JPH0334096A - Portable radiation data acquisition system - Google Patents

Abstract

PURPOSE: To make a data acquisition system small-sized and portable by using a microprocessor, whose input one or more detectors are connected to, to collect and store various detected environment information. CONSTITUTION: After a status line 72 is reset, a CPU 56 checkes the signal level from a first detector 14; and if this signal exceeds a predeterminate threshold, the CPU 56 checks the signal from a second detector 16. If this signal exceeds the threshold also, the CPU 56 sets the status line to the high level indicating a fire. Then, the CPU 56 is returned to a branch for test of signal levels of detectors 14 and 16; and when the signal of one of detectors 14 and 16 is reduced to the threshold or lower, the CPU 56 is immediately returned to the start and resets the status line 72. Since the system is operated with respect to data supplied to the input and data is stored and information for the output is generated in this manner, the small-sized portable data acquisition system is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radiation data acquisition system, and particularly to a portable radiation data acquisition system that can be used as a fire sensor.

BACKGROUND OF THE INVENTION Data acquisition systems are used to detect and record ambient environmental data such as radiation, light, and temperature data. Additionally, the data acquisition system can be used to collect and record information from other sensors such as pressure, acceleration, flow rate, etc. Traditional radiation data acquisition systems are generally bulky and do not perform well in harsh environments. These conventional systems typically include a sensor placed at the desired location to be sensed, a wire connecting the sensor to an amplifier, and a wire connecting the amplifier to a recording device. Such a configuration would require a system that requires considerable space and regulated power.

These drawbacks limit the use of conventional radiology data acquisition systems. For example, when a conventional radiological data acquisition system is placed in a vehicle, the system requires a person to monitor it and cannot operate properly because it cannot withstand the harsh operating environment of an operating vehicle. It may not be possible. Another drawback is that such systems cannot be used in certain limited spaces due to their large volume. Even if sufficient space were available, the wiring required to connect the various components would interfere with proper operation.

Another disadvantage of conventional radiation data acquisition systems is that they require frequent inspection and cannot be left unattended for long periods of time.

[Problems to be Solved by the Invention] Therefore, it is desired to provide a radiation data acquisition system that is small and portable and can be operated in a limited space. It is also desired to provide a radiation data acquisition system that can be left unattended and operated for long periods of time.

What is further desired is a radiation data acquisition system that can withstand harsh environments and is uninterrupted by the normal operation of surrounding equipment.

A fire sensor is a device that detects radiation information from one or more sensors, processes this information, and determines whether it indicates a fire. Microprocessor-controlled fire sensors have been developed to reduce system size and purify sensor data to improve fire detection capabilities while avoiding false detections (e.g., U.S. Pat. No. 4.879.15).
6 and U.S. Pat. No. 4,769,775). However, although such systems can detect the presence of a fire, once a fire has been identified, much effort is devoted to determining the cause of the fire. Fire sensors simply signal that a fire is present; they do not provide any information regarding the cause of the fire. Therefore, it would be desirable to provide a fire sensor that can provide information useful in determining the cause of a detected fire.

[Means for Solving the Problems] The present invention relates to a portable radiation data acquisition system that can collect and store data from sensors. Sensors may be placed at single or multiple locations and may detect radiation, light, or temperature, and/or pressure,
Sensing environmental information such as acceleration, other forms of information such as flow rate, etc. Due to its small size (in the example contained in the palm of a person), the sensor of the invention can be placed in difficult-to-access locations. It can also be operated unchecked for long periods of time without being disturbed by surrounding vehicles or equipment.

A data acquisition system according to the invention uses a microprocessor with one or more detectors connected to its input. The detector signal is amplified and fed into an analog-to-digital converter before being sent to the microprocessor's CPU. Microprocessors include read-only memory, random access memory, and erasable programmable read-only memory. Programs for the CPU are contained partially in both read-only memory and erasable programmable read-only memory.

Subroutines are typically contained in read-only memory. The data acquisition system can be programmed with erasable programmable read-only memory to receive and store detected data at predetermined time intervals. The frequency of accumulation of detected data depends on the application and varies over a wide range.

In one embodiment, the portable data acquisition system is configured for use as a fire sensor. In this embodiment, the detectors are selected and the detector signals are processed to provide the desired information indicative of a fire. In this way, the portable radiation data acquisition system of the present invention not only detects fires, but also records environmental parameters leading up to the fire. This information is particularly useful in investigating the cause of a fire.

Various advantages of the invention will become apparent to those skilled in the art from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings.

Embodiment One embodiment of the portable data acquisition system of the present invention is shown in FIG. The portable data acquisition system IO is controlled by a microprocessor 12 as shown. The microprocessor 12 is, for example, a Motorola MC8BHC11 type. In this embodiment, microprocessor 12 is connected to four detectors. The first and second radiation detectors 14 and IB are each capable of detecting radiation of a wavelength in a specific spectral band. These detectors 14 and 1B can also generate analog signals proportional to the detected energy. For example, the detection of two separate wavelength ranges is
and by using identical detectors as the second detectors 14 and 1B and placing appropriate filters 18 and 20 in front of each detector 14 and 1B.

Each filter 18 and 20 removes all wavelengths except the desired wavelength of energy. Alternatively, different types of detectors with different inherent spectral sensitivities can be used.

Additionally, a temperature sensor 22 is also connected to an input of the microprocessor 12. Temperature sensor 22 can generate an analog signal that is proportional to ambient temperature.

The data acquisition system IO may also receive signals from a fourth detection 3 (not shown) along external sensor line 24. This external fourth detector may be located at a remote location from data acquisition system 10. Depending on the application, external sensors may sense other types of information such as pressure, acceleration, flow rate, etc., and may also send analog signals to external sensor line 24.

Since the signal along external sensor line 24 may not be of sufficient strength to be processed by microprocessor 12, the signal is amplified by amplifier 26, the output of which is connected to input line 28 of microprocessor 12. .

Similarly, the output of the first detector 14 is connected by a conductor 30 to an amplifier 32 which is connected to an input line 34 of the microprocessor 12. The output of the second detector lO is connected by a conductor 3B to an amplifier 38, the output of which is connected to an input line 40 of the microprocessor 12. Finally, the output of the temperature sensor 22 is
is connected to an amplifier 44 whose output is connected to an input line 46 of microprocessor 12.

Analog signals from each detector are processed by a microprocessor 12.
must be digitized in order to be processed.

Hence a series of analog-to-digital converters 41! ,
50, 52, 54 respectively four input lines 34, 4
Connected to 0.46.28. These analog
The digital signals generated by digital converters 48.50.52.54 are sent to CPU 5B for processing.

As shown in FIG. 1, microprocessor 12 also includes a program line 58, which is used to place the CPU into a program mode for loading programs into microprocessor 12, as described in detail below. Programs for the CPU 58 are stored in read-only memory (
60 (hereinafter referred to as ROM) and electrically erasable programmable read-only memory (hereinafter referred to as EEFROM) 82. Typically ROM8
0 is programmed by the communication program routine and E
EPROM 62 contains program routines. R
EEP for use of subroutines stored in OM60
The program space required in ROM is kept to a minimum. Additionally, random access memory (RAM) 64 is provided for storing both data and program information.

The serial communication interface 6B is the microprocessor 2
The CPU 5B inputs and searches data. Serial communication interface 66 is connected to status and data line 88 and interrogation and data line 70.

A serial communication interface 6G is also connected to the CPU 5B.

When program line 58 is held low, C
PU56 is placed under the control of the program in ROM80,
Serial communication interface 6B may be used to input and retrieve data from CPU 56. Furthermore, with program line 58 low, a program can be loaded into EPROM 62 by an industry standard RS-232 port from an external source connected to pre-state data line B8. A status line 72 may also be provided and programmed to provide an output to an external signal or energizing device. Power to the data acquisition system IO is provided by a power supply 74, which may be an internal battery or an external power supply may be provided. When the program line 58 is not set to a low level (ground potential), the CPU 5B stores the EEPROM 8
It is operated under program control of 2.

The program in EEPROM 82 may also use subprograms in ROM 60 to save memory locations in EEPROM 82 for data storage.

Referring to FIG. 2, a program flow diagram for data acquisition system IO is shown. At the start, the program monitors the interrogation line 70 and if this line 70 is not at a high level, the program continues in a short loop. This interrogation line 70 can be coupled to the master switch of the vehicle in which the data acquisition system IO is installed. In such a case, the relevant data is only the data that occurs when the master switch is on. If the interrogation line 70 is high level, the program causes the CPU to send the analog-to-digital converter 48
, 50.52.54. After the data of analog to digital converter 48.50.52.54 is read, the data is stored in EEPROMI 36.

Although not shown in FIG. 2, it should be appreciated that the accumulated data can be compared to previous data to determine whether this data is high level. If the new data is of a higher level, E E P
It is stored as a peak in one location in the ROM and replaced by new data when it exceeds this level. The time of this peak can also be accumulated.

Also at this point, the new data is averaged with the previous data and the average is accumulated. The flow diagram in FIG. 2 shows that the sample requires 100 milliseconds. This time can be varied to almost any value, for example every 100 milliseconds, or in extreme cases every year.

Referring to FIG. 3, a flow diagram of data acquisition system 10 programmed for use as a fire sensor is shown. At the start of the program, status line 72 is pulled low (reset). This line is used as a fire monitoring output signal line, and it will be at a high level during a fire. After status line 72 is reset (switched off), CPU 5B checks the signal level from first detector 14. If this signal exceeds a predetermined threshold, the CPU
Check the signal from the second detector 18. If this signal also exceeds the threshold, CPU 56 drives the status line high indicating a fire. From there the CPU is sent back to the branch that tests the signal level from the detector. As soon as one of the detectors falls below its threshold, the CPU returns to start and resets the status line 72.

The program of FIG. 3 is for a very simple fire sensor that only requires simultaneous signals of sufficient amplitude from two detectors sensitive to different wavelengths. U.S. Patent No. 4.6
No. 91.196, No. 4.639.598, No. 4,68
No. 5,390, No. 4. (No. 179,158, No. 4,70
No. 9.775, No. 4.847.776, No. 4,472
．． Even more complex fire sensor programs such as those described in No. 715, No. 4.469.944 can be used. The more complex signal processing described in some of the above patent specifications requires even more circuitry than shown here.

Data acquisition system 10 is used both as a fire detector as described with reference to FIGS. 1 and 3 and as data acquisition system 10 as described with simultaneous reference to FIGS. be able to. This is accomplished by programming the data acquisition system IO to perform both the data storage function shown in FIG. 2 as well as the fire detection function shown in FIG. It is useful to have a fire output that latches the memory 80.62.84 so that the data stored therein is not lost after a fire. Therefore, if a fire is detected, it is possible to analyze the condition of the detector in the period preceding the fire. In this way the history of events leading to a fire is recorded. It is useful to know what changes occur in detected parameters such as radiation, light, temperature, pressure, acceleration, etc. that precede a fire. This information is very useful in diagnosing the cause of a fire and saves a great deal of time for post-fire investigations.

From the foregoing description, it can be appreciated that the present invention provides a data acquisition system that is portable, occupies a small volume, and can be left in harsh environments for long periods of time without interference from deployed equipment or vehicles. Will.

Another advantage is that through the use of EEPROM B2 no power is required for the data acquisition system 10 to retain the recorded data, so the data acquisition system IO can be removed from its location for data retrieval. Can be sent to another location.

Those skilled in the art will recognize that other advantages may be derived from the invention and that modifications may be made without departing from the scope of the invention from a study of this specification and drawings and the claims. It will be possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the portable data acquisition system of the present invention. FIG. 2 is a flow diagram of a program for a portable data acquisition system for storing data. FIG. 3 is a flow diagram of a program for a portable data acquisition iq system used in a fire detection system. to...data acquisition system, 12...microprocessor.

Claims (10)

[Claims] (1) one or more detection means for detecting environmental information and generating a detection signal in response to the detected environmental information, a central processor unit (CPU), a read-only memory, a random access memory, and a programmable a read-only memory; microprocessor means operating on and accumulating data supplied to its input and producing information thereon at its output; and after processing by said microprocessor means producing an output of said environmental information. first coupling means for coupling the detection means output to the input of the microprocessor means; and second coupling means for coupling the output of the microprocessor means to the output means. A system that records environmental information. (2) At least one of the read-only memory or the programmable read-only memory has a program for the CPU to receive and store environmental information sensed by the detection means during a predetermined period. The system according to item 1. (3) one or more detection means for detecting environmental information and generating a detection signal in response to the detected environmental information, a central processor unit (CPU), a read-only memory, a random access memory, and a programmable microprocessor means comprising a read-only memory, analyzing and accumulating data supplied to its input, and generating information corresponding thereto at its output; and output means for outputting a signal in accordance with the environmental information; a first coupling means for coupling an output of the detection means to an input of the microprocessor means; and a second coupling means for coupling the output of the microprocessor means to an output means, the microprocessor means being configured so that the analysis data is A fire sensor system, characterized in that it is programmed to send a signal to said output means when indicating a fire. (4) The one or more detection means includes a first detection means for detecting energy having a wavelength in a first spectral band and one or more additional detection means for detecting energy having a wavelength in a different second spectral band. 4. The system according to claim 3, further comprising detecting means. (5) The system according to claim 3, wherein said first coupling means further comprises amplification means and analog-to-digital conversion means. 6. The system of claim 3, wherein said second coupling means comprises serial communication interface means. 7. The system of claim 3, wherein said programmable read-only memory comprises electrically erasable programmable read-only memory. (8) At least one of the read-only memory or the programmable read-only memory stores a program for the CPU to receive and store environmental information sensed by the detection means during a predetermined period; 4. The system of claim 3, whereby changes in environmental information preceding a fire are accumulated. (9) one or more detection means for detecting environmental information and generating a detection signal in accordance with the detected environmental information; means for accumulating the detection signal at periodic time intervals; and analyzing the detection signal. means for determining whether the detected environmental information is indicative of a fire; and means for transmitting an output signal when the means for analyzing determines that a fire is present, the method comprising: means for determining whether the detected environmental information is indicative of a fire; A fire sensor system, characterized in that the accumulated detection signals are made available for determining the cause of a fire. (10) Periodically detecting environmental information by one or more detectors that generate a detection signal in response to the detected environmental information, storing the information in an information storage means at periodic time intervals, and storing the information at periodic time intervals; determining whether the signal is indicative of a fire by analyzing the environmental information obtained, and generating a signal to the output means when the analysis indicates the presence of a fire, preceding the presence of a fire. A method for determining the cause of a fire, comprising the step of analyzing information accumulated during a periodic period to assist in determining the cause of the fire.