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Configuring different tools in for your setup can be done a couple different ways. This setup step will be particularly useful for skills with rotations.
You can either enter the physical tool characteristics manually or use our Center of Gravity (CoG) Measurement Wizard to estimate the center of gravity (CoG). The in-app Center of Gravity (CoG) Measurement Wizard runs through several different poses of the mounted tool to calculate the appropriate values for your setup.
To begin, you can access the tool configuration page from the main menu on the top left corner, select ‘Tool Configuration’. Alternatively, you will find a quick path to this page from the "Create Skill" page.
(LEFT: Main Menu Option) (RIGHT: Create a Skill Option)
Step 1
The table in the screen below displays all the currently available tools (if applicable). You can choose an existing tool to re-configure by selecting ‘Edit’ or start a new configuration by clicking on "set up a new tool."
Step 2
Enter a name for the tool and then select the type of robot and sensor currently installed.
Step 3
Select "Start Measurement Process" if you would like to use the 6-step measurement process through the Center of Gravity (CoG) Measurement Wizard.
Alternatively, you can manually enter the value for Mass and X, Y, and Z coordinates if you have them prepared. For manual inputs, you can finish the setup process by tapping on the ‘Save’ button at the bottom of this page. Otherwise, proceed to the measurement process.
Using the Measurement Wizard:
The first screen describes the process for measuring the CoG. You would be asked to move the robot to 6 different poses (as indicated in the illustrations). Make sure you use the robot’s freedrive to move the robot by holding the robot arm above the force torque sensor (not after the force torque sensor). Make sure not to move the robot arm by grabbing the tool. Read the instructions carefully, and then tap on the ‘Proceed’ button.
Prepare the robot before beginning with the measurements in each pose. Please make sure the that the robot is positioned with the last joint pointing straight downwards as shown in the illustration. Once the robot is in the correct position tap on ‘Robot is ready’.
First pose
Take the first measurement in the starting position with the tool pointing straight downwards (as shown in the illustration on your tablet). Wait for 5-10 seconds so the F/T sensor is in a static state. Tap on the ‘Measure’ button once the robot is correctly placed.
Once the measurement is done by the system, a text in green indicating ‘Measurement successful’ appears. This takes a few seconds. Tap on ‘Next pose’.
Second Pose
Minding the cables, bring the tool in a straight horizontal position facing to the right or left for pose 2. Make sure to hold the robot by the robot arm, and use the robot’s freedrive mode to articulate the robot. Wait for 5-10 seconds and tap the ‘Measure’ button after the robot is correctly positioned. Once the measurement is done, tap on ‘Next pose’.
Next Poses
In a similar manner, proceed with the next 4 poses. Refer to the instructions and illustrations on each screen.
Make sure to move the robot from the robot’s arm, using freedrive.
FINISH
After you have measured all the 6 poses, click on ‘Finish’. You will see the CoG estimates for your newly created tool in main screen.
To delete a tool, tap on the Trashcan-icon. Please note that you can only delete tools not used in a skill. Please keep in mind, this data is not recoverable once deleted.
Frequently Asked Questions:
Does COG Calibration Need to Capture All Spatial Directions Precisely?
No, however it is important to span as large a vector space as possible to obtain an accurate calibration (different direction vectors if possible).
The MIRAI Training App includes the MIRAI COG Tool Wizard to help calculate the center of mass.
Follow the link below for further instructions:
Is it necessary to determine a center of mass (CoG)?
Centre of mass is the point at which the distribution of mass is equal in all directions, and does not depend on gravitational field. The distribution of mass is critical for the success of skill movements regardless of rotations or axis directions.
With this is mind, it is always recommended to enter the value for Center of Gravity when using Mirai. Failure to provide this data point can lead to unexpected behaviors such as "jittery" guidance movements, inverted directionals when guiding, and possible failed training episodes.
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