Smart car-cooling system boosts fuel efficiency

The Sentience project has announced an intelligent air-conditioning control system that can consistently improve a vehicle’s fuel efficiency by 9 per cent or more.

A research collaboration led by Ricardo Company, Sentience also involves Jaguar-Land Rover, TRL, Ordnance Survey and Orange Business Services, with part-funding provided by innovITS, the UK centre of excellence for intelligent transport systems and sustainable mobility.

The project team unveiled the Sentience research vehicle — based on a Ford Escape Hybrid — at a press launch in early March.  At that time, the vehicle exhibited the Enhanced Acceleration/Deceleration (EAD) control strategy, in which the vehicle speed is controlled to meet actual and virtual speed limits using an advanced form of adaptive cruise control linked to the hybrid powertrain system of the vehicle.

Virtual speed limits are calculated using GPS and mapping data including features such as bends and even speed bumps, as well as less predictable road features including roundabouts and traffic lights. Once EAD is operating, the driver simply steers the vehicle but can at any time manually override the system if a change of route is required or for safety reasons.

Since its initial unveiling, testing and development of the Sentience vehicle has progressed using climatically controlled test facilities at the Ricardo Midlands Technical Centre. A new Enhanced Air-Conditioning (EAC) control strategy has now been successfully developed which manages the air conditioning system in parallel with the hybrid powertrain. This is particularly useful in urban traffic with frequent stop/start transitions, according to Ricardo.

In the test vehicle, the air-conditioning compressor is driven by the engine so that when the hybrid powertrain operates in electric-only mode or the vehicle is stationary, the air-conditioning system does not operate. By linking the EAC and powertrain control strategies however, knowledge of when the combustion engine can be stopped allows the system to plan an appropriate and more efficient cooling strategy.

Cabin air temperature can thus be maintained within a narrow range while maximising the opportunities for the gasoline engine to switch off, hence minimising the time that the engine is run solely to drive the air conditioning. The subject of a Ricardo patent application, the new EAC technology is also highly applicable to all types of hybrid vehicles, including the stop-start systems which are becoming increasingly common.

“The Enhanced Air-Conditioning control system we have announced today is a further very tangible technology breakthrough for the Sentience project, which has already demonstrated the potential synergies to be realised by connecting the existing on-board systems of vehicles with mobile communications and advanced mapping technologies,” said Tom Robinson, Sentience project director for Ricard. “EAC is highly applicable to a wide range of hybrid vehicle types from simple stop-start systems to plug-in hybrids, and Ricardo will seek to exploit this technology actively in its future client programmes.”

“Our leading involvement in the Sentience project is yet a further demonstration of the clear focus of Ricardo on the development of next-generation automotive technologies that will help deliver a safer, cleaner and more environmentally sustainable future for transport,” added Dave Shemmans, CEO of Ricardo. “The very tangible outcomes of this research also underscore the Ricardo approach of delivering innovations that are capable of production-feasible and commercially successful implementation in future products that are both attractive to customers and environmentally beneficial to society.”