Lidar Ranging Method Using Circular Signal Allocation
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Solution Overview
Problem
Frequency modulated continuous wave (FMCW) and time of flight (TOF) LIDAR systems face limitations in detection efficiency due to long dwelling times required for large detection ranges, leading to a low number of detection points per second and high system costs associated with multiple light detectors.
Innovation Solution
A LIDAR ranging method that circularly allocates periodic signals to each light channel in chronological order, allowing for simultaneous transmission and reception without waiting for previous signals to return, using a light routing device to monitor beat signals or return delay times to calculate target distances, reducing the need for multiple detectors and increasing detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single light detector is used per laser beam channel, then system cost is reduced, but detection efficiency remains limited by long dwelling time
Solution Approach 1:
The patent divides the detection process into multiple channels, with each channel having its own light detector. The transmit signal is segmented into multiple periodic signals that are circularly allocated to different channels in chronological order. This segmentation allows parallel processing of multiple detection points simultaneously, improving detection efficiency while maintaining cost-effectiveness through the use of a finite number of detectors rather than requiring one detector per detection point.
Solution Approach 2:
The patent employs periodic allocation of transmit signals to different channels in a circular manner. Each channel receives periodic signals at different time intervals, allowing the system to sequentially activate multiple channels. This periodic action enables the system to overcome the dwelling time limitation by switching between channels, effectively increasing the number of detection points per second without requiring a proportional increase in the number of light detectors.
2Productivity
If multiple light detectors are configured for each laser beam channel, then detection efficiency is improved, but system cost increases significantly
Solution Approach 1:
The patent makes each light detector multi-functional by having it serve multiple channels through circular allocation. A single detector can process signals from different channels at different time periods, making it perform multiple functions. This universality allows the system to achieve high detection efficiency equivalent to having multiple detectors per channel, while actually using far fewer detectors, thereby significantly reducing system cost.
Solution Approach 2:
The system performs preliminary allocation of periodic signals to different channels in a predetermined circular sequence before actual detection occurs. This preliminary arrangement ensures that when a detector is activated, it is already configured to receive and process signals from the appropriate channel, enabling efficient time-multiplexed operation without requiring redundant detectors for each channel.
3Measurement precision
If dwelling time is extended to cover maximum detection range, then measurement accuracy is improved, but detection speed decreases
Solution Approach 1:
The patent implements dynamic channel switching where the system actively transitions between different light channels in a circular manner. This dynamic operation allows the system to maintain long dwelling times for accurate ranging measurements on distant targets while simultaneously increasing overall detection speed by processing multiple channels in sequence. The dwell time per channel remains sufficient for precision, but the cumulative detection rate across all channels is significantly enhanced.
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 increases the number of detection points per second, reduces system costs, and allows for dynamic control of scanning mode and angular resolution, improving detection precision without increasing processing capacity or costs.
Implementation Method 1
the distance to each target point is to be calculated according to a beat frequency of a reflected signal and a local oscillator signal at a local end
Implementation Method 2
calculating a target distance according to a frequency of the beat signal or a return delay time of the light pulse signal
Data Source
AI summary
The present invention discloses a light detection and ranging (LIDAR) system ranging method, including: circularly allocating, by a light routing device, each periodic signal of a transmit signal to each light channel in a chronological order, monitoring a beat signal or a returned light pulse signal in each light channel, and calculating a target distance according to a frequency of the beat signal or a return delay time of the light pulse signal. The present invention further discloses a LIDAR, including: a laser source, a light routing device, an optical scanning system, a light detector, and a data processing module. A quantity of detection points per second of each beam is increased to N times, where N is a quantity of channels of the light routing device, so as to improve the detection efficiency and reduce the requirement on transmit resources; and a scanning mode and an angular resolution can be dynamically controlled according to needs.