Collaborative Tracking Control Strategy for Autonomous Excavation of a Hydraulic Excavator

Abstract

A hydraulic excavator consists of multiple electrohydraulic actuators (EHA). Due to uncertainties and nonlinearities in EHAs, it is challenging to devise a proper control strategy. To tackle this issue, a major goal of our study is to provide an efficient control strategy to minimize tracking errors of the bucket tip position for autonomous excavation. To accomplish the goal, the study offers a collaboration of PID and fuzzy controllers that are used to compensate for contour errors and achieve accurate actuator position control, respectively. Co-simulation models including control algorithms and hydraulic components were created using Matlab and Amesim to validate the performance of the designed controllers. Simulations indicate that the proposed method enables achieving accurate tracking control for autonomous excavation with small tracking errors despite the nonlinear characteristics of the hydraulic excavator system.

New Design of an Electrical Excavator and Its Path Generation for Energy Saving and Obstacle Avoidance

“…To eliminate contour errors, the contour control approach was used to obtain the desired excavation surface. [34] and the contour error (right) [34].…”

“…In the CC [34], the error between the bucket tip's desired and actual X and Y positions, as well as the error between its desired and real angles around the Z axis, are used as inputs to three distinct PID controllers (Figure 21). The outputs of these controllers are added to the desired values of X, Y, and Theta.…”

“…Figure 20. An example of the desired trajectory (contour) of the bucket tip (left)[34] and the contour error (right)[34].…”

A Review of Fuzzy Logic Method Development in Hydraulic and Pneumatic Systems

“…In turn, Hanafi et al made an attempt to minimize tracking errors of the bucket tip position for an autonomous excavation [32]. The proposed collaboration of PID and fuzzy controllers allowed compensation for contour errors and accurate position control.…”