A Novel Joint Angle Estimation Method for Serial Manipulator Using Micro-Electromechanical Systems Sensors

This article focuses on the use of low-cost micro-electromechanical systems (MEMS) magnetic, angular rate, and gravity (MARG) sensors in the field of estimating the joint angles of revolute serial manipulators. In particular, an easy-to-install joint angle estimation method, named the incremental decomposition method (IDM), is proposed. It allows the MEMS MARG sensors to be mounted in any attitude on any position of the manipulator's links, with at least one attitude measurement unit on the output side of each joint. The IDM is completely independent from the encoder-based joint angle estimator. Hence, it can work as an assistant fault-detection criterion for the economical robotic arms. A robotic arm with six degrees of freedom is used as the experimental setup. The IDM can estimate the manipulator's joint angles by fusing the attitude quaternion output by the MARG sensors. To validate the performances and limitations of this method, five experiments have been accomplished in this article. The experimental results are reported in order, in comparison with the high-resolution encoders.