Optimal Anti-Idling Systems for Service Vehicles

Abstract

Vehicles are major sources of air pollution and greenhouse gas emissions, so any improvement in their fuel efficiency can have a significant impact on the environment and economy. In this study, a regenerative auxiliary power system (RAPS) is proposed to prevent engine idling in service vehicles. Besides preventing idling, the proposed RAPS reduces vehicle total fuel consumption by utilizing regenerative braking and an optimal charging strategy. This system employs waste energy during braking and provides the demanded auxiliary power for a service vehicle to prevent idling. In addition, the system can be retrofit onto existing vehicles. In addition, necessary tools, algorithms and methods to arrive at an optimum RAPS for anti-idling of service vehicles are designed, developed, and implemented. A generic, modular, and flexible vehicle model is created using scalable powertrain components. This model is used by the optimizer to simulate the energy efficiency of the vehicle system in order to minimize the total cost of the system during its expected life cycle. Multi-disciplinary design optimization is applied to optimize the system’s component sizes and power management control logic with respect to a cost-based objective function. Two different optimization methods, Genetic Algorithms (GA) and Simulating Annealing (SA), are utilized to find the optimal solution. Different limitations and constraints of utilizing the Electrical Storage Systems (ESS) are considered in the optimization for more accurate results. Expected changes in power consumption and fuel efficiency in the service vehicle equipped with RAPS is presented as a case study. It is shown that utilizing the RAPS has a significant impact on the total fuel consumption of the vehicle. Based on the results from case study, a prototype model of RAPS (containing generator, battery, auxiliary load, and control system) is developed for laboratory evaluation. Using the RAPS prototype as a hardware-in-the-loop (HIL) of a service vehicle, the proposed system performance is evaluated and the model is validated. It is shown that there is a close match between the experimental and simulation results. The results show that the RAPS is capable to eliminate the idling in service vehicles with considerable fuel saving.