PLC-Camera Counter Synchronization for Precise Image Log Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing techniques for synchronizing the time stamps of moving images with log records in factory automation systems require a dedicated low-delay imaging trigger line, limiting the use of widespread cameras like network cameras or webcams and restricting remote monitoring.
Innovation Solution
A control system that includes a camera with a first synchronous counter and a programmable logic controller (PLC) with a second synchronous counter, connected via a control network, which measures and guarantees communication delays to synchronize the counters with high precision, allowing the camera to add its count value to captured images and transmit them to the PLC for storage, without the need for a dedicated imaging trigger line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated low-delay imaging trigger line is used to connect camera and PLC, then time synchronization precision is improved, but device complexity and limitation of camera selection increase
Solution Approach 1:
The patent introduces a control network as an intermediary between the camera and PLC, replacing the dedicated trigger line. The control network transmits trigger signals and coordinate information, enabling time synchronization through standardized network communication rather than direct physical connection.
Solution Approach 2:
The control network serves multiple functions: transmitting trigger signals, transferring image coordinates, and enabling communication between various devices. This universal interface allows different camera types (network cameras, webcams) to connect without requiring dedicated trigger lines, reducing device complexity while maintaining synchronization capability.
2Measurement precision
If a dedicated low-delay imaging trigger line is used, then time synchronization is improved, but adaptability of camera types is reduced
Solution Approach 1:
The control network provides a universal communication interface that works with various camera types including network cameras and webcams. Instead of requiring dedicated trigger lines, the system uses standardized network protocols to transmit synchronization signals and coordinate data, enabling broad camera compatibility.
Solution Approach 2:
The control network acts as a mediator that translates and transmits synchronization commands to different camera types through standardized protocols. This intermediary layer abstracts the communication differences between various camera models, allowing the PLC to synchronize with diverse camera devices without requiring device-specific connections.
3Measurement precision
If a dedicated low-delay imaging trigger line is used, then time synchronization precision is improved, but remote monitoring capability is limited
Solution Approach 1:
The control network enables multiple communication functions including local and remote monitoring. Since the system uses standardized network protocols rather than dedicated physical connections, operators can access the system remotely through the network, enhancing ease of operation while maintaining synchronization precision.
Data Source
AI summary
A control system includes a camera including a first synchronous counter, a PLC including a second synchronous counter, and a control network connecting the camera and the PLC. The control network repeatedly synchronizes the first synchronous counter and the second synchronous counter with high precision by measuring durations of a plurality of transmission delays between the camera and the PLC. The camera adds, to a captured image obtained by image capturing, a count value of the first synchronous counter at the image capturing, and transmits the captured image to the PLC through the control network. The PLC stores, into a storage device included in the PLC, a count value of the second synchronous counter, internal data or data of a connected control target, the count value from the first synchronous counter, and image data.