This past week I did more research into the chassis design and motor requirements of the robot. I looked into the energy and cost tradeoff between various stepper / servo motors, and decided that the NEMA 17HS4401 bipolar stepper motors seem to be an efficient option. Given that our robot should not carry much weight (around 7-8 kg), the torque size of 40N should be sufficient as the motor accuracies should not be as important as computer vision detection and recognition. The proposal feedback mentioned the possibility of eliminating omnidirectional wheels in the design. The team still thinks that omnidirectional wheels in an easier option, since our robot has the horizontal movement of scanning through the shelf, as well as the vertical movement of reaching forward and backward to retrieve the item on the shelf. After some research, I found that most similar projects use two L298N motor drivers, where each connects to two motor drivers and is controlled by the Arduino board. Since the focus of our project is to accurately detect items on the shelf, I optimistically believe for now that if there is high latency between communication between the jetson nano and the Arduino, it would not be of great concern.
I am on schedule for this week. After discussion with my teammates about the research I did, I would order parts on Monday and start the CADing of the chassis. I would also begin to look into the battery requirements once the other significant components are finalized on our robot.