GB2278198A

GB2278198A - Condition indicator

Info

Publication number: GB2278198A
Application number: GB9310416A
Authority: GB
Inventors: Roger Charles Balls; David Ian Bartlett
Original assignee: Minister of Agriculture Fisheries and Food UK
Current assignee: Minister of Agriculture Fisheries and Food UK
Priority date: 1993-05-20
Filing date: 1993-05-20
Publication date: 1994-11-23
Anticipated expiration: 2013-05-20
Also published as: GB9310416D0; GB2278198B

Abstract

A condition indicator includes a detector 11, which may, for example, have two accelerometers 13, 14 mounted at right angles, connected to a comparison means such as a microcomputer 19. In use the detector 11 is mounted on an item, such as a shoe 31 on a horse's hoof 30 which will make repeated impacts with a surface, and the comparison means are programmed with a library of patterns corresponding to a series of surfaces. As the item makes impacts with a surface, signals from the detector 11, preferably averaged over a number of impacts, are compared with the patterns to give an indication of the condition of the surface, i.e. the "going" on a racecourse. The device may alternatively be used to assess the fitness condition of a human or animal limb. <IMAGE>

Description

CONDITION INDICATOR The present invention is concerned with condition indicators for indicating qualities such as the degree of hardness or slipperiness of a surface or the degree of fitness of a limb.

Condition indicators of this type might be used, for example, in the horse racing industry. In this industry, the nature of the ground over which the horses race is usually grassland, which is greatly affected by weather conditions. The nature of the ground in this industry is generally referred to as "the going" and can have a big effect on the results of a race and of the various activities connected therewith. For example some horses run better than others in "heavy going", that is when the ground is badly affected by moisture, whilst this might be reversed when the "going" is "hard", that is when the ground is affected by drought or frost." Also owners or trainers of horses may wish to withdraw them from certain races if the "going" is such that they fear the horses may aggravate an injury.

Currently the "going" is measured by subjective methods, usually by a race course official digging his heel into the ground at various points in the course circuit and giving his assessment.

According to one aspect of the present invention a condition indicator includes a detector attachable to an item which can make repeated impacts with a surface and comparison means capable of storing a library of patterns, of comparing the patterns with a signal from the detector resulting from an impact between the item and the surface, and of giving a reading based on the comparison.

The detector might consist of one or more accelerometers, a preferred arrangement being two accelerometers adapted to detect each of a vertical and a horizontal acceleration.

Alternatively the detector might include, for example, piezoelectrical material.

The comparison means will usually be a micro-computer, and will usually receive a signal direct from the detector.

The library of patterns might be programmed directly into the comparison means during assembly of the indicator, or might be programmed according to the intended use of the indicator by a user thereof.

Acceptance by the comparison means of the signal for each impact might be initiated by detection of a predetermined criterion of input from the detector, for example a change of sign of the signal.

Alternatively a separate device such as, for example, an acoustic sensor, may be used to trigger acceptance of the signal. Once the signal acceptance has been initiated it will usually be accepted over a predetermined time programmed into the comparison means.

The comparison means will usually be adapted to compare a signal representing the mean of a number of impacts between the item and the surface rather than a single impact signal. The arrangement is preferably such that the mean is continually upgraded as impacts occur.

According to another aspect of the invention a method of measuring the condition of a surface, using a condition indicator including a detector, attached to an item which makes repeated impacts with the surface, and comparison means, includes the steps of storing a library of patterns in the comparison means, of passing signals from the detector resulting from impacts between the item and the surface to the comparison means and comparing the signals with the patterns, and of giving a reading based on the comparison.

The Applicant has discovered that using the invention, in an embodiment where the detector included two accelerometers adapted to read accelerations mutually at right angles, one acceleration being substantially vertical and one substantially horizontal, similar results were obtained with the indicator secured to a horseshoe on a horse and with the indicator secured to footwear of a person.

The Applicant also discovered, by studying patterns obtained whilst calibrating an indicator according to the invention over a number of surfaces of known condition, that an animate creature adjusts its gait according to the condition of the surface over which it is moving.

According to another aspect of the invention, therefore, a method of measuring the condition of a limb of a living creature includes the steps of attaching to the limb a condition indicator including a detector and comparison means, of storing a library of patterns in the comparison means, of inducing the limb to impact on a surface, of passing signals from the detector resulting from impacts between the limb and the surface to the comparison means and comparing the signals with the patterns, and of giving a reading based on the comparison.

When the limb is the injured leg of a first horse, for example, the library of patterns might consist of a single pattern corresponding to a pattern obtained during exercise whilst uninjured or to that made by the uninjured leg of a second horse over the same surface as that used by the first horse in exercise. The comparison can be used to give an objective indication of the state of the injury as the first horse recovers. A stable of horses might maintain a master record of patterns, one corresponding to the uninjured state of each horse in the stable which can be programmed into the condition indicator when that horse is injured.

Clearly, whilst the various aspects of the invention have so far been described with reference to horses and to race-courses on which the horses race, the invention can be used for measuring the condition of a wide variety of surfaces, sporting and otherwise, and for a wide variety of animal and of human orthopaedic purposes.

One embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, of which; Figure 1 is a side elevation of a condition indicator according to the invention, Figure 2 is an end elevation of the detector of the condition indicator shown in Figure 1, Figure 3 is a side elevation of a horse's hoof, Figure 4 is an end elevation, in section, of the hoof shown in Figure 3, and Figure 5 shows a library of patterns, in the form of impulse responses, suitable for storing in a comparison means of the conditidn indicator.

A condition indicator 10 (Figure 1) has a detector 11 (see also Figure 2) having a steel mounting plate 12 on which are mounted a vertical accelerometer 13 and a horizontal accelerometer 14. On the side of the plate 12 opposite to the accelerometers 13, 14 is a dowel 15, and there is a hole 16 in the plate 12. Cables 17, held onto the plate 12 by a clamp 18, connect the components of the detector 11 to a comparison means 19 in the form of a microcomputer which might be conveniently mounted in a pack 20 along with power means, such as a battery, 21.

A horse (not shown) on which the condition indicator is to be used has fitted to one hoof 30 a shoe 31 at one side of which is welded a bracket 32 in which are a threaded hole 33 and an unthreaded hole 34. The detector 11 is attached to the bracket 32 by positioning the dowel 15 in the unthreaded hole 34 an securing the plate 12 and bracket 32 together by means of a screw passed through the hole 16 in plate 12 into the threaded hole 33 in the bracket. The comparison device is positioned in any suitable position- for example secured to part of the horse's leg, to a saddle, or in a pocket of a rider.

In use the horse is ridden over a number of surfaces of known condition and the accelerations measured by the accelerometers 13, 14 recorded in the microcomputer 19, in pattern form, preferably averaged over a plurality of strides (for example 60 to 100). The microcomputer 19 may be programmed to start accepting a signal corresponding to each impact when it senses a predetermined criterion in the input from the detector 11. The criterion might be, for example, a change in sign of the input signal. The average may advantageously be continually upgraded over a calibration run. The patterns resulting from rides over a plurality of surfaces form a library of patterns, as shown in Figure 5, where patterns from rides over soft, intermediate, and hard surfaces are shown 40, 41 and 42 respectively, in the form of acceleration against milliseconds. The acceleration shown is a combination of the readings from the two accelerometers, and is in three portions, namely downward force, ground contact and lift off force. It will be seen that for the soft pattern the acceleration remains significant whilst the hoof is in contact with the ground. This is a reading from the horizontal accelerometer, and is due to slippage of the hoof relative to the ground with this type of surface.

Once the library of patterns has been stored in the comparison means 19 the condition indicator 10 can be used by fitting to a horse as described above and riding the horse over a surface of unknown characteristics. The comparison means compares the readings of the detector 11 with the library of patterns and gives a reading corresponding to the surface condition. The reading might be, for example, displayed on a dial on the microcomputer 19, or stored therein and recovered later.

It will be realised that many variations of the condition indicator are possible within the scope of the invention. For example, the comparison means or the display means might be positioned remote from the detector 11, signals being sent by, for example, radio waves. Also many alternative types of detector are possible- for example, detectors using piezo-electric materials.

The form of the patterns used will depend on the nature of the detector 11 and on the nature of use of the indicator. For example when accelerometers, such as the accelerometers 13, 14, are used the results therefrom might be combined to form a single pattern as described above and as illustrated in Figure 5. Alternatively, in some cases it might be found useful to have separate patterns for each accelerometer, or to have patterns based on vectors.

It will also be realised that as an alternative to setting a library of patterns by calibration as described above it may be possible to store a series of libraries which can be programmed into the comparison means as required.

The condition indicator 10 need not be attached to any particular conveyor. For example the condition of a race track may be measured by an indicator 10 attached to the footwear of a track official rather than to a horse for means of calibration.

The indicator 10 can also be used to indicate the degree of recovery of an injured horse, by comparing the patterns developed during exercise with those of an uninjured horse exercising on the same surface.

Whilst the invention has been described with reference to horses and to horse race courses it will naturally be realised that it has utility with respect to the measurement of many other surfaces, sporting and otherwise, and also to the measurement of physical and orthopaedic characteristics in animals and in humans.

As an alternative to using a predetermined condition programmed into the microcomputer 19 to trigger acceptance of an impact signal a sensor, such as an acoustic sensor, might be used to trigger acceptance. Such a device might be positioned as part of the detector 11.

Claims

What is claimed is: 1. A condition indicator including a detector attachable to an item which can make repeated impacts with a surface and comparison means capable of storing a library of patterns, of comparing the patterns with a signal from the detector resulting from an impact between the item and the surface, and of giving a reading based on the comparison.
2. A condition indicator as claimed in Claim 1 wherein the detector consists of one or more accelerometers.
3. A condition indicator as claimed in Claim 2 wherein there are two accelerometers adapted to detect each of a vertical and a horizontal acceleration.
4. A condition indicator as claimed in Claim 1 wherein the detector includes piezo- electrical material.
5. A condition indicator as claimed in any one of Claims 1 to 4 wherein the comparison means is a micro-computer.
6. A condition indicator as claimed in any one of Claims 1 to 5 wherein the detector receives a signal direct from the detector.
7. A condition indicator as claimed in any one of Claims 1 to 6 wherein the library of patterns is programmed directly into the comparison means during assembly of the indicator.
8. A condition indicator as claimed in any one of Claims 1 to 6 wherein the library of patterns is programmed according to the intended use of the indicator by a user thereof.
9. A condition indicator as claimed in any one of Claims 1 to 8 wherein the comparison means is adapted to compare a signal representing the mean of a number of impacts between the item and the surface.
10. A condition indicator as claimed in any one of Claims 1 to 9 wherein the comparison means accepts a signal corresponding to an impact on detecting a predetermined criterion in the input from the detector.
11. A condition indicator as claimed in any one of Claims 1 to 9 including a sensor for initiating acceptance by the comparison means of a signal corresponding to an impact.
12. A condition indicator as claimed in Claim 11 wherein the sensor is an acoustic sensor.
13. A method of measuring the condition of a surface, using a condition indicator including a detector, attached to an item which makes repeated impacts with the surface, and comparison means, including the steps of storing a library of patterns in the comparison means, of passing signals from the detector resulting from impacts between the item and the surface to the comparison means and comparing the signals with the patterns, and of giving a reading based on the comparison.
14. A method of measuring the condition of a limb of a living creature including the steps of attaching to the limb a condition indicator including a detector and comparison means, of storing a library of patterns in the comparison means, of inducing the limb to impact on a surface, of passing signals from the detector resulting from impacts between the limb and the surface to the comparison means and comparing the signals with the patterns, and of giving a reading based on the comparison.
15. A condition indicator substantially as herein described with reference to Figures 1 to 5 of the accompanying drawings.
16. A condition indicator substantially as herein described.
17. A method of measuring the condition of a surface substantially as herein described with reference to Figures 1 to 5 of the accompanying drawings.
18. A method of measuring the condition of a surface substantially as herein described.
19. A method of measuring the condition of a limb substantially as herein described with reference to Figures 1 to 5 of the accompanying drawings.
20. A method of measuring the condition of a limb substantially as herein described.