Development of a representative operation cycle characterized by dual time series for bulldozers

Abstract

Driving cycles have been developed for various types of vehicle by different nations and in different areas, as they have a substantial effect on analysis of the fuel economy and the emissions. As the concern about the fuel consumption and the emissions of engineering machinery increases continuously, it has become necessary to develop corresponding operation cycles for engineering machinery. However, a typical operation cycle for bulldozers and the methods for its development is still lacking. Therefore, a representative operation cycle for bulldozers was developed in this study. By taking advantage of readily available data from the Controller Area Network (CAN), large amounts of cycle experimental data were acquired in a typical bulldozing process. Two parameters, namely the bulldozing resistance and the speed, were employed to represent the operation cycle. The values of these parameters were calculated on the basis of the dynamic model and the kinematic model combined with system identification methods. Experimental cycles were divided into operation segments according to the respective operating processes, and characteristic parameters for the operation segments were chosen and calculated accordingly. The optimal representative operation cycle was finally selected on the basis of the smallest Mahalanobis distance. The fuel consumption and the probability distributions of the representative operation cycle were also compared with the average fuel consumption and probability distributions of all the operation cycles and analysed. The average correlation coefficient of the probability distributions was 0.936, whereas the difference in the fuel consumptions was only 1.786%. This indicates that the developed cycle is indeed appropriate for representing the operating process of the bulldozer.

Adaptive Smoothing Power Following Control Strategy Based on an Optimal Efficiency Map for a Hybrid Electric Tracked Vehicle

“…Due to the lack of a standard drive cycle of bulldozers like that of automobiles, a representative actual drive cycle of the bulldozer, which was extracted and constructed from a large number of bulldozing experimental data in our previous research [7], was adopted for simulation and Figure 14 shows the developed HEB HIL test platform, which could be used to test and compare the real-time control effect of online strategies. The model incorporated in the HIL platform was validated by employing the practical HEB real bulldozing process data, as shown in [61].…”

“…Due to the lack of a standard drive cycle of bulldozers like that of automobiles, a representative actual drive cycle of the bulldozer, which was extracted and constructed from a large number of bulldozing experimental data in our previous research [7], was adopted for simulation and comparison. Figure 15 shows the drive cycle, including the bulldozing stage and empty returning stage.…”

“…In order to accurately calculate the resistance, the ξ was identified and the F b was extracted in our previous research [7].…”

“…In the research and development of hybrid electric construction machinery (HECM), hybrid technology of the loader and excavator has been previously achieved [5,6]. It was not until 2008 that the Caterpillar company developed a diesel-electric driven bulldozer based on HEV technology, named D7E, which attracted extensive attention worldwide due to its excellent performance of 20% energy saving, 10% productivity improvement, and 50% service life extension [7]. After that, a special project was set up to develop the first hybrid electric bulldozer (HEB) of China in 2011 [8].…”

“…At present, only a few institutions have actually developed HEBs, but research articles on control and simulation of the HEB have been increasing in recent years [7,8,44]. In [45,46], the fuel-saving control concept of D7E was briefly introduced; that is, engine control in the series system was not affected by the load torque so that the speed of the generator could be controlled within a narrow range to improve the efficiency, but the detailed control strategy was not given.…”