Introduction: Tower Versus Bug by Team NWC
Group name: Team NWC
a. Description of our team & JI
We are Team NWC (abbreviation for New Warcraft) from the University of Michigan-Shanghai Jiao Tong University Joint Institute which is located in Ming Hang District in Shanghai, China. A photo of the JI is posted above.
b. Description of the game Warzone Tower Defense
This project is our first teamwork homework and we are required to:
(1) Build a robotic car (called the “bug”) that can move towards the tower at different speeds (0.2m/s and 0.4m/s in the bug test several days before Game Day) according to its location on the path drawn on the ground, it must also stop for 2~4s on the white line.
(2) Build a paper guard tower that can trace the 3 bugs (including those made by other teams) and “kill” it with the laser on its top.
c. Competition regulations
(1) The bug must use Arduino Uno to control its movement and there is a vertical board placed on the front on the acrylic baseboard of the bug.
(2) The tower must be made of normal A4 paper (80g per sheet), and the only adhesive allowed to use in the main body of the tower is white glues. The height of the bearing structure of the tower must be at least 60cm in height.
2. Material list
(1) Arduino Uno*1 199RMB (29.4USD)
(2) Acrylic board(200mm*300mm*6mm)*3 55.5RMB (8.2USD)
(3) Acrylic board(custom made)*1 15RMB (2.2USD)
(4) Motor driving board*2 30RMB (4.5USD)
(5) Aeromodelling battery(11.1V)*1 136RMB (20USD)
(6) Gear motor*4 64RMB (9.5USD)
(7) Low gear motor*1 18RMB (2.66USD)
(8) Glue gun*2 36RMB (5.3USD)
(9) Velcro tape (both sides included) *1 16RMB (2.4USD)
(10) Tracking module*1 13.8RMB (2USD)
(11) Infrared sensor*4 21.6RMB (3.2USD)
(12) Motor cabinet*4 8.2RMB (1.2USD)
(13) Insulated rubber tape*1 6RMB (0.9USD)
(14) Screw pack*2 17.1RMB (2.5USD)
(15) Battery box(switch included)*2 9.8RMB (1.5USD)
(16) Omnidirectional wheel*8 8RMB (1.2USD)
(17) 1.5V Battery*4 8RMB (1.2USD)
(18) Ultrasonic transducer*1 9.5RMB (1.4USD)
(19) Steering Engine*1 61RMB (9USD)
(20) Stepping motor*2 72RMB (10.6USD)
TOTAL 804RMB (118.6USD)
*P.S. The cost of the items include the freight and almost all the items are purchased online.(Here in China, the most common online shopping websites are taobao.com and jd.com )
Thanks to the special network environment here, we are only able to include a hyperlink to direct you to our testing video. I beg your pardon on the dark environment of the testing video, for the game is required to be carried out in darkness and it is the most bright surrounding we can provide. The video is also included as a file above.
The video is also uploaded at youku.com, one of the largest video website in China, the hyperlink is written below
Step 1: 2.Concept Diagram (bug&tower)
The hand-painted concept diagrams of the bug and the tower are shown above.
Step 2: 3.Circuit Diagram(bug)
The circuit diagram is shown above.
Step 3: 4. Functions of All Parts
Battery: supply power to the laser
Arduino Uno: control the steering of the servo and process the information from ultrasonic sensor.
Ultrasonic sensor: to test the distance between the tower and the small car
Bread board: extend some interfaces
Servo combination: control the direction of the laser
Laser: to irradiate the small car
Aeromodelling battery: supply power to the motor
9V battery: supply power to the Arduino
Motor: drive tires
Greyscale sensor: let the small car have the tracking function
Optical sensor: let the small car be able to sense the light
Arduino Uno: control the motor and process the information from greyscale sensors and optical sensor
Bread board: extend some interfaces
Step 4: 5.How to Build a BUG (robotic Car)
1.1 Cutting and assembling the acrylic board
We draw the graph using AutoCAD360 and AutoCAD2004(in order to convert it into the form which the laser cutter can recognize), after that we use the laser cutter in our school to cut the baseboard and the vertical board. In the process, I had intended to make the two board fit with each other so that we can assemble them just by inserting one into the other. However, because of the trial of the laser (which is about 0.1mm in width), we have to fix their location by using a hot melt glue gun.
1.2 Installing motor and wheels
As is shown in the picture, we make holes on the acrylic baseboard by using electric soldering iron so that we can make small adjustments easily, either in its size or its location (for it is sometimes difficult to decide the size of the holes to be made with nothing but the screws at hand), however it is inevitable that tiny deviation sometimes occurs so we recommend making the holes with the excavator if you know the screws' exact size. Then we use screws to fix the “omnidirectional” wheel that is not omnidirectional anymore and the motors on the bottom side of the baseboard.
1.3 Connecting circuit components and assembling the car
We connect different circuit components in order with electric wires and stick them on the car, which is a most common step. However, what makes our car unique is that we assemble different opponents by using Velcro with insulated rubber tape, which I think is a quite easy and convenient combination that can be used on such small products. What’s more, I think the greatest advantage of this combination is easiness to change the location of any components stuck on the acrylic board, which is pretty useful because frequent adjustments, whether big or small, are unavoidable in the process of assembling.
Step 5: 5.How to Build a TOWER(1)
Step 2.1 Build the Paper Tower
1. Fold an A4 paper(*3) to form two lapels and stick them together to make the wall of the paper tower, which is a triangular prism. (pic.1&4)
2. Fold half of an A4 paper(*3) to form two lapels and stick them together to make the supporting construction in the centre of the paper tower,which is a smaller triangular prism with its side half the length of the larger one.(pic.2&5)
3. Make two regular triangle lids and stick them on both sides of the tower. (pic.6)
4. Repeat 1~3 to make another paper tower and glue two paper towers together with white glue.
Step 6: 5.How to Build a TOWER(2)
Step 2.2 Add the Track Connector
1. Cut off three different shapes of A4 paper .(pic.1~3)
2. Glue the track connector to the paper tower.(pic.4~7)
Step 7: 5.How to Build a TOWER(3)
Step 2.3 Make the corrugated paper base
1. Make about 15(the number is not fixed) triangular prisms, thin and long.(pic.1&2)
2. Glue them together in a row as is shown in pic.3.
(It would be better if you stick two papers on two sides of it )
3. Glue the "corrugated paper" base on the paper tower.
Step 8: 5.How to Build a TOWER(4)
Step 2.4 Make the Supporter for the cloud platform
1. Cut off two squares, one of 3cm*3cm, and the other of 6cm*6cm(pic.1)
2. Cut off an isosceles trapezoid of 3cm and 6cm long in base and 4.5cm tall in height. (pic.2)
3. Glue two squares and four isosceles trapezoids together. (pic.3&4)
Step 9: 5.How to Build a TOWER(5)
Step 2.5 Locate the cloud platform and four sensors
1. Locate the cloud platform. (pic.1&2)
2. Locate four sensors.(pic.3&4)
Step 10: 6.Problem Shooting
(1) Since the laser is too heavy for the cable to support, I suggest making the part from the bottom of the laser to the rotation axis totally fixed. As for reference, a paper row that covers this part is a feasible solution.
(2)Because the tower is 60cm in height, at least two large triangle prism are needed, so the tower may be more sustainable if you insert a cylinder in the center, between two prisms.
(3)The car may be too heavy for normal motors to drive if the acrylic board is too thick, so we suggest those boards less than 0.5cm in thickness.