HK1184270A - A remote sensing and communication system - Google Patents

Abstract

A remote sensing system and method for instrumenting the entries to manhole enclosures, in order to provide a platform and means f sensing environmental parameters within and around the enclosures and wirelessly transmitting those parameters to a distant site. T system comprises a housing (10) with sensor for monitoring environmental prararreter in the vicinity of the manhole. A microcontrol (12) in the housing sends the parameters to a radio module (13), which transmits the parameters to a communication device for alerting a user that a manhole has been tampered with.

Description

Remote sensing and communication system

The application is a divisional application based on Chinese patent application with application date of 19/5/2006, application number of 200680017209.2 (international application number of PCT/US 2006/019497) and invented and created with the name of "remote sensing and communication system".

Technical Field

The present invention relates generally to systems and methods for performing enclosure access in order to provide a platform and apparatus for sensing environmental or process parameters within or around an enclosure and wirelessly transmitting those parameters to a remote point.

Background

Sanitary and sewage systems are becoming more and more expensive to operate and are under daunting environmental, social and regulatory pressures. The mechanisms and organisations that manage the hygiene system face complex and costly problems. Three major problems facing sanitation system managers are sewage spills, treatment failures, and illegal dumping. The first two of these problems typically result in uncontrolled spills of pollutants into the environment, causing environmental damage, health threats, and expensive cleanup and abatement costs, while the third problem creates a potential hazard to the abatement system, the environment, and uncontrolled liability for health managers, respectively.

Sewage spills are becoming more common and more expensive to organizations and organizations responsible for managing waste treatment and remediation. The increased population puts severe pressure on sewage systems, the systems are becoming aged and more susceptible to leaks and spills, and the cost of spills, including cleanup, emission reduction, and penalties from regulatory agencies are all soaring. A recent market analysis by Brown and aldwell engineering, entitled "when's a Spill Worth, or a BriefLook at Community Values", investigates 676 sewage facilities in california to obtain economic value for overflow avoidance. The results of the survey show that organizations, for example, on the order of 1000 gallons for spills, are willing to spend $ 10 per gallon to avoid these spills. For larger spills, agencies would be willing to spend $ 500,000 to $ over a million to avoid spills reaching a catchment area such as a river, lake or ocean. It is not uncommon for a health institution to be penalized for millions of dollars due to sewage spills, particularly in situations where the volume of sewage is large or reaches a catchment area. Sewage spills also pose serious public relations problems for regulatory agencies, and it is not uncommon for sewage to return to residential and commercial facilities causing serious liability and expensive and time consuming clean-up for the agencies.

Sewage spills are caused by a number of problems, but there are three main reasons often mentioned: grease build-up due to illegal dumping by restaurants, other commercial establishments, or residents that use fat, lard, or grease in food or industrial processing; structural problems in sewer pipes caused by the intrusion of plant roots or the breaking of pipes, which are often more severe by throwing objects like rags into the sewer; and "infiltration and inflow", spillage due to leakage into the system, which typically occurs at high rainfall or runoff rates. Sewage spills typically start with a pipe that is blocked or full due to high flow and overflows. Currently, there is no practical early warning system to provide a system administrator with a cost-effective means of preventing spills before they occur. Spills are typically detected by the public by accidentally observing the passage of water out of a manhole or the smell of a wet area of the ground near or above the drain. By the time sewage spills are noticed by the public, it is too late-spills have occurred, the problem is just how much sewage has spilled into the environment, whether the spill has reached a clean receiving area, how much money and time it takes to solve the problem and how much fines it will be.

The second major problem with sanitation agencies is the loss of treatment due to the destruction of beneficial treatment bacteria by the sewage treatment plant. A common part of the remediation process is the natural decomposition of organic materials in the wastewater by bacteria. If the influent waste is toxic to beneficial bacteria, massive bacterial death occurs without warning, and the effluent spills or is otherwise discharged without knowing whether it is treated or untreated. An apparatus for providing early warning of toxic materials passing through a sewage collection system to a treatment plant could provide the manager with the option of diverting the influent water flow to a storage tank until the toxic material waste dissipates, which is useful and important to the health industry. Further, if the source of the toxic material can be determined, the source of the toxic material can be prevented or penalized as appropriate.

In addition, illegal dumping of objects into inspection wells is a common problem. The source of the problem is illegal operation or simply intentional destruction of commercial enterprises at the expense of the disposal of large amounts of hazardous waste, including sewage and septic trucking. Stealth dumping of illicit drug test waste is another source of problems. Rather than paying a large fee at a legitimate dumping station, the illegal transportation of hazardous waste from several trucks, including rot, to a remote manhole allows dumping of large quantities of material with little likelihood of detection or detection. This uncontrolled dumping into a sewage system is a major problem in the health industry because sewage system managers are ultimately responsible for what is dumped into their systems and there is little opportunity for the managers to catch or prevent illegal dumping.

Illegal access to manholes has forced some health authorities to weld their manholes down, which effectively prevents illegal access, but at the same time creates operational problems including delays or delays in maintenance or in emergency situations, delays in accessing the manholes through the manholes.

There are currently methods of monitoring water level and flow in manholes, for example, the Hach (Loveland, CO) Sigma 1000 and the Marsh-McBiney Flo-Dar systems are two such products. These methods have one or more of the following problems: (a) the installation requires access to the manhole, which is expensive and presents a higher safety risk; (b) the system requires wired communication, and therefore trenching around the manhole is required; (c) the system requires a continuous 120 volt ac power source, thus trenching around the manhole; (d) the entire installation is expensive, thus limiting the deployment of these systems to only a few selected manholes. A small city has 5,000 to 10,000 manholes, while a large city has more than 100,000 manholes. To provide extensive coverage, the overall cost spent by each manhole must be reasonable.

Clearly, there is a real need for a low cost and robust system and method that provides an early warning system that eliminates some of the problems and costs faced by health managers. Such a system should be inexpensive so that it is widely deployed, it provides large area communications, and it is fast enough to give the manager sufficient time to react and prevent catastrophic failure from occurring before it affects society and the environment. Such a system may also be a platform for different sensors for a variety of purposes including intrusion warning, enclosed space (e.g., gas) monitoring, water quality monitoring, flow monitoring, and environmental or pollution monitoring, and by widely covering the distribution of urban areas, such a system has a variety of uses in addition to manhole monitoring.

Disclosure of Invention

The present invention provides a system and method that combines a self-contained power supply, electronic system, communication system, computing capability and sensors into a low cost, low power device that is directly integrated and mounted to an enclosure barrier such as a manhole cover to provide sensing and rapid early warning of problems occurring within or around the enclosure barrier. Specifically, the present invention comprises: a communication unit providing communication from the device to a remote user of the system; a power supply to provide constant and reliable power to the device; a microcontroller capable of monitoring sensor inputs and controlling communications and device operation; an electronic system providing means for providing appropriate power and current to the communication device, microcontroller, and sensors; and a sensor that monitors a parameter inside or near the enclosure. The invention also provides a low-cost and low-workload installation and maintenance program. Rather than expensive and time consuming trenching at a site to provide power and communication, the present invention provides a device that is particularly low power consuming, thus enabling use of off-the-shelf small format battery packs to provide months of uninterrupted operation, and wireless communication to eliminate the need for wires.

The system and method according to the invention also provide the following advantages: (a) several months of standalone operation without the need for an external power source, although an external power source may be used when available; (b) easy integration and installation into containment barriers such as manhole covers, and therefore do not impede operation of the containment barrier and do not require physical access to the containment for installation; (c) fast and reliable communications from remote points to various real-time receivers, which may include computers and email, personal digital assistants, telephones, cell phones, and pagers; (d) an immediate warning when a sensor threshold is exceeded or the switch trips; (e) various conditions within or around the enclosure are monitored at sufficiently short intervals to provide sufficient time for timely communication and reaction to prevent activities that should be prevented, such as sewage spills or illegal entry.

In a preferred embodiment, the present invention provides a new method for sanitation system managers to routinely monitor and detect spills, anticipate spills, detect illegal entry into manholes, and monitor other environmental or process parameters of the sewage system like water flow, water level, gas content, and sewage content. In addition, the present invention quickly detects spills to react, thereby reducing damage to the environment, including potential contamination of water-receiving areas like streams, lakes, or oceans. In addition, the present invention can reduce costs for those sanitation system managers who have strict responsibility for spills that occur in their systems. Since the system is integrated directly into the manhole cover, no installation is required inside the manhole pipe itself and no access to the manhole is necessary, which further reduces the risk and cost of installation.

In another embodiment, the present invention may be used as a monitor for the environment surrounding an enclosure. For example, the invention may also be used to monitor street traffic, city air quality, or other environmental parameters when installed on the underside of a manhole cover. The present invention is more generally applicable as a sensor platform for a set of sensors that are directed to an area below the manhole, an area above the manhole, or both.

The foregoing and other features and advantages of the invention will become more apparent with reference to the specification, claims and accompanying drawings.

Drawings

The present invention will be better understood from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, in which:

FIG. 1 shows a schematic block diagram of one embodiment of the present invention;

FIG. 2 shows a schematic view of a typical manhole cover, wherein the device and antenna are attached directly to the manhole cover;

FIG. 3 shows a top view of the layout of the battery, electronic system, tilt sensor and communication system within the housing;

FIG. 4 shows a side view of the same layout within the housing, including the ultrasonic sensor;

FIG. 5 shows a schematic view of an antenna mounted on a manhole cover;

FIG. 6A shows a flow chart of a tilt sensor in one embodiment of the invention;

FIG. 6B shows a flow diagram of a ranging sensor in one embodiment of the invention.

Detailed Description

The present invention provides a system and method that combines a self-contained power supply, electronic system, communication system, computing capability, and sensors into a low cost, low power device that is integrated directly and mounted to an enclosure barrier, such as a manhole cover, to provide sensing and rapid early warning of problems occurring within or around the enclosure barrier. The sensors include, but are not limited to, level sensors, flow sensors, pressure sensors, distance measuring sensors, ultrasonic distance measuring detectors protected by waterproof material, gas sensors, odor sensors, temperature sensors, optical monitors like video cameras and also cameras, or infrared sensors. Further, the sensors may be physically separate from the manhole cover and mounted on the wall or floor of the manhole. A float switch, for example, having an infrared or ultrasonic device in communication with the housing, is remotely located at the bottom of the manhole. In the case of a float switch, there is no energy consumption until the switch closes as the liquid level rises, thus saving energy, such as that of a battery. Other types of sensors may be physically separate from the manhole cover and communicate with the housing through wired or wireless means within the enclosure or manhole.

The invention comprises the following steps: a communication unit providing communication from the device to a local or remote user of the system; a power supply to provide constant and reliable power to the device; a microcontroller capable of monitoring sensor inputs and controlling communications and device operation; an electronic system providing means for providing appropriate power and current to the communication device, microcontroller, and sensors; and a sensor that monitors a parameter inside or near the enclosure. The invention also provides a low-cost and low-workload installation and maintenance program. Rather than expensive and time consuming trenching at a site to provide power and communication, the present invention provides a device that is particularly low power consuming, thus enabling use of off-the-shelf small format battery packs to provide months of uninterrupted operation, and wireless communication to eliminate the need for wires. Solar cells or rechargeable batteries that are recharged from a portable device using direct electrical connections or capacitive or inductive connections can also provide energy.

The microcontroller is programmed with an instruction set that defines the operating state of the system. These defined states include, but are not limited to, initial test mode, field installation mode, normal operation mode, change reporting frequency, change sampling frequency, return to current status mode, return to historical data mode, reset to historical data mode, change location text string, change alert destination address string, reset communication channel, enable or disable alert, and send message to system user. These commands come from manual commands provided by the system user or from automated scripts running in the application server computer.

Unless otherwise indicated, the following terms have the following meanings:

the term "manhole" in its broadest sense includes, without limitation, underground vaults (e.g., sewer manholes or utility vaults), as well as any other enclosed area, above or below ground, having instruments or materials or aspects within or near the enclosed area that may be monitored.

The term "manhole cover" will be used in its broadest sense to include, without limitation, covers for underground vaults (e.g., sewer manholes or utility vaults), as well as enclosure barriers (e.g., doors or walls) for any enclosed area, above or below ground, having instruments or materials or aspects within or near the enclosed area that may be monitored.

The term "hardware packaging" is intended in its broadest sense to include, without limitation, a box and its contents, which holds some or all of the following: electronic systems, power supplies, input/output connections, communication devices, microcontrollers, sensors, and any environmental material used to stiffen, moisture-proof, and water-proof the box.

The term "application server computer" will be used in its broadest sense to include, without limitation, computers and communication systems that can receive messages from installed field units and send the messages to mail addresses, pagers, personal digital assistants, cell phones, and other notification devices of responsible parties. This server may also send commands from the system user to the installed field unit. The server also provides alert confirmation, statistics record keeping, customer management, report generation, maintenance record keeping and alerts, and security management. The application server computer may also translate the short-cut machine-to-machine messages into a format that can be understood by the system user.

The term "system user" shall be taken in its broadest sense to include, without limitation, a person who utilizes the system to sense and monitor changing environmental and process parameters within an area of interest thereof, such as a manager or operator of a sanitary facility.

The term "alert" will be used in its broadest sense to include, without limitation, a message to a system user to alert the user to an important condition in their system.

The term "installed field unit" is intended in its broadest sense to include, without limitation, a hardware enclosure mounted on an enclosure barrier like a manhole cover, which includes an antenna and all sensors required for the unit to operate in its intended manner.

The core component of the invention is the instrumented manhole cover. The instrumented manhole cover integrates power, communication, electronic, microcontroller(s), and sensors into a compact, low power, low cost package that can be easily mounted to the manhole cover, thus providing a versatile platform for the sensors to operate under or inside the manhole cover or over or outside the manhole cover. The purpose of this instrumented manhole is to convey urgent or time sensitive information about the monitored aspects of the environment near the manhole. Although the preferred embodiment discussed herein involves the monitoring of sewage, the present invention can also be applied to, but is not limited to, any monitoring application with respect to enclosed areas containing important assets or enclosed areas that may be used to monitor the environment outside the enclosed area. It is assumed that it is often difficult for this monitored area to be powered and provided with wired communications.

The present invention will be described hereinafter with reference to the accompanying drawings. Fig. 1 shows the composition of a preferred embodiment of the system. Referring to fig. 1, the major hardware components of the device are integrated into a single housing 10, the housing 10 is secured to the underside of a device such as a manhole cover, a containment cover, a door, a window, a wall, and the housing 10 comprises: a high capacity battery 11 having sufficient capacity to provide at least several months of power and which may be powered by a low voltage power converter 14 for both the digital microcontroller 12 and the two-way radio module 13 (although the power may also be provided by a standard ac line power supply or other power supply). The digital microcontroller 12 communicates with the two-way radio module 13 via a digital connection 15. The communication port for the external sensors of the hardware package 10 is provided either by a variable parameter sensor 21 such as temperature, pressure, chemical, or other that provides an analog output through an analog-to-digital (a/D) converter 16, or by a ranging and position sensor 22 or intrusion alert sensor 23 that provides a digital or switching signal, deployed directly on the digital microcontroller 12. The digital microcontroller 12 has output ports for controlling control output devices such as valves or actuators 24. The two-way radio module 13 communicates via radio waves 30 (although the communication may also be done via an over-the-ground communication line) via a radio network of global or national extent, or via an existing local radio network 40. The wireless network 40 then communicates, either by wire or wirelessly, with a central server 50 provided by the network provider and receives the parameters transmitted from an external antenna designed and operating in close proximity to the manhole cover metal surface. The central server 50 communicates with an application server computer 70 via an internet connection 60, wherein the application server computer 70 maintains a database 81 of system operations and application logic 82 for the system including a user interface 90. The user interface includes a variety of devices or methods including, but not limited to, pagers, cell phones, personal desktop computers via email, laptop computers using wireless connections, landline telephones, and audio and visual alerts. In addition, an additional antenna may be placed on the underside of the manhole cover for direct communication with the central server through the ground or in the case of an inverted manhole cover.

In an alternative embodiment, data or information from multiple manholes is compiled. The information may be compiled using a local wireless, wired, infrared, or acoustic communication system that locally adjusts the alert sent to the application server computer over a shared, wide-range communication system. The application server computer may also provide alerts that are sent to system users and may establish alert states in a database. In turn, the system user may acknowledge the alarm notifying the installed field unit or enclosure and may record the acknowledgement in the application server computer database. The database is then accessed to determine the response of the system user to the alert. In addition, an installed field unit can conserve battery power by changing the time between samples as a function of time of year, manual commands from the application server computer, or observations of physical conditions measured at intervals.

A preferred embodiment of the present invention as applied to a sewer manhole cover will be described hereinafter. The examples are not intended to limit the invention but merely as illustrative examples of the application and use of the invention.

The preferred embodiment of the present invention includes two main sensors: inclination and acceleration (accelerometer) sensors that can detect the movement of the manhole cover from a rest position, and an ultrasonic ranging device for detecting the level in the sewage manhole. In addition, optical devices, contact switches, and magnetic switches may be employed to detect whether the manhole cover is moved or opened. The power supply, communication system, electronic system, microcontroller and sensors are all combined into a small box-the "housing", which is fixed directly to the bottom of the manhole without obstructing the opening of the manhole cover or requiring access to the manhole for installation. The main components of the system are shown in fig. 2. Typical manhole covers 100 are made of steel or cast iron and if they are "traffic-compliant", that is, capable of supporting road vehicles on the road, they are heavy and rugged and include support vanes 120 at the bottom of the cover. The housing 110 is mounted to the bottom of the manhole by a mounting bracket screwed into the manhole cover, or directly mounted to the manhole cover by a screw, or bonded to the manhole cover by a traffic-compatible epoxy. The housing 110 is small enough to be protected by the manhole ribs 120 from crushing or protruding from the manhole ribs. The only external connection to the housing is antenna 130, which is connected through a small hole drilled in the manhole cover. An antenna cable 140 connects the housing 110 to an external antenna 130 that is capable of transmitting the parameters to a communication device, such as a cell phone, pager, personal digital assistant, or personal computer.

Fig. 3 shows a top view of a preferred schematic layout of the composition of the housing 200. All of the components of the hardware are encapsulated within NEMA-4 (e.g., manufactured by Hoffman, Inc. of Annoca, Minn.) or a higher-level encapsulation 210 that is rugged and waterproof and environmentally sealed. In fig. 3, the high capacity battery 220 is selected to maximize the amp-hour (a-H) capacity of the battery at a certain volume. A typical battery that can be used in the preferred embodiment of the present invention is a disposable lithium battery. The 6 volt supply, e.g., 10A-H, can be provided by existing off-the-shelf products (e.g., Duracell)^TMDuracell of a company^TMLithium Model 245) were constructed in parallel. A typical rated amperage for the entire target enclosure 200 is 2 milliamps (mA), with a battery pack capacity of approximately 10A-H being sufficient to provide power for uninterrupted operation for more than 6 months. A typical alkaline cell is an alternative primary cell type. Although primary battery 220 is a power source of choice for low cost, small package volume applications, the present invention is not limited to this type of power source. It may also be used as an alternative if an external ac or dc power source is indeed desirable, or a rechargeable battery (e.g. a nickel metal hydride battery) may be used in connection with a low current trickle charge from an adapter like a solar cell to charge the battery during the day.

The high capacity battery 220 in fig. 3 provides power to both the digital microprocessor 240 and the two-way digital radio module 250 in the hardware package through the low voltage power converter 260. Typically, battery 220 is 6 volts, while microprocessor 240 and two-way radio 250 operate at a lower voltage. The operating voltage is minimized and it is possible to save energyThe hardware may enter a "sleep" mode at this time. In the preferred embodiment, microprocessor 240 is (parallelax)^TMCompany) Basic Stamp 2pe, and the two-way digital radio module 250 is (Advantra)^TMCompany) Karli refex paging unit. A coaxial connector cable 270 is connected to the Karli unit 250, this connector leading to an external antenna mounted on the manhole cover. The Karli unit 250 has the capability of measuring ambient temperature and voltage input to the pager, thus providing additional sensing capability that can be reported and stored by the microprocessor.

Low voltage power converter 260, Karli two-way pager 250, and microprocessor 240 are all mounted on a single Printed Circuit (PC) board 230. A tilt and acceleration sensor 280 is also mounted on the PC board. The tilt and acceleration sensor 280 acts as a switch that is either open (normal state) or closed (when the sensor is tilted or accelerated). The state of the tilt and acceleration sensor 280 is typically checked once per second, but this frequency is variable and may depend on the particular application. If the state of the tilt and acceleration sensor 280 is found to be closed, a signal is sent to the wireless network through the pager 250 and the time and date of this closed state is saved in the microprocessor 240.

Fig. 4 shows a side view of the housing 300, which is similar to fig. 3 showing a top view. A battery 310 powers the housing. Power is supplied to the microprocessor 330 and the two-way pager 340 on the electronics board 320, as well as the ultrasonic ranging sensor 350. An example of a low cost ultrasonic ranging sensor is (parallelax)^TMCompany) PING ultrasonic sensors that provide range information up to a maximum of about 11 feet, which covers a significant portion of the depth of the manhole. A water proof (proof) or water resistant (water resistant) cover 360 that does not adversely affect the performance of the ultrasonic sensor 350 is placed in front of the ultrasonic sensor. At intervals of about once every ten minutes, the ultrasonic sensor 350 is turned on and the distance is measured using the ultrasonic waves 370. If the distance result obtained is different from the conventional value, the signal is onAnd sent to the wireless network via pager 340.

Figure 5 shows an antenna mounted on a manhole cover 400 in an embodiment of the invention. A small hole is drilled in the manhole cover and a coaxial cable 410 connected directly to the pager in the housing comes from the underside of the manhole cover and connects to a low profile strip antenna 420. The strip antenna 420 protrudes from the upper surface of the manhole cover by a dielectric spacer 430, typically 1mm to 5mm thick. The baffle, strip antenna, and connecting wires are collectively encased in a traffic-compatible epoxy 440 of the type used to affix reflectors to road surfaces.

In a preferred embodiment of the invention, the radio signal is sent through a commercial two-way paging network known as motorola^TMReFLEX from Inc. The ReFLEX network provides a secure, stable two-way communication method-using signals with frequencies in the range of 900MHz to 1000 MHz. The ReFLEX network includes spatially distributed (geographicaldistributed) transceivers that communicate not only over the air with installed field units, but also over wired connections with the internet. This allows communications from any internet connected system (e.g., application server computer) to reliably communicate with installed field units. The ReFLEX network protocol is approved by the American Association of Paging Carriers (American Association of Paging Carriers). ReFLEX communications have the advantages of wide spatial distribution, generally prioritized cellular coverage, and low monthly cost. The ReFLEX network does not require complex software to support both installed field units and application server computers. The ReFLEX system is designed to deliver compact digital messages that define specific status information, such as security alarms or excessive water levels. The information may be transmitted and encoded as one or two bytes of information. This information is marked with a unique identifying installed unit code so no further identification is required. The application server reformats the compact one or two byte information into a message that is more informative to the system user. Hexadecimal "C5" may be interpreted as a "security entry alert",while the unique installed unit code "345123" might be interpreted as "5400 blocks of main street". Such combined messages may be sent as text messages via e-mail or Short Message Service (SMS) to a cell phone, pager, or a computer based supervisory control and data acquisition (SCADA) system being monitored by a system user. It is an object to use the ReFLEX network to quickly notify responsible parties in a continuous, spatially independent manner.

In a preferred embodiment of the present invention, which is but one possible configuration and application of the present invention, communication occurs in one of the following ways by way of example and not by way of limitation. First, as a default state, each installed hardware package on a given manhole cover sends a status message to the application server computer twice a day. The purpose of this message is to assure the user that each installed hardware package and supported wireless communication system is functioning properly. Referring to fig. 1, if the expected message from the installed housing 10 does not occur in a timely manner, a maintenance alert is sent from the application server computer 70 to the system user indicating a potential problem with either the communication network to the site or the facility at the site. A second purpose of this message is to send nominal operating parameters including, but not limited to, the temperature history at the point, the wireless signal level history at the point, and the battery voltage or input voltage level. Second, the system user may send a message to the installed hardware package, essentially a response that requires it to be sent to the system user that the installed hardware is functioning properly. Third, the system user may request that the installed hardware package send back data stored in the microprocessor memory, including but not limited to temperature history, battery level, wireless signal level, alarm type and time, and current status of the sensor. Fourth, the system user may send messages to the installation site to change operating parameters including, but not limited to, warning thresholds, reporting frequencies, interrogation sensor frequencies, nominal manhole depths, addresses of maintenance messages and alarms, and addresses of installed field units. Fifth, the installed field units may send self-generated maintenance or alarm messages to the wireless network based on previous conditions. An example of how maintenance messages and alarms may be sent is discussed below.

By way of example, two types of sensors are used in the preferred embodiment of the present invention: a tilt/acceleration sensor for warning when the manhole cover is tilted or moved from a rest position, and an ultrasonic ranging detector for detecting the water level in the manhole. The following procedures are illustrative-they may also be handled in different ways and the following description is not intended to limit the scope of the invention. FIG. 6A shows a flow chart and logic for sending an alarm based on the state of the tilt sensor. The tilt sensor is a binary device that acts as a switch. When the tilt sensor is in a normal condition, it is on. It is closed when it is tilted or accelerated. The state of the tilt sensor is read 500. If the tilt sensor is on 510, the microcontroller waits for one second 530 (although any time interval greater than the microprocessor clock period may be used) and reads the tilt sensor again. The frequency is high enough to ensure that the tilt sensor will capture this change in condition when the manhole cover is moved. If the tilt sensor reads closed 520, the time and date of the event is recorded in the microcontroller and an alarm is sent to the paging network system to the system user according to a pre-agreed protocol including, for example, law enforcement in the event of an illegal entry. One minute later 531 (but this time period may be longer or shorter) the tilt sensor is read again and the program starts over. FIG. 6B shows a flow chart for sending an alarm based on a reading of an ultrasonic ranging sensor. Since the ultrasonic sensor consumes power, it is turned on only when it is used. This is shown as 540 in fig. 6B. Once the ultrasonic sensor is turned on, it immediately proceeds to a ranging operation 550. There are at least four ranging results: the result is "in range" 551, meaning that, for example, the measurement corresponds to an expected distance value to the bottom of the unsubmerged manhole stored in the microprocessor; the result is "low" 552, meaning that the distance is shorter than expected, indicating a possible flooding condition; or the result is "high" 553 or "maximum range" 554, both of which imply that the ultrasonic sensor is not operating properly and requires maintenance. In the case of "in range" 551, the ultrasonic sensor is turned off 560 and another measurement is taken after 10 minutes 570 (although this period may be any period greater than the microprocessor cycle clock) and the procedure repeats. This is normal and expected. In the case of a "low" measurement 552, a repeat measurement 580 is made to check this "low" measurement and reduce the occurrence of false measurement events. If the measurement returns a low measurement 582, then the alert is sent to the network 590 according to a pre-agreed protocol for delivery to system users, including but not limited to, e.g., system administrator's pagers and cell phones, and system user's emails. If the repeat measurement 580 returns "in range," then it is assumed that the previous measurement was in error, the ultrasonic sensor is turned off 560, the nominal 10 minute wait period repeats 570, and the process begins anew. This repeated measurement process can occur any number of times without limitation to reduce the likelihood of erroneous measurements occurring and to track the rising water of the manhole as a function of time. In the event that a "high" measurement 553, or a "maximum range" measurement 554, is present, suggesting an increased nominal range that is not likely to occur, a maintenance message is sent to the network 555 and thus to the system user according to a pre-agreed protocol.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be readily apparent to those of ordinary skill in the art in light of the disclosure that certain changes and modifications may be made thereto without departing from the spirit and scope of the appended claims.

Claims (23)

1. A remote sensing system, comprising:

a housing directly connected to a manhole cover, the housing having a communication port for a sensor that monitors a parameter around the housing;

a microcontroller inside the housing for communicating the parameter to a radio module of a two-way radio over a digital connection;

a connector cable connected to a radio module of the two-way radio, the connector cable leading to an external antenna for transmitting the parameter to a communication device;

a power supply device for supplying power to the housing; and

at least one sensor on or off the manhole cover for sensing one or more parameters selected from the group consisting of street traffic, air quality, environmental parameters, or a combination thereof.

2. A remote sensing system, comprising:

a housing connected to an underside of a manhole cover, the housing having a communication port for a sensor that monitors a parameter around the housing;

a microcontroller located within the housing for communicating the parameter to a radio module of a two-way radio over a digital connection;

a connector cable connected to the two-way radio module, the connector cable leading to an external antenna for sending the parameters to a communication device to provide fast and reliable communication from the manhole cover to a real-time receiver;

an alarm located within the housing, the alarm communicating with the communication device when a predetermined threshold of the sensor is exceeded; and

a battery for powering the housing,

wherein the microcontroller sends a self-generated maintenance message automatically or in response to an external request.

3. The system of claim 2, wherein at least one sensor is selected from the group consisting of a tilt sensor, an acceleration sensor, and a ranging sensor.

4. The system of claim 2, wherein the parameter is an environmental or procedural parameter.

5. The system of claim 2, wherein the communication device is selected from the group consisting of a cell phone, a pager, a personal digital assistant, and a personal computer.

6. The system of claim 2, further comprising a central server for receiving the parameters transmitted from the external antenna, the central server in communication with an application server computer in which the parameters are stored.

7. The system of claim 6, further comprising an additional antenna located on the underside of the manhole cover, the additional antenna being used to communicate directly with the central server through the ground.

8. The system of claim 2, wherein the housing is mounted on a device selected from the group consisting of an enclosure cover, a door, a window, a wall, and a manhole cover.

9. The system of claim 2, wherein at least one sensor is selected from the group consisting of a level sensor, a flow sensor, a pressure sensor, a ranging sensor, an ultrasonic ranging sensor, a gas sensor, a humidity sensor, a temperature sensor, and an optical sensor.

10. The system of claim 2, wherein at least one sensor monitors whether the manhole cover is moved and the alarm is triggered to notify a user if the manhole cover is moved.

11. The system of claim 10, wherein the alarm alerts a user if there is an entry into the manhole cover.

12. The system of claim 10, wherein the housing is mounted on an existing manhole cover.

13. The system of claim 10, further comprising an output port on the microcontroller to control the output device.

14. The system of claim 13, wherein the output device is selected from the group consisting of a valve and an actuator.

15. The system of claim 10, further comprising a ranging detector to measure the height of the water in the manhole.

16. The system of claim 15, wherein if the range detector detects that the level of the water in the manhole is above a predetermined level, an alarm is sent to a user informing the user of a possible dump at the manhole cover.

17. The system of claim 16, wherein the predetermined level is set in the microcontroller.

18. The system of claim 2, wherein the microcontroller is programmed with an instruction set defining an operating state, and the operating state is selected from the group consisting of an initial test mode, a field installation mode, a normal operating mode, a change reporting frequency, a change sampling frequency, a return historical data mode, a reset historical data mode, a change location text string, a change alert destination address string, a reset communication channel, an enable alert, a disable alert, and a send message to a system user.

19. The system of claim 2, wherein at least one sensor is physically separate from the manhole cover and mounted on a wall or bottom of the manhole.

20. The system of claim 2, further comprising:

a digital-to-analog converter for communicating with the analog external sensor through the at least one communication port.

21. The system of claim 2, wherein the first and second sensors are arranged in a single unit,

wherein the microcontroller, the low voltage power converter, the radio module of the two-way radio and the tilt and acceleration sensors are mounted on a single printed circuit board.

22. The system of claim 2, comprising:

a ranging detector to measure the height of the water in the manhole, the ranging detector providing at least an "in-range" measurement, a "low" measurement, a "high" measurement, and a "maximum-range" measurement.

23. A remote sensing system, comprising:

a housing connected to an underside of a manhole cover, the housing having a communication port for a sensor that monitors a parameter around the housing;

a microcontroller located within the housing for communicating the parameter to a radio module of a two-way radio over a digital connection;

a connector cable connected to the two-way radio module, the connector cable leading to an external antenna for sending the parameters to a communication device to provide fast and reliable communication from the manhole cover to a real-time receiver;

an alarm located within the housing, the alarm communicating with the communication device when a predetermined threshold of the sensor is exceeded;

a battery to power the housing; and

a tilt sensor in a first state under normal conditions, wherein

If the tilt sensor is read in the first state, the microcontroller waits for a time interval greater than the clock period of the microprocessor, then reads the tilt sensor again, and

if the tilt sensor is read in the second state, it is determined that the sensed first state has changed, so that the alarm communicates with the communication means, and the tilt sensor is read again and the work process of the tilt sensor is restarted.