Digital Hydraulic Fluid Power Technologies for Decarbonising Off-road Vehicles

Climate change is the most pressing environmental challenge of our time. The transport sector was the largest contributor to UK greenhouse gas emissions (GHG) in 2020, with an overall contribution of 24% [1]. While decarbonisation of on-road transportation, such as cars, buses and trucks, is well underway by employing electric alternatives, the important sector of off-road vehicles is technologically far behind and represents a major contributor to GHG emissions. In 2018, the total GHGs emission of UK off-road vehicles was 11,043 kilotonnes [2], which is equivalent to the GHGs emission from 12.2 Giga pounds of coal burned, or the annual energy use of 1.4m homes' [3].

Hydraulic fluid power transmission is widely used in off-road vehicles, such as construction and agricultural machinery. Current state-of-the-art hydraulic fluid power components and control technologies continue to be highly energy- and cost-inefficient and generate significant CO2 emissions, as speed and force are controlled by using metering valves to throttle the flow and control the hydraulic pressure. This is a simple but extremely inefficient method because the energy is dissipated through an orifice and consequently lost as heat; it is common for more than 50% of the input power to be wasted in this way. A recent study showed that the average energy power efficiency of fluid power systems is only 21%, and a 5% improvement in efficiency can save 0.51 quadrillion Btu of energy, which relates to a saving of US$10.1 billion and a reduction in CO2 emissions of over 33.95 million tonnes. Therefore, there is an urgent need to create new technologies to significantly improve hydraulic energy efficiency to enable efficient decarbonisation and electrification of off-road vehicles and achieve Net Zero.

To significantly improve hydraulic fluid power efficiency to over 90%, I will provide a transformative change in next-generation digital hydraulic components and control technologies by developing new additively manufactured high-performance digital hydraulic valves (WP1) and novel digital hydraulic converters (WP2) to reduce hydraulic pressure and energy losses. I will create high-fidelity analytical modelling tools to understand the underlying science of complex fluid power components and systems and establish new additive manufacturing-based designs and methodologies for energy-efficient digital valves and converters. An intelligent control platform (WP3) which will integrate model- and machine-learning-based control algorithms, will be developed to control the digital valves and converters to achieve their optimum performance and maximum efficiencies. These transformative and emerging technologies will be implemented on off-road vehicles (e.g. excavators, elevating platforms) as technology demonstrations and case studies (WP4) in order to produce future digital hydraulic fluid power products and solutions for Net Zero (WP5). I will conduct scoping studies in Phases 1 and 2 to define new research directions, deliver high-impact publications and conduct the pathways to impact activities.

The research outcomes will generate significant academic, economic and societal impact. They will ensure the UK has a unique world-leading research activity in digital fluid power and its future applications. UK-based companies will receive a competitive advantage in exploiting the deliverables from the Fellowship and in significantly influencing the application potential of digital hydraulic fluid power in the market, which can have an immense range of customers. The research outcomes will provide long-term zero-carbon machines for people living and improving their quality of life.

[1]. 2020 UK Greenhouse Gas Emissions, Final Figures. National Statistics. Department for Business, Energy & Industrial Strategy. 2022.
[2]. National Atmospheric Emissions Inventory UK Data. 2022.
[3]. Greenhouse Gas Equivalencies Calculator, the US Environmental Protection Agency. 2022.