Roll Rate Research Articles

LMI-Based H∞ Controller of Vehicle Roll Stability Control Systems with Input and Output Delays.

Many of the current research works are focused on the development of different control systems for commercial vehicles in order to reduce the incidence of risky driving situations, while also improving stability and comfort. Some works are focused on developing low-cost embedded systems with enough accuracy, reliability, and processing time. Previous research works have analyzed the integration of low-cost sensors in vehicles. These works demonstrated the feasibility of using these systems, although they indicate that this type of low-cost kit could present relevant delays and noise that must be compensated to improve the performance of the device. For this purpose, it is necessary design controllers for systems with input and output delays. The novelty of this work is the development of an LMI-Based H output-feedback controller that takes into account the effect of delays in the network, both on the sensor side and the actuator side, on RSC (Roll Stability Control) systems. The controller is based on an active suspension with input and output delays, where the anti-roll moment is used as a control input and the roll rate as measured data, both with delays. This controller was compared with a controller system with a no-delay consideration that was experiencing similar delays. The comparison was made through simulation tests with a validated vehicle on the TruckSim® software.

Development and performance evaluation of foxtail millet (Setaria italica L.) dehuller

AbstractFoxtail millet dehuller for double stage dehulling was developed and evaluated. The machine consists of a hopper, two knurled rolls, two rubber rolls, an air blower, and a grader. The machine was evaluated for foxtail millet (Setaria italica L.) at the different grain moisture content (10, 12, 14, and 17% [w.b.]), types of knurled rolls (diamond, angular, and straight knurled) and feed rate (100,200,300 kg/hr) for performance evaluation or efficiency. The maximum dehulling efficiency and cleaning efficiency of 82.24 and 82.47% was observed for 12% moisture content (w.b.), diamond‐type knurled roll and 100 kg/hr feed rate. Similarly, the maximum head grain yield of 97.82% and the minimum broken of 2.18% was observed for 12% moisture content (w.b.), diamond‐type knurled roll and 300 kg/hr feed rate. There was no significant change in the color values with the treatments. The predicted optimum condition for the machine is moisture content 12% (w.b.), diamond‐type knurled roll and feed rate of 100 kg/hr, which gave an optimum dehulling efficiency of 82.24%, head grain yield of 95.84%, broken of 4.16%, and cleaning efficiency of 82.47% with the desirability of 0.825. The economic analysis shows the suitability of the machine for small‐scale millet processors.Practical ApplicationsDehulling of millets is an essential unit operation in millet processing. This study evaluated the performance analysis of the developed dehuller for foxtail millet at different grain moisture content, types of knurled rolls, and feed rate. The process parameters were optimized, which can be used to design the dehuller for millets. The results obtained show the relevance of applying the developed dehuller for foxtail millet applications, providing an alternative processing machine for millet processing.

Features of Work of Electric Locomotive Transport in the Conditions of Iron-Ore Mines

In the article the results of research of work of mine electric locomotive transport are driven. It is marked that increase of power efficiency of electrical equipment of mine are a necessary condition for the increase of booty of iron-ore raw material. Decision of task of increase of booty of iron-ore raw material related to development and improvement of underground transport. Forming of structure of moving of iron-ore raw material takes place under influence of many mining-and-geological, technical, technological and organizational factors that influence on the size of stream of the moved loads casual character. This is determine casual character of stream of raw material that is transported. Mine electric locomotives are the basic type of transport that is used for moving of minerals within the limits of mountain drift. A model, that describes work of one electric locomotive enroute, that serves one point in that there is loading of minerals with one claotype ways, was considered. Realization of burst performance of mine electric locomotive is possible at reduction of time of his outages, that results in reduction of time of voyage and increase of middle rate of movement of rolling stock. Research of work of electric locomotive transport in the conditions of iron-ore mine was shown, that time of voyage was in limits from 440 to 530 seconds, middle speed here changes a from 1,2 to 1,78 m/s, and distance, that passes an electric locomotive in times of one voyage, makes from 596,7 to 796 meters. Importance of the modes of starting and braking was shown for realization of maximal properties on coupling of wheels of electric locomotive with rails and increase of the productivity of mine electric locomotives, and also factors that influence to work of mine electric locomotives in the mode of braking are considered. For the power supply of mine electric locomotives a device is used for connecting to parts being under electric tension. This device, pantograph, by means of the special wire, carries out a contact and connecting of electric parts of electric locomotive to the electric station. On the value of tension of the electric station influences circumstance that she is connected to the sections of tires that conduct an electric current, to that other, more power-hungry consumers are connected. So, for example, at starting of a main vent setting, by power 1600 kilowatts, there is a considerable decline of output tension value of that were fixed in limits from 195 to 276 Volt. It becomes possible because of influence of powerful electrical equipment on work of other electrical equipment in the group systems of power supply. Partly this question can be decided due to the use of the systems facilitating starting of electrical equipment. Basic factors, that influence to work of mine electric locomotives there are such that directly operate on the electromechanics system in the zone of contact of wheel with a rail (coefficient of rolling friction of wheels of electric locomotive with rails), and pantograph with a pin wire (level of tension of power supply of electromechanic). Therefore influence of these factors must be necessarily taken into account during work of mine electric locomotives. Other factors have casual character, and works of electric locomotives do not operate at all time, therefore, for reduction of their influence, a sufficient condition is implementation of preventive measures, such as introductions of the systems of the smooth starting, application of algorithms power effective management, systems of monitoring and diagnostics of work of equipment. The presence of wide range of initial conditions, such as variation of coefficient of rolling friction and rate of movement of electric locomotive, stipulates complication of calculations of descriptions of retrosystem.

Evaluation of optimum condition to improve the microstructure in hot-rolled medium carbon steel by elimination of coarse pearlite patches

The present study is aimed to eliminate the undesirable microstructure in the real working condition of the steel unit. In this work, the microstructure of hot-rolled medium carbon steel (grade 45C8) is studied for application in the automotive industry. The effect of the temperature and rolling rate on the microstructure has been thoroughly investigated by analyzing the microstructure containing ferrite and pearlite phases after each trial run of hot-rolled steel. The desired microstructure of fine ferrite and pearlite is very much essential in hot-rolled medium carbon steel for better strength and uniform properties of the material. The formation of coarse pearlite is undesirable, which may lead to breakage during drawing and hardness variation in the hot-rolled steel. Therefore, this study is focused to find the optimum condition for achieving the microstructure containing uniform distribution of fine pearlite and ferrite without the presence of blocky pearlite patches.

Combination of active braking and semi-active suspension systems to improve the roll and yaw vehicle stability

This paper presents a combined use of active chassis systems to enhance vehicle roll and yaw stability using semi-active suspension and active braking systems. The designed active braking system based on sliding mode control reduces the probability of vehicle rollover by decreasing the longitudinal velocity and lateral acceleration. Also, a semi-active suspension is proposed through fuzzy control method to improve the vehicle roll stability, which attenuates the effect of lateral acceleration on roll angle and roll rate. The lateral load transfer ratio is selected as the rollover index based on roll angle and lateral and roll accelerations. A vehicle dynamics model is built in the ADAMS environment, which includes subsystems of steering, braking and front and rear suspension, tire model and body. Also, the nonlinear characteristics of tires, bushings, springs and dampers are considered in the model. So, it can accurately express the dynamics performance of the vehicle. The control algorithm is evaluated under step steer and lane change maneuvers utilizing MATLAB and ADAMS co-simulation. Simulation results show that the proposed system with combined controllers can effectively improve the vehicle yaw stability and the rollover prevention compared with the only active braking and semi-active suspension systems.

Rotorcraft Dynamic Platform Landings Using Robotic Landing Gear

Abstract Articulating landing gear that use closed-loop feedback control are proven to expand the landing capabilities of rotorcraft on sloped and rough terrain. These systems are commonly referred to as robotic landing gear (RLG). Modern RLG systems have limitations for landing on dynamic platforms because their controllers do not incorporate fuselage roll and roll rate feedback. This work presents a proven crashworthy cable-driven RLG system for the commercial S-100 Camcopter that expands static landing zone limits by a factor of three and enables dynamic platform landings in rough sea state (SS) conditions. A new roll and foot-force feedback fused control algorithm is developed to enable ship deck landings of an RLG equipped S-100 without the need for deck lock or advanced vision-based landing systems. Multibody dynamic simulations of the aircraft, landing gear, and new control system show the benefits of this combined roll and force feedback approach. Results include experimental dynamic landings on platforms rolling under sinusoidal motion and simulated SS conditions. The experiments demonstrate, in a limited fashion, the usability of the RLG through ground experimentation, and the results are compared to simulations. Additional simulations of landings of the S-100 with rigid and active landing gear with more challenging landing conditions than experimentally tested are presented. Such results aid in understanding how RLG with this new roll and contact force fused controller prevent dynamic rollover.

A New Roll and Pitch Control Mechanism for an Underwater Glider

In this paper, a new roll and pitch control mechanism for an underwater glider is described. The mechanism controls the glider’s pitch and roll without the use of a conventional buoyancy engine or movable mass. The mechanism uses water as trim mass, with a high flow rate water pump to shift water from water bladders located at the front, rear, left, and right of the glider. By shifting water from the left water bladder to the right water bladder, a roll moment is induced. Similarly, pitch is achieved by controlling the water flow between the front and rear water bladder using a water pump. The water bladders act not only as a means for roll and pitch control but as a buoyancy engine as well. While this mechanism reduces the need for a dedicated buoyancy engine, as well as internal moving masses, motion control is more complicated, as buoyancy, roll, and pitch must be considered simultaneously. The dynamics of the system were derived and simulated, as well as validated experimentally. The glider is able to move in a sawtooth pattern with a pitch angle of 43.5?, as well as a maximum roll angle of 43.6?. Additionally, the effect of pump rate on pitch and roll rate was investigated. Both pitch and roll rates increase with increasing pump rate.

Folding Wingtips for Improved Roll Performance

Future aircraft designs look set to use longer wingspans to increase the aspect ratio and therefore overall aerodynamic efficiency of the airframe. Such larger wingspans also reduce roll rates and require increased control surface area to achieve the roll maneuver requirements for certification. In this work, the effect of using flared folding wingtips (FFWTs) on the roll performance of simple aircraft wings is investigated numerically and experimentally. A unique rolling rig is designed, manufactured, and tested, with a series of steady roll and transient tests performed for different wingspans, with and without folding wingtips. It is shown that the use of FFWTs on aircraft wings can enable improved aerodynamic performance due to the increased span while also significantly reducing the aerodynamic damping due to roll, such that the roll performance of a wing incorporating FFWTs is comparable to that of one without the additional span.

Effect of Dredging Rate, Sintering Time, Cooling Media on Corrosion Results of Carbon Steel Dredging

Metal reinforcement that has an impact on improving mechanical properties can occur in various ways, including by strain hardening mechanisms, solid solutions, second phase, prespitations, disperse, grain refinement and texture. In recent years, another method has been developed to obtain good mechanical properties without adding alloy elements, namely by the method of comprehensive plastic deformation (Severe Plastic Deformation). The purpose of this research is to conduct a study of rolling using medium carbon steel with a treatment temperature above recrystallization, rolling rate, sintering time, cooling media as an effort to develop and design new innovations about steel structures being rolled. The study of developing rolling techniques that can be applied in industry and can be applied as learning material / media in higher education requires structured research stages. The best impact value from this temper process is a temperature of 550 ° C for 1 hour where the impact value is 1.58 J / mm² with air conditioning media. In the rolling process above the recrystallization temperature 800 ° C deformation 20% the impact value is 1.7 J / mm² where the toughness indicates a ductile fracture while the deformation is 10% the impact value

System of differential equations of aircraft spatial motion dynamics with arbitrary tensor of inertia and center of gravity position

Derivation of analytic expressions making up the basis of a mathematical model of aircraft flight dynamics for the differential equations describing the change in the rate of roll, yaw and pitch, as well as flight velocity components in projections on the body-fixed coordinate axes is presented. The origin of the coordinate system does not in general coincide with the center of mass of the plane, and the axes are not the same as its main central axes of inertia. The differential equations for angular and linear velocities are reduced to the form convenient for the use of numerical methods and computer systems and make it possible to get consistent results of simulating the dynamics of aircraft spatial motion with an arbitrary tensor of inertia and center of gravity position.

Multi-orthogonal signal underwater navigation system modeling on moving platform

When the Multi-Orthogonal Signal Underwater Navigation System(MOSUNS) works on a moving platform, the movement of the platform will bring some errors to the positioning of the MOUNS. To solve this problem, a motion error model is established based on the homogeneous coordinates and the homogeneous rotation matrix, and the relationship between the positioning error and the Rotating velocity of the moving platform (roll rate, pitch rate, yaw rate) is accurately described. The motion error model is verified by the simulation of the MOSUNS on the motion platform through MATLAB.

Dynamic Behavior of the Full-Car Model in the J-Turn Maneuver by Considering the Engine Gyroscopic Effects

This study presents a new dynamic modeling of a vehicle by considering the engine dynamics. By selecting the vehicle coordinate system as the reference frame, all the force-torque equations of the sprung mass and unsprung masses are derived in this coordinate system by using the Newton’s equations of motion. Unlike the previous researches, in this work the sprung mass of the vehicle is not considered as a rigid body. The dynamics of the sprung mass components, such as gyroscopic effects of the engine crankshaft, is considered. In order to study the vehicle's dynamic behavior, in the J-turn maneuver, the governing equations of the full-car model are evaluated and validated by the numerical simulation method and ADAMS/Car software. Based on the results, the maximum roll angle and roll rate of a vehicle reach about 8 degrees and 40 degrees per second, respectively.

Vehicle’s Dynamic Behavior in Fishhook Maneuver by Considering the Engine Dynamics

In order to study on the vehicle’s dynamic behavior, this study presents a new dynamic modeling of the vehicle by considering the engine dynamics. The coordinate systems are considered separately for the sprung mass and unsprung masses. By using Newton’s equations of motion, the force-torque equations of the sprung mass and unsprung masses are derived in the vehicle coordinate system. In general, the sprung mass in modeling of the vehicle is considered as a rigid body. However, in this study the components rotation of the sprung mass such as the engine crankshaft is considered and its gyroscopic effects are exerted in the governing equations. The lateral and longitudinal forces of the tire are evaluated by Pacejka model. In fishhook maneuver, the vehicle's dynamic behavior is studied by the numerical simulation method under the supervision of the National Highway Traffic Safety Administration (NHTSA). The numerical simulation results are also validated by ADAMS/Car software. According to the results, the 15-DOF model in this research simulates the vehicle’s dynamic behavior with a good accuracy and the maximum roll rate of the vehicle reaches about 37 degrees per second.

Minimum‐series twist distributions for yawing‐moment control during pure roll*

AbstractThe main wings of most aircraft produce adverse yaw during roll. In order to control the lateral direction of the aircraft during the roll, the rudder is often mixed with the aileron. Lifting‐line theory is used here to develop spanwise lift distributions that require the minimum number of terms in the Fourier‐series solution for controlling the yawing moment during pure rolling motion using only the main wing. It is shown that the yawing moment can be controlled for arbitrary rolling moments and/or rolling rates by adding symmetric twist in the main wing. The induced‐drag penalty for using this method to control the yawing moment is significant and discussed in detail. For example, it is shown that if zero yawing moment is prescribed, the induced drag can increase by 108% for a prescribed rolling moment or by 300% during a steady rolling rate relative to the induced drag in steady level flight. Because this is the minimum‐series solution, it does not represent the solution for yaw control with minimum induced drag, since more terms could be used in the Fourier series describing the lift distribution to control yaw with less induced drag. However, the solutions presented here can be useful for aircraft with continuous trailing‐edge technologies that are limited in spanwise deflection gradients, and provide a theoretical upper bound on the minimum induced‐drag that can be expected if the main wing is used for yawing‐moment control during pure roll.

Theoretical determination of roll angular jerk of ships in irregular beam seas using PDF line integral method

The time derivative of acceleration is called a jerk, which is an important property to evaluate ride comfort in elevators, cars, and so on. Likewise, evaluation of motion sickness or ride comfort on a vessel could be achieved by this jerk property in the future. In this paper, we utilize the PDF Line Integral Method (PLIM), which was newly contrived in our previous research, for calculating not only roll angular acceleration but also roll angular jerk. The derivation of this theory, as well as numerical comparison with Monte Carlo simulation (MCS) results, are presented. Although the utilized restoring curve (GZ curve) exhibits strong asymmetricity, the proposed method successfully calculates roll angular jerk for such a condition. Since roll angular jerk is a high-order differential property, the biggest advantage of PLIM is that it only requires the information of roll and roll rate joint probability density function (PDF) to provide the PDF of jerk.

Theoretical determination of asymmetric rolling amplitude in irregular beam seas

A methodology for predicting the probability density function of roll motion for irregular beam seas is developed in the author’s previous research. In this paper, two methods for the prediction of the probability density function (PDF) of the rolling amplitude are examined. One of these methods is an approach based on a non-Gaussian PDF with the use of the equivalent linearization and the moment method, which has been used by Maki in the field of naval architecture. In the framework of this method, the instantaneous joint PDF of the roll and roll rate can be calculated. Thereby, the transformation from the joint PDF to the PDF of the total energy H is necessary. In this paper, the transformation from the joint PDF of instantaneous roll and rate to the PDF of H was conducted. The other method is the energy-based stochastic averaging method, whereby the PDF of the total energy H is determined from which the roll amplitude is calculated. It is noteworthy that the proposed theory aims to predict the PDF of the amplitude of the vessel due to wind or flooding. For such conditions, the restoring curve (GZ curve) has asymmetricity. To take into account this asymmetricity, a new theory for the transform of the PDF of the total energy H to the PDFof amplitude is proposed. The obtained theoretical results show almost complete agreement, and both of the two theoretical methods i.e., the energy-based stochastic averaging method and the non-Gaussian PDF method with the use of the equivalent linearization and moment method, show equivalent prediction performance even in the asymmetric condition.

Aileron size and location to minimise induced drag during rolling-moment production at zero rolling rate

AbstractMost modern aircraft employ discrete ailerons for roll control. The induced drag, rolling moment, and yawing moment for an aircraft depend in part on the location and size of the ailerons. In the present study, lifting-line theory is used to formulate theoretical relationships between aileron design and the resulting forces and moments. The theory predicts that the optimum aileron geometry is independent of prescribed lift and rolling moment. A numerical potential flow algorithm is used to evaluate the optimum size and location of ailerons for a wide range of planforms with varying aspect ratio and taper ratio. Results show that the optimum aileron design to minimise induced drag always extends to the wing tip. Impacts to induced drag and yawing moment are also considered, and results can be used to inform initial design and placement of ailerons on future aircraft. Results of this optimisation study are also compared to theoretical optimum results that could be obtained from morphing-wing technology. Results of this comparison can be used to evaluate the potential benefits of using morphing-wing technology rather than traditional discrete ailerons.

Corrosion behaviour of twin-roll cast 8006 aluminium alloy foil with different thicknesses for the food packaging industry

Purpose The purpose of this paper is to investigate and find out the surface and electrochemical behaviours of twin roll cast (TRC) 8006 aluminium alloy with different thicknesses due to the cold rolling rates after the TRC process. Design/methodology/approach The 8006 aluminium alloys are mostly used for the food packaging industry, as they are corrosion resistant, lightweight and shapable materials. The present work investigates the surface and corrosion behaviours of 8006 aluminium alloys at different thicknesses. TRC aluminium alloys were cold-rolled at two different reduction rates before investigation. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) tests were used to examine the phase and elemental analyses. FE-SEM and 3D profilometry also used to observe surface morphology. Open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy tests (EIS) were carried out to find out corrosion behaviours. The results show that the more cold rolling reduction (CRR), the more corrosion rate and surface affection of the TRC 8006 aluminium alloys. Findings According to the electrochemical tests (OCP, potentiodynamic polarization test and EIS) and surface morphology results (such as SEM, 3D profilometry and XRD) the more the rolling rate the less the corrosion resistance. Originality/value First corrosion behaviour investigation of twin-rolled 8006 Al alloys using electrochemical techniques. First investigation of CRR effects on electrochemical corrosion behaviour of 8006 Al alloys with 3.5 wt.% NaCl solution using EIS. First investigation of 8006 Al alloys as a food packaging material with electrochemical ways.

Rail-wheel contact forces and track irregularity estimation from on-board accelerometer data

Rolling stock approval protocols, such as UIC 518, demand monitoring of lateral and vertical forces at rail-wheel contact. Continuous monitoring through on-board instrumentation needs algorithms to convert the on-board sensor data into rail-wheel forces and track irregularities. In this work a Feed Forward Neural Network architecture, for fast and accurate estimation of rail-wheel forces and track irregularities from data obtained from a cluster of accelerometers mounted on the rolling stock, is presented. Simulation study is conducted for a passenger coach running over numerically generated set of one hundred rail tracks, each with a different irregularity. Power spectral density (PSD) function of ERRI B176 is used for creating rail irregularities. Multi-body rail coach model consists of wheel-sets, axle-box, bogie, bolster and car body. The input comprises acceleration, yaw and roll rate data from axle-box, bogie and car body, to produce contact forces and rail irregularities as outputs. Goodness of fit between actual and estimated values is illustrated through point-by-point graphs of actual and estimated track forces and irregularities. R-Squared () values, representing the fraction by which the variance of errors are less than the variance of actual values, are computed as indices of the accuracy of estimates.

Relook at Aileron to Rudder Interconnect


 
 
 The implementation of interconnect gain from aileron to rudder surface on the majority of the aircraftis to decrease sideslip which is generated because of adverse yaw with the movement of control stick in lateral axis and also enhances the turning rate performance.The Aileron to Rudder Interconnect (ARI)involves significant part to decouple the Dutch roll oscillations from roll rate response to aileron command. ARI is feed-forward gain whichis susceptible to aircraft system uncertainty. Incorrect ARI gain can lead to side slip buildup which can cause aircraft to depart in case of fault scenarios. Four systematic ARI design methods are proposed. One of the proposed methods which use the norm of ARI transfer function at roll damping frequency is suitable for online reconfiguration of control law. The reconfiguration of ARI gain is illustratedwith the simulation responses of fault scenario case of aileron surface damage.