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Demo of sensorless commutation in single-leg PWM mode. Run Tests.Comm…
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…utation.IntBEMF3.mo
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@joewa
joewa committed Dec 16, 2014
1 parent 6dd6aee commit 351268b
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72 changes: 12 additions & 60 deletions OpenBLDC/Blocks/DetectCommutationIntBEMFext.mo
View file
Expand Up @@ -28,19 +28,11 @@ block DetectCommutationIntBEMFext
"Duration from zero crossing to next commutation";
discrete Real m_reg(start=0) "Slope";
discrete Real b_reg(start=0) "y-intercept";
discrete Real v_buffer[bufsize](start=zeros(bufsize));
Integer zc_index(start=bufsize)
"Index in the ADC-buffer where the zero crossing occurs";
discrete Real duration_zc2comm(start=0)
"Duration from zero crossing to next commutation";
discrete Real time_blockstart(start=0) "Time when last block started";
discrete Real time_zc(start=0) "Time when last zero crossing occured";
Real bemf "Back EMF at the open phase";
discrete Real intBEMF(start=0) "int(BEMF)!";
//Real intBEMFext;
discrete Real time_nextblock(start=0)
"Time when next block (commutation) will occur";
discrete Real maxBEMF(start=0) "Max EMF in this cycle";
Real v_sense "Sensed voltage at the open motor pin, referenced to v_dc/2";
Boolean y_neu(start=false);
Sensors.ADCs.AdcSingleBufferedInteger adcSingleBufferedInteger(BufDepth=
bufsize, Ts=Ts_ADC)
annotation (Placement(transformation(extent={{-28,8},{-8,28}})));
Expand All @@ -63,14 +55,8 @@ algorithm
n_reg := 0;
end when;
when senseBEMF then
intBEMF :=KV;
maxBEMF:= 0;
time_blockstart := time;
for f in 1:bufsize loop
v_buffer[f] := 0;
end for;
zc_index := bufsize;
//anstieg :=0;
end when;
when maxBEMF < abs(v_sense) then
// das ist fragwürdig
Expand All @@ -80,11 +66,6 @@ algorithm

//Neueste Variante mit ADC-Modell
when adcSingleBufferedInteger.adcSingleIntegerBus.cbStart then
//sumx := 0;
//sumx2 := 0;
//sumxy := 0;
//sumy := 0;
//sumy2 := 0;
pwm_dutyCycle_int := integer(floor(10000 * pwmControlBusConnectorIn.dutyCycle));
pwm_period_int := integer(pwmControlBusConnectorIn.period / period_adc);
// CAUTION: pwm_period_int works only if period / period_adc has no fraction
Expand All @@ -93,19 +74,18 @@ algorithm
for f in 1:bufsize loop
k_sample := bufsize * k_cb_ADC + f;
// Store valid measurements in the table (e.g. high side switch is on)
// TODO Add a proper condition here
//if pulses then
k_pwm_period := mod(k_sample, pwm_period_int);
if (k_pwm_period > 1 and (k_pwm_period < ((pwm_dutyCycle_int * pwm_period_int)/10000) or sampleAll)) then
if n_reg < NREG then
n_reg := n_reg + 1;
end if;
//if n_reg >= NREG then // decrement obsolete buffer values from sums
sumx := sumx - xreg[1];
sumx2 := sumx2 - xreg[1]*xreg[1];
sumxy := sumxy - xreg[1]*yreg[1];
sumy := sumy - yreg[1];
sumy2 := sumy2 - yreg[1]*yreg[1];
sumx := sumx - xreg[1];
sumx2 := sumx2 - xreg[1]*xreg[1];
sumxy := sumxy - xreg[1]*yreg[1];
sumy := sumy - yreg[1];
sumy2 := sumy2 - yreg[1]*yreg[1];
//end if;
//if n_reg > 1 then
for f2 in 2:NREG loop
Expand All @@ -123,51 +103,25 @@ algorithm
end if;
end for;
// Check if we are ready to calculate slope and zero crossing (sufficient values and time)
// TODO Add a proper condition here
if (n_reg >= NREG and not (n_reg * sumx2 == sumx * sumx)) then
m_reg := (n_reg * sumxy - sumx * sumy) / (n_reg * sumx2 - sumx * sumx);
//m_reg := (yreg[2]-yreg[1])/(xreg[2]-xreg[1]);
b_reg := (sumy * sumx2 - sumx * sumxy) / (n_reg * sumx2 - sumx * sumx);
if m_reg < -0.1 then // slope must not be zero
k_zc := integer( -b_reg / m_reg);
if k_zc < k_sample then // the zero crossing shall have occurred in the past
duration_zc2comm_int := sqrt(-(2*KV / m_reg));
if k_zc < k_sample and time > time_nextblock then // the zero crossing shall have occurred in the past
duration_zc2comm_int := sqrt(-(2*KV_int / m_reg)) / 4; // TODO check "4"
time_nextblock := time_blockstart + (k_zc + duration_zc2comm_int) * period_adc;
end if;
end if;
end if;
// Hier schon Counter zur Zeitmessung mitlaufen lassen: bei jedem Callback +1
k_cb_ADC := k_cb_ADC + 1;
end when;

when (senseBEMF and sample(0, period_adc)) then
for f in 1:(bufsize-1) loop
v_buffer[f] := v_buffer[f+1]; // Shift buffer (ugly)
if v_buffer[f] > 0 then //and v_buffer[f+1] < 0 then
zc_index := f; // index of last value > 0
end if;
end for;
v_buffer[bufsize] := bemf; // Add new value to buffer
// Extended method
if zc_index == 25 then
time_zc := time - 25*period_adc;
duration_zc2comm := sqrt(-(2*KV*(10+10)*period_adc/(v_buffer[35]-v_buffer[15])));
end if;
if time_zc+duration_zc2comm < time and time_zc+duration_zc2comm+period_adc > time then
y_neu := true; // Puls erzeugen
else
y_neu := false;
end if;

if bemf < 0 then // Alte Methode: Integriere ab Nulldurchgang
intBEMF := intBEMF + bemf*period_adc;
end if;
end when;

y :=if intBEMF < 0 and senseBEMF then true else false;
y := if time_nextblock < time and time_nextblock + period_adc > time then true else false;

equation
v_sense = v[senseBridgeID] - v_dc / 2;
bemf = senseBridgeSign * v_sense;
signalVoltage.v = v[senseBridgeID] * vdivider;
adcSingleBufferedInteger.adcSingleIntegerBus.active = senseBEMF;
connect(adcSingleBufferedInteger.pin_n, ground.p) annotation (Line(
Expand All @@ -190,8 +144,6 @@ equation
<p>This block implements the extended back-emf integration method.</p>
<p>It determines the time of a zero crossing by evaluating the slope of the back-emf. In the next step, the slope is also used to calculate the time when the next commutation is required.</p>
<p>TODO:</p>
<p>1. Implement the ADC-DMA-method and evaluate the measurements only when the ADC callback is executed.</p>
<p>2. In case the single-leg-PWM is applied, evaluate only the measurements when high side switch is on.</p>
<p>3. In case the function is called late, i.e. the zero crossing already happened, use the earliest voltage measurements and slope to determine when the zero crossing occured.</p>
<p>1. Investigate the spike that occurs single leg mode as in Test.Commutation.IntBEMF3.</p>
</html>"));
end DetectCommutationIntBEMFext;
140 changes: 135 additions & 5 deletions OpenBLDC/Blocks/DetectCommutationIntBEMFext_old.mo
View file
Expand Up @@ -2,25 +2,68 @@ within OpenBLDC.Blocks;
block DetectCommutationIntBEMFext_old
"Detects sensorless when commutation is required by back EMF integration - extended method"
extends DetectCommutationPartial;
parameter Integer bufsize = 50 "Size of buffer";
parameter Boolean sampleAll = true "Sample only on pulses when false";
parameter Integer bufsize = 10 "Size of buffer";
parameter Real period_adc = 1e-6;
parameter Modelica.SIunits.Time Ts_ADC = 1e-6 "Sample rate of ADC";
parameter Real vdivider = 3.6/13.6 "Voltage divider of phase voltage";
parameter Integer NREG = 10 "Number of elements for a valid regression";
Integer v_dc_int(start=0) "ADC value of dc link voltage";
Integer k_cb_ADC(start=0) "Increments at each the ADC callback";
Integer sumx(start=0) "computes sum of x (time-axis)";
Integer sumx2(start=0) "computes sum of x**2";
Integer sumxy(start=0) "computes sum of x * y";
Integer sumy(start=0) "computes sum of y";
Integer sumy2(start=0) "computes sum of y**2";
Integer n_reg(start=0) "number of elements in list";
Integer yreg[NREG](start=zeros(NREG)) "Circular buffer for y";
Integer xreg[NREG](start=zeros(NREG)) "Circular buffer for x";
Integer k_sample(start=0) "Sample in the present commutation cycle";
Integer pwm_dutyCycle_int;
Integer pwm_period_int "PWM period relating to period_adc";
Integer k_pwm_period(start=0) "Indicates if the pwm sample ocurred at pwm-on";
Integer k_zc(start=0) "Sample when the zero crossing occurs";
Integer KV_int(start=0) "Integer equivalent of KV";
discrete Real duration_zc2comm_int(start=0)
"Duration from zero crossing to next commutation";
discrete Real m_reg(start=0) "Slope";
discrete Real b_reg(start=0) "y-intercept";
discrete Real v_buffer[bufsize](start=zeros(bufsize));
Integer zc_index(start=bufsize)
"Index in the ADC-buffer where the zero crossing occurs";
discrete Real duration_zc2comm(start=0)
"Duration from zero crossing to next commutation";
discrete Real time_blockstart(start=0) "Time when last block started";
discrete Real time_nextblock(start=0)
"Time when next block (commutation) will occur";
discrete Real time_zc(start=0) "Time when last zero crossing occured";
Real bemf "Back EMF at the open phase";
discrete Real intBEMF(start=0) "int(BEMF)!";
//Real intBEMFext;
discrete Real maxBEMF(start=0) "Max EMF in this cycle";
Real v_sense "Sensed voltage at the open motor pin, referenced to v_dc/2";
Boolean y_neu(start=false);
algorithm
v_sense := v[senseBridgeID] - v_dc / 2;
bemf := senseBridgeSign * v_sense;
Sensors.ADCs.AdcSingleBufferedInteger adcSingleBufferedInteger(BufDepth=
bufsize, Ts=Ts_ADC)
annotation (Placement(transformation(extent={{-28,8},{-8,28}})));
Modelica.Electrical.Analog.Basic.Ground ground
annotation (Placement(transformation(extent={{-10,-8},{10,12}})));
Modelica.Electrical.Analog.Sources.SignalVoltage signalVoltage
annotation (Placement(transformation(extent={{-28,34},{-8,54}})));

algorithm
when not senseBEMF then
k_cb_ADC := 0;
sumx := 0;
sumx2 := 0;
sumxy := 0;
sumy := 0;
sumy2 := 0;
xreg := zeros(NREG);
yreg := zeros(NREG);
m_reg := 0;
n_reg := 0;
end when;
when senseBEMF then
intBEMF :=KV;
maxBEMF:= 0;
Expand All @@ -37,6 +80,68 @@ algorithm
end when;
speedOK :=true;//maxBEMF > minEMF; TODO

//Neueste Variante mit ADC-Modell
when adcSingleBufferedInteger.adcSingleIntegerBus.cbStart then
//sumx := 0;
//sumx2 := 0;
//sumxy := 0;
//sumy := 0;
//sumy2 := 0;
pwm_dutyCycle_int := integer(floor(10000 * pwmControlBusConnectorIn.dutyCycle));
pwm_period_int := integer(pwmControlBusConnectorIn.period / period_adc);
// CAUTION: pwm_period_int works only if period / period_adc has no fraction
v_dc_int := integer(floor(v_dc*vdivider*4096/3)); // ADC value
KV_int := integer(KV * v_dc*vdivider*4096/3 / period_adc);
for f in 1:bufsize loop
k_sample := bufsize * k_cb_ADC + f;
// Store valid measurements in the table (e.g. high side switch is on)
// TODO Add a proper condition here
//if pulses then
k_pwm_period := mod(k_sample, pwm_period_int);
if (k_pwm_period > 1 and (k_pwm_period < ((pwm_dutyCycle_int * pwm_period_int)/10000) or sampleAll)) then
if n_reg < NREG then
n_reg := n_reg + 1;
end if;
//if n_reg >= NREG then // decrement obsolete buffer values from sums
sumx := sumx - xreg[1];
sumx2 := sumx2 - xreg[1]*xreg[1];
sumxy := sumxy - xreg[1]*yreg[1];
sumy := sumy - yreg[1];
sumy2 := sumy2 - yreg[1]*yreg[1];
//end if;
//if n_reg > 1 then
for f2 in 2:NREG loop
yreg[f2-1] := yreg[f2]; // Shift buffer (ugly)
xreg[f2-1] := xreg[f2]; // Shift buffer (ugly)
end for;
//end if;
yreg[NREG] := integer( senseBridgeSign*(adcSingleBufferedInteger.adcSingleIntegerBus.buffer[f] - v_dc_int / 2));
xreg[NREG] := k_sample; // Sample-number in actual commutation cycle
sumx := sumx + xreg[NREG];
sumx2 := sumx2 + xreg[NREG]*xreg[NREG];
sumxy := sumxy + xreg[NREG]*yreg[NREG];
sumy := sumy + yreg[NREG];
sumy2 := sumy2 + yreg[NREG]*yreg[NREG];
end if;
end for;
// Check if we are ready to calculate slope and zero crossing (sufficient values and time)
// TODO Add a proper condition here
if (n_reg >= NREG and not (n_reg * sumx2 == sumx * sumx)) then
m_reg := (n_reg * sumxy - sumx * sumy) / (n_reg * sumx2 - sumx * sumx);
//m_reg := (yreg[2]-yreg[1])/(xreg[2]-xreg[1]);
b_reg := (sumy * sumx2 - sumx * sumxy) / (n_reg * sumx2 - sumx * sumx);
if m_reg < -0.1 then // slope must not be zero
k_zc := integer( -b_reg / m_reg);
if k_zc < k_sample and time > time_nextblock then // the zero crossing shall have occurred in the past
duration_zc2comm_int := sqrt(-(2*KV_int / m_reg)) / 4; // TODO check "4"
time_nextblock := time_blockstart + (k_zc + duration_zc2comm_int) * period_adc;
end if;
end if;
end if;
// Hier schon Counter zur Zeitmessung mitlaufen lassen: bei jedem Callback +1
k_cb_ADC := k_cb_ADC + 1;
end when;

when (senseBEMF and sample(0, period_adc)) then
for f in 1:(bufsize-1) loop
v_buffer[f] := v_buffer[f+1]; // Shift buffer (ugly)
Expand All @@ -61,8 +166,33 @@ algorithm
end if;
end when;

if time_nextblock < time and time_nextblock + period_adc > time then
y_neu := true; // Puls erzeugen
else
y_neu := false;
end if;

y :=if intBEMF < 0 and senseBEMF then true else false;
annotation(Diagram(coordinateSystem(preserveAspectRatio = false, extent = {{-100,-100},{100,100}}), graphics), Icon(coordinateSystem(preserveAspectRatio = false, extent = {{-100,-100},{100,100}}), graphics={ Text(extent = {{-76,60},{-12,24}}, lineColor = {0,0,255}, textString = "pulses", fontSize = 48,

equation
v_sense = v[senseBridgeID] - v_dc / 2;
bemf = senseBridgeSign * v_sense;
signalVoltage.v = v[senseBridgeID] * vdivider;
adcSingleBufferedInteger.adcSingleIntegerBus.active = senseBEMF;
connect(adcSingleBufferedInteger.pin_n, ground.p) annotation (Line(
points={{-8,18},{0,18},{0,12}},
color={0,0,255},
smooth=Smooth.None));
connect(signalVoltage.n, adcSingleBufferedInteger.pin_n) annotation (Line(
points={{-8,44},{-8,18}},
color={0,0,255},
smooth=Smooth.None));
connect(signalVoltage.p, adcSingleBufferedInteger.pin_p) annotation (Line(
points={{-28,44},{-28,18}},
color={0,0,255},
smooth=Smooth.None));
annotation(Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,
-100},{100,100}}), graphics), Icon(coordinateSystem(preserveAspectRatio = false, extent = {{-100,-100},{100,100}}), graphics={ Text(extent = {{-76,60},{-12,24}}, lineColor = {0,0,255}, textString = "pulses", fontSize = 48,
horizontalAlignment = TextAlignment.Left),Text(extent = {{-76,-20},{36,-56}}, lineColor = {0,0,255}, fontSize = 48,
horizontalAlignment = TextAlignment.Left, textString = "bridgeState")}),
Documentation(info="<html>
Expand Down
4 changes: 3 additions & 1 deletion OpenBLDC/Blocks/SensorlessCtrl3phStateGraphNG.mo
View file
@@ -1,6 +1,7 @@
within OpenBLDC.Blocks;
block SensorlessCtrl3phStateGraphNG "Commutation applying PWM"
extends OpenBLDC.Icons.ControlLaw;
parameter Integer PwmMode = 1 "Two-leg (1) or single-leg (2) mode";
parameter Modelica.SIunits.Duration DelayCommutation = 5e-005
"Delay commutation";
parameter Modelica.SIunits.Duration TimeoutCommutation = 0.01
Expand All @@ -12,7 +13,8 @@ block SensorlessCtrl3phStateGraphNG "Commutation applying PWM"
Modelica.Blocks.Interfaces.BooleanOutput lCtrl[3] annotation(Placement(transformation(extent = {{250,-70},{270,-50}}), iconTransformation(extent = {{80,-70},{100,-50}})));
Modelica.Blocks.Interfaces.RealInput angle "Decoded hall" annotation(Placement(transformation(extent = {{-300,-20},{-260,20}})));
Modelica.Blocks.Tables.CombiTable1Ds combiTable1Ds(table = [0,0,0,0;1,1,-1,0;2,0,-1,1;3,-1,0,1;4,-1,1,0;5,0,1,-1;6,1,0,-1]) annotation(Placement(transformation(extent = {{-18,-60},{2,-40}})));
Modelica.Blocks.Sources.IntegerExpression integerExpression[3](each y = 1) annotation(Placement(transformation(extent = {{164,-78},{184,-58}})));
Modelica.Blocks.Sources.IntegerExpression integerExpression[3](each y=PwmMode)
annotation(Placement(transformation(extent = {{164,-78},{184,-58}})));
HalfBridgeDriver halfBridgeDriver[3] annotation(Placement(transformation(extent = {{220,38},{240,58}})));
HalfBridgeLogic halfBridgeLogic[3] annotation(Placement(transformation(extent = {{194,38},{214,58}})));
Modelica.Blocks.Interfaces.RealInput v_dc "dc link voltage" annotation(Placement(transformation(extent = {{-20,-20},{20,20}}, rotation = 90, origin = {60,-100})));
Expand Down
6 changes: 4 additions & 2 deletions OpenBLDC/Tests/Commutation/IntBEMF2.mo
View file
@@ -1,10 +1,12 @@
within OpenBLDC.Tests.Commutation;
model IntBEMF2 "Commutation based on BEMF integration with extended method"
model IntBEMF2
"Commutation based on BEMF integration with extended method, 2-leg-PWM"
extends Modelica.Icons.Example;
extends Assemblies.SensorlessBLDC(
redeclare Blocks.SensorlessCtrl3phStateGraphNG sensorlessCtrl3phPWM(
catchStart(KV_Method = 3),
redeclare Blocks.DetectCommutationIntBEMFext detectCommutation),
redeclare Blocks.DetectCommutationIntBEMFext detectCommutation(sampleAll=true),
PwmMode=1),
mechanicalLoad(w_fixed = 8000 * 2 * Modelica.Constants.pi / 60), motorVoltageCommand(k = 0.8));
annotation(experiment(StopTime = 0.003));
end IntBEMF2;
12 changes: 12 additions & 0 deletions OpenBLDC/Tests/Commutation/IntBEMF3.mo
View file
@@ -0,0 +1,12 @@
within OpenBLDC.Tests.Commutation;
model IntBEMF3
"Commutation based on BEMF integration with extended method, 1-leg-PWM"
extends Modelica.Icons.Example;
extends Assemblies.SensorlessBLDC(
redeclare Blocks.SensorlessCtrl3phStateGraphNG sensorlessCtrl3phPWM(
catchStart(KV_Method = 3),
redeclare Blocks.DetectCommutationIntBEMFext detectCommutation(sampleAll=false),
PwmMode=2),
mechanicalLoad(w_fixed = 8000 * 2 * Modelica.Constants.pi / 60), motorVoltageCommand(k = 0.6));
annotation(experiment(StopTime = 0.003));
end IntBEMF3;
4 changes: 3 additions & 1 deletion OpenBLDC/Tests/Commutation/TestIntBEMFext.mo
View file
@@ -1,7 +1,9 @@
within OpenBLDC.Tests.Commutation;
model TestIntBEMFext "Model to understand the linear regression method"
extends Modelica.Icons.Example;
Blocks.DetectCommutationIntBEMFext dC(bufsize=10, NREG=10,
Blocks.DetectCommutationIntBEMFext_old dC(
bufsize=10,
NREG=10,
sampleAll=false)
annotation (Placement(transformation(extent={{0,-6},{20,14}})));
Modelica.Blocks.Sources.BooleanStep senseBemfStep(startTime=1e-5)
Expand Down
1 change: 1 addition & 0 deletions OpenBLDC/Tests/Commutation/package.order
View file
@@ -1,4 +1,5 @@
IntBEMF1
IntBEMF2
IntBEMF3
ZeroCrossings1
TestIntBEMFext

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