12 robotic interfaces

7/29/2019 12 Robotic Interfaces

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Robotic Systems(12)


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Progress so far.

Considered robot structure and kinematics

Considered sensing systems

TactileVision

We need to examine how we control a robotic system

Remotely using TeleoperationAI approach with and without vision


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Definitions

Teleoperation - to operate a vehicle or a system over a distance

Distance can vary from tens of centimetres (micro manipulation) to millions ofkilometres (space applications). A person is always in the loop.

Motivation

TheState of the Arttrue AI is to difficult

Remove humans from hazardous environments

Reduce cost by not having to have man rated vehicles

Telepistemology - study of knowledge acquired at a distance. Telerobotics and Webcams


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Master-Slave Systems

Original master - slavesystems were mechanicalpantographs.

Developed at the ArgonneNational Laboratory

Handling radioactivematerial


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Overview

These systems are bested suited for

the tasks are unstructuredand not repetitive

the task workspace cannot be engineeredto permit the use of industrialmanipulators

key portions of the task require dexterous manipulation, especially hand-eye coordination, but not continuously

key portions of the taskrequire object recognition or situationalawareness

the needs of the display technologydo not exceed the limitations of thecommunication link (bandwidth, time delays)

the availability of trained personnelis not an issue


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Key Components

Display

Control

Drive

Effector

Control

SensorLOCAL

REMOTE

Communication


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Human Supervisory Control

Robot is theprimary controller

Operator is the

primary controller

Operator can

see the robot

Operator cant

see the robot

REMOTECONTROL

MANUALCONTROL

SHARED

CONTROL

AUTONOMY

Teleoperation


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Remote operation

The operator visual contacts to therobotic system.

Control commands are sendelectrically by wire or radio

Operator does all the intelligentwork.

Limited range


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Teleoperation

Closed loop control or Direct teleoperation

The operator controls the actuators of the teleoperators by direct signalsand gets real-time feedback.

This is possible only when the delays in the control loop are minimal.

Coordinated teleoperation

The operator again controls the actuators, but now there is some internalcontrol - remote loop - included.

No autonomy included in the remote end.

The remote loops are used only to close those control loops that theoperator is unable to control because of the delay.


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Supervisory Control

Human operators are intermittentlygiving directives and continually receivinginformation from a computer that itself closes an autonomous control loopthrough artificial effectors and sensors to the controlled process or taskenvironment

Implications Human is always involved, if only to set objectives

Information may be the lack of information (e.g., nothing interesting hashappened)

Computer is always involved.

Consider the impact of the command

Compensate for time delays Inner-loop control Safety/self-protection reflexes


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Applications

Submarines (ROV)


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Haptic Feedback

Haptic technology refers totechnology which interfaces theuser via the sense of touch byapplying forces, vibrations

and/or motions to the user.


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Medical Applications

Endoscopic surgery

Mechanical manipulation

Minimal damage, smaller

risks Telesurgery

Operate over distances


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Long delay teleoperation

No possibilities for closed loopcontrol

Autonomy required

Move and wait teleoperation

Models of robot and environment,operator loop in control


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Problem of latency

Signal speed: 300 000km/s

In practise

< 0.1 seconds - perfect, < 0.5 seconds acceptable

> 0.5 seconds increasing difficulty


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Teleoperation problems

Cognitive fatigue and lack of situation awareness

Communications: dropout, bandwidth, lag

Every part of the system has some delays

Digital systems increased the delay

Control

delay

Operators

delay

Transmission

delay

Feedback

delay


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Supervisory Control Considerations

Operator cant see enough to put together the Big Picture or situationawareness

Possible solutions

Telepresence Different perceptual displays

Go to multiple operators/observers

People dont do well when automated system suddenly turns control

over to them

Reduce level of autonomy and keep person in the loop


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Telepresence

Improves human control, reduces simulator

sickness and cognitive fatigue by providing

sensory feedback to the point that theoperator feels they are present in robots

environment

Increases bandwidth and processing

demandsNASA Robonaut Project


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Telerobotics and Telepistemology

Gives any viewer a presence over the internet

Low cost

Trojan Room Coffee Pot


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Observation

Global telepresence

Reduction of distance

The observer is telepresent in the remote environment

It is feedback used as part of a control system.


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Key Challanges

Video transmission

Large amount of data

Need for digital transmission

Control transmission

Fast response for control actions


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Augmented Reality Interface


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University of Western Australia

http://telerobot.mech.uwa.edu.au/Telerobot/images.html
http://telerobot.mech.uwa.edu.au/Telerobot/images.htmlhttp://telerobot.mech.uwa.edu.au/Telerobot/images.html

12 robotic interfaces

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