Transport robot

Abstract

The invention relates to a transport robot configured so as, when operated individually and / or in a fleet, to receive, to transport and to deposit an object, the transport robot having a frame on which a plurality of driving modules are at least indirectly arranged. In order to propose a transport robot which permits sustainable and precise steering, provision is made according to the invention for there to be arranged between the driving modules and the frame a coupling device which, in a first coupling setting, permits the frame to be adjusted in height and, in a second coupling setting, permits the driving modules to be freely rotatable with respect to the frame. (Fig. 1d)

Description

[0001] Description

[0002] Transport robots

[0003] The invention relates to a transport robot which is designed for picking up, transporting and depositing an object in individual operation and / or in fleet operation, wherein the transport robot has a frame on which a plurality of driving modules are arranged at least indirectly.

[0004] Transport robots and related controls are known in particular from WO 2023 / 274689 A1, US 2022 / 0307281 A1 and US 11,447,025 B2.

[0005] Where known transport robots allow height adjustment, the height adjustment is directly linked to the steering movements of the drive modules, and vice versa. This means that steering movements do not occur independently of the height adjustment, which negatively impacts the energy consumption and maneuvering precision of a transport robot.

[0006] It is therefore an object of the invention to propose a transport robot that allows resource-saving and precise steering.

[0007] This object is achieved by the transport robot according to claim 1. According to the invention, a coupling device is arranged between the drive modules and the frame, which, in a first coupling setting, allows a height adjustment of the frame and, in a second coupling setting, allows free rotation of the drive modules relative to the frame. This decouples steering movements of the drive modules from height adjustments of the frame, and steering movements can also be performed independently of any height adjustment. This allows steering movements to be performed in an energy-saving manner and with greater precision.

[0008] Advantageous further developments of the invention are specified below and in the subclaims.

[0009] Preferably, the frame comprises a plurality of supports connected to the drive modules. In an advantageous development of the invention, the supports are designed as flat profiles arranged parallel to the frame surface. The supports can be selected as required, particularly with regard to their length, with supports of the same length being installed on a transport robot to ensure a uniform geometry.

[0010] According to an advantageous embodiment of the invention, the frame comprises two L-shaped sections aligned in a mirror-inverted manner, which are connected to each other at their short ends via a linear drive. Alternatively, the frame comprises two C-shaped sections aligned in a mirror-inverted manner, the ends of which are each connected to each other via a linear drive. Regardless of the specific configuration of the frame sections, at least one linear drive is designed as a spindle drive with a motor, a spindle, and a nut.

[0011] Preferably, each drive module has a pair of wheels whose wheels are rotatably mounted on axle stubs, with the axle stubs preferably aligned coaxially with each other. Each wheel of the wheel pair is preferably connected to a separate motor, wherein, according to a preferred embodiment of the invention, a belt drive is arranged between the motor and the respective wheel.The axle stubs are preferably connected to a nut that receives a support bolt that is at least indirectly connected to the frame via the coupling device. The coupling device has a first coupling that creates a lockable connection between the turntable and the carrier, and a second coupling that creates a lockable connection between the support bolt and the nut, so that during the first clutch adjustment and an equal but oppositely oriented rotation of the wheels, the support bolt is displaced longitudinally axially relative to the nut. The first coupling and the second coupling are each preferably designed as a two-part ring clutch with friction linings between the rings of the ring clutch, which are frictionally connected to one another by a spring in the engaged state.To disengage such a clutch, a coil is preferably provided that opens the first and second clutches when energized and closes them when de-energized. Energizing such a coil can be implemented using simple control-technical specifications, allowing such a clutch to be precisely engaged and disengaged. Alternatively, the first clutch and the second clutch can have a magnetic coil that alternately releases one mechanical connection and establishes the other.

[0012] The transport robot is preferably connectable to a control unit configured to carry out a control method with which the target rotational speeds of the individual wheels of all wheel pairs can be specified as a function of target variables relating to a linear velocity and a yaw rate of the transport robot. According to a particularly preferred embodiment of the invention, the transport robot is controllable in different operating modes, with a precision mode preferably being provided that only allows adjustment of the steering angle of the drive modules while the transport robot is stationary, i.e., the horizontal velocity and the change in the yaw angle are equal to zero.

[0013] Finally, according to an advantageous development of the invention, it is provided that the transport robot can be connected to a control unit which is designed to carry out a formation control method with which the target rotational speeds of the individual wheels of all wheel pairs can be predetermined as a function of target variables with regard to linear speeds and yaw rates of several transport robots in a formation.

[0014] Specific embodiments of the present invention are described below with reference to the figures. They show:

[0015] Fig. 1a, b embodiments of a transport robot,

[0016] Fig. 1c, d Side views of a driving module,

[0017] Fig. 2a a top view of a vehicle and four transport robots,

[0018] Fig. 2b a side view of a recorded vehicle,

[0019] Fig. 3a is a schematic view of a transport robot,

[0020] Fig. 3b a pair of wheels,

[0021] Fig. 3c, d, e each show a schematic view of a transport robot for performing a movement in modes 1, 2 and 3,

[0022] Fig. 4a a control method,

[0023] Fig. 4b a partial method for angle adjustment,

[0024] Fig. 5a a formation of several transport robots and

[0025] Fig. 5b a fleet control

[0026] The present invention encompasses various aspects of a transport robot or a fleet of multiple interconnected / correlated transport robots. The individual aspects of the invention are described in detail below. a) Height adjustment

[0027] 1a, b show different embodiments of a single transport robot 100. The transport robot 100 has a frame 10 which is designed to receive an object to be transported. The frame 10 of the embodiment according to Fig. 1a has two L-shaped sections 111, 112 which are aligned in a mirror image to one another and whose short ends are connected to one another via a linear drive 12. As a result, the frame 10 is U-shaped in the assembled or mounted state and has an end 13 which is open to the side. In the embodiment according to Fig. 1b, the frame is composed of two C-shaped sections 141, 142 which are aligned in a mirror image to one another and whose ends are each connected to a linear drive 12. The frame according to Fig. 1b therefore has a closed and essentially annular contour.In both cases, the linear drives 12 are designed as spindle drives 121 with a motor 15, a spindle 16, and a nut 17. In both embodiments, the linear drives 12 allow adjustment of the frame length F, which is advantageous when picking up objects in the manner described later.

[0028] In the illustrated embodiment, the frame 10 of the transport robot 100 is connected to four drive modules 19 via a carrier 18. Each drive module 19 has a wheel pair 20, the wheels 211, 212 of which are rotatably mounted on axle stubs 22. The axle stubs 22 of a wheel pair 20 are aligned coaxially with one another and extend along a common axis of rotation. The wheels 211, 212 are connected to separate drive motors 23 so that they can be driven at independent speeds. The axle stubs 22 of a wheel pair 20 are connected to a turntable 24. The turntable 24 of a drive module 19 is connected to the carrier 18 so that the wheel pairs 20 can each rotate about a vertical axis with respect to the frame 10. Such a transport robot 100 can be moved in a predetermined manner on a support plane by controlling the rotational speeds of the individual wheels 211, 212.

[0029] Fig. 1c shows a first embodiment of a drive module 19 in a side view. According to this, the turntable 24 has a nut 25 to which the axle stubs 22 of a wheel pair 20 are fixed. The nut 25 is penetrated by a support bolt 26, which has a bolt head 27 for attachment to the carrier 18. The nut 25 and the support bolt 26 have corresponding threads, so that the support bolt 26 can be displaced longitudinally axially within the nut 25 by means of a rotation in the direction of arrow 28. By rotating the wheels 211, 212 of a wheel pair 20 by the same amount but in opposite directions, the nut 25 is rotated about the support bolt 26, which is arranged non-rotatably on the carrier 18, whereby the nut is displaced in the direction of arrow 29. This allows the height of the frame 10 to be adjusted in relation to the support plane.By adjusting the height of various drive modules 19 to different heights, the inclination of the frame 10 relative to the support plane can also be adjusted if necessary. Because the wheels 211, 212 of a wheel pair 20 can rotate around the support bolt 16 during the intended use of the transport robot 100 with such a turntable 24, regardless of the height adjustment of the frame 10, the set height varies at least to a small extent, which depends on the specific steering movements and the thread pitch of the combination of nut 25 and support bolt 26.

[0030] To allow continuous height adjustment of the frame 10 with respect to the support plane, a switchable coupling device 30 is provided according to the embodiment of Fig. 1d. The coupling device 30 has a first coupling 301, which, in the assembled state, creates a connection between the turntable 24 and the support 18. Furthermore, the coupling device 30 has a second coupling 302, which, in the engaged state, establishes a rotationally fixed connection between the support bolt 26 and the nut 25. The state of the first coupling 301 and the second coupling 302 is disjoint during operation of the drive module 19. This means that one of the couplings 301, 302 always establishes a rotationally fixed connection, while the other coupling releases the rotationally fixed connection.For the purpose of height adjustment, the first coupling 301, in the engaged state, establishes a rotationally fixed connection between the carrier 18 and the support bolt 26 of the turntable 24, which allows height adjustment upon appropriate rotation of the wheels 211, 212 of the wheel pair 20. This is made possible by the relative movement between the support bolt 26 and the nut 25 under the condition that the second coupling 302 releases the rotationally fixed connection between the support bolt 26 and the nut 25. Once the desired height has been set, the first coupling 301 can be transferred to a disengaged state so that the support bolt 26 is freely rotatably connected to the carrier 18. The second coupling 302 is transferred to the engaged state for this purpose in order to establish the rotationally fixed connection between the support bolt 26 and the nut 25.In this (disengaged) state of the first clutch 301 and (engaged) state of the second clutch 302, any rotational movements of the wheel pair 20 about the vertical axis can be carried out without the height of the frame 10 changing relative to the support plane, because the support bolt 26 rotates relative to the carrier 18 and not relative to the nut 25.

[0031] According to a specific embodiment of the invention, the first clutch 301 and the second clutch 302 are each designed as a two-part ring clutch with friction linings between the rings, wherein the friction linings are frictionally pressed together by a spring in the engaged state. For disengagement, a coil is preferably provided that opens the first clutch 301 and the second clutch 302 in an energized state.

[0032] Alternatively, the first clutch 301 and the second clutch 302 can also be designed in such a way that a magnetic coil integrated in the bolt head 27 alternately releases one mechanical connection and establishes the other mechanical connection, e.g. by disengaging the first clutch 301 and engaging the second clutch 302 or vice versa.

[0033] Regardless of the specific design of the first clutch 301 and the second clutch 302, the pivot bearing can be designed by an axial bearing 32 in various configurations, e.g., ball or needle bearings, or plain bearings. Furthermore, it can be designed with or without a seal.

[0034] By means of a single transport robot 100, as shown in Fig. 1a, b, different objects can be transported, which are picked up by the frame 10 or placed on the frame 10. The embodiment according to Fig. 1a is designed to pick up objects that rest on the support plane of the transport robot 100. The transport robot 100 is positioned such that the L-shaped sections 111, 1112 of the frame 10 encompass the object on the right and left sides. By pushing the L-shaped sections 111, 112 of the frame 10 together by means of the linear drive 12, the object is fixed and lifted by means of the described height adjustment. The picked up object can then be transported along predetermined trajectories and placed at the destination. The embodiment according to Fig.1b assumes that the frame 10 can move beneath a load-bearing portion of the object, so that the object can be lifted, if necessary after adjusting the support surface, by adjusting the length of the frame 10. Otherwise, the lifting and transport of the picked-up object are functionally identical.

[0035] With a fleet of multiple transport robots 100, vehicles 31 in particular can be parked automatically. Fig. 2a shows a top view of a vehicle 31 and four transport robots 100, each of which can be moved in the (unnumbered) direction of the arrow such that they each grip a vehicle wheel 33 on the left and right sides. By raising the respective vehicle wheels 22 in the manner already described, a spacing 35 is created between the vehicle wheels and the support plane 34, as shown in the side view of Fig. 2b. In this state, the vehicle can be parked by the four transport robots in a manner that significantly exceeds the typical maneuverability of vehicles with two-wheel or four-wheel steering. b) Kinematics of a single transport robot

[0036] To control the movement of a transport robot 100, a method 200 is provided with which the target rotational speeds n of the individual wheels 211, 212 of all wheel pairs 20 can be determined as a function of target variables relating to the desired linear velocity v and the desired yaw rate of the transport robot 100. To carry out the method 200, a control unit is provided which has several calculation units for data exchange and data processing.

[0037] First, Fig. 3a shows a schematic top view of a transport robot 100 with the variables relevant for controlling / regulating the movement. Shown in detail are:

[0038] - The frame length F as the sum of the basic length F o and the variable length F set by the linear drive 12 v ,

[0039] - the wheel pairs 20 with the wheels 211 , 212,

[0040] - the center point Mi of the transport robot 100,

[0041] - the centers M2 of the wheel pairs 20,

[0042] - the track width m of the individual wheel pairs 20 and

[0043] - the track width w between the centers M2 of two wheel pairs 20.

[0044] Fig. 3b shows the executable movements using the example of a wheel pair 20. The wheels 211, 212 of the wheel pair 20 can be rotated by the same amount and in the same direction, so that the wheel pair 20 moves at a linear velocity v. To set an angle δ or to change a set angle δ, the wheels 211, 212 of the wheel pair 20 are driven at different speeds n, so that the wheel pair 20 orbits around the instantaneous center M3. By independently setting the speeds n of the wheels 211, 212 of a wheel pair 20, predetermined trajectories can be followed on the contact plane. With regard to the transport robot 100, taking into account the components of the linear velocities v x , v y and the yaw rate ω between the following modes:

[0045] Mode 1: Translation of the transport robot 100, where the yaw rate disappears (ω = 0). Mode 2: Yaw of the transport robot 100 around its center Mi, where the

[0046] Components of the linear velocities v x , v y disappear (ω 0 , v x = 0, v y = 0).

[0047] Mode 3: Combination of translation and yaw ([ω 0, v x 0, v y = 0] or [ω 0, v x = 0, v y 0] or [ω 0, v x 0, v y 0]), with translation and yaw occurring instantaneously (simultaneously). Fig. 3c shows the transport robot 100 in a mode 1 setting, i.e., a setting for pure translation. With respect to the vehicle coordinate system, all wheel pairs 20 of the individual drive modules 19 are aligned identically. The respective angles δ n relative to the x-axis are:

[0048] For the special case that a translation along the y-axis is to be carried out, the angle δ n to determine:

[0049] This gives the speed v:

[0050] The speeds n of the wheels 211 , 212 result from the wheel diameters r Rad out of:

[0051] A maximum speed can be set.

[0052] Fig. 3d shows the transport robot 100 in a mode 2 setting, i.e., a setting for rotation around the vertical axis (yaw). For this purpose, the wheel pairs 20 are aligned such that the virtual rotation axes of all wheel pairs 20 intersect the center point M1 of the transport robot 100. For the angles δ n applies: The distance D between the center Mi of the transport robot 100 and the centers M2 of the wheel pairs 20 is given by the present geometry:

[0053] For the speeds v of equal magnitude but different directions n applies:

[0054] For the speeds of (virtual) wheels located in the centers of the wheel pairs 20, the speeds would be where n i = lim(n i ) a speed limit can be specified. Based on this, the speeds n of the wheels 211, 212 of the individual wheel pairs 20 are determined from:

[0055] Fig. 3e shows the transport robot 100 in a mode 3 setting, and thus in a setting for a movement resulting from a linear combination of translation and yaw. Here, the drive modules 19 are set such that the rotational axes of the wheel pairs 20 intersect the instantaneous center M3 of the rotational movement, with the instantaneous center M3 being spaced from the center Mi of the transport robot 100. under the condition that abs(y R ) > 0.5*w and abs(x R ) < 0.5*F, it follows: This results in the angles δ n :

[0056] For the velocities Vj of the centers M2 of the wheel pairs 20, the following applies:

[0057] A (virtual) wheel would have a speed ni of Here, a speed limit of n i = lim(n i). This results in the target values ​​in relation to the speeds n of the individual wheels 211 , 212 of the wheel pairs 20 as follows:

[0058] Overall, there are calculation rules for all three modes that are taken into account when controlling a transport robot 100. In particular, the calculation rules allow the control of a transport robot 100 by specifying rotational speeds n of the individual wheels 211, 212, which are determined as a function of target values ​​related to the speed v and the yaw rate ω of the transport robot 100.

[0059] Fig. 4a shows the control method 200 with the calculation units for a single transport robot 100 in a flowchart. The method 200 is started with a request 50 to perform a journey, wherein the position and orientation of the transport robot 100 are specified with (X, Y, ψ). DESThis data is transferred to a calculation unit 51 “Single Robot Navigation” for a single transport robot 100, which, taking into account position data 521 of a digital map 52, calculates the target values ​​for the horizontal speeds and the yaw rate (v x ,v y ,ω) DES This data is transferred to a calculation unit 53 “Inverse Differential Kinematics”, which calculates the setpoints for the angles (δ1, ... ,δ4) DES of the driving modules 19 and the preliminary rotation rates (n 11 , n 12 ,... ,n 42 ) P DEs of the individual wheels 211 , 212 are determined. Using the calculation unit 54 "Angle Controller", the target values ​​for the angles (δ1, ..., δ4) DES of the driving modules 19 and the preliminary rotation rates (n 11 , n 12 ,... ,n 42 ) P DEs of the individual wheels 211 , 212 the set values ​​for the rotation rates (n 11 , n 12 ,... ,n42 )DEs of the individual wheels 211, 212. If necessary, the height and the angle of the frame 10 relative to the support plane 34 can be adjusted by the request 71. Usually, the request 71 to adjust the height or the angle relative to the support plane is made when the transport robot is stationary, i.e. the horizontal speed and the yaw rate of the transport robot are zero during the height adjustment. After the target speeds of the wheels have been set with (n 11 , n 12 ,... ,n 42 )DEs are finally determined, they are transferred to the drive controllers 55. The drive controllers control the drive motors 56 of the transport robot, ie they provide a pulse-width modulated voltage signal, with the help of which the speed of the drive motors and thus of the wheels is adjusted according to the setpoint (n 11 , n 12 ,... ,n 42)DEs are controlled. The current actual values ​​of the wheel speeds (n 11 , n 12 ,... ,n 42 )ACT and the instantaneous angles (δ1, ... ,δ4) ACT of the wheel pairs are transferred to a calculation unit 57 “Odometry”, which calculates the horizontal speeds and the yaw rate (v x ,v y ,ω) 0dom1 and transferred to the calculation unit 58 "Localization". Furthermore, data from an inertial measurement unit 59 (IMU) is also transferred to the calculation unit 58 "Localization". Here, values ​​of the acceleration and the yaw rate are converted, in particular by means of an integrator 60, into the horizontal speeds and the yaw rate (v x ,v y ,ω) 0dom2converted. In addition, the calculation unit 58 "Localization" also receives image data 611 from a camera 61 and lidar data 621 from a lidar 62. The calculation unit 58 "Localization" determines the current position and the current yaw angle (X,Y,ψ) from the received input data. ACT and forwards this data to the "Single Robot Navigation" calculation unit 51, thus closing the loop of the control method 200. The previously described method 200 terminates as soon as there is no request to perform a journey.

[0060] The control method 200 also allows switching to a formation control 400, for which a switch 63 is provided. Within the framework of the formation control 400, which will be discussed in more detail later, the calculation unit 58 "Localization" transfers the current position data and the current yaw angle (X,Y,ψ) to a calculation unit 64 "Multi Robot Formation Controller". ACT, which represents the target speeds and yaw rates in the form of (v x ,v y ,ω)Des,Fc. The control of the individual transport robots 100 otherwise takes place according to the described method 200.

[0061] For adjusting the length F of the frame 10, a substantially supplementary sub-process 65 is provided. According to this sub-process, the transport robot 100 receives a request 66 to lengthen or shorten the length F of the frame 10, which occurs, for example, when picking up or setting down an object. The request 66 to change the frame length F is transmitted together with the desired frame length F D ES is transferred to a calculation unit 67 “Position Controller”, which, taking into account the current frame length and the required frame length F D ES a speed n Ls,DEs of the spindle 16, so that the frame length F changes as specified by means of a control unit 68 “Lead Screw Drive Controller” and a motor 69 “Lead Screw Plant” by setting a current speed n LS,ACT the spindle 16. The resulting instantaneous frame length F ACT is continuously transferred to the calculation unit 67 "Position Controller", which aborts the sub-process 65 as soon as the current frame length matches the target frame length. The current frame length F ACT is also transferred to the calculation unit 57 “Odometry” and the calculation unit 53 “Inverse Differential Kinematics”, so that the current frame length of the transport robot 100 is used in the calculation of the target speeds (n 11 , n 12 ,... ,n 42 ) P DEs of the wheels 211, 212 and the angle (δ1, ... ,δ4)DES are taken into account.

[0062] The control method 200 also includes a sub-method 70 for adjusting the angle of the wheel pair 20. The sub-method 70 is illustrated in Fig. 4b in the form of a flow chart. In response to a request 71 to raise the frame 10, the required rotational speeds of the wheels 211, 212 of all wheel pairs 20 are determined so that they rotate in such a way that the heights of the supports 18 and thus the angle of the frame 10 relative to the support plane 34 are set as specified. The height is adjusted while the transport robot is stationary, i.e., the horizontal speed and the yaw rate of the transport robot are zero during the height adjustment. The angle of the wheel pairs 20 is adjusted during travel based on the setpoint values ​​for the angles (δ1, ..., δ4)DES of the drive modules 19 and the preliminary rotation rates (n 11 , n 12 ,... ,n 42 ) PDEs of the individual wheels 211, 212. The final target values ​​for the rotation rates (n 11 , n 12 ,... ,n 42 )DEs of the individual wheels 211, 212 are additively subjected to a negative or positive contribution of a differential speed for setting the angle. c) Precision mode

[0063] It is intended that a single transport robot 100 can be controlled in different operating modes, which are determined depending on the task to be performed. The control architecture and thus the available operating modes are described in detail below.

[0064] A first operating mode BM1 refers to the travel of a single transport robot 100 and is independent of any loading situation.

[0065] A second operating mode BM2 refers to a precision mode 300, which is selected, for example, when picking up and / or setting down the transported object. In precision mode 300, when the transport robot 100 changes its direction of travel, the transport robot 100 is stopped. The drive modules 19 then rotate to the specified steering angle, and only then does the journey continue. In other words, precision mode 300 interrupts the normal ferry operation of the transport robot 100. Normal ferry operation is characterized by the ability to change the steering angle of the drive modules 19 instantly during travel. This results in good maneuverability but limits the shape of the trajectory curve of horizontal speed and yaw angle change.Improved maneuverability and thus more precise control in very small spaces is achieved in precision mode 300 by enabling the adjustment of the steering angle of the drive modules 19 not while moving, but only when the transport robot 100 is stationary, i.e., when the horizontal speed and change in the yaw angle are zero. This has the advantage that unwanted changes in the pose of the transport robot 100 due to steering movements of the drive modules 19 while moving are minimized, thus maintaining a previous orientation of the transport robot. Overall, by adjusting the steering angle of the drive modules while stationary, constraints resulting from the kinematics and leading to restrictions in the trajectory of the pose of the transport robot can be eliminated. This allows for significantly improved maneuverability and thus more precise control in very small spaces.

[0066] Example: In operating mode BM1, the transport robot 100 first travels straight ahead to the height of a wheel of a vehicle 31 that is to be parked by a fleet of transport robots 100. The command is then given to move parallel to the wheel from the side in order to raise the wheel, which requires translation and yaw due to the change of direction. However, because the translation and yaw occur instantaneously during a change of direction in operating mode BM1, it may happen under certain circumstances that the transport robot 100 rotates around its vertical axis and positions itself incorrectly. In precision mode 300, in contrast, the transport robot 100 stops between straight ahead and parallel travel, and the drive modules 19 are aligned in a stationary position.

[0067] Furthermore, in precision mode 300, the distance to be maintained between the transport robot 100 and obstacles is reduced compared to operating mode BM1, which improves the navigation capability of the transport robot 100, in particular when picking up an object.

[0068] The possible driving speed is also reduced so that the reduced distance to obstacles can be handled when calculating navigation data. The low preset speed provided by the precision mode also allows for manual operation via a remote control.

[0069] In precision mode 300, the transport robot 100 primarily performs translations in the form of straight-ahead and parallel travel rather than rotations. This is particularly advantageous when parking a vehicle 31, as it allows for precise positioning on the inside of the tire with limited space under the vehicle 31.

[0070] When approaching a vehicle wheel underneath the vehicle 31, the transport robot 100 in precision mode 300 can also access images from a camera aligned to the inside of the vehicle wheel in order to detect (track) the position and enable controlled alignment with respect to the vehicle wheel.

[0071] A third operating mode, BM3, relates to the length adjustment of the frame, which occurs particularly when picking up and placing down objects that are to be transported or have already been transported. During operating mode BM3, the center point Mi of the transport robot 100 does not move.

[0072] A fourth operating mode BM4 refers to a rest mode in which the transport robot 100 does not perform any movement.

[0073] A fifth operating mode BM5 relates to the lifting and setting down of an object. In this case, any existing first coupling 301 between the drive modules 19 and the supports 18 is engaged (locked), and any existing second coupling 302 is disengaged to release the frictional connection between the support bolt 26 and the nut 25. The wheels 211, 212 of the wheel pairs 20 are then controlled such that the wheel pairs 20 rotate around their common center point M2, so that the frame 10 is raised or lowered. As soon as the frame 10 has reached the desired height, any couplings 301 can be disengaged (released) and any couplings 302 can be engaged, so that no height adjustment occurs during any steering movements.

[0074] A sixth operating mode, BM6, refers to a waiting period during which all previous or pending requests are deleted or overwritten. d) Formation control

[0075] In order to transport larger objects, such as vehicles 31, several transport robots 100 operate together in a fleet in a predeterminable formation. A formation control method 400 and a formation control unit 80 are provided to control the fleet. Fig. 5a shows a formation of four transport robots 100, which are to travel a specific trajectory in this formation to transport an object (not shown). There are essentially three different proposals for the arrangement of the formation control unit 80. First, the formation control unit 80 can be located within a stationary control unit 81, which controls each individual transport robot 100 via a functionally configured interface. Alternatively, a guide robot 82 is provided, which accommodates the formation control unit 80 and is not used to transport the object.This lead robot 82 follows a trajectory at a distance from the fleet, and the individual transport robots 100 of the fleet follow the lead robot 82, which controls the individual transport robots 100 via a suitable interface. Furthermore, one of the transport robots 100 of the fleet can also be designated as the lead robot 83 with transport function, which controls the movement of the remaining transport robots 100 of the fleet.

[0076] Fig. 5b shows the process sequence of the formation control method 400 in the form of a flowchart. According to this, the target position and orientation (X, Y, ψ)F,DES of the formation are first determined using a detection unit 92 and, together with the map data 521 of a map 52, are transferred to a "Formation Path Planning" calculation unit 84, which determines the path of the formation as a "Global Plan" 85, which consists of vectors of target positions and orientations (X, Y, ψ)F,DES of the formation. The "Global Plan" 85 is supplemented by any kinematic limitations or constraints 86 and relative position data 871 from a "Formation Configurator" calculation unit 87 and transferred to a "Formation Trajectory Planning" calculation unit 88. There, the target speeds and the target yaw rates of the individual transport robots 100 are determined with (v x ,v y,ω )pn,DEs. The data is calculated using nested calculation units 89 “Cascaded Position Controller” taking into account (X,Y,ψ)pn,Des to (v x ,v y ,ω ) Pn ,DEs,C, from which nested calculation units 90 “Single Robot Inverse Differential Kinematics” derive the target values ​​of the wheel speeds n and the angle δ n for all transport robots 100. The nested calculation units 89 “Cascaded Position Controller” are connected to a position determination 91 of each individual transport robot 100, with which the positions and angles in the form of (x,y,ψ) pn ,ACT are determined. This data is also combined by a calculation unit 93 "Single Robot Poses Fusion" to form a matrix (X,Y,ψ)F,ACT and passed to the calculation unit 84 "Formation Path Planning" as input data.

[0077] List of reference symbols

[0078] 100 transport robots

[0079] 200 tax proceedings

[0080] 300 Precision Mode

[0081] 400 Formation control procedures

[0082] 10 frames

[0083] 111 L-shaped section

[0084] 112 L-shaped section

[0085] 12 Linear drive

[0086] 121 spindle drive

[0087] 13 open ending

[0088] 141 C-shaped section

[0089] 142 C-shaped section

[0090] 15 Engine

[0091] 16 spindle

[0092] 17 Mother

[0093] 18 carriers

[0094] 19 Driving module

[0095] 20 pairs of wheels

[0096] 211 Wheel

[0097] 212 wheels

[0098] 22 axle stubs

[0099] 23 Drive motor

[0100] 24 turntables

[0101] 25 Mother

[0102] 26 support bolts

[0103] 27 Bolt head

[0104] 28 Arrow direction

[0105] 29 Arrow direction

[0106] 30 Coupling device

[0107] 301 first clutch

[0108] 302 second clutch

[0109] 31 vehicles

[0110] 32 thrust bearings

[0111] 33 Vehicle wheel 34 Support plane

[0112] 35 spacing

[0113] 60 requirements

[0114] 51 Calculation unit “Single Robot Navigation”

[0115] 52 map

[0116] 521 map data

[0117] 53 Calculation unit “Inverse Differential Kinematics”

[0118] 54 Calculation unit “Angle Controller”

[0119] 55 drive controllers

[0120] 56 Drive with powered transport robot

[0121] 57 Calculation unit “Odometry”

[0122] 58 Calculation unit “Localization”

[0123] 59 Inertial measuring unit

[0124] 60 Integrators

[0125] 61 Camera

[0126] 611 Camera data

[0127] 62 LIDAR

[0128] 621 LIDAR data

[0129] 63 switches

[0130] 64 Calculation unit “Multi Robot Formation Controller”

[0131] 65 partial proceedings

[0132] 66 Request

[0133] 67 Calculation unit “Position Controller”

[0134] 68 Control unit

[0135] 69 Engine

[0136] 70 partial proceedings

[0137] 71 Request

[0138] 80 Formation Control Unit

[0139] 81 stationary control unit

[0140] 82 guidance robots

[0141] 83 guidance robots

[0142] 84 Calculation unit “Formation Path Planning”

[0143] 85 Global Plan

[0144] 86 kinematic limitation

[0145] 87 Calculation unit “Formation Configurator”

[0146] 871 position data

[0147] 88 Calculation unit “Formation Trajectory Planning”

[0148] 89 Calculation unit “Cascaded Position Controller” 90 Calculation unit “Single Robot Inverse Differential Kinematics”

[0149] 91 Position determination

[0150] 92 registration unit

[0151] 93 Calculation unit “Single Robot Poses Fusion” v Linear velocity v x , v y Cartesian components of linear velocity ω yaw rate n speed n index

[0152] F frame length

[0153] F0Basic length

[0154] F v variable length

[0155] M1Center of the transport robot

[0156] M2Center point of a wheel pair

[0157] M3Momentary pole w track width m track width r Rad Wheel diameter

Claims

Patent claims 1. Transport robot (100) which is designed for picking up, transporting and depositing an object in individual operation and / or in fleet operation, wherein the transport robot (100) has a frame (10) on which a plurality of drive modules (19) are arranged at least indirectly, characterized in that a coupling device (30) is arranged between the drive modules (19) and the frame (10), which coupling device allows a height adjustment of the frame (10) in a first coupling setting and a free rotation of the drive modules (19) with respect to the frame (10) in a second coupling setting.

2. Transport robot (100) according to claim 1, characterized in that the frame (10) has a plurality of supports (18) which are connected to the driving modules (19).

3. Transport robot (100) according to one of claims 1 or 2, characterized in that the frame (10) has two L-shaped sections (111, 112) which are aligned in a mirror-inverted manner to one another and which are connected to one another at their short ends via a linear drive (12).

4. Transport robot (100) according to one of claims 1 or 2, characterized in that the frame (10) has two C-shaped sections (141, 142) aligned in a mirror-inverted manner to one another, the ends of which are each connected to one another via a linear drive (12).

5. Transport robot (100) according to one of claims 1 to 4, characterized in that at least one linear drive (12) is designed as a spindle drive (121) with a motor (15), a spindle (16) and a nut (17).

6. Transport robot (100) according to one of claims 1 to 5, characterized in that each driving module (19) has a pair of wheels (20), the wheels (211, 212) of which are rotatably mounted on axle stumps (22), wherein the axle stumps (22) are preferably aligned coaxially with one another.

7. Transport robot (100) according to claim 6, characterized in that each wheel (211, 212) of the wheel pairs (20) is connected to a separate motor (23).

8. Transport robot (100) according to one of claims 6 or 7, characterized in that the axle stubs (22) are connected to a nut (25) which receives a support bolt (26) which is connected at least indirectly to the frame (10) via the coupling device (30), wherein the coupling device (30) has a first coupling (301) which creates a lockable connection between the turntable (24) and the carrier (18), and a second coupling (302) which creates a lockable connection between the support bolt (26) and the nut (25), so that during the first coupling setting and an equal but oppositely oriented rotation of the wheels (211, 212), the support bolt (26) is displaced longitudinally axially relative to the nut (25).

9. Transport robot (100) according to one of claims 1 to 8, characterized in that the first clutch (301) and the second clutch (302) are each designed as a two-part ring clutch with friction linings between the rings of the ring clutch, which are frictionally connected to one another by a spring in the engaged state.

10. Transport robot (100) according to claim 9, characterized in that a coil is provided for disengaging, which opens the first and second clutch (301, 302) in the energized state and closes them in the de-energized state.

11. Transport robot (100) according to one of claims 1 to 8, characterized in that the first coupling (301) and the second coupling (302) have a magnetic coil which alternately cancels one mechanical connection and establishes the other mechanical connection.

12. Transport robot (100) according to one of claims 1 to 11, characterized by a control unit which is designed to carry out a control method (200) with which the target rotational speeds of the individual wheels (211, 212) of all wheel pairs (20) can be predetermined as a function of target variables relating to a linear speed and a yaw rate of the transport robot (100).

13. Transport robot (100) according to claim 12, characterized in that the transport robot (100) can be controlled in different operating modes by means of the control method (200), wherein preferably a precision mode (300) is provided in which a change in the steering angle of the driving modules is only permitted when the robot is at a standstill.

14. Transport robot (100) according to one of claims 1 to 13, characterized in that the transport robot (100) can be connected to a control unit (80, 81) which is used for Implementation of a formation control method (400) with which the target speeds of the individual wheels (211, 212) of all wheel pairs (20) can be predetermined as a function of target variables in relation to linear speeds and yaw rates of several transport robots (100) of a formation.

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