Control Chart Using .Net

Introduction

Nowadays the automobile industry is interested in automated measuring machines to ensure quality and to compete in the global industry. Control Charts take a major role in ensuring quality by measuring automobile components. The purpose of this article is to make a simple Control Bar Chart for measuring systems like Camshafts, Crankshafts and Master Settings and so on. A digital sensor is used for measuring a Camshaft and a Crankshaft. Then the measured data is analyzed using the Control Chart.

Control Chart (ref)

The Control Charts are graphs for checking the quality of a control of a process. In Control Charts UCL/LCL or USL/LSL will be used to check with the resultant data. If the measurement data is within the range of limits then the process is OK(GOOD). If the measurement data is above or below the limits then the process is NG (NOT GOOD).

1. OK (GOOD) -> USL <= Measurement Data >= LSL
2. NG (NOT GOOD) -> Upper Range -> Measurement Data > USL
3. NG (NOT GOOD) -> Lower Range -> Measurement Data < LSL
   
   
   

In my simple Control Chart USL /LSL is used for verifying the data. USL is the Upper Specification Limit and LSL is the Lower Specification Limit. Note in this sample I have used USL/LSL.

Difference between USL/LSL and UCL/LCL

(The UCL or Upper Control Limit and LCL or Lower Control Limit are limits set by your process based on the actual amount of variation of your process. The USL or upper specification limit and LSL or lower specification limit are limits set by your customer's requirements. This is the variation that they will accept from your process. Ref)

I have been working on several automation projects. Instead of using third-party tools, I planned to create a simple program using .Net for creating a USL/LSL Control Bar chart for the master setting. The main purpose of this article is to share what I have developed to other members.

I have created a Control Chart as a User Control so that it can be used easily in all projects.

In this article I have attached a Zip file named SHANUControlChart_SRC.zip which contains:

1. "SHANUControlChart_CNT" Folder (This folder contains the Control Chart User control Source code.)
2. "SHANUControlChart_DEMO" Folder (This folder conains the Demo program that includes the Control Chart user control with Random Measurement sample using Timer control).

Using the code

1. First we will start with the User Control. To Create a user control:

1. Create a new Windows Control Library project.
2. Set the name of the project and click Ok (here my user control name is SHANUControlChart_CNT).
3. Add all the controls that is needed.
4. In the code behind declare all the public variables and Public property variables. Here USL/LSL/Nominal and Measurement Data Public property has been declared which will be used to pass the data from the Windows application.
   
   1. 'Public Property Declaration
   2. Public Property MasterData() As String
   3. Get
   4. Return lblMasterData.Text
   5. End Get
   6. Set(value As String)
   7. lblMasterData.Text = value
   8. End Set
   9. End Property
   11. Public Property USLData() As String
   12. Get
   13. Return lblUslData.Text
   14. End Get
   15. Set(value As String)
   16. lblUslData.Text = value
   17. End Set
   18. End Property
   20. Public Property LSLData() As String
   21. Get
   22. Return lblLslData.Text
   23. End Get
   24. Set(value As String)
   25. lblLslData.Text = value
   26. End Set
   27. End Property
   30. Public Property NominalData() As String
   31. Get
   32. Return lblNominalData.Text
   33. End Get
   34. Set(value As String)
   35. lblNominalData.Text = value
   36. End Set
   37. End Property
5. In my User Control I used a Timer control to always check for the measurment data and produce the Bar Chart.in the user control load. I have enabled and started the timer. The timer Tick Event calls the function "LoadcontrolChart()". In this fucntion I set all the USL/LSL and measurement data and draw the Chart Control.
   
   1. Public Sub LoadcontrolChart()
   2. Try
   3. 'For Barand GageLoad
   4. upperLimitChk = False
   5. lowerLimitchk = False
   6. errLimtchk = False
   7. Dim pointVal As Integer
   8. Dim calcvalues As Double
   9. Dim calcvalues1 As Double
   10. ' Dim upperValue As Double
   11. Dim hasread As Integer
   12. Dim UpperRange As Double
   13. Dim err As String
   14. pointVal = 3
   15. Dim ival As Integer
   16. 
       
   17. sensordata = Convert.ToDouble(lblMasterData.Text.Trim())
       
   18. frmMasteringPictuerBox.Refresh()
       
   19. upperValue = System.Convert.ToDouble(lblUslData.Text)
   20. lovervalue = System.Convert.ToDouble(lblLslData.Text)
   21. If upperValue = lovervalue Then
   22. lovervalue = lovervalue - 1
   23. End If
   25. inputValue = System.Convert.ToDouble(lblMasterData.Text)
   26. 'here we call the draw ractangle fucntion
   27. drawRectanles(barheight, barwidth, upperValue, lovervalue, loverInitialvalue, upperInititalvalue, xval, yval)
   28. 
       
   29. Catch ex As Exception
   30. End Try
   31. End Sub
   In this method we check the measurement data with the USL and LSL limit values. If the measurement data is within the range of USL and LSL then the output will be Ok. I have used the if condition to check the values as below.
   
   1. ''This method is to draw the control chart
   2. Public Sub drawRectanles(ByVal barheight As Double, ByVal barwidth As Double, ByVal uppervalue As Double, ByVal lovervalue As Double, ByVal loverinitialvalue As Double, ByVal upperinitialvalue As Double, ByVal xval As Double, ByVal yval As Double)
   3. Try
   4. Dim limitsline As Double
   5. Dim lowerlimitline As Double
   6. Dim underrange As Double
   7. Dim upperrange As Double
   8. Dim differentpercentage As Double
   9. Dim totalheight As Double
   10. Dim inputvalueCal As Double
   11. Dim finaldisplayvalue As Double
   12. Dim backColors1 As Color
   13. Dim backColors2 As Color
   14. 'this is for the range persentage Calculation
   15. differentpercentage = uppervalue - lovervalue
   16. differentpercentage = differentpercentage * 0.2
   17. 'Upper range value
   18. upperrange = uppervalue + differentpercentage
   19. 'Lover range value
   20. underrange = lovervalue - differentpercentage
   21. totalheight = upperrange - underrange
   22. 'For Upper Limit
   23. ''limitsline = barheight * 0.2 - 10
   24. limitsline = lovervalue - underrange
   25. limitsline = limitsline / totalheight
   26. limitsline = barheight * limitsline + 10
   27. 'For Lower Limit
   28. lowerlimitline = uppervalue - underrange
   29. lowerlimitline = lowerlimitline / totalheight
   30. lowerlimitline = barheight * lowerlimitline + 10
   31. 'lowerlimitline = barheight - limitsline + 10
   32. 'for finding the rangedata
   33. inputvalueCal = inputValue - underrange
   34. finaldisplayvalue = inputvalueCal / totalheight
   35. finaldisplayvalue = barheight * finaldisplayvalue
   36. Dim g As Graphics = frmMasteringPictuerBox.CreateGraphics
   37. Dim f5 As Font
   38. f5 = New Font("arial", 22, FontStyle.Bold, GraphicsUnit.Pixel)
   39. ''If condition to check for the result and display the chart accordingly depend on limit values.
   40. If inputValue = "0.000" Then
   41. If zeroDisplay = 0 Then
   42. backColors1 = Color.Red
   43. backColors2 = Color.DarkRed
   44. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 90, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   45. g.DrawString("NG -> UnderRange", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   46. lblMasterData.ForeColor = Color.Red
   48. frmMasteringlblmsg.Text = "NG -> UnderRange"
   49. Else
   50. backColors1 = Color.GreenYellow
   51. backColors2 = Color.DarkGreen
   52. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 90, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   53. g.DrawString("OK -> Good", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   54. lblMasterData.ForeColor = Color.GreenYellow
   56. frmMasteringlblmsg.Text = "OK -> Good"
   57. End If
   58. ElseIf inputValue >= lovervalue And inputValue <= uppervalue Then
   59. backColors1 = Color.GreenYellow
   60. backColors2 = Color.DarkGreen
   61. If upperLimitChk = False Then
   62. backColors1 = Color.GreenYellow
   63. backColors2 = Color.DarkGreen
   64. lblMasterData.ForeColor = Color.GreenYellow
   65. Else
   66. backColors1 = Color.Red
   67. backColors2 = Color.DarkRed
   68. lblMasterData.ForeColor = Color.Red
   69. End If
   70. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   71. g.DrawString("OK -> Good", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   73. frmMasteringlblmsg.Text = "OK -> Good"
   74. 'frmMasteringlblOrignalData.ForeColor = Color.GreenYellow
   75. ElseIf inputValue < lovervalue Then
   76. backColors1 = Color.Red
   77. backColors2 = Color.DarkRed
   78. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   79. g.DrawString("NG -> UnderRange", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   80. lblMasterData.ForeColor = Color.Red
   81. 'frmMasteringlblOrignalData.ForeColor = Color.Red
   83. frmMasteringlblmsg.Text = "NG -> UnderRange"
   84. ElseIf inputValue > uppervalue Then
   85. backColors1 = Color.Red
   86. backColors2 = Color.DarkRed
   87. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   88. g.DrawString("NG -> UpperRange", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   89. lblMasterData.ForeColor = Color.Red
   90. 'frmMasteringlblOrignalData.ForeColor = Color.Red
   92. frmMasteringlblmsg.Text = "NG -> UpperRange"
   93. Else
   94. backColors1 = Color.Red
   95. backColors2 = Color.DarkRed
   96. Dim a5 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   97. g.DrawString("Not Good", f5, a5, System.Convert.ToInt32(xval) - 40, barheight + 24)
   98. lblMasterData.ForeColor = Color.Red
   100. frmMasteringlblmsg.Text = "Not Good"
   101. End If
   103. Dim apen As New Pen(Color.Black, 2)
   104. g.DrawRectangle(Pens.Black, System.Convert.ToInt32(xval) - 2, System.Convert.ToInt32(yval) - 2, System.Convert.ToInt32(barwidth) + 3, System.Convert.ToInt32(barheight) + 3)
   106. g.DrawLine(apen, System.Convert.ToInt32(xval) - 15, System.Convert.ToInt32(limitsline), System.Convert.ToInt32(xval), System.Convert.ToInt32(limitsline))
   107. g.DrawLine(apen, System.Convert.ToInt32(xval) - 15, System.Convert.ToInt32(lowerlimitline), System.Convert.ToInt32(xval), System.Convert.ToInt32(lowerlimitline))
   108. Dim a1 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), Color.Blue, Color.Orange, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   109. Dim f As Font
   110. f = New Font("arial", 10, FontStyle.Bold, GraphicsUnit.Pixel)
   111. g.DrawString((String.Format("{0:N3}", CDbl(uppervalue.ToString))), f, a1, System.Convert.ToInt32(xval) - 40, System.Convert.ToInt32(limitsline) + 1)
   112. g.DrawString((String.Format("{0:N3}", CDbl(lovervalue.ToString))), f, a1, System.Convert.ToInt32(xval) - 40, System.Convert.ToInt32(lowerlimitline) + 1)
   113. g.DrawString((String.Format("{0:N3}", CDbl(upperrange.ToString))), f, a1, System.Convert.ToInt32(xval) - 40, 9)
   114. g.DrawString((String.Format("{0:N3}", CDbl(underrange.ToString))), f, a1, System.Convert.ToInt32(xval) - 40, barheight + 10)
   115. Dim a As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(xval, barheight + 10, barwidth, finaldisplayvalue + 1), backColors1, backColors2, Drawing.Drawing2D.LinearGradientMode.Vertical)
   117. Dim a2 As New System.Drawing.Drawing2D.LinearGradientBrush(New RectangleF(0, 0, 100, 19), Color.Black, Color.Black, Drawing.Drawing2D.LinearGradientMode.Horizontal)
   118. Dim f2 As Font
   119. f2 = New Font("arial", 12, FontStyle.Bold, GraphicsUnit.Pixel)
   120. If inputValue >= upperrange Then
   121. g.FillRectangle(a, New RectangleF(xval, 10, barwidth, barheight))
   122. g.DrawString((String.Format("{0:N3}", CDbl(inputValue.ToString))), f2, a2, System.Convert.ToInt32(xval) + 40, yval - 8)
   123. ElseIf inputValue <= underrange Then
   124. g.FillRectangle(a, New RectangleF(xval, barheight + 10, barwidth, 4))
   125. g.DrawString((String.Format("{0:N3}", CDbl(inputValue.ToString))), f2, a2, System.Convert.ToInt32(xval) + 40, barheight + 10)
   126. Else
   127. g.FillRectangle(a, New RectangleF(xval, barheight - finaldisplayvalue + 10, barwidth, finaldisplayvalue))
   128. g.DrawString((String.Format("{0:N3}", CDbl(inputValue.ToString))), f2, a2, System.Convert.ToInt32(xval) + 40, barheight - System.Convert.ToInt32(finaldisplayvalue))
   129. End If
   130. ' End If
   131. g.Dispose()
   132. Catch ex As Exception
   133. End Try
   134. End Sub
        
6. After completion, save, build and run the project.

2. Now we create a Windows application and add and test our "SHANUControlChart_CNT" User Control.

1. Create a new Windows project.
2. Open your form and then from the Toolbox right-click then choose items > browse then select your User Control DLL and add it.
3. Drag the User Control to your Windows form.
4. Place all the USL/LSL and Measurement TextBox for input from the user. In the Manual check button click pass all the data to the User Control using the public property as below.
   
   1. private void btnDisplay_Click(object sender, EventArgs e)
   2. {
   3. shanuControlChart.USLData = txtusl.Text;
   4. shanuControlChart.LSLData = txtLSL.Text;
   5. shanuControlChart.NominalData = txtNominal.Text;
   6. shanuControlChart.MasterData = txtData.Text;
   7. }
5. In my demo program I have used the timer for the randomly sampled measurement data result checking. I have used the "btnRealTime" as a toggle button. When the first time Enabled is clicked and start the timer and when the same button is clicked again the timer is stopped. When the timer is started I generated a random number and pass the various data to the User Control and check for the chart result.
   
   1. private void btnRealTime_Click(object sender, EventArgs e)
   2. {
   3. if (btnRealTime.Text == "Real Time Data ON")
   4. {
   5. btnRealTime.Text = "Real Time Data OFF";
   6. btnRealTime.ForeColor = Color.Red;
   7. timer1.Enabled = true;
   8. timer1.Start();
   9. }
   10. else
   11. {
   12. btnRealTime.Text = "Real Time Data ON";
   13. btnRealTime.ForeColor = Color.DarkGreen;
   14. timer1.Enabled = false;
   15. timer1.Stop();
   16. }
   17. }
   19. / Timer Tick Event to check for the different random sample Measurement test data.
   21. private void timer1_Tick(object sender, EventArgs e)
   22. {
   23. Random rnd =new Random();
   25. Double rndval = rnd.Next(1, 20);
   26. txtData.Text = rndval.ToString("0.000");//FormatNumber(rndval.ToString(), 3, , 0)
   27. shanuControlChart.USLData = txtusl.Text;
   28. shanuControlChart.LSLData = txtLSL.Text;
   29. shanuControlChart.NominalData = txtNominal.Text;
   30. shanuControlChart.MasterData = txtData.Text;
   31. }

Conclusion

The main purpose of this article is to create a simple and standard Control Bar Chart User Control for the automobile industry.