Search

CN-118974522-B - System for measuring physical quantity and/or position by bistable magnetic wire, and measuring method

CN118974522BCN 118974522 BCN118974522 BCN 118974522BCN-118974522-B

Abstract

A system for physical quantity measurement and/or position measurement using bistable magnetic wires (1), the system comprising an excitation element (2) for generating a magnetic field, and a sensing element (3). Within the magnetic field of the excitation element (2) a bistable magnetic wire (1) is placed, which bistable magnetic wire has a first end (11) and an oppositely placed second end (12). -magnetization adjustment of the bistable magnetic wire (1) by a single barkhausen jump from the first end (11) to the second end (12) or from the second end (12) to the first end (11), wherein the excitation element (2) and the bistable magnetic wire (1) are placed in a mutual position with an asymmetric magnetic field with respect to the bistable magnetic wire (1), wherein the amplitude of the magnetic field excited by the excitation element (2) at the first end (11) is different from the amplitude of the magnetic field excited by the excitation element (2) at the second end (12). The asymmetry of the magnetic field is due to the mutual asymmetric position of the excitation element (2) and the bistable magnet wire (1) and/or due to the asymmetric structure of the excitation element (2).

Inventors

  • Rastislav Valga

Assignees

  • RV磁性材料股份有限公司

Dates

Publication Date
20260505
Application Date
20230330
Priority Date
20220406

Claims (18)

  1. 1. A system for physical quantity measurement and/or position measurement with bistable magnet wires, the system comprising the bistable magnet wires, an excitation element (2) adapted to generate a magnetic field within the range of placement of the bistable magnet wires (1), the bistable magnet wires (1) having a first end (11) and an oppositely placed second end (12), wherein the bistable magnet wires (1) are magnetization-adjusted by a single barkhausen jump from the first end (11) to the second end (12) or from the second end (12) to the first end (11), and the system further comprises a sensing element (3) for receiving a response from the bistable magnet wires (1), It is characterized in that the method comprises the steps of, The excitation element (2) and the bistable magnetic wire (1) are placed in such a position that the amplitude of the magnetic field excited by the excitation element (2) at the first end (11) is different from the amplitude of the magnetic field excited by the excitation element (2) at the second end (12).
  2. 2. The system for physical quantity measurement and/or position measurement using bistable magnetic wire according to claim 1, characterized in that the difference in the amplitude of the magnetic field at the first end (11) and at the second end (12) is at least 5%.
  3. 3. System for physical quantity measurement and/or position measurement with bistable magnetic wires according to claim 1 or 2, characterized in that the system is adapted to measure temperature and/or pressure and/or tension and/or magnetic field and/or linear position.
  4. 4. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the coil of the sensing element (3) is separated from the coil of the excitation element (2).
  5. 5. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the bistable magnetic wire (1) has a diameter of less than 50 μm.
  6. 6. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the bistable magnetic wire (1) is covered with a layer of insulating material.
  7. 7. The system for physical quantity measurement and/or position measurement using bistable magnetic wire according to claim 6, wherein the insulating material is a layer of glass, and the thickness of the glass is up to 20 μm.
  8. 8. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the length of the bistable magnetic wire (1) is at least 1000 times the diameter of the metal core of the bistable magnetic wire (1).
  9. 9. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the excitation element (2) is placed asymmetrically with respect to the position of the bistable magnetic wire (1).
  10. 10. System for physical quantity measurement and/or position measurement with bistable magnetic wires according to claim 1 or 2, characterized in that the excitation element (2) has an asymmetric structure, the magnetic fields at its ends having different amplitudes.
  11. 11. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 10, characterized in that said excitation element (2) is formed by coils with different winding densities at said first end (11) and said second end (12) of said bistable magnetic wire (1).
  12. 12. System for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 1 or 2, characterized in that the longitudinal axis of the excitation element (2) is identical or parallel to the longitudinal axis of the bistable magnetic wire (1) or the longitudinal axis of the excitation element (2) deviates from the longitudinal axis of the bistable magnetic wire (1) by less than 30 degrees.
  13. 13. Method for physical quantity measurement and/or position measurement with bistable magnet wires, wherein an excitation element (2) emits a variable magnetic field, wherein at least one bistable magnet wire (1) is placed in the range of the magnetic field excited, which bistable magnet wire is magnetized when the magnetic field is changed by a single barkhausen jump from a first end (11) to a second end (12) of the bistable magnet wire or from the second end (12) to the first end (11), and wherein the response of the bistable magnet wire (1) is subsequently sensed by a sensing element (3), characterized in that the excitation element (2) and the bistable magnet wire (1) are held in a position in which the amplitude of the magnetic field excited by the excitation element (2) at the first end (11) is different from the amplitude of the magnetic field excited by the excitation element (2) at the second end (12).
  14. 14. Method for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 13, characterized in that the excitation magnetic field has a triangular amplitude waveform and the time (T1) of the local maximum and the time (T2) of the local minimum of the response of the bistable magnetic wire (1) are evaluated.
  15. 15. Method for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 13 or 14, characterized in that the excitation magnetic field has a frequency in a range in which the bistable magnetic wire (1) has at least one local maximum sensitivity for a specific type of measurement quantity or measurement position.
  16. 16. Method for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 14, characterized in that when evaluating the signal received from the bistable magnetic wire (1) as a response, the sum of the time (T1) of the local maximum and the time (T2) of the local minimum of the signal is evaluated.
  17. 17. Method for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 16, characterized in that the difference between the time (T2) of the local minimum and the time (T1) of the local maximum of the signal is taken into account when evaluating the signal received from the bistable magnetic wire (1) in response.
  18. 18. Method for physical quantity measurement and/or position measurement with bistable magnetic wire according to claim 13 or 14, characterized in that the response of the bistable magnetic wire (1) intercepted in the sensing element (3) is evaluated in a control unit (4).

Description

System for measuring physical quantity and/or position by bistable magnetic wire, and measuring method Technical Field The present invention relates to a combination of an excitation element and bistable magnetic wire, wherein the combination is manufactured for making various physical quantity and/or position measurements with bistable magnetic wire. The novelty of the system and method lies primarily in the specific asymmetric location of the magnetic field of the excitation element and the actual bistable magnet wire, thereby significantly improving the interpretation value of the raw measurement data. Background Bistable magnetic elements are used to measure various physical quantities and positions, where the bistable magnetic element is formed by a passive element that reacts by magnetization to a change in position or a change in a physical quantity in a magnetic field. For example, an alloy having bistable magnetic properties and a microwire made of the alloy are described in document GB2374084 a. Such microwires are capable of responding to a variety of physical quantities, but response assessment is problematic because prior art bistable magnetic elements may have complex magnetic behaviors in which magnetization occurs in multiple magnetic domains within a single microwire, rather than in a single wall jump. The use of bistable magnet wires in position measurements, angle measurements and rotation measurements is also known. The excitation of bistable magnetic wires wound on cores is illustrated in document US4484090 a. This solution does not evaluate the physical quantity. Some magnetic behaviors of bistable magnetic elements are described in the document JPH03252577a, which, however, does not address the problems associated with interpreting measured non-linear values. DE2817169A1, DE3427582A1, SU1753425A1 describe systems with a level of magnetically bistable Wiegand wire for determining that a bistable magnetic element is similar to a sensor. Due to this arrangement, the value of the physical quantity in the vicinity of the bistable magnetic element cannot be measured. The position sensor or rotation sensor according to publication EP0484716A1 uses a wiegand wire, to which a rotating permanent magnet is close. The sensor only reacts to the change of the magnetic field and does not evaluate the magnitude of the physical quantity. The wiegand sensor according to DE4107847C1 allows a contactless transmission of information about the closing of the switch, which information can react to changes in physical quantities (such as temperature, pressure, acceleration), but requires a suitable sensor by means of which the switch is subsequently controlled, i.e. the physical quantity is not measured by the bistable magnetic element itself. A new unknown technical solution is desired that is simple in structure, can improve the repeatability and interpretation of various physical quantity measurements, and eliminates the influence of noise and secondary phenomena. The bistable magnetic element itself must react to changes in the measured physical quantity and also generate a response that is transmitted contactlessly to the receiving element. Disclosure of Invention The above-mentioned drawbacks are substantially eliminated by a system for physical quantity measurement and/or position measurement using bistable magnetic wires, wherein the system comprises an excitation element for generating a magnetic field, the bistable magnetic wires being located within the range of the magnetic field. According to the invention, the bistable magnetic wire has a first end and an oppositely placed second end and is thus not wound in a spiral or coil, wherein the bistable magnetic wire is magnetization-adjusted by a single barkhausen front jump from the first end to the second end or vice versa, essentially in that the excitation element and the bistable magnetic wire are placed in a mutual position in which the amplitude of the magnetic field excited by the excitation element at the first end differs from the amplitude of the magnetic field excited by the excitation element at the second end. At each instant of non-zero excitation (and thus at a given instant), the magnetic fields at the first and second ends are different, wherein the excitation is dynamic in time. The system further comprises a receiving element for receiving a response from the bistable magnet wire. The terms "first" and "second" are used herein to designate both ends differently, and these terms are interchangeable, so the terms "first" and "second" do not denote the superiority or importance of the respective ends of the bistable magnet wire. The difference in magnetic fields at the ends at a given excitation instant results in an asymmetric magnetic field which, together with the magnetization caused by Shan Ciba khausen jumps, gives a reproducible and interpretable measurement result. For practical measurement applications, it is important that