# IK solution failed and the robot can't move to the Entry point

**URL:** <https://discourse.slicer.org/t/ik-solution-failed-and-the-robot-cant-move-to-the-entry-point/25426>\
**Category:** Development\
**Tags:** ros, robotics\
**Created:** [September 25, 2022, 5:59am UTC](https://discourse.slicer.org/t/ik-solution-failed-and-the-robot-cant-move-to-the-entry-point/25426 "2022-09-25T05:59:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![xiaosnowqiang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/xiaosnowqiang/32/16426_2.png) [@xiaosnowqiang](https://discourse.slicer.org/u/xiaosnowqiang)\
**Post date:** [September 25, 2022, 5:59am UTC](https://discourse.slicer.org/t/ik-solution-failed-and-the-robot-cant-move-to-the-entry-point/25426/1 "2022-09-25T05:59:35Z")

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Hello guys,I have go throught the ROSIGTLTutorial-ISMR2019 recently, after follow the steps of Fiducial Registration Wizard the relationship between the robot and the patient  
on rviz and 3D Slicer are Confirmed.

 ![图片](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/e/ae2c042031467c4aaee057d015dd8f63214c8992.png)  
So i continue the tutorial to execution of the plan  
（1）copy the plan and rename as Plan Reference  
（2）copy the ReferenceToRas and rename as RasToFeference and invert the transform  
 ![图片](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/6/f6b0be39c7bf270261bea73c5bfdd3c1a7b8a5be.png)  
（3）Open “RasToReference” transform in “Transforms” and Apply “RasToReference” transform to “Plan-Reference”  
 ![图片](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/3/3/33c1e8867340d7bd793ce48ea3c5e3987ba5f18e.png)  
When all the steps done，the 3D Slicer sense as show below  
 ![图片](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/8/88c998e849a9cdbc740270a7bc5a044b4ec9e0bb.png)  
And finally Send “Plan-Reference” in “I/O Configuration”，and from the ros node message the Plan is sent to ROS, but the robot didn’t moves to the  
entry, and then the target the message like the below picture  
 ![图片](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/8/f8e14b7304edcab2a38acbff6e8bf0488e6cbc56.png)  
And i also change the OMPL planner in Rviz and Moveit but it also can’t solve .  
Can someone tell me why ,and thanks in advance.  
Best wishes,  
-Jian

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [September 26, 2022, 6:24pm UTC](https://discourse.slicer.org/t/ik-solution-failed-and-the-robot-cant-move-to-the-entry-point/25426/2 "2022-09-26T18:24:34Z")

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The error indicate that the robot cannot physically reach the target position/orientation. It is either because you need to move the robot closer, in a better orientation; or the robot has not been registered correctly to the patient. It is hard to tell which one is the case here from the screenshots and high-level description.