RDE cycle generation – a statistical approach to cut down testing effort and provide a secure base to approve RDE legislation compliance

Statistically supported real driving emission calibration: Using cycle generation to provide vehicle-specific and statistically representative test scenarios for Euro 7

“…7–9 As a result, no uniform RDE validation methodology was established. 10 In literature as well as in practice, there is controversy about which form of driving profiles (synthetic, real measured, highly dynamic, “worst-case,” etc.) is particularly suitable for development and validation.…”

“…is particularly suitable for development and validation. 9,11–20 Therefore, the objective is to develop a uniform test and validation methodology for reliable compliance with RDE requirements and robust emission calibration. The first step toward this goal must consequently be the development of a methodology that allows existing tests and driving profiles to be compared quantitatively.…”

“…35–37 The review of these methods in source 10 indicates that an adequate RDE validation cannot be guaranteed by this approach due to the insufficient consideration of individual characteristics of different vehicle types. 10 Current approaches either deal with the creation of geographically and regionally realistic driving scenarios or with synthetic profiles with significantly high driving dynamics aiming to cause maximized emissions. 10–17,19 The individual combination of vehicle and powertrain, the influence of calibration and performance of exhaust after-treatment systems over lifetime are not considered in these methods.…”

“…10 Current approaches either deal with the creation of geographically and regionally realistic driving scenarios or with synthetic profiles with significantly high driving dynamics aiming to cause maximized emissions. 10–17,19 The individual combination of vehicle and powertrain, the influence of calibration and performance of exhaust after-treatment systems over lifetime are not considered in these methods. 10,38 The “WLTP random cycle-generator” approach considered by the European Union (EU) takes vehicle-related input parameters such as vehicle mass, driving resistance coefficients and effective engine power into account when creating the cycle.…”

“…10–17,19 The individual combination of vehicle and powertrain, the influence of calibration and performance of exhaust after-treatment systems over lifetime are not considered in these methods. 10,38 The “WLTP random cycle-generator” approach considered by the European Union (EU) takes vehicle-related input parameters such as vehicle mass, driving resistance coefficients and effective engine power into account when creating the cycle. Two Markov chains (commonly used for cycle generation) whose statistical background is based on the worldwide harmonized light duty vehicles test cycle (WLTC) database are used to 13–16,39–42…”