A rotational negative-inertia converter (RNIC) has a housing enclosing a flywheel configured to rotate around an axis of symmetry; a motor with a stator attached to the housing and a rotor attached to the flywheel to rotate it around the axis of symmetry; a housing angular accelerometer attached to said housing; a flywheel angular accelerometer; and a controller configured to receive measured accelerometer values from the accelerometers. The controller is configured to drive the motor to maintain the angular acceleration of the flywheel at a value proportional to the housing angular acceleration, with a predetermined proportionality constant.

A method for calibrating an ADCS testbed comprising a DUT holder with three RNICs includes: using measured angular velocities of the DUT holder and RNIC flywheels, and ZGT data, to compute moments of inertia of the DUT holder with and without a satellite with ADCS, allowing compensation for those moments by the RNICs.

A field agricultural machinery test platform, comprising a field soil groove, traveling guide rails, traveling trolleys, a hitch trolley, a hitch device mechanism, and a test system. The two guide rails are provided on both sides of the field soil groove in parallel, and the traveling trolleys are located on the guide rails; a cross beam is provided between the two guide rails, and the two ends of the cross beam are respectively connected to the traveling trolleys; the hitch trolley is provided on the cross beam, and a hitch device is provided on the hitch trolley; the test system is provided on the hitch trolley and the hitch device; a test machine is connected to the hitch device; the test system comprises an image assembly, a force test assembly, and a control assembly which are mounted on the hitch trolley.

Disclosed herein is a system for detecting rotational speed and early failures of an electronic device. The system includes a rotating disk affixed to a rotating shaft of the electronic device. The rotating disk has projections extending from its periphery. A time of flight ranging system determines distance to the projections extending from the rotating disk. Processing circuitry determines a rotational speed of the rotating shaft from the determined distances to the projections extending from the rotating disk, and detects whether the electronic device is undergoing an early failure from the determined distances to the projections extending from the rotating disk. Rotational speed is determined from the time between successive peaks in the determined distances, and early failures (for example, due to wobble of the shaft) are determined where the peaks vary unexpectedly in magnitude.

A method for isolating vibrations for centrifuge testing devices is provided. The method comprises coupling a test payload platform to a number of piezoelectric actuators and coupling the piezoelectric actuators to a reaction mass coupled to a centrifuge arm. A layer of vibration-absorbing material is sandwiched between the reaction mass and the centrifuge arm. The centrifuge arm is rotated around an axis, and the test payload platform is vibrated with the piezoelectric actuators as the centrifuge rotates, wherein the layer of vibration-absorbing material prevents vibrations from traveling down the centrifuge arm.

In accordance with at least selected embodiments, the present disclosure or invention is directed to novel or improved testing apparatus for testing lead acid batteries and/or their components, and/or the efficacy of their components, testing tables, testing systems, and/or related methods. In accordance with at least certain embodiments, the present disclosure or invention is directed to novel or improved methods for testing lead acid batteries and/or their components, and/or the efficacy of their components. In accordance with at least certain selected embodiments, the present disclosure or invention is directed to novel or improved systems for testing lead acid batteries and/or their components, and/or the efficacy of their components. In accordance with at least particular selected embodiments, the present disclosure or invention is directed to novel or improved apparatus and methods for testing a lead acid battery or batteries whereby the battery or batteries are subjected to motion typical of that experienced by the battery or batteries in use or in the field.

A soft collision target, in particular for use within the framework of non-destructive collision tests, has an illumination device that comprises at least one illuminant and a covering structure, wherein the covering structure surrounds the illuminant and is configured to absorb forces acting on the illumination device on a collision and/or to conduct them at least partly past the illuminant.

The present disclosure is directed to a method for estimating tower loads, such as tower deflection, of a wind turbine. The method includes receiving an estimate of slow variations in thrust of a tower of the wind turbine. The method also includes determining, via one or more sensors, tower accelerations of the tower of the wind turbine. Thus, the method also includes estimating the tower loads of the wind turbine as a function of the estimate of slow variations in thrust of the tower and the tower accelerations.

A test device suitable for acceleratory oblique water entry of a wedge has a frame, a water tank placed below the frame, an accelerator installed above the frame, an obliquing device connected to the frame, a wedge connected to the obliuqing device and an observation system. The frame is provided with vertical slide rails and a transverse slide rail. The accelerator mainly includes an air cylinder and an air compressor. The wedge is a flexible wedge or a rigid wedge. The observation system includes a pressure sensor, a strain sensor, a velocity sensor, an acceleration sensor and a particle image velocimetry device. The repeatability of the test process can be ensured by controlling the output pressure of the air cylinder.

A life determining device capable of performing life determination while suppressing a processing load is provided. A life determining device 1 includes a measured value acquiring unit 2 that acquires a measured value for a stressor at predetermined time intervals, an acceleration factor acquiring unit 3 that acquires a first acceleration factor, which is the ratio of a second life to a first life, at predetermined time intervals, and a life determining unit 5 that determines life expiration of a device whose life is to be determined by comparing a value obtained by multiplying an accumulated value of the first acceleration factor by a predetermined time with a second life. The acceleration factor acquiring unit 3 uses a look-up table 4 that stores a second acceleration factor for each predetermined value when it acquires the first acceleration factor.

A system and method are provided for determining a geographic location of a tower top pivot point (TPP) of a wind turbine tower having a nacelle that includes a machine head and rotor at a top thereof. At least one rover receiver of a global navigation satellite system (GNSS) is configured at a fixed position on the nacelle. A plurality of 360-degree yaw sweeps of the nacelle are conducted and the geo-location signals received by the rover receiver during the yaw sweeps are recorded. With a controller, the geo-location signals are converted into a circular plot and a radius of the plot is determined, the radius being a distance between the rover receiver and the TPP. Based on a GNSS geo-location of the rover receiver and the radius, a geo-location of the TPP is computed.