Adaptive Control of an Unbalanced Two-Axis Gimbal for Application to Inertially Stabilized Platforms

Inertially stabilized platforms are subject of interest to different engineering areas, such as telecommunications, robotics and military systems. The objective is to maintain the attitude of a desired object constant despite the movements of a host vehicle. This paper deals with the problem of stabilizing a platform using a two degree of freedom gimbal as mechanical actuator. Mechanical unbalances are considered and a MIMO version of the Binary Model Reference Adaptive Controller is employed. The algorithm employs a newly proposed differentiator based in high-order sliding modes that is global and exact. This differentiator can also be used for monitoring and estimation purposes in robotics systems. Simulation results are presented using as inputs the experimental data acquired from a vehicle going through a circuit with ground obstacles.