Volvo Construction Equipment (Volvo CE) unveiled the HX2, a prototype autonomous load carrier at Conexpo/IFPE 2017. The battery-electric vehicle with on-board hydraulics is the latest development in the company’s electric-site research project that aims to transform the quarry and aggregates industry. It predicts up to a 95% reduction in carbon emissions and up to a 25% reduction in total cost of ownership. Volvo CE showcased the first-generation of the prototype HX machine, known as HX1, at the company’s Xploration Forum in September last year. Since then, Volvo CE’s engineers have been developing the new version.
“The HX2 is fundamentally different to the HX1,” says Uwe Müller, Volvo CE’s chief project manager for the electric site project. “The HX1 was proof of concept. Once we knew it was feasible we updated the design requirements for the HX2 to incorporate shared technologies and components from the Volvo Group, such as electric motors, batteries and power electronics. Integrating a completely new drivetrain was crucial to take full advantage of the groundbreaking electromobility developments that are happening inside the Volvo Group. Another new feature is the addition of a vision system, which allows the machine to detect humans and obstacles in its vicinity.”
“The HX2 is fundamentally different to the HX1,” says Uwe Müller, Volvo CE’s chief project manager for the electric site project. “The HX1 was proof of concept. Once we knew it was feasible we updated the design requirements for the HX2 to incorporate shared technologies and components from the Volvo Group, such as electric motors, batteries and power electronics. Integrating a completely new drivetrain was crucial to take full advantage of the groundbreaking electromobility developments that are happening inside the Volvo Group. Another new feature is the addition of a vision system, which allows the machine to detect humans and obstacles in its vicinity.”
The machine measures about 18 feet long and 8 feet wide and has an operating weight of 14,300 lb. It has 4-wheel drive and 4-wheel steering with a maximum speed of 25 mph. And because the vehicle has no driver or cab, it allows a bidirectional work cycle with no reversing, and it permits crab steering for easy positioning.
According to a Volvo spokesman, the carrier will be powered by three electric motors. Two will drive the wheels. Because the carrier is powered by electricity, it’s more efficient to use an electric drive, rather than hydraulic motors. A third motor will power the unit’s hydraulic pump with rated flow of 21 gpm. High-pressure hydraulics, in turn, will handle steering actions and actuate the dump cylinders.
Because this is an autonomous machine, all hydraulics functions, such as where to steer the unit and when to dump the load, are controlled by the machine itself with no human intervention.
Also notable is that the batteries recharge every work cycle. The unit loads, hauls and dumps over an 8-minute span, and then the power pack recharges for 1 minute before initiating the next cycle.
The electric site project aims to electrify a transport stage in a quarry – from excavation to primary crushing and transport to secondary crushing. It involves developing new machines, work methods and site management systems which, together, will meet the overall performance, economic and sustainability goals.
In addition to a small fleet of HX2s, other prototype machines that make-up the electric site system include a prototype electric-hybrid wheel loader, and a grid-connected excavator. New technology encompasses machine and fleet control systems and logistics for electric machines in quarries.
Volvo CE’s prototype electric hybrid wheel loader is the LX1, which was also unveiled at the Xploration Forum last year. The machine can deliver up to a 50% improvement in fuel efficiency, as well as significant reductions in emissions and noise pollution compared to its conventional counterparts. It is currently being field tested in the U.S. by Volvo CE’s customer Waste Management – the largest environmental services and recycling company in North America. So far, feedback has been positive.
The LX1 is a “series” hybrid that incorporates a driveline that consists of electric drive motors mounted at the wheels, electric-driven hydraulics, an energy storage system, a significantly smaller diesel engine and new machine architecture, including a new design of the lifting unit. It’s this combination that enables the substantial gain in fuel efficiency. The prototype – which has 98% new parts and a fundamentally new machine design – can do the work of a wheel loader that’s one size larger.
Volvo CE teamed up with its customer Skanska Sweden, the Swedish Energy Agency and two Swedish universities – Linköping University and Mälardalen University – in October 2015 to collaborate on the $22.4 million project. Volvo CE is coordinating the project and is developing the machines and systems. Skanska Sweden is providing logistical solutions, application relevance and job site knowledge. Researchers at the universities are looking at battery aging, energy management for electric vehicles, as well as functional safety.
Skanska Sweden will incorporate the demonstration machines into its operations and test the electric site concept at a quarry in western Sweden for 10 weeks at the end of 2018. After this, Volvo CE will examine the project results to see if the concept is viable for the industry. Currently this work is just a research project, with no plans for industrialization at this stage.
“Volvo CE is committed to pushing boundaries and exploring the technology of the future,” said Jenny Elfsberg, director of emerging technologies at Volvo CE. “The HX2 and the electric site project demonstrate how Volvo CE wants to work with its customers early in the development phase to improve total site performance and sustainability, while also saving customers money.
“The concepts being developed in the electric site research project are part of Volvo CE’s long-term vision. Using electricity instead of diesel to power construction equipment in a quarry has the potential to deliver significant reductions in fuel consumption, carbon-dioxide emissions, environmental impact and cost-per-ton. The electrification of construction equipment will produce cleaner, quieter and more efficient machines – this represents the future of our industry.”
Volvo Construction Equipment
www.volvoce.com
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