JP2022158893A - Event detection method, event detection system, and program - Google Patents

Abstract

SOLUTION: To provide an event detection method that detects an event corresponding to a position of a magnetic field occurrence part by detecting magnetic fields of at least two axes generated by a predetermined magnetic field generation part, and includes a stage for acquiring an event generation part on the basis of a magnetic field detected by a magnetic sensor, a stage for selecting a detection axis for detecting an event on the basis of the event generation position, a stage for calculating a trigger threshold corresponding to the event generation position in a detection axis, and a stage for acquiring a trigger signal for showing that the magnetic field detected by the magnetic sensor and the trigger threshold satisfy a predetermined conditions.SELECTED DRAWING: Figure 1B

Description

The present invention relates to an event detection method, event detection system and program.

Patent Literature 1 describes "to provide a position sensor capable of detecting the movement of a detection target with a single detection unit even if the movement amount of the detection target becomes large". Patent Literature 2 describes "to provide a position detection sensor that has a linear output with respect to a long detection distance and is capable of position detection with high detection accuracy".
[Prior art documents]
[Patent Literature]
Patent Document 1: JP-A-2019-2835 Patent Document 2: JP-A-2003-167627

According to a first aspect of the present invention, an event detection method detects an event corresponding to the position of a magnetic field generator by detecting magnetic fields on two or more axes generated by a predetermined magnetic field generator with a magnetic sensor. obtaining an event occurrence position based on the magnetic field detected by the magnetic sensor; selecting a detection axis for event detection based on the event occurrence position; An event detection method is provided comprising the steps of calculating a trigger threshold and receiving a trigger signal indicating that the magnetic field detected by a magnetic sensor and the trigger threshold satisfy a predetermined condition.

In a second aspect of the present invention, a magnetic field generating section for generating a predetermined magnetic field, a magnetic sensor for detecting the magnetic field generated by the magnetic field generating section, and a processing section for processing the signal detected by the magnetic sensor. The processing unit includes an acquisition unit that acquires an event occurrence position based on the magnetic field detected by the magnetic sensor, a selection unit that selects a detection axis for event detection based on the event occurrence position, and and a calculator for calculating a trigger threshold according to the event occurrence position, and the magnetic sensor has an output unit for outputting a trigger signal indicating that the detected magnetic field and the trigger threshold satisfy a predetermined condition. provide the system.

According to a third aspect of the invention, a program for causing a computer to execute the event detection method according to the first aspect of the invention.

It should be noted that the above summary of the invention does not list all the features of the invention. Subcombinations of these feature groups can also be inventions.

1 is a block diagram showing an overview of an event detection system 100; FIG. More specific configurations of the magnetic sensor 20 and the processing unit 30 are shown. An example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 is shown. An example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 is shown. An example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 is shown. A state in which the magnetic field generator 10 is arranged at the reference position P0 is shown. A state in which the magnetic field generator 10 is arranged at the event generation position Pe is shown. A magnetic field waveform corresponding to the position of the magnetic field generator 10 is shown. FIG. 3C illustrates the variation in magnetic flux density and trigger signal corresponding to the magnetic field waveform of FIG. 3C; An example of a threshold determination method using a biaxial magnetic field is shown. An example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 is shown. An example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 is shown. An example of a threshold determination method using a biaxial magnetic field is shown. A comparative example of a threshold determination method using a uniaxial magnetic field is shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of a more specific threshold determination method will be shown. An example of the operational flow of the event detection system 100 is shown. 1 shows an example of the configuration of an event detection system 100. FIG. An example computer 2200 is shown in which aspects of the present invention may be embodied in whole or in part.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

FIG. 1A is a block diagram showing an overview of an event detection system 100. As shown in FIG. The event detection system 100 includes a magnetic field generator 10 , a magnetic sensor 20 and a processor 30 .

The magnetic field generator 10 generates a predetermined magnetic field. For example, the magnetic field generator 10 includes a two-pole magnet having north and south poles arranged in a predetermined direction. The magnetic field generator 10 generates a magnetic field having a predetermined magnetic field waveform according to the magnetization direction of the magnet. The magnetic field generator 10 may move in a predetermined direction to change the magnetic field waveform.

The magnetic sensor 20 detects the magnetic field generated by the magnetic field generator 10 . The magnetic sensor 20 detects magnetic fields in at least two detection axes. The magnetic sensor 20 of this example is a multi-axis magnetic sensor capable of detecting two or more magnetic fields. However, the magnetic sensor 20 may detect two or more axial magnetic fields by having a plurality of uniaxial sensors. The magnetic sensor 20 acquires measurement data obtained by detecting magnetic flux densities of magnetic fields on two or more axes. The magnetic sensor 20 generates a trigger signal when the acquired measurement data satisfies a predetermined condition. The trigger signal is an interrupt signal that notifies the state change of the magnetic sensor 20 .

The processing unit 30 processes signals detected by the magnetic sensor 20 . The processing unit 30 serially communicates with the magnetic sensor 20 and receives measurement data from the magnetic sensor 20 . Also, the processing unit 30 changes its internal state by a trigger signal from the magnetic sensor 20 . For example, the processing unit 30 changes the device provided with the processing unit 30 from the standby state to the active state in response to receiving the trigger signal.

The event detection system 100 generates a trigger signal based on detection of an event according to the relative positional relationship between the magnetic field generator 10 and the magnetic sensor 20 . The event detection system 100 of this example generates a trigger signal and executes a predetermined operation in response to the magnetic field generator 10 moving to a predetermined position.

In one example, the event detection system 100 is installed in a portable terminal such as a smartphone whose display can be stretched (for example, a rollable phone), and displays the display in response to the display being stretched to a predetermined position. Outputs a trigger signal for switching. Further, the event detection system 100 may switch the smartphone from the standby state to the active state in response to detection of an event. Further, the event detection system 100 may transition from the active state to the standby state when there is no operation for a predetermined period.

FIG. 1B shows more specific configurations of the magnetic sensor 20 and the processing section 30. As shown in FIG. The magnetic sensor 20 of this example includes a detection section 22 and an output section 24 . The processing unit 30 includes an acquisition unit 32 , a selection unit 34 and a calculation unit 36 .

The detector 22 detects the magnetic field generated by the magnetic field generator 10 . The detection unit 22 outputs the detected magnetic field measurement data (Bx, By, Bz) to the detection unit 22 or the processing unit 30 . Bx, By and Bz indicate magnetic flux densities in the X-axis direction, Y-axis direction and Z-axis direction, respectively. The detection unit 22 of this example detects magnetic flux densities in three axial directions as measurement data, but may detect magnetic flux densities in two axial directions.

The acquisition unit 32 acquires measurement data (Bx, By, Bz) from the magnetic sensor 20 . For example, the acquisition unit 32 acquires measurement data when the magnetic field generation unit 10 is positioned at a predetermined reference position P0. The reference position P0 may be any position where the magnetic sensor 20 can detect the position of the magnetic field generator 10 .

The acquisition unit 32 may also acquire information necessary for selecting a detection axis or calculating a trigger threshold, such as the event occurrence position Pe of the magnetic field generation unit 10 . A method of acquiring the event occurrence position Pe will be described later. The acquisition unit 32 outputs the acquired event occurrence position Pe to the selection unit 34 and the calculation unit 36 . The acquisition unit 32 may acquire information such as the event occurrence position Pe from the storage unit provided in the processing unit 30 .

Further, the acquisition unit 32 may acquire the detectable region and the non-detectable region according to the position of the magnetic field generator 10 for each detection axis. A detectable region is a region in which the trigger threshold is detectable in the corresponding detection axis. A non-detectable region is a region in which the trigger threshold cannot be detected in the corresponding detection axis. A case where the trigger threshold cannot be detected is, for example, a case where the position of the magnetic field generator 10 cannot be specified from the output magnetic flux density. The multiple detection axes may be selected to have detectable and non-detectable regions in different regions.

The selection unit 34 selects a detection axis for event detection based on the event occurrence position Pe. For example, the selector 34 selects a first axis parallel to a predetermined first direction in which the magnetic field generator 10 moves or a second axis orthogonal to the first axis as the detection axis. The selector 34 selects the detection axis so that the position of the magnetic field generator 10 falls within the detectable region. A specific detection axis selection method will be described later.

The calculator 36 calculates a trigger threshold according to the event occurrence position Pe on the detection axis. The trigger threshold is the magnetic flux density detected by the magnetic sensor 20 at the event occurrence position Pe on the selected detection axis. The calculator 36 outputs the calculated trigger threshold to the output unit 24 .

The output unit 24 detects a predetermined trigger threshold and outputs a trigger signal. The output unit 24 of this example generates a trigger signal when the magnetic flux density of the magnetic field detected by the detection unit 22 exceeds or falls below the trigger threshold. The output unit 24 outputs the generated trigger signal to the processing unit 30 . The processing unit 30 may execute predetermined processing in response to reception of the trigger signal.

FIG. 2A shows an example of how the magnetic field generator 10 and the magnetic sensor 20 are arranged. This figure shows the magnetic field generator 10 and the magnetic sensor 20 from the viewpoint in the Y-axis direction.

The magnetic field generator 10 of this example has N poles and S poles arranged in the X-axis direction. The X-axis direction is an example of a first direction. However, the magnetic field generator 10 may move not only in the X-axis direction, but also in the Y-axis direction, Z-axis direction, or other directions. The magnetic field generator 10 of this example has the S pole on the negative side in the X-axis direction with respect to the N pole, but is not limited to this. The distance between the magnetic field generator 10 and the magnetic sensor 20 in the Z-axis direction is not particularly limited as long as the magnetic sensor 20 can detect the magnetic field of the magnetic field generator 10 .

In this example, the shape of the magnet of the magnetic field generator 10 is a rectangular parallelepiped, but it may be other shapes such as a cylinder. The magnet material can be any material such as neodymium or ferrite. In one example, when the event detection system 100 is mounted on a rollable phone, the magnetic field generator 10 is mounted on the display side, the magnetic sensor 20 is mounted on the housing side, and the magnetic field generator 10 and the magnetic field are mounted according to the expansion and contraction of the display. The relative positional relationship of sensors 20 changes.

If the relative positional relationship between the magnetic field generator 10 and the magnetic sensor 20 changes, the magnetic sensor 20 may move, or both the magnetic field generator 10 and the magnetic sensor 20 may move. In one example, when the event detection system 100 is mounted on a rollable phone, the magnetic field generator 10 is mounted on the display side, the magnetic sensor 20 is mounted on the housing side, and the magnetic field generator 10 and the magnetic field are mounted according to the expansion and contraction of the display. A relative positional relationship with the sensor 20 changes.

FIG. 2B shows an example of how the magnetic field generator 10 and the magnetic sensor 20 are arranged. This figure shows the magnetic field generator 10 and the magnetic sensor 20 from a viewpoint in the Z-axis direction. That is, the viewpoint in this example shows a viewpoint from a position rotated by 90 degrees with respect to FIG. 2A.

The magnetic field generator 10 moves across the magnetic sensor 20 on the XY plane. The magnetic field generator 10 crossing the magnetic sensor 20 means that the magnetic field generator 10 and the magnetic sensor 20 partly overlap on the XY plane. In other words, the magnetic field generator 10 may move so as to pass over the magnetic sensor 20 . Also, the magnetic field generator 10 may move across the magnetic sensor 20 in the YZ plane. When the magnetic field generator 10 crosses the magnetic sensor 20 on a predetermined plane, it becomes easier to detect changes in the magnetic flux density according to the movement of the magnetic field generator 10, and it becomes easier to determine the trigger threshold.

Moreover, although the magnetic field generator 10 in this example moves parallel to the X-axis direction, it may move obliquely to the X-axis on the XY plane. In this way, the magnetic field generator 10 is not limited to being arranged across the magnetic sensor 20 in the XY plane, and the degree of freedom in housing design can be increased.

Although this example shows the case where the magnetic field generator 10 moves in a straight line, the present invention is not limited to this. That is, the magnetic field generator 10 may move along a curved line, or may move along any other trajectory. The magnetic field generator 10 may rotate on a predetermined circumference.

FIG. 2C shows an example of how the magnetic field generator 10 and the magnetic sensor 20 are arranged. This figure shows the magnetic field generator 10 and the magnetic sensor 20 from a viewpoint in the Z-axis direction. This figure is a top view showing the case where the magnetic field generator 10 moves on the circumference. In FIG. 2C, the magnetic field generator 10 moves across the magnetic sensor 20 in the XY plane. The magnetic field generator 10 crossing the magnetic sensor 20 means that the magnetic field generator 10 and the magnetic sensor 20 partly overlap on the XY plane. In other words, the magnetic field generator 10 may move so as to pass over the magnetic sensor 20 . Also, the magnetic field generator 10 does not have to pass over the magnetic sensor 20 .

For example, the magnetic field generator 10 may move according to folding of a foldable smartphone (for example, a foldable phone), or the magnetic field generator 10 may move according to rotation of the bezel of the smartwatch. . In the case of a foldable phone, the magnetic field generator 10 is provided on one side and the magnetic sensor 20 is provided on the other side, and the magnetic field generator 10 may move along a curve according to opening and closing. In the case of a smart watch, the magnetic sensor 20 may be provided on the main body side, the magnetic field generator 10 may be provided on the bezel side, and the magnetic field generator 10 may rotate on the circumference according to the rotating drive of the bezel.

FIG. 3A shows a state in which the magnetic field generator 10 is placed at the reference position P0. The magnetic field generator 10 of this example is arranged so that the boundary between the N pole and the S pole is located above the magnetic sensor 20 . In this example, the magnetic flux density Bx in the X-axis direction is higher than the magnetic flux density Bz in the Z-axis direction. However, the magnetic flux density detected by the magnetic sensor 20 at the reference position P0 is not limited to this.

FIG. 3B shows a state in which the magnetic field generator 10 is arranged at the event generation position Pe. That is, the event detection system 100 executes predetermined processing when the magnetic field generator 10 is placed at the position shown in the figure. The magnetic field generator 10 of this example has moved to the positive side in the X-axis direction from the reference position P0 in FIG. 3A. In this case, the component of the magnetic flux density Bz in the Z-axis direction becomes larger than when the magnetic field generator 10 exists at the reference position P0 in FIG. 3A. The relative positional relationship between the magnetic field generator 10 and the magnetic sensor 20 and the movement direction of the magnetic field generator 10 are not limited to this example as long as the trigger threshold can be detected by the magnetic sensor 20 .

FIG. 3C shows magnetic field waveforms according to the position of the magnetic field generator 10 . The horizontal axis indicates the position of the magnetic field generator 10 in the X-axis direction, and the vertical axis indicates the magnetic flux density Bz in the Z-axis direction. The magnitude of the magnetic flux density Bz measured by the magnetic sensor 20 changes according to the movement of the magnetic field generator 10 . The magnetic flux density Bz_0 is the magnetic flux density detected by the magnetic sensor 20 when the magnetic field generator 10 is placed at the reference position P0. The magnetic flux density Bz_1 is the magnetic flux density detected by the magnetic sensor 20 when the magnetic field generator 10 is arranged on the positive side in the X-axis direction with respect to the reference position P0.

The magnetic flux density Bthz is the magnetic flux density detected by the magnetic sensor 20 when the magnetic field generator 10 is placed at the event generation position Pe. The event detection system 100 of this example generates a trigger signal when the magnetic sensor 20 exceeds the magnetic flux density Bthz. In this example, a case where one detection axis is used is described for the sake of explanation, but events may be detected using two or more detection axes.

FIG. 3D shows changes in magnetic flux density and trigger signal corresponding to the magnetic field waveform of FIG. 3C. In this example, from time T0 to time T1, the magnetic field generator 10 is stopped at the reference position P0, and the magnetic flux density Bz does not fluctuate.

At time T1, the magnetic field generator 10 starts moving from the reference position P0, and the magnetic flux density gradually increases from Bz_0. At time T2, a trigger signal is generated from the magnetic sensor 20 when the magnetic flux density Bthz is exceeded. Thereafter, the magnetic field generator 10 moves to a position corresponding to the magnetic flux density Bz_1 at time T3 and stops. At time T4, the magnetic field generator 10 starts moving to the reference position P0, and stops generating the trigger signal when the magnetic flux density falls below Bthz at time T5. Thus, the event detection system 100 of this example generates the trigger signal based on the threshold determination inside the magnetic sensor 20 .

An example of a threshold determination method using a biaxial magnetic field will be described below.

FIG. 4A shows an example of a threshold determination method using biaxial magnetic fields. In this example, as shown in FIGS. 2A and 2B, the magnetic field generator 10 moves across the magnetic sensor 20 in the XY plane. The event detection system 100 of this example selectively uses the magnetic flux density Bx in the X-axis direction and the magnetic flux density Bz in the Z-axis direction. However, the event occurrence position Pe corresponds to the vicinity of the inflection point of the magnetic flux density Bz in the Z-axis direction, and if the Z-axis is used as the detection axis, the event occurrence position Pe cannot be accurately detected. Therefore, the event detection system 100 of this example detects the event occurrence position Pe using the magnetic flux density Bx that changes linearly at the event occurrence position Pe. The event detection system 100 of this example can expand the event detectable region by performing threshold determination using measurement data of two or more axes.

In this embodiment, an event can be detected even when the magnetic field generator 10 moves so as not to cross the magnetic sensor 20 in the XY plane.

FIG. 4B shows an example of how the magnetic field generator 10 and the magnetic sensor 20 are arranged. This figure shows the magnetic field generator 10 and the magnetic sensor 20 from a viewpoint in the Z-axis direction. The magnetic field generator 10 of this example is moved in a position shifted in the Y-axis direction from the magnetic sensor 20 without crossing the magnetic sensor 20 on the XY plane. In FIG. 4B, the movement amount y in the Y-axis direction is a positive value. In other words, the magnetic field generator 10 moves by y in the positive direction of the Y-axis, but the present invention is not limited to this.

FIG. 4C shows an example of a method of arranging the magnetic field generator 10 and the magnetic sensor 20 . This figure shows the magnetic field generator 10 and the magnetic sensor 20 from a viewpoint in the Z-axis direction. The magnetic field generator 10 of this example is moved in a position shifted in the Y-axis direction from the magnetic sensor 20 without crossing the magnetic sensor 20 on the XY plane. The magnetic field generator 10 may move in the XZ plane in the positive direction of the X-axis, and the movement amount y in the Y-axis direction is a negative value. That is, the magnetic field generator 10 may move by y in the negative direction of the Y-axis within the XY plane.

FIG. 4D shows magnetic field waveforms according to the position of the magnetic field generator 10 . The horizontal axis indicates the position of the magnetic field generator 10 in the X-axis direction, and the vertical axis indicates the magnetic flux density Bx in the X-axis direction and the magnetic flux density Bz in the Z-axis direction. The magnetic flux densities Bx and Bz measured by the magnetic sensor 20 change according to the movement of the magnetic field generator 10 .

The magnetic field waveforms (Bx, Bz) when the magnetic field generator 10 moves across the magnetic sensor 20 as shown in FIG. A solid line indicates the magnetic field waveform (Bxoff, Bzoff) when moving to a shifted position. In the case shown in FIG. 4C, the distance between the magnetic field generator 10 and the magnetic sensor 20 is greater than in the case of FIG. 2B, so the magnetic flux density detected by the magnetic sensor 20 is reduced.

However, as shown in FIG. 4D, in the XY plane, when the magnetic field generator 10 crosses the magnetic sensor 20 and when it moves to a position shifted in the Y-axis direction from the magnetic sensor 20, the peak of the magnetic flux density is The position of the applied magnetic field generator 10 in the X-axis direction does not change significantly. Therefore, even when the magnetic field generator 10 does not cross the magnetic sensor 20 in the XY plane, the same event detection method as in the case of crossing the magnetic sensor 20 can be applied.

Here, the strength of the magnetic flux density detected by the magnetic sensor 20 decreases as the movement amount y of the magnetic field generating section 10 in the Y-axis direction increases. Although not shown, the intensity of the magnetic flux density detected by the magnetic sensor 20 in the case of FIG. 4B is smaller than the intensity of the magnetic flux density detected by the magnetic sensor 20 in the case of FIG. 4C.

Therefore, the movement amount y of the magnetic field generator 10 can be determined by considering the magnetic flux density size at which the magnetic flux density at the position of the magnetic sensor 20 can detect an event, including the effects of external magnetic field noise and the like. By doing so, the degree of freedom in arranging the magnetic field generating section 10 and the magnetic sensor 20 is increased, so the degree of freedom in housing design can be increased.

FIG. 5 shows a comparative example of a threshold determination method using a uniaxial magnetic field. In this example, since the event occurrence position Pe corresponds to the vicinity of the inflection point of the magnetic flux density Bz in the Z-axis direction, it is difficult to accurately determine the position of the magnetic field generator near the event occurrence position Pe. Therefore, in the threshold determination method of the comparative example, an undetectable region Ru occurs in which an event cannot be detected. Therefore, in the method of the comparative example, detectable event occurrence positions Pe are limited.

FIG. 6 shows an example of a more specific threshold determination method. The event detection system 100 of this example selects and uses one of the detection axes according to the position in the X-axis direction. A solid line in the graph indicates a detectable region in which the position of the magnetic field generator 10 can be detected. A dashed line in the graph indicates an undetectable region where the position of the magnetic field generator 10 cannot be detected. In one example, the detectable region is a region that does not have an inflection point of the magnetic flux density and monotonically increases or decreases in accordance with the movement of the magnetic field generator 10 . The non-detectable region is a region in which the waveform of the magnetic flux density has an inflection point or a region in which the change in magnetic flux density according to the movement of the magnetic field generator 10 is small.

The selector 34 selects the X-axis when the event occurrence position Pe belongs to the detectable region in which the position of the magnetic field generator 10 can be detected on the X-axis. On the other hand, the selection unit 34 selects the Z-axis when the event occurrence position Pe does not belong to the detectable region of the X-axis but belongs to the detectable region of the Z-axis. Further, the selection unit 34 may select the detection axis based on the reference position P0 and the event occurrence position Pe.

The event detection system 100 of this example divides into five regions, region R1, region R2, region R3, region R1', and region R2', and selects axes. The selection unit 34 selects the Z axis as the detection axis in the regions R1, R3 and R1'. The selection unit 34 selects the X axis as the detection axis in the regions R2 and R2'.

Region R1 is the section between the starting point and boundary 1, and the monotonically decreasing magnetic flux density Bz can be used to determine the trigger threshold. Region R2 is the interval between Boundary 1 and Boundary 2, where the monotonically decreasing magnetic flux density Bx can be used to determine the trigger threshold. Region R3 is the section between Boundary 2 and Boundary 2', where the monotonically increasing magnetic flux density Bz can be used to determine the trigger threshold. Region R2' is the interval between Boundary 2' and Boundary 1' where a monotonically increasing magnetic flux density Bx is used to determine the trigger threshold. Region R1' is the interval between boundary 1' and the end point, where the monotonically decreasing magnetic flux density Bz is used to determine the trigger threshold. The area setting method is not limited to this.

As described above, the event detection system 100 sets each region so that the magnetic flux density of the selected axis does not have an inflection point, and selects the detection axis. This allows the event detection system 100 to determine trigger thresholds and generate trigger signals over a wider range.

In this embodiment, when a plurality of trigger threshold values can be set for each detection axis, an event can be detected when the magnetic field generator 10 moves in the plus or minus direction of the X axis. Further, in this embodiment, event detection can be performed even when only one trigger threshold can be set for each detection axis.

As an example, a method of detecting an event when the magnetic field generator 10 moves from the reference position P0 will be described. A method of detecting an event when the magnetic field generator 10 moves in the plus or minus direction of the X-axis will be described below, but the movement direction of the magnetic field generator 10 is not limited to this.

FIG. 7A shows a magnetic field waveform according to the position of the magnetic field generator 10. FIG. The horizontal axis indicates the position of the magnetic field generator 10 in the X-axis direction, and the vertical axis indicates the magnetic flux density Bx in the X-axis direction and the magnetic flux density Bz in the Z-axis direction. When the magnetic field generator 10 moves in the plus or minus direction of the X-axis near the reference position P0, when neither Bx nor Bz includes an inflection point, an event when the magnetic field generator 10 moves ±1 mm from the reference position P0 Detection can be performed.

For example, when the reference position P0 is 2 mm in FIG. 7A, Bx is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and according to the event occurrence position Pe− when moving to the minus side. By using Bz as the trigger threshold to perform event detection, event detection can be performed even when only one trigger threshold can be set for each detection axis.

However, for example, when the reference position P0 is 0 mm in FIG. 7A, event detection using Bx cannot be performed because the change in Bx is small around the reference position P0. Even in such a case, event detection can be performed if the magnetic sensor 20 can calculate the square root of the sum of squares Bsum of the magnetic flux density. That is, event detection can be performed by calculating a trigger threshold according to the event occurrence position Pe using the square root of the sum of squares Bsum. The square root of the sum of squares Bsum of the magnetic flux density can be expressed by the following equation (1).

FIG. 7B shows magnetic field waveforms according to the position of the magnetic field generator 10 . The horizontal axis indicates the position of the magnetic field generator 10 in the X-axis direction, and the vertical axis indicates the magnetic flux density Bx in the X-axis direction, the magnetic flux density Bz in the Z-axis direction, and the square root of the sum of the squares of the magnetic flux densities Bsum. For example, when the reference position P0 is 0 mm, by using Bsum having a symmetrical shape, it is possible to detect an event when moved ±1 mm from the reference position P0.

FIG. 7C shows magnetic field waveforms according to the position of the magnetic field generator 10 . In FIG. 7C, the reference position P0 is 0 mm as in FIG. 7B. In FIG. 7C, Bz is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and Bsum is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. They each detect events. This enables event detection even when only one trigger threshold can be set for each detection axis.

FIG. 7D is a diagram showing a case where the reference position P0 is 1 mm. In FIG. 7D, Bsum is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and Bz is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. By performing event detection respectively, event detection can be performed even when only one trigger threshold can be set for each detection axis.

FIG. 7E is a diagram showing a case where the reference position P0 is -1 mm. In FIG. 7E, Bz is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and Bsum is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. By performing event detection respectively, event detection can be performed even when only one trigger threshold can be set for each detection axis.

As described above, the event detection system 100 can detect events in both directions by using the double sum square root Bsum of the magnetic flux density. This allows the event detection system 100 to determine the trigger threshold and generate the trigger signal even when only one trigger threshold can be set for the selected detection axis.

Furthermore, in the present embodiment, when only one trigger threshold can be set for each detection axis, event detection can be performed even when the magnetic sensor 20 cannot calculate the square root of the sum of squares of the magnetic flux density. can be done.

FIG. 8A shows the magnetic field waveform according to the position of the magnetic field generator 10 when the magnetic field generator 10 does not cross the magnetic sensor 20 as shown in FIG. 4C. The horizontal axis indicates the position of the magnetic field generator 10 in the X-axis direction, and the vertical axis indicates the magnetic flux density Bx in the X-axis direction, the magnetic flux density By in the Y-axis direction, and the magnetic flux density Bz in the Z-axis direction. When the magnetic field generator 10 moves in the plus or minus direction of the X-axis near the reference position P0, when neither Bx nor Bz includes an inflection point, an event when the magnetic field generator 10 moves ±1 mm from the reference position P0 Detection can be performed.

For example, when the reference position P0 is 2 mm in FIG. 8A, Bx is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and according to the event occurrence position Pe− when moving to the minus side. By using Bz as the trigger threshold to perform event detection, event detection can be performed even when only one trigger threshold can be set for each detection axis.

However, for example, when the reference position P0 is 0 mm in FIG. 8A, event detection using Bx cannot be performed because the change in Bx is small around the reference position P0. Even in such a case, event detection can be performed by selecting the Y axis as the detection axis and using By.

FIG. 8B is a diagram showing a case where the reference position P0 is 0 mm. In this embodiment, Bz is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and By is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. By performing event detection for each, it is shown that event detection can be performed even when only one trigger threshold can be set for each detection axis, but the present invention is not limited to this. That is, the event is detected using By as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and using Bz as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. It is possible to do

FIG. 8C is a diagram showing a case where the reference position P0 is 1 mm. In this embodiment, Bz is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and By is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. By performing event detection for each, it is shown that event detection can be performed even when only one trigger threshold can be set for each detection axis, but the present invention is not limited to this. That is, the event is detected using By as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and using Bz as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. It is possible to do

FIG. 8D is a diagram showing a case where the reference position P0 is -1 mm. In this embodiment, Bz is used as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and By is used as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. By performing event detection for each, it is shown that event detection can be performed even when only one trigger threshold can be set for each detection axis, but the present invention is not limited to this. That is, the event is detected using By as the trigger threshold corresponding to the event occurrence position Pe+ when moving to the plus side, and using Bz as the trigger threshold corresponding to the event occurrence position Pe− when moving to the minus side. It is possible to do

FIG. 9 shows an example of the operational flow of the event detection system 100. As shown in FIG. This example shows a method of detecting a predetermined event and generating a trigger signal for activating the processing unit 30 after the processing unit 30 has transitioned to the standby state.

Steps S300 to S314 may be performed by the processing unit 30, and steps S200 to S206 may be performed by the magnetic sensor 20. FIG. At step S300, the processing unit 30 is set to the activated state. In step S302, in order to acquire the measurement data of the reference position P0 of the magnetic field generator 10, the magnetic sensor 20 is requested to read the measurement data. Thereby, the processing unit 30 acquires measurement data (Bx, By, Bz) at the reference position P0 from the magnetic sensor 20 . The reference position P0 of the magnetic field generator 10 is not particularly limited.

In step S304, the processing unit 30 determines the area of the reference position P0 of the magnetic field generating unit 10 from the acquired measurement data. For example, the processing unit 30 calculates the reference position P0 of the magnetic field generation unit 10 using a data table created in advance or function fitting.

In step S306, the processing unit 30 determines the area of the event occurrence position Pe. The processing unit 30 may store a preset event occurrence position Pe. The processing unit 30 may determine the area of the event occurrence position Pe from the measurement data when the magnetic field generation unit 10 is positioned at the event occurrence position Pe. In step S308, the processing unit 30 calculates a trigger threshold based on the event occurrence position Pe. The processing unit 30 may calculate the trigger threshold using a pre-created data table or function fitting.

In step S<b>310 , the processing unit 30 writes the calculated trigger threshold to the magnetic sensor 20 . As a result, the detection axis to be used and the trigger threshold are set in the magnetic sensor 20 in step S202. The magnetic sensor 20 does not need to detect magnetic flux densities for axes that are not necessary for trigger threshold determination. The magnetic sensor 20 measures the magnetic field and outputs a trigger signal to the processing unit 30 when the magnetic field exceeds or falls below the set trigger threshold (steps S204 and S206). Then, the processing unit 30 is activated by receiving the trigger signal (step S314).

FIG. 10 shows an example of the configuration of the event detection system 100. As shown in FIG. The event detection system 100 of this example differs from the example of FIG. 2A in that it includes a plurality of magnetic sensors 20 . The event detection system 100 of this example includes two magnetic sensors 20, a magnetic sensor 20a and a magnetic sensor 20b.

The magnetic sensor 20a and the magnetic sensor 20b are arranged in the X-axis direction, which is the movement direction of the magnetic field generator 10. As shown in FIG. The magnetic sensor 20a and the magnetic sensor 20b may be the same type of magnetic sensor or different types of magnetic sensors. The magnetic sensor 20b may or may not overlap the event detectable area of the magnetic sensor 20a.

By providing multiple magnetic sensors 20, the event detection system 100 can further expand the event detectable area. The processing unit 30 may select the magnetic sensor 20 to be used and determine the detection axis from among the selected magnetic sensors 20 by the same process as the process of determining the detection axis when there is one magnetic sensor 20. . Thereby, the event detection system 100 can use the optimum detection axis with the optimum magnetic sensor 20 according to the event occurrence position Pe.

FIG. 11 illustrates an example computer 2200 in which aspects of the invention may be implemented in whole or in part. Programs installed on the computer 2200 may cause the computer 2200 to function as one or more sections of an operation or apparatus associated with an apparatus according to embodiments of the invention, or to Sections may be executed and/or computer 2200 may be caused to execute processes or steps of such processes according to embodiments of the present invention. Such programs may be executed by CPU 2212 to cause computer 2200 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

Computer 2200 according to this embodiment includes CPU 2212 , RAM 2214 , graphics controller 2216 , and display device 2218 , which are interconnected by host controller 2210 . Computer 2200 also includes input/output units such as communication interface 2222, hard disk drive 2224, DVD-ROM drive 2226, and IC card drive, which are connected to host controller 2210 via input/output controller 2220. there is The computer also includes legacy input/output units such as ROM 2230 and keyboard 2242 , which are connected to input/output controller 2220 through input/output chip 2240 .

The CPU 2212 operates according to programs stored in the ROM 2230 and RAM 2214, thereby controlling each unit. Graphics controller 2216 retrieves image data generated by CPU 2212 into itself, such as a frame buffer provided in RAM 2214 , and causes the image data to be displayed on display device 2218 .

Communication interface 2222 communicates with other electronic devices over a network. Hard disk drive 2224 stores programs and data used by CPU 2212 within computer 2200 . DVD-ROM drive 2226 reads programs or data from DVD-ROM 2201 and provides programs or data to hard disk drive 2224 via RAM 2214 . The IC card drive reads programs and data from IC cards and/or writes programs and data to IC cards.

ROM 2230 stores therein programs that depend on the hardware of computer 2200, such as a boot program that is executed by computer 2200 upon activation. Input/output chip 2240 may also connect various input/output units to input/output controller 2220 via parallel ports, serial ports, keyboard ports, mouse ports, and the like.

A program is provided by a computer-readable medium such as a DVD-ROM 2201 or an IC card. The program is read from a computer-readable medium, installed in hard disk drive 2224 , RAM 2214 , or ROM 2230 , which are also examples of computer-readable medium, and executed by CPU 2212 . The information processing described within these programs is read by computer 2200 to provide coordination between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing manipulation or processing of information in accordance with the use of computer 2200 .

For example, when communication is performed between the computer 2200 and an external device, the CPU 2212 executes a communication program loaded in the RAM 2214 and sends communication processing to the communication interface 2222 based on the processing described in the communication program. you can command. The communication interface 2222 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as the RAM 2214, the hard disk drive 2224, the DVD-ROM 2201, or an IC card under the control of the CPU 2212, and transmits the read transmission data. It sends data to the network or writes received data received from the network to a receive buffer processing area or the like provided on the recording medium.

In addition, the CPU 2212 causes the RAM 2214 to read all or necessary portions of files or databases stored in external recording media such as a hard disk drive 2224, a DVD-ROM drive 2226 (DVD-ROM 2201), an IC card, etc. Various types of processing may be performed on the data in RAM 2214 . CPU 2212 then writes back the processed data to the external recording medium.

Various types of information, such as various types of programs, data, tables, and databases, may be stored on recording media and subjected to information processing. CPU 2212 performs various types of operations on data read from RAM 2214, information processing, conditional decision making, conditional branching, unconditional branching, and information retrieval, as specified throughout this disclosure and by instruction sequences of programs. Various types of processing may be performed, including /replace, etc., and the results written back to RAM 2214 . In addition, the CPU 2212 may search for information in a file in a recording medium, a database, or the like. For example, if a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 2212 determines that the attribute value of the first attribute is specified. search the plurality of entries for an entry that matches the condition, read the attribute value of the second attribute stored in the entry, and thereby associate it with the first attribute that satisfies the predetermined condition. an attribute value of the second attribute obtained.

The programs or software modules described above may be stored on computer readable media on or near computer 2200 . Also, a recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable medium, thereby providing the program to the computer 2200 via the network. do.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The execution order of each process such as actions, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is particularly "before", "before etc., and it should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if the description is made using "first," "next," etc. for the sake of convenience, it means that it is essential to carry out in this order. not a thing

10... magnetic field generator, 20... magnetic sensor, 22... detector, 24... output unit, 30... processor, 32... acquisition unit, 34... selector, 36... Calculation unit, 100... Event detection system, 2200... Computer, 2201... DVD-ROM, 2210... Host controller, 2212... CPU, 2214... RAM, 2216... graphic controller, 2218 display device, 2220 input/output controller, 2222 communication interface, 2224 hard disk drive, 2226 DVD-ROM drive, 2230 ROM, 2240 input/output chip, 2242 keyboard

Claims (13)

An event detection method for detecting an event according to the position of a magnetic field generator by detecting magnetic fields of two or more axes generated by a predetermined magnetic field generator with a magnetic sensor,
obtaining an event occurrence position based on the magnetic field detected by the magnetic sensor;
selecting a detection axis for event detection based on the event occurrence position;
calculating a trigger threshold according to the event occurrence position on the detection axis;
An event detection method comprising: obtaining a trigger signal indicating that the magnetic field detected by the magnetic sensor and the trigger threshold satisfy a predetermined condition. moving the magnetic field generator in a predetermined first direction;
The event detection method according to claim 1, comprising selecting a first axis parallel to the first direction or a second axis orthogonal to the first axis as the detection axis. 3. The step of moving the magnetic field generator in a predetermined first direction includes moving the magnetic field generator along the first axis or the second axis so that the magnetic field generator passes over the magnetic sensor. 3. The event detection method according to 2. The step of selecting the detection axis includes:
selecting the first axis when the event occurrence position belongs to a detectable region in which the position of the magnetic field generator can be detected on the first axis;
The event detection according to claim 2 or 3, further comprising selecting the second axis when the event occurrence position does not belong to the detectable area of the first axis but belongs to the detectable area of the second axis. Method. obtaining a reference position of the magnetic field generator;
The event detection method according to any one of claims 1 to 4, comprising: selecting the detection axis based on the reference position and the event occurrence position. calculating the square root of the sum of squares of the magnetic field detected by the magnetic sensor;
The event detection method according to any one of claims 1 to 5, comprising: calculating a trigger threshold corresponding to the event occurrence position using the square root sum of squares. a magnetic field generator that generates a predetermined magnetic field;
a magnetic sensor for detecting the magnetic field generated by the magnetic field generator;
a processing unit that processes the signal detected by the magnetic sensor,
The processing unit is
an acquisition unit that acquires an event occurrence position based on the magnetic field detected by the magnetic sensor;
a selection unit that selects a detection axis for event detection based on the event occurrence position;
a calculation unit that calculates a trigger threshold corresponding to the event occurrence position on the detection axis,
An event detection system comprising an output unit for outputting a trigger signal indicating that the magnetic field detected by the magnetic sensor and the trigger threshold satisfy a predetermined condition. 8. The selection unit according to claim 7, wherein the selection unit selects, as the detection axis, a first axis parallel to a predetermined first direction in which the magnetic field generation unit moves, or a second axis orthogonal to the first axis. event detection system. The event detection system according to claim 8, wherein the magnetic field generator has an N pole and an S pole arranged in the first direction. 10. The event detection system of claim 8 or 9, comprising a plurality of magnetic sensors arranged in the first direction. The event detection system according to any one of claims 7 to 10, wherein the magnetic sensor is a multi-axis magnetic sensor capable of detecting two or more magnetic fields. The processing unit calculates the square root of the sum of squares of the magnetic field detected by the magnetic sensor,
12. The event detection system according to any one of claims 7 to 11, wherein the square root sum of squares is used to calculate a trigger threshold corresponding to the event occurrence position. A program for causing a computer to execute the event detection method according to any one of claims 1 to 6.

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