GB2462720A

GB2462720A - Autonomous Irrigation Robot

Info

Publication number: GB2462720A
Application number: GB0914326A
Authority: GB
Inventors: Michael Dorna; Ulrich-Lorenz Benzler; Peter Biber; Klaus Marx; Thilo Koeder; Christopher Koch; Anke Svensson; Joachim Platzer; Amos Albert; Juergen Graefenstein
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2008-08-19
Filing date: 2009-08-14
Publication date: 2010-02-24
Also published as: GB0914326D0; DE102008041323A1

Abstract

An irrigation robot 1 and system, comprises a drive means for steering and moving the irrigation robot on a working region 9, an irrigation means 13 and an intelligence means 4 disposed on the robot for autonomously controlling the drive means and/or the irrigation means. Preferably the control of the drive means is based on positional means 5 information signals of the robot obtained from a GPS, satellite signals, radar, infrared sensors, cameras and/or by determining a length/angle of hose 7 unwound from its real 6 which is connected to the robot. The intelligence means may also receive moisture sensor data as well as weather data. A preprogrammed or self-generated digital map of the working region may be used to determine which regions thereof may or may not require watering. Additionally the drive means may include and electric motor 3 and a turbine and an energy conversion means for generating electrical energy from the flow of water and or the environment. Also the robot may include a docking means 8.

Description

Description Title

Autonomous irrigation robot and irrigation system

Prior art

The invention relates to an irrigation robot according to the preamble of Claim 1, and to an irrigation system according to Claim 13.

Known from US 2006/0009876 Al is an irrigation system having, in addition to irrigation robots that are movable on a working region, a stationary "intelligent" central station that ascertains the position of the irrigation robots on the working region and controls the drive means of the irrigation robots on the basis of this positional information. The disadvantage in the case of the known irrigation system is the necessity of having to provide "intelligent" base stations, which makes it difficult to expand the robot system with further irrigation robots that do not work autonomously.

Known from WO 02/065828 Al is an irrigation system in which a sprinkler is arranged on a slide structure, the sprinkler mounted on the slide being movable exclusively along a straight path. As a result, many sprinklers, or slide structures, are required, which are pulled in parallel paths. Such an irrigation system is not suitable for the garden environment.

Known from EP 1 157 606 A2 is a movable irrigation robot that uses the water power for the purpose of progressive movement, through supplying a turbine. Further, the water power is also used to wind a traction cable on a drum, with the result that movements are only possible along a straight line.

A stationary sprinkler, having regulated water-jet positioning in a horizontal and in a vertical plane, is known from US 5,280,854.

US 5,366,157 likewise describes a stationary sprinkler, in which the positional orientation is effected purely mechanically and actuation is effected by water power.

Irrigation systems having a water nozzle that is adjustable about two axes are known from O 2001/054823 and WO 2007/065680.

Disadvantageous in the case of all purely stationary systems is the restriction of a limited reach. Larger irrigation sections cannot usefully be covered, owing to interference factors, such as wind, and in the case of wind it is even necessary to assume large losses of water, owing to its being carried away.

Disclosure of the invention

Technical object The invention is based on the object of proposing an optimized irrigation robot, by means of which a working region and also, if appropriate, regions adjoining the working region can be irrigated according to need.

Further, the object consists in proposing a correspondingly optimized irrigation system.

Technical solution This object is achieved, in respect of the irrigation robot, by the features of Claim 1, and, in respect of the irrigation system, by the features of Claim 13.

Advantageous developments of the invention are specified in the dependent claims. All combinations of at least two features disclosed in the description, the claims and/or the figures come within the scope of the invention.

The invention is based on the concept, not to provide the intelligence means for the regulated control of the drive means, realized for steering and progressively moving the irrigation robot on the working region, on a central base station, as in the prior art, but to provide the irrigation robot itself with such an intelligence means (logic unit) In this case, the intelligence means is suitable for controlling the drive means, in particular taking as a basis a tracing strategy for irrigating, or tracing, the working region, in particular a garden area, according to need. In the case of a corresponding realization of the irrigation means, it is advantageous if the intelligence means can also control, in particular shift, these irrigation means, and/or set the water quantity.

Irrigation means, in the simplest case, are understood to be a water outlet, preferably realized as a nozzle.

Preferably, the irrigation means additionally comprise a shut-off valve that is controllable by means of the (internal) intelligence means, and/or a controllable water pump, and/or adjusting means, which can be controlled by the intelligence means, for adjusting the water outlet position, preferably in two planes (vertical plane/horizontal plane) . An advantage of a controllable, movable spray design, which has at least one degree of freedom of motion, preferably a plurality of degrees of freedom of motion, in particular regulated degrees of freedom of motion, is that more distant individual plants or more distant planted regions can be irrigated in a reliably targeted manner. Owing to the aforementioned intelligence means (logic) being integrated into the irrigation robot, it is possible, for the first time, to realize an irrigation robot that can navigate autonomously, preferably independently of a base station. The fact that an irrigation robot realized according to the invention can navigate autonomously results in a further advantage, namely, that an irrigation system equipped with such an irrigation robot can easily be expanded with further irrigation robots, without the necessity of new programming or re-programming of a base station for this purpose. A further advantage of an irrigation robot realized according to the concept of the invention consists in that, owing to the autonomous method of operation, there is no limitation in respect of the garden shape. Moreover, only a minimal amount of installation resource is required, as a result of which the costs for an irrigation system equipped with such an irrigation robot are minimized, since it is necessary to provide only at least one supply station, for supplying the irrigation robot with water and/or electrical energy.

In development of the invention, provision is made, advantageously, whereby the intelligence means is realized to control the drive means and/or the irrigation means on the basis of positional information relating to the position of the robot vehicle on the working region. This positional information is preferably relative positional information relating to the relative position of the robot vehicle in relation to at least one supply station, preferably realized as tap-pillar for water.

Preferred quite particularly is an embodiment in which position determining means, for supplying the intelligence means of the irrigation robot with positional information, are arranged on the robot vehicle. Radar and/or infrared sensors, for example, can be used for this purpose.

Moreover, it is conceivable for a position sensor, integrated in the irrigation robot, to have at least one camera, the image information of which is evaluated directly in the irrigation robot, preferably by means of an appropriate image-processing software, in respect of the acquisition of positional information. Additionally, or alternatively, the integral position determining means can comprise a receiver for satellite positioning signals, in particular for GPS signals. Additionally, or alternatively, it is conceivable for the position determining means of the irrigation robot to be supplied with sensor information of the irrigation system, the corresponding sensors being arranged outside of the irrigation robot, i.e. externally, for example on a supply station. The sensors can be, for example, direction-finding transmitters, which mark the position of salient points, for example the position of supply stations and/or limit positions of the working region. It is possible in this case to use external cameras, etc. or reflection elements for reflecting signals, such as radar signals and/or light signals, etc. emitted by the irrigation robot.

In development of the invention, provision is made, advantageously, whereby the integral intelligence means is realized in such a way that it controls the drive means and/or the irrigation means on the basis of information relating to the nature of the working region or of an adjoining region to be irrigated. This information can be, for example, information relating to the position of the boundaries of the working region and/or relating to the position of regions of the working region that are to be watered and/or not to be watered. For the purpose of supplying the intelligence means with such information, it is conceivable to program corresponding coordinates or, preferably, to realize the intelligence means in such a way that it is capable of autonomously generating a digital map (collection of coordinates) of the working region, preferably in a calibration mode of the irrigation robot.

Additionally, or alternatively, it is possible for the integral intelligence means to be realized in such a way that the latter controls the driving means and/or the irrigation means on the basis of weather information that is obtained, for example, via the Internet, and/or on the basis of date information and/or time information. In this way, it is possible for the intelligence means not to effect any irrigation around mid-day, and/or on Sundays and/or holidays. It is particularly preferred if the intelligence means controls the drive means on the basis of ground moisture information, i.e. on the basis of need.

Further, it is advantageous if the control of the drive means and/or the irrigation means is effected via the intelligence means in dependence on the type of plants.

The information relating to the irrigation requirements of differing plant genera can be stored, for example, in a databank of the intelligence means, or be procured externally, for example via the Internet, in particular upon request. Moreover, it is possible for the intelligence means to be realized in such a way that it controls the irrigation robot on the basis of a work plan (time, section to be traced, etc.), preferably a preprogrammed work plan or one that can be modified by the user.

Preferred quite particularly is an embodiment in which the robot vehicle has sensors that allow determination of the plant type to be irrigated. For example, a camera can be provided for this purpose, the image information of which is evaluated by means of a corresponding image processing software.

Preferably, the irrigation robot comprises docking means, for docking to at least one supply station. Particularly preferably, the docking means are realized for docking a hose and/or a water line of the irrigation robot to a corresponding docking mechanism of the supply station.

Additionally, or alternatively, docking means for docking to an electrical energy supply station can be provided. It is particularly preferred if the irrigation robot is supplied with both water and electrical energy at a supply station.

In development of the invention, provision is made, advantageously, whereby the irrigation robot has a hose winding mechanism, which, preferably, is realized in such a way that the hose is always under a certain tension, as a result of which the hose, as is to be explained later, can be used to identify the position of the robot vehicle on the working region relative to the supply station.

There are various possibilities for supplying the drive means with energy. Thus, it is conceivable, for example, for the drive means to comprise a water turbine (water motor) , which can be supplied (driven) with the water delivered by the supply station. Preferred, however, is an embodiment in which the drive means comprise at least one electric motor, which is to be supplied with electrical energy. In the simplest case, the electrical energy is delivered from the supply station, via a corresponding electric-power cable, a corresponding winding mechanism preferably being provided either on the irrigation robot or on the supply station in this case. Preferred quite particularly, however, is an embodiment in which the energy for supplying the electrical drive means is generated directly in the irrigation robot itself, through utilization of the flow energy of the water and/or through utilization of the temperature differences between the water and the environment. The thus obtained electrical energy can also be used for adjusting the irrigation means.

The latter are preferably adjustable by means of at least one electric motor and/or directly through water power.

In development of the invention, provision is made, advantageously, whereby the position determining means ascertain the position of the robot vehicle on the basis of the unwound and/or wound-up hose length (water-hose length) relative to the supply station. In this case, the measurement of the wound-up or unwound hose length can be captured, for example, electrically, by means of a resistance wire, or also optically, by means of reflection light barriers, etc. Additionally, or alternatively, it is possible to determine this relative position with the aid of a position cable, which is preferably provided in addition to the hose. The advantage of such a position cable, in particular realized as a wire cable, consists in that this cable can be wound up more rapidly and more easily, and can be kept under an at least approximately constant tension. Additionally, or alternatively, angular sensors can be provided, in particular on a hose suspension, for the purpose of determining the position of the robot vehicle, by means of which sensors it is possible to determine the position of the hose relative to a fixed axis and/or relative to the longitudinal central axis of the irrigation robot, thus relative to the alignment of the irrigation robot. The position of the irrigation robot can be easily determined, in particular in a polar coordinate system relative to a supply station, on the basis of at least one of these items of angular information, preferably on the basis of both items of angular information. The angular information can be effected, for example, via incremental encoders, preferably having a defined zero point, absolute encoders having encoded discs, resolvers, etc. In addition or as an alternative to the aforementioned position determining possibilities, further sensors, for example GPS sensors (GPS receivers) or video sensors can be provided and/or odometry data can be utilized, which is particularly advantageous if the irrigation robot undocks, preferably autonomously, from a supply station and moves (autonomously) to an adjacent supply station.

Particularly preferred is an embodiment, in particular in combination with a position cable, in which the (water-) hose and/or the position cable is/are equipped with at least one signal line, via which sensor information can be -10 -sent to the irrigation robot, in particular to the intelligence means of the robot vehicle.

In development of the invention, provision is made, advantageously, whereby the intelligence means is realized to control the drive means and/or the irrigation means on the basis of request signals from external sensors. In other words, for example, external moisture sensors that measure the ground moisture are realized in such a way that, in the case of non-attainment of a minimum moisture, these sensors emit a request signal that is received by the irrigation robot and causes the intelligence means to guide the irrigation robot to the corresponding robot and to perform irrigation tasks there.

Additionally, or alternatively, internal moisture sensors, for example infrared sensors, by means of which the ground moisture can be determined, can be provided on the irrigation robot. Thus, the intelligence means can decide automatically at each position whether or not irrigation is necessary. Particularly preferably, the irrigation robot, particularly when it is not actually irrigating, executes a patrol run, on which the irrigation requirement of area portions of the working region is ascertained.

The invention also presents an irrigation system comprising at least one previously described, autonomously navigating irrigation robot, and comprising at least one supply station, for water and/or electrical energy, to which the irrigation robot can move. Particularly preferably, the irrigation system comprises at least two supply stations, it being yet further preferred if the irrigation robot, after it has irrigated the region around a first supply -11 -station, undocks automatically from the latter and, in particular with the use of odometry data and/or GPS data and/or video signals, etc., travels to the second supply station (water and/or electrical power) and docks to the latter. Preferably, the supply stations are supplied with water and/or energy via lines (supply line network) buried under the working region. Additionally, or alternatively, a line system laid above-ground can be realized. The number of supply stations will depend, in particular, on the garden geometry, the size of the garden (the position of obstacles) and the maximum reach of the irrigation robot.

Preferred quite particularly is an embodiment of the irrigation system in which at least one transmitter, for transmitting a positional signal, is integrated into the supply station, such that the irrigation robot, or the position determining means, can determine the position of the irrigation robot relative to the supply station in a comparatively simple manner. If, in particular, the weight, and consequently the energy consumption, of the irrigation robot is to be minimized, an embodiment is realizable in which a hose winding mechanism for the water-hose and/or a positioning cable mechanism is/are arranged on the supply station.

If the hose winding mechanism and/or the position-cable winding mechanism is/are arranged on the supply station, the at least one supply station can additionally be equipped with means for determining the amount of the unwound and/or the wound-up (water-)hOSe and/or with means for determining the length of the unwound and/or the wound-up position cable. Further, means can be provided for -12 -determining the angular position of the hose, or of the position cable, relative to a predefined direction.

Preferably, in the aforementioned case, the supply station comprises means for communicating this positional information to the position determining means of the irrigation robot. The data transmission can be realized both via a radio connection and via a cable connection.

Brief description of the drawings

Further advantages, features and details of the invention are disclosed by the following description of preferred exemplary embodiments and with reference to the drawings, wherein: Fig. 1: shows a schematic representation of an irrigation robot, Fig. 2: shows a top view of a typical working region, having supply stations in tap pillars distributed over the working region, and of an irrigation robot realized for docking to the supply stations, Fig. 3: shows, in a schematic representation, the maximum mobility range of an autonomous irrigation robot, Fig. 4: shows, in a schematic representation, a possibility for determination of the position of the irrigation robot, and Fig. 5: shows an alternative possibility for determination of position.

-13 -Embodiments of the invention In the figures, like elements and elements having the same function are denoted by the same references.

Fig. 1 shows a highly schematic side view of an autonomous irrigation robot 1. The irrigation robot 1 comprises drivable wheels 2, a separately controllable electric motor 3 being assigned to each wheel 2 in the exemplary embodiment shown. The electric motors 3 are connected to an intelligence means 4 (logic means), which is realized for autonomously navigating and controlling the electric motors 3. The irrigation robot 1 is steerable, in that not all electric motors 3 are operated simultaneously, or are not operated with the same power. It is particularly preferred if the electrical energy for operating the electric motors 3 is generated with the aid of the available water power.

The intelligence means 4 obtains positional information from position determining means 5, which, in addition to the intelligence means 4, are likewise a constituent part of the irrigation robot 1. These position determining means can comprise sensors, not represented in greater detail, such as a GPS receiver and/or a video camera.

Additionally, or alternatively, the position determining means 5 can be connected, in a signal-carrying manner, to sensors, to be explained later with reference to Figs. 4 and 5, for the purpose of position determination.

The regulated controlling of the electric motors 3 with the aid of the intelligence means 4 in dependence on positional -14 -information renders possible autonomous navigation of the irrigation robot 1.

The irrigation robot 1 comprises a hose winding mechanism 6, for winding-up a water-hose. Alternatively, this hose winding mechanism 6 can also be arranged on a supply station, which is to be explained later. This measure results in a reduction of the weight of the irrigation robot 1, as a result of which its energy consumption is minimized.

A free end of the hose 7 is provided with docking means (coupling mechanism), by means of which the irrigation robot 1 can dock autonomously to the aforementioned supply stations for the purpose of being supplied with water.

Shown in Fig. 2 is a top view of a typical working region 9, realized as a garden, in or on which an irrigation robot 1 can move autonomously. Arranged in a distributed manner over the working region 9 in the exemplary embodiment shown are four supply stations (Zl -Z4), which serve to supply the irrigation robot 1 with water and, preferably, also with electrical energy. For this purpose, the working region 9 is to be prepared in advance, in that a preferably underground supply-line system, not shown, is established. The number of supply stations is dependent on, inter alia, the garden geometry, the size of the garden, the obstacles and the maximum reach of the irrigation robot 1. As further shown by Fig. 2, the supply station denoted by the reference Zi is arranged directly at a house 10, and is connected to the domestic water supply and to the domestic electricity supply mains.

-15 -The substantially circular boundary 11 of the mobility range 12 of the irrigation robot 1 can be seen from Fig. 3.

In the case of a hose 7 of ten metres in length, every point could be reached by means of the irrigation robot 1 on an area of approximately 300 m2. The actual irrigation area extends beyond the mobility region 12, however, since the irrigation robot 1 is preferably equipped with correspondingly realized irrigation means 13 having a spray mechanism, as a result of which points outside of the (drivable) mobility region 12 can be irrigated. As further shown by Fig. 3, the position of the irrigation robot 1, in particular of the integral intelligence means of the irrigation robot 1, can be specified with the aid of a polar coordinate system relative to the supply station Z1.

In the case of a known position of the supply station, the global position of the irrigation robot 1 is thus defined.

To enable the irrigation means 13 to be actuated (controlled) by means of the intelligence means 4, it is advantageous for the intelligence means to be supplied with information relating to the orientation of the irrigation robot 1. A global locating system, such as, for example, a satellite locating system or an integral and/or external video sensing technology can be used for this purpose.

Moreover, it is possible for the orientation of the robot vehicle to be determined via angular sensors, preferably on the hose structure, in particular in the region of the hose winding mechanism 6.

Fig. 4 shows a possibility for exactly determining the position of the irrigation robot 1 relative to a supply station Zi, and thus a possibility for determining the position of the irrigation robot 1 on the working region 9.

-16 -The angle of the (tensioned) hose 7 relative to a defined axis 14 (which corresponds, for example, to the celestial direction North) can be determined with the aid of an appropriate angular sensor, not shown, for example an incremental encoder having a defined zero point, an absolute encoder having encoded discs, or a resolver, etc. Further, an angle 13 between the (tensioned) hose 7 and the longitudinal central axis L, thus the orientation of the irrigation robot 1, can be determined by means of a further angular sensor, likewise not shown, that is mounted on the irrigation robot 1, preferably on the hose structure. The wound-up and/or unwound hose length can be measured by means of an appropriate measuring device, as a result of which sufficient measurement values are available (relating to the position and orientation) in order to control the electric motors 3 and the irrigation means 13 with high precision via the intelligence means 4. A yet greater precision/robustness can be achieved if the measurements are supported by further sensor data, such as odometry values, inertial sensors or other locating systems, such as GPS and/or radio locating methods. Sometimes the previously described angular measurement and/or hose length measurement can even be omitted entirely, if locating is otherwise realized with sufficient precision.

An alternative possibility for ascertaining the position of the irrigation robot 1 is shown schematically in Fig. 5.

The figure shows the non-tensioned (water-) hose 7 between a supply station Zl and the irrigation robot 1. The supply station Zl is connected to the irrigation robot 1 via a position cable 15 (steel cable), in addition to the hose 7.

The position cable 15 is tensioned. A position-cable winding mechanism 16, by means of which the position cable -17 -can be held under tension, is assigned to the irrigation robot 1.

In a manner analogous to the exemplary embodiment according to Fig. 4, the angles a and 3 -on the one hand, the angle a between the greatly tensioned position cable 15 and a defined axis 14, and the angle between the tensioned position cable 15 and the orientation, or longitudinal central axis, of the irrigation robot 1 -can be determined with the aid of appropriate angular sensors. The advantage of the structure shown in Fig. 5 consists in that it is technically easier to hold in tension a position cable 15, preferably realized as a wire cable, than to hold in tension the hose 7. The position cable structure serves additionally for angular determination, for the purpose of measuring the distance between the irrigation robot 1 and the supply station Zi. In the case of the exemplary embodiment shown in Fig. 5, the hose 7 can lie loosely on the ground. Preferably, the hose 7 serves as a carrier for signal lines between the irrigation robot 1 and the supply station Z1.