Development of a control system for automated cab roof deflectors for articulated trucks

The adverse effects of emissions from the global transport industry on the environment have become increasingly apparent, with significant emphasis placed on their reduction through various initiatives. In the UK, Heavy Goods Vehicles (HGV’s) are used to transport 68 % of all goods. The majority of trucks are articulated (Truck and Trailer) – rather than rigid vehicles. Surveys show that within the UK in 2014, HGV’s travelled approximately 18,769 million kilometres (1). The CO2 emissions from transport industry are estimated to account for 25% of entire emissions, with HGV’s responsible for 23 % of transport emissions (2, 3). Any improvement in fuel economy within transport industry will thus have direct bearing on management of emissions.
Outer dimensions of HGV’s are regulated by the local and European laws, with the design of these vehicles optimized to maximise cargo volume rather than aerodynamic efficiency. The goal of this research was to reduce fuel consumption of articulated HGV’s by reducing the aerodynamic drag by modifying flow field around the vehicles (4, 5). A number of post market add-on devices for commercial vehicles have been adapted as standard equipent. Whilst some of these devices like the cab roof fairing have become popular, others like the base bleeding devices have been largely discarded by the industry due to practical limitations like obstruction caused in normal operations e.g. loading.
Studies have shown that streamlined matching of trailer shape and cab roof deflector for smooth airflow can reduce fuel consumption of articulated trucks by approximately 7.6% (6). Researchers found out that just the positioning of a cab roof deflector (CRD) can influences the fuel consumption of an articulated truck by about 4 % (7). Existing cab roof deflectors are optimised for a single trailer height. However in practice HGV’s will be required to operate with a range of trailer heights. To maintain efficiency it would require a change in the deflector position each time the trailer size is altered. Furthermore it is required to respond to changing
crosswind conditions with changing CRD positioning for maximum efficiency Through this research project a control system for automated dynamic CRD adjustment has been developed. Its concept can be employed for any combination of truck and trailer. The control system has been developed to always adjust the CRD to the optimum position for reducing aerodynamic drag. The reduction in aerodynamic drag is directly related to the reduction of fuel consumption.