Dual-Axis Manual Control: Performance Degradation, Axis Asymmetry, Crossfeed, and Intermittency

2019 ◽  
Vol 49 (2) ◽  
pp. 113-125 ◽  
Author(s):  
Sarah Barendswaard ◽  
Daan Marinus Pool ◽  
Marinus M. Van Paassen ◽  
Max Mulder
Keyword(s):  
Performance Degradation ◽  
Manual Control ◽  
Control Performance

scholarly journals Human manual control precision depends on vestibular sensory precision and gravitational magnitude

2018 ◽  
Vol 120 (6) ◽  
pp. 3187-3197 ◽  
Author(s):  
Marissa J. Rosenberg ◽  
Raquel C. Galvan-Garza ◽  
Torin K. Clark ◽  
David P. Sherwood ◽  
Laurence R. Young ◽  
...  
Keyword(s):  
Manual Control ◽  
Control Performance ◽  
Control Task ◽  
Altered Gravity ◽  
Control Precision ◽  
Functional Implications ◽  
Potential Risk Factors ◽  
And Performance ◽  
Human Exploration ◽  
Roll Tilt

Precise motion control is critical to human survival on Earth and in space. Motion sensation is inherently imprecise, and the functional implications of this imprecision are not well understood. We studied a “vestibular” manual control task in which subjects attempted to keep themselves upright with a rotational hand controller (i.e., joystick) to null out pseudorandom, roll-tilt motion disturbances of their chair in the dark. Our first objective was to study the relationship between intersubject differences in manual control performance and sensory precision, determined by measuring vestibular perceptual thresholds. Our second objective was to examine the influence of altered gravity on manual control performance. Subjects performed the manual control task while supine during short-radius centrifugation, with roll tilts occurring relative to centripetal accelerations of 0.5, 1.0, and 1.33 GC (1 GC = 9.81 m/s2). Roll-tilt vestibular precision was quantified with roll-tilt vestibular direction-recognition perceptual thresholds, the minimum movement that one can reliably distinguish as leftward vs. rightward. A significant intersubject correlation was found between manual control performance (defined as the standard deviation of chair tilt) and thresholds, consistent with sensory imprecision negatively affecting functional precision. Furthermore, compared with 1.0 GC manual control was more precise in 1.33 GC (−18.3%, P = 0.005) and less precise in 0.5 GC (+39.6%, P < 0.001). The decrement in manual control performance observed in 0.5 GC and in subjects with high thresholds suggests potential risk factors for piloting and locomotion, both on Earth and during human exploration missions to the moon (0.16 G) and Mars (0.38 G). NEW & NOTEWORTHY The functional implications of imprecise motion sensation are not well understood. We found a significant correlation between subjects’ vestibular perceptual thresholds and performance in a manual control task (using a joystick to keep their chair upright), consistent with sensory imprecision negatively affecting functional precision. Furthermore, using an altered-gravity centrifuge configuration, we found that manual control precision was improved in “hypergravity” and degraded in “hypogravity.” These results have potential relevance for postural control, aviation, and spaceflight.

Predictor Displays for Complex, Dynamic Tasks: A Preliminary Investigation

1986 ◽  
Vol 30 (7) ◽  
pp. 684-688 ◽  
Author(s):  
K. B. Bennett ◽  
D. D. Woods ◽  
E. M. Roth ◽  
P. H. Haley
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Precise Measurement ◽  
Preliminary Investigation ◽  
Development Program ◽  
Manual Control ◽  
Control Performance ◽  
Control Task ◽  
Complex Dynamic ◽  
Operator Performance

The operators of nuclear power plants are asked to perform a task that has proven to be particularly difficult: manual control of feedwater during startup. We have initiated a research and development program to address human factors issues related to this task. An analysis of cognitive aspects of the feedwater control task was used to develop a generic part-task simulator. New displays to enhance manual control performance (including a predictor display) were developed with the simulator. The test capability provided by the simulator allowed precise measurement of performance differences associated with these displays in a mixed-fidelity laboratory experiment. The results suggest that the displays reduced the complexity of the task and resulted in improved operator performance.

The Effects of Vibration on Manual Control Performance

Ergonomics ◽  
1976 ◽  
Vol 19 (2) ◽  
pp. 203-216 ◽  
Author(s):  
C. H. LEWIS ◽  
M. J. GRIFFIN
Keyword(s):  
Manual Control ◽  
Control Performance
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