PASTOOR, Jan, Lambertus (Populierlaan 131, LA Rijswijk, NL-2282, NL)
| CLAIMS 1. Unmanned self-propelled device (1) for carrying out activities in a space in which contaminants can occur, wherein the device comprises a frame 5 (7) and means (3) for moving the device through said space, wherein the device further comprises a detector (20) for detecting a body, which detector is provided with an exposed outer detecting surface (21), wherein the frame is provided with cleaning means (12) for cleaning said outer surface, and wherein the frame is provided with means (13) for operating the cleaning means in dependence on a o movement of the device. 2. Device according to claim 1 , wherein the operating means are active at a change in the direction of travel of the device. 3. Device according to claim 1 or 2, wherein the operating means are active at reversal of the direction of travel of the device. 5 4. Device according to claim 1 , 2 or 3, wherein the operating means are configured for co-operation with a fixed surface of the space, which surface is stationary with respect to the device. 5. Device according to claim 4, wherein the operating means are configured for co-operation with a wall in a stable, such as a floor or side wall.0 6. Device according to claim 4 or 5, wherein the operating means comprise an operating member (13) which is mounted on the frame so as to be rotatable about a centre line (H), wherein the operating member is provided with an operation surface (17) for frictional engagement of the fixed surface. 7. Device according to claim 6, wherein the operating member (13) is capable of being pressed towards the centre line, when viewed in radial direction, and is provided with a biasing means for biasing the operating member (13) from a pressed-in position to an extended position. 8. Device according to claim 6 or 7, wherein the operating member (13) is bar-shaped and the operation surface (17) is located at the end of the bar. 9. Device according to claim 6, 7 or 8, wherein the operating member (13) is mounted on the frame in order to be entrained passively with said surface along the stationary surface when the device is travelling, and to be rotated by the braking action of the fixed surface for operation of the cleaning means at reversal of the direction of travel. 10. Device according to one of the preceding claims, wherein the cleaning means (12) comprise a sweeper which is mounted on the frame. 11. Device according to claim 10, wherein the sweeper (14) is mounted on the operating member (13) for a movement coinciding therewith. 12. Device according to one of the preceding claims, provided with a carrier (4) for moving material over a stable floor. 13. Device according to claim 12, wherein the carrier is a feed scraper. 14. Device according to claim 12, wherein the carrier is a manure scraper. 15. Device according to one of the preceding claims, wherein the detector is an ultrasonic detector. 16. Device according to one of the preceding claims, wherein the device is self-steering. 17. Device provided with one or more of the characterizing features described in the attached description and/or shown in the attached figures. |
BACKGROUND OF THE INVENTION
The invention relates to a mobile device for carrying out activities in a space in which contaminants occur, wherein the device is provided with one or more detection means, such as a sensor, and can, in particular, be self-propelled.
When carrying out activities in such a space, either confined, such as a stable, a milking box, a feed alley, or less confined, such as a land, the functioning of a detector used by an above-mentioned device can decline in the course of time as a result of contaminants which are deposited on detecting surfaces which are hit by dirt. In a stable, the contaminants will in particular consist of manure falling from an animal and manure splashing from the stable floor. The same problem can occur in a pasture. On a land, contamination can be caused by soil material.
In the past, a few solutions for this problem have been proposed.
In one type thereof, external facilities are used.
EP 0.688.498 describes a milking robot with a robot arm on which a detector with an optical (laser) sensor is mounted to determine the position of the teats of a cow to be milked. The lens of the sensor is screened by a piece of glass whose outer surface can be cleaned automatically by a sponge disposed on the inner side of a sliding hood which covers the piece of glass in the non- used position. EP 0.716.566 also shows a milking robot with a robot arm on which a detector with an optical (laser) sensor is mounted to determine the position of the teats of a cow to be milked. The piece of glass which screens the sensor can be cleaned with the aid of a stationary sprayer and blower. Another known milking robot uses a stationary sponge to clean the piece of glass of a detector. A disadvantage thereof is that the cleaning is limited to a particular area, and that facilities have to be provided in the surroundings, such as a milking box or a stable. In a pasture, it is even more difficult to provide these facilities. Additionally, these facilities occupy space and can be susceptible of being damaged.
In another type, which is indeed capable of cleaning autonomously, extensive facilities are provided on the device itself.
NL 1033591 describes a self-propelled device for removing manure, which is provided with detection means for recognizing heaps of manure on a floor and animals or legs of animals. The optical sensor is protected by a flat front side, made of synthetic material, of an exit optical device. This optical device, or piece of glass, can become contaminated. In order to reduce the risk of contamination, the device is provided with means for retracting and extending the sensor in an active manner.
US 4.843.561 describes a harvesting machine which is provided with a CCD camera or the like for recognizing an object to be harvested. The lens is screened by a piece of glass, which can be cleaned by a sweeper and a sprayer to be activated by means provided on the machine, if desired, after it has been established that a certain degree of contamination has been reached.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device of the type mentioned in the preamble, in which the cleaning of the outer surface of the detector does not need special external facilities.
It is an object of the invention to provide a device of the type mentioned in the preamble, in which simple means suffice for the cleaning of the outer surface of the detector. It is an object of the invention to provide a device of the type mentioned in the preamble, in which the cleaning of the outer surface of the detector can be carried out with simple means provided on the device itself.
In order to achieve at least one of the objects, the invention provides, from one aspect, an unmanned self-propelled device for carrying out activities in a space in which contaminants can occur, wherein the device comprises a frame and means for moving the device through said space, wherein the device further comprises a detector for detecting a body, which detector is provided with an exposed outer detecting surface, wherein the frame is provided with cleaning means for cleaning said outer surface, and wherein the frame is provided with means for operating the cleaning means in dependence on a movement of the device. The device is thus autonomous in cleaning said outer surface. It is then possible to maintain a simple arrangement by using the displacement of the device for keeping the outer surface sufficiently clean.
It is observed that said space, to be described differently as (potentially) contaminated space, can, in addition to a stable, also be an external space, such as an external milking or feeding space or a mowing field or land.
In the case of an optical sensor, the exposed outer detecting surface may be the aforementioned piece of glass. In the case of an ultrasonic sensor, it may be the membrane.
In a simple embodiment, the operating means are active at a change in the direction of travel of the device. This change can, in particular, be a reversal of the direction of travel of the device. The operating means can be configured for co-operation with a surface of the space which is stationary with respect to the device, in particular with a wall in a stable, such as a floor or side wall, it being possible to use elements which are anyhow present.
In one development thereof, which is in particular suitable for application at a change of the direction of travel of the device, the operating means comprise an operating member which is mounted on the frame so as to be rotatable about a centre line, wherein the operating member is provided with an operation surface for frictional engagement of the fixed surface.
In one embodiment thereof, the operating member is capable of being pressed towards the centre line, when viewed in radial direction, and is provided with a biasing means for biasing the operating member from a pressed- in position to an extended position. The operating member is thus moved through a dead point at reversal of the direction of travel.
In a simple embodiment, the operating member is bar-shaped and the operation surface is located at the end of the bar.
In a further embodiment thereof, the operating member is mounted on the frame in order to be entrained passively with said surface along the stationary surface when the device is travelling, and to be rotated by the braking action of the fixed surface for operation of the cleaning means at reversal of the direction of travel.
In one embodiment, the cleaning means comprise a sweeper which is mounted on the frame and which may be provided on the operating member for a movement coinciding therewith, so as to achieve a further simplification of the arrangement.
As already pointed out, the device may be equipped for one or more of a plurality of possible functions. The device may, for example, be provided with a carrier for moving material over a stable floor, such as a feed scraper or a manure scraper. The contaminants can then consist of feed material and animal excrements, possibly by splashing from the floor.
The device according to the invention can be self-steering. It is pointed out that by unmanned self-propelled and self-steering device are meant both at least substantially autonomously travelling and steering devices, whether or not programmed for this purpose, such as the Discovery manure scraper of the registered trademark LeIy, and devices in which the travelling and/or steering are/is remotely controlled. In both cases, a motor for the travelling of the device is provided in the device itself.
The aspects and features described in this description and the claims of the application and/or shown in the figures of this application may, where possible, also be used separately from each other. These separate aspects may be the subject of divisional patent applications related thereto. This holds in particular for the features and aspects which are described per se in the dependent claims.
BRIEF DESCRIPTION OF THE FIGURES
The invention will be explained with reference to an exemplary embodiment shown in the attached figures, in which: Figures 1A and 1 B show a side and a top view of an exemplary embodiment of a device according to the invention, and
Figures 2A-C show successive stages in reversing the direction of travel of the device according to Figures 1A and 1 B. DETAILED DESCRIPTION OF THE FIGURES
The device 1 shown in Figures 1A and 1B for removing manure from floor 100 of a passageway of a stable comprises a frame 7 with a relatively heavy, block-shaped concrete housing 2. The frame 7, screened by a hood 50 at its front, is supported on the floor 100 by two wheels 3 and a manure scraper 4 located in front of the housing 2 and having a sweeping strip 26 of synthetic material. The housing 2 is provided on both sides with current collectors 6, by means of which a non-shown accumulator, included in the housing 2, can be charged by an external charging station, as used in the manure scraper device which is offered by LeIy (registered trademark) under the name Discovery (registered trademark). The wheels 3 are driven by means of electric motors 31 , individually controlled by a control unit 30 which is capable of being programmed remotely, so that the device 1 can follow autonomously a certain working route, in a repeating manner, for example first in the direction A and then moving back in the direction B, in order to bring the device 1 to the starting point of a next path, parallel to the previous one.
For following a straight path on the floor 100, the control unit 30 uses the signals from two ultrasonic sensors 20. Said sensors 20 have membranes 21. Alternatively, there may be provided optical sensors, in which case there will be provided windows. In order to remove dirt, in particular manure, from the membranes or windows 21 , the device is provided with sweeping devices 12 which become automatically active at reversal of the direction of travel.
Each sweeping device 12 is pivotably mounted on the rest of the device 1 about a laterally directed horizontal shaft 10 with centre line H. The shafts 10 are located straight above the sensor windows 21. The sweeping devices 12 each comprise a bar member 13 whose upper end 11 is mounted on the shaft 10. On the bar member 13 there is mounted a brush or wiper 14 which projects radially therefrom. Below the brush 14, the bar member 13 forms a tube- shaped member 15, in which a non-shown compression spring is included, by means of which a lower bar member 16 is biased downwardly, which lower member 16 forms a telescopic assembly with the member 15. The bar member 16 is provided at its lower end with a rubber ball 17. During operation, see Figure 1A, the device 1 moves in the direction A and the sweeping devices 12 are tilted rearwardly and drag with the rubber balls 17 over the floor 100. The membranes or windows 21 are then free. When the device 1 is moved back, direction F, the reversing movement of the sweeping devices 12 is obstructed by engagement between the balls 17 and the floor 100. Thereby, see Figure 2A, a force D is exerted on the compression spring in the tube-shaped member 15, wherein the bar member 16 will move upwardly and the sweeping device 12 will be shortened. As a result thereof, it becomes possible for the sweeper 12 to pivot about the shaft 10 in direction C, towards a vertical position, see Figure 2B, and subsequently to a position opposite to that of Figure 2A, as shown in Figure 2C. In the meantime, out of its own accord as it were, the brush 14 is moved over the membrane or window 21 , while the surface thereof is swept. In the position of Figure 2C, the compression spring has again been able to extend the bar member 16. The ball 17 has continuously remained in contact with the floor 100. When the device will again be moved in the direction A, the same process will take place, in reversed direction.
The above-mentioned description serves to illustrate the operation of preferred embodiments of the invention, and not to limit the scope of the invention. On the basis of the above-mentioned explanation, it will be obvious for a person skilled in the art that there are many variations falling within the spirit and scope of the present invention.