An Overview of and Prospects for Research on Energy Savings in Wheel Loaders

Abstract

Wheel loaders consume a large amount of energy, and research on energy savings in wheel loaders has been carried out for decades. This paper introduces several types of wheel loaders and compares their structures. The research progress of the energy savings of three different forms of wheel loaders is reviewed, including a diesel engine wheel loader, a hybrid wheel loader, and an electric wheel loader. In particular, the energy-saving control methods of an electric wheel loader in the working cycle are analyzed, as construction machinery electrification is an emerging trend. Based on the analysis of the driving features and the working process of a wheel loader, energy-saving control methods are introduced including the resistance reduction method, optimized control strategies, intelligent control, and unmanned WL research. Comparing various energy-saving research methods and the advantages of electric wheel loaders, the pure electric wheel loaders are advised to be researched at present and in the future. Controlling the torque distribution of the front and rear motors of electric wheel loaders and assistant drive control are proposed to be significant research prospects for energy savings in wheel loaders usage.

Efficiency Comparison of Electric Wheel Loader Powertrains with Dual Motor Input in Distributed Driving Modes

“…𝑇 indicates the sum average torque of the front and the rear motors. The energy conversion efficiency of the motor can be calculated using Formula (11). The comparison of Figures 14-16 indicates that the motor power fluctuates most sharply in the F-drive mode during the motor acceleration phase, and the fluctuation is more prominent in the rear motor than in the front motor.…”

“…T Sum indicates the sum average torque of the front and the rear motors. The energy conversion efficiency of the motor can be calculated using Formula (11).…”

“…Currently, engine-driven loaders still dominate the market, but the environmental pollution caused by economic production activities cannot be underestimated [2,3]. With the increased severity in environmental protection requirements [4], the trend towards lower cost and higher efficiency batteries [5][6][7] and the development of motor drive control [8][9][10] electric wheel loaders (EWLs) will certainly become the mainstream of the future market [11]. EWLs can reduce noise and exhaust emissions, and the low-speed, high-torque mechanical characteristics of the motor are better suited to the low speeds at which WLs often operate [12].…”

Energy-Saving Impact and Optimized Control Scheme of Vertical Load on Distributed Electric Wheel Loader

“…Therefore, to facilitate vehicle control, the development of VCU software is imperative. The VCU's composition, illustrated in Figure 3, is categorized into the controller housing, hardware circuit, underlying software, and application layer software [27]. As shown in Figure 4…”

Design and Testing of Innovative Type of Dual-Motor Drive Electric Wheel Loader

“…Through the discussion and comparison of energy-saving research in WLs, Fei et al proposed that the control of torque distribution between the front and rear motors of an EWL is essential for achieving energy savings in WL operations [12]. Torque distribution research on electric vehicles covers topics ranging from two-axle drive [13,14] to four-wheel independent drive [15][16][17].…”