Fault detection for appliances based on energy consumption data

A non-transitory computer-readable medium comprising software code adapted, when executed on a processing device, to perform a method of detecting a fault in a device, comprising:

• receiving an energy consumption signal for the device, the energy consumption signal indicating a varying energy consumption of the device over time during operation of the device;
• selecting at least one basis function from a database storing information defining a plurality of basis functions, wherein each basis function defines a signal pattern associated with a respective known fault type;
• each basis function having a shape which matches the shape of an expected consumption signal when the respective fault type is present;
• repeatedly determining a correlation between the at least one basis function and the energy consumption signal while varying one or more parameters of the basis function, wherein determining the correlation comprises computing correlation values between a plurality of portions of the energy consumption signal and the basis function for each of a plurality of values of the one or more parameters;
• determining presence of an operating fault in the device in dependence on the determined correlation values;
• and
• generating an output based on the determination, wherein generating the output comprises one or more of:
• transmitting an electronic message to a user device indicating at least one of:
• presence of the fault, absence of the fault, and a detected fault type;
• and
• transmitting a control signal to the device or a control system associated with the device to change at least one of:
• an activation state of the device, an operating state of the device, and an operating configuration of the device.

A computer-implemented method of detecting a fault in a device, comprising:

• receiving an energy consumption signal for the device, the energy consumption signal indicating a varying energy consumption of the device over time during operation of the device;
• selecting a basis function from a database storing information defining a plurality of basis functions, each basis function defining a signal pattern associated with a respective known fault type, each basis function having a shape which matches the shape of an expected consumption signal when the respective fault type is present;
• wherein the selected basis function comprises a windowed function and is parameterized by at least one parameter, the at least one parameter comprising one or more of:
• a width parameter indicating a width of the basis function and/or signal window over which correlation is performed;
• and a shape parameter controlling the shape of the basis function;
• evaluating a correlation between the basis function and the energy consumption signal, wherein evaluating the correlation comprises computing correlation values between a plurality of portions of the energy consumption signal and the basis function for one or more values of the at least one parameter;
• determining presence of an operating fault in the device in dependence on the correlation values;
• and
• generating an output based on the determination, wherein generating the output comprises one or more of:
• transmitting an electronic message to a user device indicating at least one of:
• presence of the fault, absence of the fault, and a detected fault type;
• and
• transmitting a control signal to the device or a control system associated with the device to change at least one of:
• an activation state of the device, an operating state of the device, and an operating configuration of the device.