Large heavy goods vehicles are used in an urban context for various applications including deliveries to city centre supermarkets, department stores and convenience stores as well as refuse collection and construction projects. Previous research has shown that maximizing the carrying capacity of such vehicles can significantly reduce their fuel consumption and CO2 emissions per unit of freight transported . A feature of urban delivery is start-stop operations due to traffic control measures and traffic congestion. Under these conditions, hybrid vehicle technologies and particularly regenerative braking can be beneficial. Energy that would otherwise be dissipated in the brakes during stopping can be stored and re-used to accelerate the vehicle. This can reduce energy consumption by 20-30%, depending on the drive cycle .
A key barrier to increasing the capacity of urban delivery vehicles is their manoeuvrability in confined city-centre locations. Use of steered rear axles, particularly on trailers can provide the additional manoeuvrability needed to increase the length of such vehicles and/or enable use of articulated vehicle configurations in situations where rigid lorries had to be used previously.
Preliminary modelling work indicates that combining an actively steered semi-trailer [2, 3] with a hydraulic regenerative braking system [4, 5] could reduce the fuel used in B2B delivery and refuse collection by as much as 40-50% compared with smaller conventional vehicles. By adding regenerative braking hardware to an existing test vehicle, developed by the CVDC for research into active steering [2, 3], we will test this hypothesis.
- Develop hardware and controller software for hydraulic regenerative braking on a semitrailer with steeredPredict theoretical performance benefits for delivery of urban freight.
- Implement the hydraulic regenerative braking system on an existing CVDC testTest its performance on the test track. Predict CO2 reduction for delivery of urban freight in comparison with conventional rigid vehicles.
The work will result in: (i) a prototype semitrailer with active steering and hydraulic regenerative braking system, (ii) control strategies for minimizing the fuel consumption (iii) quantification of the fuel consumption benefits and emissions reductions available for urban delivery vehicles (iv) Analysis of situations where this technology would be beneficial and would pay back quickly.
Academic impact: The methodologies developed for design optimization and optimal control of hydraulic regenerative braking systems will be directly applicable to other applications of these technologies – for example for other types of vehicles. The research will identify vectors for future research, vehicle development and policy options for urban freight. Dissemination will be through the normal academic channels.
Commercial and Social Impacts: This project is focussed on meeting medium term (2020) national targets for CO2 reduction from freight transportation. Should the research live up to expectations, a clear strategy will become available for reducing the emissions of B2B high capacity urban freight vehicles by up 40-50%, essentially meeting the 2020 target (34 per cent of 1990 levels) for this important logistics activity. There is a risk of adverse social impact through introduction of larger vehicles into urban centres. An associated project in the CVDC is addressing aspects of this risk by development of automated systems to prevent urban accidents between HGVs and vulnerable road users.
1.Hunt, SW, Odhams, AMC, Roebuck, RL, and Cebon,‘Parameter measurement for heavy vehicle fuel consumption modelling’ Proc IMechE Vol 225, Part D: J Auto Eng, pp567-590, 2011 DOI: . http://dx.doi.org/10.1177/2041299110394512
2.Odhams, A.M.C., et al., Active Steering of a Tractor Semitrailer.IMechE J Auto Eng, Part D Journal of Automobile Engineering, 2011. 225(7): p. 847-869.
3. Roebuck, R.L., A.M.C. Odhams, and D. Cebon. Implementation of Active Steering on a Multiple Trailer Long Combination Vehicle. in Proc 9th International Symposium on Advanced Vehicle Control, AVEC 10. 2010. Loughborough, UK.
4. Midgley, WJ. and Cebon, D. ‘Comparison of Regenerative Braking Technologies for Heavy Vehicles’. IMechE J Auto Eng, 226 (7) pp 957-970, 2012 DOI: http://dx.doi.org/10.1177/0954407011433395 (Sage Highly Commended Paper Award, 2012).
5. Cathcart, H., W. Midgley, and D. Cebon, Modelling of hydraulic regenerative braking systems for heavy vehicles. Submitted to Transp Res Part D: Transport and Environment, 2011.