Test Methodology to Quantify and Analyze Energy Consumption of Connected and Automated Vehicles 2019-01-0116
A new generation of vehicle dynamics and powertrain technologies are being developed to leverage information streams enabled via V2X connectivity. Most control algorithms used to reduce energy consumption of a vehicle operate on simplified models of the underlying powertrain. It is not unexpected if the energy consumption reduction realized on a vehicle differs from the original prediction. While algorithms that enable improvements in energy efficiency are being studied in detail, a methodology to measure and analyze these improvements in energy efficiency on a vehicle are yet to be explored fully. A procedure to test and accurately measure energy consumption benefits of a Connected Automated Vehicle (CAV) is presented. A traffic simulator is built to model traffic flow in Fort Worth, Texas with sufficient accuracy. The benefits of a traffic simulator are two-fold: (1) Generation of repeatable traffic scenarios and (2) Evaluation of robustness of control algorithms by introducing disturbances. The traffic simulator is interfaced with a chassis dynamometer on which the real vehicle is tested. Algorithms leverage information from the traffic simulator to produce control policies that are optimal in energy consumption. The control policy results in a specific speed of the “ego” vehicle. This speed is relayed back into the traffic simulator which, in turn, coordinates movement of the vehicles surrounding the ego vehicle. While traffic simulator and chassis dynamometer provide controlled test environments, an advanced instrumentation and measurement scheme enables in-situ efficiency calculations across the powertrain by analyzing energy flows during transient operation of the vehicle. Details of the measurement scheme along with chassis dynamometer results are presented.
Sankar B. Rengarajan, Scott Hotz, Charles Hirsch, Peter Lobato, Michael Gross, Purser Sturgeon, Jayant Sarlashkar