US20150343293A1

US20150343293A1 - Measuring device for detecting a hitting movement of a hitting implement, training device, and method for training a hitting movement

Info

Publication number: US20150343293A1
Application number: US14/654,586
Authority: US
Inventors: Ann Koo; Uwe Richter
Original assignee: Applejack 199 LP
Current assignee: Applejack 199 LP
Priority date: 2012-12-21
Filing date: 2013-12-20
Publication date: 2015-12-03
Also published as: CN105007995B; WO2014097265A1; US20160101316A1; US9914018B2; US20140235348A1; CN105007995A; DE102012224321A1; US9457229B2; US9272199B2; US20140179455A1; TWI577430B; TW201542279A; DE102012224321B4

Abstract

The invention relates to a measuring device for detecting a hitting movement of a hitting implement. The measuring device comprises at least one two-dimensional acceleration sensor for detecting a two-dimensional acceleration vector (

_xy). The measuring device comprises at least one one-dimensional acceleration sensor for detecting a one-dimensional acceleration vector (

_z). In addition, the measuring device comprises a first rotation angle sensor for detecting a first rotation angle of the two-dimensional acceleration vector (

_xy) about a z-axis.

Description

The invention relates to a measuring device for detecting a hitting movement of a hitting implement according to the preamble of Claim 1, a training device for training a hitting movement of a hitting implement according to the preamble of Claim 20, and a method for training a hitting movement of a hitting implement on a distinguished swing path according to the preamble of Claim 27.
A measuring device of the type mentioned above, serving for determining a hitting movement, comprises at least one two-dimensional acceleration sensor for detecting a two-dimensional acceleration vector, at least one one-dimensional acceleration sensor for detecting a one-dimensional acceleration vector, wherein the at least one one-dimensional acceleration vector is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the detected one-dimensional acceleration vector runs substantially orthogonally with respect to the two-dimensional acceleration vector detected by the at least one two-dimensional acceleration sensor, and a first rotation angle sensor for detecting a rotation angle of the two-dimensional acceleration vector about a z-axis, wherein the first rotation angle sensor is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the z-axis extends substantially orthogonally with respect to the two-dimensional acceleration vector. For sports involving hitting a ball with a hitting implement, such as e.g. golf, baseball, tennis or ice hockey, as is known it is advantageous to guide the hitting implement on a distinguished swing path during the hitting movement. Otherwise, considerable deviations from the intended trajectory of the ball can occur. Guiding the hitting implement on a distinguished path can be learned and trained. This necessitates identifying the distinguished swing path and ascertaining the deviation of the hitting implement from said distinguished swing path.
DE 10 2006 008 333 B4 discloses a measuring device of the type described in the introduction. Said measuring device determines the data relevant to training a hitting movement predominantly by means of the acceleration sensors. However, the starting point of a hit cannot always be determined unambiguously from the data obtained by the acceleration sensors. This entails the consequence that data dependent on the starting point of the hit, such as e.g. the hitting velocity or the point in time of the greatest acceleration, may also be erroneous. A further problem, for example in golf, is that a sensor which is sensitive to putting exceeds its range in the case of a swing at higher velocity. Accordingly, the measuring device from the prior art is not suitable both for putting and for swings at higher velocity.
The invention addresses the problem of specifying a measuring device having increased precision.
This problem is solved by the features of Claim 1.
Accordingly, the measuring device comprises a second rotation angle sensor for detecting a second rotation angle of the one-dimensional acceleration vector about a y-axis, wherein the second rotation angle sensor is arranged with respect to the at least one one-dimensional acceleration sensor in such a way that the y-axis extends substantially perpendicularly to the one-dimensional acceleration vector. This measuring device, for example when used for golf, can detect swings at higher velocity and likewise putting movements.
The rotation angle sensors can generally be means for detecting the angular velocity. Such means are gyroscope sensors, for example. The gyroscope sensors are advantageously embodied as microelectromechanical systems, so-called MEMS. For specific applications, mechanical gyroscope sensors can also be used. For the sake of simplicity, the two rotation angle sensors can be structurally identical. Furthermore, the two rotation angle sensors can be integrated in one component. Since they are provided for measuring two rotation angles about two axes that run substantially orthogonally with respect to one another, the two rotation angle sensors are are arranged substantially orthogonally with respect to one another. The rotation angle sensors are suitable for resolving movements of a duration of a few milliseconds. If gyroscope sensors are used as rotation angle sensors, then preferably those having a measurement range of 50 to 2000°/s, in particular of 400 to 800°/s, particularly preferably of 550 to 650°/s, should be chosen.
In accordance with one embodiment, the measuring device comprises at least one two-dimensional acceleration sensor and two one-dimensional acceleration sensors. In accordance with a further embodiment, the measuring device comprises two two-dimensional acceleration sensors and two one-dimensional acceleration sensors. The two two-dimensional acceleration sensors and the two one-dimensional acceleration sensors are preferably sensitive in different measurement ranges in each case. Accordingly, one two-dimensional acceleration sensor and one one-dimensional acceleration sensor can be designed and provided for measurements of slow hits in a measurement range of 0 to 15 g, in particular of 0 to 10 g. By contrast, the other two-dimensional acceleration sensor and the other one-dimensional acceleration sensor can be designed and provided for measurements of fast hits in a measurement range of 5 to 250 g, in particular of 15 to 100 g.
In accordance with one embodiment, the measuring device comprises two two-dimensional acceleration sensors for detecting a two-dimensional acceleration vector, two one-dimensional acceleration sensors for detecting a one-dimensional acceleration vector, wherein the one-dimensional acceleration sensors are arranged with respect to the two-dimensional acceleration sensors in such a way that the detected one-dimensional acceleration vector runs substantially orthogonally with respect to the two-dimensional acceleration vector detected by the two-dimensional acceleration sensors, a first rotation angle sensor for detecting a first rotation angle of the two-dimensional acceleration vector about a z-axis, wherein the first rotation angle sensor is arranged with respect to the two-dimensional acceleration sensors in such a way that the z-axis extends substantially orthogonally with respect to the two-dimensional acceleration vector, and a second rotation angle sensor for detecting a second rotation angle of the one-dimensional acceleration vector about a y-axis, wherein the second rotation angle sensor is arranged with respect to the one-dimensional acceleration sensors in such a way that the y-axis extends substantially perpendicularly to the one-dimensional acceleration vector. In accordance with this embodiment, the two-dimensional acceleration sensors are sensitive in different measurement ranges in each case. In addition, the one-dimensional acceleration sensors are sensitive in different measurement ranges in each case. In particular, the two-dimensional acceleration sensors and/or the one-dimensional acceleration sensors are designed to carry out measurement simultaneously in each case.
Alternatively, the measuring device can also comprise only respectively one two-dimensional acceleration sensor and one-dimensional acceleration sensor. In order nevertheless to be able to detect both fast hits and slow hits by means of one measuring device, an amplifier can be provided for each sensor. Suitable amplifiers are, for example, continuously variable amplifiers which amplify by a factor of 1 to 16.
The sensors for measuring the acceleration and the rotation angles of the hitting implement can be embodied as microelectromechanical systems, so-called MEMS. MEMS have the advantage that, firstly, they can be produced cost-effectively and, secondly, they have a low energy consumption. In addition, they usually have a higher reliability than conventional systems.
In order to be able to analyze the temporal profile of a hit, it is expedient additionally to provide a means for time measurement. Consequently, a point in time can be assigned to each measurement point of the acceleration and rotation angle sensors and the hit can be analyzed in a temporally resolved manner.
In accordance with one embodiment, the measuring device comprises computing means, which are provided for processing the raw data determined by the acceleration sensors and rotation angle sensors and for providing conditioned data. The conditioned data are data which the user can use directly for assessing the quality of his/her hitting movement. Such conditioned data are, for example, the orientation of the hitting implement, the maximum acceleration, the duration of the individual phases of the hit, and the force distribution and/or accelerations during the individual phases and the swing path. From these conditioned data, it is possible to derive further data such as, for example, the point in time of the highest velocity of the hitting implement and therefrom the location and/or the angle at the point in time of the highest velocity.
The computing means can additionally have an interface in order to transmit the raw data and/or the conditioned data to external data processing systems. Alternatively, the sensors can also have an interface of this type. In this case, it is possible to dispense with a computing means as part of the measuring device and the data can be processed directly on external data processing systems.
Since it is often unnecessary for the totality of all the conditioned data to be provided, an operating element can be provided, with which a user can select which conditioned data are generated by the computing means. As a result, computing time can be saved, such that the conditioned data are available more rapidly. Moreover, the desired conditioned data are more easily evident to the user.
As mentioned in the introduction, the measuring device is intended to serve to train the movement of a hitting implement on a distinguished swing path. Deviations from this swing path can have the effect that the ball misses its target. Therefore, it is of particular interest whether the hitting movement deviates from the distinguished swing path, and if so when and to what extent. For this purpose, it is necessary for the measurement data to be processed and evaluated by the computing means in real time. Furthermore, the computing means can be provided for comparing the raw data determined by the acceleration sensors and rotation angle sensors and/or the conditioned data with corresponding reference data that correspond to the distinguished swing path. In order to inform the user about the occurrence of the deviation as early as at the moment when said deviation occurs, the measuring device can comprise a signal generator. The latter supplies the user with a signal, for example, as soon as a deviation is measured. Alternatively, a signal can be generated by the signal generator only if the difference (deviation) between the raw data and/or the conditioned data exceeds a defined limit value. Moreover, the intensity of the signal can correlate with the magnitude of the deviation. The signal can be acoustic, optical and/or mechanical.
Advantageously, all sensors and, if present, also the means for time measurement, the computing means and the signal generator are accommodated in a housing. A securing means is provided on the housing in order to secure the measuring device releasably on a hitting implement. Simple handling of the measuring device is made possible as a result. Alternatively, the measuring device can also be secured non-releasably on the hitting implement. By way of example, the measuring device can be arranged in a cavity of the hitting implement. In accordance with a further alternative, the securing means can be embodied such that it enables the measuring device to be secured indirectly or directly on a body of a user of the measuring device. In particular, the securing means can be provided for securing the measuring device on a hand or in the vicinity of a wrist, such that the hitting movement of the hitting implement can be detected via the movement of the hand holding the hitting implement. By way of example, the securing means can be a glove or a wristband.
A training device for training a hitting movement of a hitting implement is specified in Claim 20. In accordance with one specific configuration, the training device comprises a hitting implement, with which a user trains the hitting movement, and at least one measuring device for detecting the hitting movement of the hitting implement. The hitting implement defines a hitting implement axis. The measuring device is secured releasably on the hitting implement. The measuring device comprises at least one two-dimensional acceleration sensor for detecting a two-dimensional acceleration vector. In addition, the measuring device comprises at least one one-dimensional acceleration sensor for detecting a one-dimensional acceleration vector, wherein the at least one one-dimensional acceleration sensor is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the detected one-dimensional acceleration vector runs substantially orthogonally with respect to the two-dimensional acceleration vector detected by the at least one two-dimensional acceleration sensor. Furthermore, the measuring device comprises a first rotation angle sensor for detecting a first rotation angle of the two-dimensional acceleration vector about a z-axis, wherein the first rotation angle sensor is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the z-axis extends substantially orthogonally with respect to the two-dimensional acceleration vector. The training device is distinguished by the fact that the measuring device comprises a second rotation angle sensor for detecting a second rotation angle of the one-dimensional acceleration vector about a y-axis, wherein the second rotation angle sensor is arranged with respect to the at least one one-dimensional acceleration sensor in such a way that the axis extends substantially orthogonally with respect to the one-dimensional acceleration vector.
There are diverse possibilities for aligning the measuring device on the hitting implement, since the sensors in their entirety are not spherically symmetrical. In one advantageous configuration, the measuring device can be oriented in relation to the hitting implement axis in such a way that the two-dimensional acceleration sensor detects a two-dimensional acceleration vector of the hitting implement which runs orthogonally with respect to the hitting implement axis, that the one-dimensional acceleration sensor detects a one-dimensional acceleration vector of the hitting implement which runs parallel to the hitting implement axis, that the first rotation angle sensor detects a first rotation angle of the hitting implement about the hitting implement axis, and that the second rotation angle sensor detects a second rotation angle of the hitting implement about the y-axis, which extends substantially perpendicularly to the hitting implement axis.
In accordance with one particularly advantageous embodiment, the training device comprises at least one body sensor besides the measuring device secured on the hitting implement. The at least one body sensor is a sensor provided for measuring the movement of a body or of a body part of a user of the training device. For this purpose, the at least one body sensor can be secured indirectly or directly on at least one location of the body of the user. The body sensor can comprise at least one acceleration sensor, at least one rotation angle sensor or a combination of at least one acceleration sensor and at least one rotation angle sensor. The measurement of the at least one body sensor is advantageously effected simultaneously with the measurement of the measuring device. This embodiment makes it possible, during a hit, to detect simultaneously the movement of the hitting implement (by means of the measuring device) and the movement of the body or of a body part (by means of the at least one body sensor).
The training device can advantageously have computing means provided for comparing a measurement signal of the at least one body sensor with a corresponding reference signal. This computing means can be the above-described computing means of the measuring device or an additional computing means. Since, moreover, the computing means of the measuring device can be suitable for comparing the raw data and/or reference data of the acceleration sensors and rotation angle sensors of the measuring device with corresponding reference signals, the computing means can determine, both for the hitting implement and for the body or a body part, a deviation of the measured movement (position) from a reference movement (reference position), which corresponds for example to the ideal movement (position). Since the measuring device and the at least one body sensor perform measurement simultaneously, a deviation of the movement of the hitting implement from a reference signal can be assigned the body (part) posture or the body (part) movement or the deviation thereof from a corresponding reference signal at the point in time of the deviation of the movement of the hitting implement.
In order to inform the user of a determined deviation of the body (part) posture or of the body (part) movement, a signal generator can be provided. The signal generator can be the above-described signal generator of the measuring device or an additional signal generator. Accordingly, it is advantageously possible to indicate to a user that, firstly, the swing path of the hitting implement deviates from the distinguished swing path and, if appropriate, what deviation of the body (part) posture or of the body (part) movement was present at the point in time of the deviation of the movement of the hitting implement. The user can thus identify the body (part) posture or body (part) movement causing the deviation of the hitting implement from the distinguished swing path and can correct it in order to improve the hitting movement of the hitting implement.
The signal generator can output an acoustic, optical or mechanical signal. The acoustic signal can be, in particular, a spoken announcement describing the deviating (erroneous) posture or movement of the body or of a body part and of the hitting implement. The optical signal can be, in particular, a graphical representation of the deviating (erroneous) posture or movement of the body or of a body part and of the hitting implement, which is depicted in comparison with that posture or movement of the body or of a body part and of the hitting implement which corresponds to the reference signal. The body can be represented as an avatar, for example. The graphical representation can depict the events without a temporal delay, such that a user can identify a deviation at the moment when it occurs. Alternatively, the optical signal can be output after the performance of a hit in a sequence of images which together depict the course of the entire hitting movement. The mechanical signal can be, in particular, a vibration signal.
In accordance with one embodiment, the measuring device of the training device is a measuring device in accordance with one or more embodiments of the invention.
A method for training a hitting movement of a hitting implement on a distinguished swing path by means of a training device is specified in Claim 27. Advantageous developments of the method are evident from the claims dependent thereon.
In accordance with one specific configuration of the method, provision can be made, in particular, for the training device used for the method to comprise a hitting implement and at least one measuring device for detecting the hitting movement of the hitting implement, said at least one measuring device being secured on the hitting implement, wherein the training device is a training device according to one of the embodiments of the invention. When the training device is used as intended, the second rotation angle sensor detects a second rotation angle of the hitting implement about the y-axis, which extends substantially perpendicularly to the distinguished swing path.
The method can serve, for example, for comparing a measured swing path with an ideal reference swing path. For this purpose, the sensors of the measuring device determine raw data, which the computing means of the measuring device converts into conditioned data. Conditioned data are taken to mean the conditioned data mentioned by way of example further above. Accordingly, the orientation of the hitting implement, the maximum acceleration, the duration of the individual phases of the hit, the force distribution and/or accelerations during the individual phases and the swing path can be involved. Furthermore, it is possible to determine the maximum velocity of the head of the hitting implement and the position of the head of the hitting implement at the point in time of the highest velocity relative to the point in time of hitting the ball. The conditioned data are subsequently compared with reference data, and the difference is determined. Advantageously, a signal generator generates a signal if the difference between the conditioned data and the reference data exceeds a defined limit value. The signal is generated at the moment when the deviation from the reference data is present. In this case, the strength of the signal can correlate with the magnitude of the difference. The user is thus informed of the deviation at the moment when the deviation occurs. That is to say that said user knows from the situation at what points the hitting movement is not ideal. Accordingly, it is not necessary for said user, after the hit, to identify the corresponding moment on the basis of the conditioned data or, something which is even more difficult, to find the calculated point in time in the actual movement sequence.
The data can also be evaluated after a hit in terms of the temporal relationship in order to determine additional or more precise parameters. Examples thereof include precisely reading the position of the start of the swing from smoothed measurement data or determining the rhythm of the swing from the total amount of data between the start of the swing and hitting the ball (impact).
The invention will be described in detail below on the basis of exemplary embodiments in conjunction with the drawings.

In the figures:

FIG. 1 shows a schematic illustration of a measuring device in accordance with one embodiment of the invention for detecting a hitting movement of a hitting implement;

FIG. 2 shows a schematic illustration of a training device comprising the measuring device from FIG. 1 in the state incorporated as intended;

FIG. 3 shows the training device from FIG. 2 illustrated from a different perspective;

FIG. 4 shows a schematic illustration of measurement signals in the x-direction of two-dimensional acceleration sensors of the measuring device from FIG. 1 as a function of time;

FIG. 5 shows a schematic illustration of measurement signals in the y-direction of the two-dimensional acceleration sensors from FIG. 4 as a function of time;

FIG. 6 shows a schematic illustration of measurement signals in the z-direction of one-dimensional acceleration sensors of the measuring device from FIG. 1 as a function of time;

FIG. 7 shows a schematic illustration of a measurement signal of a first rotation angle sensor of the measuring device from FIG. 1 as a function of time;

FIG. 8 shows a schematic illustration of a measurement signal of a second rotation angle sensor of the measuring device from FIG. 1 as a function of time;

FIG. 9 shows a schematic illustration of possible positions of a body sensor as part of a training device comprising the measuring device from FIG. 1 and at least one body sensor; and

FIG. 10 shows a schematic illustration of the measurement signal of the measuring device from FIG. 1 in combination with the measurement signal of the body sensor from FIG. 9 in comparison with a reference signal in each case.

The measurement signals illustrated in FIGS. 4 to 8 were measured simultaneously by the different sensors.
FIG. 1 schematically illustrates a measuring device 2 in accordance with one embodiment of the invention. The measuring device 2 is provided for measuring movements of a hitting implement 4 which hits a ball, designated hereinafter as hitting movements. A hitting movement is subdivided into the following sections: start of the swing (a), backswing (b), forward swing (c) and hitting the ball (d). The measuring device 2 measures the hitting movements in a temporally resolved manner, such that the relevant time period between the start of the swing (a) and hitting the ball (d) can be evaluated.
The measuring device 2 is suitable, for example, for measuring hitting movements in golf, baseball, tennis and ice hockey. In the exemplary embodiment (FIGS. 2 and 3), the measuring device 2 serves for measuring hitting movements with a hitting implement 4 in the form of a golf club.
In the exemplary embodiment, the measuring device 2 comprises two two- dimensional acceleration sensors 6 a, 6 b for detecting a two-dimensional acceleration vector
_xyand two one- dimensional acceleration sensors 8 a, 8 b for detecting a one-dimensional acceleration vector
_z. In this case, the one- dimensional acceleration sensors 8 a, 8 b are arranged with respect to the two- dimensional acceleration sensors 6 a, 6 b in such a way that the one-dimensional acceleration vector
_zruns substantially orthogonally with respect to the two-dimensional acceleration vector
_xy. Besides the acceleration sensors 6 a, 6 b, 8 a, 8 b, the measuring device 2 comprises a first rotation angle sensor 10 for detecting a first rotation angle θ. In this case, the first rotation angle sensor 10 is arranged with respect to the two- dimensional acceleration sensors 6 a, 6 b in such a way that the first rotation angle θ corresponds to the rotation angle of the two-dimensional acceleration vector
_xyabout an axis z extending substantially orthogonally with respect to the two-dimensional acceleration vector
_xy. In addition, the measuring device 2 comprises a second rotation angle sensor 12 for detecting a second rotation angle φ. In this case, the second rotation angle sensor 12 is is arranged with respect to the one- dimensional acceleration sensors 8 a, 8 b in such a way that the second rotation angle φ corresponds to the rotation angle of the one-dimensional acceleration vector
_zabout a y-axis extending substantially perpendicularly to the one-dimensional acceleration vector
_z. The second rotation angle φ is accordingly the rotation angle in the swing plane.
The two- dimensional acceleration sensors 6 a, 6 b operate in two different, partly overlapping measurement ranges. In this case, the measurement range of one two-dimensional acceleration sensor 6 a extends from 5 to 250 g and is suitable particularly for fast hits. In this case, the measurement range of the other two-dimensional acceleration sensor 6 b extends typically from 0 to 15 g and is suitable particularly for slow hits.
The two- dimensional acceleration sensors 6 a, 6 b can be constructed from in each case two one-dimensional acceleration sensors. These one-dimensional acceleration sensors of a two- dimensional acceleration sensor 6 a, 6 b can be structurally identical with regard to the measurement range. For specific applications it may also be advantageous to choose different measurement ranges for these one-dimensional acceleration sensors. Furthermore, the one-dimensional acceleration sensors of the two-dimensional acceleration sensor 6 a can be structurally identical to the one-dimensional acceleration sensor 8 a and the one-dimensional acceleration sensors of the two-dimensional acceleration sensor 6 b can be structurally identical to the one-dimensional acceleration sensor 8 b. Alternatively, the one-dimensional acceleration sensors can also be embodied differently. The two- dimensional acceleration sensors 6 a, 6 b are advantageously accommodated in one component.
The rotation angle sensors 10, 12 are means for detecting the angular velocity. In accordance with one embodiment, the rotation angle sensors 10, 12 are gyroscope sensors. The rotation angle sensors 10, 12 are arranged orthogonally with respect to one another in order to measure the rotation angles θ and φ. The rotation angle sensors 10, 12 operate in a measurement range of 50 to 2000°/s.
In the exemplary embodiment, the acceleration sensors 6 a, 6 b, 8 a, 8 b and the rotation angle sensors 10, 12 are microelectromechanical systems, generally known as MEMS.
The measuring device 2 furthermore comprises a means 14 for time measurement. The means 14 for time measurement measures the time in parallel with the acceleration sensors 6 a, 6 b, 8 a, 8 b and the rotation angle sensors 10, 12 in order to be able to assign a point in time to each measurement value detected by the acceleration sensors 6 a, 6 b, 8 a, 8 b and the rotation angle sensors 10, 12.
A computing means 16 is provided for receiving and evaluating the raw data supplied by the acceleration sensors 6 a, 6 b, 8 a, 8 b, the rotation angle sensors 10, 12 and the means 14 for time measurement. On the basis of the raw data determined and on the basis of physical models, the computing means 16 calculates in a time-dependent manner the position of the hitting implement in space, and also its orientation and velocity in the course of the hit. The calculated values can be compared with reference data. The functioning of the computing means 16 will be illustrated in detail further below in connection with the description of a method for training a hitting movement, in which the measuring device 2 is used.
The computing means 16 comprises a memory and a processor. The memory stores programs which serve for evaluating the raw data supplied by the acceleration sensors 6 a, 6 b, 8 a, 8 b, the rotation angle sensors 10, 12 and the means 14 for time measurement. In addition, the memory stores a multiplicity of reference data which correspond to ideal swing sequences and serve for comparison with measured hitting movements. The computing means 16 is accessible externally via an interface 18. Consequently, firstly, the raw data supplied by the acceleration sensors 6 a, 6 b, 8 a, 8 b, the rotation angle sensors 10, 12 and the means 14 for time measurement, and/or the data evaluated by the computing means 16 can be transmitted by the computing means 16 to external data processing systems. Secondly, the interface also enables the programs and/or reference data to be updated and/or replaced. The interface 18 is, for example, a USB connection, a Bluetooth interface, an infrared interface or some other customary wireless or wired interface. Preferably, the interface is a Bluetooth interface in order to be able thereby to establish a link to smartphones as external data processing systems.
The measuring device 2 furthermore has an operating element 20, with which a user can select which program(s) is/are to be executed by the computing means 16. In addition, a user can select, by means of the operating element 20, a reference data set with which the hitting movements that are subsequently to be measured are to be compared.
The acceleration sensors 6 a, 6 b, 8 a, 8 b, the rotation angle sensors 10, 12, the means 14 for time measurement and the computing means 16 are arranged in a compact housing 22. The housing 22 has a securing means 24, by means of which the measuring device 2 can be secured releasably on the hitting implement 4.
The measuring device 2 furthermore has a signal generator 26. The signal generator 26 is fitted to the housing 22 on the outside, for example. Alternatively, the signal generator 26 can also be accommodated in the housing 22. The signal generator 26 outputs acoustic and/or optical signals. For specific applications, the signal can also be a vibration signal. Signals are output by the signal generator 26 if the difference between the values calculated by the computing means 16 and the reference data exceeds a limit value. In this case, the limit value can be defined by the user.
FIGS. 2 and 3 illustrate a training device 30 in accordance with one embodiment of the invention from two different perspectives. The training device 30 is suitable for training a hitting movement of a hitting implement 4. For the sake of better illustration, FIGS. 2 and 3 show the training device 30 together with a user. The swing path extends perpendicularly to the plane of the drawing in FIG. 2, and parallel to the plane of the drawing in FIG. 3.
The training device 30 comprises the measuring device 2 already described and a hitting implement 4, with which a hitting movement is intended to be trained. The hitting implement extends along a hitting implement axis A. The measuring device 2 is secured on the hitting implement 4. Preferably, the measuring device 2 is secured on the hitting implement 4 via the securing means 24. In the exemplary embodiment, the hitting implement 4 is a golf club. However, as described in the introduction, the hitting implement can also be a hitting implement used for other ball sports.
In this case, the measuring device 2 is secured on the hitting implement 4 in such a way that the two-dimensional acceleration vector a_xydetected by the two- dimensional acceleration sensors 6 a, 6 b runs orthogonally with respect to the hitting implement axis A. From the above-described relative arrangement of the two- dimensional acceleration sensors 6 a, 6 b, of the one- dimensional acceleration sensors 8 a, 8 b, of the first rotation angle sensor 10 and of the second rotation angle sensor 12 with respect to one another and from the relative arrangement of the hitting implement 4 and of the two- dimensional acceleration sensors 6 a, 6 b, the following relationships arise: the one-dimensional acceleration vector a_zdetected by the one- dimensional acceleration sensors 8 a, 8 b runs parallel to the hitting implement axis A. The first rotation angle θ, which is detected by the first rotation angle sensor 10, corresponds to the rotation angle of the hitting implement 4 about the hitting implement axis A. The second rotation angle φ, which is detected by the second rotation angle sensor 12, corresponds to the rotation angle of the hitting implement 4 about a y-axis, which extends substantially perpendicularly to the hitting implement axis A.
In order to be able to use the training device 30 for training a hitting movement on a distinguished swing path, the measuring device 2 is to be arranged with respect to the hitting implement axis A in such a way that, when the training device 30 is used as intended, the y-axis, about which the second rotation angle φ rotates, extends substantially orthogonally with respect to the distinguished swing path.
The method for training a hitting movement with the hitting implement 4 on a distinguished swing path is based on the fact that the acceleration sensors 6 a, 6 b, 8 a, 8 b, the rotation angle sensors 10, 12 and the means for time measurement 14 determine raw data which are transmitted to the computing means 16 and are processed by the computing means 16, which converts the raw data into conditioned data such as, for example, the orientation, maximum acceleration, duration of individual phases of the hitting movement, force distributions and accelerations during the individual phases and swing path. These steps are carried out in real time, such that the conditioned data are available to the user directly during hitting.
Since a user who trains a specific movement cannot necessarily read errors solely from the conditioned data of said user's hitting movement, the method provides for comparing the conditioned data with reference data and for determining the difference between the conditioned data and the reference data. For this purpose, a multiplicity of reference data are available to the user, from which said user can select, by means of the operating element 20, the reference data corresponding to the hitting movement which said user would like to train. If a difference between the measured hitting movement and the selected reference data is ascertained, a signal is generated by the signal generator 26. In this case, the strength of the signal varies with the magnitude of the difference. In the exemplary embodiment, the signal is an acoustic signal that becomes louder as the difference increases.
Professional players who do not necessarily rely on a comparison of the measured data with reference data can also access the conditioned data directly. A comparison with reference data does not take place in this case.
The conditioned data and the difference between them and the reference data are determined in real time, that is to say during hitting. Consequently, the user instantaneously identifies which phases of the swing movement are erroneous. In addition, all the data (raw data, conditioned data, difference data) can be transmitted to an external data processing system via the interface 18. This allows more extensive analyses of the hits after the hits have been performed. By way of example, it is thus possible to determine how, upon multiple repetition of a specific type of hitting or in the long term over a number of training stages, the hitting quality has improved.
FIGS. 4 to 8 schematically illustrate, for a hit using a hitting implement 4 in the form of a golf club, the measurement signals of the individual sensors 6 a, 6 b, 8 a, 8 b, 10, 12 as a function of time. In this case, the relevant phases of start of the swing (a), backswing (b), forward swing (c) and hitting the ball (d) are indicated in each measurement signal. In this case, backswing (b) should be understood to mean the phase between the start of the swing (a) and the moment of the highest position of the hitting implement. The forward swing (c) is accordingly the phase between the moment of the highest position of the hitting implement and hitting the ball (d). The duration of a hit is typically between 600 and 1000 ms, depending on the player. The hit illustrated in FIGS. 4 to 8 has a length of approximately 1000 ms. The relative duration of backswing and forward swing is not depicted in a manner true to scale, but rather only schematically, in FIGS. 4 to 8. In general, the duration of the backswing is approximately three times the duration of the forward swing.
FIG. 4 shows how the magnitude of the acceleration vector
_xas one component of the two-dimensional acceleration vector
_xychanges in the course of the hit. As can be discerned from FIG. 3, the acceleration vector
_xis directed perpendicularly to the hitting implement axis A and runs substantially parallel to the distinguished swing path. Two graphs are illustrated in FIG. 4. The graph illustrated as a solid line corresponds to a measurement of one two-dimensional acceleration sensor 6 a, which performs measurement in a range of 10 to 100 g. The value of the acceleration
_xmeasured by the acceleration sensor 6 a is read on the left-hand ordinate axis in FIG. 4. The measurement by the other two-dimensional acceleration sensor 6 b takes place in parallel (dashed line), this acceleration sensor performing measurement in a range of 0 to 10 g. The value of the acceleration
_xmeasured by the acceleration sensor 6 b is read on the right-hand ordinate axis in FIG. 4. While the backswing (b) is measured by the sensor 6 b with a good resolution, the signal of this sensor 6 b is saturated for the forward swing (c). Conversely, the backswing (b) is not sufficiently resolved by the sensor 6 a, but the forward swing (c) is mapped very well. Consequently, the sensor 6 b should be used for the evaluation of the backswing (b) and the sensor 6 a should be used for the evaluation of the forward swing (c). The acceleration vector
_xof the backswing (b) is negative and has a parabolic profile. The acceleration vector
_xof the forward swing (c) is positive and likewise has a parabolic profile having a peak at the moment of hitting the ball (d).
FIG. 5 shows how the magnitude of the acceleration vector
_yas the other component of the two-dimensional acceleration vector
_xychanges in the course of the hit. As can be discerned from FIG. 3, the acceleration vector
_yis directed perpendicularly to the hitting implement axis A and runs substantially perpendicularly to the distinguished swing path. In the case of an ideal hit, there is no acceleration in the y-direction, and the acceleration vector
_yis therefore equal to zero during the entire hit. The profile of the acceleration vector
_yin FIG. 5 originates solely from the rotation of the hitting implement about the hitting implement axis A. Two graphs are illustrated in FIG. 5, too, analogously to FIG. 4. The amplitudes of the backswing (b) and of the forward swing (c) are substantially identical in magnitude and differ only in their sign. Since the amplitudes are generally rather small, the sensor 6 b is preferably used for evaluating the entire hit.
One aim of training is to guide the hitting implement as much as possible in one plane, that is to say to minimize the excursion of the hitting implement from the plane. This aim can be trained by checking the profile of the acceleration vector
_ywith the aid of the sensors 6 a, 6 b.
FIG. 6 shows the profile of the magnitude of the acceleration vector
_zextending parallel to the hitting implement axis A. Two graphs are illustrated in FIG. 6, too, analogously to FIG. 4. The graph illustrated as a solid line was measured by one one-dimensional acceleration sensor 8 a and the graph illustrated as a dashed line was measured by the other one-dimensional acceleration sensor 8 b. The respectively associated ordinate axes are correspondingly indicated. The profile of the acceleration vector
_zof the forward swing qualitatively corresponds to the profile of the acceleration vector
_xthe forward swing. The profile of the acceleration vector
_zof the backswing also substantially corresponds to the profile of the acceleration vector
_xof the backswing, except that the sign is now positive. For evaluating the measurement of the acceleration vector
_z, the procedure analogous to the procedure for the acceleration vector
_xshould be adopted.
Proceeding from the measurement values
_x,
_yand
_zof the acceleration sensors 6 a, 6 b, 8 a, 8 b, it is possible to determine the response position, that is to say the position of the hitting implement 4 directly before the golf strike.
FIG. 7 shows how the first rotation angle θ of the hitting implement 4 about the hitting implement axis A changes during hitting. The profile of the value of the first rotation angle θ during hitting in this case corresponds to a parabola. Often, the first angle θ at the start of the swing (a) is not identical to the first angle θ when hitting the ball (d). That is to say that the head of the hitting implement changes its orientation during hitting on account of a rotation of the entire hitting implement 4 about the hitting implement axis A. The difference between the two angles yields the so-called open-close value of the hitting implement 4. That is to say that the difference is a measure of whether the ball will deviate from the sought trajectory more likely towards the left or towards the right. Ideally, the head of the hitting implement is guided perpendicularly to the distinguished swing path during hitting. One aim of training is to minimize the difference between these two angles. This aim can be trained by checking the profile of the first angle θ with the aid of the first rotation angle sensor 10.
One problem that frequently occurs is so-called YIP. This is a spasm of the wrist, resulting in an uncontrolled rotation of the hitting implement 4 about the hitting implement axis A. The YIP is measured by the first rotation angle sensor 10. The movement takes place on a time scale of approximately 50 ms. In order to detect this, a resolution of 50 to 5000 Hz, in particular of 500 to 2000 Hz, is required. The YIP is manifested as a hook-shaped deviation in the time-dependent profile of the first angle θ (see FIG. 7). Another aim of training is to reduce the YIP. This aim can be trained by checking the profile of the first angle θ with the aid of the first rotation angle sensor 10.
FIG. 8 shows how the second rotation angle φ of the hitting implement 4 about the y-axis changes during hitting. The second rotation angle φ thus corresponds to the angle covered by the hitting implement 4 during hitting in the swing plane. The temporal profile of the second angle φ qualitatively corresponds to that of the first angle θ. In the case of the second angle θ, too, it can often be observed that the values at the start of the swing (a) and when hitting the ball (d) differ. The so-called driving angle can be derived from the difference. The driving angle is the angle formed between the driving surface of the head of the hitting implement and a vertical when hitting the ball (d). One aim of training, in the case of specific hits, is first to minimize the difference in driving angles between the position at the start of the swing (a) and the position when hitting the ball (d). In the case of other hits, it may be of importance, rather, to reproduce the driving angle as precisely as possible. These aims can be trained by checking the profile of the second angle φ with the aid of the second rotation angle sensor 12.
Alternatively, the determination is also possible by means of the two- dimensional acceleration sensors 6 a, 6 b, in which case the component in the x-direction (see FIG. 3), in particular, is of importance. However, the measurement accuracy that can be achieved by the second rotation angle sensor 12 is higher than that of the acceleration sensors 6 a, 6 b, and so the measurement of the second rotation angle sensor 12 should be preferred.
The two- dimensional acceleration sensors 6 a, 6 b together with the one- dimensional acceleration sensors 8 a, 8 b and the first rotation angle sensor 10 supply the relevant data for determining the velocity and the acceleration of the hitting implement 4 in the form of a golf club along the swing path during hitting.
A further important item of information is the temporal profile of the acceleration vector
_z(along the hitting implement axis). If more than one measurement range is recorded synchronously, both the slow accelerations of a putting movement and the high accelerations of a swing can be detected without exceeding a range. From the temporal profile of the acceleration vector
_z, it is possible to determine the maximum velocity of the head of the hitting implement and the position of the head of the hitting implement at the point in time of the highest velocity relative to the point in time of hitting the ball (d). One typical aim of training is to achieve the effect that the point in time of the highest velocity and the point in time of hitting the ball (d) coincide. A further aim of training is to optimize the maximum velocity, that is to say for example to maximize it or train it to a target value.
FIG. 9 illustrates a further embodiment of the training device 30. The training device from FIG. 9 differs from that from FIGS. 2 and 3 in particular in that, in addition to the measuring device 2 serving for the measurement of the movement of the hitting implement 4, provision is made of at least one body sensor 50 a-50 i suitable for detecting the movement of the body of the user of the training device 30 or of a body part of the user of the training device 30. The at least one body sensor 50 a-50 i is provided for being secured directly or indirectly on at least one location of the body of the user of the training device 30. The number of body sensors 50 a-50 i can be chosen by the user of the training device 30 depending on the training aim. FIG. 9 illustrates by way of example nine body sensors 50 a-50 i as dots, in order to illustrate suitable body locations where a respective body sensor 50 a-50 i can be fitted. Accordingly, a hand (body sensor 50 a), a region in the vicinity of the wrist (body sensor 50 b), an upper arm (body sensor 50 c), the head (body sensor 50 d), the back (body sensor 50 e), the pelvis (body sensor 50 f), a thigh (body sensor 50 g), a region in the vicinity of the ankle (malleolus) (body sensor 50 h) and/or a foot (body sensor 50 i) are suitable body locations for detecting the movement of the body or of a body part during hitting. The body sensors 50 a, 50 b and 50 c are preferably fitted to the hand or the arm holding the hitting implement 4. What is common to all these positions is that they are preferably not provided directly on a joint.
The training device from FIG. 9 comprises the measuring device 2 described in the introduction, which in turn comprises a computing means and a signal generator. In the embodiment from FIG. 9, the computing means and the signal generator of the measuring device 2 serve, firstly, for processing and outputting the measurement data or the information derived therefrom of the measuring device 2 and, secondly, for processing and outputting the measurement data or the information derived therefrom of the at least one body sensor 50 a-50 i.
FIG. 10 illustrates by way of example an optical signal of the signal generator of the training device from FIG. 9. The representation of a person by means of a dashed contour line depicts the measurement data of the at least one body sensor 50 a-50 i, while the representation of a person by a solid contour line corresponds to a reference data set. Accordingly, the swing path represented as a dashed line and the hitting implement 4 with a dashed contour line depict the measurement data of the measuring device 2, while the swing path represented as a solid line and the hitting implement 4 with a solid contour line correspond to a reference data set. The reference data sets can correspond, in particular, to the preferred body posture or the distinguished swing path.
The optical signal from FIG. 10 is displayed to the user after the hitting movement has been performed. Alternatively, such a signal can be displayed during hitting, such that the user can identify at any point in time during hitting whether there is a deviation with respect to a preferred body posture and/or stance with the hitting implement.

Claims

1-32. (canceled)

33. Measuring device for detecting a hitting movement of a hitting implement, comprising:

at least one two-dimensional acceleration sensor for detecting a two-dimensional acceleration vector (

_xy),

at least one one-dimensional acceleration sensor for detecting a one-dimensional acceleration vector (

_z), wherein the at least one one-dimensional acceleration sensor is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the detected one-dimensional acceleration vector (

_z) runs substantially orthogonally with respect to the two-dimensional acceleration vector (

_xy) detected by the at least one two-dimensional acceleration sensor,

a first rotation angle sensor for detecting a first rotation angle (θ) of the two-dimensional acceleration vector (

_xy) about a z-axis, wherein the first rotation angle sensor is arranged with respect to the at least one two-dimensional acceleration sensor in such a way that the z-axis extends substantially orthogonally with respect to the two-dimensional acceleration vector (

_xy), wherein:

a second rotation angle sensor for detecting a second rotation angle (φ) of the one-dimensional acceleration vector (

_z) about a y-axis, wherein the second rotation angle sensor is arranged with respect to the at least one one-dimensional acceleration sensor in such a way that the y-axis extends substantially perpendicularly to the one-dimensional acceleration vector (

_z).

34. Measuring device according to claim 33, wherein the first rotation angle sensor and the second rotation angle sensor are means for detecting the angular velocity.

35. Measuring device according to claim 33, wherein the first rotation angle sensor and the second rotation angle sensor are gyroscope sensors.

36. Measuring device according to claim 33, wherein the first rotation angle sensor and the second rotation angle sensor are structurally identical and are arranged substantially orthogonally with respect to one another.

37. Measuring device according to claim 35, wherein the gyroscope sensors are sensitive in a measurement range of 50 to 2000°/s.

38. Measuring device according to claim 33, wherein the measuring device comprises two two-dimensional acceleration sensors, which are sensitive for different measuring ranges in each case.

39. Measuring device according to claim 38, wherein one two-dimensional acceleration sensor is sensitive in a measurement range of 0 to 10 g.

40. Measuring device according to claim 38, wherein the other two-dimensional acceleration sensor is sensitive in a measurement range of 15 to 100 g.

41. Measuring device according to claim 38, wherein the measuring device comprises two one-dimensional acceleration sensors, wherein one one-dimensional acceleration sensors is structurally identical to said one two-dimensional acceleration sensor and the other one-dimensional acceleration sensors is structurally identical to the other two-dimensional acceleration sensor.

42. Measuring device according to claim 33, wherein the measuring device has a means for time measurement, which measures the time during the hitting movement.

43. Measuring device according to claim 33, wherein the measuring device has computing means provided for converting the raw data determined by the acceleration sensors and rotation angle sensors into conditioned data comprising orientation, maximum acceleration, duration of individual phases of the hitting movement, force distributions and accelerations during the individual phases and swing path.

44. Measuring device according to claim 43, wherein the measuring device comprises an operating element, with which a user can select which conditioned data are generated by the computing means.

45. Measuring device according to claim 42, wherein the measuring device comprises a housing, which encloses all the sensors, the means for time measurement and the computing means.

46. Measuring device according to claim 33, wherein the measuring device comprises a securing means provided for securing the measuring device releasably or non-releasably on a hitting implement.

47. Measuring device according to claim 33, wherein the measuring device comprises a securing means provided for securing the measuring device indirectly or directly on a body of a user including on a hand or in the vicinity of a wrist.

48. Measuring device according to claim 43, wherein the computing means are provided for comparing the raw data and/or the conditioned data with reference data.

49. Measuring device according to claim 48, wherein a signal generator is provided, which generates a signal if the difference between the conditioned data and the reference data exceeds a defined limit value.

50. Training device for training a hitting movement of a hitting implement, comprising:

a hitting implement, with which a user trains the hitting movement, and

at least one measuring device for detecting the hitting movement of the hitting implement, said at least one measuring device being secured on the hitting implement and comprising:

_xy),

_xy) detected by the at least one two-dimensional acceleration sensor, and

_xy), wherein:

the measuring device comprises comprises a second rotation angle sensor for detecting a second rotation angle (φ) of the one-dimensional acceleration vector (

_z) about a y-axis, wherein the second rotation angle sensor is arranged with respect to the at least one one-dimensional acceleration sensor in such a way that the y-axis extends substantially orthogonally with respect to the one-dimensional acceleration vector (

_z).

51. Training device according to claim 50, wherein the hitting implement extends along a hitting implement axis (A), and in that the measuring device is oriented in relation to the hitting implement axis (A) in such a way that:

the two-dimensional acceleration sensor detects a two-dimensional acceleration vector (

_xy) of the hitting implement which runs orthogonally with respect to the hitting implement axis (A),

the one-dimensional acceleration sensor detects a one-dimensional acceleration vector (

_z) of the hitting implement which runs parallel to the hitting implement axis (A),

the first rotation angle sensor detects a first rotation angle (θ) of the hitting implement about the hitting implement axis (A), and

the second rotation angle sensor detects a second rotation angle (φ) of the hitting implement about the y-axis, which extends substantially perpendicularly to the hitting implement axis (A).

52. Training device according to claim 50, wherein the training device comprises at least one body sensor which is designed for indirect or direct securing on a body of a user and is provided for detecting a movement of the body, wherein the at least one body sensor measures simultaneously relative to the measuring device.

53. Training device according to claim 52, wherein computing means are provided, which are suitable for comparing a measurement signal of the at least one body sensor with a reference signal.

54. Training device according to claim 53, wherein the computing means are provided for assigning a deviation of a measurement signal of the measuring device from a corresponding reference signal to the simultaneously measured measurement signal of the at least one body sensor and, if appropriate, a deviation of the measurement signal of the at least one body sensor from the reference signal.

55. Training device according to claim 54, wherein a signal generator is provided, which is suitable for indicating to a user the assignment of the deviation of the measurement signal of the measuring device from the corresponding reference signal to the simultaneously measured measurement signal of the at least one body sensor and, if appropriate, to the deviation of the measurement signal of the at least one body sensor from the corresponding reference signal.

56. Method for training a hitting movement of a hitting implement on a distinguished swing path by means of a training device, wherein the training device comprises a hitting implement and at least one measuring device for detecting the hitting movement of the hitting implement, said at least one measuring device being secured on the hitting implement, wherein:

the training device is a training device according to claim 50.