Patent Publication Number: US-2002008702-A1

Title: Interactive scalable digital oscilloscope display

Description:
RELATED APPLICATIONS  
       [0001] Not Applicable  
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002] Not Applicable  
       MICROFICHE APPENDIX  
       [0003] Included herewith is a microfiche appendix illustrating the preferred computer program incorporated as part of the disclosure hereof including 1 sheet with a total of 43 frames.  
       BACKGROUND OF THE INVENTION  
       [0004] 1. Field of the Invention  
       [0005] The present invention relates to the field of engine analyzers in the display of data therefrom. In particular, the invention is concerned with a data display apparatus operable to produce a waveform display representative of a waveform having a plurality of segments.  
       [0006] 2. Description of the Prior Art  
       [0007] Engine analyzers are used to display waveforms characteristic of the operation of an engine including segments representative of the firing of each cylinder. The waveforms tend to be complex and difficult to analyze visually. Moreover, it would be helpful to analyze and compare data from different sources such as the primary and secondary of the engine coil, but prior art systems are unable to accomplish this effectively. Accordingly, the prior art points out the need for improvement in the display of complex waveforms.  
       SUMMARY OF THE INVENTION  
       [0008] The present invention satisfies the prior art needs discussed above and provides a distinct advance in the state of the art. More particularly, the data display apparatus hereof provides for a visually enhanced display of complex waveforms including waveforms derived from different sources.  
       [0009] The preferred data display apparatus in accordance with the present invention includes an image display device coupled with a computer. The computer stores waveform data representative of a waveform having a plurality of data segments and is operable, under program control, for producing display signals and to provide the signals to the display device for producing a waveform display with a plurality of data segments in different colors.  
       [0010] In preferred forms, a cursor snaps along the waveform and the display presents a numerical display of the position coordinates of the cursor. The preferred embodiment is also operable to present a plurality of waveforms derived from different sources. Other preferred aspects of the present invention are disclosed herein. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011]FIG. 1 is a schematic representing the preferred data display apparatus in accordance with the present invention shown in use with a vehicle;  
     [0012]FIG. 2 illustrates a waveform display presented on the display device of FIG. 1;  
     [0013]FIG. 3 illustrates another waveform display presented on the display device of FIG. 1;  
     [0014]FIG. 4 illustrates a display showing two waveforms derived from different sources as displayed on the display device of FIG. 1;  
     [0015]FIG. 5 illustrates a display showing the use of crosshair cursors for measuring the firing line of a cylinder;  
     [0016]FIG. 6 illustrates a display for comparing values among cylinders;  
     [0017]FIG. 7 illustrates another display for comparing values among cylinders;  
     [0018]FIG. 8 illustrates another display for comparing values among the cylinders;  
     [0019]FIG. 9 illustrates the enlargement of a waveform corresponding to a selected form; and  
     [0020]FIG. 10 illustrates waveforms from two different sources. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0021]FIG. 1 illustrates preferred data display apparatus  10  in accordance with the present invention showing use with vehicle  12 . Preferred apparatus  10  includes engine analyzer  14 , computer  16 , display device  18  and computer mouse  20 .  
     [0022] Engine analyzer  14  is a conventional unit such as Bear Model  270  engine analyzer. In use, connectors such as clips  22 ,  24  are used to connect analyzer  14  to selected engine components of the vehicle  12  such as the primary or the secondary of the coil, or the fuel injectors, for example. Analyzer  14  receives signals that represent a waveform characteristic of the operation of the vehicle&#39;s engine. In particular, the waveform typically includes segments that represent the firing of the individual cylinders. Analyzer  14  converts the analog engine signals to digital signals in the form of waveform data representative of the waveform and having a plurality of data segments representative of the waveform segments.  
     [0023] Computer  16  is preferably a conventional personal computer having interface card operable to connect with engine analyzer  14  to receive the waveform data therefrom. Computer  16  includes waveform data storage such as random access memory (RAM) for storing the waveform data. The microfiche appendix included as part of a disclosure hereof illustrates preferred program  26  for operating computer  16  as a special purpose computer in accordance with the present invention.  
     [0024] Display device  18  is a conventional computer monitor. Conventional mouse  20  is connected to computer  16  for moving the cursor on display device  18 .  
     [0025] In operation, program  26  responds to the waveform data by producing a waveform display representative thereof on display device  18 . FIG. 2 illustrates an example of a waveform display  28 . In this display, the individual segments  30   a ,  30   b , and  30   c  are separated and presented in a receding fashion representative of a three-dimensional display. If apparatus  10  is used for engine analysis, there would be a segment presented for each cylinder of the engine. For clarity of illustration, FIG. 2 illustrates only three segments.  
     [0026] In the preferred embodiment, boundary areas adjacent the edges of the display (within  26  pixels) are “live” in that computer  16  and program  26  respond to placement of cursor in one of these boundary areas. This response includes changing the display by moving the display up, down, left, right or diagonally.  
     [0027] As those skilled in the art appreciate, the number of data points in each data segment are not necessarily equal. For example, some engines present an “odd fire” in which some of the cylinders do not fire for as long as other cylinders. In such cases, the number of data points for the various segments will not be equal. Program  26  handles each segment individually regardless of the number of data points.  
     [0028] In the preferred embodiment, program  26  generates the display signals so that each segment  30   a - c  is in a different color. As those skilled in the art will appreciate, and as illustrated in FIG. 2, such data displays can be complex. However, the presentation of the individual segments in different colors enhances the ability for visual analysis of the waveform and thereby enhances a technician&#39;s troubleshooting ability by more readily comparing one segment to another.  
     [0029] Program  26  is also operable to generate cross-hair cursor  32  on the display. As is typical, the horizontal line of the cursor represents the y-axis line and the vertical line of the cursor represents the x-axis line. Program  26  is operable to determine the position of cursor  32  relative to the waveform and to orient the x-axis line as a tangent to the waveform at the data point on which the cursor is residing. This provides additional aid in visualizing the data itself and the performance of the engine. In the preferred embodiment, program  26  snaps cursor  32  along the waveform. That is, as the user moves the mouse  20 , program  26  moves the cursor horizontally according to the mouse movements but positions the cursor vertically according to the position of the waveform. In this way, the cursor remains on the waveform and tracks the waveform. In addition, both the x-axis and the y-axis lines can be moved independently.  
     [0030] Display  28  also includes numerical display  34 , which contains six pieces of information as shown. These include the amplitude and time position of the lefthand cursor crosshair (lefthand column), the amplitude and time position of the righthand cursor crosshair (righthand column), and the absolute difference, or “delta” of these two crosshairs (center column). The units of time (ms) and the amplitude (kV) are only for illustration in that other units may be used. With this information, the same data point on various waveform segments can be compared as a substantial enhancement to the analytical ability provided by program  26 .  
     [0031]FIG. 3 illustrates the single waveform segment such as segment  30   a  in an enlarged format. By using mouse  20  to position cursor  32  on a selected segment, the user can click on this segment. Program  26  responds by the graying-out other segments and enlarging the selected segment. This enables enhanced visual analysis of the waveform and of a particular segment. Such is an advantage if the operation of a particular cylinder is suspected as being out of specification.  
     [0032]FIG. 4 illustrates waveforms  36  and  38  derived from two different sources. Computer  16  is operable to store first and second waveform data received from engine analyzer  14  and program  26  produces first and second waveforms  36 ,  38  representative thereof on display device  18 . For example, waveform  36  could represent the firing of a particular cylinder as monitored at the primary of the coil and waveform  38  could represent the firing of that same cylinder as monitored at the secondary of the coil. Program  26  displays both waveforms thereby enhancing the ability for visual analysis.  
     [0033] FIGS.  5 - 10  illustrate other displays that can be generated. FIG. 5 shows how the crosshair cursors can be useful in measuring the ‘firing line’ of a cylinder. The left cursor (A) is placed at the beginning of the firing, the right cursor (B) is at the end of the firing. The readout above shows that the first cursor&#39;s horizontal line is 0.3 ms from the start of the wave, and the second cursor is at 2.2 ms. The delta value shown (center value) is the difference between the two cursors, or 1.90 ms. The vertical values, in kV, are similarly shown. The left cursor shows 7.49 kV, the right cursot shows 7.01 kv, with the delta showing 0.48 kv.  
     [0034]FIG. 6 illustrates how the crosshair cursor can be positioned on one cylinder (here cylinder  3 ) and be useful to compare with values in the other cylinders. The vertical cursor line is adjusted to always maintain the same “slant” that the 3d cylinder display has.  
     [0035]FIG. 7 illustrates how the crosshair cursor can be positioned on one cylinder (here cylinder  3 ) and be useful to compare with values in the other cylinders. The vertical cursor line is adjusted to always maintain the same “slant” that the 3d cylinder display has.  
     [0036]FIG. 8 illustrates how the crosshair cursor can be positioned on one cylinder (here cylinder  3 ) and be useful to compare with values in the other cylinders. The vertical cursor line is adjusted to always maintain the same “slant” that the 3d cylinder display has.  
     [0037]FIG. 9 is a view illustrating when a segment is selected, is enlarged to fill the display while the other segments are “grayed-out.” FIG. 10 is another illustration showing waveforms from different sources on the same display. For example, in FIG. 10 the upper waveform is a secondary waveform and the lower is a diode pattern waveform.  
     [0038] Those skilled in the art will appreciate that the present invention encompasses many variations in the preferred embodiment described herein. For example, the invention can be used to provide an enhanced visual display of waveforms from a wide variety of sources and not limited to engine analysis. In such cases, the preferred apparatus would not include the engine analyzer.