Linear acceleration compensation sensor

Abstract

FIELD: measurement technology.SUBSTANCE: linear acceleration compensating sensor is equipped with two magnetic systems, each of which is made in the form of a magnetic circuit, in the internal cavity of which a magnet is installed, connected to a concentrator and two coils, electrically connected to each other and mounted on bushings, the sensitive element is installed between covers, which are equipped with through holes, through which bushings with coils are coaxially mounted on the planar surface of the sensitive element on both sides, and both parts of the housing are equipped with seats in which magnetic systems are installed in such a way that the same poles of the magnets are located opposite each other, whereas the coils are placed in the gaps of the magnetic systems between the concentrator and the magnetic circuit, so that the coils are in the magnetic flux flowing in the gap.EFFECT: increase in the accuracy of acceleration conversion and an increase in resistance to external destabilizing factors.1 cl, 1 dwg

Description

[0001] The invention relates to the field of measurement technology and is intended to convert linear acceleration into a proportional change in current.

[0002] Currently, there is a problem of improving the accuracy of acceleration conversion and increasing the resistance of accelerometers to external destabilizing factors.

[0003] An acceleration sensor described in the invention entitled "Sensing Structure of a Piezoresistive Acceleration Sensor and an Acceleration Sensor" [China Patent for Invention No. CN 117607489, IPC G01P 15 / 12, priority 01 / 17 / 2024, published 02 / 27 / 2024] is known, comprising a frame and a sensing unit. The frame forms a first accommodation space, and the sensing unit is located in the first accommodation space. The sensing unit includes a mass block, a first support beam and a second support beam. The mass block has a main body and a convex portion protruding from the main body; one end of the first support beam is connected to a first longitudinal position of the main body of the mass block, and the other end is connected to the frame; one end of the second support beam is connected to the first longitudinal position of the main body of the mass block. At the second longitudinal position, the other end is connected to the frame.In this case, the longitudinal direction of the mass block is the sensing direction of the mass block; the first support beam and the second support beam are respectively located on opposite sides of the main body of the mass block, and the extension direction of the convex portion of the mass block is consistent with the first support beam and the second support beam. The extension directions of the two support beams are parallel; the mass block exerts a force on the first support beam and the second support beam under the action of acceleration.

[0004] The disadvantages of the known technical solution are:

[0005] - direct measurement of the change in resistance of a piezoresistive sensor during acceleration leads to nonlinearity of the output signal, hysteresis of the transfer characteristic, and relatively high sensitivity to temperature changes, which in turn reduces the accuracy of the sensor;

[0006] - the asymmetrical arrangement of the support beams and the use of beams of different cross-sections leads to the sensor's sensitivity to lateral acceleration, which in turn increases the additional error of the sensor and reduces its resistance to external mechanical influences.

[0007] This device is accepted as a prototype, as it is closest in technical essence to the claimed invention.

[0008] The technical result that the claimed invention is aimed at achieving is to increase the accuracy of acceleration conversion and to increase resistance to external destabilizing factors.

[0009] The specified technical result is achieved in that the compensating linear acceleration sensor contains a housing made of two parts, a sensitive element installed in the internal cavity of the housing and made in the form of a pendulum with strain gauges and contact pads located on its planar surface, characterized in that it is equipped with two magnetic systems, each of which is made in the form of a magnetic circuit, in the internal cavity of which a magnet is installed, connected to a concentrator, and two coils electrically connected to each other and mounted on bushings, the sensitive element is installed between covers that are provided with through holes through which bushings with coils are coaxially installed on the planar surface of the sensitive element on both sides, and both parts of the housing are equipped with seats in which magnetic systems are installed in such a way that the same poles of the magnets are located opposite each other,in this case, the coils are placed in the gaps of the magnetic systems between the concentrator and the magnetic circuit, so that they are in the magnetic flux flowing in the gap.

[0010] The introduction of two magnetic systems and two coils into the sensor design enables a compensation principle, eliminating nonlinearity in the strain gauge characteristics, eliminating hysteresis, and reducing the sensor's temperature error. The inclusion of covers between which the sensing element is mounted limits its travel, which in turn ensures the sensor's resistance to external destabilizing factors. Thus, the combination of all the above features creates conditions for increased acceleration conversion accuracy and increased resistance to external destabilizing factors, ensuring resistance to harsh mechanical and climatic influences.

[0011] The presence in the claimed invention of features that distinguish it from the prototype allows it to be considered as meeting the condition of “novelty”.

[0012] The new features contained in the distinctive part of the invention formula are not identified in technical solutions of a similar purpose; on this basis, a conclusion can be drawn about the compliance of the claimed invention with the condition of “inventive step”.

[0013] The technical solution is illustrated by the drawing.

[0014] The figure shows a cross-section of the linear acceleration compensator.

[0015] The linear acceleration compensator contains a housing, a sensing element 1, two bushings 2, two coils 3 and two magnetic systems.

[0016] The housing is made of a non-magnetic material and consists of two identical parts 4, mirror-image-joined to form the housing's internal cavity. Each part 4 is equipped with a mounting seat located symmetrically opposite one another. One of the parts 4 contains through-holes, into which the terminals 5 are installed through an insulator.

[0017] Sensing element 1 is located within the housing and is shaped like a pendulum with strain gauges and contact pads (not shown) arranged on its planar surface. The contact pads are connected to current terminals 5 for electrical communication with an external consumer (not shown). Sensing element 1 is positioned between upper 6 and lower 7 covers, mounted on opposite sides of the pendulum and limiting its travel. The travel of sensitive element 1 is limited to a value that prevents deformation in the suspensions exceeding the elastic limit, ensuring the sensor's resistance to external mechanical influences (impacts, excessive acceleration, vibration). Upper 6 and lower 7 covers are provided with central through holes.

[0018] Bushings 2 are installed directly on the sensitive element 1 from its opposite sides through openings in the upper 6 and lower 7 covers.

[0019] Coils 3 are identical and coaxially mounted on the bushings 2 protruding from the surface of the upper 6 and lower 7 covers on opposite sides. Coils 3 are electrically connected to each other in a sequential pattern, with the start (or end) of one coil's winding being connected to the start (or end) of the second coil. The winding directions of coils 3, when mounted coaxially on opposite sides of sensing element 1, are opposite (e.g., one coil has a left-hand winding direction, and the other a right-hand winding direction).

[0020] The magnetic systems are identical and consist of magnets 8, magnetic cores 9, and concentrators 10. Magnets 8 are fixed between magnetic cores 9 and concentrators 10. Magnetic cores 9 are installed in the mounting seats of housing parts 4 opposite each other. The poles of magnets 8 are installed in the magnetic systems so that in the sensor, like poles are opposite each other. Magnetic cores 9 are equipped with projections directed toward concentrators 10. A gap is formed between concentrators 10 and the projections of magnetic cores 9, in which coils 3 are located.

[0021] The device operates as follows

[0022] Acceleration causes sensing element 1 to shift, a deflection detected by strain gauges that transmit a signal to the load. The external load's measuring circuit detects the change in the load's resistance and generates a control signal, which is fed to coils 3, which are connected to the load's feedback circuit. The electric current flowing in coils 3 interacts with the magnetic flux passing through the gap between concentrator 10 and magnetic core 9, resulting in an ampere force acting on coils 3. This force (according to the "left-hand rule") moves coils 3 axially. Since coils 3 are rigidly mechanically connected to sensing element 1, they move it to its initial position, at which the change in the load's resistance is zero. The current required to return sensing element 1 to its initial position is directly proportional to the acceleration.

[0023] Thus, the above information indicates that the following set of conditions are met when using the claimed invention:

[0024] • The means embodying the claimed invention when carried out relates to measuring equipment intended for converting linear acceleration into a proportional change in current;

[0025] • For the claimed device in the form as it is characterized in the claim, the possibility of its implementation has been confirmed;

[0026] • The means embodying the claimed invention, when implemented, is capable of providing an increase in the accuracy of acceleration conversion and an increase in resistance to external destabilizing factors.

[0027] Therefore, the claimed invention meets the condition of “industrial applicability”.

Claims

A compensating linear acceleration sensor comprising a housing made of two parts, a sensitive element installed in the internal cavity of the housing and made in the form of a pendulum with strain gauges and contact pads located on its planar surface, characterized in that it is equipped with two magnetic systems, each of which is made in the form of a magnetic circuit, in the internal cavity of which a magnet is installed, connected to a concentrator and two coils electrically connected to each other and installed on bushings, the sensitive element is installed between covers, which are provided with through holes, through which bushings with coils are coaxially installed on the planar surface of the sensitive element on both sides, and both parts of the housing are equipped with seats in which magnetic systems are installed in such a way that the same poles of the magnets are located opposite each other,in this case, the coils are placed in the gaps of the magnetic systems between the concentrator and the magnetic circuit so that the coils are in the magnetic flux flowing in the gap.

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