ROBOT SYSTEM, DEVICE, AND METHOD FOR APPLYING A PROCESS FORCE TO AN OBJECT

Abstract

The present invention relates to a robot system, a device, and a method for applying a process force (F.sub.P) to an object within the scope of a task to be performed by a robot in relation to the object, the robot system allowing an amplification of the input force (F.sub.EIN) input by a user with simultaneous feedback control, so as to thus enable a sensitive control of tasks.

Claims

1. Robot system comprising a multi-axis manipulator for applying a process force (F.sub.P) to an object with respect to a task by means of which the manipulator interacts with the object, wherein the manipulator is designed, upon contact with the object, to detect an input force (F.sub.EIN) directly exerted on the manipulator by a contact of an user, amplify the input force (F.sub.EIN) depending on a defined conversion factor to a desired value of the process force (F.sub.P) in relation to the task, detect a counterforce (F.sub.GR) which is produced when the manipulator comes into contact with the object, and transmit this counterforce (F.sub.GR) to the user depending on a defined conversion factor.

2. Robot system according to claim 1, in which the manipulator is further designed to change the conversion factor for the amplification to the value of the process force (F.sub.P) during the performance of the task.

3. Robot system according to claim 1, in which the conversion factor for the counterforce (F.sub.GB) corresponds to the reciprocal of the conversion factor for the process force (F.sub.P).

4. Robot system according to claim 1, in which the manipulator comprises at least one means for detecting the input force (F.sub.EIN) by the user.

5. Robot system according to claim 1, in which the manipulator comprises at least one means for transmitting the counterforce (F.sub.GB) to the user.

6. Robot system according to claim 4, in which the means are arranged at an end effector of the manipulator.

7. Robot system according to claim 1, in which the robot system is compliance-controlled.

8. Device for applying a process force (F.sub.P) to an object comprising: at least one input device configured to determine an input force (F.sub.EIN) with respect to the object, the input device comprising at least one means for detecting the input force (F.sub.EIN); and a robot system with a manipulator which is designed to apply a process force (F.sub.P) to the object on contact with the object and, depending on a defined conversion factor, to amplify the input force (F.sub.EIN) to the value of the process force (F.sub.P) during application; wherein the manipulator is further configured to detect a counterforce (F.sub.GR) which is set up when the manipulator contacts the object, and wherein the input device is configured to map this counterforce (F.sub.GR) as a function of a defined conversion factor.

9. Device according to claim 8, in which the input device is formed separately from the manipulator and is designed to determine the input force (F.sub.EIN) upon contact with the manipulator.

10. Device according to claim 8, in which the input device is arranged on the manipulator.

11. Device according to claim 9, in which the input device is designed to be actuated by a manipulator of another robot system.

12. Device according to claim 9, in which the input device is a structure portable and/or operable by a user.

13. Device according to claim 12, in which the structure is rigid and designed to cooperate with an end effector of the manipulator.

14. Device according to claim 8, in which the input device is further designed to determine the movement of the manipulator upon contact of the input device with the manipulator.

15. Device according to claim 8, in which the robot system is compliance-controlled.

16. A method for processing workpieces, comprising: using the robot system according to claim 1 on an object, in which the object is a workpiece and the manipulator is designed to process the workpiece by means of an end effector.

17. A method for lifting and/or guiding and/or gripping objects, comprising: using the robot system according to claim 1 on an object, wherein the object is an item and the manipulator is designed to lift and/or guide and/or grip the item by means of an end effector.

18. A method for manipulating human beings, comprising: using the robot system according to claim 1 on an object, wherein the object is a human being and the manipulator is designed to process parts of the human body by means of an end effector.

19. A method, comprising: using the robot system according to claim 1 to teach the manipulator of the robot system with respect to the motion sequence and the force profile of the task to be performed by the manipulator.

20. Wheelchair for a user comprising at least one robot system according to claim 1.

21. Method of applying a process force (F.sub.P) to an object by a manipulator of a robot within the scope of a task to be performed by the manipulator with respect to the object, comprising the steps of setting an input force (F.sub.EIN) by a user with respect to the object; amplifying the input force (F.sub.EIN) to a value of a process force (F.sub.P) by the manipulator according to a defined conversion factor; applying the process force (F.sub.P) to the object by the manipulator; detecting a counterforce (F.sub.GR) resulting when the manipulator contacts the object; and transmitting the counterforce (F.sub.GR) to the user.

22. Method according to claim 21, in which the transmission of the counterforce (F.sub.GB) takes place according to a defined conversion factor which corresponds to a reciprocal value of the defined conversion factor with respect to the process force (F.sub.P).

23. Method according to claim 21, in which the input force (F.sub.EIN) is entered by the user via a contact directly on the manipulator.

24. Method according to claim 21, in which the input force (F.sub.EIN) is input by the user via an input device cooperating with the manipulator.

25. Method according to claim 24, in which the counterforce (F.sub.GB) is transmitted to the user by the input device.

26. Method according to claim 21, in which the defined conversion factor is variable in relation to the process force (F.sub.P) so that the process force (F.sub.P) is dynamically variable when applied to the object.

27. Method according to one of claim 21, in which at least one threshold value is assigned to the defined conversion factor with respect to the process force (F.sub.P) or to the process force (F.sub.P).

28. A method for processing workpieces, comprising: using the device according to claim 8 on an object, in which the object is a workpiece and the manipulator is designed to process the workpiece by means of an end effector.

29. A method for lifting and/or guiding and/or gripping objects, comprising: using the device according to claim 8 on an object, wherein the object is an item and the manipulator is designed to lift and/or guide and/or grip the item by means of an end effector.

30. A method for manipulating human beings, comprising: using the device according to claim 8 on an object, wherein the object is a human being and the manipulator is designed to process parts of the human body by means of an end effector.

31. A method, comprising: using the robot system according to claim 1 to teach the manipulator of the robot system with respect to the motion sequence and the force profile of the task to be performed by the manipulator.

32. Wheelchair for a user comprising at least one device according to claim 8.

Description

[0059] Further advantages and features of the present invention result from the description of the embodiments as shown in the enclosed drawings, in which

[0060] FIG. 1 shows a first embodiment according to the invention;

[0061] FIG. 2 shows a second embodiment according to the invention;

[0062] FIG. 3a-d schematically show different arrangement variants for an input device with respect to the second embodiment;

[0063] FIG. 4 shows a third embodiment according to the invention;

[0064] FIG. 5 shows a fourth embodiment according to the invention;

[0065] FIG. 6 shows a fifth embodiment according to the invention; and

[0066] FIG. 7 shows the arrangement of a manipulator according to the invention on a wheelchair.

[0067] FIG. 1 shows a first embodiment according to the invention.

[0068] A multi-axis manipulator 1 of a robot system of lightweight construction has an end effector 2 at its distal end, with which the manipulator 1 is to interact with an object not shown here, e.g. to push it down.

[0069] The manipulator 1 can be guided arbitrarily in space according to its degrees of freedom given by the number of articulated arms by guiding contact by means of the hand 3 of a user, if the manipulator 1 is e.g. in its gravity compensated mode.

[0070] As soon as the distal end of the end effector 2 comes into contact with an object, e.g. to press it down, the user applies an input force F.sub.EIN via his hand 3, which is detected by an input device 4 located at the proximal end of the end effector 2.

[0071] In a controller of the robot system, corresponding conversion factors are stored, which determine the amplification with which the input force F.sub.EIN is to be converted by the manipulator 1 into an output force and then applied to the object as a process force F.sub.P.

[0072] It goes without saying that on contact with the object a counterforce F.sub.GR is generated in the manipulator 1 or in the end effector 2, which is measured in these elements.

[0073] In order to enable feedback control of the entire process for the user, it is now provided according to the invention that this inherent counterforce F.sub.GR is mapped via a corresponding reducing conversion factor to a counterforce F.sub.GR, which is transmitted to the user via his hand 3 by means of corresponding actuators or the like within the input device 4 in a haptic manner.

[0074] FIG. 2 shows a further embodiment according to the invention.

[0075] In this case, the input device 5 is designed as a rigid glove which is firmly connected, i.e. force-transmittingly, to the distal end of the end effector 2. However, as FIGS. 3a to 3d show, any arrangement of the glove 5 on the end effector 2 is conceivable, depending on how guidance and force application is to be carried out by the user.

[0076] Inside the glove 5 there is at least one sensor (not shown) to detect the input force exerted by the user as soon as the glove 5 comes into contact with an object not shown here.

[0077] First, the user can guide manipulator 1 with its end effector 2 to the object in its gravity-compensated state via the glove 5. When the glove 5 comes into contact with the object, the user then applies an increased or amplified process force, which is transmitted from the manipulator 1 to the object via the rigid structure of the glove 5. Such an arrangement is suitable, for example, for physiotherapeutic applications such as massages.

[0078] The feedback control for the presentation of a reduced counterforce is also carried out inside the glove 5, for example, via corresponding actuators. A varying counterforce can result from muscle hardening in the above example.

[0079] FIG. 4 shows a further embodiment according to the invention.

[0080] Instead of a stiff glove 5, only a thimble 6 is attached to the distal end of the end effector 2, which can serve as a force sensor in itself or can itself be designed as a stiff structure with an integrated force sensor. This arrangement is advantageous if the end effector 2, in addition to the sensor 6, carries a mechanism (e.g. a screw head) with which it interacts with the object.

[0081] Another embodiment is shown in FIG. 5. A gripping mechanism 7, which can be attached to a distal end of a manipulator 1, has two gripping fingers 8 that can be moved relative to each other. On the outer sides of the gripper fingers 8, corresponding sensors 9 are provided as input devices, so that a user can easily apply an input force by lightly pressing the sensors 8, which the gripping mechanism 7 amplifies by taking into account a gain factor when gripping an object.

[0082] FIG. 6 shows an embodiment according to the invention, in which the input device 6 of the force amplifying manipulator 10 of a robot system interacts with an end effector 7 of a manipulator of another robot system. The manipulator 11 is therefore intended to apply the corresponding process force with respect to an object, e.g. gripping, and is guided and force-amplifyingly supported by the manipulator 10, whereby the counterforces resulting from the action of the manipulator 11 are transmitted to the manipulator 10 via the input device 6, thus enabling the feedback control of the manipulator 10, wherein preferably both manipulators 10 and 11 being compliance controlled.

[0083] A particular field of application of a device according to the invention is in the field of care. It is therefore intended that a manipulator 1 according to the invention is attached to a wheelchair 12 which can be activated by the user via a corresponding input device at the end of the manipulator 1, e.g. for lifting or placing objects in the immediate vicinity of the wheelchair.