Vehicle Decelerating Factor Estimation via Dynamic Speed Thresholds
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Solution Overview
Problem
Existing decelerating factor estimation devices for vehicles face accuracy and time efficiency issues, particularly when vehicle speed exceeds a predetermined value, leading to deviations in estimated decelerating factors and prolonged estimation times.
Innovation Solution
A decelerating factor estimating device that adjusts its estimation process based on vehicle speed and acceleration thresholds, prioritizing the estimation of vehicle weight, air resistance coefficient, and road load, and stops estimation when vehicle behavior stability control is actuated or vehicle weight abnormalities are detected, to enhance accuracy and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the vehicle speed exceeds a predetermined value, then the estimation computation is prohibited to avoid errors, but the estimation time becomes excessively long
Solution Approach 1:
The patent dynamically adjusts the vehicle speed threshold for prohibiting estimation computation based on whether the vehicle weight is converging. When weight convergence is detected, the threshold is raised (e.g., from 40 km/h to 60 km/h), allowing estimation to continue at higher speeds. This dynamic adaptation resolves the contradiction by enabling time-efficient estimation under stable conditions while maintaining accuracy prohibitions when necessary.
Solution Approach 2:
The patent changes the parameter of the speed threshold based on the convergence state of vehicle weight estimation. By monitoring whether the estimated weight has stabilized (convergence detection), the system adjusts the speed threshold parameter accordingly, allowing the estimation process to operate at higher speeds when reliable, and prohibiting it when unreliable, thus balancing accuracy and time requirements.
2Measurement precision
If the estimation computation is prohibited when vehicle speed exceeds a predetermined value, then estimation accuracy is maintained, but the device complexity increases due to convergence detection requirements
Solution Approach 1:
The patent implements a feedback mechanism where the convergence state of vehicle weight estimation is continuously monitored and used to adjust the speed threshold for computation prohibition. The convergence detection unit provides feedback about estimation stability, which feeds back to the determination unit to dynamically set appropriate speed thresholds, creating a self-regulating system that balances accuracy and simplicity.
3Adaptability or versatility
If multiple decelerating factors are estimated simultaneously, then comprehensive vehicle control is achieved, but the estimation time increases
Solution Approach 1:
The patent segments the estimation process by prioritizing vehicle weight estimation first, then using the converged weight value to enable subsequent estimation of other decelerating factors like air resistance coefficient and road load. This sequential segmentation allows comprehensive multi-factor estimation while reducing total time by enabling factors to be estimated in stages rather than all simultaneously.
Data Source
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AI summary
A decelerating factor estimating device (1) configured to estimate a decelerating factor of a vehicle (2) includes a drive force acquiring unit (62) configured to acquire a drive force of the vehicle (2); a vehicle speed acquiring unit (60) configured to acquire a vehicle speed of the vehicle (2); an acceleration acquiring unit (61) configured to acquire an acceleration of the vehicle (2); and a decelerating factor estimating unit (63, 64, 65, 68) configured to estimate a plurality of decelerating factors based on a relationship of the acquired drive force, speed, and acceleration, wherein the decelerating factor estimating unit (63, 64, 65, 68) determines a type of the decelerating factor to estimate based on a traveling state of the vehicle, and at the time an estimated value of a first decelerating factor is converging, further widens a range of the traveling state of the vehicle to execute an estimation process of a second decelerating factor than a case where the estimated value of the first decelerating factor is not converging.