Method and module for detecting the state of a coupling device, and associated turbine engine and aircraft

Module for controlling the operation of a coupling device for an aircraft turbomachine, the turbomachine comprising a rotary shaft and an electric machine, the coupling device being configured to connect a rotor shaft of the electric machine to the rotary shaft and having two operating states, a coupled state so as to secure the rotor shaft and the rotary shaft and a decoupled state so as to separate the rotor shaft and the rotary shaft, the module comprising:

• first determining means configured to determine a control state of the coupling device delivered in the form of a control command in the coupled state or in the decoupled state of the coupling device;
• second determining means configured to determine the rotational speed of the electric machine;
• third determining means configured to determine the rotational speed of the rotary shaft;
• first comparison means configured to compare the rotational speed of the electric machine with a time evolution profile of the rotational speed of the electric machine determined from the rotational speed of the rotary shaft and the control state of the coupling device, the first comparison means being configured to determine an operating deviation;
• second comparison means configured to compare the operating deviation with a detection threshold;
• and
• means for determining a failure configured to identify the existence of a failure or absence of a failure of the coupling device according to the result delivered by the second comparison means;
• wherein the second comparison means are also configured to determine the value of the detection threshold from at least one control parameter, the operating deviation and the rotational speed of the electric machine.