Sensor Clock Correction for Stable Airbag Data Transmission
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Solution Overview
Problem
Current methods for data transmission between sensor units and control units in airbag systems, such as those using the PSI5 standard, face limitations due to oscillator clock deviations, leading to potential data collisions and instability, especially in synchronous communication modes, which can result in safety issues during vehicle operations.
Innovation Solution
A method and device that correct transmission parameters by comparing the sensor clock signal with a reference clock signal, allowing for adaptive adjustments to maintain stable data transmission even with oscillator clock deviations, using a correction factor and an oscillator monitor to ensure fault-free communication across various communication modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the sensor oscillator clock deviation is allowed to vary over service life, then the adaptability of the communication system is improved, but the reliability of data transmission deteriorates due to potential data collisions
Solution Approach 1:
The patent dynamically adjusts transmission parameters (data rate, number of time slots, bit length) based on the measured oscillator clock deviation. The control unit determines the actual clock frequency of the sensor and modifies communication parameters accordingly to prevent data collisions while maintaining reliable transmission across varying operational conditions and service life.
2Productivity
If the data rate is increased to improve communication efficiency, then the productivity is improved, but the stability of transmission deteriorates due to tighter timing constraints and increased susceptibility to clock deviation
Solution Approach 1:
The patent implements dynamic adaptation of transmission parameters based on real-time oscillator performance monitoring. The system can switch between different data rates and time slot configurations depending on the measured clock deviation, allowing high-speed transmission when the oscillator is stable and automatic degradation to more robust, lower-speed modes when deviation increases, thus maintaining stability across varying conditions.
3Quantity of substance
If the number of bus users is increased to improve system capacity, then the quantity of substance is improved, but the reliability of transmission deteriorates due to increased probability of data collisions
Solution Approach 1:
The patent adjusts communication parameters including the number of time slots and data rate based on the number of active bus users and their oscillator characteristics. By monitoring clock deviations across multiple sensors and adapting the transmission scheme accordingly, the system can accommodate more bus users while maintaining reliable transmission through coordinated parameter optimization.
Data Source
AI summary
A method corrects at least one transmission parameter for data transmission between a sensor unit and a control unit. A sensor timing signal is generated by a sensor oscillator with a predetermined period. The at least one transmission parameter is determined on the basis of the sensor timing signal. A reference timing signal is generated by a reference oscillator with a predefined reference period. The sensor timing signal is compared with the reference timing signal. A deviation of a current period of the sensor timing signal from a reference period is determined on the basis of the comparison. The at least one transmission parameter is corrected on the basis of the determined deviation.