eXact: Sustainable Construction Starts with Excavation

Construction should be sustainable. Contractors, authorities, as well as contracting entities are aware of this. But does sustainability not already start during the excavation phase? Clearly not, since topics such as electrification and sustainability are still on the backburner when it comes to construction machinery. This is certainly the impression gained by eight aspiring mechanical engineers at ETH Zürich. Reason enough to take the matter into their own hands. As part of a focus project, the students have made it their mission to fully electrify an excavator. But that's not all. The ambitious team, which goes by the name of eXact, is taking this a step further and is also fitting the electric excavator with augmented reality features. This will improve the human-machine interface and open up new opportunities in terms of accuracy and efficiency – both factors that contribute to sustainability in the construction phase as a result of a more targeted approach. Jonas Rogge, who heads the team and is also responsible for the mechanics, says: "We want to make the most efficient use of renewables." Rogge adds that this way, eXact aims to contributesignificantly to electrification on construction sites.

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Partners and sponsors of eXact

The eight undergraduate mechanical engineering students have been working on the project since September 2022. They are guided by supervisors Professor Andreas Kunz from the Innovation Center Virtual Reality at ETH and Stefan Schneider, whose successful company Suncar HK AG is also the result of an ETH focus project. The eXact team has moved to premises at Technopark Zurich, made available to them by ETH. eXact depends on sponsors for financing the project. These include construction equipment manufacturer Volvo, who is providing an ECR25 excavator, as well as Syslogic, the experts in embedded computers, who are contributing hardware components including an AI-enabled control computer.

The project is divided into two sections: work on the excavator and work on the human-machine interface. The Volvo ECR25 is one of the first electric excavators on the market. So eXact is not actually starting from scratch, but is going one step further and significantly improving the efficiency of the electric excavator. It has become evident that the hydraulics of the excavator are extremely power-hungry, which affects its energy efficiency. eXact has therefore decided to replace the hydraulic linear actuators with appropriate electric linear actuators, which offer a much higher level of efficiency compared to hydraulics. This will make operation of the modified excavator much more environmentally friendly than the series product. Plus, it is possible to achieve considerably more working hours with a single battery charge – a convincing argument on construction sites.

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