METHOD AND APPARATUS FOR EVALUATING THE QUALITY OF CHARACTERISTICS OF MOTION OF AN ANIMAL-HUMAN-DYAD

Abstract

The invention relates to method for evaluating the quality of characteristics of motion of an animal-human-dyad comprising an animal and a human and using at least one rein for riding the animal, wherein the quality of characteristics of motion is the loss of regularity of rhythm in the motion of the animal, the method comprising obtaining rein tension data indicating the tension in the rein (10) by means of a rein tension measuring device (20), wherein the the following steps are executed by a processing unit (90): processing the rein tension data into a frequency spectrum; identifying a prominent frequency component in the frequency spectrum; analysing the frequency spectrum by determining a power spectral density of the frequency spectrum over a frequency range which contains the prominent frequency component; and evaluating the loss of regularity of rhythm in the motion by comparing the determined power spectral density with a reference value. Further, the invention relates to an apparatus for evaluating the quality of characteristics of motion of an animal-human-dyad, wherein the apparatus comprises a rein tension measuring device, a transmitter unit, a receiving unit, a processing unit and a notification unit.

Claims

1. Method for evaluating the quality of characteristics of motion of an animal-human-dyad comprising an animal and a human and using at least one rein for riding the animal, wherein the quality of characteristics of motion is the loss of regularity of rhythm in the motion of the animal, the method comprising: obtaining rein tension data indicating the tension in the rein by means of a rein tension measuring device; processing by a processing unit the rein tension data into a frequency spectrum; identifying a prominent frequency component in the frequency spectrum; analysing the frequency spectrum by determining a power spectral density of the frequency spectrum over a frequency range which contains the prominent frequency component; and evaluating the loss of regularity of rhythm in the motion by comparing the determined power spectral density with a reference value.

2. Method according to claim 1, wherein the frequency spectrum is analysed within a frequency sub-range spanning the prominent frequency component.

3. Method according to claim 1, wherein the frequency spectrum is analysed only within an overall frequency range limited by a first frequency threshold and a second frequency threshold.

4. Method according to claim 1, wherein the frequency range and/or a frequency sub-range is analysed to determine a signal-to-noise ratio (s/n).

5. Method according to claim 4, wherein the signal-to-noise ratio of at least the prominent frequency component is determined.

6. Method according to claim 4, wherein the signal-to-noise ratio of two or more prominent frequency components are determined and that a ratio of their values is determined.

7. Method according to claim 1, wherein the reference value is the prominent frequency component and/or the reference value is a value that correlates to a stride frequency or a gait frequency of the animal or a second harmonic of the stride frequency or the gait frequency of the animal.

8. Method according to claim 1, wherein the obtaining of the rein tension data indicating the tension in the rein comprises measuring the rein tension by at least one strain gauge inserted into the rein.

9. Method according to claim 1, further comprising: determining an average of the rein tension using the rein tension data and comparing with a reference value or reference table of rein tension values.

10. Apparatus for evaluating the quality of characteristics of motion of an animal-human-dyad comprising an animal and a human and using at least one rein for riding the animal, wherein the quality of characteristics of motion is the loss of regularity of rhythm in the motion of the animal, the apparatus comprising: at least one rein tension measuring device configured to obtain rein tension data; a transmitter configured to transmit the rein tension data; a receiver configured to receive the rein tension data; and a processor configured to: process the rein tension data into a frequency spectrum, identify a prominent frequency component in the frequency spectrum, analyse the frequency spectrum by determining the power spectral density over a frequency range which contains the prominent frequency, evaluate the loss of regularity of rhythm in the motion by comparing the determined power spectral density with a reference value, and notify about the loss of regularity of rhythm in the motion based on the processed data.

11. (canceled)

12. Apparatus according to claim 10, wherein the at least one rein tension measuring device is embedded in the at least one rein.

13. Apparatus according to claim 10, further comprising an electric cable for transmitting signals from the at least one rein tension measuring device to the transmitter, the electric cable being embedded in the at least one rein.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0081] In the following the invention will be explained, by way of preferred embodiments, in more detail with reference to the drawings, wherein

[0082] FIG. 1 shows a horse's head with part of the apparatus of the invention;

[0083] FIG. 2 is an exploded plan view of part of the apparatus of FIG. 1;

[0084] FIG. 3 is a plan view of a rein tension sensor unit of the apparatus of FIG. 1

[0085] FIG. 4 shows a schematic diagram of part of the apparatus;

[0086] FIG. 5 shows a graph indicating a power spectral density PSD(f) versus frequency f and further parameters of the method of the invention;

[0087] FIG. 6 shows an enlarged section of the graph of FIG. 6;

[0088] FIG. 7 depicts a graphical representation of a look-up table where a Figure of Merit F M can be assigned to an average force value FR measured by the apparatus of the invention.

[0089] FIG. 1 shows a horse's head and a bridle 12 mounted on the horse's head. The bridle 12 holds a bit 14 which has two side rings 16 and a mouthpiece 18. A first side ring 16 is positioned on the left side of the horse's head and a second side ring 16 is positioned on the right side of the horse's head as seen by a rider positioned on the horse. The mouthpiece 18 is inserted into the horse's mouth and extends between the two side rings 16. Further, reins 10 are connected to each of the side rings 16. Thus, one of the reins 10 is mounted to the first side ring 16 and the other one of the reins 10 is mounted to the second side ring 16. The rider holds the reins 10 for giving commands to the horse. When pulling the reins 10 a force is transmitted via the reins 10 to the side ring and subsequently to the mouthpiece 18 of the bit 14.

[0090] To measure the force in the reins each rein 10 comprises a rein tension measuring device 20 as a part of the apparatus of the invention. The rein tension measuring device 20 comprises a rein tension sensor unit 30 which can also be designated as force transducer or strain gauge.

[0091] FIG. 2 depicts an exploded plan view of the rein tension measuring device 20 showing the rein tension sensor unit 30 and attachment units 50, 60 with holes 52, 62 for fastening to the reins 10 by a suitable fastener. The rein tension sensor unit or force transducer 30 is placed between the attachment units 50, 60. Further, an electric cable 40 is provided for transmitting signals from the rein tension sensor unit 30 to a transmitter unit 70.

[0092] The rein tension measuring device 20 is inserted into each of two reins 10 one on each side of the animal so that a time-series signal can be measured from each which is proportional to the time-series rein tension on each side of the animal. The rein tension sensor units 30 are hidden from view by being fully encased in the construction material of the reins 10. Preferably, also the attachment units 50, 60 are embedded and encased in the material of the reins 10.

[0093] Referring to FIG. 3 the rein tension sensor unit 30 is preferably smaller than 50 mm in length L and width W and less than 15 mm in depth. In a further preferred embodiment the rein tension sensor unit 30 is preferably smaller than 20 mm in length W and width W and less than 10 mm in depth. In another preferred embodiment the rein tension sensor unit 30 is 19 mm in length W, 16 mm in width W and 6 mm in depth.

[0094] Preferably, each end of the rein tension sensor unit 30 is provided with suitable mechanical attachment units 50, 60 with holes 52, 62 so that it can be attached to the construction material of the reins 10 using a suitable fastener. A preferred fastener is a rivet fastener but alternatives are possible.

[0095] Also preferred the electrical cable 40 is hidden from view by being fully encased in the construction materials of the reins.

[0096] It is known that force transducers can be mounted to the reins but with the disadvantage of visual discontinuity. The transducers of the prior art attach to the reins or bridlework using clips or hooks and are designed for temporary use. These items make regular use of the transducers difficult and further distract from the desirable visual continuity of traditional reins and bridlework. A further disadvantage is that the electrical cables which are necessary to carry signals from the force transducer to the transmitter are also visible and obtrusive and may become trapped in the bridlework or by the rider's hands during riding.

[0097] The rein tension sensor unit 30 and electric cable 40 is preferably of a small form factor and consequently of light weight so that it can be unobtrusively hidden by the material of the reins 10 and form part of the visual continuity of the reins. The cable carrying signals to the transceiver is also embedded into the reins thus improving the visual continuity and helping prevent the possibility of trapping in the bridlework when in use. To assist with the embedding of the rein tension sensor unit 30 it is provided with mechanical attachments one at each of opposite ends that are provided with suitable holes for fastening directly and permanently to the material of the reins such as nylon webbing or other material so that there is no need for clips or bolts on the rein tension sensor unit 30 to which the reins 10 must attach. These features make the rein tension sensor unit 30 more readily usable on a regular basis and less likely to be objectionable to judges of the governing bodies of the equestrian sports.

[0098] The rein tension sensor unit 30 on each side of the animal send the measured rein tension data via the transmitter unit 70 to a receiving unit 80. Subsequently, the received data can be processed using a processing unit 90. Preferably, each pair of signals is sampled within a particular span of time and is recorded and stored for post-processing. The members of the pair of signals can be labelled Left and Right for example. Each data set comprises a time-ordered list of Left and Right signals whose magnitude represents the force acting in the reins at particular intervals of time. Each list is called a time-series.

[0099] The transmitter unit 70 can comprise at least one data collecting unit, an amplifier, an A/D converter and/or a wireless transmitter. As shown schematically in FIG. 4, the transmitter unit 70 comprises a first data collecting unit 72 for collecting the rein tension data of the first (or left-side) rein tension unit 30 and second data collecting unit 74 for collecting the rein tension data of the first (or left-side) rein tension unit 30. Further, a data converting unit 76 is provided comprising an amplifier and an A/D converter for converting the data into suitable signals. Further, the transmitter unit 70 comprises a wireless transmitter 78 for wireless transmitting the signals to the receiving unit 80 for further processing by the processing unit 90. Finally, the processed data can be notified to a display unit 100 for informing a user about the quality of characteristics of the motion of the horse-rider-dyad.

[0100] Based on FIGS. 5 and 6, in the following a preferred embodiment of the method of the invention for evaluating the quality of characteristics of motion of an animal-human-dyad between an animal and a human using a rein 10 for riding the animal is described. In a first step rein tension data indicating the tension in the rein 10 is obtained. Preferably, the rein tension in the rein 10 is measured by at least one strain gauge inserted into the at least one rein 10. In a second step the rein tension data is processed into a frequency spectrum f (Hz). In a third step a prominent frequency component f.sub.0 in the frequency spectrum is identified. In a fourth step the frequency spectrum is analysed by integrating the power spectral density PSD (I) of the frequency spectrum over a frequency range f.sub.s which contains the prominent frequency component f.sub.0. Finally, the quality of characteristics of motion is evaluated by comparing the integral of the power spectral density PSD(f) value determined over the range f.sub.s with a reference value found by integrating over a frequency range f.sub.w.

[0101] Preferably, the frequency spectrum is analysed only within an overall frequency range limited by a first frequency threshold f.sub.L and a second frequency threshold f.sub.U. For example, the first frequency threshold f.sub.L is about 0.5 Hz and the second frequency threshold f.sub.U is about 5.0 Hz. Preferably, the frequency spectrum is analysed within a frequency sub-range f.sub.s spanning the prominent frequency component. By analysing the frequency spectrum over the frequency range f.sub.w and the frequency sub-range f.sub.s preferably a signal-to-noise ratio (s/n) is determined. Preferably, the reference value is the prominent frequency component f.sub.0 and/or the reference value is a value that correlates to the stride frequency f.sub.c or f.sub.T or gait frequency of the animal or the second harmonic of that frequency.

[0102] In the following a preferred embodiment of the method of the invention is described. The preferred embodiment of the method includes the determination of the frequency-dependent power spectral density PSD(f) of each of the Left and Right time-series rein tension data and the identification of the prominent frequency component f.sub.o of the power spectral density PSD(f) within a (restricted) frequency range f.sub.w that contains the stride frequency or multiple thereof for a particular mode of motion of the animal, for example f.sub.c or f.sub.T, that itself lies within a larger restricted frequency range having upper and lower frequency limits f.sub.U and f.sub.L respectively.

[0103] A suitable small range of frequencies, f.sub.s spanning the centre frequency is then defined and the integral of PSD(f), I.sub.s between the upper f.sub.s,u and lower f.sub.s,l limits of this range is computed. This integral can be represented as:

I.sub.s=.sub.f.sub.s,l.sup.f.sup.s,uPSD(f).Math.df(1)

[0104] Included in the method is the computation of the integral of PSD(f) over a wider range of frequencies, f.sub.w spanning f.sub.o with upper and lower frequency limits f.sub.w,u, and f.sub.w,l, respectively. This integral can be represented as

I.sub.w=.sub.f.sub.w,l.sup.f.sup.w,uPSD(f).Math.df(2)

[0105] The final step in the method is to calculate the ratio, R of these two integrals as

[00001]$\begin{array}{cc}R=\frac{I_s}{I_w}& \left(3\right)\end{array}$

[0106] The lower limit of R depends on the spectral distribution of noise in the calculated range between frequency limits and f.sub.w,u and f.sub.w,l.

[0107] In the specific example where there can be considered to be so-called white noise becomes a number lying between f.sub.s/f.sub.w, being the lowest value, and 1.

[0108] FIG. 5 shows the power spectral density PSD(f) versus frequency f and parameters of the method of the invention, wherein the parameters include the prominent frequency f.sub.o, the larger restricted frequency range upper and lower limits f.sub.U and f.sub.L and the wider range of frequencies f.sub.w over which the computation of the integral of the PSD(f) is carried out.

[0109] FIG. 6 shows further the parameters of the method of the invention f.sub.w,u, f.sub.w,l, f.sub.s,l, f.sub.su, f.sub.s

[0110] Preferably f.sub.w is around 1.4 Hz and f.sub.s is around 0.6 Hz but other values are possible which will be apparent to those skilled in the art.

[0111] The values of f.sub.w,u, f.sub.w,l, f.sub.s,l, f.sub.su, are chosen according to the mode of motion of the animal.

[0112] Amongst the various modes of motion of 4 legged animals are the modes walk, trot and canter.

[0113] For walk, preferably f.sub.w,u and f.sub.w,l are around 4.6 and 2.6 Hz, respectively although other values are possible.

[0114] For trot, preferably f.sub.w,u and f.sub.w,l are around 4.4 and 2.4 Hz, respectively although other values are possible.

[0115] For canter, preferably f.sub.w,u and f.sub.w,l are around 2.2 and 1.2 Hz, respectively although other values are possible.

[0116] Other modes of motion are possible and values of f.sub.w,u and f.sub.w,l can then be chosen appropriately by those skilled in the art.

[0117] The ratio R represents a definition of the signal-to-noise ratio

[00002]$\frac{s}{n}$

of the PSD of a general time-series signal and that a value R=1 indicates that there is no noise within the measured range of frequencies. Conversely where R=f.sub.s/f.sub.w all is white noise within the measured range of frequencies and the signal if present becomes part of that noise.

[0118] A measure of quality of the characteristics of motion of the horse/rider dyad is the qualitative sensation in the rider of an irregularity in the otherwise ideal rhythmical tension in the reins. When judging the equestrian sports by observation of the motion of the horse/rider dyad the observed quality of the characteristics of motion of the horse/rider dyad is measured as a perceived loss of ideal regularity of rhythm in the motion.

[0119] Using the method of the invention it can then be made objective that a perceived loss of regularity in the rhythm of the motion of an animal/human dyad or the sensation by the human of irregularity in the rhythmical tension in the reins can be quantified as a value in the s/n.

[0120] Regarding the ranges of frequencies, the choice of limits f.sub.U and f.sub.L are preferably 5 Hz and 0.5 Hz (f.sub.s and f.sub.0,s).

[0121] It is advantageous to the application of the method of the invention to ignore contributions to the PSD that lie below 0.5 Hz as these contributions may be regarded as arising from quasi-random events such as instantaneous corrective impulses applied from the rider through the reins to the horse that are usually acceptable to judges of the governing bodies of the equestrian sports.

[0122] Similarly, it is advantageous to the application of the method of the invention to ignore contributions to the PSD that lie above 5 Hz as these are due to random noise that is unconnected with the measurement of the quality of motion of the dyad as will now be explained.

[0123] The frequency range f.sub.w must be chosen suitably so that the stride frequency or multiple thereof of the animal lies within them. The stride frequency of the animal depends on its physiology and mode of motion.

[0124] For example one mode of motion of a four legged animal is called canter and in the horse a typical frequency at canter f.sub.c lies within a range 1.12 Hzf.sub.c2.2 Hz making f.sub.c=1 Hz.

[0125] A further example of a mode of motion of a four legged animal is called trot and in the horse a typical frequency at trot f.sub.T also lies within a range 1.2 Hzf.sub.T2.2 Hz making f.sub.T=1 Hz.

[0126] Further advantageous in the application of the method is to choose a range f.sub.2,T spanning the doubled frequency of the typical stride frequency of trot which is called the second harmonic frequency f.sub.2,T so that 2.4 Hz<f.sub.2,T4.4 Hz making f.sub.2,T=2 Hz

[0127] It is further advantageous to choose a range f.sub.2,w spanning the doubled frequency of the typical stride frequency of walk which is called the second harmonic frequency f.sub.2,w so that 2.6 Hzf.sub.2,w<4.6 Hz making f.sub.2,w=2 Hz

[0128] Preferably, the method can be used to compute the PSD ratio in trot at the stride frequency R.sub.T and also at the second harmonic frequency R.sub.2,T.

[0129] By further application of the method particularly when the mode of motion of the horse is trot it is possible to compute the ratio P of the values R.sub.T and R.sub.2,T so that P=R.sub.2,T/R.sub.T which lies between values of zero and infinity.

[0130] When P is high there is indicated an unevenness in the full stride at trot of the horse which is a condition called laterality.

[0131] When the horse has no such condition such a high ratio of R.sub.T to R.sub.2,T could also indicate a rhythmical unleven application by the rider of forces to the reins. This is also called laterality. When there is no such laterality present the ratio will be zero.

[0132] A further method of the invention, referring to FIG. 7, includes the computation of the average force in the reins F.sub.R for each of the Left and Right time-series data and comparison of those values with a look-up table defining requirements for success in the equestrian sports. Requirements for success might be stipulated by the governing bodies that define and organise the equestrian sports and might include requirements that the average force in the reins must lie within an acceptable range of values spanning an ideal central value F.sub.o.

[0133] By way of example one such look-up table could comprise the definition of a figure of merit FoM whose maximum value is an optimum average tension in the reins F.sub.o which is kept substantially constant within a range of higher or lower average rein tensions to either side of F.sub.o.

[0134] Further higher or lower to either side of the optimum average rein tension the FoM attenuates progressively to zero.

[0135] Preferably, a look-up table is provided giving a figure of merit FoM being a value lying between 0 and 1 versus the independent variable FR. (see FIG. 7).

[0136] FIG. 7 depicts a graphical representation of a look-up table of the invention where a Figure of Merit FoM can be assigned to an average force value F.sub.R measured by the apparatus of the invention. The defined optimum average force in the reins F.sub.o indicated in the figure is 22 N and the range in the independent variable to either side where the FoM is substantially optimised lies between around 15 N and 30 N.

[0137] One example of an algorithm for providing a look-up table is given as

FoM.sub.L,R()=1[P cos.sup.2()[sin.sup.2()].sup.2 exp [C(cos.sup.1())]](4)

wherein FoM.sub.L,R() is the figure of merit of the parameter for comparison with either the Left or Right average rein tension and P and C are constants. The parameter gives a suitable scale for the independent variable and is given as

[00003]$\begin{array}{cc}=\frac{F_R-F_o}{W}& \left(5\right)\end{array}$

wherein W is a suitably chosen variable that governs the overall range or width of applicability of the independent variable.

[0138] By way of example the particular form of the FoM depicted in FIG. 7 where the force units are given in Newtons has F.sub.o=22, P=26.5, C=0.8 and W=25

[0139] The FoM just described may be multiplied with R to give a better overall objective indication of the quality of the characteristics of motion of the horse/rider dyad.

[0140] A further method of the invention is the computation of the ratio of the average rein tension between the left and right time series average rein tensions and a method to provide a figure of merit that is a maximum when that ratio is 1. This further figure of merit can be further multiplied with R and FoM to give a more refined measure of the quality of the characteristics of motion of the horse/rider dyad.

LIST OF REFERENCE SIGNS

[0141] 10 rein [0142] 12 bridle [0143] 14 bit [0144] 16 side ring [0145] 18 mouthpiece [0146] 20 rein tension measuring device [0147] 30 Rein tension sensor unit [0148] 40 electric cable [0149] 50 attachment unit [0150] 52 attachment hole [0151] 60 attachment unit [0152] 62 attachment hole [0153] 70 transmitter unit [0154] 72 first data collecting unit [0155] 74 second data collecting unit [0156] 76 data converting unit [0157] 78 wireless transmitter [0158] 80 receiving unit [0159] 90 processing unit [0160] 100 notification unit (display unit) [0161] L length [0162] W width