Based on our individual design concepts the team came up with priorities for the future design:
Preliminary R&D
- Allow the AEV to be able to move backwards as easy as forwards
- Create a symmetrical front to back design
- Make sure the AEV is balanced on the track
- Include aerodynamics to save energy
- Make the AEV as light as possible
- Avoid over-complicating the design
Advanced R&D
- Use Coasting method to preserve as much energy as possible
- Avoid large drainage in lithium ion battery
With these priorities in mind, our team came up with and built a sample AEV. In order to make our design more symmetrical, we used the X shaped frame instead of the T shaped frame that we had all implemented in our individual drawings. This X shaped design allows us to put the motors and propellers in the middle of the AEV, which we believe will allow the vehicle to travel with ease in both directions instead of just one. This is very important, as our AEV has to go forward to pick up the caboose, but also has to travel backwards on the way back. In order to balance the AEV on the track, our team did some testing on where to place the battery in order that the vehicle is balanced. After some tests, we found that placing the battery on the right wing allows the AEV to be almost perfectly balanced. In the future, we hope to design and 3D print parts that will allow our AEV to be more aerodynamic.
Below is a sketch and image of our sample design AEV:
The team carried the above design into the Performance Testing stage of the AEV Design project. The following conclusions were made from the Performance Tests.
Performance Testing
- Battery placement on the top of the AEV between the Arduino and arm is the best placement
- A ziptie can be used to secure the battery here, which saves cost of materials as well as vehicle weight.
- More energy was used when the battery was secured to the bottom of the AEV due to more drag/friction force
- Reflectance Sensors must be utilized in order to write accurate codes
- Using time commands is too inaccurate due to battery differences and voltage drainage
With these ideas in mind, the team stuck with the original design and completed the Final Performance Test with great efficiency and accuracy. Solidworks drawings of the final model can be found below.
