Development of A Low-Inertia 5-DOF Hybrid Manipulator for Moxibustion

In this paper, a low-inertia hybrid manipulator for moxibustion, which has five degrees of freedom (DOF), is presented. It consists of a 3-DOF serial mechanism and an unique 2-DOF parallel mechanism, the serial mechanism is used to adjust the space position of moxa cone, and the parallel mechanism is used to adjust the posture of moxa cone to ensure that it is always perpendicular to the local plane where the acupoint is. The manipulator integrates the advantages of serial and parallel mechanism, such as compact and flexible structure, higher loading capacity, large workspace. Because the three joints at the end of the manipulator are driven indirectly by the four-bar linkage, all the actuators (such as motors and reducers) are placed at the base. Thus, the manipulator is very light except the base, the inertia is greatly reduced and it is more suitable for high-speed motion. At the same time, no power cable is laid along the arm, which avoids the repeated bending of the cable caused by the joint rotation, improves the reliability, and is more convenient for maintenance. For real-time performance, a software framework was developed based on μC/OS-II.