Six-Channel Digitizer Time Alignment for Inertial Sensor Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inertial navigation systems face errors due to time misalignment of sensor samples from analog sensors, leading to inaccuracies in estimating the position, orientation, and velocity of a mobile device, especially when using time multiplexed systems which introduce complexity, power consumption, and latency.
Innovation Solution
A method involving a six-channel digitizer that delays the digitization of analog signals from sensors to align digital output signals in time, effectively eliminating systematic delays and errors caused by different processing times of various sensors, allowing for concurrent acquisition of critical navigation signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different analog sensors utilize filters with different processing delays, then each sensor can be optimized for its specific function, but the sensor outputs become time-misaligned leading to navigation errors
Solution Approach 1:
The patent applies preliminary action by calculating the processing delays of each sensor channel in advance and storing these delay values. Before digitization, the system uses these pre-calculated delay values to determine the appropriate sampling offsets for each channel, ensuring that all sensor outputs are time-aligned at the digitizer without requiring real-time delay compensation.
2Device complexity
If a time multiplexed system is used to acquire sensor data, then device complexity is reduced, but latency increases and measurement accuracy deteriorates due to time misalignment
Solution Approach 1:
The patent applies segmentation by dividing the sensor acquisition system into multiple independent concurrent channels, each dedicated to a specific sensor type (accelerometer, gyroscope, magnetometer). Each channel has its own analog-to-digital converter that operates simultaneously, eliminating the time multiplexing bottleneck while maintaining manageable system complexity through modular channel design.
3Measurement precision
If multiple analog-to-digital converters are used to simultaneously digitize sensor signals, then time alignment is achieved, but device complexity and power consumption increase
Solution Approach 1:
The patent applies universality by designing a multi-functional digitizer architecture that can handle multiple sensor channels simultaneously using a shared control mechanism. The system uses a single master clock and control logic to coordinate multiple ADCs, allowing them to operate in parallel with minimal overhead, thereby reducing power consumption compared to fully independent ADC systems while maintaining time alignment.
Data Source
AI summary
The subject matter disclosed herein relates to a system and method for receiving a plurality of signals generated by a plurality of sensors adapted to detect physical movement of a mobile device with respect to a plurality of coordinate axes. A time at which at least one of the received signals is digitized is delayed to provide an output of digitized versions of the received plurality of signals synchronized with respect to a common point in time.