A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method comprises: obtaining measurements representative of strain in the propeller drive shaft using multiple primary strain sensors, each primary strain sensor providing respective measurements representative of strain; wherein the primary strain sensors are located around a circumference of the drive shaft of the propeller; and wherein each strain sensor is located such that it crosses a plane defined by the radial direction of a blade and the central axis, the plane being bounded by the central axis. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from hub arms of a propeller hub, which in turn extend radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method comprises obtaining measurements representative of the strain in each of at least some of the hub arms using strain sensors, each of the strain sensors being provided on a respective hub arm. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

A method for monitoring an aircraft engine during flight, which includes the steps of: for at least one characteristic frequency of the operation of the engine, measuring at least one synchronous vibration level value; for at least one module of the engine, estimating an out-of-balance value of the module in accordance with the one or more vibration level values measured and at least one sensitivity coefficient; estimating a balancing margin of the module in accordance with the out-of-balance value of said module and a maximum threshold; (d) estimating a remaining number of flights of the aircraft prior to balancing and/or a quality indicator of a preceding balancing operation in accordance with the one or more estimated balancing margins and data representing past balancing operations of the engine.

A method for monitoring an aircraft engine during flight, which includes the steps of: for at least one characteristic frequency of the operation of the engine, measuring at least one synchronous vibration level value; for at least one module of the engine, estimating an out-of-balance value of the module in accordance with the one or more vibration level values measured and at least one sensitivity coefficient; estimating a balancing margin of the module in accordance with the out-of-balance value of said module and a maximum threshold; (d) estimating a remaining number of flights of the aircraft prior to balancing and/or a quality indicator of a preceding balancing operation in accordance with the one or more estimated balancing margins and data representing past balancing operations of the engine.

A device (10) and method for sensor diagnostic monitoring and detection of an imbalance of a rotating machine (1) has steps of (a) detecting acceleration signals (Sb) of the housing (2) or of a non-rotating component of the rotating machine (1) by a sensor (20); (b) detecting signals (Sd) for the determination of the rotation speed of the rotating machine (1) by a second sensor; and (c) supplying and evaluating of sensor signals (Sb, Sd) by an evaluation unit (40, 50, 60). An acceleration component that is acquired occurs with the rotation speed of the rotating machine. This component is compared with a predetermined limit value.

A device (10) and method for sensor diagnostic monitoring and detection of an imbalance of a rotating machine (1) has steps of (a) detecting acceleration signals (Sb) of the housing (2) or of a non-rotating component of the rotating machine (1) by a sensor (20); (b) detecting signals (Sd) for the determination of the rotation speed of the rotating machine (1) by a second sensor; and (c) supplying and evaluating of sensor signals (Sb, Sd) by an evaluation unit (40, 50, 60). An acceleration component that is acquired occurs with the rotation speed of the rotating machine. This component is compared with a predetermined limit value.

A method and apparatus for dynamically balancing a tire/wheel assembly of a motor vehicle is provided. The wheel of the tire/wheel assembly has raceways along the circumference of the wheel containing balancing media that provide dynamic rotational harmonic center of moment compensation for manufacturing imperfections. Balancing media may be solid bearings, fluid, or a combination thereof, and the balancing media moves along the raceways to certain areas of the wheel to compensate for the mass imbalances on the correspondingly opposing side of the wheel. The raceways have any combination of mathematically-described geometric cross-sectional area shapes, and the balancing media may be shaped accordingly. In another embodiment, the raceways may be noncontiguous and may have different orientations throughout the wheel. The present invention also provides sensors for real-time management of the balancing media to inform the driver of sudden changes in the state of the tire/wheel assembly.

A method and apparatus for dynamically balancing a tire/wheel assembly of a motor vehicle is provided. The wheel of the tire/wheel assembly has raceways along the circumference of the wheel containing balancing media that provide dynamic rotational harmonic center of moment compensation for manufacturing imperfections. Balancing media may be solid bearings, fluid, or a combination thereof, and the balancing media moves along the raceways to certain areas of the wheel to compensate for the mass imbalances on the correspondingly opposing side of the wheel. The raceways have any combination of mathematically-described geometric cross-sectional area shapes, and the balancing media may be shaped accordingly. In another embodiment, the raceways may be noncontiguous and may have different orientations throughout the wheel. The present invention also provides sensors for real-time management of the balancing media to inform the driver of sudden changes in the state of the tire/wheel assembly.

A turbine overspeed trip test data logging system is a portable system by which an operator can electronically gather and log data for a turbine overspeed test. A plurality of sensors can be affixed to various components of the turbine for gathering test data to be received and compiled into a turbine test log by a processing unit. A method for processing the gathered sensor data is also provided.

A turbine overspeed trip test data logging system is a portable system by which an operator can electronically gather and log data for a turbine overspeed test. A plurality of sensors can be affixed to various components of the turbine for gathering test data to be received and compiled into a turbine test log by a processing unit. A method for processing the gathered sensor data is also provided.