Table of Contents
The detailed design section of our project will focus on the specific design of components and sub-components within the system. Each component is relevant to that of the overall design of the project. Based upon our system and sub-system level designs, the detailed design includes layout of our enclosure (box), the powering control board, the motorized mount, and all other sub components.
Prototyping, Engineering Analysis, Simulation
- Updated Feasibility Analysis
This is the prototype code that lays down the plan as described in the programming flowchart.
- The moment of inertia was re-calcuated based on the purchased mount solution as well at the camcorder that will be used. Using the parallel axis theroem, the mass moment of inertia was found to be 9.56lb*ft^2. This was much larger than previously estimated, mostly in part to the different camera/camcorder.
- With the new moment of inertia calculated, the Camera Mount Limitations could be derived.
Detailed Solution Design
Hardware Enclosure DesignThe layout inside the enclosure was also important to take into consideration. Due to space limitations of the enclosure itself, it's important to carefully lay out each major component that needs to go inside the enclosure. The major components to go inside the enclosure include the micro-controller, the Geo-PNT, the battery, and the power control board. The goal of the enclosure is to allow the system to be used regardless of the transportation medium.
The system should be water resistant in case of sudden rain. Special attention was taken to design as water resistant an enclosure to protect the hardware and electronics. Other options are being considered for protection of the mount and camera.
Transportation MountingFor testing as well as the marketing video, a car will be used to showcase the capabilities of the Geo-PNT. The system will be mounted in the back of a truck bed on a stand. This will allow for unobstructed view for the camera as well as maximum sky-view for the GPS antenna.
Detailed drawings of all components can be found here
Power Control Board Schematic & Layout
The power control board will regulate the battery to the various voltages required for each sub-component. These sub-components that require the various voltages include the micro-controller, servo driver board (to power the motorized mount), and the Geo-PNT. Each of these components require 9V, 6V, and 12V respectively, each with their own current limitations. Based upon these constraints, a power control circuit was able to be constructed to regulate the 12V battery, and also give an indication of its status. The schematic was designed using Novarm's DipTrace software.
Once the schematic was completed and components carefully selected, the final "printed-circuit-board" was created again using Novarm's DipTrace software. The input power (coming in essence from the battery) will connect through a 2.1mm x 5.5mm barrel connector. The battery status indicator will mounted to the backside of the PCB, and the PCB will be mounted to a side wall of the box with a cutout, so as to be seen from the outside. A section of the board was designated for proto-typing space, if expansion or re-design is necessary during the building and testing phase. It is also worth note that mostly through-hole components were selected (aside from the ICs, diodes, and inductors) in the attempt to decrease complexity for soldering and troubleshooting.
Cables and Assemblies Diagram
The system will be comprised of several different cables or connections between each component. The chart below shows the analysis performed by the team for each cable required to link each respective component within the box and system.
Bill of Material (BOM)Each sub-system within the project was broken down into a component level, which then comprised a budget. From the budget, it was possible to derive a bill of materials (BOM). Each component of the system was broken down into 6 categories: Internal Box Mechanical Hardware, External Mechanical Hardware, External Electrical Hardware, Internal Box Electrical Hardware, PCB, and Video/Demonstration.
A link below is provided for a more detailed view of the finalized bill of material, showing every single component that will be utilized in the system with price, manufacturer, manufacturer part number, and a link to each component.
Each sub-system has a testing method individual of the other systems in order to verify that all components are in working condition before assembly.
Tables were used to list all functions of each subsystem to ensure the tests were designed around verifying all aspects of a component.
- Build up the OWL System
- Test individual components to the test plan
- build up the car mount
- Edit the CAD package as necessary
- At the completion of MSD I, all electrical design considerations have been met in terms of powering each component in the system.
- Moving forward, the Gerber files for the PCB will need to be exported and sent off for ordering, while all other components on the board will also need to be ordered.
- Once parts come in, the board can be assembled, tested, and modified as necessary for our needs.
- In terms of the cables, all cables will need to be ordered and also made to begin the testing and verification of our system, since all components need to be linked.
- After receiving the microcontroller and shields, we will begin first to implement our programs required for testing components on our test plan.
- After this, we will begin working on the pointing algorithm and implementaton.
- Meanwhile, we will work on using OpenCV to develop our error handling program. An example of this software can be found here.
- We have began to implement our edge detection algorithms using previous experience with Sobel edge detection on still images using VHDL.