LiDAR Readout Weighting for Long-Range Time-of-Flight Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lidar sensors in focal plane array arrangements face limitations in transmission power due to chip size and heating, leading to range restrictions and reliability issues in object detection, particularly at long distances, with increased manufacturing effort and costs.
Innovation Solution
A reading device for lidar systems employs a weighting unit that assigns individual weighting parameters based on the signal-to-noise ratio of sensor elements, using a maximum ratio combining approach to enhance detection accuracy and reliability by selectively weighting sensor elements with higher signal strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transmission power is increased to improve detection range and reliability, then the detection performance improves, but the manufacturing effort and cost increase
Solution Approach 1:
The patent changes the parameter of power distribution by activating only a subset of transmission elements rather than all elements simultaneously. This reduces the total power required while maintaining detection capability through selective activation of specific transmission elements paired with corresponding sensor elements in macrocells.
Solution Approach 2:
The transmission elements and sensor elements are divided into macrocells, where each macrocell contains multiple sensor elements paired with specific transmission elements. This segmentation allows the system to activate only the necessary subset of elements for each macrocell, reducing overall power consumption and manufacturing complexity.
2Length of stationary object
If the transmission power is increased to extend detection range, then the detection range improves, but the chip heating increases
Solution Approach 1:
Instead of activating all transmission elements at full power, the system uses partial action by activating only a subset of transmission elements corresponding to the macrocells being measured. This provides sufficient power for the required detection range while avoiding excessive power consumption that would cause chip heating.
Solution Approach 2:
The system measures different macrocells in sequence rather than all simultaneously, creating a periodic measurement pattern. This time-multiplexed approach allows the chip to be cooled between measurements while maintaining the ability to measure all macrocells, effectively extending detection range without sustained high power consumption.
3Measurement precision
If all sensor elements are used equally to improve detection accuracy, then the measurement precision improves, but the signal processing complexity increases
Solution Approach 1:
The patent applies local quality by assigning different weights to different sensor elements based on their signal-to-noise ratio. Sensor elements with higher signal quality receive higher weights in the summation, while those with lower signal quality receive lower weights. This localized differentiation improves measurement precision without requiring all sensor elements to contribute equally, reducing processing complexity.
Solution Approach 2:
The system changes the parameter of equal weighting to variable weighting based on signal-to-noise ratio. By dynamically adjusting the weight assigned to each sensor element's detections, the system optimizes measurement precision while managing processing complexity through a straightforward weighting mechanism rather than complex processing for all elements.
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 method improves the range and reliability of object detection by optimizing signal processing, allowing for more efficient use of sensor elements and reducing the need for excessive power, thus maintaining cost-effectiveness and energy efficiency.
Implementation Method 1
A lidar sensor is based on the transmission of light pulses and the detection of the reflected light
Implementation Method 2
A lidar sensor is based on the transmission of light pulses and the detection of the reflected light
Implementation Method 3
a lidar receiving unit with a plurality of sensor elements for receiving the light pulses
Implementation Method 4
By means of a propagation time measurement, a distance to the site of the reflection can be calculated
Data Source
AI summary
The present invention relates to a reading device for determining a signal propagation time of a light pulse between a lidar transmission unit and a lidar receiving unit of a lidar measuring device in a focal plane array arrangement, comprising: an input interface for receiving detections from multiple sensor elements of the lidar receiving unit, said sensor elements being arranged in a macrocell paired with a transmission element of the lidar transmission unit; a weighting unit for determining a respective individual weighting parameter for each of the plurality of sensor elements, said weighting parameter being based on a signal-to-noise ratio of the sensor element; a summation unit for generating a histogram with an allocation of the detections to the detection times of the detections, said summation unit being configured to weight the detections on the basis of the individual weighting parameters; a propagation time unit for determining the signal propagation time on the basis of the generated histogram; and an output unit for outputting the signal propagation time. The invention additionally relates to a method for determining a signal propagation time and to a lidar measuring device in a focal plane array arrangement for detecting objects in a surroundings of a vehicle.