Fighter Cockpit Research Articles

A cognitive load assessment method for fighter cockpit human-machine interface based on integrated multi-criteria decision making

The primary interface for communication between pilots and aircraft systems is the fighter cockpit Human-Machine Interface (HMI). Since reduced cognitive load ensures that pilots will operate the aircraft safely and effectively, it is critical to evaluate pilot cognitive load during HMI. A cognitive load assessment method, based on multi-criteria decision-making, is proposed to accurately quantify the relationship between the HMI and the cognitive load in the fighter’s cockpit. Firstly, based on the integrated Multi-Criteria Decision-Making (MCDM) method, the Step-wise Weight Assessment Ratio Analysis (SWARA) and MEthod based on the Removal Effects of Criteria (MEREC) methods are used to assign subjective and objective weights, respectively. Moreover, the Combined Compromise Solution (CoCoSo) method is applied to rank the scenarios to establish a cognitive load assessment model for the cockpit HMI of the fighter jet. Secondly, an evaluation standard system of fighter cockpit HMI is proposed, drawn upon multiple sets of eye-movement criteria and subjective assessment criteria. Moreover, cognitive load experiments of fighter cockpit HMI are conducted using eye-tracking technology to get the objective physiological cognitive data as well as the subjective assessment data of the subjects. Consequently, the parameter data sets of the eye-movement criteria and the subjective criteria for the evaluation of cognitive load are obtained. The proposed method is applied to analyze the cognitive load assessment of a fighter jet cockpit HMI layout. This application aims to verify the effectiveness of the assessment method in evaluating the cognitive load of the HMI layout. Through sensitivity and comparison analyses, the model was further verified to have excellent robustness and applicability for cognitive load assessment. The advantages of this method can be seen through the comparison, which is that it has higher discriminability when assessing the degree of cognitive load. At the same time, it has higher flexibility in dealing with complex and ambiguous cognitive load assessment information.

AIR FORCE EXPERIENCE INFLUENCES A PILOT’S VISUAL PERCEPTION: PRELIMINARY RESULTS

Abstract: The objective was to characterize visual scanning of a jet fighter cockpit by pilots with different air force experiences using the eye movement monitoring method and flight simulator under G-Force. Total, 36 pilots with various experiences in piloting MIG-29 participated in the study. Pilots performed basic manoeuvres required for patrolling the air space, including taking off, turning, landing. Experiments were conducted using an human carrying centrifuge with the MIG-29 flight simulator mode. The visual scene was divided into 22 ROI affiliated to cockpit’s instrument and out of widow area. Eye-tracking was performed with The GLASSES portable google sensor manufactured by Sensomotoric Instruments GmBH (SMI, Tetlow, Germany). ANOVA of total dwell time and average fixation duration recorded in each flight phase were run to evaluate statistical significance between the expertise at 95% confidence (p<0.05). Significant differences in total dwell time and fixation duration on selected ROI were revealed between pilots various experiences, i.e. while patrolling air space regarding attitude director indicator (ADI) and exhaust gas temperature (EGT). The median duration of fixation was also significantly different on altimeter while turning. Fixation duration on airspeed indicator, EGT, IPV were unique for each group during approach landing. Also, the total duration time on the altimeter and ADI were significantly different.

SEMG-based fighter pilot muscle fatigue analysis and operation performance research

Fatigue has a tremendously adverse impact on pilot performance. This study aims to explore the Biceps Brachii (BB), Rectus Femoris (RF), Flexor Carpi Radialis (FCR), and Tibialis Anterior (TA) activities of fighter pilots in the early and late combat stages, and the target hitting time. A total of 13 volunteers were recruited to conduct simulated combats inside a real fighter cockpit. The surface Electromyography (sEMG) was collected from all volunteers in the initial and final 20s of flight, and the target hitting time during three simulated combats was recorded. The root mean square (RMS) values of right BB and TA were significantly higher than the left side values (p ​< ​0.001), while insignificant differences were found in the RMS values between the bilateral RF and FCR. Compared to the early flight period, the median frequency (MF) values of BB and TA were significantly lower during the late flight period, and the RMS values were significantly higher (p ​< ​0.047). Contrastively, the RMS values of FCR and RF differed insignificantly during the late flight period. Regarding the target hitting time, a significant difference was noted between task 1 and rask3. Subjects exhibit varying levels of muscle fatigue for different muscle groups before and after the flight. The muscle fatigue levels are asymmetrical on the left and right sides. Muscle fatigue might reduce the pilots' operational ability. This study provides a reference for fighter pilot fatigue protection and treatment.

Physiological Characteristics and Operational Performance of Pilots in the High Temperature and Humidity Fighter Cockpit Environments.

During military operations in high-temperature and relative humidity (RH) conditions, the physiological state and combat capability of pilots are affected severely. In a fighter cockpit, experiments were conducted on thirteen voluntary subjects wearing pilot suits at 21 °C/30%, 30 °C/45%, and 38 °C/60% RH, respectively, in order to examine the physiological changes of pilots in combat thoroughly. The target strike performance, core and skin temperatures, pulse rate, and other parameters were measured and investigated. Significant inter-condition differences were noted in the pulse rate, core temperature, mean skin temperatures, and sweat amount, which increased markedly with elevating temperature and RH. Contrastively, blood oxygen saturation (SpO2) dropped with such elevations. Concerning the skin temperature, the chest and back skin temperatures remained stable, while the temperatures at the hands, feet, and lower arms underwent larger changes with the increasing temperature and humidity. At 38 °C/60% RH, the sweat amount was 3.7 times that at 21 °C/30% RH. The subjects’ operational error rates increased as the core temperatures rose, showing high correlations (r2 = 0.81). The results could serve as a theoretical basis for the design of pilot protective equipment and the control of aircraft cockpit temperature.

선호도 평가 기반 전투기 조종석 디스플레이의 표적 심벌 설계 방향 제안

선호도 평가 기반 전투기 조종석 디스플레이의 표적 심벌 설계 방향 제안

Bone Conduction as a Viable Alternative to Current Communications Systems in Fighter Cockpits.

Effective voice communication is essential when operating aircraft. Because of the loud operating environment in fighter cockpits, it has been a challenge to provide effective communication while simultaneously protecting the hearing sense. The objective of this study was to determine the feasibility of using bone conducting transducers (BCT) in place of legacy communications systems in fighter cockpits. A military flight helmet was modified and outfitted with BCT and air-conducting speakers. BCT were independently tested against air-conducting speakers using a clinical audiometer under three conditions: without earplugs, with earplugs, and with earplugs in the presence of 100-dB broad-spectrum noise. Three test subjects were given an audiological examination using tones of varying intensity ranging from 100 Hz to 8000 Hz. The lowest hearable intensity indicated by button press was recorded for each frequency. In the presence of 100-dB ambient noise, bone conducting transducers performed better than air-conducting speakers at all frequencies. Hearability of BCT by audiogram was, on average, 10-20% lower intensity (dB) than air-conducting speakers. Currently, USAF pilots wear two layers of hearing protection; i.e., the helmet's integrated earcup and some form of ear plug (e.g., foam earplug or custom-molded earbud). Our results suggest that bone conducting audio transducers may be better for layered hearing protection than air-conducting speakers when used with foam earplugs. Given the cost, complexity, and non-interoperability of custom-molded earphones, helmet-integrated bone conducting transducers and foam earplugs may be a better option for sustained airborne operations.Bradke BS, White Z, Poston J. Bone conduction as a viable alternative to current communications systems in fighter cockpits. Aerosp Med Hum Perform. 2018; 89(10):927-930.

Simulating extreme environments: Ergonomic evaluation of Chinese pilot performance and heat stress tolerance

High-temperatures in the cockpit environment can adversely influence pilot behavior and performance. To investigate the impact of high thermal environments on Chinese pilot performance in a simulated cockpit environment. Ten subjects volunteered to participate in the tests under 40°C and 45°C high-temperature simulations in an environmentally controlled chamber. Measures such as grip strength, perception, dexterity, somatic sense reaction, and analytical reasoning were taken. The results were compared to the Combined Index of Heat Stress (CIHS). CIHS exceeded the heat stress safety limit after 45 min under 40°C, grip strength decreased by 12% and somatic perception became 2.89 times larger than the initial value. In the case of 45°C, CIHS exceeded the safety limit after only 20 min, while the grip strength decreased just by 3.2% and somatic perception increased to 4.36 times larger than the initial value. Reaction and finger dexterity were not statistically different from baseline measurements, but the error rate of analytical reasoning test rose remarkably. Somatic perception was the most sensitive index to high-temperature, followed by grip strength. Results of this paper may help to improve environmental control design of new fighter cockpit and for pilot physiology and cockpit environment ergonomics research for Chinese pilots.

An Experiment Based Reach Model for Fighter Cockpit Design

Reach envelope is one of the design tools to ensure industrial workspace accommodates users. As for fighter pilots, their reach capability must be considered during the design of cockpit. Normally fighter seat back rest angle is between 13°and 30°, and due to the fact that postural change affects the reach capability of the pilot, the reach envelope can be different under different seat backrest angle, which is normally ill considered and thus limits the cockpit design. This research employed a reach envelope transformation model based on the anthropometric measurement approach to transform experiment based reach envelope at 0° of back rest angle to that at other seat back rest angles. 12 male subjects’ Reach data under 4 different seat angles and other anthropometric data were collected using motion capture system with a sample rate of 120Hz. A simplified model of human body was introduced and modified using the captured data from 4 subjects, with which other subject’s reach points at 0° seat backrest angle were transformed to reach points at other seat backrest angles. Comparison between the transformed envelope and measured reach envelope indicated that the average of difference, SD of difference was -5.5 and 42.76(mm) respectively.

A Common Work Space for a mutual enrichment of Human-machine Cooperation and Team-Situation Awareness

Especially in life-critical systems decision-making entails cognitive functions such as monitoring, as well as fault prevention and recovery. People involved in the control and management of such systems play two kinds of roles: positive thanks to their unique involvement and capacity to deal with the unexpected; and negative with their ability to make errors. But they are also able to detect and correct these mistakes and able to learn from them. Thus human-machine system designer can allow the humans an innovative behavior to be “aware” and to cope with unknown situations by enhancing Situation Awareness (SA). As humans are more and more involved in collective works the constructs of team-SA are important. But the literature shows a great variety and some incoherence in their definitions. That makes difficult to build a design methodology favoring human SA. In parallel, human machine cooperation models have been developed in the last two decades and validated in different dynamic application fields: Air Traffic Control, fighter aircraft cockpit, reconnaissance robot. These studies showed an increase of the problem solving capabilities and a decrease of workload when the tasks are performed by cooperative teams. In this paper we first synthesize main team-SA constructs, we then present principles of humans-machines cooperation and present a Common Work Space as a medium that allow cooperation. We propose to extend it in order to enrich team-SA constructs.

Four-node finite element of a two-dimensional functional spline to simulate a regular aircraft surface

The Gramian matrix of a four-node finite element is obtained using generalized differentiation to calculate a functional two-dimensional interpolation spline. The numerical results of testing that confirm the interpolation process convergence when applying a sequence of functional two-dimensional splines calculated by the method suggested are presented. Also given are the results of solving an applied problem of simulating an external surface of the fighter cockpit canopy.

Optimizing the Presentation of Uav Images in an Attack Helicopter Cockpit

Future Unmanned Aerial Vehicles (UAV) will collaborate more directly with military manned aircraft. TNO Defence, Security and Safety investigated how to present UAV sensor images in a fighter aircraft cockpit in order to maximize target identification and flying performance. Ten military pilots performed several Close Air Support missions in a helicopter simulator using four different display configurations. The orientation of the electronic map was either North-Up or Heading-Up. The UAV sensor image was either non-aligned (unadjusted image orientation: the image is presented as seen from the UAV viewpoint), or aligned with the orientation of the electronic map (adjusted image orientation, either resulting in a North-Up orientation or a Heading-Up orientation with respect to the helicopter, depending on the orientation of the electronic map). The pilots reported that they generally preferred the aligned UAV sensor image in combination with a Heading-Up map. This preference was reflected in their performance: targets were identified twice as fast, and the waypoint trajectory was flown more efficiently.

3-D Audio in the Fighter Cockpit Improves Task Performance

A flight simulator experiment was conducted to explore the benefits of 3-dimensional (3-D) audio to support in-cockpit tasks regarding performance and workload. In half of the conditions, 1 or 2 tasks requiring information from a head-down display (HDD) were supported by 3-D audio. The performance on several tasks improved when 3-D audio was present, whereas no negative performance effects were found. Furthermore, the frequency of eye movements to the HDD was reduced more than 50% in all 3-D audio conditions. Physiological measures were not affected, indicating that mental effort was the same in all conditions. Only a small reduction in subjective workload in some 3-D audio conditions was observed. Pilots were also able to process the information from 2 independent 3-D auditory displays that were present at the same time. The results show that pilots can perform flight and in-cockpit tasks more efficiently when they are supported by 3-D audio.

New eyes

Short-sightedness is a common problem. Daedalus proposes two answers. First, a screen that appears at optical infinity, like the 'head-up' display in a fighter cockpit, for televison viewers and so on. Second, flexible spectacle lenses, made of a piezoelectric polymer, that will gradually adapt the wearer's vision to perfection.

Effects of Virtually-Augmented Fighter Cockpit Displays on Pilot Performance, Workload, and Situation Awareness

Virtually-augmented display concepts are being developed at the US Air Force Armstrong Laboratory's Synthesized Immersion Research Environment (SIRE) Facility at Wright-Patterson Air Force Base, Ohio, for use in future USAF crew stations. These displays incorporate aspects of virtual environment technology to provide users with intuitive, multisensory representations of operationally relevant information. This paper describes an evaluation that was recently conducted to contrast the effects of conventional, F-15 types of cockpit displays and virtually-augmented, multisensory cockpit displays on pilot-aircraft system performance, workload, and situation awareness in a simulated air combat task. Eighteen military pilots from the United States, France, and Great Britain served as test pilots. The results indicate a statistically significant advantage for the virtually-augmented cockpit configuration across all three classes of measures investigated. The results are discussed in terms of their relevance for the continuing evolution of advanced crew station design.

Acoustic-phonetic analysis of normal, loud, and Lombard speech in simulated cockpit conditions

It has long been recognized that raising one's voice causes perceptible changes in the speech signal beyond mere increase in overall intensity. This paper reports the results of an extensive analysis of speech produced in a simulated fighter cockpit environment, with helmet and oxygen mask in place. Eight talkers each produced 56 utterances under three conditions: (1) normal, (2) loud (nominally 10 dB above normal), and (3) Lombard (evoked by 90 dB of pink noise played through a headset). A total of 17 671 phonemes were hand marked for analysis using 18 acoustic features (ten frequency bands, spectral COG, low- and high-frequency spectral tilt, F0, F1–3, and duration). For most speakers, both loud and Lombard conditions showed the following shifts in comparison with the normal condition: (1) For vowels and sonorant consonants, lower (0–500 Hz) and higher (5–8 kHz) frequency bands lost energy relative to the mid (1–4 kHz) frequencies; (2) also for vowels and sonorants, F0, F1, and spectral COG all rose; and (3) for fricatives, affricates, and voiceless stops, lower (0–3 kHz) frequencies lost energy relative to higher (4–8 kHz) frequencies. There was much variation in these effects among talkers. [Work supported by Air Force Institute of Technology.]

Dynamic Function Allocation in Fighter Cockpits

The objective of this study was to investigate alternatives for allocating the tasks associated with defensive counter measures in a fighter cockpit environment. The three methods allocated the functions either totally to the operator or a simulated expert system and dynamically at the operator's request to either. The analysis of the objective data showed there were no significant performance differences among the three treatment conditions. However, the analysis of post treatment subjective data showed the subjects did have confidence in the simulated expert systems's ability to handle the threats (p &lt; .01) and they had a significant preference for some form of computer assistance during the missions (p &lt; .01).

CADAM Applications in the Design and Evaluation of Aircraft Displays

The Grumman F-14D fleet air superiority fighter represents a step forward in the application of integrated controls and displays to the reduction of the high workload in the multiple task operational environment. System requirements necessitate the implementation of an avionics display system that would present flight status information efficiently and in a manner most conducive to enhancing F-14D pilot and Radar Intercept Officer (RIO) performance. In order to accomplish this, Human Factors Engineers at Grumman Corporation elected to utilize multi-color Computer Aided Design and Manufacturing (CADAM) in the design and evaluation of the Weapon Status Panel, Head-Up and Multi-Function display systems. The multi-color CADAM was used because of its unique ability to present this information efficiently, realistically and at the earliest stage in the design phase. This paper discusses the rationale for using the color CADAM as a design and evaluation tool and presents examples of specific computer generated display formats for use in the F-14D tactical fighter cockpit avionics system.

A Comparison of Manual and Vocal Response Modes for the Control of Aircraft Systems

The objective of this study was to determine how a vocal response mode compared to a manual response mode for data entry in a fighter cockpit simulator. Specifically, both vocal and manual response modes were compared in single and dual task conditions on the basis of pilot flight performance, response time, and errors while accomplishing several communication, navigation, and weapons tasks. The results indicated that the manual response mode was more effective than the vocal response mode in terms of response time data; however, the vocal response mode was more effective in terms of flying performance data.

Crew System Assessment Methods Applied to Derivative Fighter Cockpits

Representatives from five Air Force Laboratories were tasked to perform an assessment of conceptual cockpit designs being considered for a derviative, dual role fighter weapon system. An in-cockpit “role playing” exercise, demonstrating the tasks of a composite weapon system mission scenario, was employed in obtaining expert subject opinion data.

Getting the Picture in Fighter Cockpits

This narrated, color, 16 1/2 minute film describes the type of experiments being performed in the Air Force's Flight Dynamics Laboratory's Digital Synthesis Simulator. The purpose of these experiments is to develop new controls/displays concepts for the next generation fighter aircraft. The simulator is fixed-base and its cockpit is the size of an A-7. The cockpit's electro-mechanical instruments have been replaced with six cathode ray tubes (CRTs). Two of the CRTs are color and four are black-and-white. Through software programming, new display and control concepts are implemented on the display surfaces. Past work discussed in the film includes: development of multifunction control logic, design of integrated monochrome display formats, and development of color-coded formats. On-going projects discussed in the film include: designing pictorial formats to replace current alphanumeric formats; designing computer-generated synthetic terrain displays to replace current radar displays; and designing algorithms which enable the cockpit computer to identify emergency conditions and perform the necessary emergency procedures for the pilot. The film emphasizes the necessity of a research team composed of members with different areas of expertise. For example, the Digital Synthesis Simulation team is composed of human factors psychologists, pilots, engineers, and software and hardware experts. It also emphasizes the necessity to examine the human factors design of equipment in as near an operational setting as possible before production is pursued.