Dynamic Tire Circumference Estimation Using Kalman Filtering
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Solution Overview
Problem
Existing methods for determining tire circumference in vehicles are imprecise due to dynamic influences such as tire slip, temperature, and load fluctuations, which affect the accuracy of parking and maneuvering operations.
Innovation Solution
A method using a Kalman filter to calculate dynamic tire circumference based on yaw rate, wheel speed, steering angle, and dynamic track width, allowing for real-time adjustments and improved accuracy in driving maneuvers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If predefined values for tire circumference and track width are used, then the device complexity is reduced, but the measurement precision deteriorates due to dynamic influences during driving
Solution Approach 1:
The patent applies dynamics by transitioning from static predefined values to dynamic real-time determination of tire circumference and track width. The system continuously calculates these parameters during driving operations using sensor data and geometric relationships, allowing the values to adapt to changing driving conditions such as tire deformation, load variations, and steering angles, thereby maintaining measurement precision without excessive complexity increase
Solution Approach 2:
The patent implements feedback by using measured driving parameters (wheel speeds, steering angles, vehicle positions) to continuously update and refine the tire circumference and track width values. This closed-loop approach allows the system to compensate for dynamic influences and maintain accurate measurements throughout the driving cycle
2Measurement precision
If real-time dynamic determination of tire circumference is implemented, then the measurement precision is improved, but the device complexity increases due to additional sensors and calculations
Solution Approach 1:
The patent applies universality by utilizing existing multi-functional sensors and control units already present in modern vehicles. The system uses standard sensors (wheel speed sensors, steering angle sensors, GPS receivers) for their primary purposes while simultaneously leveraging their data for tire circumference determination, thereby avoiding additional dedicated hardware and reducing overall device complexity
Solution Approach 2:
The patent implements self-service by having the vehicle's existing control units and processing systems perform the additional calculations for tire circumference determination. The vehicle's onboard computer utilizes its existing computational resources to process sensor data and calculate dynamic parameters, eliminating the need for separate dedicated processing hardware
3Productivity
If dynamic tire circumference values are used in parking assistance systems, then the productivity of parking maneuvers is improved through higher accuracy, but the loss of time increases due to real-time calculations
Solution Approach 1:
The patent applies preliminary action by continuously calculating and maintaining updated tire circumference values during normal driving operations before parking maneuvers are initiated. This ensures that accurate dynamic values are already available when parking assistance is activated, eliminating calculation delays during the actual parking operation and improving overall productivity
Solution Approach 2:
The patent implements continuity of useful action by maintaining continuous real-time calculation of tire circumference values throughout all driving operations. This uninterrupted calculation ensures that accurate values are always available for immediate use in parking maneuvers without requiring additional processing time, thereby maintaining high productivity
Data Source
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AI summary
The present invention relates to a method and a device for determining a dynamic tyre circumference of a means of transport. The method comprises the following steps: receiving a first signal (S1) representing a yaw rate of the means of transport, a second signal (S2) representing a wheel rotation speed of a wheel of the means of transport, a third signal (S3) representing a steering angle of the means of transport, and a fourth signal (S4) representing a dynamic track width of the means of transport; determining a first output signal (A1) of a first Kalman filter (K1) representing the dynamic tyre circumference of the wheel using the first signal (S1), the second signal (S2), the third signal (S3) and the fourth signal (S4) as input signals for the first Kalman filter (K1); and using the first output signal (A1) in a control unit of the means of transport.