Integrated System Build & Test
Table of Contents
Team Vision for Integrated System Build & Test PhaseDuring this phase, the team was focused on a few different important topics:
- Completing and purchasing the redesigned PCB
- Getting remote control functionality
- Completing the sonar mount
- Wiring and testing ultrasonics in mount
- Some basic obstacle detection using the LiDAR
- Troubleshooting/fine tuning subsystem parameters
PCB DesignIn order to redesign the PCB, a number of different tasks had to be performed. Firstly, the key functions of the board were identified based on the team's desired functions and systems in place. With all these functions in mind, the circuitry for the board was then designed. The team then received input from multiple subject matter experts to identify any areas of concern. Lastly, the design was changed based on the subject matter experts feedback and sent to be fabricated and printed.
Screenshots of the PCB can be seen below:
Remote Control ModeAlso completed in this phase was remote control functionality. This was done by setting Arduino 1 to control the cart's subsystems. Then, communication was established between the remote control and a ROS node where the ROS node would send signals to the Arduino based on the input from the remote. This was then tested to ensure that constant, correct communication was established between the control and the subsystems.
The remote control can be seen below:
Vehicle SimulationDuring this phase, the vehicle simulation model was looked into deeper to provide realistic, actual data for outputs of the cart based on certain inputs. This was done by first adapting the simulation to accept external input. Then obstacle detection and stopping was looked into to try and get the simulation to respond to obstacles in the path. The next point would be for the simulation to be able to avoid obstacles.
Below can be seen of some input from the simulation:
UltrasonicsAll seven ultrasonics were tested together. After passing the various tests, they were they put into the mount. The mount had been decided by the team and the customer to be more of a prototype mount just to collect data while a future phase will be responsible for constructing a more safe, reliable mount.
Pictures of the mount with the ultrasonics put into them can be seen below:
Microcontroller & Computer CommunicationOriginally, the team planned on using ROSserial for the communication between the microcontroller and the computer. When trying to implement this, many issues had occurred. These issues involved being that it was not very fast, reliability problems after approximately 10 minutes, and problems using Arduino Due in conjunction with it. Because of this, the team decided to use ROSdue, a custom solution built from scratch. This method used Arduino Serial and also allows the team to meet its requirements for communication. These requirements involve being fast, lightweight, and robust.
- Uses ROS node and Arduino library
- 115200 Baud Rate (Adjustable)
- Interfaces for both publisher and subscriber
- There is s 3-way handshake for subscribers
- Timeout of 0.5 seconds
- Robust - Message length checksum
- Robust - Character range and type verification
- Robust - Automatically restarts when failure occurs
Risk and Problem Tracking
Functional Demo Materials
Plans for next phaseThe plans for the next phase include:
- Finishing up the ultrasonics programming
- Diving deeper into obstacle detection using LiDAR
- Configuring the IMU
- Continuing with vehicle simulation
- GPS implementation
- Path Following Control
- Obstacle Detector
For more information about the future of this project, please click here to see the remaining schedule for MSD II.