Development of a Fuel Economy and Exhaust Emissions Test Method with HILS for Heavy-Duty HEVs

The objective of this study was to develop a test method for heavy-duty HEVs using a hardware-in-the-loop simulator (HILS) to enhance the type-approval-test method. To achieve our objective, HILS systems for series and parallel HEVs were actually constructed to verify calculation accuracy. Comparison of calculated and measured data (vehicle speed, motor/generator power, rechargeable energy storage system power/voltage/current/state of charge, and fuel economy) revealed them to be in good agreement. Calculation error for fuel economy was less than 2%. To establish an HILS method, the following items were carried out: (a) Typical HEV models for the HILS system were proposed to enable them to be adapted to all types of heavy-duty HEVs which will be launched over the next few years in Japan; (b) Test procedures for HEV components such as engines, motors/generators and batteries were proposed to measure the parameters of HEV models; and (c) A verification procedure for the HILS system was developed.