Abstract: A gimbal drive module comprising an elbow (24) formed of composite material and having two legs. On one leg, elbow (24) includes an azimuth drive module (26). On the other leg, elbow (24) includes an elevation drive module (30). Azimuth drive module (26) and elevation drive module (30) include motors which when energized enable displacement of the respective legs in order to control the azimuth and elevation of elbow (24) to enable pointing of a structure, such as an antenna (18), as may be located on a second elbow outboard end (20).

Abstract: A high precision pointing mechanism (10), particularly for use in space applications. The precision mechanism includes a motor assembly (26) connected to a displaceable elbow (24). A controller (166) determines a motor torque command (170) in accordance with a position error (168). The position error is used to generate proportional gain (172), derivative gain (182), and integral gain (194) compensation terms. The sum of the proportional compensation component (172) and derivative compensation component (182) is used to generate a proportional-derivative compensation component. The proportional-derivative compensation component is input to a hyperbolic tangent function (188), which substantially models the friction characteristic of the high precision pointing mechanism (10). The output from the hyperbolic tangent function (188) is used in combination with the proportional-derivative compensation component and the integral compensation component to generate the motor torque command (170).