Energy-efficient home-automation device and method for tracking the displacement of a monitored object

Home-automation device comprising at least one displacement detector (20) for an object, named monitored object, comprising:

• a housing (36),
• an accelerometer (33) fixed to the housing and adapted to provide signals, named acceleration signals, representing an acceleration of the housing (36) in at least one fixed direction of the housing (36),
• an orientation sensor (34) fixed to the housing and adapted to provide signals, named orientation signals, representing a momentary orientation of at least one fixed direction of the housing (36),
• a memory comprising data representing:
• at least one predetermined value, named triggering value,
• at least one predetermined value, named scaling value,
• a processing unit (31) for the acceleration signals and orientation signals,
• wherein the processing unit (31) is programmed to:
• be able to identify a predetermined event, named triggering event, representing a variation in the acceleration of the housing, at least from the acceleration signals and said triggering value,
• upon detection of a triggering event:
• perform, at least from the acceleration signals, a calculation for determining a value, named displacement energy, said calculation comprising at least one sum of accelerations over time,
• after a set time, named waiting time, from the triggering event has passed, acquire orientation signals provided by the orientation sensor (34) representing the momentary orientation, named final orientation, of the housing,
• compare said displacement energy to said scaling value.

Method for operating a displacement detector for an object, named monitored object, said displacement detector comprising:

• a housing (36),
• an accelerometer (33) fixed to the housing and adapted to provide signals, named acceleration signals, representing an acceleration of the housing (36) in at least one fixed direction of the housing (36),
• an orientation sensor (34) fixed to the housing and adapted to provide signals, named orientation signals, representing the momentary orientation of at least one fixed direction of the housing (36),
• a memory comprising data representing:
• at least one predetermined value, named triggering value,
• at least one predetermined value, named scaling value,
• a processing unit (31) for the acceleration signals and orientation signals,
• wherein the processing unit (31):
• processes the acceleration signals so as to be able to identify, using said triggering value, a predetermined event, named triggering event, representing a variation in the acceleration of the housing,
• upon detection of a triggering event:
• performs, at least from the acceleration signals, a calculation for determining a value, named displacement energy, said calculation comprising at least one sum of accelerations over time,
• after a set time, named waiting time, from the triggering event has passed, acquires orientation signals provided by the orientation sensor (34) representing the momentary orientation, named final orientation, of the housing,
• compares said displacement energy to said scaling value.