ShanghaiJiaoTong University(SJTU) is a top university in China. Engineering is one of the best expertise in SJTU. The Joint Institute is a famous institute SJTU, also the institute has win a lot of honors all over the world. The Joint Institute is established to become a leading international research institute which educates innovative future leaders. In JI, we construct a model university which emulates the successful experience of the University of Michigan. We focus on the practical experience which is so important for engineer. The VG100， intro to engineering, is designed to cultivate the practical ability for freshman.
(2) Competition description
The competition is held in order to test our hovercraft. Each team and their hovercraft will be graded according to the performance in the competition. The competition is divided into two parts: time trails and tournament.
In time trails, each group has one chance to finish the a timed trial. As long as the hovercraft can work and complete the trail in 3 minutes, it is successful in this part of competition. However, only the top 16 groups are able to take part in the tournament.
In tournament, two competitors, which are decided randomly, will share the race-track. Each team has to complete two laps and the hovercraft which firstly touch the final line will win. In this part, crash is not recommended.
Lifting height: <2cm
Maximum mass: 800g
Maximum size: 30cm*30cm*30cm
Power supply: Maximum two battery(<12v each one)
Central control circuit: Arduino series
Remote control: Mandatory
Time in time trail: 19 seconds 6th in 19 groups
Place in the tournament: top 16
Step 1: Concept of Design
In our design, we choose the foamed plastics as the material of main ship body instead of the acrylic board because the foamed plastics has much lower density and well stability compared with the acrylic board. Also, foamed plastic is easy to be operated. Then, the skirt is one of the most important part of hovercraft because it can reduce the friction and determine the speed and stability. We use the plastic film, which is a kind of softer and more flexible material, because it can meet the need of irregular shape.
As for the propelling system, we choose the ducted fan and brushless motor for its high power and efficiency. Also, there is a fans to provide lifting force. Turning system is significant in the competition. A flexible and easy control swerve can help a lot. In order to achieve this goal, we fix two tail vanes which is used in helicopter to provide turning force.
The link of the video of the hovercraft competition:
Step 2: Materials List
42RMB($6.77USD) Arduino UNO R3
200RMB($32.26USD) Lithium battery, 11.1V 2200mAh
38RMB($6.13USD) Lithium battery charger 7.4V-11.1V
94RMB($15.16USD) Ducted fan 70mm diameter, brushless motor/output: 650w
75RMB($12.10USD) Electronic speed controller 40A
70RMB($11.29USD) Tail vane
29RMB($4.68USD) USB Bluetooth adapter
5RMB($0.81USD) DuPont Line
20RMB($3.23USD) Motor module
38RMB($6.13USD) Sealing machine
50RMB($8.06USD) Foamed plastic EPS
75RMB($12.10USD) Plastic incisory tool
50RMB($8.06USD) PS3 Joystick
Step 3: Build the Main Board
1.Draw the outline with a mark pen and cut the plastic foam with a fervent pen
2.Dig a 6cm*6cm hole at the center of the main board
Step 4: Make the Air Cushion
1.Draw the outline on the plastic film with a mark pen and cut the plastic film with a knife
2.Cut of two holes with different sizes on the plastic film with a knife
3.Merger the edge of the plastic film with the sealing machine
4.Fix the air cushion onto the main board with hot melt
Step 5: Fix the Fan Providing Lift Force
1.Fix two small sticks in the hole of the main board
2.Put the lift fan into the hole and use the hot melt to seal the edges
Step 6: Fix the Other Fans
1.Cut a plastic foam cuboid whose size is 12 cm*12 cm*5 cm
2.Cut a circle hole whose radius is 3.5 cm
3.Put the fan into the hole and seal the edges with hot melt
4.Cut two small holes on the cuboid
5.Fix the two fans into the small holes and seal the edges
6.Fix the whole cuboid onto the main board
Step 7: DIY a T-plug Spigot
The spigot serves as a parallel connection of the power output. It is
connected to the 12-V lithium polymer battery which provides electric power for the motors, the Arduino board and the motor driver. The wires need to be welded together carry the current.
Step 8: Modulate the Voltage Stabilization Board
The voltage stabilization board is then connected to the Arduino board
to provide 5-V electric power. The voltage is measured by a multitester. The rotary knob is adjusted by a screwdriver. Figure shows the voltage stabilization board.
Step 9: Modulate the Electronic Speed Controller
The ducted fan needs an electronic speed controller to drive and control
the brushless motor. The modulation is done according to the instructions. The brushless motor should be initialized using Arduino program. Figure shows the electronic speed controller and the connection of the electronic speed controller with the ducted fan.
Step 10: Add an Extension Board to the Arduino
The remote control is connected to the Arduino via Bluetooth, so it
needs an extension board to plug in the Bluetooth adaptor. Figure shows the Bluetooth adaptor which is plugged to the extension board with USB spigot.
Step 11: Connect the Arduino Board
The Arduino board is the central processor of the whole system. It is
connected to the Bluetooth adaptor, the electronic speed controller, and the motor driver. The circuit is connected as shown in the Figure which demonstrate the connection of the wires.
Step 12: Programming
1. Download Arduino IDE version 1.0.5 on
the URL: http://arduino.googlecode.com/files/arduino-1.0.5... double click the set-up package.
2. Download the latest library for USB Host Shield on a Github repository: https://github.com/felis/USB_Host_Shield_2.0/arch... . Extract the file and move the whole directory to the library files of Arduino (for example, D:\Program Files\Arduino\libraries), and rename the extracted directory to “USB_Host_Shield_20”.
3. Copy an example project file, at the path of \USB_Host_Shield_20\examples\Bluetooth\SPP\ SPP.ino and create a new directory called “Hovercraft” at anywhere you like, then rename paste the file SPP.ino to that directory and rename it to “Hovercraft.ino”.
4. Modify the Hovercraft.ino so that the
code inside is exactly the same as the program at: http://pan.baidu.com/share/link?shareid=259536841... .
5. Download script language Python at https://www.python.org/ftp/python/3.4.1/python-3.... , and double click the file to set up Python.
6. Open the “Control Panel” on your computer, enter the “Devices and Printers” section. Power up the arduino board with USB Host Shield and Bluetooth Dongle, click the “add devices” at the top left of the menu you will find a device called “Arduino”(Note: you should have a bluetooth dongle on your computer as well), then double click it. The system may ask you for the PIN code of buletooth pairing, don't be panic, print code 0000 in the input box. Then you will see the device “Arduino” in the “device” section as the following picture:(if you use ubuntu computer, use the tool “blueman” to search and connect the device, the steps are similar)
7. Create a Python script file called
“Control.py” in the “Hovercraft” directory. Copy the code at http://pan.baidu.com/share/link?shareid=2584198637&uk=2889776080&third=15 into it.
8. Plug a joystick to your PC/laptop(ubuntu or windows operating systems are recommended) via USB wire, double click the file “Control.py”, then you can test the controling program by doing this.