Wheel Speed Sensor Offset Compensation Without Signal Interruption
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Solution Overview
Problem
Existing methods for detecting and compensating signal errors in wheel speed sensors used in automotive electronic braking systems often require interruption of signal transmission, which is unsafe and prevents error detection during vehicle operation.
Innovation Solution
A non-invasive method using a shift register, averaging unit, and low-pass filter to detect and compensate for signal errors without interrupting the signal transmission, allowing for continuous error detection and correction by calculating the difference between the first and last elements of the shift register and determining the offset using a reference current value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If invasive measurement methods are used to check the WSS transmission channel, then measurement precision is improved, but signal transmission continuity deteriorates due to interruption
Solution Approach 1:
The patent replaces invasive physical measurement methods with a digital signal processing approach. Instead of interrupting signal transmission to measure channel parameters physically, the system uses digital correlation algorithms to continuously analyze the sensor signal and detect errors non-invasively, thereby maintaining signal continuity while achieving measurement precision
Solution Approach 2:
The patent introduces a correlation algorithm as an intermediary between the sensor signal and error detection process. This intermediary processes the signal digitally without requiring physical interruption or decoupling of the transmission channel, enabling continuous error detection while preserving signal integrity
2Measurement precision
If measurement is performed outside safety-critical periods, then measurement precision is improved by avoiding interference, but productivity deteriorates due to limited measurement windows
Solution Approach 1:
The patent enables continuous error detection by performing correlation-based analysis on every incoming sensor signal sample. This eliminates the need to wait for non-safety-critical periods, as the measurement process itself does not interfere with signal transmission or system operation, thereby improving both precision and productivity simultaneously
3Measurement precision
If decoupling of signal transmission is implemented for measurement, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent eliminates the need for physical decoupling mechanisms by replacing invasive measurement hardware with digital signal processing. The correlation algorithm operates on the existing signal transmission path without requiring additional decoupling components, switches, or isolation mechanisms, thereby reducing device complexity while maintaining measurement precision
Data Source
AI summary
An offset compensation device, a sensor device and a method for offset compensation for sensor signals are described. The offset compensation device comprises a shift register containing elements in a number, an averaging unit and a low-pass filter. The method involves storing sensor values in the shift register, calculating a difference between the first element of the shift register and the last element of the shift register, determining multiple mean values, determining the lowest signal level using the low-pass filter, determining the offset by calculating the difference between the lowest signal level and a reference current value, and correcting the sensor values using the determined offset. Determining the mean values comprises starting averaging when the difference between the first element of the shift register and the last element of the shift register is greater than a threshold value, and stopping when the difference is less than the threshold value.