External Illumination Synchronization for Vision Systems

Solution Overview

Problem

The uncertainty in delays between sending trigger signals to external devices like cameras or illumination assemblies and their reactions, due to unknown communication channel delays and manufacturing tolerances, leads to unpredictable synchronization of image capture and illumination, affecting image quality.

Innovation Solution

A system and method that involves transmitting series of exposure and illumination signals with varying time-differentials to identify a peak-brightness frame, allowing synchronization of the imaging and illumination assemblies by associating the corresponding time-differential with subsequent activations, ensuring coordinated operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If trigger signals are transmitted through wired or wireless communication means with gateways, then external devices can be controlled from the host, but delays between trigger transmission and device response become unknown and difficult to anticipate

Engineering Contradiction:

Improveremote device controlVSAvoidtrigger signal delay

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The system performs preliminary calibration by transmitting multiple calibration signals with varying time differentials before actual operation. The host device measures the response times during calibration and stores this information to compensate for communication delays during normal operation, allowing predictable synchronization without requiring real-time delay measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the external devices' response times to adjust and compensate for communication delays. By measuring actual response times during calibration and operation, the host device can dynamically adjust trigger timing to account for variable delays in wired or wireless communication channels.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If multiple calibration signals with varying time differentials are transmitted to identify peak-brightness frame, then synchronization accuracy is improved, but the complexity of signal transmission and processing increases

Engineering Contradiction:

Improvesynchronization accuracyVSAvoidsignal transmission complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary calibration by transmitting multiple calibration signals with varying time differentials before actual operation. The host device measures the response times during calibration and stores this information to compensate for communication delays during normal operation, allowing predictable synchronization without requiring real-time delay measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system varies the time differential parameter between trigger signals and illumination signals during calibration to identify the optimal synchronization point. By systematically changing this parameter and measuring brightness responses, the system determines the peak-brightness frame that indicates optimal synchronization without requiring complex real-time adjustment mechanisms.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If manufacturing tolerances are accounted for in device response times, then synchronization reliability is improved, but the complexity of compensating for variations increases

Engineering Contradiction:

Improvesynchronization reliabilityVSAvoidcompensation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary calibration by transmitting multiple calibration signals with varying time differentials before actual operation. The host device measures the response times during calibration and stores this information to compensate for communication delays during normal operation, allowing predictable synchronization without requiring real-time delay measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system allows each device to self-calibrate by automatically measuring its own response time characteristics during the calibration process. The host device and external devices work together to determine optimal synchronization parameters without requiring manual intervention or complex external compensation mechanisms, with each component automatically adjusting based on measured performance.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11997394B2Systems and methods for calibrating and operating imaging systems with illumination external to a host

Publication Date: 2024.05.28 ZEBRA TECHNOLOGIES CORP

AI summary

At least some embodiments are directed to systems and methods to optimize relative signal delays in vision systems having illumination assemblies separate from a host. In an example embodiment there is a system that includes a host device having, an imaging assembly coupled to the host device and operable to capture image data, and an illumination assembly coupled to the host device and operable to provide illumination. The system is configured such that the host transmits, to the imaging assembly, a series of exposure signals causing the imaging assembly to capture a series of frames and transmits, to the illumination assembly, a series of illumination signals causing the illumination assembly to provide the illumination as a series of strobes. Thereafter the host evaluate each frame to identify a peak-brightness frame and from that, based on a corresponding illumination signal, determines an appropriate relative signal delay for future operations.