文摘
Friction is inherent in mechanisms. In this paper a controller consisting of three schemes, proportional gain, pulse, and ramp (PPR), is proposed to achieve precise and fast pointing control under the presence of friction. Design of the PPR controller is based on two distinctive features of friction, the varying sticking force and presliding displacement of contacts. The latter is the main idea behind the ramp scheme to replace integration control, which induces slow dynamics in the sticking state. Simulation results demonstrate the robustness and effectiveness of the proposed controller.