Abstract:
An intruder detection and warning system has a plurality of infrared sensors for receiving infrared radiation from respective contiguous areas of premises in need of security. A central illumination unit including a rotatable light is operated to project a beam illuminating a selected one of the contiguous areas of the premises in response to the received infrared radiation by the infrared sensor in the selected area indicating presence of a person in the selected area. Initially a polite message randomly selected from a group of different polite messages is broadcast to request the intruder to leave the premises. When continued presence of the intruder is detected, the light beam is moved away from and then back to the selected area and a further message randomly selected from a group of different more demanding messages is broadcast to demand the intruder to leave the premises. Thus computerized control of the central illumination unit to selectively illuminate areas monitored by respective infrared sensors to detect intruders mimics manual monitoring and security enforcement to more effectively deter intruders. Control of the illumination unit with an associated video camera is passed to a remote monitoring station upon continued failure of the intruder to vacate the premises.

Description:
BACKGROUND OF THE INVENTION 
   The prior art contains many intruder detection and warning systems including systems employing one or more infrared sensors along with lights, video cameras, video recorders, monitors, warning devices and/or warning messages. 
   Security of various facilities is an increasing concern. Interception of intruders on premises is an important part of security. Visual monitoring of live video monitors displaying scenes of the premises is often used but fatigue, distractions and other human factors can result in failure to detect intrusions. Infrared detection of intruders is commonly used and can alert or activate visual monitoring. One disadvantage of visual monitoring is the high cost of personnel to perform the visual monitoring. Some systems employ lights, noise and/or warning messages triggered by infrared sensors to deter or scare away intruders but often such lights, noise or warning messages are ineffective as intruders recognize such measures as being generated by computers that can be ignored. Additionally large area premises require employment of multiple intrusion detection and warning systems to cover respective sections of the premises adding to the cost of such prior art systems. 
   Thus there exists a need for effective intruder interception systems with low operating costs. 
   BRIEF SUMMARY OF THE INVENTION 
   The invention is summarized in a intruder detection and warning system having a plurality of infrared sensors for receiving infrared radiation from respective contiguous areas of premises in need of security; logic or computer processing for indicating if the received infrared radiation from each of the contiguous areas is from one or more persons intruding on the premises; an illumination unit including a rotatable light which can be operated to project a beam illuminating a selected one of the contiguous areas of the premises; and a control responsive to the indicating means indicating presence of a person on one of the contiguous areas for operating the illumination unit to project a beam of light on the area where the presence of the person is indicated. 
   An object of the invention is to provide a relatively low cost intruder detection and warning system that effectively deters many intruders and reduces the need for manual operation to view intrusions. 
   An advantage of the invention is that relatively simple passive infrared sensors can be spaced about a central illumination and communication unit with automatic operation of the illumination unit mimicking manual operation to direct a light beam to the area where infrared radiation detected by a respective sensor indicates presence of a person. 
   Additional features enhancing the appearance of manual operation include provision of light beam movement away and back to the area where a person is detected, and random selection of a broadcast message from different messages and/or different voices requesting the intruder to vacate the premises. 
   Other objects, advantages and features of the invention will be apparent form the following detailed description of the invention and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of an intruder detection and warning system in accordance with the invention. 
       FIG. 2  is a perspective view of an illumination, camera and communication unit in the system of  FIG. 1 . 
       FIG. 3  is perspective view of a personnel infrared sensor unit in the system of  FIG. 1 . 
       FIG. 4  is table showing messages stored in the system of  FIG. 1 . 
       FIG. 5  is a diagram illustrating operation of one portion of the system of  FIG. 1  to direct a light beam over a selected area. 
       FIG. 6  is a diagram similar to  FIG. 5  but with the light beam directed to another selected area. 
       FIG. 7  is a diagram similar to  FIGS. 5 and 6  but with the light beam directed to still another selected area. 
       FIG. 8  is a step diagram of a main program employed to control the illumination, camera and communication unit of  FIGS. 1 and 2 . 
       FIG. 9  is a step diagram of an analyze sensor inputs procedure of the program of  FIG. 8 . 
       FIG. 10  is a step diagram of warning procedure of the program of  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As shown in  FIGS. 1 ,  5 - 7 , the invention is embodied in a intruder detection and warning system which includes one or more illumination, camera and communication units  20 , each of which are disposed in premises centrally with respect to a corresponding plurality of personnel infrared sensor units, such as units  22   a,    22   b,    22   c,    22   d  and  22   e  (shown in detail as unit  22  in  FIG. 3 ) deposed to sense the presence of a person or persons in respective contingent areas  24   a,    24   b,    24   c,    24   d  and  24   e  of the premises. Particularly as shown in  FIGS. 5 ,  6  and  7 , each unit  20  can be operated to rotate a light  26  to project a light beam  28  to selectively illuminate any one of the areas  24   a,    24   b,    24   c,    24   d  or  24   e.  For example,  FIG. 5  shows light beam  28  illuminating area  24   c,    FIG. 6  shows light beam illuminating area  24   b  and  FIG. 7  shows light beam  28  illuminating area  24   e.  Since the rotatable light  26  is disposed centrally in the premises and the light beam is projected onto only a portion of the premises such as the selected one of the areas  24   a,    24   b,    24   c,    24   d  and  24   e,  an intruder illuminated by the light beam is given the impression that the intruder detection and warning system is under manual control. Thus an intruder will be deterred from continuing the intrusion. 
   Additionally the system includes a plurality of stored messages,  FIG. 4 , such as message 1   a,  message 1   b,  message 1   c,  . . . of group  1  and message 2   a,  message 2   b,  message 2   c , . . . of group  2 . The messages of group  1  are different polite messages (different in that they are recorded by different people and/or have different wording) and the messages of group  2  are different demanding messages. Examples of polite messages are: “You are on private property, please leave” or “You are in a restricted area, please leave.” Examples of demanding messages are: “Please leave the area immediately or police will be called” or “You have two minutes to leave the area before you are arrested for trespassing.” Typically the demanding message will include a threat of enforcement. When an intruder is first detected on the premises, a randomly selected one of the polite messages of group  1  is broadcast on the premises. If the intruder is still detected after a delay period, such as two to five minutes, a randomly selected one of the demanding messages of group  2  is broadcast on the premises. Often intruders intending to inflict damage, steal goods or spy on premises will make repeat visits to the premises. The broadcast of different messages during repeated visits gives the intruder the impression that the intruder&#39;s presence is monitored by security personnel and thus intrusions are further deterred. 
   Referring back to  FIG. 1 , the intruder detecting and warning system also includes a control unit  32  connected to the illumination, camera and communication units  20 , a remote monitoring facility or center  34  with a video display monitor  36  connected to the control unit  32  and possibly connected to many other intruder detecting and warning systems (not shown), and a video recorder for recording video frames viewed by the unit  20 . Typically the control unit  32  and the video recorder are mounted in a building (not shown) or other secure enclosure while units  20  and  22  are mounted outside on posts, outside portions of buildings, etc. Data from and to personnel infrared sensor units  22  is transmitted data by wireless or radio links to the unit  20 . Cables connect the units  20  to the control unit  32  for transmitting the data from the infrared sensors along with light position and video signals. Control and message signals from the control unit  32  are transmitted by cables to the illumination, camera and communications units. The remote monitoring facility  34  is connected by cable or by dedicated or dial-up telephone lines to the control unit  34 . 
   Alternatively, the personnel infrared sensor units  22  can be connected directly by cables in a star arrangement (not shown) or a ring arrangement (not shown) to the control unit  32 . 
   Referring to  FIG. 2 , the illumination, camera and communication unit  20  has a housing  42  which can be mounted on a support (not shown), such as under eaves of a building or on a crossbar on a post. The rotatable light  26  includes a rotating and pivoting mounting  44  containing internal motors which rotate the light  26  in a horizontal plane and pivot the light  26  in a vertical plane. The light  26  is a spot light which projects a beam such, as a 400,000 candle-power beam, sufficient to illuminate a selected area in the premises under security while leaving non-selected areas non-illuminated. Preferably rotary position sensors such as potentiometers (not shown) provide signals indicating the horizontal and vertical rotary positions of the light  26  to the control unit  32 . A video camera such as a color CCD video camera  46  is mounted on the housing of the light  26  for being rotated and pivoted with the light. The camera  46  has motorized zoom control as well as automatic and motorized focusing control. Additional a speaker and microphone arrangement  48  is mounted on the housing  42  for broadcasting messages in the premises and receiving responses for transmission to the monitoring station  34 . The housing  42  contains electronic circuitry for handling radio transmissions to and from the units  22 , for handling cable transmissions to and from the control unit  32 , for processing light and camera horizontal and vertical position signals, for providing signals to operate the light positioning motors, for providing signals operating the zoom and focus controls of the camera  46 , for providing amplified audio signals to the speaker and receiving and processing audio signals from the microphone. 
   The personnel sensor unit  22 ,  FIG. 3 , includes a housing  52  which can be mounted on a post (not shown) and which supports a passive infrared personnel sensor  54  and a solar panel  56 . Typically the sensor  54  includes an infrared array sensor (not shown) with optics for directing infrared from arc portions of the viewed field onto respective members of the array. The housing contains a rechargeable battery (not shown) which is recharged by the solar panel and contains electronic circuitry for handling radio transmission to and from the unit  20 , for processing signals from the passive infrared sensor  54  and for controlling the charging of the battery. 
   A main program,  FIG. 8 , employed by a microprocessor in the control unit  32  controls operation of the light and camera positioning motors and the message broadcasting facilities in the illumination and communication unit  20 . At startup step  60  the system is initialized and then in step  62  a timer such as a sixty minute timer is set to the desired minimum period between system checks. In step  64  the procedure of  FIG. 9  is called to analyze inputs from the field sensors to determine if one or more persons are present in the areas monitored by personnel infrared sensor units  22  associated with the unit  20 , such as sensor units  22   a,    22   b,    22   c,    22   d  and  22   d  monitoring respective areas  24   a,    24   b,    24   c,    24   d  and  24   e  when there are five such sensors. 
   In step  66  of  FIG. 9  it is determined if a person is present in area- 1 . The analysis of the signal(s) generated by infrared sensors to determine the presence of a person can be either by logic or computer processing in the passive sensing unit  22  monitoring area- 1  or in the control unit  32  based upon infrared readings transmitted to control unit  32 . The presence of a person in the viewed field is determined based upon signal strength, duration, movement, etc. If step  66  is true then area- 1  flag is set in step  68 ; otherwise the area- 1  flag is reset in step  70 . The procedure for area- 1  represented by steps  66 ,  68  and  70  is repeated for each of the areas associated with the unit  20 ; for example steps  72 ,  74  and  76  similar to respective steps  66 ,  68  and  70  are performed for area- 2  and steps  78 ,  80  and  82  similar to steps  66 ,  68  and  70  are performed of area-N. Where the passive sensing units  22  sense arrays of arc increments, the angular location of the person within each area can be determined. When two adjacent areas indicate the present of a person in angular areas which overlap, a determination that only one person is present in the overlapping portions of the areas being viewed. Furthermore the overlapped area can be designated as a separate area, for example area- 6  can be the overlapping portions of area- 1  and area- 2  and the determination of a person within this overlapped area would result in the resetting of area- 1  and area- 2  flags and the setting of area- 6  flag. This would enable the search light to centered on the overlapped area. 
   After returning to the main program of  FIG. 8 , step  84  determines if the unit  20  is controlled by the remote monitoring station  34 . If true, the program continues to cycle through step  64  to determine presence of one or more intruders and present the results to the monitoring station. If step  84  is false, step  86  determines if any person has been found on the premises by procedure  64  and, if true, the warning procedure of  FIG. 10  is called in step  88 . 
   In the warning procedure of  FIG. 10 , the spot light is directed successively to all areas where a person or intruder has been found in the procedure  64 . More particularly, step  90  determines if area- 1  flag is set indicating a person is in area- 1 . When no person is in area- 1 , the area- 1  flag has not been set by the procedure  64  and thus procedure  88  advances to step  92  which determines if the area- 2  flag is set. The procedure continues to look for set area flags of all the areas through area-N flag in step  98  whereupon a false returns the procedure to the main program of  FIG. 8 . 
   When an area flag is found set, such as area- 1  flag being found set in step  90 , the procedure directs the spot light to that flagged area and to broadcast one or more warnings to the intruder. For the example of area- 1  flag being set, step  102  determines if area- 1  level is set to initial state 0. If true, step  104  sets the area- 1  level to 1, step  106  turns the light  26  on, and step  108  rotates and pivots the light  26  to illuminate area- 1 . The horizontal and vertical positions needed for the light  26  to illuminate area- 1  are predetermined and stored in a non-volatile memory for being recalled and used to position the light. Then in step  110 , a randomly selected message from the first group of messages is broadcast from the speaker  48 . This first message is a polite message requesting the intruder to leave the area. The recording of one or more video frames in the video recorder  38  is performed in step  112  and an area- 1  timer is set in step  114  to a value equal to a time period sufficient to allow the intruder to leave area- 1 . 
   When step  102  is false, i.e., after the initial movement of the spot light and broadcast of a polite warning to the intruder, step  116  determines if the area- 1  level is now 1, and if true step  118  determines if the intruder has had sufficient time to leave area- 1  by determining if area- 1  timer has lapsed. When true, step  120  sets area- 1  level to 2. Next, step  122  rotates the light  26  to the left from area- 1 , to the right past area- 1  and then back to area- 1 , and pivots the light  26  down from area- 1 , up past area- 1  and the back to area- 1 . This rotation of the light is designed to give the appearance of the light being operated by manual controls to deter further intrusion. Step  124  records one or more additional video frames in the video recorder  38  and step  126  broadcasts a second message selected from the second group of messages followed by setting the area- 1  timer again in step  114 . The second message is more demanding then the first message and may include a threat of enforcement, such as a threat to call the police or have the intruder arrested. 
   The program proceeds to step  128  when step  116  is false wherein it is determined of the area- 1  level is 2. If true, step  130  determines of enough time has elapsed for the intruder to leave the premises after the second warning message by determining if the area- 1  timer is 0. When true, step  132  sets the area- 1  level to 3 and step  134  passes control to the remote monitoring station  34 . Further automatic operation of the illumination, camera and communication unit  20  is prevented by step  84  of the main program. After remote control is discontinued, step  136  will be false causing the program to proceed to step  138  where the area- 1  level is set back to 0 and then to step  140  where the light is turned off. 
   The procedure of  FIG. 10  described above by the even numbered steps  102  through  140  is a warning procedure for an intruder detected in area- 1 . If any of steps  90 ,  118  and  130  are false or after completion of steps  114  and  140 , the warning procedure advances to step  150  where it is determined if area- 2  flag is set to indicate that a person is in area- 2 . When true a warning procedure  152  having steps similar to the even numbered steps  102  through  140  is performed for area- 2 . Similar procedures are performed for each of the areas area- 1  through area-N such as indicated by warning procedure  156  for area-N. 
   It is noted that when intruders are sensed in two or more areas, the light beam is successively moved to each of the areas where intruders are found. Thus intrusions by several people will not result in failure to detect and warn any of the several intruders. 
   After each cycle through the warning procedure of  FIG. 10 , the main program from step  88  returns to step  64  so that the system continues to detect the presence of intruders in any of the areas. 
   When all the areas are found clear of intruders, the program proceeds to step  160  when it is determined if any area level is greater than zero. If true, step  162  resets all area levels back to zero, step  164  performs an area patrol by horizontally sweeping the light beam through all the areas at two or more successive vertical positions, and step  166  then turns the light off. If step  160  is false, step  170  determines if the sixty minute timer is 0 and if true, proceeds to step  172  where a system check is preformed to determine if all components are operating properly. After the system check, the program returns to step  62  to again set the sixty minute timer. 
   The foregoing description and accompanying drawings are only illustrative of the invention and many variations, modification and changes in detail can be made without departing from the scope and spirit of the invention.