Trajectory Planning and High-Precision Motion Control of Excavators Based on Independent Metering Hydraulic Configuration

This study investigates the trajectory optimization and high-precision motion control of excavators based on an independent metering hydraulic system. Considering both operational efficiency and motion smoothness, we propose a motion control method for excavator manipulators based on time-energy-jerk integrated optimal trajectory planning. The nondominated sorting genetic algorithm II (NSGA-II) algorithm is used to optimize interpolated trajectory based on five-time B-splines in the joint space. To ensure that excavators can accurately execute the planned optimal trajectory, the corresponding arms must be controlled with high precision. The oil inlet flow and the oil return pressure controllers are designed based on the independent metering hydraulic system. The flow controller is designed based on time-logarithmic barrier Lyapunov function to determine the virtual control rate and uses the Levant filter for filtering. The corresponding error transformations are employed to avoid the problem of the explosion of complexity in the traditional backstepping controller designs while ensuring that transient behavior of system tracking errors remains within specified boundaries. The uncertain components and nonlinear functions in the manipulator system are approximated by neural network (NN). Additionally, the pressure controller is used to keep the oil return pressure low to reduce system’s energy consumption. Finally, comparative simulations are conducted to verify the superiority of the proposed controller.