LIDAR Laser Power Calibration via Charge Duration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Developing LIDAR systems that are both accurate and cost-effective for applications such as autonomous vehicles is challenging due to the need for precise laser power control and calibration to ensure accurate distance measurements and reduce power consumption.
Innovation Solution
A laser power calibration and correction system that generates a power profile for each laser emitter, allowing for precise adjustment of light pulses based on charge duration to achieve a specified power level, reducing the need for slow power convergence and improving accuracy and power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser power is increased to improve measurement accuracy, then measurement precision improves, but power consumption increases
Solution Approach 1:
The patent implements dynamic laser power adjustment by controlling the charge duration of the laser driver circuit. The system adapts laser pulse power in real-time based on detected target reflectivity and distance, rather than using fixed high power. This allows the system to maintain measurement accuracy while minimizing power consumption by using only the necessary power level for each measurement scenario.
Solution Approach 2:
The patent changes the charge duration parameter of the laser driver to control output power. By adjusting this electrical parameter, the system can precisely control laser pulse energy to match the minimum required for accurate measurement, thereby reducing unnecessary power consumption while maintaining measurement precision.
2Stability of the object's composition
If laser power is adjusted slowly to converge to desired level, then power stability improves, but response time deteriorates
Solution Approach 1:
The patent performs preliminary power calibration by measuring the actual output power of each laser emitter and storing correction factors in a power profile. This pre-characterization allows the system to immediately apply the correct charge duration for desired power levels without slow convergence, achieving both fast response and stable power output.
Solution Approach 2:
The system implements feedback through power profiling, where the actual laser output is measured and used to adjust subsequent pulse parameters. This closed-loop approach ensures rapid convergence to the desired power level while maintaining stability, as the system learns from previous measurements and corrects for variations immediately.
3Manufacturing precision
If individual laser calibration is performed for each emitter, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The patent creates a power profile (a digital copy or lookup table) that stores the calibrated power characteristics of each laser emitter. Instead of complex real-time adjustment mechanisms, the system uses these pre-stored profiles to quickly determine appropriate charge durations, simplifying the hardware while maintaining high precision through software-based compensation.
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 achieves accurate and efficient LIDAR operations by adjusting laser pulse power in real-time, enhancing measurement accuracy and reducing power consumption, while ensuring eye safety and accounting for variations in reflective properties of different objects.
Implementation Method 1
a laser that directs highly focused light in the direction of an object or surface
Implementation Method 2
measuring properties of the reflections of the light
Implementation Method 3
the system may measure the 'flight time' of a light signal as it travels from the laser, to the surface, and back to the light sensor
Implementation Method 4
The light sensor may comprise a photodetector such as a photomultiplier or avalanche photodiode (APD) that converts light intensity to a corresponding electrical signal
Data Source
AI summary
A LIDAR system emits laser pulses, wherein each pulse is associated with a power level. A laser emitter is adjusted during operation of a LIDAR system using power profile data associated with the laser. The power profile data is obtained during a calibration procedure and includes information that associates charge duration for a laser power supply with the actual power output by laser. The power profiles can be used during operation of the LIDAR system. A laser pulse can be emitted, the reflected light from the pulse received and analyzed, and the power of the next pulse can be adjusted based on a lookup within the power profile for the laser. For instance, if the power returned from a pulse is too high (e.g., above some specified threshold), the power of the next pulse is reduced to a specific value based on the power profile.