PLANNING A PATH OF A DRIVELESS MOBILE ROBOT

Description

[0001] The present invention relates to a method for planning, in particular following, a path of a driverless mobile robot and a system or computer program product for carrying out the method.

[0002] Driverless mobile robots are often required to approach poses or follow path (segments) that are specified in different reference systems.

[0003] An example is an environment-related reference system or a map of the environment ("environment map") in which the robot navigates and is supposed to approach an object. Once it is sufficiently close to the object, it switches to an object-related reference system, continues navigating in this system, and approaches the object.

[0004] Previously, a path was first planned in the environment-related reference frame, followed by the object-related reference frame. The disadvantage is that the robot has to stop when switching from one path to the other, or from one reference frame to the other.

[0005] Another example is multiple environment-related reference systems or environment maps into which an entire environment is divided, for example, for storage reasons. Here, too, it is currently not possible to plan a continuous path across two or more reference systems.

[0006] US 2017 / 247029 A1 relates to a travel control device comprising: a transformation unit configured to project the driving lane and the object onto a lane coordinate system in which a center line of the driving lane is a first coordinate axis and an axis orthogonal to the first coordinate axis is a second coordinate axis, by performing a coordinate transformation based on the shape of the driving lane and the position of the object in a plane coordinate system; an area calculation unit configured to calculate a drivable area in which the vehicle can travel in the lane coordinate system; a travel trajectory generation unit configured to perform an inverse transformation of the coordinate transformation by the transformation unit based on the drivable area and generate a travel trajectory of the vehicle in the plane coordinate system;and a control unit configured to perform steering control on the vehicle.;

[0007] According to US 2002 / 105296 A1, the current position of a workpiece is sequentially updated in a conveyor coordinate system, and the path of a robot for following the workpiece is formed by transforming the position of the workpiece from the conveyor coordinate system into a robot coordinate system.

[0008] An object of an embodiment of the present invention is to improve the operation of a driverless mobile robot, in particular its path planning.

[0009] This object is achieved by a method having the features of claims 1 and 11, respectively. Claims 13 and 14 protect a system or computer program product for implementing a method described herein. The subclaims relate to advantageous developments.

[0010] According to one embodiment of the present invention, a method for planning a path of a driverless mobile robot to approach a second pose, which is specified in a second reference system, from a first pose, which is specified in a first reference system, comprises the step, which is repeated one or more times in one embodiment: Transforming the second pose into a common reference system in which the first pose is also described or specified; and / or transforming the first pose into a or the common reference system in which the second pose is also described or specified;

[0011] In one embodiment, the mobile robot has a mobile base or platform; in a further development, it has a preferably steerable chassis. In one embodiment, the driverless mobile robot is a so-called AGV ("Automated Guided Vehicle"). The present invention is particularly suitable for this purpose due to the operating conditions of AGVs.

[0012] In one embodiment, a pose within the meaning of the present invention comprises a position, in particular a one-, two- or three-dimensional one, position and / or an orientation, in particular a one-, two- or three-dimensional one, particularly preferably a two-dimensional position and one-dimensional orientation. In one embodiment, a pose within the meaning of the present invention comprises a position, in particular a one-, three- or particularly preferably two-dimensional one, position and / or an orientation, in particular a two-, three- or particularly preferably one-dimensional one, of the mobile base or platform, in one embodiment of a chassis, of the mobile robot. In one embodiment, the first pose is a pose of the mobile robot, in one development of a mobile base or platform, in one embodiment of a chassis, of the mobile robot, and / or the second pose is a pose of the mobile robot, in one development of a mobile base or platform.Platform, in one embodiment of a or the chassis of the mobile robot. In one embodiment, the transfer track transfers the mobile robot, in a further development, a or the mobile base or platform, in one embodiment, a or the chassis of the mobile robot, from the first to the second pose.

[0013] In particular, the common reference system can be the first reference system. Then, in one embodiment, the second pose is transformed into the common = first reference system, in which the first pose is specified.

[0014] This allows particularly efficient path planning to be realized in one version.

[0015] In another embodiment, the common reference frame is the second reference frame. Then, in one embodiment, the first pose is transformed into the common = second reference frame, in which the second pose is specified.

[0016] This allows particularly precise path planning to be achieved in one version.

[0017] Likewise, the common reference frame may be a different reference frame from the first and second reference frames. Then, in one embodiment, the first and second poses are transformed into this common reference frame so that they are described therein.

[0018] This allows a particularly variable path planning to be realized in one version.

[0019] According to one embodiment of the present invention, the method comprises the step, repeated one or more times in one embodiment: planning a transfer path from the first pose to the second pose in the common reference system on the basis of the first and second poses described in this common reference system.

[0020] By transforming one of the first and second poses into the other reference system in which the other of the first and second poses is specified, or by transforming the first and second poses into a common reference system and thus describing the first and second poses in the common reference system, a transfer path can advantageously be planned in one embodiment and, in a further development, can be followed, in one embodiment without stopping the robot when changing from one to the other reference system.

[0021] In one embodiment, the first pose is specified on a first path segment, in a further development by a first path segment, in the first reference system or, if appropriate, only the first path segment (and thereby implicitly a or the first pose) is specified in the first reference system, and the transfer path is planned on the basis of the first pose described in the common reference system by planning it on the basis of the first path segment described in the common reference system, which in one embodiment is transformed into this, (and thereby implicitly on the basis of a or the first pose).

[0022] Additionally or alternatively, in one embodiment, the second pose is specified on a second path segment, in a further development by a second path segment, in the second reference system or, if appropriate, only the second path segment (and thereby implicitly one or the second pose) is specified in the second reference system, and the transfer path is planned on the basis of the second pose described in the common reference system by planning it on the basis of the second path segment described in the common reference system, which in one embodiment is transformed into this, (and thereby implicitly on the basis of one or the second pose).

[0023] Accordingly, a path or the planning of a path of the driverless mobile robot for approaching a second pose, which is specified in a second reference system, from a first pose, which is specified in a first reference system, can comprise, in particular be, a path or the planning of a path for at least partially traveling the first path segment (and thus from a (possibly only implicitly specified) first pose on the first path segment) and, in particular, subsequently at least partially traveling the second path segment (and thus approaching a (possibly only implicitly specified) second pose on the second path segment). A transfer path or a planning of a transfer path from the first pose to the second pose in the common reference system on the basis of the first and second poses described in this common reference system can accordingly comprise a transfer path orplanning a transfer path from the first path segment (and thus from a (possibly only implicitly specified) first pose on the first path segment) to the second path segment (and thus into a (possibly only implicitly specified) second pose on the second path segment) on the basis of the first and second path segments described in this common reference system (and thus the (possibly only implicitly) first and second pose described in the common reference system).

[0024] In one embodiment, the second pose is transformed into the common reference frame by transforming the second path segment into the common reference frame. Additionally or alternatively, in one embodiment, the first pose is transformed into the common reference frame by transforming the first path segment into the common reference frame.

[0025] By using path segments, in one embodiment, the planning and / or operation can be improved, in particular its efficiency and / or precision can be increased. In one embodiment, the first path segment and / or the second path segment is a rectilinear path segment. As a result, in one embodiment, the planning and / or operation can be further improved, in particular its efficiency and / or precision can be further increased.

[0026] In one embodiment, the transfer path transfers (the robot) continuously, in one embodiment (on a) continuously differentiable path, from the first to the second path segment, whereby it can deviate from the first path segment before a path end of the first path segment and can be placed on the second path segment after a path start or before a path end of the second path segment.

[0027] In one embodiment, this can improve the operation of the robot, in particular reducing load and / or cycle time.

[0028] In one embodiment, in at least one, in particular initial, run or at least one of the steps of the method, the transformation of one of the first and second path segments into the common reference system is determined on the basis of a predetermined relation, in one embodiment of an identity, a pose, in one embodiment of an end pose, on the first path segment to a pose, in one embodiment of an initial pose, relative to, in one embodiment on, the second path segment.

[0029] By determining, in particular in a first pass of transforming one of the first and second path segments and planning a transfer path, the transformation on the basis of the predetermined relation, in particular with the proviso that the end pose on the first path segment should be equal to the initial pose on the second path segment, in one embodiment the transfer path can advantageously be planned, in particular initially, even without initialization or calibration of the second reference system.

[0030] Conveniently, a pose used during initialization, in particular calibration, of the second reference system is an initial pose on the second path segment. However, a different pose relative to the second path segment can also be used, in particular a pose used during initialization, in particular calibration, of the second reference system. Accordingly, in one embodiment, the transformation is determined with the proviso that the final pose on the first path segment should be equal to the pose used during initialization, in particular calibration, of the second reference system.

[0031] Additionally or alternatively, in one embodiment, in at least one, in particular further or subsequent, run or at least one of the steps of the method, the transformation of one of the first and second poses, in particular of one of the first and second path segments, into the common reference system is determined on the basis of a predetermined relation, in particular identity, of a pose, in particular actual pose, of the robot, which is described in the reference system in which this one of the first and second poses or this one of the first and second path segments is predetermined, to a pose, in particular actual pose, of the robot, which is described in the common reference system.

[0032] By determining the transformation (in each case) on the basis of the predetermined relation, in particular in one or more subsequent passes of transforming and planning a transfer path, in particular with the proviso that the actual pose of the robot described in the reference system from which the transformation is carried out should be equal to the actual pose of the robot in the common reference system, in one embodiment the precision can advantageously be increased, in particular the transformation and / or transfer path can be updated.

[0033] As explained above, the transformation can be determined not on the basis of the actual poses but in particular also on the basis of an end pose on the first path segment and a pose that is used during an initialization, in particular calibration, of the second reference system.

[0034] Additionally or alternatively, in one embodiment, in at least one, in particular further or subsequent, run or at least one of the steps of the method, the transformation of one of the first and second poses, in particular of one of the first and second path segments, into the common reference system is determined on the basis of a predetermined relation, in particular identity, of a pose, in particular actual pose, of the robot, which is described in the reference system in which this one of the first and second poses or this one of the first and second path segments is predetermined, to a pose, in particular actual pose, of the robot, which is described in the common reference system.

[0035] In one embodiment, the first reference system is an environment-related reference system in or by means of which the robot, in a further development, navigates at least temporarily. In one embodiment, the robot localizes itself at least temporarily in the first, in particular environment-related, reference system. In one embodiment, the first reference system is calibrated relative to an environment, in particular a plurality of landmarks, for example using SLAM or the like.

[0036] Additionally or alternatively, in one embodiment, the second reference system is an object-related reference system, which in one embodiment is specified, in particular calibrated, relative to an object that the robot is intended to approach in one embodiment. In one embodiment, the robot localizes itself at least temporarily in the second, in particular object-related, reference system.

[0037] In an alternative embodiment, the second reference system is another environment-related reference system, in particular one that is adjacent to the first reference system or at least partially overlaps it. In a further development, the robot navigates at least temporarily in or by means of the second reference system. In one embodiment, the robot localizes itself at least temporarily in this second, in particular also environment-related, reference system.

[0038] In one embodiment, the robot navigates, in particular in a first phase, using the first reference system, and, in particular in a second phase, using the second reference system, in one embodiment switching from the first to the second reference system, in a further development without stopping. In one embodiment, in the second phase, it moves to the second pose specified in the second reference system or at least partially along the second path segment specified in the second reference system, preferably using the pose or path segment specified in the second reference system, in particular directly or in the second reference system. Additionally or alternatively, in one embodiment, in the first phase, the robot moves at least partially along the first path segment specified in the first reference system, preferably using the path segment specified in the first reference system, in particular directly or in the first reference system.

[0039] A reference system within the meaning of the present invention comprises, in one embodiment, a map, and can in particular be such a map.

[0040] In one embodiment, the system, in particular the robot, has a first localizer which determines the pose of the robot relative to or in the first reference system, in one embodiment updates this multiple times, in a further development already before and / or during the planning and / or traversing of the path. Additionally or alternatively, the system, in particular the robot, in one embodiment has a second localizer which determines the pose of the robot relative to or in the second reference system, in one embodiment updates this multiple times, in a further development only during the planning and / or traversing of the path. Accordingly, the first reference system in one embodiment is a reference system in or relative to which thea first localizer determines the pose of the robot, in particular relative to an environment, in one embodiment updated several times, in a further development already before and / or during the planning and / or traversing of the path, and / or the second reference system is a reference system in or relative to which the or a second localizer determines the pose of the robot, in particular relative to an object, in one embodiment updated several times, in a further development only during the planning and / or traversing of the path.

[0041] According to one embodiment of the present invention, a method for operating the robot comprises the steps, repeated one or more times in one embodiment: Planning a path according to a method described here; and traversing the path with the robot, in one embodiment using the first reference system, the second reference system and / or the common reference system, in a further development by switching from the first to the second reference system.

[0042] In one embodiment, the transfer path, and in a further development the transformation into the common reference system, is updated once or several times during the run.

[0043] In one embodiment, the robot can advantageously move on the basis of poses or path segments specified in two reference systems, preferably without stopping when changing.

[0044] According to one embodiment of the present invention, a system, in particular hardware and / or software, in particular program technology, is set up to carry out a method described here and / or comprises: Means for, in particular multiple, transforming one of the first and second poses into a common reference system in which the other of the first and second poses is also described; and means for, in particular multiple, planning a transfer path from the first pose to the second pose in this common reference system on the basis of the first and second poses described therein.

[0045] In one embodiment, the system or its means comprises: Means for traversing the path with the robot, in particular using the first, second and / or common reference system; and / or means for planning the transfer path based on the first pose described in the common reference system, by planning the transfer path based on the first path segment described in the common reference system, in particular transformed therein; and / or means for planning the transfer path based on the second pose described in the common reference system, by planning the transfer path based on the second path segment described in the common reference system, in particular transformed therein;and / or means for transforming the first pose into the common reference system by transforming the first path segment into the common reference system, and / or for transforming the second pose into the common reference system by transforming the second path segment into the common reference system; and / or means for determining the transformation of one of the first and second path segments into the common reference system based on a predetermined relation, in particular identity, of a pose, in particular end pose, on the first path segment to a pose, in particular initial pose, relative to, in particular on, the second path segment;and / or means for determining the transformation of one of the first and second poses, in particular of one of the first and second path segments, into the common reference system on the basis of a predetermined relation, in particular identity, of a pose, in particular an actual pose, of the robot, which is described in the reference system in which this one of the first and second poses or this one of the first and second path segments is predetermined, to a pose, in particular an actual pose, of the robot, which is described in the common reference system; and / or means for updating the transfer path and / or transformation into the common reference system during travel. ;

[0046] A means within the meaning of the present invention can be designed in hardware and / or software, in particular a processing unit, in particular a microprocessor unit (CPU), graphics card (GPU) or the like, which is preferably connected to a memory and / or bus system in terms of data or signals, and / or can have one or more programs or program modules. The processing unit can be designed to execute instructions implemented as a program stored in a memory system, to detect input signals from a data bus and / or to output signals to a data bus. A memory system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state and / or other non-volatile media. The program can be designed in such a way that it embodies the methods described here oris capable of executing, so that the processing unit can execute the steps of such methods and thus in particular plan the path or operate, in particular control, the robot. In one embodiment, a computer program product can have, in particular be, a storage medium, in particular a non-volatile one, for storing a program or with a program stored thereon, wherein executing this program causes a system or a controller, in particular a computer, to execute a method described here or one or more of its steps.

[0047] In one embodiment, one or more, in particular all, steps of the method are carried out fully or partially automatically, in particular by the system or its means.

[0048] In one embodiment, the system comprises the robot.

[0049] Further advantages and features emerge from the subclaims and the exemplary embodiments. The following shows, partially schematically: Fig. 1: a driverless mobile robot and a first reference system during path planning of the robot according to an embodiment of the present invention; Fig. 2: a second reference system during path planning; Fig. 3: an initially planned transfer path; Fig. 4: the first reference system during further path planning while the robot is traversing the path; Fig. 5: the second reference system during further path planning while the robot is traversing the path; Fig. 6: a transfer path updated during traversing; and Fig. 7: a method for planning the path according to an embodiment of the present invention.

[0050] Fig. 1shows an AGV 3 and a first, environment-related reference system, indicated by x 1 , y 1 , in which the AGV 3 initially navigates, and in which a first path segment s 1 with an end pose p s1, e (indicated by the filled circle with orientation bar) is specified.

[0051] In a second reference system, which is Fig. 2 is indicated by x 2 , y 2 , a second path segment s 2 with an initial pose p s2, a and an end pose p s2, e is specified, which the AGV 3 is to approach. This second reference system can in particular be an object-related or other environment-related reference system, in particular one adjacent to the reference system x 1 , y 1 or at least partially overlapping it.

[0052] In a first step S10 (cf. Fig. 7), the second path segment s 2 is transformed into the first reference system x 1 , y 1 , which is used as the common reference system. As a result, all poses of the second path segment s 2 , possibly only implicitly specified, are also (implicitly) transformed into the first reference system x 1 , y 1 .

[0053] This transformation into the common reference system is determined on the basis of an identity of the final pose p s1, e on the first path segment s 1 to the initial pose p s2, a on the second path segment s 2. In other words, the second reference system or path segment is transformed into the common or first reference system in such a way that the initial pose p s2, a is identical to the final pose p s1, e. In this way, the second reference system does not have to be initialized or calibrated at this point in time, in particular by a (second) localizer. Instead of the initial pose p s2, a, another pose relative to the second path segment can also be used, in particular a pose in which the reference system is initialized or calibrated.

[0054] Then, in a step S20, an initial transfer path t12 from the first path segment s1 to the second path segment s2 is planned in this common reference system on the basis of the two path segments s1, s2 now described in this (cf. Fig. 3 ), which is continuously differentiable and transfers from the first to the second path segment.

[0055] Now, in step S30, the AGV 3 can begin to travel the first path segment s1. The second reference system is then initialized.

[0056] In a step S40, the second path segment s 2 is transformed analogously into the first reference system x 1 , y 1 .

[0057] This transformation into the common reference system is now determined on the basis of an identity of the actual pose 2 pi of the robot in the second reference system x 2 , y 2 to the actual pose 1 pi of the robot in the common or first reference system x 1 , y 1. In other words, the second reference system or path segment is transformed into the common or first reference system in such a way that the actual poses 1 pi , 2 pi are identical therein.

[0058] Then, in a step S50, the transfer path t12 is updated (cf. Fig. 6 ).

[0059] In step S60, the AGV 3 continues along the planned path, whereby steps S40 and S50 can be repeated one or more times. Once it reaches the transfer path, this path can be kept constant and, if necessary, switched to the second reference system for navigation without the AGV 3 having to stop.

[0060] Although exemplary embodiments have been explained in the foregoing description, it should be noted that numerous modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the foregoing description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various changes, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and equivalent combinations of features. List of reference symbols

[0061] p s1, e End pose of the first path segment p s2, a Start pose of the second path segment p s2, e End pose of the second path segment 1 pi Actual pose, described in the first reference system 2 pi Actual pose, described in the second reference system s 1 First path segment s 2 Second path segment, described in the second reference system 1 s 2 Second path segment, described in the first reference system t 12 Transfer path x 1 , y 1 First reference system x 2 , y 2 Second reference system 3AGV (robot)

Claims

1. A method of planning a path of a driverless mobile robot (3) for moving to a second pose, which is specified in a second reference system, from a first pose, which is specified in a first reference system, wherein the method comprises the following steps, in particular the following repeated steps: transforming (S10, S40) the one of the first and second poses into a common reference system, in which the other of the first and second poses is also described; and planning (S20, S50) a transition path (t12) from the first pose to the second pose in said common reference system on the basis of the first and second poses described in said common reference system.

2. The method according to claim 1, characterised in that the first pose is specified on a first path segment, in particular by a first path segment, in the first reference system, and the transition path is planned on the basis of the first pose described in the common reference system, by the transition path being planned on the basis of the first path segment described in the common reference system.

3. The method according to claim 2, characterised in that the first pose is transformed into the common reference system by the first path segment being transformed into the common reference system, and / or in that the transition path is planned on the basis of the first pose described in the common reference system by the transition path being planned on the basis of the first path segment transformed into the common reference system.

4. The method according to any one of the preceding claims, characterised in that the second pose is specified in the second reference system on a second path segment, in particular by a second path segment, and the transition path is planned on the basis of the second pose described in the common reference system, by the transition path being planned on the basis of the second path segment described in the common reference system.

5. The method according to claim 4, characterised in that the second pose is transformed into the common reference system by the second path segment being transformed into the common reference system and / or in that the transition path is planned on the basis of the second pose described in the common reference system by the transition path being planned on the basis of the second path segment transformed into the common reference system.

6. The method according to claim 2 or 3 and claim 4 or 5, characterised in that the transition path transitions continuously, in particular in such a manner that it can be differentiated continuously, from the first path segment to the second path segment.

7. The method according to claim 2 and claim 4, characterised in that a transformation of the one of the first and second path segments into the common reference system is determined (S10) on the basis of a specified relation, in particular an identity, of a pose, in particular of an end pose, on the first path segment, to a pose, in particular an initial pose, in relation to the second path segment, in particular on the second path segment.

8. The method according to any one of the preceding claims 1, 2 or 4, characterised in that the common reference system is the first reference system or the second reference system.

9. The method according to any one of the preceding claims, characterised in that the transformation of the one of the first and second poses into the common reference system is determined (S50) on the basis of a specified relation, in particular an identity, of a pose, in particular of an actual pose, of the robot, which pose, in particular actual pose, is described in the reference system in which said one of the first and second poses is specified, to a pose, in particular an actual pose, of the robot, which pose, in particular actual pose, is described in the common reference system.

10. The method according to any one of the preceding claims, characterised in that the first reference system is an environment-related reference system, and the second reference system is an object-related or other environment-related reference system, in particular an object-related or other environment-related reference system which is adjacent to, or which overlaps at least in part with, the first reference system.

11. A method of operating a driverless mobile robot (3), wherein the method comprises the steps of: planning (S10, S20, S40, S50) a path for moving from a first pose to a second pose in accordance with a method according to any one of the preceding claims; and moving (S30, S60) along the path with the robot, in particular with the aid of the first, second and / or common reference system.

12. The method according to the preceding claim, characterised in that the transition path and / or the transformation into the common reference system is updated, in particular during the movement along the path.

13. A system for planning a path of a driverless mobile robot (3), in particular for operating the robot, which system is configured to carry out a method according to any one of the preceding claims 1 to 12, and / or which comprises: means for transforming the one of the first and second poses into a common reference system in which the other of the first and second poses is also described; and means for planning a transition path (t12) from the first pose to the second pose in said common reference system on the basis of the first and second poses described in this common reference system; in particular means for moving along the path with the robot, in particular with the aid of the first, second and / or common reference system.

14. A computer program product comprising a program code which is stored on a computer readable medium, for carrying out a method according to any one of the preceding claims 1 to 12.