Dynamic ADC Sampling for TOF Distance Measurement
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Solution Overview
Problem
Existing distance measurement systems using Analog to Digital Converters (ADC) for Time of Flight (TOF) measurements face high power consumption and large memory requirements due to long sampling periods, limiting their range and temporal resolution.
Innovation Solution
The system determines an estimated time of arrival for measurement pulses, triggering the ADC to sample at a high resolution only prior to this time, with the sampling period fixed to capture the pulses, reducing power consumption and memory needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If ADC-based TOF measurement uses a long sampling period to cover a large TOF range, then the distance measurement range is extended, but power consumption increases and memory requirements increase
Solution Approach 1:
The system performs a preliminary coarse measurement phase to estimate the time of arrival of the measurement pulses. Based on this preliminary estimation, the system triggers the high-resolution ADC sampling only in the time window just prior to the anticipated arrival, rather than maintaining continuous sampling throughout the entire TOF range. This preliminary action enables the system to achieve large measurement ranges while minimizing power consumption and memory usage.
2Length of stationary object
If ADC-based TOF measurement uses a long sampling period to cover a large TOF range, then the distance measurement range is extended, but memory requirements increase
Solution Approach 1:
The system performs a preliminary coarse measurement phase to estimate the time of arrival of the measurement pulses. Based on this preliminary estimation, the system triggers the high-resolution ADC sampling only in the time window just prior to the anticipated arrival, rather than maintaining continuous sampling throughout the entire TOF range. This preliminary action enables the system to achieve large measurement ranges while minimizing power consumption and memory usage.
3Length of stationary object
If ADC-based TOF measurement uses a long sampling period to cover a large TOF range, then the distance measurement range is extended, but temporal resolution is limited
Solution Approach 1:
The measurement process is divided into two distinct phases: a coarse measurement phase that covers the entire TOF range to estimate pulse arrival time, and a fine measurement phase that uses high-resolution ADC sampling only during the critical time window just prior to the anticipated pulse arrival. This segmentation allows the system to achieve both large measurement ranges and high temporal resolution simultaneously.
Solution Approach 2:
The ADC sampling window is made dynamic rather than static. The system adjusts the timing and duration of the high-resolution sampling window based on the preliminary estimation of pulse arrival time. This dynamic adaptation allows the system to concentrate sampling resources precisely when needed, achieving high temporal resolution within the context of a large measurement range.
4Length of stationary object
If ADC-based TOF measurement uses a long sampling period to cover a large TOF range, then the distance measurement range is extended, but system cost increases
Solution Approach 1:
The system performs a preliminary coarse measurement phase to estimate the time of arrival of the measurement pulses. Based on this preliminary estimation, the system triggers the high-resolution ADC sampling only in the time window just prior to the anticipated arrival, rather than maintaining continuous sampling throughout the entire TOF range. This preliminary action enables the system to achieve large measurement ranges while minimizing power consumption and memory usage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach lowers power consumption, reduces memory requirements, and enables faster tracking without increasing system cost or power consumption, while maintaining accurate distance measurements across a large range.
Implementation Method 1
an ultrasonic transducer to measure Time of Flight (TOF) of a signal
Implementation Method 2
an ultrasonic transducer to measure Time of Flight (TOF) of a signal
Data Source
AI summary
An electronic device and methods for providing high resolution ranging measurements are disclosed. The electronic device includes a pulse generator, a memory, an ADC, a timer, a comparator, a processing unit, connectors for coupling to a transceiver and instructions stored in the memory. The instructions, when performed by the processing unit, performs a method that determines an estimated time of arrival of a series of measurement pulses in the signal and turns on, prior to the estimated time of arrival, the ADC to capture the series of measurement pulses using a first resolution provided by sampling the signal at a rate equal to or greater than the Nyquist rate. The ADC remains on for a fixed time period sized to capture the series of measurement pulses.