# RGBD Camera Eye in Hand Calibration

Hello I am new to robotics. So far I have a basic understanding of the camera calibration. One would need rotation and transformation matrices to convert a point from camera coordinate system to robot/arm coordinate system. However; when camera is in hand, as robot moves camera coordinate system will change? I am a bit lost over here as resources are mostly research papers with lots of maths. Any useful links or keywords would be very appreciated! :)

## 1 Answer

When you get the pose of an object using a camera, you get that position in relation to the camera frame. If you want that pose in relation to the robot frame, first you have to find the pose transformation from the robot to the camera. If the camera is static and the base is static, the object pose in relation to the robot would be:

$^{base}T_{object} = ^{base}T_{camera} * ^{camera}T_{object}$

Now, if the camera is not static, let's say, it's in the robot hand, which is your case, then the transformation is fixed in relation to the hand. In this case, the transformation would be:

$^{base}T_{object} = ^{base}T_{endEffector} * ^{endEffector}T_{camera} * ^{camera}T_{object}$

the transformation from base to end effector is given by direct kinematics. Once you have the transformation from end effector to camera, you can find the object pose in relation to the robot frame.