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| Team | Year | SAR Score | Extreme Retrival Score | Equipment Servicing Mission | Picture | Number of Fingers in gripper | DOF in end effector | Allen Key feature | Other comments |
|---|---|---|---|---|---|---|---|---|---|
Ryerson Rams Robotics | 2019 | 90 | 77 |
| 4 | 1 | Not apparent | 4 fingers make it easy to grab rocks They are lacking strength in the wrist | |
| IMPULS | 2019 | 80 | 69 |
| 2 | 1 | Not apparent | Very rigid stiff | |
| PCz Rover Team | 2019 | 80 | 42 |
| 2 | 1 | Not apparent | Interchangeable end nubs | |
| Stanford Student Robotics | 2019 | 64 | 57 |
| 2 | 1 | Not apparent | rubber band in v grove for compliance. | |
| Michigan Mars Rover Team | 2019 | 32 | 54.5 |
| 2 - one fixed | 1 | Not apparent | no compliance? - didn't score well for extreme retrieval. perhaps it is correlated Arm is very interesting, no fancy links just direct drive through a gearbox. Not very aesthetic though. | |
| Michigan Mars Rover Team | 2020 | 96 |
| 2 | 2 | Allen key has its own lead screw on the outside of the claw. Might be off center of rotation | No slip ring wires allow a certain number of twists Wire management is also kinda a mess on this bot. | ||
| Stanford Student Robotics | 2020 | 94 |
| 2 | 1 | Allen key coupled with the central lead screw that controls the jaws | Wrist looks like it has no slip ring. Jaws fold back, exposing the allen key, and the axis 6 screws in the screw. Looks like a coaxial axle is used to control both axis 6 and the jaws. They have a very good design. | ||
| BRACU University Mongol-Tori | 2020 | 93 |
| 2 shovels | 1 | Not apparent | Chain driven axis 6 is interesting. piston rod driven gripper is also interesting. Allows for axis six to 'wrap around' it without any issues. A sort of mechanical slip ring. | ||
| Missouri S&T Mars Rover Design team | 2020 | 93 |
| 2 spring loaded | 1 | Opposite side of the differential. Looks like it has multiple tooling bits! | gripper looks like it only half works, as one complies fully and the other does not. 2 cameras for each tool which doubles the expense there. Nice small cameras though. | ||
| Mars Rover Manipal | 2020 | 92 |
| 2 | 2 | Differential wrist with isolated Allen key with its own motor. | Very simple and cheap good design. Very epic CAD render transitions | ||
| Team Anveshak | 2020 | 91 |
| 2 | 2 | Allen Key is 90° from the claw and has its own motor | A nice compliant mechanism Very good claw. Love the Erasers. |
Additional Notes:
From other teams it seems strength of gripper is the biggest contributor to performance. the great variation in grippers also suggests also that the performance in each mission is heavily dependent on the performance of the arm and control system. This can be seen from IMPULS' very simple digit claw that has no compliance. compared to Michigan though, they have a cup shape grove which may help slightly
A lot of good teams, also have solenoids to trigger keyboard keys. this way the alignment can be done before hand without relying on dynamic precision.
Also note that no one uses slip rings! Also note that no one uses coaxial transmission shafts. It might be too difficult to design/too difficult to manufacture or just decided to go direct with the motor.
End Effector
This is the claw, tool bit and key stroke pusher rolled into one. It is used to grip items in retrieval missions, turn cap screws with a hex drive feature, and push keys on a keyboard. Previously, our team has used an square end Allen key to turn the cap screw as well as push the keys. Some teams use a solenoid to push keys.
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