Patent Publication Number: US-2023151567-A1

Title: System and method for oncoming traffic warning at a work zone

Description:
FIELD 
     The present specification relates generally to traffic safety in a road construction work zone, and more particularly to a system and method for traffic warning at a road construction work zone. 
     BACKGROUND 
     Personnel at a road construction work zone are often required to work relatively close to moving traffic. As such, personnel must rely on driver compliance with speed limits and careful driving to avoid accidents causing injury or death. 
     SUMMARY 
     As discussed below, a system and method are set forth for traffic warning at a road construction work zone. In one aspect, a motion sensor is associated with least one traffic cone in communication with a portable alert unit for warning a user of oncoming traffic. 
     In an aspect, a system is provided for traffic warning at a road construction work zone, comprising at least one a motion sensor associated with at least one traffic cone proximate the road construction work zone for transmitting laser pulses in a direction of oncoming traffic and detecting reflected laser pulses from the oncoming traffic and in response transmitting an alert signal; and a portable alert unit for receiving the alert signal and generating a warning of the oncoming traffic. 
     In another aspect, a method is set forth, comprising pairing the portable alert unit and at least one motion sensor, activating the at least one motion sensor to transmit laser pulses in a direction defined by a lens, receiving the reflected laser pulse from the oncoming traffic, calculating distance of the oncoming traffic, transmitting an alert to the portable alert unit, and generating an alarm of the oncoming traffic at the portable alert unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description when considered in connection with the drawing figures, wherein like numerals denote like elements and wherein: 
         FIG.  1    is a schematic illustration of a road construction work zone. 
         FIG.  2    is a schematic illustration depicting a motion sensor associated with a traffic cone in communication with a portable alert unit, according to an embodiment. 
         FIG.  3    is a schematic illustration depicting a portable alert unit, in accordance with an embodiment. 
         FIG.  4    is a schematic illustration depicting a motion sensor, in accordance with an embodiment. 
         FIG.  5    is a block diagram showing internal components of the portable alert unit of  FIG.  3   . 
         FIG.  6    is a block diagram showing internal components of the motion sensor of  FIG.  4   . 
         FIG.  7    is a flowchart showing operation of the motion sensor of  FIG.  4    and portable alert unit of  FIG.  3   , according to an embodiment. 
     
    
    
     It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of illustrated embodiments of the present disclosure. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The description of exemplary embodiments of the present disclosure provided below is merely exemplary and is intended for purposes of illustration only; the following description is not intended to limit the scope of the invention disclosed herein. Moreover, recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the stated features. 
     Turning to  FIG.  1   , a road construction work zone  100  is depicted for a roadway  110 , around which traffic must divert. Traffic cones  120  are positioned to guide oncoming traffic  130  around the work zone  100 . As discussed above, personnel working within the road construction work zone  100  must rely on driver compliance with speed limits and careful driving to avoid accidents causing injury or death. 
     A system is shown in  FIG.  2    for warning personnel of oncoming traffic, according to an embodiment. In one aspect, a motion sensor  200  is associated with at least one traffic cone  210  and communicates with a portable alert unit  220  for warning a user  230  of oncoming traffic. 
     As shown in  FIG.  3   , the portable alert unit  220  may include an actuator  300  (e.g. a button) for activating initiation of communication with a motion sensor  200 , a speaker  310  for broadcasting an audio warning signal and one or more lights  320  indicating operating status of the portable alert unit  220 . Internal components the portable alert unit  220  are discussed below with reference to  FIGS.  5  and  7   . 
     As shown in  FIG.  4   , motion sensor  200  is shaped to fit into an opening (e.g. a top circular hole) in the traffic cone  210 . In an embodiment, the motion sensor  200  includes a tapered body portion  400  adapted to fit into the opening and a head portion  410  that forms a “plug” for the opening. The motion sensor  200  includes a transmitting lens  420 A and receiving lens  420 B, and additional internal components discussed below with reference to  FIGS.  6  and  7   . 
     Turning to  FIG.  5   , internal components of an exemplary portable alert unit  220  are shown including a processor  500  connected to a packet radio controller  510 , speaker  310  lights  320  and a vibrator/shaker  330  for causing the unit  220  to vibrate. In an embodiment, lights  320  can include a multi-colour LED display. Packet radio controller  510  is activated by a switch  300  for initiating communication with the motion sensor  200  via radio module  520  (e.g. a 2.4 GHz radio module) and antenna  530 . 
     Turning to FIG. 6 , internal components of an exemplary motion sensor  200  are shown including a processor  600  connected to a LIDAR (Light Detection and Ranging) sensor  620  and a radio module  625  having an antenna  630 . In an embodiment, LIDAR sensor  620  comprises a transmitter  635 , which can be a laser diode, a receiver  640 , which can be a photodiode, transmitting lens  420 A, receiving lens  420 B, and a timer and analog-to-digital (A/D) converter  650 . 
     In an embodiment, radio modules  520  and  625  are Class 1 radios having a range of up to 100 metres (300 ft) at 20 dBm and 100 mW. Because the devices communicate via radio signals, the portable alert unit  220  and motion sensor  200  do not need to be in visual line of sight of each other. In other embodiments, LoRa (Long Range) or other suitable low-power wide-area network modulation techniques may be used for communication between the portable alert unit  220  and motion sensor  200 . 
     In operation, a user  230  activates the portable alert unit  220  by pressing button  300 . This initiates a pairing process between the portable alert unit  220  and motion sensor  200  ( 700  in  FIG.  7   ), wherein the radio modules  520  and  625  share addresses, names and profiles according to an authentication process, as is known in the art. Upon completion of pairing, portable alert unit  220  may cause lights  320  to be illuminated (e.g. flashing green lights). 
     Next, at  710 , processor  600  of motion sensor  200  activates the LIDAR sensor  620  causing the transmitter  635  to emit laser pulses in a direction defined by lens  420 A. As shown in  FIG.  4   , the head portion  410  of motion sensor  200  may include indicia, such as an arrow, indicating the direction of the laser beam (i.e. to assist placement of the motion sensor  200  for detecting oncoming traffic  130 ). In the event of oncoming traffic  130 , the laser pulses are reflected and received by lens  420 B and receiver  640  (step  720 ). Timer and A/D converter  650  calculates the amount of time that each transmitted pulse is reflected back to receiver  640  to calculate the distance between the oncoming traffic  130  and motion sensor  200  in traffic cone  210  (step  730 ). This timing information is transmitted to processor  600  and in the event that the distance is less than a chosen threshold (e.g. 300 ft) an alert signal is transmitted from motion sensor  200  to the portable alert unit  220  via the radio connection (step  740 ). In response to receiving the alert signal, processor  500  of portable alert unit  220  generates a suitable alarm (step  750 ), such as one or more of an audio alert via speaker  310 , flashing red lights  320 , and internal vibration via vibrator/shaker  330 . 
     Upon being alerted to oncoming traffic  130 , the user (e.g. worker) can take appropriate protective measures such as departing safely from the work zone  100 . 
     Alternatives and modifications are contemplated. For example, rather than using a single motion sensor  200 , a relay of sensors may be provided using a gateway wherein the alert signal is transmitted from one sensor to an adjacent sensor for further extending the range of operation of the traffic warning system. 
     It is also contemplated that, rather than using a single LIDAR sensor  620 , multiple such sensors may be incorporated into the motion sensor  200  and aimed via associated lenses in additional directions (e.g. rear view, side views, etc.) 
     The present invention has been described above with reference to a number of exemplary embodiments and examples. It should be appreciated that the particular embodiments shown and described herein are illustrative of the invention and its best mode and are not intended to limit in any way the scope of the invention as set forth in the claims. The features of the various embodiments may stand alone or be combined in any combination. Further, unless otherwise noted, various illustrated steps of a method can be performed sequentially or at the same time, and not necessarily be performed in the order illustrated. It will be recognized that changes and modifications may be made to the exemplary embodiments without departing from the scope of the present invention. For example, although much of the disclosure relates to verifying a recorded audio communication between two or more devices, exemplary systems and methods can be used for other applications, such as determining a context of a recording from a relatively small sample of the recording. These and other changes or modifications are intended to be included within the scope of the present invention, as expressed in the following claims.