Bilateral Teleoperation of
Download
1 / 18

Bilateral Teleoperation of Multiple Cooperative Robots over - PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on

Bilateral Teleoperation of Multiple Cooperative Robots over Delayed Communication Network: Application. Dongjun Lee Mark W. Spong Oscar Martinez-Palafox d-lee@control.csl.uiuc.edu, {mspong,pomartin}@uiuc.edu

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Bilateral Teleoperation of Multiple Cooperative Robots over ' - jesus


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Bilateral Teleoperation of

Multiple Cooperative Robots over

Delayed Communication Network: Application

Dongjun Lee

Mark W. Spong

Oscar Martinez-Palafox

d-lee@control.csl.uiuc.edu, {mspong,pomartin}@uiuc.edu

Research partially supported by the Office of Naval Research (N00014-02-1-0011 and N00014-05-1-0186), the National Science Foundation (IIS 02-33314 and CCR 02-09202), and the College of Engineering at the University of Illinois.


Outline

1. Review of the Proposed Control Framework

2. Simulation Results

3. Semi-Experimental Results

4. Conclusions


Bilateral Teleoperation of Cooperative Multi-Robots

Combine advantages of

- bilateral teleoperation: human intervention in uncertain environments

- multi-robot cooperation: mechanical strength/dexterity & robustness/safety

- applications:

remote construction/maintenance of space/under-water/civil structures

in possibly hazardous environments


behavior of overall group

(and grasped object)

Locked System

internal formation shape

(cooperative grasping)

Shape System

Passive

decoupling

Semi-Autonomous Teleoperation

Coupling:

dropping object!!!

- Passive Decomposition [Lee&Li, CDC03] decomposes slave dynamics into

decoupled shape (formation shape) and locked (overall group motion) systems

- Local grasping control of decoupled shape system: secure/tight grasping regardless of human command via delayed comm. Channel

- Bilateral teleoperation of locked system: by operating the master robot of manageably small DOF, human can tele-control the behavior of the grasped object over the delayed comm. channel while perceiving external forces


inertia

Dynamics of multiple

slave robots

(n1+n2+…+nN-DOF)

Stack-up

n-DOF product system

(n=n1+n2+…+nN-dimensional)

master’s DOF

System Modelling and Grasping Shape Function

Dynamics of

a single master

(m-DOF)

velocity

Coriolis

control

human force

Grasping Shape Function: Rn→Rn-m

grasping shape function describes internal group formation shape

desired (constant)

grasping shape


locked system

shape system

desired grasping shape

Local Grasping Control

FF cancellation of internal force:

although dynamics is decoupled, other

effects (e.g. object’s inertia) can still perturb

the shape system through internal force FE

Passive Decomposition and Local Grasping Control

Decomposed Slave Dynamics

Locked system:

abstracts overall behavior of

multiple slave robots

and grasped object

passive

decoupling

Shape system:

describes internal group

formation of slave robots

(i.e. cooperative grasping)


Locked

System

Shape system

(locally controlled)

Scattering-Based Teleoperation of Locked System

Dynamics of

Master Robot and Slave Locked System

(both are m-DOF)

human/combined

external forces

control

Scattering-Based Teleoperation of Locked system:

- humans can tele-control the behavior of the grasped object over delayed comm.

channel while perceiving external forces acting on the object and slaves

- asymptotic position coordination/static force reflection


Outline

1. Review of the Proposed Control Framework

2. Simulation Results

3. Semi-Experimental Results

4. Conclusions


Three 3-DOF Slave Robots

3-DOF Master

agent1

deformable

object

(no friction)

(x,y)-translation

yaw rotation

agent3

agent2

Simulation Settings

Delay 0.5s

Delay 0.5s

- grasping shape function is defined s.t. three slaves form an equilateral triangle

(w/ side length L) whose rotation is specified by the heading of agent 2

- human operator can tele-control the position and rotation of the triangle

by operating 3-DOF master robot (translation and yaw)

- 10% identification errors for inertias of robots (nominal: m=1kg, I=1kgm2)


Simulation: Importance of Decoupling

With Passive Decoupling Control

Without Passive Decoupling Control

- no grasped object (just motion coordination) w/ PD-based grasping control

- without decoupling control, grasping shape (i.e. shape system) is perturbed

by human command and overall group behavior

- slight grasping shape distortion w/ decoupling is due to inertial uncertainty


Simulation: Heavy Object Fixtureless Manipulation

Without Feedforward Cancellation

of Internal Force

With Feedforward Cancellation

of Internal Force

- even if dynamics is decoupled, inertial effect of object (w/ frictionless contact) perturbs cooperative grasping through the internal force FE

- this perturbation can be cancelled out by feedforward cancellation of the internal

force FE (or also by large enough PD-gains)


due to grasping shape deformation

good load balance due to grasping rigidity

Heavy Object Manipulation: Contact/Human Force

- human can perceive the total inertias of the grasped object and the slave robots

- human can also perceive sensation of grasping loss

- better load-balancing is achieved w/ FF-cancellation of the internal force FE,

as grasping shape becomes more rigid


Simulation: Force Reflection

Three 3-DOF Slave Robots

agent1

deformable

object

agent3

agent2

human

force

external force

due to object’s

deformation

- external forcing (x-direction) on the grasped object is faithfully reflected to the

human operator (i.e. haptic feedback)

- load balancing among slaves is degraded as the grasped object is deformed

in the rigidly-maintained grasping shape


Outline

1. Review of the Proposed Control Framework

2. Simulation Results

3. Semi-Experimental Results

4. Conclusions


2-DOF Master

Three 2-DOF Slave Robots

agent2

deformable

object

PHANToM Desktop:

constrained on plane

(i.e. (x,y)-translation)

agent3

agent1

Semi-Experiment Setting

Delay 0.5s

external force

Delay 0.5s

- three slave robots: 2-DOF point mass dynamics (only x,y translations)

- Phantom Desktop is used as master with its workspace constrained on (x,y)-plane

- Grasping shape function:

: specifies rotation and shape of the triangle formed by the three slaves


human perceives

inertias of object/slaves

due to object deformation

secure/precise grasping w/ FF-term

Semi-Experiment: Deformable Object Manipulation

- x-directional motion (full-range) w/ fixtureless grasping

- grasping security is preserved regardless of human command

- human can perceive the combined inertia of slaves and grasped object

- increase of some slaves' contact force due to inertia/deformation of object


Semi-Experiment: Obstacle Perception

human perceives

external force

due to object deformation

Secure/precise grasping w/ FF-term

- external force (x-direction) on the grasped object center

- force generated by the PI-action in the local impedance controls

- object’s deformation again leads in unbalanced load sharing among slaves


Conclusions

We propose a control framework for bilateral teleoperation of multiple

cooperative robots over delayed master-slave comm. channel:

- passive decomposition: the decoupled shape (cooperative grasping)

and locked (behavior of the grasped object) systems

- local grasping control for the shape system: high precision

cooperative grasping regardless of human command/comm. delays

- scattering-based bilateral teleoperation of the locked system:

human can tele-control behavior of the cooperatively grasped

object by operating a small-DOF of the master robot, while

perceiving combined force on the slaves and the grasped object

over the delayed comm. channel

- enforce energetic passivity: interaction safety and stability

- Semi-experiment and simulation results are presented and

validate efficacy of the proposed control framework

Possible impacts on emerging or traditional applications:

- remote construction/maintenance of space/under-water/civil

structures in hostile/hazardous environments


ad