CN117029655B - Magnetic field type plane two-dimensional linear displacement sensor based on combined measurement mode - Google Patents

Abstract

The present invention relates to a magnetic field type plane two-dimensional linear displacement sensor based on a combined measurement method, belonging to the technical field of precision measurement sensors. The sensor comprises a fixed scale and a movable scale, wherein the fixed scale comprises a fixed scale substrate and a surface excitation winding, and the movable scale comprises a movable scale substrate and a surface induction winding. When the movable scale moves relative to the fixed scale, the displacement induction signal pickup array outputs signals U _X and U _Y through a logic circuit, and the direction of dimensional movement is determined by the difference between the output signals φ _X and φ _Y of the F _X and F _Y induction windings, and the positive and negative of the single-dimensional direction are determined by the output signals U _F1 , U _F2 , U _F3 , and U _F4 of the Z _X and Z _Y induction windings. The U _X and U _Y traveling wave signals are compared with the same frequency reference signals respectively, and the phase difference is represented by the number of interpolated high-frequency clock pulses, and the linear displacement of the movable scale relative to the fixed scale in the X direction and the Y direction is converted. Beneficial effects: simple structure, high measurement resolution, easy batch manufacturing, low cost and the like.

Description

A magnetic field type planar two-dimensional linear displacement sensor based on combined measurement method

Technical Field

The present invention belongs to the technical field of precision measurement sensors, and in particular relates to a magnetic field type planar two-dimensional linear displacement sensor based on a combined measurement method.

Background technique

As the world is undergoing a huge wave of industrial manufacturing upgrading and transformation, the demand for two-dimensional linear displacement measurement has risen accordingly. For example, CNC positioning tables, microscope stages, and photolithography machine double workbenches all require precise positioning and orientation in two dimensions. There are generally two methods for measuring two-dimensional linear displacement in a plane. One is to install two one-dimensional linear displacement sensors orthogonally in space on the plane to obtain the two-dimensional linear displacement of the plane respectively. However, this measurement method has strict requirements on the spatial orthogonal installation accuracy of the two one-dimensional linear displacement sensors. The installation positioning error will directly affect the measurement accuracy of the two-dimensional linear displacement of the plane and produce Abbe errors. The other is to use a two-dimensional linear displacement sensor to obtain the linear displacement of two orthogonal dimensions in space respectively. Commonly used two-dimensional grating sensors obtain the displacement by counting the grating lines evenly divided in space, and use spatial precision lines to meet the requirements of accurate displacement measurement. They rely on complex electronic subdivision technology to improve the measurement resolution, making the structure of the measurement system more complex, increasing the cost, and having poor anti-interference ability, which is easily affected by interference from the working environment.

In recent years, a time-grating linear displacement sensor that uses clock pulses as the displacement measurement reference has been developed in China to improve the displacement measurement accuracy and resolution. At present, the magnetic field type two-dimensional time-grating linear displacement sensor developed based on the time-grating principle has many structural layers, complex excitation coil structure, large harmonic interference, and limited measurement accuracy. Therefore, it is necessary to develop a two-dimensional displacement sensor with simple structure and high precision.

Summary of the invention

In order to solve the above technical problems, the present invention provides a magnetic field type planar two-dimensional linear displacement sensor based on a combined measurement method. The fixed-length substrate adopts an excitation winding with a special spatial arrangement to generate a uniformly distributed repetitive orthogonal magnetic field along the X and Y spatial dimensions. The moving scale adopts an induction winding with a special shape and an array arrangement to suppress the harmonic components of the displacement sensing signal, improve the measurement accuracy, reduce the number of sensor coil layers and the complexity of winding, simplify the sensor structure, and reduce the manufacturing cost.

The technical solution of the present invention to solve the above technical problems is as follows: A magnetic field type planar two-dimensional linear displacement sensor based on a combined measurement method comprises: a fixed scale and a moving scale which is directly opposite to the fixed scale and parallel to the fixed scale and has an air gap, the fixed scale comprises a fixed scale substrate and an excitation winding arranged on the fixed scale substrate, the moving scale comprises a moving scale substrate and an induction winding arranged on the moving scale substrate, the X direction is set as the measuring direction, the direction parallel to the fixed scale substrate and perpendicular to the X direction is the Y direction, and the direction perpendicular to the fixed scale substrate is the Z direction; the characteristics are:

The excitation winding is composed of square excitation coils with a side length of _Le1 that are evenly and equidistantly arranged along the X-axis and the Y-axis, wherein the excitation coils in odd-numbered rows along the X-axis direction are connected in series to form a sine winding or a cosine winding, no winding is arranged in the odd-numbered columns, and the sine windings or cosine windings in the even-numbered columns adjacent to the odd-numbered columns are wound in opposite directions; the excitation windings in even-numbered rows along the X-axis direction are connected in series to form a cosine winding or a sine winding, no winding is arranged in the even-numbered columns, and the cosine windings or sine windings in the odd-numbered columns adjacent to the even-numbered columns are wound in opposite directions;

The induction winding unit includes an X and Y dimension judgment array, a single-dimensional direction judgment array, and a displacement sensing signal pickup array;

The X and Y dimension judgment array comprises an _FX induction winding and an _FX induction winding composed of a plurality of square coils and a plurality of rectangular coils. The _FX induction winding is composed of a square coil and two rectangular coils whose length along the Y axis is constant and whose length along the X axis is halved. The _FX induction winding comprises _DX1 , _DX2 , and _DX3 ; the _FX induction winding is composed of a square coil and two rectangular coils whose length along the X axis is constant and whose length along the Y axis is halved. The _FX induction winding comprises _DX1 , _DX2 , and _DX3 ; the coils _DX1 and _DX1 are spaced apart by NL _i5 , wherein N is 1, 2, 3, 4, ..., and the distances between the coils _DX1 and _DX2 , _DX2 and _DX3 , _DX1 and _DX2 , and _DX2 and _DX3 are all L _i5 , so as to judge the movement directions in the X and Y dimensions;

The single-dimensional direction judgment array comprises a Z _X induction winding composed of X ₂₁ , X ₂₂ , X ₂₃ , and X _24, and a Z _Y induction winding composed of Y ₂₁ , Y ₂₂ , Y ₂₃ , and Y _24. The four induction windings of the Z _X induction winding are arranged in a "田" shape in which the starting positions in the X-axis direction differ by jW+L _i1 +L _i6 , and the starting positions in the Y-axis direction differ by jW+L _i1 +L _i4 ; the four induction windings of the Z _Y induction winding are arranged in a "田" shape in which the starting positions in the Y-axis direction differ by jW+L _i1 +L _i6 , and the starting positions in the X-axis direction differ by jW+L _i1 +L _i4 , so as to judge the positive or negative of the single-dimensional motion direction;

The displacement sensing signal pickup array includes sensing windings arranged along the X-axis and the Y-axis, wherein the MX sensing array is used to measure the displacement in the X-axis direction, and the MX sensing array is divided into an MX ₁ sensing winding composed of _X11 , _X13 , _X15 , and _X17 coils and an MX ₂ sensing winding composed of _X12 , _X14 , _X16 , and _X18 coils; the MY sensing array is used to measure the displacement in the Y-axis direction, and the MY sensing array is divided into an MY ₁ sensing winding composed of _Y11 , _Y13 , _Y15 , and _Y17 coils and an MY ₂ sensing winding composed of _Y12 , _Y14 , _Y16 , and _Y18 coils; the _X11 coil, the _X13 coil, the _X15 coil, and the _X17 coil are arranged in the X-axis direction and the _Y11 coil, the Y13 coil, the _Y15 coil, and the _Y18 coil are arranged in the Y-axis direction. The starting positions of the _X17 coils in the Y-axis direction differ by jW+L _i1 +L _i3 ; the starting positions of the _X11 coil and the _X15 coil, the _X13 coil and the _X17 coil in the Y-axis direction, and the starting positions of the _Y11 coil and the _Y15 coil, the _Y13 coil and the _Y17 coil in the X-axis direction differ by jW+L _i1 +L _i4 ; the starting positions of the _X11 coil and the _X12 coil, the _X15 coil and the _X16 coil in the X-axis direction, and the starting positions of the _Y11 coil and the _Y12 coil, the _Y15 coil and the _Y16 coil in the Y-axis direction differ by jW+L _i1 +L _i5 ;

During measurement, two sine and cosine current excitation signals of the same frequency and amplitude are applied to the sine and cosine windings of the fixed-length substrate respectively. When the movable-length substrate moves parallel to the fixed-length substrate, the _MX1 and _MX2 induction windings and the _MY1 and _MY2 induction windings generate four electrical signals _UX1 , _UX2 , _UY1 and _UY2 respectively. The direction of movement is determined according to the difference between the output signals _φX and _φY of the _FX induction winding and the _FX induction winding. The positive and negative directions of the single-dimensional directions are determined by the direction identification circuit according to the output signals _UF1 and _UF2 of the _ZX induction winding and the output signals _UF3 and _UF4 of the _ZY induction winding. Finally, the two differential induction signals _UX1 and _UX2 are output as traveling wave signals _UX with displacement information in the X direction through the logic circuit. The two differential induction signals _UY1 and _UY2 output by the MY induction array are output as traveling wave signals _UY with displacement information in the _Y direction through the logic circuit. The _Y traveling wave signal is compared with the reference signal of the same frequency. The phase difference is represented by the number of interpolated high-frequency clock pulses. After conversion, the linear displacement of the moving scale relative to the fixed scale in the X and Y directions is obtained.

Preferably, the cosine winding includes an A excitation winding and a D excitation winding connected in series, the excitation winding A and the D excitation winding are wound in opposite directions, the A excitation winding includes a connected A1 excitation winding and an A2 excitation winding, the A1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+2, 4n2+1} , the A2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+4, 4n2+3} , the D excitation winding includes a connected D1 excitation winding and a D2 excitation winding, the D1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+4, 4n2+1, the D2 excitation winding is formed by connecting square excitation coils numbered C 4n1+4, 4n2+3} . The sine winding comprises _a B excitation winding and an E excitation winding connected in series, the B excitation winding is wound in the opposite direction to the E excitation winding, the B excitation winding comprises a connected B1 excitation winding and a B2 excitation winding, the B1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+1, 4n2+2} , the B2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+3, 4n2+4} , the E excitation winding comprises a connected E1 excitation winding and an E2 excitation winding, the E1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+3, 4n2+2} , the E2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+1, 4n2+4} , wherein Ca _,b represents excitation coils, Ba _,b represents the gap between two adjacent excitation coils, and the distance is _Le2 , a and b represent the X-axis number and the Y-axis number respectively, a＝4n1+i, b＝4n2+i, i is 1 or 2 or 3 or 4, n1 is all integers from 0 to _M1-1 in sequence, _M1 represents the total number of poles of the excitation winding coil in the X direction, n2 is all integers from 0 to _M2-1 in sequence, _M2 represents the total number of poles of the excitation winding coil in the Y direction.

Preferably, the coils of the displacement sensing signal pickup array are composed of a plurality of square induction coils with a length and a width both being L _i1 .

Preferably, the coil of the displacement sensing signal pickup array is composed of a plurality of sinusoidal coils, and the sinusoidal coil is formed by mirroring two half-sine coils along the bottom, and the half-period space width of the sinusoidal coil is L _i1 , and the half-period space height is L _i1 .

Preferably, the coils of the displacement sensing signal pickup array are composed of a plurality of circular coils with a radius of _Li1 /2.

Preferably, the two rectangular coils in the _FX induction winding in the X and Y dimension judgment array have a length of _Li1 along the Y axis and a length of _Li1 /2 along the X axis; the two rectangular coils in the _FX induction winding have a length of _Li1 along the X axis and a length of _Li1 /2 along the Y axis.

Preferably, the coils of the _ZX induction winding and the _ZY induction winding in the one-dimensional direction determination array are composed of a plurality of square induction coils whose length and width are both _Li1 .

Preferably, the coils of the _ZX induction winding and the _ZY induction winding in the single-dimensional direction judgment array are composed of multiple sinusoidal coils, and the sinusoidal coil is formed by mirroring two half-sine coils along the bottom, and the half-cycle space width of the sinusoidal coil is _Li1 , and the half-cycle space height is _Li1 .

Preferably, the coils of the _ZX induction winding and the _ZY induction winding in the single-dimensional direction determination array are composed of a plurality of circular coils with a radius of _Li1 /2.

Preferably, the U _X and U _Y traveling wave signals are respectively shaped into square waves with the reference signal of the same frequency by a shaping circuit, and then phase comparison is performed.

Beneficial effects: The present invention adopts a staggered arrangement of square excitation coils to achieve simultaneous encoding in the X-axis and Y-axis directions on the same plane. The two induction windings in the same direction form a differential structure. When the induction winding outputs a signal, the common-mode interference is eliminated by differentiating the differential signal through a logic circuit, thereby further improving the anti-interference ability; the number of sensor coil layers and the complexity of winding are reduced through a special coil structure and arrangement, simplifying the sensor structure; using PCB manufacturing technology, it does not rely on ultra-precision manufacturing processes, and reduces manufacturing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram showing the corresponding relationship between a fixed-size substrate and a movable-size substrate in Embodiment 1 of the present invention;

FIG2 is a schematic diagram of the coil structure and signals of a fixed-length substrate in Example 1 of the present invention;

FIG3 is a schematic diagram of the coil structure of the movable ruler substrate in Example 1 of the present invention;

FIG4 is a block diagram of the signal processing principle of Embodiment 1 of the present invention;

FIG5 is a schematic diagram showing the corresponding relationship between the fixed-size substrate and the movable-size substrate in Embodiment 2 of the present invention;

FIG6 is a schematic diagram of the coil structure of the movable ruler substrate in Example 2 of the present invention;

FIG7 is a schematic diagram showing the corresponding relationship between the fixed-size substrate and the movable-size substrate in Example 3 of the present invention;

FIG8 is a schematic diagram of the coil structure of the movable ruler substrate in Example 3 of the present invention.

In the accompanying drawings, the components represented by the reference numerals are listed as follows:

1. Fixed-length substrate; 11. Excitation winding; 2. Moving-length substrate; 22. Induction winding unit.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

Example

The present invention is described in detail below with reference to the accompanying drawings. The fixed-length structure, the F _X induction winding and the F _Y induction winding in the X and Y dimension judgment arrays in the moving ruler are consistent in the three different embodiments. The difference between the three different embodiments is that the winding shapes of the MX induction signal pickup array, the MY induction signal pickup array, and the single-dimensional direction judgment arrays Z _X and Z _Y in the moving ruler are square windings in embodiment 1, sinusoidal windings formed by splicing two half-sine bottoms in embodiment 2, and circular windings in embodiment 3. They are described as follows:

Embodiment 1: A magnetic field type planar two-dimensional linear displacement sensor based on a combined measurement method as shown in FIGS. 1 to 3 comprises a fixed-size substrate 1 and a movable-size substrate 2. The lower surface of the movable-size substrate is mounted parallel to the upper surface of the fixed-size substrate, and a gap of d=0.4 mm is left.

As shown in FIG2 , 16 rows of square excitation coils (i.e., m ₁ =16, M ₁ =4) are arranged side by side on the upper surface of the fixed-length substrate 1, and each row is composed of 8 square excitation coils of the same size arranged evenly, with a total of 16 columns (i.e., m ₂ =16, M2 =4). The width _Le1 of a square excitation coil is 2.8 mm, the distance _Le2 between two adjacent square excitation coils can be 3.0-3.2 mm, the distance _Le3 between two adjacent rows or columns of excitation coils is equal to 0.2-0.4 mm, the starting positions of the excitation coils in the odd rows or columns along the same direction of the row (or column) are the same, the starting positions of the excitation coils in the even rows or columns along the same direction of the row (or column) are the same, and the starting positions of the excitation coils in the odd rows (or columns) are staggered by _Le2 from the starting positions of the excitation coils in the even rows (or columns) in the same direction of the row (or column).

The coils arranged on the fixed-length substrate 1 are numbered, and Ca _,b represents the excitation coil, Ba _,b represents the gap between two adjacent excitation coils, and a and b represent the X-axis coordinate and Y-axis coordinate respectively (a=4n1+i, b=4n2+i, i is 1, 2, 3, 4). Among them, the square excitation coils numbered C _{4n1+2, 4n2+1} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal lead wire to form an A1 excitation winding; the square excitation coils numbered C _{4n1+4, 4n2+3} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal lead wire to form an A2 excitation winding; the square excitation coils numbered C _{4n1+1, 4n2+2} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal lead wire to form a B1 excitation winding; the square excitation coils numbered C _{4n1+3, 4n2+4} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal lead wire to form a B2 excitation winding; The square excitation coils numbered _{4n1+4, 4n2+1} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal leads to form the D1 excitation winding; the square excitation coils numbered C _{4n1+2, 4n2+3} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal leads to form the D2 excitation winding; the square excitation coils numbered C _{4n1+3, 4n2+2} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal leads to form the E1 excitation winding; the square excitation coils numbered C _{4n1+1, 4n2+4} (n1 is 0, 1, 2, ...; n2 is 0, 1, 2, ...) are connected in series into a group through the excitation signal leads to form the E2 excitation winding. A1 excitation winding is connected with A2 excitation winding to form A excitation winding; B1 excitation winding is connected with B2 excitation winding to form B excitation winding; D1 excitation winding is connected with D2 excitation winding to form D excitation winding; E1 excitation winding is connected with E2 excitation winding to form E excitation winding. A excitation winding and D excitation winding are wound in opposite directions, connected in series to form a cosine winding, into which a cosine excitation current is passed; B excitation winding and E excitation winding are wound in opposite directions, connected in series to form a sine winding, into which a sine excitation current is passed. A pole pair in the X-axis direction or the Y-axis direction is composed of four adjacent square coils in the A, B, D, and E excitation windings, and the pole pair width W = 2 (L _e1 +L _e2 ).

As shown in Figure 3, for the convenience of explanation, the above parameters j = 0, N = 2. The lower surface of the movable ruler base 2 is provided with a coil array consisting of multiple induction coils of the same size and different arrangement directions, which are divided into displacement induction signal pickup arrays in the X direction and the Y direction. There are four induction windings _X11 , _X13 , _X15 , _X17 in the displacement sensing signal pickup array, which form the _MX1 induction winding, and _X12 , _X14 , _X16 , _X18 form the _MX2 induction winding; the starting positions of the induction coils _X11 , _X13 , _X15 , _X17 in the _MX1 induction winding differ by _Li1 + _Li3 ( _Li3 ＝7/6L _e1 +7/6L _e2 ) along the X direction, and the starting positions of the induction coils _X11 , _X13 , _X15 , _X17 in the _MX1 induction winding differ by _Li1 + _Li4 ( _Li4 ＝L _e1 +L _e2 +L _e3 ) along the Y direction. The _MX1 induction winding is taken as a whole, and the _MX2 induction winding can be obtained by moving jW+ _Li5 ( _Li5 ＝L _e2 ) to the right along the X axis.

_Y11 , _Y13 , _Y15 , _Y17 form the _MY1 induction winding, and _Y12 , _Y14 , _Y16 , _Y18 form the _MY2 induction winding; the starting positions of the _Y11 , _Y13 , _Y15 , _Y17 induction coils in the _MY1 induction winding differ by _Li1 + _Li3 ( _Li3 = 7/6L _e1 + 7/6L _e2 ) along the Y direction, and the starting positions of the _Y11 , _Y13 , _Y15 , _Y17 induction coils in the _MY1 induction winding differ by _Li1 + _Li4 ( _Li4 = _Le1 + _Le2 + _Le3 ) along the X direction. The _MY1 induction winding is taken as a whole, and the _MY2 induction winding can be obtained by moving jW+L _i5 (L _i5 = _Le2 ) upward along the Y axis.

The MX ₁ and MX ₂ induction windings are arranged along the X-axis direction, and the MY ₁ and MY ₂ induction windings are arranged along the Y-axis direction. The length and width L _i1 of the induction winding in each induction winding is 2.8 mm, and the four induction coils in each induction winding are arranged in a "田" shape. The distance L _i3 between the induction coils X ₁₁ and X ₁₃ in the MX ₁ induction winding is 7.0-7.4 mm, and the distance L _i4 between the induction coils X ₁₁ and X ₁₅ is 6.0-6.4 mm. The distance between the induction coils X ₁₂ and X ₁₄ in the MX ₂ induction winding is L _i3 , and the distance between the induction coils X ₁₂ and X ₁₆ is L _i4 . In the induction windings MX ₁ and MX ₂ in the same direction, the distance L _i5 between the induction windings X ₁₁ and X ₁₂ , X ₁₃ and X ₁₄ , X ₁₅ and X ₁₆ , and X ₁₇ and X ₁₈ is 3.0-3.2 mm. The MY ₁ and MY ₂ inductive windings are arranged in the Y-axis direction in the same manner as the MX ₁ and MX ₂ inductive windings in the X-axis direction. The MX ₁ and MX ₂ inductive windings in the X-axis direction output traveling wave signals U _X1 and U _X2 , which constitute a differential signal, and finally output a traveling wave signal U _X through a logic circuit. The MY ₁ and MY ₂ inductive windings in the Y-axis direction output traveling wave signals U _Y1 and U _Y2 , which constitute a differential signal, and finally output a traveling wave signal U _Y through a logic circuit.

As shown in Figure 3, the dimension judgment array in the X-direction and Y-direction on the lower surface of the moving ruler substrate 2 has two square coils with a length and width of _Li1 and four rectangular windings with a length of _Li1 and a width of _Li2 , among which the winding intervals between _DX1 and _DX1 are 2L _i5 , and the intervals between _DX1 and _DX2 , _DX2 and _DX3 , _DX1 and _DX2 , and _DX2 and _DX3 are _Li5 . In the other eight square windings with length and width _Li1 , the spacing distance _Li6 between the windings _X21 and _X22 , _X23 and _X24 , _Y21 and _Y22 , and _Y23 and _Y24 is 0.96-1 mm; the spacing distance between the windings _X21 and _X23 , _X22 and _X24 , _Y21 and _Y23 , and _Y22 and _Y24 is _Li4 , and they are divided into two groups and arranged in the X-axis direction and the Y-axis direction.

As shown in Figure 2, when the induction winding on the lower surface of the movable ruler substrate 2 and the excitation winding of the fixed-length substrate 1 generate relative motion, two cosine and sine excitation currents of the same frequency and amplitude are applied to the fixed-length substrate 1: I _a =I _m cosωt, I _b =I _m sinωt, where the amplitude of the excitation signal is I _m =5A, and the frequency of the excitation signal is ω=10kHz. When the movable ruler substrate 2 generates a linear displacement relative to the fixed-length substrate 1, the induction winding in the displacement sensing signal pickup array under the movable ruler substrate will output a traveling wave signal U ₀ , which is expressed as follows:

Wherein, Ke _is the magnetic induction coefficient, and s is the linear displacement of the movable scale substrate 2 relative to the fixed scale substrate 1 in the moving direction.

When the movable ruler substrate moves in the X-axis direction or the Y-axis direction, the MX ₁ and MX ₂ induction windings in the X-axis direction generate traveling wave signals U _X1 and U _X2 through magnetic field coupling; the MY ₁ and MY ₂ induction windings in the Y-axis direction generate traveling wave signals U _Y1 and U _Y2 through magnetic field coupling. The expressions are:

The signal processing method is shown in FIG4 . The differential signals U _X1 and U _X2 , and the differential signals U _Y1 and U _Y2 are respectively passed through the logic circuit to finally obtain the X-axis traveling wave signal U _X and the Y-axis traveling wave signal U _Y . The expression is:

When the induction winding on the lower surface of the movable ruler substrate 2 moves in the alternating magnetic field generated by the excitation winding of the fixed ruler substrate 1, the X and Y dimension judgment arrays will generate induction signals, where the array consisting of two square windings and four rectangular windings will output two signals containing the changes in the area of the windings. The magnetic flux change of the induction winding is:

Φ(t,x)＝B·ΔS (4)

B represents the magnetic induction intensity of the magnetic field in which the induction winding is located, and ΔS represents the change area of the induction winding facing the excitation winding.

When the moving ruler moves, the square windings D _X1 and D _Y1 , and the rectangular windings D _X2 , D _X3 , D _Y2 , and D _Y3 are analyzed one by one. D _X1 and D _X2 windings are connected in series in the same winding direction, and D _X2 and D _X3 windings are connected in series in opposite winding directions to form the F _X induction winding; D _Y1 and D _Y2 windings are connected in series in the same winding direction, and D _Y2 and D _Y3 windings are connected in series in opposite winding directions to form the F _Y induction winding. The overall magnetic flux change is obtained from the overall area change through coupling. For example, when the moving ruler moves in the X-axis direction, assuming that the magnetic induction intensity B = ±I _m sinωt, the total magnetic flux of the F _Y induction winding is:

Φ _Y (x) = 0, x∈[0,W] (5)

F _X Total magnetic flux of the induction winding:

When the movable ruler moves in the Y-axis direction, the total magnetic flux of the F _Y induction winding is:

F _X Total magnetic flux of the induction winding:

Φ _X (y) = 0, y∈[0,W] (8)

When the moving ruler moves in the X(Y) direction, the amplitude of the φ _Y (φ _X ) signal does not change (that is, the overall facing area of the coil winding does not change), and the amplitude of the φ _X (φ _Y ) signal changes (that is, the overall facing area of the coil combination changes periodically). Then, it is shaped into a square wave signal by a shaping circuit for binarization operation. When φ _X and φ _Y are expressed as "10", it means that the moving ruler moves in the X direction. When φ _X and φ _Y are expressed as "01", it means that the moving direction of the moving ruler changes and moves in the Y direction. When φ _X and φ _Y are expressed as "00" or "11", it means that the moving ruler maintains the original direction of movement. The moving direction of the moving ruler is determined in this way.

When the direction of motion is determined to be the X direction, the two quasi-traveling wave signals U _F1 and U _F2 output by the Z _X induction winding in this direction are selected and shaped into square wave signals for phase comparison; when the direction of motion is determined to be the Y direction, the two quasi-traveling wave signals U _F3 and U _F4 output by the Z _Y induction winding in this direction are selected and shaped into square wave signals for phase comparison. (or ) changes, it moves in the opposite direction of the original movement direction. If the original phase difference does not change, it moves in the original movement direction to determine the positive or negative direction of the movement. Taking the X direction as an example, the expression is:

Taking the Y direction as an example, the expression is:

The movable ruler substrate 2 and the fixed ruler substrate 1 move relative to each other, and the phase angle of the induced signal will change periodically. When the movable ruler substrate 2 and the fixed ruler substrate 1 move relative to each other by one pole distance, the phase angle of the induced signal (i.e. ) changes for one cycle. After the X-direction traveling wave signal U _X and the Y-direction traveling wave signal U _Y are shaped into square wave signals by the shaping circuit, they are compared with the reference signals of the same frequency. The phase differences Δt _X and Δt _Y are represented by the number of interpolated high-frequency clock pulses. After conversion, combined with the judgment of the movement direction, the linear displacement of the moving ruler relative to the fixed ruler in the X and Y directions is obtained. (See Figure 4)

Where W is a complete pole pitch, _NX and _NY are the complete pole pitches of the moving ruler in the X and Y directions, and _TX and _TY are the clock cycles of the sensing signals in the X and Y directions, respectively.

Example 2: As shown in Figures 5 and 6, most of the structures of a magnetic field-type planar two-dimensional displacement sensor based on a combined measurement method in this embodiment are the same as those in Example 1, except that the windings in the displacement sensing signal pickup array and the single-dimensional direction judgment array are changed from a square winding with a side length of 2.8 mm in Example 1 to a sinusoidal winding formed by splicing two half-sine bottoms in Example 2, and the parameters of the sinusoidal coil composed of the half-sine are: the width of the coil is 2.8 mm, and the height from top to bottom is 2.8 mm.

Example 3: As shown in Figures 7 and 8, most of the structures of a magnetic field-type planar two-dimensional displacement sensor based on a combined measurement method in this embodiment are the same as those in Example 1, except that the windings in the displacement sensing signal pickup array and the one-dimensional direction judgment array are changed from square windings with a side length of 2.8 mm in Example 1 to circular windings with a radius of 1.4 mm in Example 3.

In the description of the present invention, it is necessary to understand that the terms "center", "length", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "inside", "outside", "peripheral", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred system or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

In the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A magnetic field type planar two-dimensional linear displacement sensor based on a combined measurement method, comprising a fixed ruler and a movable ruler which is parallel to the fixed ruler and has an air gap, the fixed ruler comprising a fixed ruler substrate (1) and an excitation winding (11) arranged on the fixed ruler substrate (1), the movable ruler comprising a movable ruler substrate (2) and an induction winding unit (22) arranged on the movable ruler substrate (2), the X direction is set as the measurement direction, the direction parallel to the fixed ruler substrate (1) and perpendicular to the X direction is the Y direction, and the direction perpendicular to the fixed ruler substrate (1) is the Z direction; the characteristics are as follows: The excitation winding (11) is composed of square excitation coils with a side length of _Le1 that are evenly and equidistantly arranged along the X-axis and the Y-axis, wherein the excitation coils in odd-numbered rows along the X-axis direction are connected in series to form a sine winding or a cosine winding, the odd-numbered columns are not arranged with windings, and the sine windings or cosine windings of the even-numbered columns adjacent to the odd-numbered columns are wound in opposite directions; the excitation windings in even-numbered rows along the X-axis direction are connected in series to form a cosine winding or a sine winding, the even-numbered columns are not arranged with windings, and the cosine windings or sine windings of the odd-numbered columns adjacent to the even-numbered columns are wound in opposite directions; The induction winding unit (22) comprises an X and Y dimension judgment array, a single-dimensional direction judgment array and a displacement sensing signal pickup array; The X and Y dimension judgment array comprises an _FX induction winding and an _FX induction winding composed of a plurality of square coils and a plurality of rectangular coils. The _FX induction winding is composed of a square coil and two rectangular coils whose length along the Y axis is constant and whose length along the X axis is halved. The _FX induction winding comprises _DX1 , _DX2 , and _DX3 ; the _FX induction winding is composed of a square coil and two rectangular coils whose length along the X axis is constant and whose length along the Y axis is halved. The _FX induction winding comprises _DX1 , _DX2 , and _DX3 ; the coils _DX1 and _DX1 are spaced apart by NL _i5 , wherein N is 1, 2, 3, 4, etc., and the distances between the coils _DX1 and _DX2 , _DX2 and _DX3 , _DX1 and _DX2 , and _DX2 and _DX3 are all _Li5 , so as to judge the movement direction of the X and Y dimensions. The two rectangular coils in the _FX induction winding have a length of _Li1 along the Y axis and a length of _Li1 /2 along the X axis; The length of the two rectangular coils in the _Y induction winding along the X axis is _Li1 , and the length along the Y axis is _Li1 /2; The single-dimensional direction judgment array comprises a Z _X induction winding composed of X ₂₁ , X ₂₂ , X ₂₃ , and X ₂₄ and a Z _Y induction winding composed of Y ₂₁ , Y ₂₂ , Y ₂₃ , and Y _24. The coils of the Z _X induction winding and the Z _Y induction winding are composed of a plurality of square induction coils whose length and width are both _Li1 . The four induction windings of the Z _X induction winding are arranged in a "田" shape in which the starting positions in the X-axis direction differ by jW+ _Li1 + _Li6 and the starting positions in the Y-axis direction differ by jW+ _Li1 + _Li4 . The four induction windings of the Z _Y induction winding are arranged in a "田" shape in which the starting positions in the Y-axis direction differ by jW+ _Li1 + _Li6 and the starting positions in the X-axis direction differ by jW+ _Li1 + _Li4 , so as to judge the positive and negative of the single-dimensional motion direction. _Li6 is X ₂₁ and X ₂₂ , X ₂₃ and X ₂₄ , Y ₂₁ and Y ₂₂ , Y ₂₃ and Y ₂₄ windings; _Li4 is the spacing distance between X ₂₁ and X ₂₃ , X ₂₂ and X ₂₄ , Y ₂₁ and Y ₂₃ , Y ₂₂ and Y ₂₄ windings; The displacement sensing signal pickup array includes sensing windings arranged along the X-axis and the Y-axis. The coils of the displacement sensing signal pickup array are composed of a plurality of square sensing coils with a length and a width of _Li1 . The MX sensing array is used to measure the displacement in the X-axis direction. The MX sensing array is divided into an _MX1 sensing winding composed of _X11 , _X13 , _X15 , and _X17 coils and an _MX2 sensing winding composed of _X12 , _X14 , _X16 , and _X18 coils. The MY sensing array is used to measure the displacement in the Y-axis direction. The MY sensing array is divided into an _MY1 sensing winding composed of _{Y11, Y13, Y15, and Y17 coils and an MY2 sensing winding composed of Y12, Y14, Y16, and Y18 coils. The X11 coil , the X13 coil , the X15 coil , and} the X17 coil are arranged in the X-axis direction and the _Y11 coil and the _Y17 coil are arranged in the Y-axis direction. The starting positions of the _X13 coil, the _X15 coil and the _Y17 coil in the Y-axis direction differ by jW+L _i1 +L _i3 ; the starting positions of the _X11 coil and the _X15 coil, the _X13 coil and the _X17 coil in the Y-axis direction, and the starting positions of the _Y11 coil and the _Y15 coil, the _Y13 coil and the _Y17 coil in the X-axis direction differ by jW+L _i1 +L _i4 ; the starting positions of the _X11 coil and the _X12 coil, the _X15 coil and the _X16 coil in the X-axis direction, and the starting positions of the _Y11 coil and the _Y12 coil, the _Y15 coil and the _Y16 coil in the Y-axis direction differ by jW+L _i1 +L _{i5 ,} L _i3 is the distance between the _X11 and _X13 , _X12 and _X14 induction coils, L _i4 is the distance between the _X11 and X15, X12 and X16 induction coils, L i6 is the distance between the X11 and _X15 , _X12 and _X16 induction coils, L _i5 is the distance between the induction coils _X11 and _X12 , _X13 and _X14 , _X15 and _X16 , and _X17 and _X18 ; During measurement, two sine and cosine current excitation signals of the same frequency and amplitude are applied to the sine and cosine windings of the fixed-length substrate (1) respectively. When the movable-length substrate (2) moves parallel to the fixed-length substrate (1), the _MX1 and _MX2 induction windings and the _MY1 and _MY2 induction windings respectively generate four electrical signals _UX1 , _UX2 , _UY1 and _UY2 . The direction of movement is determined according to the difference between the output signals _φX and _φY of the _FX induction winding and the FX induction winding. The positive and negative directions of the single-dimensional directions are determined by the direction identification circuit according to the output signals _UF1 and _UF2 of _{the ZX} induction winding and the output signals _UF3 and _UF4 of the _ZY induction winding. Finally, the two differential induction signals _UX1 and _UX2 are output as traveling wave signals _UX with displacement information in the _X direction through the logic circuit. The two differential induction signals _UY1 and _UY2 output by the MY induction array are output as traveling wave signals _UY with displacement information in the Y direction through the logic circuit. The traveling wave signals of U _{and Y} are compared with the reference signals of the same frequency respectively. The phase difference is represented by the number of interpolated high-frequency clock pulses. After conversion, the linear displacement of the moving ruler relative to the fixed ruler in the X and Y directions is obtained. The cosine winding includes an A excitation winding and a D excitation winding connected in series, wherein the A excitation winding is wound in the opposite direction to the D excitation winding, wherein the A excitation winding includes an A1 excitation winding and an A2 excitation winding connected, wherein the A1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+2, 4n2+1} , wherein the A2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+4, 4n2+3} , wherein the D excitation winding includes a D1 excitation winding and a D2 excitation winding connected, wherein the D1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+4, 4n2+1, wherein the D2 excitation winding is formed by connecting square excitation coils numbered C 4n1+4, 4n2+1} , wherein the D The sine winding comprises _a B excitation winding and an E excitation winding connected in series, the B excitation winding is wound in the opposite direction to the E excitation winding, the B excitation winding comprises a connected B1 excitation winding and a B2 excitation winding, the B1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+1, 4n2+2} , the B2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+3, 4n2+4} , the E excitation winding comprises a connected E1 excitation winding and an E2 excitation winding, the E1 excitation winding is formed by connecting square excitation coils numbered C _{4n1+3, 4n2+2} , the E2 excitation winding is formed by connecting square excitation coils numbered C _{4n1+1, 4n2+4} , wherein Ca _{, b} represent excitation coils, and the gap distance between two adjacent excitation coils is _Le2 , a and b represent the X-axis number and the Y-axis number respectively, a=4n1+i, b=4n2+i, i is 1 or 2 or 3 or 4, n1 is all integers from 0 to _M1-1 in sequence, _M1 represents the total number of pole pairs of the excitation winding coil in the X direction, n2 is all integers from 0 to _M2-1 in sequence, _M2 represents the total number of pole pairs of the excitation winding coil in the Y direction; the pole width W=2(L _e1 +L _e2 ). 2. According to claim 1, the magnetic field type planar two-dimensional linear displacement sensor based on the combined measurement method is characterized in that the coil of the displacement sensing signal pickup array is composed of multiple sinusoidal coils, and the sinusoidal coil is formed by two half-sine coils mirrored along the bottom, and the half-cycle space width of the sinusoidal coil is _Li1 , and the half-cycle space height is _Li1 . 3. The magnetic field type planar two-dimensional linear displacement sensor based on combined measurement method according to claim 1, characterized in that the coil of the displacement sensing signal pickup array is composed of a plurality of circular coils with a radius of _Li1 /2. 4. The magnetic field type planar two-dimensional linear displacement sensor based on the combined measurement method according to claim 1 is characterized in that the coils of the Z _X induction winding and the Z _Y induction winding in the single-dimensional direction judgment array are composed of multiple sinusoidal coils, and the sinusoidal coil is formed by two half-sines mirrored along the bottom, and the half-period space width of the sinusoidal coil is _Li1 , and the half-period space height is _Li1 . 5. The magnetic field type planar two-dimensional linear displacement sensor based on combined measurement method according to claim 1, characterized in that the coils of the _ZX induction winding and the _ZY induction winding in the single-dimensional direction judgment array are composed of multiple circular coils with a radius of _Li1 /2. 6. The magnetic field type planar two-dimensional linear displacement sensor based on combined measurement method according to claim 1, characterized in that the U _X and U _Y traveling wave signals are respectively shaped into square waves by shaping circuits with reference signals of the same frequency, and then phase comparison is performed.