Integrated wheel loader simulation model for improving performance and energy flow

This paper describes an integrated wheel loader simulation model for improving performance and energy flow. The proposed integrated wheel loader simulation model includes a driver model that is designed to perform the two objectives of working and driving. The driver model for working was designed according to eight conditions considered as events and environment information. The driver model for driving is composed of throttle, brake, and steering inputs which represent an actual driver's input characteristics. By analyzing experimental test data of V-pattern working, human driving characteristics have been derived and applied in the driver model by using linear quadratic regulator (LQR) and model predictive control (MPC). The wheel loader dynamic simulation model with the driver model used in this study consists of four parts: mechanical powertrain, hydraulic powertrain, vehicle dynamic model, and working dynamic model with a simplified load model. All simulation models have been constructed in the Matlab/Simulink environment, and the proposed driver model has been validated from experimental test data. Working performance with the optimized path, energy flow, and loss analysis during V-pattern working was predicted and evaluated with the developed human driver and dynamic simulation model of a wheel loader. The driver model can be utilized in the design stage for prediction and evaluation of a wheel loader's working performance. It is also expected that an investigation of the optimal working pattern and energy flow for various working cycles of wheel loaders will be possible with the driver-model-in-the-loop simulation. (C) 2015 Elsevier B.V. All rights reserved.