HILS using a minimum number of joint module testbeds for analyzing a multi-DoF manipulator

In general, a multi-degree of freedom (DoF) robot has many joints that are difficult to model precisely in numerical simulation. Although a Hardware-in-the-Loop Simulator (HILS) is one of the solutions for simulating of such robots, a standard HILS requires to have as many joint testbeds as the robot has joints. In order to reduce the number of testbeds, this paper proposes a HILS to analyze the motion of the multi-DoF robot without modeling complex joint parts by using a minimum number of joint testbeds. This paper discusses two HILS algorithms, a TIM (Time Increment Method) and a JSM (Joint Switch Method) and the two algorithms are compared based on numerical simulation of a two DoF manipulator. the JSM can conduct HILS faster than the TIM. The accuracy of the simulated motion depends on the motion to be analyzed. Also, in order to verify the proposed algorithm, an experiment with a real testbed was conducted. The max difference of the end effector was around 0.02 m compared with a real manipulator and it was shown that the JSM successfully conducted simulation using only one testbed.