Online Soil-bucket Interaction Identification for Autonomous Excavation

Online identification of soil-bucket interaction is significant for the development of an autonomous excavation strategy. This paper presents a method for identifying multiple unknown soil parameters in real-time using the novel Modified Newton Raphson Method. The new approach involving a model selection strategy based on Parallel Execution Model, Flexible Parallel Execution Model and Hybrid Execution Model consisting of the Mohr-Coulomb soil model and the Chen and Liu Upper Bound soil model is examined. The identification of unknown soil parameters is achieved by minimizing the error between the measured forces and the modeled forces computed by the soil model. The results demonstrate that the proposed estimation scheme is accurate when comparing to the measured soil parameters. In addition, the reduced processing time of convergence and high robustness with respect to initial conditions show that the proposed method has real time estimation capability. The proposed method is very promising and highly suitable for soil-bucket interaction identification for an autonomous excavation system in an unpredictable, dynamic environment.