This invention relates to monitoring the operation of kitchen appliances.

Kitchen appliances may suffer from operational faults. Faults can range from minor faults which are mildly inconvenient for the user, such as an oven light not working, to a major fault where the appliance will not function at all. Faults in appliances can frustrate users, who cannot carry out day-to-day tasks such as laundry and cooking if their appliance develops a fault. Such faults may also be detrimental to the reputation of suppliers of appliances. Therefore, it is important to identify and fix such faults as quickly as possible.

Traditionally, when the user of a kitchen appliance identifies or suspects a fault with their appliance, a service engineer will be called out to inspect the appliance. Often the origin of the fault is unclear, and the service engineer may have to investigate a number of possible origins before identifying the true cause. This can be a lengthy process which can be costly to the consumer or, in the case of a warranty repair, the supplier.

There is a need for an improved way to identify faults in kitchen appliances to allow them to be rectified quickly and efficiently.

According to one aspect of the present invention there is provided a monitoring system for a kitchen appliance comprising: a sensor device configured to measure at least one operational parameter of an appliance, the at least one operational parameter being dependent on the installation state of the appliance, the sensor device comprising at least one sensor for sensing the at least one operational parameter of the appliance and a processing device configured for analysing data sensed by the at least one sensor by means of a predetermined algorithm, wherein the processing device is configured to detect a deviation from an expected change in the at least one operational parameter over time to estimate whether the data is indicative of a fault with the appliance. The fault may be a result of the appliance having not been installed correctly. On detecting such a fault, the system may generate an alert.

The sensor may be one of a temperature sensor, a humidity sensor, a light sensor, a current sensor, a voltage sensor, a power sensor or an accelerometer.

The system may be configured to store data previously sensed by the sensor device and the estimation of whether the data is indicative of a fault may be dependent on detecting a deviation of a predetermined form between data currently sensed by the sensor device and that previously sensed data.

The deviation of a predetermined form may be a deviation by greater than a threshold from an average formed over at least part of the previously sensed data.

The system may be configured to analyse data received from the at least one sensor to compare the received data with one or more data patterns which are indicative of a device having a fault and to generate an alert on detecting a commonality between data currently sensed by the sensor device and one or more of the patterns.

The system may be configured to store data previously sensed in respect of multiple appliances and determined to be indicative of a fault and the estimation of whether the data is indicative of a fault may be dependent on detecting a commonality between data currently sensed by the sensor device and that previously sensed data.

The system may be configured to generate an alert indicating the fault with the data for which a commonality has been detected in data currently sensed by the sensor.

The present invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

Figure 1 shows a system for monitoring a kitchen appliance. Figure 2 illustrates power profiles as a function of time for kitchen appliances.

Figures 3 and 4 show examples of a sensing device fitted to a kitchen appliance.

Figure 1 is a schematic diagram of a system for monitoring the operational parameters of a kitchen appliance. The system comprises a sensing device 1 , a relay device 2 and a data centre 3.

The sensing device 1 is configured to be situated within or attached to a kitchen appliance and comprises a number of sensors 4, 5, 6, and 7, a power source connection 8, a processor 9, a memory 10 and a transceiver 1 1 . The processor 9 is configured to execute software stored in a non-transient form in memory 8 in order to cause the sensor device to perform its functions. Processor 9 communicates with the sensors 4-7. The processor receives data gathered by the sensors and communicates with the transceiver to transmit data. The transceiver could operate in the ISM (industrial, scientific and medical band) and could be a Bluetooth (e.g. Bluetooth Low Energy) or IEEE 802.1 1 transceiver. The transceiver could operate according to other protocols.

The sensing device may be detachable or may be integrated with the kitchen appliance. The sensing device may be powered by same power source as the appliance or a separate power source via power source connection 8. The transceiver may be a wireless transceiver, or the transceiver may be connected via a wired connection to the relay device 2.

Relay device 2 is configured to relay communications from the sensing device 1 to the data centre 3. Relay device 2 comprises a processor 12, a transceiver 13, a memory 14 and an uplink transceiver 15. Processor 12 is configured to execute software stored in a non-transient form in memory 14 in order to cause the relay device to perform its functions. The processor 12 can communicate with transceivers 13, 15. The transceiver 13 is configured to communicate with transceiver 9 of the sensing device. The uplink transceiver 15 may use any suitable wired or wireless protocol for establishing a link 16 with the data centre 3. For example, the uplink transceiver could be an IEEE 802.1 1 wireless transceiver or a wired Ethernet transceiver. The link 16 may operate over a publicly accessible communications network such as the internet. The relay device, may be a cellular telephone, for example a smartphone. The relay device may be a communications hub.

The data centre 3 comprises a data store 17 and a processing station 18 which includes a processor 19 and a memory 20. The data store is connected to receive and store data received from the relay device 2. The processor 19 is configured to execute software stored in a non-transient form in memory 20 in order to analyse the data stored in the data store 17. The processor is also configured to carry out predetermined actions when certain conditions are met in the data, for example by issuing an alert to a supplier or user, as indicated at 21.

The sensing device can be equipped with any number of sensors for measuring any parameters relevant to the appliance that is being monitored. Examples of such sensors may include temperature sensors (e.g. thermistors or thermocouples), humidity sensors (e.g. resistive or capacitive humidity sensors), light sensors (e.g. photodiodes), conductivity sensors (e.g. by means of resistance measurement), accelerometers or sensors for measuring the voltage and/or current consumed by the appliance or components of the appliance. Where a sensor is an accelerometer, the accelerometer may be, for example a piezoelectric or gyroscopic accelerometer. The accelerometer may be a single axis accelerometer or a multi-axis accelerometer.

The processor 9 of the sensing device executes the software code stored in memory 10. This causes it to take measurements from the sensors 4-7. The processor 9 may process the measurements locally to the sensing device. For example, the processor may carry out averaging or smoothing of the measurements or discard spurious or redundant measurements. The processor 9 may store the measurements temporarily in memory 10 until a link is established with relay device 2, until a predetermined number of measurements have been gathered, or until a predetermined time has elapsed since the last transmission of measurements to the relay device. From time to time, the sensor device transmits the measurements to the relay device 2 via transceiver 1 1. The sensor device may transmit the measurements to the relay device at a predetermined frequency.

The processor 12 of the relay device causes the transceiver 15 to transmit the measurements to the data centre 3. The processor 12 may store the measurements temporarily in memory 14 until a link is established with the data centre 3, until a predetermined number of measurements have been gathered at the relay device, or until a predetermined time has elapsed since the last transmission of measurements from the relay device to the data centre. At the data centre, received measurements are stored in database 17.

At the data centre, the measurements are analysed from time to time, for instance every time measurements are received, or for example every 1 to 5 hours. The analysis proceeds by comparing the measurements against a set of criteria, the definitions of which have been previously stored in memory 20.

The measurements may be analysed to determine whether a measured parameter, or a value derived by calculation from one or more measured parameters (for example, power values, calculated from voltage and current measurements), exceeds or drops beneath a threshold. For example, the analysis could determine whether the power consumed by the kitchen appliance drops below a threshold value. An alert may be generated if the measured parameter exceeds or drops beneath the threshold.

The threshold could be an absolute value pre-stored in the memory 20 or could be determined by the data centre based on previous measurements for the same appliance. For example, the power threshold could be the average of the minimum power values measured for the same appliance over each of the previous seven days. Therefore, the system can identify abnormalities related to a particular appliance rather than to a batch or model of identically manufactured appliances in general.

The system may detect when a measured parameter falls out of an acceptable range of parameter values. For example, measurements lying within a range between two values for a certain parameter may be deemed as indicating normal operation. If the measured parameter value then falls out of this range, this may indicate a fault in the appliance and an alert may be generated.

The device may monitor a parameter over a window of time. A threshold value or a range of acceptable operational values may be set based on the data that has been previously monitored by the sensors over a given time period. Thus, the threshold may be a dynamically calculated threshold which changes over time.

The system may be configured to detect a deviation from an expected change in a measured parameter over time. The measurements can be analysed to determine whether a time series of values of one or more measured parameters, or values derived by calculation from one or more measured parameters, indicates a variation that matches a predetermined form that is indicative of a fault in the appliance. For example, if a pattern of change in a measured parameter is observed over a particular time period that is known to be indicative of a fault, an alert may be generated.

The received data may be analysed to compare the received sensor data with one or more data patterns which are indicative of a device having a fault and to generate an alert on detecting a commonality between data currently sensed by the sensor device and one or more of the patterns. For example, the data may be compared with a stored pattern which is known to indicate that the fan of an appliance is not functioning correctly. On detecting a commonality between the detected data and the stored pattern, an alert can be generated to inform the user or the supplier that the fan may be failing.

The system may store data, for example in data store 17, that has been previously sensed in respect of multiple appliances and determined to be indicative of a fault. The system may estimate whether the data is indicative of a fault by detecting a commonality between data currently sensed by the sensor device and that previously sensed data. On detecting a commonality, the system may generate an alert.

Figure 2 illustrates possible measurements taken from three appliances of the same model over a period of seven days. The power for appliances A and C follows a normal variation. The power for appliance B decreases below a threshold, Ρτ, which has previously been determined to be indicative of a particular fault. The power for appliance B dropping beneath the threshold may not alone be sufficient to trigger an alert, as the pattern of power variation in the three appliances is slightly different generally. However, the region shown at 25 indicates a pattern of power decrease that has previously been determined from measurements in a significant population of appliances of that model to be characteristic of a specific fault. Since the power decrease for appliance B matches that profile, appliance B may be determined to be suffering from that fault.

The power decrease may be indicative of a particular component of the appliance having failed. For example, the power consumed by the device may decrease by an amount corresponding to the power consumption of a particular component.

In another example, the temperature of the appliance may be monitored. The temperature values measured by the temperature sensor may exceed a threshold value or may show conformity with a pattern of measurements previously determined to be indicative of a fault. For example, an increase in temperature in excess of a predetermined value may be indicative of a cooling component, such as a fan, having failed. This may be observed concurrently with a decrease in the measured power, corresponding to the failure of the component.

In a further example, the temperature of an appliance may be monitored over time. If a time series of measurements indicates that the appliance does not heat up or cool down at the expected rate, an alert may be generated. For example, if an oven takes longer than expected to reach the temperature selected by the user, this may be indicative of a fault with the heating system. Similarly, if the oven takes longer than expected to cool down after use, as determined by a time series of temperature measurements, this may be indicative of a fault in the cooling system.

The temperature may also be monitored to indicate that the appliance has reached the temperature set by the user or a program of the appliance. If the appliance heats up to a temperature that is outside of a predetermined range of the set temperature, this may indicate that the appliance is not reaching, or is overshooting, the set temperature.

Where one or more of the sensors comprises an accelerometer, data from the accelerometer may be used for detecting abnormal movement or vibration in appliances. For example, an accelerometer may detect abnormally high amounts of vibration in a washing machine, which may be indicative of a fault.

Data from the accelerometer may also be used in conjunction with data from the other sensors to determine the activity state of the appliance at a given time. For example, when the sensor device is in a washing machine, the accelerometer may indicate substantial variation in acceleration over a period of, e.g., 5 seconds, which may be indicative of the appliance being operational (drum spinning); or the accelerometer may indicate no substantial variation in acceleration over a period of, e.g., 5 minutes, which may be indicative of the appliance not being in operation. Data from the accelerometer may be used to determine the stage in the cycle of use of the appliance (e.g. laundry cycle) at which certain values of parameters measured by the other sensors are occurring, which may further help to identify a particular fault.

In another non-limiting embodiment, the parameter(s) measured by the sensor(s) of the sensing device may be dependent on the installation state of the appliance. The measured parameters may be parameters which are affected by incorrect installation of the appliance. For example, a sensor may measure a parameter which is indicative of the level of vibration experienced by the appliance, the stability of the appliance, the degree of horizontal orientation of the appliance, or the water pressure delivered to the appliance. These parameters are dependent on the appliance being installed correctly by the engineer or kitchen fitter. Thus, a deviation from an expected change in these operational parameters over time may indicate that the appliance has not been installed correctly and as a result there is a fault with the appliance that needs to be fixed. Such faults relating to the incorrect installation of the appliance may include a defective component, loose mechanical fixings or fittings, low water pressure, excessive water pressure, the appliance not being level (horizontal), loose electrical connections, excessive vibration, or incorrect calibration of the appliance. Further examples of faults for different appliances are detailed at the end of the description.

An appliance may include multiple sensor devices like sensor device 1 , each positioned at a different location within or on the appliance. The measurements from each sensor device can be sent to the data centre. Time-series of measurements from each sensor device can be compared to identify data indicative of a fault, and the relative pattern of variation between the measurements from different sensor devices might provide a suggestion that the appliance is suffering from one fault rather than another. Data can be gathered from sensors located at these positions in a significant population of appliances to identify characteristics of a specific fault.

A further advantage of the appliance comprising multiple sensor devices is that if one device fails, continuity of measurement can be maintained by the other sensor devices. Furthermore, sensors in certain locations on the appliance may provide better measurement accuracy for certain parameters. For example, measurement of temperature at the roof of an oven may provide a better indication of a fault than one by the door, which may be more affected by temperature fluctuations when the oven door is opened.

Figures 3 and 4 show examples of how the sensor device 1 can be positioned within an appliance. Figure 3 shows multiple sensor devices 1 positioned within an oven 23. Figure 4 shows a sensor device 1 positioned within a washing machine 24.

In the examples described above the main data analysis is performed at the data centre 3, but it could be performed at the relay unit 2 or at the sensor device 1.

The processor 12 may process the measurements locally at the relay device. For example, the processor may compare the measurements to predetermined forms whose characteristics are stored in memory 14, and if such forms are detected in the measurements it may present an alert to a user or supplier. When an alert is presented according to any of the described embodiments, the alert may be provided by means of a user interface device such as a display 22 or a speaker. Alternatively, the processor may instruct an email or text message to be sent to the user or the supplier alerting them to the identified problem. Alternatively, the processor may instruct for an appointment to be arranged with a service engineer to visit the user to fix the appliance.

This arrangement can be used to monitor the operational state of an appliance with a suspected fault. It may also be used to monitor an appliance that is not showing characteristics of a fault in order to provide an alert if that appliance develops characteristics that may be indicative of a fault.

As described above, the system may comprise a storage device configured to store data previously sensed by the sensor device, for example at data store 17. The storage device may also store information indicative of the usage history of the appliance. The information indicative of the usage history of the appliance may include, for example, the frequency of use of the appliance or of certain programs of the appliance. In one example, where the appliance is a washing machine, the information may include parameters such as the average weight of a typical load of washing. The processor of the system may be configured to analyse the data collected by the sensors and the information indicative of the usage history of the appliance to determine an expected variation with time for an operational parameter measured by the sensor from the previously sensed data and the information indicative of the usage history of the appliance. The processor may also compare operational parameter data currently sensed by the sensor with the expected variation for that parameter. The processor may detect a deviation from the expected variation to estimate whether the data is indicative of a fault with the appliance. Thus, operational data plus user behaviour can be used to compare the measured data from the sensors against expected normal baseline of operation of an appliance within a specific usage group to determine whether there is a fault with the appliance. Some non-limiting examples of appliances that could be monitored include dishwashers, washing machines, fridges, freezers, ovens, microwaves, hobs, extractor fans/hoods, kettles, coffee machines and grills.

In one embodiment of the invention, the appliance may be a washing machine. In this embodiment, a fault associated with the appliance may be, but is not limited to, a defective component, insufficient power input, excessive power input, insufficient water drainage, insufficient water input, pipework blockage, overheating of the appliance, underheating of the appliance, excessive sustainable drainage systems (SuDs) caused by detergent, foreign objects in the basket or tub of the machine, excessive clothing load, water leakage, unlevel grounding, improper position of washer feet, unbalanced clothing load or contaminated residue in the appliance. A defective component of the appliance may include, but is not limited to, a power supply, a mains supply, a washer motor, a safety lock, a drum, an agitator, a timer, a timer knob, a drain pump, a filter, a belt, a main drive motor, a fill hose, a water inlet valve, a water hose a door seal, a tub, a tub seal or a detergent dispenser.

In a secondary embodiment of the invention, the appliance may be a freezer. In this embodiment a fault associated with the appliance may be, but is not limited to, a defective component, loss of refrigerant, pipework blockage, pipework choke, air channel blockage or obstruction, over-accumulation of ice, build-up of debris, overheating of the appliance, over-freezing of the appliance, insulation failure, a shortage of gas or spillage of fluid. A defective component of the appliance may include, but is not limited to, a power supply, a mains supply, a condenser coil, an evaporator coil, an electric fan, an expansion valve, a compressor vessel, a fan motor, a thermostat, a thermistor, a light bulb, a door switch, a changeover valve, an expansion valve, a heat-exchanging pipe, a defrost tray or a door seal.

In another embodiment of the invention, the appliance may be a refrigerator. In this embodiment a fault associated with the appliance may be, but is not limited to, a defective component, loss of refrigerant, pipework blockage, pipework choke, air channel blockage or obstruction, an accumulation of ice or frost, a build-up of debris, overheating of the appliance, overcooling of the appliance, insulation failure, a shortage of gas or spillage of fluid. A defective component of the appliance may include, but is not limited to, a power supply, a mains supply, a condenser coil, an evaporator coil, an electric fan, an expansion valve, a compressor vessel, a fan motor, a thermostat, a thermistor, a light bulb, a door switch, a changeover valve, an expansion valve, a heat-exchanging pipe, a defrost tray or a door seal.

In another embodiment of the invention, the appliance may be an oven. In this embodiment, a fault associated with the appliance may be, but is not limited to, a defective component, insufficient power input, excessive power input, gas pipework blockage, overheating of the appliance and underheating of the appliance. A defective components of the appliance may include, but is not limited to, a power supply, a mains supply, a timer, a timer knob, a filter, a fan, a light, a heating element or a cooling element.

The appliance may be a thermostatically controlled appliance or may be a non- thermostatically controlled appliance.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.