-
2006-10-17
11/234,907
2005-09-26
US 7,124,041 B1
2006-10-17
-
-
Edward Raymond
2025-09-26
Certain exemplary embodiments can comprise a method for detecting a circuit fault, comprising: for a sensor coupleable to an input circuit, the sensor characterized by an output signal operating voltage range: automatically causing the sensor to be electrically disconnected from the input circuit; automatically causing an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor; automatically causing the invalid sensor voltage to be removed from the input circuit; automatically causing the sensor to be electrically connected to the input circuit; and, in the event that an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically providing notification that a circuit fault is associated with the sensor.
Get notified when new applications in this technology area are published.
G06F15/00 IPC
Digital computers in general ; Data processing equipment in general
This application claims priority to, and incorporates by reference herein in its entirety, now abandoned U.S. Provisional Patent Application Ser. No. 60/613,440, filed 27 Sep. 2004.
Measuring systems often comprise and/or interface with numerous sensors, several and/or each of which can substantially simultaneously output, provide, and/or transmit a signal indicative of a value of a detected and/or measured physical parameter, such as a position, temperature, pressure, flowrate, voltage, current, etc. Such sensor signals can be received by a receiver such as a data logger, and embedded system, a microcontroller, and/or an automated monitoring and/or control system, such as a programmable logic controller (PLC). To manage a potentially large number of incoming sensor signals, such measuring systems and/or receivers can utilize multiplexing (and/or de-multiplexing), such as time-division multiplexing, frequency-division multiplexing, and/or wave-division multiplexing, etc., to extract each sensor signal from its respective time slice, frequency, wavelength, channel, sub-channel, etc.
From the receiver's perspective, there is a possibility that a received sensor signal indicates a parameter value that is inaccurate and/or other than what was output and/or transmitted, potentially even if the received value is within a range of expected, reasonable, and/or valid values for that sensor's parameter. Such anomalies can occur because of a fault, such as a break in a wire or conductor, corrosion-generated high resistance in a conductor and/or junction, an induced voltage and/or current due to a neighboring conductor and/or magnetic field, multiple sensors connected to a conductor intended for a single sensor, ground faults due to failures in conductor insulation, arc faults, poor insulation, poor shielding, etc. Thus, it can be desirable to test the sensor circuit to detect if a fault is occurring.
To detect certain faults, a measuring system can utilize a stimulus circuit that can apply a stimulus, bias, and/or voltage to the sensor circuit, either continuously or in a pulsed manner, which can force the received and/or input sensor signal to a known âinvalidâ state and/or value if a fault occurs. The application of a constant stimulus, however, can add a constant error and/or distortion to the received signal. The application of a pulsed stimulus can cause time-varying perturbations to the received signal, which can corrupt logged data and/or make data analysis more difficult. Even if the perturbations are allowed to dissipate, the pulsed stimulus can add considerable additional time to the multiplexed scan time for each channel and/or sub-channel. Hence, improved systems, methods, and/or devices for detecting circuit faults, such as sensor circuit faults, is disclosed.
Certain exemplary embodiments can comprise a method for detecting one or more circuit faults. The method can utilize at least one stimulus and/or input circuit that is coupled to and/or controlled by a microcontroller, which can report to a monitoring, supervisory, and/or SCADA system, such as a PLC. Any number of multiplexed sensor signals can be provided to the input circuit, each sensor characterized by an expected and/or valid output signal operating voltage range. For each sensor coupled to the input circuit, via instructions stored in the microcontroller, the microcontroller can: automatically cause: the sensor to be electrically disconnected from the input circuit; an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor; the invalid sensor voltage to be removed from the input circuit; the sensor to be electrically connected to the input circuit; and, if an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically provide notification that a circuit fault is associated with the sensor.
A wide variety of potential embodiments will be more readily understood through the following detailed description of certain exemplary embodiments, with reference to the accompanying exemplary drawings in which:
FIG. 1 is a schematic of an exemplary embodiment of a system 1000;
FIG. 2 is a block diagram of an exemplary embodiment of an information device 2000; and
FIG. 3 is a flowchart of an exemplary embodiment of a method 3000.
When the following terms are used substantively herein, the accompanying definitions apply:
Certain exemplary embodiments can comprise a method for detecting a circuit fault, comprising: for a sensor coupleable to an input circuit, the sensor characterized by an output signal operating voltage range: automatically causing the sensor to be electrically disconnected from the input circuit; automatically causing an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor; automatically causing the invalid sensor voltage to be removed from the input circuit; automatically causing the sensor to be electrically connected to the input circuit; and, in the event that an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically providing notification that a circuit fault is associated with the sensor.
FIG. 1 is a side view of an exemplary embodiment of a system 1000, which can comprise any number of sensors 1100, such as a position sensor 1120, a thermocouple 1140, and/or an RTD 1160. Note that a sensor can have any number of conductors attached thereto.
Electrically coupled and/or coupleable to one or more sensors 1100, such as via multiplexed sensor circuit(s) 1180, can be an input circuit 1200 and/or a data logger 1300. Input circuit 1200 can comprise a capacitor 1210, which can help hold a voltage provide by and/or to sensor 1100 and/or sensor circuit 1180. A switch and/or channel selector 1220, can be used to isolate the input circuit from one or more sensors 1100 and/or sensor circuits 1180, and/or to select a particular sensor 1100 and/or sensor circuit 1180 for testing. Resistors 1232, 1234 can be used to match impedance and/or prevent a large applied voltage from harming input circuit 1200. Capacitor 1240 can help hold a voltage applied to input circuit 1200, whether by a sensor 1100, a sensor circuit 1180, or a stimulus circuit 1500. An operational amplifier 1250 can determine a differential voltage provided to input circuit 1200, which can be indicative of a received signal value and/or an input circuit voltage value. An analog-to-digital converter 1260 can convert an analog received signal value and/or input circuit voltage value to a digital value. A microcontroller 1400 can receive the digital value, interpret that value, and/or notify a communicatively coupled monitoring, supervisory, and/or SCADA system 1600, such as a PLC, of its interpretation of the received signal value and/or the status of the sensor 1100, sensor circuit 1180, and/or received signal value.
Any number of multiplexed sensor signals can be provided to input circuit 1200. Each sensor 1100 can be characterized by an expected and/or valid output signal operating voltage range. For example, for a pressure sensor, an output signal voltage, received signal voltage, and/or input circuit voltage ranging from about 1.5 volts to about 3.5 volts might be considered âvalidâ and a voltage value below 1.5 volts or above 3.5 volts might be considered âinvalidâ and/or consistent with a sensor fault and/or a circuit fault.
For each sensor 1100 coupled to the input circuit 1200, via instructions stored in microcontroller 1400 and/or coupled thereto, microcontroller 1400 can:
repeatedly and/or automatically cause any of the following activities:
Thus, if there is a substantial circuit fault, the invalid voltage applied to input circuit 1200 likely will not quickly dissipate upon re-connection of sensor 1100 and/or sensor circuit 1180, and instead will likely linger for sufficient time for microcontroller 1400 to recognize that a circuit fault exists. This can hold particularly true for circuit faults such as wire breaks, and also can be true for other types of circuit vaults. âPartialâ circuit faults, such as high resistance, can be indicated by a measured voltage that slowly dissipates once the stimulus circuit is disconnected and the sensor circuit reconnected. Intermittent circuit faults can be indicated by a difference between the stability of the measured voltage when microcontroller 1400 is testing the received signal versus simply detecting the received sensor signal. Similar analysis of the measured voltage, received signal voltage, input circuit voltage, etc., and/or time-varying changes therein, can yield additional insights into the condition, health, and/or status of sensors 1100 and/or sensor circuits 1180.
Microcontroller 1400 can be programmed via monitoring system 1600 and/or via a human/machine interface coupled to microcontroller 1400. For example, microcontroller 1400 can comprise a flash ROM, such as an EEPROM, via which instructions created and/or stored on monitoring system 1600 are transferred to microcontroller 1400. Those instructions can comprise instructions for receiving and/or storing an identity of one or more sensors 1100 and receiving and/or storing a corresponding output signal operating voltage range for each sensor 1100. Thus, for example, via its instructions, microcontroller 1400 can âknowâ that a valid operating voltage range for pressure sensor P101 is 1.5 volts to 3.5 volts.
Via further instructions, microcontroller 1400 can measure the input circuit voltage, cause the output signal voltage to be recorded, and/or transmit the notification to monitoring system 1600.
FIG. 2 is a block diagram of an exemplary embodiment of an information device 2000, which in certain operative embodiments can comprise, for example, microcontroller 1400 and/or monitoring system 1600 of FIG. 1. Information device 2000 can comprise any of numerous components, such as for example, one or more network interfaces 2100, one or more processors 2200, one or more memories 2300 containing instructions 2400, one or more input/output (I/O) devices 2500, and/or one or more user interfaces 2600 coupled to I/O device 2500, etc.
In certain exemplary embodiments, via one or more user interfaces 2600, such as a graphical user interface presented by a microcontroller and/or monitoring system, a user can view a rendering of information related to programming, operating, and/or monitoring the microcontroller, and/or a status of one or more sensors, sensor circuits, input circuits, and/or stimulus circuits.
FIG. 3 is a flowchart of an exemplary embodiment of a method 3000. At activity 3100, a sensor and/or sensor circuit can be disconnected and/or caused to be disconnected from the input circuit. At activity 3200, an invalid voltage can be applied to the input circuit. At activity 3300, the invalid input voltage can be removed from the input circuit. At activity 3400, the sensor and/or sensor circuit can be re-connected, such as via a selected input channel, to the input circuit. Note that activities 3300 and 3400 can be reversed. At activity 3500, a voltage in the input circuit, such as across the op-amp, can be measured. At activity 3600, the measured voltage value can be interpreted. At activity 3700, if the measured voltage value remains invalid, a notification can be provided that a circuit fault exists. If the measured voltage value has returned to a value that is valid, a notification of that value can be provided, that value being approximately and/or precisely indicative of the value output by the sensor. Other interpretations and/or notifications are also possible.
Certain exemplary embodiments were simulated using Orcad's PSpice simulator to determine if one or more disclosed systems, methods, and/or devices would work under ideal conditions. The simulation results were positive. Certain exemplary embodiments were then implemented in a prototype module. The test results were again positive.
Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, such as via an explicit definition, there is no requirement for the inclusion in any claim herein (or of any claim of any application claiming priority hereto) of any particular described or illustrated characteristic, function, activity, or element, any particular sequence of activities, or any particular interrelationship of elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all subranges therein. Any information in any material (e.g., a United States patent, United States patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
1. A method for detecting a circuit fault, comprising:
for a measurement system comprising a sensor coupleable to an input circuit, the sensor characterized by an output signal and an output signal operating voltage range, the input circuit comprising a microcontroller:
automatically causing the sensor to be electrically disconnected from the input circuit;
while the sensor is electrically disconnected from the input circuit, automatically provoking an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor;
after application of the invalid sensor voltage to the input circuit, automatically eliciting the invalid sensor voltage to be removed from the input circuit;
after application of the invalid sensor voltage to the input circuit, automatically effecting the sensor to be electrically connected to the input circuit; and then,
in the event that an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically providing notification that a circuit fault is associated with the sensor.
2. The method of claim 1, further comprising:
receiving an identity of the sensor.
3. The method of claim 1, further comprising:
receiving the output signal operating voltage range for the sensor.
4. The method of claim 1, further comprising:
automatically measuring the input circuit voltage.
5. The method of claim 1, further comprising:
in the event that the input circuit voltage value is within the output signal operating voltage range for the sensor, automatically providing notification of the input circuit voltage value.
6. The method of claim 1, further comprising:
recording the output signal.
7. The method of claim 1, further comprising:
performing said method for a plurality of multiplexed sensors.
8. The method of claim 1, further comprising:
transmitting the notification to a programmable logic controller.
9. The method of claim 1, wherein:
said method is performed repeatedly.
10. The method of claim 1, wherein:
the input circuit comprises a channel selector.
11. The method of claim 1, wherein:
the input circuit comprises an operational amplifier.
12. The method of claim 1, wherein:
the input circuit comprises an analog-to-digital converter.
13. The method of claim 1, wherein:
the input circuit comprises a capacitor.
14. The method of claim 1, wherein:
a data logger is electrically connected to the sensor.
15. The method of claim 1, wherein:
a programmable logic controller is communicatively coupled to the microcontroller.
16. The method of claim 1, wherein:
the sensor is a thermocouple.
17. The method of claim 1, wherein:
the sensor is a resistance temperature detector.
18. The method of claim 1, wherein:
the sensor is a position sensor.
19. A machine-readable medium storing machine instructions for a plurality of activities, the activities comprising:
for a measurement system comprising a sensor coupleable to an input circuit, the sensor characterized by an output signal and an output signal operating voltage range, the input circuit comprising a microcontroller:
automatically causing the sensor to be electrically disconnected from the input circuit;
with the sensor electrically disconnected from the input circuit, automatically provoking an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor;
upon application of the invalid sensor voltage to the input circuit, automatically eliciting the invalid sensor voltage to be removed from the input circuit;
after removal of the invalid sensor voltage from the input circuit, automatically effecting the sensor to be electrically connected to the input circuit; and
thereafter, in the event that an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically providing notification that a circuit fault is associated with the sensor.
20. A system for detecting circuit faults, comprising:
an input circuit coupleable to a sensor, the sensor characterized by an output signal and an output signal operating voltage range, the input circuit comprising:
a microcontroller adapted to:
automatically cause the sensor to be electrically disconnected from the input circuit;
with the sensor electrically disconnected from the input circuit, automatically provoke an invalid sensor voltage to be applied to the input circuit, the invalid sensor voltage having a value outside the output signal operating voltage range for the sensor;
upon application of the invalid sensor voltage to the input circuit, automatically elicit the invalid sensor voltage to be removed from the input circuit;
after removal of the invalid sensor voltage from the input circuit, automatically effect the sensor to be electrically connected to the input circuit; and
thereafter, in the event that an input circuit voltage value is outside the output signal operating voltage range for the sensor, automatically provide notification a circuit fault is associated with the sensor.