DE202022102574U1 - Calibration aid - Google Patents

Abstract

Calibration device (11) for calibrating an inertial measuring sensor system (4) of an electronic pen (1), comprising:
a housing (12) for holding an electronic pen (1),
wherein the housing (12) has at least one holding means (6, 7) for fixing an electronic pen (1) received by the housing (12).

Description

State of the art

The invention relates to a device for calibrating an inertial measuring sensor system of an electronic pen, a system comprising an electronic pen and a device for calibrating an inertial measuring sensor system of the electronic pen.

When detecting movements and positions of an electronic pen using inertial measuring systems, such as acceleration sensors or rotation rate sensors, the data from said sensors must be integrated once or twice in order to produce a speed signal or angle signal (first integration) or a location signal (second integration). to obtain an electronic pen. Small errors in the measurements of accelerations and/or angular velocities by the inertial measuring sensors of the electronic pen can lead to larger errors in the determination of the speed during the first integration, which in turn lead to even larger errors in the location signal that increase quadratically over time after integration of the Speed signal can lead.

For example, since a new position of the electronic pen is determined, starting from a predetermined determined position, errors in determining the speed and location of the electronic pen can continue to accumulate.

In addition to the inherent inaccuracies of numerical integration methods, possible sources of error can also include, among other things, inaccuracies in analog-to-digital conversions of measurement sensor signals, zero point errors, e.g. due to inadequate calibration of the measurement sensors, random interference or noise components inherent in the system.

In particular, zero point errors in an inertial measuring sensor system of known electronic pens that are not or only insufficiently accurately calibrated, such as zero point errors in signals from acceleration sensors that are not or only imprecisely calibrated in known electronic pens, can undesirably add up squarely over time and the accuracy with which the position and movement of an electronic pen can be determined.

Task

It is therefore an object of the invention to provide means which enable a simplified and/or improved calibration of an inertial measuring sensor system of an electronic pen, in particular an improved calibration of acceleration sensors of an electronic pen.

Solution

This is achieved according to the invention by a calibration device for calibrating an inertial measuring sensor system of an electronic pen according to protection claim 1, and by a system according to the independent system protection claim, comprising a device for calibrating an inertial measuring sensor system of an electronic pen and an electronic pen.

Advantageous embodiments and further developments are the subject of the subclaims.

An exemplary device for calibrating an inertial measuring sensor system of an electronic pen can include a housing for receiving an electronic pen, wherein the housing can have at least one holding means for fixing an electronic pen received by the housing.

An inertial measuring sensor system of an electronic pen can be understood here to mean, among other things, that the measuring sensor system comprises acceleration sensors, for example at least one three-dimensional acceleration sensor which can measure accelerations along three orthogonal spatial axes of a three-dimensional inertial measuring system. Said orthogonal spatial axes of the acceleration sensor/measuring sensor system can also be referred to as sensor axes.

In addition, the inertial measuring sensor system of an electronic pen can include at least one yaw rate sensor, for example a three-dimensional yaw rate sensor, which can, for example, measure rotations about the axes of said three-dimensional inertial measuring system.

The exemplary inertial measuring sensor system of an exemplary electronic pen can be configured / arranged in such a way that the exemplary three-dimensional inertial measuring system with three orthogonal spatial axes / sensor axes in which accelerations and / or rotation rates can be measured can be oriented in such a way that a Spatial axis of the inertial measuring system or a sensor axis is parallel to the longitudinal axis of the electronic pen or coincides with the longitudinal axis of the electronic pen or that a spatial axis of the inertial measuring system or a sensor axis is not oriented parallel or only approximately parallel to the longitudinal axis of the electronic pen. Any unwanted or unintentional deviations in the alignment of sensor axes in relation to the longitudinal axis of the electronic pen can be corrected or compensated for via an appropriate calibration.

An electronic pen can be understood here as meaning, among other things, that the electronic pen has, for example, at least one electrical voltage source, as well as one or more electronic components that can be supplied by the voltage source, such as a digital control unit or a digital computing unit with one or more processors, as well can include at least one communication module for receiving and transmitting data and instructions.

Electronic pens have the advantage, among other things, that they can combine the functionality and simplicity of writing with a pen on a surface with the diverse possibilities of electronic data processing, since what is written can be converted directly into an electronic data processing format.

Fixing an electronic writing pen received by the housing can be understood, among other things, in particular, to mean that the electronic writing pen can be fixed in a predeterminable alignment or orientation in the housing, i.e. can be arranged firmly in a predeterminable orientation or predeterminable orientation or predeterminable position .

Surprisingly, it was found that such a device, in which an electronic pen is fixed in said device housing, enables a more precise calibration of the zero points of the inertial measuring sensors of an electronic pen, in particular a more precise calibration of the zero points of the acceleration sensors of an electronic pen, without one exact alignment along the axes of the earth-fixed coordinate system is required.

In particular, it was surprisingly found that during a calibration process of the inertial measuring sensor system of the electronic pen, in which the inertial measuring sensor system is rotated about at least one axis or a spatial axis of one/of the three-dimensional inertial measuring system of the inertial measuring sensor system and in which measurement data of the inertial measuring sensor system is stored at several rotational positions, in particular measurement data or acceleration signal data from the acceleration sensors / the acceleration sensor, are recorded, the measurement data, in particular the acceleration signal data from the acceleration sensors / the acceleration sensor, are almost free of noise if during said calibration process, i.e. during said rotation of the inertial measuring sensor system, the electronic pen is in a calibration device described here is fixed, so that when the calibration device described here rotates, the electronic pen together with its inertial measuring sensor system rotates in a well-defined manner.

In addition, rotation of the electronic pen by means of the calibration device with predeterminable rotation positions, i.e. rotations by predeterminable known angles, can also enable the calibration of rotation rate sensors of the inertial measurement sensor system, i.e. the calibration of the scale values of rotation rate sensors.

For example, by holding the position of the electronic pen using the calibration device described here as an example in a predeterminable rest position for a predeterminable period of time, e.g. on the order of seconds or shorter, measured values can be recorded in the axes of the rotation rate sensors and averaged around zero points in the axes of the rotation rate sensors.

Subsequent rotations of the electronic pen can then be used to scale the axes of the rotation rate sensors by means of the calibration device described here as an example by predefinable known rotation angles/rotation positions/rotation angle positions.

The at least one holding means of the calibration device can be configured in such a way that a recorded electronic pen can be fixed or firmly arranged centrally or centered within the housing, or centered within the calibration device.

In addition, the at least one holding means of the calibration device can be configured in such a way that it can fix a recorded electronic pen in a position/alignment/orientation in the housing in such a way that the longitudinal axis of a/the received electronic pen is at least approximately aligned with an axis, e.g the / a longitudinal axis of the housing can collapse.

Such a fixation of a recorded electronic pen within the housing of the calibration device can further reduce the noise in the measurement data of the inertial measurement sensor system of the electronic pen, in particular the noise in acceleration measurement values from at least one acceleration sensor of the inertial measurement sensor system, and thus an even more precise calibration of the inertial Enable measurement sensors.

Above all, such a fixation simplifies a more precise holding of the recorded electronic pen in predeterminable rotation angle positions or in predeterminable spatial alignments/orientations.

For example, the calibration device described here as an example can make it possible to rotate the recorded electronic pen by exactly 180° between the recording of measurement data from the inertial measuring sensor system, so that possible errors in the orientation, e.g. possible angular errors in the alignment of the electronic pen to axes, e.g. The main axes of the calibration device cancel each other out when determining zero point errors.

The at least one holding means can alternatively be configured to fix a recorded electronic pen in such a way that the longitudinal axis of the recorded electronic pen is oriented at least approximately parallel to the longitudinal axis or parallel to another axis, for example a side axis, of the housing.

Even in such a configuration of the at least one holding means, the noise in acceleration measured values from at least one acceleration sensor of the inertial measuring sensor system of the electronic pen is significantly reduced compared to a calibration process without using the calibration device.

For the sake of completeness, it should be noted that, for example, one/the longitudinal axis of the electronic writing pen can be defined or selected in such a way that the writing tip or writing lead of the electronic writing pen can lie on the longitudinal axis of the electronic writing pen.

The cross section of the housing of the calibration device can, for example, be rotationally symmetrical and/or cylindrical or polygonal, for example rectangular.

For example, the housing of the calibration device can be designed like a tube.

Alternatively, the housing of the calibration device can be designed, for example, cubic or cuboid. For example, the housing of the calibration device can also serve as a packaging box/box.

A rotationally symmetrical, for example a cylindrical or tube-like cross-sectional profile, in particular a circular-cylindrical cross-sectional profile of the housing of the calibration device, can, among other things, facilitate a more uniform rotation of the calibration device, which can also reduce noise in acceleration measured values from at least one acceleration sensor of the inertial measuring sensor system.

A polygonal cross-section or a polygonal or cuboid cross-sectional profile of the housing of the calibration device can, among other things, make it easier to achieve a well-defined sequence of rotation positions nen / rotation angle / rotation angle positions of the calibration device and to run through when the calibration device is rotated with the electronic pen recorded.

For example, an integer multiple can be selected for the number of side surfaces of the housing of the calibration device, which, among other things, simplifies the evaluation of the measurement data of the inertial measuring sensor system, which can be recorded at the angle of rotation / angle of rotation positions of the calibration device defined by the different side surfaces, since so a well-defined sequence of measurement data can be obtained.

The rotation of the calibration device with the electronic pen attached can take place freely in space, e.g. in the air, or preferably on a flat base/flat surface.

Alternatively or additionally, a sequence of measurements over several revolutions can be collected by means of an exemplary calibration device, which allows free rotation about an axis, with an evaluation algorithm determining a section of this sequence which comprises an integer number of revolutions. The acceleration signal due to the acceleration due to gravity makes it possible to reliably determine the angular position even without prior calibration and thus to determine a specification for the integrated signal of the yaw rate sensor. By using an integer number of revolutions as a basis, a previous calibration of the acceleration sensor can be dispensed with and angular deviations between the axis of the electronic pen and the axis of the rotation rate sensor can be reliably determined.

For the sake of completeness, it should be noted that when turning the calibration device with the electronic pen in place to carry out a calibration process, the electronic pen or the inertial measuring sensor system of the electronic pen should be switched on/activated.

The housing of the calibration device can also have different cross-sections/different cross-sectional profiles in sections.

For example, it is conceivable that the housing ends have a polygonal cross-sectional profile, while the housing between the ends has a different cross-sectional profile, for example a cylindrical cross-sectional profile.

It is also conceivable that the housing ends have a cylindrical polygonal cross-sectional profile, while the housing between the ends has a different cross-sectional profile, for example a polygonal cross-sectional profile.

The cross-sectional profiles of the ends of the housing can have a larger diameter than the cross-sectional profile of the housing between the housing ends, so that, for example, when the calibration device is rotated on a flat surface, the geometry of the cross-sectional profiles of the ends of the housing predetermine the traversable/acceptable rotation positions and angles of rotation of the calibration device can.

In other words, for example, the ends of the housing of the calibration device can optionally define the contact surface of the calibration device with a flat base/flat surface.

As already mentioned, the housing of the calibration device can be cubic or cuboid, for example, i.e. have six different side surfaces. Such an exemplary six-sided calibration device can then be rotated/tilted one after the other in a predefinable fixed sequence with a recorded electronic pen, so that the calibration device can remain in a rest position on each of its six sides for a predefinable period of time, e.g. a few seconds, in which the inertial measuring sensor system receives measurement data can accommodate.

For example, the average values of the measurement data that were recorded on opposite sides of the calibration device during the rest position of the calibration device can be used to determine the zero points of the relevant axes and the integrated angular velocity over 180 ° for scaling said axes.

For example, the zero points of the axes of the rotation rate sensors of the inertial measuring sensor system can be measured/determined in a first rest position, so that these can already be used in the subsequent rotations when the rotation rates are integrated.

For the acceleration sensors, the measurement data recorded on opposite sides of the calibration device can be used for scaling the axes that are perpendicular to the side surfaces and the measurement data in the two orthogonal axes can be used to determine zero points in said orthogonal axes.

The at least one holding means can be flexible. This can be understood to mean, for example, that the holding means can be elastic or that the holding means is at least partially formed/made of a material which can have flexible or elastic material properties.

In addition, the holding means can be designed so that it can fill the majority of the interior of the housing of the calibration device, for example more than 50% or more than 75% of the internal volume of the housing of the calibration device.

For example, it is conceivable that the holding means comprises an elastic foam material, for example polyurethane, and can be designed, for example, as a foam insert inside the housing of the calibration device, wherein said exemplary foam insert can have a defined cutout for receiving and fixing the electronic pen.

Said exemplary section can therefore have a contour surface that is complementary to the shape of the electronic pen.

An elastic element inside this cuboid, e.g. a foam insert with a defined cutout to accommodate the pin, allows fixation.

Alternatively or additionally, it is conceivable that the holding means is designed as a clamping mechanism. For example, it is conceivable that the holding means can be designed as a crown with flexible points, whereby the flexible points of the crown can clamp and fix the electronic pen.

It is also conceivable, for example, for the crown-like holding means to be integrated in a housing cover of the housing of the calibration device.

The use of polypropylene would be conceivable as an exemplary material for such a clamping mechanism.

Such an optionally possible exemplary embodiment, in which the at least one holding means has flexible or elastic properties, can, among other things, prevent undesirable shocks/vibrations or shocks, which can be transmitted to the inertial measuring sensor system of the electronic pen held by the calibration device when the calibration device is moved. dampen or weaken.

This can also contribute to a further reduction of noise in the measurement data/measurement signals of the inertial measurement sensor system of the electronic pen and thus lead to an improved accuracy of the calibration of the inertial measurement sensor system.

In particular, comparatively high deflections or peaks in the data from the inertial measuring sensors, triggered by undesirable shocks/vibrations or shocks, can be avoided.

Said deflections or peaks in the data of the inertial measuring sensor system can undesirably affect the accuracy of the calibration, since such peaks or deflections in the data of the inertial measuring sensor system cannot be resolved with sufficient accuracy at a limited measuring frequency.

The at least one holding means can also be configured or designed in such a way that the fixation or fastening of the electronic pen to be picked up/held in the housing of the calibration device in a predeterminable spatial alignment or orientation via a releasable connection, for example via clamping and/or screwing and/or pressing and/or plugging together and/or positive connection and/or magnetic interaction and/or negative pressure or Suction pressure application can be realized.

In an exemplary screw connection, it would be conceivable, among other things, for one end of the electronic pen to have a thread profile which is complementary to a hollow profile of the at least one holding means, so that the end of the electronic pen can be screwed into the hollow profile of the at least one holding means.

Alternatively or as a support, the use of an adhesive connection that can be removed without leaving any residue would also be conceivable when connecting the holding means to the electronic pen.

Depending on the design, an exemplary calibration device can have one or at least two holding means, for example one holding means can be arranged at one end of the housing of the calibration device.

However, the exemplary at least two holding means can also be arranged at other locations on the housing of the calibration device.

The use of at least two holding means can enable a more stable/low-vibration fixation of an electronic pen to be picked up/received in the housing of the calibration device.

The at least one holding means can be designed in such a way that it can enable a flat and/or punctual/discrete holding contact with the electronic pen.

For example, for low-vibration fixation of an electronic pen to be picked up/held by a flat-acting holding means, for example a holding means as a foam insert with a suitable cutout can be used, the holding means designed as a foam insert being able to have an oversize relative to the cavity of the calibration device housing into which it can be inserted .

Likewise, the use of at least two holding means can make it easier to fix the electronic pen to be picked up in such a way that the longitudinal axis of the recorded electronic pen can be oriented parallel to the longitudinal axis of the housing, or that the longitudinal axis of the recorded electronic pen is aligned with the longitudinal axis of the Housing can collapse.

The use of a flat holding means or at least two discrete holding means also contributes to reducing noise in the measurement data/measurement signals of the inertial measurement sensor system of the electronic pen.

The at least one holding means can also be integrated into a housing cover of the housing of the calibration device.

For example, the at least one holding means can be integrated into a housing cover at one end of the housing.

When using at least two holding means, for example, one holding means can be integrated into a housing cover at both ends of the housing.

Said exemplary housing covers can be removable. A detachable connection of the housing cover(s) to the housing can be established, among other things, via clamping and/or screwing and/or pressing and/or positive locking and/or magnetic interaction.

As a result, a more compact design of the calibration device can be achieved and, among other things, the insertion of an electronic pen into the housing of the calibration device can be made easier.

In the case of the calibration device or the housing of the calibration device, it can also be advantageous if it is permeable to electromagnetic waves, for example to enable data and command communication with an external digital computing unit.

This can enable the transmission of measurement data from the inertial measurement sensor system of the electronic pen to an external digital computing unit for processing and evaluating the measurement data.

The electronic pen can, for example, have a communication module which can, for example, enable encrypted wireless data transmission in accordance with the Bluetooth Low Energy (BLE) standard.

Alternatively or additionally, wired data and command communication between the electronic pen and an external digital computing unit is conceivable, even if the electronic pen is located in the calibration device.

1. 1. Ein Einlegen des elektronischen Schreibstiftes in eine wie hierin beispielhaft beschriebene Kalibriervorrichtung, wobei beim bzw. vor dem Einlegen des elektronischen Schreibstiftes, der elektronische Schreibstift bzw. die inertiale Messsensorik aktiviert / eingeschaltet werden kann.
2. 2. Ein Drehen der Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift um wenigstens eine Achse, z.B. eine/die Längsachse, der Kalibriervorrichtung, wobei während der Drehung der Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift Messdaten der inertialen Messsensorik des elektronischen Schreibstiftes aufgenommen werden können, und wobei die aufgenommenen Messdaten Beschleunigungsmesswerte von wenigstens einem Beschleunigungssensor der inertialen Messsensorik und/oder Drehratenmesswerte von wenigstens einem Drehratensensor umfassen können.
3. 3. Eine Bestimmung wenigstens eines Nullpunktfehlers in wenigstens einer Achse des / eines Beschleunigungssensors der inertialen Messsensorik durch Auswertung der aufgenommenen Messdaten.
4. 4. Eine Kalibrierung der inertialen Messsensorik des elektronischen Schreibstiftes auf Grundlage des wenigstens einen bestimmten Nullpunktfehlers.

An exemplary method for calibrating an inertial measuring sensor system of an electronic pen can include one, some or all of the following steps:

1. 1. Inserting the electronic pen into a calibration device as described here by way of example, whereby the electronic pen or the inertial measuring sensor system can be activated/switched on when or before inserting the electronic pen.
2. 2. Rotating the calibration device with the electronic pen inserted about at least one axis, for example one/the longitudinal axis, of the calibration device, wherein during the rotation of the calibration device with the electronic pen inserted, measurement data from the inertial measurement sensor system of the electronic pen can be recorded, and the recorded measurement data Acceleration measured values from at least one acceleration sensor of the inertial measurement sensor system and/or yaw rate measured values from at least one yaw rate sensor may include.
3. 3. A determination of at least one zero point error in at least one axis of the acceleration sensor of the inertial measuring sensor system by evaluating the recorded measurement data.
4. 4. A calibration of the inertial measuring sensor system of the electronic pen based on the at least one specific zero point error.

Preferably, the calibration device can be rotated or tilted about three axes that are orthogonal to one another with the electronic pen inserted.

For the sake of completeness, it should be mentioned that the electronic pen may have to be switched on or activated before it is inserted into the calibration device or before the calibration device begins to rotate, so that the inertial measuring sensor system can be activated or put on standby to receive measurement data to be able to record and/or, if necessary, to establish a communication connection with an external digital computing unit.

The exemplary method step of recording measurement data from the inertial measurement sensor system during the rotation of the calibration device with the electronic pen inserted can in particular include the case/the possibility that the calibration device moves during the measurement data recording, i.e. rotates during the measurement data recording, i.e. also the case/the Possibility of recording measurement data when the calibration device does not move and is, for example, in a rest position or holding position for a predetermined period of time during a rotation process from one rotation angle position to another rotation angle position.

The term rotation or the rotation process of the calibration device in the exemplary method described above therefore includes both continuous and stepwise rotations, said stepwise rotations being able to have well-defined rest positions with well-defined rotation angle positions at/in/at which the calibration device does not move.

Said exemplary longitudinal axis of the calibration device can therefore be understood as an axis of rotation for a rotation of the calibration device with the electronic pen inserted. However, a rotation process of the calibration device can also include rotations or tilts about other axes of the calibration device, for example rotations or tilts about edge or side axes of the calibration device.

The exemplary calibration of the inertial measurement sensor system of the electronic pen based on the at least one specific zero point error can be understood to mean, among other things, that the measurement data of the inertial measurement sensor system or the sensor axes are corrected, for example by changing the position of the zero points of the measurement data or the sensor axes the amount of the determined/determined zero point errors is corrected, for example by appropriate addition or subtraction of the determined/determined zero point error value. In addition, the term calibration of the inertial measuring sensor system of the electronic pen can also be understood to mean that the measurement data of the inertial measuring sensor system can be scaled or standardized.

The rotation of the calibration device with the electronic pen inserted about one/the longitudinal axis of the calibration device can be done continuously and/or stepwise.

A step-by-step rotation of the calibration device with the electronic pen inserted can, for example, include a sequence or sequence of rotations or rotation angle positions.

The rotation angle steps between successive rotations/rotation angle positions can be freely selectable, i.e., for example, they can be the same or different.

The direction of rotation for a continuous rotation and/or for each angle of rotation of a step-by-step rotation can be freely selected.

A rotation operation may also include a combination of continuous and stepwise rotations of the calibration device.

A rotation process can in particular also include a sequence or sequence of rotations or tilts about different axes or different edges of a calibration device. The rotation process of the calibration device can therefore include rotations or tilts about a large number of different axes of the calibration device. Preferably, the rotation process can include a predetermined sequence of axes around which rotations or tilts take place.

A rotation process preferably covers a sufficient number of rotation angle positions in order to be able to collect measuring points of the inertial measuring sensor system of the electronic pen located in the calibration device over at least one full revolution or over at least a quarter or at least half a revolution.

For example, it would be conceivable to collect measuring points of the inertial measuring sensor system at at least six different rotation angle positions distributed over one revolution.

The distribution of rotational angle positions over a full revolution can be uniform or uneven, with an uneven distribution, for example, adjacent rotational angle positions can differ by, for example, more than 10°.

As mentioned, the rotation process of the calibration device can include rotations or tilts about several different axes of the calibration device, so that, for example, an alignment of the electronic pen received by the calibration device in different discrete spatial directions can be made possible.

For example, the calibration device can be cuboid and, for example, enable alignment in at least six different discrete directions, two of which lie in pairs on axes orthogonal to at least one other direction. For example, the side surfaces of the calibration device can determine different orientations of the calibration device. In the case of an exemplary cuboid calibration device, the six different side surfaces can define, for example, six different orientations of the calibration device.

1. 1. Ein Ruhen / Halten der Kalibriervorrichtung in einer Ruheposition mit Kalibration der Nullpunkte der Achsen der Drehratensensoren der inertialen Messsensorik des elektronischen Schreibstiftes und gleichzeitige Aufnahme von Messdaten der Beschleunigungssensoren. Hierbei kann beispielsweise die Kalibriervorrichtung auf einer Fläche der Kalibriervorrichtung ruhen.
2. 2. Drehen der Kalibriervorrichtung um eine definierte Achse um 180° mit Integration der Drehratensensordaten zur Ermittlung des Winkels der Drehung. Das Ergebnis der Integration, korrigiert um den in Schritt 1 ermittelten Nullpunkt, kann dabei zur Skalierung der Achse des Drehratensensors, um den die Drehung erfolgte, verwendet werden.
3. 3. Ein Ruhen / Halten der Kalibriervorrichtung in der neuen Ruheposition, d.h. z.B. Ruhen auf der um 180° gedrehten gegenüberliegenden Fläche der Kalibriervorrichtung. Dabei können in der neuen Ruheposition wiederum Messdaten der Beschleunigungssensoren aufgenommen werden.
4. 4. Drehung / Kippung der Kalibriervorrichtung auf eine weitere Fläche der beispielhaften sechs Flächen der Kalibriervorrichtung.
5. 5. Ein Ruhen / Halten der Kalibriervorrichtung in der neuen Ruheposition und Aufnahme von Messdaten der Beschleunigungssensoren.
6. 6. Wiederholung der Schritte 2 bis 5, bis Messdaten in allen Ruhepositionen für alle (sechs) Seiten der Kalibriervorrichtung aufgenommen werden konnten.
7. 7. Auswertung der Messdaten. Dabei kann die Summe der Werte der Messdaten in/entlang jeweils einer Achse/Sensorachse für alle, z.B. sechs, während der Ruhepositionen eingenommenen verschiedenen Ausrichtungen der Kalibriervorrichtung , zur Ermittlung der Nullpunkte der jeweiligen Achse / Sensorachse dienen.

An exemplary rotating curtain or calibration process of a calibration device on a support surface with a recorded electronic pen can then include, for example, one, some or all of the following steps.

1. 1. Resting/holding the calibration device in a rest position with calibration of the zero points of the axes of the yaw rate sensors of the inertial measuring sensors of the electronic pen and Simultaneous recording of measurement data from the acceleration sensors. Here, for example, the calibration device can rest on a surface of the calibration device.
2. 2. Rotate the calibration device around a defined axis by 180° with integration of the rotation rate sensor data to determine the angle of rotation. The result of the integration, corrected by the zero point determined in step 1, can be used to scale the axis of the rotation rate sensor around which the rotation took place.
3. 3. Resting/holding the calibration device in the new resting position, ie resting on the opposite surface of the calibration device that has been rotated by 180°. Measurement data from the acceleration sensors can be recorded in the new rest position.
4. 4. Rotation / tilting of the calibration device onto another surface of the exemplary six surfaces of the calibration device.
5. 5. Resting/holding the calibration device in the new resting position and recording measurement data from the acceleration sensors.
6. 6. Repeat steps 2 to 5 until measurement data could be recorded in all rest positions for all (six) sides of the calibration device.
7. 7. Evaluation of the measurement data. The sum of the values of the measurement data in/along one axis/sensor axis for all, for example six, different orientations of the calibration device adopted during the rest positions can be used to determine the zero points of the respective axis/sensor axis.

The scaling of the acceleration sensor axes can then be obtained, for example, after correcting all values of the measurement data around the respective zero point and dividing the measured values obtained in the axis parallel to the acceleration of gravity by the number of measurements.

The recording of measurement data from the inertial measurement sensor system of the electronic pen located in the calibration device, in particular the recording of acceleration measurement values from at least one acceleration sensor of the inertial measurement sensor system, can also take place continuously and/or step by step.

It was surprisingly found that if one takes into account the measurement data of the inertial measuring sensor system of the electronic pen collected during the continuous and/or stepwise rotation of the calibration device with the electronic pen inserted, in particular the acceleration measured values of at least one acceleration sensor of the inertial measuring sensor system, depending on the rotation angle position ( en) of the calibration device, a low-noise and well-defined relationship results between the acceleration measured values of at least one acceleration sensor of the inertial measuring sensor system depending on the angular position of the calibration device, which can be well described with a model function, in particular with a trigonometric model function, and from the zero point error in the axes/measuring axes/sensor axes of the at least one acceleration sensor of the inertial measuring sensor system can be determined, which can serve as a basis for the calibration of the acceleration sensor or the inertial measuring sensor system.

In particular, it was found that the relationship between the acceleration measured values of at least one acceleration sensor of the inertial measuring sensor system of the electronic pen located in the calibration device can be described almost by an ideal sinusoidal curve depending on the rotational angular position of the calibration device.

A suitable model function, in particular a suitable trigonometric function for modeling the recorded acceleration measured values depending on the rotation angle positions of the calibration device, or depending on the continuously and / or stepwise changing rotation angle positions of the calibration device, can therefore, for example, include a sine function or a sine function with or without Be a displacement term, e.g. with a vertical displacement term.

A determination of at least one zero point error in at least one axis of the acceleration sensor of the inertial measuring sensor system can then be achieved by evaluating the recorded measurement data by modeling the recorded acceleration measured values depending on the rotation angle positions assumed during the rotation of the calibration device using a suitable trigonometric function, for example by a sine function , whereby the at least one zero point error in at least one axis of the acceleration sensor can be determined based on a specific shift of the modeled trigonometric function to the zero line.

For example, the recorded acceleration measurements can then be modeled as a function of the rotation angle positions of the calibration device with a modeling function that includes a sine function and a vertical displacement term (displacement term with respect to one/the ordinate axis).

An optimization algorithm can then be used to find those parameter values of the parameters of the modeling function that best describe the measured course of the recorded acceleration measurements depending on the rotation angle positions of the calibration device or minimize a cost function.

The sum of the error squares of the distances between the model function curve and the measuring points can be used as an example cost function to be minimized.

For example, the model function curve can then be determined which minimizes the sum of the error squares of the distances between the model function curve and the measuring points.

For example, the amplitude and/or the phase/the phase angle and/or the frequency of the sine function and/or a vertical displacement term can be used as parameters to be optimized.

In order to determine the optimal parameter values in this multidimensional model parameter space, which determine the model function that best describes the measurement data, a parameter value search can be carried out over a grid of the model parameter space, i.e. a brute force method, or other optimization algorithms, such as a downhill Simplex method can be used.

The determined vertical displacement / the value of the vertical displacement of the model function / model function curve that best describes the measurement data / the acceleration measurement values with respect to the zero line can then serve as a measure for the zero point error, or as a zero point error value, in the corresponding acceleration sensor axis.

In particular, said determined vertical displacement / said value of the vertical displacement of the measurement data, or the vertical displacement of the model function that best describes the recorded acceleration measured values with respect to the zero line, can then be used as a measure of the zero point error in acceleration sensor axes that are orthogonal or approximately orthogonal to the axis of rotation or rotation axis of the calibration device.

However, it is also conceivable that the optimal parameter values of the model function and/or the vertical shift of the best-fitting model function to the zero line in order to determine a zero point error of an acceleration sensor of the inertial measurement sensor system can also be determined or estimated differently, i.e. without using optimization algorithms can, for example by using an appropriately trained neural network.

Before the above-described exemplary modeling of the recorded acceleration measured values by a model function such as the above-described exemplary trigonometric model function or the exemplary sine function with displacement term, the angular orientation of the coordinate system of the inertial measurement sensor system/the angular orientation of the axes of the electronic pen can be determined from the measurement data of the inertial measuring sensor system of the electronic pen orthogonal three-dimensional inertial measuring system / the angular orientation of the sensor axes of the inertial measuring sensor system in relation to the axis of rotation can be determined.

Said angular orientation of the sensor axes of the inertial measuring sensor system in relation to the axis of rotation can be determined, for example, as follows from measurement data of the inertial measuring sensor system. For example, the orthogonal three-dimensional inertial measuring system is spanned by the exemplary axes/sensor axes X, Y and Z that are orthogonal to one another.

For example, if ax1 is the acceleration measurement value in the direction of the Said angular errors / the angular orientation of the sensor axes of the inertial measuring sensor system in relation to the gravity vector are determined from the formula: $$\text{Angular error}=arctan\left(\frac{ax1}{ax2}\right)$$

Therein arctan is the arctangent function. If ax2 is less than zero, the angular orientation is obtained by additionally adding π to the value obtained from the formula.

Therefore, the amplitude of the trigonometric function obtained by minimizing the error squares can be proportional to the position/distance/offset of the axis of the acceleration sensor in relation to the axis of rotation.

The proportionality factor can be calculated directly by using the arctangent function using the measured value when the axis of the acceleration sensor is almost vertical. Due to a possible angular error between the sensor axis and the rotation axis of the calibration device, the sensor axis will not be exactly vertical even after the calibration device has been rotated by exactly 90°. However, this possible error only leads to deviations of the measured values from their ideal target value in the amount of the cosine function. For small angles, this has only very small deviations from the value 1, which it would achieve if the sensor axis was aligned exactly vertically, which is why, despite a possible angle error, a very precise measurement of the angle between the sensor and rotation axis is possible, since the denominator of the argument is the Arctangent function allows very precise normalization.

Before turning the calibration device with the electronic pen inserted, it is also optionally conceivable for the calibration device to be at rest, i.e. not to be moved, in order to be able to determine a zero point of a rotation rate sensor/zero points of rotation rate sensors of the inertial measuring sensor system and to be able to calibrate the rotation rate sensors accordingly.

Such a zero point error correction/zero point error calibration of the rotation rate sensors of the inertial measuring sensor system allows, for example, to separate possible errors due to a possible angular deviation of the sensor axis and a zero point error of the sensor in the same axis of the recorded acceleration measured values and thus also the accuracy of the modeling of the recorded acceleration measured values by a model function to further improve.

In order to further improve the accuracy with which the recorded acceleration measurements can be modeled, it is also conceivable that the zero points of the rotation rate sensors are determined several times during a calibration process with a calibration device, for example in each/a rest position of the calibration device when the calibration device is rotated step by step .

In other words, an iterative procedure can be carried out in order to be able to gradually determine and correct zero point errors of the yaw rate sensors and zero point errors of the acceleration sensors through repeated measurements and averaging over the repeated measurements.

A rest position can be understood here as meaning, among other things, a position or position of the calibration device in which the yaw rate sensors of the inertial measuring sensor system do not experience any yaw rate changes and/or the acceleration sensors of the inertial measuring sensor system experience no or only a negligibly small gravitational acceleration, or in which the Target measurement signals from the rotation rate sensors and/or the target measurement signals from the acceleration sensors of the inertial measurement sensor system are below a predeterminable measurement signal threshold.

The rotation of the calibration device with the electronic pen inserted about at least one axis / about one/the longitudinal axis / about one/the rotation axis of the calibration device can also be carried out on a flat surface/flat surface/smooth surfaces, e.g. on a desk.

This makes it particularly easy to find a position of the calibration device that is perpendicular to the axis of gravitational acceleration.

This can also lead to a reduction in scatter or a reduction in noise in the measurement data of the inertial measurement sensor system, which in turn can also increase the accuracy with which the measurement sensor system of the electronic pen can be calibrated.

As already mentioned, the rotation of the calibration device with the electronic pen inserted about one/the longitudinal axis of the calibration device can be carried out continuously and/or stepwise.

For example, a step-by-step rotation of the calibration device with the electronic pen inserted about at least one axis/around one/the longitudinal axis of the calibration device can comprise a sequence of rotation processes in which the calibration device is in a rest position between two successive rotation processes, in which the calibration device is for not moved for a predetermined period of time and measurement data from the inertial measuring sensor system being recorded in a rest position of the calibration device. For example, it is conceivable that measurement data from the inertial measurement sensor system are only, i.e. exclusively, recorded in a rest position of the calibration device.

For example, said predeterminable period of time in which the calibration device is in a rest position can be on the order of seconds, for example 5 to 10 seconds. With an exemplary measuring frequency of 100 Hz, between 500 and 1000 measured values per rest position can be collected and averaged.

However, other, longer or shorter, time periods are also conceivable depending on the measurement frequency used.

Said exemplary step-by-step rotation of the calibration device with the electronic pen inserted about at least one axis of the calibration device / about at least one axis of the housing of the calibration device can, for example, include at least one rotation process with a rotation of the calibration device by 180 °.

Enabling a precise rotation of the calibration device by 180° makes it possible, as already mentioned, to minimize possible sources of error when determining the zero point of the axes of the acceleration sensors of the electronic pen, since possible angular errors in the alignment of the electronic pen with axes, e.g. main axes, of the calibration device cancel each other out if the measurement data from the acceleration sensors are recorded and evaluated at two rotational positions of the calibration device that are 180° different to determine the zero point / zero point error.

As also already mentioned, the calibration device can comprise a housing with six side surfaces. The housing of the calibration device/the calibration device can therefore be cubic or cuboid.

An exemplary rotation of the calibration device with the electronic pen inserted can in particular include a sequence of rotation processes in which each of the side surfaces of the calibration device / each of the side surfaces of the housing of the calibration device assumes an orientation at least once in which the respective side surface acts as a support surface of the calibration device on a flat surface can serve.

As already mentioned, a rest position of the calibration device can be determined or detected in that the inertial measuring sensor system does not measure any measurement signal changes or no measurement signals, such as changes in rotation rate and/or acceleration signals, or the measurement signals are below a predeterminable measurement signal threshold.

Such optional rest positions of the calibration device in different rotation angle positions during a step-by-step rotation of the calibration device with the electronic pen inserted offer numerous advantages.

For example, in each rest position, several acceleration measurement values for the respective rotation angle position of the calibration device can be measured, stored and averaged, so that the accuracy with which acceleration values can be determined per rotation angle position of the calibration device is increased.

Likewise, several yaw rate sensor measurements can be made and saved in each rest position, which, among other things, can also be averaged and can enable a more precise determination of the zero point error of the yaw rate sensors.

In addition, the measurement data of the inertial measurement sensor system recorded in a rest position of the calibration device are exposed to less interference, such as shocks or vibrations, and are therefore generally more accurate per se than measurement data that are recorded while the calibration device is moving.

In this way, a more precise and less noisy measurement data set can be generated, which can improve the accuracy of the modeling of the recorded acceleration measured values described above as an example depending on the rotation angle positions assumed during the rotation of the calibration device, which consequently leads to a more precise determination of zero point errors of the acceleration sensors and thus to an improved one Calibration of the inertial measuring sensors can lead.

A continuous or stepwise rotation process preferably covers a sufficient number of rotation angle positions in order to be able to collect measuring points of the inertial measuring sensor system of the electronic pen located in the calibration device over at least one full revolution or over at least a quarter of a revolution or over at least half a revolution.

For example, it is conceivable that a step-by-step rotation process includes an integer number of rotation angle positions or an integer number of revolutions, for example at least three revolutions, with each rotation step being carried out evenly.

In particular, for example, when using a cuboid-shaped calibration device, it is conceivable that the step-by-step rotation process includes turning or tilting the calibration device, in which each side surface of the calibration device defines a rotation angle position in which measurement data can be recorded.

As mentioned, the rotation of the calibration device with the electronic pen inserted can be carried out about at least one axis, e.g. the longitudinal axis/axis of rotation or a side axis/edge axis, of the calibration device/the calibration device housing on a flat surface.

This can make it easier to set or reach said rest positions of the calibration device, as well as increase the quietness of movement at a rest position of the calibration device that has been reached, which in turn can also lead to a reduction in the measurement data scatter or measurement data noise.

As mentioned, the cross section of the housing of the calibration device can be, for example, cylindrical or polygonal. In particular, the cross section of the housing/the cross section profile of the calibration device can be designed to be rotationally symmetrical.

For example, the housing of the calibration device can be tubular or cylindrical.

A rotationally symmetrical, for example a cylindrical or tube-like cross-sectional profile, in particular a circular-cylindrical cross-sectional profile of the housing of the calibration device, can, among other things, facilitate a more uniform rotation of the calibration device, which also reduces noise in the measurement data of the inertial measurement sensor system, in particular in acceleration measurement values of the acceleration sensor of the inertial measurement sensor system, can reduce.

A polygonal cross-section or a polygonal cross-sectional profile of the housing of the calibration device can, among other things, make it easier to determine and run through a well-defined sequence of rotational positions/angles of rotation/angles of rotation of the calibration device when the calibration device is rotated with the electronic pen attached.

In addition, with a polygonal cross-sectional profile of the housing of the calibration device, for example with a cuboid design of the calibration device housing, well-defined rest positions of the calibration device can be assumed when the calibration device is rotated step by step, since at For example, for each rotation angle position of a step-by-step rotation, the calibration device can rest on a side surface of the housing of the calibration device for a predetermined period of time.

A polygonal cross-sectional profile of the housing of the calibration device, as is the case, for example, with a cuboid-shaped calibration device, thus enables a more stable rest position of the calibration device during gradual rotation.

This in turn can further reduce the noise in measurement data of the inertial measurement sensor system, which is assumed during the rest positions when the calibration device is rotated step by step, and thus enable a more precise calibration of the inertial measurement sensor system of the electronic pen.

1. 1. Einlegen des elektronischen Schreibstiftes in die Kalibriervorrichtung.
2. 2. Ruhen der Kalibriervorrichtung in einer Halte-/Ruheposition und Messung von Drehraten und Beschleunigungen in allen Achsen der inertialen Messsensorik und Speichern der Messdaten;
3. 3. Bestimmung wenigstens eines Nullpunktfehlers in wenigstens einer Achse des Drehratensensors der inertialen Messsensorik durch Auswertung der aufgenommenen Messdaten.
4. 4. Rotation / Drehung / Kippung der Kalibriervorrichtung um 180° auf eine gegenüberliegende Seite, dabei Messung und Integration der Drehraten. Ermittlung des Kalibrierfaktors der Skalierung um die Rotationsachse nach Korrektur um den vorher ermittelten Nullpunktfehler.
5. 5. Ruhen der Kalibriervorrichtung in der neuen Position, dabei Messung von Beschleunigungen in allen Achsen der inertialen Messsensorik und Speichern der Messdaten.
6. 6. Rotation / Drehung / Kippung der Kalibriervorrichtung auf eine weitere Seitenfläche und Wiederholung der vorherigen Schritte 4 bis 6, bis Messdaten auf allen sechs Seiten/Seitenflächen gesammelt wurden.
7. 7. Kalibrierung / Skalierung der Beschleunigungssensoren und Drehratensensoren der inertialen Messsensorik in allen Achsen der inertialen Messsensorik. Dabei können die integrierten Drehraten über die 180°-Drehungen mit Pi normiert werden und einen Faktor bilden, mit dem zukünftige Messungen der Drehrate um ihren Skalierungsfehler korrigiert werden können. Dann können z.B. die Mittelwerte der in den Ruhephasen/an den Ruhepositionen gesammelten Beschleunigungswerte jeweils paarweise ausgewertet gemäß folgender beispielhafter Formeln:

$$\text{Nullpunktfehler in X}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}1+X2+\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}4+X5+\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6}{6}\right)-\text{Sollwert}\left(X0\right)$$

$$\text{Nullpunktfehler in Y}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}1+Y2+\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4+Y5+\mathrm{<figure-callout\; id="6"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}6}{6}\right)-\text{Sollwert}\left(Y0\right)$$

$$\text{Nullpunktfehler in Z}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1+Z2+\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}4+Z5+\mathrm{<figure-callout\; id="6"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}6}{6}\right)-\text{Sollwert}\left(Z0\right)$$

$$\text{Winkelfehler der X}-\text{Achse in der X}-\text{Z}-\text{Ebene}=\text{Arctan}\left(\frac{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}1+X2-2-Sollwert\left(X0\right)}{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}\right)$$

$$\text{Winkelfehler der X}-\text{Achse in der X}-\text{Y}-\text{Ebene}=\text{Arctan}\left(\frac{\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}4-2-Sollwert\left(X0\right)}{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}\right)$$

$$\text{Winkelfehler der Y}-\text{Achse in der Y}-\text{Z}-\text{Ebene}=\text{Arctan}\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}1+Y2-2-Sollwert\left(Y0\right)}{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}\right)$$

$$\text{Winkelfehler der Y}-\text{Achse in der X}-\text{Y}-\text{Ebene}=\text{Arctan}\left(\frac{Y5+\mathrm{<figure-callout\; id="6"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}6-2-Sollwert\left(Y0\right)}{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}\right)$$

$$\text{Winkelfehler der Z}-\text{Achse in der X}-\text{Z}-\text{Ebene}=\text{Arctan}\left(\frac{Z5+\mathrm{<figure-callout\; id="6"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}6-2-Sollwert\left(Z0\right)}{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}\right)$$

$$\text{Winkelfehler der Z}-\text{Achse in der Y}-\text{Z}-\text{Ebene}=\text{Arctan}\left(\frac{\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}4-2-Sollwert\left(Z0\right)}{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}\right)$$

$$\text{Skalierungsfehler der X}-\text{Asche}=\frac{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}{Sollwert\left(1g\right)}$$

$$\text{Skalierungsfehler der Y}-\text{Asche}=\frac{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}{Sollwert\left(1g\right)}$$

$$\text{Skalierungsfehler der Z}-\text{Asche}=\frac{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}{Sollwert\left(1g\right)}$$

For example, an integer multiple can be selected for the number of side surfaces of the housing of the calibration device, which, among other things, simplifies the evaluation of the measurement data of the inertial measuring sensor system, which can be recorded at the angle of rotation / angle of rotation positions of the calibration device defined by the different side surfaces, since so a well-defined sampling of measurement data can be obtained. In an exemplary cubic or cuboid design of the housing of the calibration device, the calibration device/the housing of the calibration device has, for example, six side surfaces and an exemplary method for calibrating an inertial measuring sensor system of an electronic pen can have one, some or all of the following steps.

1. 1. Insert the electronic pen into the calibration device.
2. 2. Resting the calibration device in a holding/rest position and measuring rotation rates and accelerations in all axes of the inertial measuring sensor system and saving the measurement data;
3. 3. Determination of at least one zero point error in at least one axis of the rotation rate sensor of the inertial measurement sensor system by evaluating the recorded measurement data.
4. 4. Rotation / rotation / tilting of the calibration device by 180° to an opposite side, thereby measuring and integrating the rotation rates. Determination of the calibration factor of the scaling around the axis of rotation after correction for the previously determined zero point error.
5. 5. Rest the calibration device in the new position, thereby measuring accelerations in all axes of the inertial measuring sensor system and saving the measurement data.
6. 6. Rotate/rotate/tilt the calibration device onto another side surface and repeat previous steps 4 to 6 until measurement data has been collected on all six sides/side surfaces.
7. 7. Calibration / scaling of the acceleration sensors and rotation rate sensors of the inertial measuring sensor system in all axes of the inertial measuring sensor system. The integrated rotation rates can be standardized over the 180° rotations with Pi and form a factor with which future measurements of the rotation rate can be corrected for their scaling error. Then, for example, the average values of the acceleration values collected in the rest phases/at the rest positions can be evaluated in pairs according to the following exemplary formulas:

$$\text{Zero point error in X}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}1+X2+\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}4+X5+\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6}{6}\right)-\text{Setpoint}\left(X0\right)$$

$$\text{Zero point error in Y}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}1+Y2+\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4+Y5+\mathrm{<figure-callout\; id="6"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}6}{6}\right)-\text{Setpoint}\left(Y0\right)$$

$$\text{Zero point error in Z}=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1+Z2+\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}4+Z5+\mathrm{<figure-callout\; id="6"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}6}{6}\right)-\text{Setpoint}\left(Z0\right)$$

$$\text{Angular error of the X}-\text{Axis in the X}-\text{Z}-\text{level}=\text{Arctane}\left(\frac{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}1+X2-2-SOllwert\left(X0\right)}{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}\right)$$

$$\text{Angular error of the X}-\text{Axis in the X}-\text{Y}-\text{level}=\text{Arctane}\left(\frac{\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="X"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">X</figure-callout>}4-2-SOllwert\left(X0\right)}{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}\right)$$

$$\text{Angular error of the Y}-\text{Axis in the Y}-\text{Z}-\text{level}=\text{Arctane}\left(\frac{\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}1+Y2-2-SOllwert\left(Y0\right)}{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}\right)$$

$$\text{Angular error of the Y}-\text{Axis in the X}-\text{Y}-\text{level}=\text{Arctane}\left(\frac{Y5+\mathrm{<figure-callout\; id="6"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}6-2-SOllwert\left(Y0\right)}{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}\right)$$

$$\text{Angular error of the Z}-\text{Axis in the X}-\text{Z}-\text{level}=\text{Arctane}\left(\frac{Z5+\mathrm{<figure-callout\; id="6"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}6-2-SOllwert\left(Z0\right)}{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}\right)$$

$$\text{Angular error of the Z}-\text{Axis in the Y}-\text{Z}-\text{level}=\text{Arctane}\left(\frac{\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Z</figure-callout>}3+\mathrm{<figure-callout\; id="4"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}4-2-SOllwert\left(Z0\right)}{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}\right)$$

$$\text{X scaling error}-\text{ash}=\frac{\left|X5-\mathrm{<figure-callout\; id="6"\; label="X"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">X</figure-callout>}6\right|}{SOllwert\left(1G\right)}$$

$$\text{Y scaling error}-\text{ash}=\frac{\left|\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="DE202022102574U1\_0015.png"\; state="\{\{state\}\}">Y</figure-callout>}3-\mathrm{<figure-callout\; id="4"\; label="Y"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Y</figure-callout>}4\right|}{SOllwert\left(1G\right)}$$

$$\text{Z scaling error}-\text{ash}=\frac{\left|\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="DE202022102574U1\_0014.png"\; state="\{\{state\}\}">Z</figure-callout>}1-Z2\right|}{SOllwert\left(1G\right)}$$

For example, X1, Y1, Z1 are the mean values of the measured accelerations when the calibration device is oriented on its base and the Z axis of the calibration device is parallel to the acceleration due to gravity, while the other two axes are each oriented perpendicular to the acceleration due to gravity. X2, Y2, Z2 are the mean values of the measured acceleration after the calibration device has been rotated by 180° so that it lies with its base facing upwards. Therefore, the Z axis of the calibration device is again parallel to the acceleration due to gravity, while the other two axes are again oriented perpendicular to the acceleration due to gravity.

X3, Y3, Z3 are the mean values of the measured acceleration after the calibration device has been rotated on its long side, whereby the Y axis of the calibration device is now oriented parallel to the acceleration due to gravity and the other two axes are each oriented perpendicular to the acceleration due to gravity. X4, Y4 and Z4 are the mean values of the measured acceleration after a rotation of the calibration device by 180 ° to the side opposite the long side, with the Y axis of the calibration device now again being oriented parallel to the acceleration of gravity and the other two axes each oriented perpendicular to the acceleration of gravity be.

X5, Y5, Z5 are the mean values of the measured acceleration after the calibration device has been rotated to its transverse side, with the X6, Y6 and Z6 are the mean values of the measured acceleration after rotating the calibration device by 180° to the side opposite the transverse side, with the be.

Setpoint (X0) is the error-free measured value of the acceleration sensor in its of the acceleration sensor in its Z axis at 0g.

Setpoint (1g) is the error-free measured value of the acceleration sensor with gravitational acceleration acting parallel to the sensor axis. This value should be the same for all three axes.

A uniform sampling of measurement data from the inertial measurement sensor system during the rotation of the calibration device facilitates the modeling and optimization of the said model function and can thus also improve the accuracy of the calibration of the inertial measurement sensor system.

The rotation of the calibration device with the electronic pen attached can take place freely in space, for example in the air, or preferably on a flat base/flat surface.

As already mentioned, the housing of the calibration device can also have different cross-sections/different cross-sectional profiles in sections.

The method steps for processing, evaluating and modeling the recorded measurement data for determining at least one zero point error in at least one axis of one/of the acceleration sensor of the inertial measuring sensor system can be carried out, for example, by a digital computing unit of the electronic pen and/or by an external digital computing unit, the external digital computing unit can be in communication with the electronic pen.

The process steps for processing, evaluating and modeling the recorded measurement data and the calibration of the inertial measuring sensors of the electronic pen based on the evaluation of the recorded measurement data can therefore be carried out with computer assistance.

A digital computing unit can be understood to mean that the digital computing unit can have one or more processors, for example a central processing unit (CPU).

An exemplary system for calibrating an inertial measuring sensor system of an electronic pen can therefore include a calibration device and an electronic pen with inertial measuring sensor system. The calibration device can have the features described here by way of example.

For the sake of completeness, it should be noted that it can be advantageous if the axes of the exemplary three-dimensional inertial measuring system of the inertial measuring sensor system of an electronic pen to be calibrated, e.g. the sensor axes in which accelerations and/or rotation rates can be measured, are oriented in such a way that a spatial axis / Main axis of the inertial measuring system or a sensor axis is parallel to one of the longitudinal axis of the electronic pen or coincides with the longitudinal axis of the electronic pen.

However, such an exemplary arrangement or orientation of the measuring sensor system in the electronic pen or such an exemplary orientation of the orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system with respect to one/the longitudinal axis of the electronic pen is not absolutely necessary in order to calibrate the to be able to carry out inertial measurement sensors.

In fact, internal tests have unexpectedly shown that even with an orientation of the orthogonal three-dimensional inertial measuring system, in which a spatial axis / main axis / sensor axis of the inertial measuring system of the inertial measuring sensor system has an oblique angle, for example an angle of up to ±3° or more, in relation to one/to the longitudinal axis of the electronic pen, an astonishingly precise calibration of the inertial measuring sensor system can be achieved with the means described herein.

The means and methods described here by way of example for calibrating or supporting the calibration of an inertial measuring sensor system of an electronic pen compared to known means and methods enable a hitherto unattainable simplification while at the same time providing high quality and accuracy in the calibration of an inertial measuring sensor system of an electronic pen, in particular regarding the correction of zero point errors in sensor axes of inertial acceleration sensors.

In particular, this also means that the positions and movements of the electronic pen can be recorded with improved accuracy when it is used on a writing surface and/or when the electronic pen moves in free space.

In addition, the calibration device described herein can also serve as a storage means for an electronic pen.

For example, if you try to determine a zero point error of the acceleration sensor of the inertial measuring sensor system of the electronic pen via a rotation of the electronic pen without a calibration device described here, you will find that the scatter or noise of the measurement data of the acceleration sensor of the inertial measuring sensor system is too large is in order to be able to carry out a technically meaningful modeling between acceleration measurement values and rotation angle positions of the electronic pen, since the acceleration measurement values can no longer be described by a sinusoidal curve or can no longer be described with sufficient accuracy depending on the rotation angle positions.

The measurement of acceleration measured values in which the electronic pen is rotated about its longitudinal axis without the calibration device described herein produces a scatter distribution of the acceleration measured values with respect to the angle of rotation that is difficult or impossible to compensate for.

From this distribution of acceleration measurement values, which would be obtained without the use of a calibration device described herein, no relationship between acceleration measurement values and the rotational angle position of the electronic pen can be derived for precise calibration purposes, so that in this case the acceleration measurement values are not a basis for a sufficiently accurate calibration of the inertial measurement sensors of the electronic pen.

Without the use of the calibration device described herein, any existing zero point errors in the axes/measuring axes/sensor axes of the at least one acceleration sensor of the inertial measuring sensor system cannot be corrected, and the measuring sensor system of the electronic pen cannot be calibrated or cannot be calibrated with sufficient precision in this regard.

The calibration device described herein and the calibration method described herein allow decoupling of shocks and vibrations of the electronic pen, which can be triggered, for example, by trembling or restless or jerky movements of the user leading/holding the pen, and which can greatly affect the quality of calibration measurements.

The calibration device described herein and the calibration method described herein also enable a decoupling of interference influences caused by the shape and geometry of the housing of the electronic pen, which can prevent or hinder a uniform, well-defined rotation of the electronic pen about its longitudinal axis for calibration purposes, for example due to a non-rotationally symmetrical shape of the electronic pen, whereby, for example, protruding and irregularly shaped structural components of the electronic pen can affect a uniform, well-defined rotation of the electronic pen about its longitudinal axis.

• 1: Beispielhafter elektronischer Schreibstift.
• 2a: Beispielhafte Seitenansicht einer Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift.
• 2b: Beispielhafte perspektivische schräge Seitenansicht einer Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift.
• 3a: Beispielhafte Messreihe mit kontinuierlicher Drehung ohne Kalibriervorrichtung, Messung senkrecht zur horizontalen Drehachse.
• 3b: Beispielhafte Messreihe mit Kalibriervorrichtung und kontinuierlicher Drehung, Messung senkrecht zur horizontalen Drehachse.
• 3c: Beispielhafte Messreihe mit Kalibriervorrichtung und kontinuierlicher Drehung, Messung parallel zur horizontalen Drehachse.
• 3d: Beispielhafte Messreihe mit Kalibriervorrichtung und schrittweiser Drehung.
• 4: Beispielhaftes Flussdiagram für beispielhaftes Kalibrierverfahren.
• 5: Beispielhafte Kalibriervorrichtung für schrittweise Drehung.

The following figures represent some technical aspects by way of example, which are only intended to provide a better understanding of the means described herein for calibrating an inertial measuring sensor system of an electronic pen.

• 1 : Exemplary electronic writing pen.
• 2a : Example side view of a calibration device with an electronic pen inserted.
• 2 B : Exemplary perspective oblique side view of a calibration device with an inserted electronic pen.
• 3a : Example of a series of measurements with continuous rotation without a calibration device, measurement perpendicular to the horizontal axis of rotation.
• 3b : Example series of measurements with calibration device and continuous rotation, measurement perpendicular to the horizontal axis of rotation.
• 3c : Example series of measurements with calibration device and continuous rotation, measurement parallel to the horizontal axis of rotation.
• 3d : Example series of measurements with calibration device and step-by-step rotation.
• 4 : Exemplary flowchart for an exemplary calibration procedure.
• 5 : Exemplary calibration device for stepwise rotation.

The 1 shows an exemplary electronic pen 1, which or its exemplary inertial measuring sensor system 4 can be calibrated with a calibration device described herein.

As already mentioned, the electronic pen 1 can, for example, have at least one electrical voltage source (not shown) and one or more electronic components (not shown) that can be supplied by the voltage source, such as a digital control unit or a digital computing unit with one or more processors, as well have at least one communication module for receiving and transmitting data and instructions.

The inertial measuring sensor system 4 can also be supplied with electrical voltage from the voltage source.

The exemplary inertial measuring sensor system 4 can be arranged near the writing tip 5 of the electronic writing pen 1.

The inertial measuring sensor system 4 can, as described above, have acceleration sensors and/or yaw rate sensors, which can measure accelerations and/or yaw rates in a three-dimensional inertial measuring system with three spatial axes/sensor axes that are orthogonal to one another.

For example, the inertial measuring sensor system 4 can be arranged or oriented in such a way that a spatial axis of the inertial measuring system or a sensor axis is parallel to the longitudinal axis 2 of the electronic pen 1 or coincides with the longitudinal axis 2 of the electronic pen 1, or that a spatial axis of the inertial measuring system or A sensor axis is not oriented parallel or only approximately parallel to the longitudinal axis 2 of the electronic pen 1.

In the exemplary case shown, the exemplary sensor axis/spatial axis of the inertial measuring system of the inertial measuring sensor system 4, which is marked with a dashed line and with the reference number 3, is parallel to the exemplary longitudinal axis 2 of the electronic pen 1.

The exemplary writing tip or writing lead 5 can lie on the longitudinal axis 2 of the electronic writing pen 1.

The 2a shows a side view of an exemplary calibration device 11 with a recorded electronic pen 1, the electronic pen 1 being identical to that in the 1 electronic pen 1 shown can be.

The exemplary calibration device 11 has two exemplary holding means 6, 7, which can each be arranged at one end of the housing 12 of the calibration device 11.

Said exemplary holding means 6, 7 can be integrated into the housing cover 8, 9 of the housing 12 of the calibration device 11.

The housing covers 8, 9 can be detachably connected to the housing 12 of the calibration device 11, so that an electronic pen 1 can be inserted into the calibration device 11 and removed again.

As mentioned, the exemplary housing covers 8, 9 together with the holding means can be connected to the housing 12 of the calibration device 11, for example via clamping and/or screwing and/or plugging together and/or pressing and/or positive locking and/or magnetic interaction or via other detachable connection options .

For example, the housing covers 8,9 can be designed like a plug.

The exemplary holding means 6, 7 can be configured in such a way that they can fix, i.e. firmly arrange, the recorded electronic pen 1 in the calibration device 11, i.e. within the housing 12 of the calibration device 11.

The electronic pen 1 can be fixed via the holding means 6, 7 via detachable connections between the holding means 6, 7 and the ends of the electronic pen 1.

Examples of detachable connections between the holding means 6, 7 and the electronic pen 1 can be achieved, for example, via clamping and/or screwing and/or pressing and/or plugging together and/or positive locking and/or magnetic interaction and/or negative pressure or Suction pressure application or similar can be realized.

In the exemplary case shown, the holding means 6, 7 are configured so that the electronic pen 1 is fixed centrally within the housing 12 or centrally within the calibration device 11.

In the exemplary case shown, the holding means 6, 7 are in particular configured to fix the position/orientation/alignment of the recorded electronic pen 1 in such a way that the longitudinal axis 2 of the recorded electronic pen 1 is aligned with the longitudinal axis 10 of the housing 12 or with the longitudinal axis the calibration device 11 coincides.

In the exemplary case shown, the exemplary sensor axis/spatial axis 3 of the inertial measuring system of the inertial measuring sensor system 4 is parallel to the exemplary longitudinal axis 2 of the electronic pen 1 and thus also parallel to the longitudinal axis 10 of the calibration device.

The longitudinal axis 10 of the calibration device or the housing of the calibration device 11 also forms the axis of rotation for rotations of the calibration device with the electronic pen 1 inserted for calibrating the electronic pen 1.

As mentioned, the calibration device 11 or the housing 12 of the calibration device 11 can, among other things, be rotationally symmetrical with respect to the longitudinal axis 10 of the housing 12 or with respect to the longitudinal axis of the calibration device 11.

The 2 B shows an exemplary perspective side view of the in 2a Calibration device 11 shown with electronic pen 1 inserted.

The reference numbers of the 2 B therefore correspond to the reference numbers 2a or the 1 .

In this perspective, the exemplary rotational symmetry of the calibration device 11 or the calibration device housing 12 with respect to the longitudinal axis 10 of the housing 12 or with respect to the longitudinal axis of the calibration device 11 can be clearly seen.

In the example shown, the calibration device 11 or the housing 12 of the calibration device 11 is cylindrical or tube-like, the housing covers 8, 9 also being able to have a rotationally symmetrical cross section, in particular a circular cross section.

As already mentioned, however, rotationally symmetrical polygonal cross-sectional profiles are also conceivable for the calibration device 11 or for the housing 12 and the housing cover of the calibration device 11

In the perspective shown, it can also be clearly seen that the holding means 6, 7 can fix the electronic pen 1 centrally or centered within the calibration device 11, so that, for example, the longitudinal axis 2 of the electronic pen 1 received by the calibration device 11 is aligned with the longitudinal axis 10 of the Calibration device 11 or can coincide with the longitudinal axis of the calibration device housing 12.

As also already mentioned, the inertial measuring sensor system 4 can be arranged or oriented in such a way that a spatial axis of the inertial measuring system or a sensor axis is parallel to the longitudinal axis 2 of the electronic pen 1 or coincides with the longitudinal axis 2 of the electronic pen 1, or that a spatial axis of the inertial measuring system or a sensor axis is not oriented parallel or only approximately parallel to the longitudinal axis 2 of the electronic pen 1.

In the exemplary case shown, the exemplary sensor axis/spatial axis 3 of the inertial measuring system of the inertial measuring sensor system 4 is parallel to the exemplary longitudinal axis 2 of the electronic pen 1.

Since in the example shown the longitudinal axis 2 of the electronic pen 1 coincides with the longitudinal axis 10 of the calibration device 11, the sensor axis/spatial axis 3 of the inertial measuring system of the inertial measuring sensor system 4 of the electronic pen 1 is therefore also parallel with respect to the longitudinal axis 10 of the calibration device 11.

The 3a shows an exemplary measurement series 16 of measurement data 17 of an inertial measurement sensor system of an electronic pen without using a calibration device described herein.

The measurement data 17 represent, for example, acceleration measurements measured by the inertial measurement sensor system along a sensor axis/an axis of an orthogonal three-dimensional inertial measurement system of the inertial measurement sensor system of an electronic pen as a function of measured rotation angle positions.

The rotation angle positions can be measured, for example, by acceleration sensors of the inertial measuring sensor system, which can measure accelerations in the axes of said orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system. For example, if gravity is measured along two axes of the inertial measuring system, the angle of rotation or the angle of rotation position relative to the effect of gravity can be measured with acceleration sensors.

When recording the measurement data 17, the electronic pen was rotated several times, in the present case more than six times, continuously, i.e. without specific rest or holding positions, about its longitudinal axis and during the rotation process, acceleration measurements were taken continuously or quasi-continuously at fixed time intervals during the rotation process measured by at least one acceleration sensor of the inertial measuring sensor system of the electronic pen. The rotation speed of the calibration device 11 was approximately 2 seconds per revolution and the measuring frequency was 100 Hz. However, the rotation of the calibration device can also be carried out at other rotation speeds.

The time course 18 shown represents, by way of example, the acceleration measurements measured by an acceleration sensor of the inertial measuring sensor system of the electronic pen along an exemplary sensor axis/an axis of a/the orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system depending on the angular position of the electronic pen.

The abscissa axis 13 therefore represents the time course of the rotation of the electronic pen and the ordinate axis 14 represents the acceleration values/acceleration measured values measured by the inertial measuring sensor system of the electronic pen along the/an exemplary sensor axis.

In this example, a periodic relationship between measured acceleration values and the rotation angle position of the electronic pen, which continuously changes over time, can be recognized, but the clearly recognizable scatter/noise in the measured acceleration values prevents a zero point error in one Sensor axis can be determined with sufficient precision.

As already mentioned, a vertical shift/a shift in the course of the acceleration signal measured in an axis of an acceleration sensor along the ordinate 14 with respect to the zero line (dashed line) or the zero point 15 can serve as a measure of the zero point error in said acceleration sensor axis.

However, the measured acceleration signal 18 shown is simply too noisy to be able to determine a displacement, in particular a vertical displacement, of the acceleration signal 18 in relation to the zero point 15 of the ordinate axis 14 with sufficient accuracy for calibration purposes of the inertial measuring sensor system of the electronic pen.

Even if one were to model the measured acceleration signal 18 using a model function, the error in determining the displacement of the acceleration signal 18 would be too large to be able to meaningfully use a specific displacement of the acceleration signal 18 as a basis for determining a zero point error in an acceleration sensor axis.

The acceleration signal 18 measured without a calibration device is therefore completely unsuitable for calibrating the inertial measuring sensor system of the electronic pen.

The 3b shows an exemplary measurement series 22 of measurement data 23 of an inertial measurement sensor system of an electronic pen using a calibration device described herein.

The measurement data 23 represent, for example, acceleration measurements measured by the inertial measuring sensor system along a sensor axis/an axis of a/the orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system of an electronic pen as a function of measured rotation angle positions, while the electronic pen is in an exemplary calibration device and this is together with the electronic pen rotates around one/the longitudinal axis of the calibration device.

Said sensor axis can correspond to the sensor axis in which/along which the measurement data 17 of the measurement series 16 is also recorded during the 3a illustrated turning process of the electronic pen were recorded.

The rotation angle positions that are assumed/passed through by the calibration device during rotation can be measured, for example, by rotation rate sensors of the inertial measuring sensor system of the electronic pen, which can measure the rotation rates in the axes of said orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system. Alternatively, the signal can first be calibrated from the data from two acceleration sensors that are orthogonal to one another and to the axis of rotation in such a way that both sensors achieve the same measured value in both directions (positive and negative) if the series of measured values of the individual sensor is in each case over the angle of rotation Maximum and its minimum reached. This then ensures that both sensors are calibrated in both the zero point and the sensitivity with respect to the sensor axis. A correction of the uncalibrated measured value must be set both by a constant element (proportional to the zero point error) and by a proportionality factor of the measured value. The angle of rotation can then be calculated directly using the arctangent function of the ratio of the two orthogonal, calibrated acceleration measurements.

When recording the measurement data 23, the calibration device with the electronic pen picked up/inserted was rotated continuously, i.e. without specific rest or holding positions, by slightly more than one revolution about one/the longitudinal axis of the calibration device and during the rotation process the rotation was continuous or quasi-continuous Acceleration measurements are measured over the time course of the rotation process by at least one acceleration sensor of the inertial measuring sensor system of the electronic pen.

The time course 24 shown represents, by way of example, the acceleration measurement values measured by an acceleration sensor of the inertial measuring sensor system of the electronic pen along an exemplary sensor axis/an axis of a/the orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system depending on the rotational angular position of the calibration device.

The abscissa axis 19 therefore represents the angular position of the calibration device or the angular position of the electronic pen located in the calibration device.

The ordinate axis 20 represents acceleration values/acceleration measured values measured by the inertial measurement sensor system of the electronic pen along the/an exemplary sensor axis.

For the sake of completeness, it should be mentioned that in comparison to the 3a shown course 18 of the acceleration signal, which is in 3b The curve 24 of the acceleration signal shown is stretched because measurement data was only recorded over a little more than one revolution.

In addition, in the series of measurements 22 of the 3b the rotation process of the calibration device with the electronic pen inserted is carried out with a different direction of rotation compared to the rotation process which corresponds to the measurement series 16 of the 3a underlying.

The exemplary differences mentioned between the in 3a and 3b However, the turning processes shown do not in any way prevent a comparison of the two turning processes for a better understanding of technical aspects of the invention.

Independent of the different number of revolutions and independent of the different direction of rotation and also independent of possible different rotation speeds, at first glance it is clear 3b It can be seen that when using the calibration device, a significantly less noisy curve 24 of the acceleration measured values or the acceleration signal results than in comparison to the one in the 3a shown course 18 without using the calibration device.

The use of the calibration device enables the generation of an almost noise-free acceleration signal from the acceleration sensors of the inertial measuring sensor system of the electronic pen during a rotation process of the calibration device with the electronic pen recorded.

The acceleration signal 24 generated using the calibration device represents an almost ideal sinusoidal curve, which, as described above, can be modeled with great accuracy.

As mentioned, a vertical shift/a shift 25 of the course of the acceleration signal measured in an axis of an acceleration sensor along the ordinate 20 with respect to the zero line (dashed) or the zero point 21 can serve as a measure of the zero point error in said acceleration sensor axis.

In contrast to the acceleration signal 18 without a calibration device, the acceleration signal 24 generated by using the calibration device can now be modeled with sufficient accuracy, for example by a model function as described above, which can include a sine function and a vertical displacement term.

Using an optimization algorithm as described above, those parameter values of the parameters of the modeling function can then be found which best describe the measured course of the recorded acceleration measured values depending on the rotation angle positions of the calibration device or minimize a cost function.

The determined vertical displacement / the value of the vertical displacement of the model function / model function curve that best describes the measurement data / the acceleration measured values / the acceleration signal with respect to the zero line 21 can then serve as a measure for the zero point error, or as a zero point error value, in the corresponding acceleration sensor axis .

As already mentioned, it was surprisingly found that a practically noise-free acceleration signal, which is suitable for calibrating the inertial measuring sensor system of an electronic pen, can be generated even if the longitudinal axis or the rotation axis of the calibration device is not exactly aligned with one of the longitudinal axis of the electronic pen and/or with a sensor axis/axis of the inertial measuring system of the inertial measuring sensor system of the electronic pen coincides or is not exactly parallel.

The 3c represents a further exemplary measurement series 28 of measurement data 29 of an inertial measurement sensor system of an electronic pen using a calibration device described herein.

In contrast to the previous illustrations ( 3a and 3b) , in which the measured values are shown along an axis of the acceleration sensor that is perpendicular to the axis of rotation, the values of the axis of the acceleration sensor that is approximately parallel to the axis of rotation can be seen here.

The fact that the signal can again be modeled by a sine function is due to an exemplary angular error, an exemplary non-zero angular orientation that the sensor axis assumes in relation to the axis of rotation. Both the individual measured values (29) and the model function (30) are shown. The model function was found by minimizing the error squares.

The measurement data 29 represent, for example, acceleration measurements measured by the inertial measurement sensor system along a sensor axis/an axis of an orthogonal three-dimensional inertial measuring system of the inertial measuring sensor system of an electronic pen depending on measured rotation angle positions, while the electronic pen is in an exemplary calibration device and this, together with the electronic pen, rotates about one/the longitudinal axis of the calibration device.

The abscissa axis 26 in turn represents the rotation angle positions of the calibration device or the rotation angle position of the electronic pen located in the calibration device.

The ordinate axis 27 represents acceleration values/acceleration measured values measured by the inertial measurement sensor system of the electronic pen along the/an exemplary sensor axis.

It should also be mentioned that in the example shown, the acceleration sensor axis in which the measurement data 29 were measured is not or not exactly parallel to the axis of rotation of the calibration device, or does not coincide with the axis of rotation of the calibration device, but the course 39 of the acceleration signal / or the measurement data 29 has a sufficiently large signal-to-noise ratio so that a zero point error can be determined for calibration purposes.

In the 3c In addition, a model function/model function curve 30 (best fit curve) that best describes the measurement data 29 or the course 39 of the measurement data is shown as an example.

By modeling the measurement data 29 with the model function, as already explained, the vertical displacement of the model function / model function curve 30 can be determined with respect to the zero point 40 / the zero line and thus a zero point error value can be determined in the corresponding acceleration sensor axis.

It should also be mentioned that in the example shown, the acceleration sensor axis in which the measurement data 29 were measured is not or not exactly parallel to the axis of rotation of the calibration device, or does not coincide with the axis of rotation of the calibration device, but the course 39 of the acceleration signal / or the measurement data 29 has a sufficiently large signal-to-noise ratio so that a zero point error can be determined for calibration purposes.

The distance or offset 32 of the symmetry axis 31 of the model function from the zero axis 40 of the sensor signal characterizes the zero point error of the sensor. This is constant over time and therefore produces a constant shift in the measured values in one direction.

In contrast, the amplitude 33 of the model function characterizes the angular error between the axis of rotation and the sensor axis. The arctangent of half the amplitude, normalized by the measured value of the sensor axis when aligned parallel to the axis of gravitational acceleration, results in the angular error between the axis of rotation of the calibration device and the sensor axis.

As already mentioned, the inertial measuring sensor system of the electronic pen can be configured in such a way, or a calibration process can be carried out, in such a way that acceleration measured values were only recorded in a well-defined rest position of the calibration device, i.e. the calibration device remains in a certain rotation angle position for a period of time not moved.

In 3d an exemplary section of an exemplary measurement series 34 is shown, in which the calibration device with the electronic pen inserted was rotated over 180 ° about its Y axis. The reference numbers 35, 36 and 37 identify sequences of integrated measured values around one of the three sensor axes of an exemplary rotation rate sensor of the inertial measurement sensor system of the electronic pen. The term sequence refers to the running sum over time, which is obtained by integrating the rotational speed over time and adding all measured values up to the respective point in time of the measurement during one rotation.

The rotation took place in the time range 38 and it can be clearly seen that the rotation took place mainly around the Y-axis (sequence 37), while the other two sequences 36 and 37 show practically no change in their value over time. There are small fluctuations in the time range 38 of the rotation alone, since the rotation did not take place exclusively around the Y axis.

In the case shown, an exemplary calibration device was used which has a polygonal cross section and whose side surface geometry can determine the rotation angle positions/angle steps and said rest positions that can be assumed during a rotation process. The angle change integrated when the calibration device rotates from one side to the opposite side would be exactly π if the rotation rate sensor delivers correct values. For the exemplary calibration, a factor can therefore be calculated from π divided by the integrated angle change. Future measurements can then be corrected with this factor to obtain a calibrated angular velocity.

For the sake of completeness, it should be mentioned that the in 3a , 3b , 3c and 3d exemplary turning operations carried out were carried out on a flat surface.

However, it should be noted that the use of a flat surface as a base for performing the rotations is purely optional.

The 4 represents an exemplary schematic flowchart for an exemplary method 10 for calibrating an inertial measurement sensor system of an electronic pen.

• • Ein Einlegen, 101, des elektronischen Schreibstiftes in eine wie oben beispielhaft beschriebene Kalibriervorrichtung.
• • Ein Drehen, 102, der Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift um wenigstens eine Achse, z.B. eine/die Längsachse, der Kalibriervorrichtung, wobei während der Drehung der Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift Messdaten der inertialen Messsensorik des elektronischen Schreibstiftes aufgenommen, 103, werden, und wobei die aufgenommenen Messdaten Beschleunigungsmesswerte von wenigstens einem Beschleunigungssensor der inertialen Messsensorik umfassen können.
• • Eine Bestimmung, 104, wenigstens eines Nullpunktfehlers in wenigstens einer Achse des Beschleunigungssensor der inertialen Messsensorik durch Auswertung der aufgenommenen Messdaten.
• • Eine Kalibrierung, 105, der inertialen Messsensorik des elektronischen Schreibstiftes auf Grundlage des wenigstens einen bestimmten Nullpunktfehlers.

The exemplary method 100 can include one, some or all of the following steps:

• • Insertion, 101, of the electronic pen into a calibration device as described above as an example.
• • A rotation, 102, of the calibration device with the electronic pen inserted about at least one axis, for example one/the longitudinal axis, of the calibration device, with measurement data from the inertial measurement sensors of the electronic pen being recorded during the rotation of the calibration device with the electronic pen inserted, 103, and wherein the recorded measurement data can include acceleration measurement values from at least one acceleration sensor of the inertial measurement sensor system.
• • A determination, 104, of at least one zero point error in at least one axis of the acceleration sensor of the inertial measuring sensor system by evaluating the recorded measurement data.
• • A calibration, 105, of the inertial measuring sensor system of the electronic pen based on the at least one specific zero point error.

The 5 represents an exemplary cuboid-shaped calibration device 200, ie a calibration device that has a cuboid-shaped housing 199.

The calibration device 200 or the calibration device housing 199 therefore has six different sides or side surfaces 201, 202, 203, 204, 205, 206 and twelve edges / edge axes / side axes 207, 208, 209, 210, 211, 212, 213, 214 , 215, 216, 217, 218 on.

The calibration device 200 can accommodate an electronic pen and fix it in a predeterminable alignment/orientation within the calibration device housing 199.

However, for reasons of clarity, an electronic pen recorded by the calibration device 200 is not shown. However, it can be assumed, for example, that an electronic pen is accommodated and fixed in the calibration device 200 in such a way that an axis, e.g. the longitudinal axis, of the electronic pen is parallel or approximately parallel to one of the edge axes / side axes 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218 of the calibration device 200 is aligned.

The reference number 219 denotes, by way of example, a three-dimensional orthogonal coordinate system, which is spanned by the three orthogonal axes x, y, z. Said axes can, for example, correspond to the axes of the acceleration sensors and/or rotation rate sensors of the inertial measuring sensor system of an electronic pen, which can be picked up and calibrated by the calibration device 200.

In the example shown, the xy coordinate plane is parallel to the side surfaces 205, 206 of the calibration device 200.

The calibration device 200 is shown in an exemplary rest position, in which the side surface 205 can serve as an exemplary support surface on a flat surface (not shown).

1. 1. Kippen / Drehen / Rotieren der Kalibriervorrichtung 200 aus der dargestellten (ersten) Ruheposition, in der sie auf der Fläche 201 ruht, um 180° um die Seitenachsen 208 und 212, also um eine Achse parallel zur X-Achse des Koordinatensystems 219, sodass die Kalibriervorrichtung 200 in eine Ruheposition überführt wird, in der die Seitenfläche 203 als Auflagefläche der Kalibriervorrichtung 200 dienen kann. Dies kann beispielsweise der Kalibration der Skalierung der inertialen Messsensorik entlang der Z-Achse dienen.
2. 2. Kippen / Drehen / Rotieren der Kalibriervorrichtung 200, ausgehend von einer Ruheposition in der die Kalibriervorrichtung 200 auf der Seitenfläche 205 ruht, um 180° um die Seitenachsen 207 und 209, also um eine Achse parallel zur Y-Achse des Koordinatensystems 219, sodass die Kalibriervorrichtung 200 auf Seitenfläche 206 ruht. Dies kann beispielsweise der Kalibration der Skalierung der inertialen Messsensorik entlang der X-Achse dienen.
3. 3. Kippen / Drehen / Rotieren der Kalibriervorrichtung 200, ausgehend von einer Ruheposition in der die Kalibriervorrichtung 200 auf der Seitenfläche 202 ruht, um 180° um die Seitenachsen 216 und 217, also um eine Achse parallel zur Z-Achse des Koordinatensystems 219, sodass die Kalibriervorrichtung 200 auf Seitenfläche 204 ruht. Dies kann beispielsweise der Kalibration der Skalierung der inertialen Messsensorik entlang der Y-Achse dienen.

An exemplary sequence of step-by-step rotation processes of the calibration device 200 with a recorded electronic pen as part of a method for calibrating an inertial measuring sensor system of an electronic pen can include one, some or all of the following rotation steps/rotation steps/tilting steps.

1. 1. Tilting/rotating/rotating the calibration device 200 from the illustrated (first) rest position, in which it rests on the surface 201, by 180° about the side axes 208 and 212, i.e. about an axis parallel to the X-axis of the coordinate system 219, so that the calibration device 200 is transferred to a rest position in which the side surface 203 can serve as a support surface for the calibration device 200. This can be used, for example, to calibrate the scaling of the inertial measuring sensors along the Z axis.
2. 2. Tilting/rotating/rotating the calibration device 200, starting from a rest position in which the calibration device 200 rests on the side surface 205, by 180° about the side axes 207 and 209, i.e. about an axis parallel to the Y-axis of the coordinate system 219, so that the calibration device 200 rests on side surface 206. This can be used, for example, to calibrate the scaling of the inertial measuring sensors along the X-axis.
3. 3. Tilting/rotating/rotating the calibration device 200, starting from a rest position in which the calibration device 200 rests on the side surface 202, by 180° about the side axes 216 and 217, i.e. about an axis parallel to the Z axis of the coordinate system 219, so that the calibration device 200 rests on side surface 204. This can be used, for example, to calibrate the scaling of the inertial measuring sensors along the Y axis.

As described above, measurement data from the acceleration sensors and rotation rate sensors can be collected during the exemplary rotation processes and/or in the rest positions in order to calibrate the inertial measurement sensors of the electronic pen.

This is followed by 9 pages with the 1 , 2a , 2 B , 3a , 3b , 3c , 3d , 4 and 5 .

1

Beispielhafter elektronischer Schreibstift

2

Beispielhafte Längsachse des elektronischen Schreibstiftes (gestrichelte Line mit erster Strichlänge)

3

Beispielhafte Sensorachse / Raumachse eines beispielhaften dreidimensionalen Inertialmesssystems der inertialen Messsensorik des elektronischen Schreibstiftes (gestrichelte Line mit zweiter Strichlänge)

4

Beispielhafte inertiale Messsensorik

5

Beispielhafte Schreibspitze / Schreibmine

6

Beispielhaftes (erstes) Haltemittel / Haltelement / Halterung

7

Beispielhaftes (zweites) Haltemittel / Haltelement / Halterung

8

Beispielhaftes (erstes) Ende des Gehäuses der Kalibriervorrichtung / Gehäusedeckel

9

Beispielhaftes (zweites) Ende des Gehäuses der Kalibriervorrichtung / Gehäusedeckel

10

Beispielhafte Längsachse der Kalibriervorrichtung / Längsachse des Gehäuses der Kalibriervorrichtung / Längsachse der Kalibriervorrichtung / Rotationsachse der Kalibriervorrichtung

11

Beispielhafte Kalibriervorrichtung

12

Beispielhaftes Gehäuse der Kalibriervorrichtung

13

Beispielhafte Abszissenachse für Drehwinkelpositionen oder Drehwinkel von elektronischem Schreibstift

14

Beispielhafte Ordinatenachse für gemessene Beschleunigungswerte / Beschleunigungsmesswerte

15

Beispielhafter Nullpunkt der Ordinatenachse für gemessene Beschleunigungswerte/Nulllinie

16

Beispielhafte Messreihe von Beschleunigungswerte ohne Verwendung einer Kalibriervorrichtung

17

Beispielhafter Messpunkt / Beschleunigungsmesswert

18

Beispielhafter (zeitlicher) Verlauf der Messpunkte / Beschleunigungsmesswerte / Beschleunigungssignal

19

Beispielhafte Abszissenachse für Drehwinkelpositionen oder Drehwinkel von Kalibriervorrichtung, bzw. für Drehwinkelpositionen oder Drehwinkel von elektronischem Schreibstift

20

Beispielhafte Ordinatenachse für gemessene Beschleunigungswerte / Beschleunigungsmesswerte

21

Beispielhafter Nullpunkt der Ordinatenachse für gemessene Beschleunigungswerte/Nulllinie

22

Beispielhafte Messreihe von Beschleunigungswerte mit Verwendung einer Kalibriervorrichtung

23

Beispielhafter Messpunkt / Beschleunigungsmesswert

24

Beispielhafter (zeitlicher) Verlauf der Messpunkte / Beschleunigungsmesswerte / Beschleunigungssignal

25

Beispielhafte vertikale Verschiebung

26

Beispielhafte Abszissenachse für Drehwinkelpositionen oder Drehwinkel von elektronischem Schreibstift

27

Beispielhafte Ordinatenachse für gemessene Beschleunigungswerte / Beschleunigungsmesswerte

28

Beispielhafte Messreihe von Beschleunigungswerte mit Verwendung einer Kalibriervorrichtung

29

Beispielhafter Messpunkt / Beschleunigungsmesswert (an einer bestimmten Ruheposition und einer bestimmten Drehwinkelposition in einer Folge von schrittweisen Drehwinkelschritten)

30

Beispielhafte die Messreihe am besten beschreiben Modellfunktion (Best-Fit-Model)

31

Beispielhafte Symmetrieachse der Modellfunktion

32

Beispielhafter Abstand bzw. Offset der Symmetrieachse der Modellfunktion von der Nullachse / beispielhafter Nullpunktfehler / beispielhafte Nullpunktabweichung der Modellfunktion des Verlaufs der Messpunkte / Beschleunigungsmesswerte / des Beschleunigungssignals

33

Beispielhafte Amplitude der Modellfunktion des Verlaufs der Messpunkte / Beschleunigungsmesswerte / des Beschleunigungssignals

34

Beispielhafte Messreihe von aufintegrierten Drehratenwerten eines Drehratensensors einer inertialen Messsensorik eines elektronischen Schreibstiftes für eine beispielhafte Drehung einer Kalibriervorrichtung mit eingelegtem elektronischen Schreibstift um 180°

35

Beispielhafter Verlauf / beispielhafte Folge der aufintegrierten X-Werte des Drehratensensors

36

Beispielhafter Verlauf / beispielhafte Folge der aufintegrierten Z-Werte des Drehratensensors

37

Beispielhafter Verlauf / beispielhafte Folge der aufintegrierten Y-Werte des Drehratensensors

38

Beispielhafter zeitlicher Bereich, in der die Kalibriervorrichtung um 180° gedreht wird/wurde

39

Beispielhafter (zeitlicher) Verlauf der Messpunkte / Beschleunigungsmesswerte / des Beschleunigungssignals

40

Beispielhafte Nulllinie, beispielhafter Nullpunkt

41

Beispielhafte Abszissenachse, beispielhafte Zeitachse, beispielhafte chronologische Abfolge von Messpunkten

42

Beispielhafte Ordinatenachse, beispielhaftes aufintegriertes Drehratensensorsignal / aufintegrierte Drehratenmesswerte, beispielhafte Drehwinkel, beispielhafte Messeinheit Radiant (rad)

100

Beispielhaftes Verfahren zur Kalibrierung einer inertialen Messsensorik eines elektronischen

101, 102, 103, 104, 105

Beispielhafte Verfahrensschritte

199

Beispielhaftes quaderförmiges Gehäuse einer Kalibriervorrichtung

200

Beispielhafte quaderförmige Kalibriervorrichtung

201, 202, 203, 204, 205, 206

Beispielhafte Seiten / Seitenflächen der Kalibriervorrichtung / des Kalibriervorrichtungsgehäuses

207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218

Beispielhafte Kantenachsen / Seitenachsen der Kalibriervorrichtung / des Kalibriervorrichtungsgehäuses

219

Beispielhaftes dreidimensionales orthogonales Koordinatensystem

The reference numbers are assigned as follows.

1

Exemplary electronic writing pen

2

Example of the longitudinal axis of the electronic pen (dashed line with first line length)

3

Exemplary sensor axis / spatial axis of an exemplary three-dimensional inertial measuring system of the inertial measuring sensor system of the electronic pen (dashed line with second line length)

4

Exemplary inertial measurement sensors

5

Exemplary writing tip/refill

6

Exemplary (first) holding means / holding element / holder

7

Exemplary (second) holding means / holding element / holder

8th

Exemplary (first) end of the calibration device housing / housing cover

9

Example (second) end of the calibration device housing / housing cover

10

Exemplary longitudinal axis of the calibration device / longitudinal axis of the housing of the calibration device / longitudinal axis of the calibration device / axis of rotation of the calibration device

11

Exemplary calibration device

12

Exemplary housing of the calibration device

13

Example abscissa axis for rotation angle positions or rotation angle of electronic pen

14

Example ordinate axis for measured acceleration values/acceleration measurement values

15

Example of zero point of the ordinate axis for measured acceleration values/zero line

16

Example series of measurements of acceleration values without using a calibration device

17

Example measuring point / acceleration measurement value

18

Example (over time) of the measuring points / acceleration measured values / acceleration signal

19

Example abscissa axis for angle of rotation positions or angle of rotation of calibration device, or for angle of rotation positions or angle of rotation of electronic pen

20

Example ordinate axis for measured acceleration values/acceleration measurement values

21

Example of zero point of the ordinate axis for measured acceleration values/zero line

22

Example series of measurements of acceleration values using a calibration device

23

Example measuring point / acceleration measurement value

24

Example (over time) of the measuring points / acceleration measured values / acceleration signal

25

Example vertical displacement

26

Example abscissa axis for rotation angle positions or rotation angle of electronic pen

27

Example ordinate axis for measured acceleration values/acceleration measurement values

28

Example series of measurements of acceleration values using a calibration device

29

Example measuring point / acceleration measurement value (at a specific rest position and a specific rotation angle position in a sequence of gradual rotation angle steps)

30

Examples of the series of measurements that best describe the model function (best-fit model)

31

Example symmetry axis of the model function

32

Example distance or offset of the symmetry axis of the model function from the zero axis / example zero point error / example zero point deviation of the model function of the course of the measuring points / acceleration measured values / the acceleration signal

33

Example amplitude of the model function of the course of the measuring points / acceleration measured values / the acceleration signal

34

Exemplary measurement series of integrated rotation rate values of a rotation rate sensor of an inertial measurement sensor system of an electronic pen for an exemplary rotation of a calibration device with an inserted electronic pen by 180°

35

Example course/example sequence of the integrated X values of the yaw rate sensor

36

Example course/example sequence of the integrated Z values of the yaw rate sensor

37

Example course/example sequence of the integrated Y values of the yaw rate sensor

38

Example of a time range in which the calibration device is/was rotated by 180°

39

Example (over time) of the measuring points / acceleration measured values / the acceleration signal

40

Example zero line, example zero point

41

Example of abscissa axis, example of time axis, example of chronological sequence of measuring points

42

Example of ordinate axis, example of integrated yaw rate sensor signal/integrated yaw rate measured values, example of angle of rotation, example of measurement unit radian (rad)

100

Exemplary method for calibrating an inertial measuring sensor system of an electronic

101, 102, 103, 104, 105

Example procedural steps

199

Exemplary cuboid housing of a calibration device

200

Exemplary cuboid calibration device

201, 202, 203, 204, 205, 206

Example sides/side surfaces of the calibration device/calibration device housing

207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218

Example edge axes / side axes of the calibration device / the calibration device housing

219

Exemplary three-dimensional orthogonal coordinate system

Claims (6)

Calibration device (11) for calibrating an inertial measuring sensor system (4) of an electronic pen (1), comprising: a housing (12) for holding an electronic pen (1), wherein the housing (12) has at least one holding means (6, 7) for fixing an electronic pen (1) received by the housing (12). Calibration device (11) according to the previous claim, wherein the at least one holding means (6, 7) is configured to fix a recorded electronic pen (1) centrally within the housing (12) and / or wherein the at least one holding means (6, 7) is configured to fix a recorded electronic pen (1) so that the longitudinal axis (2) of the recorded electronic pen is oriented parallel to the longitudinal axis (10) of the housing (12) or that the longitudinal axis (2) of the recorded electronic Pen coincides with the longitudinal axis (10) of the housing (12). Calibration device (11) according to one of the preceding claims, wherein the cross section of the housing is rotationally symmetrical and/or is cylindrical or polygonal, e.g. rectangular, and/or wherein the housing is cubic or cuboid. Calibration device (11) according to one of the preceding claims, wherein the holding means is flexible and / or wherein the housing (12) has at least two holding means (6, 7) and wherein one holding means is arranged at one end of the housing and / or wherein the holding means fills the majority of the interior of the housing of the (12) calibration device (11). Calibration device (11) according to one of the preceding claims, wherein the at least one holding means (6, 7) is integrated into a housing cover (8, 9) or housing base of the housing and/or wherein the housing (12) is permeable to electromagnetic waves. System comprising a calibration device (11) according to one of the previous device claims and an electronic pen (1) with inertial measuring sensors.

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