Effects of Input Shaping on Manual Control of Flexible and Time-Delayed Systems
Objective: The objective was to study the performance of a manual tracking task with system flexibility and time delays in the input channel and to examine the effects of input shaping the human operator’s commands. Background: It has long been known that low-frequency, lightly damped vibration hind...
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Published in | Human factors Vol. 56; no. 7; pp. 1284 - 1295 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Los Angeles, CA
SAGE Publications
01.11.2014
Human Factors and Ergonomics Society |
Subjects | |
Online Access | Get full text |
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Summary: | Objective:
The objective was to study the performance of a manual tracking task with system flexibility and time delays in the input channel and to examine the effects of input shaping the human operator’s commands.
Background:
It has long been known that low-frequency, lightly damped vibration hinders performance of a manually controlled system. Recently, input shaping has been shown to improve the performance of such systems in a compensatory-display tracking task. It is unknown if similar improvements are seen with pursuit-display tasks, or how the improvement changes when time delays are added to the system.
Method:
A total of 18 novice participants performed a pursuit-view tracking experiment with a spring-centered joystick. Controlled elements included an integrator, an integrator with a lightly damped flexible mode, and an input-shaped integrator with a flexible mode. The input to these controlled elements was delayed between 0 and 1 s. Tracking performance was quantified by root mean square tracking error, and subjective difficulty was quantified by ratings on a Cooper–Harper scale.
Results:
Performance was best with the undelayed integrator. Both time delay and flexibility degraded performance. Input shaping improved control of the flexible element, with a diminishing benefit as the time delay increased. Tracking error and subjective rating were significantly related. Some operators used a pulsive control strategy.
Conclusion:
Input shaping can improve the performance of a manually controlled system with flexibility, even when time delays are present.
Application:
This study is useful to designers of human-controlled systems, especially those with problematic flexibility and/or time delays. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0018-7208 1547-8181 |
DOI: | 10.1177/0018720814528004 |