Research on dynamics of hybrid pouring robot and attitude stability control of ladle

Abstract

In this paper, the vibration characteristics of the designed hybrid truss-type movable heavy-load pouring robot (pouring robot) and the pose control of the parallel working arm are studied. The dynamic-static method is used to simplify the truss and parallel working arm of the pouring robot into a forced vibration system composed of spring, damping, and mass body, based on this the 9-degree-of-freedom vibration equation of the pouring robot is established, the analysis of the amplitude–frequency characteristics shows that the four input vibrations of the pavement have basically the same influence on the ladle, which will cause the ladle to resonate. Kane’s method is used to establish the lower mobility dynamic equation of the parallel working arm, the Jacobian matrix of force-driven and torque-driven coupling are given. Based on the vibration characteristics of the pouring robot and the dynamic model of the parallel working arm, an adaptive sliding mode control method with radial basis function neural network compensator and Newton–Euler iterative estimator are proposed to realize the pose control of the ladle, the Lyapunov theorem proves the stability of the control method, the simulation results show that adaptive sliding mode control has better control performance, faster response speed, higher convergence accuracy, and better robustness than traditional sliding mode control algorithm. The paper provides a reference and research basis for the suppression of ladle vibration when the pouring robot is transferred, which is affected by the road roughness.

Design, simulation, control of a hybrid pouring robot: enhancing automation level in the foundry industry

“…Therefore, in order to realize heavy-duty pouring tasks at different stations, the design method of hybrid mobile robot arm is adopted instead of the traditional articulated robot arm. For instance, Li et al designed the hybrid truss heavy-load pouring robot and proposed a Newton-Euler iterative estimation method to realize ladle attitude control [12]- [14]. While this factory overhead crane-like lifting method allows for heavy-duty pouring, the top-down working arm allows for limited spatial flexibility and reduced robot tipping capability.…”