Abstract:
A system where the height of road vehicles can be determined using two vertical columns, one column having a vertical linear array of sensors, facing and aligned with an opposite column having a vertical linear array of sources. The columns are spaced apart enough for the road vehicle to pull in between. The sensors and sources are mounted at increasing height levels until they reach the top of the columns, or a height that is well above any possible maximum height that a road vehicle may have, or height that is needed to be measured. As the vehicle pulls in between the two columns, a computer consecutively tests the sensors starting from the bottom to see which, if any, of the sensors has its light source blocked. The accumulated number of blocked light sensors is counted to reveal the height of that portion of the vehicle between the columns.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to vehicle height determination, and more particularly to an arrangement of sensors to measure the height of road vehicles, to ensure compliance with height restrictions, and particularly to sensors mounted vertically on one pole and sources mounted on an opposite pole.  
           [0003]    2. Description of the Related Art  
           [0004]    Devices to detect the maximum height of road vehicles commonly use a single source and sensor that are placed at the maximum allowable height so that if a vehicle that is overheight, it will block the source at that height and the sensor can activate an alarm. Devices of this type are shown in U.S. Pat. No. 4,916,429 to Hicks et al issued Apr. 10, 1990; U.S. Pat. No. 3,896,414 to Rulo issued Jul. 22, 1975 and U.S. Pat. No. 2,366,152 to Lauterbach issued Dec. 26, 1944.  
           [0005]    Also, U.S. Pat. No. 4,284,971 to Lowery et al issued on Aug. 18, 1981 uses an arrangement similar to Hicks et al, but has more than one set of sensors spaced at different locations along the roadway.  
           [0006]    The present invention uses multiple sensors and matching sources arranged vertically between a point well below the height of any vehicle to the maximum height of any vehicle and provide an actual height measurement of the highest point. The sources on one pole are on one side and the sensors are on another pole on the other side of the vehicle.  
           [0007]    Other devices used to measure the maximum height of road vehicles commonly use a single source and sensor that depend on the vehicle reflecting the light from the source to the sensor to determine the height of the vehicle, such as is taught in U.S. Pat. No. 6,195,019 to Nagura issued Feb. 27, 2001. The present invention depends on the light source being blocked by the vehicle and the sensors detecting darkness.  
           [0008]    Other devices measure the height of objects that the vehicle is to go under such as bridges via light sources and sensors mounted on the vehicle such as in U.S. Pat. No. 3,716,863 to Roth issued Feb. 13, 1973.  
           [0009]    Other systems measure and warn the driver of a vehicle that the vehicle height is two high using a radio transmitter on the bridge or overhang and a radio receiver in the vehicle such as U.S. Pat. No. 3,419,847 to Bonney issued Dec. 31, 1968.  
           [0010]    Also, other devices that measure the height of vehicles use a single sensor such as a video camera and use image processing to separate the vehicle (obstacle) from the background as in U.S. Pat. No. 5,331,312 to Kudoh issued Jul. 19, 1994. Likewise, U.S. Pat. No. 5,392,034 to Kuwagaki issued Feb. 21, 1995 discloses a vertical arrangement of multiple light sensors and light sources on separate poles on opposite sides of the road, that take a profile, but not a height measurement, of a vehicle in transit down the road.  
           [0011]    Other devices that measure the height of vehicles using a single sensor include U.S. Pat. No. 5,546,188 to Wangler et al issued Aug. 13, 1996; U.S. Pat. No. 5,793,491 to Wangler et al issued Aug. 11, 1998; U.S. Pat. No. 5,896,190 to Wangler et al. Apr. 20, 1999. These devices appear to depend on reflection from the vehicle rather than a blocking of light from source to sensor.  
           [0012]    It would be desirable to have a device to measure maximum height of a vehicle using multiple sensors and corresponding multiple light sources in vertical columns on either side of the vehicle where the measurement is done through a successive counting of the sensors at each height that is dark or blocked, which process includes a time delay. Such an arrangement overcomes the problems of false height readings due to birds or antennas. Such an arrangement allows the measurement of variety of vehicles having different or varying heights.  
           [0013]    None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, an arrangement of a plurality of sensors to determine an actual measurement of maximum vehicle height solving the aforementioned problems is desired.  
         SUMMARY OF THE INVENTION  
         [0014]    The present invention is a system where the height of road vehicles can be determined using two vertical columns in which one column has a vertical linear array of sensors facing and aligned with an opposite column having a vertical linear array of sources. The columns are spaced apart enough for a road vehicle to pull in between. Each of the vertical arrays of sensors and corresponding sources are mounted at increasingly consecutive height levels until they reach the top of the columns or a height that is above any possible maximum height that a road vehicle may have or a height that is needed to be measured.  
           [0015]    In operation, as the road vehicle pulls up in between the two columns, a computer consecutively tests the sensors starting from the bottom to see which of the sensors has its light source blocked or is dark. The accumulated number of light sensors that has its corresponding light source blocked is counted with respect to the distance between each light source and reveals the height of that portion of the vehicle that is between the columns. It is then important for the driver of the road vehicle to pull up through the two columns far enough to measure the highest point of the vehicle.  
           [0016]    Generally, the first encountered portions of the vehicle may not be the highest point of the vehicle structure. An operator or driver can use both a visual sighting and a reading from the height measurement display panel to judge if the highest point of the vehicle has pulled in between the two columns. When the maximum height of the vehicle has been read, it can be compared to ensure that it is below any height restrictions of the road. Such overheight road vehicles can be barred from travel on the road. Thus, accidents between vehicles and low bridges or overhangs are prevented.  
           [0017]    Optionally, the system can include a mat or plate of the kind typically used to provide vehicle weight measurements. Optionally, the system can be used at drive through restaurants etc. where a roof overhang provides a limit on the vehicle height. The system can be designed to be more automated by having the computer compare the height readings to maximum heights and provide warning alarms or gate closures. Optionally, the computer in the system can be physically included inside the sensor column.  
           [0018]    Optionally, a remote computer can be connected wirelessly to the computer inside the sensor column making the maximum height measurements. Also, the computer inside the sensor column can create and store a log of each maximum height of each vehicle passing through the columns. The computer inside the sensor column can also be connected wirelessly to the maximum height display, alarm or gate closing device.  
           [0019]    Accordingly, it is a principal object of the invention to provide a sensor arrangement to determine vehicle height that can determine the maximum height of a variety of different and varying height vehicles.  
           [0020]    It is another object of the invention to provide a sensor arrangement to determine vehicle height that is not prone to errors caused by birds or vehicle antennas.  
           [0021]    It is a further object of the invention to provide a sensor arrangement to determine the maximum vehicle height accurately at whatever portion of the vehicle is highest.  
           [0022]    Still another object of the invention is to provide a sensor arrangement to determine vehicle height using a successive approximation of the vertical height of a plurality of sensors that are triggered by the body of the vehicle which blocks a certain number of light sources.  
           [0023]    It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.  
           [0024]    These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is an environmental, three dimensional, perspective view of an arrangement of sensors and sources to determine vehicle height according to the present invention.  
         [0026]    [0026]FIG. 2 is another three dimensional, perspective view of an arrangement of sensors and sources like FIG. 1 in which the vehicle to be measured is in a different position.  
         [0027]    [0027]FIGS. 3A and 3B are a flow diagram of the algorithm used by the computer to calculate the height of the road vehicle.  
         [0028]    [0028]FIG. 4 is a block diagram of the computer and its attached hardware and sensors.  
         [0029]    [0029]FIG. 5 is a block diagram of a remote computer and its attached hardware that receives and logs vehicle height information.  
         [0030]    [0030]FIG. 6 is a flow diagram of the algorithm used by the remote computer for logging the maximum height of all the vehicles passing through the columns. 
     
    
       [0031]    Similar reference characters denote corresponding features consistently throughout the attached drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    [0032]FIG. 1 shows a three dimensional perspective view of a vertical arrangement of sensors  12 - 18  on one vertical column  30  on one side of the vehicle  45  to be measured and a vertical arrangement of light sources  22 - 28  on another vertical column  40  on the other side of the vehicle  45  to be measured. The light sensors  12 - 18  and sources  22 - 28  are arranged to be aligned with each other at measured incremental heights. A light source  22  and its corresponding sensor  12  will be essentially the exact same height from level ground. Thus, when a vehicle  45  begins to drive through columns,  30  and  40 , it will block only a certain number of lights from light sources  28 ,  27  from reaching its light sensor  18 ,  17 .  
         [0033]    As shown in FIG. 2, a front part of the truck  45  to be measured pulls in first and only the first two light sensors  18 ,  17  are dark i.e., have their light sources blocked. Thus, the computer will recognize that the truck&#39;s  45  current height is only a number of feet and inches corresponding to the front part of the truck  45 , that blocks light sources  27 ,  28 . The front part of a truck  45  will not be overheight and not trigger any alarm.  
         [0034]    As shown in FIG. 1, the truck  45  is required to pull further through the two columns  30 ,  40 . The truck  45  at its highest point will have more sensors  18 - 15  be dark corresponding to a taller part of the truck  45 . The truck  45  can be required to move its whole portion through the columns  30 ,  40  and thus any part of the truck  45  that is too tall would trigger an overheight alarm. At any point as in FIGS.  1  or  2  or as the whole truck  45  pulls through the two columns  30 ,  40 , a digital display  44  can provide a reading of the height of the truck  45 .  
         [0035]    If the system is used at a station at the side of the highway for measuring trucks, the station may include a weight sensor  50  for weight measurement, weight display  42 , and a bump  47  in the road to let the driver of the truck  45  know the best position for a weight and/or height measurement.  
         [0036]    Sensors  12 - 18  and sources  22 - 28  as shown in FIGS. 1 and 2 are arranged vertically each spaced 0.5″, 0.75″ or 1″ inch apart from each other. The sensors  12 - 18  and sources  22 - 28  are placed starting at a height corresponding to a height just below the lowest height of a vehicle that is expected to be measured. This height might be about 3.9 feet high for a car with the smallest height of 4 feet. Enough of the sensors  12 - 18  and sources  22 - 28  are placed at the successive heights mentioned above until the highest point is reached. The highest point would be a little above or at the maximum height allowed for a vehicle by law or at the limits of the road due to bridges, overhangs etc. For example, sensor  18  and light source  28  would be placed 4 feet from the ground, sensor  17  and light source  27  would be placed 4 feet 1 inch from the ground and sensor  16  and light source  26  would be 4 feet 2 inches from the ground and so on. Also, if the lowest bridge on the road is 14 feet then the highest sensor and corresponding source would be 14 feet 1 inch from the ground. The number of sensors is equal to the height of the highest sensor minus the height of the lowest sensor divided by the distance between each sensor.  
         [0037]    The CPU  54  of FIG. 4 for evaluating the height and optionally the weight measurements can be incorporated into the sensor column  30  of FIGS. 1 and 2. The CPU  54  can be connected wirelessly through a wireless data link to the light sources  22 - 28 , station computer  52 , display  44 , display  42 , weight sensor  50  and drop gate (not shown).  
         [0038]    In FIG. 4 reset and control switches  62  can put CPU  54  in a reset mode which includes an operational check or validity check of the sensors. This validity check of the sensors is done by setting each one of the individual sources on one at a time and checking that each of the corresponding sensors are activated by the corresponding sources while no objects are allowed between the columns.  
         [0039]    [0039]FIGS. 3A and 3B together show a flow diagram showing the steps that the CPU  54  in FIG. 4 takes in calculating the height of the vehicle. CPU  54  tests each of the sensors along the column successively while accumulating a height value until the first sensor that is not blocked is found. The variables used in FIGS. 3A and 3B are: n is the number of the sensor being tested; h is the value of the height in inches, feet or meters; i is the distance in inches, feet or meters between each sensor and a is the actual height of the first sensor.  
         [0040]    In FIGS. 3A and 3B, the algorithm starts at START  80  when the computer  54  has finished resetting or has finished a previous measurement. Next at step  82  the computer sets height h equal to zero, sets i equal to the increment which is the spacing between the sensors and sets n equal to 1 or the first sensor. Next at step  84  the computer displays h on the height display which at first is 0. Next at step  86  the computer checks the nth sensor to see if it is blocked. If the nth sensor is not blocked then the value of h is compared at step  96  for an overheight value and an overheight alarm is set at step  94  if h is overheight. Then h is displayed at step  84  and the whole process is started over again. If the nth sensor is blocked then a delay at step  88  is invoked and a possible object is being measured. Next at step  90 , the computer checks the same nth sensor again to see if it is blocked. If the nth sensor is blocked then the object being measured is at least as high as the nth sensor. If the nth sensor is not blocked after the delay, then an antenna or bird may have falsely activated the nth sensor The value of h is checked at step  96  to see if it is overheight, if h is overheight the overheight alarm is set at step  94 . Then the process starts over at the displaying of h at step  84 .  
         [0041]    If the nth sensor is blocked (an object is being measured) and n is equal to 1 at step  98  then h is set equal to i plus a and n is incremented by 1 at step  100 . If the nth sensor is blocked and n is not equal to 1 at step  98  then h is set equal to the sum of the previous value of h plus the increment i and n is incremented by 1 at step  102 . Steps  100  and  102  are the only steps where h is accumulated. Next at step  104 , if n is not equal to the last sensor then the value of h is tested to see if its value is overheight at step  96 . If h is overheight the overheight alarm is set at step  94 . Next h is displayed again at step  84  and the rest of the process is continued again. However, if n is equal to the last sensor at step  104  the overheight alarm is set and the height h is displayed at step  92  and the whole process of measuring is started again from the beginning at step  80 .  
         [0042]    The delay at step  88  and/or successive checking of sensors with accumulation of height (as in steps  82 ,  84 ,  86 ,  88 ,  90 ,  98 ,  100 ,  102 ,  104 ,  96 ,  94 ) above serve to avoid the false readings caused by an object like a bird that might pass through the columns  30 ,  40  in FIG. 1. If a bird passes through the columns  30 ,  40  it will block the light for only one or two sensors  13 ,  14  more likely in the middle of the vertical columns. Since the first sensor  18  does not have it&#39;s light blocked in this situation, then the algorithm above will never sense the bird. In case the bird flies through the columns  30 ,  40  at the height of the first sensor  18  then the delay at step  88  in FIG. 3A should be long enough for the bird to finish flying through the columns  30 ,  40  in FIGS. 1 and 2 and not be detected on the second check  90  in FIG. 3A of the same sensor  18  in FIG. 1.  
         [0043]    Thus, the false reading of the height of a bird is avoided. Other objects like the bird might be a visor or scoop that extends out horizontally from the rear roof of a vehicle. Like the bird such an object has no height below it so no false measurement reading will be made in the same way as the bird example above.  
         [0044]    In the case of an antenna that might not be damaged by or damage a bridge or overhang, the antenna has further vertical height to be measured. However, the antenna is thin enough that the delay  88  in FIG. 3A and the movement of the vehicle  45  through the columns  30 ,  40  in FIG. 1 will cause the antenna not to be measured.  
         [0045]    [0045]FIG. 4 shows the arrangement of computer electronics that calculates the height of the vehicle. Reset and control switches  62  provide an operator of the system a means to control, set, reset or validate the system using programs on CPU  54 . CPU  54  uses light emitter control  64  and reset control switches  62  to turn on and off the light sources  22 - 28  in FIG. 1 to allow an operator to shutdown the system or change light source elements or test and align the light sources  22 - 28  with its corresponding sensor  12 - 18  by allowing light sources  22 - 28  to operate one at time instead of all at once as in a normal operating mode as in the routine of FIGS. 3A and 3B.  
         [0046]    In FIG. 4, light emitter control  64  can have a microcontroller or other logic device with relays to control the power applied to the light sources. During normal measuring operations light emitter control  64  will either keep all light sources  22 - 28  in FIG. 1 on all of the time or pulse them on and off at an optimal rate. The pulsing light sources  22 - 28  can be used to overcome effects of ambient light falsely triggering the sensors  12 - 18 , when testing at step  86  in FIG. 3A for a blocked sensor assumes that a non-dark sensor without a pulsing light (sunlight) is the same as if the sensor was blocked or dark.  
         [0047]    In FIG. 4, CPU  54  uses weight sensor  66 ,  50  in FIGS. 1 and 2, to calculate and provide weight information to the operator via the weight display  56 ,  42  in FIGS. 1 and 2, in situations where the present invention is used in a road side station that needs weight and height measurement. CPU  54  uses separate inputs from the array of light sensors  68 ,  12 - 18  in FIGS. 1 and 2, to calculate and provide to the operator via the height display  58 ,  44  in FIGS. 1 and 2, information about the height of the vehicle.  
         [0048]    In situations where there is no full time operator to check a height display as in a drive through restaurant, the CPU  54  uses separate inputs from the array of light sensors  68 ,  12 - 18  in FIGS. 1 and 2, to calculate and provide a signal to an overheight alarm  60 , if the height measured is over a predetermined amount. The predetermined amount might be the height of the roof or overhand at the drive through restaurant.  
         [0049]    In both situations where a road side station that needs weight and height measurement and uses an attendant or where there is no full time attendant, a drop gate maybe used which is activated by the same signal as the overheight alarm  60 , that is generated by CPU  54 . The drop gate should be placed at an optimal distance from the columns  30 ,  40  so that the vehicle  45  can pull through the columns  30 ,  40  at a position revealing its maximum height, but the drop gate has room to drop down in front of the vehicle. In addition, the drop gate still needs to be placed before the overhang.  
         [0050]    In FIG. 4, optionally, CPU  54  can be placed inside sensor column  30  of FIG. 1. In this case it would naturally have wired connections to the light sensors  68  of FIG. 4 or  12 - 18  of FIGS. 1 and 2 and reset control switches  62  of FIG. 4. CPU  54  can have wired connections to weight display  54 ,  42  in FIGS. 1 and 2, height display  58 ,  44  in FIGS. 1 and 2, overheight alarm  60 , light emitter control  64  and weight sensor  66 ,  50  in FIGS. 1 and 2.  
         [0051]    In FIG. 4, optionally, CPU  54  can communicate wirelessly over a wireless data link using a transmitter  57  to a remote computer  52  in FIGS. 1 and 2 and to weight display  54 ,  42  in FIGS. 1 and 2; to height display  58 ,  44  in FIGS. 1 and 2; to overheight alarm  60 ; to light emitter control  64  and weight sensor  66 ,  50  in FIGS. 1 and 2.  
         [0052]    [0052]FIG. 5 shows an arrangement of the remote computer  72  and its peripherals. Remote computer  72  can be connected by cable to CPU  54  of FIG. 4 or through a wireless radio link using receiver  70  in FIG. 5 which receives signals from CPU  54  via transmitter  57  in FIG. 4. Remote computer  72  in FIG. 5 provides the operator  52  in FIG. 1 with information on the maximum height and/or weight of the vehicle currently between the columns  30 ,  40 , overheight and overweight alarms and logging information regarding previous vehicles maximum height or weight amounts and vehicle identification which can be displayed on display  74 . The remote computer  72  can use permanent storage  76  for storing a log of each of the measured vehicle&#39;s maximum height and optionally weight. The remote computer  72  might provide a connection and/or manual control of the overheight alarm and drop gate  78 .  
         [0053]    [0053]FIG. 6 shows a flow chart of the algorithm that the remote computer  72  in FIG. 5 uses to monitor and record the maximum height of each vehicle  45  in FIG. 1 as it finishes passing through the two columns  30 ,  40 . In FIG. 6, the algorithm starts at step  106 , then initializes the values for hi which is value of the maximum height of the vehicle as it finishes passing through the columns; and i is set equal to zero to indicate first entry of a vehicle  45  through the columns  30 ,  40  in FIG. 1. Next at step  110  in FIG. 6, the value of h, the current or instantaneous height of the vehicle  45  in FIG. 1, is received from CPU  54  in FIG. 4. Next at step  112 , h is checked to see if it is zero. If h is equal to zero, then at step  118  i is checked to see if it is equal to zero or the first portion of the vehicle entering through the columns. If i is equal to zero, the vehicle  45  has just started entering the columns  30 ,  40  in FIG. 1, and at step  110  h needs to be received again. If i is not equal zero, a number of measurements have been received and if h is also equal to zero, then the vehicle has cleared the columns. Then hi and vehicle identification can be logged and stored at step  120 . The algorithm is restarted at step  106 .  
         [0054]    If h is not equal to zero at step  112 , then at step  114  h is checked to see if it is larger than the previously recorded value hi for the vehicle. If h is not greater than hi at step  114  then another value of h is received at step  110 . If h is greater than hi at step  114  then hi becomes the value of h and i is incremented by 1 at step  116 . Therefore, only the largest values of h are stored in hi. Next at step  110 , another value of h is received.  
         [0055]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.