Abstract: A variable speed drive includes an output terminal for delivering a drive voltage; a power inverter for generating the drive voltage; a drive controller for controlling the generation of the drive voltage; and a current sensor for providing a drive current intensity signal to the drive controller. The drive controller includes a PWM generator; a control law module; and a state variable estimator estimating a state variable of the controlled AC electric motor.

Abstract: A variable speed drive includes an output terminal for delivering a drive voltage; a power inverter for generating the drive voltage; a drive controller for controlling the generation of the drive voltage; and a current sensor for providing a drive current intensity signal to the drive controller. The drive controller includes a PWM generator; a control law module; and a state variable estimator estimating a state variable of the controlled AC electric motor.

Abstract: A method and device estimate an amplitude of a periodic component in a measured analog signal, e.g. from an electric motor, and adapt a control law for an external entity, e.g., a variable speed drive (VSD) controlling the motor, based on the estimated amplitude. The measured analog signal is converted by delta-sigma modulation to a digital signal that is applied to at least one filter. Periodic signals of independent known periodic functions are also applied to the at least one filter. In response, the at least one filter provides the estimated amplitude of the periodic component in the measured analog signal that may be used to adapt the control law. A monitoring value for the electric motor may also be based on the estimated amplitude of the periodic component.

Abstract: A variable speed drive comprises an output for delivering a drive voltage to an electric motor, power inverter, a drive controller, and a current sensor. The drive controller includes a PWM generator, a control law module, and a state variable estimator for estimating a state variable of the electric motor. The module computes a target voltage signal based on state variable estimates provided by the estimator and outputs the target voltage signal to the PWM generator. The generator approximates the target voltage signal with a PWM control signal, controls the inverter using the control signal, computes, based on the deviation between the control signal and the target voltage signal, an estimation support signal, and outputs the estimation support signal to the estimator. The estimator estimates a state variable of the motor based on the estimation support signal and the drive current, and outputs the estimate to the module.

Abstract: A variable speed drive comprises an output for delivering a drive voltage to an electric motor, power inverter, a drive controller, and a current sensor. The drive controller includes a PWM generator, a control law module, and a state variable estimator for estimating a state variable of the electric motor. The module computes a target voltage signal based on state variable estimates provided by the estimator and outputs the target voltage signal to the PWM generator. The generator approximates the target voltage signal with a PWM control signal, controls the inverter using the control signal, computes, based on the deviation between the control signal and the target voltage signal, an estimation support signal, and outputs the estimation support signal to the estimator. The estimator estimates a state variable of the motor based on the estimation support signal and the drive current, and outputs the estimate to the module.

Abstract: An iterative method for determining scattering coefficients of the cavity of a laser gyro in operation supporting two counter-propagating modes, comprises steps of: determining a set of variables dependent on characteristic physical quantities of the laser gyro, one reference variable per dependency relationship being selected from the variables; measuring values of the characteristic physical quantities of the laser gyro in operation; determining measured values of the variables; estimating, via an iterative method, estimated values of the coefficients minimising a discrepancy between the measured values of the reference variables and estimated values of the reference variables, which are estimated from the values of the coefficients and the measured values of the variables other than the reference variables; and determining estimated values of the scattering coefficients from the estimated values of the coefficients.

Abstract: A method for estimating amplitude of a periodic component in a measured signal, wherein the method comprises the following operations: performing a delta-sigma modulation on a received analog signal to obtain a digital signal; applying at least one filter to the digital signal and to a first periodic signal to estimate a first amplitude signal representative of the first periodic signal in the digital signal. The method further comprises a control operation of: adapting a control law of an external entity based on at least the first amplitude signal; or calculating a monitoring value based on at least the first amplitude signal.

Abstract: An iterative method for determining scattering coefficients of the cavity of a laser gyro in operation supporting two counter-propagating modes, comprises steps of: determining a set of variables dependent on characteristic physical quantities of the laser gyro, one reference variable per dependency relationship being selected from the variables; measuring values of the characteristic physical quantities of the laser gyro in operation; determining measured values of the variables; estimating, via an iterative method, estimated values of the coefficients minimising a discrepancy between the measured values of the reference variables and estimated values of the reference variables, which are estimated from the values of the coefficients and the measured values of the variables other than the reference variables; and determining estimated values of the scattering coefficients from the estimated values of the coefficients.

Abstract: The invention concerns a method for determining the concentrations of chemical components of a product, in particular air, in a distillation column, said method involving implementing a model for estimating the concentration of the components from measurements carried out by one or a plurality of sensors, said model using an adjustment parameter making it possible to take into consideration operating variations of the column, the method also includes a step which involves detecting the values of said adjustment parameter that are outside a nominal variation range of said parameter in order to diagnose a fault D in one or a plurality of said sensors.

Abstract: A control method implemented in a power converter including an inverter connected to a synchronous electric motor including permanent magnets, the electric motor being modeled in the power converter by a mathematical model of currents in the electric motor expressing a flux current and a torque current on the basis of magnetic-saturation parameters. The control method identifies magnetic-saturation parameters during a learning procedure including applying a static voltage signal and a high-frequency voltage signal along an axis of the flux and/or an axis of the torque of the motor to cause an oscillation of the current on the axis of the flux and/or on the axis of the torque.

Abstract: A control method implemented in a power converter including an inverter connected to a synchronous electric motor including permanent magnets, the electric motor being modeled in the power converter by a mathematical model of currents in the electric motor expressing a flux current and a torque current on the basis of magnetic-saturation parameters. The control method identifies magnetic-saturation parameters during a learning procedure including applying a static voltage signal and a high-frequency voltage signal along an axis of the flux and/or an axis of the torque of the motor to cause an oscillation of the current on the axis of the flux and/or on the axis of the torque.

Abstract: A method of controlling a multilevel inverter of NPC (Neutral Point Clamped) type. The method includes regulating the electrical potential of the mid-point when the inverter operates at full voltage, that is to say in overmodulation. In this case, the method firstly determines the position of the control voltage vector in one of the six identical triangles covering the hexagonal vector space and thereafter decomposes the control voltage vector in the triangle by taking account of control combinations, defined in this triangle, for the switching arms.

Abstract: The invention relates to a method for determining the position of a rotor flux vector of an electric motor (M), comprising a step of injecting a first current vector into a first reference frame (x+, y+) rotating at a first frequency (?) relative to a reference frame (d, q) synchronous with the rotation of the motor, and a second current vector into a second injection reference frame (x?, y?) rotating at a second frequency opposite to the first frequency, a step of determining a first stator flux induced voltage delivered at the output of a first integrator module (12) synchronous with the first reference frame (x+, y+) and a second stator voltage delivered at the output of a second integrator module (13) synchronous with the second reference frame (x?, y?), a step of regulating the position of the rotor flux vector by minimizing the error (?) between a real position and an estimated position (?S) of the rotor flux vector, the error being determined based on the second induced voltage.

Abstract: The invention relates to a method of controlling a multilevel inverter of NPC (Neutral Point Clamped) type. The method consists in particular in regulating the electrical potential of the mid-point when the inverter operates at full voltage, that is to say in overmodulation. In this case, the method firstly consists in determining the position of the control voltage vector (U) in one of the six identical triangles covering the hexagonal vector space and thereafter in decomposing the control voltage vector (U) in the triangle by taking account of the control combinations, defined in this triangle, for the switching arms.

Abstract: The invention is a method for real-time estimation of the instantaneous engine speed produced by each cylinder of an internal-combustion engine, from an instantaneous engine speed measurement at the end of the engine transmission system. A physical model, representing in real time the dynamics of the transmission system according to the crankshaft angle and to coefficients of a Fourier series decomposition of the instantaneous speed produced by each cylinder, is constructed. These coefficients are determined in real time from coupling between the model and an adaptive type non-linear estimator. The instantaneous speed produced by each cylinder is then deduced from these coefficients. The mean torque produced by each cylinder can also be deduced therefrom. An application is: engine controls.

Abstract: The invention relates to a method for determining the position of a rotor flux vector of an electric motor (M), comprising a step of injecting a first current vector into a first reference frame (x+, y+) rotating at a first frequency (?) relative to a reference frame (d, q) synchronous with the rotation of the motor, and a second current vector into a second injection reference frame (x?, y?) rotating at a second frequency opposite to the first frequency, a step of determining a first stator flux induced voltage delivered at the output of a first integrator module (12) synchronous with the first reference frame (x+, y+) and a second stator voltage delivered at the output of a second integrator module (13) synchronous with the second reference frame (x?, y?), a step of regulating the position of the rotor flux vector by minimizing the error (?) between a real position and an estimated position (?S) of the rotor flux vector, the error being determined based on the second induced voltage.

Abstract: The present invention relates to a method of estimating the fuel/air ratio in each cylinder of an injection internal-combustion engine comprising an exhaust circuit on which a detector measures the fuel/air ratio of the exhaust gas. An estimator based on a Kalman filter is coupled with a physical model representing the expulsion of the gases from the cylinders and their travel in the exhaust circuit to the detector. The method has application to engine controls.

Abstract: A clutch comprises at least one damper (22) having rotating input (24) and output (26) elements, elastic elements having a circumferential effect carried by the first (28) and second (30) guide washers connected in rotationally fixed manner to one of the input (24) and output (26) elements and via a web (36) connected in a rotationally fixed manner to the other input (24) and output (26) element. The clutch also comprises friction assemblies (44), which are activated by angular displacements relative to the guide washers (28, 30) and to the web (36) and which have a friction element (46) capable of being coupled to the web (36) via the complementary circumferential stops that interact only when the web (36) angularly displaces in a predetermined direction with regard to the guide washers (28, 30).

Abstract: A clutch comprises at least one damper (22) having rotating input (24) and output (26) elements, elastic elements having a circumferential effect carried by the first (28) and second (30) guide washers connected in rotationally fixed manner to one of the input (24) and output (26) elements and via a web (36) connected in a rotationally fixed manner to the other input (24) and output (26) element. The clutch also comprises friction means (44), which are activated by annular displacements relative to the guide washers (28, 30) and to the web (36) and which have a friction element (46) capable of being coupled to the web (36) via the complementary circumferential stops that interact only when the web (36) angularly displaces in a predetermined direction with regard to the guide washers (28, 30).

Abstract: The present invention relates to a method of estimating the fuel/air ratio in each cylinder of an injection internal-combustion engine comprising an exhaust circuit on which a detector measures the fuel/air ratio of the exhaust gas. An estimator based on an adaptive nonlinear filter is coupled with a physical model representing the expulsion of the gases from the cylinders and their travel in the exhaust circuit to the detector. The estimator is also coupled with an estimation of the fuel/air ratio measured from at least one variable of said model such as the total mass of exhaust gas and the mass of fresh air. The method has application to engine controls.