Introduction: Tower-Defense-Versus-Bugs

(1)University and course Introduction

We are group CIVA (C for cooperate, I for innovate, V for value and A for appreciate) from Shanghai Jiaotong University Joint Institute(JI).(fig.1) In fig.2, the first row from left to right are Chen Jiayi, Shen Qi, and the second row from left to right Zhan yan, Zhu Ruiyang and Qiu Tianyu. Fig.3 is our team logo. SJTU is one of the top universities in China, and JI is a leading institute specialising in engineering which has just won the ABET certification. As freshmen, we are required to of 1 13 Instructor:Dr . Shane Johnson & Irene Wei

fig.1 fig.2 fig.3 attend VG100, introduction to engineering, a course in which students work in teams to learn to cooperate, innovate and communicate.

(2)Competition Introduction

The first project of the course is in the form of competition. Our competition is like the game tower defence. Each team is required to make a paper tower with a laser on the top and a bug, which is actually a robotic car. Three bugs (randomly chosen) will approach the tower in the fixed path one by one and the tower will have to use the laser to kill them before they reach it.

(3)Rules of the competition

• Every enemy bug will be chosen randomly.

• The three-round race goes on in ascending sequence.

• Bugs won’t be killed in the first 0.5m protection area.

• The game starts after the bugs pass the protection area.

• Bugs should stop at the white line 1.5m away from the starting line for 2-4s (if it hasn’t been killed then)

.• When the bug goes faster than 0.4m/s, it can’t be killed by the laser.

• Kill the bugs one by one before they reach the tower.

• No touching of the bug and tower after the game begins. • Substitutes for motors, wheels, laser and photosensors are not allowed.

(4)Competition regulations and requirements

Paper tower

• Height: Minimum 60cm

• Material: A4 80g; white glue

• Stacking: Maximum 3 sheets


• Speed: 0.2-0.3m/s

• Motor specification: <12V • Size: 15*10cm vertical front board

• Height: 5cm high from the ground (photosensor)

• Routine: Go straight

• Function: Stop as soon as irradiated by the laser

(5)Tournament video

Attached below is the performance of our bug on the game day. We managed to kill one bug at the distance of 1.8m.

Step 1: Concept Diagram

Step 2: Material List

Step 3: Paper Tower Step 1: Circuit Diagram

Step 4: Paper Tower Step 2: Building the Tower

1. Divide a piece of a4 paper into six equal parts and tear them apart in the middle.

2. Draw two horizontal lines at the top and bottom about 1cm from the edges. (fig.2.1)

3. Cut along the 1cm line and fold along the drawn lines. (fig.2.2)

4. Make twelve of these slips.

Step 5: Paper Tower Step 3 Making the Base

1. Divide a piece of a4 paper into halves and then draw six equidistant lines. (fig.2.3)

2. Keep four of them and fold along the lines. (fig.2.4)

3. Stick the first and last part together to form six triangular prisms. (fig.2.5)

Step 6: Paper Tower Step 4 Making the Base Assembling the Tower

1. Use white glue to stick six slips together one by one to form a hexagon pillar. (fig.2.6)

2. Add a base to the tower. (fig.2.7)

3. Stick another pillar onto the fixed one.

4. Stick the little triangular prisms onto the top of the tower. (fig.2.8)

5. Put Arduino, steering platform, laser and battery onto the top of the tower.

6. Stick four ultrasonic modules onto each side of the tower on the bottom.

7. Connect all the wires as designed. (fig.8)

8. Upload your program into your Arduino with Arduino IDE and test your laser.

TIP: You can use Dupont wires of the same colour to connect each ultrasonic module to avoid connecting mistake.

Step 7: Paper Tower Step 5 Final System View

Step 8: Bug Step 1: Circuit Diagram

Step 9: Step 2: Cutting the Acrylic Board

1. Determine where you would like to locate your components and draw the outlines and locations of each part.

2. Use an automatic laser cutter (in which case you should do the drawing by software AutoCad) to cut the board or by hand and drill the holes (usually the diameter is 2mm or 3mm according to the size of screws you choose). (fig.3.1&3.2)

Step 10: Bug Step 3: Preparing the Components

1. Solder the two motors with two Dupont lines each. (fig.3.3)

2. Insert a coupler into the back tires and then insert the motor into the coupler. (fig.3.4)

3. Solder the photosensor. (fig.3.5)

Step 11: Bug Step 4: Assembling the Bug

1. Fix all the components including motors, brackets, Arduino, L298N and battery onto the board with screws and nuts. (fig.4.1)

2. Stick two fixed casters and a tracking sensor onto the board in the front. (fig.4.2)

3. Fix the front vertical board onto the base board and fasten it with two L-brackets. (fig.4.3) 4. Fix another motor bracket onto the front board to support the photosensor. (fig.4.4)

5. Fix two pieces of white paper closely next to the photosensor making the total width 4cm (same as the white line on the game path) to enable diffuse reflection. (fig.4.5)

Step 12: Bug Step 5: Final System View

Step 13: Problem Shooting

If you have the following questions, we have listed solutions to each of them.

Q1: Why I can’t change the speed of the motor of the car?

A1: Make sure that you have connect the ground and the negative pole of the battery.

Q2: How can l enable the bug to go straight?

A2: Adjust the data of the two driving motors on your program to make sure they rotate at the same speed.

Q3: Are there any potential danger?

A3: First, don’t turn it on when you are not sure the motor can rotate, or it may burn up. Second,some elements are acute, be careful while using it.

Q4: My bug follows the wrong way, the BV1750 will always out of the way.

A4: Check if you have chosen the right GY-30 sensors.

Step 14: Conclusion

The rules and requirements of the game are easy to understand, while it takes huge amount of time programming, adjusting, testing and solving problems that may occur unexpectedly. And this special experience really developed our skills to cooperate and communicate. Hope this manual will be of some help to you and may you success!