ABSTRACT
As legislative and market pressures increase on conventionally powered vehicles, new development tools will be needed to meet the demands and to deal with increasing systems complexity. To that end, this paper introduces a new technique for the replication of real-world driving in the laboratory environment. As part of HORIBA’s RDE+ suite of development tools, HORIBA Torque Matching (HTM) improves on existing “road load simulation” techniques by being able to achieve very close replication of tailpipe emissions (with very low test-to-test variation), both in terms of mass and temporal evolution. Additionally, it can do so without the requirement for performing vehicle coast down testing or surveying road grades along test routes, in order to build an accurate, simulated road-load. Instead the exact road-load is generated implicitly by the technique.
Discussion of how the replication technique is performed is followed by demonstration using both a conventional ICE vehicle and a hybrid vehicle. Thus demonstrating the applicability of the HTM approach, not only to existing vehicles, but also to electrification technologies such as hybrid and BEVs.
Firstly, convectional vehicle replications were performed at sea-level and at high altitude (using altitude simulation equipment). CO2 emissions replication is shown to be 2% or less of the respective road test and critical emissions like NO x shown to be within 5%. Finally the technique is applied to a hybrid vehicle, demonstrating not only very close emissions replication (CO2, NO x < 2%) but also accurate replication of the hybrid systems including energy regeneration from braking, battery state of charge and critical system temperatures.
Keywords: RDE, RDE+, Chassis Test, real-world Driving, Replication, Hybrid, High Altitude
