Multi-Pulse LiDAR Distance Sensing for Noise-Resistant Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LiDAR systems face challenges in accurately measuring distances due to noise interference and signal processing limitations, particularly in environments with complex reflections.
Innovation Solution
The implementation of a silicon photomultiplier (SiPM) integrated on a semiconductor substrate, combined with a control circuit that identifies reflected light pulses and measures distance based on time differences between successive emission pulses, utilizing a digital processing section with filters to enhance signal reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional light detectors are used in LiDAR systems, then the device structure is simpler, but noise interference increases and measurement precision deteriorates
Solution Approach 1:
The patent changes the operational parameters of the light detector by applying variable bias voltages during different phases (integration phase, transfer phase, reset phase). This parameter modulation enables the detector to differentiate between signal photons and noise photons, thereby reducing noise interference and improving distance measurement accuracy without requiring a completely different detector architecture.
2Reliability
If multiple pulses are emitted for distance measurement, then measurement reliability improves, but the complexity of identifying reflected light pulses increases
Solution Approach 1:
The patent implements a feedback mechanism where the control circuit monitors the detection results from multiple pulses and uses this information to identify and select valid reflected light pulses. The system compares detection results across multiple pulses, identifies consistent returns, and uses this feedback to determine the most reliable distance measurement, thereby managing the complexity of multi-pulse signal processing.
Solution Approach 2:
The patent performs preliminary actions by pre-defining integration periods for each pulse and pre-establishing the relationship between emission pulses and detection windows. This preliminary configuration allows the system to efficiently process multiple pulses without real-time complex decision-making, reducing the operational complexity while maintaining high reliability.
3Reliability
If integration time is extended to improve signal detection, then signal reliability improves, but the response time increases and productivity decreases
Solution Approach 1:
The patent employs periodic action by dividing the measurement process into discrete integration periods corresponding to each emitted pulse. Each integration period is optimized for a specific pulse return window, allowing the system to accumulate signal over multiple periodic cycles without extending the total measurement time excessively. This periodic structure maintains both signal reliability and measurement speed.
Solution Approach 2:
The patent segments the total integration time into multiple separate integration periods, each associated with a specific pulse emission and return window. This segmentation allows parallel processing of multiple pulses and enables the system to achieve high signal reliability through cumulative integration while maintaining fast response by processing segments concurrently rather than sequentially.
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
Enhances distance measurement accuracy by reducing noise interference and improving signal processing, enabling precise distance calculations even in complex environments.
Implementation Method 1
LiDAR illuminates a target with laser light and detects a strength of reflected light from the target with a sensor
Implementation Method 2
detects a strength of reflected light from the target with a sensor (light detector)
Implementation Method 3
measures a distance to the target based on a change over time in a light intensity signal output from the sensor
Data Source
AI summary
A distance measurement device includes a light source; an optical system configured to emit emission light from the light source and to receive reflected light of the emission light; a plurality of pixels configured to detect the received reflected light, each including at least one sensor, and arranged in a pixel area on a substrate; and a control circuit. The control circuit is configured to: identify first reflected light detected in a first pixel in association with first emission light; and measure a distance based on a time difference between the first emission light and the identified first reflected light. The first emission light includes a first, second, and third pulse in succession. A first interval between the first and second pulse differs from a second interval between the second and third pulse.