Status report on research and validation programs concerning:

• HILS Model Library
• WHVC Test Cycle
• System Work Concept
• Rated Power Determination for a Hybrid Vehicle
• Family Concept-Validity of Certification
• Validation Test Phase 2 (VTP2) Validation Results−Sub-presentations of VOLVO, MAN and IVECO
• VTP2 conclusions & discussion of further actions

Proposal from the research institutions involved in assessing and adapting hardware-in-the-loop simulation (HILS) methodologies to the evaluation of heavy-duty hybrids for the anticipated second phase work to produce a HILS tool for use in GTR 4 hybrid vehicle provisions.

Assessment of hardware-in-the-loop simulation (HILS) methodologies and proposals for enhancements (e.g. more topologies, component library, temperature signals to include cold start tests).

Summary report (identical to document HDH-10-03) on the assessment of the hardware-in-the-loop simulation (HILS) methodology for heavy-duty hybrid emissions proposed by Japan.

26. The Secretary of the informal group on HDH introduced GRPE-64-07, GRPE-64-13 and GRPE-64-14. He illustrated the results of the ninth and tenth HDH informal group meetings and summarized the results of the research programme on an emissions and CO2 test procedure for HDH (now finalized). Underlining that more work is needed before a worldwide test procedure can be drafted, he stated that the discussion on chassis dynamometer and power-pack testing is expected to continue on the basis of inputs from ongoing programs by the Contracting Parties (with the delivery of inputs expected by the end of 2012), that the validation step 1 based on SILS (Software-in-the-loop simulation) is expected to start in June 2012, and that the validation step 2 with real heavy duty vehicles should start around March 2013.

27. Illustrating an updated roadmap, the HDH Secretary announced a delay of a few months with respect to the original plan. Following some considerations on financial issues related to validation step 1, he outlined the agenda of the next meetings of the HDH group.

28. GRPE acknowledged the work progress of the HDH informal group, endorsed validation 1 and the revised roadmap, and agreed that a formal request to WP.29 to extend the mandate of the HDH group is not necessary for the time being. GRPE agreed that the group should meet in conjunction with its session in January 2013.

Investigation into various methods in use for evaluating heavy-duty hybrid emissions and CO2 performance.

Mr. Planer presented working paper HDH-09-13. He briefly summarized the results of the TU Vienna work package and indicated that the final report would be available, soon.

Meanwhile, the final report has been published and circulated to the HDH group as working paper HDH-09-15. He then went on with the suggested validation phase 1 (pages 17 to 19).

As already introduced at the 8th HDH meeting, validation phase 1 is intended to verify the suggested changes of the research institutes to the Japanese HILS method. The proposal is based on the ECU as software in the loop as basis for further programming and software development. As task 1, a serial hybrid simulator would be developed, since the ECU is considered easier to implement. The simulator would cover both the WHVC and the WHDHC as input cycles for the simulation, and would be extended with a library for non-electric components, a library of new components, such as planetary gear box, power split, and with thermal models (exhaust gas aftertreatment components, coolant, lube oil, battery and electric motor). Task 2 would adapt the simulator to a parallel hybrid. As a result of tasks 1 and 2, task 3 would consist of amendments to the Japanese procedure with respect to the methods for component testing, test cycle definition and the simulation method. In task 4, an interface system would be defined to be used for real ECUs.

The participants principally agreed to the proposal. It was common understanding that starting with the serial hybrid would be most beneficial. JARI indicated that they had completed a serial hybrid model, which would be made available to TU Vienna for the validation study. JARI further informed that they already have a simple serial hybrid ECU and would support TU Vienna in developing the software ECU. OICA agreed to deliver input to task 1.4.

OICA offered to sponsor at least part of validation phase 1 depending on the total budget needed. The secretary asked the participants to consider contributing to the validation. In order to get a clearer picture, Mr. Planer was asked to submit a quote to the secretary by mid-April. Task 6 on page 19 (real vehicle testing) of working paper HDH-09-13 is not considered part of validation phase 1, but validation phase 2 and should therefore not be part of the quote. In order to meet the revised project plan the program should start no later than June 2012. Final approval of validation phase 1 will be on the agenda for the 10th HDH meeting.

Mr. Martinez indicated that EU COM would most likely take over the budget for validation phase 2. Intention would be to run this validation at JRC. OICA will check by the 11th HDH meeting (October 2012) which HDVs could be offered for this validation. It is expected to run at least one parallel and one serial hybrid.

TU-Wien presentation on its work with IFA on the assessment of HILS methodology and suggestions for the GTR validation test program.

Mr. Planer presented working paper HDH-09-13. He briefly summarized the results of the TU Vienna work package and indicated that the final report would be available, soon.

Meanwhile, the final report has been published and circulated to the HDH group as working paper HDH-09-15. He then went on with the suggested validation phase 1 (pages 17 to 19).

As already introduced at the 8th HDH meeting, validation phase 1 is intended to verify the suggested changes of the research institutes to the Japanese HILS method. The proposal is based on the ECU as software in the loop as basis for further programming and software development. As task 1, a serial hybrid simulator would be developed, since the ECU is considered easier to implement. The simulator would cover both the WHVC and the WHDHC as input cycles for the simulation, and would be extended with a library for non-electric components, a library of new components, such as planetary gear box, power split, and with thermal models (exhaust gas aftertreatment components, coolant, lube oil, battery and electric motor). Task 2 would adapt the simulator to a parallel hybrid. As a result of tasks 1 and 2, task 3 would consist of amendments to the Japanese procedure with respect to the methods for component testing, test cycle definition and the simulation method. In task 4, an interface system would be defined to be used for real ECUs.

The participants principally agreed to the proposal. It was common understanding that starting with the serial hybrid would be most beneficial. JARI indicated that they had completed a serial hybrid model, which would be made available to TU Vienna for the validation study. JARI further informed that they already have a simple serial hybrid ECU and would support TU Vienna in developing the software ECU. OICA agreed to deliver input to task 1.4.

OICA offered to sponsor at least part of validation phase 1 depending on the total budget needed. The secretary asked the participants to consider contributing to the validation. In order to get a clearer picture, Mr. Planer was asked to submit a quote to the secretary by mid-April. Task 6 on page 19 (real vehicle testing) of working paper HDH-09-13 is not considered part of validation phase 1, but validation phase 2 and should therefore not be part of the quote. In order to meet the revised project plan the program should start no later than June 2012. Final approval of validation phase 1 will be on the agenda for the 10th HDH meeting.

Mr. Martinez indicated that EU COM would most likely take over the budget for validation phase 2. Intention would be to run this validation at JRC. OICA will check by the 11th HDH meeting (October 2012) which HDVs could be offered for this validation. It is expected to run at least one parallel and one serial hybrid.

Mr. Planer presented the work program of the Institute for Powertrains & Automotive Engineering (IFA) at the TU Vienna. He started with a general overview of the Japanese HILS method. He concluded that the Japanese process, which verifies simulated results with real data, is a promising concept. In some cases, the model verification might not be accurate enough with cycles other than the JE05 cycle. If model verification fails, component models would have to be improved as often as needed in order to pass the verification test, which could require high efforts. If components are very complex (such as combustion engine), input data for the simulation model might increase, significantly. An extended HILS concept, as shown on page 15 (“engine-in-the-loop”) is suggested for further consideration by the Informal Group.

For the component testing, common methods are used to obtain the component parameters relevant for the simulation models. In the current engine model, influence of temperature is neglected, since engine testing is done under hot condition in Japan. For the gtr n°4, which contains cold and hot start testing, temperature influence need to be taken into consideration. Finally, component testing strongly depends on the requirements of the model. Therefore, the modelling depth is dependent of the desired accuracy.

In summary, the Japanese model is judged to be a good basis, but need to be refined for a global regulation. The suggestions for a global regulation are shown on page 17 [of document HDH-08-03].

The proposed next steps are shown on page 19 [of document HDH-08-03]. As a first step, a real real heavy duty hybrid vehicle should be simulated with the Japanese open source model. This software simulation should use a relatively simple hybrid model, e.g. a serial hybrid. As a second step, a sensitivity analysis should elaborate the influence of individual models and the model depth for each component on the overall quality of the result. Finally, it is necessary to find the break even point between minimal simulation effort and maximum model quality.

Mr. Planer also recommended to consider possible alternatives, such as the extended HILS method and powerpack testing.

The real heavy duty hybrid simulation is not part of the current TU Vienna work package. The secretary asked Mr. Planer to prepare a quote for this program. The program would become the first validation study and would start in June 2012.

Mr. Schneeweiss presented the work program of the Institute for Powertrains & Automotive Engineering (IFA) at the TU Vienna. After a general introduction, he first focused on the interface model. The major task of the interface is connecting the simulation model and the hardware ECU (see slide 10). The interface model is manufacturer specific and remains confidential, but must be disclosed to the approval authority. In case of multiple ECUs, the most important functions of less important control units could be implemented via the interface model of the HILS system, which is a kind of simplified software-in-the-loop.

The Japanese simulation model is realized with Simulink, a well established programming language, which is based on physical models and lookup tables (see slide 15). The most important model is the powertrain model (see slide 16). In Japan, five different powertrain models exist, but for a worldwide regulation more powertrain models would likely have to be developed. In order to solve this problem, IFA is proposing a component library. Components are physical entities (e.g. engine, motor-generator, battery, clutch, gearbox etc.) that are combined to result in a special powertrain topology. IFA also suggests to develop temperature models to take into account hybrid control strategies for optimized engine warmup. Prof. Hausberger added that this would also be needed for the warm-up of any aftertreatment system. The Chairman recalled that the WHDC procedure includes a cold start and a hot start test, and this issue must be dealt with in a global regulation. It was agreed that this could finally result in two different engine cycles for cold start and hot start.

The Chairman then raised the question where the models would be defined. It was general understanding that the gtr could only include some base models, like in Japan. Furthermore, it will not be possible to amend the gtr every time a new model is proposed by a manufacturer. The Secretary proposed an approach of defining in the gtr general guidelines of model construction on the basis of the component library proposed by IFA. With this approach, verification of the models becomes more important.

IFA then introduced an alternative to the Japanese vehicle based approach for consideration of the group. This alternative uses the premise that engine work of a conventional powertrain (on the WHTC) and of a hybrid powertrain (from HILS) should be comparable. The simulation would be done using the engine WHTC torque from WHTC speed input signal at the gearbox, as illustrated in slide 26. The approach is elaborated in more detail in working paper HDH-07-05rev by TU Graz.

IFA is proposing to do the model verification by comparing simulation results to actual measured data from test track driving using a random driving cycle. This is due to problems, which might occur in chassis dyno testing (correct recuperation, high cost).

IFA concluded that the Japanese component testing provisions could basically be used for a global regulation. Component testing strongly depends on the modeling depth and on the desired accuracy. Under this aspect, Mr. Jackson asked how the durability of the hybrid systems would be taken into account. This is currently not included in the Japanese regulation, but the Chairman emphasized that at least some aspects like durability of the storage system should be covered by the gtr.

Finally, Mr. Schneeweiss indicated that the final report would be issued by the end of 2011.

Mr. Schneeweiss presented the work program of the Institute for Powertrains & Automotive Engineering (IFA) at the TU Vienna. After a general overview of the institute and its core competences, he emphasized IFA’s experience with simulation models and hybrid drivetrains. He then explained the project approach in detail.

On behalf of Prof. Hausberger (TU Graz), Mr. Schneeweiss presented the work program of the Institute for Internal Combustion Engines and Thermodynamics (IVT) at the TU Graz. After an introduction about the institute, he gave an overview of the project approach. Tasks 5.1 (analysis of typical profiles for vehicle speed and propulsion power) and 5.3 (elaboration of options to use the HILS method in HDV CO2 procedures) will ensure the link to the EU HDV-CO2 project.