Satellite Docking Simulator based on Hardware-in- the-loop Hybrid …robotics.estec.esa.int/ASTRA/Astra2013/Presentations/... · 2013. 8. 16. · control system - Robot 1 with 6 DOF

12th Symposium on Advanced Space Technologies in Robotics and Automation ASTRA 2013, 15 - 17 May, ESA/ESTEC, Noordwijk, the Netherlands

M. Zebenay, T. Boge, R. Lampariello, and D. Choukroun

Satellite Docking Simulator based on Hardware-in- the-loop Hybrid Contact Model

www.DLR.de • Chart 1 > ASTRA203 >May 17, 2013

Outline

- Introduction- Hardware-in-the-loop Docking Simulator Concept- Hybrid Contact Model- Conclusion


Introduction On-Orbit Servicing Missions

- Extension of the operational lifetime or improvement of the performance of a spacecraft (S/C)

- Possible tasks of a servicing satellite:- Rendezvous and inspection of a non-cooperative client S/C- Docking with the client and take over attitude & orbit control

- Examples of future On-Orbit missions- DEOS

- A German technology demonstration mission in Low Earth Orbit - SMART-OLEV

- Orbital lifetime extension of geostationary satellites


Hydraulic Stewart platform (NASA)

Hydraulic manipulator

(CSA)

Air-floating test bedTohoku University

Introduction HIL contact/docking simulators

Industrial robots(DLR)


Introduction The new European Proximity Operations Simulator (EPOS 2.0) facility design concept

-PC-based real-time facility control system

- Robot 1 with 6 DOF - Carrying client satellite mock-up - Motion simulation of client

satellite

- Robot 2 with 6 DOF on a 25 m rail system - Carrying RV sensors and docking

system of servicing satellite- Motion simulation of servicing

satellite


-Contact Dynamics=System dynamics+ Modeling of contact forces

-Modeling of Contact Dynamics

- Dynamics of the system

- Contact force

Introduction Contact Dynamics

f

Iwwmvw

wv

ImE

cc

cc

c

c

00

qnc bgkf )(


cf

cf

With damping Without damping

Non-Linear dampingLinear damping

Lea and Wang (1983)

Hunt-Crossley model (1975)

Hertz (1896)

Spring-Dashpot Impact pair

qnc bgkf )(

0

gkf nc

)1,1,1(

nqgbkfc

)1,1(

qgkbf nc

1,,1,,0,0

)(exp

2

qifgifg

Qg

kbgf nc

)1,(

qg

bkfn

nnc

Introduction Models on the contact forces


cf

cf

Hardware-in-the-loop Docking Simulator Concept

Docking simulator concept based on EPOS facility

Robots with highly accurate position control

Docking interfaces examples: probe and nozzle

Force/torque sensor

Free floating dynamics of Satellites

Challenges

Time delay

High stiffness



-Docking simulator concept in 1D:

ST

ST

mmmmm

11m

cb

ck

cb

Tm Sm

ck



-Stability analysis-based on delay sweeping method.- Steps:

- examine the stability at h=0.- check the - axis crossings of the roots of C(s,h).

+ + 2sm

1

1

she

)sb(k- cc

u

Fm

mxcxrx sheFin

0)(),(11

2 shcc emks

mbshsC

j

www.DLR.de • Chart 10> ASTRA203 >May 17, 2013

ST

ST

mmmmm

1


-Stability when h=0

-Stability when h>0

- Computing a crossover frequency and a crossing time :

-Stability window of the system is:

0)0,(11

2 mks

mbssC cc

)(tan122

14

1

21

2

21

2

14

2

c

cc

cc

cccc

kwb

wh

mk

mb

mbw

)(tan10 1c

cc

cc k

wbw

hh

cw

chh 0 chh


0)(),(11

2 shcc emks

mbshsC

Hybrid Contact Model 1D docking simulator

- Hybrid Contact Model combines:- Contact forces data from F/T sensor - Virtual contact model

- Allows - Easy tuning of contact parameters- Physical consistency


Hybrid Contact Model Test setup

- Applied a constant contact force of 10N.- Relative motion command is sent to the chaser

robot - The target is simulated by the stationary

structure- Initial parameters:

- Chaser - mass of 750kg- initial velocity of 0.03m/s

- Target - mass of 10^6 kg- zero initial velocity


Hybrid Contact Model Results

- Unstable simulation- kc = 2510N/m - bc = 20Ns/m - m1 =749.4kg- h = 16ms and - hc=8ms

- Stable simulation- kc=2510 N/m - bc=60Ns/m- m1=749.4kg:- h=16ms- hc=23.8ms



- Extend the docking simulator to 3D:- Design a passive compliance device that

supports:- 1D docking simulation- 2D/3D docking simulation

- Compensate the non-contact forces from F/T sensor

- Rigid body dynamics of the satellites- Extend the virtual contact model computation

- contact force=F/T sensor + virtual contact model

- contact torque computed from the contact force



- Virtual forces can computed in two ways:- Compute the virtual force parallel to each of the

passive compliance legs

- Computing the virtual normal force at the contact point


zdydxd

bb

b

dzdydx

kk

kf

fff

vz

vy

vx

vz

vy

vxS

v

SSv

Sc

000000

000000

vf

vb

vknbkf bv

Sv )(

EPOS

F/Tsensor

CoMvk

vb

Hybrid Contact Model Test setup

- Docking interfaces of :- Probe- Cone

- Assumed desired contact parameters:- Stiffness of 3000N/m and- Zero damping

- The robots are simulated by time delay- Initial parameters:

- Chaser - initial position of [0.78 0.5 2.5]- linear velocity of [0 0 0.03m/s]- angular position and velocity of [ 0 0 0]- mass of 750kg

- Target - initial position of [0.6 0.5 4.4]- angular position of [0 0 180degree] - linear and angular velocity of [0 0 0]- mass of 1050kg




0 10 20-15

-10

-5

0

5

10

15

t[s]

fx[N

]

0 10 20-1

-0.5

0

0.5

1

t[s]

fy[N

]

0 10 20-3

-2

-1

0

1

2

3

t[s]

fz[N

]

0 10 20-15

-10

-5

0

5

10

15

t[s]

fvx[

N]

0 10 20-1

-0.5

0

0.5

1

t[s]

fvy[

N]

0 10 20-3

-2

-1

0

1

2

3

t[s]

fvz[

N]

0 10 20-1

-0.5

0

0.5

1

t[s]

Tor

que-

x[N

m]

0 10 20-2

-1

0

1

2

t[s]

Tor

que-

y[N

m]

0 10 20-1

-0.5

0

0.5

1

t[s]

Tor

que-

z[N

m]

0 10 20-1

-0.5

0

0.5

1

t[s]

Tor

que-

vx[N

]

0 10 20-2

-1

0

1

2

t[s]

Torq

ue-v

y[N

m]

0 10 20-1

-0.5

0

0.5

1

t[s]

Tor

que-

vz[N

m]

Contact force from F/T sensor

Contact force from virtual contact model

Contact torque from F/T sensor

Contact torque from virtual contact model



0 10 20

-20

-10

0

10

20

t[s]

fx+

fvx[

N]

0 10 20-4

-2

0

2

4

t[s]

fy+

fyv[

N]

0 10 20-4

-2

0

2

4

t[s]

fz+

fzv[

N]

0 10 20

-2

0

2

x 10-3

t[s]

vx[m

/s]

0 10 20

-2

0

2

x 10-3

t[s]

vy[m

/s]

0 10 20

-2

0

2

x 10-3

t[s]

vz[m

/s]

0 10 20

-2

0

2

t[s]

Tor

que-

x[N

m]

0 10 20

-2

0

2

t[s]

Tor

que-

y[N

m]

0 10 20

-2

0

2

t[s]

Tor

que-

z[N

m]

0 10 20

-0.01

0

0.01

t[s]

wx[

rad/

s]

0 10 20

-0.01

0

0.01

t[s]

wy[

rad/

s]

0 10 20

-0.01

0

0.01

t[s]w

z[ra

d/s]

Conclusion

- Presented a docking simulator concept based on Hybrid contact model- The simulator

- Allows to tune the contact parameters in software- Can be used for 1D, 2D and 3D

- Stability window is determined as a function of:- Robots controller time delay- Contact parameters and- Simulated satellite masses

- Future work:- Validate the 3D concept experimentally


Thank You!

��12th Symposium on Advanced Space Technologies in Robotics and Automation�ASTRA 2013, 15 - 17 May, ESA/ESTEC, Noordwijk, the Netherlands OutlineIntroduction�On-Orbit Servicing MissionsSlide Number 4Slide Number 5Introduction�Contact DynamicsIntroduction�Models on the contact forcesHardware-in-the-loop Docking Simulator Concept�Hardware-in-the-loop Docking Simulator Concept Hardware-in-the-loop Docking Simulator Concept Hardware-in-the-loop Docking Simulator ConceptHybrid Contact Model�1D docking simulatorHybrid Contact Model�Test setupHybrid Contact Model�Results��Hybrid Contact Model�3D docking simulatorHybrid Contact Model�3D docking simulatorHybrid Contact Model�Test setupHybrid Contact Model�ResultsHybrid Contact Model�ResultsHybrid Contact Model�ResultsConclusion Slide Number 22

Documents

Satellite Docking Simulator based on Hardware-in- the-loop Hybrid …robotics.estec.esa.int/ASTRA/Astra2013/Presentations/... · 2013. 8. 16. · control system - Robot 1 with 6 DOF