Jan-C. Meyer 11.05.2015, Noordwijk

Tentacles based clamping mechanism for ADR ASTRA 2015

OHB System AG

Active Debris Removal – Mechanism

Slide 2

≠

Tentacles based clamping mechanism - Introduction

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Agenda

Slide 3

Introduction

Mechanism requirements

Trade-off and baseline selection

Multi-body simulation

Mechanism Design

Tentacles based clamping mechanism

ASTRA 2015, ESTEC, 11.05.2015

Mechanism Requirements

Introduction

Mechanism requirements

Trade-off and baseline selection

Multi-body simulation

Mechanism Design

OHB System AG

Requirements Categorisation

Slide 5

The functionalities reveal three main categories of requirements necessary to provide a full picture of the system. These are as follows:

Mechanism system requirements

Target interface requirements

Chaser interface requirements

Tentacles based clamping mechanism – Mechanism requirements

Chaser

Mechanism System Requirements

Chaser Interface Requirements

Target Interface Requirements

Target

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Driving Requirements

Slide 6

Clamping mechanism

Target shape and kinematic properties •In line with ESA‘s e.Deorbit study

Target pose uncertainty •Indirect requirement on the capture time

Link stiffness Forces and

torques to be transferred

Capability of releasing the target after clamping

Chaser and launcher

requirements

Tentacles based clamping mechanism – Mechanism requirements

ASTRA 2015, ESTEC, 11.05.2015

Trade-off and baseline selection

Introduction

Mechanism requirements

Trade-off and baseline selection

Multi-body simulation

Mechanism Design

OHB System AG

Trade-off methodology and criteria

Slide 8

Six categories of criteria

S/C interface rates the constraints put on the chaser platform

Fexibility indicates the mechanism‘s ability to adjust its position on the target

Weights are determined by pairwise comparison between the criteria

Tentacles based clamping mechanism – Trade-off

criteria

options

Mechanism baseline selection

0.176

0.028

0.127

0.141

0.302

0.226

0.00 0.10 0.20 0.30 0.40

Cost

Flexibility

Mass

Performance

Risk

S/C Interface

Category Weight

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Trade-off options (1/3)

Slide 9

Tentacles based clamping mechanism – Trade-off

Two booms tentacle

Option A

Boom on a capture

mechanism

Option B

Boom tentacle

Option C

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Trade-off options (2/3)

Slide 10

Tentacles based clamping mechanism – Trade-off

Collapsible tube mast tentacle

Option D

Three booms tentacle

Option E

Linear tongs

Option F

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Trade-off options (3/3)

Slide 11

Tentacles based clamping mechanism – Trade-off

Hook tentacle

Option G

Tong and hook

tentacle

Option H

Tong and hook

tentacle II

Option I

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Trade-off results

Slide 12

Tentacles based clamping mechanism – Trade-off

4.81 4.85

5.66

4.28 4.76

5.74

5.00 5.45

0

1

2

3

4

5

6

7

Option A Option B Option C Option E Option F Option G Option H Option I

Score range is 1 to 10

Three options with high scores – C, G, I

Option G is an evolution of option C

Option I is specifically designed for e.Deorbit platform

Option I can be realised with two tentacles only

Option I is chosen as baseline

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Baseline design overview

Slide 13

Tentacles based clamping mechanism – Trade-off

ASTRA 2015, ESTEC, 11.05.2015

Deployment Capture

Multi-body Simulation (MBS)

Introduction

Mechanism requirements

Trade-off and baseline selection

Multi-body simulation

Mechanism Design

OHB System AG

MBS Model Description

Slide 15

Two step methodology: Worst-case identification Detailed analysis for mechanism component

sizing Worst-case is determined by finding the

combination of parameters that maximises the x-component of Torque1 and Torque2

Feasibility of solution is constrained by HDRA maximum holding torque

Design parameters and requirements are adapted to create feasible solution

Tentacles based clamping mechanism – Multi-body simulation

Harmonic Drive Rotary Actuator (HDRA)

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

MBS worst-case visualisation

Slide 16

Tentacles based clamping mechanism – Multi-body simulation

Isometric view Front view fitting the camera to the Chaser

Side view fitting the camera to global

reference

ASTRA 2015, ESTEC, 11.05.2015

Mechanism Design

Introduction

Mechanism requirements

Trade-off and baseline selection

Multi-body simulation

Mechanism Design

OHB System AG

Design overview

Slide 18

Two tentacles

Two booms each

Connected by a rotary actuator

One linear actuator for lateral extension each

Two HDRMs each

Four linear actuators for target clamping

Tentacles based clamping mechanism – Mechanism Design

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Mechanism components

Slide 19

Tentacles based clamping mechanism – Mechanism Design

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Mechanism operations

Slide 20

• Sequential boom tentacle deployment • Reduction of deployment shocks • Simpler handling of perturbations

by AOCS • Time for deployment is

(practically) not limited • Easier failure handling

• Capturing consists of two parts: • Capture (HDRA) • Clamping (LEMA Z)

Tentacles based clamping mechanism – Mechanism Design

Deployment

ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Function tree

Slide 21

• F1: Capture target Tentacles

• F2: Release target Open tentacles

• F3: Establish rigid connection Brakes + preload mechanism

• F4: Operate on host satellite Power, data, and mechanical interfaces

• F5: Survive launch and space environment HDRM + environmental specifications

Tentacles based clamping mechanism – Mechanism Design

Capturetarget

F1

F1.1Provide sufficient

opening for target

F1.2

Close mechanism

F1.3

Measure capturing progress

F1.3.1Measure

opening angle

F1.3.2Measure opening/

closing speed

F1.3.3Detect target

contact

Releasetarget

F2

Establish rigid connection

F3

F3.1Prevent relative motion between

target and chaser

F3.2

Maintain rigid connection

F3.3

Measure status of locked

mechanism

F3.1.1Prevent

translation in3-axes

F3.1.2Prevent

rotation in3-axes

Operate on host satellite

F4

F4.1

Fit into VEGA fairing envelope

F4.2

Deploy mechanism

F4.3Provide

mechanical interface to host

satellite

F4.4

Provide power interface to host

satellite

F4.5

Provide data interface to host

satellite

Survive launch and space

environment

F5

F5.1

Survive launch conditions

F5.2

Operate in specified thermal

environment

F5.3

Survive EMC/ESD

environments

ASTRA 2015, ESTEC, 11.05.2015

Conclusions and outlook

OHB System AG

Tentacles based clamping mechanism

Slide 23 ASTRA 2015, ESTEC, 11.05.2015

OHB System AG

Conclusions and outlook

Slide 24

Definition of a clamping mechanism has been performed

Component sizing supported by multi-body simulation

Operational and functional design Including FMEA

Mechanism and technology development roadmap

Validation test plan including Test facility identification

Further evaluated for evolving e.Deorbit mission

Tentacles based clamping mechanism

Image: www.faz.net

The presented activity was part of an ESA contract under the Basic Technology Research Programme. It is part of the Clean Space Branch 4 Roadmap.

ASTRA 2015, ESTEC, 11.05.2015

Jan-C. Meyer 12.03.2015, Noordwijk

Tentacles based clamping mechanism Mechanism Final Presentation Days