4.1 Presentation by research institutes on validation test program 1

Working paper HDH-14-03e is a joint presentation of the three institutes tasked with conducting validation test program 1.

Prof Fredriksson started with an overview of the new model structure (pages 4 to 12). Rationale for the new model structure was a greater flexibility of the modeling approach that allows various combinations of engines, gear boxes and energy storage systems. The new model structure for serial and parallel hybrids was made available for testing at the end of April. It includes a comprehensive component model library, a new signal naming convention based on AUTOSAR and the restructuring of the vehicle models. Relevant powerpack components were included in the library toolbox, while previously developed models were transferred into the model library. The models will be further developed until the end of June 2013 based on feedback from OICA members and other stakeholders.

Mr. Silberholz reported on positive feedback from OEMs on the new model structure. Open issues from the discussions are the actuation of different brake systems in the driver model and time vs. distance based slope pattern. He continued with a detailed analysis of the road slope calculation methods (30 sec moving average method vs. minicycle approach, pages 15-19). The two options are considered not directly comparable due to big deviations in resulting reference power pattern. Reason is that the WHTC denormalization method leads to operation points at lower loads and speeds for hybrid powertrains. Therefore, the WHDHC calculation tool may be not suitable any longer. Further investigations on this item will continue.

As a conclusion of validation test program 1, extensive changes on models and model structure were made, the next model release (including stakeholder remarks) will be available shortly, the comprehensive model and work program documentation will start, and drive cycle modifications need further investigation.

Status of validation test program 2

Dr. Perujo presented working paper HDH-14-04. Test program and timetable were set up between the participating OEMs and JRC before the start of the test program. The input parameters rolling resistance coefficient, air resistance coefficient and total weight were determined and selected in accordance with Kokujikan No. 281, paragraph 10-5. It was decided to carry out the tests with as many auxiliaries as possible shut down and to measure/estimate the power consumption of the auxiliaries required for the proper operation of the vehicle. In order to get repeatable results, a daily test sequence was agreed.

Validation test program 2 at JRC started with the Volvo parallel hybrid bus in May. Preliminary results are shown on pages 9 and 10. The Iveco vehicle is about to start, the MAN bus will follow by the end of June. Data processing will be done during July, August and September. The final report is planned to be released by mid September 2013.

4.3 Discussion

The Chairman asked about the selected naming convention. Prof. Fredriksson responded that AUTOSAR is widely used within the automotive industry.

Mr. Olechiw (USA) asked if the 30 sec moving average method for slope determination, as proposed by Japan, was no longer considered. Mr. Silberholz expressed a strong preference for the minicyle approach. Mr. Dekker (NL) emphasized that a representative negative work is absolutely essential and efforts would need to be made for an appropriate solution. The secretary reminded that fixed slopes should also be considered, but Mr. Silberholz expressed reservation. Mr. Narusawa (JP) indicated that Japan will investigate the minicycle approach favored by the institutes and come back with a response at the next HDH meeting. The secretary asked the institutes and Japan to closely cooperate in the development of the final method.

Mr. Olechiw (USA) requested to include powertrain verification as an option to whole vehicle verification in the gtr, and to validate the HILS method with emission results. He asked for further discussion on how to maintain and update the models and the required level of validation in the gtr. EPA also confirmed to take part in validation test program 2.