Miscellaneous Tips

Maya Tips

• Use the Dope Sheet to modify or move keyframes
• Do not play the animation on a loop or scrub the timeline back and forth, reset the animation by letting go of the time-slider and clicking where you'd like to start viewing the animation. Scrubbing back and forth may show inaccurate joint values due to accumulated joint rotations. Releasing the cursor and reclicking will correct the joint values.
• Use parent constraints for grasping. Be careful to keyframe Blend Parent and the Parent constraint as "0" the keyframe before grasping, and change both to "1" for the duration of the grasping, and do another "1" to "0" switch to let go of the object. Right click each value box and click "Key Selected" to keyframe this attribute. ** The Blend Parent value will interpolate between 0 and 1 which can cause strange movement during the transition. Check the Blend Parent and Parent Constraint values to troubleshoot and add any missing . ** Blend Parent is found in the Channel Box of the child object, underneath the translate/rotate/scale values. The Parent Constraint information is found in the Channel Box inside the "Shapes" section

Singularities If your robot's default home position is in a singularity it is best to set an FK keyframe with the exact joint poses, then use FK to move the robot out of singularity and set another FK keyframe (example: move J5 of a Kuka from 0 to 30 degrees). If you want to transition to inverse kinematic control set an IK keyframe immediately after the last FK frame (without moving the robot).

Kuka EntertainTech Tips

• By default you should begin your animation in the robot's home position (usually 0/-90/90/0/0/0 for A1-6)
• Kuka recommends sending the same pose several times before moving the robot, therefore it is recommended to start the animation with several frames stationary in the home position (ex: FK keyframe in home position at frame 0 and again at frame 12)
• Mimic can detect whether your program violates velocity limits but it can not yet detect Acceleration or Jerk limits. The Kuka logging feature can help with debugging. *** In file mdrEmily.ini: set the variable DERIVATES to MAXIMA to log the max speed/accel/jerk for each axis or ALL to log speed/accel/jerk for each command in the table (every 12 ms step). *** Any change to the mdrEmily.ini requires a “cold boot/reload files" *** The log can be found in C:\KRC\ROBOTER\LOG. *** Multiply the timestamp by your fps rate to determine the keyframe location of your issue. Look for sudden jerky movements, usually a jump or reorientation from an improper IK-FK switch or a missing blend parent keyframe can cause jerky movement. You can look at the Emily file at that time stamp and look for big jumps or oscillations in values, or check the animation itself (you may need to change the timeline to milliseconds to see movement between two keyframes)