Trajectory tracking control of intelligent excavator employing an improved ABSMC based on parameter hierarchical

As intelligent operation of excavators becomes an inevitable trend, achieving high-precision trajectory tracking control is crucial for enhancing automated task accuracy. An Adaptive Backstepping Sliding Mode Control (ABSMC) algorithm based on a hierarchical parameter strategy to address the complex modeling and strong nonlinearity challenges in excavator electro-hydraulic position servo systems is proposed in this paper. First, online parameter identification and dead-zone compensation techniques are employed to improve modeling accuracy. The hierarchical parameter strategy optimizes control parameter configuration, resolving system parameter uncertainties. Furthermore, by integrating Backstepping Control with Sliding Mode Control (SMC), the algorithm reduces design complexity while effectively handling system nonlinearities and mitigating SMC chattering. Finally, simulations including step, ramp, sinusoidal signals, and excavation trajectories and field tests on an 8-ton electric excavator were conducted. Results demonstrate that ABSMC confines excavation trajectory tracking errors within 60 mm. Compared to Proportional-Integral-Derivative (PID) control and SMC, ABSMC reduces average tracking errors by 66.7% and 57.1%, and root mean square errors by 68.2% and 56.9%, respectively, providing a reliable solution for intelligent excavator control.