Study on Human Action Imitation System Based on Nao Robot

• 1、School of Information Engineering，Wuhan University of Technology,WuHan 430070

Abstract：A human action imitation system based on Nao robot is proposed in this paper. Firstly an improved Nao robot three-dimensional coordinate transformation algorithm is designed to convert the coordinate data in three-dimensional space into the corresponding Nao robot joint angle. The traditional Nao robot space coordinate conversion algorithm inversely pushes the θ value by calculating the cosθ value of the angle between the two joint vectors. This method has large calculation errors and is susceptible to external environmental noise interference. Aiming at these problems, this paper proposes an improved spatial transformation algorithm. The algorithm takes the extended Kalman filter as the basic framework and divides the process of spatial coordinate transformation into two steps: measurement and estimation. Firstly, the inverse kinematics and Newton iteration method are used to solve the problem of the joint coordinates of the known robot joints, and then the joint data obtained by the solution is input into the extended Kalman filter framework to establish the extended Kalman filte. The final prediction is the robot joint angle data. Experiements improve the accuracy and anti-interference of our space conversion algorithm comparing to the traditional algorithm. Finally, a Kinect is used to capture the human action data, which is transformed into joint angles for a Nao robot with above improved algorithm.Then the Nao imitate the human action.

Keywords： Nao robot Space coordinate transformation Action imitation