Methodology of Excavator System Energy Flow-Down

Abstract

Due to the strengthening of air-quality regulations, researchers have been investigating methods to improve excavator energy efficiency. Many researchers primarily conducted simulation studies employing mathematical models to analyze the energy consumption of excavator systems, which is necessary to examine the fuel efficiency improvement margin and the improvement effect. However, to effectively study the improvement of excavator efficiency, the real-time energy consumption characteristics must be examined through simulations and analyses of actual equipment-based energy consumption. Accordingly, this study establishes an energy flow-down model for the entire excavator system based on actual equipment tests. A measurement system is built to measure the required data, thereby establishing an experimental methodology for modeling each component. This paper presents an excavator system energy flow-down methodology that integrates the energy flow-down model, measurement system, and experimental methodology. This methodology was applied to dig and dump operations, and the energy consumption characteristics were analyzed. An analysis of the operating modes indicates that 59.8% of the total fuel energy was consumed in the engine system, 17% in the hydraulic system, and 23.2% in the hydraulic actuation systems. The methodology can be used to help analysis of the fuel efficiency improvement margin under various conditions.

Electrification of Compact Off-Highway Vehicles—Overview of the Current State of the Art and Trends

“…In [103] the energy flow of an excavator was analyzed in detail and it was shown that the actual energy to the final load was only the 26.6% of the hydraulic energy converted in the pump, confirming the rather low efficiency of the hydraulic system. Furthermore, in order to harness the benefits of electrification with respect to torque control, better dynamics, more accurate movements, and so on, standard hydraulic systems require the control of flow, pressure and direction, mainly by means of pressure drops, which can be regarded as intentional losses of energy [104]. Nonetheless, hydraulics is still considered essential in most off-highway vehicles and machinery due to its great power density; thus, its complete replacement is currently limited to niche products.…”

Retrofitting Battery Electric Machinery with Unchanged Hydraulic System and Enhanced Control Strategies

“…Mobile hydraulics has the highest power-to-weight ratio for actuator movement, which makes it extremely difficult to replace. At the same time, hydraulics is the biggest source of inefficiencies after the combustion engine [7], and its average energy efficiency is only as high as 21% [8]. To increase the overall efficiency of the machinery, industry and academia are researching both disruptive and incremental innovations.…”

Energy Flow Analysis of Excavator System Based on Typical Working Condition Load

“…In the above studies, simple signals such as constants, steps, and ramps are often used to simulate the working load, which are difficult to accurately represent the actual working condition, which will inevitably lead to deviations in the results of energy flow analysis and the effect of energy-saving schemes. In response to this problem, An et al proposed an excavator energy flow analysis method based on operating data [21], but the study did not involve the construction of typical working condition load and could not be further applied to mathematical models. Therefore, it is urgent to build up the typical working condition load of the excavator, realize the accurate analysis of the energy flow, obtain the energy margin of the excavator system, and provide accurate simulation load for the mathematical model.…”