Abstract:
A device system and a process for monitoring an industrial plant offers the persons working at the plant with the greatest possible protection. Signal transmitters ( 4, 5 ), which are fastened to persons ( 2, 3 ) or mobile objects, send or trigger a code related to a person or mobile object. Position marks ( 31, 32, 33, 34, 41, 42, 61, 62, 71, 72, 36, 37, 74 ), which provide a position code and a direction code for passing through an entrance or an exit, are arranged at entrances and exits of an industrial plant ( 21, 22 ). A receiving unit ( 15, 35, 43, 63, 73 ) receives the code of the signal transmitters combined with the position code and direction code. A computing and evaluating unit ( 12 ) is connected with the receiving unit and generates a topology for the persons or mobile objects to enter or leave the industrial plant.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of priority under 35 U.S.C. § 119 of DE 103 47 894.9 filed Oct. 15, 2004, the entire contents of which are incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention pertains to a device and a process for entering or leaving an area in a controlled manner. 
   BACKGROUND OF THE INVENTION 
   Areas in the form of complex industrial plants normally have means for displaying information on the operation and on the monitoring of the plant. The monitoring comprises, on the one hand, the checking of process parameters and, on the other hand, the detection of accidents, which may develop, for example, because of leaky line systems. Prior-art monitoring systems for industrial plants are devices for measuring gas concentrations, which are arranged stationarily as stationary measuring heads, or they are mobile measuring systems, which are carried by persons. Such a device for measuring gas concentrations has become known from DE 198 58 022 C2. A satellite-supported positioning system GPS (global positioning system) is used to determine the position of the stationary and mobile measuring heads. However, these positioning systems cannot be used in closed spaces, and it is not possible to determine the direction of a movement because of the limited resolution. 
   Hazardous working areas are secured in industrial plants such that only certain persons can enter them. It is known from DE 33 21 790 A1 that an active or passive transponder is associated with individual pieces of clothing of the persons to be protected. A code, which contains a personal code, can be assigned to this transponder, so that only authorized persons, who carry certain items of equipment provided with transponders, can enter the hazardous areas. The prior-art personal monitoring system comprises no position recognition that would enable a head of operations sitting in a monitoring center to determine the instantaneous position of the employees. 
   SUMMARY OF THE INVENTION 
   The basic object of the present invention is to provide a device and a process that make it possible for the persons working in an area to have the greatest possible protection. 
   According to the invention, a device enabling persons or mobile objects to enter or leave an area in a controlled manner includes signal transmitters, which are fastened to persons or mobile objects and which send or trigger a code related to a person or mobile objects. Position marks are provided at entrances and exits of the area, which provide a position code and a direction code for the passage by an entrance or an exit. A receiving means is provided for receiving the code of the signal transmitters combined with the position and direction code. A computing and evaluating unit is connected with the receiving means and is designed to generate a topology for persons or mobile objects to enter or leave the area. 
   According to another aspect of the invention, a process is provided for enabling persons or mobile objects to enter or leave an area in a controlled manner. Signal transmitters are fastened to the persons or mobile objects. The signal transmitters send or trigger a code related to the person or mobile objects. Position marks are arranged at the entrances and exits of the area, which provide a position code and a direction code for the passage by an entrance or an exit. A receiving means is provided, which is designed to receive the code of the signal transmitter combined with the position code and the direction code. A topology is generated for the persons or mobile objects to enter or leave the area with a computing and evaluating unit, which is connected with the reception means. 
   The advantage of the present invention is essentially that individual data sets, comprising a personal code, a position code and a direction code, are generated by signal transmitters located at entrances or exits of the area, and the topology for entering and leaving the area can be determined from these codes in a central computing and evaluating unit. It is thus possible to determine from a central location which persons are present in a corresponding area. The accuracy of the positioning can be increased by arranging additional position marks in the area. The position marks are designed such that they generate both a position code and a direction code, from which the direction in which a person has passed by the position mark can be inferred. Whether a person has entered or left the area can be determined from the direction code. If, for example, a person is only passing by the position mark without entering or leaving the area, no direction code is generated, but it is only recorded that the person is in the vicinity of the position mark. 
   The position mark for recognizing the direction is designed such that two individual position marks, with which an individual position code is associated, are arranged next to one another, so that the direction can be inferred from the sequence in which the person passed by the individual position marks. The signal transmitters, which communicate with the position marks, are advantageously designed as active or passive transponders. The transponders can be easily accommodated in a chip card carried by the person or in the clip of a gas measuring device being carried. 
   As an alternative or in addition to persons, mobile objects may also be provided with signal transmitters or transponders. 
   A central meeting point, at which a position mark communicating with the central computing and evaluating unit is located, is advantageously provided in the area itself or outside the area. If a state of alarm or warning is triggered in the area, the persons located in the area leave the area via the exits. The persons who have passed by and the direction in which they have passed by are recognized by the position marks. However, it may also happen that persons do not leave the area via the exits, but head for safety by another route. There is an instruction for this stating that all persons shall meet at the central meeting point. Using the position mark located at the meeting point, it is possible to determine which persons have reached the meeting point based on the codes sent by the transponders. 
   The areas are advantageously provided with monitoring means for sending measured signals to the computing and evaluating unit. Means for recognizing and localizing a state of alarm or warning from the measured values are present in the computing unit, and the position data of the individual persons, who are located in the area, are compared with the position of the state of alarm or warning. The computing and evaluating unit then generates an escape signal, with which luminous hands are actuated, which show the way to a safe exit. 
   In addition to the indication of the escape route, the actuation of door closing mechanisms or ventilators may advantageously also be incorporated in the alarm plan. Thus, only the escape doors that make it possible to leave the building or the industrial plant safely will be unlocked by the computing and evaluating unit in the state of alarm or warning. Escape routes that lead into the hazardous area are blocked. Ventilators that are located at the source of the fire are shut off automatically by the computing and evaluating unit in case of a fire alarm. 
   The area is advantageously an industrial plant with walkable buildings located therein, wherein position marks are arranged at entrances or exits of the industrial plant and the buildings. 
   Gas indicator systems and fire alarm systems are provided as monitoring means. Escape routes within the areas are indicated by luminous hands or luminous strips. 
   An exemplary embodiment of the present invention is shown in the drawings and will be explained in greater detail below. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which the preferred embodiment of the invention is illustrated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view showing the design of a positioning system; and 
       FIG. 2  is a schematic view showing an industrial plant according to the present invention with a positioning system corresponding to  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  schematically shows a positioning system  1  for persons  2 ,  3 , who are not specifically shown in  FIG. 1  and are provided with active transponders  4 ,  5 . The area to be monitored extends over a radius of R=50 m, and the area is divided into individual rectangular segments  6 . The position of the segments  6  can be indicated by a combination of letters A–D on the abscissa and numbers  1  through  6  on the ordinate. 
   A first position mark  7  is illustrated as an example in segment  6  “D 2 ” and a second position mark  8  in segment “C 5 .” The other segments  6  are likewise provided with position marks, which are not shown in  FIG. 1  for the sake of greater clarity. Each of the position marks  7 ,  8  has a floor loop  9 ,  10 , which extends over the segment “D 2 ” or the segment “C 5 .” Space coordinates can be stated for the entire area by means of position marks and corresponding floor loops in adjacent fields. 
   The position marks  7 ,  8  permanently send coded space coordinates. If the active transponder  4  comes into the area of the floor loop  10  of the position mark  8 , it is activated by the carrier frequency imitated via the floor loop  10  and receives the space coordinate of the position mark  8 . This space coordinate is transmitted together with an individual code of person  2  to a central reception point  11 , which is in connection with a central computing and evaluating unit  12 . The data communication for the position mark  8  and the transponder  4  is indicated by arrows  13 ,  14 . The codes for the persons  2 ,  3  are permanently programmed in the corresponding transponders  4 ,  5 , so that information is present on the instantaneous position of the persons  2 ,  3  in the computing and evaluating unit  12  at any time on the basis of the space coordinates of the position marks  7 ,  8 . 
     FIG. 2  schematically shows an industrial plant  20 , which comprises a production area  21 , a warehouse  22  with an entrance  15 , a doorway  23  with an adjacent parking area  24  and an office building  25 . There is an entrance  26  for employees between the doorway  23  and the office building  25 , and there is an emergency exit  27  behind the office building  25 . The parking area  24  can be reached via a turnstile  28  from the production area  21 . The entrances and exits of the production area  21  as well as the entrance  15  to the warehouse  22  are provided with position marks. Thus, four position marks  31 ,  32 ,  33 ,  34  with a reception point  35  are located in the area of the doorway  23 . The entrance  15  to the warehouse  22  has two position marks  41 ,  42  with the reception point  43 , and the emergency exit likewise has two position marks  61 ,  62  and a reception point  63 , the turnstile  28  has two position marks  71 ,  72  with a reception point  73 , and the entrance  26  has two position marks  36 ,  37  for the reception point  35 . 
   A position mark  74 , which communicates with the reception point  73 , is located in the parking area  24  at a meeting point  17 . The meeting points  35 ,  43 ,  63 ,  73  are connected with the central computing and evaluating unit  12  via signal lines  81 . The positions of the individual position marks and persons are illustrated on a monitor  122  in the form of a topology. 
   A gas indicator system  82 , which responds to toxic gases and sends a warning signal to the computing and evaluating unit  12  via a signal line  83  when a limit value is exceeded, is located within the production area  21 . A fire alarm system  84  located within the warehouse  22  is connected with the computing and evaluating unit  12  via the signal line  85 . 
   The monitoring of the industrial plant  20  is carried out as follows: 
   Person  2  with the transponder  4  enters the production area  21  via the entrance  26 . Person  2  now comes into the ranges of action of the position marks  36 ,  37  one after another. The space coordinates belonging to the position marks  36 ,  37  and the code of person  2  are transmitted to the reception point  35  and forwarded to the computing and evaluating unit  12 . A direction code, which states that person  2  has entered the production area  21 , is obtained from the sequence in which the position marks  36 ,  37  are passed by. 
   Person  3  with the transponder  5  in the production area  21  wants to perform work in the warehouse  22 . To enter the warehouse  22 , he passes by the position marks  41 ,  42  in the order position mark  42  and position mark  41 . Together with the code of person  3 , which is stored in the transponder  5 , and the space coordinates of the position marks  41 ,  42 , the computing and evaluating unit  12  receives information via the reception point  43  that person  3  is located within the warehouse  22 . 
   A passenger car  54  occupied by four persons  50 ,  51 ,  52 ,  53  wants to drive through the doorway  23  to the production area  21 . The persons  50 ,  51 ,  52 ,  53  carry personal transponders  55 ,  56 ,  57 ,  58 . The transponders  55 ,  56  are detected by the position marks  32 ,  31  during the entry into the production area  21 , and the transponders  57 ,  58  come into the range of action of the position marks  34 ,  33 . It is established from the order in which the position marks  32 ,  31 ;  34 ,  33  are passed by and the direction code resulting therefrom that the persons  50 ,  51 ,  52 ,  53  have entered the production area  21  in the passenger car. 
   An alarm plan for the industrial plant  20  makes provisions for the persons  2 ,  3 ,  50 ,  51 ,  52 ,  53  located in the area to come to a meeting point  17  with the position mark  74  in the parking area  24 . The persons must pass through the turnstile  28  along the position marks  71 ,  72  to do so. As an alternative, provisions are made, if the escape route via the turnstile  28  is blocked, for the persons to leave the production area  21  via the emergency exit  27  along the position marks  61 ,  62 . 
   The gas indicator system  82  reports a gas alarm via the signal line  83  to the computing and evaluating unit  12 . Since the gas alarm is from the vicinity of the emergency exit  27 , the emergency exit  27  is blocked, and the computing and evaluating unit  12  activates luminous hands  86  showing the escape route via the turnstile  28  via a signal line  85 . Persons who pass through the turnstile  28  are detected by the position marks  71 ,  72  before they reach the meeting point  17  at the position mark  74 . Persons who do not pass through the turnstile  28  and leave the production area by other routes, for example, via a fence, are detected by the position mark  74  at the meeting point  17 . 
   In an alternative case of warning, when a fire is reported by the fire alarm system  84  in the warehouse  22 , the escape route via the turnstile  28  is blocked, and the luminous hands  88 , which show the escape route via the emergency exit  27 , are actuated via the signal line  87 . It can be determined by means of the position marks  61 ,  62  at the emergency exit  27  which persons have passed by the emergency exit  27 . 
   If the person  3  is still in the warehouse  22  in case of a fire, the transponder  5  sends the information on whether the person  3  is still in the warehouse  22  or has already left it combined with the position marks  41 ,  42  and the reception point  43 . The computing and evaluating unit  12  can then immediately send an instruction on whether the firefighting operations can be started or whether the person  3  must first be rescued from the warehouse  22 . Since it is possible at any time to recognize the whereabouts of persons within and outside buildings at any time, it is possible to immediately decide in case of a warning or alarm which persons must be brought to safety from an area at risk. 
   While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.