Rollover Index for Rollover Mitigation Function of Intelligent Commercial Vehicle’s Electronic Stability Control

This paper describes a rollover index for detection or prediction of impending rollover in different driving situations using minimum sensor signals which can be easily obtained from an electronic stability control (ESC) system. The estimated lateral load transfer ratio (LTR) was used as a rollover index with only limited information such as the roll state of the vehicle and some constant parameters. A commercial vehicle has parameter uncertainties because of its load variation. This is likely to affect the driving performance and the estimation of the dynamic state of the vehicle. The main purpose of this paper is to determine the rollover index based on reliable measurements and the parameters of the vehicle. For this purpose, a simplified lateral and vertical vehicle dynamic model was used with some assumptions. The index is appropriate for various situations although the vehicle parameters may change. As part of the index, the road bank angle was investigated in this study, using limited information. Since the vehicle roll dynamics are affected by the road bank angle, the road bank angle should be incorporated, although previous studies ignore this factor in order to simplify the problem. Because it increases or reduces the chances of rollover, consideration of the road bank angle is indispensable in the rollover detection and mitigation function of the ESC system. The performance of the proposed algorithm was investigated via computer simulation studies. The simulation studies showed that the proposed estimation method of the LTR and road bank angle with limited sensor information followed the actual LTR value, reducing the parameter uncertainties. The simulation model was constructed based on a heavy bus (12 tons).

Realisation and testing of novel fully articulated bird-inspired flapping wings for efficient and agile UAVs

Large birds have evolved an effective wing anatomy and mechanics, enabling airborne mastery of manoeuvres and endurance. For these very reasons, they are difficult to replicate and study. The aim of the present work is to achieve active wing articulations to mimic natural bird flapping towards efficient and agile Unmanned Aerial Vehicles (UAVs). The proposed design, bio-mimicking the black-headed gull, Larus ridibundus, has three active and independent servo-controlled wing joints at the shoulder, elbow and wrist to achieve complex controls. The construction of the wing is realised through a polymeric skin and carbon fibre–epoxy composite spars and ribs. The wing movements (flapping, span reduction and twisting) envelopes of the full-scale robotic gull (Robogull) are examined using the Digital Image Correlation (DIC) technique and laser displacement sensing. Its aerodynamic performance was evaluated in a wind tunnel at various flapping parameters, wind speeds and angles of attack. It is observed that a flapping amplitude of 45 $^\circ$ is more favourable than 90 $^\circ$ for generating higher lift and thrust, while also depending on the presence of span reduction, twist and wind speed. The model performs better at a flying velocity of 4m/s as compared with 8m/s. Both lift and thrust are high at a higher flapping frequency of 2.5Hz. Combined variation of the flapping frequency and stroke ratio should be considered for better aerodynamic performance. The combination of a lower stroke ratio of 0.5 with a flapping frequency of 2.5Hz generates higher lift and thrust than other combinations. Span reduction and wing twist notably and independently enhance lift and thrust, respectively. An increase in the angle-of-attack increases lift but decreases thrust. The model can also generate a significant rolling moment when set at a bank angle of 20 $^\circ$ and operated with independently controlled flapping amplitudes for the wings (45 $^\circ$ for the left wing and 90 $^\circ$ for the right wing). Based on the optimal values for the flapping amplitude (45 $^\circ$ ), flapping frequency (2.5Hz) and flying velocity (4m/s), the Strouhal number (St) of the Robogull model is 0.24, lying in the optimal range ( $0.2 < \mathrm{St} < 0.4$ ) for natural flyers and swimmers.

Data Processing in the Pilot Training Process on the Integrated Aircraft Simulator

Flight safety is an integral part of air transportation. Flight accidents are highly unlikely to appear but most of them are caused by the human factor. The aircrew training system for abnormal operations relies on integrated aircraft simulator-based exercises. Crew needs to be trained not to degrade piloting technique quality when facing increased psychophysiological tension. Therefore, methods evaluating the characteristics of ergatic aircraft control systems, warning systems for deterioration due to failures in avionics systems, piloting technique quality, and abnormal operation algorithms are necessary. An analysis of the bank angle has revealed that there are hidden increased tension manifestations in the human operator expressed in the transition of the flight parameter variation from a stationary random process to deterministic fluctuations in the form of a sinusoid. The goal of the research is to increase the efficiency of pilots’ training using integrated aircraft simulators based on the design and implementation of statistical data processing algorithms. To achieve the goal of the research, two algorithms for detecting deterministic fluctuations based on the Neyman-Pearson criterion and the optimal Bayesian criterion are developed. The presented algorithms can be used in the integrated simulator software to automate the decision-making process on piloting quality.

Increasing Altitude and the Optokinetic Cervical Reflex

INTRODUCTION: When an aircraft banks pilots will reflexively tilt their heads in the opposite direction, known as the optokinetic cervical reflex (OKCR). This is elicited by the appearance of the horizon and is an attempt to keep the moving horizon stable on the pilots retina to help maintain spatial orientation. The appearance of the horizon and the visual environment changes at higher altitudes and there is little research studying the effects of this. Our hypothesis was that increasing altitude would alter the visual cues present and decrease the OKCR.METHODS: There were 16 subjects who flew two flights in a flight simulator while their head tilt, aircraft altitude, and angle of aircraft bank were recorded. The flights were at an altitude of under 1500 ft above ground and above 15,000 ft above ground.RESULTS: Aircraft bank caused head tilt in the opposite direction at both altitudes. A two-way ANOVA with Bonferroni post hoc tests showed that 86% of aircraft bank angles from 0 to 90 in either direction had a head tilt that was statistically significantly smaller at high altitude.DISCUSSION: This study shows that there appears to be a difference between the OKCR at low and high altitude. Pilots at higher altitude seem to exhibit a smaller head tilt for the same aircraft bank angle. More research is required to fully understand why there is a decrease in the OKCR at high altitude, as well as the actual consequences of the decreased reflex on pilot orientation.Stewart MA, Pingali S, Newman DG. Increasing altitude and the optokinetic cervical reflex. Aerosp Med Hum Perform. 2021; 92(5):319325.

Signs of Reincarnation: Exploring Beliefs, Cases, and Theory by James Matlock

At 1606:22, Clipper 759 informed the tower that it was ready for takeoff. At 1606:24, the local controller cleared the flight for takeoff, and at 1606:30, the first officer acknowledged the clearance. The acknowledgement was the last radio transmission received from Clipper 759. On July 8, 1982, Pan American World Airways Flight 759 (Clipper 759), a Boeing 727-235, N4737, was a regularly scheduled passenger flight from Miami, Florida, to Las Vegas, Nevada, with an en route stop at New Orleans, Louisiana. About 1607:57 central daylight time, Clipper 759, with 7 crewmembers, 1 nonrevenue passenger on the cockpit jumpseat, and 137 passengers on board, began its takeoff from runway 10 at the New Orleans International Airport, Kenner, Louisiana. At the time of flight 759’s takeoff, there were showers over the east end of the airport and to the east end of the airport along the airplane’s intended takeoff path. The winds at the time were gusty, variable, and swirling. Clipper 759 lifted off the runway, climbed to an altitude of between 95 feet to about 150 feet above the ground, and then began to descend. At 1608:57, the Ground Proximity Warning System (GPWS) activated and “Whoop whoop pull up whoop. . . .” was recorded. The airplane struck a line of trees about 2,376 feet beyond the departure end of runway 10 at an altitude of about 50 feet above the ground. The airplane continued on an eastward track for another 2,234 feet hitting trees and houses and then crashed into a residential area about 4,100 feet from the end of the runway. The airplane was destroyed during the impact, explosion, and subsequent ground fire. One hundred forty-five persons on board the airplane and eight persons on the ground were killed in the crash. Six houses were destroyed; five houses were damaged substantially.1,2 Moreover, nine people on the ground suffered severe injuries. The aircraft hit the ground with a considerable left bank angle, firstly hitting an oak tree with the left wing, cutting the power and the telephone lines mounted on poles, then destroying the houses of the Schultz family, the neighboring house, and a few others, and eventually cartwheeled and broke into pieces. Kerosene spilled from the ruptured tanks and ignited although there was a thunderstorm with heavy rain; three members of the Schultz family staying in their house were badly burned, one of them died in hospital. Among those killed on the ground—actually the first victim along the swathe of destruction caused by the crashing/impacting aircraft—was Jennifer Schultz, then eleven years of age, who was in the carport (perhaps was talking on the telephone, sitting on a swing there as she used to do) when disaster struck. On March 11th, 2008, in Bartlesville, Oklahoma, a girl, Rylann, was born to the O’Bannion family. Rylann appeared to be developing earlier than usual, but she showed some curious habits, e.g., for some time she kept sleepwalking. She started complaining that her hair touching her back hurt her back; she drew dramatic fits about putting on shirts. The clothing, she would complain, hurt her back, neck, and shoulders—it felt like her skin was burning. Referring to a photograph she mentioned time and again, she had been “bigger” than on that picture, a statement that didn’t make sense to her mother at that point in time. Eventually, at the age of three years and five months, again touching the topic of having been “bigger” before, she said: “Mommy, I died. I was in our backyard. It was raining. I was alone but I wasn’t scared. Then the rain shocked me. It was raining a lot. There was a loud noise, then the rain shocked me. I floated up to the sky then.” As the O’Bannion family subscribed to the Catholic faith, reincarnation was not a subject to consider. Over time, Rylann added new bits of memory; at the age of five she started talking about what happened to her “in heaven” after her death (meeting God and Jesus, and ‘Grandy Sally’ whom she never had met in reality), and that “you can choose to come back if you died before you were supposed to.” Once, out of the blue, she said “I remember the name of Jennifer.”

Turbulence Scale in Compound Channel

&lt;p&gt;The study of turbulence in a compound channel would address the nature of sedmient transport and bank erosion activity. The study would also give insights of embankment and levee breaches at the time of high flood. Experimental investigations were conducted on two compound channels of 31&lt;sup&gt;0&lt;/sup&gt; and 45&lt;sup&gt;0&lt;/sup&gt; bank angle in the laboratory flume to study the turbulece scale. Velocity data were recorded with Nortek Velocimeter at seven different locations (3 locations at the upstream, 3 locations at the downstream and 1 location at the middle) of the compound channel. Turbulence scale like Taylor microscale (&amp;#955;&lt;sub&gt;T&lt;/sub&gt;)&amp;#160;estimates the length scale of the inertial sub- range. The Taylor scale is calculated as:&lt;/p&gt;&lt;p&gt;&lt;img src=&quot;https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.0042175ca60061700501161/sdaolpUECMynit/12UGE&amp;app=m&amp;a=0&amp;c=2968072e536f82f8e38df248a26aa4a7&amp;ct=x&amp;pn=gepj.elif&amp;d=1&quot; alt=&quot;&quot; width=&quot;199&quot; height=&quot;148&quot;&gt;&lt;/p&gt;&lt;p&gt;The Taylor microscale analysis showed dominance in the main channel for 45&lt;sup&gt;0&lt;/sup&gt; bank angle as compared to 31&lt;sup&gt;0&lt;/sup&gt; bank angle. In the location of slope midpoint and floodplain region of the compound channel, Taylor microscale was more dominant for 31&lt;sup&gt;0&lt;/sup&gt; bank angle. Another important observation in both the compound channels (31&lt;sup&gt;0&lt;/sup&gt; and 45&lt;sup&gt;0&lt;/sup&gt; bank angle) is the dominance of Taylor microscale at the upstream section of the channel as compared to the downstream part of the channel. The results from the study would help us to get a better understanding of the role of turbulence in the morphological changes in a compound channel with different bank angles.&lt;/p&gt;

Hydrodynamic Analysis of KVLCC2 Ship Sailing near Inclined Banks

The hydrodynamic forces of KVLCC2 ship sailing near inclined banks are calculated by using CFD based on RANS equation. Corresponding CFD uncertainty analysis is conducted according to the procedure recommended by ITTC. An unstructured grid, tetrahedral grid, is employed for discretization. To control the number of grids, global element scale factor is selected as the same as refinement ratio. In numerical simulation, straightforward and oblique navigation conditions are investigated. The variation of transverse force and yaw moment with the ship-shore distance, bank angle, water depth, and drift angle are analyzed. Both hull model and hull-propeller-rudder model are considered in numerical simulation. The simulation results show the hydrodynamic characteristics of ship sailing near inclined banks.

Generation of Radiation Patterns Equivalent to In-Flight Measurements

Comparison of in-situ measured antenna radiation patterns (RPs) to modeled ones is vital for validation of both. Inflight measured RPs do not always produce a standard conic or elevation cut (constant θ or ϕ angle, respectively), but rather Great Circle (GC) cuts at the aircraft bank angle of interest. WIPL-D’s post-processing routines, on the other hand, do not produce GC cuts in normal setups. A manipulation of the aircraft orientation in xyz-coordinates is required to accomplish this task. Under standard conditions in WIPL-D, the fuselage is positioned parallel to the x-axis and the wings parallel to the y-axis. A model rotation of 90° with respect to the y-axis allows for the generation of GC cuts, where θ and ϕ swap roles. This makes comparison between in-flight measurements and computed data cumbersome. This paper investigates several options to produce non-standard RPs in WIPL-D and MATLAB (using WIPL-D results) that are equivalent to those of in-flight measurements.

Rapid Algorithm for Generating Entry Landing Footprints Satisfying the No-Fly Zone Constraint

An online estimation algorithm of landing footprints based on the drag acceleration-energy profile is proposed for an entry hypersonic vehicle. Firstly, based on the Evolved Acceleration Guidance Logic for Entry (EAGLE), drag acceleration-energy profiles are designed. To track the drag acceleration-energy profile obtained by the interpolation, a drag acceleration tracking law is designed. Secondly, based on the constraint model of the no-fly zone, flying around strategies are proposed for different conditions, and a reachable area algorithm is designed for no-fly zones. Additionally, by interpolating the minimum and maximum drag acceleration profiles, the terminal heading angle constraint is designed to realize the accurate calculation of the minimum and maximum downrange ranges by adjusting the sign of the bank angle. In this way, the distribution of landing footprints is more reasonable, and the boundary of a reachable area is more accurate. The simulation results under typical conditions indicate that the proposed method can calculate landing footprints for different situations rapidly and with the good adaptability.