Context-Aware Real-Time Power Adjustment for Steerable Lidar
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Solution Overview
Problem
Conventional lidar systems face limitations in increasing signal-to-noise ratio (SNR) while maintaining eye safety and managing thermal capabilities, especially in applications requiring higher power levels for effective scanning.
Innovation Solution
A context-aware real-time power adjustment system for steerable lidar, which dynamically modulates the power of the optical signal based on the lidar system's position, direction, and environmental factors, such as a 3D map, previous scans, and sensor data, to optimize power usage and maintain eye safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power level of the optical signal is increased to improve SNR, then the signal-to-noise ratio is improved, but eye safety is compromised
Solution Approach 1:
The patent applies dynamic power adjustment by continuously modulating the laser power level based on real-time scan position and environmental conditions. The controller dynamically increases power when scanning safe areas (sky, ground) and decreases power when scanning potential eye zones (horizontal plane at vehicle level), resolving the contradiction between maintaining high SNR and ensuring eye safety throughout the scan cycle.
Solution Approach 2:
The patent implements local quality control by applying different power levels to different spatial regions of the scan field. High power is applied to regions where it is safe (above the vehicle, below the vehicle, or far from the horizontal centerline), while low power is applied to regions where eye exposure risk exists. This spatially differentiated power strategy allows the system to achieve high SNR in safe regions while protecting eyes in sensitive regions.
2Measurement precision
If the power level of the laser source is increased to enhance detection capability, then the detection range is improved, but thermal management becomes more difficult
Solution Approach 1:
The patent employs periodic action by using short, intense laser pulses rather than continuous high-power emission. The laser operates in pulsed mode where high power is delivered only during the brief pulse duration needed for measurement, followed by off periods that allow thermal dissipation. This periodic high-power operation enables extended detection range while preventing excessive heat accumulation in the laser source.
Solution Approach 2:
The system dynamically adjusts power levels based on detection needs and thermal conditions. When high detection range is required, the controller increases power temporarily; when thermal limits are approached, power is reduced. This dynamic power management allows the system to operate at the boundary of thermal capabilities, maximizing detection range without exceeding thermal limits.
3Object-affected harmful factors
If the exposure time is reduced to maintain eye safety at higher power levels, then eye safety is maintained, but the signal-to-noise ratio decreases
Solution Approach 1:
The patent resolves this contradiction through dynamic power-time coordination. When the scan is in eye-safe regions, the system uses longer exposure times with high power to maximize SNR. When the scan enters eye-sensitive regions, the system automatically reduces power levels while maintaining appropriate exposure times. This dynamic coordination of power and time parameters allows the system to achieve high SNR in safe regions while maintaining eye safety in sensitive regions.
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 allows for higher power levels when needed, enhancing SNR and enabling detection of objects at farther distances while ensuring eye safety and managing thermal limitations, thus improving the performance and reliability of lidar systems in various applications.
Implementation Method 1
A direct TOF lidar system emits an optical signal that includes short pulses of light, such that the pulses of light can reflect off a target in an environment
Implementation Method 2
A delay between transmission and reception can be utilized to determine the distance between the direct TOF lidar system and the target
Implementation Method 3
Measurement of a frequency shift and/or a phase shift for each reflected optical chirp relative to a reference optical chirp can provide a measure of a distance and/or a velocity of the target
Data Source
AI summary
Various technologies described herein pertain to context aware real-time power adjusting for steerable lidar. A lidar system can include a laser source (e.g., FMCW) configured to emit an optical signal. The lidar system can further include a scanner configured to direct the optical signal emitted by the laser source from the lidar system into an environment. The optical signal can be directed over a field of view in the environment during time periods of frames. The lidar system can further include a controller configured to modulate a power of the optical signal emitted by the laser source between the frames and/or within one or more of the frames. The controller can modulate the power of the optical signal emitted by the laser source based on a position of the lidar system in the environment and a direction in which the optical signal is to be transmitted into the environment.