the role of workload for work organisation in a remote tower control center institute for flight...

The Role of Workload for Work Organisation in a

Remote Tower Control Center

Institute for Flight Guidance, German Aerospace Center (DLR)

C. Möhlenbrink, A. Papenfuss, J. Jakobi

The Role of Workload for Work Organisation in a Remote Tower Control Center C. Moehlenrbink June 2011

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The Role of Workload for Work Organisation in a Remote Tower Control Center

Overview

Background

Introduction

Hypotheses

Method

Results

Discussion

Conclusion


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BackgroundConcept Study Vito (Virtual tower)

What`s the potential of automation

for tower control?

Technologies for „Virtuel Reality“

Novel Videotechnologies

Immersive Visualisation

Head-mounted displays

Telepresence

„Wearable computing“


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BackgroundRApTOr (2005-2007)

RTO-Experimental System

Installed at Braunschweig airport

Prove of technical feasibility

Experimental system running since 2005

4 Camera / Zoomcamera

Resolution requirement: 30cm/500 mPanoramacamera System (4 cameras +

PTZ)

Gbit/s – fiber optics LAN

RTO-Console

“Augmented Vision” Videopanorama


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BackgroundRAiCe: Remote Tower Operation Center (start 2008)

Research question of interest:

How can air traffic control be organized in a control center

What is the role of workload for the evaluation of new ATC-concepts

Is it possible, one controller operating two small-sized airports?

Approach:

High fidelity simulations as work probe for a remote tower center

Braunschweig

Erfurt


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IntroductionWorkload Concept

Def. Workload:[Goper & Donchin 86]

Limitation on the capacity of an information processing system.

taskload versus workload

timeline models

strategy shifs

Influencing factors in aerodrome control: [Vogt et al. 2006]

Aerodrome complexity

VFR traffic

Calculated take-off times

Staffing

Technological support


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(1) Working condition: Single Operator

IntroductionDesigning a Remote Tower Center

Far-view Braunschweig

Far-view Erfurt

BWE

ERF

BWE BWEBWE

ERF ERFERF

weather data integrated (far-view)

RADAR BWE

RADAR ERF

flight strips:black: Depart. EDDE

yellow: Arrival EDDE

black: Depart. EDVE

yellow: Arrival BWEZoomcamera EDVE Zoomcamera EDDE


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IntroductionDesigning a Remote Tower Center(2) Working Condition: Controller (PL) operating BWE

Controller (PL) operating ERF

Far-view Erfurt

ERF

BWE

ERF ERFERF

BWE BWEBWE

Weather data integrated (far-view)

RADAR ERF

RADAR BWE

Flight stirps ERF:black: Departure ERF

yellow: Arrival EDDV

+ Zoomcamera BWE + Zoomcamera ERF

Flight strips BWE:black: Departure BWE

yellow: Arrival BWE



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IntroductionDesigning a Remote Tower Center(3) Working Condition: Team Variant

PL (ERF + BWE) and CO (ERF + BWE)

Far-view Erfurt

ERF

BWE

ERF ERFERF

BWE BWEBWE

Weather data integrated (far-view)

RADAR ERF

RADAR BWE

Flight stirps ERF:black: Departure ERF

yellow: Arrival EDDV

+ Zoomcamera BWE + Zoomcamera ERF

Flight strips BWE:black: Departure BWE

yellow: Arrival BWE



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IntroductionDesigning a Remote Tower Center


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Augmented Vision Aspects

Control and surveillance!

Aim: Reducing Head-down times

Callsign:- Integration into the far-view - based on transponder data

Alternative:

- Movement detection

- based on a Live-video:

IntroductionTechnological Support

VP-CGD

D-EAF


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Identification of

safety-critical situations

Modified Cooper-Harper Scale

Expert rater:

• Hierachical structure of questions:

– No major influence

– Capacity

– „workload“

– impossible


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Hypothesestraffic hypotheses

H1a: For ISA workload ratings (2 min interval) it is expected that the workload ratings are higher for the heavy traffic than for low traffic.

H1b: Under low traffic, the single operator has significantly higher workload ratings compared to all other working conditions. The same assumption is made for heavy traffic.

H1c: From a theoretical point of view it is predicted that the workload of the single controller operating two airports under low traffic load is not significantly higher, than the workload of controllers operating one airport with low traffic.


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Hypothesesaugmented vision hypotheses and expert ratings

H2 Augmented vision hypotheses

For the between-subject-factor it is predicted that working with the callsign displayed on the video, workload is significantly lower compared to working without the callsign in the video.

It is assumed that this effect is independent of the working positions or traffic load.

Expert Ratings

Identifying crucial constraints for the Remote Tower Center Concepts

safety critical situation, when one controller is operating two airports


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MethodHigh-fidelity simulation: Remote Tower Center

Data recording:

process data:

* throughput

Subjective data:

* ISA workload ratings

* Shape questionnaires

* post-run interviews

* final questionnaire

Objective data:

* eye-data recordings

* radio com

Heatmap

Interact


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MethodSample

Sample:

• 12 controllers

Deutsche Flugsicherung (DFS)

• Age: mean=34.6 [25,60] years

• valide controller license

Movements n

< 15.000 IFR movements 2

< 35.000 IFR movements 6

> 100.000 IFR movements 4


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MethodTraffic Scenarios

Mixed traffic IFR & VFR

total 16 aircraft

raising traffic load over time: - 1st half, low traffic load

- 2nd half, heavy traffic load

Events:

Two parallel landings

Two paralle starts

Pa ra lle Eve nts on Runw a ys (BW E, ERF)w hile a single controlle r ope ra te d tw o a irports

(T ra in i n g : 1 2 co n tro l l e rs, 2 4 si m u l ti o n ru n sHisto g ra m m re p re se n ts 1 5 s ti m e i n te rva l s)

num

ber

9

5

3

9

4

6

0 15 30 45 60 75 900

2

4

6

8

10

12

14

16

4

23

5 5

1

0 15 30 45 60 75 90

6

4 4

12

1

0 15 30 45 60 75 900

2

4

6

8

10

12

14

16

2

7

4

01

0

0 15 30 45 60 75 90

B W E -Touc hdown + E RF-A irborne B W E -A irborne + E RF-A irborne

B W E -Touc hdown + E RF-Touc hdownB W E -A irborne + E RF-Touc hdown


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MethodIdentification of critical situations

Modified Cooper-Harper Scale

S1: Landing on airport A + taxing traffic on airport B

S2: Similar call signs for aircraft of airport A and B

S3: Simultaneous pilot requests at airport A and B

S4: Simultaneous starts at airport A and B

S5: Simultaneous landing at airport A and B

S6: Conflict on airport A, start/landing on airport B


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MethodInstantaneous Self-Assessment Scale

„Online“

1 2 3 4 5

Workload 5


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MethodExperimental Design

Exp. Conditions

Between subject factor (1): Augmentation

(1) no augmentation (2) callsign

within subject factor (2): working design variants C1-C3

*working positions (SO, TC/CO, BC/ EC)

within-factor (3) C1 C2 C3 C1 C2 C3

(3) Traffic

(1) low SO TC/CO BC/EC SO TC/CO BC/EC

(2) high SO TC/CO BC/EC SO TC/CO BC/EC


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ResultsTraffic (low, high) ISA-Workload-Ratings

Main effect traffic load:

heavy traffic higher workload

low traffic: lower workload

Main effect position:

TL, CO, SC higher workload

BC, EC lower workload

Interaction effect traffic*position

BC, EC WL: low ~ heavy traffic

TL, CO, SC low traffic low WL

heave traffic high WL


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ResultsAugmented Vision (yes, no) ISA-Workload-Ratings

Main effect augmentation:

callsign lower workload

no callsign higher workload

Main effect augmentation*position:

TL, CO, SC callsign effect

BC, EC no callsign effect

Additional analysis:

Augmentation (between-subject factor)

Correlation (team variable, augm.)

r=.87*


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ResultsRatings for critical situations

Situations of interest (N=216)

No major influence

Influence on Efficiency

Influence on Safety

Impossible to handle !

(S1) land / taxi 21 6 5 5

(S2) callsign 8 1 1 0

(S3) requests 7 8 0 0

(S4) start / start 14 7 6 6

(S5) land / land 4 6 7 7

(S6) conflict /land 3 4 3 1

(R1) rest category 24 42 11 9

TOTAL 81 74 33 28


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DiscussionRole of Workload for Work Organisation

One controller operating two airports * workload raises* task prioritization* two mental traffic pictures?

Each controller operating one airport * workload low

* task prioritization* mental traffic pictures?* social aspects? Low traffic periods

Each controller operating one airport * workload raises

* timing conflicts* two mental traffic pictures?* redundancy

Single operator

One operator for each airport

Team (PL,CO)


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DiscussionRole of Augmented Vision Effect

Previous studies for remote tower

no callsign effect

(within-subject design)

Operating two airports

callsign effect

(training + between subject design)

more demanding callsign effect?problem: high correlation with

team variable head-down time issueSeperation of information

VP-CGD

D-EAF


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DiscussionIdentification of Critical Situations for the RTC

Expert judgment (here: online monitoring of one controller operating two airports)

Smooth operations:parallel starts (ok)

parallel landings (ok)

…but

33 situations influencing safety, due to…?28 situations safety critical, due to…?

Shortcomings: No comparable data for other working conditions

Role of redundancy in ATC today


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Conclusion

Workload concept insufficient for the

evaluation of work design variants

Workload as an independent variable influencing controller strategies

Work methods offered by different staffing concepts

Role of safety critical situations

Future work

Deeper analysis of expert judgements

robust traffic concepts for RTC?

the role of workload for work organisation in a remote tower control center institute for flight...

Documents

remote tower control

role of workload

work organisation

remote tower operation

aerodrome control

traffic control

introduction workload

view braunschweig slide