Aiming at the shortcomings of the robot in the application of processing and assembly in the fields of precision and other aspects

a design scheme of a seven-degree-of-freedom manipulator with multi-motor coaxial drive is proposed. At the waist

shoulder and elbow joints of the robotic arm

a joint structure driven by a double motor coaxially is arranged. The anti-backlash control method and synchronous control method for coaxial drive of dual motors are proposed

and the transition conditions for smooth switching between the above two control algorithms are given. On the basis of the underlying control

the upper-level control system of the manipulator is built using ROS and EtherCAT bus technology. The experimental results show that the seven-degree-of-freedom manipulator system designed in this paper has certain advantages in accuracy and load capacity.