Sensorless External Force Detection Method for Humanoid Robot Arm based on BP Neural Network

In order to improve the safety performance of the robot, this paper proposes an external force detection method for humanoid robot arm without using joint torque sensors, which can detect the external force of the joint space in real time during the operation of the robot. First, Analyses on the structure of the humanoid robot arm is performed, and the model of robot external force detection is established based on robot dynamics and motor dynamics. Then, the error of detection model is analyzed, and the robot dynamic model error is compensated by using the BP network, in order to obtain more accurate external force detection value of the robot. Experiments show that the method can effectively improve the detection accuracy, and the obtained external force detection data can be applied not only to the collision detection in the static state of the robot, but also to the online collision detection when the robot is running, which can ensure the safe operation of the robot.