Lateral Roll Research Articles

History of Low-Order Equivalent Systems for Aircraft Flying Qualities

Introduction F ROM the beginnings of the evolution of flight, there evolved an appreciation of the advantages of an aircraft that was easy for the pilot to fly. Among the insights for which they are famous is the Wright brothers’ realization that when the ability to balance and steer became understood, then aviation would truly have arrived. As the balance between stability and control became better understood, aircraft emerged with sufficiently good flying (or handling) qualities to allow air-to-air combat, reliable passenger transport, and a host of other uses. As aeronautical engineers examined the measurable factors that seemed to bestow good flying qualities, they followed the urge of all engineers, which is to write down those lessons, rules of thumb, and guidelines that make the job easier the next time. From the observations of these engineers, and especially from dedicated research using special-purpose variable-stability aircraft, the community began to document characteristics that were preferred for good flying qualities, along with characteristics that would indicate poor qualities. Most of the early flying-qualities work involved essentially steady-state characteristics like stick force variation with steady, trimmed speed. Dynamic behavior was not so well understood, though early aviators did comprehend the slow tradeoff between altitude and speed in Lanchester’s phugoid mode. They also knew all too well the sinister origins of the slow divergence called the spiral mode. The quick lateral-directional oscillations of the Dutch roll were commonly experienced. Appreciation of the rigidbody modes of motion greatly improved in the first half of the 20th century, including the faster lateral roll mode and the quick angle-of-attack oscillations of the short-period mode. By the middle of the 20th century, engineers realized that the time constants, damping ratios, and natural frequencies of all of these modes could be correlated with flying qualities, good or bad. The stage was set for formal requirements, in the form of military specifications, to define the good and bad values of these modal parameters.

ROBUST GAIN‐SCHEDULED CONTROL OF A VERTICAL TAKEOFF AIRCRAFT WITH ACTUATOR SATURATION VIA THE LMI METHOD

ABSTRACTThis paper presents a robust gain‐scheduled approach for the control of a vertical/short takeoff. and landing (V/STOL) aircraft. The nonlinear aircraft dynamics exhibit non‐minimum phase characteristics arising from the parasitic coupling effect between the aircraft's lateral force and rolling moment. The undesired coupling effect also causes modelling uncertainy of the aircraft dynamics. The nonlinear aircraft dynamics are considered to be composed of a nominal linear parameter varying (LPV) system and a linear system with a norm bounded uncertainy matrix multiplied by the parasitic uncertain non‐minimum phase coupling parameter. The nominal LPV system is considered to be affinely dependent on a measurable varying parameter. The ranges of the varying parameter and its variation as well as its parasitic induced uncertain matrix are addressed by introducing the parameter‐dependent invariant ellipsoid interpretation for dealing with the issue of affinely quadratic stabilization. In this paper, the relations among the magnitude of actuator saturation, the maximum achievable relative stability, and the sustainable coupling uncertainty are investigated for the considered robust gain‐scheduled design.

Atmospheric Disturbances that Generate Intermittent Turbulence in Nocturnal Boundary Layers

Using the unprecedented observational facilities deployed duringthe 1999 Cooperative Atmosphere-Surface Exchange Study (CASES-99),we found three distinct turbulent events on the night of 18October 1999. These events resulted from a density current,solitary wave, and internal gravity wave, respectively. Our studyfocuses on the turbulence intermittency generated by the solitarywave and internal gravity wave, and intermittent turbulenceepisodes associated with pressure change and wind direction shiftsadjacent to the ground. Both the solitary and internal gravitywaves propagated horizontally and downward. During the passage ofboth the solitary and internal gravity waves, local thermal andshear instabilities were generated as cold air was pushed abovewarm air and wind gusts reached to the ground. These thermal andshear instabilities triggered turbulent mixing events. Inaddition, strong vertical acceleration associated with thesolitary wave led to large non-hydrostatic pressure perturbationsthat were positively correlated with temperature. The directionaldifference between the propagation of the internal gravity waveand the ambient flow led to lateral rolls. These episodic studiesdemonstrate that non-local disturbances are responsible for localthermal and shear instabilities, leading to intermittentturbulence in nocturnal boundary layers. The origin of thesenon-local disturbances needs to be understood to improve mesoscalenumerical model performance.

三次元蛇型ロボットにおける体幹ねじり型移動の解析とＧＡによる移動形態推移時の運動計画

We analyze the the lateral rolling type of locomotion, present path planning of shape transition, and develop a 3-dimensional snake-like robot. First we propose one of a lateral rolling type of locomotion “Twisting mode” and analyze the principle of the locomotion based on statics. Next, the motion planning using Genetic Algorithm for transition of locomotion modes is explained and simulation results for the GA research are shown. Finally, we explain the designed prototype system and experimental results are shown.

Adaptation of the macular vestibuloocular reflex to altered gravitational conditions in a fish ( Oreochromis mossambicus)

Young fish ( Oreochromis mossambicus) were exposed to microgravity (μg) for 9 to 10 days, or to hypergravity (hg) for 9 days. For several weeks after termination of μg and hg, the roll-induced static vestibuloocular reflex (rVOR) was recorded. In stage 11 12 -fish, the rVOR amplitude (angle between the maximal up and down movement of an eye during a complete 360° lateral roll) of μg-animals increased significantly by 25% compared to 1g-controls during the first post-flight week but decreased to the control level during the second post-flight week. Microgravity had no effect in stage 14 16 fish on the rVOR amplitude. After 3g-exposure, the rVOR amplitude was significantly reduced for both groups compared to their 1g-controls. Readaptation to 1g-condition was completed during the second post-3g week. We postulate a critical period during which the development of the macular vestibuloocular reflex depends on gravitational input, and which is limited by the first appearence of the rVOR. At this period of early development, exposure to microgravity sensitizes the vestibular system while hypergravity desensitizes it.

Assessment of open-loop rollover control of articulated vehicles under different manoeuvres

In this paper, a comprehensive three-dimensional heavy vehicle model is developed to investigate the effectiveness of an open-loop roll instability control. The steering system compliance, roll steer, bump steer, Ackerman steer and wrap steer are incorporated in the vehicle model, along with a comprehensive tyre model and ABS algorithm. Time delays due to a driver's reaction and the transportation lag of the braking system are characterized by a variable called the reaction delay. The rollover indicators in terms of roll safety factor, tractor and trailer lateral accelerations and roll angles, and the rearmost axle roll angle are investigated for their effectiveness for open-loop roll stability control in various cornering and evasive manoeuvres, road conditions, braking efforts, and different reaction delays.

Inhibitory effects of tandospirone, a 5-HT 1A agonist, on medial vestibular nucleus neurons responding to lateral roll tilt stimulation in rats

An electrophysiological study was performed using chloral hydrate-anesthetized rats to determine whether tandospirone, a 5-HT 1A agonist, affects neuronal activities of the medial vestibular nucleus (MVN), since serotonergic innervation and 5-HT 1A receptors are present in this nucleus. Tandospirone applied microiontophoretically at a current of 20–60 nA caused an inhibition of tilt-induced firing of α-type neurons, which showed increased and decreased firing with lateral tilt ipsilateral and contralateral to the recording site, respectively, along with that of β-type neurons which exhibited the reverse responses to ipsilateral and contralateral tilt stimulation. The inhibition was antagonized during simultaneous, iontophoretic application of WAY-100635 (20–60 nA), a 5-HT 1A receptor antagonist, although WAY-100635 alone rarely affected spontaneous or tilt-induced firing in either type of neurons. These results suggest that tandospirone acts on a 5-HT 1A receptor to inhibit transmission of otolith information to α- and β-type MVN neurons.

System Embedding. Classes of the Control Laws

Consideration was given to control of the linear systems using the precompensator and controller. By means of the technology of system embedding, the problem was reduced to the linear matrix equations for which the general structures of classes of all were obtained. In doing so, problems using both the regular and nonregular (with nonreversible precompensator) control laws were encompassed. The generally nonformalizable dependence of the structure of controller class on the choice of the precompensator was shown to be the basic distinction of the nonregular laws. The solution was illustrated by an instructional example and an example of control of the aircraft lateral (roll–yaw) motion.

The modelling and simulation of vehicle handling Part 4: Handling simulation

This is the last in a series of four papers (Parts 1 to 4) looking at the application of computer-based analysis methods to model vehicles and simulate vehicle handling. The material contained in these papers is based on a study carried out in order to investigate the influence of suspension and tyre modelling on the outputs predicted by vehicle handling simulations. The papers deal with analysis methods, vehicle modelling, tyre modelling (which appeared in the previous two Issues) and handling simulation. In this paper an example of a vehicle handling simulation based on a high-speed lane change manoeuvre is presented. The effects of suspension modelling on the accuracy of simulation outputs is discussed on the basis of results obtained using the four vehicle models described in Part 2 of this series. Measured outputs such as lateral acceleration and roll angle are compared with measurements taken from the vehicle during the same manoeuvre on the proving ground. The influence of the tyre models described in Part 3 on the simulation outputs is shown. The effects of vehicle and tyre modelling on computer simulation time are also summarized. The paper concludes by demonstrating how a simple vehicle and tyre model can be used to carry out sensitivity studies varying vehicle and tyre design parameters.

Cholinergic and glutamatergic transmission in medial vestibular nucleus neurons responding to lateral roll tilt in rats

The responses of the medial vestibular nucleus (MVN) neurons to lateral tilt and the neurotransmitters mediating otolith information to MVN neurons were investigated using rats. A computer-operated goniometer was tilted 20° clockwise and counterclockwise at an angular speed of 5°/s and paused in the inclined positions for 10 s to record neuronal responses in the static phase. The 185 MVN neurons recorded were classified into eight types according to their responses to tilt (α, β, γ, δ, ε, ζ, η and θ). A majority showed increased firing in response to ipsilateral tilting and decreased firing in response to contralateral tilting (α type: 31.4%) or exhibited the reverse pattern (β type: 36.8%). Further, other groups of neurons increased (γ type) or decreased (δ type) firing rates to either side tilting and increased (ε and ζ type) or decreased (η and θ type) firing only on one side. Atropine or l-glutamic acid diethyl ester hydrochloride (GDEE) applied microiontophoretically antagonized tilt-induced firing of α type neurons in 58.8% or 60.0%, respectively, and of β type neurons in 66.7% or 58.3%, respectively. When the effects of atropine and GDEE were examined in the same neurons, antagonizing effects of both drugs on tilt-induced firing were obtained in 28.6% and 40.0% of α and β type neurons, respectively. These results suggest that both acetylcholine and glutamate act as neurotransmitters in the transmission of otolith information to most MVN neurons.

Light-dependent suppression of the vestibulo-ocular reflex during development.

In the fish Oreochromis mossambicus, light conditions affect the development of the roll-induced vestibuloocular reflex (rVOR). During development under continous light-dark conditions the rVOR amplitude, which is the maximum eye movement during a complete 360 degrees lateral roll, shows a secondary drop after a first peak at stage 17 by 64% (36.3 degrees at stage 17; 13.0 degrees at stage 20). This drop was shifted by 2 stages to older postembryonal stages and was 33% (29.2 degrees at stage 20; 19.5 degrees at stage 22) less pronounced in animals which were exposed to complete darkness for several days. Because the period of rVOR diminution is sensitive to light conditions, it is likely that outgrowing visual projection fibres reorganize the neuronal network underlying visual-vestibular behavior thus transiently suppressing the rVOR.

A Finite Element Tire Model and Vibration Analysis: A New Approach

Abstract A complete finite element tire model was developed for the purposes of vehicle dynamics analyses and full vehicle finite element model real time proving ground simulations. The tire model was validated through simulations of some of the very important global, static and dynamic mechanical properties such as the tire radial and lateral stiffnesses, free-drop test, and low-speed rolling cornering stiffness. The three-dimensional free vibration and harmonic/randomly forced vibrations with ground contact of the tire model were studied here. One of the main purposes for the present study is to provide a new approach toward tire and vehicle NVH studies. All the analyses were nonconventional in the sense that, instead of NASTRAN-type modal analysis, the explicit nonlinear dynamic finite element code LS/DYNA3D was used to conduct all the analyses in the time domain, and the vibration modes were decomposed via fast fourier transformation.

鉄道車両の振動乗り心地に影響する要因 振子式車両の左右振動穫速度とロール角速度

鉄道車両の振動乗り心地に影響する要因 振子式車両の左右振動穫速度とロール角速度

Experimental investigation of thermomechanical effects during direct chill and electromagnetic casting of aluminum alloys

The deformation and the temperature field within direct chill (DC) and electromagnetic (EM) cast aluminum ingots have been measured in-situ using a simple experimental set-up. The deformation of the cross section of the cold ingots has also been characterized as a function of the casting speed, alloy composition and inoculation condition. The pull-in of the lateral rolling faces has been found to occur in two sequences for DC cast ingots whereas that associated with EMC was continuous. The pull-in was maximum at the center of these faces (about 7-9%) and strongly depended upon the casting speed. Near the short sides of the ingots, the deformation was only about 2% and was nearly independent of the casting parameters and alloy composition. Based upon these measurements, it was concluded that the pull-in of the rolling faces was mainly due to the bending of the ingots induced by the thermal stresses. This conclusion was further supported by a simple two-dimensional thermoelastic model.

Lateral Roll Force in Asymmetrical Rolling and Its Influence on Rolling Stability.

Roll system forces and their relationships with each other during asymmetrical rolling have been studied for deciding the direction and magnitude of the lateral roll forces that could affect the rolling stability, rigidity and loading conditions of a rolling mill. Results obtained from experiment is in agreement with theoretical analysis which indicates that kinematical asymmetry in strip rolling creates lateral roll forces and magnitude of the forces is dependent on the angle of force inclination affected by roll speed mismatch ratio i, pass reduction e and applid strip tensions T. It has been found that, for optimizing mill design and operation, front tension (or tension difference) in asymmetrical rolling should not exceed the level which is required to preserve rolling stability. The appropriate value of i should not be higher than 1.28 to avoid bearing overloading whilst still retain roll force reduction characteristics of cross shear rolling.

A rippling muscle disease gene is localized to 1q41: evidence for multiple genes.

Rippling muscle disease (RMD) is an inherited disorder of skeletal muscle in which mechanical stimuli provoke electrically silent contractions. Patient symptoms are muscle cramps, pain, and stiffness, particularly during or following exercise. Clinical signs are balling of muscle following percussion and a characteristic lateral rolling movement of muscle occurring after contraction followed by stretching. We report a new 44-member pedigree segregating RMD as an autosomal dominant trait. A genetic linkage study in this family, using a novel approach of testing closely spaced highly polymorphic markers in affected individuals, localized the responsible gene to the distal end of the long arm of chromosome 1 with a maximum multipoint lod score of 3.56 (theta = 0). In this family, RMD is localized to a 12-cM region near D1S235. We studied two previously reported German families for linkage to the same locus, and this same area did not cosegregate with the disease, a finding that shows that different genetic defects can cause a similar clinical phenotype (genetic heterogeneity). An understanding of the defect in contraction control within the muscle fibers in this disease may lead to a better understanding of muscle force transduction, intracellular calcium homeostasis, or both.

The development of the static vestibulo-ocular reflex in the southern clawed toad, Xenopus laevis. II. Animals with acute vestibular lesions.

Acute hemilabyrinthectomized tadpoles of the Southern Clawed Toad (Xenopus laevis), younger than stage 47 (about 6 days old), perform no static vestibulo-ocular reflex (Fig. 1). Older acute lesioned animals respond with compensatory movements of both eyes during static roll. Their threshold roll angle, however, depends on the developmental stage. For lesioned stages 60 to 64, it is 75 degrees while stage 52 to 56 tadpoles respond even during a lateral roll of 15 degrees (Figs. 1 and 2). Selective destruction of single macula and crista organs revealed that the static vestibulo-ocular reflex is evoked by excitation of the macula utriculi (Figs. 3 and 4) even in young tadpoles. The results demonstrate that bilateral projections of the vestibular apparatus must have developed at the time of occurrence of the static VOR, that during the first week of life the excitation of a single labyrinth is subthreshold (Fig. 1). We discuss the possibility whether the loss of the static VOR during the prometamorphic period of life (Fig. 2) is caused by increasing formation of multimodal connections in the vestibular pathway.

Studies of somatostatin-induced barrel rotation in rats

Somatostatin (SRIF) has been reported to induce abnormalities of motor behavior in rats when injected intraventricularly. Following an injection, non-lesioned rats develop unilateral extension of the limbs, a twist about the long axis, and repeated lateral rolling, called “barrel rotation”. It has not been clear whether this behavior is due to a pharmacologic action of SRIF, such as an effect of SRIF on systems of motor control. Prior reports observed the response only at high doses of SRIF, and found no dose-response relationship for it. We have investigated whether this response is due to a pharmacologic effect of SRIF. We have also studied where SRIF acts, when injected intraventricularly, to induce this response. We have found that SRIF-induced rotation increases linearly with doses up to 10 μg and thereafter declines. Biologically inactive analogues of SRIF did not induce barrel rotation. Dose-response studies of intraventricular and intracerebral microinjections indicated that SRIF acts at the vestibular nuclear complex (VNC) to induce rotation. At VNC, 0.25 μg SRIF produced postural abnormalities. We conclude that barrel rotation is due to a pharmacologic action of SRIF, and that SRIF does act upon a system of motor control, the VNC, to induce this response.

Electroencephalographic studies of chlorpromazine methiodide and somatostatin-induced barrel rotation in rats

It has been reported that intraventricular injection of chlorpromazine methiodide (CPZMI), a quaternary ammonium derivative of chlorpromazine, in rats induces abnormal, twisting postures which may serve as an experimental model of the human movement disorder dystonia. We have shown elsewhere that the behavior induced by intraventricular CPMZI is identical to what has been called “barrel rotation”, first observed to follow intraventricular injection of somatostatin (SRIF), which consists of twisting about the long axis, with repetitive lateral rolling. The suitability of barrel rotation, induced by CPZMI or SRIF, as an experimental model for dystonia depends on its physiologic basis. Human dystonia is clinically not a convulsive phenomenon. SRIF-induced barrel rotation has been reported to be associated with epileptiform activity recorded by the electroencephalogram (EEG). The purpose of this study was to investigate EEG activity during CPZMI- and SRIF-induced rotation. We found that CPZMI barrel rotation was not associated with epileptiform activity in cortex, amygdala, or hippocampus, and contrary to prior reports, neither was SRIF rotation. Both CPZMI and SRIF injected in high doses could induce epileptiform activity, but this was associated with clonic motor phenomena and not barrel ratation. We conclude that electroencephalographic criteria do not exclude either CPZMI- or SRIF-induced rotation as models for movement disorders, but their validity as such requires further study.

Intra- and Interspecific Aggression By the Central American Midas Cichlid Fish, Cichlasoma Citrinellum

AbstractIntra- and interspecific aggression by the Central American cichlid fish, Cichlasoma citrinellum, was studied to examine the similarity in aggression toward different species and the degree to which interspecific responses depended on intraspecific cucs. One hour encounters were staged between C. citrinellum focal individuals, and subordinate opponents of the same species, C. zaliosum, Pseudotropheus zebra and Haplochromis polystigma. C. zaliosum is a strikingly similar and sympatric species while P. zebra and H. polystigma are morphologically dissimilar allopatric species. Attention was focussed on the effects of species similarity and feeding cues on interspecific aggression. Analyses were based on the relationship between stimuli from opponents and responses by the focal individual. A "conditional chance" technique was developed for this purpose and its reliability was tested against a computerized agonistic exchange with known parameters. The conditional chance method proved to be more accurate than traditional chi-square or information theoretical measures. At least a portion of the causation of interspecific aggressive response depends on the same cues as intraspecific behavior. The intensity of the aggressive response decreased with increasingly dissimilar opponents, but the qualitative response characteristics remained largely the same. Notable exceptions were a failure to honor an apparent appeasement signal, Lateral Roll, when given by another species and a lack of aggressive response when a strongly dissimilar species withdrew or fled. Differences were found in the aggressiveness of response by different focal individuals. However, focal individuals disagreed most strongly in their response to the similar species, C. zaliosum. Two responsed very aggressively and, while support for the hypothesis is weak, they may have perceived their opponents as odd conspecific fish. The others showed less aggression and their response resembled that shown to dissimilar species. Observing the opponent feed acted as an experiential cue and served to increase the aggressiveness of response to all subsequent stimuli from that opponent. While the duration of this increase and the effects of different feeding types are not known, response to ecological cues such as feeding could help to focus "mistaken-identity" aggression on competitors. This could be a first evolutionary step toward minimizing the maladaptive effects of interspecific aggression without forsaking the defense of resources against competitive species.