Science Buddies: "Ask an Expert"

I am making a mount that could fit any of your basic cameras, go pros, nikon, canon, anything like that. It would use PIR sensors to detect where a person is and use a servo motor to turn the mount.
Also I am in EDD and for one of the objectives our STEM principles need to be reviewed by an expert of some sort. So if anyone could look them over and give me feedback that you be great thanks!

Science: PIR Sensors
This project will use several passive infrared sensors. All objects emit heat energy in the form of radiation. The term passive in this instance refers to the fact that PIR devices do not generate or radiate any energy for detection purposes. They work entirely by detecting the energy given off by other objects. PIR sensors don't detect or measure "heat"; instead they detect the infrared radiation emitted or reflected from an object.
Technology: Using Circuit Boards, Sensors, and Servos
In this project I will use a Aurduino Uno circuit board that will connect to a servo motor the will have the camera mount on top of it. Also the PIR sensors will connect to the circuit board sending a signal to the servo motor. Creating a adjustable mount that can fit all sizes of cameras. I will need to design and test a mount that will be able to adjust in width as well as height to accommodate for the sizes of different cameras. A design where the sides of the mount would be able to slide in and out of each other. As well as click into place so there would be no sliding while the camera is moving. This incorporates STEM principles of technology using digital electronics to make the camera move. (sketches will be posted later)

Engineering: Creating a Camera mount that will move
In this project, the problem is too many home burglars get away and are never caught. My solution is to create a camera mount that will be able to track the motion of the burglar. This mount would reduce the amount of cameras needed to have sufficient coverage of a house because when the camera turns it can see more of the house. Also giving the authorities more evidence on who the person is and what they might have done in the house.


Aurduino Layout.PNG
Mathematics: Angles of PIR sensors
The view angle of a standard PIR sensor is 110 in the x and 70 in y. But in my project I am going to flip them on there sides so the angle is 70 degrees horizontally. This will allow for the camera to turn more and keep the object in the center of the frame. Positioning the sensors correctly will give the device around 280 degrees of sight which would be plenty depending on where the camera was mount. If more range was needed another sensor could be added.

Using the difference between two PIR sensors is certainly one way to do this. You'll need to pay attention to the coverage of each sensor and consider the overlap of the "views" of each. I can't really explain how you get that right but you'll get it through experimentation.

The camera mount can really be as simple as using a plate with a rubbery surface for grip and a standard tripod mount screw. You could mount it on a servo but I'll guess that won't be very strong mechanically. You might have better results if you think of a lazy susan. Imagine one with a rubbery surface and a tripod screw coming up from the center. That will hold the camera securely and let it spin. Instead of a standard servo, a continuous rotation servo that was attached to the lazy susan through a gear mechanism or a belt would let you then rotate the disc as far as you deemed necessary from the data from your sensors.

Alternatively, some sort of level mechanism attached to a standard servo might work, but I predict better results from a more stable mount like the lazy susan rather than just perching the camera on top of a standard servo.

Good luck with the project. I have a Gigapan camera mount that doesn't track motion but instead uses camera motion to take all possible images in a scene and stitches them into a huge picture. This is one of their platforms (http://www.gigapan.com/cms/shop/epic-100) and maybe that will give you some idea of what a commercial platform looks like, They use the lazy susan sort of solution as the rotating base and then a geared setup to control vertical motion.

Howard