Dynamic Vehicle Speed Profiles for Reproducible RDE Simulation
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Solution Overview
Problem
Current methods for testing motor vehicles under Real-Driving Emissions (RDE) legislation face challenges in replicating real-world driving conditions, making it difficult to assess the effectiveness of modifications and ensuring compliance due to the variability and unpredictability of road tests, which are costly and inefficient.
Innovation Solution
A method for generating a dynamic speed profile based on route data from digital maps, allowing for the simulation of real-world driving scenarios on a test bench or through model-based testing, which includes determining a static speed profile, dynamizing it with maximum target deceleration, and converting it into a time-based dynamic speed profile with calculated accelerations and decelerations to mimic actual vehicle operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If real-world road tests are conducted to assess RDE compliance, then the realism and applicability of testing is improved, but the reproducibility and controllability of test conditions deteriorates
Solution Approach 1:
The patent creates a digital copy of real-world driving conditions by generating virtual speed profiles from digital map data that replicate actual route characteristics, speed limits, and traffic patterns. This allows realistic RDE testing to be performed in controlled environments without requiring repeated real-world road tests, thereby maintaining realism while improving reproducibility.
2Adaptability or versatility
If multiple test drives on different roadways with different drivers are conducted to cover wide range of conditions, then the statistical coverage and comprehensiveness is improved, but the cost and effort of troubleshooting increases
Solution Approach 1:
The patent performs preliminary testing using generated speed profiles that represent various driving conditions before actual prototype testing. By simulating different routes, speed limits, and driving patterns in advance, potential issues can be identified and addressed during the development phase, reducing the need for costly troubleshooting during later RDE compliance testing.
Solution Approach 2:
The speed profile generation system serves multiple functions: it can simulate various driving conditions, routes, and scenarios from a single digital map data source. This universal testing platform replaces the need for multiple separate test drives with different drivers and routes, providing comprehensive coverage while reducing time and cost.
3Measurement precision
If test bench testing is used to achieve reproducible and controlled test conditions, then the transparency of modification effects and measurement precision is improved, but the discrepancy between homologation and real-world emission values increases
Solution Approach 1:
The patent changes the parameters of test bench testing by inputting dynamically generated speed profiles that reflect real-world driving patterns, route characteristics, and speed limit variations. This transforms traditional static test bench procedures into dynamic simulations that maintain measurement precision and controllability while improving representativeness of real-world conditions.
Data Source
AI summary
The invention relates to a method for generating a dynamic speed profile of a motor vehicle which is suitable for simulating in particular actual vehicle operation on a route, comprising the following procedural steps: determining a route-based static speed profile for the route resolved into route segments based on information from a digital map; determining a route-based dynamized speed profile on the basis of the route-based static speed profile which factors in a defined maximum target deceleration to reach mandatory speed minima of the speed profile; determining a time-based dynamic speed profile resolved into time increments on the basis of the route-based dynamized speed profile, wherein an applied acceleration is determined in each time increment based on the speed dictated by the speed profile in a route segment corresponding to the respective time increment and the applied speed in the time increment; and outputting the time-based dynamic speed profile.