Driving Resistance Prediction From Insufficient Tire Warm-Up
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Solution Overview
Problem
Current methods for measuring driving resistance, such as rolling resistance and inertia resistance, require a lengthy warm-up process, which is inefficient and time-consuming, making it challenging to accurately measure these resistances in an insufficient warm-up state.
Innovation Solution
A method that involves measuring driving data during constant-speed and acceleration sections in an insufficient warm-up state, using a relational expression to predict rolling resistance and inertia resistance based on the change slope and magnitude of rolling resistance, allowing for determination of these resistances without a full warm-up process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full warm-up process is performed to reach equilibrium rolling resistance, then measurement accuracy is improved, but measurement time increases significantly
Solution Approach 1:
The patent applies preliminary action by performing a brief warm-up period (e.g., 30 seconds to 2 minutes) before measurement rather than the traditional full warm-up (1-1.5 hours). This preliminary warming of the tire allows the system to capture the rolling resistance change rate and predict equilibrium values without completing the full warm-up process, thus reducing time loss while maintaining measurement accuracy within acceptable error margins (5% or less).
Solution Approach 2:
The patent uses copying by measuring rolling resistance during the insufficient warm-up state and using the change rate to predict (copy) the equilibrium rolling resistance value that would be obtained after full warm-up. This predictive approach creates a virtual copy of the equilibrium state without requiring the actual time-consuming warm-up process to complete.
2Loss of time
If rolling resistance is measured during insufficient warm-up state, then measurement time is reduced, but measurement stability deteriorates due to continuous changes in rolling resistance
Solution Approach 1:
The patent applies feedback by continuously monitoring the rolling resistance change rate during the measurement process. The system calculates the rate of change of rolling resistance with respect to time (dFf/dt) and uses this feedback information to predict the equilibrium value. This feedback mechanism allows the system to compensate for the instability inherent in the insufficient warm-up state and derive accurate equilibrium predictions.
Solution Approach 2:
The patent embraces dynamics by explicitly accounting for the dynamic nature of rolling resistance during warm-up. Rather than assuming static equilibrium conditions, the method captures the dynamic change rate and uses it to predict the eventual equilibrium state. This dynamic approach allows measurements to be taken during the transition period rather than waiting for static equilibrium.
3Productivity
If a brief warm-up period is used instead of full warm-up, then productivity is improved, but measurement precision may be compromised
Solution Approach 1:
The patent uses copying to predict the equilibrium rolling resistance value based on measurements taken during the brief warm-up period. By calculating the change rate and extrapolating to predict the equilibrium value, the system creates an accurate copy of what the measurement would be after full warm-up, thereby maintaining precision while improving productivity.
Solution Approach 2:
The patent applies parameter changes by shifting from measuring the absolute rolling resistance value at equilibrium to measuring the rate of change of rolling resistance during the warm-up process. This parameter transformation allows the system to use brief warm-up data to predict equilibrium values, thereby improving measurement efficiency without sacrificing accuracy.
Data Source
AI summary
A method for determining driving resistance in an insufficient warm-up state includes measuring driving data including at least first rolling resistance when a vehicle travels to include at least one constant-speed driving section in an insufficient warm-up state and determining a second rolling resistance based on the first rolling resistance measured in the constant-speed driving section, wherein the second rolling resistance is a rolling resistance predicted in the sufficient warm-up state.