Motion control for earth excavation robot based on force pre-load and cross-coupling compensation

In the earthmoving automation procedure, the properties of large inertia, strong nonlinearity and flow coupling of multiple actuators are not considered comprehensively in relevant studies, which restricts the accuracy and efficiency performance of leveling tasks. To solve the problem of limited accuracy caused by the difficulty in modeling hydraulic flow coupling and the hysteresis of terminal compensation, we proposed a coordinated motion control method for an automatic earth excavation robot, which reduced the contour error from the perspective of force preloading and terminal control compensation. Various experiments show that the motion coordination of the proposed controller is significantly better than the PID-based controller and the contour-based controller. Due to its stability in multiple conditions, we believe the system will provide an effective earthmoving automation solution for different types of excavators in control. For further study, the soil force estimation will be integrated to improve the system performance under more tasks.