Lidar Pulse Energy Control for Terrain Adaptive Range

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Solution Overview

Problem

Conventional LIDAR systems face limitations in range and sensitivity due to laser safety constraints and operational parameters, requiring inefficient distribution of light energy, especially when scanning environments with varying elevation angles.

Innovation Solution

A LIDAR system dynamically adjusts the energy of each light pulse based on the elevation angle component of the emission vector, providing higher energy for longer ranges and lower energy for closer objects, while maintaining average power within safe limits, using a controller to manage the light source and pulser circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the amount of energy per light pulse is increased to extend detection range, then LIDAR range is improved, but laser safety constraints and operational parameters are violated

Engineering Contradiction:
Improvedetection rangeVSAvoidlaser safety constraints
Core Design Contradiction:
Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the energy of each light pulse based on the elevation angle component of the emission vector. The controller modifies pulse energy in real-time according to the scanning angle, using higher energy for long-range detection at certain angles while maintaining safety limits at other angles, thus resolving the contradiction between extended range and safety constraints

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the energy parameter of light pulses based on elevation angle. By varying the pulse energy parameter dynamically according to the scanning geometry and terrain, the system achieves extended detection range where needed while maintaining compliance with laser safety standards across all operating conditions

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If light energy is distributed uniformly across all scanning angles, then coverage is improved, but energy efficiency deteriorates

Engineering Contradiction:
Improvescan coverageVSAvoidenergy efficiency
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The system applies different energy levels to different parts of the scanning field based on elevation angle. Instead of uniform energy distribution, the controller allocates higher energy to specific angular regions where long-range detection is needed, and lower energy to regions where objects are closer or detection range is less critical, thus improving overall energy efficiency while maintaining necessary coverage

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies partial action by using higher energy only when and where needed (at specific elevation angles for long-range detection) rather than uniformly across all scans. This selective energy application improves efficiency by avoiding excessive energy use in regions where it is not necessary for detection

Inventive Principle:
Principle #16Partial or excessive action

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 more efficient and controlled light energy distribution, enhancing detection capabilities without exceeding laser safety standards, particularly in semi- and fully-autonomous vehicles by optimizing energy use based on terrain and object proximity.

Implementation Method 1

The light source is configured to emit light at least one light pulse toward an environment of the vehicle

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP3695247B1Terrain adaptive pulse power in a scanning lidar
Publication Date: 2024.12.18 WAYMO LLC
  • EP3695247B1 patent drawingFigure 1
  • EP3695247B1 patent drawingFigure 2A~2B
  • EP3695247B1 patent drawingFigure 3

AI summary

The present disclosure relates to systems and methods involving Light Detection and Ranging (LIDAR or lidar) systems. Namely, an example method includes causing a light source of a LIDAR system to emit light along an emission vector. The method also includes adjusting the emission vector of the emitted light and determining an elevation angle component of the emission vector. The method further includes dynamically adjusting a per pulse energy of the emitted light based on the determined elevation angle component. An example system includes a vehicle and a light source coupled to the vehicle. The light source is configured to emit light along an emission vector toward an environment of the vehicle. The system also includes a controller operable to determine an elevation angle component of the emission vector and dynamically adjust a per pulse energy of the emitted light based on the determined elevation angle component.