LiDAR Light Detection Circuit for Crosstalk and Pulse Sampling
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Solution Overview
Problem
Current LiDAR systems face challenges with crosstalk interference, unnecessary power consumption, and reduced detection accuracy due to the constant operation of photodetectors in non-measurement channels and the inefficiency of high-speed ADCs in sampling pulse signals with low duty cycles.
Innovation Solution
A light detection circuit with an array of photodetector units and switches that selectively activate only the required photodetectors, reducing interference and power consumption, and a pulse signal peak detection system using a multi-channel sampling and holding circuit with a medium to low-speed ADC for improved sampling accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If photodetectors in non-measurement channels remain constantly operational, then the system maintains readiness for multi-channel detection, but crosstalk interference increases and power consumption rises
Solution Approach 1:
The patent implements dynamic control of photodetector operation states through switch units. Each photodetector can be dynamically switched between operational and non-operational states based on whether its corresponding channel is currently being measured. This dynamic state management eliminates crosstalk interference from non-measurement channels while maintaining the ability to quickly activate any channel when needed, thus resolving the contradiction between detection readiness and crosstalk prevention.
2Adaptability or versatility
If photodetectors in non-measurement channels remain constantly operational, then the system maintains detection capability across all channels, but unnecessary power consumption increases
Solution Approach 1:
The patent employs dynamic power management by controlling the operational state of each photodetector through switch units. When a channel is not currently being measured, its photodetector is switched off to eliminate unnecessary power consumption. The system maintains adaptability by能够快速激活任何通道当需要时，从而在保持多通道检测能力的同时显著降低功耗。
Solution Approach 2:
The patent implements periodic activation of photodetectors based on measurement requirements. Instead of continuous operation, each photodetector is activated only during its designated measurement period and deactivated otherwise. This periodic action pattern maintains the system's ability to perform multi-channel detection while dramatically reducing overall power consumption by ensuring that at any given time, only the necessary photodetectors are operational.
3Speed
If high-speed ADC is used for sampling pulse signals with low duty cycles, then sampling rate is sufficient, but sampling accuracy decreases when echo pulses are close
Solution Approach 1:
The patent implements a pre-sampling preparation stage where the sampling and holding circuit is ready before the actual pulse arrives. The circuit includes a holding capacitor that is pre-charged and ready to capture the pulse signal. This preliminary preparation ensures that when the pulse arrives, even if it's close to another pulse, the circuit is in the optimal state to accurately capture and hold the signal peak, thereby improving sampling accuracy without requiring excessively high sampling rates.
Solution Approach 2:
The patent introduces a sampling and holding circuit as an intermediary between the ADC and the pulse signal. This intermediary circuit captures the pulse signal and holds its peak value, allowing the ADC to accurately convert the signal even at moderate sampling rates. The holding function ensures that the pulse information is preserved and ready for conversion, improving measurement precision without sacrificing sampling speed.
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 solution prevents crosstalk, reduces energy waste, and enhances detection accuracy by selectively activating photodetectors and using a multi-channel sampling system to effectively sample pulse signals even when echo pulses are close, thereby improving the overall performance of LiDAR systems.
Implementation Method 1
an array of photodetector units including a plurality of photodetector units for receiving light signals and generating corresponding electrical signals
Data Source
AI summary
A light detector comprising: an array of photodetectors for receiving light signals and generating electrical signals corresponding to the light signals, an array of switches comprising a plurality of first switches, each of the plurality of first switches couples to a respective one of the array of photodetectors, and each of the plurality of first switches is configured to control an operating state of the respective one of the array of photodetectors for a signal output terminal of the respective one of the array of photodetectors to output the electrical signals, and a selector configured to select the respective one of the array of photodetectors in the operating state to output the electrical signals.