Position measurement method and sensor based on multi-head magnetoresistance effect sensor

Abstract

The present application provides a position measurement method and sensor based on a multi-head magnetoresistance effect sensor, which relates to the field of security technology. The multi-head magnetoresistance effect sensor includes a magnetic strip and at least two magnetic heads. The magnetic strip is fixedly connected to an actuating component. The actuating component can drive the magnetic strip to slide in a set direction in a cavity. Each magnetic head is arranged at a different position of the cavity along the set direction. The length of the magnetic strip is slightly greater than the spacing between adjacent magnetic heads. The method includes: obtaining the electrical signal output by each magnetic head according to the monitored magnetic field change during the process of the actuating component driving the magnetic strip to slide in the cavity along the set direction, and determining the position information of the actuating component in the cavity based on the electrical signal. The scheme relays the range of each magnetic head by setting multiple magnetic heads, so that the magnetic strip can be made shorter, further reducing the length of the device cavity, thereby reducing the size of the entire device and reducing the space occupancy rate.

Description

Technical Field

[0001] The present application relates to the field of security technology, and in particular to a position measurement method and sensor based on a multi-head magnetoresistive effect sensor. Background Art

[0002] The Tunnel Magneto Resistance (TMR) sensor uses the tunnel magnetoresistance effect of magnetic multilayer film materials to sense the magnetic field and can be used to measure physical quantities such as magnetic field, current, and displacement.

[0003] In the prior art, a linear TMR sensor is a magnetic head and a magnetic strip. The magnetic head and the magnetic strip undergo relative displacement to generate a magnetic field change, and then output an electrical signal change to measure the displacement.

[0004] However, the existing linear TMR sensor has a relatively long magnetic strip, which causes the entire sensor to occupy a relatively large space. Summary of the invention

[0005] The present application provides a position measurement method and a sensor based on a multi-head magnetoresistive effect sensor, which are used to solve the problem of the long magnetic strip length of the existing linear TMR sensor.

[0006] In a first aspect, an embodiment of the present application provides a position measurement method based on a multi-head magnetoresistance effect sensor, wherein the multi-head magnetoresistance effect sensor comprises a magnetic strip and at least two magnetic heads, wherein the magnetic strip is fixedly connected to an actuating component, wherein the actuating component can drive the magnetic strip to slide in a set direction in a cavity, wherein each magnetic head is arranged at a different position of the cavity along the set direction, wherein the length of the magnetic strip is slightly greater than the spacing between adjacent magnetic heads, and wherein the method comprises:

[0007] Acquiring the electrical signals output by each magnetic head according to the monitored magnetic field changes when the actuating component drives the magnetic strip to slide along the set direction in the cavity;

[0008] Based on the electrical signal, position information of the actuating component in the cavity is determined.

[0009] In a possible design of the first aspect, the length of the magnetic strip is slightly larger than the sum of the spacing between adjacent magnetic heads and an error threshold.

[0010] In another possible design of the first aspect, determining the position information of the actuating component in the cavity includes:

[0011] Acquiring a target electrical signal output by a target magnetic head when the actuating component drives the magnetic strip to slide, wherein the magnetic strip is within a measuring range of the target magnetic head when the sliding is completed;

[0012] Based on the target electrical signal, the specific position of the magnetic stripe in a single magnetic field cycle is obtained, wherein the magnetic stripe is composed of a plurality of N-pole and S-pole cycles, and adjacent N-pole and S-pole form a cycle distance. Each time the magnetic stripe slides a cycle distance, it correspondingly experiences a magnetic field cycle;

[0013] Obtaining the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide;

[0014] Determining a total sliding distance of the magnetic strip in the cavity based on the total number of magnetic field cycles, the cycle distance and the specific position;

[0015] Based on the total sliding distance, position information of the actuating component in the cavity is determined.

[0016] In another possible design of the first aspect, obtaining the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide includes:

[0017] Constructing a coordinate reference origin within the range of intersection of adjacent magnetic heads, and controlling the magnetic strip to slide to the coordinate reference origin, the total number of magnetic field cycles experienced by the magnetic strip at the coordinate reference origin being a set initial value;

[0018] When the actuating component drives the magnetic strip to slide within the measuring range of the adjacent magnetic head, if the magnetic head slides in the positive direction, the number of magnetic field cycles is accumulated once based on the set initial value each time the magnetic strip slides a cycle distance;

[0019] If the magnetic head slides in the reverse direction, the number of magnetic field cycles is reduced once based on the set initial value each time the magnetic strip slides a period distance.

[0020] In another possible design of the first aspect, obtaining the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide includes:

[0021] If the actuating component drives the magnetic strip to slide out of the measuring range of the adjacent magnetic head, the number of magnetic field cycles when the measuring range is exceeded is recorded;

[0022] Obtaining the sub-number of magnetic field cycles experienced when the actuating component drives the magnetic strip to slide within the measuring range of other magnetic heads;

[0023] The sum of the quantity value and the sub-quantity is taken as the total number of the magnetic field cycles.

[0024] In another possible design of the first aspect, determining the position information of the actuating component in the cavity based on the total sliding distance includes:

[0025] Acquiring electrical signals respectively output by adjacent magnetic heads when the magnetic strip slides to the coordinate reference origin;

[0026] Determining the position coordinates of the coordinate reference origin based on the electrical signals respectively output by the adjacent magnetic heads;

[0027] Based on the total sliding distance and the position coordinates of the coordinate reference origin, the absolute position coordinates of the actuating component in the cavity are determined.

[0028] In another possible design of the first aspect, determining the absolute position coordinates of the actuating component in the cavity includes:

[0029] J=K n +R

[0030] R=T*M+t

[0031] In the above formula, J is the absolute position coordinate of the actuating component when sliding ends, Kn is the position coordinate of the coordinate reference origin, T is the total number of magnetic field cycles, M is the cycle distance, and t is the specific position.

[0032] In another possible design of the first aspect, acquiring a specific position of the magnetic strip within a single magnetic field cycle based on the target electrical signal includes:

[0033] t = arctan (A / B)

[0034] In the above formula, A is the first voltage value output by the target magnetic head, B is the second voltage value output by the target magnetic head, and t is the specific position.

[0035] In another possible design of the first aspect, determining the position information of the actuating component in the cavity based on the electrical signal includes:

[0036] Obtaining the total number of magnetic field cycles experienced by the actuating component driving the magnetic strip from the beginning of sliding to the end of sliding;

[0037] Acquiring a target electrical signal output by a target magnetic head when the actuating component drives the magnetic strip to slide, and when the sliding ends, the magnetic strip is within a measuring range of the target magnetic head;

[0038] Based on the target electrical signal, obtaining a specific position of the magnetic stripe within a single magnetic field cycle;

[0039] Based on the specific position, the total number of magnetic field cycles and the cycle distance, the relative displacement of the actuating component is determined as the position information.

[0040] In a second aspect, an embodiment of the present application provides a multi-head magnetoresistive effect sensor, comprising: a magnetic strip and at least two magnetic heads; the magnetic strip is fixedly connected to an actuating component, the actuating component can drive the magnetic strip to slide along a set direction in a cavity, each magnetic head is arranged at a different position of the cavity along the set direction, and the length of the magnetic strip is slightly greater than the spacing between adjacent magnetic heads;

[0041] The magnetic head is used to output an electrical signal according to the change of the magnetic field detected when the magnetic strip slides, and the electrical signal is used to determine the position information of the actuating component in the cavity.

[0042] The position measurement method and sensor based on a multi-head magnetoresistive effect sensor provided in the embodiment of the present application relay the measuring ranges of each head by setting up multiple heads, so that the magnetic strip can be made shorter, further reducing the length of the device cavity, thereby reducing the size of the entire device and reducing space occupancy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description, are used to explain the principles of the present application;

[0044] Figure 1 It is a schematic diagram of the structure of a single-head TMR sensor;

[0045] Figure 2 A schematic diagram of the structure of a multi-head TMR provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of head spacing constraint provided in an embodiment of the present application;

[0047] Figure 4 A signal diagram provided for an embodiment of the present application;

[0048] Figure 5 A schematic diagram of the magnetic stripe structure provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of a flow chart of a method for determining the position of an actuating component provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram of a flow chart of a method for determining a magnetic field period provided in an embodiment of the present application;

[0051] Figure 8 A schematic diagram of a magnetic head range relay provided in an embodiment of the present application;

[0052] Fig. 9 A schematic diagram of the structure of a position measurement device provided in an embodiment of the present application;

[0053] Fig.10 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0054] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] The current linear magnetoresistance sensor (Tunnel Magneto Resistance, TMR) is a magnetic head with a magnetic strip. The magnetic head and the magnetic strip undergo relative displacement to generate electrical signal changes to measure the displacement. However, the length of the magnetic strip will increase the space occupied by the device.

[0057] For example, Figure 1 It is a schematic diagram of the structure of a single-head TMR sensor. Figure 1 As shown in the figure, assuming that the length of the magnetic strip is 10 cm, the length of the entire TMR sensor must be at least 20 cm, so that the magnetic strip can slide left and right in the cavity. It can be seen that the longer the magnetic strip, the larger the size of the entire TMR sensor will be, and the more space it will occupy.

[0058] In response to the above problems, the present application provides a multi-head magnetoresistive effect sensor, which relays the measuring range of each head by arranging multiple magnetic heads on the cavity. In this way, the length of the magnetic strip can be made shorter, and the corresponding cavity length can also be made shorter, thereby reducing the size of the entire device and reducing the space occupancy rate.

[0059] The technical solution of the present application is described in detail below through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0060] First, some embodiments are used to elaborate in detail on the multi-head TMR structure provided in this application.

[0061] Figure 2 As shown in the structure schematic diagram of the multi-head TMR provided in the embodiment of this application, Figure 2 the magnetic stripe is fixedly connected to the actuating component, and the actuating component can slide left and right in the device cavity (that is, the actuating component can drive the magnetic stripe to slide in the cavity along the set direction), and multiple magnetic heads are fixed on the cavity. When the magnetic stripe slides left and right together with the actuating component, each magnetic head successively monitors the magnetic field change and outputs an electrical signal, and the position information of the actuating component is obtained by analyzing the electrical signal.

[0062] Among them, there is 1 magnetic stripe, and there are at least 2 magnetic heads. In addition, the number of magnetic heads has no upper limit. Figure 2 The total length of the movement range of the actuating component in [reference document] is L.

[0063] In this embodiment, the purpose of installing multiple magnetic heads is for relay. That is, when the magnetic stripe is about to slide out of the measurement range of one magnetic head, it is necessary to ensure that the magnetic stripe is about to enter or has entered the measurement range of another magnetic head, thereby realizing relay. Therefore, constraint conditions need to be configured to constrain the installation distance between each magnetic head and the length of the magnetic stripe.

[0064] Exemplarily, Figure 3 As shown in the schematic diagram of the magnetic head spacing constraint provided in the embodiment of this application, Figure 3 in the multi-head TMR provided by this solution, the sliding distance of the magnetic stripe is measured by multiple magnetic heads in relay. Therefore, the length of the magnetic stripe can be set as Q, and the distance between adjacent two magnetic heads is Pa-b (for example, the distance between magnetic head 1# and magnetic head 2# in [reference document 1] is P 1-2 ), then for all Pa-b, the constraint of Pa-b < Q should be satisfied.

[0065] Among them, for the convenience of structural design, the magnetic heads do not need to be arranged at equal intervals, and it is only necessary to satisfy the constraint of Pa-b < Q, and this constraint condition can meet the requirements of various application scenarios. In addition, in some other embodiments, assuming the maximum error threshold is W, then the multi-head TMR can be designed according to the constraint of Pa-b + W < Q. This is mainly considering that there are certain errors in the production, manufacturing and installation of the multi-head TMR. By designing the error threshold W, measurement errors of the multi-head TMR can be avoided.

[0066] In this embodiment, after determining the structure of the multi-head magnetoresistive effect sensor, the actuating component can drive the magnetic stripe to slide in the cavity along the set direction. During the sliding process, each magnetic head will output an electrical signal according to the monitored magnetic field change. Among them, this electrical signal can be used to determine the position information of the actuating component in the cavity.

[0067] The embodiment of the present application provides multiple magnetic heads to relay the measuring ranges of the various magnetic heads, so that the magnetic strip can be made shorter, further reducing the length of the device cavity, thereby reducing the size of the entire device and reducing space occupancy.

[0068] Taking the multi-head TMR used for position measurement as an example, the working principle of the multi-head TMR provided by the present application is introduced through some embodiments below.

[0069] In some embodiments, when the magnetic strip slides under the magnetic head and causes the magnetic field to change, the electrical signal fed back by the magnetic head is specifically divided into two-phase signals A and B (A and B can be understood as the first voltage value and the second voltage value output by the magnetic head), where A and B satisfy the trigonometric function waveform change law, and A and B are trigonometric functions with a phase angle difference of 90 degrees. Let A=sinθ, B=cosθ, and then construct the trigonometric function arctan(sinθ / cosθ), where the trigonometric function arctan(sinθ / cosθ) can be regarded as a periodic function and is linear within a single cycle, thereby converting the complex trigonometric function waveform signal into a linear signal, and the specific position t within the single cycle can be solved by analyzing the position of the linear signal, that is:

[0070] t = arctan(A / B)

[0071] For example, Figure 4 A signal diagram provided for an embodiment of the present application, such as Figure 4 As shown, arctan(sinθ / cosθ) is a periodic linear signal, the ordinate represents A / B, and the abscissa represents t. By calculating arctan(A / B), the specific position t of the magnetic stripe within a single magnetic field cycle can be determined.

[0072] Continue to refer to the above Figure 4 ,from Figure 4 It can be seen that arctan(A / B) is a periodically changing waveform, that is, A and B output by the magnetic head can only determine the specific position t of the magnetic stripe in this magnetic field cycle, but it is not clear how many magnetic field cycles the magnetic stripe has experienced when sliding in the device cavity (the magnetic stripe is composed of multiple N-pole and S-pole cycles, and the adjacent N-pole and S-pole form a period distance. Each time the magnetic stripe slides a period distance, it experiences a magnetic field cycle. Therefore, if you need to calculate how far the magnetic stripe has slid in the device cavity, you need to determine how many magnetic field cycles the magnetic stripe has experienced when sliding in the device cavity.

[0073] in, Figure 5 A schematic diagram of the magnetic stripe structure provided in the embodiment of the present application, such as Figure 5As shown, the magnetic stripe is composed of multiple alternating cycles of N poles and S poles, and adjacent N poles and S poles form a period distance M. Assuming that there is only one magnetic head in the device cavity, if the magnetic stripe undergoes T magnetic field cycles, the relative position R of the actuating component analyzed by the single magnetic head can be expressed as:

[0074] R=T*M+t=T*M+arctan(A / B)

[0075] In the above formula, t is the specific position, M is the period distance, and T is the number of magnetic field cycles experienced by the magnetic stripe.

[0076] Figure 6 A flow chart of a method for determining the position of an actuating component provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the position information of the actuating component in the cavity can be determined specifically through the following steps.

[0077] Step S610: Acquire the target electrical signal output by the target magnetic head when the actuating component drives the magnetic stripe to slide, wherein the magnetic stripe is within the measuring range of the target magnetic head when the sliding is finished.

[0078] Step S620: Based on the target electrical signal, the specific position of the magnetic stripe within a single magnetic field cycle is obtained.

[0079] The magnetic stripe is composed of multiple N-pole and S-pole periods, and adjacent N-pole and S-pole form a period distance. Every time the magnetic stripe slides a period distance, it experiences a magnetic field cycle.

[0080] Step S630: Obtain the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide.

[0081] Step S640: Determine the total sliding distance of the magnetic strip in the cavity based on the total number of magnetic field cycles, cycle distance and specific position.

[0082] Step S650: Determine the position information of the actuating component in the cavity based on the total sliding distance.

[0083] In this embodiment, when the actuating component drives the magnetic strip to slide in the device cavity, the magnetic strip may pass through multiple magnetic heads, and finally be within the range of a certain magnetic head after the sliding is completed. This magnetic head is represented by a target magnetic head. After the target magnetic head detects the change of the magnetic field, it will output a target electrical signal (i.e., A and B mentioned above), and the specific position t of the magnetic strip in a single magnetic field cycle can be calculated through A and B.

[0084] Furthermore, if the relative position R of the actuating component needs to be analyzed, the total number of magnetic field cycles T needs to be determined, and then the relative position R of the actuating component is finally calculated through the above formula R=T*M+t=T*M+arctan(A / B).

[0085] In actual applications, when the magnetic stripe starts to slide, it is not known which magnetic field cycle the magnetic stripe is currently in (usually a multi-head TMR starts to slide only after power is turned on. At the moment of power-on, a certain head can detect the magnetic field change and output A and B, but it is impossible to determine which magnetic field cycle the magnetic stripe is in at the moment of power-on. Figure 4 It is not clear which magnetic field cycle the magnetic strip is in when the sliding ends, so the total number T of the magnetic field cycles mentioned above cannot be calculated. The only way is to determine whether the magnetic head has advanced one magnetic field cycle based on the change of the electrical signal output by each magnetic head. If it has advanced one magnetic field cycle, T increases by 1, and if it has retreated one magnetic field cycle, T decreases by 1. By determining the total number of magnetic field cycles based on the change of the electrical signal output by each magnetic head, the relative displacement of the magnetic strip in the cavity can be determined, thereby determining how far the actuating component has moved.

[0086] Specifically, in actual applications, since the magnetic heads arranged on the cavity of the device are interconnected, when a magnetic strip slides into the measuring range of one magnetic head, the magnetic head can monitor the change in the magnetic field and output a continuously changing electrical signal. When the magnetic head slides into the measuring range of another magnetic head, the other magnetic head can monitor the change in the magnetic field and output a continuously changing electrical signal. In this way, by monitoring the changes in the electrical signals of each magnetic head, it is possible to understand how many magnetic field cycles the magnetic strip has experienced during the sliding process, thereby analyzing the relative position R of the actuating component (i.e., the sliding distance of the magnetic head driven by the actuating component).

[0087] Specifically, the calculation of the relative position R can be achieved through the following steps:

[0088] Step 1: Obtain the total number of magnetic field cycles that the actuating component drives the magnetic strip to experience from the beginning of sliding to the end of sliding.

[0089] Step 2: Obtain the target electrical signal output by the target magnetic head when the actuating component drives the magnetic strip to slide.

[0090] Step 3: Based on the target electrical signal, obtain the specific position of the magnetic stripe within a single magnetic field cycle.

[0091] Step 4: Determine the total sliding distance of the magnetic strip in the cavity based on the total number of magnetic field cycles, cycle distance and specific position;

[0092] Step 5: Based on the total sliding distance, determine the position information of the actuating component in the cavity.

[0093] The magnetic stripe is within the measuring range of the target magnetic head at the end of sliding.

[0094] In this embodiment, taking the target electrical signals output by the target head including A0 and B0 as an example, the specific position t of the magnetic stripe within a single magnetic field cycle under the target head can be calculated by t=arctan(A0 / B0), and then the total number of magnetic field cycles experienced by the actuating component in the process of driving the magnetic stripe to slide can be recorded, and the sliding distance of the magnetic stripe driven by the actuating component can be calculated by the formula R=T*M+t, thereby analyzing the relative position of the actuating component.

[0095] The embodiment of the present application can determine the total sliding distance of the magnetic strip in the cavity by utilizing the total number of magnetic field cycles, cycle distance and specific position, thereby realizing position measurement of a multi-head magnetoresistive effect sensor.

[0096] Furthermore, in some embodiments, Figure 7 A flow chart of a method for determining a magnetic field period provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, it may specifically include the following steps:

[0097] Step S710: constructing a coordinate reference origin within the cross-range of the adjacent magnetic heads, and controlling the magnetic strip to slide to the coordinate reference origin;

[0098] Step S720: when the actuating component drives the magnetic strip to slide within the measuring range of the adjacent magnetic head, if the magnetic head slides in the positive direction, the number of magnetic field cycles is accumulated once based on the set initial value every time the magnetic strip slides one cycle distance;

[0099] Step S730: If the magnetic head slides in the reverse direction, then the number of magnetic field cycles is reduced once based on the set initial value each time the magnetic strip slides a cycle distance.

[0100] The total number of magnetic field cycles experienced by the magnetic stripe when it is at the coordinate reference origin is the set initial value.

[0101] In this embodiment, a two-dimensional coordinate system can be established when the magnetic strip slides in the cavity, and the horizontal axis of the coordinate system is used to describe the sliding distance of the magnetic strip in the cavity. The origin of the coordinate system can be a position point within the range of intersection of two adjacent magnetic heads. Figure 2 or Figure 3 , the coordinate reference origin can be established in the first magnetic field cycle within the cross range of head 1# and head 2#, and each time the multi-head TMR is powered on, it will first come to the coordinate reference origin.

[0102] For example, Figure 8 The schematic diagram of the head range relay provided in the embodiment of the present application is as follows: Figure 8As shown in FIG. 1 , a coordinate reference origin is set within the cross range of the measurement range of head 1# and head 2#. Then, at the coordinate reference origin, the absolute coordinates of head 1# and head 2# are respectively:

[0103]

[0104] In the above formula, T1 is the number of magnetic field cycles experienced by head 1# during the sliding process of the magnetic stripe, and T2 is the number of magnetic field cycles experienced by head 2# during the sliding process of the magnetic stripe. 11 K is the absolute coordinate of the coordinate reference origin at head 1#, 12 is the absolute coordinate of the coordinate reference origin at head 2#, M is the periodic distance, A1 and B1 are the two voltage values ​​output by head 1# when the magnetic strip moves to the coordinate reference origin, A2 and B2 are the two voltage values ​​output by head 2# when the magnetic strip moves to the coordinate reference origin.

[0105] Among them, each time the multi-head TMR is powered on, when the magnetic strip is controlled to come to the coordinate reference origin, T1=0, T2=0, and then, driven by the actuating component, the magnetic strip increases T1 by 1 and T2 by 1 for each forward magnetic field cycle, and decreases T1 by 1 and T2 by 1 for each backward magnetic field cycle.

[0106] In this embodiment, the above Figure 8 It only proposes to construct a coordinate reference origin between head 1# and head 2#. In practical applications, the coordinate reference origin can be constructed within the range of intersection of any two adjacent heads. The total number of magnetic field cycles experienced when the magnetic strip is at the coordinate reference origin is the set initial value (for example, the value is 0). Then, when the actuating component drives the magnetic strip to slide within the range of adjacent heads, the total number of magnetic field cycles increases by 1 for each forward magnetic field cycle, and decreases by 1 for each backward magnetic field cycle.

[0107] In addition, in order to ensure the accuracy of position measurement, the magnetic stripe is only configured with two moving directions (i.e., positive direction and reverse direction) in the device cavity, where the positive direction can be understood as the forward direction of the magnetic stripe, and the reverse direction can be understood as the backward direction of the magnetic stripe.

[0108] By constructing a coordinate reference origin within the cross-range of the measuring ranges of adjacent magnetic heads, the embodiment of the present application can more accurately measure the total number of magnetic field cycles experienced by the magnetic stripe during its sliding process, thereby improving the calculation accuracy of the total sliding distance of the magnetic stripe.

[0109] In other embodiments, since the multi-head TMR provided by the present application uses multiple heads for relay, in actual applications, the actuating component may leave the measuring range of a certain head while driving the magnetic strip to slide, and enter the measuring range of another head at the same time. At this time, it is necessary to accurately record the total number of magnetic field cycles of the magnetic strip during the sliding process. Specifically, this can be achieved through the following steps:

[0110] Step (1) If the actuating component drives the magnetic strip to slide out of the measuring range of the adjacent magnetic head, the number of magnetic field cycles when the measuring range is exceeded is recorded;

[0111] Step (2) obtaining the sub-number of magnetic field cycles experienced when the actuating component drives the magnetic strip to slide within the measuring range of other magnetic heads;

[0112] In step (3), the sum of the quantity value and the sub-quantity is taken as the total number of magnetic field cycles.

[0113] In this embodiment, when the magnetic strip slides under the drive of the actuating component and slides out of the measuring range of a certain magnetic head, the number of magnetic field cycles experienced by the magnetic strip at the magnetic head during the sliding process no longer changes (the number of magnetic field cycles can be recorded at this time), and at the same time, the magnetic strip enters the measuring range of the next magnetic head, and continues to record the number of magnetic field cycles experienced by the magnetic strip at the next magnetic head during the sliding process. The two numbers are combined to form the total number of magnetic field cycles experienced by the magnetic strip during the sliding process.

[0114] For example, continue with the above Figure 8 For example, when the magnetic strip slides within the measuring range of head 2#, T2 increases by 1 for each magnetic field cycle. When the magnetic strip slides out of the measuring range of head 2# and enters the measuring range of head 3#, T2 will no longer continue to accumulate (assuming that when the magnetic strip slides out of the measuring range of head 2#, the value of T2 is 10). At this time, the value of T3 can be continued to be recorded, and then T2 and T3 are summed to obtain the total number of magnetic field cycles that the head has experienced when sliding under the drive of the actuating component.

[0115] By recording the number of magnetic field cycles and sub-numbers, the embodiment of the present application can still accurately determine the total number of magnetic field cycles experienced by the magnetic stripe when the magnetic stripe slides out of the measuring range of a certain magnetic head, thereby further improving the calculation accuracy of the total sliding distance of the magnetic stripe.

[0116] Furthermore, the above embodiments have mentioned how to determine the relative displacement of the actuating component (i.e., the sliding distance of the magnetic head in the device cavity). Based on the above embodiments, in some embodiments, the above coordinate reference origin can also be used to calculate the absolute position of the magnetic strip in the device cavity, thereby determining the absolute position of the actuating component, which can be specifically achieved through the following steps:

[0117] Step ① obtaining electrical signals respectively output by adjacent magnetic heads when the magnetic strip slides to the coordinate reference origin;

[0118] Step ②: determining the position coordinates of the coordinate reference origin based on the electrical signals respectively output by the adjacent magnetic heads;

[0119] Step ③ determines the absolute position of the magnetic strip in the cavity based on the total sliding distance and the position coordinates of the coordinate reference origin.

[0120] In this embodiment, it has been mentioned above that each time the multi-head TMR is powered on, it will first come to the coordinate reference origin. Figure 8 Based on the electrical signals output by head 1# and head 2#, the absolute coordinates at the coordinate reference origin can be obtained as follows:

[0121]

[0122] Among them, when the head 1#K 11 When moving within the left range: fusion coordinate J=R1, when at head 2#K 12 Right K 21 When moving within the left range, the fusion coordinate J=K 11 +R2, and so on. Within the entire fused range, each position has its displacement coordinate value, so the fused absolute coordinate system can be established to determine the absolute position of the magnetic strip in the device cavity and the absolute position of the actuating component based on the fused coordinates. Among them, R1=T1*M+arctan(A1 / B1),R2=T2*M+arctan(A2 / B2).

[0123] in, Figure 8 Only the fusion coordinate J calculated when the coordinate reference origin is set at head 1# and head 2# is used to determine the absolute position. In practical applications, when the coordinate reference origin is set within the range of intersection of any two adjacent heads, the absolute position can be calculated by the following formula:

[0124] J=K n +R

[0125] R=T*M+t

[0126] In the above formula, J is the coordinate of the absolute position when the magnetic head ends sliding, Kn is the position coordinate of the coordinate reference origin, T is the total number of magnetic field cycles, M is the cycle distance, t is the specific position, and R represents the sliding distance of the magnetic strip driven by the actuating component.

[0127] The embodiment of the present application can determine the absolute position of the actuating component by utilizing the absolute coordinates at the coordinate reference origin and the sliding distance of the magnetic strip driven by the actuating component, so that the multi-head magnetoresistive effect sensor can be adapted to different measurement requirements, thereby improving the practicality of the multi-head magnetoresistive effect sensor.

[0128] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0129] Fig. 9 A schematic diagram of the structure of a position measurement device provided in an embodiment of the present application is shown in FIG. Fig. 9 As shown, the position measurement device 900 includes an electrical signal acquisition module 910 and a position information determination module 920 .

[0130] The electrical signal acquisition module is used to acquire the electrical signals output by each magnetic head according to the monitored magnetic field changes when the actuating component drives the magnetic strip to slide in the cavity along the set direction. The position information determination module is used to determine the position information of the actuating component in the cavity based on the electrical signals.

[0131] Optionally, the sum of the spacing between adjacent magnetic heads and the error threshold is smaller than the length of the magnetic stripe.

[0132] Optionally, the position information determination module can be specifically used to: obtain the target electrical signal output by the target magnetic head when the actuating component drives the magnetic stripe to slide; based on the target electrical signal, obtain the specific position of the magnetic stripe within a single magnetic field cycle; obtain the total number of magnetic field cycles experienced by the actuating component when driving the magnetic stripe to slide; based on the total number of magnetic field cycles, cycle distance and specific position, determine the total sliding distance of the magnetic stripe in the cavity; based on the total sliding distance, determine the position information of the actuating component in the cavity.

[0133] Among them, the magnetic stripe is within the range of the target magnetic head at the end of sliding. The magnetic stripe is composed of multiple N-pole and S-pole cycles. Adjacent N-pole and S-pole form a cycle distance. Every time the magnetic stripe slides a cycle distance, it correspondingly experiences a magnetic field cycle.

[0134] Optionally, the position information determination module can be specifically used to: construct a coordinate reference origin within the range of intersection of adjacent magnetic heads, and control the magnetic stripe to slide to the coordinate reference origin; when the actuator drives the magnetic stripe to slide within the range of adjacent magnetic heads, if the magnetic head slides in the positive direction, then the number of magnetic field cycles is accumulated once on the basis of the set initial value each time the magnetic stripe slides a cycle distance; if the magnetic head slides in the reverse direction, then the number of magnetic field cycles is accumulated once on the basis of the set initial value each time the magnetic stripe slides a cycle distance.

[0135] The total number of magnetic field cycles experienced by the magnetic stripe when it is at the coordinate reference origin is the set initial value.

[0136] Optionally, the position information determination module can be specifically used for: if the actuating component drives the magnetic stripe to slide out of the measuring range of an adjacent magnetic head, then recording the number of magnetic field cycles when the measuring range is exceeded; obtaining the sub-number of magnetic field cycles experienced when the actuating component drives the magnetic stripe to slide within the measuring range of other magnetic heads; and taking the sum of the number value and the sub-number as the total number of magnetic field cycles.

[0137] Optionally, the position information determination module can be specifically used to: obtain the electrical signals respectively output by adjacent magnetic heads when the magnetic stripe slides to the coordinate reference origin; determine the position coordinates of the coordinate reference origin based on the electrical signals respectively output by adjacent magnetic heads; determine the absolute position of the magnetic stripe in the cavity based on the total sliding distance and the position coordinates of the coordinate reference origin.

[0138] Optionally, the position information determination module may be specifically configured to calculate the absolute position using the following formula:

[0139] J=K n +R

[0140] R=T*M+t

[0141] In the above formula, J is the coordinate of the absolute position when the head slides to the end, Kn is the position coordinate of the coordinate reference origin, T is the total number of magnetic field cycles, M is the cycle distance, and t is the specific position.

[0142] Optionally, the location information determination module may be specifically configured to calculate the specific location using the following formula:

[0143] t = arctan (A / B)

[0144] In the above formula, A is the first voltage value output by the target magnetic head, B is the second voltage value output by the target magnetic head, and t is the specific position.

[0145] Optionally, the position information determination module can be specifically used to obtain the total number of magnetic field cycles experienced by the actuating component driving the magnetic strip from the beginning to the end of sliding; obtain the target electrical signal output by the target magnetic head when the actuating component drives the magnetic strip to slide; based on the target electrical signal, obtain the specific position of the magnetic strip in a single magnetic field cycle; based on the specific position, the total number of magnetic field cycles and the cycle distance, determine the relative displacement of the actuating component as the position information. Wherein, the magnetic strip is within the range of the target magnetic head at the end of sliding.

[0146] The device provided in the embodiment of the present application can be used to execute the method in the above-mentioned embodiment. Its implementation principle and technical effect are similar and will not be repeated here.

[0147] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. For example, the electric signal acquisition module can be a separately established processing element, or it can be integrated in a certain element of the above device for implementation. In addition, it can also be stored in the memory of the above device in the form of program code, and called and executed by a certain processing element of the above device. The implementation of other modules is similar. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in the processor element or instructions in the form of software.

[0148] Fig.10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.10 As shown, the electronic device 1000 includes: at least one processor 1001, a memory 1002, a bus 1003 and a communication interface 1004. Among them: the processor 1001, the communication interface 1004 and the memory 1002 communicate with each other through the bus 1003. The communication interface is used to communicate with other devices. The communication interface includes a communication interface for data transmission and a display interface or an operation interface for human-computer interaction. The processor is used to execute the computer execution instructions stored in the memory, and specifically can execute the relevant steps in the method described in the above embodiment.

[0149] The processor may be a central processing unit, or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement an embodiment of the present invention. The one or more processors included in the review device may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs. The memory is used to store computer execution instructions. The memory may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

[0150] This embodiment also provides a computer-readable storage medium, in which computer instructions are stored. When at least one processor of an electronic device executes the computer instructions, the electronic device executes the methods provided in the above-mentioned various implementation modes.

[0151] This embodiment also provides a computer program product, which includes computer instructions stored in a readable storage medium. At least one processor of the electronic device can read the computer instructions from the readable storage medium, and at least one processor executes the computer instructions so that the electronic device implements the methods provided in the above various embodiments.

[0152] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0153] It is to be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and are not intended to limit the scope of the embodiments of the present application. In the embodiments of the present application, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A position measurement method based on a multi-head magnetoresistance effect sensor, It is characterized in that The multi-head magnetoresistive effect sensor comprises a magnetic strip and at least two magnetic heads, wherein the magnetic strip is fixedly connected to an actuating component, and the actuating component can drive the magnetic strip to slide along a set direction in a cavity, and each magnetic head is arranged at a different position of the cavity along the set direction, and the length of the magnetic strip is slightly greater than the sum of the spacing between adjacent magnetic heads and an error threshold. The method comprises: Acquiring the electrical signals output by each magnetic head according to the monitored magnetic field changes when the actuating component drives the magnetic strip to slide along the set direction in the cavity; Based on the electrical signal, position information of the actuating component in the cavity is determined.

2. The method according to claim 1, It is characterized in that The determining the position information of the actuating component in the cavity includes: Acquiring a target electrical signal output by a target magnetic head when the actuating component drives the magnetic strip to slide, wherein the magnetic strip is within a measuring range of the target magnetic head when the sliding is completed; Based on the target electrical signal, the specific position of the magnetic stripe in a single magnetic field cycle is obtained, wherein the magnetic stripe is composed of a plurality of N-pole and S-pole cycles, and adjacent N-pole and S-pole form a cycle distance. Each time the magnetic stripe slides a cycle distance, it correspondingly experiences a magnetic field cycle; Obtaining the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide; Determining a total sliding distance of the magnetic strip in the cavity based on the total number of magnetic field cycles, the cycle distance and the specific position; Based on the total sliding distance, position information of the actuating component in the cavity is determined.

3. The method according to claim 2, It is characterized in that The obtaining of the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide comprises: Constructing a coordinate reference origin within the range of intersection of adjacent magnetic heads, and controlling the magnetic strip to slide to the coordinate reference origin, the total number of magnetic field cycles experienced by the magnetic strip at the coordinate reference origin being a set initial value; When the actuating component drives the magnetic strip to slide within the measuring range of the adjacent magnetic head, if the magnetic head slides in the positive direction, the number of magnetic field cycles is accumulated once based on the set initial value each time the magnetic strip slides a cycle distance; If the magnetic head slides in the reverse direction, the number of magnetic field cycles is reduced once based on the set initial value each time the magnetic strip slides a period distance.

4. The method according to claim 3, It is characterized in that The obtaining of the total number of magnetic field cycles experienced by the actuating component when driving the magnetic strip to slide comprises: If the actuating component drives the magnetic strip to slide out of the measuring range of the adjacent magnetic head, the number of magnetic field cycles when the measuring range is exceeded is recorded; Obtaining the sub-number of magnetic field cycles experienced when the actuating component drives the magnetic strip to slide within the measuring range of other magnetic heads; The sum of the quantity value and the sub-quantity is taken as the total number of the magnetic field cycles.

5. The method according to claim 3, It is characterized in that The determining, based on the total sliding distance, the position information of the actuating component in the cavity comprises: Acquiring electrical signals respectively output by adjacent magnetic heads when the magnetic strip slides to the coordinate reference origin; Determining the position coordinates of the coordinate reference origin based on the electrical signals respectively output by the adjacent magnetic heads; Based on the total sliding distance and the position coordinates of the coordinate reference origin, the absolute position coordinates of the actuating component in the cavity are determined.

6. The method according to claim 5, It is characterized in that The determining the absolute position coordinates of the actuating component in the cavity comprises: J=K n +R R=T M+t In the above formula, J is the absolute position coordinate of the actuating component when sliding ends, Kn is the position coordinate of the coordinate reference origin, T is the total number of magnetic field cycles, M is the cycle distance, and t is the specific position.

7. The method according to claim 2, It is characterized in that The obtaining, based on the target electrical signal, a specific position of the magnetic strip within a single magnetic field cycle comprises: t = arctan (A / B) In the above formula, A is the first voltage value output by the target magnetic head, B is the second voltage value output by the target magnetic head, and t is the specific position.

8. The method according to claim 1, It is characterized in that The determining, based on the electrical signal, position information of the actuating component in the cavity comprises: Obtaining the total number of magnetic field cycles experienced by the actuating component driving the magnetic strip from the beginning of sliding to the end of sliding; Acquiring a target electrical signal output by a target magnetic head when the actuating component drives the magnetic strip to slide, and when the sliding ends, the magnetic strip is within a measuring range of the target magnetic head; Based on the target electrical signal, obtaining a specific position of the magnetic stripe within a single magnetic field cycle; Based on the specific position, the total number of magnetic field cycles and the cycle distance, the relative displacement of the actuating component is determined as the position information.

9. A multi-head magnetoresistance effect sensor, It is characterized in that include: A magnetic strip and at least two magnetic heads; the magnetic strip is fixedly connected to an actuating component, the actuating component can drive the magnetic strip to slide along a set direction in the cavity, each magnetic head is arranged at a different position of the cavity along the set direction, and the length of the magnetic strip is slightly greater than the sum of the spacing between adjacent magnetic heads and an error threshold; The magnetic head is used to output an electrical signal according to the change of the magnetic field detected when the magnetic strip slides, and the electrical signal is used to determine the position information of the actuating component in the cavity.

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