CN114413749B

CN114413749B - Magnetic field sensing device and magnetic field sensing method

Info

Publication number: CN114413749B
Application number: CN202210329506.1A
Authority: CN
Inventors: 秦文辉; 袁辅德
Original assignee: Suzhou Novosense Microelectronics Co ltd
Current assignee: Suzhou Novosense Microelectronics Co ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2022-06-10
Anticipated expiration: 2042-03-31
Also published as: CN114413749A

Abstract

The invention provides a magnetic field sensing device and a magnetic field sensing method, which aim to enable each magnetic sensor in a first group of magnetic sensors and a second group of magnetic sensors to be in a corresponding first working state and a second working state alternately according to time sequence through a switching circuit, so as to alternately generate a signal output corresponding to the first working state and a signal output corresponding to the second working state, further eliminate errors caused by micro dislocation of a magnetic source of radial magnetization, and simultaneously obtain a first differential output and a second differential output for determining angle information associated with a target magnetic field source, therefore, an output processing circuit has no difference in time for the final formation of the first differential output and the second differential output. The technical scheme of the invention not only has higher output bandwidth, but also has extremely low time delay error, and simultaneously has the characteristic of resisting external electromagnetic interference.

Description

Magnetic field sensing device and magnetic field sensing method

Technical Field

The present invention relates to the technical field of sensors for measuring rotation angles, in particular to the technical field of magnetic angle sensors.

Background

Measuring the rotation angle of an object, such as a gear or a rotating shaft of a mechanical device; or measuring the position and movement information of a moving object, such as the opening and closing stroke of a valve, plays an important role in the industrial, automotive, and even commercial fields, and the measurement can realize monitoring and alarming of various systems, such as idle sliding, and the like, and various automatic feedback control of actions, such as action or attitude control, or triggering of various operations, and the like. In the above application fields, various measurements are usually realized by magnetic sensing, because the magnetic sensing has the advantages of non-contact measurement, excellent vibration resistance, wear resistance and oil stain resistance, and sufficient accuracy and reaction speed.

Generally, a device for measuring a rotation angle or position comprises a magnetic sensor and a magnetic encoder, which is generally composed of a permanent magnet in which magnetized regions are regularly arranged and alternately arranged in south and north poles, and the structure generates a periodically changing magnetic field intensity and direction, and the magnetic field is a signal; the magnetic sensor detects the strength or direction change of the magnetic field and generates an electric signal to be output. Among the magnetic sensors widely used today are devices designed based on the principles of hall effect, anisotropic magnetoresistance, giant magnetoresistance, tunneling magnetoresistance, etc.; among them, the hall device is a technology with the longest history and the widest application range, and has the excellent compatibility with a CMOS (Complementary Metal Oxide Semiconductor) process and a relatively small sensor size, so that it has the best cost efficiency in terms of IC (Integrated Circuit Chip) size and packaging of a subsequent stage.

Fig. 1 illustrates a schematic circuit configuration diagram of a magnetic field sensing device including four magnetic sensors and a control circuit in the prior art, fig. 2 illustrates a schematic configuration diagram of a target magnetic field source (magnetic encoder) corresponding to the magnetic field sensing device in fig. 1, fig. 3 illustrates a schematic configuration diagram of four magnetic sensors of the magnetic field sensing device in fig. 1 placed on a magnet, fig. 4A illustrates a schematic diagram of a polarity configuration of the four magnetic sensors of the magnetic field sensing device in fig. 1 in a first setting, and fig. 4B illustrates a schematic diagram of a polarity configuration of the four magnetic sensors of the magnetic field sensing device in fig. 1 in a second setting.

As shown in fig. 1-3, the prior art US8030916B2 discloses a measurable magnetic field sensing device, which includes four magnetic sensors, four amplifiers, four signal conditioners, and a signal adding device. The signal output ends of the four magnetic sensors are electrically connected with the input ends of the four amplifiers in a one-to-one correspondence mode, the output ends of the four amplifiers are electrically connected with the four signal regulators in a one-to-one correspondence mode, and therefore four independent outputs are formed and electrically connected to one signal adding device.

In the prior art, the four magnetic sensors (10 ', 11', 12 ', 13') are integrated into a whole, and are alternately set to a first setting and a second setting by a signal conditioner in one-to-one correspondence with each of the magnetic sensors in fig. 1 to alternately generate a first state output and a second state output. The first setting and the second setting are used for configuring the polarity sign of the output signal of each magnetic sensor, then multiplying the outputs of the four magnetic sensors by the corresponding polarity signs, and then carrying out addition operation in the signal adding device to obtain a first state output and a second state. For example, under a first setting, the outputs of the magnetic sensor 10 'and the magnetic sensor 11' are multiplied by a positive sign; the outputs of the magnetic sensor 12 'and the magnetic sensor 13' are multiplied by a negative sign (reverse), and then the four outputs in the first setting are calculated by a signal adding device to obtain a first sum value, namely a first state output corresponding to a first time point. Under a second setting, the outputs of the magnetic sensor 10 'and the magnetic sensor 13' are multiplied by a negative sign; the outputs of the magnetic sensor 11 'and the magnetic sensor 12' are multiplied by a positive sign, and then the four outputs under the second setting are calculated by a signal adding device to obtain a second sum value, namely a second state output corresponding to a second time point.

When the magnet 9' rotates clockwise, the first state output will present a waveform change of a first sine wave, and the second state output will present a waveform change of a second sine wave; the phase difference between the first sine wave and the second sine wave is 90 degrees, namely one of the first sine wave and the second sine wave is a sine wave and the other is a cosine wave. Based on the first state output and the second state output, rotation angle information associated with the target magnetic field source can be calculated.

In the prior art, the output result of the four magnetic sensors needs to be added in the signal adding device to generate the first state output, and the output result of the four magnetic sensors needs to be added in the signal adding device to generate the second state output, so the magnetic field sensing device can only collect the first state output and the second state output in a time-sharing manner, and the difference of the time inevitably causes the angle information finally generated by operation to have errors.

Exemplarily, in G_HALLThe amplitude B0 of the magnetic field, which is the electrical amplification factor of the magnetic sensor 10', is given by the following equation and depends on the angle α:

B_10’=B0·sin(α)。

thus, as shown in fig. 4A, in a first setting, the total system signal of all the magnetic sensors is provided by the magnetic sensor 10 ', the magnetic sensor 11', the magnetic sensor 12 ', and the magnetic sensor 13' to a signal output equal to:

V_K1=B₀·G_HALL·(+sin(α+45°)-sin(α+135°)-sin(α+225°)+ sin(α+315°))。

the result after conversion is:

V_K1=2√2·B0·G_HALL·sin(α)。

thus, as shown in fig. 4B, in the second setting, the total system signal of all the magnetic sensors is provided by the magnetic sensor 10 ', the magnetic sensor 11', the magnetic sensor 12 ', and the magnetic sensor 13' to signal outputs equal to:

V_K2=2√2·B0·G_HALL·cos(α)。

based on the results of the first setting being provided to the signal output and the results of the second setting being provided to the signal output, the following calculations are performed, and the angle information can be found:

α=arctan(V_K1:V_K2)。

in the prior art, the output result of the four magnetic sensors needs to be added in the signal adding device to generate the first state output, and the output result of the four magnetic sensors needs to be added in the signal adding device to generate the second state output, so the magnetic field sensing device can only collect the first state output and the second state output in a time-sharing manner, and the difference of the time inevitably causes the angle information finally generated by operation to have errors. The sampling of the second state output is not the absolute value of the current value, but the output result obtained by adding the time shift to the value corresponding to the position of the first state output. In general, the sampling error for the second state output is directly proportional to the speed at which the object under test is rotating, which creates an uncertainty accuracy problem for applications requiring instantaneous angle information.

In addition, if the magnetic field sensing device is a digital output, the operation mechanism of the first setting and the second setting formed by alternately setting the signal regulator is used, and the digital sampling output is also required to be alternately performed, so that the response bandwidth of the magnetic field sensing device is required to be reduced to half of the sampling bandwidth, which is an unavoidable limitation for the application requiring high-speed response.

Disclosure of Invention

In order to overcome the disadvantages of the prior art, the present invention provides a magnetic field sensing apparatus and a magnetic field sensing method.

The purpose of the invention is realized by adopting the following technical scheme:

according to an aspect of the present invention, there is provided a magnetic field sensing device comprising: a first set of magnetic sensors and a second set of magnetic sensors, the first set of magnetic sensors and the second set of magnetic sensors being located at different locations on the same plane to receive magnetic field signals of a target magnetic field source, and the first set of magnetic sensors and the second set of magnetic sensors each comprising at least two magnetic sensors; at least one switching circuit, electrically connected to the first set of magnetic sensors and the second set of magnetic sensors, respectively, for alternately switching each magnetic sensor in each set of magnetic sensors between at least two different operating states in time sequence to generate corresponding at least two different signal outputs; an output processing circuit electrically connected to the at least one switching circuit to receive and process the signal output corresponding to different operating states for each of the magnetic sensors, to simultaneously derive a first differential output corresponding to the first set of magnetic sensors and a second differential output corresponding to the second set of magnetic sensors, and to determine angle information associated with the source of the target magnetic field based on the first differential output and the second differential output.

Optionally, the output processing circuit processes the signal output corresponding to different operating states of each of the magnetic sensors in the following manner: performing preset addition and subtraction operations on at least two different signal outputs corresponding to at least two different working states of each magnetic sensor in the first group of magnetic sensors, and performing preset differential operations on operation results corresponding to different magnetic sensors in the first group of magnetic sensors to obtain a first differential output; and performing preset addition and subtraction operation on at least two different signal outputs corresponding to at least two different working states of each magnetic sensor in the second group of magnetic sensors, and performing preset differential operation on operation results corresponding to different magnetic sensors in the second group of magnetic sensors to obtain the second differential output.

Further, each of the magnetic sensors includes 2ⁿThe magnetic sensor comprises a plurality of magnetic sensor units connected in parallel, wherein each magnetic sensor unit comprises four electrodes, the four electrodes comprise two electrodes configured in a first direction and two electrodes configured in a second direction perpendicular to the first direction, and n is a positive integer greater than or equal to 1; each of the magnetic sensors includes four junctions, one of the four electrodes of each of the magnetic sensor cells is connected to one of the four electrodes of the remaining magnetic sensor cells to form one junction, two junctions of the four junctions serve as signal input terminals, the other two junctions serve as signal output terminals, and in the same operating state, driving current directions of two adjacent magnetic sensor cells are perpendicular to each other.

Further, the four contacts of each magnetic sensor are electrically connected to the at least one switching circuit, and the at least one switching circuit switches the connection relationship between the four contacts in each magnetic sensor and a power supply terminal and a ground terminal according to a preset time sequence, so that each magnetic sensor alternately generates signal outputs corresponding to at least two different working states.

Further, the magnetic field sensing device further comprises: the at least one amplifier is electrically connected between the at least one switching circuit and the output processing circuit, and is used for amplifying signal outputs of the magnetic sensors in the first group of magnetic sensors and the second group of magnetic sensors corresponding to at least two different working states and inputting the amplified signal outputs to the output processing circuit.

Further, the at least one switching circuit includes a first switching circuit electrically connected to the first set of magnetic sensors for causing each of the magnetic sensors in the first set of magnetic sensors to alternately generate signal outputs corresponding to at least two different operating states, and a second switching circuit electrically connected to the second set of magnetic sensors for causing each of the magnetic sensors in the second set of magnetic sensors to alternately generate signal outputs corresponding to at least two different operating states.

Further, the at least one amplifier includes a first amplifier and a second amplifier, the first amplifier is electrically connected between the first switching circuit and the output processing circuit for amplifying the signal output of each of the magnetic sensors in the first group of magnetic sensors, and the second amplifier is electrically connected between the second switching circuit and the output processing circuit for amplifying the signal output of each of the magnetic sensors in the second group of magnetic sensors; wherein the amplification of the first amplifier and the second amplifier are independently adjusted.

Further, the magnetic field sensing device further comprises: a correction device that stores correction information corresponding to each of the magnetic sensors in the first and second groups of magnetic sensors; the output processing circuit is electrically connected between the correction device and the first amplifier and between the correction device and the second amplifier, and the output processing circuit respectively feeds back correction information corresponding to each magnetic sensor acquired from the correction device to the first amplifier and the second amplifier so as to respectively adjust the amplification factors of the first amplifier and the second amplifier.

Further, the magnetic field sensing device further comprises: and the result output module is electrically connected with the output end of the output processing circuit so as to output the angle information according to a preset mode.

Further, the magnetic field sensing device further comprises a substrate, and the first set of magnetic sensors and the second set of magnetic sensors are disposed on the same side of the substrate.

Optionally, the magnetic sensor is a horizontal hall sensor for sensing a magnetic field component perpendicular to a plane in which the magnetic sensor is located.

Optionally, the magnetic sensor is a vertical hall sensor for sensing a magnetic field component parallel to a plane in which the magnetic sensor is located.

Optionally, the magnetic sensor is a magneto-resistive sensor for sensing a magnetic field component parallel or perpendicular to a plane in which the magnetic sensor lies.

Optionally, the at least two different operating states comprise four different operating states.

According to another aspect of the embodiments of the present invention, there is also provided a magnetic field sensing method including: providing a first set of magnetic sensors and a second set of magnetic sensors, the first set of magnetic sensors and the second set of magnetic sensors being located at different locations on the same plane to receive magnetic field signals of a target magnetic field source, and the first set of magnetic sensors and the second set of magnetic sensors each comprising at least two magnetic sensors; driving each magnetic sensor in each group of magnetic sensors to alternately switch between at least two different working states according to a time sequence so as to generate at least two corresponding different signal outputs; processing the signal outputs corresponding to different operating states of each of the magnetic sensors to simultaneously obtain a first differential output corresponding to the first set of magnetic sensors and a second differential output corresponding to the second set of magnetic sensors, and determining angle information associated with the target magnetic field source based on the first differential output and the second differential output.

Further, the processing the signal output corresponding to each of the magnetic sensors in different operating states to simultaneously obtain a first differential output corresponding to the first set of magnetic sensors and a second differential output corresponding to the second set of magnetic sensors comprises: performing preset addition and subtraction operations on signal outputs of at least two different working states corresponding to each magnetic sensor in the first group of magnetic sensors, and performing preset differential operations on operation results corresponding to different magnetic sensors in the first group of magnetic sensors to obtain the first differential output; and performing preset addition and subtraction operation on the signal output of each magnetic sensor in the second group of magnetic sensors corresponding to at least two different working states, and performing preset differential operation on the operation results corresponding to different magnetic sensors in the second group of magnetic sensors to obtain the second differential output.

Further, the driving each magnetic sensor in each set of magnetic sensors to alternately switch between at least two different operating states according to a time sequence to generate at least two corresponding different signal outputs includes: and switching the connection relation between the four contacts in each magnetic sensor and a power supply end and a ground end according to a preset time sequence so that each magnetic sensor alternately generates signal outputs corresponding to at least two different working states.

Further, amplifying the signal output before processing the signal output for each of the magnetic sensors for a different operating state.

Further, the amplifying the signal output before processing the signal output for each of the magnetic sensors for a different operating state comprises: amplifying the signal output of each of the magnetic sensors of the first set of magnetic sensors using a first amplifier, amplifying the signal output of each of the magnetic sensors of the second set of magnetic sensors using a second amplifier; wherein the amplification of the first amplifier and the second amplifier are independently adjusted.

Further, before amplifying the signal output of each of the magnetic sensors of the first group of magnetic sensors and the signal output of each of the magnetic sensors of the second group of magnetic sensors, the amplification factors of the first amplifier and the second amplifier are respectively adjusted according to pre-stored correction information corresponding to each of the magnetic sensors.

Further, after the angle information associated with the target magnetic field source is determined, the angle information is output according to a preset mode.

Further, the at least two different operating states include four different operating states.

The magnetic field sensing device and the magnetic field sensing method provided by the embodiment of the invention aim to enable each magnetic sensor in a first group of magnetic sensors and a second group of magnetic sensors to be in a corresponding first working state and a second working state alternately according to a time sequence through a switching circuit, so that a signal output corresponding to the first working state and a signal output corresponding to the second working state are generated alternately, further, errors caused by micro dislocation of a magnetic source magnetized in a radial direction are eliminated, a first differential output and a second differential output for determining angle information associated with a target magnetic field source can be obtained simultaneously, and therefore, the output processing circuit has no difference in time for the final formation of the first differential output and the second differential output. Therefore, the technical scheme of the invention not only has higher output bandwidth, but also has extremely low time delay error, and simultaneously has the characteristic of resisting external electromagnetic interference.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other embodiments based on these drawings without creative efforts.

Fig. 1 shows a schematic circuit configuration diagram of a magnetic field sensing device including four magnetic sensors and a control circuit in the related art.

Fig. 2 is a schematic structural diagram of a target magnetic field source (magnetic encoder) corresponding to the magnetic field sensing device in fig. 1.

Fig. 3 shows a schematic view of the arrangement of four magnetic sensors of the magnetic field sensing device of fig. 1 placed on a magnet.

FIG. 4A shows a schematic diagram of a polarity configuration of four magnetic sensors of the magnetic field sensing device of FIG. 1 in a first setting.

FIG. 4B shows a schematic diagram of a polarity configuration of the four magnetic sensors of the magnetic field sensing device of FIG. 1 in a second setting.

Fig. 5 shows a schematic circuit structure diagram of a magnetic field sensing device according to an embodiment of the present invention.

Fig. 6 is a schematic top view of the four magnetic sensors of fig. 5 in combination with a target magnetic field source.

Fig. 7 is a schematic side view of the four magnetic sensors of fig. 5 in a configuration with a target magnetic field source.

Fig. 8 shows a magnetic field strength diagram of four first signal outputs of the magnetic field sensing device of the present invention in the configuration of fig. 7 without external magnetic field interference.

FIG. 9 is a magnetic field strength diagram showing four first signal outputs of the magnetic field sensing device of the present invention in the configuration of FIG. 7 with external magnetic field disturbances.

Fig. 10 shows a schematic diagram of the angle operation of the magnetic field sensing device of the present invention.

Fig. 11-12 respectively illustrate specific exemplary schematic diagrams of each magnetic sensor structure in a magnetic field sensing device provided by an embodiment of the present invention.

Fig. 13 is a schematic circuit diagram of a magnetic field sensing device according to still another embodiment of the present invention. FIG. 14 illustrates a flow chart of the operation of a magnetic field sensing method of an embodiment of the present invention.

Detailed Description

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In view of the technical problems in the background art, an object of the present invention is to provide a rotation angle magnetic field sensing apparatus having a high output bandwidth, a very low delay error, and resistance to external disturbance magnetic fields. Therefore, it becomes especially important to develop a new magnetic field sensing device.

The present invention will be described in further detail with reference to the accompanying drawings and detailed description, in order to make the objects, features and advantages thereof more comprehensible.

Example one

Fig. 5 is a schematic circuit diagram of a magnetic field sensing device according to an embodiment of the present invention, fig. 6 is a schematic top view diagram of the configuration of the four magnetic sensors and the magnetic target field source in fig. 5, and fig. 7 is a schematic side view diagram of the configuration of the four magnetic sensors and the magnetic target field source in fig. 5.

As shown in fig. 5 to 7, the magnetic field sensing device of the embodiment of the present invention includes: a first set of magnetic sensors 101 and a second set of magnetic sensors 102, at least one switching circuit 400, and an output processing circuit 600; the first set of magnetic sensors 101 and the second set of magnetic sensors 102 are located at different positions on the same plane to receive magnetic field signals of a target magnetic field source, and each of the first set of magnetic sensors 101 and the second set of magnetic sensors 102 comprises at least two magnetic sensors; wherein each magnetic sensor outputs a voltage proportional to the strength of the magnetic field measured by each magnetic sensor. The at least one switching circuit 400 is electrically connected to the first group of magnetic sensors 101 and the second group of magnetic sensors 102, respectively, and is configured to alternately switch each magnetic sensor in each group of magnetic sensors between at least two different operating states according to a time sequence to generate at least two corresponding different signal outputs; that is, each of the magnetic sensors in the first set of magnetic sensors 101 may alternately generate signal outputs corresponding to at least two different operating states, and each of the magnetic sensors in the second set of magnetic sensors 102 may alternately generate signal outputs corresponding to at least two different operating states. The output processing circuit 600 is electrically connected to the at least one switching circuit 400, for receiving and processing the signal output corresponding to each of the magnetic sensors in different operating states, for simultaneously obtaining a first differential output corresponding to the first set of magnetic sensors 101 and a second differential output corresponding to the second set of magnetic sensors 102, and for determining angle information associated with the magnetic field source of interest based on the first differential output and the second differential output.

In the embodiment of the present invention, the switching circuit 400 is electrically connected to the first group of magnetic sensors 101 and the second group of magnetic sensors 102, respectively, and is configured to alternately switch each magnetic sensor in each group of magnetic sensors between at least two different operating states according to a time sequence, so as to generate at least two corresponding different signal outputs. For simplicity of illustration, the switching circuit 400 may illustratively cause each of the magnetic sensors in the first and second sets of

magnetic sensors

101 and 102 to generate a state output corresponding to the first operating state in a first operating state at a first timing sequence, and to generate a state output corresponding to the second operating state in a second operating state at a second timing sequence. Wherein, the first working state of the first time sequence and the second working state of the second time sequence are generated alternately according to the time sequence. Therefore, by the switching circuit 400, each magnetic sensor in the first and second sets of

magnetic sensors

101 and 102 can be alternately in the corresponding first and second operating states according to the time sequence, so as to alternately generate a signal output corresponding to the first operating state and a signal output corresponding to the second operating state, thereby eliminating errors caused by small misalignment of the magnetic source of radial magnetization.

Thus, the output processing circuit 600 receives four different signal outputs corresponding to the first group of magnetic sensors 101 by time-series sampling, and performs a predetermined addition and subtraction operation on the four different signal outputs to obtain the first differential output; the output processing circuit 600 receives four different signal outputs corresponding to the second group of magnetic sensors 102 by time-series sampling, and performs a predetermined addition and subtraction operation on the four different signal outputs to obtain the second differential output. Illustratively, as shown in fig. 5, four different signals transferred between the first set of magnetic sensors 101 and the output processing circuit 600 are represented by four connecting lines; four different signals are also communicated between the second set of magnetic sensors 102 and the output processing circuit 600 as indicated by the four connections.

That is, the first differential output and the second differential output for determining the angle information associated with the target magnetic field source may be obtained simultaneously, so that the output processing circuit 600 may not have temporal differences in the final formation of the first differential output and the second differential output. Therefore, the technical scheme provided by the invention not only has higher output bandwidth, but also has extremely low delay error.

Illustratively, in the embodiment of the present invention, the first group of magnetic sensors 101 includes a magnetic sensor 1A and a magnetic sensor 1B, and the second group of magnetic sensors 102 includes a magnetic sensor 2A and a magnetic sensor 2B. Specifically, the magnetic field sensing device further includes a substrate 1000, and the first group of magnetic sensors 101 and the second group of magnetic sensors 102 are disposed on the same side of the substrate 1000. The plane of the substrate 1000 is parallel to the X-Y plane and the four magnetic sensors (1A, 1B, 2A, 2B) form a two by two square array, the source of the target magnetic field being a cylindrical permanent magnet 900 (also called a magnetic encoder) with a radial unidirectional orientation, the circular cross-section of which is parallel to the plane of the substrate 1000 and the height of the cylinder of the permanent magnet 900 is parallel to the Z direction. The permanent magnet 900 may be disposed above or below the substrate 1000, the geometric center of the square array formed by the four magnetic sensors (1A, 1B, 2A, 2B) coincides with the center of the permanent magnet 900, and the distances between two adjacent magnetic sensors are equal, that is, the distance between the magnetic sensor 1A and the magnetic sensor 2A, the distance between the magnetic sensor 1A and the magnetic sensor 2B, the distance between the magnetic sensor 2A and the magnetic sensor 1B, and the distance between the magnetic sensor 1B and the magnetic sensor 2B are equal. The

magnetic sensors

1A and 1B are arranged at diagonal positions of the square array and parallel to the Y direction; the

magnetic sensors

2A and 2B are arranged at diagonal positions of the square array and parallel to the X direction; the permanent magnet 900 has its N pole arranged in the-X direction and S pole arranged in the + X direction, and the magnetic pole boundary of the permanent magnet 900 is parallel to the Y axis and passes through the center of the permanent magnet 900.

It should be noted that the embodiment shown in fig. 5 to 7 described above is a magnetic field sensing device including four magnetic sensors for the sake of simplicity of representation, and any magnetic field sensing device that is actually symmetrical about the center may be used in the present invention. For example, eight magnetic sensors may be placed on a circle having central symmetry on the same plane, and an angle between two adjacent magnetic sensors of the eight magnetic sensors is 45 °.

As shown in fig. 7, the magnetic field lines of the permanent magnet 900 are emitted from the N pole and converge toward the S pole through an arc path in the space. In the current position, the four magnetic sensors of the magnetic field sensing device are located at positions that can respectively generate magnetic field components corresponding to X, Y, Z three directions.

Example one

As shown in fig. 11, in the present embodiment, each of the magnetic sensors in the magnetic field sensing device includes two magnetic sensor cells connected in parallel. For example, a first magnetic sensor cell 201 and a second magnetic sensor cell 202 connected in parallel, the first magnetic sensor cell 201 having four electrodes, electrode 301, electrode 302, electrode 303, and electrode 304; the second magnetic sensor cell 202 has four electrodes, which are electrode 305, electrode 306, electrode 307, and electrode 308; connecting electrode 301 with electrode 306 to form a contact 3A, connecting electrode 302 with electrode 307 to form a contact 3B, and connecting electrode 304 with electrode 305 to form a contact 3C; connecting the electrode 303 and the electrode 308 to form a contact 3D; the contact 3A, the contact 3B, the contact 3C, and the contact 3D constitute four contacts of the magnetic sensor.

Specifically, the switching circuit 400 has the contact 3B and the contact 3C as signal input terminals, and the contact 3A and the contact 3D as signal output terminals, respectively. For example, the output is generated by the contact 3A and the contact 3D by connecting the contact 3B to the power source terminal and the contact 3C to the ground terminal, whereby the signal output corresponding to the first operating state of each of the magnetic sensors can be obtained. The switching circuit 400 has the contact 3A and the contact 3D as signal input terminals, and the contact 3B and the contact 3C as signal output terminals. For example, the contact 3A is connected to the power source terminal, the contact 3D is connected to the ground terminal, and outputs are generated from the contact 3B and the contact 3C, whereby a signal output corresponding to the second operating state of each of the magnetic sensors can be obtained. By means of the switching circuit 400, each magnetic sensor in the magnetic field sensing device can be alternately switched between a first operating state and a second operating state in time sequence, so as to alternately generate a signal output corresponding to the first operating state and a signal output corresponding to the second operating state. With each magnetic sensor structure shown in fig. 11, the driving currents in two adjacent magnetic sensing units of the magnetic sensor can be made perpendicular to each other, and the orthogonality of the driving currents can suppress zero drift of each of the magnetic sensors due to production process unevenness.

Example two

As shown in fig. 12, in the present embodiment, each of the magnetic sensors in the magnetic field sensing device includes four magnetic sensor cells connected in parallel. For example, a first magnetic sensor cell 201, a second magnetic sensor cell 202, a third magnetic sensor cell 203, and a fourth magnetic sensor cell 204 connected in parallel, the first magnetic sensor cell 201 having four electrodes, which are an electrode 301, an electrode 302, an electrode 303, and an electrode 304, respectively; the second magnetic sensor cell 202 has four electrodes, which are electrode 305, electrode 306, electrode 307, and electrode 308; the third magnetic sensor unit 203 has four electrodes, which are an electrode 309, an electrode 310, an electrode 311, and an electrode 312; the fourth magnetic sensor cell 204 has four electrodes, which are an electrode 313, an electrode 314, an electrode 315, and an electrode 316; connecting the electrode 303, the electrode 306, the electrode 309 and the electrode 316 to form a contact 3G; connecting electrode 301, electrode 308, electrode 311 and electrode 314 to form a contact 3E; connecting the electrode 304, the electrode 307, the electrode 310 and the electrode 313 to form a contact 3H; connecting electrode 302, electrode 305, electrode 312 and electrode 315 to form a contact 3F; the contact 3E, the contact 3F, the contact 3G, and the contact 3H constitute four contacts of the magnetic sensor.

Specifically, in the switching circuit 400, when the contact 3E and the contact 3F are used as signal input terminals, the contact 3G and the contact 3H are used as signal output terminals, respectively. For example, the contact 3E is connected to the power source terminal, the contact 3F is connected to the ground terminal, and the output is generated by the contact 3G and the contact 3H, whereby the signal output corresponding to the first operating state of each of the magnetic sensors can be obtained. When the contact 3G and the contact 3H are used as signal input terminals, the contact 3E and the contact 3F are used as signal output terminals, respectively. For example, by connecting the contact 3G to the power source terminal, the contact 3H to the ground terminal, and generating outputs from the contact 3E and the contact 3F, a signal output corresponding to the second operating state of each of the magnetic sensors can be obtained. Then, the connection relationship between the two contacts and the power supply terminal and the ground terminal at the time of signal input is changed, for example, the contact 3F is connected to the power supply terminal, the contact 3E is connected to the ground terminal, and the output is generated by the contact 3H and the contact 3G, whereby the signal output corresponding to the third operating state of each of the magnetic sensors can be obtained. For example, by connecting the contact 3H to the power source terminal, the contact 3G to the ground terminal, and generating outputs from the contact 3F and the contact 3E, a signal output corresponding to the fourth operating state of each of the magnetic sensors can be obtained. By the switching circuit 400, each of the magnetic sensors in the magnetic field sensing device can be alternately switched among the first operating state, the second operating state, the third operating state and the fourth operating state in time sequence, so as to alternately generate a signal output corresponding to the first operating state, a signal output corresponding to the second operating state, a signal output corresponding to the third operating state and a signal output corresponding to the fourth operating state. With each magnetic sensor structure shown in fig. 12, the driving currents in two adjacent magnetic sensor units of each magnetic sensor can be made perpendicular to each other, and the orthogonality of the driving currents can suppress zero drift of each magnetic sensor caused by production process unevenness.

Exemplarily, in an embodiment of the present invention, for example, as shown in fig. 11, each of the magnetic sensors in the magnetic field sensing apparatus described above includes two magnetic sensor units connected in parallel. At a first time point, four magnetic sensors (1A, 1B, 2A, 2B) in the magnetic field sensing device are driven simultaneously, and the four magnetic sensors (1A, 1B, 2A, 2B) of the magnetic field sensing device are enabled to work in a first working state simultaneously through a switching circuit so as to generate four sets of first signal outputs corresponding to the first working state simultaneously. At a second point in time, the four magnetic sensors (1A, 1B, 2A, 2B) of the magnetic field sensing device are simultaneously operated in a second operating state by the switching circuit to simultaneously generate four second signal outputs corresponding to the second operating state.

Alternatively, in another embodiment of the present invention, in addition to the four magnetic sensors (1A, 1B, 2A, 2B) in fig. 11 being switchable between the first operating state and the second operating state in time series by the switching circuit, the four magnetic sensors (1A, 1B, 2A, 2B) in fig. 11 being switchable between the first operating state, the second operating state, the third operating state, and the fourth operating state in time series by the switching circuit.

As shown in fig. 5 to 7, for example, in the output processing circuit 600, the first signal output corresponding to the magnetic sensor 1A and the first signal output corresponding to the magnetic sensor 1B are subjected to a differential operation, that is, the first signal output corresponding to the magnetic sensor 1A and the first signal output corresponding to the magnetic sensor 1B in the first set of magnetic sensors 101 are added or subtracted to generate the first differential output corresponding to the first set of magnetic sensors 101; a second differential output corresponding to the second group of magnetic sensors 102 is generated by performing a differential operation between the first signal output corresponding to the magnetic sensor 2A and the first signal output corresponding to the magnetic sensor 2B, that is, by adding or subtracting the first signal output corresponding to the magnetic sensor 2A and the first signal output corresponding to the magnetic sensor 2B in the second group of magnetic sensors 102; and the first differential output and the second differential output have the characteristic of resisting the interference of the external magnetic field.

For example, in the output processing circuit 600, the second signal output corresponding to the magnetic sensor 1A (generated corresponding to the second operating state of the magnetic sensor 1A at the second time point) and the second signal output corresponding to the magnetic sensor 1B (generated corresponding to the second operating state of the magnetic sensor 1B at the second time point) are differentially operated, that is, the second signal output corresponding to the magnetic sensor 1A and the second signal output corresponding to the magnetic sensor 1B in the first set of magnetic sensors 101 are added or subtracted, so that the first differential output corresponding to the first set of magnetic sensors 101 can be generated. The second signal output corresponding to the magnetic sensor 2A (generated corresponding to the second operating state of the magnetic sensor 2A at the second point in time) and the second signal output corresponding to the magnetic sensor 2B (generated corresponding to the second operating state of the magnetic sensor 2B at the second point in time) are differentially operated, that is, the second signal output corresponding to the magnetic sensor 2A and the second signal output corresponding to the magnetic sensor 2B in the second group of magnetic sensors 102 are added or subtracted, so that the second differential output corresponding to the second group of magnetic sensors 102 can be generated.

It is to be understood that, for the sake of convenience of explanation, the signal output generated by the four magnetic sensors (1A, 1B, 2A, 2B) set in the first operating state at the first point in time will be output as a first signal; the signal output set in the second operating state by the four magnetic sensors (1A, 1B, 2A, 2B) at the second point in time is output as the second signal, and so on.

Fig. 8 is a schematic diagram showing magnetic field strengths of four first signals output by the magnetic field sensing device of the present invention in the configuration of fig. 7 without external magnetic field interference, and fig. 9 is a schematic diagram showing magnetic field strengths of four first signals output by the magnetic field sensing device of the present invention in the configuration of fig. 7 with external magnetic field interference.

For example, if the four magnetic sensors are all horizontal hall sensors, the four magnetic sensors are used for sensing a magnetic field component perpendicular to the plane of the substrate 1000. That is, in fig. 7, the direction of the magnetic field sensed by each magnetic sensor (1A, 1B, 2A, 2B) is the Z-axis direction perpendicular to the plane of the substrate 1000. Specifically, based on the configuration of fig. 7, the magnetic sensor 2A is located in the N-pole region of the permanent magnet 900, where the magnetic field direction is in the-Z direction, so that the first signal output generated by the magnetic sensor 2A is in the-Z direction, which is-bs in fig. 8; the magnetic sensor 2B is located in the S-pole region of the permanent magnet 900, where the magnetic field direction is in the + Z direction, so that the first signal output by the magnetic sensor 2B is in the + Z direction, which is bs in fig. 8; the

magnetic sensors

1A and 1B are both located in a region at the boundary of the magnetic poles of the permanent magnet 900, the magnetic field direction of the region is parallel to the + X direction, and the current position is exactly parallel to the direction of the magnetic lines of force, so that the magnetic field components in the Z-axis direction sensed by the

magnetic sensors

1A and 1B are both 0. By differential operation, in the configuration of fig. 7, for example, the first signal output generated by the magnetic sensor 1A and the first signal output generated by the magnetic sensor 1B are subtracted to obtain a first differential output corresponding to the first group of magnetic sensors 101 as 0; the first signal output generated by the magnetic sensor 2A and the first signal output generated by the magnetic sensor 2B are subtracted to obtain a second differential output 2bs corresponding to the second group of magnetic sensors 102, as indicated by S in fig. 8.

When external magnetic field interference occurs, the X and Y components in the interference magnetic field do not cause the magnetic sensor to generate output, and the component in the Z-axis direction of the interference magnetic field is superimposed on the signal magnetic field bs as shown in bi of fig. 9, and since the distances between the magnetic sensor 2A and the magnetic sensor 2B from the center of the permanent magnet 900 are equal (as shown in fig. 7), the absolute values of the first signal outputs generated by the magnetic sensor 2A and the magnetic sensor 2B are equal, but the signs are opposite. Through superposition of the external interference magnetic field, the first signal output generated by the magnetic sensor 2A becomes (-bs + bi), and the first signal output generated by the magnetic sensor 2B becomes (bs + bi); the first signal outputs generated by the magnetic sensor 1A and the magnetic sensor 1B both become bi; by a differential operation, for example, subtracting the first signal output generated by the magnetic sensor 2B from the first signal output generated by the magnetic sensor device 2A, a second differential output corresponding to the second group of magnetic sensors 102 is obtained as S =2bs, as shown by S in fig. 9. Subtracting the first signal output generated by the magnetic sensor 1B from the first signal output generated by the magnetic sensor 1A results in a first differential output corresponding to the first set of magnetic sensors 101 being zero. Therefore, the output of the magnetic field sensing device cannot be influenced by the existence of the external interference magnetic field, and the anti-interference characteristic is realized.

It should be understood that in other embodiments, if the four magnetic sensors are vertical hall sensors, the four magnetic sensors are used for sensing the magnetic field component parallel to the plane of the magnetic sensors. The implementation is similar and will not be described herein.

In other embodiments, if the four magnetic sensors are all magnetoresistive sensors, the magnetic sensors are configured to sense a magnetic field component parallel or perpendicular to a plane in which the magnetic sensors are located. The implementation is similar and will not be described herein.

For example, in the manner shown in fig. 5, for the first group of sensors 101, two different signal outputs (for example, alternately formed by the first operating state and the second operating state of the magnetic sensor 1A) in two different operating states corresponding to the magnetic sensor 1A in the first group of magnetic sensors 101 are time-divisionally sampled to the output processing circuit 600, and two different signal outputs (for example, alternately formed by the first operating state and the second operating state of the magnetic sensor 1B) in two different operating states corresponding to the magnetic sensor 1B in the first group of magnetic sensors 101 are time-divisionally sampled to the output processing circuit 600. Similarly, with respect to the second group sensor 102, two different signal outputs (for example, alternately formed by the first operating state and the second operating state of the magnetic sensor 2A) in two different operating states corresponding to the magnetic sensor 2A in the second group sensor 102 are time-divisionally sampled to the output processing circuit 600, and two different signal outputs (for example, alternately formed by the first operating state and the second operating state of the magnetic sensor 2B) in two different operating states corresponding to the magnetic sensor 2B in the second group sensor 102 are time-divisionally sampled to the output processing circuit 600.

In the embodiment of the present invention, the two different signal outputs generated by switching the operating state of the magnetic sensor 1A in the first group of magnetic sensors 101 via the switching circuit 400 may be time-divisionally sampled and received by the output processing circuit 600, and the two different signal outputs generated by switching the operating state of the magnetic sensor 1B in the first group of magnetic sensors 101 via the switching circuit 400 may be time-divisionally sampled and received by the output processing circuit 600; similarly, the two different signal outputs generated by the switching of the operating state of the magnetic sensor 2A in the second group of magnetic sensors 102 via the switching circuit 400 may be sampled and received by the output processing circuit 600 at different times, and the two different signal outputs generated by the switching of the operating state of the magnetic sensor 2B in the second group of magnetic sensors 102 via the switching circuit 400 may be sampled and received by the output processing circuit 600 at different times.

It should be understood that, during the process of sampling the signal output corresponding to at least two different operating states of each magnetic sensor in the first set of magnetic sensors 101, the output processing circuit 600 may also simultaneously sample the signal output corresponding to at least two different operating states of each magnetic sensor in the second set of magnetic sensors 102, and the invention is not limited thereto.

After the sampling is completed, the output processing circuit 600 processes the signal output corresponding to each of the magnetic sensors in different operating states as follows: performing preset addition and subtraction operations on at least two different signal outputs corresponding to at least two different working states of each magnetic sensor in the first group of magnetic sensors 101, and performing preset differential operations on operation results corresponding to different magnetic sensors in the first group of magnetic sensors 101 to obtain the first differential output; performing a preset addition-subtraction operation on at least two different signal outputs corresponding to at least two different operating states of each magnetic sensor in the second set of magnetic sensors 102, and performing a preset differential operation on an operation result corresponding to a different magnetic sensor in the second set of magnetic sensors 102 to obtain the second differential output.

Specifically, the performing a preset differential operation on the operation results corresponding to different magnetic sensors in the first group of magnetic sensors 101 includes: the first differential output is obtained by adding or subtracting the signal output value corresponding to the magnetic sensor 1A and the signal output value corresponding to the magnetic sensor 1B. The preset differential operation of the operation results corresponding to different magnetic sensors in the second group of magnetic sensors 102 includes: the second differential output is obtained by adding or subtracting the signal output value corresponding to the magnetic sensor 2A and the signal output value corresponding to the magnetic sensor 2B.

Further, the magnetic field sensing device further comprises: a result output module 800, wherein the result output module 800 is electrically connected to an output end of the output processing circuit 600 to output the angle information according to a preset mode. The preset mode may include, for example: PWM forms, signal current modes, etc.

As shown in fig. 10, after the first differential output and the second differential output are generated in the output processing circuit 600, the angle can be calculated based on the first differential output and the second differential output. Exemplarily, the current configuration of the permanent magnet 900 in fig. 7 is defined as an angle zero point, and the horizontal axis thereof is an angle θ of the permanent magnet rotation; the vertical axis represents the output of the magnetic sensor, and the output indicated by the solid black line in the diagram of fig. 10 represents the second differential output generated by the

magnetic sensors

2A and 2B, and the output indicated by the dashed black line represents the first differential output generated by the

magnetic sensors

1A and 1B. The first differential output presents a sine waveform with a period of 360 degrees along with the rotation angle of the signal magnetic field, and the equation is S sin theta; the second differential output presents a cosine waveform with a period of 360 degrees along with the rotation angle of the signal magnetic field, and the equation is S × cos θ, wherein S is the magnetic field sensitivity of the magnetic sensor and has a unit of mV/V, that is, the signal output voltage value under a unit of driving voltage. And dividing the first differential output by the second differential output to obtain S sin theta/S cos theta = tan theta, and then rotating the angle theta = arctan (sin theta/cos theta). The lower diagram of fig. 10 shows the relationship between the rotation angle output of the magnetic field sensing device and the rotation angle of the magnetic field, and the magnetic field sensing device can output 360 ° period angle information by the phase determination of the first differential output and the second differential output, and finally generate the final output by the result output module 800.

It has been found that if the driving currents of the magnetic sensors can be set to be perpendicular to each other in different magnetic sensor units, the zero drift of each magnetic sensor caused by the production process unevenness can be greatly optimized by canceling each other in the signal superposition process due to the orthogonality of the driving currents in the different magnetic sensor units.

Therefore, in the embodiment of the present invention, each of the magnetic sensors includes 2ⁿA plurality of magnetic sensor cells connected in parallel, wherein each magnetic sensor cell comprises four electrodes including two electrodes arranged in a first direction and two electrodes arranged in a second direction perpendicular to the first direction, wherein n isA positive integer greater than or equal to 1; each of the magnetic sensors includes four contacts, one of the four electrodes of each of the magnetic sensor cells is connected to one of the four electrodes of the remaining each of the magnetic sensor cells to form one contact, two of the four contacts serve as signal input terminals (the two contacts are applied with a power supply signal and a ground signal, respectively), the other two contacts serve as signal output terminals, and in the same operating state, driving current directions of two adjacent magnetic sensor cells are perpendicular to each other.

The four contacts of each of the magnetic sensors are electrically connected to the at least one switching circuit 400, and the at least one switching circuit 400 switches the connection relationship between the four contacts in each of the magnetic sensors and the power supply terminal and the ground terminal according to a preset timing, so that each of the magnetic sensors alternately generates signal outputs corresponding to at least two different operating states.

Alternatively, a first operation of inputting signals to the four contacts in each of the magnetic sensors and a second operation of outputting signals are alternately performed to obtain corresponding signal outputs in two different operation states corresponding to each of the magnetic sensors.

Optionally, the at least two different operating states comprise four different operating states. For example, a first operation of inputting signals to two of the four contacts in each of the magnetic sensors and a second operation of outputting signals to the other two contacts are alternately performed, a connection relationship between the two contacts at the time of signal input and the power supply terminal and the ground terminal is changed, and a third operation of inputting signals to two of the four contacts in each of the magnetic sensors and a fourth operation of outputting signals to the other two contacts are alternately performed, so that four different operating states corresponding to each of the magnetic sensors are obtained.

Example two

Fig. 13 is a schematic circuit diagram of a magnetic field sensing device according to still another embodiment of the present invention.

As shown in fig. 13, in order to amplify the signal output generated by each of the magnetic sensors corresponding to at least two different operating states, the output processing circuit 600 is further configured to process the signal output corresponding to each of the magnetic sensors corresponding to the different operating states. Optionally, the magnetic field sensing device further comprises: at least one amplifier 500, the at least one amplifier 500 being electrically connected between the at least one switching circuit 400 and the output processing circuit 600, the at least one amplifier 500 being configured to amplify the signal output of each of the first set of magnetic sensors 101 and the second set of magnetic sensors 102 corresponding to at least two different operating states, and input the amplified signal output to the output processing circuit 600.

Further, the at least one amplifier 500 includes a first amplifier 501 and a second amplifier 502, the first amplifier 501 is electrically connected between the first switching circuit 401 and the output processing circuit 600 for amplifying the signal output of each of the magnetic sensors in the first set of magnetic sensors 101, and the second amplifier 502 is electrically connected between the second switching circuit 402 and the output processing circuit 600 for amplifying the signal output of each of the magnetic sensors in the second set of magnetic sensors 102; wherein the amplification factors of the first amplifier 501 and the second amplifier 502 are independently adjusted.

Further, the magnetic field sensing device further comprises: a correction device 700, wherein the correction device 700 stores correction information corresponding to each of the magnetic sensors in the first group of magnetic sensors 101 and the second group of magnetic sensors 102; the output processing circuit 600 is electrically connected between the correction device 700 and the first amplifier 501 and the second amplifier 502, and the output processing circuit 600 feeds back correction information corresponding to each of the magnetic sensors acquired from the correction device 700 to the first amplifier 501 and the second amplifier 502, respectively, so as to adjust the amplification factors of the first amplifier 501 and the second amplifier 502, respectively. And correcting the signal output of each magnetic sensor corresponding to at least two working states by adjusting the amplification factors of the first amplifier and the second amplifier.

As described above, in the switching circuit 400, two or four signal outputs in different operation states alternately appear by switching the connection relationship between the four contact power source terminals and the ground terminals of the magnetic sensor. The signal outputs in different operating states are connected to at least one amplifier 500, the correction information is read by the correction device 700, and the signal outputs in different operating states are corrected by the output processing circuit 600 in a manner of adjusting the amplification factor of at least one amplifier 500. The amplifier 500 performs analog differential operation and state operation on a plurality of signal outputs in different operating states in the first group of magnetic sensors 101 to generate a first signal output and a first differential output, and the amplifier 500 performs analog differential operation and state operation on a plurality of signal outputs in different operating states in the second group of magnetic sensors 102 to generate a second signal output and a second differential output; in the embodiment of the present invention, the order of the differential operation and the analog operation is not limited, and the corrected output is connected to an output processing circuit 600, and sampling is performed in the output processing circuit 600; after sampling, the angle operation is performed to generate 360-degree periodic angle information, and finally, final device output is generated through the result output module 800. The difference between this method and the above is that the state operation and the differential operation are performed at the analog end, and the state operation and the differential operation are performed at the digital end. Thus creating some differences in circuit architecture.

According to yet another aspect of an embodiment of the present invention, there is provided a magnetic field sensing method.

FIG. 14 illustrates a flow chart of the operation of a magnetic field sensing method of an embodiment of the present invention. As shown in fig. 14, the method includes:

step S101, providing a first group of magnetic sensors and a second group of magnetic sensors, wherein the first group of magnetic sensors and the second group of magnetic sensors are located at different positions on the same plane to receive magnetic field signals of a target magnetic field source, and each of the first group of magnetic sensors and the second group of magnetic sensors comprises at least two magnetic sensors;

step S102, driving each magnetic sensor in each group of magnetic sensors to alternately switch between at least two different working states according to a time sequence so as to generate at least two corresponding different signal outputs;

step S103, processing the signal outputs corresponding to different operating states of each of the magnetic sensors to obtain a first differential output corresponding to the first group of magnetic sensors and a second differential output corresponding to the second group of magnetic sensors at the same time, and determining angle information associated with the target magnetic field source based on the first differential output and the second differential output.

Steps S101 to S103 will be specifically described below.

In step S101, as shown in fig. 5-7, for example, a first set of magnetic sensors 101 and a second set of magnetic sensors 102 are disposed at different positions of the same substrate 1000 above a target magnetic field source, the plane of the substrate 1000 is parallel to the X-Y plane, wherein the first set of magnetic sensors 101 includes a magnetic sensor 1A and a magnetic sensor 1B, the second set of magnetic sensors 102 includes a magnetic sensor 2A and a magnetic sensor 2B, the four magnetic sensors form a two-by-two square array, specifically, the target magnetic field source is a cylindrical permanent magnet 900 with a radial unidirectional alignment, the circular cross section of the cylindrical permanent magnet is parallel to the plane of the substrate, the height of the cylindrical permanent magnet is parallel to the Z direction, the geometric center of the two-by-two square array formed by the four magnetic sensors (1A, 1B, 2A, 2B) coincides with the center of the circle of the permanent magnet 900, and the distances between two adjacent magnetic sensors are equal, that is, the distance between the magnetic sensor 1A and the magnetic sensor 2A, the distance between the magnetic sensor 1A and the magnetic sensor 2B, the distance between the magnetic sensor 2A and the magnetic sensor 1B, and the distance between the magnetic sensor 1B and the magnetic sensor 2B are equal. The

magnetic sensors

2A and 2B are arranged at diagonal positions of the square array and parallel to the X direction; the permanent magnet 900 has its N pole arranged in the-X direction and S pole arranged in the + X direction, and the magnetic pole boundary of the permanent magnet 900 is parallel to the Y axis and passes through the center of the permanent magnet 900. The permanent magnet 900 performs a rotation motion in a plane parallel to the X-Y, while the first group of magnetic sensors 101 and the second group of magnetic sensors 102 remain stationary in the plane parallel to the X-Y, and the positions of the N pole and the S pole of the permanent magnet 900 are changed by the rotation motion of the permanent magnet 900 in the plane parallel to the X-Y, so that the magnetic field signal received by each magnetic sensor in the first group of magnetic sensors 101 and the second group of magnetic sensors 102 is changed.

In step S102, each of the magnetic sensors (1A, 1B, 2A, 2B) in the magnetic field sensing apparatus may be formed by the magnetic sensor structure shown in fig. 11 or 12, specifically, each of the magnetic sensors includes four contacts, two of the four contacts are used as signal input terminals, the other two contacts are used as signal output terminals, the four contacts of each of the magnetic sensors are electrically connected to the at least one switching circuit, and the at least one switching circuit switches the connection relationship between the four contacts in each of the magnetic sensors and the power supply terminal and the ground terminal according to a preset timing, so that each of the magnetic sensors alternately generates signal outputs corresponding to at least two different operating states.

Exemplarily, in an embodiment of the present invention, as shown in fig. 11 for example, each magnetic sensor in the above-mentioned magnetic field sensing device includes two magnetic sensor units connected in parallel, for example, a first magnetic sensor unit 201 and a second magnetic sensor unit 202 connected in parallel, wherein four contacts of each magnetic sensor are 3A, 3B, 3C, and 3D, respectively. At a first time point, four magnetic sensors (1A, 1B, 2A, 2B) in the magnetic field sensing device are simultaneously driven, and the four magnetic sensors (1A, 1B, 2A, 2B) are simultaneously set in a first working state through the switching circuit 400, that is, the contact 3B in each magnetic sensor in the magnetic field sensing device is connected with a power supply end, the contact 3C is connected with a ground end, and the contact 3A and the contact 3D generate outputs, so that four signal outputs corresponding to the first working state can be simultaneously generated. At a second time point, the four magnetic sensors (1A, 1B, 2A, 2B) in the magnetic field sensing device are simultaneously driven, and the four magnetic sensors (1A, 1B, 2A, 2B) are simultaneously set in a second operating state by the switching circuit 400, that is, the contact 3A in each magnetic sensor in the magnetic field sensing device is connected to the power supply terminal, the contact 3D is connected to the ground terminal, and the contact 3B and the contact 3C generate outputs, so that four signal outputs corresponding to the second operating state can be simultaneously generated. The four magnetic sensors (1A, 1B, 2A, 2B) in the magnetic field sensing device can be switched alternately between the first operating state and the second operating state synchronously and time-sequentially by the switching circuit 400, so that each magnetic sensor in each group of magnetic sensors generates two corresponding different signal outputs time-sequentially.

In another embodiment of the present invention, by the switching circuit 400, in addition to the four magnetic sensors (1A, 1B, 2A, 2B) in fig. 11 being switchable between the first operating state and the second operating state in time series, the four magnetic sensors (1A, 1B, 2A, 2B) in fig. 11 being switchable between the first operating state, the second operating state, the third operating state, and the fourth operating state in time series by the switching circuit 400. Illustratively, for example, at the third time point, the switching circuit 400 connects the contact 3C and the contact 3B in each magnetic sensor of the magnetic field sensing device to the power supply terminal, and the output is generated by the contact 3D and the contact 3A, so that four signal outputs corresponding to the third operating state can be generated simultaneously. At the fourth time point, the switching circuit 400 connects the contact 3D of each magnetic sensor in the magnetic field sensing device to the power supply terminal, the contact 3A is connected to the ground terminal, and the output is generated by the contact 3C and the contact 3B, so that four signal outputs corresponding to the fourth operating state can be generated at the same time. The switching circuit 400 can be used to alternately switch the four magnetic sensors (1A, 1B, 2A, 2B) of the magnetic field sensing device among the first operating state, the second operating state, the third operating state and the fourth operating state synchronously according to a time sequence, so that each magnetic sensor in each group of magnetic sensors generates four different corresponding signal outputs according to the time sequence.

For convenience of explanation, signals generated by the four magnetic sensors (1A, 1B, 2A, 2B) set in the first operating state at a first time point are output as first signal outputs; the signal output set in the second operating state by the four magnetic sensors (1A, 1B, 2A, 2B) at the second point in time is output as the second signal, and so on.

In step S103, with continued reference to fig. 5-10 and 13, for example, in the output processing circuit 600, the first signal output corresponding to the magnetic sensor 1A and the first signal output corresponding to the magnetic sensor 1B may be subjected to a differential operation, i.e., the first signal output generated by the magnetic sensor 1A and the first signal output generated by the magnetic sensor 1B may be added or subtracted to obtain the first differential output corresponding to the first group of magnetic sensors 101. In the output processing circuit 600, the first signal output corresponding to the magnetic sensor 2A and the first signal output corresponding to the magnetic sensor 2B may be differentially operated, that is, the first signal output generated by the magnetic sensor 2A and the first signal output generated by the magnetic sensor 2B may be added or subtracted to obtain the second differential output corresponding to the second group of magnetic sensors 102.

Similarly, in the output processing circuit 600, the second signal output corresponding to the magnetic sensor 1A (generated in response to the second operating state of the magnetic sensor 1A at the second time point) and the second signal output corresponding to the magnetic sensor 1B (generated in response to the second operating state of the magnetic sensor 1B at the second time point) may be differentially operated, that is, the second signal output generated by the magnetic sensor 1A and the second signal output generated by the magnetic sensor 1B may be added or subtracted to obtain the first differential output corresponding to the first set of magnetic sensors 101. In the output processing circuit 600, the second signal output corresponding to the magnetic sensor 2A (generated in response to the second operating state of the magnetic sensor 2A at the second time) and the second signal output corresponding to the magnetic sensor 2B (generated in response to the second operating state of the magnetic sensor 2B at the second time) may be subjected to a differential operation, that is, the second signal output generated by the magnetic sensor 2A and the second signal output generated by the magnetic sensor 2B may be added or subtracted to obtain the second differential output corresponding to the second group of magnetic sensors 102.

It should be noted that, the first differential output and the second differential output have a characteristic of resisting external magnetic field interference, which can be referred to the description in the foregoing embodiments specifically, and are not described herein again.

magnetic sensors

1A and 1B. The first differential output presents a sine waveform with a period of 360 degrees along with the rotation angle of the signal magnetic field, and the equation is S sin theta; the second differential output presents a cosine waveform with a period of 360 degrees along with the angle of rotation of the signal magnetic field, and the equation is S × cos θ, wherein S is the magnetic field sensitivity of the magnetic sensor and has the unit of mV/V, namely the signal output voltage value under the unit driving voltage. And dividing the first differential output by the second differential output to obtain S sin theta/S cos theta = tan theta, and then rotating the angle theta = arctan (sin theta/cos theta). The lower graph of fig. 10 shows the relationship between the rotation angle output of the magnetic field sensing device and the rotation angle of the signal magnetic field, and the magnetic field sensing device can output 360 ° period angle information by the phase determination of the first differential output and the second differential output. It should be understood that specific steps, other aspects and effects of the magnetic field sensing method can be found in the foregoing embodiments, and are not described herein again.

Further, in order to improve zero drift of each of the magnetic sensors due to production process unevenness, each of the magnetic sensors includes 2ⁿMagnetic sensor cells connected in parallel, each magnetic sensor cell including four electrodes including two electrodes arranged in a first direction and two electrodes arranged in a second direction perpendicular to the first direction, wherein n is 1 or moreA positive integer; each of the magnetic sensors includes four junctions, one of the four electrodes of each of the magnetic sensor cells is connected to one of the four electrodes of the remaining magnetic sensor cells to form one junction, two junctions of the four junctions serve as signal input terminals, the other two junctions serve as signal output terminals, and in the same operating state, driving current directions of two adjacent magnetic sensor cells are perpendicular to each other.

Further, the method further comprises: before processing the signal output of each magnetic sensor corresponding to different working states, amplifying the signal output so as to facilitate subsequent processing and operation output.

Illustratively, the magnetic sensing device sets four magnetic sensors (1A, 1B, 2A, 2B) in a first operating state, a second operating state, a third operating state and a fourth operating state synchronously at a first time point, a second time point, a third time point and a fourth time point, respectively, by the switching circuit 400, the four magnetic sensors (1A, 1B, 2A, 2B) generating four first signal outputs corresponding to the first operating state, four second signal outputs corresponding to the second operating state, four third signal outputs corresponding to the third operating state and four fourth signal outputs corresponding to the fourth operating state in time sequence.

Specifically, the output ends of the four magnetic sensors (1A, 1B, 2A, 2B) are electrically connected with at least one amplifier, and the first signal output generated by the four magnetic sensors (1A, 1B, 2A, 2B) in the first working state is connected to the at least one amplifier, so that the first signal output generated by each magnetic sensor is amplified. Likewise, the second signal outputs generated by the four magnetic sensors (1A, 1B, 2A, 2B) in the second operating state are coupled to at least one amplifier to amplify the second signal output generated by each magnetic sensor. Likewise, the third signal output generated by the four magnetic sensors (1A, 1B, 2A, 2B) in the third operating state is coupled to at least one amplifier to amplify the third signal output generated by each magnetic sensor. Similarly, the fourth signal output generated by the four magnetic sensors (1A, 1B, 2A, 2B) in the third operating state is coupled to at least one amplifier to amplify the fourth signal output generated by each magnetic sensor.

Further, the amplifying the signal output before processing the signal output for each of the magnetic sensors for a different operating state comprises: amplifying the signal output of each of the magnetic sensors of the first set of magnetic sensors 101 using a first amplifier 501 and amplifying the signal output of each of the magnetic sensors of the second set of magnetic sensors 102 using a second amplifier 502; wherein the amplification factors of the first amplifier 501 and the second amplifier 502 are independently adjusted.

Further, the method further comprises: the amplification factors of the first amplifier 501 and the second amplifier 502 are respectively adjusted according to pre-stored correction information corresponding to each of the magnetic sensors before amplifying the signal output of each of the magnetic sensors of the first group of magnetic sensors 101 and the signal output of each of the magnetic sensors of the second group of magnetic sensors 102. The signal outputs corresponding to at least two operating states of each of the magnetic sensors are corrected in such a manner as to adjust the amplification factors of the first amplifier 501 and the second amplifier 502. That is, using the correction information, the first amplifier 501 may individually amplify the signal output of each of the magnetic sensors in the first set of magnetic sensors 101; using the correction information, the second amplifier 502 may individually amplify the signal output of each of the magnetic sensors of the second set of magnetic sensors 102.

As can be seen from the above, the magnetic field sensing apparatus and the magnetic field sensing method according to the embodiments of the present invention are designed to enable each of the magnetic sensors in the first set of magnetic sensors and the second set of magnetic sensors to be alternately in the corresponding first operating state and the second operating state according to the time sequence by the switching circuit, so as to alternately generate a signal output corresponding to the first operating state and a signal output corresponding to the second operating state, thereby eliminating an error caused by a slight misalignment of the magnetic source of radial magnetization, and simultaneously obtain the first differential output and the second differential output for determining the angle information associated with the target magnetic field source, and thus, the output processing circuit does not have a temporal difference in the final formation of the first differential output and the second differential output. Therefore, the technical scheme of the embodiment of the invention has higher output bandwidth, extremely low time delay error and the characteristic of resisting external electromagnetic interference.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, which is defined by the appended claims.

Claims

1. A magnetic field sensing device, characterized in that the magnetic field sensing device comprises:

a first set of magnetic sensors and a second set of magnetic sensors, the first set of magnetic sensors and the second set of magnetic sensors being located at different positions on the same plane to receive magnetic field signals of a target magnetic field source, and the first set of magnetic sensors and the second set of magnetic sensors each comprising at least two magnetic sensors;

at least one switching circuit, electrically connected to the first set of magnetic sensors and the second set of magnetic sensors, respectively, for alternately switching each magnetic sensor in each set of magnetic sensors between at least two different operating states in time sequence to generate corresponding at least two different signal outputs;

an output processing circuit electrically connected to the at least one switching circuit to receive and process the signal output for each of the magnetic sensors for different operating states to simultaneously derive a first differential output corresponding to the first set of magnetic sensors and a second differential output corresponding to the second set of magnetic sensors, and to determine angle information associated with the target magnetic field source based on the first differential output and the second differential output.

2. The magnetic field sensing device according to claim 1, wherein said output processing circuitry processes said signal output for each of said magnetic sensors for a different operating state in a manner such that:

performing preset addition and subtraction operations on at least two different signal outputs corresponding to at least two different working states of each magnetic sensor in the first group of magnetic sensors, and performing preset differential operations on operation results corresponding to different magnetic sensors in the first group of magnetic sensors to obtain a first differential output;

and performing preset addition and subtraction operation on at least two different signal outputs corresponding to at least two different working states of each magnetic sensor in the second group of magnetic sensors, and performing preset differential operation on operation results corresponding to different magnetic sensors in the second group of magnetic sensors to obtain the second differential output.

3. The magnetic field sensing device according to claim 2,

each of the magnetic sensors includes 2ⁿMagnetic sensor cells connected in parallel, each magnetic sensor cell including four electrodes including two electrodes arranged in a first direction and arranged in a second direction perpendicular to the first directionTwo upward electrodes, wherein n is a positive integer greater than or equal to 1;

each of the magnetic sensors includes four junctions, one of the four electrodes of each of the magnetic sensor cells is connected to one of the four electrodes of the remaining magnetic sensor cells to form one junction, two junctions of the four junctions serve as signal input terminals, the other two junctions serve as signal output terminals, and in the same operating state, driving current directions of two adjacent magnetic sensor cells are perpendicular to each other.

4. The magnetic field sensing device according to claim 3,

the four contacts of each magnetic sensor are electrically connected to the at least one switching circuit, and the at least one switching circuit switches the connection relationship between the four contacts in each magnetic sensor and a power supply terminal and a ground terminal according to a preset time sequence, so that each magnetic sensor alternately generates signal outputs corresponding to at least two different working states.

5. The magnetic field sensing device according to any one of claims 1 to 4, further comprising:

the at least one amplifier is electrically connected between the at least one switching circuit and the output processing circuit, and is used for amplifying signal outputs of the magnetic sensors in the first group of magnetic sensors and the second group of magnetic sensors corresponding to at least two different working states and inputting the amplified signal outputs to the output processing circuit.

6. The magnetic field sensing device according to claim 5,

the at least one switching circuit includes a first switching circuit electrically connected to the first set of magnetic sensors for causing each of the magnetic sensors in the first set of magnetic sensors to alternately generate signal outputs corresponding to at least two different operating states, and a second switching circuit electrically connected to the second set of magnetic sensors for causing each of the magnetic sensors in the second set of magnetic sensors to alternately generate signal outputs corresponding to at least two different operating states.

7. The magnetic field sensing device according to claim 6,

the at least one amplifier comprises a first amplifier and a second amplifier, the first amplifier is electrically connected between the first switching circuit and the output processing circuit for amplifying the signal output of each of the magnetic sensors in the first set of magnetic sensors, and the second amplifier is electrically connected between the second switching circuit and the output processing circuit for amplifying the signal output of each of the magnetic sensors in the second set of magnetic sensors;

wherein the amplification of the first amplifier and the second amplifier are independently adjusted.

8. The magnetic field sensing device according to claim 7, further comprising:

a correction device that stores correction information corresponding to each of the magnetic sensors in the first and second groups of magnetic sensors;

the output processing circuit is electrically connected between the correction device and the first amplifier and between the correction device and the second amplifier, and the output processing circuit respectively feeds back correction information corresponding to each magnetic sensor acquired from the correction device to the first amplifier and the second amplifier so as to respectively adjust the amplification factors of the first amplifier and the second amplifier.

9. The magnetic field sensing device according to claim 1, further comprising:

and the result output module is electrically connected with the output end of the output processing circuit so as to output the angle information according to a preset mode.

10. The magnetic field sensing device according to claim 1,

the magnetic field sensing device also includes a substrate, the first set of magnetic sensors and the second set of magnetic sensors being disposed on a same side of the substrate.

11. The magnetic field sensing device according to claim 1,

the magnetic sensor is a horizontal Hall sensor and is used for sensing a magnetic field component perpendicular to the plane of the magnetic sensor.

12. The magnetic field sensing device according to claim 1,

the magnetic sensor is a vertical hall sensor for sensing a magnetic field component parallel to a plane in which the magnetic sensor is located.

13. The magnetic field sensing device according to claim 1,

the magnetic sensor is a magnetoresistive sensor for sensing a magnetic field component parallel or perpendicular to a plane in which the magnetic sensor lies.

14. The magnetic field sensing device according to claim 1, wherein the at least two different operating states comprise four different operating states.

15. A magnetic field sensing method, the method comprising:

providing a first set of magnetic sensors and a second set of magnetic sensors, the first set of magnetic sensors and the second set of magnetic sensors being located at different locations on the same plane to receive magnetic field signals of a target magnetic field source, and the first set of magnetic sensors and the second set of magnetic sensors each comprising at least two magnetic sensors;

driving each magnetic sensor in each group of magnetic sensors to alternately switch between at least two different working states according to a time sequence so as to generate at least two corresponding different signal outputs;

processing the signal outputs corresponding to different operating states of each of the magnetic sensors to simultaneously obtain a first differential output corresponding to the first set of magnetic sensors and a second differential output corresponding to the second set of magnetic sensors, and determining angle information associated with the target magnetic field source based on the first differential output and the second differential output.

16. The method of claim 15, wherein the processing the signal output for each of the magnetic sensors for a different operating state to simultaneously obtain a first differential output for the first set of magnetic sensors and a second differential output for the second set of magnetic sensors comprises:

performing preset addition and subtraction operations on signal outputs of at least two different working states corresponding to each magnetic sensor in the first group of magnetic sensors, and performing preset differential operations on operation results corresponding to different magnetic sensors in the first group of magnetic sensors to obtain the first differential output;

and performing preset addition and subtraction operation on the signal output of each magnetic sensor in the second group of magnetic sensors corresponding to at least two different working states, and performing preset differential operation on the operation result of different magnetic sensors in the second group of magnetic sensors to obtain the second differential output.

17. The magnetic field sensing method of claim 16,

each of the magnetic sensors includes 2ⁿMagnetic sensor units connected in parallel, each magnetic sensor unit including four electrodes including two electrodes arranged in a first direction and two electrodes arranged perpendicular to the first directionTwo electrodes in a second direction, wherein n is a positive integer greater than or equal to 1;

18. The method of claim 17, wherein actuating each magnetic sensor of each set of magnetic sensors to alternately switch between at least two different operating states in a time sequence to generate corresponding at least two different signal outputs comprises:

and switching the connection relation between the four contacts in each magnetic sensor and a power supply end and a ground end according to a preset time sequence so that each magnetic sensor alternately generates signal outputs corresponding to at least two different working states.

19. The magnetic field sensing method according to any one of claims 15 to 18, further comprising:

amplifying the signal output for each of the magnetic sensors prior to processing the signal output for a different operating state.

20. The magnetic field sensing method of claim 19, wherein said amplifying the signal output prior to processing the signal output for each of the magnetic sensors for a different operating state comprises:

amplifying the signal output of each of the magnetic sensors of the first set of magnetic sensors using a first amplifier, amplifying the signal output of each of the magnetic sensors of the second set of magnetic sensors using a second amplifier;

21. The magnetic field sensing method of claim 20, further comprising:

adjusting the amplification factors of the first amplifier and the second amplifier, respectively, according to pre-stored correction information corresponding to each of the magnetic sensors, before amplifying the signal output of each of the magnetic sensors of the first group of magnetic sensors and the signal output of each of the magnetic sensors of the second group of magnetic sensors.

22. The magnetic field sensing method of claim 15, further comprising:

and after the angle information associated with the target magnetic field source is determined, outputting the angle information according to a preset mode.

23. The magnetic field sensing method of claim 15, wherein the at least two different operating states comprise four different operating states.