Team Vision for System-Level Design Phase
We plan to gain a greater understanding of the systems and determine the feasibility of our future plans by:
- Decomposing the system's functions
- Brainstorming concepts for new system features
- Reviewing all code together as a team
- Testing the GPS with RTK
- Testing the usability of the new donated IMU
- Testing the feasibility of updating the GUI
- Updating functional and physical diagrams of the system architecture
- Updating the risk register
- Diagnosing and replacing the steering controller
Functional Decompositionhere to view the document.
Functional Breakout Diagramhere to view the document.
ROS System Diagramhere to view the document.
Feasibility: Prototyping, Analysis, Simulation
- The current GUI is very basic, bare minimum needed for basic testing functionality.
- No maps, LIDAR, GPS, etc are shown.
- A GUI will be implemented to cover all basic needs for ImagineRIT.
- GUI shall show a set map, and options for the passenger to choose end locations.
- GUI should, on destination selection, change to show information such as LIDAR data, moving gps coordinates, motor and sensor data, as well as other information.
- GUI should be simple to use.
- A template GUI will be constructed, laying out the overarching design for each component.
The intended operating area is shown below:
The previous team's GPS feasibility analysis was repeated in and around the new operating area.here to view the document.
GPS with RTK
- From prior experience, getting a functioning RTK GPS is not worth it.
- Development time is long and not guaranteed.
- RTK will only work in select places on campus.
- Will not work next to buildings or trees.
- Takes a long time to get RTK lock.
- Will be used for collision avoidance.
- Will be the external source of data used in mapping and navigation planning.
- The main implementation will make our precision as low as our accuracy.
- IMU will be fused with single point precision GPS.
- Will give more accurate current position data.
- Currently working well.
Risk Assessmenthere to view the document.
Diagnosing and replacing the steering controller
Issues with Steering Controller
- When steering system was powered on there were no signs of life from the controller.
- Controller should blink LED when powered.
- LED should extinguish shortly after power on.
- Commands to steering system were ignored by the controller.
- Fuse was not blown.
- Grounding wire to controller was overloaded and burnt.
- Presence of proper drive signals and operation of the control loop were verified.
- An electrical resistance check between all connections was executed.
- Invasive measures were used after preliminary tests failed to provide a reason for the broken controller
- It was found that 48V battery voltage entered the steering system through the power lead.
- This short between power systems occurred due to a wire splice rubbing on the motor terminal for an extended period of time.
- The short only required the stock drive system of the APM to occur.
- Click here to view the report.
- The short and break in the connection was repaired temporarily with a cable shroud and electrical tape.
- The burnt ground wire and power wire was re-run.
- The existing connectors were added to the new controller and the new controller installed and tested.
New Risks Generated
- The 12V battery is in need of being replaced.
- It will discharge completely overnight and can not support the draw of the steering and braking systems.
- In general, the battery maintenance and the electrical integrity of the cart need to be assessed and upgraded.
Design Review Materials
Plans for next phase
- Continue research of LIDAR localization implementation
- Begin design and prototype of path planning algorithms
- Draft sketches of new GUI
- Evaluate current obstacle avoidance performance
- Design brake switch
- Begin creating test plans for MSD II to confirm ERs and CRs
- Update risk register
- Create a Bill of Materials