Time-of-Flight Sensor Calibration With Fiber Optic Phase Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight (TOF) sensors are affected by environmental factors and sensor configurations, leading to inaccuracies in distance measurements due to phase delays, temperature effects, and undefined optical paths, which are difficult to control and estimate, resulting in calibration challenges.
Innovation Solution
A calibration system using a fiber optic cable as a defined path for light signals, combined with diffusers to create a homogenized phase front, which calibrates each pixel of the TOF sensor, compensating for pixel-to-pixel variations and thermal effects, even after assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional calibration methods are used without controlled optical paths, then the calibration process is simpler, but measurement precision deteriorates due to undefined optical paths and environmental interference
Solution Approach 1:
A fiber optic cable is introduced as an intermediary element to define a controlled optical path between the light source and the TOF sensor. This mediator enables precise calibration by eliminating undefined optical paths and environmental interference, directly resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The calibration system creates a controlled, isolated optical environment using the fiber optic cable and enclosure to protect the measurement path from external factors such as ambient light and temperature variations. This inert optical environment ensures consistent and accurate calibration results
2Measurement precision
If no phase front equalization is performed, then the calibration process is faster, but measurement precision deteriorates due to pixel-to-pixel variations and thermal effects
Solution Approach 1:
The system changes the optical parameter of phase front uniformity by introducing diffusers that transform the light into a homogenized phase front. This parameter change equalizes the optical path length across different pixels, compensating for pixel-to-pixel variations and thermal effects, thereby improving depth map precision
Solution Approach 2:
Diffusers are employed to create a homogenized phase front that is uniform across the sensor array. This homogeneity ensures that all pixels receive equal optical conditions, eliminating pixel-to-pixel variations and improving measurement precision without requiring complex individual pixel calibration
3Measurement precision
If environmental factors are not controlled during calibration, then the calibration process is more practical, but measurement precision deteriorates due to temperature and ambient light effects
Solution Approach 1:
The calibration system creates a controlled optical environment using an enclosure and fiber optic cable to isolate the measurement path from external factors such as ambient light and temperature variations. This inert optical environment ensures consistent and accurate calibration results while maintaining practical operability
Solution Approach 2:
The fiber optic cable acts as a mediator that decouples the calibration process from environmental factors. By routing light through the fiber, the system eliminates the influence of ambient light and temperature on the optical path, enabling accurate calibration in practical settings
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 provides accurate and reliable calibration of TOF sensors by equalizing phase fronts, reducing pixel-to-pixel variations and thermal impacts, ensuring consistent and precise depth map generation.
Implementation Method 1
A calibration system using a fiber optic cable as a defined path for light signals
Implementation Method 2
combined with diffusers to create a homogenized phase front
Implementation Method 3
a time-of-flight (TOF) sensor can be used to measure distance to one or more objects in an environment
Data Source
AI summary
Systems and techniques are provided for calibrating time-of-flight (TOF) sensors. An example method can include sending, from a TOF sensor system coupled to a calibration assembly, a light signal to a fiber optic cable coupled to the calibration assembly; receiving, by the calibration assembly, the light signal from the fiber optic cable; diffusing the light signal via one or more diffusers on the calibration assembly; generating, by the TOF sensor system, one or more measurements based on the diffused light signal; and based on the one or more measurements, determining one or more calibration values configured to compensate for one or more errors in the one or more measurements.