Changing Collaborative Settings on Cobots

Yaskawa human-collaborative HC-series robots are highly capable of completing a variety of repetitive tasks. From welding to handling, the proper collaborative robot with the right peripherals can positively impact a wide range of production settings. Extremely repeatable and reliable, cobots enable an environment where humans and robots can work together or side-by-side, increasing flexibility. However, there are still limits to what can be achieved.

To gain the most versatility out of your cobot with a wide range of applications and end of arm tooling, and to maintain a safe working environment, it can be helpful to know how to knowledgeably change specific functions inside the via the robot teach pendant. Incorrect or suboptimal settings can either slow down or cause unnecessary errors. They could also create a potentially unsafe environment that requires additional safety mitigation. With that in mind, here are several concepts to consider when updating the settings for your collaborative robot.

Avoidance Function
This function calls for an interrupt job when a force is introduced, allowing you to temporarily move the robot out of the way and then resume the job to its programmed path. There are three modes:

 

• Joint Mode: allows movement of all joints according to the external force, including the tool posture.

• Translation Mode: allows movement of only the Tool Center Point (TCP) according to external forces while keeping the current tool posture.

• Stop Mode: completely halts operation of the robot

Having a general understanding of these can be helpful to eliminating potential collisions.

Force Monitor
Inherently safe by design, Power and Force Limiting (PFL) robots can work with or in close proximity to human workers without additional safety devices or process interruption – as PFL technology allows the robot to monitor external forces applied to its body. If this force exceeds a calculated safe threshold, the robot stops to protect workers from potentially harmful contact situations.

If PFL alarms are being triggered, check the Force Monitor pendant function. At a glance, you can read live torque values that can help determine if the correct tool data was initially entered and diagnose what external forces are causing disruption.

Speed Limit Function
With safety and risk assessments in mind, it is important to understand the various speed limits that are set for the robot to run in collaborative mode. These can vary depending on your tooling, height of robot, and more. The Speed Limit Function allows altering of speed limits (in compliance with ISO TS15066 or ANSI/RIA TR R15.606 standards for collaborative robots), as well as enables different speed limits by I/O.

External Force Limit
It is important to adjust the external force limit of your Power and Force Limiting robot for a given application depending on the tool, speed of the robot and the preferred force. Likewise, it is important to make sure the limits that will trip the robot are below threshold values and considerations according to ISP 15066 standards for collaborative robots. Keep in mind this will change per application, end of arm tool, as well as with different workpieces and objects in the work area.

Torque Sensor Calibration
Whether your robot has crashed or an alarm has been triggered, torque sensors will inevitably need recalibrated. While this step is a simple task, failing to do so could cause unintended job interruptions.

Safety Mode Security Level
This functionality permits the user to access all safety related functions, configurations, settings, etc. This access is essentially the doorway to making adjustments in the Safety Logic Circuit.
 
Safety Logic Circuit
As implied, this is where the robot user can set logical instructions for certain safety functions to be enabled or disabled during robot operation. A user can add or remove ladder rungs, as well as enable or disable collaborative operation/PFL. For example, this function can help make adjustments for an area scanner or light curtain to detect an operator in close proximity to the robot, enabling PFL for safety.

Note: users must still comply with ISO TS15066 or ANSI/RIA TR R15.606 standards for collaborative robots to disable collaborative operations/PFL correctly.

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While this is not a comprehensive list of cobot settings, these concepts can be extremely helpful to optimizing your productivity for a better ROI. As always, if you have concerns about your robotic application, please reach out to our experts via our 24/7 customer service hotline.

* Video descriptions provided by Yaskawa Process Engineer, Josue Alvarado