Evasive Maneuvers Research Articles

Space evasive maneuvers: what is the viable technological parameters?15 / Manobras evasivas do espaço: quais são os parâmetros tecnológicos viáveis?

Space Debris (SD) is the by-product of space missions and Earth's gravitational capture in the dynamics of the Solar System. Their accumulation in this environment constitutes a real and permanent risk for these missions. Mathematical and computational analysis for the relative dynamics between SD and a space vehicle, considering the Earth's gravitational and propulsion forces, is performed in this work. Exhaustive numerical simulations of the model were performed for suboptimal technological parameters (power factor, exhaust speed) and physical parameters (start and duration of propulsion) suitable for evasive maneuvers for minimum fuel consumption and relative distance accuracy. The simulation results identify important patterns that help us understand the characteristics of space vehicle propellant control parameters for evasive maneuvers.

Vestibular and oculomotor function in male combat sport athletes

ObjectivesTo investigate for differences in vestibulo-ocular function between active male combat sport athletes and a healthy control group. In addition, to explore the relationship between symptom-based outcome measures with vestibulo-ocular function. DesignCross-sectional. Methods40 male adult combat sport athletes and 40 active male control participants were recruited from 4 martial arts schools and a University campus in Queensland, Australia. All participants completed a standardised protocol which was used to assess vestibulo-ocular function. The protocol included 3 components: 1) oculomotor function, 2) benign paroxysmal positional vertigo screening, and 3) vestibulo-ocular reflex function. The Post-Concussion Symptom Scale, Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were used as symptom-based outcome measures. ResultsMore combat sport athletes had oculomotor abnormalities than control group participants. There were no between group differences in benign paroxysmal positional vertigo, vestibulo-ocular reflex function and the video-head impulse test gain (ms). Combat sport athletes had higher symptom-based outcome scores. The Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were found to have moderate positive relationships with the total number of abnormalities detected in the combat sport group. ConclusionsVestibulo-ocular function is imperative for combat sport athletes to perform evasive manoeuvres and land their own strikes. The present study findings may aid clinicians in the identification of combat sport athletes with underlying vestibulo-ocular dysfunction, prompting further investigation.

Analyses on Aerodynamic and Inertial Loads of an Airborne Pod of High Performance Fighter Jet

A fighter performing a reconnaissance mission is equipped with a pod that drives optical/infrared sensors for acquiring and identifying target information on the lower part of the fuselage. Due to the nature of the reconnaissance mission, the fighter performs high speed evasive maneuvers, and the resulting load should be considered importantly for the development of the pod. This paper concerns a numerical investigation into the inertial and aerodynamic loads of the airborne pod of high performance aircrafts. For the aerodynamic load analysis, the pylon and pod shapes are added to the fighter 3D model, and the commercial software was used for static and dynamic analysis. Considering the practical mission conditions, the common/extreme conditions were established respectively in the static and dynamic situations of pods and the driving torque could be tripled under dynamic conditions. In the analysis of inertia load, a 3-DOF model considering roll and turning maneuvers was derived by the Lagrangian method, and then the numerical integration method was applied to the analysis. As a results, it was conformed that the inertia load was generally induced at a low level compared to the aerodynamic load, but depending on the unbalance mass condition of the pod, the inertia load cannot be negligible.

Ship collision avoidance behaviour recognition and analysis based on AIS data

A novel approach is proposed to automatically identify the ship collision avoidance behaviour from ship trajectories based on an improved Sliding Window Algorithm. The approach has three main stages: (1) determining the ships’ obligations according to the Convention on the International Regulations for Preventing Collision at Sea (COLREGs); (2) assessing the rudder angle according to the true bearing of the target ship; (3) identifying the corresponding ship handling behaviour from the ship trajectory taking into account the Rate of Turn and its derivative based on the Sliding Window Algorithm. Four typical encounter scenarios are studied to demonstrate the feasibility and effectiveness of the proposed method. The approach is then applied to near collision scenarios identified in the maritime traffic off the continental coast of Portugal, which allowed the characterization of the relative and spatial distributions of the locations at which the ships take evasive manoeuvres. The results show that the approach can be applied to accurately detect the ship collision avoidance behaviour from Automatic Identification System trajectory data, and the characterization of the collision avoidance behaviour can potentially be used by situational awareness systems and as the basis for ship collision avoidance decision-making.

State Prediction of Human-in-the-Loop Multi-rotor System with Stochastic Human Behavior Model

Reachability analysis is a widely used method to analyze the safety of a Human-in-the-Loop Cyber Physical System (HiLCPS). It allows the HiLCPS to respond against an imminent threat in advance by predicting reachable states of the system. However, it could lead to an unnecessarily conservative reachable set if the prediction only relies on the system dynamics without explicitly considering human behavior, and thus the risk might be overestimated. To avoid the conservativeness, we present a state probability distribution function (pdf) prediction method which takes into account a stochastic human behavior model represented as a Gaussian Mixture Model (GMM). In this paper, we focus on the multi-rotor controlled by a human operator in a near-collision situation. The stochastic human behavior model is trained using experimental data to represent the human operators’ evasive maneuver. Then, we can retrieve a human control input pdf from the trained stochastic human behavior model using the Gaussian Mixture Regression (GMR). The proposed algorithm predicts the multi-rotor's future state pdf by propagating the pdf of the retrieved human control input according to the given dynamics, which yields closed-loop analysis of the HiLCPS. Human subject experiment results are provided to demonstrate the effectiveness of the proposed algorithm.

Safe and efficient maneuvering of a Maritime Autonomous Surface Ship (MASS) during encounters at sea: A novel approach

When introducing a collision avoidance system on a Maritime Autonomous Surface Ship (MASS) for encounters at sea, it may seem reasonable to assume that an approaching ship will follow the procedures presented in the International Regulations for Preventing Collisions at Sea (COLREG). Experience has shown, though, that mariners sometimes, based on good seamanship, make situational adaptations where they deviate from the steering rules in the COLREG. Their goal may be to improve efficiency in own operations or simply due to courtesy of a perhaps less maneuverable approaching ship. In this paper an analysis has been performed to characterize the situations when such deviations typically occur and to estimate the conditional probability of such deviations, given the respective situation. Furthermore, the paper proposes a design for how an artificial intelligence (AI) system may handle these situations through an Extended Timeframe for AI Decision (ETAD). We suggest that the AI system search through the available clusters of situations before it normally would suggest an evasive maneuver. If the identified situation is similar to situations where the probability of an approaching ship deviating the COLREG and give way is significant, the AI could be given an extended timeframe, await its maneuver, and thereby improve the efficiency of the operation without jeopardizing the safety.

Influencing Human Escape Maneuvers With Perceptual Cues in the Presence of a Visual Task

Visual engagement is common in many situations where human operators must perform tasks in challenging environments. This visual engagement has the potential to impact the safety of these operators when dealing with dynamic threats. Perceptual cues have been shown to elicit physical evasion maneuvers, thereby improving safety. In this article, we investigate the effects of cues and visual engagement on rapid whole-body responses. The visual task, inspired by the Trail Making Test (TMT), served as a proxy for visual engagement in the real world. Our continuous TMT minigame and threat simulation are implemented in a virtual reality environment. Participants attempt to maximize their performance score by quickly solving TMTs and dodging dynamic threats from various in-plane directions. They are provided with no cues (control), visual cues, and vibrotactile cues indicating impending threat directions. Participant’s ability to dodge threats is quantified by failure rate and reaction time within field of view and for all approach directions. An index of difficulty highlighted perceptual cue response sensitivity to varying threat speeds and sizes. This article provides two core key contributions and other interesting findings: 1) the results illustrate that tactile cues enable statistically significantly better dodging rates than visual cues or with human vision alone (control condition); and 2) that visual engagement degrades human evasion performance in a statistically significant way. Finally, tactile cue responses appear to be less sensitive than visual cues to visually engaging tasks within the higher portion of difficulty index range that is investigated.

Carabid adaptation to a collembolan diet: hunting efficiency and nutritional value

1. Collembola are an important potential food source for carnivorous arthropods living on the soil surface. Nevertheless, due to their effective evasive manoeuvres, Collembola are not an easy prey. Several carabid groups, however, have evolved morphological specialisations to overcome this otherwise effective defence strategy. The adaptive value of this specialisation is still unclear, since some generalist carabids also consume collembolans.2. Feeding experiments with the collembolan specialist Notiophilus biguttatus and four generalist carnivorous carabids revealed that the specialised species are more efficient in hunting Collembola than the generalist species.3. A comparison between specialised and generalist carabid species subjected to a pure collembolan diet further suggests that Collembola are only a dietary supplement for generalists: the generalist carnivore Bembidion lampros decreased in weight and had a higher mortality rate when fed exclusively with collembolans.4. Analogously, a third experiment shows that edaphic mites or other non‐collembolan soil arthropods are just a nutritional supplement for N. biguttatus, since mortality increased when they were fed exclusively with these groups. The adaptation toward Collembola as prey, in contrast, does not constrain N. biguttatus, since they even increased in weight when fed with drosophila.5. The enhanced hunting efficiency of N. biguttatus on Collembola compared to generalist species supports the hypothesis that the convergent evolution of mandibles in all collembolan specialist carabids is highly adaptive. The advantage of specialisation most probably is reinforced by the fact that generalist carabids are not real competitors for specialists, due to their poor efficiency in utilising collembolans.

The Potential of Hypersonic Weapons and the Great Military Powers Strategy regarding their Production. Case Study

Hypersonic missiles are a new category of weapons that have sparked intense debate among security experts. The hypersonic weapons, this combination of speed, accuracy, surprise, and maneuverability makes the defense against them more difficult than against standard ballistic or cruise missiles and therefore makes them more destabilizing. Capable of traveling over five times the speed of sound (Mach 5), and of performing evasive maneuvers mid-flight, they are considered practically impossible to intercept using conventional missile defense systems. Innovative nuclear and conventional weapon delivery systems are impressive and developing. These are grouped into three categories: intercontinental ballistic missiles, hypersonic delivery systems and new advanced strategic weapon delivery capabilities. These and other technological advances being made simultaneously may also impact arms control and strategic stability. Other characteristics of hypersonic systems, however, are potentially advantageous compared with ballistic missiles. Of particular interest are the ability to fly at low altitude, making detection by earth-based sensors difficult; the ability to maneuver during flight to avoid detection and interception; and the unpredictability of targets, since hypersonic vehicles do not follow a ballistic trajectory.

Impactul tehnologiilor emergente și disruptive asupra domeniului militar

Hypersonic missiles are a new category of weapons that have sparked intense debate among security experts. The hypersonic weapons, this combination of speed, accuracy, surprise, and maneuverability makes the defense against them more difficult than against standard ballistic or cruise missiles and therefore makes them more destabilizing. Capable of traveling over five times the speed of sound (Mach 5), and of performing evasive maneuvers mid-flight, they are considered practically impossible to intercept using conventional missile defense systems. Innovative nuclear and conventional weapon delivery systems are impressive and developing. These are grouped into three categories: intercontinental ballistic missiles, hypersonic delivery systems and new advanced strategic weapon delivery capabilities. These and other technological advances being made simultaneously may also impact arms control and strategic stability. Other characteristics of hypersonic systems, however, are potentially advantageous compared with ballistic missiles. Of particular interest are the ability to fly at low altitude, making detection by earth-based sensors difficult; the ability to maneuver during flight to avoid detection and interception; and the unpredictability of targets, since hypersonic vehicles do not follow a ballistic trajectory.

The Interaction between the LEO Satellite Constellation and the Space Debris Environment

The wide application of satellite constellations in the field of space-based global communications and remote sensing has led to a substantial increase in small-satellite launch plans, a sharp increase in the density of space objects in low-Earth orbit (LEO), and a reduction in available orbit and frequency resources. This will further aggravate the trend of deterioration of the space debris environment. Taking the Starlink constellation as an example, this paper describes the influence of the constellation from the environmental debris flux of the satellite, the evaluation of the number of evasion maneuvers, the change of risk level, the success rate of post mission disposal (PMD) and the growth rate of space objects. The simulation results show that the collision risk of the Starlink constellation is related to the orbital parameters, and the higher success rate of post-mission disposal (PMD) can reduce the collision risk of the constellation. The large constellations increases the growth rate of space objects, and even if all the satellites are disposed of after the mission, the impact of constellations on the space environment can not be offset.

Evaluation of static belt fit and belt torso contact for children on belt-positioning booster seats

Objective: Previous studies have indicated that gap between the seatbelt and torso (reduced belt torso contact) for children on belt-positioning booster seats (BPBs) may lead to less torso engagement and increased likelihood of shoulder belt slip-off during evasive vehicle maneuvers, potentially increasing injury risk during crashes. However, current BPB belt fit measures do not quantify belt gap and may not be able to fully discriminate between designs which provide good vs. poor dynamic outcomes. The goal of this study was to evaluate both novel (belt gap characteristics) and conventional measures of seatbelt fit for BPB-seated children. Methods: Ten BPBs and three seatbelt anchor locations were investigated. Fifty volunteers (4-14 years) were recruited and each evaluated on six unique combinations of BPB and seatbelt anchor location on a vehicle rear seat in a laboratory setting. A 3 D coordinate measurement system quantified positions of anatomic, seatbelt, BPB, and vehicle reference points. Novel belt gap (gap size, length, location, and percent torso contact) and conventional belt fit (position of belt on shoulder and pelvis) metrics were calculated using anatomic and seatbelt landmarks. Variation in belt fit and belt gap outcomes due to BPB, seatbelt anchor location, and anthropometry were investigated. Results: BPBs produced significantly different outcomes, while seatbelt anchor location did not. BPBs with features that directly routed the lower portion of the shoulder belt more forward on the buckle side produced the largest (29.3 ± 12.6 mm) and longest (106.9 ± 68.2 mm) belt gap on average, while BPBs that pulled the belt less forward or did not directly route the belt produced the smallest (13.9 ± 6.7 mm) and shortest (16.9 ± 33.9 mm) gap on average. Belt gap outcomes were not strongly correlated with conventional belt fit metrics, indicating that evaluation of belt gap may provide additional insight when attempting to discriminate between BPBs which provide good vs. poor seatbelt engagement during vehicle maneuvers and crashes. Conclusions: This is the first study to evaluate belt gap characteristics for BPB-seated children. Results suggest that belt fit and belt gap are influenced by BPB design, particularly lower shoulder belt routings, and may have implications for belt engagement during dynamic events.

Rapid algorithm for covariance ellipsoid model based collision warning of space objects

The recent decades have witnessed a tremendous growth in the number of satellites and debris in space, leading to an increasingly high risk of collision between space objects. Collision warning aims at assessing the collision risk between space objects and attempts to identify possible collisions in order for satellites to perform evasive maneuvers in advance. Current collision warning methods are based on the computation of collision probability and comparison with some tolerance threshold. Such a threshold is usually set according to experience. In contrast, this paper proposes to use covariance ellipsoid with a user defined Mahalanobis distance to represent the most possible region in which the relative position vector distributes. Zero vector represents the collision event, and once it enters this ellipsoid, a collision warning occurs. A collision warning function along with a definite threshold is then formulated based on this criterion. Moreover, in order to rapidly predict the possible collision intervals, a self-adaptive Hermite interpolation technique is applied to approximate the collision warning function by piecewise cubic polynomials for efficient roots finding. Finally, the proposed collision warning criterion has been evaluated in several collision scenarios. Comparison experiments are also conducted with the brute force method and analytical propagators. The simulation shows that the calculation of collision warning interval based on the proposed criterion is effective, and the self-adaptive Hermite interpolation method performs high efficiency and accuracy.

Engagement-Scenario-Based Decoy-Effect Simulation Against an Anti-ship Missile Considering Radar Cross Section and Evasive Maneuvers of Naval Ships

The survivability of a naval ship is the ability of the ship and its onboard systems to remain functional and continue a designated mission in man-made hostile environments. A passive decoy system is primarily used as a weapon system for improving the survivability of a naval ship. In this study, an engagement scenario-based simulation program was developed for decoy effectiveness assessments against an anti-ship missile (ASM), which tracks a target with sea-skimming and active radar homing. The program can explain the characteristics of a target ship, such as the radar cross section and evasive maneuvers, as well as the operational performance of the onboard decoy system, the guidance method of the ASM, and the engagement environment’s wind speed and direction. This paper describes the theory and formulations, configuration, and user interface of the developed program. Numerical examples of a decoy effect assessment of a virtual naval ship against an ASM are presented.

Are novice drivers competent to take over control from level 3 automated vehicles? A comparative study with experienced drivers

With level 3 automated vehicles poised to appear on the roads soon, takeover remains a major challenge. At present, the effect of manual driving experience on takeover performance is unknown. Therefore, a simulator study was conducted to investigate the influence of driving experience (novice and experienced) on takeover performance in different takeover time budgets (7 s and 5 s) and in combination with a visual secondary task (i.e., surrogate reference task). Data from 48 young and middle-aged participants consisting of 24 novice and 24 experienced drivers were used for this study. Researchers found that the overall stability of evasive maneuvers by novice drivers was considerably worse than that by experienced drivers. A detailed analysis showed that the influence of driving experience on takeover stability was mainly reflected in longitudinal control rather than lateral control. A significant interaction between driving experience and visual secondary task showed that the latter had a substantial impact on the takeover stability of experienced drivers but not on that of novice drivers. Researchers also found that rich manual driving experience cannot make the takeover process of experienced drivers more stable than that of novice drivers under conditions of eye-off-road. In addition, no significant difference was found between novice and experienced drivers in automation disengagement time, takeover time and minimum time to collision. Results indicate that novice drivers have poor takeover stability and weak adaptability, but their longitudinal collision risk is not deteriorated by the lack of manual driving experience.

Maximally efficient prediction in the early fly visual system may support evasive flight maneuvers.

The visual system must make predictions to compensate for inherent delays in its processing. Yet little is known, mechanistically, about how prediction aids natural behaviors. Here, we show that despite a 20-30ms intrinsic processing delay, the vertical motion sensitive (VS) network of the blowfly achieves maximally efficient prediction. This prediction enables the fly to fine-tune its complex, yet brief, evasive flight maneuvers according to its initial ego-rotation at the time of detection of the visual threat. Combining a rich database of behavioral recordings with detailed compartmental modeling of the VS network, we further show that the VS network has axonal gap junctions that are critical for optimal prediction. During evasive maneuvers, a VS subpopulation that directly innervates the neck motor center can convey predictive information about the fly's future ego-rotation, potentially crucial for ongoing flight control. These results suggest a novel sensory-motor pathway that links sensory prediction to behavior.

A Novel Maneuver-Based Driving Envelope Generation Approach for Driving Safety Assessment

It is of utmost importance for advanced driver assistance systems to evaluate the risk of the current situation and make continuous decisions about what kind of evasive maneuver can be initiated. The purpose of this paper is to establish efficient indicators to evaluate the risk of candidate driving maneuvers for a human-in-the-loop vehicle. A novel safe driving envelope generation method is proposed, which takes various constraints into consideration, including the human operation, vehicle motion limits, and collision avoidance with road boundary and obstacles. The efficiency of the proposed method is validated by simulation experiments and real vehicle tests. The results show that the feasibility of candidate driving maneuvers can be efficiently determined by computing the driving envelope, and the proposed driving envelope method can be easily implemented for real-time applications.

FEAR RHETORIC IN THE ONLINE NEWS DISCOURSE ON THE COVID-19 PANDEMIC IN TEUN VAN DIJK’S CRITICAL DISCOURSE ANALYSIS

The news media, once thought to be only as a tool of information delivery, has subtly shifted its roles as an agent of (de)constructing thoughts, introducing, or denoting fear especially in appalling news. This raises a question whether the news on the COVID-19 pandemic is only for transmitting news updates on the pandemic condition or agenda-driven. However, research tapping into the imbued messages in language complexity in this context seems minimal. This study aims to uncover the language elements that sign fear in a news text. This research focuses on how fear is imbued in three online English-language newspaper articles in Indonesia published by the Jakarta Post, thereby the rhetoric of fear. The three articles discussed the spread of COVID-19 in Indonesia. In this study, CDA is devised to reveal the traces of fear-embedded language choices found in the three online newspaper articles. Researchers used the critical analysis discourse model of Teun A. Van Dijk (1993) and the three elements of discourse (1993): micro, macro, and superstructure. Findings indicated that there were common uses of euphemism, dysphemism, and orthophemism to refine the language being conveyed. This study classified euphemism into five objectives: (1) evasive maneuver to prevent mass panic; (2) speech refinement to soften offence, insults, and/ or other language expressions that may result to humiliation; (3) diplomacy tool; (4) language replacement for taboo or vulgar language choices or those endowed with negative connotation (5) tool for satire, sarcasm and subtle criticism. This study also revealed some linguistic decisions, such as lexicon choices and strategies on sentence construction, subtly evident not only to impose fear, but at the same time to dispose it. Researchers hope that this study may assist the readers in pinpointing subtleties in author’s tone and tendency.

An empirical ship domain based on evasive maneuver and perceived collision risk

This paper introduced a new ship domain concept and an analytical framework. The ship domain takes the point of the ship's first evasive maneuver as a basis and correlates it with the navigator-perceived collision risk level. The first evasive maneuver of a ship is detected based on the ship turning point identification and ship intention estimation. The available maneuvering margin (AMM) is utilized as a proxy to measure the perceived collision risk by the navigator. Interpreting the first evasive maneuver in terms of this AMM over a large sample of vessel encounters taken from automatic identification system (AIS) data finally enables an empirical estimation of the size of this ship domain. The method is applied to AIS data in the Northern Baltic Sea, and separate ship domains are constructed for the give-way and stand-on vessels with different maneuverability characteristics. Compared to the existing proximity-based ship domain, this ship domain explicitly incorporates the dynamic nature of the encounter process and the navigator's evasive maneuvers. Several advantages of this proposed ship domain concept and limitations of the presented modeling approach are discussed. Finally, possible future applications are explained, including waterway safety assessment and navigational decision support systems to reduce ship-ship collision risk.

Mining patterns of near-crash events with and without secondary tasks

The engagement of secondary tasks, like using a phone or talking to passengers while driving, could introduce considerable risks to driving safety. This study utilizes a near-crash dataset extracted from a naturalistic driving study to explore the patterns of near-crash events with or without the involvement of secondary tasks as a surrogate approach to understand the impact of these behaviors on traffic safety. The dataset contains information about driver behaviors, such as secondary tasks, vehicle maneuvers, other conflict vehicles’ maneuvers before and during near-crash events, and the driving environment. The patterns for near-crashes with or without the involvement of secondary tasks are mined by adopting the apriori association rule algorithm. Finally, the mined rules for the near-crash events with or without the involvement of the secondary tasks are analyzed and compared. The results demonstrate that near-crashes with the involvement of secondary tasks often occur with drivers in a relatively stable and presumably predictable environment, such as an interstate highway with a constant speed. This type of near-crash is highly associated with the leading vehicle’s sudden slowing or stopping since there is no expectation of any interruptions for these drivers performing the secondary tasks. The most common evasive maneuver in this kind of emergency is braking. Near-crashes without the involvement of secondary tasks is often associated with lane-changing behavior and sideswipe incidents. With shorter reaction time and awareness of the driving environment, the drivers in this type of near-crash can often make more complex maneuvers, like braking and steering, to avoid a collision. Understanding the patterns of these two types of near-crash incidents could help safety researchers, traffic engineers, and even vehicle designers/engineers develop countermeasures for minimizing potential collisions caused by secondary tasks or improper lane changing behaviors.