【Introduction】

We are group 3,JI-artisan(logo:Fig.3), from Shanghai Jiao Tong University Joint Institute(Fig.1). Our campus is located in Minhang district of Shanghai. Figure.2 is a picture of the JI building we saw on the microblog of JI, which is our favourite original picture of the campus. JI aims at cultivating engineers with leadership and provides students with an solid and excellent foundation of both technological and communicating skills.

Group members: Shi Li ; Guan Kaiwen ; Wang Tianyi ; Liu Yongle ; Ervin Tjitra (Fig.4)

Instructors:

Professor Shane. Johnson, Ph.D.(Tech)

Tel: +86-21-34206765-2201 Email: shane.johnson@sjtu.edu.cn

Professor Irene Wei, Ph.D.(TC)

Tel+86-21-3420-7936 E-mail: irene.wei@sjtu.edu.cn

Teaching Assistant:

Li Jiaqi(Tech) Zhou Xiaochen(Tech)

Liu Xinyi(TC) Ma Zhixian(TC)

【Course & Project Information】

In the VG100 course, Introduction of engineering(2017 Fall), instructed by Dr. Shane Johnson and Dr. Irene Wei, we are to participate in a game called the Naval Battle.

During the game, when our robot attempted to lift up a big ball one of the tape we used to stick the servo motor to the robot body fell off which then made the chain to fall apart, and we spent quite some time to repair. But eventually we continued the game with the time remaining, and we managed to move 1 big ball and 4 small balls to the other side.

Our final score is 8 and we rank 14 out of all 22 groups.

Our video of the game: http://v.youku.com/v_show/id_XMzExMjE3MjUwMA==.html

Project objectives:

In this project, the objective is to design and build a robot for a game called Naval Battle (detailed rules and regulations attached below). The robot should be able to move big balls and small balls placed by TAs before a wall in 3 minutes given time.

Our project:

Our robot mainly consists of lifting system and moving system.

In the lifting system, we use servo motors to control two gear wheels and attached to each of them are chains which hold two forks. All of them are controlled using a PS2 remote controller. The big balls are to be moved using the forks just like a forklift, and two wooden boards fixed on the outer sides of the forks are meant to prevent the forks from moving apart from each other considering the weight of the big balls in between.

In the moving system, we use 2 motors to move the robot, an Arduino board and PS2 controller to control the speed and direction of the robot.

【Game Rules&Competition Regulations】

The robot has a limit size of 350mm(length)*350mm(width)*200mm(height) in the starting position of the competition.

Only the motors provided can be used, and servo motors of any types are allowed in addition.

The game have a limit of 3 minutes and the final score is calculated according to the final positions of the balls.

The field(Fig.5&6)of the game is 2000 millimeters in length and 1500 millimeters in width with surrounding walls standing at 70 millimeters. In the middle of the field, a wall(Fig.7) of 70 millimeters high and 18 millimeters wide is placed 50 millimeters above the ground which splits the field into two sides.

Four wooden balls(diameter:70mm) are placed by TAs on the field, and to move each one to the other side gives 4 points. Also placed by TAs are 8 small balls which gives 1 point for moving each to the other side.

A 5 point penalty will be given if a big ball has gotten out of the field, and a 2 point penalty for a small ball.

Step 1: Circuit Diagram

Step 2: Concept Diagram

Figure 1 and 2 are our concept diagram. Figure 2 is an explosive view.

Our robot mainly consists of lifting system and moving system.

In the moving system, we use 2 motors to move the robot, an Arduino board and PS2 controller to control the speed and direction of the robot.

Figure 3 and 4 are our fabricated prototype.

Step 3: Prepare the Materials & Tools

Tools :

Drill
Screw driver
Soldering gun and electric soldering iron
Ruler
Pencil
502 glue

Figure 1-11 are pictures of our materials and tools.

Figure 12-15 are prices, quantities and TAOBAO links for our materials.

Step 4: Software Setup

We use Arduino to progam so as to control the motor and the servo motor.

To buy a Arduino board and learn how to program it, visit the website: https://www.arduino.cc

Step 5: Component Fabrication

Wood bars and boards need to be processed for assembly.

The inner axle holder(Fig.1):

Take 4 centimeter of wood bar, and drill two holes(Φ= 3mm) at the position of 5mm from both ends of it. Then, drill a shallow hole(Φ= 5mm) at 2 centimeters from one end of it at a vertical direction.

The outer axle and board holder(Fig.2):

Take 8 centimeters of wood bar, and drill two holes(Φ= 3mm) at the position of 5mm and 35mm from one end of it. Then drill two holes(Φ= 3mm) at 45mm and 70mm from that end and a shallow one at 20mm from that end, but at vertical direction.

The clapboard(Fig.3):

Take two pieces of wood of 5cm*17cm, then cut off a small rectangle of 25mm*15mm at one corner of both piece.

The baseboard (Fig.4) and the roof(Fig.5):

Take two pieces of wood of 17cm*20cm, cut them and drill holes (Φ= 3mm) as can be seen on Figure4&5.

The upper clapboard holder(Fig.6):

Take 5 centimeter of wood bar, and drill one hole(Φ= 3mm) at the position of 5mm from one end of it, then

another bigger one(Φ= 4mm) at 5mm from the other end of it, but at a vertical direction.

The caster holder(Fig.7):

Take a piece of wood bar of 1cm*4cm, and stick the caster in the middle of it.

Step 6: Assembly

1. Fix the axle holders on the baseboard with screws. Remember to put the axle with the small gear in the big shallow holes as you do it. And paste the caster at the back of the board. (Figure1→2)

2. Turn your board over, and fix two motors on the plate. Note that the wires are already welded onto them for further convenience, but the welding spot can be vulnerable.(Figure2→3→4)

3. Fix the four supporting poles at each corner of the baseboard.(Figure4→5)

4. Fix the arduino board and the motor controller on the baseboard, using copper pillars and screws. And tie the battery for motors on one of the poles in the back.(Figure5→6→7→8→9)

5. Fix the roof onto the four supporting poles.(Figure9→10)

6. Fix the clapboards on the roof with the upper clapboard holders. Paste the PS2 wireless receiver under the roof.(Figure10→11)

7. Put the servo motors on the front edges of the roof, and then hang up the chains.(Figure11→12→13)

8. Tape the battery and the step-down module for the servo motors and then connect them.(Figure13→14)

Step 7: Troubleshooting & Ready to Yell

Hope you get inspiration from our manual. If you have any question, you may contact us through email : shili2017@sjtu.edu.cn or visit us at UMJI in Shanghai JiaoTong University (Minhang)

Possible error, notice and solution

Breaking chain:
Our chain is made up of several identical units. Therefore the orientation of their connecting part is very important. If your chain breaks up during the process of rising, check that if the force exerted to them lies in the same direction of breaking their connection. If so, turn your chain around and re-assemble it. Also, remember to check if the chain is too loose, if so, remove some fractions of the chain.

The shallow hole:

When drilling the shallow holes designed for the axles, it’s usually hard to estimate the depth of drilling. If your holes are too deep so that your axle falls out, instead of remaking this part, try stuffing something soft into the hole to make it shallower.

Fixing the wood parts:

Usually, self fixing screws are able to penetrate the wood board, if you find this difficult, try drilling small holes at corresponding places to make it easier.

Adjusting the potentiometer:

If you find your servo motors rotating automatically without you giving orders after connected, cut off the power source and adjust their potentiometers with a screw driver. Re-connect, check, and repeat the procedures above (if necessary) until they stop moving out of control.

Flat bases for servo motors:

The small piece of wood under the servo motors are designed to provide them with flat bases. Note that the holes on these pieces should be big enough for the screws’ tops, and match their positions.

Fixing the wheels:
If the two wheels are not in the same line, the car will be hard to go straight forward and may incline to one side. Make sure to fix the two wheels in the same line.

Caution:

1. When using the electric drill, wear safety goggles and use proper clamps. Beware of mechanical injuries!

2. Cut off the power when connecting wires. In terms of power lines, pay special attention to short circuits.