EP-4739580-A1 - SPLIT STEWART PLATFORM SERVICER CAPTURE MECHANISM AND ASSOCIATED METHODS

Abstract

A capture system attachable to a servicer spacecraft for capturing and controlling a space object includes three triangular arm assemblies. Each triangular arm assembly is independently controllable and includes a cross brace and two linear actuator struts, attached together at one end to form an apex, and connected with the cross brace via joints at the opposing end. The triangular arm assembly further includes an end effector, connected with the two linear actuator struts at the apex. The capture assembly is maneuvered to the space object to enable the end effector to grapple onto a feature of the space object without a priori knowledge of a specific shape of the feature of the space object. An associated method is also disclosed.

Inventors

• HOWARD, Russell Duane
• Wilson, Kieran

Assignees

• Katalyst-Atomos Transition, LLC

Dates

Publication Date

20260513

Application Date

20240703

Claims (15)

1. 1. A capture system attachable to a servicer spacecraft for capturing and controlling a space object by the servicer spacecraft, the capture system comprising: three triangular arm assemblies, each one of the three triangular arm assemblies including a cross brace, two linear actuator struts, each one of the two linear actuator struts including a first end and a second end, the first ends of the two linear actuator struts being attached together to form an apex, and each one of the second ends of the two linear actuator struts being connected with the cross brace via a joint, and an end effector connected with the two linear actuator struts at the apex, wherein each one of the three triangular arm assemblies is independently controllable for maneuvering the end effector on each one of the three triangular arm assemblies toward the space object to enable the end effector to grapple onto a feature of the space object without a priori knowledge of a specific shape of the feature of the space object.
2. 2. The capture system of claim 1, wherein the end effector includes a wrist joint.
3. 3. The capture system of claim 2, wherein the wrist joint is spring-loaded to a nominal position.
4. 4. The capture system of claim 1, wherein the end effector includes a grip actuator configured for capturing the feature and rigidizing a grasp on the feature, once the feature has been captured by the grip actuator.
5. 5. The capture system of claim 1, wherein at least one of the two actuator struts includes at least one of a telescoping ball screw linear actuator, an extendable truss, a rotary joint.
6. 6. The capture system of claim 5, wherein each one of the three triangular arm assemblies is configured to maneuver the end effector toward the feature with six degrees of freedom.
7. 7. The capture system of claim 1, wherein the end effector associated with each one of the three triangular arm assemblies is configured to capture a different portion of the feature of the space object from the end effector of associated with the other ones of the three triangular arm assemblies.
8. 8. The capture system of claim 1, wherein the three triangular arm assemblies are further configured to maneuver the space object to a predetermined attitude and distance with respect to the servicer spacecraft.
9. 9. A method for capturing and controlling a space object using a servicer spacecraft, the method comprising: providing a capture system including three triangular arm assemblies, each one of the three triangular arm assemblies including a cross brace, two linear actuator struts, each one of the two linear actuator struts including a first end and a second end, the first ends of the two linear actuator struts being attached together to form an apex, and each one of the second ends of the two linear actuator struts being connected with the cross brace via a joint, and an end effector connected with the two linear actuator struts at the apex, attaching the capture system to the servicer spacecraft, independently maneuvering the end effector on each one of the three triangular arm assemblies toward the space object, and grappling a feature of the space object with the end effector on each one of the three triangular arm assemblies, wherein grappling is performed without a priori knowledge of a specific shape of the feature of the space object.
10. 10. The method of claim 9, further comprising maneuvering the space object to a predetermined attitude and distance with respect to the servicer spacecraft.
11. 11. A capture system attachable to a servicer spacecraft for capturing and controlling a space object by the servicer spacecraft, the capture system comprising: at least two triangular arm assemblies, each one of the two triangular arm assemblies including a cross brace, two linear actuator struts, each one of the two linear actuator struts including a first end and a second end, the first ends of the two linear actuator struts being attached together to form an apex, and each one of the second ends of the two linear actuator struts being connected with the cross brace via a joint, and an end effector connected with the two linear actuator struts at the apex, wherein each one of the two triangular arm assemblies is independently controllable for maneuvering the end effector on each one of the two triangular arm assemblies toward the space object to enable the end effector to grapple onto a feature of the space object without a priori knowledge of a specific shape of the feature of the space object, and wherein the capture system further comprises a third arm assembly having at least three actively-controlled degrees of freedom.
12. 12. The capture system of claim 11, wherein the third arm assembly includes at least one of a third triangular arm assembly and a robotic arm assembly, and wherein each one of the two triangular arm assemblies and the third arm assembly is configured to maneuver the end effector toward the feature with six degrees of freedom.
13. 13. The capture system of claim 11, wherein the end effector includes a wrist joint.
14. 14. The capture system of claim 13, wherein the wrist joint is spring-loaded to a nominal position.
15. 15. The capture system of claim 11, wherein the end effector includes a grip actuator configured for capturing the feature and rigidizing a grasp on the feature, once the feature has been captured by the grip actuator.

Description

Split Stewart Platform Servicer Capture Mechanism and Associated Methods REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the benefit of US Provisional Pat. App. No. 63/524,808, filed 2023-07-03 and titled "Split Stewart Platform Servicer Capture Mechanism and Associated Methods," which application is incorporated hereby in its entirety by reference. FI ELD OF TH E I NVENTION [0002] The present invention relates to grappling mechanisms. In particular, but not by way of limitation, the present invention relates to grappling mechanisms for use in space rendezvous and capture operations. DESCRIPTION OF RELATED ART [0003] Grappling mechanisms are frequently used in space rendezvous and capture operations, such as the rendezvous of a servicer satellite with a client satellite. Such grappling operations are difficult as adjustment and control are required in multiple dimensions. While a variety of grappling and capture systems exist, there is still a need for an improved servicer capture mechanism to accommodate a variety of capture features on target objects while enabling flexible yet precise control over preferably six degrees of freedom. SU M MARY OF TH E I NVENTION [0004] The following presents a simplified summary relating to one or more aspects and/or embodiments disclosed herein. As such, the following summary should not be considered an extensive overview relating to all contemplated aspects and/or embodiments, nor should the following summary be regarded to identify key or critical elements relating to all contemplated aspects and/or embodiments or to delineate the scope associated with any particular aspect and/or embodiment. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects and/or embodiments relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below. [0005] In an embodiment, a capture system attachable to a servicer spacecraft for capturing and controlling a space object by the servicer spacecraft is disclosed. The capture system includes three triangular arm assemblies. Each one of the three triangular arm assemblies includes a cross brace and two linear actuator struts. Each one of the two linear actuator struts includes a first end and a second end, with the first ends of the two linear actuator struts being attached together to form an apex. Each one of the second ends of the two linear actuator struts are connected with the cross brace via a joint. Each one of the three triangular arm assemblies further includes an end effector, which end effector is connected with the two linear actuator struts at the apex. Further, each one of the three triangular arm assemblies is independently controllable for maneuvering the end effector on each one of the three triangular arm assemblies toward the space object to enable the end effector to grapple onto a feature of the space object without a priori knowledge of a specific shape of the feature of the space object. [0006] In certain embodiments, the end effector includes a wrist joint. In embodiments, the wrist joint is spring-loaded to a nominal position. [0007] In a further embodiment, the end effector includes a grip actuator configured for capturing the feature and rigidizing a grasp on the feature, once the feature has been captured by the grip actuator. [0008] In certain embodiments, at least one of the two actuator struts includes at least one of a telescoping ball screw linear actuator, an extendable truss, a rotary joint. In embodiments, each one of the three triangular arm assemblies is configured to maneuver the end effector toward the feature with six degrees of freedom. [0009] In embodiments, the end effector associated with each one of the three triangular arm assemblies is configured to capture a different portion of the feature of the space object from the end effector of associated with the other ones of the three triangular arm assemblies. [0010] In certain embodiments, the three triangular arm assemblies are further configured to maneuver the space object to a predetermined attitude and distance with respect to the servicer spacecraft. [0011] In another embodiment, a method for capturing and controlling a space object using a servicer spacecraft is disclosed. The method includes providing a capture system including three triangular arm assemblies. Each one of the three triangular arm assemblies includes a cross brace and two linear actuator struts. Each one of the two linear actuator struts includes a first end and a second end, wherein the first ends of the two linear actuator struts being attached together to form an apex and each one of the second ends of the two linear actuator struts being connected with the cross brace via a joint. Each one of the three triangular arm assemblies furth includes an end effector connected with the two linear actuator struts at the apex. The method furthe