NZ614229A - Dry matter meter measurement detection method and apparatus - Google Patents

Abstract

Disclosed is a dry matter capacitance meter suitable for determining the dry matter content of forage. The meter has a capacitance probe for determining a capacitance value indicative of the dry matter content of at least a representative sample of the forage. A motion sensor contacts the ground and detects the occurrence of a sampling action completed by the meter, and a data storage element records capacitance probe measurement values indicative of dry matter content of forage. A processor reads recorded capacitance probe measurements from the data storage element and calculates the dry matter content of the forage.

Description

COMPLETE SPECIFICATION Title: Dry Matter Meter Measurement Detection Method and Apparatus I, Graham Bruce Lynch, a New Zealand citizen, of 15 Ingleton Terrace, Woodstock, Hamilton, 3214, New Zealand, do hereby declare this invention described in the following statement to be true: 2 Dry Matter Meter Measurement Detection Method and Apparatus Technical Field This invention relates to the measurement of dry matter, for example to determine the amount of dry matter in a farm pasture. In preferred embodiments the invention may be used to detect the occurrence of measurement events or actions, and also preferably to validate the detection of such actions.

Background art Knowledge of the amount of dry matter in a pasture is helpful to a farmer in estimating whether there is enough feed in a paddock or similar area to cater for a herd or flock of farm animals. Dry matter content is strongly related to the metabolisable energy in a given food source.

It is known to estimate the dry matter content of a farm pasture using different methods. Farmers generally prefer to estimate dry matter content by carrying out an eye assessment, with the proviso that some calibration of this method using an instrument of some kind is advised in earlier farming years, and to achieve more consistent results between farm workers. Rising plate meters, sward sticks, capacitance probes, mobile ultrasonic probes and infrared beam scanners are examples of equipment being used on farms.

A more accurate method to determine dry matter content as used by scientists and researchers is a cut, weigh and dry technique (CWD). This is the process of removing a set area, or quadrat, of standing forage from a paddock, drying it and then weighing it to determine the amount of dry matter content in the given area. The standard unit of measurement is usually expressed in terms of kilograms of dry matter per hectare (kgDM/ha).

CWD information can then be compared to eye assessments or instrument readings on the same quadrats. Once calibrated in this way, the faster techniques of eye assessment or instrument use can be utilised to more accurately estimate the dry matter content of much larger areas of forage. 3 Scientists, researchers, and farmers find it useful to measure dry matter content to: compare the effects of different types of fertiliser or different fertiliser regimes, compare the effects of different levels of irrigation, compare growth rates or dry matter levels of different pasture species or cultivars, and to measure residual pasture i.e. the amount of pasture remaining after the area has been grazed.

It can be seen that an accurate and easy to use forage dry matter instrument would be useful in the agricultural sector, especially if gains in productivity are important.

It is known to use dry matter meters of the capacitance type to measure the dry matter content of a pasture. With such meters a capacitance probe is grounded upright against the pasture and a capacitance reading is taken. The amount of pasture, e.g. grass or the like, around the probe affects the capacitance reading as compared with a reading taken in air alone. By way of calculation it is then possible to obtain a dry matter value expressed in terms of kilograms of dry matter per hectare of pasture (kg/ha or kgDM/ha).

Current capacitance-based measurement techniques for standing forage first take an initial reference reading in air i.e. measure capacitance in the air. All subsequent dry matter content readings in the area of growing forage are then based around this reference. During measurement operations, the probe commonly senses the difference in air/pasture capacitance readings to automatically trigger the collection of a valid data point.

Capacitance-based measurements take a reading between two conductive surfaces. In the case of common dry matter content meters, the two conductors are the outer conductor of the probe and the conductor which is connected to the inner conductor, in this case, soil. Soil becomes less conductive when the moisture content is reduced, sometimes to the point where little to no change in capacitance occurs, relative to air. In very dry conditions there may not be a large enough difference between capacitance in air and capacitance when taking dry matter readings to trigger a sample event. 4 At least one previous offering to the market used a mechanical switch, operated by the user of the meter, to accept a capacitance reading at each required site in the forage.

A problem with checking for a difference between capacitance in the air and in the pasture is the comparatively long sampling time that the probe needs to be placed into the pasture sward for an event reading to be triggered. This can be a problem when the operator wishes to use the meter probe whilst driving in or riding on a vehicle e.g. taking readings whilst holding the probe with one hand off the side of a quad bike presents usability issues.

Another problem with capacitance probes is inconsistency between operators when measuring dry matter content. For example one operator may ground the probe very lightly on the soil surface and another may force it quite firmly into the ground. If this grounding action is completed too forcefully, or too lightly it may cause inconsistent dry matter readings to occur. For example, a capacitance reading is expected to be higher if the capacitance probe is forcibly pressed into the ground rather than if it rested very lightly as there may not be a good ground connection - thus causing a low reading.

Existing types of dry matter or pasture meters contain sensitive electronic components, and rough handling or high forces applied to a meter can damage it. With these prior art meters the manufacturer cannot easily determine whether broken meters returned under warranty claims have failed because of manufacturing defects or through inappropriate handling by users.

With current hand-held capacitance dry matter meters the operator must walk across each paddock to take readings. On medium to large farms it becomes time-consuming or arduous to walk the distance required to take measurements. It is known that dry matter meters exist which must be either mounted to a vehicle or towed by a vehicle to take measurements of standing forage, however none of these use the capacitance technique.

Furthermore, current handheld capacitance-based meters cannot be used easily with vehicles, nor do they allow for the automation of measurement recording. 40 It is an object of a preferred form of the invention to go at least some way towards providing an improved means for estimation of dry matter content in an area of standing forage using the capacitance technique, or at least provide the public with a useful choice. In particular it would be of advantage to have improvements in respect of dry matter or pasture meters which could reliably detect that a valid measurement action has been completed by the user to trigger the recording of a capacitance value. It would also be of advantage to have an improved system, mechanism or apparatus which allowed an existing handheld capacitive pasture meter to be mounted in association with a vehicle and preferably to automatically take measurements in pasture as the vehicle travels.

Disclosure of Invention According to one aspect of the invention there is provided a dry matter capacitance meter suitable for determining the dry matter content of forage, the meter including a motion sensor means adapted to detect the occurrence of a sampling action completed by the meter.

According to a further aspect of the invention there is provided a dry matter capacitance meter suitable for determining the dry matter content of forage, the meter including a capacitance probe for determining a capacitance value indicative of the dry matter content of at least a representative sample of the forage, a motion sensor means adapted to detect the occurrence of a sampling action completed by the meter, a data storage element arranged to record capacitance probe measurement values indicative of dry matter content of forage when a sampling action is detected by the motion sensor means, a processor arranged to read from the data storage element recorded capacitance probe measurements to calculate the dry matter content of the forage.

According to yet another aspect of the invention there is provided a dry matter capacitance meter substantially as described above, wherein the data storage element is arranged to record capacitance probe measurements only when the occurrence of a detected sampling action has been validated.

According to one aspect of the present invention there is provided a method for determining the dry matter content of forage involving the 40 steps of: 6 a) detecting the occurrence of at least one sampling action with a motion sensor means; and b) for each sampling action detected, recording a capacitance value indicative of the dry matter content of the forage using a dry matter capacitance meter; and c) calculating the dry matter content of the forage using the recorded capacitance values.

According to yet another aspect of the present invention there is provided a method for determining the dry matter content of forage involving the steps of: a) detecting the occurrence of at least one sampling action with a motion sensor means; and b) validating the occurrence of a detected sampling action, and c) for each sampling action detected and validated, recording a capacitance value indicative of the dry matter content of the forage using a dry matter capacitance meter; and d) calculating the dry matter content of the forage using the recorded capacitance values.

According to yet another aspect of the invention there is provided a set of instructions executable by a programmable device arranged to implement a method for determining the dry matter content of forage substantially as described above.

Reference in general throughout this specification will be made to the invention being used to measure the dry matter content of pasture or short standing forage. However, in some other embodiments the invention may be used with forage types other than pasture, such as for example lucerne. In other embodiments the invention may also be used to assess non-forage based crops such as for example a variety of cereal crops. The term “forage” as used in this specification should be interpreted to mean a food source – either for livestock or for humans - which is typically grown in the ground.

The present invention is adapted to provide improvements to the accuracy of capacitance-based dry matter meters. 7 Preferably the invention may use the same form of capacitance probe as is used in current prior art capacitance based dry matter meters. These forms of capacitance probes are well known, with a significant body of experimental data having been collected in respect of performance of such probes.

Preferably a meter provided in accordance with the invention may include a data storage element. Such an element may be employed to store and subsequently retrieve a number of capacitance measurements generated through exposing the meter to forage. Those skilled in the art should appreciate that a wide range of digital data storage technologies may be employed to implement such a data storage element and therefore will not be described in detail throughout this specification.

Preferably a meter provided in accordance with the invention includes a processor adapted to retrieve data stored by the meter and to execute a dry matter calculation process. The process or calculation executed uses stored capacitance value measurements as input parameters to a dry matter calculation.

Those skilled in the art will also appreciate that in some embodiments a processor used by the invention need not necessarily be mounted or housed within a common enclosure employed to deploy other components of the invention.

For example in some instances a processor may be provided remote from the other components of the invention but in communication with same – such as, for example, where a Bluetooth or Wi-Fi link connects a smart phone processor running App software to the remaining components of the invention.

Furthermore, those skilled in the art will also appreciate that a similar hardware architecture may also be employed in some embodiments in relation to the data storage element used by the invention. Again a communications link can be used to provide a smart phone or equivalent separate user terminal with information to be stored by memory components provided by the smart phone.

Reference in general throughout this specification is also made to the 40 invention recording measurements comprised of capacitance values. The term 'recording' should be understood to encompass the general 8 collection of information in respect of measured capacitance, where in some embodiments this information may only be stored for a short period of time, or where the actual measurement taken is used to derive or identify a further related value or indicator. For example, in some embodiments a measured capacitance value may be recorded in the form of a rolling or cumulative average (or similar derivative) of measured values.

As referenced above the invention includes a motion sensor means used to detect the occurrence of at least one sampling action. A motion sensor means employed in conjunction with the invention is provided by any appropriate sensor, switch triggered by the motion of the meter, or transducer capable of indicating that a meter is in motion or has ceased to move. In a variety of embodiments such a motion sensor means may potentially also detect whether a meter is experiencing vibration, or has been tilted on an angle, and in some instances whether the meter has been tilted away from a vertical orientation or an orientation perpendicular to a horizontal plane. Those skilled in the art will appreciate that a motion sensor means provided with the invention allows for the automatic detection of sampling actions without the intervention of a human operator.

In a further preferred embodiment a motion sensor means may also be capable of supplying an output signal to associated electronics and/or software integrated within the meter, where this output signal is representative of the extent or degree of motion detected. Those skilled in the art will appreciate that this output signal may be measured and provide an output signal value which may be used and potentially recorded in conjunction with the invention.

In one preferred embodiment a motion sensor may be provided by an accelerometer. Accelerometers are readily available electrical components which can be easily integrated within the existing pasture meter housing.

Accelerometers can provide output signals indicating both the size and direction of a force experienced by the meter and can also indicate the angle of orientation or tilt experienced by a meter.

However in other embodiments a range of alternative motion sensors may be used. Those skilled in the art will appreciate that piezoelectric 40 transducers, pressure sensors, mechanical switches or gyrometers may 9 all alternatively be used to implement a motion sensor means in an alternative embodiment.

Reference in general will also be made to the invention incorporating or utilising a motion sensor as a motion sensor means. Those skilled in the art will appreciate that a range of different components can be used to implement a motion sensor or motion sensor means as discussed above.

Those skilled in the art will also appreciate that the location of a motion sensor means relative to other components of the meter will vary in a number of different embodiments. For example, in some cases a motion sensor means may be located inside a housing provided for the meter, or in other cases where the sensor used operates by contact with the ground, this sensor may be provided at the bottom ground contacting end of the meter in other embodiments.

The present invention employs a motion sensor to detect whether a sampling action has been completed with, or by, a meter. Such sampling actions are performed by the meter being moved vertically downwards to place the terminating capacitance probe of the meter in contact with the ground and the forage to be measured.

In a preferred embodiment the main shaft or body of the meter is held approximately vertically upright throughout the entire sampling action, with a capacitance measurement being recorded when the capacitance probe of the meter is in near contact with any forage and the tip is currently grounded, as signalled automatically by the status of the motion sensor.

The motion sensor employed by the invention can detect when a meter is in motion, and/or when an end of the meter (preferably being associated with the capacitance probe) is placed in contact with the ground and forage. The invention can therefore be used to ensure that capacitance measurements are only taken by a meter when a sampling action is performed correctly. The use of the motion sensor ensures that a forage capacitance reading can be recorded irrespective of any detected change in capacitance experienced by the meter’s probe. As indicated above, with prior art meters, changes in capacitance experienced with very dry soils and low forage densities may not be great enough in isolation to indicate 40 the occurrence of a sampling action. Requiring the operator to press a switch to take each sample, is an extra task that slows up the data gathering.

Preferably a dry matter capacitance meter may include a display screen configured to present a warning message when the motion sensor detects when a sampling action is not performed correctly. A warning message may be presented when the motion sensor means detects that the meter has been grounded with a force greater or less than a threshold value, or when the meter has been grounded at an angle tilted away over a threshold angle from a vertical orientation.

In some embodiments the invention may include an audio alarm element adapted to issue an audio alarm when a sampling action is not performed correctly. In such embodiments an audio alarm can be issued when the motion sensor means detects that the meter has been grounded with a force greater or less than a threshold value, or when the motion sensor means detects that the meter has been grounded at an angle tilted away from a vertical orientation.

For example, in one possible embodiment a warning message can be presented on the display of the meter or an audible warning alarm sounded, if the motion sensor detects that a sampling action is not being performed correctly. For example, in some instances these user warnings can be provided if the meter is not being dropped vertically into pasture, alternatively if the meter is being grounded too forcefully or too softly by an operator.

In a preferred embodiment the invention includes a data storage element arranged to record capacitance probe measurements only when the occurrence of a detected sampling action has been validated. The validation process completed may vary in different embodiments depending on the form and capabilities of the motion sensor provided.

Furthermore, in embodiments where the invention includes a processor, the processor may be used to execute this validation process. Set out below are a selection of possible validation processes which may be utilised in various embodiments of the invention, where any applicable combination of same may be employed in a single embodiment if desired: 11 • In some embodiments the processor compares an output signal of the motion sensor means to at least one threshold value and validates the sampling action if the output signal of the motion sensor means is above or below said at least one threshold value.

In some cases the motion sensor may be more affected by a vertical impact than impacts caused by a horizontal source. Thus a shock on the vertical axis would cause a larger output by the sensor. This in turn could be interpreted by the processor as to whether or not to take a dry matter reading.

• In some embodiments the sampling action validation process executed by the processor validates a sampling action when in receipt of a user activation command. For example, in some cases the invention may include a user command input means such as a keypad or similar means which allows for the entry of a user activation command indicating that the user wishes to measure the dry matter content in an area of growing forage. In such cases the motion sensor may only be enabled when the operator selects to measure dry matter content. The sensor will be disabled via the processor or other equivalent electronics and/or software when the operator has finished taking dry matter readings e.g. the operator has pressed a button on a keypad to indicate this.

• In some embodiments the sampling action validation process executed by the processor validates a sampling action when the output signal of the motion sensor means indicates that the orientation of the meter is within an acceptable range of angles deviating from a vertical orientation. For example in cases where a motion sensor is formed by an accelerometer capable of detecting a shock and also the angle of the probe relative to vertical. If the capacitance probe is not within a set angle of vertical after a shock is detected (for example 30 degrees) no reading will be taken, as determined by via the processor or other equivalent electronics and/or software.

• In some embodiments the sampling action validation process executed by the processor validates a sampling action when the time between consecutive sampling actions is determined to be within a threshold period.For example in some case the invention may include a timing means. If the operator has set the probe into measurement mode and not taken a reading for some time (e.g. 10 seconds) the processor or other equivalent electronics and/or 40 software may determine the shock or vibration is a false trigger. If another shock or vibration occurs within 0.5 to 10 seconds, this 12 may be determined to be normal sampling behavior and measurements can continue to be taken. An example of when this could be a problem is if the operator is climbing over an electric fence whilst the probe is in measurement mode. If the probe hits the fence it may sense vibration and also a capacitance reading due to electric fields surrounding the fence, and thus a false reading will be triggered. A timing means may alternatively (or in addition) be used to ensure the readings taken are periodic. When a capacitance probe is used for measuring dry matter, the operator walks, or drives across an area of forage. The probe is periodically placed vertically against the forage to allow for the collection of multiple samples for averaging accuracy. It is seen that the processor or other equivalent electronics and/or software may be used to ignore readings that are not periodic in nature. For example after one reading is taken, the user may be given a certain period of time to take another sample. If a sample is not taken the probe may go into a standby mode until periodic sampling begins again. Additionally it will be incorrect to take samples in quick succession (e.g. taking readings at times less than 0.5 seconds apart), thus there may be a ‘dead time’ between samples as determined by the processor.

• In some embodiments the invention may account for inconsistency between operators when measuring dry matter content. For example one operator may place the probe very lightly on the soil surface and another may force it quite firmly into the ground. It is seen that the sensor means may be used to determine how hard the probe is pressed into the ground. If it is done too firmly, or too softly, it may be determined by the electronics/software means as an invalid reading. This error may be indicated to the operator via an audio and/or visual means (e.g. an audio buzzer or an error message on an LCD display).

In a further preferred embodiment the data storage element may also be adapted to record an output signal value provided by the motion sensor.

In such embodiments the data storage element may record motion sensor measurements in a memory buffer to track whether the meter is being handled roughly or being exposed to high levels of force. In such embodiments, if the meter breaks, this memory buffer of motion sensor readings can be used to determine whether a manufacturer’s warranty has been invalidated. 40 13 According to yet another aspect of the invention there is provided a dry matter capacitance meter substantially as described above which is associated with an automatic actuation system, said system including a mounting structure capable of connection to a vehicle, and a carriage movably engaged with the mounting structure, and a drive element arranged to move the carriage relative to the mounting structure with a substantially vertical motion.

According to yet another aspect of the invention there is provided a dry matter capacitance meter substantially as described above which is associated with an automatic actuation system, said system including a mounting structure capable of connection to a vehicle, and a carriage movably engaged with the mounting structure, and a locking element arranged to releasably engage a dry matter capacitance meter to the carriage, and a drive element arranged to reciprocate the carriage relative to the mounting structure with a substantially vertical motion.

A further aspect of the invention provides an automatic actuation system which is arranged for use with a dry matter capacitance meter substantially as described above. This actuation system can allow the meter to operate automatically when being towed or otherwise carried by a vehicle, with the actuation system automatically completing a number of sampling actions with the meter as the vehicle moves. The capacitance probe might be removable from the actuation apparatus and able to be used manually during a paddock walk, or the components could be modified to be used only in the larger combined assembly.

Such an automatic actuation system includes a mounting structure capable of connection to a vehicle. Those skilled in the art should appreciate that a range of different mounting structures may be provided, ranging from a frame clamped, bolted or otherwise attached to the side or end of the vehicle – through to a frame incorporating wheels and a towing linkage which can be pulled behind a vehicle. The mounting structure employed will therefore provide a static framework on which the other components of the system are deployed.

An automatic actuation system also includes a carriage which is movable engaged with the mounting structure. This carriage is arranged to move 40 to impart a vertical motion relative to the mounting structure. In preferred embodiments the carriage may in use be reciprocated up and 14 downwards to facilitate the performance of a number of periodic sampling actions.

However in alternatives embodiments the carriage may not necessarily complete a movement which is strictly reciprocal or entirely vertical. For example in one alternative embodiment a carriage may be formed by a wheel like structure where the metering components of the invention are mounted to the rim of this wheel. Rotation of the carriage wheel will therefore impart both a horizontal and vertical motion to these components and in practice will move same upwards and downwards to automatically complete sampling actions.

In a preferred embodiment a carriage may be formed by a rack and pinion assembly. This assembly can be arranged so that the pinion is used to drive the rack vertically upwards or downwards as required in the performance of a sampling action.

However, those skilled in the art should appreciate that a range of alternative mechanical systems may be used in other embodiments to form a carriage of the actuation system. References in isolation to use a rack and pinion system should in no way be seen as limiting.

Preferably the actuation system includes a drive element which is arranged to reciprocate the carriage relative to the mounting frame with a substantially vertical motion. In a preferred embodiment where the carriage is formed from a rack and pinion assembly, this drive element may be used to impart rotational motion to the pinion to drive a vertical motion in the rack.

In a preferred embodiment a drive element may be formed by an electric motor, which in some instances may also integrate or incorporate a gearbox assembly. Electric motors are readily available and can be deployed at relatively low cost, and be can be powered either by a battery provided within the actuation system, or alternatively through a power supply cable connected to the battery of the vehicle involved.

Reference in general will also be made in this specification to the actuation system including a drive element formed by an electric motor.

However those skilled in the art should appreciate that other forms of 40 drive elements or systems may alternatively be used in conjunction with this invention. For example in one alternative embodiment a drive element may be formed by a mechanical power take-off linked to the wheels of a towed mounting frame.

An actuation system provided by the invention may also include a locking element. This locking element is arranged to releasably engage a dry matter capacitance meter to or with the carriage. In a preferred embodiment such a locking element may be formed by a clamp which at least partially encloses a region on the shaft of a meter, locking the meter on to the carriage and allowing the carriage to reciprocate the meter to perform a number of sampling actions.

However, in some alternative embodiment a locking element may not necessarily be provided, with the measurement components of the invention being fixed in place relative to the carriage. Those skilled in the art will appreciate that a locking element that releasably engages other components of the invention may not be required in all embodiments.

In a preferred embodiment a locking element may be provided with a pivotal connection to the carriage. In such instances this pivotal connection can allow the bottom end of a meter to pivot out and away from impacts with obstacles on the ground, potentially preventing the capacitance probe end of the meter from being damaged.

In a preferred embodiment the actuation system may also include a cleaning system associated with the lower region or end of the mounting structure. This cleaning system may be employed to wipe, scrub or brush debris from the bottom end of a meter after the meter has performed a sampling action. For example in one further preferred embodiment a pair of sponges may be deployed underneath the carriage at a point below the maximum downward travel allowed to the carriage. The bottom end of a meter clamped to the carriage will therefore be forced through this pair of sponges on both the downward and upward strokes of a sampling action.

Those skilled in the art will also appreciate that other forms of cleaning systems may also be employed in conjunction present invention. For example, in one alternative embodiment the sponges referenced above may be substituted for a set of brushes if required.

The present invention may provide many potential advantages over the 40 prior art. 16 The present invention provides a number of potential improvements on the prior art for capacitance-based dry matter or pasture meters. The invention can be used to reliably detect the occurrence of properly executed sampling actions to ensure that the meter records a forage capacitance measurement at the correct time. Furthermore, detected sampling actions can also be validated in some embodiments to check that the current capacitance reading provided by the meter does relate to a valid forage capacitance sample.

In a variety of embodiments the invention may facilitate use of the meter from a quad bike or similar vehicle – where, for example, the user holds the meter off the side and takes samples by hand as they travel. The motion sensor means employed by the invention can act substantially faster than prior art meter reading detection methods, as is required with the use of a meter on a moving vehicle.

The present invention may also facilitate the automatic recording of dry matter meter readings with the use of the vehicle. In such embodiments an automatic actuation system may be provided with a meter to automatically and periodically perform sampling actions to trigger the automatic recording of forage capacitance values as a vehicle travels through an area.

Brief description of the drawings A series of example embodiments of the invention is now discussed with reference to the drawings in which: • Figure 1 shows a schematic view of a dry matter capacitance meter provided in accordance with a preferred embodiment of the invention where an accelerometer provides a motion sensor means, and • Figure 2 shows a schematic view of a dry matter capacitance meter associated with an automatic actuation system as provided in a further embodiment of the invention, and • Figure 3 shows a schematic view of a dry matter capacitance meter provided in accordance with an alternative embodiment of the invention where a switch provides a motion sensor means.

Best modes for carrying out the Invention 40 17 Figure 1 shows a schematic view of a dry matter capacitance meter provided in accordance with a preferred embodiment of the invention.

The device shown in figure 1 includes a capacitance-based probe with the added feature of a motion sensor means (1) to detect the occurrence of a sampling action and therefore whether or not a dry matter reading should be taken. The sensor (1) is capable of detecting a sudden motion, vibration and a change in angle of the associated capacitance-based probe. This data will then be processed and validated by the dry matter meter (2) by means of on-board electronics and software to indicate whether or not a reading of dry matter content should be taken.

The sensor may be any suitable sensor useful for this purpose. For example, a piezoelectric sensor, an accelerometer, pressure sensor, mechanical switch or a gyrometer can all be used in a range of embodiments of the invention. In the embodiment shown in figure 1 an accelerometer provides the motion sensor.

Furthermore the invention validates detected sampling actions to stop false triggering i.e. a reading being taken after an unwanted or unexpected shock or vibration on the probe.

In the embodiment shown readings are only validated if the accelerometer determines that the meter is being held approximately vertically upright and if the force used to ground the end of the meter is between a minimum and maximum allowable range.

The motion sensor means is also connected to a data storage means (not shown) normally used to record capacitance values, but in this embodiment the date storage means is used to log motion sensor data for warranty purposes. For example the size of the last 20 excessive shocks may be stored, and if a shock is seen to be of unnecessary force a warranty can be considered void.

Figure 2 shows a schematic view of a dry matter capacitance meter associated with an automatic actuation system as provided in a further embodiment of the invention.

The invention shown in this embodiment includes a mounting structure in 40 the form of a frame (3) connected to a vehicle by means of a tow bar or other arrangement. The frame has wheels (7) to allow for ease of towing. 18 The system holds a meter or probe (5) using a locking element, formed in this embodiment by a clamping means (6), the probe and clamping means being movable in a reciprocal vertical motion to enable a pasture reading to be taken.

The vertical motion is achieved using a carriage, formed in this embodiment by a rack and pinion arrangement (1). The pinion is driven by a drive element, formed in this embodiment by an electric motor and gearbox (2), the direction and speed of which is controlled by electronics/software means (8). The electronics/software means (8) monitors the current through the electric motor to determine if the probe is pressed against the soil. The electronics/software means is contained in suitable water-proof enclosure and mounted to the frame. In this embodiment the electronics/software means is powered by the battery already in a vehicle towing the invention - e.g. through a standard trailer plug adapter.

The clamping means also has a pivoting means (4) to prevent the probe from breaking due to vehicle movements. There is also provided an automated cleaning means to wipe the probe after each usage e.g. a sponge. This will prevent higher than usual readings due to soil or other matter sticking to the probe. The invention also includes a remote control means to initiate dry matter readings.

Figure 3 shows a schematic view of a dry matter capacitance meter provided in accordance with an alternative embodiment of the invention where a switch provides a motion sensor means. In reference to figure 3, reference ‘1’ is the outer conductor of a capacitance probe, ‘2’ is the inner conductor of the same probe and ‘3‘is a motion sensor means provided by a mechanical switch. (Redraw with longer switch being shown).

In this embodiment the motion sensor means is located at the base of the probe. A dry matter reading is taken when the switching mechanism 3 is engaged. Using this method will ensure that a reading will not be taken until the inner conductor is resting on the forage base layer, and perhaps lodged into the soil. The switch 3 also includes a spring bias return system to reset the switch position when the end of the meter is lifted from the ground. 40 In a further alternative embodiment (not shown) the mechanical switch 3 is replaced with a pressure sensor. This pressure sensor can be used to 19 determine how firmly the probe is pressed into the ground i.e. a reading may not be triggered until a certain ‘pressure threshold’ is reached as determined by a processor or electronics/software means integrated into the meter.

It is to be understood that the present invention is not limited to the embodiments described herein and further and additional embodiments within the spirit and scope of the invention will be apparent to the skilled reader from the examples illustrated with reference to the drawings. In particular, the invention may reside in any combination of features described herein, or may reside in alternative embodiments or combinations of these features with known equivalents to given features.

Modifications and variations of the example embodiments of the invention discussed above will be apparent to those skilled in the art and may be made without departure of the scope of the invention as defined in the appended claims

Claims (42)

What I Claim Is:

1. A dry matter capacitance meter suitable for determining the dry matter content of forage, the meter including 5 a capacitance probe for determining a capacitance value indicative of the dry matter content of at least a representative sample of the forage, a motion sensor means adapted to detect when a sampling action is completed by the meter being placed in contact with the ground, 10 a data storage element arranged to record capacitance probe measurement values indicative of dry matter content of forage when a sampling action is detected by the motion sensor means, a processor arranged to read from the data storage element recorded capacitance probe measurements to calculate the dry 15 matter content of the forage.

2. A dry matter capacitance meter as claimed in claim 1 wherein the meter is adapted to measure the dry matter content of pasture or short standing forage.

3. A dry matter capacitance meter as claimed in any previous claim 20 wherein the motion sensor means detects when the capacitance meter is in motion.

4. A dry matter capacitance meter as claimed in any previous claim wherein the motion sensor means detects when the meter is experiencing vibration. 25

5. A dry matter capacitance meter as claimed in any previous claim wherein the motion sensor means detects when the meter has been tilted away from a vertical orientation.

6. A dry matter capacitance meter as claimed in any previous claim wherein a motion sensor means is provided by an accelerometer. 30

7. A dry matter capacitance meter as claimed in any previous claim which includes a display screen configured to present a warning message when the motion sensor means detects when a sampling action is not performed correctly. 21

8. A dry matter capacitance meter as claimed in claim 7 wherein a warning message is presented when the motion sensor means detects that the meter has been grounded with a force greater or less than a threshold value. 5

9. A dry matter capacitance meter as claimed in claim 7 wherein a warning message is presented on the display screen when the motion sensor means detects that the meter has been grounded at an angle tilted away from a vertical orientation.

10. A dry matter capacitance meter as claimed in any previous claim 10 which includes an audio alarm element adapted to issue an audio alarm when a sampling action is not performed correctly.

11. A dry matter capacitance meter as claimed claim 10 wherein an audio alarm is issued when the motion sensor means detects that the meter has been grounded with a force greater or less than a 15 threshold value.

12. A dry matter capacitance meter as claimed in claim 10 wherein an audio alarm is issued when the motion sensor means detects that the meter has been grounded at an angle tilted away from a vertical orientation. 20

13. A dry matter capacitance meter as claimed in any previous claim wherein the data storage element records capacitance probe measurements only when the occurrence of a detected sampling action has been validated.

14. A dry matter capacitance meter as claimed in claim 13 wherein the 25 processor executes a sampling action validation process to enable the recording of capacitance probe measurements by the data storage element.

15. A dry matter capacitance meter as claimed in claim 14 wherein the sampling action validation process executed by the processor 30 compares an output signal of the motion sensor means to at least one threshold value and validates the sampling action if the output signal of the motion sensor means is above or below said at least one threshold value.

16. A dry matter capacitance meter as claimed in claim 14 wherein the 35 sampling action validation process executed by the processor 22 validates a sampling action when in receipt of a user activation command.

17. A dry matter capacitance meter as claimed in claim 14 wherein the sampling action validation process executed by the processor 5 validates a sampling action when the output signal of the motion sensor means indicates that the orientation of the meter is within an acceptable range of angles deviating from a vertical orientation.

18. A dry matter capacitance meter as claimed in claim 14 wherein the sampling action validation process executed by the processor 10 validates a sampling action when the time between consecutive sampling actions is determined to be within a threshold period.

19. A dry matter capacitance meter as claimed in any previous claim wherein the data storage element records an output signal value provided by the motion sensor. 15 20. A dry matter capacitance meter as claimed in any previous claim which includes an automatic actuation system, said system including a mounting structure adapted to connect to a vehicle, and a carriage movably engaged with the mounting structure, and

20 a drive element arranged to move the carriage relative to the mounting.

21. A dry matter capacitance meter as claimed in claim 20 wherein the drive element is arranged to reciprocate the carriage relative to the mounting. 25

22. A dry matter capacitance meter as claimed in claim 20 or claim 21 which includes a locking element arranged to releasably engage a dry matter capacitance meter to the carriage

23. A dry matter capacitance meter as claimed any one of claims 20 to 22 wherein the actuation system connects the meter to a vehicle 30 and automatically completes sampling actions as the vehicle moves.

24. A dry matter capacitance meter as claimed in any one of claims 20 to 23 wherein the carriage and mounting structure define a rack and pinion assembly. 23

25. A dry matter capacitance meter as claimed in claim 24 wherein the drive element imparts rotational motion to the pinion to impart a linear vertical motion to the rack.

26. A dry matter capacitance meter as claimed any one of claims 20 to 5 25 wherein the drive element is formed by an electric motor.

27. A dry matter capacitance meter as claimed any one of claims 20 to 26 wherein the drive element includes a gearbox assembly.

28. A dry matter capacitance meter as claimed any one of claims 20 to 27 wherein the locking element is formed by a clamp. 10

29. A dry matter capacitance meter as claimed any one of claims 22 to 28 wherein the locking element is pivotably connected to the carriage.

30. A dry matter capacitance meter as claimed any one of claims 20 to 29 which includes a cleaning system associated with a lower region 15 of the mounting structure.

31. A dry matter capacitance meter as claimed in claim 30 wherein the cleaning system includes a pair of sponges deployed underneath the carriage below the maximum downward travel of the carriage.

32. A dry matter capacitance meter as claimed in claim 30 wherein the 20 cleaning system includes a pair of brushes deployed underneath the carriage at a point below the maximum downward travel allowed to the carriage.

33. A method for determining the dry matter content of forage involving the steps of: 25 i. detecting with a motion sensor means the occurrence of at least one sampling action completed by the end of the meter being placed in contact with the ground ; and ii. validating the occurrence of a detected sampling action, and iii. for each sampling action detected and validated, recording a 30 capacitance value indicative of the dry matter content of the forage using a dry matter capacitance meter; and i. calculating the dry matter content of the forage using the recorded capacitance values. 24

34. A method for determining the dry matter content of forage as claimed in claim 33 which includes the additional step of presenting a warning message or issuing an audio alarm when a detected sampling action is determined to be invalid. 5

35. A method for determining the dry matter content of forage as claimed as in claim 33 or claim 34 wherein sampling actions are validated by comparing an output signal of the motion sensor means to at least one threshold value with the sampling action being validated if the output signal of the motion sensor means is 10 above or below said at least one threshold value.

36. A method for determining the dry matter content of forage as claimed as in claim 33 or claim 34 wherein sampling actions are validated if a user activation command has been received.

37. A method for determining the dry matter content of forage as 15 claimed as in claim 33 or claim 34 wherein sampling actions are validated when the output of the motion sensor means indicates that the orientation of the meter is within an acceptable range of angles deviating from a vertical orientation.

38. A method for determining the dry matter content of forage as 20 claimed as in claim 33 or claim 34 wherein sampling actions are validated when the time between consecutive sampling actions is determined to be within a threshold period.

39. A method for determining the dry matter content of forage as claimed as in any one of claims 33 to 38 which includes the 25 additional step of recording the output signal of the motion sensor used to detect the occurrence of a sampling action.

40. A set of instructions executable by a programmable device arranged to implement a method for determining the dry matter content of forage as claimed in any one of claims 33 to 39. 30

41. A dry matter capacitance meter substantially as herein described with reference to and as illustrated by the accompanying drawings and/or examples.

42. A method for determining the dry matter content of forage substantially as herein described with reference to and as illustrated 35 by the accompanying drawings and/or examples