Mechatronics 1A Study Robot (EV3)
Jordan, Justin, Rita, Sunil
The problem is that when students are studying, they will be too busy to get up and go grab what they need/want. The robot will be used to care for students who are either studying on any flat surface alone or with a group. It will dispense Advil, Tylenol, caffeine pills, and skittles depending on the recipient's needs. The EV3 will need to be redesigned to fit the cartridge carousel, as well as the sensors, and motors that need to be mounted to it. 2 motors will be used for the cartridge carousel, one to spin the carousel and one to dispense the items, which will both have controlled movement through the encoders. Another 2 motors will be used to drive the robot around. The buttons on the EV3 brick will allow for user input, while the gyro and color sensors will be used to determine where and how to move the robot. Additionally, the ultrasonic sensor will be used to detect whether a cartridge is empty or not. On the following page includes sketches of the EV3 and mechanisms for the dispenser. Timers will be used to wait a given time between the loops that the robot goes around, and loops will be used to repeat the times the robot goes around the path. Finally, decisions will be used to keep the robot on track, check if a button has been pressed, determine a user’s selection, etc. The bot will move around the table in a path laid out by colored tape using the color sensor. It will stop when a person needs something from the bot by pressing the middle button. Then, the bot will prompt and wait for a selection to be made of what needs to be dispensed, using the left, right, up, or down button. The group will be able to select what items they want to be dispensed by loading different cartridges that can be swapped out. There will be an ultrasonic sensor placed at the top of the rotating carousel of cartridges that will detect when there are no more items in the current cartridge. It will then prompt and wait for the user to replace the cartridge and press the enter button again to allow the robot to continue its path. At the bottom of the carousel there is a motor with a special wheel that only allows for a certain amount of items to be dispensed at one time (i.e. only dispense 2 Advil pills at a time). The program starts with the robot going slowly around the tape loop every 20 minutes. The center button can be pressed to go around the tape loop instantly and override the timer. When the robot has completed two loops without any user input, the program ends. One challenging aspect will be the dispenser and how it works. Being able to dispense one item at a time will be the main hurdle. The sizes of the items being dispensed will also need to be taken into consideration, which may result in a change of the items. Multiple sketches will be made to assess what needs to be done for the final design. Another aspect of the robot that we expect to be challenging is detecting when the cartridges are empty, as the ultrasonic might not be able to give us an accurate/correct reading.
Figure 1: Sketch of EV3 and how the dispenser and sensors will be placed.
Figure 2 & 3: Preliminary sketch of one dispenser mechanism.
Figure 4: Preliminary sketch of one dispenser mechanism.