When asked about future trends, Zhou Ge, Caterpillar's regional product manager for excavators, said that Caterpillar began designing and developing hybrid electric products in 2007. Based on customer feedback, the return on investment for hybrid electric products was slow. After about three years of research and testing, we did not bring hybrid electric excavators to market. Then we began researching hydraulic hybrid products and found that the advantages of hydraulic hybrid were more obvious. The design of hydraulic hybrid is simple, service personnel can easily understand it, and maintenance is convenient. By installing an accumulator on the machine, energy can be recovered, stored, and released when the swing decelerates.

　　Mr. Zachary, Caterpillar's global product manager for small and medium hydraulic excavators, said that from a manufacturer's perspective, there is no difference in applying this technology to 20-ton and 36-ton products, but for customers, the higher the tonnage, the higher the return on investment for hydraulic hybrid. That is why we first launched the Cat 336EH hybrid excavator (see the bauma exhibition special report in Issue 5, 2013 of this journal). One of our customers reported that the overall fuel consumption of the hybrid product they used was reduced by 25%. Of course, for smaller machines, we have also made other improvements to reduce fuel consumption.

　　At bauma 2013, we also saw some other manufacturers researching hydraulic hybrid, but so far, Caterpillar is the only manufacturer that has officially launched a hydraulic hybrid excavator. Caterpillar's hydraulic hybrid excavator was named one of the most creative products in the United States in 2013, and the only excavator product to receive this honor.

　　Zhou Ge said that for the hybrid electric approach, the initial investment is relatively large. Although it can effectively reduce fuel consumption, it is difficult to see tangible returns within a few years. From this perspective, the development of hybrid electric technology will be greatly limited, especially since the cost and expense of batteries are also very high.

　　The fact that hybrid electric power can be used in automobiles does not mean it is equally applicable to excavators. Excavators are different from automobiles; they already have hydraulic systems, so using hydraulics is obviously more advantageous. That is why we ultimately developed hydraulic hybrid. During operation, excavators experience significant instantaneous hydraulic fluctuations, and a large portion of the high-pressure oil energy is wasted. By storing hydraulic energy and releasing it, rather than converting it, we reduce the conversion to electrical energy and can use energy more efficiently.

　　How to balance fuel consumption and product performance?

　　Zachary said that generally, we want to reduce fuel consumption while maintaining machine performance. Take the D2 series excavators as an example. They are the same as standard models in terms of quality, performance, reliability, and durability. Fuel consumption is reduced by improving the engine structure, adding a hydraulic pump to the engine, and appropriately reducing engine speed so that the engine and equipment work better together.

　　Zhou Ge used an analogy to describe the relationship between fuel consumption and machine power performance: a person cannot work without eating; to do more work, one must eat more. Machines are the same. If you want them to work, you must provide fuel. Therefore, when we designed products in the past, we focused more on productivity, and fuel consumption was relatively high. The current D2 series specifically addresses this issue. Without affecting efficiency and productivity, reducing fuel consumption through more technological innovation is our ideal approach. It is not simply a matter of reducing one aspect to improve another; our products need to maintain the productivity customers require while also reducing fuel consumption. For our hydraulic hybrid product, some customers have reported that fuel consumption can be reduced by 30% to 40% without any impact on product performance.

　　In addition to hybrid technology, a control technology called "L5" increases the coordination between the engine and hydraulic system. The two systems interact to reduce engine speed while maintaining product performance, thereby reducing fuel consumption. So although the Cat 336D2 is not a hybrid, with "L5" control technology, fuel consumption has been reduced by nearly 7%.

　　In addition, the Cat 336D2 offers three different power output modes: high, medium, and low. Some customers focus on productivity and can choose high power mode. If the equipment's application is relatively simple, low power mode can be selected to effectively reduce fuel consumption.

　　Future technology trends for excavators

　　Excavators are products with high technology content and high entry barriers. It can be said that technology leads the future. What are the future technology trends for excavators? Zachary said that excavators are a good choice for customers, and the excavator market will continue to grow to some extent. At the same time, we need to focus on how to reduce customers' ownership and operating costs. Our existing technology will also be continuously improved to maximize equipment value. Whether it is us or our competitors, we will all be committed to reducing customers' operating costs while making machine operation more convenient and simpler.

　　Hydraulic hybrid technology reduces product fuel consumption while ensuring superior equipment performance. Such hybrid products will be increasingly introduced to the market.

　　Another trend is intelligent management solutions. With intelligent technology management models and more intelligent management, construction personnel will no longer need to measure how deep a trench should be dug or master the digging angle. Sensors on the equipment can automatically detect the accuracy of operations. This reduces manual input and greatly improves accuracy and efficiency.