Models describing muscle behavior and control

Aerospace Engineerin

Biophysics in aircraft control: A model of the neuromuscular system of the pilot's arm

Aerospace Engineerin

Designing for Situation Awareness: the World behind the Glass

In the design of human-machine interfaces and automation, an important question is how to obtain and validate a design that is capable of supporting the operator’s understanding and situation awareness of the process under control. Whereas many research efforts address the question of ‘what is the operator aware of?’ – the awareness – only a few investigations focus on studying what the operator should be aware of in the first place, i.e., ‘what is the situation?’ In this paper we briefly discuss some of our research activities which aim at answering this second question, following an ‘ecological approach’ to interface design. The clever use of automation tools and novel visualizations will be presented that allows human operators working in aviation (pilots, air traffic controllers) in dealing with complex tasks. The airborne self-separation task will be discussed, as an example of showing how ecological interfaces can support pilots in their decision makingControl & OperationsControl & Simulatio

Ecological Interface Design of a Tactical Airborne Separation Assistance Tool

In a free-flight airspace environment, pilots have more freedom to choose user-preferred trajectories. An onboard pilot support system is needed that exploits travel freedom while maintaining spatial separation with other traffic. Ecological interface design is used to design an interface tool that assists pilots with the tactical planning of efficient conflict-free trajectories toward their destination. Desired pilot actions emerge from the visualization of workspace affordances in terms of a suitable description of aircraft (loco)motion. Traditional models and descriptions for aircraft motion cannot be applied efficiently for this purpose. Through functional modeling, more suitable locomotion models for trajectory planning are analyzed. As a result, a novel interface, the state vector envelope, is presented that is intended to provide the pilot with both low-level information, allowing direct action, and high-level information, allowing conflict understanding and situation awareness.Control and OperationsAerospace Engineerin

Modeling the Coupled Difference Threshold of Perceiving Mass and Stiffness from Force

Abstract—Just notable difference (JND) thresholds for the perception of manipulator dynamic properties are relevant for tele-operation and simulation of vehicles. Manipulator dynamic properties are characterized by multiple variables (describing mass, spring and damping for a linear manipulator) and the JND threshold for any of these variables is affected by variation in the remaining variables. In previous work, we demonstrated and modeled the coupling of the stiffness JND and the mass JND, and investigated the effects of stiffness and mass properties on the damping JND. In this work we investigate how changes in the damping parameter affect the JND in perceiving stiffness and mass. In an experiment our subjects were instructed to discriminate between different levels of manipulator’s stiffness or mass, while tracking a prescribed sinusoidal manipulator movement. Results show that the JND in spring force and the JND in inertia force are identical, and increase for higher damping levels. The JND model developed in our previous work can successfully describe the experimental observations, thereby providing an extension of Weber’s law. The impedance of the manipulator is considered as the reference stimulus in the frequency domain, so that a single ratio describes the JND thresholds for all three properties. Index Terms—Just noticeable difference, Mass-spring-damper systems, Frequency response function, Weber’s law, hapticsControl & SimulationControl & Operation

Operational alerting concept for commercial single pilot operations systems

Reducing high workload levels are a major challenge to enable single pilot operations. Where the pilot is currently supported with many automated systems, the role of mission planner is relatively unsupported, i.e., the flight crew is required to integrate and combine information from various sources to extract the implications on the missions’ high-level goals to determine if the mission can still be completed safely and successfully. An operational alerting display is developed to provide the pilot with a clear overview of the current and future operational flight constraints. This enables the pilot to determine if the initial plan is valid under the existing conditions. The display is not limited to system malfunctions, but combines the full spectrum of operational constraints, e.g., weather and airport operations. The display concept was tested on usability with a commercial pilot to provide a preliminary performance indication on the effectiveness of the concept

Stiffness-force feedback in UAV tele-operation

Aerospace Design, Integration and OperationsAerospace Engineerin

Human Threshold Model for Perceiving Changes in System Dynamics

Limitations of a haptic device can cause distortions of the force feedback it presents. Just-noticeable difference (JND) in system dynamics is important for creating transparent haptic interaction. Based on the previous work, this article presents a unified model that extends the existing JND rule. Our approach projects the JNDs in the mechanical properties of a second-order mass-spring-damper system onto the real and imaginary components of the system's frequency response function (FRF). We discuss the results of two experiments and show that the JNDs obtained for both the real and imaginary components can be expressed as the same fraction of, and thus are proportional to, the magnitude of the total system's FRF. Furthermore, the findings are generalized to cases where the system's dynamics order is different than two. What results is a unified model that accurately describes the threshold for changes in human perception of any linear system dynamics with only two dimensions: the real and imaginary axes in the complex plane.Control & Simulatio

Revisiting Active Manipulators in Aircraft Flight Control

This study revisits the active manipulator developed for manual aircraft control. The active manipulator sends the force applied by the pilot to the aircraft while feeding back the aircraft rotational velocity bymeans of its deflection angle. We find that the activemanipulator, in comparison with the conventional passive manipulator, greatly facilitates target following and disturbance rejection in compensatory tasks. We also find that greater improvements in task performance are associated with higher forcing-function bandwidths. The findings are accounted for by the fact that the active manipulator changes the effective controlled element dynamics into an integrator, and integrates the disturbance rejection into the neuromuscular system. Furthermore, we demonstrate that the haptic feel of the activemanipulator depends on the dynamics of the aircraft. With further exploration, we reveal that human haptic perception of the active manipulator could be characterized by mass-spring-damper properties.Control & SimulationControl & Operation

An abstraction hierarchy and functional model of airspace for airborne trajectory planning support

Aerospace Engineerin