Patent Abstract:
A method and apparatus for enhancing the safety in a work zone surrounding operating equipment including identifying workers within said work zone and warning unauthorized workers within said work zone.

Full Description:
This application claims the benefit of Provisional Application No. 60/356,785, filed Feb. 13, 2002. 

   TECHNICAL FIELD 
   The present invention is directed to a method and apparatus for enhancing safety within a work zone and particularly directed to enhancing worker safety in the work zone associated with a work vehicle operating on a construction site. 
   BACKGROUND OF THE INVENTION 
   It is desirable to enhance worker safety particularly that of ground personnel working around the area of heavy equipment such as a construction vehicles on a construction site. If an operator of a large construction vehicle does not see a ground worker near such equipment, it is possible for a strike and run-over incident to occur. 
   SUMMARY OF THE INVENTION 
   An apparatus for enhancing the safety in a work zone surrounding operating equipment including means for identifying workers within said work zone and means for warning unauthorized workers within said work zone. 
   A method for enhancing the safety in a work zone surrounding operating equipment including the steps of identifying workers within said work zone and warning unauthorized workers within said work zone. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which: 
       FIG. 1  is a schematic illustration of a construction vehicle and workers using a safety apparatus in accordance with the present invention; 
       FIG. 2  is a schematic illustration of a vehicle control unit in accordance with the present invention; 
       FIG. 3  is a schematic illustration of a worker&#39;s portable warning unit in accordance with the present invention; 
       FIG. 4  is a flow diagram of a control process for the vehicle controller in accordance with the present invention; and 
       FIG. 5  is a flow diagram of a control process for the worker&#39;s portable warning unit in accordance with the present invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENT 
   Referring to the drawings, each vehicle  20  on a construction site  22  includes an associated vehicle mounted transceiver unit  24  mounted in the operator cab  26  and accessible to the vehicle operator  28 . Each ground worker  30 ,  32 ,  34  wears an associated portable worker transceiver while he is on the construction site  22 . 
   The vehicle mounted transceiver unit  24  may be mounted within the cab  26  and connected to the vehicle battery  48  for power so that when the vehicle  20  is turned on, i.e., is operating, the vehicle mounted transceiver unit  24  is powered. Alternatively, the vehicle mounted transceiver unit can be removably mounted within the vehicle cab, e.g., magnetically, Velcro, etc., and is connectable to the vehicle battery  48  via a plug in socket such as a cigarette-type socket  50 . The vehicle mounted transceiver unit  24  could alternatively be powered by a self-contained battery. 
   The vehicle mounted transceiver unit  24  transmits a communication signal through an antenna  56  having a signal strength that transmits over an area having an adjustable or selectable radius  60  surrounding the vehicle  20 . This area surrounding the vehicle over which the vehicle&#39;s transmitted signal can be received is referred to as the zone of danger or work zone of the vehicle. Since the zone of danger is vehicle-type dependent, e.g., backhoe, crane, etc., the size of the zone established by the vehicle transceiver is preferably adjustable. Alternatively, a particular vehicle mounted transceiver unit can be specifically arranged to have a fixed transmission diameter if it is going to be mounted in a known vehicle. Having the transmission diameter or work zone area variable allows a more universal application of a single vehicle mounted transceiver unit that can be used in any construction vehicle type. The present invention is also applicable to other heavy operating equipment such as a crane. 
   The signal emitted by the vehicle mounted transceiver unit  24  can be a radio-frequency (“RF”) signal having controllable signal strength. Those skilled in the art will appreciate that other types of known communication signal may be used. 
   The size of the vehicle work zone or zone of danger surrounding a work vehicle is further dependent on the type and congestion of a particular construction site. In a typical congested construction site, it is anticipated that the signal strength for a front-end loader would be adjusted to provide a 15-foot danger zone around the vehicle. In a quarry operation where it is rare for ground personnel to be near the heavy equipment work vehicles, a 50-foot zone could be established. 
   The vehicle mounted transceiver unit  24  would include a display  70 , a data entry device  72  such as a keyboard or keypad, an audible warning device  74 , a visual warning device  76 , and a signal strength adjustment device  78 . The codes that match worker&#39;s portable units  40  that are permitted to be in the work area  80  can be entered through the data entry device  72 . Signal strength to control the size of the work or danger zone  80  can be adjusted via the control  78  or alternatively through the data entry device  72 . 
   The worker&#39;s portable warning device  40  is attachable to the worker&#39;s helmet or clothing in any known manner of attachment. The device  40  includes an antenna  90  for receiving and transmitting signals from and to vehicle mounted control units of vehicles or equipment within the construction site  22 . The devices  40  further include a source of electrical energy such as a battery  92 , an ON/OFF switch  94 , a battery indicating light  96 , an audible warning device  98 , and a visual warning device  100 . All persons on the construction site would be required to wear a portable worker unit  40 . A person wearing the portable unit  40  has no ability to override the functions of the unit  40 . 
   Certain workers are permitted or authorized to be within the work zone of selected pieces of equipment. For example, pipe-laying workers  30  would be permitted to be within the work zone of a backhoe with which they are working but may not be permitted to be within the working or danger zone of other vehicles or pieces of equipment on the work site. Other workers  32 ,  34  would not be permitted to be in the working zone  80 . By way of another example, riggers or ironworkers may be permitted within the work or danger zone of a crane with which they are associated. 
   Each portable worker&#39;s units  40  have an associated code that identifies that unit, and, in effect, identifies that associated worker. Workers permitted to be in the work zone of a particular vehicle have their code from their associated unit programmed into the vehicle mounted control unit  24  of that vehicle. This can be preprogrammed either at the factory or through the data entry device  72 . 
   During operation, the vehicle transceiver of the vehicle mounted control unit  24  transmits an interrogation signal, in effect, looking for workers within its zone of danger or work zone  80 . If a worker comes within the zone, his potable unit receives the interrogation signal, transmits its code to the vehicle unit. If the vehicle mounted control unit  24  determines that the received code from a worker&#39;s portable unit  40  is that of an authorized worker, no further action is taken. If the code does not match, the alarms  74 ,  76  are activated to warn the vehicle operator  28 . The unit  24  further transmits an alarm signal to the portable unit  40  of the unauthorized worker, e.g.,  32 , which, in turn, activates his alarms  98 ,  100 . 
   The vehicle operator has the ability to override the alarm if desired through the data entry device  72  or via a reset switch. 
     FIG. 4  shows a flow diagram of a control process  200  for the vehicle mounted controller  24 . The process starts at step  202 . At step  204 , codes or communication information to identify authorized workers are entered. This can be accomplished via the data entry  72  or preprogrammed at the time of manufacture. In step  206 , the vehicle based unit transmits a signal to communicated with any worker carried portable unit  40  that is within it&#39;s work zone. The signal strength is adjusted to define the work zone based on the vehicle and the type of work site. In step  208 , a determination is made as to whether a return signal is received. This may be in the form of a signal having a code that identifies the worker carried portable unit  40 . If the determination is negative meaning no worker is within the work area  80 , the process loops back to step  206 . The steps  206  and  208  are continuously performed until a return signal is received. From an affirmative determination is step  208 , a determination is made in step  210  as to whether the return signal identifies an authorized worker or not. If the determination is affirmative, the process loops back to step  206 . The steps  206 ,  208  and  210  continuously repeat until an unauthorized worker is identified as being within the work zone of the vehicle based unit. An unauthorized worker leads to an affirmative determination in step  210 . From an affirmative determination in step  210 , the process proceeds to step  212  in which the alarm is activated in the vehicle based unit  24  to warn the vehicle operator of the unauthorized worker in the work zone  80 . The vehicle based unit sends a signal to the portable unit to activate the portable unit alarm to also warn the worker that he is in a work zone in which he is not authorized to be in. In step  214 , a determination is made as to whether the work zone area  80  has been cleared of the unauthorized worker. If the determination is negative in step  214 , a determination is made in step  216  as to whether the vehicle operator has manually overridden the alarm. If the determination in step  216  is negative, the process loops back to step  212  and both alarms remain activated. From affirmative determinations in either steps  214  or  216 , the process proceeds to step  218  in which the alarm of the vehicle based unit is reset. The process then loops back to step  206 . 
     FIG. 5  shows a flow diagram of a control process  250  for the worker&#39;s portable warning unit  40 . The process starts at step  250  and proceeds to step  254  in which a determination is made as to whether an interrogation signal has been received from a vehicle based unit. If the determination is negative, the process loops back upon itself and continues to monitor for receipt of an interrogation signal. From an affirmative determination in step  254 , the process then transmits its identification code to the vehicle based system in step  256 . The process then proceeds to step  258  in which the portable unit determines if an alarm signal has been received from the vehicle based unit. If the determination is negative, this means that the worker must be an authorized worker for that work zone and the process loops back to step  254  without an alarm being activated. If the determination is step  258  is affirmative, the process proceeds to step  260  in which the alarm of the worker unit  40  is activated. The process then loops back to step  254 . If no further interrogation signal is received, i.e., the worker has left the work zone  80 , its alarm would be reset and then again continuously monitor for another interrogation signal. 
   From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, other type of signal communication arrangements between a vehicle based unit and the portable worker unit can be used other than that describe above in the exemplary embodiment to identify workers within a work zone and to warn unauthorized workers and the equipment operator of the unauthorized worker within the work zone. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.

Technology Classification (CPC): 4