Design of a novel deployable mechanism for capturing tumbling debris

Abstract

Large quantities of man-made debris from decades of space exploration threaten the safety of future space activities. It is therefore urgent to perform active debris removal missions to maintain access to usable orbital space. This paper proposes a novel deployable end-effector and detumbling mechanism to capture tumbling debris. Three mechatronic subsystems for capture, transmission, and actuation are highly integrated in the end-effector, allowing compact storage during space transport. Grippers composed of constant-torque hinges endow the mechanism with a deployable function and ensure a steady envelope by means of caging, without the need for precise tracking and complex control. With only one actuator, simultaneous motion of the six grippers is implemented by arranging gears in a unique manner. The grippers are optimally designed to enlarge their envelope while reducing weight. A contact detumbling mechanism, composed of three dampers along three axes, is also provided based on revolute friction to slow tumbling debris with residual angular momentum. Two slip rings are ingeniously embedded in each damper to transmit electricity under conditions of signal interference and cable interwinding. Simulations of capturing and detumbling demonstrate the feasibility and effectiveness of the proposed mechanism.

Constant Torque Mechanisms: A Survey

“…The Power Assistance Mechanisms can provide their power in one or both angular directions. An example of a one-way mechanism is a Deploy mechanism, like e.g., in aerospace appendages [10][11][12] where the constant torque mechanism, usually a constant torque spring, provides the energy to deploy the solar panels of a satellite. This one-way assistance can also be found in reeling systems, like e.g., in fishing lines, automotive hoods, dog leashes, measuring tape or seat belts, and in several winding toys where a constant torque mechanism, usually a specially tied rubber band or small constant torque spring, is used as an elastic motor to drive the toy [13][14][15].…”

“…The B-motor configuration, on the other hand, produces the highest torque of both types. This implies that this configuration is mostly used in applications requiring significant torque and energy (e.g., space applications [10][11][12]14] and robotics [3,5]). The torque of a constant torque spring in the B-motor configuration is given by…”