towards measure the mass of the stage

logbook.md

@@ -401,3 +401,64 @@ Y(lower stage): 1N max 0.1N min.. depends on the magnetic poles
 #2out20 -> Force 2.5N iqCmd=402
 #2out30 -> Force 3N   iqCmd=603  (changes in torque at poles)
 Weight: ca 750g
+
+*** 27.1.2017 ***
+==================
+
+Friction force of Parker stage: see blue logbook.
+Calculate the current at a given force:
+
+import numpy as np
+import plt as matplotlib.pyplot
+
+F=np.array([+300, +100, 0.,-50,-100,-150,-200,-250,-300])
+i=np.array([+625, 214, 38.,-104,-207,-300,-400,-500,-600])
+
+plt.plot(i,F,'.-')
+
+average  Motor[3].iqMeas -610.949923065
+average  Motor[3].iaMeas 432.573485303
+average  Motor[3].ibMeas -699.459308138
+-> icMeas 432.573485303-699.459308138=-266.885822835
+
+
+Check cur_bits to current
+-------------------------
+
+Block motor 4
+set current to 10%:    #4out10
+Measure current with amp meter and ./move_record.py
+
+Motor[4].PhasePos=313
+
+gelb 293 mA
+idCmd=0
+average  Motor[4].iqMeas 452.897308732
+average  Motor[4].iaMeas -274.830633873
+average  Motor[4].ibMeas 523.056988602
+               -> icMeas 248.226
+
+rot 560 mA
+average  Motor[4].iqMeas 452.719438794
+average  Motor[4].iaMeas -264.325534893
+average  Motor[4].ibMeas 523.057788442
+               -> icMeas 258.73
+
+schwarz 290mA
+average  Motor[4].iqMeas 453.042713114
+average  Motor[4].iaMeas -252.726254749
+average  Motor[4].ibMeas 523.302539492
+               -> icMeas 270.57
+
+PhasePos=0    ia=-512 ib=260   ic=240
+PhasePos=682  ia=250  ib=250   ic=500
+PhasePos=1364 ia=320  ib=-500  ic=180
+
+https://de.wikipedia.org/wiki/D/q-Transformation
+ia=-sin(phi)*iq
+ib=-sin(phi-120deg)*iq
+ic=-sin(phi-240deg)*iq
+
+...cant yet figure out the scaling...
+
+measure the mass of the stage... c ant figure it out...