Control with TrackCam Vision Feedback and MATLAB - Revision history

Ilya Mikhelson at 22:01, 11 September 2009

2009-09-11T22:01:33Z

Ilya Mikhelson at 21:59, 11 September 2009

2009-09-11T21:59:32Z

Ilya Mikhelson at 21:58, 11 September 2009

2009-09-11T21:58:31Z

Ilya Mikhelson: /* skeleton.cpp */

2009-09-11T21:52:56Z

skeleton.cpp

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Ilya Mikhelson: /* integrationTestPutSample.m */

2009-09-11T21:52:22Z

integrationTestPutSample.m

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Ilya Mikhelson: /* sweepOfSampleRatesSineWave */

2009-09-11T21:51:52Z

sweepOfSampleRatesSineWave

Ilya Mikhelson: /* inputOutputSineWave.m */

2009-09-11T21:51:21Z

inputOutputSineWave.m

Ilya Mikhelson: /* testInputCard.m */

2009-09-11T21:50:50Z

testInputCard.m

Ilya Mikhelson: /* testOutput.m */

2009-09-11T21:50:24Z

testOutput.m

Ilya Mikhelson: /* testInputOutput.m */

2009-09-11T21:49:46Z

testInputOutput.m

@@ Line 89: / Line 89: @@
 ===Timing===
-The timing of the system is detailed on the timing diagrams (Fig 5 and 6).  The idea, which is not fully implemented yet, is to have there be two pictures already taken when the MATLAB program calls the MEX-file, so that the program waits for only one more picture to be taken and then grabs all three and processes them all.  To implement this, the frame time has to be just a little shorter than half of the total processing time, including the MEX-file processing and the MATLAB processing.
+The timing of the system is detailed on the timing diagrams (Fig 5 and 6).  The idea, which is not fully implemented yet, is to have there be two pictures already taken when the MATLAB program calls the MEX-file, so that the program waits for only one more picture to be taken and then grabs all three and processes them all.  To implement this, the frame time has to be just a little shorter than half of the total processing time, including the MEX-file processing and the MATLAB processing.  With a frame time of 500 microseconds, the system keeps up fine and can take pictures at 2000 frames per second.  However, tweaking the frame time and exposure time to fit more neatly with processing time can make the system more efficient and perhaps even put the rate to over 2000 Hz, depending on how fast the processing can be done.
 [[image:TimingDiagram.jpg|thumb|500px|'''Figure 5:''' Timing Diagram.|left]]

@@ Line 91: / Line 91: @@
 The timing of the system is detailed on the timing diagrams (Fig 5 and 6).  The idea, which is not fully implemented yet, is to have there be two pictures already taken when the MATLAB program calls the MEX-file, so that the program waits for only one more picture to be taken and then grabs all three and processes them all.  To implement this, the frame time has to be just a little shorter than half of the total processing time, including the MEX-file processing and the MATLAB processing.
-[[image:TimingDiagram.jpg|thumb|500px|'''Figure 5:''' Sweep of requested sample rates.|left]]
+[[image:TimingDiagram.jpg|thumb|500px|'''Figure 5:''' Timing Diagram.|left]]
-[[image:TimingDiagramDetail.jpg|thumb|500px|'''Figure 6:''' Sweep of requested sample rates.|right]]
+[[image:TimingDiagramDetail.jpg|thumb|500px|'''Figure 6:''' Blowup of Timing Diagram.|right]]
 ==Next Steps==

@@ Line 94: / Line 94: @@
 [[image:TimingDiagramDetail.jpg|thumb|500px|'''Figure 6:''' Sweep of requested sample rates.|right]]
+==Next Steps==
+In the future, more things can be done to further speed up the system.  First of all, using separate cores for the camera and processing may speed up the system as the two tasks would run in parallel.  This would require shared memory.  Another step that can be taken is to implement all the MATLAB computations in C.  This would help because C is quicker than MATLAB and because MATLAB wouldn't have to access the MEX-file every time it wants to take a picture.  Also, using a real-time operating system like Linux RTAI would also speed up the process.  Stripping down Windows makes it close to real-time, but in reality it is not real-time.
 ==Code==

@@ Line 511: / Line 511: @@
 ===sweepOfSampleRatesSineWave===
+ <nowiki>
+clear all
+close all
+freq = 50;
+amp = 1;
+sampRateIn = 50000;
+timeIn = 10;
+trigger = timeIn*sampRateIn;
+AI = analoginput('mcc',0);
+AO = analogoutput('mcc',1);
+addchannel(AI,[0:5],[1:6]);
+addchannel(AO,[0:5],[1:6]);
+set(AI,'SampleRate',sampRateIn)
+set(AI,'SamplesPerTrigger',trigger)
+set(AO,'SampleRate',ceil(1/500))
+time = 1/sampRateIn:1/sampRateIn:timeIn;
+sweep = zeros(100,3);
+for sr = 500:100:10000
+    sampRate = sr;
+    dt = 1/sampRate;
+    t = 0:dt:timeIn;
+    outputwave = amp*sin(2*pi*freq*t);
+    outputwave = outputwave';
+    outputwave(:,2) = amp*sin(2*pi*freq*t);
+    outputwave(:,[3 4 5 6]) = 0;
+    start(AI)
+    tic
+    for ii = 1:length(outputwave)
+        while(toc<(dt*ii))
+        end
+        putsample(AO,outputwave(ii,:));
+        %fprintf('pause: %f\n',dt-time);
+        %data(ii,:) = getsample(AI);
+    end
+    data = getdata(AI);
+    stop(AI);
+    meaningfulData = data(:,1);
+    NFFT = 2^nextpow2(length(meaningfulData)); % Next power of 2 from length of y
+    Y = fft(meaningfulData,NFFT)/length(meaningfulData);
+    f = sampRateIn/2*linspace(0,1,NFFT/2+1);
+%     figure
+%     plot(f,2*abs(Y(1:NFFT/2+1)))
+%     title(['Single-Sided Amplitude Spectrum of y(t) (',num2str(freq),' Hz) @ ',num2str(sampRate),' Hz'])
+%     xlabel('Frequency (Hz)')
+%     ylabel('|Y(f)|')
+%     axis([0,2*freq,0,amp])
+    [a,b] = max(Y(1:NFFT/2+1));
+    actualFreq = f(b);
+    sweep(sr/100,1) = sr;
+    sweep(sr/100,2) = actualFreq;
+end
+figure
+plot(sweep(:,1), sweep(:,2));
+</nowiki>
 ===integrationTestPutSample.m===

@@ Line 438: / Line 438: @@
 ===inputOutputSineWave.m===
+ <nowiki>
+clear all
+close all
+sampRate = 200;
+dt = 1/sampRate;
+freq = 50;
+amp = 1;
+sampRateIn = 50000;
+timeIn = 10;
+trigger = timeIn*sampRateIn;
+AI = analoginput('mcc',0);
+AO = analogoutput('mcc',1);
+addchannel(AI,[0:5],[1:6]);
+addchannel(AO,[0:5],[1:6]);
+set(AI,'SampleRate',sampRateIn)
+set(AI,'SamplesPerTrigger',trigger)
+set(AO,'SampleRate',ceil(1/500))
+time = 1/sampRateIn:1/sampRateIn:timeIn;
+t = dt:dt:timeIn;
+outputwave = amp*sin(2*pi*freq*t);
+outputwave = outputwave';
+outputwave(:,2) = amp*sin(2*pi*freq*t);
+outputwave(:,[3 4 5 6]) = 0;
+start(AI)
+tic
+a = 0;
+for ii = 1:length(outputwave)
+    while(toc<(dt*ii))
+    end
+    putsample(AO,outputwave(ii,:));
+    z = sampleMexFile(ii,ii,ii);
+end
+data = getdata(AI);
+stop(AI);
+delete(AI)
+clear AI
+meaningfulData = data(:,1);
+plot(time,meaningfulData);
+[YfreqDomain,frequencyRange] = positiveFFT(meaningfulData,sampRateIn);
+positiveFFT = figure;
+stem(frequencyRange,abs(YfreqDomain));
+xlabel('Freq (Hz)')
+ylabel('Amplitude')
+title('FFT')
+grid
+axis([0,2*freq,0,amp])
+NFFT = 2^nextpow2(length(meaningfulData)); % Next power of 2 from length of y
+Y = fft(meaningfulData,NFFT)/length(meaningfulData);
+f = sampRateIn/2*linspace(0,1,NFFT/2+1);
+figure
+plot(f,2*abs(Y(1:NFFT/2+1)))
+title(['Single-Sided Amplitude Spectrum of y(t) (',num2str(freq),' Hz) @ ',num2str(sampRate),' Hz'])
+xlabel('Frequency (Hz)')
+ylabel('|Y(f)|')
+axis([0,2*freq,0,amp])
+[a,b] = max(Y(1:NFFT/2+1));
+actualFreq = f(b);
+fprintf(['\nRequested frequency: ',num2str(freq), ' Hz\n']);
+fprintf(['Actual frequency: ',num2str(actualFreq), ' Hz\n']);
+</nowiki>
 ===sweepOfSampleRatesSineWave===

@@ Line 393: / Line 393: @@
 ===testInputCard.m===
+ <nowiki>
+clear all
+close all
+dt = 1/500;
+freq = 30;
+sampRateIn = 50000;
+trigger = 100000;
+time = 1/sampRateIn:1/sampRateIn:trigger/sampRateIn;
+AI = analoginput('mcc',0);
+addchannel(AI,[0:5],[1:6]);
+set(AI,'SampleRate',sampRateIn)
+set(AI,'SamplesPerTrigger',trigger)
+start(AI)
+data = getdata(AI);
+meaningfulData = data(:,1);
+plot(time,meaningfulData);
+freqData = zeros(trigger,1);
+counter = 0;
+for ii = 2:trigger
+    if (abs(meaningfulData(ii) - meaningfulData(ii-1)) < .05)
+        counter = counter + 1;
+    elseif ((counter ~= 0) && (ii-counter > 3))
+        freqData(counter) = freqData(counter) + 1;
+        counter = 0;
+    elseif (ii-counter == 3)
+        counter = 0;
+    end
+end
+figure
+stem(time,freqData);
+for jj = 1:trigger
+    if (freqData(jj) ~= 0)
+        fprintf('%u pulses had duration of: %f \n',freqData(jj),jj/sampRateIn);
+    end
+end
+</nowiki>
 ===inputOutputSineWave.m===