System and method for controlling a speed of rotation of an aircraft turbine engine with fault management

A control system for an aircraft turbine engine, the turbine engine (10) comprising:

• a combustion chamber (13),
• a fuel metering valve including a metering slide (12), a position of which determines a volumetric flow rate of fuel injected into the combustion chamber and an actuator (11) arranged to displace the metering slide depending on a control electric current (I_com),
• a position sensor (14) arranged to measure a position of the metering slide and deliver a position measurement (M_Pos),
• a speed sensor (15) arranged to measure a rotational speed of the turbine engine and deliver a rotational speed measurement (M_XNBP), and
• a monitoring unit (16) arranged to deliver a rotational speed setpoint (C_XNBP), to detect a failure of the position sensor and to deliver a failure signal (Sd) in the case of detection of a failure of the position sensor,
• the control system (100) comprising:
• a nominal-mode processing chain (110) including:
• a global corrector (21) arranged to receive the rotational speed setpoint (C_XNBP) and the rotational speed measurement (M_XNBP) and determine a fuel mass flow rate setpoint (C_WF) depending on the rotational speed setpoint (C_XNBP) and the rotational speed measurement (M_XNBP),
• a converter (22) arranged to convert the fuel mass flow rate setpoint (C_WF) into a position setpoint (C_Pos), and
• a local corrector (23) arranged to receive the position setpoint (C_Pos) and the position measurement (M_Pos) and determine a nominal-mode control electric current (I_nom) depending on the position setpoint (C_Pos) and the position measurement (M_Pos),
• a degraded-mode processing chain (120) including a direct corrector (122) arranged to receive the rotational speed setpoint (C_XNBP) and the rotational speed measurement (M_XNBP) and determine a degraded-mode control electric current (I_deg) depending on the rotational speed setpoint (C_XNBP) and the rotational speed measurement (M_XNBP), and
• a mode management module (130) arranged to receive the failure signal (Sd), the nominal-mode control electric current (I_nom) and the degraded-mode control electric current (I_deg), and to deliver, to the actuator (11) of the fuel metering valve, the nominal-mode control electric current (I_nom) in the absence of reception of the failure signal and the degraded-mode control electric current (I_deg) in the case of reception of the failure signal.