Sensor Timestamp Register for Low-Jitter Sample Synchronization
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Solution Overview
Problem
Current sensor technologies face challenges in accurately assigning measurement data to a precise measurement time due to timing jitter caused by mismatches between output data rate and readout data rate, leading to degraded accuracy in sensor fusion and increased power consumption and complexity.
Innovation Solution
Incorporating a sampling timer register in the sensor's digital backend to track the age of data samples and a sample counter to estimate real output data rate, allowing the control unit to reconstruct the data generation time and synchronize sensor data effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the readout data rate is increased to reduce timing jitter, then the timing precision is improved, but the power consumption and workload of the control unit increase
Solution Approach 1:
The sensor performs preliminary actions by generating timestamps at the moment of data sampling and storing them with the sensor data in the digital backend. This preliminary time stamping eliminates the need for the control unit to perform frequent readings to achieve timing precision, as the time information is already captured and stored with the data, thereby reducing the control unit's workload and power consumption while maintaining accurate timing information.
2Measurement precision
If the output data rate is increased to reduce timing jitter, then the timing precision is improved, but the noise on sensor data increases and hardware complexity increases
Solution Approach 1:
The invention segments the timing function by introducing a dedicated sample timer register that independently tracks sampling time, separate from the data rate generation. This segmentation allows the system to maintain accurate timing information without increasing the output data rate, thereby avoiding the associated noise and hardware complexity while still achieving precise timing for sensor data.
3Use of energy by moving object
If the sensor data is read asynchronously at a lower readout data rate, then the power consumption is reduced, but the timing jitter between data generation and readout increases
Solution Approach 1:
The invention implements feedback by storing the timestamp generated at sampling time with the sensor data in the digital backend. When the control unit reads the data asynchronously at a lower rate, it retrieves the pre-captured timestamp along with the data, allowing it to reconstruct the accurate sampling time without needing to read at the original data rate. This feedback mechanism maintains timing precision while enabling lower power consumption through asynchronous reading.
Data Source
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AI summary
The invention relates to a sensor having a detection element, an analogue frontend and a digital backend; wherein the digital backend is to be connected to a control unit via a digital interface, wherein the sensor provides sampled data in the digital backend. The sensor contains means for providing time information relating to the sampled data in the digital backend, which information can be accessed by the control unit by means of the digital interface. The invention also relates to a method for assigning an item of time information to sampled measurement data from a sensor.