Advanced Research and Design 1: Testing Prototyped Parts [6]
Ways for us to compare protyped parts:
- Attach parts we already have to create the piece
- Use our grant to 3D print a piece
- Use different configurations of plastic pieces. That is, create a base and test many types of wings on the base. Create one type of wings and test many types of bases.
- Create a part in Solid Works and find the volume and mass- attempt to calculate how this piece will run.
After we have compared prototyped parts, the prototypes that are the lightest weight and most cost-effective will be tested in trials to collect data. After this data is collected and compared to the parent design, the AEV may be modified in size or weight to complete the desired task of speed and cost efficiency.
Testing the parts began by half of the team creating the desired part with pieces already in the AEV kit, while the other half of the team created the part in SolidWorks. The team worked to create a base piece that would replace the need for multiple pieces on the base. It also supplies a space for the battery to be securely held, making the need for zip-ties void. The piece created by the team was very heavy and off-balanced, and made the AEV only able to move at 80% power.
The part on SolidWorks was thinned to 1/4″, and linearly spaced holes were placed throughout to reduce the weight of the part. These holes were also placed in spaces that allow for screws to be inserted that hold the wheel arm and arduino in place. Once the piece was 3D printed, the AEV design was turned on its side, to increase balance. The new part only required the addition of the wheel arm, battery, arduino, and motors. This part hangs off the track perpendicularly to the ground, meaning that it is totally balanced. Additionally, the reduced need for zip-ties and plastic parts means that the part is very aerodynamic and as light as possible, making it run with very little power; as low as 35%.
Our prototyped part, fully assembled with the AEV is shown below:
Also in Advanced Research and Design was Performace Test 1. The vehicle was required to travel up the first hill, pause at the stop sign for 7 seconds, and then proceed. The code our team used to complete this is shown below, as well as a video of the AEV completing the run.
celerate(4,0,70,2); //accelerate all motors from 0 to 70 percent power in 2 seconds
goToAbsolutePosition(-255); //Go to 255 ticks in the negative direction
brake(4); //Brake all motors
reverse(4); //reverse all motors
motorSpeed(4,75); //set all motors to 75 percent power
goFor(1); //go for 1 second
brake(4); //brake all motors
reverse(4); //reverse all motors
motorSpeed(4,0); //all motors set to zero percent power
goFor(7); //stand still for 7 seconds
celerate(4,0,70,2); //accelerate all motors from 0 to 70 percent power in 2 seconds
motorSpeed(4,70); //set all motors to 70 percent power
goFor(2); //go for 2 seconds at set power
brake(4); //brake all motors
Advanced Research and Design 2: Reflectance Sensors [6]
An issue that Group L was consistently running into was the operation of the reflectance sensors. They seemed to only work sometimes, and work other times. The times they did work, they rarely were able to operate with the position functions correctly. In order to focus on this for aR&D 2, the team came up with possible problems related to reflectance sensors:
- incorrect orientation in Arduino
- poor wire connectivity
- wires not laying flush against wheel arm
- incorrect destination in sketchbook
In order to attempt to fix these, the team referenced the Reflectance Sensor Manual [4], and went over the instructions very slowly; essentially starting from scratch with these sensors. The team discovered the correct orientation of the sensors, shown below:
The team discovered a way to keep these sensors plugged in at all times, by simply removing the wheel arm and placing the vehicle in the box. With this orientation, the sensors always run correctly. If the wires are not flush against the wheel arm, as shown below, the magnetic tape will not track the progress correctly.
The zip tie was added to ensure the wires stay positioned correctly. Poor wire connectivity was solved by replacing the wires, and various TA’s were consulted to ensure the correct sketchbook destination. With these measures having been taken, the team was able to complete 10 reflectance sensor tests, with the expected results (positive direction vs. negative direction) arising each time. An excerpt of these is shown below:
Advanced Research and Design 3: Propeller Configuration [6]
Potential Propeller Configuration:
- Propellers on either side of AEV
- 2 small propellers, both on the same side
- 2 large propellers, both on the same side
How we will test:
- Check the power that each configuration takes to run
- Test how far the AEV moves at a set power and time
Hypothesis:
Potential configuration 1 will not move the AEV, as our vehicle is not designed for the propellers to be placed on both sides. The larger propellers will move the vehicle further, faster, with less energy. We already know that the AEV is more powerful when it is pushing. Orienting the propellers so that they are pulling the AEV when no caboose is attached, and pushing the AEV when there is a caboose.
The results, for movement of the vehicle are:
| Small Propellers | With Caboose? | Power Input | Time | Distance Travelled |
| Trial 1 | No | 50% | 30 s | 30 in |
| Trial 2 | Yes | 50% | N/A | Doesn’t Move |
| Large Propellers | ||||
| Trial 1 | No | 25% | 10 s | 35 in |
| Trial 2 | Yes | 25% | N/A | Doesn’t Move |
| Trial 3 | No | 50% | 10 s | 300 + in |
| Trial 4 | Yes | 50% | 10 s | 230 in |
Energy consumption is:
Figure 1: Small Propellers, 50% power, with caboose
Figure 2: Large Propellers, 50% power, no Caboose
Figure 3: Large Propellers, 50% power, with caboose
Figure 4: Large Propellers, 25% power, no caboose
Figure 5: Small Propellers, 50% power, no caboose
Figure 6: Performance Test 2 data:
