Effects of controlled element dynamics on human feedforward behavior in ramp-tracking tasks

Area of Science:

• Human-computer interaction
• Control theory
• Human factors engineering

Background:

• Manual control tasks often involve predictable signals, allowing for feedforward control alongside feedback.
• Human adaptation to controlled element dynamics in feedforward control is not well understood.

Purpose of the Study:

• To investigate how humans adapt their feedforward control dynamics to varying controlled element dynamics.
• To examine the effect of target signal ramp steepness on feedforward control.
• To analyze human control behavior in combined ramp-tracking and disturbance-rejection tasks.

Main Methods:

• A human-in-the-loop experiment was conducted using a pursuit display.
• Participants controlled vehicle-like systems with dynamics ranging from single integrator to double integrator.
• Three levels of ramp steepness were tested across different controlled element dynamics.

Main Results:

• Feedforward control was observed across all tested controlled elements and ramp steepness levels.
• Human operators demonstrated adaptation to controlled element dynamics, achieving near-perfect inversion.
• Ramp steepness did not significantly affect the feedforward model parameters.

Conclusions:

• Humans effectively utilize feedforward control to adapt to system dynamics in manual control tasks.
• The degree of adaptation suggests a robust capability for inverting controlled element dynamics.
• Feedforward control adaptation is primarily driven by system dynamics, not target signal steepness in this context.