Abstract: A sensorless collision detection method of robotic arm based on motor current includes acquiring an output current of a robotic arm joint motor; building a neural network, and using a backpropagation algorithm to update the weights and the deviations of the neural network to obtain an estimated current value; judging whether collision occurs by comparing the collision detection threshold with the error value between the output current of the robotic arm joint motor and the estimated output current of the neural network. The detection method is easy to operate and has higher universality.