Abstract:
The system and method invention herein disclosed and claimed is measuring device that can remotely measure the distance between two points on a surface.

Description:
TECHNICAL FIELD 
       [0001]    This invention is associated with distance measuring devices. 
       BACKGROUND OF THE INVENTION 
       [0002]    Measuring devices, such as rulers and tape measures, have been used for a long time to measure the distance between two points. Typically one end of the measuring device is held or anchored at one point, and the position of a second point along the measuring device is noted. 
         [0003]    When measuring the distance between two points that exceed arm&#39;s breadth, two people are typically involved in making the measurement with a tape measure. One person holds the end of the device at point one, and the second person extends the tape measure until it abuts the second point. 
         [0004]    Devices have been invented and developed that allow one person to measure the distance between the device and, say, a point where two walls abut one another usually at right angles. In such cases, the device is placed at one end of a wall, and a laser beam is projected to the adjoining wall such that it reflects back along the same path and the distance is measured by noting the round-trip time and computing the distance based on light speed (e.g. d=c/2 t). 
         [0005]    There are instances where one wants to measure the distance between two points that are high up on a wall, say, and would not be easily measured using a tape measure without having to use two people and two ladders, for example. In that case, using a laser-based device is a problem, too, because one would need the use of ladders and one would have to affix a reflecting target at the second point. 
         [0006]    It would be very useful if one had a handheld device, like the laser “tape” measure, that could be pointed at one point, and then activated; and subsequently pointed at the second point, and activated; and it would quickly determine the distance between those two points. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The invention herein disclosed and claimed is a system and method for remotely measuring the distance between two points. 
         [0008]    The device uses a laser transceiving component to measure the distance between it and a first point. It then uses the same laser transceiving component to measure the distance between it and a second point. As the device is rotated and moved while detecting the distances between it and points one and two, its position in three dimensions (x,y and z) is sampled by measuring changes in three dimensional (3D) spatial position and angular orientation. In addition, the beam&#39;s angle with respect to a horizontal reference plane (e.g. a floor) is also measured for points one and two. 
         [0009]    With the data noted during the measuring instances plus the changing 3D data sampled as the device is moved and rotated between the two measuring instances, one can establish the distances of two sides of a triangle, that is the distance between the device and a first point and the distance between the device and a second point. The point where the device resides in 3D may change during those measurement instances. However, the two positions can be resolved to a single equivalent point, and the three points that result are then contained within a plane. One then has two sides of a triangle and the included angle and can calculate the length of the third side using sine and cosine laws. Furthermore, by measuring the angle of the beam with respect to a horizontal reference plane (e.g. a floor) when the first point distance is measured and when a second point distance is measured, one can determine each point&#39;s vertical distance from the horizontal reference plane and any vertical displacement between a first point and a second point. And, if one measures the distance between the device and two points located essentially along a vertical line, one can measure the angular orientation of the measuring device with respect to the two points and determine if the line is truly vertical or if one point is displaced horizontally with respect to the other point. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0010]      FIG. 1  depicts use of a laser “tape” measure to measure a distance, L, along a wall (Wall A) to an adjoining wall (Wall B). The perspective is looking down from a top view. 
           [0011]      FIG. 2  depicts use of a laser “tape” measure to measure a distance, L, along a wall (Wall A) to an adjoining wall (Wall B). The perspective is looking from a front view. 
           [0012]      FIG. 3A  depicts one embodiment of the system disclosed and claimed. It is a laser measurement device comprising a laser transceiving subsystem plus subsystems for measuring 3D position, angular orientation, and laser beam angle with respect to a horizontal reference plane; and a processing subsystem which calculates distance based on laser measurements and geometric relationships. 
           [0013]      FIG. 3B  depicts another embodiment wherein the subsystems comprising the system in  FIG. 3A  do not include a processing subsystem. Instead, data from the system is conveyed wirelessly to another entity where processing can be done, such as a laptop, smartphone, tablet, and the like. 
           [0014]      FIG. 4  depicts using a measuring device, such as that of  FIG. 3A , for measuring a first point, A. The distance between the device&#39;s laser beam source/detector and a first point is shown as S 1 . The device&#39;s position in three dimensions is shown as X 1 , Y 1  and Z 1 . 
           [0015]      FIG. 5  shows that in addition to measuring distance S 1 , the device also measures the angle between the laser beam and ground reference. That angle is shown as β 1 . Knowing this angle and side, SI, one can easily find the right triangle formed by sides S 1 , V 1  (the vertical component projection), and H 1  (the horizontal component projection). The points of the right triangle are A, the device&#39;s laser source, and the intersection of V 1  and H 1 . 
           [0016]      FIG. 6  shows a system, such as that of  FIG. 3A , where the distance between a second point (B) and the device can be measured. In addition, the 3D position is now X 2 , Y 2  and Z 2 , the angle between beam and horizontal reference plane is β 2 , and the beam will have effectively rotated through an angle α as it is swept from point A to point B. The difference in angular orientation between a first point and second point would be α. 
           [0017]    As in  FIG. 5 ,  FIG. 7  shows that in addition to measuring the distance S 2 , the device also measures the angle between the laser beam and horizontal reference plane. That angle is shown as β 2 . Knowing this angle and side, S 2 , one can easily find the right triangle formed by sides S 2 , V 2  (the vertical component projection), and H 2  (the horizontal component projection). The points of the right triangle are B, the device&#39;s laser source, and the intersection of V 2  and H 2 . 
           [0018]      FIG. 8  shows an exemplary flow diagram for one embodiment of the method disclosed and claimed where one can find the distance between a first point and second point using a system such as that of  FIG. 3A . 
           [0019]      FIG. 9  shows an exemplary flow diagram for another embodiment of the method disclosed and claimed where one can find the vertical distance of a first point and a second point relative to a ground surface, and the horizontal displacement of a first point relative to a second point when points are located on an essentially vertical line. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Measuring the linear distance between two points can be done by noting the position of said points along a measuring reference of known length divided into precise length fractions. An example would be a ruler or tape measure. 
         [0021]    One can also measure the linear distance between two points by using a measuring device containing a laser transceiver and circuitry operative to measure round-trip flight of light between the device located at a first point and a reflecting surface located at the second point. 
         [0022]    As shown in  FIG. 1 , from a top view perspective, a laser measuring device at the left-hand edge of Wall A sends a laser beam parallel to Wall A that reflects off of adjoining Wall B and whose reflected beam is detected by said device. The round-trip flight is measured as D 1  and the length of the measuring device is a fixed D 2 . Thus, the length, L, is the sum of D 1  and D 2 . 
         [0023]      FIG. 2  illustrates the same measuring process from a front perspective. Note that for measurement accuracy, the measuring device should be transmitting and receiving a beam that is parallel to Wall A&#39;s surface and parallel to Wall A&#39;s bottom edge. 
         [0024]    Note that a conventional laser measuring device can only measure distances between itself and a reflecting point. It cannot measure the distance between a first point and a second point that are remote from the device, such as two points on a wall. It can however measure the distance between a first point and the measuring device, and between a second point and the measuring device. However, in order to use plane geometric relationships in order to calculate the distance between a first point and a second point, the measuring devices position in space and the angle between the beam when measuring the first point, and the beam when measuring the second point must also be measured. In addition, the angle between the beam and a horizontal reference plane, such as a floor, may also be measured when taking each distance reading (e.g. between the device and a first point and between the device and a second point). With the distances between the device and a first point, and between the device and a second point, plus measuring the device&#39;s position in three-dimensional (3D) space when making each measurement, plus the angular change in laser beam when making each measurement, plus the angles between said beam and a horizontal reference plane when making each measurement will provide all the data required to determine the distance between a first point and a second point, and to measure any vertical or horizontal displacement of a second point relative to a first point. 
         [0025]      FIG. 3A  depicts a system for measuring the distance between a first point and a second point remotely located from said device. The handheld system contains a laser transceiving subsystem  301  that can send a beam of laser light, in a straight line, from the laser source to a point of interest. The light reflected back to said system can be measured in terms of round trip time and a distance, d, is calculated by d=c/2 t, where d is distance, c is speed of light, and t is round-trip time. The system further comprises a subsystem  302 , such as an accelerometer or GPS receiver that can detect changes in spatial position. The system further comprises a subsystem  303  that can detect changes in angular orientation of the device&#39;s laser beam, such as a gyroscopic detector. The system further comprises a subsystem  304  that can detect the laser beam&#39;s angle with respect to a horizontal reference surface, such as a floor. An electronic miniature “level” could detect the angular displacement between the beam and the horizontal, for example. The system further comprises a subsystem  306  operative to convey (e.g. receive and send) signals between itself and the other subsystems. The system further comprises a subsystem  305  operative to control, capture, store and execute programmed algorithms. The system further comprises an activating control  307  that initiates a series of actions comprising sending and receiving a laser beam signal, measuring 3D position and subsequent changes in position, measuring angular rotation and resulting angular change, measuring laser beam angle relative to a horizontal reference plane, gathering resulting data, storing said data, executing programmed algorithms, displaying selected results. The system further comprises a display subsystem (not shown). 
         [0026]      FIG. 3B  shows a system, such as that shown in  3 A, where the processing subsystem and display subsystem may be embodied in another system, such as a laptop, smartphone, or tablet. The data captured and stored in the measuring system is conveyed, wirelessly, to the adjunct system where an application processes that data to find and display predetermined parameters. 
         [0027]      FIG. 4  illustrates a measuring of the distance between a system as in  FIG. 3A or 3B  and a first point (A) on a wall surface. The distance measured between the system&#39;s laser source and a first point is S 1 . This measurement makes use of the laser transceiving subsystem. The 3D position subsystem detects the system&#39;s position and X 1 , Y 1  and Z 1  data are determined and stored. In addition the angle of the laser beam with a horizontal reference plane is measured (β 1 ) and stored. 
         [0028]      FIG. 5  shows how the data that results from the actions of  FIG. 4  provide the distance between the system&#39;s laser source and a first point A, the angle between the laser beam and horizontal reference plane β 1 , the position in space of the device when the measurement is made (X 1 , Y 1  and Z 1 ). Knowing Z 1  and β 1  and S 1  one can determine the vertical component projection V 1 . Knowing S 1  and V 1 , one can determine H 1 , the horizontal component projection. As a result one can conceptually construct the triangle formed by points A, the device&#39;s laser source, and the intersection of V 1  and H 1 . 
         [0029]      FIG. 6  depicts a measurement of a second point involving pointing the system&#39;s laser beam at a second point B and measuring the distance between said second point and the system&#39;s laser source. This is shown as S 2 . Again, the 3D position subsystem detects the spatial position of the system and its coordinates X 2 , Y 2  and Z 2 . In addition, the angular position subsystem detects that the system has rotated through an angle α. In addition a subsystem has also determined the angle of the laser beam with the horizontal reference plane. It is angle β 2 . 
         [0030]      FIG. 7  illustrates that the data for S 2 , β 2  and Z 2  supports conceptual construction of a triangle with sides S 2 , V 2  and H 2 . In addition, the determination of rotation angle α supports conceptual construction of a triangle with sides S 1  (not shown) and S 2  in addition to the included angle α. If X 1 , Y 1  and Z 1  are equal to X 2 , Y 2  and Z 2 , then the point of the system&#39;s laser source is the same for both measurements S 1  and S 2 , and simple application of law of sines and cosines will yield the distance between points A and B. However, if X 1 , Y 1 , Z 1  are not equal to X 2 , Y 2  and Z 2 , it is well known in plane geometry how to compensate for the differences and have the two positions coincide with commensurate small changes in S 1 , S 2  and α. Once the compensation is made, again a simple application of law of sines and cosines will yield the distance between A and B, or a first point and second point located remotely from said system. 
         [0031]    One can also determine whether two points on a wall, say, form a line parallel with a horizontal reference plane. By using the findings for H 1  and H 2 , and compensating for any differences in Z 1  and Z 2 , one can determine the vertical displacement of a first point from a second point relative to the horizontal reference plane. Furthermore, by measuring two points along a line that is essentially vertical, one can determine any deviation from the vertical by noting any change in angular orientation of the beam when measuring a first point and when measuring a second point. 
         [0032]    The method for applying the system to measure the distance between a first point and a second point relies on an interaction between a person wielding the measuring system and the system&#39;s coordinated subsystem interactions. 
         [0033]    Standing on a floor, some distance from a first point on a wall or other essentially vertical surface, a user activates the laser beam and points it on said first point. With the beam essentially shining on said first point, the user activates the measuring sequences which result in measuring the distance between the system laser source and said first point, the system&#39;s current spatial position, the system&#39;s current angular orientation with respect to a fixed reference (e.g. the north direction of a compass) and the angle of the beam with the horizontal reference plane. All resulting measurements are then stored. 
         [0034]    Now, rotating the system and activating the beam, the user points it at a second point. With the beam essentially shining on said second point, the user activates the measuring sequences which result in measuring the distance between the system laser source and said second point, the system&#39;s current spatial position, the system&#39;s current angular orientation, the angle of the beam with the horizontal reference plane. One can determine the angle of rotation between the position of beam at the time of first point measurement and the position of the beam at the time of second point measurement. The angle of rotation is simply the difference in angular orientation at the times of first and second measurement. All resulting measurements are then stored. 
         [0035]    With the results from the first measurement event and those from the second measurement event, the system executes one or a plurality of algorithmic programs which make use of all the stored measurement results and yield the distance between said first point and said second point. The distance may then be displayed on the system for the user&#39;s perusal. 
         [0036]    The stored measurement event results can also be used to find the vertical displacement of the first and second points from the horizontal reference plane, and relative to one another. The stored measurement event results can also be used to find the horizontal displacement of the first and second points relative to one another. If horizontal displacement in three dimensions is zero, the points lie on a vertical line. Those results may also be displayed on the system for the user&#39;s perusal. 
         [0037]    Various integral measurements, such as the α angle or β angles, and the distances between the system&#39;s laser source and said first point, and the distances between the system&#39;s laser source and said second point may also be displayed. 
         [0038]    Note that the use of laser measurement to measure the distance between a laser measuring device and a point of interest is prior art. A conventional laser measuring device could measure the distance between itself and a first point, and between itself and a second point. But without the spatial positioning and angular orientation data at hand, one cannot accurately determine the distance between a first and second point. It is the combination of subsystems in the measuring system and their coordinated application that results in a novel, handheld, measuring device capable of measuring the distance between a first point and a second point remotely located from the measuring device. The mathematical methods for finding the length of a third side of a triangle with knowing the lengths of two sides and an included angle is basic plane geometry. However, the subsystems for determining the position of the measuring point (e.g. the spatial position of the system) and angular orientations, and then computing the distance between a first and second point using that data is unique in a handheld measuring device. Furthermore, the measuring system need not be securely anchored in position in order to determine the distance between two points remote to the device. The subsystems of which it is comprised serve to correct for changes in position to yield reasonably accurate results.