Yaw Rate Offset Calculation via Signal Threshold Monitoring
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Solution Overview
Problem
Existing methods for determining the offset of yaw rate sensors in vehicles lack precision and do not account for factors like temperature drift and aging, and fail to provide a method for repeated offset calculation during vehicle use.
Innovation Solution
A method involving a control unit that monitors pinion angle, wheel speed, and yaw rate signals, waiting for these signals to be below thresholds for specific time periods, then calculates and stores the average yaw rate as offset, allowing for repeated precise determination and compensation for temperature changes and other influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the offset is calculated using the average yaw rate signal value, then the calculation is simple, but the precision is low and does not account for temperature drift and aging
Solution Approach 1:
The system performs preliminary checks before offset calculation by monitoring vehicle speed, steering angle, and yaw rate signals. It waits for specific conditions (vehicle at rest or moving straight, steering wheel centered) to be met for a predetermined time period before initiating the offset calculation, ensuring high precision while maintaining simplicity
Solution Approach 2:
The system changes the parameters used for offset calculation from simple time-averaged yaw rate to a multi-parameter approach considering vehicle speed, steering angle, yaw rate signal, and temporal conditions. This allows precise offset determination that accounts for temperature drift and aging effects
2Measurement precision
If the offset calculation is performed continuously, then the precision is improved, but the computational load and system complexity increase
Solution Approach 1:
The system performs offset calculation periodically rather than continuously, triggered only when specific conditions are met (vehicle at rest or moving straight, steering wheel centered). This reduces computational load and system complexity while maintaining high precision through repeated updates during normal vehicle operation
3Measurement precision
If the offset calculation requires specific vehicle conditions (at rest or moving straight), then the precision is improved, but the frequency of offset updates decreases
Solution Approach 1:
The system ensures continuous useful action by monitoring vehicle conditions constantly and immediately performing offset calculation whenever the required conditions (vehicle at rest or moving straight, steering wheel centered) are met. This maintains high precision while maximizing update frequency within the constraints of physical vehicle operation conditions
Data Source
Figure 1~2
AI summary
The present invention relates to a method for calculating the offset of a yaw rate signal, wherein the method comprises the following steps: a. Observing the pinion angle signal p, the at least one wheel speed signal w, and the yaw rate signal y, for a time t; b. If the pinion angle speed signal p is below a threshold pmax, and the wheel speed signal w is below a threshold wmax, and the yaw rate signal y is below a threshold ymax, the start a waiting time t1; c. If after t1 the signals p, w and y are still below their thresholds, then start a calculation for a time t2 of the yaw rate offset yo, wherein the average yaw rate ya is acquired for a time t2; and d. If during t2 the signals p, w and y remain below their thresholds, then the average yaw rate ya is stored as yaw rate offset yo; e. If the signals p, w and y still remain below their thresholds, then proceed to step c, if at least one of the signals p, w and y exceeded the respective thresholds, then proceed to step a.