Force application device for a robot system

Abstract

In a force application device for a robot system, wherein the force application device is connectable on the one hand to a robot assembly and on the other hand to a support device for the robot assembly, wherein at least one force can be applied from the support device to the robot assembly via the force application device, it is provided that the force application device has at least one fixing device which is designed to be clamped to the robot element, has at least one rotation device, wherein the rotation device is rotatable about a first axis relative to the fixing device, and has at least one suspension element which is pivotably attached to the rotation device about a second axis, wherein the second axis is orthogonal to the first axis.

Description

[0001] The invention relates to a force application device for a robot system, which can be connected on the one hand to a robot device and on the other hand to a support device for the robot device, wherein at least one force can be applied from the support device to the robot device via the force application device, according to claim 1.

[0002] Robotic devices are known that are manufactured specifically for use in space. Space robotic devices are designed for conditions in space. Since no gravitational forces act on the space robotic device in space, a large portion of the forces required due to gravity can be neglected in the design of the space robotic device. This allows the joints and / or actuators to be smaller, lighter, and more energy-efficient.

[0003] However, the robotic devices will also be operated on Earth, for example to test or improve them. To do this, the robotic device must be supported, as otherwise the joints would be subjected to excessive strain or the actuators would be unable to move the robotic device. Support devices exist for this purpose which assist the robotic devices on Earth. This can be done, for example, with helium balloons or planar, active or passive support tables. Helium balloons, which can have a diameter of several meters depending on the payload, contribute to reducing the load through their buoyancy. These are mounted on the robotic device at the designated points and pull the robotic device upwards at this point with a constant force. Planar, movable support tables can, for example, glide over smooth floors and support the joints of the robotic device.However, with this method, the robotic devices can only perform planar movements.

[0004] To apply a force in any direction to a robotic device, especially a tubular robotic device such as a robot arm, a force application device can be used. The challenge here is that the force to be applied is not necessarily perpendicular to the robot arm. Often, a measurement of the direction and intensity of the applied force is also necessary.

[0005] Knots are a simple way to apply a force to a robotic device, especially a tubular robotic device. They utilize the flexibility of the rope to compensate for different orientations of the applied force relative to the tubular structure. However, the direction and intensity of the force are unknown.

[0006] There are many mounting options for circular structures, such as robot arms. However, most mounting options are limited in their flexibility. For example, a simple clamp connection has no way of applying external force. Other clamp mechanisms have eyelets for applying forces. The disadvantage, however, is that the force can only be applied in the direction of the eyelet, since the clamp is firmly attached to the circular structure.

[0007] A force application device for a robot system can be connectable on the one hand to a robot device and on the other hand to a support device for the robot device, wherein at least one force can be applied from the support device to the robot device via the force application device.

[0008] The object of the present invention is to provide a force application device in which the force application is flexible.

[0009] The features of claim 1 serve to solve this problem.

[0010] The invention advantageously provides a force application device which - has at least one fixing device which is designed to be clamped to the robot element, - has at least one rotation device, wherein the rotation device is rotatable about a first axis relative to the fixing device, and - at least one suspension element which is pivotally mounted on the rotation device about a second axis, wherein the second axis is orthogonal to the first axis.

[0011] Due to the fixing device, the rotation device and the suspension element, the force application with the force application device is very flexible.

[0012] The fixing device can have at least one clamping device by means of which the fixing device can be clamped to the robot element.

[0013] A clamping device is a device that connects two parts together using a clamping connection. A clamping connection is a type of joining technique used to mechanically join two or more components without permanently altering or damaging them. Clamping connections use physical pressure to hold the parts together and are therefore detachable and often adjustable.

[0014] The clamp connection can be a clamp connection, wherein the clamp connection preferably has a screw by means of which the clamp connection can be contracted and thus causes a frictional connection to secure it against displacement.

[0015] At least one bearing can be provided between the fixing device and the rotating device, wherein the bearing is preferably a ball bearing.

[0016] In this way, there are few friction losses when rotating the rotating device to the fixing device.

[0017] The suspension element can be attached to the rotation device in such a way that the suspension element is pivotable only about the second axis relative to the rotation device.

[0018] At least one bearing can be provided between the rotation device and the suspension element, wherein the bearing is preferably a ball bearing.

[0019] In this way, there are few friction losses when rotating the rotating device to the suspension element.

[0020] At least one first angle sensor device can be provided which measures the angle of rotation between the fixing device and the rotation device.

[0021] Furthermore, at least one second angle sensor device can be provided which measures the angle of rotation between the rotation device and the suspension element.

[0022] At least one force sensor may be provided which measures the force acting on the suspension element.

[0023] The force sensor can be arranged on the suspension element or separately from it.

[0024] A safety rope guide for a safety rope may be provided.

[0025] The safety rope guide can be arranged in such a way that a safety rope arranged in the safety rope guide has no contact with the fixing device during normal operation.

[0026] A robot system can be provided with a robot device, in particular a space robot device with at least one movable robot element and at least one actuator for moving the at least one robot element, a support device for supporting the robot device when using the space robot device in the gravitational field of the Earth, with at least one force application device according to one of claims 1 to 10, wherein the force application device is connected to the robot element at least at one point and applies at least one force to the robot element which at least partially compensates for the force of gravity acting on the robot element.

[0027] The support device may be a cable robot system having at least two cable elements connected to the force application device, wherein each cable element is connected to at least one motor that can move the respective cable element so that the direction and amount of force that can be applied to the robot element via the force application device can be adjusted.

[0028] The robotic device can be attached to a base. The base can be fixed in space. Alternatively, it can also be movable.

[0029] In the following, an embodiment of the present invention is explained in more detail with reference to the drawings.

[0030] They show schematically Fig. 1 the robot system, Fig. 2 an excerpt from Fig. 1, which shows the force application device, Fig. 3 a force application device, Fig. 4 a fixing device of the force application device Fig. 5 a safety rope guide, Fig. 6 A safety rope guide made of Fig. 5.

[0031] In Fig. 1 shows a robot system 1. The robot system 1 has a robot device 2. The robot device 2 is preferably a space robot device. The robot device 2 has at least one movable robot element 4. In the present exemplary embodiment, at least three movable robot elements 6, 4 and 8 are provided. The at least one movable robot element 4 can be moved with at least one actuator 13. In the present exemplary embodiment, an actuator 15 is provided which can move the robot element 6. Furthermore, an actuator 13 is provided which can move the robot element 4 and an actuator 11 is provided which can move the robot element 8. Furthermore, joints 14, 12 and 10 are provided around which the respective robot elements 6, 4 and 8 can rotate.

[0032] In the present embodiment, the robot device 2 is preferably a robot arm. Furthermore, the robot device is preferably attached to a base 16, which can preferably be fixed in space. The robot system 1 also has a support device 3, which can support the robot device 2 when the robot device is used in the Earth's gravitational field.

[0033] Furthermore, at least one force application device 30 is provided, which is connected to the at least one robot element 4 at at least one point and to which at least one force can be applied to the at least one robot element 4, which force at least partially compensates for the gravitational force acting on the robot device 2. This means that at least a portion of the force exerted on the robot element 4 via the force application device 30 acts counter to the gravitational force. By applying the force and partially compensating for the gravitational force, the robot device 2 is supported. The robot device 2 should be supported at least enough so that the actuators 12 and 15 can move the robot elements 6 and 4.

[0034] Alternatively, the force application device 30 can also be arranged on the robot element 6 or 8.

[0035] The illustrated support device 3 is preferably a cable robot system that has at least two cable elements, in the present embodiment four cable elements 18, 20, 22, 24, which are connected to the force application device 30. In the illustrated embodiment, four cable elements 18, 20, 22, and 24 are provided, and each cable element 18, 20, 22, 24 is connected to at least one motor 38, 36, 34, 32 that can move the respective cable element 18, 20, 22, 24. By actuating the respective motor 38, 36, 34, 32, for example, the respective cable element 18, 20, 22, 24 can be rolled up, thus moving the respective cable element 18, 20, 22, 24. At point 48, the four cable elements 18, 20, 22, 24 are connected to a suspension element 26. The suspension element 26 is part of the force application device 30.

[0036] Depending on how tightly the individual cable elements 18, 20, 22, 24 are wound, a force is exerted on the force-applying device 30 and thus on the robot element 4. By adjusting the motors and moving the cable elements 18, 20, 22, 24, the magnitude and direction of the applied force acting on the force-applying device 30 and thus on the at least one robot element 4 can be adjusted. The cable elements 18, 20, 22, 24 are deflected via deflection elements 41, 43, 45, and 47. The deflection elements 41, 43, 45, and 47 are preferably arranged above the robot element 4.

[0037] At least one force sensor 28 may be provided which measures the force acting on the suspension element 26.

[0038] In addition, further sensor devices 42, 44, 40 and 46 can be provided which measure the forces in the cable elements 18, 20, 22 and 24.

[0039] The invention is not limited to four cable elements 18, 20, 22, and 24, but can also be implemented with more or fewer cable elements. However, at least two cable elements should be provided so that the direction and magnitude of the force can be varied.

[0040] In Fig. 2 is an excerpt from the Fig. 1, in which the force application device 30 is shown in more detail. The force application device 30 is rotatable about two essentially orthogonal axes 50, 52. Depending on the location of the robot element 4 and how the motors 38, 36, 34, 32 were actuated and thus the cable elements 18, 20, 22, 24 were moved, the suspension element 26 has a different position relative to the robot element 4. The force application device 30 aligns itself accordingly.

[0041] The force application device 30 is thus moved passively, depending on the position of the cable elements and the robot element 4. The first axis 50 of the force application device 30 is preferably arranged coaxially with the axis of the robot element 4. The second axis 52 is arranged orthogonally to the first axis 50.

[0042] In Fig. 3 shows the force application device 30 in more detail. The force application device 30 has at least one fixing device 220, at least one rotation device 200, and at least one suspension element 26.

[0043] The fixing device 220 can be clamped to the robot element 4. The at least one rotation device 200 is rotatable about a first axis 50 relative to the fixing device 220. The at least one suspension element 26 is pivotally mounted on the rotation device 200 about the second axis 52, wherein the second axis 52 extends orthogonally to the first axis 50.

[0044] The illustrated fixing device 220 is ring-shaped. The fixing device 220 can be slid onto a round, tubular structure, for example, on a robot arm.

[0045] The fixing device 220 is in Fig. 4 and can have at least one clamping device 226 by means of which the fixing device 220 can be clamped to the robot element 4.

[0046] The clamping connection 226 can preferably be a clamp connection, as shown, wherein the clamp connection preferably has a screw by means of which the clamp connection can be tightened. The clamping connection 226 can be tightened radially, and a frictional connection can be established through the contact force between the clamping connection 226 and the robot element 4.

[0047] The rotation device 200 can be mounted circumferentially around the fixing device 220 by means of a bearing, preferably a ball bearing. Thus, the rotation device 200 can be rotated axially around the fixing device 220 and around the robot element 4 by an angle α of 360 degrees or more.

[0048] At least one first angle sensor device 100 can be provided, which measures the angle of rotation α between the fixing device 220 and the rotating device 200. The first angle sensor device 100 can comprise a rotary encoder disk and a sensor unit. The rotary encoder disk can be connected to the fixing device 220, and the sensor unit can be attached to the rotating device 200.

[0049] Furthermore, at least one second angle sensor device 102 can be provided, which measures the angle of rotation θ between the rotation device 200 and the suspension element 26. The suspension element 26 is attached to the rotation device 200 in a tangentially rotatable manner. The suspension element 26 represents the connection of the force application device 30 to an external force application, which can be, for example, a cable connection.

[0050] Furthermore, a force sensor 28 can be provided which measures the force acting on the suspension element 26.

[0051] A safety rope guide 300 for a safety rope 345 may be provided. A safety rope guide 300 is shown in the Fig. 5 and Fig. 6 is shown in more detail.

[0052] The safety cable guide 300 can be arranged such that a safety cable 345 arranged in the safety cable guide 300 has no contact with the fixing device 220 during normal operation.

[0053] This safety cable guide 300 is preferably arranged on the rotation device 200. The safety cable guide 300 preferably secures a safety cable 345 during nominal operation. The safety cable 345 is secured such that it has no contact with the fixing device 220 or the robot element 4 to prevent friction.

[0054] The safety rope 345 is in the safety rope guide 300 between outer cover wings 310 and inner slide rails 320. The number of slide rails 320 is arbitrary, but there should be at least enough that the safety rope 345 does not touch the robot element 4.

[0055] The safety cable 345 serves as a redundant connection between the robot element 4 and an external force application. The safety cable 345 is designed as a loop that is guided around the robot element 4. The other end 340 of the safety cable 345 can be connected to the external force application. If the force application device 30 fails, for example, due to a break in the suspension element 26, the safety cable 345 tightens and the loop closes around the tubular robot element 4. This creates a secure connection between the force application and the robot element 4.

Claims

[1] Force application device for a robot system, wherein the force application device is connectable on the one hand to a robot device and on the other hand to a support device for the robot device, wherein at least one force can be applied from the support device to the robot device via the force application device, characterized by that the force application device - has at least one fixing device which is designed to be clamped to the robot element, - has at least one rotation device, wherein the rotation device is rotatable about a first axis relative to the fixing device, and - at least one suspension element which is pivotally mounted on the rotation device about a second axis, wherein the second axis is orthogonal to the first axis. [2] Force application device according to claim 1, characterized bythat the fixing device has at least one clamping device by means of which the fixing device can be clamped to the robot element. [3] Force application device according to claim 2, characterized by that the clamping connection is a clamp connection, wherein the clamp connection preferably has a screw by means of which the clamp connection can be contracted. [4] Force application device according to one of claims 1 to 3, characterized by that at least one bearing is provided between the fixing device and the rotating device, wherein the bearing is preferably a ball bearing. [5] Force application device according to one of claims 1 to 4, characterized by that the suspension element is attached to the rotation device in such a way that the suspension element is pivotable only about the second axis relative to the rotation device. [6] Force application device according to one of claims 1 to 5, characterized by that at least one first angle sensor device is provided which measures the angle of rotation between the fixing device and the rotation device. [7] Force application device according to one of claims 1 to 6, characterized by that at least one second angle sensor device is provided which measures the angle of rotation between the rotation device and the suspension element. [8] Force application device according to one of claims 1 to 7, characterized by that at least one force sensor is provided which measures the force acting on the suspension element. [9] Force application device according to one of claims 1 to 8, characterized by that a safety rope guide is provided for a safety rope. [10] Force application device according to claim 9, characterized bythat the safety rope guide is arranged in such a way that a safety rope arranged in the safety rope guide has no contact with the fixing device during normal operation. [11] Robot system, with a robot device, in particular a space robot device with at least one movable robot element and at least one actuator for moving the at least one robot element, a support device for supporting the robot device when using the space robot device in the gravitational field of the Earth, with at least one force application device according to one of claims 1 to 10, wherein the force application device is connected to the robot element at least at one point and applies at least one force to the robot element which at least partially compensates for the force of gravity acting on the robot element, [12] Robot system according to claim 11, characterized bythat the support device is a cable robot system having at least two cable elements connected to the force application device, wherein each cable element is connected to at least one motor that can move the respective cable element so that the direction and amount of force that can be applied to the robot element via the force application device can be adjusted.

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