Tip deflection measurement and state observation of a flexible robot arm

The knowledge of position, velocity, and acceleration at the tip of a robot arm is useful for advanced control of robots, which is especially true for a flexible robot arm. In this paper, a sensor system is presented to measure in real-time the structural deflections at the tip of a flexible robot arm. This measurement provides a measurement for the tip state observation. A dynamic model of a flexible arm is developed by using the Hamilton's principle. A state space model is obtained with all the state variables having their physical meanings. Based on the dynamic model, an effective state observer is developed by employ the Kalman filter. Numerical simulation results are given to show the effectiveness of the observer.