#6 Development of the phase aggression criterion for adverse rotorcraft pilot coupling prediction and real-time detection (pac)

Development of the Phase Aggression Criterion for Adverse Rotorcraft Pilot Coupling Prediction and Real-time Detection (PAC)

Host institution

University of Liverpool (UK) – School of Engineering

Supervisors

Dr. Mike Jump

Co-tutoring institution

To be decided: Delft University of Technology (The Netherlands) or Politecnico di Milano (Italy)

Start date

Strictly before end of May 2017

Duration

36 months + 12 months

Gross salary

44.896,00 € per year

Work location

Mainly Liverpool (UK) and Delft (The Netherlands) or Milano (Italy)

Objective

Adverse Aircraft/Rotorcraft –Pilot Coupling (A/RPC) have challenged designers since the first manned flight of the Wright Brothers, well over a century ago. A/RPCs are unwanted phenomena originating from an anomalous/undesirable disconnect between the pilot’s intentions and the aircraft’s response. Such phenomena have always been a potential flight safety-critical issue for both fixed- and rotary-wing aircraft. They may result in annoying aircraft oscillatory/non-oscillatory instabilities which degrade the vehicle’s flying qualities, increase the structural strength requirements and sometimes even result in catastrophic accidents. A/RPC events were, and perhaps still are better known as Pilot Induced Oscillations (PIO) and Pilot Assisted Oscillations (PAO). PIO implies that the pilot inadvertently excites divergent vehicle oscillations whereas PAO are the result of involuntary control inputs of the pilot in the loop that may destabilize the aircraft due to inadvertent man-machine couplings. Today it is agreed that the cause of a particular undesirable A/RPC is not necessarily nor entirely due to the pilot but it is often ultimately associated with some anomalous aircraft design features. The project will focus primarily on PIO phenomena.

PIO events have traditionally been divided into three categories. Oscillations found to be linear in nature were termed Category I and often the result of excessive control phase lags. Quasi-linear oscillations, often the result of rate or saturation limits, were termed Category II oscillations. These oscillations are dependent upon both the pilot control input frequency and amplitude. Oscillations where dynamics were non-linear in nature are termed Category III. These are usually the result of some combination of Cat.I/Cat.II triggers, or additional triggers due to vehicle non-linearities. Due to the complexity of the phenomena and perhaps due to their categorisation, methods to predict, detect and, to a lesser degree, alleviate PIO phenomena have proliferated but are not necessarily ‘joined up’ throughout the aircraft life cycle. Motivated by this issue, the Phase-Aggression Criterion (PAC) was developed at the University of Liverpool during the EC-FP7 programme ARISTOTEL.

PAC was developed to a point where it could predict PIO events during, for example, conceptual design and could detect PIO events once they had occurred during ‘simulated flight’. All of this work was undertaken for rate-command response-type rotorcraft systems only, typical of legacy rotorcraft systems. The new research post has been created to develop an enhanced version of PAC to incorporate adverse-rotorcraft pilot coupling prediction and detection criteria for a wider range of typical helicopter response types e.g. attitude command. The criterion will also be further expanded to address the alleviation aspect of the ARPC problem by assessing the method’s utility as a warning system by coupling it to a cockpit display system.

As such, the planned project will address:
• Prediction and detection of A/RPCs for response types typical of more advanced helicopter configurations using PAC
• Development and assessment of a cockpit warning system to provide the pilot with useful cueing that an A/RPC is about to occur.
• Development and assessment of means of alleviating A/RPC events either before or as they are occurring.

The project will produce a set of validated design charts and develop new display concepts and training paradigms that could be used to predict and detect ARPC events for helicopters with ‘advanced’ response types. These will be made available to all NITROS partners. Furthermore, the project will provide a set of recommendations regarding the efficacy of the use of cockpit warning systems for ARPC events pilot’s awareness of environmental hazards during operations. A/RPC are known to be the worst case scenarios and reducing them will improve safety by 2-3%, allowing a generalized reduction of pilot workload.

Research profile

This researcher will be working at the University of Liverpool together with Delft University of Technology to obtain a double doctorate award. During the research, secondments are planned with Leonardo and the Civil Aviation Authority to gain an insight into helicopter design, operational and regulatory challenges with respect to A/RPC. The ESR will also engage and share knowledge with other ESRs as part of the Marie Skłodowska-Curie Actions Innovative Training Network – NITROS.

The ESR will develop skills in flight modelling and simulation as well as flight trial conduct and assessment. They will learn to understand and analyse complex dynamic systems and phenomena that include human-in-the-loop interactions. The ESR will be focused on developing tools and techniques that are useful to the relevant user community.

Research field

• Helicopter Design
• Assessment & Operations
• Flight modelling and simulation, flight mechanics and dynamics
• Flight trial preparation, conduct and analysis
• Human-machine interaction display/haptics development
• Development of design and operation requirements

Requirements

• First class degree (or equivalent) in Aerospace Engineering or a closely related subject
• Applicants with a high-scoring 2:i (or equivalent) will be considered on a case-by-case basis
• Very good communication/proficiency in the English Language
• Excellent teamwork and interpersonal skills
• Must be able to self-manage and work independently
• Self-motivated

Additional desirable requirements:
• Flight mechanics modelling and modelling of complex dynamic systems
• FLIGHTLAB modelling
• Experience in designing and running real-time piloted simulation experiments
• Experience in human factors experimentation and analysis
• Display/haptic cueing design
• Computer programming – C++/Matlab/Simulink
• Very good planning/project management and research skills