MEET THE TEAM
Project Overview
In this year's ME218b project, we were tasked with building robots to help Stanford expedite its ever-expanding construction efforts. Each robot needed to drive from the starting line to "staging areas," marked by triangles on the playing field. At each staging area, the robot unlocked the area for construction by sensing the frequency of a pulsing magnetic field located under the area and reporting the frequency back to a Logistic Operations Coordinator (LOC). Once a construction site (orange bucket) was unlocked, the robot shot the construction materials into the construction site. If a construction bot ran out of construction materials, it could drive to the supply depot to retrieve additional construction materials (foam balls). The team that delivered the most materials was declared victor.
In essence, the robot needed to drive autonomously, navigate, shoot and reload balls, and communicate using several different methods. For mobility, we used two Maxon motors to independently command two wheels. For navigation, we used two RLC tuned circuits to follow a 20 kHz pulsing line underneath the playing field. To shoot construction materials (foam balls), we used a flywheel motor, encoder and ramp to launch the balls. Finally, we communicated directly with the LOC using Synchronous Serial Interface (SSI) communication. We also used an infrared LED to request balls from the depot and a photo transistor to aim at the construction zones.
In essence, the robot needed to drive autonomously, navigate, shoot and reload balls, and communicate using several different methods. For mobility, we used two Maxon motors to independently command two wheels. For navigation, we used two RLC tuned circuits to follow a 20 kHz pulsing line underneath the playing field. To shoot construction materials (foam balls), we used a flywheel motor, encoder and ramp to launch the balls. Finally, we communicated directly with the LOC using Synchronous Serial Interface (SSI) communication. We also used an infrared LED to request balls from the depot and a photo transistor to aim at the construction zones.
Project Specifications
- Be autonomous and un-tethered.
- Use TI's Tiva Launchpad as the microcontroller for the robot
- Use the motor's provided to navigate the playing arena.
- Use only NiCd batteries. No more than two 7.2V batteries may be used for the drive motors.
- Indicate to the audience whether our bot is on team Red or team Green.
- Be fully contained within a 1’ cube at the beginning and end of the game.
- Carry a maximum of 5 foam balls at a time
- Cost less than $200
- Must be constructed as part of ME218b - it may not be based on a commercial or otherwise pre-existing platform.
Project Description
The nitty-gritty details:
The 2017 Stanford ME218B competition was a tournament of autonomous robots, otherwise known as TaRgeted Extremely Ballistic Universal Containerized Heavy Engineering Trucks (TREBUCHETs). The project’s goal was to demonstrate mastery of concepts from the 218b course. Specifically we applied our knowledge of motors and motor drivers, SPI communication, signal conditioning, hierarchical state machines and noise reduction, to build our TREBUCHETs. As described above, the theme of this year’s competition was construction.
The LOC communicated when the game was active to the TREBUCHETs. At this point, each TREBUCHET communicated with the LOC to determine the requested staging area. The robots navigated to the instructed staging area and "unlocked" it by correctly reporting the local magnetic field frequency. An inductor underneath each staging area generated the pulsing magnetic field. The LOC used a synchronous serial signaling method to transfer data into and out of the LOC compatible with SPI communication. The the LOC operated as a slave device on the SPI network. After unlocking each construction site, the TREBUCHET shot construction materials six feet to reach the construction site. Each field also had one "Supply Depot" to distribute additional construction material packages (foam balls).
The 2017 Stanford ME218B competition was a tournament of autonomous robots, otherwise known as TaRgeted Extremely Ballistic Universal Containerized Heavy Engineering Trucks (TREBUCHETs). The project’s goal was to demonstrate mastery of concepts from the 218b course. Specifically we applied our knowledge of motors and motor drivers, SPI communication, signal conditioning, hierarchical state machines and noise reduction, to build our TREBUCHETs. As described above, the theme of this year’s competition was construction.
The LOC communicated when the game was active to the TREBUCHETs. At this point, each TREBUCHET communicated with the LOC to determine the requested staging area. The robots navigated to the instructed staging area and "unlocked" it by correctly reporting the local magnetic field frequency. An inductor underneath each staging area generated the pulsing magnetic field. The LOC used a synchronous serial signaling method to transfer data into and out of the LOC compatible with SPI communication. The the LOC operated as a slave device on the SPI network. After unlocking each construction site, the TREBUCHET shot construction materials six feet to reach the construction site. Each field also had one "Supply Depot" to distribute additional construction material packages (foam balls).
me218bprojectdescription1617.pdf |