RDE Plus - A Road to Rig Development Methodology for Whole Vehicle RDE Compliance: Overview 2020-01-0376
To aid Original Equipment Manufacturers (OEM) in meeting Real Driving Emissions (RDE) regulation criteria  across the moderate and extended boundary conditions of temperature, altitude and driving style, an integrated Road to Rig (R2R) whole vehicle development, calibration and verification approach known as RDE Plus (RDE+) has been developed by HORIBA.
Connecting testing on the road, chassis dynamometer, Engine-in-the-Loop (EiL) and virtual testing methodologies, real world driving scenarios can be deployed by OEMs further upstream during vehicle and engine development programmes; hence reducing development timescales and costs that will otherwise inevitably increase due to RDE regulations.
Reported in the current paper is a brief introduction to the baseline RDE road tests followed by replication of several real RDE cycles that cover the RDE moderate and extended boundary conditions with the vehicle driven by a robot driver on the chassis dynamometer. A HORIBA Multi-function Efficient Dynamic Altitude Simulation (MEDAS) system was used to emulate altitude, temperature and humidity with the RDE regulation parameter va_pos as a percentage of its limit used to parameterise driving style. For all routes, there was a good correlation in vehicle and engine performance as well as gaseous emissions.
Prior to removing the engine from the test vehicle to complete the correlation of road, chassis dynamometer and EiL testing (the test vehicle was undergoing chassis dynamometer work at the time of writing), a replica vehicle was tested utilising the EiL test methodology described in the current paper. Combining the EiL setup with a virtual toolset incorporating a virtual vehicle (the same as physically tested), driver and test route the effects of driving style on engine performance and emissions were investigated.
Several different driving styles (catagorised using the same metric above) were adopted for a fixed RDE route. In adopting the most aggressive driver, there was an increase in cycle tailpipe CO2, NOx and PN emissions of 22%, 132% and 116% respectively compared to the gentlest driver. Further performance and emissions results for the differing driving style are reported in the current paper.
This paper is the second in a series of technical papers from HORIBA on the RDE+ programme. It follows SAE Technical Paper 2019-01-0756 presented at WCX2019.