Safety Parameter Update
The Safety Parameter Update feature allows you to change various safety settings of the robot, such as collision sensitivity and the FS004 threshold.
When the Safety Parameter Update button is clicked on the Modify Robot Setting Panel , the Safety Parameter Update Panel opens as shown
The fields in the panel are auto-populated with either the default settings (if the user has not changed the settings previously) or the last setting the user changed.
Note: All settings are saved on the Cortex. Thus, if a user changes these settings, any other user connecting to the same cortex via another device will use the changed settings.
Field Descriptions
Collision Sensitivity
This setting allows you to adjust the sensitivity of the robot's collision detection. This impacts how much force the robot applies to its surrounding environment before the collision error is reported and the robot's motion is stopped.
This field is currently only available for the xArm6 and xArm7 robots. The value can be set between 1-5, where,
1 represents the lowest sensitivity; essentially, a lot of force is required to trigger a collision error. This setting is generally used when the robot needs to apply a large force to an object during a task, such as plugging a socket or twisting a control lever.
5 represents the highest sensitivity. Essentially, a collision error will trigger with a low amount of force. This setting is typically used when the robot is performing a delicate task and the safety of the surrounding area is the top priority.
Note: The default value for the collision sensitivity is 3
The change will be implemented as soon as the settings is saved, it does not require a restart of the Cortex or the AMAS VR app.
FS004 Threshold
FS004 is a safety setting that restricts the arm's motion at high velocity. It also prevents the arm from moving rapidly when reaching a singularity or during an ambiguous solution (a position when 2 or more joint position sets can reach the same point).
The FS004 threshold (in radians) limits the difference of each joint on the robot between the current robot position (in radians) and the next commanded position (in radians, computed by the cortex to reach the position the digital twin is moved to in the AMAS VR app).
Default value: 0.5 radians (1 radian = 57.29578 degrees)
Note: The Larger the FS004 threshold, the more significant distance the robot can move.
In addition, the AMAS VR app sends commands at a frequency of 50 Hz (0.02 secs), so based on the allowed threshold, the robot might make a rapid motion.
Using the FS004 field in the Safety Parameter Panel, the threshold can be set for each joint independently. The change will be implemented as soon as the settings are saved; it does not require a restart of the Cortex or the AMAS VR app.
Generally, the first 3 joints (4 in the case of a 7DoF arm) of a robot arm provide the maximum change in the robot's position. Thus, it is suggested that the threshold for these joints be kept low (or default value).
Examples to showcase the effects of changing the threshold.
Example 1:
FS004 threshold : [0.5, 0.5, 0.5, 0.5, 0.5, 0.5] radian
Current Robot Joint Position : [1.24, 0.51, 1.8, 2.4, 0.2, 1.2]
Computed Joint Position : [1.26, 0.55, 1.98, 2.52, 0.8, 1.4]
Joint Differences : [0.02, 0.04, 0.18, 0.12, 0.6, 0.2]
In this example, the FS004 warning is triggered. The user then needs to clear the error in the AMAS VR app.
Example 2:
FS004 threshold : [0.5, 0.5, 0.5, 0.5, 0.8, 0.5] radian
Current Robot Joint Position : [1.24, 0.51, 1.8, 2.4, 0.2, 1.2] radian
Computed Joint Position : [1.26, 0.55, 1.98, 2.52, 0.8, 1.4] radian
Joint Differences : [0.02, 0.04, 0.18, 0.12, 0.6, 0.2] radian
In this example, all the joint differences are below the threshold, so the robot will move to these computed joint angles, even though in the earlier setting, it was flagged as an error.
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