Patent Application
20140095104
This application claims the benefit and priority of Great Britain Patent Application No. 1217622.8 filed Oct. 2, 2012. The entire disclosure of the above application is incorporated herein by reference.
The present technique relates to monitoring the operating condition of an apparatus, the apparatus comprising a variety of devices and a plurality of temperature sensors.
The proposed technique will now be described by way of example only with reference to the accompanying drawings, in which:
A method and apparatus for monitoring the condition of an apparatus is described. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the technique may be practised without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
In one aspect, a method for monitoring the condition of an apparatus is described. In other aspects, the proposed technique encompasses apparatus and a computer-readable medium configured to carry out the foregoing actions, as well as a data carrier carrying thereon or therein data indicative of instructions executable by processing means to cause those means to carry out the foregoing actions. Examples are CD-ROMs, memory sticks, dongles, transmitted signals, downloaded files etc. In particular, the method may be implemented in an apparatus for which temperature is a concern.
Clearly the apparatus may comprise more devices, temperature sensors etc than those shown. The apparatus shown is simplified for the understanding of the proposed technique and an apparatus as implemented is likely to include many more components. Devices 102 may be electronic devices such as discrete semi-conductor devices (for instance diodes, transistors etc.) or integrated circuits (ICs) or individual units (e.g. power supply etc) or other devices such as mechanical devices, electrical devices or physical parts (e.g. PCB temperature or enclosure temperature). Temperature sensors may comprise thermistors or the like. Cooling components 108 may be a fan or ventilation openings controlled by one or more flaps or other cooling components to cool the devices 102 within the apparatus 100.
In operation the microprocessor controls the devices 102 according to an operating mode of the apparatus. For example, the operating mode could, for instance, be a cooling component 108 (e.g. a fan) operating when a device is working at full power, this being a subset of the devices of the apparatus, or an operating mode in which the cooling component 108 is operating and all devices are in a sleep mode or an operating mode in which a cooling component 108 is operating and the devices are not operating or any other operating mode.
The microprocessor stores data relating to expected temperatures when devices are operating in a given operating mode of the apparatus. This data may be in the form of temperature profiles for instance as shown in
For instance:
DTn=Tn×mn×d
Where Tn is the actual temperature sensed by the sensor 104n
mn is the operating performance of the associated device 102n e.g. 0% to 100%
d is the distance of sensor 104n from the associated device 102n
Or alternatively:
DTn=Tn+(k*accI*mn*d)
Where Tn is the actual temperature sensed by the sensor 104n
m is the operating performance of the associated device 102n e.g. 0% to 100%
d is the distance of sensor 104n from the associated device 102n
k is a coefficient determined during testing,
accI is the accumulated current through the switching device
Thus the determined temperature DTn is not simply the temperature sensed remotely by the sensor 102 but it is intended to be a more accurate estimation of the actual temperature of the device in the specified operating mode. Where the device 102 is a discrete semiconductor device (e.g. a transistor, a diode or the like) the determined temperature DTn gives an estimation of the actual junction temperature of the device.
Other temperature profiles may be stored for other operating modes of the device for example: one or more fans on or off, one or more devices on or off, or ratios (0 to 100%) of device off and on, and the current passing through the devices etc.
The profile may be differential profiles i.e. profiles that indicate the differences between the temperature determined from one sensor and the temperature determined from another sensor. For instance, as shown in
The apparatus monitors for conditions such as an incorrectly installed fan, blocked inlet or outlet vents, a clogged fan, a worn out fan, an unstable fan operation or other operating conditions of the apparatus. This monitoring is based on the stored temperature profile data. The stored data may relate to an expected temperature profile for a given operating condition and may relate to a faulty operating condition. For instance, the stored data may include a temperature profile relating to the expected temperature profile for a fan installed the wrong way around. If the microprocessor determines that the temperature profile of the apparatus is similar to the stored temperature profile relating to the expected temperature profile for a fan installed the wrong way around, then an alert may be issued with this as the detected fault.
The operation of the system will now be described. During operation of the apparatus 100 the microprocessor 106 receives signals from and sends signals to other components of the apparatus e.g. electronic devices 102, the sensors 104 and the fans 108. At any point during operation of the apparatus, the microprocessor is aware of how components are operating. The microprocessor 106 receives input from the temperature sensors 104 situated around the apparatus 100. When the temperature sensed via a sensor 104 is equal to or greater than a threshold value, this triggers the microprocessor to undertake a review of the temperatures within the apparatus 100.
To this end, the microprocessor reads the temperature sensed by the sensors 104 and, for each sensor 104n relevant to the operating mode of the apparatus, determines the temperature DTn indicating a current temperature of the device 102n associated with the sensor 104. The microprocessor then determines the differences ΔDT in the determined temperatures DTn and compares these determined differences ΔDTn against the stored profile for the relevant sensors for the current operating mode of the apparatus.
For example
The microprocessor stores temperature profiles relating to the sensors 1041 and 1042 for various operating modes of the device.
1. Fan on
2. 1021 on 100%
3. 1022 off 0%.
For this profile the difference in temperature between the temperature determined from the reading of sensor 1041 and the determined temperature of sensor 1042 is indicated as a value of x. This is the expected difference in determined temperature ΔDT when the above operating conditions are in effect.
1. Fan on
2. 1021 on 100%
3. 1022 on 100%.
In this case the determined temperature differential ΔDT i.e. the difference between the determined temperature based on the reading from 1041 and the determined temperature based on sensor 1042 is given as y. This is the expected difference in determined temperature ΔDT when the above operating conditions are in effect.
1. Fan on
2. 1021 off (0%)
3. 1022 off (0%).
In this case the determined temperature differential ΔDT i.e. the difference between the determined temperature based on the reading from 1041 and the determined temperature based on sensor 1042 is given as z. This is the expected difference in determined temperature ΔDT when the above operating conditions are in effect.
The operation of the system shown in
To this end the microprocessor receives (operation 800) the temperature readings from the first temperature sensor 1041 and the second temperature sensor 1042. The microprocessor then determines if any of the sensed temperatures are above a trigger threshold (operation 802). If not, the microprocessor returns to receiving the temperature reading (operation 800). If a sensed temperature is above a trigger threshold, for each relevant sensor, microprocessor (operation 804) determines the temperature DTn of a device indicating a current temperature of the device 102n associated with the sensor 104n. The microprocessor then (operation 806) determines the difference ΔDT between the determined temperature of the first device and the determined temperature of the second device and then the microprocessor (operation 808) compares this determined difference ΔDT against the stored profile for the relevant temperature sensors and the current operating mode of the apparatus. On the basis of this comparison, the microprocessor (operation 810) may determine whether the apparatus is operating as expected for the current operating mode and that there is not an alarm condition (operation 810 answered in the negative) or may determine that the apparatus is not operating as expected for the current operating mode and that there is an alarm condition (operation 810 answered in the positive). When the microprocessor (operation 810) determines that the apparatus is operating as expected for the current operating mode and that there is not an alarm condition, then the microprocessor returns to monitoring the sensed temperatures (operation 800). When the microprocessor (operation 810) determines that the apparatus is not operating as expected for the current operating mode and that there is an alarm condition (operation 810 answered in the positive), then the microprocessor may cause an alert to be issued (operation 812). This may take the form of a visual alert to a user of the apparatus or a message sent to a remote destination or the like.
For example, for the operating mode related to the profile shown in
During manufacture, incorrect fan installation in the product may be detected by sensing the direction of the blown air or the direction of rotation of the blade. Detecting an incorrect mounting of a fan in the field is currently quite difficult without difficult checks or putting additional sensors into the product, incurring extra cost.
The proposed technique uses sensors already fitted to the apparatus to measure device temperatures within a product and compare the reading from these sensors to thermal profiles stored in the software to determine the blown air direction or even the absence or presence of blown air. The devices in the product are of varying distances and positions from the fan so the temperature profiles within the product will vary according to the blown air direction, speed, operating mode and other variables in the system. Early warnings can be presented accordingly.
The apparatus described may be provided in variable speed drives, for example as used in manufacturing. These now typically include an installer replaceable fan that is usually manufactured in such a way that the supporting structure of the fan is symmetrical in all three axes allowing the fan to be mounted in a number of ways. This in turn causes problems in ensuring the correct orientation of the fan when installed in the product. There are rarely any mechanical features preventing incorrect mounting. This can be a serious issue as it can result in a fan moving air in an incorrect direction if mounted the wrong way, dramatically altering cooling within the product. The proposed solution provides a way in which the apparatus itself may detect fault conditions (e.g. a fan mounted in the wrong way round when installed) thereby allowing a warning to be presented to the user. The reliability of the apparatus should therefore be improved through correctly mounted fans, reduction in customer's support calls and a reduced chance of damaged drives through thermal overload.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1217622.8 | Oct 2012 | GB | national |
