Control of Flexible Manipulators affected by Non-Linear Friction Torque based on the Generalized Proportional Integral Concept

In this article, a new method to control an uncertain flexible robotic arm using a conventional motor with a gear actuator strongly affected by non-linear friction torque is proposed. This control method does not require friction compensation and hence the estimation of this term because the control scheme is robust with respect to this effect. On the other hand, the only variables to measure are the motor shaft and tip angular positions. Velocity measurements, which always introduce errors and noises, are not required.