16 results about "Linear variable differential transformer" patented technology

A measurement correction method and signal conditioning apparatus for a linear variable differential transformer sensor. The correction method comprises the following steps: acquiring a compensation fitting coefficient (101); obtaining a root mean square value signal of an excitation voltage signal, a phase difference signal and a root mean square value signal of an induced voltage signal of when a linear variable differential transformer sensor is used to measure the displacement of an object to be measured (102); and on the basis of the numerical value of the root mean square value signal of the excitation voltage signal, the numerical value of the phase difference signal and the numerical value of the root mean square value signal of the induced voltage signal of said object and in view of the compensation fitting coefficient, performing temperature drift compensation, so as to obtain a corrected displacement measurement value (103). The above solution can compensate for the displacement data drift caused by the impact of temperature on a linear variable differential transformer sensor, thereby reducing the impact of temperature drift on the output of the linear variable differential transformer sensor.

The utility model belongs to the technical field of aviation electromechanics, and relates to a servo actuation control device. The device comprises a DSP (Digital Signal Processor) processing module, an LVDT (Linear Variable Differential Transformer) sensor acquisition module, a watchdog module, an electromagnetic valve driving module and a servo valve driving module, wherein the LVDT sensor acquisition module, the watchdog module, the electromagnetic valve driving module and the servo valve driving module are all connected with the DSP processing module. Under the cooperation of the electromagnetic valve and the servo valve, the hydraulic flow and direction acting on the steering engine are controlled, so that the steering engine is driven to move, and the position of the steering engine and a monitoring result are periodically reported to a flight control computer. And meanwhile, event data in operation can be recorded in the NVM, so that subsequent ground maintenance and management are facilitated.

The invention relates to a simulation method and device for a linear variable differential transformer. The method comprises the steps that ideal parameters and interference parameters of input signals of a primary coil and inherent parameters and environmental parameters of the linear variable differential transformer are obtained; performing signal simulation according to the ideal parameter and the interference parameter to obtain an actual input signal of the primary coil; calculating the inherent parameters, the environmental parameters and the actual input signal of the primary coil through a secondary coil output signal calculation model to obtain a secondary coil output signal; and carrying out demodulation calculation on the output signal of the secondary coil to obtain displacement data. By introducing the magnetic conductivity difference and environmental interference of the secondary coil, the analog signal truly reflects non-ideal characteristics, errors and jitter in actual operation are reproduced, and the simulation precision is improved.

The utility model discloses a kind of temperature drift test fixtures for linear differential transformer type displacement sensor, shell pedestal and vertical fixed plate are respectively fixedly installed on the top of bottom plate, pull rod pedestal is placed on the top of bottom plate and between shell pedestal and vertical fixed plate, shell connecting device is located on the upper portion of shell pedestal, pull rod connecting device is located on the upper portion of the pull rod pedestal, the both ends of transverse guide rod are connected with shell pedestal and vertical fixed plate respectively, and middle section passes through the corresponding through-hole on the pull rod pedestal, the screw rod of first transverse adjusting bolt mounted on vertical fixed plate and the screw rod of second transverse adjusting bolt mounted on shell pedestal are respectively contacted with the both sides of pull rod pedestal.The utility model is convenient for accurately adjusting the relative position between pull rod and shell, to realize the function of shell positioning and pull rod movement control, and the concentricity between pull rod and shell can be guaranteed, so it can be used to test the temperature drift of specified position point.

The utility model provides an LVDT displacement sensor for an adjusting type valve actuator, and relates to the field of sensors.The LVDT displacement sensor for the adjusting type valve actuator comprises a coil framework, the coil framework is hollow, a connecting rod is installed in the middle of the coil framework, and the two ends of the connecting rod extend out of the coil framework; a first coil and a second coil are arranged on the side portion of the coil framework, a spring tray is arranged at the upper end of the connecting rod, a spring is arranged in the spring tray, and the bottom of the connecting rod is connected with an adjusting type valve actuator. The device is simple, stable and reliable in structure and high in measurement precision, and the control precision of the adjusting type valve can be greatly improved.

This invention discloses a method and system for full-range displacement measurement using a linear variable differential transformer (LVDT) displacement sensor. The method demodulates the differential output signal of the LVDT secondary coil, simultaneously extracting amplitude and phase information. Based on pre-calibrated zero-point residual vector parameters, two displacement estimates are calculated in parallel using amplitude-domain and phase-domain solution models, respectively. A fusion weight is generated based on the current amplitude information, and the two displacement estimates are adaptively weighted and fused to obtain the final displacement measurement value. This invention utilizes the complementary characteristics of high phase sensitivity near the zero point and high amplitude linearity far from the zero point, achieving continuous and smooth switching between the two observation quantities through fusion weights. This eliminates the zero-point measurement dead zone without altering the sensor's structure, realizing continuous high-precision displacement measurement across the entire range.

The utility model relates to the technical field of steam turbines, and discloses a steam turbine admission regulating valve LVDT abrasion-proof connecting device which comprises an LVDT mounting plate and a DEH admission regulating valve and further comprises a ball head rod, a connecting ball head and a ball head seat, and a fixing seat is fixedly mounted at the upper end of the LVDT mounting plate; when the connecting device is used, the connecting device has an adjusting freedom degree, and when friction is caused by axial and radial misalignment between the LVDT iron core and the sleeve, the connecting ball head and the ball head seat can rotate, swing and incline smoothly with a very small sphericity gap, so that the abrasion probability is effectively reduced, the durability is improved, and the service life of the LVDT iron core is prolonged. According to the device, lubricating grease can be rapidly injected and automatically blocked when being added, and when the lubricating grease in the rotating inner cavity is reduced, the piston presses the lubricating grease in the lubricating grease storage pipe into the rotating inner cavity, so that the lubricating grease in the rotating inner cavity is automatically supplemented, and the maintenance frequency of the ball cup and the connecting ball head is greatly reduced.

The invention relates to the technical field of structural safety monitoring, and discloses a multi-degree-of-freedom displacement monitoring system which comprises a six-degree-of-freedom loading platform which is of a Stewart structure and comprises a counter-force platform, a loading platform body and six actuators. The displacement sensor group comprises six LVDT (Linear Variable Differential Transformer) ejector rod type displacement meters which are respectively connected between the loading beam and the ground beam through spherical hinges; the data acquisition module is used for acquiring analog signals of the six LVDTs in real time and converting the analog signals into digital signals; and the coordinate conversion module is used for converting the elongation of the six LVDTs into six-degree-of-freedom displacement of a test piece control point based on an incremental kinematics transformation method. The monitoring system is compact in structure, convenient to install, high in universality and suitable for six-degree-of-freedom loading tests of various complex structures such as bridges, pier columns and cylinders, and reliable technical support is provided for structure mixing tests and quasi-static tests.

The application discloses a kind of soil centrifuge simulation marine environment pile multi-direction loading test device and method thereof, belong to civil centrifuge test technical field, the device includes: model box, square frame, sliding mechanism, at least one aluminum pipe mounting section, rotary transmission mechanism, backing plate, thrust loading mechanism, load sensor, linear variable differential transformer, multiple miniature pore pressure sensor, at least one multi-position laser displacement meter;The method is applied to the above-mentioned one kind of soil centrifuge simulation marine environment pile multi-direction loading test device;Not only can the displacement accumulation of fan foundation in the whole life cycle under the action of multi-direction, cyclic loading under multi-direction loading, stiffness variation law, but also can study the evolution law of different seabed soil settlement, consolidation and other physical and mechanical properties, and is evaluated and analyzed through multi-angle.

A thermal static calibration apparatus for testing viscous fan clutches and a method thereof is provided. The apparatus (100) includes a test rig (110) with a specialized mechanical fixture (120) designed to securely hold a half-assembled viscous fan clutch (130). This clutch comprises critical elements such as a cover (140), valve lever (150), dividing disc assembly (160), pin (170), and bimetal strip (180). Positioned orthogonally to the clutch, an air heater (190) directly heats the bimetal strip, causing controlled thermal expansion. A Linear Variable Differential Transformer (LVDT) (200) measures valve lever displacement during this process. The data recording module (210) captures temperature and deflection readings, enabling the generation of a temperature versus deflection graph. By analysing the graph's slope, the engagement temperature of the viscous fan clutch (130) is determined. Finally, a computational technique calculates the optimal pin length based on this engagement temperature.

The invention provides a special test device for an LVDT (Linear Variable Differential Transformer), and belongs to the technical field of airborne servo sensors. The device comprises a bottom plate, a supporting rod arranged on the bottom plate, a fixing and supporting assembly arranged on the supporting rod and used for fixing an LVDT stator part to be tested, a guide groove formed in the bottom plate, and a sliding block sliding on the guide groove. The coupling rod is fixed on the sliding block and is used for fixing an LVDT mover part to be tested; and the scales are engraved on the bottom plate and are used for indicating the position of the sliding block. The device is small in size and mass, high in universality, wide in application range and capable of meeting test requirements in different environments such as temperature, vibration and impact.

The invention provides an in-situ test method for early mechanical properties of a cement-based material, and relates to the technical field of material tests.The in-situ test method comprises the steps that a miniature temperature stress test device is adopted for test piece pouring, and the test device comprises a pouring mold, a water supply machine, a positioning rod, a linear variable differential transformer and a temperature detector; vertically placing the testing device on a universal testing machine; a periodic loading-unloading cycle is applied to the test piece by moving the upper end of the pouring mold, the basic creep compliance is tested, and a complete curved surface function is obtained through fitting according to the instantaneous elastic modulus and the basic creep compliance of each age; restraining deformation of the test piece through a universal testing machine, and measuring stress evolution of the test piece; authigenic deformation and temperature deformation are tested under the no-load condition; the temperature deformation coefficient is measured by controlling temperature circulation. According to the method, through collaborative optimization on the structure and the method, the test difficulty is greatly reduced while the test precision and the boundary reliability are ensured, and the parameterization research capability is remarkably improved.

The utility model belongs to the technology of LVDT (Linear Variable Differential Transformer), and relates to an iron core assembly structure of a linear differential transformer type displacement sensor. The iron core assembly comprises a connecting rod (1) and a mover iron core (2), the connecting rod (1) of the iron core assembly is of a stepped cylinder structure, and the mover iron core (2) is of a cylindrical sleeve structure. The connecting rod (1) and the rotor iron core (2) are installed in a sleeved mode, a side face seam and a bottom face seam are welded and fixed in a laser welding mode, the effect that the rotor iron core (2) affects a magnetic field in a stator assembly is guaranteed, and meanwhile the connecting strength of the rotor iron core (2) is guaranteed through the two welding seams. The risk that the relatively long iron core assembly is broken from the welding position is avoided, the reliability of the product is improved, and the iron core assembly is more suitable for aviation equipment products.

The utility model discloses a linear variable differential transformer (LVDT) displacement sensor, which is characterized in that a plurality of groups of guide bearings and reset springs are arranged in a shell of the LVDT displacement sensor, and high-temperature-resistant epoxy resin is filled in an induction coil; the problems that the measurement precision is reduced and the reliability is insufficient due to thermal expansion and mechanical vibration of a traditional sensor in a high-temperature environment are solved. Specifically, the filling of the high-temperature-resistant epoxy resin effectively prevents the deformation of the induction coil at a high temperature and the reduction of the insulation performance, and the structural design of the guide bearing and the reset spring ensures the stable movement and accurate reset of the iron core in the measurement process. Therefore, compared with a traditional displacement sensor, the displacement sensor has higher performance stability, reliability and measurement accuracy in a high-temperature environment.

The utility model relates to the technical field of turbine speed regulation, in particular to an LVDT (Linear Variable Differential Transformer) connecting structure for a low-pressure regulating valve of a feed pump turbine. The LVDT connecting structure comprises a clamping plate and a connecting plate, the valve rod and the LVDT induction rod are connected through the clamping plate and the connecting plate, all the components are detachably connected, and installation, debugging, maintenance and replacement are convenient. And when a certain part is damaged, the part can be independently disassembled for maintenance or replacement, so that the maintenance cost is reduced. The linear motion of the valve rod is transmitted to the LVDT induction rod through the clamping plate and the connecting plate in sequence, the rod-shaped structure is prevented from being broken as far as possible through the arrangement of the plate-like structure, then transmission of a valve rod motion signal to the LVDT induction rod can be stably and reliably achieved, the accuracy of measuring the position signal of the valve rod by the LVDT is guaranteed, and the accuracy of measuring the position signal of the valve rod is improved. Measurement signal misalignment caused by breakage of a connection structure is avoided, so that stable adjustment of a water feed pump turboset valve is guaranteed, and the safety and stability of operation of a set and a power grid are improved.

The application discloses a novel method and corresponding measuring device for rapidly measuring key mechanical parameters of rock, including scratch hardness, Brinell hardness, Young's modulus and Mohr-Coulomb parameters (uniaxial compressive strength and internal friction angle). The equipment system comprises a portable frame, which contains a set of horizontal linear driving equipment, equipped with a set of linear encoders for accurately measuring horizontal displacement; the vertical direction contains a set of servo vertical driving equipment, equipped with a set of incremental magnetic encoders for accurately measuring vertical displacement, and a set of linear variable differential transformers (LVDT) for accurately sensing the slight concave-convex fluctuation of the rock surface; the servo motor drives the hemispherical composite piece through a screw rod; the size of the force in the horizontal and vertical directions of the scratch is measured by a bidirectional force sensor installed above the composite piece. The horizontal linear motor and the vertical servo motor are both loaded at a uniform speed; according to the size of the measured force, the scratch hardness and the Brinell hardness of the rock can be calculated; according to the theoretical solution of the slip line field hemispherical tooth, the Mohr-Coulomb parameters of the rock, including the uniaxial compressive strength (or cohesive force) and the internal friction angle, can be inversely calculated. When the vertical servo motor is loaded alone, the Brinell hardness of the rock can also be calculated; the Young's modulus can be calculated by the stiffness during unloading.