This week we accomplished a lot; we completely finished the driving subsystem with the controller and we were able to start verification of this system. We had to revamp the driving because the motors were under powered and we also revamped the robotic arm to position the camera in a central location to simplify the task of alignment. These decisions to change the arm and the drive train was to mitigate the risk of time. The largest risk we have right now is that we are unsure if we will have enough time to properly verify and validate our design once we complete it. We also broke one of the servos and luckily we have a spare but frying another one would be a major setback when we have to wait for delivery. We updated the Gantt chart last week and we are feeling much more confident about our timeline; as we have been working some things have become complex and others simpler than we expected.
Verification has occurred for driving and controlling and we will begin verification for the arm this week. As far as full system validation we plan on driving the rover this week and trying to pickup items when we align the rover properly using our own vision. We will not be incorporating the camera just yet but we will be driving blindly to work on fine tuning the object detection. For validation of our proposed latency, as Hayden mentioned, we’ll be using a high frame rate camera to check how long signals take to go from button press to robot movement. So far, the movement has been pretty close to instantaneous, so we haven’t needed to worry about it too much. In terms of drive validation, we have validated our drive- the Rover moves in the fashion that we intended it to, and can connect from quite a distance and remain relatively seamless in operation. As Varun mentioned in his report, we’ll be verifying consistency of the arm subsystem by power cycling the rover and determining with a vertical marker if the Rover got to the correct Y and Z positions. After that, we’ll begin working to bring the separate systems together. Considering the simplification that the new arm brings, we should be pretty solid in terms of progress.
Biggest risk right now is the Servos breaking in testing, causing a large lead time to get new ones. The contingency plans are to switch to a smaller, more common, high-torque servo for the second stage in case this servo breaks. Quite a lot of changes were made to the overall system to better facilitate testing- however, the overall block diagram has not changed this week.
(HomeRover’s overarching redesign!)