATLAB@ and SIMULINK@* software packages. The work is carried out on a rigid two link planar manipulator experimenting with a number of external disturbances. The results are directly compared to an equivalent system which employs the conventional model-based Proportional-Derivative (PD) control method. 1.0 INTRODUCTION As the tasks of the robotic application are becoming more complex and challenging, the motion and force control of an arm is a vital consideration in designing a robotic system. The classical PD control [I], though structurally simple and relatively stable could only provide satisfactory performance at relatively low speed operations. At high speed, the performance degrades considerably due to system dynamics and friction (disturbances). There is also a problem of tuning of the 52