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UbiquityRobotics / ubiquity_main

Main documentation as well as other misc files
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URDF for loki needs to be updated #30

Closed davecrawley closed 6 years ago

rohbotics commented 6 years ago

@waynegramlich can you put the measurements in this ticket? Thanks

waynegramlich commented 6 years ago

Notes for Rev. F

Remember, the Y axis is inverted in KiCAD.

Sonar Locations

The locations of the sonars read from the KiCAD footprint locations are shown in the table below. The KiCAD angle is next to useless since the angle changes from front to back. The actual angle is more useful, where 0 degrees points along the X axis.

Connector Side X(mm) Y(mm) KiCAD Angle(.1 deg) Actual Angle(deg) Comment
N5 Bottom 349.5 100 -90.0(deg) 0 Faces Forward
N6 Top 345.351435 79.143753 1125 22.5
N7 Bottom 333.53732 61.46268 3150 45.0
N8 Top 312.31 55.215 1575 67.5
N9 Bottom 145 45.5 0(deg) 90.0 Faces Left
N10 Top 124.143753 49.648565 2025 112.5
N11 Bottom 106.46268 61.46268 450 135
N12 Top 94.648565 79.143753 2475 157.5
N13 Bottom 90.5 100 +90.0(deg) 180 Points backward
N14 Top 94.648565 120.856247 2925 202.5
N15 Bottom 106.46268 138.53732 1350 225
N16 Top 124.143753 150.351435 3375 247.5
N1 Bottom 145 154.5 180.0(deg) 270 Points Right
N2 Top 312.61 144.415 225 292.5
N3 Bottom 333.53732 138.53732 2250 315
N4 Top 345.351435 120.856247 675 337.5

Motor Locations

The center point is between the two motors:

Connector X Y Comment
N32 271 42.5 Left Motor
N33 271 157.5 Right Motor

Camera Hole Locations

The four camera holes

Hole X Y
H5 126 103.5
H6 113.5 103.5
H7 126 82.5
H8 113.5 82.5
rohbotics commented 6 years ago

Thanks Wayne, I made a PR to ubiquity launches to update the URDF.

waynegramlich commented 6 years ago

In many practitioners of software engineering that believe in the philosophy that if something is hard to write it should be equally hard to read. Alas, I do not subscribe to that philosophy. The rpy field for each of the sonar rotations should be of the form rpy="0 0 R". I feel that all entries of the form rpy="3.1415 0 R" are confusing. A comment that shows the rotation in degrees would be helpful as well. <!-- 180deg --> for the rpy="0 0 3.1415926" entry. The mesh entries are all commented out. Perhaps doing a simple mesh where the sonar is represented as a block?

jim-v commented 6 years ago

It should be possible to get rid of the 180 degrees rotation around the x axis by negating the y component of translation.

rohbotics commented 6 years ago

The rpy="3.1415 0 R is for the sonars that are upside down on the bottom of the loki. I just clarified this in a comment.

@jim-v In URDF the rotation is about the center of the link (not the joint origin) so is independent of translation.

Fixed the mesh issue.

waynegramlich commented 6 years ago

I have looked for the comment and could not find it. The comment should specify the origin and orientation of the sonar .stl file. The comment should mention that a rotation of 180 degrees along the X axis is used to flip the sonar to the bottom surface of the PCB. I still encourage that the Z axis rotation be supplied as a comment in degrees.

rohbotics commented 6 years ago

@waynegramlich I missed a commit/push. I added the Z axis rotation in degrees as well.

waynegramlich commented 6 years ago

I'm happy, if you are happy. I'd close the issue out, but I'd probably screw up. So, I'll let you close the issue.