SE2150877A1 - Method of controlling robot for human lifting, control system, robot and robot system - Google Patents

Abstract

A method of controlling a robot (14), the method comprising providing a robot (14) having a base (18) and a manipulator (20) movable relative to the base (18); and controlling the robot (14) to adopt a lifting mode (38) such that at least one property of the robot (14) associated with lifting of the robot (14) by a human (10) is improved. A control system (30) for controlling a robot (14), a robot (14) comprising a control system (30), and a robot system (12) comprising a robot (14) and a programming device (16), are also provided.

Description

1O METHOD OF CONTROLLING ROBOT FOR HUMAN LIFTING,CONTROL SYSTEM, ROBOT AND ROBOT SYSTEM Technical Field The present disclosure generally relates to control of a robot for being liftedby a human. In particular, a method of controlling a robot to adopt a liftingmode for lifting by a human, a control system for controlling a robot, a robotcomprising a control system, and a robot system comprising a robot and a programming device, are provided.Background Industrial robots are most often too heavy for being lifted directly by ahuman without any additional equipment, such as a forklift or a traverse.Recently, more lightweight robots have been introduced. Such robots may bepossible to lift and carry directly by a human. However, small robots,collaborative or industrial, lack a clear procedure for how to manually grab,lift and carry them safely. Since the robot typically comprises a manipulatorthat can adopt a wide range of different poses and that has a plurality ofpinching points, it is not clear where and how to manually grab the robot forsafe and ergonomic transportation. This is a problem that naturally occurswhen an object is light enough to lift for one person. That is, if the object canbe carried manually, it will likely be carried manually. This may result ininjuries to the human from unergonomic lifting procedures or from handsgetting pinched by a manipulator. It may also result in the human dropping the robot during transportation in case the grip is lost.Summary One object of the present disclosure is to provide a method of controlling arobot, which method enables the robot to be lifted and carried by a human in a safe, simple and/ or ergonomic manner. 1O A further object of the present disclosure is to provide a method ofcontrolling a robot, which method enables an improved user experience, such as improved interaction between the human and the robot.

A still further object of the present disclosure is to provide a method ofcontrolling a robot, which method enables an efficient transportation of the robot by being lifted by the human.

A still further object of the present disclosure is to provide a control systemfor controlling a robot, which control system solves one, several or all of the foregoing objects.

A still further object of the present disclosure is to provide a robot comprisinga control system, which robot solve one, several or all of the foregoing objects.

A still further object of the present disclosure is to provide a robot systemcomprising a robot and a programming device, which robot system solves one, several or all of the foregoing objects.

According to a first aspect, there is provided a method of controlling a robot,the method comprising providing a robot having a base and a manipulatormovable relative to the base; and controlling the robot to adopt a lifting modesuch that at least one property of the robot associated with lifting of the robot by a human is improved.

The lifting mode may alternatively be referred to as a carry mode. The liftingmode enables the robot to be easily and safely carried by the human for transportation to a different location.

In the lifting mode, various parameters of the robot may be controlled tooptimize the robot for being grabbed, lifted and carried by the human. Themethod enables an ease of process modularity that is difficult to obtain byrobots that are too heavy for manual lifting. By manually lifting and movingthe robot, assembly lines can be adjusted quickly and adapt to production needs, resulting in an agile production line. 1O The method may further comprise receiving a lifting command from thehuman; and controlling the robot in the lifting mode in response to receivingthe lifting command. By means of the lifting command, the robot is informed that the human intends to manually lift the robot for transportation.

The lifting command may be received by a programming device associatedwith the robot. The lifting command may for example be input by means of adedicated button on the programming device or by navigating through menuson a display of the programming device to make a selection that constitutesthe lifting command. The programming device then instructs the robot to adopt the lifting mode.

The lifting mode may comprise activating one or more brakes of themanipulator. By activating the one or more brakes, a pose of the manipulatorcan be locked in the lifting mode. In this way, unwanted movements of themanipulator during manual transportation can be avoided. Such unwantedmovements may cause the center of gravity of the robot to change, which inturn may result in the human dropping the robot. The improved propertiesmay in this case be stiffness of the robot, ease of handling and/ or a security against pinching the fingers of the human. Each brake may be a power-offbrake.

The lifting mode may comprise controlling the manipulator to adopt acompact pose. The improved properties may in this case be ease of handlingand a security against collision between the robot and external objects when the robot is carried by the human.

The lifting mode may comprise controlling the manipulator to position one ormore lifting features on the manipulator for manually lifting the robot. Thelifting features may be exposed or presented to the human in this position ofthe robot. The improved properties may in this case be ease of handling and/ or user experience. By grabbing the lifting features, a more ergonomiclifting and carrying of the robot is enabled. Moreover, risks of dropping the robot and hand fatigue are reduced. The lifting features may be designed in 1O such a way as to enable a strong grip by the human and/ or to minimize a riskof pinching the human. The lifting features may be indicated clearly, forexample by unique coloring, lighting and/ or texture. The lifting features may be constituted by links of the manipulator.

The lifting mode may comprise controlling the manipulator to adopt a posewhere a center of gravity of the robot is as close as possible to the base. Theimproved properties may in this case be ease of handling and a securityagainst collision between the robot and external objects when the robot is carried by the human.

The method may further comprise communicating one or more instructionsassociated with the lifting to the human. Such instructions may comprisecommunicating to the human where the lifting features are and/ or whetherthe human should wait for the robot to finish a task. The instructions may be audible or visual.

The method may further comprise communicating to the human that therobot has adopted the lifting mode. The communication may be audibleand/ or visual. Visual communication can take place through a display on a programming device and/ or by means of lights or displays on the robot.

By means of this communication, the human can intuitively be informed thatit is safe to disconnect, grab, hold, lift and carry the robot. When a trustedprocedure like this is in place, a transportation task can be carried out faster.The transportation task can for example easily be incorporated into a workflow.

According to a second aspect, there is provided a control system forcontrolling a robot having a base and a manipulator movable relative to thebase, the control system comprising at least one data processing device and atleast one memory having at least one computer program stored thereon, theat least one computer program comprising program code which, whenexecuted by the at least one data processing device, causes the at least one data processing device to perform the step of controlling the robot to adopt a 1O lifting mode such that at least one property of the robot associated with lifting of the robot by a human is improved.

The at least one computer program may comprise program code which, whenexecuted by the at least one data processing device, causes the at least one data processing device to perform any of the steps of the first aspect.

According to a third aspect, there is provided a robot comprising a controlsystem according to the second aspect. The robot may have a mass of less than 20 kg.

According to a fourth aspect, there is provided a robot system comprising arobot according to the third aspect and a programming device configured to receive a lifting command from the human.Brief Description of the Drawings Further details, advantages and aspects of the present disclosure will becomeapparent from the following description taken in conjunction with the drawings, wherein: Fig. 1: schematically represents an environment including a human and arobot system comprising a robot and a programming device; Fig. 2: schematically represents the environment in Fig. 1 when thehuman commands the robot to adopt a lifting mode; and Fig. 3: schematically represents the environment in Figs. 1 and 2 when the human lifts the robot.Detailed Description In the following, a method of controlling a robot to adopt a lifting mode forlifting by a human, a control system for controlling a robot, a robotcomprising a control system and a robot system comprising a robot and aprogramming device, will be described. The same or similar reference numerals will be used to denote the same or similar structural features. 1O Fig. 1 schematically represents an environment including a human 10 and arobot system 12. The robot system 12 comprises a robot 14 and aprogramming device, here exemplified as a teach pendant unit, TPU, 16. Therobot 14 is here exemplified as a collaborative robot. The robot 14 may for example have a mass of 13 kg.

The robot 14 comprises a base 18 and a manipulator 20 connected to the base18. The manipulator 20 comprises a plurality of links and may beprogrammable in three or more axes, such as in six or seven axes. Themanipulator 20 of this example comprises two lifting features 22. In Fig. 1,one lifting feature 22 constituted by an edge of one of the links can be seen.The manipulator 20 comprises a further link (not visible in Fig. 2), parallelwith the link comprising the visible lifting feature 22, that also comprises alifting feature 22. The edges of the link may be curved to provide a smoothgrip to the human 10, as described below. The manipulator 20 furthercomprises one brake 24 for each axis. The brakes 24 are here power-off brakes.

In Fig. 1, the robot 14 is in a working mode 26 where the manipulator 20moves relative to the base 18 to perform various tasks. In the specific pose ofthe manipulator 20 shown in Fig. 1, a center of gravity 28 of the robot 14 liesquite far outside the base 18. In this pose of the manipulator 20, it may bedifficult for the human 10 to lift the robot 14.

The robot 14 comprises a control system 30. The control system 30 is in thisexample arranged in the base 18. The control system 30 comprises a dataprocessing device 32 and a memory 34. The memory 34 has a computerprogram stored thereon. The computer program comprises program codewhich, when executed by the data processing device 32, causes the dataprocessing device 32 to perform, or command performance of, various steps as described herein. 1O The TPU 16 is in signal communication with the control system 30. The TPU16 of this specific example comprises a plurality of buttons and a display (notdenoted).

In this example, the human 10 wants to lift and move the robot 14 to adifferent location. The reasons for this may be many. The human 10 may for example want to incorporate the robot 14 into a different workflow.

As shown in Fig. 2, the human 10 inputs a lifting command 36 to the TPU 16.The lifting command 36 may for example be issued by pushing a button onthe TPU 16. The TPU 16 thereby informs the robot 14 that the human 10wants to lift the robot 14. In response, the control system 30 controls therobot 14 to adopt a lifting mode 38. The lifting mode 38 improves severalproperties of the robot 14 associated with lifting of the robot 14 by the human10.

The lifting mode 38 of this specific example comprises moving themanipulator 20 to a compact pose 40. The manipulator 20 is now folded toenable a smaller footprint of the robot 14 when being carried by the human .

In the compact pose 40, the lifting features 22 are positioned above the base18 for access by the hands of the human 10. The links of the manipulator 20can thereby function as handles in the lifting mode 38. Moreover, the centerof gravity 28 is now much closer to the base 18 (compared with Fig. 1) and is positioned above the base 18 and below the lifting features 22.

The lifting mode 38 of this specific example further comprises activating eachbrake 24. In this way, the manipulator 20 is locked in the pose 40 shown in Fig. 2.

Once the robot 14 has adopted the lifting mode 38, this is communicated tothe human 10, for example by an audible signal and/ or via the display on the TPU 16. Instructions 42 on how to lift the robot 14 are presented by the TPU 1O 16. The lifting features 22 may also be marked by blinking lights to make it even further clear to the human 10 where to grab the robot 14.

The commanding of the lifting mode 38 by the human 10 and the adoption ofthe lifting mode 38 by the robot 14 provides a clear, safe and easy-to-understand procedure. The human 10 can now confidently approach,disconnect, grab, lift and carry the robot 14 in an ergonomically correct manner.

Fig. 3 schematically represents the environment in Figs. 1 and 2 when thehuman 10 lifts the robot 14 by his /her hands. Once the human 10 has carriedthe robot 14 to a desired location, the human 10 puts down the robot 14 andconnects it. Once the robot 14 has been setup at the new location, the TPU 16 may present an option to the human 10 to disengage the lifting mode 38.

While the present disclosure has been described with reference to exemplaryembodiments, it will be appreciated that the present invention is not limitedto what has been described above. For example, it will be appreciated that thedimensions of the parts may be varied as needed. Accordingly, it is intendedthat the present invention may be limited only by the scope of the claims appended hereto.

Claims (1)

1. A method of controlling a robot (14), the method comprising: - providing a robot (14) having a base (18) and a manipulator (20)movable relative to the base (18); and - controlling the robot (14) to adopt a lifting mode (38) such that at leastone property of the robot (14) associated with lifting of the robot (14) by a human (10) is improved. The method according to claim 1, further comprising:- receiving a lifting command (36) from the human (10); and- controlling the robot (14) in the lifting mode (38) in response to receiving the lifting command (36). The method according to claim 2, wherein the lifting command (36) is received by a programming device (16) associated with the robot (14). The method according to any of the preceding claims, wherein thelifting mode (38) comprises activating one or more brakes (24) of the manipulator (20). The method according to any of the preceding claims, wherein thelifting mode (38) comprises controlling the manipulator (20) to adopt a compact pose (40). The method according to any of the preceding claims, wherein thelifting mode (38) comprises controlling the manipulator (20) to positionone or more lifting features (22) on the manipulator (20) for manuallylifting the robot (14). The method according to any of the preceding claims, wherein thelifting mode (38) comprises controlling the manipulator (20) to adopt apose (40) where a center of gravity (28) of the robot (14) is as close as possible to the base (18). 1O 10. 11. 12. 13. 14. The method according to any of the preceding claims, furthercomprising communicating one or more instructions (42) associated with the lifting to the human (10). The method according to any of the preceding claims, furthercomprising communicating to the human (10) that the robot (14) has adopted the lifting mode (38). A control system (30) for controlling a robot (14) having a base (18) anda manipulator (20) movable relative to the base (18), the control system(30) comprising at least one data processing device (32) and at least onememory (34) having at least one computer program stored thereon, theat least one computer program comprising program code which, whenexecuted by the at least one data processing device (32), causes the atleast one data processing device (32) to perform the step of: - controlling the robot (14) to adopt a lifting mode (38) such that at leastone property of the robot (14) associated with lifting of the robot (14) by a human (10) is improved. The control system (30) according to claim 10, wherein the at least onecomputer program comprises program code which, when executed bythe at least one data processing device (32), causes the at least one data processing device (32) to perform the steps of any of claims 2 to 9. A robot (14) comprising a control system (30) according to claim 10 or 11. The robot (14) according to claim 12, wherein the robot (14) has a mass of less than 20 kg. A robot system (12) comprising a robot (14) according to claim 12 or 13and a programming device (16) configured to receive a lifting command (36) from the human (10).