Beginners: please read this post and this post before posting to the forum.
0 Members and 1 Guest are viewing this topic.
Jim,Thank you.And yes the circuit board components are surface mount.In fact, they also replaced the usual RC transmitter / receiver arrangement and they are instead using an IR led transmitter for the joystick controller with a single IR receiver on board the craft to receive the control signals. This means that you have to keep the controller / transmitter pointed at the craft never breaking direct line of sight or the craft is programmed to shut off - but it actually works surprisingly well... and of course substituting an IR receiver for an RC receiver really reduces the weight. So they've managed to pack an IR receiver, 3 rate gyros, a microcontroller, a voltage regulator, 4 power transistors and probably 4 fly-back diodes onto a circuit board that's just 1" square! Amazing!!The IR transmitter is interesting. It looks like a typical 2 joystick game controller - but as I mentioned it has 4 IR leds in front to transmit the signal. There's also a switch to choose "EZ" or "NORM" mode. So all of that information is being coded and transmitted on the IR light beam - the mode, the position of the right joystick and the position of the left joystick.... I assume that it's being sent as some kind of serial data string.... it'd be interesting to break it down and decode it. Also as I mentioned, it's also being used as a "heartbeat" indicator - as long as the craft is receiving a signal, it keeps running.... but if the signal is lost or the transmitter is turned off, the microcontroller on the craft immediately shuts down the motors. Of course if the craft is in the air when it loses signal and shuts down it's going to fall to the ground.... but it really is amazingly durable and it has survived numerous crashes so far without any damage!Dr. Bruce.==================BruceI was very impressed with the 4 rotor helicopter you demonstrated at Sept RSSC meeting!The overall performance was good, it seems to rely on the same functional principle that counter-rotating propellers - with independent speed control, can be used to adjust pitch, roll, and yaw axis of the aircraft. If I recall correctly, that is the same operating principal as the vehicles you personnaly constructed.Styrofoam (foamed white polystryrene plastic) is an amazing structural material! It has a very high strength/weight ratio, even better than balsa wood. Unfortunately these materials aren't very strong. But they are very tough (they deform to absorb impacts, instead of breaking). Perhaps that is why the material was chosen by the vehicle designer?Did they reduce the weight of the electronics by choosing surface-mount components?=====================Hi RSSC members! The Senario Flying Saucer that I demonstrated at the last RSSC meeting is apparently very popular - it's currently sold out on most sites! I bought mine from Amazon (not currently in stock), but I also found it in stock here: http://tinyurl.com/5j5vc9I'm slowly gaining proficiency flying it. It has two modes: "EZ" and "NORM". In "easy" mode, it seems to be integrating the rate gyro information to create a heading hold type action - it's more stable, but I almost feel that it's fighting me resisting my attempts to make it change position. In fact, if I send it forward, then release the forward joystick, it actually backs up a little before stabilizing. However, in "normal" mode I think that the rate gyros are acting like rate gyros - they're there just to dampen the motion... just enough to compensate for a human operator's slow reflexes. In normal mode, I tell it to go forward an it goes forward more easily (it doesn't seem to be resisting me) and when I release the joystick, it goes forward a little further before settling down and stabilizing. I won't tell you how many times I've crash landed this thing - but it's still intact and flying without any damage.... it's very well designed and made. I'm sorry if this sounds like a commercial - I'm just excited to finally have something that I can actually fly! Dr. Bruce.
Accelerometers don't work because there is too much vibration.
The main issue is that you will need gyro's to stabilize, so that adds a lot to the complexity and cost.
It will be close to impossible to make a quad without gyro stabilization, how else will you get it to level?
Hmmm didn't think that would be a problem . . . I'll dampen out the vibration frequency with some caps on the outputs then. You wouldn't by any chance know the vibration frequency and expected g-force amplitude (I'm guessing no, but I want to work around it).