Depth Camera Trigger Synchronization for Precise Sensor Fusion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The accuracy of driving information for unmanned apparatuses is limited by the fusion accuracy of detection information from multiple sensors, necessitating improved methods to enhance sensor fusion precision.

Innovation Solution

A multi-sensor fusion system with a trigger module and GPS positioning system synchronizes depth camera modules using pulse signals to align local time with UTC time, reducing trigger time errors and enabling precise timestamping for improved image information fusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple depth camera modules are triggered independently without centralized synchronization, then each camera can operate autonomously, but the trigger time errors between cameras increase and fusion accuracy deteriorates

Engineering Contradiction:
Improvetrigger time accuracyVSAvoidsynchronization system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the trigger signal generation function into a single centralized trigger module that controls all depth camera modules. This centralization ensures unified trigger timing across all cameras, eliminating trigger time errors between independent cameras while maintaining operational autonomy through standardized trigger interfaces.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The trigger module acts as an intermediary between the control system and multiple depth camera modules. It receives synchronization signals and distributes standardized trigger signals to all cameras, mediating the timing coordination without requiring complex direct communication between cameras themselves.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If local clock time is used for timestamping without GPS synchronization, then the system operates independently, but time alignment errors accumulate and fusion precision decreases

Engineering Contradiction:
Improvetime alignment accuracyVSAvoidsystem independence
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses GPS synchronization to provide a universal time reference that serves all depth camera modules and the host computer. This universal time source ensures consistent timestamping across the entire system, enabling accurate time alignment for fusion while maintaining operational independence through standardized time distribution.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If trigger signals are distributed to all depth camera modules simultaneously from a single source, then trigger time consistency is improved, but signal transmission complexity increases

Engineering Contradiction:
Improvetrigger time consistencyVSAvoidsignal distribution complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The trigger module generates periodic trigger signals at standardized intervals that are distributed to all depth camera modules. This periodic action ensures consistent trigger timing across all cameras while using simple, repeatable signal patterns that reduce transmission complexity compared to custom timing protocols.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4250724B1Multi-sensor fusion system and autonomous mobile apparatus
Publication Date: 2025.08.13 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4250724B1 patent drawingFigure 1
  • EP4250724B1 patent drawingFigure 2
  • EP4250724B1 patent drawingFigure 3

AI summary

The present disclosure relates to a multi-sensor fusion system and an autonomous mobile apparatus. The multi-sensor fusion system includes: a trigger module (1) including a pulse signal output (11), the pulse signal output (11) being used to output a pulse signal; and a plurality of depth camera modules (2; 3), at least one depth camera module (2) including a trigger signal generation module (21) and a trigger signal output (22), the trigger signal generation module (21) being used to generate a trigger signal according to the pulse signal, and the trigger signal output (22) being connected to the trigger signal generation module (21), and used to output the trigger signal, where the trigger signal is used for triggering the at least one depth camera module (2) to perform an exposure operation, and other depth camera modules (3) perform exposure operations according to the received trigger signal output by the trigger signal output (22).