Date: 3/31/2023
Number of Runs: 1
Reflection:
The goal of Performance Checkpoint 4 was for the robot to travel to complete the passport stamp task as soon as the light turned on. Points were incrementally awarded as the robot progressed in flipping the passport lever, and bonus points were awarded for returning the lever to its initial position after stamping. After a series of failed practice runs due to misalignment, our robot passed the performance checkpoint on Friday and received bonus points.
Our passport stamp mechanism is a servo-controlled, two-pronged fork that interfaces with the passport lever wheel to rotate the lever in a range of 180 degrees. The fork is 3D-printed and mounted directly to a Futaba servo propeller. We chose this design because it is relatively space-efficient and requires only a single servo; it also cost about $6 in total. Fortunately, our Futaba servo proved more than capable of supporting the weight of the fork and entire passport lever.
However, this design is not perfect. Our design did not function as we expected it to originally. Our robot experienced more problems this time round than with prior performance tests. There were both software and hardware problems that needed to be addressed. The prongs are wide with sharp edges, and minor differences in height between the servo and passport lever wheel occasionally prevent the prongs from fitting. Along with some imprecision in our RPS navigation, these problems caused all of our practice runs to fail, including a practice run we attempted after our successful graded run. We have so far been unable to replicate that run.
Before the individual showcase, we plan to sand-down the prongs and fillet the edges in the hope that they guide the prongs into the lever wheel in cases of minor misalignment. We may also explore supplementary methods of aligning the prongs because our RPS navigation code is already operating at maximum precision; any more and the robot would be stuck in an alignment loop (which we experienced while tuning the precision).