In this iRVision Tech Short, we will go over how to use the CHK_POS vision support tool to verify whether a robot position is reachable before motion is attempted. This topic is especially relevant when working with vision-guided applications where part locations can vary and robot motion may approach the limits of the work envelope. By validating reachability ahead of time, we can reduce motion faults and build more reliable robot programs.
We begin with an overview of what CHK_POS does and where it fits within the iRVision software suite. CHK_POS is designed to check whether a robot can move to a target position using a vision-based offset before executing the move. This simple check helps prevent common motion alarms such as Position Not Reachable, which can interrupt production and require troubleshooting. We will also touch on where CHK_POS is located in the iRVision Operator’s Manual and how it is configured.
From there, we will walk through a practical demonstration using FANUC ROBOGUIDE. In this example, we use an iRVision process to locate virtual parts and generate position offsets. The robot is intentionally placed near the edge of its reachable workspace to demonstrate how motion failures can occur when reachability is not checked in advance. This sets the stage for showing how CHK_POS can be added to the program to evaluate whether a move is possible before it is executed.
We then show how to interpret the CHK_POS status output and use simple conditional logic to respond. In this scenario, if the position is not reachable with the active tool, the program switches to an alternate gripper that allows the part to be picked successfully. This demonstrates how CHK_POS can support smarter tool selection and more flexible automation strategies without adding unnecessary complexity.
Requirements to follow along include:
- Basic familiarity with FANUC robot programming
- An understanding of iRVision concepts such as RUN_FIND and GET_OFFSET
- Access to iRVision and ROBOGUIDE
In this video, we will learn how to:
- Use CHK_POS to validate robot reachability
- Prevent position not reachable motion alarms
- Apply CHK_POS results in program logic
- Adapt tool usage based on reachability
- Improve robustness in vision-guided applications
By the end of this Tech Short, we will have a clear understanding of how CHK_POS can be used to prevent avoidable errors and improve the reliability of vision-based robot applications.
