I have an issue at my house right now...Young hoodlums of unknown origin have been sneaking onto my property and stealing things off my deck, and animals have been getting into my garbage.
I want to build a robot that when motion is detected with a passive ir sensor, a webcam will activate and start recording, however I want the sentry to track the movement with some precision, since the target (hoodlum or rodent) will be of different sizes.
So my question is, do I use an PIR sensor array to track movement? How should I go about doing this? Does anyone know any good references on motion tracking?
You can do an array of ir sensors and recievers set up along a known intrusion path for short range intereference detection,(if the signal is broken then thats where a camera would point) but the amount that you need for a yard could be a bit much. Stillā¦the much antiquated but still very effective, floodlight at the slightest mottion Iāve found works wonders plus blinds said hooligans.
yet another way is using a standard computer web camā¦ most come with software that detects motion(changes in pixil density??) and can be set to be very sensetive. I donāt recall if you can get any output data and use it, but itās possible.
well you could also use a well you could also use a simple relay to active the camera if you already have one and donāt want to spend money on another one
A web cam can be interfaced A web cam can be interfaced with a PC in such a way as to record and track motionā¦However I think it only works with Windowsā¦havent found a Linux version yet. But you can use the Java Media Framework(JMF) to capture and perform operations on real time streaming video.
Iām looking for a device that records my walking motions digitally, and can control servos to imitate my walking forces, balance etcā¦
You see, Iāve got this āmechanical spring-loaded bipedal walking frameā that assists in the walking motion (google search āspring walkerā to understand what I mean), and what I want to do with it is turn it into a autonomous walking robot.
Iāve been thinking that if I attached servos and a computer (brain) to it to record my walking motions, then I can get it to walk on its ownā¦without me strapped into it, that is. But I need advice on what kind of servos (make, model) to use thatās powerful enough to move the walking frame. And, also what kind of device or program would allow me to record and save my actions in such a manner that I donāt have to keep sorting out the data to tell the computer "when this, do this, etc (if p then q)? Presumably thereās a device out there that would do all this for me, and not too expensive?
I figured I could utilize the info gained by IR sensors taped to the frame to help with the decision making of what king of motion to do at a given situation (i.e. that it doesnāt try to clime a hill when walking on the road, or walking when itās suppost to clime, etc.) Can you advise on what IR sensors are good for this particular job?
I donāt know the scale of this kind of project, or if itās too difficult to do without expert roboticists on hand, but Iād like to try anyway.
using some kind of camera to using some kind of camera to do that sounds very very very hard. why not try some sensors like gyros (but i donāt really know if you can apply those to your frame) to detect how much the axles the frame is made of rotate? (then you need to find a way to store these variables on a timeline so that at the end of the experiment you can check what happened.
Yeah, a camera might not be the best method to get raw motion data that a computer can useā¦but if I use a stepper motor, on the other hand, I can simply send a series of pulses to the motor, and it will rotate an angle proportional to the number of pulses. In theory, if we know how many pulses have been sent, we know where the motor is, and we know the velocity of the motor is proportional to the pulse frequency. If I do the math backwards, and knew how many pulses it took to get the motor to a particular place, then I could match my walking by literally knowing how many pulses it takes to walk a certain distance and program that into a controllerā¦However, Iāve read somewhere stepper motors do not generate much torque, and as a result, slipping can occur (i.e. where the motor turns when no pulses are given or the motor fails to turn in response to the pulses). Also, that the control electronics are somewhat more complicated to do.
Then again if I used a permanent magnet brushed DC gearhead motor, it would be better than a stepper motor, since the advantages of DC motors include: simple to drive, cheap, and relatively high power-to-weight ratio. A disadvantage is that Iād need a sensor, such as an encoder or tachometer, to keep track of the position or velocity of the motor (this would be the raw motion data I mentioned above). According to BaseOverApex (posted elsewhere), with a DC gearhead motor there is a direct link between torque & price (greater torque=higher price).
Emmmā¦what to do? Itās starting to go over my head a little, I have to admit!
