Autoflight System Research Articles

Research on automatic flight control system flight mode operation logic

The auto-flight system of modern civil aircraft is the main man-machine interaction system, and its flight mode operation function is jointly completed by FMCP hardware and auto-flight control system software. In order to achieve a complex flight mode operation control logic design, first the hardware and software composition and specific functions of flight mode operation control are clarified. Then the flight mode operation function is refined and logically sorted out. Finally, the software and hardware models of flight mode operation control are established through Simulink. This paper verifies whether the realization of the mode operation control function meets the expectation.

Effect of working parameter on droplet deposition in pumpkin top dressing using multi-rotor UAV

With the wide utilization of UAV in agricultural experiment and field management, plant protection UAV became a highly usage equipment for famers. Topdressing for pumpkin is important, when pumpkin fruit are expanding. It is difficult for farmers and other spraying machines to work on the farm, because all the fields is covered with leaves and stalks. A field test were launched to explore UAV working parameters on pumpkin topdressing, and distribution of droplets on face or back leave were measured to reflect the spraying quality and quantity of machine. During filed experiment, parameters of each flight was set by auto-flight system, and flight speed was stable. Through field experiment and data analysis, it was found that when the flying height was 2.5 m and the flying speed was 3 m/s, the total amount of droplet deposition reached the maximum, and the droplet attachment level on the back leaves was the highest. This parameters could be a guidance when using UAV for topdressing in pumpkin or other kinds of crops.

Plan B for Eliminating Mode Confusion: An Interpreter Display

ABSTRACT For more than three decades, aviation human factor researchers have analyzed the autoflight system interface (autopilot, autothrottle, flight management system) and articulated its flaws; the design issues are well known. More importantly, autoflight “mode confusion” has contributed to airplane accidents and incidents. A handful of design efforts have produced new interface designs that succeeded in removing or reducing pilot confusion and errors. Despite these efforts, interfaces on the most recent jet transports have changed little, and mode confusion continues to contribute to safety events. The failure to improve interface design is due to economic factors, such as maintaining common type ratings, and reducing certification risk and training costs. This paper reviews previous re-designs as the primary input to a proposed design for an “interpreter” display. The proposed display, implemented as a retrofitted supplementary display, depicts actual autoflight system behavior – What’s it doing now? What will it do next? – in a simple, graphical format. This paper describes the foundational design principles underlying this new display and initial display evaluation work.

Automated trajectory generation and airport selection for an emergency landing procedure of a CS23 aircraft

Aircraft in general aviation usually are operated in single pilot mode. Especially, in case of an incapability of the pilot to control the aircraft, an automated emergency procedure is desirable in order to reduce the risk of fatalities. The finding of a solution for an emergency landing maneuver includes preselecting possible landing sites with regard to the available aircraft capabilities and creation of feasible trajectories to these sites. A search tree in four-dimensional search space with an efficient implementation of a rapidly exploring random tree algorithm (RRT*) is created. The algorithm performance is increased by use of basic geometrical sets to construct the final route as a combination of Dubins path segments. To further reduce the route length, a gradient based local optimization routine is added after completion of the RRT* algorithm. At the moment of creation, terrain avoidance is verified and accordance with legal airspace structure is considered. An emergency procedure is created by combining a selected landing site and a flyable trajectory to this site. Each of these combinations is scored, and the most promising emergency landing procedure is chosen and delivered to flight management system of the aircraft. The flight management system controls a full-authority auto-flight system that is capable of performing en-route flight and auto-land procedures as well.

Pilot Designation and Dedesignation of Traffic Targets to the Autoflight System

This study examined flight crew designation and dedesignation of target aircraft, with the objective of assessing flight crews’ responses to errors in coupled operations: errors that may be caused by the flight crew, or that may originate outside the flight crew but then need to be detected and resolved by them. The study examined two potential air traffic operations selected to be representative of operations that couple traffic information to the autoflight system: advanced flight-deck interval management and closely spaced parallel operations. Both of these operations couple the autoflight to a traffic target designated by the flight crew, such that the autoflight system commands a flight path relative to this other aircraft. Twelve pilots each flew 12 scenarios in an integrated flight-deck/air traffic control simulation facility. Each scenario had a pitfall representing foreseeable conditions conducive to error by the flight crew or the air traffic controller, and requiring flight crew intervention. Although some of these events were easily identified and resolved by the participants, others were not, creating conditions where the operations were not performed as desired. These results highlighted the need for pilot training, operational procedures that changed the roles of the flight deck and air traffic control, and flight-deck systems used to designate targets for these types of operations.

Work Models that Compute to Describe Multiagent Concepts of Operation: Part 1

This paper describes a simulation framework and engine created to address several concerns in the design of multiagent concepts of operation, focused on the construct of “work.” This framework incorporates the capabilities of several approaches, including cognitive work analysis, system-level modeling, and agent-based simulation. The framework promotes consistent, systematic models of the collective work performed by any number of agents within a concept of operation. As a side benefit, the ability to simulate work models also provides a mechanism to validate that the description of a concept of operation provides a complete and accurate representation of the agents’ collective activities and of the work environment they act upon. The framework defines several computational structures: “actions” describing work processes, “resources” describing the state of the environment, “decision actions” for strategy selection, and “functions” allowing compositional modeling at multiple levels of abstractions. Timing constructs ensure correct temporal semantics, even with a wide variety of computational models, including discrete event forms and integration of continuous dynamics. Actions can be allocated during run time to agents that then execute them. Representative results from a study of function allocation between a flight crew and an autoflight system illustrate the insight provided by these models and their simulation.

Can We Automate Compliance to Collision Avoidance Resolution Advisories?

The Traffic alert and Collision Avoidance System (TCAS) was designed to prevent mid-air collisions by portraying a time-critical “resolution advisory” (RA) to the pilot. Complying with a TCAS RA is generally considered the safest course of action and takes priority over all other forms of air traffic management; however, pilot compliance with TCAS RAs is surprisingly low. One proposed solution is an ‘Auto-RA’ function which couples the autoflight system to TCAS such that, when the autopilot is engaged, it automatically executes any corrective RAs. This paper describes a study in an integrated flight deck / air traffic control simulator examining how pilots interact with TCAS with and without an ‘Auto-RA’ function. A prior study found that pilots allowed the autoflight system to fly the RA maneuver in 83% of the runs, but the situations where the pilots disconnected the Auto-RA function generally involved scenarios where pilots received confusing guidance from the RA, and conflicting instructions from air traffic control. Further, once clear of the conflict, pilots appeared to have trouble remembering which autoflight modes they had had engaged before the RA, and air traffic instructions requiring particular speed or altitude targets that were effectively erased by the Auto-RA function. Thus, this study particularly focused on particularly problematic traffic encounters, and on situations where the Auto-RA might disrupt pilots from meeting a specified air traffic restriction.

Petri net-based modelling of human–automation conflicts in aviation

Analyses of aviation safety reports reveal that human–machine conflicts induced by poor automation design are remarkable precursors of accidents. A review of different crew–automation conflicting scenarios shows that they have a common denominator: the autopilot behaviour interferes with the pilot's goal regarding the flight guidance via ‘hidden’ mode transitions. Considering both the human operator and the machine (i.e. the autopilot or the decision functions) as agents, we propose a Petri net model of those conflicting interactions, which allows them to be detected as deadlocks in the Petri net. In order to test our Petri net model, we designed an autoflight system that was formally analysed to detect conflicting situations. We identified three conflicting situations that were integrated in an experimental scenario in a flight simulator with 10 general aviation pilots. The results showed that the conflicts that we had a-priori identified as critical had impacted the pilots' performance. Indeed, the first conflict remained unnoticed by eight participants and led to a potential collision with another aircraft. The second conflict was detected by all the participants but three of them did not manage the situation correctly. The last conflict was also detected by all the participants but provoked typical automation surprise situation as only one declared that he had understood the autopilot behaviour. These behavioural results are discussed in terms of workload and number of fired ‘hidden’ transitions. Eventually, this study reveals that both formal and experimental approaches are complementary to identify and assess the criticality of human–automation conflicts.Practitioner Summary: We propose a Petri net model of human–automation conflicts. An experiment was conducted with general aviation pilots performing a scenario involving three conflicting situations to test the soundness of our formal approach. This study reveals that both formal and experimental approaches are complementary to identify and assess the criticality conflicts.

Goms on the Flight Deck: A Case Study of the Boeing 777 MCP

Despite the extensive literature available on GOMS methods for predicting task performance, there are relatively few hands-on examples of GOMS being used in an applied setting. This proof-of-concept paper will describe the use of CPM-GOMS and NGOMSL, in combination with an existing RAFIV, to evaluate the Boeing 777 autoflight system.

Reducing Errors in Automated Cockpits Through Cognitive Engineering Principles

Most navigational errors in automated aircraft are the result of incorrect input to the aircraft's autoflight system. The complaint is heard that the pilot is not “in the loop.” These concerns can be traced directly to the information available to the pilot. If we evaluate the task of navigating a highly-automated aircraft from a cognitive engineering perspective, we can design flight deck procedures that minimize the navigational errors and increase the detection of those errors before they result in an undesirable outcome. This paper evaluates what control action the pilot takes, what information is needed to verify the correctness of the control input, and what can be done to get the needed information when it is needed. Actual incidents of navigational errors resulting from improper input are reviewed. It is argued that both pilots should verify the input to the flight management system at the time of input. This is the only reliabl means of detecting input errors. Procedures are recommended for pilot confirmation at the time of input that take advantage of human cognition to reduce the probability that input errors will go undetected.

A pilot-centered autoflight system concept

Ease of use has become a primary concern in avionics recently. Pilot training time represents a significant cost to aircraft operators, and the importance of human factors considerations in safety has been highlighted by the FAA, who notes that human error is a cause in roughly 70% of aircraft accidents. These concerns have led to a new focus on human-centered design, which seeks to define system functionality based on the user's perspective rather than that of the designer. We have used the principles of user-centered design to develop a new autoflight system concept that integrates the autopilot and flight management system functions into a single user interface that most pilots can learn to use within about fifteen minutes. This is in contrast to the weeks required to learn a typical flight management system.

The VNAV Tutor: addressing a mode awareness difficulty for pilots of glass cockpit aircraft

One of the major tasks of pilots of modern aircraft is monitoring and understanding the status and behavior of the auto-flight system, i.e., mode awareness. In order to maintain mode awareness in the dynamic environment, pilots must be continuously vigilant of indications from several locations within the cockpit. Lacking accurate and complete system knowledge and interfaces that clearly present the system state and constraints, pilots may misunderstand the control modes, pilots often cite vertical path navigation (VNAV) as a flight management system function that "surprises" them. The VNAV Tutor, a computer-based training system, was developed to address this issue. The VNAV Tutor attempts to improve pilots' understanding of VNAV control modes and the interaction of the mode control panel functions with the flight management system during VNAV usage. An evaluation showed that the VNAV Tutor enhanced both the conceptual understanding and the operational use of the vertical navigation function by pilots transitioning to aircraft with sophisticated auto-flight systems.

Mode Awareness in Advanced Autoflight Systems

An examination of autoflight systems in modem aircraft was made, with empasis on the complex mode structure which is suspect in several recent accidents. Aviation Safety Reporting System reports from 1990-94 were examined. Flight Mode Annunciator conventions were inventoried. Focussed interviews with pilots and check airmen were conducted. Principal results identified the lack of a consistent global model of the AutoFlight System architecture and identified the vertical channel as requiring enhanced feedback. An Electronic Vertical Situation Display to help mitigate the identified problems was prototyped.