I’m working together with Majid on this project. He is designing the AI right now, and I’m designing the hardware-platform.
Påsse at CRF buildt a big capacitor-bank that could be charged with very much energy.
The capacitors are connected in series to a coil of very wide cable. When the energy is released to the coil it generates a gigantic magnetic field in a few milliseconds.
The Pirate cars PID-regulator get’s goal-value from a tachometer inside the gearbox. A IR-reflex-sensor (ITR8307) is located on the shell off the gearbox and is pointed to one of the gears inside. That gear is painted half black. The tachometer can pick up 6 pulses per revolution of the wheel.
Pirat-Bilen V.2 @ YouTube
Two days after christmas me and my friend, Andreas Svensson, were going to watch Avatar 3D, the tickets was sadly canceled due to SF the bitch. We then started to think of something else to do, Andreas: “..how about that fireworks-launcher we spoke of a few mounths back?..” And so it was decided.
We had a short deadline, roughly about 5 days.
BTW. Explodet is short for Explosive Detonator.
20:00 – At new years’s eve, five days of constant work, we finally made it. It was ready for testing.
21:59 – We arrived at the party, I had not slept for 36 hours
22:06 – I started programming at the party, Andreas went to pick up some equipment
22:25 – Party-cat Sigge was showing interest in Explodet, discrete sniffing and foxy glimts from the eyes was seen.
22:53 – Unfortunately the software wasn’t ready, still had hope I would program it outside
22:55 – We went out to setup all the gear
23:10 – The fireworks launching-ramp was rigged
23:21 – The 230V-generator and 2×500W halogen lights was rigged.
23:40 – Explodet is up and running
23:41 – I found out that it was to cold to program, -15 degrees C. We decided to launch the fireworks remotely (by pushing down spacebar) was good enough.
23:55 – Cable setup
24:00 – Still cable setup
00:01:01 – Success! First firework fuse is sparkling.
00:01:05 – Disaster! The firework won’t lift off, 20 peoples is throwing them selves down the hill.
00:01:30 – It all went well! 🙂
01:15 – The final fireworks went off in a beautiful sparkling rain.
01:16 – Starting to bring the rig down
04:00 – Finally home!
Specs. and parts
- Case: a cheap aluminum-case
- Screen: a leftover from Andreas, Samsung SyncMaster940NW
- Computer: a leftover from Andreas, a minicase with 1GHz Celeron, 760MB SD-Ram, 4xUSB1.1, Firewire, IR-Com, CD-Drive
- Operationsystem is Windows XP Proffessional
- Software: Written in Visual Basic 6.0
- Interfaceboard: Velleman K8061, 33 input/outputs: including analogue / digital and + 1PWM output
- Relay-card: 8×12V Relays
- Battery: PB 12V 7,2Ah
- Ignite-coil: Nikrothal 80 0,7 mm 1 hg
Research at Chalmers Pyrotekniska Förening
Before launch-day I went to visit Chalmers Pyrotekniska Förening. They showed me their fireworks-launching-case, it had 50 manually trigged outputs. They also had a sequencer with 25 automatically trigged outputs.
Just before the project had started Andreas said: “I’ve 20″ wide screen to no use at home, wouldn’t it be nice to mount it inside?”
I asked him how wide it was. “Roughly 245mm” I went to measure the case “It would fit, the case is 248mm!”
We started out by placing the 20″ screen inside the case. It was a perfect fit!
I started to build the relay-card. First I mounted a 12V 1A voltage-regulator UA7815.
In the middle of te 3:rd building-day Peter came around to fix his Guitarhero-controller. We then watched Monsters VS. Aliens an when Peter inserted the audio-cable into his computer he destroyed the christmas-coke-tree. We rebuild it again.
The fireworks the bought from Chalmers Pyrotekniska Förening!
The autonomous pirate-car was a huge success at Dreamhack W09, so Benjamin has built a new one. The Pirate-Car V2.
The chassi is from a RC-car, the stearing system has been modified with a servo and it has a better steering-radius. The motor and gearbox is original but it has a reflex-sensor built in the gearbox, the reflex-sensor is aimed to a gear that is painted half black. The sensor can pick up 3 peaks per revolution, these seams to be enough to make the PID-regulator stable.
The autonomous part
The Pirate-Car navigates by it self, it goes around tables, chairs, walls with no problems.
The two front sensors ,left and right, separately calculates how the car should turn. The two turn-values are then subtracted and makes a delta-value that is put out to the steering-servo. This works pretty well, in a corridor the car senses both walls and navigates right between the walls.
The Pirate-Car could sense if it’s stuck in several ways
- Front-center-sensor senses a object close enough
- Front-left and front-right sensors senses a object close enough at the same time
- PID-regulator is delivering a high output that indicates a spinning wheel
If it’s stuck it starts the reversing-procedure, it reverse until the front-sensors feel it’s free or the back-sensors indicates a object.
The main-PCB has a IR-eye hooked up, this eye could pick up commands from IR-remote-controls. Benjamin has written a nice protocol for picking up commands.
Currently two commands could be sent:
- Shut the H-bridge on/off
- Increase/decrease the PID-regulators goal-value
With a Introkit09 we built a remote-control, we used the existing IR-diode to send out IR-commands. But the signal was weak, we then tied to switch to another type (TSAL6400) which were much brighter.
- Make a chaseing-mode, if someone/something tries to catch up the Pirate-Car it goes faster
- When it slows down, brake-lights will glow
- When someone tries to fuck with it, a loud annoying sound and flashing lights will go off
- Following-mode, it tries to follow a person around
The autonomous part