A metrological technique in which the internal mass-density distribution of an object is obtained by measuring the object's inertia. The object is rotated about at least one arbitrary axis while dynamic properties are measured. Moment of inertia is derived from the torque and angular acceleration of the object, which can be used to calculate and estimate the internal mass-density distribution of the object.

An input-side control device includes: a feedback controller that generates a first control input signal for eliminating the difference between a model speed signal m and a speed detection signal by using the signal difference between a higher order torque command signal Tref and an axial torque detection signal Tsh to generate the model speed signal m which corresponds to the rotational speed of an inertial body having a set moment of inertia Jset moving under a torque corresponding to the signal difference; a feed-forward controller that generates a second control input signal by multiplying the signal difference by k.Math.Jdy/Jset; and a low-pass filter that generates a torque command signal Tr from a signal obtained by combining the outputs of the controllers and attenuating components at a higher frequency than a cut-off frequency fc set in the vicinity of the resonant frequency.

An input-side control device includes: a feedback controller that generates a first control input signal for eliminating the difference between a model speed signal m and a speed detection signal by using the signal difference between a higher order torque command signal Tref and an axial torque detection signal Tsh to generate the model speed signal m which corresponds to the rotational speed of an inertial body having a set moment of inertia Jset moving under a torque corresponding to the signal difference; a feed-forward controller that generates a second control input signal by multiplying the signal difference by k.Math.Jdy/Jset; and a low-pass filter that generates a torque command signal Tr from a signal obtained by combining the outputs of the controllers and attenuating components at a higher frequency than a cut-off frequency fc set in the vicinity of the resonant frequency.

Moments of inertia for an object, such as an aerial vehicle, may be determined by suspending the object from at least two filars, or cables, that are aligned in parallel and of equal length. After imparting a rotation upon the object about a vertical axis, data regarding oscillations of the object may be captured using an inertial measurement unit associated with the object. The captured data may be used to calculate a moment of inertia about the vertical axis, and to determine a vector corresponding to the vertical axis. After suspending the object, imparting rotations to the object and capturing data with the object in a number of orientations, a moment of inertia tensor may be calculated about the object's principal axes based on the moments of inertia about vertical axes in such orientations and the vectors.

A weight distribution associated with an unmanned aerial vehicle (UAV) may be determined prior to dispatch of the UAV and/or after the UAV returns from operation (e.g., a flight). In some embodiments, one or more UAVs may be placed on or proximate to a physical metrics acquisition (PMA) device. The PMA device may include a configurable scale and may be used to determine a distribution of weight of the UAV at three or more points associated with the UAV. The distribution of weight may be used generate analytics, which may include a total weight of a vehicle, a center of mass of the vehicle (in two or more dimensions), power requirements of the UAV for a given flight task (e.g., how much battery power the UAV requires, etc.), and/or other analytics. In various embodiments, the PMA device may perform moment of inertia tests for the UAV.

The present invention provides a large-scale high-speed rotary equipment measuring and intelligent learning assembly method and device based on vector minimization geometry center, mass center, the center of gravity and the center of inertia, belonging to the technical field of mechanical assembly. The method includes the steps of establishing a four-parameter circular profile measuring model for a single stage of rotor, simplifying the established four-parameter circular profile measuring model for the single stage of rotor, and establishing a four-target optimization model of the geometry center, mass center, the center of gravity and the center of inertia of multiple stages of rotors based on the angular orientation mounting position of each stage of rotor. The device include a base, an air flotation shaft system, an aligning and tilt regulating workbench, precise force sensors, a static balance measuring platform, an upright column, a lower transverse measuring rod, a lower telescopic inductive sensor, an upper transverse measuring rod and an upper lever type inductive sensor.

The present invention provides a large-scale high-speed rotary equipment measuring and intelligent learning assembly method and device based on vector minimization geometry center, mass center, the center of gravity and the center of inertia, belonging to the technical field of mechanical assembly. The method includes the steps of establishing a four-parameter circular profile measuring model for a single stage of rotor, simplifying the established four-parameter circular profile measuring model for the single stage of rotor, and establishing a four-target optimization model of the geometry center, mass center, the center of gravity and the center of inertia of multiple stages of rotors based on the angular orientation mounting position of each stage of rotor. The device include a base, an air flotation shaft system, an aligning and tilt regulating workbench, precise force sensors, a static balance measuring platform, an upright column, a lower transverse measuring rod, a lower telescopic inductive sensor, an upper transverse measuring rod and an upper lever type inductive sensor.

Devices are provided to measure the mass inertia of moving surfaces (e.g., aircraft components). In certain embodiments, the devices will include a support frame formed by first and second structural frame members which form a space for positioning of a moving surface to be measured for mass inertia. A pivot joint assembly is supported by an upper portion of the first structural frame member while a distance alignment device is arranged at a lower portion of the support frame. The second structural frame member including an extension and a dynamometer supported operatively by the extension. The first structural frame member includes a comparator clock at a lower portion thereof. The support device is therefore operatively connected to the pivot joint assembly so as to be pivotally movable about a pivot axis relative to the support frame between first and second positions such that the support device is in operative cooperation with the distance alignment device when in the first position thereof and the dynamometer when in the second position thereof.

Devices are provided to measure the mass inertia of moving surfaces (e.g., aircraft components). In certain embodiments, the devices will include a support frame formed by first and second structural frame members which form a space for positioning of a moving surface to be measured for mass inertia. A pivot joint assembly is supported by an upper portion of the first structural frame member while a distance alignment device is arranged at a lower portion of the support frame. The second structural frame member including an extension and a dynamometer supported operatively by the extension. The first structural frame member includes a comparator clock at a lower portion thereof. The support device is therefore operatively connected to the pivot joint assembly so as to be pivotally movable about a pivot axis relative to the support frame between first and second positions such that the support device is in operative cooperation with the distance alignment device when in the first position thereof and the dynamometer when in the second position thereof.

The invention relates to an adapter for a gravity pendulum, which adapter comprises a support for fastening a gravity body to be measured and at least two seat parts arranged at the support. The at least two seat parts comprise ellipsoid caps which can be held on a holder or on seating faces of a holder and are used to oscillate the adapter.