Abstract:
A system for graphic display of point-to-point distance measurements in an object measuring system includes display of a graphic drawing representing the object and depictions of measured points representing their locations on the object and displays of lines between the points of selected pairs of displayed points to indicate where a distance measurement is taken. For each line there is displayed an indication that the measured distance is (a) within tolerance limits of a standard distance, (b) shorter than the standard distance by a difference greater than a lower tolerance limit or (c) greater than the standard distance by a difference exceeding an upper tolerance limit. There may simultaneously be displayed an alphanumeric table indicating the points, the measured and standard distances and the differences, which table may utilize the same tolerance indication scheme as the graphical representation.

Description:
BACKGROUND 
   This application relates to measuring systems for objects and, in particular, to systems designed for making dimensional measurements on automotive vehicles for the purpose of collision damage repair. However, it will be appreciated that the principles described herein could have application to measurement of any type of object. 
   Various types of measuring devices have been utilized on vehicles, e.g., to attempt to determine how much a vehicle frame or body deviates from standard specifications in order to determine the amount of repair or straightening that may be needed. Such systems include ultrasonic measuring systems, optical systems, systems using mechanical sensors and systems using a bar with movable pointers thereon. The systems may “measure” the distance between points by determining the three-dimensional coordinates of points and then calculating the distance between the points, or by directly measuring the distance between selected points, and may then compare such measured distances with standard distances for these pairs of points. Typically, the measured distances, the standard distances and differences therebetween are presented to the user in an alphanumeric fashion which may be difficult and time-consuming for the operator to read and interpret. 
   SUMMARY 
   There is disclosed herein an improved measurement system which avoids disadvantages of prior systems while affording additional structural and operating advantages. 
   The system provides to an operator information about measured distances and differences between such measured distances and standard distances in a readily understood fashion. 
   There is disclosed a display system for a measuring system which determines the positions in space of predetermined points on an object and measures distances between points of selected pairs of such points, the display system comprising a storage device storing a library of information relating to objects to be measured including standard distances between points of predetermined pairs of points on such objects and/or coordinates of points which can be used to calculate such standard distances, a display device, and a processor operating under stored program control and coupled to the storage device and to the display device and comparing measured distances between points of selected pairs of points on an object with corresponding standard distances, the program including a routine for causing display of a graphical representation of the object being measured and predetermined points thereon and, for each selected pair of such points, a line between the points, the routine causing a display for each such line of an indication as to whether or not the measured distance represented by the line is within predetermined tolerance limits for the corresponding standard distance. 
   There is also a disclosed method of displaying data in a measuring system which determines the positions in space of predetermined points on an object and measures distances between points of selected pairs of such points, the method comprising storing a library of information relating to objects to be measured including standard distances between points of predetermined pairs of points on such objects and/or coordinates of points which can be used to calculate such standard distances, comparing measured distances between pairs of points on the object with corresponding standard distances from the library, displaying on a display screen a graphical representation of the object being measured and predetermined points thereon, for each of selected pairs of displayed points displaying a line between the points of the pair, and displaying in association with each such line an indication as to whether or not the measured distance represented by the line is within predetermined tolerance limits for the corresponding standard distance. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated. 
       FIG. 1  is a functional blocked diagrammatic view of an embodiment of a measurement system; 
       FIG. 2  is a flowchart diagram illustrating the software routine of the system of  FIG. 1  for calculating and displaying measured distance data and the difference between such data and standard measurement values; 
       FIG. 3  is a screen print of a display screen in accordance with the embodiment of  FIGS. 1 and 2 ; and 
       FIG. 4  is a screen print of another display screen in accordance with the embodiment of FIGS.  1  and  2 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , there is illustrated a measurement system, generally designated by the numeral  10 , the hardware portions of which may be similar to those in U.S. Pat. No. 6,115,927. The system  10  may include probe and dynamic reference frame (DRF) tools  11  including a hand-held probe including optical emitters and a digital reference frame which also carriers optical emitters, these emitters all being sensed or viewed by an array of camera sensors  12 , which may include three camera modules or sensors fixed relative to one another. In use, the emitters on the dynamic reference frame are fixed relative to one another and the dynamic reference frame is, in turn, fixed relative to the automobile body or other object being measured. The hand-held probe emitters are also fixed relative to one another and the camera sensors  12  are fixed relative to one another. The system  10  also includes a control unit  13  which includes a tool board  14  and tool board registers  15  to which the probe/DRF tools  11  are coupled. The control unit  13  also includes a digital signal processing (DSP) board  16  which includes DSP registers  17  and 3 DSP applications  18  respectively coupled to the camera sensors  12 . The control unit  13  also includes a processor board  19  which runs an embedded software application  20  which is coupled to the tool board registers  15 , the DSP registers  17  and the DSP applications  18 . The embedded application  20  senses the probe/DRF emitters and the camera sensors  12  and calculates, by triangulation, the three-dimensional coordinates of points on the object being measured which are engaged by the hand-held probe. 
   The system  10  also includes a host computer  21  which includes a database  22  and host application software  23 . The database  22  stores standard or reference information regarding a number of different known vehicle bodies, including the standard distances between points of selected pairs of such points and/or coordinates of points which can be used to calculate such standard distances. The application software  23  is coupled to the database  22  and to a display device  25 , such as a CRT display. 
   Referring now to  FIGS. 2 and 3 , the operation of the system  10  will be described.  FIG. 2  illustrates, in flowchart form, the program software routine  30  which is run by the application program  23  in the host computer  21  for controlling the display device  25  to generate and display a screen display of the type illustrated in FIG.  3 . Initially, the user will select a predetermined vehicle with respect to which points and distances are to be measured, whereupon the host application  23  will cause to be displayed on the display device  25  a graphical representation of the object being measured and the locations thereon of suggested points to be measured. The user may then, utilizing the hand-held probe and the embedded application  20  and host application  23 , measure the locations on the vehicle of points corresponding to the displayed points or other points selected by the user, whereupon the embedded application will determine the coordinates for each such point. First, at  31 , the host application software routine obtains from the embedded application  20  in the control unit  13  measured data for a first vehicle point and then, at  32 , obtains the measured data for a second vehicle point and then, at  33  calculates the measured distance between the first and second vehicle points. The routine also, at  34 , obtains from the database  22  the standard data for the first vehicle point, at  35  obtains the standard data for the second vehicle point and, at  36 , calculates the standard distance between the standard first and second vehicle points. Then, at  37 , the routine calculates the difference between the measured distance between the first and second points and the standard distance between those points and then, at  38  reads stored tolerance limits, which are either previously specified by the user or are default application tolerances. Then, at  39 , the routine checks to see if the calculated difference from  37  is within the tolerance limits from  38 . These tolerance limits may include an upper limit and a lower limit. If the difference between measured and standard distances is within the tolerance limits for that distance, the routine then, at  40 , draws a line  49  between the measured vehicle points utilizing a predetermined color (e.g. light gray, designated by solid lines,) which immediately visually informs the user of a location of the distance measured and also immediately indicates visually that the difference between the measured and standard distances for that set of points is within tolerance limits. If, at  39 , the measured distance is less than the standard distance by a difference greater than the lower tolerance limit, the routine then, at  41 , draws a line between the measured vehicle points using a second color (possibly red, designated in small dashed lines), indicating the location of the distance being measured and immediately visually indicating that the measured distance is less than the standard distance by greater than the lower tolerance limit. If, at  39 , the measured distance is greater than the standard distance by a difference greater than the upper tolerance limit, the routine then at  42  draws a line between the measured vehicle points using a third color (possibly blue, designated by long dashed lines), providing an immediate graphical indication of the location of the distance being measured and the fact that the measured distance is greater than the reference or standard distance by an amount which exceeds the upper tolerance limit. 
   The system  10  will proceed through the software routine  30  for each pair of points, the distance between which is to be measured. Referring to  FIG. 3 , there will be displayed on the display device  25  a screen display  45 , which includes a selector icon  46 , activation of which (by touch screen or clicking on a mouse cursor or the like) will permit the operator to select the identifying data for the vehicle to be measured. There will then be displayed on the display device  25  a graphical background diagram  47  of the vehicle or portion thereof being measured, including the locations of predetermined points thereon (six of which are, respectively, designated L 1 -L 6 .) As the software routine  30  operates on selected pairs of these points, lines  49  which are drawn between the points of the pair in colors corresponding to whether the measured distance differs from the standard distance by an amount which (a) is within tolerance limits, or (b) which is less than the lower tolerance limit or (c) which is greater than the upper tolerance limit. 
   The screen display  45  simultaneously displays the results of the measurement in a table  50 , which has column headings  51 ,  52 ,  53  and  54  which, respectively, indicate the designation of the points, the distance between which is being measured, the reference or standard distance between those points, the measured distance between those points, and the difference between the reference and measured distances between columns  52  and  53 . A column  55  indicating by a plus sign or a minus sign whether the measured distance is less than or greater than the standard distance. The data displayed in the table  50  utilizes the same color scheme as in the graphical display  47 , the rows for the differences which are within tolerance limits being depicted in a first color, the rows for distance differences which are less than the lower tolerance limit being illustrated in the second color, and the rows for distance differences which are greater than the upper tolerance limits being illustrated in the third color. 
     FIG. 4  illustrates another screen display  65  which relates to measured distances between points on another portion of the vehicle, such as the trunk area. The background display  67  includes an illustration of points (designated L 1 -L 6 ), distances between which are to be measured and, as the distances are measured, draws lines  69  in appropriate colors to indicate whether the difference between the measured and standard distances are within or without tolerance limits, as explained above. The display  65  also includes a table  70  with column heading  71 - 75  respectively corresponding to columns  51 - 55 , described above, the tabulated data being depicted utilizing the same color scheme as is used on the graphical display  67 . 
   While specific colors are referred to in the foregoing description, it will be appreciated that any desired colors could be utilized and graphical representations other than color could be used. For example, lines could be displayed in different weights or thicknesses, in different constructions, such as solid, dashed, etc., or blinking at different rates. Also, the specific number of measured points shown in the drawings is simply by way of illustration, and the display could include any number of pairs of points. 
   The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants&#39; contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.