Vehicle Range Calculation with Dynamic Tire Rolling Resistance
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Solution Overview
Problem
Existing methods for determining a vehicle's range value fail to accurately account for changes in the rolling resistance coefficient of tires over time, leading to inaccuracies in estimating the actual range a vehicle can achieve, especially considering the energy available for movement.
Innovation Solution
The method involves determining a dynamic rolling resistance coefficient by taking into account the static rolling resistance coefficient, tire pressure, temperature, current tread depth, and other factors such as ambient temperature, wheel load, air resistance, slope resistance, acceleration resistance, rolling resistance, propulsion efficiency, and wheel-specific drive energy to accurately calculate the range value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the static rolling resistance coefficient is used for range determination, then the calculation is simple, but the accuracy deteriorates as tire service life increases
Solution Approach 1:
The patent transitions from using a static rolling resistance coefficient to a dynamic rolling resistance coefficient that changes over time based on tire wear. The dynamic coefficient is determined as a function of the static coefficient and a wear factor that increases with tire service life, allowing the range determination to adapt to the actual tire condition while maintaining a relatively simple calculation approach.
Solution Approach 2:
The patent introduces a wear factor as a new parameter that modifies the static rolling resistance coefficient to obtain the dynamic rolling resistance coefficient. This parameter change accounts for tire degradation over time, enabling more accurate range determination without requiring completely new measurement systems.
2Ease of operation
If tire wear is not considered, then the determination process is simple, but the actual range cannot be accurately determined
Solution Approach 1:
The patent determines the wear factor in advance based on tire service life or mileage before using it to calculate the dynamic rolling resistance coefficient. This preliminary determination of the wear factor allows the system to account for tire degradation without adding complexity to the actual range determination process.
Solution Approach 2:
The wear factor acts as an intermediary parameter that bridges the gap between simple static coefficient measurements and the complex reality of tire degradation. By introducing this intermediate factor, the patent enables accurate range determination while keeping the overall process relatively simple.
Data Source
Figure 1
AI summary
The invention relates to a method for determining the range of a vehicle (1), comprising the following steps: - providing a vehicle (1), wherein the vehicle (1) has at least one vehicle tire (2); - providing an evaluation device (3), wherein the evaluation device (3) is suitable for determining the range of the vehicle (1) as a function of the energy available for the movement of the vehicle (1) and as a function of the rolling resistance coefficient of the at least one vehicle tire (1); - determining a static rolling resistance coefficient of the at least one vehicle tire (2); - determining the range of the vehicle (1) as a function of the static rolling resistance coefficient and the energy available for the movement of the vehicle (1); - determining a pressure prevailing in an interior (4) of the at least one vehicle tire (4);- Determining the temperature of at least one vehicle tire (2); - Determining the current tread depth of at least one vehicle tire (2); - Determining the dynamic rolling resistance coefficient of at least one vehicle tire (2) as a function of the static rolling resistance coefficient, pressure, temperature, and current tread depth; - Changing the vehicle's range value (1) as a function of the dynamic rolling resistance coefficient of at least one vehicle tire (2).