Recent content by angier

Thnx for your help! If we take into account also air resistance etc. the equations change definitely. How to write equations of motion for such a case, where also this forces are present?

I have some more questions regarding movement of the doors. Can we assume that while the doors are moving, we have uniform circular motion, at least in the middle of the period (definitely not in the beginning while we are pushing them with hands and in the end, when they slow down). By assuming...

OK, I understand this. The only thing that makes me bewildered was after I was looking at another paper: http://ocw.mit.edu/courses/aeronautics-and-astronautics/16-07-dynamics-fall-2009/lecture-notes/MIT16_07F09_Lec29.pdf where this pitch, yaw and roll are described. If you go to the page 3 you...

Dear Simon, I am working on a project for intelligent door, no study stuff anymore. :) We want to distinguish between different people entering the house or something and then apply the data to artificial intelligence software. How can you measure the distance vs time? What kind of sensor?

Dear jbriggs444, did you mean applying 3x3 matrix 3-times probably, first around z-axis, then x-axis and on the end y-axis to get the new ax,ay,az vector of acceleration?

Thnx to both, Simon Bridge and jbriggs444! I am aware of the problems you have mentioned, but we will try and we see what comes out. There is another challenge. What if the z axis is not exactly in the direction towards the center of the Earth and also the x-axis not exactly towards the origin...

Basically we get data from accelerometer, which means ax, ay and az. So if I set the coordinate system as I have described above, this means that ax=w2R(w-angular velocity, R-radius) will be radial acceleration, ay=aR(a-angular acceleration) will be tangential acceleration and az will measure...

I prefer the natural system of axis orientation, so x is horizontal, y is away from the door and z vertical. So, the y-axis will be tangential to path the door makes. In this way also door is accelerating in y direction. And yes, tangential acceleration is a product radius and angular...

Dear Simon! Can you be more specific, I need more help! Thanks in advance!

I am working on a project where we will use a 3-axis accelerometer on the door and using the ax, ay, az data to calculate position and angle of the door. The accelerometer will be positioned near doorhandle. So the initial position of coordinate system will be there, where the accelerometer is...