Reflectance Sensor Testing
Function and Importance:
The reflectance sensors are able to detect the light that is reflected from the silver portions of the wheel. This reading is cut off each time the black surface of the wheel passes by the sensor (cutting of the reflection of light). The sensor is able to count how many times this occurs and create an accurate reading of how far the wheel has rotated. By tracking the rotations of the wheel, the reflectance sensors allow us to program how many times we want the wheels to turn and in doing so, program the distance we would like the AEV to travel.
AEV Concept Design
Individual Concept Designs:
Jesse Nadinic –
Description: The concept for this AEV design is to create a narrow face to reduce air resistance but to also have enough room to secure both the arduino board and the battery while keeping the motors out of the way of the other components of the AEV. Except for the structures supporting the arduino and the battery, the AEV will lie flat so that although the back end of the arduino is wider than the front, it is still relatively unaffected by air resistance.
Pros: Aerodynamic, Easy setup.
Cons: Need to curve front (may need an extra part), Possible structural implications with all of the battery weight on the thin front end of the AEV.
Nick Crawley –
Description: The goal of this design was to be as aerodynamic as possible through curvature and weight. The front the AEV design has domed surface that will house the battery, and this will cause wind to not affect the AEV as much as if the surface was flat. The design also uses very little material so that the least amount of power is required to move the design.
Pros: Light, Aerodynamic.
Cons: Difficult to construct.
Xian Zhang –
Description: The concept of this AEV design is to create a structure that can hold the weight of the battery and arduino board while running down the monorail. The design above shows a prototype sketch of a possible AEV design. To make the structure more aerodynamic, the front of the structure is more narrow than the back. This structure is also designed to use less material, which will require less power to drive down the monorail.
Pros: Sturdy design.
Cons: Bulky (weighs more than other proposed designs).
Initial Group Concept Design:
Description: The two AEV designs we will base our initial team design from are going to be Nick and Jesse designs. The initial design will use the narrow body of both designs so the that the AEV is as light as possible to require the least amount of force to move it. Both of the designs had a housing compartment for the battery, so the initial design will also have a housing compartment for the battery. Unfortunately, the domed/curved housing compartment on the front of Nick’s design will not be used due to the difficulty at which it would be to construct.
Pros: Maintains sleek body shape while neatly packing the AEV into a smaller, more aerodynamic space.
Cons: In the case of a crash the AEV will most likely take a lot of damage.
Final AEV Model:
The final AEV model is built to be as light weight as possible. With all of the major components located around the base of the support arm, the support arm is able to provide much more balance as the AEV’s weight is centralized. This design is extremely similar to the initial team concept design with the exception of the body structure. The body uses the same sleek design that was pulled from Jesse and Nick’s designs but the base has now been 3D printed to get rid of even more unused space. As can be seen in the Advanced R&D section, 3D printing was far lighter, and more cost efficient while also providing a similar level of strength. The two motor configuration was pulled from the testing done during the Advance R&D phase which showed that a two motor “pull” method would yield the farthest distance. For this reason the final design puts the two motors on the same side so that they can be used to pull the AEV once the additional load (the caboose) is added.
Research and Development Lab Four (Data Analysis Tool)
Energy v. Time Plot:
Energy v. Distance Plot:
Concept Screening and Scoring
(Click the picture to make clear)