Dynamic analysis of open-loop mechanisms with multiple spatial revolute clearance joints

Dynamic model of a typical open-loop mechanism with multiple spatial revolute clearance joints were established based on the Newton-Euler equations and the Hertzian contact deformation theory. An augmented constraint violation correction method was presented to solve the nonlinear dynamic equations of motion, which improved the global convergence and stability effectively. The nonlinear dynamic behaviors of a serial robot manipulator with two spatial revolute clearance joints were studied to demonstrate the effects of the location and coupling relationship of the clearance joints. Numerical results show that the influence of spatial revolute clearance joint on the dynamic behaviors of the open-loop mechanism is relatively stronger than that of the planar ones. The location of the spatial revolute clearance joints is an important factor to dynamic behavior of the system. The closer the spatial revolute clearance joint is to the end-effector, the stronger influence it has on the system. The spatial revolute clearance joints interact significantly with each another, which exhibits vigorous vibration with a higher frequency, larger amplitude, and deeper penetration. This work provides new insights into investigating the nonlinear dynamic behaviors of the systems with spatial revolute clearance joints.