Phase Offset Compensation in Time-of-Flight Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight imaging systems face inaccuracies in distance measurement due to temperature-induced phase offsets between illumination and sensor systems, which can take several minutes to stabilize, affecting the precision and speed of depth mapping.
Innovation Solution
A compensation component calculates a phase offset using remote temperature measurements and a model representing transient heat flow, allowing for faster convergence to accurate phase offset values, even during temperature transitions, by considering the time derivative of the measured temperature and thermal time constants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature measurements are taken directly at the driver location, then the phase offset calculation is accurate, but the measurement time is long due to slow thermal stabilization
Solution Approach 1:
The patent places temperature sensors at strategic locations that experience temperature changes earlier than the driver location, allowing the system to predict and compensate for thermal drift before it affects the driver. This preliminary detection enables faster phase offset correction without waiting for full thermal stabilization at the driver location.
Solution Approach 2:
The patent introduces remote temperature sensors as intermediary measurement points that correlate with driver temperature through thermal modeling. These sensors serve as proxies, providing timely temperature data that is then used to calculate phase offset corrections, effectively decoupling the measurement location from the critical driver location.
2Measurement precision
If the system waits for thermal stabilization before measurement, then measurement accuracy is high, but the productivity is low
Solution Approach 1:
The patent implements a feedback mechanism where remote temperature sensors continuously monitor thermal conditions and feed this information to a phase offset compensation algorithm. The system dynamically adjusts phase offset values based on real-time temperature data, maintaining measurement accuracy without requiring thermal stabilization, thus enabling continuous operation and improved productivity.
Solution Approach 2:
The patent changes the measurement parameter from direct driver temperature to remotely sensed temperature that correlates with driver temperature through a thermal model. This parameter transformation allows the system to obtain timely temperature information from locations that stabilize faster, maintaining accuracy while reducing wait time and increasing operational speed.
3Device complexity
If temperature sensors are placed remote from drivers, then the system complexity is reduced, but the measurement accuracy deteriorates
Solution Approach 1:
The patent uses a thermal model as an intermediary that mathematically relates remote sensor readings to driver temperature. This model compensates for the spatial separation between sensors and drivers, maintaining measurement accuracy while allowing simple, non-intrusive sensor placement that reduces system complexity.
Solution Approach 2:
The patent replaces the mechanical approach of placing sensors directly at driver locations with a computational approach using thermal modeling. This substitution allows remote sensing while maintaining accuracy through algorithmic compensation, simplifying the physical sensor placement while preserving measurement precision.
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
The system achieves accurate and rapid stabilization of phase offset calculations, reducing measurement inaccuracies and enabling timely adjustments during power changes or temperature fluctuations, thus improving the speed and precision of distance determination in time-of-flight imaging.
Implementation Method 1
A temperature sensor is configured to provide a measured temperature representing a temperature at one of the illumination driver or the sensor driver and located at a position remote from the one of the illumination driver and the sensor driver
Implementation Method 2
A compensation component is configured to calculate a phase offset between the illumination system and the sensor system from at least the measured temperature and a model representing transient heat flow within the system
Data Source
AI summary
Systems and methods are provided for imaging a surface via time of flight measurement. An illumination system includes an illumination driver and an illumination source and is configured to project modulated electromagnetic radiation to a point on a surface of interest. A sensor system includes a sensor driver and is configured to receive and demodulate electromagnetic radiation reflected from the surface of interest. A temperature sensor is configured to provide a measured temperature representing a temperature at one of the illumination driver and the sensor driver and located at a position remote from the one of the illumination driver and the sensor driver. A compensation component is configured to calculate a phase offset between the illumination system and the sensor system from at least the measured temperature and a model representing transient heat flow within the system.