GB2494201A

GB2494201A - Wildlife repelling device

Info

Publication number: GB2494201A
Application number: GB1115297.2A
Authority: GB
Inventors: Robert Head; Steven Rothwell
Original assignee: Vitacress Ltd
Current assignee: Vitacress Ltd
Priority date: 2011-09-05
Filing date: 2011-09-05
Publication date: 2013-03-06
Also published as: GB201115297D0

Abstract

A wildlife repelling device 100 is configured for connection to harvester 105, the wildlife repelling device comprises an oscillator operable to generate an ultrasound signal, an amplifier operable to amplify- the generated ultrasound signal, and an ultrasound emitter 115 operable to convert the ultrasound signal into an ultrasound wave and being configured so that when mounted on the leafed produce harvester, the ultrasound wave emitted from the ultrasound emitter 115 is directed to a predetermined area in front of the harvester 105. The device 100 is preferably mounted to the harvester 105 via a ball and socket bracket and includes more than one emitter 115.

Description

A Wildlife Repelliκg Device

The present invention relates to a method and device for repelling wildlife.

When harvesting leafed products, wildlife and in particular rodents such as mice and insects such as crickets and grasshoppers can be caught in the harvesting process. If the wildlife is not removed during the washing and bagging process, there is a possibility that the wildlife can be erroneously placed in the bagged salad. Clearly, this is undesirable.

It is an aim of the present invention to reduce the likelihood of wildlife being placed into the bagged salad.

It is known that wildlife, such as rodents and certain insects dislike ultrasound. Known rodent repelling devices are meant for large areas and are omnidirectional. Therefore, in order to reduce the likelihood of a rodent being placed in harvested produce one could try to repel rodents from the field to be harvested. However, this would require a very large number of known rodent repellent devices in the field. However, this would be expensive and may not be effective given the large area to be cleared. Moreover, continual exposure of rodents to low level ultrasound has also been show to lead to rapid habituation. Therefore, a different solution to this problem is required.

According to a first aspect, there is provided a wildlife repelling device configured for connection to a leafed produce harvester, the wildlife repelling device comprising: an oscillator operable to generate an ultrasound signal, an amplifier operable to amplify the generated ultrasound signal, and an ultrasound emitter operable to convert the ultrasound signal into an ultrasound wave and being configured so that when mounted on the leafed produce harvester, the ultrasound wave emitted from the ultrasound emitter is directed to a predetermined area in front of the harvester.

The phrase "in front of the harvester" should be construed to mean in the direction the harvester is moving. As the ultrasound emitter is directional and provides an ultrasound barrier that moves slightly in front of the harvester, the rodents will hear the ultrasound approaching and increasing in intensity and will move away from the harvester. This reduces the likelihood of the wildlife being caught by the harvester. Moreover, the term "wildlife" should be construed to mean rodents, such as mice and rats, as well as insects such as crickets and grasshoppers that are sensitive to ultrasound.

The ultrasound emitter may be configured to be mounted to the harvester using a movable bracket arranged to allow movement of the ultrasound emitter. This allows the ultrasound wave to be directed towards different focal areas in front of the harvester.

The movable bracket may include a ball and joint socket which may be locked in position.

The device may comprise a plurality of ultrasound emitters wherein each emitter has an amplifier associated therewith. Each amplifier may be operable to be controlled independently of one another. This allows a certain ultrasound "pattern" to be made in front of the harvester.

The device may be operative in one or more mode selected from: sweep oscillation between 22-26 kHz; pulsing oscillation on/off at 25 kHz; 28 kHz continuous; 22 kHz continuous; and test at 10 kHz continuous. These modes have been found to be particularly effective at repelling rodents whilst being inaudible to humans. The mode may be selected by a user.

The emitter may be configured to produce 120dB of ultrasound at an area 1 metre from the harvester. This again has been shown to be particularly effective at repelling rodents, eliciting an involuntary running response and is beyond the power of any known and commercially available rodent repellent systems.

Embodiments of the present invention will be described, by way of example only, with reference to the following figures in which:

Figure 1 shows a harvesting device having a wildlife repeller according to embodiments of the invention attached thereto;

Figure 2 shows an aerial view of the arrangement in Figure 1;

Figure 3 shows a mechanism by which the emitter shown in the embodiment of Figure 1 is attached to the harvester; Figure 4 shows a block diagram of the rodent repelling device according to embodiments of the present invention; and

Figure 5 shows a schematic diagram of a test kit according to embodiments of the present invention.

Referring to Figure 1, a harvester 105 is harvesting leafed produce 120. The leafed produce may be salad leaves such as lettuce, spinach or rocket and the like or may be herbs such as watercress, coriander or dill and the like. The harvester 105 has a harvesting tool 110 attached underneath the harvester 105. The harvesting tool 110 harvests the leafed produce 120 grown in a field. The harvesting tool 110 is known in the art and will not be explained hereinafter. It should be noted that, as explained above in the introduction, the harvesting tool 110 will harvest the leafed produce 120 and may also collect wildlife such as rodents within the harvesting tool 110 which may be ultimately placed into the bagged salad or herb product.

In embodiments of the present invention, a rodent repelling device 100 is attached to the front of the harvester 105. It should be noted here that although the following embodiment relate to a rodent repelling device, the present invention is not so limited and may repel any wildlife that is sensitive to ultrasound. As shown in Figure 1, the rodent repelling device 100 includes an ultrasound emitter 1 15. The ultrasound emitter 115 is arranged to direct ultrasound approximately 1m in front of the harvester 105. However, the distance which the ultrasound is directed may vary. It should be also noted here that the ultrasound emitter 115 will effectively focus the ultrasound at a particularly point or small area located in front of the harvester 105. The function and construction of the rodent repelling device 100 will be explained later with reference to Figure 4.

Referring to Figure 2, the harvester 105 and the rodent repelling device 100 is viewed from above. As can be seen in this figure, the rodent repelling device 100 comprises four ultrasound emitters 115. These ultrasound emitters are located on the front of the harvester 105 and are placed across the width of the harvester 105. In other words, the ultrasound emitters 115 are mounted to the front of the harvester 105 such that the spread of the ultrasound emitted from the ultrasound emitters 115 extends along the full width of the harvester 105. This arrangement ensures that ultrasound is applied to an area of the ground around 1 m in front of the width of the harvester 105. As the ultrasound extends beyond the width of the harvester 105, any rodents located in front of the harvester 105 will be repelled reducing the likelihood of a rodent being caught in the harvesting tool 110.

As will be seen by the skilled person, the arrangement of each ultrasound emitter 115 is such that the emitter 115 produces a cone of ultrasound approximately 10° from the centre line of the emitter 115. Specific details of each ultrasound emitter 115 will be given in the discussion of Figure 4.

Referring to Figure 3, one mechanism by which each ultrasound emitter 115 is mounted to the front of the harvester 105 is described. Attached to the front of the harvester 105 is a hollow cylindrical tube 305. The hollow cylindrical tube 305 has a hole located therein allowing a screw mechanism 310 to be inserted. At the open end of the hollow cylindrical tube 305, a ball joint 320 is inserted. The ball joint 320 engages with the screw mechanism 310 so that when tightened, the ball joint 320 is held in place. The ultrasound emitter 115 is connected to the ball joint 320. By attaching the ultrasound emitter 115 to the hollow cylindrical tube 305 using a ball joint 320 and a screw mechanism 310, the position of the ultrasound emitter 115 can be adjusted in both the vertical and horizontal directions as indicated by arrows 300. Additionally, roll may be applied to the ultrasound emitter 115 should this be required. By having this arrangement, the orientation of the ultrasound emitter 115 may be easily changed and reconfigured. This is advantageous during setup of the rodent repelling device 100 as it allows the ultrasound to be directed where appropriate.

Referring to Figure 4, an embodiment of the rodent repelling device 100 will now be described. In particular, a block diagram 400 showing the major electronic components of the rodent repelling device 100 is described.

In the block diagram 400 the four ultrasound emitters 115A-115D are shown. These emitters are piezoelectric emitters. Each emitter is 80 mm in diameter and has a sensitivity of 92 dB. Each emitter operates up to a maximum frequency of 30 kHz and has a maximum rated power of 200 Watts (RMS). One emitter may be the "Power Pro Piezo Horn" (part number D320909102) manufactured by Intimidation Audio. This HiFi is selected as it is unusually rated upto 30kHz. As would be appreciated, most HiFi speakers are only rated upto 20kHz which is the limit of human hearing. Each emitter is controlled by a high-voltage amplifier 430A-430D. Each high-voltage amplifier operates on a 12 V supply which is provided by a regulating and filtering device

410. The high- voltage amplifiers each have a high impedance input and a five volt logic level.

Additionally, the input to each high voltage amplifier 430A-430D is 12 Watt and each amplifier has an output of 60 V peak to peak. This output is fed to the respective ultrasound emitter 1 15A-115D. The type of construction of the high-voltage amplifier 430A-430D is traditional in the field of human audible amplifiers. However, the type of construction, in embodiments of the present invention, has been applied to the ultrasound. This is unconventional because the power requirements for ultrasound have, to date, been much lower than the power requirements for human audible amplifiers. However, as the construction of the high power amplifiers 430A-430D uses conventional techniques applied to the ultrasound region, the specific construction of each amplifier will not be described any further.

The input to each high-voltage amplifier 430A-430D is controlled by a respective driving circuit 425A-425D. The respective driving circuits are known and drive each high power amplifier 430A-430D.

A driver controller 420 has four output lines. Each output line is connected to the input of each of the respective driving circuits 425A-425D. The driver controller 420 is configured to control the power applied to each of the emitters 115A-115D. In other words, the driver controller 420 provides each respective driving circuit 425A-425D with a signal at an appropriate frequency and amplitude. The driver controller 420 is controlled by microprocessor 405 as will be explained later.

A variable oscillator 415 operating in five modes is provided to the input of the driver controller 420. The selection of the operating mode of the variable oscillator 415 is also controlled by the microprocessor 405. The microprocessor 405 is controlled by one or more user input devices such as a touchscreen device, keyboard, mouse as indicated by 440.

As noted above, a regulator 410 is connected to the battery of harvester 105. The regulator provides a power supply of 12-14.8 V of filtered and regulated DC electricity. This power supply is fed to each of the electronic components within the block diagram 400. The power lines 435 are shown in Figure 4 as dashed lines. In operation, a user manipulates one of the user input devices 440 to instruct the microprocessor 405 to select one of five modes of operation. The five modes of operation are:

Mode 1 - sweep oscillation between 22-26 kHz;

Mode 2 - pulsing oscillation on/off at 25 kHz;

Mode 3 - 28 kHz continuous;

Mode 4-22 kHz continuous; and

Mode 5 - test at 10 kHz continuous.

Typically, the user will select the operating mode from a display (not shown).

If the user selects mode one, the microprocessor 405 instructs the variable oscillator 415 to generate an output signal that sweeps between 22 kHz and 26 kHz over a period of 500ms. Clearly, the length of time taken to sweep between 22 kHz and 26 kHz may vary as would be appreciated by the skilled person.

In addition to selecting the mode, the user may also choose an ultrasound pattern that may be provided in front of the harvester 105. In other words, the user may select mode one which enables each emitter to have an output ultrasound waveform that sweeps between 22 kHz and 26 kHz over a particular period, and also configures each emitter on the front of the harvester 105 to emit the ultrasound at different amplitudes. This feature is provided by each emitter being controlled by independent driving circuits and amplifiers. This enables the user of the device to have more control over the ultrasound waveform produced at the front of the harvester 105. The driver controller 420 controls each emitter driver 425A-425D such that each emitter 115A-115D emits ultrasound of a particular amplitude to provide the ultrasound pattern at the front of the harvester 105 as required by the user.

If the user selects mode two, the microprocessor 405 controls the variable oscillator 415 to pulse oscillations at 25 kHz. The duty cycle (i.e. the relationship between the "on" time and "off time) of the pulse can be varied by the user as required. However, as a default, the duty cycle of the pulse is 200ms. In this embodiment, the microprocessor 405 controls the variable oscillator 415 to adjust the duty cycle. In other words, the microprocessor 405 controls the variable oscillator 415 to switch on and produce a 25kHz oscillation and switch off to stop production of the 25kHz oscillation. However the invention is not so limited. Indeed, it is possible that the variable oscillator 415 may produce a continuous output and the driving controller 420 controls the "off period applied to each of the driving circuits 425A-425D.

In addition, the user may again control the microprocessor 405 to control the ultrasound pattern at the front of the harvester 105.

If the user selects mode three, the microprocessor 405 controls the variable oscillator 415 to produce a continuous output signal of 28 kHz. Again, the pattern at the front of the harvester 105 may be altered in dependence upon the user input.

If the user selects mode four, the microprocessor 405 controls the variable oscillator 415 to produce a continuous output signal of 22 kHz. The continuous signal is output to the driving control circuit 420. The continuous signal is then fed to the independent driving circuits 425A-425D to produce an ultrasound pattern at the front of the harvester 105 in accordance with the user requirements.

As would be appreciated, the operation of the rodent repellent device 100 in the first four modes is in the ultrasound spectrum. In other words, the sound would be audible to rodents but not to humans. In order to calibrate the rodent repellent device 102 so that the ultrasound pattern appears around 1 m in front of the harvester 105 and covers the entire width of the harvester as shown in Figures 1 and 2, it is advantageous to provide a test mode which is audible to humans. If the user selects the test mode (mode five) a continual signal at 10 kHz will be emitted from the ultrasound emitters 115A-115D. This audible signal is used to test the ultrasound pattern that would appear in front of the harvester 105. As the audible signal can be heard by humans, it is advantageous to reduce the volume of the emitted signal at 10 kHz. The direction of the emitter can be adjusted as well to ensure that appropriate directionality of each emitter is provided.

Figure 5 shows a test arrangement 500 whereby the orientation of the emitter and the amplitude and calibration settings for the driving circuits, amplifiers and oscillator are determined.

A sound receiver 505 is placed a distance D from the emitter 1 15. In embodiments, the distance is 1 m from the emitter 115 whereas the invention is not so limited. The sound receiver 505 is configured to receive either ultrasound at one of the frequencies in any one of the particular ultrasound modes described above or the 10 kHz audible signal. The sound receiver 505 is placed as close to the ground as possible in embodiments to replicate the position of the rodent. The signal received from the emitter 115 is processed in the test processor 510.

The position and direction of the emitter 115 is adjusted so that the sound receiver 505 receives the maximum amount of ultrasound from the emitter. The gain of the amplifiers within the rodent repellent 100 is adjusted to ensure that the signal level received at the sound receiver 505 is at least 120 dB. Additionally, the variable oscillator 415 is tuned to ensure that the sound received at the sound receiver 505 is that the frequency selected by the user.

Although only a single sound receiver 505 is shown in Figure 5, in other embodiments, a plurality of sound receivers may be provided. The test processor 510 may then isolate any one or more receivers and "listen" to level of ultrasound received at that sound receiver or receivers. This enables the calibration to take account of the rodent being located anywhere in the path of the harvester 105.

The emitter is calibrated when first applied to the harvester 105. Additionally, the emitter and the rodent repelling device 100 may be calibrated periodically during operation. For example, the emitter and rodent repelling device 100 may be calibrated at the start of every day or may be weekly or monthly as required.

Although the foregoing describes the emitter being mounted to the harvester using a ball and socket arrangement, the invention is not limited. Any type of mounting is envisaged. Indeed, in order to allow the ultrasound to be directed, it is advantageous to allow the direction of the mounted emitter to be moved. This may be performed by a user or may be moved automatically depending upon the type of ultrasound pattern required in front of the harvester.

Claims

CLAIMS 1. A wildlife repelling device configured for connection to a leafed produce harvester, the wildlife repelling device comprising: an oscillator operable to generate an ultrasound signal, an amplifier operable to amplify the generated ultrasound signal, and an ultrasound emitter operable to convert the ultrasound signal into an ultrasound wave and being configured so that when mounted on the leafed produce harvester, the ultrasound wave emitted from the ultrasound emitter is directed towards a predetermined area in front of the harvester.
2. A wildlife repelling device according to claim 1 , wherein the ultrasound emitter is configured to be mounted to the harvester using a movable bracket arranged to allow movement of the ultrasound emitter.
3. A wildlife repelling device according to claim 2, wherein the movable bracket is a ball and joint socket which may be locked in position.
4. A wildlife repelling device according to any preceding claim comprising a plurality of ultrasound emitters wherein each emitter has an amplifier associated therewith.
5. A wildlife repelling device according to claim 4, wherein each amplifier is operable to be controlled independently of one another.
6. A wildlife repelling device according to any preceding claim operative in one or more mode selected from: sweep oscillation between 22-26 kHz; pulsing oscillation on/off at 25 kHz; 28 kHz continuous; 4-22 kHz continuous; and test at 10 kHz continuous.
7. A wildlife repelling device according to claim 6, wherein the mode is selected by a user.
8. A wildlife repelling device according to any preceding claim, wherein the emitter is configured to produce 120dB of ultrasound focussed at an area 1 metre from the harvester.