Method of determining the axial displacement or axial position of a shaft of an electronic control device

Abstract

Method for determining the axial displacement or axial position of a shaft of an electronic control device The present invention relates to a method for determining the axial displacement or axial position of a magnetized shaft, such as a setting stem (3) of a timepiece, of an electronic control device (1). The method is based on a new function obtained by multiplying the norm of the magnetic field generated by the magnetized shaft by a selected compensation function that depends only on the angle of rotation of the shaft in a plane orthogonal to the axis of rotation of the shaft. The main advantage of introducing the compensation function is that it is possible to simplify the processing of the measurement and strongly minimize the required memory resources, as there is no need to store a large number of different curves corresponding to different angle positions, which would have been necessary if the norm had been used directly to determine the axial displacement / position. By applying the proposed method using the new function, the axial displacements / positions of the shaft can be detected in a sufficiently precise manner, preferably by using a single magnetic sensor.

Description

Technology Field

[0001] The present invention relates to a method for determining the axial displacement or axial position of a shaft of an electronic control device. The shaft may be, for example, a setting stem of a timepiece. The present invention focuses on a magnetic crown stem associated with an electronic control module comprising a magnetometer, wherein the magnetic field of a magnet attached to the stem is measured to determine the axial position / displacement of the stem. The present invention also relates to an apparatus configured to carry out the method. Background Technology

[0002] In a first type of electronic crown stem, the axial position of the stem is generally determined by electrical contacts that close or open at stable mechanical positions of the stem, designated as T1, T2, and T3, where T1 refers to the idle position, T2 refers to the date setting position, and T3 refers to the time setting position. If the electronic control device also causes the stem to act as a press button, an additional position T0 is defined, which refers to the position where the crown is pressed and the stem contacts the end electrical contacts. These electrical contacts are mechanically actuated by many parts of relatively high complexity that contact the stem.

[0003] In a specific electronic control device equipped with a magnet for detecting rotation of a crown stem, the magnet forms a sliding portion to maintain its axial position as the stem moves. The sliding portion has a central hole with a square profile, and the stem includes at least a portion having a corresponding square section passing through the square hole so that the magnet is driven by rotation by the stem. A major disadvantage of the solution described above is that as many electrical contacts as there are stable positions of the stem, they are required. The electrical contacts must not undergo oxidation over time and must withstand shock. Furthermore, the number of mechanical parts is large, and their assembly is relatively complex and expensive.

[0004] In a second type of electronic crown stem having a magnetic system, the magnet is attached to the stem and moves axially and rotationally together with the stem. The detection of the stem's rotation is implemented at position (T1) using a magnetometer. Pressing the crown activates the end switch (position (T0)). Thus, the crown stem is used as a pusher, and when the switch is pressed, it can be determined that the crown stem is in position (T0). When the crown is pressed to activate the switch, the stem often rotates involuntarily while the rotation of the stem is still detected by the magnetometer. This involuntary rotation can be interpreted by the watch as an action to be undertaken before pressing the switch (verification for inputting a selected item) (e.g., changing the selected item in a displayed menu).

[0005] European Patent EP 3210083 B1 relates to a method for detecting the angular position of a magnet fixedly mounted on a control stem, wherein the magnet is radially magnetized. The detection of the axial position of the magnet is mentioned only very briefly and is not described. The method proposed in EP 3210083 B1 is based on measurements of three magnetic field components of the magnetic field generated by the magnet, and the magnetic field vector describes ellipses for different axial positions and full rotations of the magnet, as illustrated in FIG. 1. When these ellipses are projected onto a two-dimensional (2D) plane (XY), the resulting 2D curves remain elliptical, as illustrated in FIG. 2. To accurately determine the angular position of the control stem, it is instead necessary to have circular curves in the XY plane. For this purpose, the magnetic field vector is projected onto a two-dimensional (2D) plane (XY) using a given transformation matrix. However, as can be seen in FIG. 3, for a pre-selected transformation matrix, the projection describes a circle only for a given axial position of the magnet / stem. Projections for other axial positions describe an ellipse. Although not mentioned in EP 3210083 B1, it can be assumed that the radii of the two circles shown in FIG. 3 of this patent document are used for the detection of axial displacement / position (the radius decreases as the rod and thus the magnet move away from the magnetic sensor / magnetometer). However, as mentioned, it is observed that a circle is obtained only for a given axial position with a pre-selected transformation matrix. Therefore, for all other axial positions, first, there is inaccuracy in the detection of the stem's rotation angle value, and second, since the length of the projected measured magnetic field vector also depends on the rotation angle, it cannot provide an accurate axial position, and such a vector describes an ellipse by changing the rotation angle over 360°.Consequently, unless the axial position of the stem is known, the axial position of the stem cannot be accurately determined, and furthermore, the angular position of the stem cannot be accurately determined either. Therefore, the method for determining the axial position proposed in document EP3210083B1 is, first of all, unclear and lacks detailed descriptions. Additionally, the teachings of this patent document do not leave to those skilled in the art the means to efficiently and accurately measure magnets, particularly bipolar magnets, and thus the axial position of the stem. The problem to be solved

[0006] The object of the present invention is to overcome at least some of the aforementioned disadvantages of existing solutions of magnetized control rods or shafts. Accordingly, the object of the present invention is to provide a solution for determining the axial displacement or axial position of a shaft of an electronic control device, such as a crown stem array of a watch. means of solving the problem

[0007] According to a first aspect of the present invention, a method is provided for determining the axial displacement or axial position or control value of a shaft of an electronic control device for a given function or operation, depending on the axial displacement or axial position of the shaft as described in claim 1.

[0008] The present invention has the advantage of enabling the detection of the axial displacement or axial position of the crown stem with a relatively high level of certainty (when the present invention is applied to a watch) without using electrical contacts and corresponding mechanical parts.

[0009] In a specific mode, the present invention enables the detection of axial displacement or axial position of a shaft to prevent or ignore the detection of shaft rotation, to avoid taking involuntary actions regarding shaft rotation, or to adjust the intensity of the function of an electronic watch.

[0010] Software implementation in a microcontroller or digital signal processor for determining the axial displacement or axial position of a stem is relatively simple. Furthermore, most magnetometers have three measurement axes, which, therefore, allows these magnetometers to be used for determining the axial displacement according to the present invention without incurring additional costs by adding a sensor dedicated solely to measuring the axial displacement.

[0011] According to a second aspect of the present invention, an electronic control module for determining the axial displacement or axial position of a shaft of an electronic control device is provided as described in claim 12. According to a third aspect of the present invention, a timepiece comprising an electronic control module is provided. Other aspects of the present invention are described in the appended dependent claims. Brief explanation of the drawing

[0012] Other features and advantages of the present invention will become apparent from the following description of non-limiting exemplary embodiments with reference to the accompanying drawings. - Figure 1, which has already been described, illustrates measurements of 3D components of a magnetic field as a function of the rotation angle of a bipolar magnet having a radial magnetization axis (two magnetic polarities are radially opposite) and the axial position of the magnet, according to EP 3210083 B1. - Figure 2, which has already been described, illustrates measurements of 2D components of a magnetic field as a function of the rotation angle of a bipolar magnet and the axial position of the magnet, according to EP 3210083 B1. - Figure 3, which has already been described, illustrates the 2D components of a magnetic field projected onto the XY plane by using a transformation matrix to have a circle at z = 0.0 in this plane as a function of the rotation angle of the bipolar magnet and the axial position of the magnet according to EP 3210083 B1. - FIG. 4 illustrates an example of an electronic control device according to the present invention in an isometric view. - FIG. 5 illustrates values ​​for the magnetic field component x as a function of the rotation angle of the setting stem and the axial displacement / position of the setting stem in the electronic control device of FIG. 4. - FIG. 6 illustrates values ​​for the magnetic field component y as a function of the rotation angle of the setting stem and the axial displacement / position of the setting stem in the electronic control device of FIG. 4. - FIG. 7 illustrates values ​​for the magnetic field component z as a function of the rotation angle of the setting stem and the axial displacement / position of the setting stem in the electronic control device of FIG. 4. - FIG. 8 shows values ​​for the norm of the magnetic field as a function of the axial displacement / position and rotation angle of the setting stem in the electronic control device of FIG. 4. - FIG. 9 illustrates compensation functions that compensate for the dependence of the magnetic field norm on the rotation angle for three different axial positions, each depending on the rotation angle of the setting stem. - FIG. 10 illustrates values ​​for functions (G(z,θ)) identical to the magnetic field norm multiplied by a single selected compensation function, used in the first mode of the present invention to select the relationship between the possible values ​​of these functions and the corresponding axial displacements / positions of the setting stem for all possible rotation angles of the setting stem in the electronic control device of FIG. 4. - FIG. 11 illustrates values ​​for functions (G(z,θ)) identical to the magnetic field norm multiplied by another single selected compensation function, used in the second mode of the present invention to select the relationship between the possible values ​​of these functions and the corresponding axial displacements / positions of the setting stem for all possible rotation angles of the setting stem in the electronic control device of FIG. 4. - Figure 12 is a flowchart summarizing the steps of the proposed method. Specific details for implementing the invention

[0013] Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention will be described in the context of detecting axial displacement or axial position of a shaft of an electronic control device of a timepiece, wherein the shaft in this example is a setting stem associated with an outer crown of the electronic control device. An electronic control device as described below comprises at least a crown, a setting stem, a magnetic element integrally mounted on the stem, and an electronic control module formed by a magnetometer and a signal processor. In this configuration, a magnetic field is generated by the magnetic element of the rotating stem. However, the teachings of the present invention are not limited to such environments or applications.

[0014] Identical or corresponding functional and structural elements appearing in different drawings are assigned the same reference numerals. As utilized herein, "and / or" means any one or more of the items in the list combined by "and / or". In one example, "x and / or y" means any element of the set of three elements {(x), (y), (x, y)}. That is, "x and / or y" means "one or both of x and y". In another example, "x, y and / or z" means any element of the set of seven elements {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. That is, "x, y and / or z" means "one or more of x, y, and z". Furthermore, the term "comprising" is used herein as an open term. This means that while the object encompasses all listed elements, it may also include additional unnamed elements. Therefore, the word "equip" is interpreted in the broader sense of "include," "contain," or "impose."

[0015] In this description, a magnetic field is a vector field that describes the magnetic effects of electric currents and magnetized materials. The term "magnetic field" is sometimes used for two distinct but closely related fields denoted by the symbols B and H. H is measured in amperes per meter, and B is measured in Tesla, which is equivalent to Newtons per meter per ampere. H and B differ in the way they describe magnetization. In a vacuum, B and H are identical except for their units, but in magnetized materials, they differ by the magnetization (M) of the material. In the following description, the magnetic field is expressed as B, but H may be used interchangeably.

[0016] FIG. 4 illustrates an example of an electronic control device (1) to which the teachings of the present invention may be applied. A rotatable element or shaft (3) is illustrated, which, in this example, is a setting stem of a timepiece such as a wristwatch. The stem (3) defines a rotation axis (5) that coincides with the center or longitudinal axis of the stem (3). Such a setting stem is also known as a crown stem. Thus, the rotatable element (3) (i.e., the stem) of this example may be a small, elongated piece having a diameter in the range of, for example, 0.5 mm to 1 mm. The stem (3) is provided with a magnet (7), which is assembled with the stem to be integral in rotation and axial displacement in the stem and its inner end region (i.e., at the end of the setting stem opposite the crown and located in the timepiece case, where the setting stem is terminated by the crown). In this example, the magnet is configured as a ring through which the stem passes. The magnet (7) is preferably a bipolar permanent magnet having radial magnetization, and the two magnetic polarities are radially opposite relative to the axis of rotation (5), and is hereinafter referred to as a ‘bipolar magnet’ or simply a ‘magnet’.

[0017] The stem (3) and thus the magnet (7) have only two degrees of freedom, one rotating about the axis of rotation (5) and the other translating along this axis of rotation (5). The angle of rotation of the magnet and thus the stem is denoted by θ, and the axial displacement / position of the magnet and thus the stem is denoted by z along the axis of rotation.

[0018] A magnetometer (9) mounted on a circuit board (11), particularly a printed circuit board (PCB), measures the magnetic induction fields of a magnet along three orthogonal axes (X, Y and Z), and the reference frame of this magnetometer, each, B x , B y and B zIt forms a Z-axis parallel to the axis of rotation (5) of the stem and thus the magnet, and the plane XY is perpendicular to the axis of rotation (5). In this example, the center of the magnetometer located at the origin of the reference frame defines a zero position (z = 0) for the bipolar magnet (7) and thus the stem along the axis of rotation; that is, the crossing of the XY plane by the axis of rotation (5) defines an axial position zero (z = 0) for the magnet and thus the stem (3). In this example, an optional switch (13) is also provided for selectively enabling and disabling the magnetometer and / or activating selected functions of the timepiece.

[0019] The magnetic field lines generated by the magnet (7) affect a magnetometer (9), which is a 3-axis sensor device that measures the incident magnetic field along three measurement axes, namely the X, Y, and Z axes. The magnetometer (9) may be, for example, a small surface-mount device (SMD) that is fitted to the PCB (11) and connected to the PCB via SMD connections.

[0020] In this example, the magnetometer (9) is a Hall effect sensor device, which is a device used to measure the magnitude or strength of a magnetic field. The output voltage of the Hall sensor is directly proportional to the magnetic field strength through it. The magnetometer (9) has a first magnetic field component (B) along the first axis, which is the X-axis in this case. x The intensity of ), in this case, a second magnetic field component (B) along the second axis, which is the Y-axis. y The intensity of ), and in this case, a third magnetic field component (B) along the third axis, which is the Z-axis. zThey are arranged to determine the strength of ). In this example, these three axes are orthogonal to each other. A temperature sensor (not shown in the drawings) may be additionally provided to measure the temperature. The temperature sensor may, if provided, be integrated into, for example, the magnetometer (9). The behavior of the Hall sensors typically depends on the temperature at which they operate. Instead of a system containing a single 3-axis magnetometer, for example, each is a magnetic field component (B x , B y and B z It should be noted that it may include three independent magnetic field sensors configured to measure one of the different ones. In this case, all three sensors may or may not be in the same plane.

[0021] According to the present invention, a method for determining the axial displacement or axial position of a magnet (7) along a rotation axis (5) and thus a stem (3) comprises components (B) of a magnetic induction field. x , B y and B z It is based on the measurement of ). These magnetic field components depend on the rotation angle (θ) of the bipolar magnet, but also depend on the position of this magnet along the rotation axis (5), which is parallel to the Z-axis but away from the rotation axis. The symbol θ is used interchangeably in this description for both the rotation angle of the magnetic field (and thus of the magnet (7)) and the rotation angle of the stem (3). Magnetic field components (B) as a function of the rotation angle (θ) of the magnet x , B y and B zThe values ​​of ) for three different axial displacements / positions (z = 0.0 mm, z = 0.5 mm, and z = 1.0 mm), respectively, can be seen in FIGS. 5, 6, and 7. The magnetic field components are compensated for hard iron coefficients to eliminate effects caused by parasitic magnetic fields and possibly temperature fluctuations. That is, the main actions of the compensation are as follows: eliminating offsets caused by the manufacturing of the Hall sensors; eliminating distortions caused by the presence of parasitic fields, particularly those generated by the circuit board hosting the magnetometer; and possibly further eliminating the effects of temperature. FIGS. 5, 6, and 7 illustrate the values ​​of the compensated magnetic field components.

[0022] When taken independently, these components are not sufficient to detect the axial displacement or axial position of the magnet. Additionally, component (B z ) has two zero crossings per rotation of the magnet. However, if we take the norm of the magnetic field (in this example, the Euclidean norm), that is,

[0023] ,

[0024] An interesting behavior is obtained, namely that as the magnet (7) moves further along the axis of rotation from the magnetometer (9), its value decreases. Furthermore, the value of the norm is never zero. This is illustrated in FIG. 8. In practice and for reasons of computational savings, the square root is often not calculated, and the square of the norm is used. However, in this example, the norm is calculated and used.

[0025] As can be seen in FIG. 8, the value of the norm depends not only on the axial displacement / position but also strongly on the rotation angle (θ). To avoid or minimize this angular dependence, the method introduces a first function (F(θ)), also referred to as a compensation function, which depends only on the rotation angle / angular position (θ). That is, the value of the selected compensation function does not depend on the axial displacement / position. The compensation function is selected to obtain a second function (G(z,θ)) which, when the norm of the magnetic field is multiplied by the compensation function, depends predominantly on the axial position of the shaft (stem) and depends less on or not on the rotation angle of the shaft:

[0026]

[0027] This second function (G(z,θ)) is shown in FIGS. 10 and FIGS. 11 along the rotation axis (5) (where z is used as a variable along the rotation axis parallel to the Z-axis) for two different specific compensation functions, respectively, where the envelopes of all possible curves of G(z,θ) resulting from the dependence of the second function (G(z,θ)) on the angle position (θ) for all angle positions (θ) are shown. The two different specific compensation functions will be described later in this description. In these figures, it can be seen that the variance of the second function (G(z,θ)) for all rotation angles / angle positions is much smaller than the corresponding variance for the norm.

[0028] The method continues with a second function (G(z,θ)) because it is possible to determine the axial displacement or position (z) of the magnet (7) / stem (3) with sufficient precision for several applications by selecting only one specific compensation function (F(θ)) (named 'compensation function') for each specific application. The main advantage of introducing the compensation function is that it is possible to simplify the processing of measurements and strongly minimize the required memory resources, as there is no need to store a large number of different curves corresponding to different rotation angles / angle positions, since this would have been necessary by using a norm directly to determine the axial displacement / position (see FIG. 8).

[0029] Desirable individual compensation function (F z (θ)) is graphically represented in FIG. 9 for axial positions (z) from 0.0 mm (individual compensation function with maximum amplitude) to 1.0 mm (individual compensation function with minimum amplitude), where it can be seen that these individual compensation functions depend to some extent on the axial position. Between the two extreme compensation functions (corresponding to z = 0.0 mm and z = 1.0 mm, respectively), for a given position range (0.0 mm to 1.0 mm), a specific compensation function (F) corresponding to each angular position for the average / median of all individual compensation functions across the axial position (z) is given. m (θ)) is expressed. Therefore, the function (F m (θ)) corresponds to either the mean reward function or the median reward function.

[0030] All desirable individual compensation functions are general compensation functions (F) that depend on the axial position (z) and the angular position (θ). G is defined by (z,θ):

[0031]

[0032] However, the axial position is, by definition, unknown prior to the method being performed, and the method is actually implemented to determine the axial displacement / position of the magnet / stem. Accordingly, the method of the present invention advantageously has a preferred general compensation function (F) illustrated in FIG. 9. G (z, θ)(z = 0.0 mm and z = 1.0 mm, two extreme compensation functions (F z A single specific compensation function (F(θ)) is selected based on (θ) being expressed, and all other desirable individual compensation functions being located between them).

[0033] A single specific compensation function (referred to as the 'compensation function'), i.e., its amplitude, is specific to each electronic control device of the present invention. According to a preferred embodiment of the present invention, a single specific compensation function (F(θ)) is selected in relation to the application in which the axial displacement / position determination method is implemented. For example, if the method is used to detect distinct axial displacements / positions of the stem according to a first mode, such as stable positions (T1, T2, and T3), an average / intermediate compensation function (F m (θ)) may be favorably selected. This compensation function is as follows:

[0034]

[0035] This means that for the first mode, as can be seen in FIG. 10, an average or median value (shown as a solid line in FIG. 9) is taken to minimize the deviation over the entire displacement / position range (z = 0.0 to 1.0 mm) in the corresponding second function (G(z, θ)) due to the angular position. In FIG. 10, for the compensation function (F(θ)), an average / median compensation function (F mFor a second function (G(z,θ)) as a function of axial position (z) by selecting (θ), curve (UC1) is the upper limit and curve (LC1) is the lower limit. Based on these upper and lower limit curves (UC1 and LC1), the method establishes / selects a relationship between the values ​​(g) of G(z,θ) and the axial positions (z) based on all angular positions (θ). Generally, the method selects a relationship between control values ​​that establishes a first set of possible second values ​​and a second set of possible axial displacements or axial positions or / and for each second value of the first set, a corresponding axial displacement or axial position of the shaft or a corresponding range or corresponding control value of the axial displacements or positions of the shaft.

[0036] In the example provided in FIG. 10, the three position ranges (R1, R2, and R3) are defined for positive values ​​of the axial positions (z) of the stem around three corresponding distinct stable axial positions (T1, T2, and T3) that the stem may have. The position ranges (R1, R2, and R3) are selected to cover all possible positions without overlap and with sufficient margin for the individual axial positions (T1, T2, and T3), taking into account the manufacturing tolerances of the various elements forming the electronic control device and also the tolerances arising from the assembly of these elements. It should be noted that for each range (Rn, n=1,2,3), there is a corresponding range (Pn, n=1,2,3) that includes all possible values ​​(g) of the second function (G(z,θ)) for this range (Rn). Conversely, the range (Rn, n=1,2,3) does not include all possible values ​​(z) for the individual ranges (Pn) of G(z,θ). Advantageously, the selected relationship defines distinct non-overlapping ranges (Pn) of g values ​​for the corresponding axial position ranges (Rn) of the axial positions. That is, the ranges (Pn) of the second values ​​are distinguished so that the ranges of the second values ​​do not overlap with each other. This is illustrated in FIG. 10. Thus, for any possible second value, there exists only one position range (Rn) and a corresponding axial position (Tn).

[0037] Meanwhile, a different compensation function may be selected if a displacement / position determination method is used according to a second mode to detect the axial displacement of the stem (3) from position (T1) to position (T0), for example, to disable the determination of the rotation angle of the stem (3) or to ignore the determination of the rotation angle of the stem (3) when the stem is pressed by the user. This type of operation is particularly useful when different menus are displayed by rotating the stem in a given position of the stem (typically the unpressed position of the stem), while the pressure of the stem in a second position of the stem (typically the pressed position of the stem) is used, for example, to select a given function or input a menu. In this example, when the stem is pressed, the user may inadvertently rotate the stem at the same time, which will result in different menus unless rotation detection is disabled or ignored. In this scenario, the compensation function (F(θ)) can be defined as follows, where the pressure of the stem in the initial phase can be determined by taking a value z = P to be more accurate at the start of the displacement from the axial position (P):

[0038]

[0039] If the pressure function is intended from the axial position (T1) (around z=0), z=0 is introduced into the compensation function as shown in FIG. 11. For the compensation function (F(θ)), a compensation function (F) having P=0. P By selecting (θ)), for the second function (G(z,θ)) as a function of the axial position (z), curve (UC2) is the upper bound and curve (LC2) is the lower bound. The threshold value (g) for G(z,θ) Th ) may also be selected, and below that threshold, the detection of stem rotation should no longer be considered. This is exemplified in Fig. 11, where negative position values ​​along the rotation axis are illustrated. That is, the threshold value (gTh ) is defined for G(z,θ), and the method includes disabling or ignoring the determination of the rotation angle of the shaft / stem (3) when the value (g) of G(z,θ) is below a threshold value.

[0040] Accordingly, as described, the compensation function can advantageously be performed depending on the use case or application of the displacement or position determination method.

[0041] Once the compensation function (F(θ)) has been selected and once the current rotation angle (θ) of the stem has been measured, the value of the second function (G(z,θ)) can be calculated. It should be noted that the rotation angle may be measured or determined in accordance with the teachings of EP3705902A1. As described in EP3705902A1, the value of the current rotation angle of the stem in a plane orthogonal to the axis of rotation of the shaft is two of the magnetic field components orthogonal to the axis of rotation, namely, components (B x , B y It is determined based on ). Then, the value of G(z,θ) is the current rotation angle (θ c When ) is first applied to the compensation function (F(θ)), the measured magnitude (N) of the magnetic field c ) is the value of the compensation function (g c It can be calculated by multiplying by ).

[0042] The compensation function is selected such that the values ​​(g) of G(z,θ) depend predominantly on the axial position (z) of the shaft and depend relatively less or no on the rotation angle (θ) of the shaft. The upper and lower curves represent the uncertainty for any value (g) of the axial displacement / position.

[0043] In short, if the proposed method is used to detect stable mechanical positions such as positions (T1, T2 and / or T3) (first mode), a set of non-overlapping ranges of values ​​(P1, P2 and P3) for a second function (G(z,θ)) corresponding to these stable positions of the stem including possible errors / mispositioning may be defined as further illustrated in FIG. 10. If rotation detection is prevented (second mode), a threshold value (g) for G(z,θ) Th Select ), and below that threshold, the value of the angle should no longer be considered. This is exemplified in Fig. 11.

[0044] The flowchart of FIG. 12 summarizes the method for determining the axial displacement or axial position of at least partially magnetized stem of an electronic control device. In step 101, first, second, and third magnetic field components, which are, in this case, orthogonal to each other, are measured by a magnetometer (9). This step generally includes a step of compensating the magnetic field components to account for the inflection coefficients. In step 102, the current rotation angle value (θ) of the stem (3) in a plane orthogonal to the rotation axis (5) of the stem c The )(current angle position) is determined based on at least two of the magnetic field components orthogonal to the axis of rotation. In step 103, the current norm (N) as the square or non-square of the magnetic field c This is calculated based on the first, second, and third magnetic field components: The guy depends on the axial displacement of the shaft along the axis of rotation and the angle of rotation of the shaft.

[0045] In step 104, a first function (F(θ)), referred to as a compensation function, is selected for at least a mode / application, for example, for the aforementioned first and second modes, and in such case, an appropriate mode is selected for the current mode (detection of an axial position among a set of possible stable axial positions or detection of activation of a press button function). The selected compensation function depends on the rotation angle of the shaft but does not depend on the axial displacement of the shaft. In step 105, a first value (V), referred to as a compensation function value c ) is the current rotation angle value (θ c For ), this is determined by applying the current rotation angle value to the selected compensation function: . Acquired value (V c ) is stored in the memory of the electronic crown module.

[0046] In step 106, the second value of the aforementioned second function is calculated by multiplying the calculated value of the magnetic field by the determined value of the compensation function: According to the present invention, the compensation function is selected such that the second function depends predominantly on the axial position of the shaft and depends relatively less or no on the rotation angle of the shaft. In particular, the compensation function is defined such that, for example, as illustrated in FIG. 10 and FIG. 11, the bundle of second functions (G(z,θ)) is defined sufficiently narrowly so that G(z,θ) can provide a relatively good approximation for the axial position (z) for all θ and thus allow the determination of the position (z) with a relatively low margin of error, thereby clearly distinguishing between given distinct positions (T1, T2, T3), or the stem (3) allows activation of the function to prevent, for example, premature selection of the function from the menu through rotation of the stem, a specific threshold value (D) ThIt is particularly possible to determine whether pressurization has been applied exceeding ). In practice, the present invention relies on extreme curves, namely upper and lower curves, for positions (T1, T2, and T3) having the margin of error. For pressure detection, the present invention generally relies on the lower curve, given a threshold value (g Th For values ​​of g smaller than ), the stem at least has the corresponding displacement value (D) given by this lower curve. Th This is because it can be concluded that it is pressurized by ).

[0047] In step 107, a relationship is selected between control values ​​that establish a first set of possible second values ​​and a second set of possible axial displacements or axial positions, or / and for each second value of the first set, a corresponding axial displacement or axial position of the shaft or a corresponding range or corresponding control value of the axial displacements or positions of the shaft. The control values ​​relate to the adjustment of the function or operation of the timepiece. More specifically, the control values ​​in this example may provide intensity adjustment for the function of the timepiece, depending on the axial displacement or axial position of the shaft. It should be noted that the second function (G(z)) may not be used directly, but rather the present invention may simply use ranges defined by the lower and upper curves (envelopes), namely g -> Rz, where Rz is the range of possible axial positions for a given value (g) of the second function (G(z)). Thus, a relationship between g and z is selected, but by definition, it does not need to be a function that provides a single value of z for each g. Furthermore, for a mode connected to the detection of pressure for a stem having at least that specific displacement, the algorithm uses the acquired g c The axial displacement (z) is not determined from the value of , but instead, the current value (g cThe function command is determined directly based on ). Although there is an implicit connection with the stem's axial position, in this case, the algorithm operates such that there is no specific step to determine the axial displacement (z) before the action.

[0048] In step 108, the axial displacement or axial position (z) of the shaft relative to the sensor array (9) c ), or control value, the calculated second value (g c It is determined by applying ) to the selected relationship between the first set and the second set.

[0049] The data processing steps of the method described above may be executed by a digital signal processor (DSP), which are, therefore, computer-implemented processing steps. The DSP may be part of a magnetometer or may be a standalone device. The DSP may also include memory, or a standalone memory unit may be used, for example, to store different functions and measurement values.

[0050] Accordingly, the solution proposed by the present invention enables the detection of the axial displacement or axial position of the stem in an analog manner without electrical contacts. When the magnetometer (9) and the angle determination algorithm operate during the movement of the stem (3), the angle of the crown and then the axial position can be known with sufficient accuracy to clearly determine specific axial positions or axial position ranges using a single electronic component configured to perform the necessary calculations. Then, in particular, by eliminating the mechanical complexity of the electrical contacts, it is possible to detect the adjustment positions (T1, T2, and T3) (for the first mode). Regarding the second mode, when the crown is pressed to reach T0 to verify the operation or enter the menu, a slight rotation of the crown may occur to generate an angle increment sufficient to cause an involuntary change of the menu in the watch. By monitoring the axial position of the crown according to the method of the present invention, rotation detection can be prevented or ignored once a given axial displacement or axial position value is reached in order to avoid an involuntary change of the menu.

[0051] In the above regard, at least the following use cases are possible application scenarios of the present invention: detection of distinct positions of the stem (e.g., T1 to T3) according to the first mode, particularly preventing or ignoring angle detection during the axial movement of the stem when selecting a function (menu) by pressing the crown (second mode 2), and intensity adjustment of the electronic watch function (third mode). The intensity adjustment function may involve moving the hands of the watch slower or faster when setting the time, or may be served as an interface for a game, for example.

[0052] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustrations and descriptions should be considered exemplary or typical rather than limiting, and the present invention is not limited to the disclosed embodiments. Other embodiments and variations may be understood and achieved by those skilled in the art when practicing the claimed invention based on the study of the drawings, the disclosure, and the appended claims.

[0053] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude the plural. The mere fact that different features are described in mutually distinct dependent claims does not indicate that a combination of these features cannot be used advantageously. Any reference numerals in the claims should not be interpreted as limiting the scope of the invention.

Claims

Claim 1 A method for determining a control value for a given function or operation by means of a magnetic sensor array (9) and a processing unit that collectively form an electronic control module, wherein the method comprises the following steps performed by the electronic control module: a step (101) of measuring first, second, and third magnetic field components of the magnetic field generated by the permanent magnetization member along the first, second, and third axes connected to the magnetic sensor array, wherein the third axis is parallel to the displacement axis; and a step of compensating the first, second, and third magnetic field components for the coefficients; - a current rotation angle value (θ) of the shaft (3) in a plane orthogonal to the displacement axis (5) of the shaft based on the first and second compensated magnetic field components. c Step (102) of determining ) - squared or non-squared norm (N) of the magnetic field based on the first, second, and third compensated magnetic field components c As a step (103) for calculating ), the norm is the norm (N) of the magnetic field which depends on the axial position of the shaft along the displacement axis (5) and the rotation angle of the shaft (3). c A step (103) of calculating ) - a step (104) of selecting a compensation function (F(θ)) that depends on the rotation angle (θ) of the shaft (3) but does not depend on the axial displacement or axial position (z) of the shaft; - the current rotation angle value (θ c With respect to ), by applying the current rotation angle value to the compensation function, a first value (V) referred to as the compensation function value is obtained. c Step (105) for determining ) - the calculated value (N) of the magnetic field c ) and the determined above compensation function value (V c By multiplying by ), the second value (g c As a step (106) of calculating ), the compensation function is selected such that the second value (g) depends on the axial position of the shaft and does not depend on the rotation angle of the shaft. c A step of calculating ) (106); - a step of selecting a relationship between a first set of possible second values ​​and a second set of possible axial displacements or axial positions or / and control values ​​(107), wherein the control values ​​depend on the possible axial displacements or axial positions to establish a corresponding axial displacement or axial position of the shaft or a corresponding range of axial displacements or positions of the shaft or a corresponding control value for each second value of the first set, the first set and the second set or / and control values; - the calculated second value (g c A step (108) of determining the axial displacement or axial position of the shaft, or the control value, for the magnetic sensor array (9) by applying the selected relationship between the first set and the second set. Claim 2 In claim 1, the step of selecting the relationship between the first set and the second set is a method for determining the axial displacement or axial position or control value of the shaft, which establishes a corresponding range of second values ​​for each of the possible stable axial positions of the shaft (3). Claim 3 A method for determining an axial displacement or axial position or control value of a shaft, wherein the ranges of the second values ​​are distinguished so as not to overlap each other. Claim 4 In claim 1, the step of selecting the relationship is a threshold value (g) for the second value. Th A method for determining the axial displacement or axial position or control value of a shaft, comprising the step of defining ) and the step of determining the axial displacement or axial position or the control value, wherein the step of determining the axial displacement or axial position or the control value includes the step of disabling or ignoring the determination of the rotation angle of the shaft (3) when the second value is less than or equal to the threshold value. Claim 5 A method for determining an axial displacement or axial position or control value of a shaft, wherein the control values ​​in the step of selecting the relationship provide strength adjustment for the function of a timepiece integrating an electronic control device including the shaft and the electronic control module, depending on the axial displacement or axial position of the shaft. Claim 6 A method for determining an axial displacement or axial position or control value of a shaft, wherein, in any one of claims 1 to 5, the compensation function is selected based on how the axial displacement or position of the shaft is used. Claim 7 In paragraph 2 or 3, the compensation function (F(θ)) is as follows: In the formula, z represents the axial displacement or axial position along the rotation axis (5) of the shaft (3), and θ represents the rotation angle of the shaft (3) in a plane orthogonal to the rotation axis (5). A method for determining the axial displacement or axial position or control value of a shaft representing the above magnetic field. Claim 8 In paragraph 4, the above compensation function (F(θ)) is as follows: In the equation, θ represents the rotation angle of the shaft (3) in a plane orthogonal to the rotation axis (5), and z = P represents a given axial displacement or axial position along the rotation axis (5) of the shaft (3) where axial displacement is to be detected. A method for determining the axial displacement or axial position or control value of a shaft representing the above magnetic field. Claim 9 A method for determining the axial displacement or axial position or control value of a shaft, wherein the axial position P = 0, in claim 8. Claim 10 A method for determining an axial displacement or axial position or control value of a shaft, wherein, in any one of claims 1 to 5, 8 and 9, the magnetic sensor array is a 3-axis magnetometer (9) or is formed by three sensors, each configured to determine a different component among the magnetic field components. Claim 11 A method for determining an axial displacement or axial position or control value of a shaft, wherein, in any one of claims 1 to 5, 8 and 9, the electronic control module is integrated into a timepiece, the shaft (3) is a setting stem associated with the crown of the timepiece, and the permanent magnetization portion of the shaft is a bipolar magnet fixed to the shaft and having radial magnetization. Claim 12 An electronic control device (1) for determining a control value for a given function or operation depending on an axial displacement or axial position along a displacement axis (5) of a shaft (3), or said axial displacement or axial position of said shaft, wherein the shaft is provided with a permanent magnetization unit (7) and configured to rotate around a displacement axis, and the electronic control device includes a control module comprising a magnetic sensor array (9) and a processing unit, and the electronic control module includes the following means: - means for measuring first, second, and third magnetic field components of a magnetic field generated by said permanent magnetization unit along an orthogonal first axis, a second axis, and a third axis connected to said magnetic sensor array, said means for measuring the first, second, and third magnetic field components of said magnetic field, said third axis being parallel to said displacement axis; and means for compensating the first, second, and third magnetic field components for the coefficients; - a current rotation angle value (θ) of the shaft (3) in a plane orthogonal to the displacement axis (5) of the shaft (3) based on the first and second compensated magnetic field components c Means for determining ) - the norm (N) of the squared or non-squared magnetic field based on the first, second, and third compensated magnetic field components. c As a means of calculating ), the norm is the norm (N) of the magnetic field, which depends on the axial position of the shaft along the displacement axis (5) and the rotation angle of the shaft (3). c Means for calculating ) - Means for selecting a compensation function (F(θ)) that depends on the rotation angle (θ) of the shaft (3) but does not depend on the axial displacement or axial position (z) of the shaft; - Means for selecting the current rotation angle value (θ c With respect to ), by applying the current rotation angle value to the compensation function, a first value (V) referred to as the compensation function value is obtained. c Means for determining ) - a second value (g) by multiplying the calculated value of the magnetic field by the determined compensation function value c As a means for calculating ), the compensation function comprises the second value (g) which is selected such that the second value depends on the axial position of the shaft and does not depend on the rotation angle of the shaft. c Means for calculating ) - means for selecting a relationship between a first set of possible second values ​​and a second set of possible axial displacements or axial positions or / and control values, wherein the control values ​​depend on the possible axial displacements or axial positions to establish a corresponding axial displacement or axial position of the shaft or a corresponding range or corresponding control value of the axial displacements or positions of the shaft for each second value of the first set; and - means for determining the axial displacement or axial position of the shaft or the control value for the magnetic sensor array (9) by applying the calculated second value to the selected relationship between the first set and the second set. Claim 13 A timepiece comprising the electronic control device described in paragraph 12.

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