Trailer-mounted, laser-based weed control device having a safety system, and safety system

Abstract

The invention relates to a trailer-mounted, laser-based weed control device having a safety system, and to a corresponding safety system. The trailer-mounted, laser-based weed control device comprises a vehicle trailer (1), which can be attached to a towing vehicle (2) and has at least one weed control module with a laser unit. The safety system comprises: a laser protection enclosure (10), which encloses the modules on all sides and is open only towards the ground and has laser protection curtains (10.2) arranged in the region close to the ground; a monitoring unit; a wheel sensor system for detecting ground contact and movement of the wheels (11); and an open-loop and closed-loop control unit, which allows the energy supply only when all safety conditions are met. The device is suitable in particular for mobile agricultural outdoor applications for safe laser-based weed control.

Description

[0001] Trailer-mounted, laser-based weed control device with a safety system and safety system

[0002] The invention relates to a trailer-mounted, laser-based weed control device equipped with a safety system, and to a corresponding safety system for such a trailer-mounted, laser-based weed control device. The trailer-mounted, laser-based weed control device and the safety system are particularly suitable for mobile laser-based agricultural machinery used in the field, where high-energy laser radiation is employed and safe operation under varying environmental conditions must be ensured.

[0003] The devices and methods for laser-based weed control are based on the principle that weeds on agricultural land are eradicated by targeted irradiation with a high-energy laser beam. The laser radiation causes thermal decomposition of the plant material and consequently its biological elimination. Since it is a chemical-free and non-invasive method, laser-based weed control is considered particularly environmentally friendly. Such a weed control method is described, for example, in WO 00 / 03589 A1.

[0004] To control weeds using targeted laser treatment, the first step is to identify the weeds growing among the crops in the agricultural fields. This is typically done using an image acquisition and processing device. A section of the field is photographed, and the image is analyzed for characteristic plant features. The identified plants are then distinguished as either crops or weeds. Next, a laser unit targets the identified weed, triggering the irradiation or treatment with a high-energy laser beam. Crops identified as weeds are spared from the laser treatment.

[0005] KAUFMANN® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 EP 2848 120 A1 and US 2022 / 0117218 A1 further disclose weed control devices with a vehicle trailer towed or driven by an agricultural tractor, on which the devices for laser-based weed control are installed. EP 2848 120 A1 discloses a laser-based system for removing unwanted plants, in which plants in an agricultural field are detected by means of three-dimensional imaging and distinguished as crop plants or weeds based on their characteristics. The device can be installed on an agricultural vehicle or implement and comprises a laser source, an image processing unit, and a control unit for precisely directing the laser beam.

[0006] From WO 2021 / 055485 A1, an autonomous system for laser-based weed control is known, in which a target area is detected using at least one predictive camera, unwanted plants are identified and assigned to one or more target modules. The system can be mounted on a vehicle and operated while moving relative to the surface, taking position and motion data into account to correct the target alignment.

[0007] WO 2024 / 165111 A1 describes a laser-based weed control module and a device equipped with it for agricultural use, in which a picture recognition unit, in particular a stereo camera, distinguishes between cultivated plants and weeds within the image capture area. A laser unit with a laser diode and laser optics is controlled based on the determined position data so that an identified vital part of the weed plant is selectively irradiated with a laser beam. The weed control module has a housing and can be arranged in a device with several modules, which are, for example, installed on an agricultural trailer and movable relative to the agricultural area via a chassis or rail system.

[0008] However, the operation of high-energy lasers involves hazards that exceed the usual hazard potential of agricultural facilities.

[0009] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 Beyond this, a suitable safety concept or suitable safety devices are required for the agricultural use of laser-based weed control devices to ensure sufficient operational safety of the laser systems. An important aspect here is the prevention of the uncontrolled emission of laser radiation.

[0010] The object of the present invention is therefore to provide a trailer-mounted, laser-based weed control device with a safety system, and a safety system for such a trailer-mounted, laser-based weed control device, which prevents the uncontrolled emission of laser radiation during agricultural use of the trailer-mounted, laser-based weed control device. In particular, it is to be ensured that no persons are injured by the laser radiation during the use of the trailer-mounted, laser-based weed control device.

[0011] This problem is solved by a trailer-mounted, laser-based weed control device with the features of claim 1 and by a safety system according to claim 10. Advantageous embodiments of the invention are specified in claims 2 to 9.

[0012] According to the invention, a trailer-mounted, laser-based weed control device is proposed, comprising a vehicle trailer, also called a trailer, which can be connected to a towing vehicle and is movable over the ground by means of at least one wheel. One or more weed control modules for laser-based weed control are arranged or installed on the vehicle trailer. The towing vehicle, for example a tractor, to which the vehicle trailer can be connected, serves to drive the vehicle trailer in the usual manner; the towing vehicle itself can be part of the trailer-mounted, laser-based weed control device.

[0013] Each of the weed control modules has at least one laser unit, in particular a semiconductor laser-based unit, for laser-based weed control. The weed control modules and the vehicle trailer are preferably designed as follows:

[0014] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 trained as described in WO 2024 / 165111 A1. In this respect, reference is made to WO 2024 / 165111 A1, the contents of which are hereby incorporated into this patent application.

[0015] The trailer carrying the weed control modules is conventionally constructed as a wheeled vehicle. It can preferably be connected to the towing vehicle in such a way that the trailer can be lifted, meaning it can be raised so that the trailer's wheel(s) are suspended freely. This allows for improved transport, particularly when crossing roads or uneven terrain before or after field application.

[0016] The vehicle trailer can be equipped with two sets of wheels, that is, with two pairs of wheels, each with two wheels that touch the ground during operation.

[0017] Alternatively, the trailer can have only one pair of wheels, with both wheels in contact with the ground during ferry operation. In this case, the coupling to the towing vehicle serves as a third support to ensure the vehicle remains correctly oriented. It is also possible for the trailer to have only a single wheel, with lateral stability being ensured by the coupling to the towing vehicle.

[0018] According to the invention, the trailer-mounted, laser-based weed control device further comprises a safety system to ensure the operational safety of the laser units.

[0019] The safety system according to the invention comprises a laser safety enclosure that completely encloses the weed control modules installed on the vehicle trailer and is open only at the bottom. As a result of this laser safety enclosure, the trailer-mounted, laser-based weed control device forms a closed system. The laser safety enclosure has laser safety curtains in the area near the ground, which are made of flexible material and designed such that, during normal operation of the vehicle trailer, they remain in contact with the

[0020] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 The floor follows the unevenness of the ground and forms a low-level seal between the laser safety enclosure and the ground.

[0021] The safety system for the trailer-mounted, laser-based weed control device also includes a control and regulation unit as well as several safety elements for intervening in the electrical power supply of the weed control modules.

[0022] The safety system includes a monitoring unit as one of its safety elements. This unit monitors and verifies the presence and / or integrity of the laser safety curtains. The monitoring unit may, for example, incorporate mechanical loss sensors that register when laser safety curtains tear, or optical monitoring sensors that check the presence of all laser safety curtains using image surveillance.

[0023] The safety system also includes, as a further safety element, wheel sensors to detect the wheel movement and ground contact of the trailer's wheels. The wheel sensors comprise ground contact sensors and motion sensors. The ground contact sensors monitor whether the wheels are in contact with the ground. The motion sensors monitor whether the wheels are in motion.

[0024] The control and regulation unit of the safety system is designed to release the energy supply to the laser unit(s) only when the laser safety enclosure is in a closed state, the monitoring unit detects the presence and integrity of the laser safety curtains, and the wheel sensors detect both the ground contact of the wheels and their wheel movement.

[0025] The safety elements of the safety system, which are integrated into the energy supply of the weed control modules, are interconnected by means of the control unit in such a way that the release of the

[0026] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 Energy supply to the weed control modules only occurs when all safety elements have assumed their respective release position.

[0027] For example, the control unit interrupts the energy supply to the weed control modules when the monitoring unit signals that the laser safety curtains or part of the laser safety curtains are missing.

[0028] The ground contact sensors transmit information to the control unit indicating whether ground contact exists. For example, if the vehicle trailer is lifted so that not all wheels are touching the ground, the control unit interrupts the power supply to the weed control modules.

[0029] The motion sensors also transmit information to the control unit indicating whether the wheels are in motion. If the wheels remain stationary for more than a brief period, the control unit interrupts the power supply to the weed control modules. This prevents accidents, especially when the vehicle trailer is parked. The motion sensors can also be configured—by specifying a predefined shutdown time—so that a brief standstill during normal operation, i.e., during laser-based weed control in a field or agricultural area, does not necessarily trigger an interruption.

[0030] The trailer-supported, laser-based weed control device according to the invention, with its safety system, offers particularly high operational reliability while maintaining unrestricted mobility in agricultural field use.

[0031] The all-around laser safety enclosure, open only at the bottom, creates a closed system that effectively prevents uncontrolled escape of laser radiation. At the same time, the opening at the bottom allows

[0032] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 the intended use of the laser units for laser-based weed control.

[0033] The laser safety curtains, positioned near the ground, ensure a close seal between the laser safety enclosure and the ground.

[0034] Due to their flexible design, they follow uneven ground contours while remaining in contact with the ground, ensuring reliable sealing even on uneven terrain or with changing soil conditions. This significantly improves operational reliability, especially in real-world field applications.

[0035] The monitoring unit, which tracks the presence and / or integrity of the laser safety curtains, ensures that the protective effect is not only designed but also functionally guaranteed. Loss or damage to laser safety curtains interrupts the energy supply, thus preventing an unsafe operating condition.

[0036] The wheel sensors, which detect ground contact and wheel movement of the trailer's wheels, ensure that the laser units are only activated during their intended operating state, i.e., during laser-based weed control in a field or agricultural area. Specifically, the system prevents energy from being released when the trailer is lifted or when the wheels are stationary. This reliably prevents operation during transport, lifting, or parking.

[0037] The control and regulation unit links all safety-relevant conditions together and releases the energy supply to the laser units only when all specified conditions are met.

[0038] This creates a particularly robust and fault-tolerant security architecture.

[0039] Overall, the combination of laser safety enclosure, ground-level laser safety curtains, monitoring unit, wheel sensors, and safety-oriented control and regulation unit provides a safety solution tailored to mobile agricultural use, offering a high level of protection for

[0040] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 operator and environment ensured while enabling efficient laser-based weed control.

[0041] The largest component of a laser safety enclosure is typically a housing made of solid wall material, which provides sufficient protection against laser radiation penetration. The walls can be constructed from metal sheets or plates, for example.

[0042] Part of the laser safety enclosure and / or part of the housing of the laser safety enclosure may also be a laser safety hood that can be opened to access the weed control modules and is closed during operation.

[0043] The soft or flexible laser safety curtains arranged in the base area of ​​the laser safety enclosure, which yield upon contact with the ground, consist in particular of soft or flexible materials, for example, coated fabrics or composite materials, such as those used for laser shielding in static installations. Preferably, the laser safety curtains are designed to withstand the impact of a laser beam from a weed control module operating at full power for at least 10 seconds. Typically, several laser safety curtains are attached to the vehicle trailer, arranged in a frame-like fashion around the trailer near the ground, completely covering the area down to the ground when the wheels are in contact with the ground. In particular, a double set of laser safety curtains can be provided, i.e., two laser safety curtains arranged one behind the other or overlapping.

[0044] To securely close the gap between the conventionally constructed housing of the laser safety enclosure and the ground, the laser safety curtains can be slightly oversized vertically so that they lie on the ground with a slight curve when the vehicle trailer is properly grounded. As the vehicle travels over the ground, the laser safety curtains slide along the surface, following any unevenness while maintaining continuous contact with the ground. A particular embodiment of the

[0045] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 The laser safety enclosure consists of a brush-like or lamellar design of the laser safety curtains, which is characterized by particularly good floor adaptability.

[0046] The safety system may include, among other safety features, one or more emergency stop buttons or switches for manually interrupting the operation of the weed control device. When the emergency stop button is activated, the power supply to the weed control modules is interrupted directly or via the control unit, thereby stopping the laser emission and bringing the entire system to a safe state. The emergency stop button is typically designed to lock mechanically and can only be reset after deliberate unlocking by the operator.

[0047] Furthermore, the safety system can include one or more safety position switches for the laser safety hood as additional safety elements, which monitor the position of the laser safety hood. If the laser safety hood is open or not closed correctly, the safety position switches, or the control unit controlled by them, interrupt the power supply to the weed control modules. Preferably, two safety position switches are installed on the laser safety hood, whereby the power supply to the weed control modules is only enabled when both safety position switches are closed.

[0048] A main switch located in the towing vehicle, which can also be part of the safety system, authorizes the commissioning of the weed control device and thus enables or, if necessary, interrupts the power supply to the weed control modules. The main switch can, for example, be a key switch that can only be activated with a designated key.

[0049] Furthermore, the safety system may include one or more warning lights as additional safety elements, which indicate the functional status of the

[0050] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 The weed control device must signal its functionality. Only if it is functioning correctly or shows no malfunction will the energy supply to the weed control modules be enabled.

[0051] Regarding further details and embodiments of the proposed trailer-based, laser-based weed control device or its safety system, reference is made to the German utility model application with application number 202025 101 098.4, the contents of which are hereby incorporated into this patent application.

[0052] The invention further comprises combinations of the features of the embodiments described above. It thus also extends to realizations that each exhibit a combination of features from several of the described embodiments, provided that these embodiments are not expressly described as mutually exclusive.

[0053] The invention is explained in more detail below with reference to exemplary embodiments and the schematic drawings, wherein identical or similar features are designated with the same reference numerals. These show:

[0054] Fig. 1 : a first embodiment of the trailer-mounted, laser-based weed control device with the safety system in perspective view;

[0055] Fig. 2: a second embodiment of the trailer-mounted, laser-based weed control device with the safety system in perspective view;

[0056] Fig. 3: the first embodiment of the trailer-mounted, laser-based weed control device equipped with the safety system, including the towing vehicle, in perspective view;

[0057] Fig. 4: the safety elements of the safety system of the trailer-mounted, laser-based weed control device installed in the towing vehicle in perspective view;

[0058] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 Fig. 5: the second embodiment of the trailer-mounted, laser-based weed control device equipped with the safety system, including the towing vehicle in perspective view;

[0059] Fig. 6: the laser safety curtains of the safety system in perspective view;

[0060] Fig. 7: the first embodiment of the trailer-mounted, laser-based weed control device with the safety system with the laser safety hood closed in perspective view;

[0061] Fig. 8: the first version of the trailer-mounted, laser-based weed control device with the safety system in perspective view with the laser safety hood open;

[0062] Fig. 9: the second version of the trailer-mounted, laser-based weed control device equipped with the safety system, including the towing vehicle with the vehicle trailer raised, in perspective view;

[0063] Fig. 10: the second version of the trailer-mounted, laser-based weed control device equipped with the safety system, including the towing vehicle with the vehicle trailer raised, in perspective view;

[0064] Fig. 11: a third embodiment of the trailer-mounted, laser-based weed control device with laser protection enclosure in a schematic, perspective view;

[0065] Fig. 12: a fourth embodiment of the trailer-supported, laser-based weed control device with laser protection enclosure in a schematic, perspective view.

[0066] In the first embodiment of the trailer-mounted, laser-based weed control device, shown in Fig. 1, Fig. 3, Fig. 7 and Fig. 8, the two wheels 11 are located inside the laser safety enclosure 10, while in the second embodiment of the trailer-mounted, laser-based weed control device, shown in Fig. 2, Fig. 5, Fig. 9 and Fig. 10, the two wheels 11 are arranged outside the laser safety enclosure 10.

[0067] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 The vehicle trailer 1 is attached to the towing vehicle 2, a tractor, as shown, for example, in Fig. 3, Fig. 5, Fig. 9 and Fig. 10. The towing vehicle 2 can raise or lift the vehicle trailer 1, whereby the wheels 11 – see Fig. 9 and Fig. 10 – are lifted off the ground.

[0068] The laser safety enclosure 10 – see in particular Fig. 2, Fig. 7 and Fig. 8 – is largely formed as a housing made of a sheet metal housing, which also includes the hinged laser safety hood 10.1. Between the lower edge of this housing and the ground, a frame made of flexible laser safety curtains 10.2 extends as part of the laser safety enclosure 10. Fig. 5 and Fig. 6 illustrate how the flexible laser safety curtains 10.2 conform to the ground when the weed control device is moved.

[0069] The preferred positions of the emergency stop buttons 12 on the vehicle trailer 1 are shown in Fig. 3 and on the towing vehicle 2 in Fig. 4. Fig. 4 also shows the main switch 13, which is designed as a key switch. Figs. 3 and 9 further illustrate the position of the warning lights 15. The two protective cover safety position switches 14 are shown in Fig. 8.

[0070] Fig. 11 and Fig. 12 show further embodiments of the laser safety enclosure 10 of the trailer-supported, laser-based weed control device.

[0071] Reference symbol list

[0072] 1 vehicle trailer

[0073] 2 Towing vehicle

[0074] 10 Laser safety enclosures

[0075] 10.1 Laser safety hood

[0076] 10.2 Laser safety curtains

[0077] 11 wheels

[0078] 12 emergency stop buttons

[0079] 13 Main switches

[0080] 14 protective hood safety position switches

[0081] 15 Warning light

[0082] KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026

Claims

1. Patent claims 1. Trailer-mounted, laser-based weed control device, comprising - a vehicle trailer (1) attachable to a towing vehicle (2) and movable over the ground by means of one or more wheels (11) , - one or more weed control modules arranged on the vehicle trailer (1), each with at least one laser unit for laser-based weed control, and - a safety system to ensure the operational safety of the laser units, characterized by the fact that - the safety system includes a laser protection enclosure (10) that completely encloses the weed control modules installed on the vehicle trailer (1) and is only open towards the ground, - the laser safety enclosure (10) has laser safety curtains (10.2) in the area near the ground, which are made of flexible material and are designed in such a way that, when the vehicle trailer (1) is operated as intended, they follow unevenness in the ground when in contact with the ground and form a ground-level seal between the laser safety enclosure (10) and the ground, - the safety system includes a monitoring unit that monitors the presence and / or integrity of the laser safety curtains (10.2), - the safety system includes wheel sensors for detecting the wheel movement and ground contact of the wheel(s) (11) of the vehicle trailer (1), and - the safety system has a control and regulation unit which is set up to release the energy supply to the laser unit(s) only when the laser safety enclosure (10) is in a closed state, the monitoring unit detects the presence and integrity of the laser safety curtains (10.2) and the wheel sensors detect both the ground contact of the wheel(s) (11) and their wheel movement.

2. Trailer-mounted, laser-based weed control device according to claim 1, characterized in that the laser safety enclosure (10) is a KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026 laser protective hood (10.1) which is movable between an open state and a closed state.

3. Trailer-supported, laser-based weed control device according to claim 2, characterized in that the safety system comprises at least one protective hood safety position switch (14) which monitors the closed state of the laser protective hood (10.1).

4. Trailer-mounted, laser-based weed control device according to claim 3, characterized in that two protective hood safety position switches (14) are provided, wherein the control unit is further configured to release the energy supply to the laser unit(s) of the weed control modules only when both protective hood safety position switches (14) indicate the closed state of the laser protective hood (10.1).

5. Trailer-supported, laser-based weed control device according to one of claims 1 to 4, characterized in that the laser safety enclosure (10) has a double set of laser safety curtains (10.2) in the area near the ground.

6. Trailer-supported, laser-based weed control device according to one of claims 1 to 5, characterized in that the laser protection curtains (10.2) are designed in a brush-like or lamellar manner.

7. Trailer-supported, laser-based weed control device according to one of claims 1 to 6, characterized in that the safety system comprises at least one emergency stop button (12) which, when actuated, interrupts the energy supply to the laser unit(s).

8. Trailer-mounted, laser-based weed control device according to one of claims 1 to 7, characterized in that the safety system comprises a main switch (13) arranged in the towing vehicle (2), by means of which the commissioning of the laser units can be authorized. KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.20269. Trailer-mounted, laser-based weed control device according to one of claims 1 to 8, characterized in that the safety system comprises at least one warning light (15) which signals the functional status of the weed control device, wherein the control unit is further configured to release the energy supply to the laser unit(s) of the weed control modules only when the at least one warning light (15) is functional and / or does not indicate a malfunction.

10. Safety system for a trailer-mounted, laser-based weed control device according to one of claims 1 to 9, characterized by: - the laser safety enclosure (10), which is designed to enclose weed control modules arranged on the vehicle trailer (1) on all sides and to be open only towards the ground, wherein the laser safety enclosure (10) has laser safety curtains (10.2) arranged in the area near the ground and constructed of flexible material, - the monitoring unit for monitoring the presence and / or integrity of the laser safety curtains (10.2), - the wheel sensors for detecting ground contact and wheel movements of the wheel(s) (11) , and - the control and regulation unit which is set up to release the energy supply to the laser unit(s) only when the laser safety enclosure (10) is closed, the monitoring unit detects the presence and integrity of the laser safety curtains (10.2) and the wheel sensors detect both the ground contact of the wheel(s) (11) and their wheel movement. - Six pages of drawings follow - KAUFMANN ® Patent and Trademark Attorneys K 43229.2 / 8.6 26.02.2026

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