Recent content by MechatronO

Hmm. Food for thoughts. I should try to understand the issue of rotation in a rotating coordinate system first. Because, if the coordinate system is rotating exactly the same as some solid object, the rotation of the object in this coordinate system must be zero. But, it seems like rotation...

vanhees71: Hmm. Is there some way of seeing this algebraically?

But we have three general forces that are the respective input torques for each axis, and three general coordinates that are the euler angles, right?

Lately when doing a simulation for a quadrocopters most reports I've come across regarding modeling use Eulers equation of motion. That makes sense, as the quadrocopter is a body rotating in 3 dimensions. Then I tried to model the system using Lagrange equations instead but I don't get the...

So I'm trying to identify a system that happens to be a synchronus generator via linear regression. I've got a model with the unknown coefficients A, B and C, and the measured variables I, w and T according to I(w, T) = A*T + B*w + C 1. What I fear is that I could get multiple solutions that...

The Minnesota Iceman is described on Wikipedia as "sideshow exhibit that depicts a man-like creature frozen in a block of ice." http://en.wikipedia.org/wiki/Minnesota_Iceman What is claimed to be the same 'Iceman' is now put on exhibit at this place...

Typo. More suggestions?

We got a circle with a radius R. From a distance D from the centerpoint a line is inserted at an offset angle A1 from a line drawn though the centerpoint C of the circle, see the picture below. http://cdn.imghack.se/medium/0861cdab13b8957018f8e167342f2b8e.png I would like the are of...

Consider a DC motor, being switched by a H bridge that is controlled by a PI current regulator. As long as the error (SetCurrent-Current) is positive everything is good. However, when this goes negative we have a problem as you couldn't set a negative duty cycle. How is this solved in...

Say we want a set of random values that are distributed according to some distribution function f(x). A common way to accomplish that is to find the cumulative distribution function F(x) for the distribution and then solve for x according to F(x) = Y x = F'(Y) Then x will be...

No, s= tf('s');

I have a transfer function L(s) = A(s)/B(s) that I call Ls. However, when defining H(s)= L(s)/(1+L(s)) by %% Ls = -70.6s^2 - 2003 s + 3375 -------------------------- s^3 + 119.6 s^2 + 2806 s %% Hs = Ls / (1+Ls) things go wild. The highest...

Seems like the biggest mystery in the world this switch frequency issue, have posted in two forums and nobody seem to know. I tried to evalute Iavg = 1/T∫i(t) dt today, and came up with some rather clumpsy though exact expressions. As I couldn't simplify them enough to get an...

I've been looking around for formulas on how to calculate different aspects of DC motors and buck converters such as average current. The reason is that I'm about to pick switch frequency for a motor, and don't know what characterics I can expect if I alter the switch frequency. Papers and...

I'm taking a course in probability and statistics and encountered an exercise with a formulation that doesn't make sense at all to my English-as-second-language ears. I will recite the exercise here and maybe you could help my settle wether if the original formulation is bad, or if I've...