A device for maintaining a robot arm in at least one predefined position for use in aerospace applications, including robot arms and spacecraft.

Abstract

A device for maintaining a robot arm (600) in at least one predefined position for aerospace use, said robot arm (600) having several robot elements (610, 612, 614, 616, 618) connected to each other by means of robot joints (602, 604, 606, 608), and the device (200) having a removable locking device that locks by complementary shape; a robot arm (600) for aerospace use, said robot arm (600) having several robot elements (610, 612, 614, 616, 618) connected to each other by means of robot joints (602, 604, 606, 608), and such a device (200); and a spacecraft comprising at least one such robot arm. (600). Fig. 7

Description

Title of the invention: Device for maintaining a robot arm in at least one predefined position for use in aerospace, robot arm and spacecraft applications

[0001] The present invention relates to a device for maintaining a robot arm in at least one predefined position for aerospace applications. The present invention further relates to a robot arm for aerospace use. The present invention further relates to a spacecraft.

[0002] When using robot arms on Earth, it is always possible to use brakes to immobilize the robot arm if necessary for safety reasons or other requirements. These brakes generally consist of brake pads and a brake disc, the friction of which allows for locking or braking. For aerospace applications using robot arms, additional aspects must be taken into account. On the one hand, the formation of brake dust must be absolutely avoided. On the other hand, it must be ensured that the brake can be released as well as activated under all circumstances, which is not so easy with conventional braking mechanisms. In space, however, it is imperative to brake or immobilize a robot arm to prevent any unwanted movement.This may be necessary, for example, when a satellite is captured in space with the robotic arm and the service satellite system and the captured target satellite must be safely brought to burn up in the Earth's atmosphere.

[0003] In space, additional specific challenges arise: The extreme environment of space, with its vacuum, weightlessness, extreme temperature fluctuations, and ionizing radiation, demands special manufacturing conditions. Conventional pneumatic or hydraulic drive systems are problematic due to the risk of leakage and the risk of working fluids freezing. Furthermore, absolute freedom from contamination is necessary, as even the smallest particles can damage sensitive sensors or optical systems. Maintenance-free operation is essential because repairs are not possible in space. At the same time, the highest reliability requirements must be met, as a failure of the locking device can lead to the failure of an entire space mission.

[0004] Solutions known from prior art, such as those developed, for example, for direct-drive industrial robots, generally use pneumatic or hydraulic cylinders with complex receiving and locking systems that have active drive units. In this context, it is Referred to document DE 10 2018 110 079 A1, which concerns a safety device for a manipulator, such as an industrial robot, particularly one with direct drive. The safety device comprises at least one receiving unit, at least one locking unit, and at least one drive unit. The receiving unit is rotationally fixed to a first manipulator arm. The locking unit is rotationally fixed to a second manipulator arm, which can be moved relative to the first manipulator arm via a joint around a rotation and / or pivot axis by means of a manipulator drive, particularly a direct drive. The locking unit can be moved from a release position to a locking position by means of the drive unit.In the release position, the first and second manipulator arms are allowed to move, specifically to rotate, relative to each other. In the locking position, the locking unit engages with the receiving unit transversely to the direction of movement, specifically to the direction of rotation around the axis of rotation and / or pivoting, forming a rearward grip, and prevents movement of the first and second manipulator arms relative to each other, particularly around the axis of rotation and / or pivoting. However, such systems are unsuitable for aerospace applications because they are prone to leaks, require working fluids that can outgas or freeze in a vacuum, and require extensive maintenance due to their complexity.

[0005] The present invention aims to structurally and / or functionally improve the device mentioned in the preamble. The present invention further aims to structurally and / or functionally improve the robotic arm mentioned in the preamble. The present invention further aims to structurally and / or functionally improve the spacecraft mentioned in the preamble.

[0006] Advantageous embodiments and / or further developments of the present invention are described below.

[0007] The device according to the present invention makes it possible to maintain a robot arm in at least one predefined position for aerospace applications. The robot arm comprises several robot elements. The robot elements are connected to each other by means of robot joints. The device includes a removable locking device that locks by complementary shape.

[0008] Unlike known pneumatic or hydraulic drive systems, the locking device of the device according to the present invention can operate entirely mechanically and is therefore suitable for vacuum applications, maintenance-free, and completely free from contamination. The locking device can be used both in a normally locked (fail-safe) configuration and in a normally released configuration, depending on the mission requirements.

[0009] According to one embodiment, the locking device may have at least one perforated disc. The locking device may have at least one locking bolt. The at least one locking bolt may be moved between a release position and a locking position. The locking action by complementary shape of the locking device may be achieved by engaging the at least one locking bolt in corresponding recesses or slots. The locking bolt may be arranged transversely to a direction of movement of a robot element to be immobilized. This arrangement ensures reliable force transmission without wear from friction and prevents the formation of particles. The locking device may have one perforated disc and at least one locking bolt for each robot joint.At least one locking bolt can be moved in the extension direction of its longitudinal axis. The bidirectional drive of the locking bolt allows both tightening and loosening of the connection through corresponding stress in both directions. At least one locking bolt can be moved passively under the effect of a preload force and / or actively using an actuating device.

[0010] According to one embodiment, the at least one perforated disc may have at least one hole. The at least one perforated disc may have several holes. The holes may be arranged evenly in the circumferential direction. The holes may be arranged uniformly in the circumferential direction. The at least one locking bolt may correspond to the at least one hole. The at least one locking bolt may be designed and / or installed to engage with the at least one hole in order to secure the robot arm.

[0011] According to one embodiment, at least one locking bolt may have a conical end associated with at least one perforated disc. At least one locking bolt may also have a spherical cross-section end associated with at least one perforated disc.

[0012] According to one embodiment, the locking device may have at least one mechanical energy accumulator. The at least one mechanical energy accumulator may be designed and / or installed to exert force on the at least one locking bolt. The at least one mechanical energy accumulator may be designed and / or installed to exert force on the at least one locking bolt in the direction of the locking position. The at least one mechanical energy accumulator may be designed and / or installed to exert force on the at least one locking bolt in the direction of the release position. The at least one mechanical energy accumulator may have at least one spring. The at least one spring may be made in the form of a compression spring and / or a helical spring. The mechanical energy accumulator can be designed and / or implemented to store energy over long periods without requiring a working fluid.

[0013] According to one embodiment, the device may have at least one retention / release device. The retention / release device may also be called a Hold Down and Release Mechanism (HDRM). The retention / release device may be designed and / or implemented to hold and / or release at least one locking bolt. The retention / release device may be designed and / or implemented to hold at least one locking bolt in the release position and / or to allow movement in the locked position. The retention / release device may be designed and / or implemented to hold at least one locking bolt in the release position and / or to allow movement in the locked position.The retention / release device can meet the stringent requirements of aerospace technology and be implemented in accordance with established aerospace standards (such as ECSS-E-ST-33-01C). The retention / release device can be specifically developed for use in spacecraft and characterized by its reliability, redundancy, and low-shock activation. Unlike industrial locking devices or safety mechanisms, the retention / release device must be qualified for the extreme conditions of space and operate for years without maintenance. The retention / release device can operate without pyrotechnics and can be implemented, for example, using shape memory alloy (SMA) elements, paraffin actuators, or other proven aerospace technologies.This ensures controlled and repeatable detonation without the drawbacks of explosive devices or other single-use elements.

[0014] According to one embodiment, the locking device can be redundant, with several independent locking bolts and / or several independent mechanical energy accumulators being provided. This ensures the functionality of the system even in the event of failure of certain components. The redundancy can be implemented both as active redundancy, in which all systems operate simultaneously, and as passive redundancy, in which backup systems are activated if necessary.

[0015] According to one embodiment, all components of the blocking device can be manufactured from space-qualified materials. Such materials can be designed and / or adapted to withstand extreme temperature ranges from -150°C to +120°C and / or be resistant to ionizing radiation. The materials used can exhibit minimal outgassing properties and meet to space-specific requirements, for example to the NASA Outgassing Database (ASTM E595).

[0016] According to one embodiment, the locking device can be thermally designed so that it functions reliably even under extreme temperature fluctuations. At least one mechanical energy accumulator can be sized so that it retains its spring force even at low temperatures. If necessary, a heating device and / or thermal insulation can be provided.

[0017] According to one embodiment, all moving parts can be arranged so as to prevent particle generation. All surfaces can be coated with a suitable coating to prevent particle emission. The locking device can operate completely without lubricant to prevent outgassing into the vacuum.

[0018] The objective of the present invention is further achieved by a robotic arm designed and / or capable of being deployed for aerospace use. The robotic arm can be designed and / or deployed to grasp and / or hold space objects. The robotic arm comprises several robotic elements. The robotic elements are connected to each other by means of robotic joints. Two robotic elements can each be connected to each other by means of a robotic joint. The robotic arm comprises the device according to the present invention.

[0019] The objective of the present invention is further achieved by a spacecraft comprising at least one such robotic arm. The spacecraft may be a space vehicle, a space station, a space probe, an artificial satellite, for example a service satellite, or a rover. According to one embodiment, the device may be designed and / or deployed to immobilize a robotic arm during critical maneuvers, such as trajectory changes, to hold a payload during interorbital transport, and / or to provide secure positioning during docking or coupling maneuvers. During space missions for satellite repair or maintenance, the robotic arm may be immobilized during work phases to allow for precise operations.

[0020] According to one embodiment, the device can be designed and / or deployed for on-orbit servicing missions in which autonomous or semi-autonomous operations are performed. For this purpose, the reliability of the jamming device is critical, as malfunctions cannot be corrected by human intervention. Mechanical energy storage enables safe functionality even in the event of a power failure or communications interruption. In active space debris disposal scenarios, the jamming device can help keep captured objects securely in place while the combined system is oriented in a controlled manner for combustion in the Earth's atmosphere. The resulting accelerations and structural loads necessitate a particularly robust and reliable fixing.

[0021] In summary and in other words, the present invention provides, among other things, a device and / or a method for securing a robot arm.

[0022] In order to safely immobilize the robot arm without generating additional brake dust and while simultaneously ensuring a reliable braking function, a special mechanism comprising a spindle and a disc can be mounted on a joint of the robot. The disc may have bores at a predefined interval. This predefined interval between the bores can define the engagement positions of the "locking" brake.

[0023] A mechanism can be installed in addition to the disc, said mechanism being able to be constructed in various ways. For example, the mechanism comprises a spindle, a spring, and a locking and unlocking mechanism (HDRM). Such an HDRM can be fully qualified for the required space and environmental conditions. If the HDRM is triggered, the spindle moves toward the disc and engages in the corresponding holes in the disc. The holes can be precisely aligned beforehand, since an absolute position of a robot joint is always provided, thus ensuring that a final position of the robot arm is known.

[0024] On the one hand, the spindle can taper conically, which prevents torsion from being exerted, for example, even with considerable force, if the robot arm has grasped another satellite. Another spindle shape can be spherical at the tip. This spherical shape allows for clamping and, at the same time, enables rotation above the braking point with an increased, non-nominal force on the robot joint / motor. This is made possible by the fact that the spherical tip does not fully penetrate the disc. If force is applied, the spindle is pushed upwards by the spring force and again engages in the next hole of the disc. This also allows for subsequent adjustment. This may be necessary if the robot arm still needs to be moved despite the clamping.

[0025] The present invention enables a unique "shimming" at certain articulation positions of a robot arm in space, with the possibility of extending said method to reach other positions of the robot arm under certain conditions. The solution according to the present invention has, in particular, the following advantages: - Fully compatible with use in a vacuum without risk of leakage thanks to the absence of pneumatic or hydraulic working fluids. - Operation free from contamination and without generation of particles thanks to a blocking action by complementary shape and not by friction. - Maintenance-free operation throughout the mission thanks to mechanical energy storage. - Maximum reliability thanks to simple and proven mechanical principles. - Bidirectional functionality for both fail-safe and fail-operational configurations. - Weight optimization through the elimination of complex hydraulic or pneumatic systems. - Thermal stability in extreme space environments. - Implementation with the possibility of redundancy for critical missions. - Compatibility with established aerospace standards, such as ECSS. - Reproducible and controlled triggering, without pyrotechnic elements.

[0026] These advantages make the device according to the present invention particularly suitable for long-duration space missions, which require maximum reliability while requiring no maintenance.

[0027] Examples of embodiments of the present invention are described in more detail below with reference to the figures, which show schematically and by way of example: [Fig. 1] a perforated disc of a locking device of a device for holding a robot arm, [Fig.2] a device for holding a robot arm, with a locking device and a retention / release device, [Fig.3] a device for holding a robot arm, with a locking device and a retention / release device, [Fig.4] a locking device for a device used to hold a robot arm, with a perforated disc and a locking bolt with a spherical cross-section end, [Fig. 5] a locking device for a device used to hold a robot arm, with a perforated disc and a conical-ended locking bolt, [Fig. 6] a locking device for a device to hold a robot arm, with a perforated disc and two locking bolts and [Fig.7] a robot arm, with several robot elements, connected together using robot joints, and a device for holding the robot arm.

[0028] Figure 1 shows a perforated disc 100 of a locking device for a device used to hold a robot arm. The perforated disc 100 has holes distributed uniformly in the circumferential direction, such as hole 102.

[0029] Figures [2] and [3] show a device 200 for holding a robot arm with a locking device 202 and a retention / release device 204. The locking device 202 has a perforated disc 206, such as the perforated disc 100 according to [1], a locking bolt 208, and a mechanical energy accumulator 210. The locking bolt 208 can be moved between a release position and a locking position. The mechanical energy accumulator 210 is designed and / or arranged to exert force on the locking bolt 208 in the direction of the locking position. The retention / release device 204 is designed and / or arranged to hold the locking bolt 208 in the release position and / or to release the locking bolt 208 from the locking position. In [Fig.[2], the locking bolt 208 is held in the release position by means of the retention / release device 204, on [Fig.3], a movement of the locking bolt 208 into the locking position has been made possible.

[0030] Fig. 4 shows a locking device 300, such as the locking device 202 according to Fig. 2 and Fig. 3, of a device, such as the device 200 according to Fig. 2 and Fig. 3, for holding a robot arm, with a perforated disc 302, such as the perforated disc 206 according to Fig. 2 and Fig. 3, and a locking bolt 304, such as the locking bolt 208 according to Fig. 2 and Fig. 3, having an end in the form of a spherical section 306.

[0031] Fig. 5 shows a locking device 400, such as the locking device 202 according to Fig. 2 and Fig. 3, of a device, such as the device 200 according to Fig. 2 and Fig. 3, for holding a robot arm, with a perforated disc 402, such as the perforated disc 206 according to Fig. 2 and Fig. 3, and a locking bolt 404, such as the locking bolt 208 according to Fig. 2 and Fig. 3, having a conical end 406.

[0032] Fig. 6 shows a locking device 500, such as the locking device 202 according to Fig. 2 and Fig. 3, of a device such as the device 200 according to Fig. 2 and Fig. 3, for holding a robot arm, with a perforated disc 502, such as the perforated disc 206 according to Fig. 2 and Fig. 3, and two locking bolts 504, 506.

[0033] Figure 7 shows a robot arm 600, with several robot elements 610, 612, 614, 616, 618, connected to each other by means of robot joints 602, 604, 606, 608, and a device for holding the robot arm. The device has a locking device, such as the locking device 202 according to [Fig.2] and [Fig.3], with a perforated disc and a locking bolt for each robot joint 602, 604, 606, 608.

[0034] Numerical references 100 Perforated Disc 102 Hole 200 Device 202 Locking device 204 Detention / Release Device 206 Perforated disc 208 Locking bolt 210 Energy accumulator 300 Locking device 302 Perforated disc 304 Locking Bolt 306 Extremity 400 Locking device 402 Perforated disc 404 Locking Bolt 406 Extremity 500 Locking device 502 Perforated disc 504 Locking Bolt 506 Locking Bolt 600 Robot Arms 602 Robot Articulation 604 Robot Articulation 606 Robot Articulation 608 Robot Articulation 610 Robot element 612 Robot element 614 Robot element 616 Robot element 618 Robot element

Claims

Demands

1. Device (200) for maintaining a robot arm (600) in at least one predefined position in the context of an aerospace use, in which the robot arm (600) has several robot elements (610, 612, 614, 616, 618) connected to each other by means of robot joints (602, 604, 606, 608), characterized in that the device (200) has a removable locking device (202, 300, 400, 500) that locks by complementary shape.

2. Device (200) according to claim 1, characterized in that the locking device (202, 300, 400, 500) has at least one perforated disc (100, 206, 302, 402, 502) and at least one locking bolt (208, 304, 404, 504, 506) that can be moved between a release position and a locking position.

3. Device (200) according to claim 2, characterized in that at least one perforated disc (100, 206, 302, 402, 502) has several holes (102).

4. Device (200) according to at least one of claims 2 to 3, characterized in that at least one locking bolt (208, 304, 404, 504, 506) has a conical or partially spherical end (306, 406) associated with at least one perforated disc (100, 206, 302, 402, 502).

5. Device (200) according to at least one of claims 2 to 4, characterized in that the locking device (202, 300, 400, 500) has at least one mechanical energy accumulator (210) which is designed and / or installed to stress at least one locking bolt (208, 304, 404, 504, 506) in the direction of the locking position.

6. Device (200) according to at least one of claims 2 to 5, characterized in that the device (200) has at least one retention / release device (204) which is designed and / or installed to retain at least one locking bolt (208, 304, 404, 504, 506) in the release position and / or to release its movement in the locking position.

7. Robot arm (600) for aerospace use, wherein the robot arm (600) has several robot elements (610, 612, 614, 616, 618) connected to each other by means of robot joints (602, 604, 606, 608), characterized in that the robot arm (600)

8. presents a device (200) according to at least one of the preceding claims. Spacecraft, characterized in that the spacecraft has at least one robot arm (600) according to claim 7.

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