Absolute magnetostrictive displacement measurement tape

Abstract

The invention discloses an absolute magnetostrictive displacement measurement tape, which is characterized in that a magnetic mark is embedded in a through hole of a groove layer according to a certain coding rule and is fixed between a steel wire layer and a coating layer, the tape is vertically suspended in the application process, and the perpendicularity of the tape is guaranteed through the pulling force provided by a spring at the bottom; the magnetostrictive displacement sensor is installed on a measured object and can sense the magnetic marks in the magnetic tape at any time, and the magnetic mark coding rule ensures that the distance between any group of interphase magnetic marks is not larger than the measurement range of the magnetostrictive displacement sensor so as to ensure that at least two magnetic marks can be sensed at any time. Meanwhile, the coding rule ensures that any group of adjacent magnetic marks are inconsistent, so that the absolute position of the first sensed magnetic mark can be determined by combining the time interval of pulses excited by the magnetic marks on the displacement sensor with the sound velocity to convert the distance between the adjacent magnetic marks, and then the transition time of the first pulse signal in the magnetic marks is combined; therefore, the absolute position of the object fixed by the magnetostrictive displacement sensor can be measured and determined in real time.

Description

Technical Field

[0001] The invention relates to an absolute magnetostrictive displacement measuring magnetic tape, in particular to a magnetostrictive displacement measuring magnetic tape used for detecting the absolute running position of a moving part. Background Art

[0002] Absolute magnetostrictive linear ruler is an ultra-long range absolute position measurement system used in elevator cars and unmanned vehicles. It is mainly composed of magnetostrictive displacement sensor and magnetic encoding system. The magnetostrictive displacement sensor detects the position encoding information in the magnetic encoding system in real time as the object being inspected moves, thereby achieving accurate absolute positioning. Absolute magnetostrictive displacement measurement tape is a form of magnetic encoding system with the following characteristics:

[0003] 1) The distance between any two magnetic scales in the absolute magnetostrictive displacement measurement tape is not the same;

[0004] 2) The distance between any two sets of interphase magnetic scales in the absolute magnetostrictive displacement measurement tape shall not be greater than the effective range of the magnetostrictive displacement sensor;

[0005] 3) During operation, a certain gap will be maintained between the absolute magnetostrictive displacement measuring tape and the magnetostrictive displacement sensor.

[0006] The absolute magnetostrictive displacement measuring tape is used in conjunction with the magnetostrictive displacement sensor. It is the first of its kind in the field of ultra-long range measurement. The existing similar technology is the magnetic scale technology. The invention patent with patent number CN114538225A, "A magnetic scale elevator position identification system", discloses an elevator car positioning system based on a magnetic scale. The magnetic scale tape is continuously encoded, and the tolerance requirements for the magnetic scale width and the magnetic scale spacing are very high. The manufacturing process is more complicated and the cost is higher. The magnetic scale tape is made of soft magnetic rubber and is easily broken even after adding a backing steel belt. The magnetic field strength after magnetization is also easily disturbed by the external magnetic field and will gradually weaken over time. Summary of the invention

[0007] The invention provides an absolute magnetostrictive displacement measuring magnetic tape, which is suitable for an absolute magnetostrictive linear ruler to realize absolute position measurement and can be used for a long time after being installed once.

[0008] The present invention can be achieved through the following technical solutions:

[0009] An absolute magnetostrictive displacement measuring magnetic tape comprises a top mounting structure, a magnetic tape body and a bottom mounting structure; the top mounting structure comprises a top fixing plate and rivets, the rivets fixing the magnetic tape body to prevent the magnetic tape body from falling off from the mounting hole of the top fixing plate; the bottom mounting structure comprises a bottom connecting plate, a spring and a bottom fixing plate connected in sequence, the magnetic tape body being fixed to the bottom connecting plate; the magnetic tape body comprises a steel wire layer, a groove layer, a magnetic mark and a coating layer, the steel wire layer being made of a group of parallelly distributed steel wires wrapped by a flexible material; the groove layer being arranged on the steel wire layer and evenly provided with through holes, the magnetic mark being fixed in the through holes.

[0010] Furthermore, the magnetic tape body and the bottom connecting plate are connected and fixed by rivets.

[0011] Furthermore, the width of the through holes in the groove layer is smaller than the distance between adjacent through holes.

[0012] Furthermore, the steel wire layer, groove layer and coating layer are flexible strips, and the types of materials thereof include but are not limited to rubber and polyurethane.

[0013] Furthermore, the through holes of the magnetic mark and the slot layer are in the shape of a circle, a rectangle or a square.

[0014] Furthermore, the steel wire layer, the groove layer and the coating layer are fixed by coupling agent bonding or hot melt bonding.

[0015] Furthermore, the magnetic marker is made of a permanent magnet and cooperates with the sensor to excite the ultrasonic guided wave signal.

[0016] Furthermore, the magnetostrictive displacement sensor is installed on the object to be measured and can sense the magnetic marks in the magnetic tape at all times. The magnetic mark arrangement scheme is as follows: Assuming that the spacing between adjacent through holes is L, the effective measurement range of the magnetostrictive displacement sensor is M. If the distance between the magnetic marks is too small, it will affect the measurement accuracy. Therefore, there is a minimum spacing requirement between the magnetic marks. Assuming that the minimum spacing between the magnetic marks is N, the through holes where the odd-numbered magnetic marks are located are numbered as P(2n-1)=(G+1)*(n-1)+1, n=1, 2, 3, ...; the through holes where the even-numbered magnetic marks are located are numbered as P(2n)=(G+3)*(n-1)+1+X, n=1, 2, 3, ...; X is related to the number of through holes with the minimum magnetic mark spacing, and G is related to the number of through holes with the maximum magnetic mark spacing. The function of int() is to get the integer part; if G is an odd number, then the value of G is subtracted by 1; the maximum value of n

[0017] In the present invention, the magnetic mark is embedded in the through hole of the slot layer according to a certain coding rule and fixed between the steel wire layer and the coating layer. The steel wire layer ensures the tensile strength of the magnetic tape and the coating layer is used to protect the magnetic mark and prevent it from falling off. The magnetic tape is vertically suspended during application and the tension provided by the spring at the bottom ensures verticality. The magnetostrictive displacement sensor is installed on the object to be measured and can sense the magnetic mark in the magnetic tape at all times. The magnetic mark coding rule ensures that the spacing between any group of interlaced magnetic marks is not greater than the measurement range of the magnetostrictive sensor to ensure that at least two magnetic marks can be sensed at all times. At the same time, the coding rule ensures that any group of adjacent magnetic marks are inconsistent. Therefore, the absolute position of the first magnetic mark sensed can be determined by combining the pulse time interval excited by the magnetic mark on the displacement sensor with the sound velocity conversion to calculate the spacing between adjacent magnetic marks, and then combined with the transit time of the first pulse signal in the magnetic mark, the absolute position of the object fixed by the magnetostrictive displacement sensor can be measured and determined in real time.

[0018] The beneficial effects of the present invention are:

[0019] The magnetic scale arrangement method of the present invention can ensure that the magnetostrictive displacement sensor can cover at least two magnetic scales during the movement process, and maximize the effective measurement range of the magnetostrictive displacement sensor, increase the sparseness of the magnetic scale arrangement to reduce the cost, and ensure that the distances between any two groups of adjacent magnetic scales are different. By identifying the component distance of the magnetic scale and combining the pulse signal transit time corresponding to the first magnetic scale, the absolute position of the object fixed by the magnetostrictive displacement sensor can be measured. If the present invention is implemented, it can provide real-time and accurate absolute position information input for the motion control of industrial equipment such as elevator cars and unmanned vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall schematic diagram of the present invention.

[0021] Figure 2 It is a schematic diagram of the top installation structure of the present invention.

[0022] Figure 3 It is a schematic diagram of the bottom installation structure of the present invention.

[0023] Figure 4 It is a schematic diagram of the magnetic tape structure of the present invention.

[0024] Figure 5 It is a distribution diagram of the magnetic tape slot structure of the present invention.

[0025] Figure 6 It is a schematic diagram of the assembly of the magnetic tape and the sensor of the present invention.

[0026] Figure 7 Graph 1 is a signal diagram measured in the embodiment.

[0027] In the figure:

[0028] 1. Top mounting structure, 2. Magnetic tape body, 3. Bottom mounting structure, 4. Top fixing plate, 5. Rivet, 6. Bottom connecting plate, 7. Spring, 8. Bottom fixing plate, 9. Steel wire layer, 10. Groove layer, 11. Magnetic mark, 12. Coating layer, 13. Through hole width, 14. Distance between adjacent through holes, 15. Magnetostrictive displacement sensor, 16. First pulse transit time, 17. First group of pulse interval. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, an absolute magnetostrictive displacement measuring magnetic tape of the present invention comprises a top mounting structure 1, a magnetic tape body 2 and a bottom mounting structure 3. Figure 2 The top mounting structure 1 is shown, which includes a top fixing plate 4 and a rivet 5. The rivet 5 is used to fix the tape body 2 to prevent the tape body 2 from falling off from the mounting hole of the top fixing plate 4. Figure 3 The bottom mounting structure 3 is shown, which includes a bottom connecting plate 6, a spring 7 and a bottom fixing plate 8. The tape body 2 and the bottom connecting plate 6 are also fixed by rivets. The function of the spring 7 is to provide a certain degree of tension to ensure the vertical installation of the tape body 2. Figure 4 The figure shows a magnetic tape body 2, which includes a steel wire layer 9, a groove layer 10, a magnetic mark 11 and a coating layer 12. The steel wire layer 9 is made of a group of parallel steel wires wrapped with a flexible material, and its main function is to ensure the tensile strength of the magnetic tape body 2; uniformly distributed through holes are arranged in the groove layer 10, and its main function is to fix the magnetic mark 11 and ensure the spacing between adjacent magnetic marks; the magnetic mark 11 is made of a permanent magnet material, and cooperates with the sensor to excite the ultrasonic guided wave signal; the coating layer 12 is a flexible strip material, and its main function is to prevent the magnetic mark 11 from falling off or being damaged.

[0031] like Figure 5 As shown, the through holes in the slot layer 10 are evenly distributed, and the through hole width 13 is smaller than the distance 14 between adjacent through holes;

[0032] The steel wire layer 9, the groove layer 10 and the coating layer 12 are flexible strips, and the types of materials thereof include but are not limited to rubber and polyurethane.

[0033] The through holes of the magnetic mark 11 and the slot layer 10 may be in the shape of a circle, a rectangle or a square.

[0034] The steel wire layer 9, the groove layer 10 and the coating layer 12 are fixed by coupling agent bonding or hot melt bonding.

[0035] The magnetic scale arrangement scheme is as follows:

[0036] Assume that the spacing 14 between adjacent through holes is L, and the effective measurement range of the magnetostrictive displacement sensor 15 is M. If the distance between the magnetic marks is too small, the measurement accuracy will be affected. Therefore, there is a minimum spacing requirement between the magnetic marks, and it is assumed that the minimum spacing between the magnetic marks is N. Set the through hole number where the odd-numbered magnetic marks are located to P(2n-1)=(G+1)*(n-1)+1, n=1, 2, 3, ...,; set the through hole number where the even-numbered magnetic marks are located to P(2n)=(G+3)*(n-1)+1+X, n=1, 2, 3, ...; X is related to the number of through holes with the minimum magnetic mark spacing, and G is related to the number of through holes with the maximum magnetic mark spacing. The function of int() is to get the integer part; if G is an odd number, then the value of G is subtracted by 1; the maximum value of n

[0037] like Figure 5 As shown, assuming that the shape of the through hole in the magnetic scale 11 and the slot layer 10 is rectangular, and the through hole width 13 is 8 mm, the distance 14 between adjacent through holes can be set to 12 mm (i.e., L = 12 mm); assuming that the effective measurement range of the magnetostrictive displacement sensor 15 is 2000 mm (i.e., M = 2000 mm). The minimum distance between the magnetic scales is 100 mm (i.e., N = 100 mm);

[0038] From this we can calculate, Because 163 is an odd number, the value of G is subtracted by 1, that is, G = 162, the maximum value of n Therefore, at most 2*n can be arranged in a tape. max =148 magnetic marks, and the position of each magnetic mark can be determined by combining the above-mentioned through-hole numbering formula, as shown in Table 1.

[0039] Table 1 Magnetic scale layout distribution table

[0040] Magnetic label number 1 2 3 4 5 … 147 148 Through hole number 1 10 164 175 327 … 11900 12055

[0041] Table 1 means that magnetic mark No. 1 is set at through hole No. 1, magnetic mark No. 2 is set at through hole No. 10, and so on. At the same time, the distribution of the spacing between adjacent magnetic marks can be calculated, as shown in Table 2.

[0042] Table 2 Distribution of adjacent magnetic scale spacing

[0043]

[0044]

[0045] Table 2 means that the distance between magnetic mark No. 1 and magnetic mark No. 2 is 9 through holes, the distance between magnetic mark No. 2 and magnetic mark No. 3 is 154 through holes, and so on. From Table 2, it can be seen that the minimum number of through holes for the magnetic mark spacing is 9, which is converted into a magnetic mark spacing of 9*12=108mm>100mm, which meets the minimum magnetic mark spacing requirement.

[0046] The magnetic scale spacing can be divided into two categories, one is odd increasing (9, 11, 13, ..), and the other is even decreasing (154, 152, ...). Therefore, the spacing between any two sets of adjacent magnetic scales is different. In addition, the number of through holes between the magnetic scale spacing of any two sets of interlaced magnetic scales is 163 or 165 (for example, the number of through holes between the spacing between magnetic scales No. 1 and No. 3 is 163, and the number of through holes between magnetic scales No. 2 and No. 4 is 165). The maximum interlaced magnetic scale spacing can be obtained as 165*12=1980mm<2000mm, which meets the requirement that the magnetostrictive displacement sensor 15 always covers at least 2 magnetic scales during movement, such as Figure 6 shown.

[0047] Before the actual measurement, the sensor will learn all the adjacent magnetic mark spacings on the tape and determine the absolute position of the first magnetic mark in each group of spacings. During the measurement process, the typical signals detected by the sensor are as follows: Figure 7 As shown, the magnetic scale spacing corresponding to the first pulse group can be converted according to the first pulse interval 17 combined with the sound velocity, thereby determining the absolute position of the magnetic scale corresponding to the first pulse. The absolute position of the sensor zero point can be determined by combining the distance information converted from the first pulse transit time 16.

[0048] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An absolute magnetostrictive displacement measuring magnetic tape, characterized in that: It comprises a top mounting structure (1), a magnetic tape body (2) and a bottom mounting structure (3); The top mounting structure (1) comprises a top fixing plate (4) and a rivet (5), wherein the rivet (5) fixes the tape body (2) to prevent the tape body (2) from falling off from the mounting hole of the top fixing plate (4); The bottom mounting structure (3) comprises a bottom connecting plate (6), a spring (7) and a bottom fixing plate (8) which are connected in sequence, and the magnetic tape body (2) is fixed to the bottom connecting plate (6); The magnetic tape body (2) comprises a steel wire layer (9), a groove layer (10), a magnetic mark (11) and a coating layer (12); the steel wire layer (9) is made of a group of parallel steel wires wrapped with a flexible material; the groove layer (10) is arranged on the steel wire layer (9) and is evenly provided with through holes, and the magnetic mark (11) is fixed in the through holes.

2. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The magnetic tape body (2) and the bottom connecting plate (6) are connected and fixed by rivets.

3. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The through hole width (13) in the groove layer (10) is smaller than the distance (14) between adjacent through holes.

4. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The steel wire layer (9), groove layer (10) and coating layer (12) are flexible strips, and the types of materials thereof include but are not limited to rubber and polyurethane.

5. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The through holes of the magnetic mark (11) and the slot layer (10) are in the shape of a circle, a rectangle or a square.

6. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The steel wire layer (9), the groove layer (10) and the coating layer (12) are fixed by coupling agent bonding or hot-melt bonding.

7. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The magnetic marker (11) is made of a permanent magnet and cooperates with the sensor to excite the ultrasonic guided wave signal.

8. The absolute magnetostrictive displacement measuring magnetic tape according to claim 1, characterized in that: The magnetostrictive displacement sensor is installed on the object to be measured and can sense the magnetic mark in the magnetic tape at all times. The magnetic mark arrangement scheme is as follows: Assuming that the distance between adjacent through holes (14) is L, the effective measurement range of the magnetostrictive displacement sensor (15) is M, and assuming that the minimum distance between the magnetic marks is N, The through-hole numbers where the odd-numbered magnetic marks are located are set to P(2n-1)=(G+1)*(n-1)+1, n=1, 2, 3, ...,; the through-hole numbers where the even-numbered magnetic marks are located are set to P(2n=(G+3)*(n-1)+1+X, n=1, 2, 3, ...; X is related to the number of through-holes with the minimum magnetic mark interval, and G is related to the number of through-holes with the maximum magnetic mark interval. The function of int() is to get the integer part; if G is an odd number, then the value of G is subtracted by 1; the maximum value of n

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