EP-4152926-B1 - APPARATUS AND METHOD FOR ELECTRICALLY KILLING PLANTS

EP4152926B1EP 4152926 B1EP4152926 B1EP 4152926B1EP-4152926-B1

Inventors

DIPROSE, Andrew
DIPROSE, Michael

Dates

Publication Date: 20260513
Application Date: 20210518

Claims (15)

Electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising: an electrical energy supply unit; an applicator unit comprising an applicator electrode; a return unit comprising a return electrode; electrical circuitry; the electrical energy supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode, and the return electrode, wherein said electrical circuitry implements a plant treatment mode and a detection mode, wherein the electrical circuitry in the detection mode to determine a plant in operative proximity to the transmission circuit to receive the electrical energy directly or via an electrical arc from the applicator electrode, and based on said determination activate the plant treatment mode in which treatment electrical energy, for killing or at least attenuating plant growth, is applied through the transmission circuit.
The electrical apparatus of claim 1, wherein a detection system implements the detection mode, wherein in the detection mode the detection system is arranged to apply detection electrical energy through the transmission circuit and to determine a plant in operative proximity to the transmission circuit based on one or more properties of the detection electrical energy though the transmission circuit as having crossed a threshold.
The electrical apparatus of claim 2, wherein the detection electrical energy is selected not to kill or attenuate plant growth.
The electrical apparatus of any of claims 2 to 3, wherein the detection electrical energy is implemented with a lower or a higher electrical quantity than the treatment electrical energy, wherein the electrical quantity is one or more of the following: frequency; voltage; current; power; duty; phase.
The electrical apparatus of any preceding claim, wherein in the detection mode the electrical circuitry is configured to periodically perform a check for the determination of a plant in operative proximity to the transmission circuit.
The electrical apparatus of claim 5, wherein after an initial determination if a plant is in operative proximity to the transmission circuit, a frequency of the checks is increased.
The electrical apparatus of any of claims 5 to 6, wherein the electrical circuity is arranged to receive velocity information and to determine a frequency of checking based on the velocity information.
The electrical apparatus of any preceding claim, wherein the detection mode determines, during the plant treatment mode, a plant not in operative proximity to the transmission circuit and based on said determination deactivates the plant treatment mode.
The electrical apparatus of any preceding claim, wherein a detection system implements the detection mode, the detection system arranged to determine the presence of a human or animal in operative proximity to the transmission circuit, and based on said determination prevent the transmission of treatment electrical energy through the transmission circuit.
The electrical apparatus of any preceding claim, wherein the detection system implements a camera system that is arranged to determine, in the detection mode, a plant in operative proximity to the transmission circuit.
The electrical apparatus of any preceding claim, wherein a detection system implements the detection mode and comprises a proximity sensor that is arranged to determine a plant in operative proximity to the transmission circuit.
The electrical apparatus of any preceding claim, wherein a detection system implements a plurality of different plant detection implementations, to determine a plant in operative proximity to the transmission circuit.
The electrical apparatus of any preceding claim, wherein a camera system determines plant information from one or more images of the plant and the treatment electrical energy is selected based on the plant information.
Use of the apparatus of any preceding claim for treatment of a plant.
A method of treating a plant with electrical energy, the method comprising: detecting a plant in operative proximity of a transmission circuit to receive the electrical energy directly or via an electrical arc from the applicator electrode, comprising an applicator electrode, and a return electrode, and; based on the detection of the plant, applying electrical energy to kill or at least partially attenuate growth of the plant.

Description

TECHNICAL FIELD The present disclosure relates to electric apparatus that is configured to attenuate plant growth by the application of electrical energy thereto. BACKGROUND In properties both commercial and domestic, it is common to kill or at least control the growth of unwanted plants, commonly referred to as weeds. Conventional methods include treatment with a pesticide or more particularly a herbicide. However, there is a growing concern over such treatment for environmental reasons and unwanted exposure of herbicides to humans and animals. Moreover, weeds are increasingly becoming naturally resistant so herbicides are becoming more and more ineffective. As a result of these numerous drawbacks, consumers are increasingly demanding organic produce, for which the use of herbicides is increasingly prohibited. Prior art in this technical field is for example document EP 3 569 767 A1. Consequently, there is a desire for alternative treatments, which do not include the above drawbacks. An example includes treatment by the application of electrical energy. US 4338743 discloses such apparatus, wherein an electrical energy is applied at 14.4 kV at 60 ± 5 Hz to plants. Such apparatus have failed to become widespread in the market over concern over safety. For example, the high voltage may in some instances increased the risk combustion of the weed and/or surrounding material, which in areas that represent fire risk, is particularly undesirable. Therefore, despite the effort already invested in the development of said apparatus further improvements are desirable. SUMMARY The present disclosure provides electrical apparatus to kill a plant or at least attenuate plant growth. The apparatus includes an electrical energy supply unit; an applicator unit comprising an applicator electrode; a return unit comprising a return electrode and; electrical circuitry. The electrical energy supply unit is arranged to apply electrical energy through a transmission circuit comprising the applicator electrode and the return electrode and a plant. In embodiments, the electrical circuitry implements a plant treatment mode and a detection mode. In the detection mode the electrical circuitry to determine a plant in operative proximity to the transmission circuit, and based on said determination activate the plant treatment mode in which treatment electrical energy, for killing or at least attenuating plant growth, is applied to the transmission circuit. As used herein "a plant in operative proximity to the transmission circuit" may refer to a plant arranged to receive electrical energy from the transmission circuit (e.g. including in direct contact or proximal to the applicator electrode, e.g. such that it can receive the electrical energy directly or via an electrical arc). By implementing a detection mode and a plant treatment mode, the apparatus can apply electrical energy though the transmission circuit that is optimal for killing a plant only when a plant is detected. In this way the apparatus may be safer and/or more energy efficient. In embodiments, a detection system implements the detection mode. The detection system may be arranged to apply detection electrical energy through the transmission circuit. The detection system may determine a plant in operative proximity to the transmission circuit based on one or more properties of the detection electrical energy (e.g. properties that may include current, voltage, power, phase) though the transmission circuit crossing a threshold (including having crossed, i.e. being over the threshold as opposed to only the state of being below then over the threshold). By implementing plant detection based on property of the detection electrical energy through the transmission circuit, detection may be conveniently implemented without a dedicated sensor arrangement. In embodiments the detection electrical energy is selected not to kill or attenuate plant growth, e.g. it may be selected to be non-destructive to the plant compared to the treatment electrical energy. The detection electrical energy may be selected to be less dangerous to a human compared to the treatment electrical energy. In embodiments, the detection electrical energy is implemented with a lower or a higher electrical quantity than the treatment electrical energy, wherein the electrical quantity is one or more of the following: frequency; voltage; current; power; duty; phase. By implementing the detection electrical energy with a different electrical quantity it can be distinguished from the treatment electrical energy, e.g. when applied in an off cycle of the treatment electrical energy. In embodiments, the detection electrical energy is implemented with a lower energy than the treatment electrical energy. The lower energy of the detection electrical energy may be implemented by one or more of the voltage, current, phase, duty. By applying the detection electrical energy in the transmission circuit at lower energy in detection