Ball array type magnetic resistance linear time grating displacement sensor and displacement measurement method

Abstract

The invention relates to the technical field of precision linear displacement measurement sensors, and discloses a ball array type reluctance linear time grating displacement sensor and a displacement measurement method.The ball array type reluctance linear time grating displacement sensor comprises a stator and a mover, and the stator comprises a stator base body and a plurality of steel balls installed in the stator base body; the rotor comprises a rotor base body and a sine / cosine winding fixed on the outer surface of the rotor base body, the sine winding is provided with an S + excitation winding, an S-excitation winding and a sine induction winding, and the cosine winding is provided with a C + excitation winding, a C-excitation winding and a cosine induction winding. The sine induction winding and the cosine induction winding respectively generate two paths of electric signals U1 and U2, a traveling wave signal U carrying linear displacement information is output through the logic circuit and is compared with a same-frequency reference signal Uf in phase, and displacement decoupling is achieved. The device can effectively reduce the magnetic field edge effect, improves the displacement signal sensing quality, does not depend on an ultra-precision manufacturing process, simplifies the overall structure, and reduces the manufacturing cost.

Description

Background Art

[0002] In the field of semiconductor manufacturing or ultra-precision machining, displacement measurement is often required to have high measurement accuracy and resolution while also having a large range. The large-range precision displacement measuring instruments commonly used in engineering practice mainly include laser interferometers and grating displacement sensors represented by gratings. Since the measurement error of laser interferometers increases with the increase of measurement stroke, it is sensitive to the use environment. Changes in air temperature and humidity, air pressure, carbon dioxide content, and airflow disturbances will cause measurement errors. It is not suitable for long-term working applications. Therefore, grating displacement sensors are more in line with the use requirements.

[0003] The grating displacement sensor includes the ball grating displacement sensor. The ball grating displacement sensor has the advantages of long service life, strong anti-interference ability and stable movement speed, but the measurement accuracy and resolution are limited by the processing accuracy of the sphere and it is difficult to further improve. Summary of the invention

[0004] The invention provides a ball array type magnetoresistive linear time-grid displacement sensor and a displacement measurement method.

[0005] In the first aspect, the present invention provides a ball array type magnetoresistive linear time-grid displacement sensor. The present invention includes a stator and a mover, the stator includes a stator matrix and a plurality of steel balls tightly mounted in the stator matrix, the mover includes a mover matrix and a sine winding and a cosine winding axially fixed to the outer surface of the mover matrix, the stator matrix and the mover matrix are both made of non-magnetic conductive materials, the stator matrix and the mover matrix are both hollow cylindrical structures, the mover is sleeved outside the stator, and the stator and the mover are coaxially installed, the sine winding is provided with an S+ excitation winding, an S- excitation winding and a sine induction winding, and the cosine winding is provided with a C+ excitation winding, a C- excitation winding and a cosine induction winding.

[0006] The sinusoidal winding is provided with a plurality of coils, and the sinusoidal winding includes an S+ excitation winding, an S- excitation winding and a sinusoidal induction winding, wherein the S+ excitation winding is composed of a coil numbered A 2i-1 The S-excitation winding consists of a coil numbered A 2i The sinusoidal induction winding consists of coil X 1 The cosine winding is composed of a plurality of coils, wherein i is a positive integer; the cosine winding comprises a C+ excitation winding, a C- excitation winding and a cosine induction winding, wherein the C+ excitation winding is composed of a coil numbered B 2i-1 The C-excitation winding consists of a coil numbered B 2i The cosine induction winding consists of coil X 2 Composition, where i is a positive integer;

[0007] The winding direction of the two adjacent excitation coils in the sinusoidal winding is not fixed, and the wiring method is not fixed. The winding direction and wiring method of the coils for the purpose of establishing an alternating time-varying magnetic field are all possible, that is, the coils numbered A 2i The coil number is A 2i-1 The coil is wound in the opposite direction and connected in the forward direction, or numbered A 2i The coil number is A 2i-1 The coils are wound in the same direction, connected in reverse, and are numbered A 2i The coil number is A 2i-1 The coils are arranged at equal intervals and alternately, connected in series to form an excitation winding and a sinusoidal excitation current is passed through it.

[0008] The winding direction of the two adjacent excitation coils in the cosine winding is not fixed, and the wiring method is not fixed. Any coil arrangement method and wiring method for the purpose of establishing an alternating time-varying magnetic field are acceptable, that is, numbered B 2i Coil numbered B 2i-1 The coil is wound in the opposite direction and connected in the forward direction, or numbered B 2i Coil numbered B 2i-1 The coils are wound in the same direction, connected in reverse, and are numbered B 2i Coil numbered B 2i-1 The coils are arranged at equal intervals and alternately, connected in series to form an excitation winding and a cosine excitation current is passed through it.

[0009] The coil X in the sinusoidal winding 1 A is set in the sinusoidal winding 1 The coil number is A 2i The axial position center point of the coil, the cosine winding coil X 2 Set in the cosine winding numbered B 1 Coil numbered B 2i The axial position center point of the coil;

[0010] The sinusoidal winding is numbered A 2i The coil number is A 2i-1 The coil and the cosine winding numbered B 2i Coil numbered B 2i-1 The size of the coil is the same as that of the sinusoidal winding coil X 1 With the cosine winding in coil X 2 The same size.

[0011] Taking the diameter of a steel ball as a measurement period, the number in the sinusoidal winding is A 1 The coil and cosine winding are numbered B 1The distance between the centers of the coils in the axial direction is a first preset multiple of the measurement period, wherein the first preset multiple is (M+1 / 4), M is a positive integer; the adjacent numbered A in the sinusoidal winding 2i The coil number is A 2i-1 The coils are spaced apart along the axial center on the outer surface of the mover substrate by a second preset multiple of the measurement cycle, wherein the second preset multiple is 1 / N 1 , N 1 is a positive integer; the adjacent numbers in the cosine winding are B 2i Coil numbered B 2i-1 The coils are spaced apart along the axial center on the outer surface of the mover substrate by a third preset multiple of the measurement period, wherein the third preset multiple is 1 / N 2 , N 2 Is a positive integer.

[0012] Optionally, the adjacent numbers in the sinusoidal winding are A 2i The coil number is A 2i-1 The coil and the coil X in the sine winding 1 They are all printed on different PCB boards using PCB manufacturing technology. The adjacent ones in the cosine winding are numbered B. 2i Coil numbered B 2i-1 The coil and the cosine winding in X 2 The coils are all printed on different PCB boards using PCB manufacturing technology.

[0013] Optionally, the stator base is made of stainless steel.

[0014] Optionally, the mover matrix is ​​made of microcrystalline glass ceramics.

[0015] Optionally, the winding direction and connection mode of two adjacent coils in the sine winding are preferably connected in a way that the magnetic field is most uniform. The winding direction and connection mode of two adjacent coils in the cosine winding are preferably connected in a way that the magnetic field is most uniform.

[0016] The beneficial effects of the present invention are as follows: the stator matrix and the mover matrix are both made of non-magnetic conductive materials, so the magnetic field propagation path is constrained inside the tightly installed steel balls by utilizing the magnetic resistance characteristics of the non-magnetic conductive materials, and by changing the number A in the sinusoidal winding 2i The coil number is A 2i-1 The coil and cosine winding are numbered B 2i Coil numbered B 2i-1The excitation signal of the coil controls the main distribution area and direction of the magnetic field, which can effectively reduce the edge effect of the magnetic field and improve the sensing quality of the displacement signal. In addition, both the sine winding and the cosine winding can be manufactured using PCB technology, which does not rely on ultra-precision manufacturing processes, simplifies the overall structure, and reduces manufacturing costs.

[0017] In a second aspect, the present invention provides a displacement measurement method, which is applied to a ball array type magnetoresistive linear time-grid displacement sensor as described above, comprising:

[0018] Applying a sinusoidal current excitation signal to the S+ excitation winding and the S- excitation winding in the sinusoidal winding on the outer surface of the mover base, and applying a cosine current excitation signal to the C+ excitation winding and the C- excitation winding in the cosine winding; wherein the sinusoidal current excitation signal and the cosine current excitation signal have the same frequency and the same amplitude;

[0019] When the rotor moves linearly relative to the stator axial direction, the sine induction winding and the cosine induction winding output standing wave signals U 1 , U 2 ;

[0020] The two standing wave signals U 1 and U 2 After being processed by the logic circuit, a traveling wave signal U with linear displacement information is output;

[0021] The traveling wave signal U is compared with the reference signal U f Perform phase comparison to determine the phase difference;

[0022] The phase difference and the same frequency reference signal U are measured by high-frequency clock pulses f Interpolation is performed to determine the number of the first high-frequency clock pulses for interpolating the phase difference and the interpolation of the same-frequency reference signal U f The number of second high-frequency clock pulses;

[0023] The linear displacement of the mover relative to the stator is determined according to the number of the first high-frequency clock pulses and the number of the second high-frequency clock pulses. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Figure 1 A schematic diagram of the structure of a ball array type magnetoresistive linear time-grid displacement sensor according to an embodiment of the present invention;

[0026] Figure 2 is a cross-sectional structural diagram of a mover according to an embodiment of the present invention;

[0027] Figure 3is a cross-sectional structural diagram of a stator according to an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of a sine winding, a cosine winding, a sine induction winding and a cosine induction winding;

[0029] Figure 5 PCB printed coil winding schematic diagram for S+ excitation winding, S- excitation winding, C+ excitation winding and C- excitation winding;

[0030] Figure 6 A cross-sectional schematic diagram of a ball array type magnetoresistive linear time-grid displacement sensor according to an embodiment of the present invention;

[0031] Figure 7 PCB printed coil winding schematic diagram for sine induction winding and cosine induction winding;

[0032] Figure 8 It is a cross-sectional schematic diagram of a ball array type magnetoresistive linear time-grid displacement sensor in the second embodiment;

[0033] Fig. 9 It is a cross-sectional schematic diagram of a ball array type magnetoresistive linear time-grid displacement sensor in Example 3;

[0034] Fig.10 A schematic flow chart of a displacement measurement method according to an embodiment of the present invention;

[0035] Fig.11 The figure is a flow chart of a displacement measurement method according to another embodiment of the present invention.

[0036] Description of the drawings: stator 1, stator matrix 11, mover 2, mover matrix 21, sine winding 22, cosine winding 23, sine induction winding X 1 , cosine induction winding X 2 , steel ball 12. DETAILED DESCRIPTION

[0037] The following examples are provided to further explain and supplement the present invention and do not constitute any limitation to the present invention.

[0038] A ball array type magnetoresistive linear time-grid displacement sensor and a displacement measurement method according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0039] like Figure 1-4As shown, the present invention provides a ball array type magnetoresistive linear time-grid displacement sensor, comprising a stator 1 and a mover 2, wherein the stator 1 comprises a stator base 11 and a plurality of steel balls 12 tightly mounted in the stator base 11, the mover 2 comprises a mover base 21 and a sine winding 22 and a cosine winding 23 axially fixed on the outer surface of the mover base 21, the stator base 11 and the mover base 21 are both hollow cylindrical structures, the mover 2 is sleeved outside the stator 1, and the stator 1 and the mover 2 are coaxially mounted.

[0040] The diameter of a steel ball 12 is taken as a measurement period, such as Figure 4 As shown, a sinusoidal winding 22 is provided in a measurement cycle W, and the sinusoidal winding 22 is provided with an S+ excitation winding, an S- excitation winding and a sinusoidal induction winding, wherein the S+ excitation winding is composed of a winding numbered A 2i-1 The S-excitation winding consists of a coil numbered A 2i The sinusoidal induction winding consists of coil X 1 In addition, a cosine excitation winding 23 is provided in a measurement cycle W, and the cosine winding 23 is provided with a C+ excitation winding, a C- excitation winding and a cosine induction winding X 2 , C+ excitation winding is numbered B 2i-1 The C-excitation winding consists of a coil numbered B 2i The cosine induction winding consists of coil X 2 where i is a positive integer.

[0041] The S+ excitation winding and the S- excitation winding in the sine winding 22 are wound in opposite directions, that is, numbered A 2i The coil number is A 2i-1 The coils are wound in opposite directions and are numbered A 2i The coil number is A 2i-1 The coils are arranged in series with equal spacing and alternating arrangement to form an excitation winding and a sinusoidal excitation current is passed through; the C+ excitation winding and the C- excitation winding in the cosine winding 23 are wound in opposite directions, that is, numbered B 2i Coil numbered B 2i-1 The coils are wound in the opposite direction and are numbered B 2i Coil numbered B 2i-1 The coils are arranged at equal intervals and alternately, connected in series to form an excitation winding and a cosine excitation current is passed through it.

[0042] The sine winding 22 is numbered A 2i The coil number is A 2i-1 The cosine winding 23 is numbered B 2i Coil numbered B 2i-1 The coils of the same size, the coil X in the sinusoidal induction winding 1Coil X in the cosine induction winding 2 The same size.

[0043] The stator base 11 and the mover base 21 are both made of non-magnetic materials. Each excitation coil of the sinusoidal winding 22 and the X of the sinusoidal induction winding 1 The coils are printed on different PCB boards using PCB manufacturing technology. Each excitation coil of the cosine winding 23 and the X of the cosine induction winding 2 The coils are all printed on different PCB boards using PCB manufacturing technology. 2i Coil, A 2i-1 Coil and cosine winding (23) B 2i Coil, B 2i-1 The coils have the same size, and the X 1 Coil and cosine winding (23) in X 2 The coils are the same size.

[0044] The induction coil X in the sinusoidal winding 22 1 Set in the sine winding 22 numbered A 1 The coil number is A 2i At the axial center point of the coil, that is, at the axial center point of the sine winding 22, the induction coil X in the cosine winding 23 2 Set in the cosine winding 23 numbered B 1 Coil numbered B 2i The axial center point of the coil, that is, the axial center point of the cosine winding 23.

[0045] In this embodiment, the stator base 11 and the mover base 21 are both made of non-magnetic conductive materials:

[0046] Optionally, the stator base 11 is made of stainless steel;

[0047] Optionally, the mover matrix 21 is made of microcrystalline glass ceramics.

[0048] Optionally, the number of the sinusoidal winding 22 is A 2i The coil number is A 2i-1 The coil and the coil X in the sinusoidal induction winding 1 All are printed on different PCB boards using PCB manufacturing technology and are numbered A 2i The coil number is A 2i-1 The coils are arranged in series with equal spacing and alternating arrangement to form an excitation winding and a sinusoidal excitation current is passed through; the cosine winding 23 is numbered B 2i Coil numbered B 2i-1 The coil and the cosine induction winding coil X 2All are printed on different PCB boards using PCB manufacturing technology, numbered B 2i Coil numbered B 2i-1 The coils are arranged at equal intervals and alternately, connected in series to form an excitation winding and a cosine excitation current is passed through it.

[0049] like Figure 5 As shown, the sinusoidal winding 22 is numbered A 1 Take the coil as an example, numbered A 1 The coil is printed on a PCB board in the sine winding using PCB manufacturing technology. The sine winding 22 is numbered A 2i The coil number is A 2i-1 The coil size and cosine winding of the coil 22 are numbered B 2i Coil numbered B 2i-1 The coils of the coils are the same size.

[0050] like Figure 7 As shown, the induction coil X in the sinusoidal winding 22 1 For example, the induction coil X 1 The induction coil X in the sinusoidal winding 22 is printed on a PCB board in the sinusoidal winding using PCB manufacturing technology. 1 The coil size and cosine winding 23 in the induction coil X 2 The coils are the same size.

[0051] In this embodiment, the diameter of a steel ball 12 is W, and the diameter W of a ball is used as a measurement period. The first excitation coil in the sine winding 22 and the first excitation coil in the cosine winding 23 are spaced apart in the axial direction by a distance of a first preset multiple of the measurement period, that is, the first excitation coil numbered A in the sine winding 22 is 1 The coil and cosine winding 23 are numbered as B 1 The centers of the coils are spaced axially a distance equal to a first preset multiple of the measurement period, where the first preset multiple is (M+1 / 4), where M is a positive integer.

[0052] like Figure 4 As shown, the first excitation coil A on the sinusoidal winding 1 The first excitation coil A on the cosine winding 1 The center distance is (M+1 / 4)W.

[0053] The distance between two adjacent excitation coils in the sinusoidal winding 22 on the outer surface of the rotor base 21 along the axial center is a second preset multiple of the measurement period, that is, numbered A 2i The coil number is A 2i-1 The distance of the coils on the outer surface of the mover substrate 21 along the axial center is a second preset multiple of the measurement period, wherein the second preset multiple is 1 / N1 , where N 1 Is a positive integer.

[0054] The distance between two adjacent excitation coils in the cosine winding 23 on the outer surface of the rotor base 21 along the axial center is a third preset multiple of the measurement period, that is, numbered B 2i Coil numbered B 2i-1 The distance of the coils on the outer surface of the mover substrate 21 along the axial center interval is a third preset multiple of the measurement period, wherein the third preset multiple is 1 / N 2 , where N 2 Is a positive integer.

[0055] like Figure 4 As shown, the center distance between two adjacent excitation coils in the sinusoidal winding 22 is L 2 , that is, the two adjacent windings numbered A in the sine winding 22 2i The coil number is A 2i-1 The center spacing between the coils is L 2 The center distance between two adjacent excitation coils in the cosine winding 23 is L. 2 , that is, the two adjacent numbers in the cosine winding 23 are B 2i Coil numbered B 2i-1 The center spacing between the coils is L 2 , where L 2 =a measurement period of the second preset multiple or a measurement period of the third preset multiple.

[0056] The present invention is described in detail below in conjunction with the accompanying drawings. A ball array type magnetoresistive linear time-grid displacement sensor is described using three specific embodiments. The difference between the three embodiments lies in the arrangement positions of the excitation coils of the same size constituting each group of excitation windings, the fixed-length structures in the three different embodiments are consistent, and the parameters in the sine winding and the cosine winding in the moving-length structure are consistent.

[0057] Embodiment 1

[0058] A ball array type magnetoresistive linear time-grid displacement sensor comprises a stator 1 and a mover 2, wherein the stator 1 comprises a stator matrix 11 made of stainless steel material and a high-precision steel ball 12 tightly mounted in the stator matrix 11. Figure 6 As shown, the diameter of a single high-precision steel ball 12 is one measurement cycle W = 12 mm, and the outer surface diameter d of the stator matrix 11 is 2 =14mm.

[0059] The mover 2 includes a mover base 21 made of PVC material and a sine winding and a cosine winding arranged on the outer surface of the mover base 21. The stator base 11 and the mover base 21 are both hollow cylindrical structures. The mover 2 is sleeved outside the stator 1, and the stator 1 and the mover 2 are coaxially installed. There are multiple PCB boards in the sine winding, and each PCB board is printed with an excitation coil or an induction coil using PCB manufacturing technology. There are also multiple PCB boards in the cosine winding, and each PCB board is printed with an excitation coil or an induction coil using PCB manufacturing technology. Among them, the excitation coil A in the sine winding 22 2i Coil, A 2i-1 The coil size of the coil is the same as the exciting coil B in the cosine winding 23 2i Coil, B 2i-1 The coils have the same coil size, the induction coil X in the sinusoidal winding 22 1 The coil size and cosine winding 23 in the induction coil X 2 The coil size is the same, and the outer surface diameter d of the mover base 21 3 =18mm, thickness of a single PCB board in a sine winding or cosine winding L 1 =1mm.

[0060] like Figure 5 As shown, the sinusoidal winding 22 is numbered A 2i The coil number is A 2i-1 The coil size of the coil is the same as the cosine winding 23 numbered B 2i Coil numbered B 2i-1 The coils have the same coil size, and the radius of a single excitation coil is R 1 =12mm, line width of a single excitation coil δ 1 =1mm

[0061] like Figure 6 As shown, a sinusoidal winding 22 is set in a measurement cycle W, including an S+ excitation winding, an S- excitation winding and a sinusoidal induction winding. The S+ excitation winding and the S- excitation winding are wound in opposite directions. The S+ excitation winding and the S- excitation winding are alternately arranged in series with each other. Among them, the S+ excitation winding is composed of a winding numbered A 1 The coil number is A 3 The S-excitation winding consists of a coil numbered A 2 The coil number is A 4 The four excitation coils are connected in series and a sinusoidal excitation current is passed through them. In addition, a cosine winding 23 is set in a measurement cycle W, including a C+ excitation winding, a C- excitation winding and a cosine induction winding. The C+ excitation winding and the C- excitation winding are wound in opposite directions. The C+ excitation winding and the C- excitation winding are alternately arranged and connected in series with each other. The C+ excitation winding is composed of a C+ excitation winding numbered B 1 Coil numbered B3 The C-excitation winding consists of a coil numbered B 2 Coil numbered B 4 The four excitation coils are connected in series and cosine excitation current is passed through them.

[0062] like Figure 6 As shown, the number of excitation coils in a measurement cycle W is set to 4, and two adjacent excitation coils in the sine winding or cosine winding are spaced L along the axial center on the outer surface of the rotor base 21. 2 =3mm arrangement.

[0063] like Figure 6 As shown, the first excitation coil A in the sinusoidal winding 1 The first excitation coil B in the cosine winding 2 The distance of the measuring cycle with the center spacing being the first preset multiple in the axial direction:

[0064] (M+1 / 4)W (M is 4).

[0065] The induction coil X in the sinusoidal winding 22 1 The coil size and cosine winding 23 in the induction coil X 2 The coil size is the same as Figure 7 As shown, the radius of a single induction coil R 2 =11mm, the line width of a single induction coil δ 2 =1mm.

[0066] like Figure 6 As shown, the induction coil X in the sinusoidal winding 22 1 In the axial direction, they are respectively 2 The coil number is A 3 The coil center spacing L 3 =1.5mm, that is, located at the axial center of the sine winding 22; the induction coil X in the cosine winding 23 2 In the axial direction, they are respectively 2 Coil numbered B 3 The coil center spacing L 3 =1.5mm, that is, located at the axial center point of the cosine winding 23.

[0067] Optionally, the winding directions of two adjacent excitation coils in the sinusoidal winding (22) are opposite, wherein the coils numbered A 2i , number A 2i-1 The excitation coils (where i is a positive integer) are connected in series through the excitation signal lead to form a group, forming a sinusoidal excitation winding, and a sinusoidal excitation current is passed; the winding directions of the two adjacent excitation coils in the cosine winding (23) are opposite, wherein the number is B 2i, numbered B 2i-1 The excitation coils (where i is a positive integer) are connected in series through excitation signal leads to form a cosine excitation winding, and a cosine excitation current is passed through it.

[0068] Optionally, the sine winding (22) is numbered A 2i The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming an S-excitation winding, and a negative sinusoidal excitation current is passed through the sinusoidal winding (22) numbered A 2i-1 The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming an S+ excitation winding, and a positive sinusoidal excitation current is passed; the cosine winding (23) is numbered B 2i The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming a C-excitation winding, and a negative cosine excitation current is passed through the cosine winding (23) numbered B 2i-1 The excitation coils composed of coils are connected in series into a group through the excitation signal lead to form a C+ excitation winding, and a positive cosine excitation current is passed through;

[0069] Optionally, the sine winding (22) is numbered A 2i The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming an S-excitation winding, and the sine winding (22) is numbered A 2i-1 The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming an S+ excitation winding. The S+ excitation winding and the S- excitation winding are wound in opposite directions and are connected in series to form a sine winding, and a sine excitation current is passed; the cosine winding (23) is numbered B 2i The excitation coils composed of the coils are connected in series through the excitation signal lead to form a group, forming a C-excitation winding, and the cosine winding (23) is numbered B 2i-1 The excitation coils composed of the coils are connected in series into a group through the excitation signal lead to form a C+ excitation winding. The C+ excitation winding and the C- excitation winding are wound in opposite directions and are connected in series to form a cosine winding, and a cosine excitation current is passed through;

[0070] Embodiment 2

[0071] The difference between the second embodiment and the first embodiment lies in the arrangement positions of the four excitation coils of the same size constituting each group of excitation windings. Figure 6 As shown, in the first embodiment, the four excitation coils are spaced L along the axial center within a measurement cycle W. 2 =3mm arrangement, such as Figure 8 As shown, in the second embodiment, the four excitation coils are changed to be spaced L along the axial center within a measurement cycle W. 2 =4mm arrangement.

[0072] The induction coil X in the sinusoidal winding 22 1In the axial direction, they are respectively 2 The coil number is A 3 The coil center spacing L 3 =2mm, that is, located at the axial center of the sine winding 22; the induction coil X in the cosine winding 23 2 In the axial direction, they are respectively 2 Coil numbered B 3 The coil center spacing L 3 =2mm, that is, located at the axial center point of the cosine winding 23.

[0073] Embodiment 3

[0074] The difference between the third embodiment and the first and second embodiments lies in the number and arrangement positions of the excitation coils of the same size constituting each group of excitation windings.

[0075] like Fig. 9 As shown, in the third embodiment, the number of excitation coils in the sine winding or cosine winding is set to 2 within a measurement cycle W, and two adjacent excitation coils are spaced L along the axial center on the outer surface of the mover substrate 21. 2 =12mm, that is, one measurement cycle W is spaced apart.

[0076] The induction coil X in the sinusoidal winding 22 1 In the axial direction, they are respectively 1 The coil number is A 2 The coil center spacing L 3 =2mm, that is, located at the axial center of the sine winding 22; the induction coil X in the cosine winding 23 2 In the axial direction, they are respectively 1 Coil numbered B 2 The coil center spacing L 3 =2mm, that is, located at the axial center point of the cosine winding 23.

[0077] like Fig.10 As shown, a displacement measurement method is applied to a ball array type magnetoresistive linear time-grid displacement sensor as described above, comprising:

[0078] S1. Apply a sinusoidal current excitation signal to the S+ excitation winding and the S- excitation winding in the sinusoidal winding on the outer surface of the mover base, and apply a cosine current excitation signal to the C+ excitation winding and the C- excitation winding in the cosine winding; wherein the sinusoidal current excitation signal and the cosine current excitation signal have the same frequency and amplitude.

[0079] S2. When the rotor moves linearly relative to the stator axis, the sine induction winding and the cosine induction winding output standing wave signals U 1 , U 2.

[0080] S3, the two standing wave signals U 1 and U 2 After being processed by the logic circuit, a traveling wave signal U with linear displacement information is output.

[0081] S4 combines the traveling wave signal U with the reference signal U f Perform phase comparison to determine the phase difference.

[0082] S5, through the high-frequency clock pulse phase difference and the same frequency reference signal U f Interpolation is performed to determine the number of the first high-frequency clock pulses for interpolating the phase difference and the interpolation of the same-frequency reference signal U f The number of second high-frequency clock pulses.

[0083] S6. Determine the linear displacement of the mover relative to the stator according to the number of the first high-frequency clock pulses and the number of the second high-frequency clock pulses.

[0084] Optionally, another embodiment is used to illustrate a displacement measurement method, such as Fig.11 As shown, the details are as follows:

[0085] Two sinusoidal excitation currents I with the same frequency and amplitude are applied to the sinusoidal excitation winding and cosine excitation winding on the outer cylindrical surface of the rotor base. a and cosine excitation current I b :I a =I m sinωt、I b =I m cosωt, where the amplitude of the excitation signal is I m =5A, the frequency of the excitation signal is ω=10kHz. When the mover and the stator produce relative motion, the sine induction winding and cosine induction winding in the displacement induction winding on the outer surface of the mover base will output two orthogonal standing wave signals:

[0086]

[0087] Among them, U 1 , U 2 They respectively represent the standing wave signals output by the sine induction winding and the cosine induction winding, Ke represents the magnetic field coupling coefficient, and x represents the displacement of the mover relative to the stator in the direction of movement.

[0088] The two orthogonal standing wave signals output by the sine induction winding and the cosine induction winding are superimposed after signal preprocessing to output a traveling wave signal U, wherein the signal preprocessing includes an amplification circuit, a filtering circuit and a zero-crossing comparison circuit, and the superposition process is as follows:

[0089]

[0090] Same frequency reference signal U f =K e I m sin(ωt), since the traveling wave signal U and the reference signal U of the same frequency f There is a phase difference between the two, which is calculated by the number of interpolated high-frequency clock pulses ΔT. In the same cycle as the traveling wave signal, the reference signal U f The number of interpolated high-frequency clock pulses is T, and the displacement x of a ball array magnetoresistive linear time-grid displacement sensor can be calculated by the number of two high-frequency clock pulses:

[0091]

[0092] N is the number of measurement cycles of a ball array type magnetoresistive linear time-grid displacement sensor.

[0093] Those skilled in the art know that the present invention can be implemented as a system, method or computer program product. Therefore, the present disclosure can be specifically implemented in the following forms, namely: it can be complete hardware, it can be complete software (including firmware, resident software, microcode, etc.), or it can be a combination of hardware and software, generally referred to as "circuit", "module" or "system" herein. In addition, in some embodiments, the present invention can also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable medium contains computer-readable program code. Computer-readable storage media can be, for example, but not limited to - electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination of the above.

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0095] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A ball array type magnetoresistive linear time-grid displacement sensor, comprising a stator (1) and a mover (2), characterized in that: The stator (1) comprises a stator base (11) and a plurality of steel balls (12) tightly mounted in the stator base (11); the mover (2) comprises a mover base (21) and a sine winding (22) and a cosine winding (23) axially fixed to the outer surface of the mover base (21); the stator base (11) and the mover base (21) are both hollow cylindrical structures; the mover (2) is sleeved outside the stator (1), and the stator (1) and the mover (2) are coaxially mounted; the sine winding (22) is provided with an S+ excitation winding, an S- excitation winding and a sine induction winding; and the cosine winding (23) is provided with a C+ excitation winding, a C- excitation winding and a sine induction winding; The sinusoidal winding (22) is provided with a plurality of coils, and the sinusoidal winding (22) comprises an S+ excitation winding, an S- excitation winding and a sinusoidal induction winding, wherein the S+ excitation winding is composed of a coil numbered A 2i-1 The S-excitation winding consists of a coil numbered A 2i The sine induction winding is composed of a coil X1, wherein i is a positive integer; a plurality of coils are arranged in the cosine winding (23), and the cosine winding (22) includes a C+ excitation winding, a C- excitation winding and a cosine induction winding, wherein the C+ excitation winding is composed of a coil numbered B 2i-1 The C-excitation winding consists of a coil numbered B 2i The cosine induction winding is composed of a coil X2, wherein i is a positive integer; the sine winding (22) is numbered A 2i The coil number is A 2i-1 The coil and the cosine winding (23) are numbered B 2i Coil numbered B 2i-1 The coils are the same size; The coils in the S+ excitation winding and the S- excitation winding are equally spaced, alternately arranged and connected in series with each other to form an excitation winding, and the coils in the C+ excitation winding and the C- excitation winding are equally spaced, alternately arranged and connected in series with each other to form an excitation winding; The coil X1 in the sinusoidal winding (22) is arranged between the coil numbered A1 and the coil numbered A2 in the sinusoidal winding (22). 2i The coil X2 in the cosine winding (23) is arranged at the axial center point of the coil, and the coil numbered B1 and the coil numbered B2 in the cosine winding (23) are arranged at the axial center point of the coil. 2i At the axial center point of the coil, the coil X1 in the sine winding (22) and the coil X2 in the cosine winding (23) have the same size.

2. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 1, characterized in that: The stator base (11) is made of non-magnetic material.

3. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 1, characterized in that: The mover base (21) is made of non-magnetic material.

4. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 1, characterized in that: The winding directions of the two adjacent excitation coils in the sinusoidal winding (22) are not fixed, and the connection method is not fixed. Any coil winding direction and connection method for the purpose of establishing an alternating time-varying magnetic field are acceptable, that is, numbered A. 2i The coil number is A 2i-1 The coil is wound in the opposite direction and connected in the forward direction, or numbered A 2i The coil number is A 2i-1 The coils are wound in the same direction, connected in reverse, and are numbered A 2i The coil number is A 2i-1 The coils are arranged in series with equal spacing and alternating arrangement to form an excitation winding and a sinusoidal excitation current is passed through; The winding direction of the two adjacent excitation coils in the cosine winding (23) is not fixed, and the connection method is not fixed. The winding direction and connection method of the coils for the purpose of establishing an alternating time-varying magnetic field are all possible, that is, numbered B 2i Coil numbered B 2i-1 The coil is wound in the opposite direction and connected in the forward direction, or numbered B 2i Coil numbered B 2i-1 The coils are wound in the same direction, connected in reverse, and are numbered B 2i Coil numbered B 2i-1 The coils are arranged at equal intervals and alternately, connected in series to form an excitation winding and a cosine excitation current is passed through it.

5. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 1, characterized in that: Taking the diameter of a steel ball (12) as a measurement period, the coil numbered A1 in the sine winding (22) and the coil numbered B1 in the cosine winding (23) are spaced apart in the axial direction by a distance that is a first preset multiple of the measurement period.

6. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 1, characterized in that: The adjacent ones in the sinusoidal winding (22) are numbered A 2i The coil number is A 2i-1 The coils are spaced axially from each other on the outer surface of the mover base (21) by a distance equal to a second preset multiple of the measuring period, and the adjacent coils numbered B in the cosine winding (23) are 2i Coil numbered B 2i-1 The coils are spaced apart along the axial center on the outer surface of the mover base (21) by a distance of a third preset multiple of the measurement cycle.

7. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 6, characterized in that: The first preset multiple is (M+1 / 4), where M is a positive integer.

8. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 7, characterized in that: The two preset multiples are 1 / N1, where N1 is a positive integer.

9. The ball array type magnetoresistive linear time-grid displacement sensor according to claim 7, characterized in that: The three preset multiples are 1 / N2, where N2 is a positive integer.

10. A displacement measurement method, applied to a ball array type magnetoresistive linear time-grating displacement sensor as claimed in any one of claims 1 to 9, characterized in that: include: Applying a sinusoidal current excitation signal to the S+ excitation winding and the S- excitation winding in the sinusoidal winding on the outer surface of the mover base, and applying a cosine current excitation signal to the C+ excitation winding and the C- excitation winding in the cosine winding; wherein the sinusoidal current excitation signal and the cosine current excitation signal have the same frequency and the same amplitude; When the mover produces axial linear motion relative to the stator, the sine induction winding and the cosine induction winding output standing wave signals U1 and U2 respectively; The two standing wave signals U1 and U2 are processed by the logic circuit to output a traveling wave signal U with linear displacement information; The traveling wave signal U is compared with the reference signal U f Perform phase comparison to determine the phase difference; The phase difference and the same frequency reference signal U are controlled by a high frequency clock pulse. f Interpolation is performed to determine the number of the first high-frequency clock pulses for interpolating the phase difference and the number of the first high-frequency clock pulses for interpolating the same-frequency reference signal U f The number of second high-frequency clock pulses; The linear displacement of the mover relative to the stator is determined according to the number of the first high-frequency clock pulses and the number of the second high-frequency clock pulses.

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