Hybrid Vehicle Travel Control with Speed Profile Approximation
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Solution Overview
Problem
Existing travel control systems for hybrid vehicles cannot quantitatively predict the amount of regenerative energy that can be recovered, limiting their ability to optimize energy use and fuel efficiency.
Innovation Solution
A travel control device that creates a predicted speed profile using a predetermined approximation model, such as a sum of Gaussian functions, to estimate the recoverable regenerative energy, and determines the power source based on this prediction, considering factors like road surface, slope, load weight, and weather.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a speed profile is created without using an approximation model, then the prediction of regenerative energy recovery can be more accurate, but the calculation complexity and processing time increase significantly
Solution Approach 1:
The patent transforms the complex speed profile prediction problem into a parameter optimization problem by using an approximation model with adjustable parameters. The model changes parameters such as peak positions, amplitudes, and widths of Gaussian functions to fit the predicted speed profile, thereby reducing calculation complexity while maintaining prediction accuracy for regenerative energy recovery
Solution Approach 2:
The approximation model serves as an intermediary between the raw speed profile data and the regenerative energy calculation. Instead of directly calculating regenerative energy from complex speed variations, the model provides a simplified intermediate representation that captures essential features (acceleration/deceleration phases) while reducing computational burden
2Measurement precision
If regenerative energy prediction is performed without early stage approximation, then the prediction can be more precise, but the prediction cannot be made at an early stage for travel control optimization
Solution Approach 1:
The patent performs preliminary approximation of the speed profile using an analytical model that can be evaluated early in the travel control process. By pre-establishing the approximation model with predicted speed characteristics, the system can estimate regenerative energy recovery in advance, allowing sufficient time for optimization decisions before actual braking events occur
Solution Approach 2:
The approximation model is designed to be dynamic and adaptable, allowing it to adjust to different driving conditions and speed profiles in real-time. This enables early stage prediction while maintaining precision across varying operational scenarios through dynamic parameter adjustment
3Measurement precision
If the speed profile is created based on detailed travel history analysis, then the prediction of regenerative energy can be more accurate, but the processing time and computational resources increase
Solution Approach 1:
The patent extracts only the essential features from detailed travel history data that are relevant to regenerative energy prediction, such as acceleration and deceleration patterns, rather than processing the entire raw dataset. This selective extraction maintains prediction accuracy by focusing on critical parameters while significantly reducing processing time and computational resource requirements
Data Source
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AI summary
A travel control device (10) mounted on a vehicle including an electric motor and an internal combustion engine (21) as a power source includes a creation unit (11) configured to create a speed profile in which a speed of the vehicle at each time is predicted, an estimation unit (12) configured to approximate the speed profile with a predetermined approximation model and estimate a predicted amount of regenerative energy based on an approximation result, the regenerative energy being energy that is recoverable by regenerative braking of the electric motor, and a determination unit (13) configured to determine the power source to be used for traveling based on the predicted amount of the regenerative energy.