A VEXciting New Experiment
By Dustin Brandl
Introduction/Background Information:
Design Brief:
The general design brief for the VEX robotics groups is to design and construct a remote, battery operated vehicle with capabilities to perform amphibious tasks. Brandl’s individual design brief is to design and construct all of the electrical components of a small, remote controlled vehicle that is positively buoyant and will complete all of the designated challenges.
Specifications:
· Must be able to safely move eggs without damaging them
· Must fit in the pool which is made from materials that are present in the lab.
· The pool is built with the dimensions10’by 10’by 10’
· Must be able to efficiently complete all of the challenges
· Cannot crush or damage the piping plover eggs
· Launch or place a ball through the hoop
· Tug a small vessel and drop it
· Plant a buoy
· Sink a ship
· Cut a line of twine
· Must be remote operated
· Must be built from the VEX kit
Limitations:
· Must be finished by May 2012· Must stay within budget
· The supplies which we were given
· Energy
· Team members (two people)
Testing Procedures:
The final solution of the terrestrial VEX robot must be able to safely relocate the eggs of the endangered piping plover without damaging the surrounding environment. The final solution for the aquatic variant of the VEX robot must be able to maneuver around a 8’ by 8’ by 8” tank and complete a set of challenges. These challenges are placing a ball through a hoop, towing a friendly vessel, planting a buoy, and sinking an enemy vessel.
Brandl’s group gave a series of tests, ranging from preliminary tests to final tests, on the VEX robot design in order to create the optimum VEX robot. There are a various amounts of testing that go into the process of creating a VEX robot, and these include exploratory tests, assessment tests, validation tests, and comparison tests. Exploratory tests are questions which are asked by each group in order to begin designing. Assessment tests are used to determine the creation and development the alternate solutions. Validation tests are the tests given to each alternate solution during the rationale process to determine the best solution. Comparison tests are tests given to possible the apparatuses in order to define the better solution.
Alternate Solutions:Before Brandl could begin construction, he had to first decide what would be the best method for completing each challenge. During his process of finding different alternate solutions, Brandl had to draw each of his ideas of completing each task. They are listed below.
Scoop- The scoop will be mounted on the front end of the VEX robot and only be used for the terrestrial challenge. A winch and pulley system will be attached to the scoop in order to allow it to move up and down. As it approaches the piping plover nest, the scoop will be lowered and the robot moved forward. The eggs will slide into the scoop, and then it will be raised.
Slingshot- The sling shot will be mounted to the VEX robot’s aquatic variant at an angle. A ball will be placed in the sling of the slingshot and a mechanical arm, attached to the rack gear box bracket, will pull the sling back. At the proper moment, the sling will be released and the ball will fly through the air and through the help.
Magnet- The magnet will be attached to the aft end the VEX robot and to the stranded vessel. Once the VEX robot has lined up with the opposing magnets, they will be turned on. The VEX robot will carry on to the destination at which point the magnets will be turned off and the vessel will have reached its destination.
Bucket- A small bucket will be attached to the side of the VEX robot. This will be dipped into the water and the water will be dumped into the enemy vessel. This will eventually sink the enemy vessel.
Rationale Report:
After Brandl had gathered his ideas on what to make, he had to decide what he was actually going to use on the VEX robot that would be his senior project. Before Brandl could begin any construction on the VEX robot, he had to first conduct a rationale report in order to find the best apparatus for each challenge. For each challenge, he came up with three alternate solutions that could be used to complete each task. The next part of this process is to decide which solution would
Solution 1
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Solution 2
|
Solution 3
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Challenge 1: Placing a Ball Through a Hoop
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Criteria
|
Claw
|
Catapult
|
Pinball Mechanism
|
Access of Materials
|
5
|
3
|
2
|
Accuracy
|
4
|
2
|
2
|
Ease of Production
|
4
|
4
|
3
|
Efficiency
|
5
|
4
|
3
|
Total
|
18
|
13
|
10
|
Challenge 2:Towing a Friendly Vessel
|
Claw
|
Mechanical Arm
|
Magnets
|
Criteria
| |||
Access of Materials
|
5
|
5
|
2
|
Accuracy
|
4
|
5
|
5
|
Ease of Production
|
4
|
5
|
2
|
Efficiency
|
4
|
4
|
5
|
Total
|
17
|
19
|
14
|
Challenge 3: Sinking Enemy Vessel
|
Claw
|
Mechanical Arm
|
Bucket
|
Criteria
| |||
Access of Materials
|
5
|
5
|
4
|
Accuracy
|
3
|
4
|
4
|
Ease of Production
|
4
|
4
|
2
|
Efficiency
|
2
|
4
|
2
|
Total
|
14
|
17
|
12
|
Challenge 3: Planting a Buoy
|
Claw
|
Mechanical Arm
|
Slide
|
Criteria
| |||
Access of Materials
|
5
|
5
|
4
|
Accuracy
|
4
|
3
|
5
|
Ease of Production
|
4
|
4
|
4
|
Efficiency
|
5
|
3
|
4
|
Total
|
18
|
15
|
17
|
Plan of Procedures:
After Brandl had decided what to produce on the final product, he had to come up with a step-by-step instruction guide on how to build his VEX robot. Keep in mind that Brandl is the electrical engineer. The plan of procedures for the electrical engineer begins while the plan of procedures for the mechanical engineer is being completed.
1. Attach the PIC Microcontroller to the center of the structural hull with a screw at each corner.
2. Attach the receiver module to the left of the PIC Microcontroller with a screw in each corner.
4. Connect the power pack into the appropriate port on the PIC Microcontroller.
5. Attach a servo to the inside, forward, starboard side of the hull with two screws in order to attach to the mechanical arm.
6. Connect the servo wire to the motor port on the PIC Microcontroller.
7. Attach a motor to the port, aft, projection of structure and connect it to the shaft. This shaft connects to the claw.
8. Connect the motor to the 29-motor controller and connect that to the PIC Microcontroller.
9. Connect a servo to the claw.
10. Connect the servo wire to the servo extension wires.
11. Connect the end of the servo extension wire to the PIC Microcontroller.
13. Attach the shafts to the propellers to these motors.
14. Connect the wires of the motors to the 29 motor controllers.
15. Connect the 29 motor controller wires to the PIC Microcontroller.
16. Charge the battery to the remote controller and the power pack.
Final Product Construction:
Now that Brandl had completed all of the steps, he could now begin production. The mechanical engineer had his own plan of procedures that he had to follow in order for Brandl to do his part. Both Brandl and Brzozowski followed their plan of procedures in order to complete their VEX robot. Images of construction have been distributed throughout the article. When the “fine-bombing night” came around, Brandl and Brzozowski were able to complete each challenge in front of a large audience. Overall the project was a success.