Not Applicable
1. Field of Invention
This invention pertains to a system for monitoring an outdoor perimeter. More particularly, this invention relates to a system for monitoring and distinguishing between a variety of occurrences along a perimeter bounded by a single conductor wire that communicates with piezoelectric sensors.
2. Description of the Related Art
Residential and light commercial security systems have become an increasingly popular addition to many homes and businesses. These systems are typically based on the electronic detection of a breach in the perimeter of a structure. A breach is detected at either the perimeter itself or the interior of the structure. The perimeter is generally defined as the entrance/egress points to a structure such as doors and windows. Perimeter breaches are generally detected by magnetic sensors which monitor the opening and closing of doors and windows and by frequency sensors attuned to the sound of glass breakage. Interior breaches are generally detected by heat and motion detectors which monitor moving objects having a temperature greater than the ambient temperature. While providing a warning of intrusion, both the detection of perimeter and interior breaches occur after damage to the structure or entry has been obtained. For security purposes it is desirable that the bounded perimeter of interest be divided into zones which define the approximate property lines and/or selected sections thereof.
Similarly, motion sensors are used to turn on outdoor lighting thereby providing a deterrent to intrusion onto the property. However, these sensors are indiscriminate in that they may be triggered by small animals, children, or other moving objects which are not considered security risks. Further, because of the difficulty in accurately setting the range, and the accurate detection zone of each sensor, setting up a comprehensive coverage area limited to the boundaries of one's property is difficult at best. Finally, it should be noted that while the external sensors could be connected to a central alarm system, the inability to discriminate between legitimate security risks and stray animals and the difficulty in defining the protection area render such a system unreliable.
Ideally, a monitoring system could identify and announce activity along the monitored perimeter. Accordingly, there is a need for a monitoring system which allows a boundary of protection to be easily defined. Further, there is a need for a monitoring system capable of identifying potential threats to security so as to avoid false alarms.
In accordance with various features of the present invention a system for monitoring and distinguishing between various activities along a perimeter bounded by a single conductor wire is provided. The system includes at least one piezoelectric sensor in communication with the conductor wire which bounds a protected zone such as the perimeter of the property or selected sections thereof. The signal generated by the activation of the piezoelectric sensor is read by a signal processing device to determine if a security breach has occurred. If a security breach has occurred, an appropriate alarm is energized.
The described security system is adaptable for use as a pet containment system as well. The pet that is being contained wears a signal receiver that also delivers a behavior-correcting electroshock stimulus. The signal-producing conductor wire defines the property's perimeter as described above. When the pet wearing the signal receiver traverses the signal-producing conductor wire, a corrective electroshock stimulus is delivered to the animal. This negative stimulus conditions the pet to remain within the property's perimeter as defined by the conductor wire and in this way contains the pet. The pet containment application of this security system is designed to function with previously installed pet containment systems. The signal produced by the conductor wire, for example, is capable of reproducing the signal produced by the previously used signal-producing wire boundary in order to avoid the cost involved in purchasing new signal receivers for the pet.
The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:
A system for monitoring a wire-bounded perimeter is illustrated generally at 10 in the figures. The system for monitoring a wire bounded perimeter, or monitoring system 10, uses at least one sensor 12 located at a predetermined location around a protected area 14 to identify activity at the perimeter of the protected area 14.
The transponder 18 serves as the controller for the monitoring system 10. Specifically, the transponder 18 supplies power, receives data from the sensors 12, processes the received data, displays information about the processed data, and communicates with external devices, such as a conventional residential and light commercial security system (not shown). The processing device 20 sequences the operation of these functions. One skilled in the art will recognize that the processing device can be implemented in a variety of ways including discrete logical components (not shown) and a microprocessor (not shown). In the illustrated embodiment, the processing device 20 is a microprocessor for allowing the functionality of the transponder 18 to be varied, with minimal hardware changes, through the use of software. Typical functions of the processing device 20 include providing timing to control signal traffic across the conductor wire 16, requesting information from the sensors 12, and analyzing the information received from the sensors 12. Additionally, the processing device 20 generates an output which is sent to an external interface 30. The external interface 30 translates the output into a form which is usable by a conventional residential and light commercial security system, allowing the monitoring system 10 of the present invention to be integrated with an existing structural intrusion detection system. Such integration allows the monitoring system 10 to be monitored by an off-premises security monitoring company if desired.
Many of these functions compete for transmission time across the single conductor wire 16. The gateway 22 manages access to the conductor wire 16. One skilled in the art will recognize that a variety of electrical components can be used to implement the gateway 22 including switches, multiplexers, gates, and universal asymmetric receiver-transmitters (UARTs). In the illustrated embodiment, the gateway 22 is a UART responsive to the processing device 20. Among the signals competing for use of the conductor wire 16 are information signals directed to one or more sensors 12 from the processing device 20 and information signals from one or more sensors 12 directed to the processing device 20. In general, the conductor wire 16 carries a power signal from the power supply 32. Data signals are encoded into the base signal by applying a modulation technique, such as frequency shift keying.
To monitor activity near the perimeter of the protected area 14, the transponder 18 requests information from each sensor 12 by sending a data packet containing the appropriate command characters to the particular sensor 12. When energized, each sensor 12 detects local activity and sends the detected activity signal to the transponder 18 for processing. The transponder 18 compares the detected activity to a variety of exemplary activity signals. Using the comparison result, the transponder then categorizes detected activity within one of the predetermined classes. One skilled in the art will recognize that various types of sensors 12 can be used depending upon the desired monitoring capabilities of the system, including, but not limited to, seismic, infrared, and audio sensors. Further, one skilled in the art will recognize that various levels of sophistication in the discrimination process can be used to provide more specific identification of the activity source.
In the illustrated embodiment, a variety of DC power sources 38 are shown. First is a power conditioning in-line zener diode 38A connected to the conductor wire 16 for generating a DC voltage drop used to power the sensor 14A. Next is a DC transformer 38B for converting the AC voltage traveling through the conductor wire 16 into a DC voltage. Finally, independent power sources 38C, and 38D are shown. Each of the independent power sources 38C, and 38D can be a battery or a solar cell. One skilled in the art will recognize that the independent power source 38D provides the greatest benefit when used in a mobile sensor such that it can be readily moved without the need for connection to an external power source.
Each of the sensors 12 is provided with a unique identification, or address, allowing the transponder 18 to communicate with a particular sensor 12. Communication is accomplished using a data packet having a header containing at least a frame synchronization code, at least one command character, at least one address character, and a security code. One skilled in the art will recognize that other information may be included, including, but not limited to, packet size and checksum information. In the illustrated embodiment, the data packet is transmitted using an RS-232 data format. The frame synchronization code is made up of sixteen (16) consecutive logical one bits coupled with no more than four (4) stop bits between the characters in the data packet. The command packet is transmitted through the conductor wire 16 using any appropriate modulation scheme. The preferred embodiment utilizes frequency shift keying (FSK) for transmitting the data packet. One method for implementing a FSK transmission is to use a higher frequency, such as 18 kHz, to transmit a logical one and a lower frequency, such as 14 kHz, to transmit a logical zero.
When a request is received by the sensor 12, the activity measurement device 40 is activated to detect local activity. The activity measuring device 40 is positioned and adjusted such that activities near to or approaching the perimeter of the protected area 14 from the outside are detected. The detected activity signal is then encoded by the sensor processing device 32 and transmitted to the transponder 18, of
Those skilled in art will recognize that the activity measurement device 40 may be another piezoelectric-based device without departing from the scope or spirit of the present invention. Those skilled in the art will also recognize that the activity measurement device 40 may be a device other than the discussed devices, such as seismic, infrared, and audio sensors, without departing from the scope or spirit of the present invention.
Returning now to the illustrated embodiment of
One skilled in the art will recognize that the ultimate function of the monitoring system 10 is to detect and categorize the activity prior to penetration of the protected area 14. In this regard, various components of the system are interchangeably located without interfering with the objects of the present invention. Specifically, the digital signal processing device 68, the comparison device 24, the memory device 26, and the processing device 20 may be located in each sensor 12 so that the transponder 18 simply collects the results and displays the information.
One skilled in the art will recognize that both the transponder 18 and the sensors 12 can include additional electronics, including modulators, demodulators, amplifiers, filters, etc., to enhance the basic function, accuracy, and reliability of the present invention without interfering with the scope of the present invention. Further, one skilled in the art will recognize that, within each of the sensors 12 and the transponders 18, signals can be communicated between the various components using a variety of methods including the use of a bus.
Referring now to
The indicator device 28 operates in a manner similar to the indicator device 28 shown in
The voltage generated by the compression of the piezoelectric sensor 12, or local activity signal, is read as a filtered local activity signal by the digital signal processing device 68. The digital signal processing device 68 turns the local activity signal into a filtered local activity signal. Both the magnitude and the pattern of the voltage in the local activity signal are interpreted by the digital processing device 68 as it is converted into a filtered activity signal. The digital signal processing device 68 relays the filtered activity signal to a comparison device 24 that compares the filtered local activity signal to at least one reference signal. This comparison result is then relayed to the processing device 20 and the system takes appropriate measures according to the result. It is in this way determined whether or not the entity generating the local activity signal is a security risk.
The indicator device 28 also includes CONTACT ON, PERIMETER ALERT, CABLE BREAK and PWR (power) displays as shown in
The stress on the sensor 12 varies with soil conditions. Typically sandy soil is less responsive than dry soil. In order to overcome this drawback, a calibration unit 88 is integrated into the system in the preferred embodiment as is shown in
In the calibration unit 88 of
What has been disclosed is an external perimeter monitoring system using strategically placed piezoelectric sensors connected to a transponder by conductor wire conductors through which data signals and power signals are sequenced. Activity detected at the sensors are analyzed to classify the source of the activity and an alert is generated if necessary. The external perimeter monitoring system is capable of interfacing with a conventional residential or light commercial security system to allow off-premises monitoring. Further, an alternate embodiment of the external perimeter monitoring system is integrated with a conventional electronic pet confinement system allowing the conductor wire to serve as a radio frequency antenna defining the confinement boundary with the confinement signal added to the data signal and power signal sequencing.
While a preferred embodiment has been shown and described, it will be understood that it is not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and the scope of the invention as defined in the appended claims.
This application is a continuation-in-part of U.S. patent application Ser. No. 09/522,087 filed Mar. 10, 2000.
Number | Date | Country | |
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Parent | 09522087 | Mar 2000 | US |
Child | 11627718 | Jan 2007 | US |