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Dependencies: mbed
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Diff: GPA.cpp
- Revision:
- 3:769ce5f06d3e
- Parent:
- 0:78ca29b4c49e
- Child:
- 6:2cc56521aa16
diff -r a30512c3ac73 -r 769ce5f06d3e GPA.cpp --- a/GPA.cpp Mon Apr 09 05:50:04 2018 +0000 +++ b/GPA.cpp Mon Apr 09 08:01:29 2018 +0000 @@ -1,72 +1,83 @@ /* GPA: frequency point wise gain and phase analyser to measure the frequency - respone of dynamical system - + respone of a dynamical system + hint: the measurements should only be perfomed in closed loop assumption: the system is at the desired steady state of interest when the measurment starts - + exc(2) C: controller | P: plant - v + v exc(1) --> o ->| C |--->o------->| P |----------> out ^ | | | --> inp | exc: excitation signal (E) | | inp: input plant (U) -------------------------------- out: output plant (Y) - + instantiate option 1: GPA(float fMin, float fMax, int NfexcDes, int NperMin, int NmeasMin, float Ts, float Aexc0, float Aexc1) - + fMin: minimal desired frequency that should be measured in Hz fMax: maximal desired frequency that should be measured in Hz NfexcDes: number of logarithmic equaly spaced frequency points NperMin: minimal number of periods that are used for each frequency point - NmeasMin: maximal number of samples that are used for each frequency point + NmeasMin: minimal number of samples that are used for each frequency point Ts: sampling time - Aexc0: excitation amplitude at fMin + Aexc0: excitation amplitude at fMin Aexc1: excitation amplitude at fMax - + hints: the amplitude drops with 1/fexc, if you're using - Axc1 = Aexc0/fMax the d/dt exc = const., this is recommended + Axc1 = Aexc0/fMax then d/dt exc = const., this is recommended if your controller does not have a rolloff. if a desired frequency point is not measured try to increase Nmeas. - - pseudo code for a closed loop measurement with a proportional controller Kp: - - float inp = "measurement of inputsignal"; - float out = "mesurement of outputsignal"; - float exc = myGPA(inp, out); - float off = "desired steady state off the system"; - + + pseudo code for a closed loop measurement with a controller C: + excitation input at (1): - inp = Kp*(exc + off - out); - + + - measuring the plant P and the closed loop tf T = PC/(1 + PC): + desTorque = pi_w(omega_desired - omega + excWobble); + inpWobble = desTorque; + outWobble = omega; + excWobble = Wobble(excWobble, outWobble); + + - measuring the controller C and the closed loop tf SC = C/(1 + PC) + desTorque = pi_w(omega_desired - omega + excWobble); + inpWobble = n_soll + excWobble - omega; + outWobble = desTorque; + excWobble = Wobble(inpWobble, outWobble); + excitation input at (2): - inp = Kp*(off - out) + exc; + - measuring the plant P and the closed loop tf SP = P/(1 + PC): + desTorque = pi_w(omega_desired - omega) + excWobble; + inpWobble = desTorque; + outWobble = omega; + excWobble = Wobble(excWobble, outWobble); + usage: - exc = myGPA(inp, out) does update the internal states of the gpa at the - timestep k and returns the excitation signal for the timestep k+1. the - results are plotted to a terminal (putty) over serial cennection and look - as follows: + exc(k+1) = myGPA(inp(k), out(k)) does update the internal states of the + gpa at the timestep k and returns the excitation signal for the timestep + k+1. the results are plotted to a terminal (putty) over a serial + connection and look as follows: ----------------------------------------------------------------------------------------- fexc[Hz] |Gyu| ang(Gyu) |Gye| ang(Gye) |E| |U| |Y| ----------------------------------------------------------------------------------------- - 7.01e-01 1.08e+01 -7.45e-02 1.08e+01 -7.38e-02 9.99e-01 9.99e-01 1.08e+01 - + 1.000e+00 2.924e+01 -1.572e+00 1.017e+00 -4.983e-02 5.000e+00 1.739e-01 5.084e+00 + in matlab you can use: dataNucleo = [... insert measurement data here ...]; g = frd(dataNucleo(:,2).*exp(1i*dataNucleo(:,3)), dataNucleo(:,1), Ts, 'Units', 'Hz'); gcl = frd(dataNucleo(:,4).*exp(1i*dataNucleo(:,5)), dataNucleo(:,1), Ts, 'Units', 'Hz'); - + if you're evaluating more than one measurement which contain equal frequency points try: dataNucleo = [dataNucleo1; dataNucleo2]; [~, ind] = unique(dataNucleo(:,1),'stable'); dataNucleo = dataNucleo(ind,:); - + autor: M.E. Peter -*/ +*/ #include "GPA.h" #include "mbed.h" @@ -146,7 +157,8 @@ pi2Tsfexc = pi2Ts*fexc; } } - fexcPast = fexc; + // secure sinarg starts at 0 (numerically maybe not given) + sinarg = 0.0f; // filter scaling scaleG = 1.0f/sqrt((float)Nmeas); // filter coefficients @@ -170,6 +182,7 @@ if(jj == Nmeas) { jj = 1; ii += 1; + fexcPast = fexc; // calculate the one point dft float Ureal = 2.0f*scaleG*(cr*sU[1] - sU[2]); float Uimag = 2.0f*scaleG*ci*sU[1]; @@ -183,12 +196,12 @@ float absGye = Ymag/Aexc; float angGye = (atan2(Yimag, Yreal) + piDiv2); // user info - if(ii == 1) { + if(ii == 2) { printLine(); printf(" fexc[Hz] |Gyu| ang(Gyu) |Gye| ang(Gye) |E| |U| |Y|\r\n"); printLine(); } - printf("%11.2e %10.2e %10.2e %10.2e %10.2e %10.2e %10.2e %10.2e\r\n", fexc, absGyu, angGyu, absGye, angGye, Aexc, Umag, Ymag); + printf("%11.3e %10.3e %10.3e %10.3e %10.3e %10.3e %10.3e %10.3e\r\n", fexc, absGyu, angGyu, absGye, angGye, Aexc, Umag, Ymag); } else { jj += 1; }