Space handling device

Abstract

A space handling device (1; 101) with at least one articulated arm arrangement (3; 103, 203), which has at least one articulated arm (30, 34) and at least one coupling element (49) which is designed for coupling to a space object (2; 102), is characterized in that at least one attitude control device (5; 105) is provided on the articulated arm arrangement (3; 103, 203).

Description

The invention relates to a space handling device according to the preamble of claim 1, and it further relates to an arrangement comprising a space object and at least one such space handling device coupled thereto, and a space object having at least one such space handling device.Handling devices are often fixedly arranged on the outside of space stations, which are required for external work at the space station and which are usually formed by an articulated arm robot or comprise such a robot. It may also be necessary to temporarily provide or couple other space objects, such as satellites, to an external handling device, for example in order to carry out maintenance or repair work on the space object.Finally, special service spacecraft can also be provided, which are equipped with an external handling device in order to be able to grip and retain, for example, defective satellites or satellites to be maintained. In all these applications, movement of the manipulator causes a momentum to act on the space object to which the manipulator is attached or to which the manipulator is coupled. This pulse must usually be compensated by the position control means of the space object. However, the attitude control means of space objects, for example satellites, are often not designed to compensate for the pulses of a moving manipulator that is only temporarily coupled to the space object, or considerable energy resources of the space object are consumed for such compensation. Moreover, the attitude control means of the space object must be designed in the case of coupling to the manipulator and its movement, thus becoming larger and heavier.In the case of subsequent attachment of a handling device to a space object not originally designed for this purpose, its position control means are also not designed for the movement of the handling device. This can lead to the possibility that reaction wheels of the space object present can run into a saturation and that the fuel provided for position control engines is not sufficient or is consumed too much.It is useful to use the position control means of a satellite only for the daily orientation of the satellite and not for any special cases such as the attachment and operation of a manipulator to the structure of the satellite in order to compensate for the pulses produced thereby. This is the case above all when a handling device is used only for maintenance work on a satellite which is not designed for this purpose.From U.S. Pat. No. 6,285,928 B1 conventional attitude control devices of spacecraft are known, which control the angular momentum of the spacecraft and use reaction wheels, for example in a quad arrangement, which supply a momentum in different axes.U.S. Pat. No. 8,113,468 B2 discloses attitude control devices of spacecraft with gimbaled engines in combination with reaction wheel assemblies.WO 2016 / 128 389 A1 discloses a satellite which has electric engines which are mounted on an articulated arm which can be moved about a plurality of axes in order to be able to adjust the direction of thrust of these engines.DE 603 13 133 T2 shows and describes a system and a method for compensating dynamic imbalance. In this case, a satellite is equipped with a rotary assembly which is mounted asymmetrically thereon and can be rotated about an axis of rotation. Due to the rotational assembly mounted on the satellite asymmetrically to its spin axis, it causes a dynamic imbalance. The rotary assembly is therefore in turn provided with at least one impulse unit which is mounted on the rotary assembly by means of a gimbal unit and which is designed to generate a compensation torque which compensates for the dynamic imbalance.U.S. Pat. No. 5,390,288 A discloses a control device for a space handling robot, which control device has a first sensor for determining the position and speed of the satellite carrying the handling robot and a second optical sensor for determining the position and speed of a target body to be gripped by the handling robot and moving through the space independently of the satellite. Based on the position and speed data detected by these sensors, the handling robot is controlled to grip the target body.It is an object of the present invention to provide an improved space handling apparatus which can be easily attached to a space object or with which a space object can be easily retrofitted, and an arrangement comprising a space object and such a space handling apparatus and a space object with such a space handling apparatus.The part of the object directed to the space handling device is achieved with the features of claim 1. the part of the object directed to the arrangement of a space object and such a space handling device is achieved with the features of claim 9 and the part of the object directed to the space object with such a space handling device is achieved with the features of claim 10.A space handling device according to the invention is provided with at least one articulated arm arrangement which has at least one articulated arm and at least one coupling element which is designed for coupling to a space object, and is distinguished according to the invention in that at least one position control device is provided on the articulated arm arrangement.The provision according to the invention of a separate position control device on the articulated arm arrangement makes the space handling device autonomous with regard to position control, so that the position control means of a space object, for example a satellite to which the space handling device is temporarily or permanently attached, are not subjected to position control tasks which are required by the operation of the space handling device in order to stabilize the position of the space object provided with the space handling device in space. The outer space handling device forming a robot, for example, can thus compensate for disturbances in the overall system of outer space object and outer space handling device itself caused by their movements.Further preferred and advantageous design features of the outer space handling device according to the invention are the subject matter of the dependent claims 2 to 8.The position regulating device preferably has at least one reaction wheel which is rotatable about an axis of rotation by means of a rotational drive. The position regulating device can also have two or three reaction wheels which are each rotatable about one of the three spatial axes and which each have their own rotation drive.It is also particularly advantageous if the position regulating device has a housing or a frame in which the at least one reaction wheel with the rotation drive assigned to it is provided.An embodiment of the invention is preferred in which the position control device is attached to an articulated arm or forms an articulated arm of the articulated arm arrangement.The position control device can be coupled or couplable to the articulated arm arrangement, preferably to an articulated arm or a gripper.The position control device can thus either be installed fixedly in the articulated arm or it can be located in a housing which can be gripped by the articulated arm arrangement and can grip and carry the articulated arm arrangement with it.It is also particularly advantageous if the position control device is arranged on the articulated arm arrangement such that it can rotate about an axis, for example an articulated arm longitudinal axis.The position control device is preferably provided at a free end of the articulated arm arrangement, wherein the latter is preferably provided with a handling means, in particular with a gripping arm or a tool holder.A position control device attached to an articulated arm or integrated into an articulated arm of the articulated arm arrangement is able to compensate the impulse in any direction thanks to the positionability and the orientability of the articulated arm.It is also advantageous if a manipulator articulated arm arrangement is provided in addition to the articulated arm arrangement having the position control device. These two articulated arm arrangements are preferably coupled to one another via a control device, so that the articulated arm arrangement having the position control device is synchronized with the manipulator articulated arm arrangement in such a way that the articulated arm arrangement provided with the position control device compensates the pulses and moments emanating from the manipulator articulated arm arrangement, so that they do not exert any influences on the position and orientation of a space object coupled to the space handling apparatus.Finally, it is also advantageous if control and drive means are provided which make the space handling device a separate and controlled moving spacecraft, whereby this becomes a maintenance and service spacecraft.One solution to the object underlying this invention relates to an arrangement comprising a space object, in particular a satellite or a space station, and at least one space handling device according to the invention coupled thereto. Such an arrangement can be formed in particular when the space handling device is to be attached or coupled to the space object only for a limited period of time.A further solution to the object underlying this invention relates to a space object, in particular a satellite or a space station, having at least one space handling device according to the invention, to which the space handling device is thus permanently attached.By using the own attitude control device, the space handling apparatus can generate a torque both by the rotation speed of the reaction wheel in the attitude control device and by a rotation of the entire attitude control device and its rotation speed (gyroscope effect), which minimizes the torque exerted on the space object, for example the satellite, by the movement of the space handling apparatus, for example the robot.Preferred exemplary embodiments of the invention with additional design details and further advantages are described and explained in more detail below with reference to the attached drawing.It shows: FIG. 1 shows a first embodiment of a space handling apparatus constructed in accordance with the invention coupled to a satellite structure; FIG. 2A shows a schematic illustration of a position control device with a reaction wheel in a first side view; FIG. 2B shows a schematic illustration of the position control device from FIG. 2A in a second side view at right angles to the view from FIG. 2A ; FIG. 3 shows a second embodiment of a space handling device designed according to the invention and coupled to a satellite structure, and FIG. 4 shows a schematic illustration of a control circuit for controlling and regulating a space handling device according to the invention.FIG. 1 shows a first embodiment of a robotizing space handling apparatus 1 configured according to the invention coupled to a structure 20 of a space object 2, for example a satellite. This outer space handling device 1 has an articulated arm arrangement 3 with a central robot torso 4 and a first articulated arm 30 arranged thereon by means of a first torso joint 31 and a second articulated arm 34 arranged thereon by means of a second torso joint 35.The first articulated arm 30 comprises a first rigid articulated arm member 41 which is mounted on the robot torso 4 by means of the first torso joint 31. At the free end of the first articulated arm member 41, a second rigid articulated arm member 42 is mounted by means of a joint 32, and at the free end of the second articulated arm member 42, a third rigid articulated arm member 43 is mounted by means of a joint 33. At the free end of the third articulated arm member 43, a first gripper 44 is articulated by means of a gripper joint 34.The second articulated arm 34 is constructed in principle like the first articulated arm 30, except for the difference described below. The second articulated arm 34 comprises a first rigid articulated arm member 45 which is mounted on the robot torso 4 by means of the second torso joint 35. At the free end of the first articulated arm member 45 a second rigid articulated arm member 46 is mounted by means of a joint 36 and at the free end of the second articulated arm member 46 a third rigid articulated arm member 47 is mounted by means of a joint 37. At the free end of the third articulated arm member 47, in a deviation from the first articulated arm 30, a position regulating device 5 is mounted by means of a joint 38. At another end of the position control device 5, a second gripper 48 is articulated as an end effector by means of a second gripper joint 39.All joints of both the first articulated arm 30 and the second articulated arm 34 are designed as pivot joints and / or pivot joints, wherein a pivot joint enables a relative pivoting movement of the two elements of the articulated arm connected to it about a pivot axis which extends at right angles to the longitudinal axis of these elements, and wherein a pivot joint enables a relative rotational movement of the two elements of the articulated arm connected to it about an axis of rotation which extends parallel to the longitudinal axis or along the longitudinal axis of these elements. Each joint 31, 32, 33, 34, 35, 36, 37, 38, 39 is assigned at least one joint drive-not shown-which can generate a pivoting and / or rotational movement in the respectively assigned joint.In the example shown, the first gripper 44 forms a coupling element 49, with which the articulated arm arrangement 3 is coupled to the structure 20 of the space object 2; the articulated arm arrangement 3 is held with gripper 44 virtually firmly on the space object 2. Alternatively, the articulated arm arrangement 3 can also dock on the outer space object 2 by means of a docking element 40 provided on the robot torso 4.FIGS. 2A and 2B show a greatly simplified schematic illustration of the position control device 5 with a frame or a housing 51 which is designed as a cube in the example shown and a reaction wheel 50 which is rotatable about an axis of rotation Z by means of a bearing arrangement 53 which has a rotational bearing 52. For this purpose, the reaction wheel 50 is mounted on a shaft 54 which is in turn rotatably mounted in the rotational bearing 52. The shaft 54 is rotationally operatively coupled to the rotatable rotor 55 of a drive device 56, which is formed by an electric motor, for example. The drive device 56 is functionally connected wirelessly or in a wired manner to a control device 6 provided in the central robot torso in order to receive control signals from the control device 6. The control device 6 is also coupled to the respective joint drives of the individual joints 31, 32, 33, 34, 35, 36, 37, 38, 39 for the transmission of control signals.The mode of operation of such a position control device with a reaction wheel is generally known to the person skilled in the art and is therefore not explained in greater detail here.The housing 51 of the position control device 5 is provided on two sides facing away from each other with a docking module 57, 58, respectively, which is coupled to the adjacent joint 38 or 39, respectively, in the example of FIG. 1. Preferably, the housing 51 can be pivoted about the respective adjacent joint 38, 39 and rotated in the docking modules 57, 58 about a common axis of rotation X of the docking modules 57, 58 situated opposite one another.Although the position control device 5 is shown in the figures only with one reaction wheel 50, the position control device 5 can also have, preferably in the housing 51, two or three reaction wheel arrangements 59 of the same construction as described above, the axes of rotation of which are at right angles to one another and are aligned in three spatial coordinate directions running orthogonally to one another.The space handling device 1 shown is particularly suitable as a robot which is docked for mounting purposes or service work on the space object 2, for example a satellite. In the example shown in FIG. 1, the outer space handling device 1 is coupled with its first gripper 44 to a structure 20 of the outer space object 2. This robot may already be present on the satellite from the beginning or it may have been brought there by a service satellite.The space handling device 1 can move almost arbitrarily relative to the space object 2 to which it is docked by means of the joint drive and can perform work in space or on the space object 2 by means of its free end effector, for example the second gripper 48. In this case, movements of the space handling device 1 carried out trigger pulses and torques which, in a conventional articulated arm robot coupled to a satellite, would have an effect on the position of the satellite in space and would change it, so that the position control means of the satellite would have to compensate for this. In the outer space handling device 1 of the invention, on the other hand, pulses and torques caused by the movements of the outer space handling device 1 are compensated by the position control device 5 integrated into the outer space handling device 1 itself or coupled thereto, so that they do not influence the position and orientation of the outer space object 2 in space at all.The reaction wheel 50 of the position control device 5 generates a torque by its rotation and by changes in speed. The rotational speed is controlled by the control device 6 and the drive device 56 coupled to it. The bearing arrangement 53 and the housing 51 take over the force transmission of the generated torque, which is passed on to the articulated arm arrangement 3 via the docking modules 57, 58.FIG. 3 shows an alternative embodiment of a outer space handling device 101 according to the invention with a first articulated arm arrangement 103 and a second articulated arm arrangement 203. Further articulated arm arrangements can also be provided. The articulated arm arrangements 103, 203 are in principle constructed in the same way as the articulated arm arrangement 3 in FIG. 1 and for this purpose consist of articulated arm members connected to one another via joints. Each articulated arm arrangement 103, 203 forms a separate robot mounted stationary or temporarily on the structure 120 of the space object 102 by means of a respective docking station 149, 249. The position control device 105 having at least one reaction wheel 150 is attached to the free end of the first articulated arm 103, which position control device is constructed and functions in the same way as the position control device 5 described in connection with FIGS. 1, 2A and 2B. A gripper 248 or a tool holder is provided as an end effector at the free end of the second articulated arm arrangement 203, so that this second articulated arm arrangement 203 can perform manipulation tasks.A control device-not shown-controls and synchronizes the movements of the articulated arm arrangements 103, 203 and controls the drive device of the reaction wheel 150 of the position regulating device 105 in order to compensate for movement-related pulses and torques of the space handling apparatus 101 so that they do not substantially act on the space object 102. The first articulated arm arrangement 103 equipped with the position control device 105 thus compensates for the movements of the second articulated arm arrangement 203. As in the example of FIG. 1, the control device also controls the joints of the articulated arm arrangements 103, 203. When the second articulated arm arrangement 203 of the outer space handling apparatus 101 now moves, the first articulated arm arrangement 103 equipped with the position control device 105 can move in such a way that the effects of the reaction wheel 150 in the position control device 105 minimize the rotational effects of the entire outer space handling apparatus 101 on the outer space object 102. Consequently, counter-torques to the torques induced by the movement of the articulated arm arrangements 103, 203 are generated by the position control device 105. The invention thus enables both new control concepts and also utilization of independent robot groups, which do not have to coordinate their movement to position control of the space object.FIG. 4 schematically shows a control circuit for position control of the outer space handling device 1, 101 according to the invention. The input of the control loop forms a base position and orientation of the space object 2, 102 at an initial time T=0 or any desired end position and orientation of the space object 2, 102 at the respective time T=t and the position and orientation of the end effector at the respective time. These predetermined values are compared against the measured values X e( t), X b( t). Using the difference, a computer of the control device 6 calculates either the desired speed or the desired torque of the reaction wheel 50, 150. These values are then fed into the system.In FIG. 4, X desired target position X measured position e end effector b base q common vector r vector of the reaction wheel.Reference numerals in the claims, the description and the drawings are used merely for better understanding of the invention and are not intended to limit the scope of protection.List of reference characters1 Outer space handling device 2 outer space object 3 articulated arm arrangement 4 central robot torso 5 position control device 6 control device 20 structure of 2 30 first articulated arm 31 first torso joint 32 joint 33 joint 34 second articulated arm 35 second torso joint 36 joint 37 joint 38 joint 39 second gripper joint 40 docking element 41 first rigid articulated arm member 42 second rigid articulated arm member 43 third rigid articulated arm member 44 first gripper 45 first rigid articulated arm member 46 second rigid articulated arm member 47 third rigid articulated arm member 48 second gripper 49 coupling element 50 reaction wheel 51 housing 52 rotational bearing 53 bearing arrangement 54 shaft 55 rotatable rotor 56 drive device 57 docking module 58 docking module 59 reaction arrangements 101 outer space handling device 102 outer space object 103 first articulated arm arrangement 105 position control device 120 structure of 102 150 Reaction wheel 203 Second articulated arm arrangement 248 Gripper X Axis of rotation Z Axis of rotation

Claims

Space handling apparatus (1; 101) having at least one articulated arm arrangement (3; 103, 203) which has at least one articulated arm (30, 34) and at least one coupling element (49) which is designed for coupling to a space object (2; 102), characterized in that at least one position control device (5; 105) is provided on the articulated arm arrangement (3; 103, 203).Outer space handling apparatus (1; 101) according to claim 1, characterised in that the position regulating device (5; 105) has at least one reaction wheel (50; 150) which is rotatable about an axis of rotation (Z) by means of a rotational drive (56).Outer space handling device (1; 101) according to claim 1 or 2, characterized in that the position control device (5; 105) is attached to an articulated arm (30, 34) or forms an articulated arm (30, 34) of the articulated arm arrangement (3; 203).Outer space handling device (1; 101) according to claim 1 or 2, characterised in that the position control device (5; 105) is or can be coupled to the articulated arm arrangement (3; 203).Outer space handling device (1; 101) according to claim 3 or 4, characterised in that the position control device (5; 105) is arranged on the articulated arm arrangement (3; 103, 203) such that it can rotate about an axis (X).Outer space handling device (1; 101) according to one of the preceding claims, characterized in that the position control device (5; 105) is provided at a free end of the articulated arm arrangement (3) and the latter is preferably provided with a handling means, in particular with a gripping arm (48) or a tool holder.Outer space handling device (1; 101) according to one of the preceding claims, characterized in that a manipulator articulated arm arrangement (203) is provided in addition to the articulated arm arrangement (103) having the position control device (105).Space handling device (1; 101) according to one of the preceding claims, characterized in that control and drive means are provided which make the space handling device (1; 101) a separate and controlledly movable spacecraft.Arrangement comprising a space object (2; 102), in particular a satellite or a space station, and at least one space handling device (1; 101) according to one of the preceding claims coupled thereto.A space object (2; 102), in particular satellite or space station, having at least one space handling device (1; 101) according to one of claims 1 to 7.

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