Browse Topic: Camber

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Experimental Analysis of Multi-Link Rigid Axle Suspension Camber Variation with Vehicle Load2024-26-005401/16/2024
Increased popularity on SUV category in the market has led to high focus on performance attributes of SUVs. Considering higher weight & CoG for achieving handling performance target is always a challenge. Static Wheel Alignment parameters, especially Camber have shown significant contribution in Handling attributes of vehicle. This paper presents an experimental study on change in wheel camber under the influence of different vehicle loading conditions. In SUVs, generally wheel is subjected to large deflection from its high static loads which makes it quite difficult to maintain an ideal camber angle. Hence, it is important to analyze the camber angle variations under actual loading conditions. An in-house fixture is developed to emulate the actual vehicle loading conditions at rear wheel end. The multi-link rigid axle suspension with watt's link assembly is mounted on the chassis-frame which is rigidly fixed to ground and loads are achieved through hydraulic actuators at Wheels. Axle
Jani, Harshil, Rasal, Shraddhesh, Hussain, Inzamam, Asthana, Shivam, ahire, Manoj, Vellandi, Vikraman, Senniappan, Moorthy
Active control of Camber and Toe angles to improve vehicle Ride Comfort2022-01-112003/29/2022
This paper is part of the European OWHEEL project. It proposes a method to improve the comfort of a vehicle by adaptively controlling the Camber and Toe angles of a rear suspension. The purpose is achieved through two actuators for each wheel, one that allows to change the Camber angle and the other the Toe angle. The control action is dynamically determined based on the error between the reference angle and the actual angles. The reference angles are not fixed over time but dynamically vary during the manoeuvre. The references vary with the aim of maintaining a Camber angle close to zero and a Toe angle that follows the trajectory of the vehicle during the curve. This improves the contact of the tire with the road. This solution allows the control system to be used flexibly for the different types of manoeuvres that the vehicle could perform. An experimentally validated sports vehicle was used to carry out the simulations. The original rear suspension is a Trailing-arm suspension. It
Marotta, Raffaele, Strano, Salvatore, Terzo, Mario, Tordela, Ciro, Ivanov, Valentin
Three-axle Bus Handling Dynamics Evaluation Index2022-01-034103/29/2022
This paper evaluates the handling characteristics of three-axle bus by using the unique comprehensive vehicle handling evaluation index. With the theory of total variance, the generalized side-slip angle unified transfer function is introduced to derivate the evaluation indexes of reaction time, transition time, damping ratio and total variance considering the suspension roll steer and camber thrust. The three-axle bus suspension roll steer and camber thrust produces extra lateral force. The three-axle vehicle response degree following the step steer input is analyzed with the effect of suspension roll on three-axle bus by using the total variance approach. The vehicle designers could use this approach to get optimization design parameters of bus suspension. The unique total variance evaluation index considering the suspension roll steer is useful and could serve as an important tool for evaluating the effect of suspension roll on three-axle bus handling dynamics.
Ding, Jinquan
Cutting Edge - Double Bevel Cross SectionsJ738_202001 (Current)01/15/2020
This standard is for cutting edge sections typically used in earth-moving machinery defined in SAE J1116 and ISO 6165: a Scrapers as defined in ISO 7133. b Dozers as described in ISO 6747. c Loaders as described in ISO 7131. d Graders as described in ISO 7134. Hole spacing is defined ISO 7129. Hole conformation is defined in SAE J740.
MTC1, Earthmoving Machinery
Theoretical and Fundamental Consideration to Accord between Self-Steer Speed and Rolling in Maneuverability of Motorcycles2018-32-004910/30/2018
This paper considers the phenomenon that the self-steer speed when riders bank a motorcycle. This paper points out that this phenomenon originates from capsize mode. Further, it is specified that the first order differential equation representing capsize mode is included in the equation of motion of the steering system. Furthermore, it is specified that this differential equation is the first order differential equation for the roll angle. Therefore, as the roll angle increases, the roll angle further increases and the steering angle also changes, which is the mechanism of capsize mode. Finally, as a result of parameter studies, it is stated that the design parameters that most affect capsize mode were front and rear camber stiffness.
Sakai, Hideki
Numerical and Experimental Second Law Analysis of a Low Thickness High Chamber Wing Profile2018-01-195510/30/2018
This paper presents a coupled numerical and experimental study of an unconventional wing profile such as cp-180-050-gn (Cambered plate C = 18% T = 5% R = 0.78). This wing profile deals with low speeds. It is not currently used on any aircraft model. Otherwise, it presents interesting performances that can be exploited for the design of low-speed STOL or VTOL aircraft by mean of the very high lift that it can generate and can fit with different uses such as VAWT, cyclorotors drones, which are designed explicitly for low-speed operations. After a preliminary CFD assessment of the wing a complete experimental characterisation also at high angles of attack has been performed. The excellent agreement between CFD and experiments has allowed producing a complete analysis of the behaviour of the wing profile both before and after stall conditions. This study has the objective of analysing the viability of such an unconventional wing in traditional or over-stalling conditions. A complete
Trancossi, Michele, Sharma, Shivesh
Identification and Resolution of Vehicle Pull and Steering Wobble Using Virtual Simulation and Testing2018-01-189510/05/2018
A vehicle drifts due to several reasons from its intended straight path even in the case of no steering input. Vehicle pull is a condition where the driver must apply a constant correction torque to the steering wheel to maintain a straight-line course of the vehicle. This paper presents an investigation study into the characteristics of a vehicle experiencing steering drift. The aim of the work is to study vehicle stability and the causes of vehicle drift/pull during straight line to minimize vehicle pull level and hence optimize safety measures. A wobble in the steering wheel feels like the steering wheel is shaking to the left and right. This may get worse, if speed increases. This paper focuses on modelling and evaluating effects of suspension parameters, differential friction, brake drag variation, Unbalanced mass in the wheel assembly and C.G. location of the vehicle under multibody dynamic simulation environment. Asymmetry of geometry and compliance between left and right side
Anthonysamy, Baskar, Barde, Vishal, Medithi, Naveen, S, Senthil, N, Balaramakrishna
Study on Energy Loss due to Cornering Resistance in Over-Actuated Vehicles using Optimal Control2017-01-156803/28/2017
As vehicles become electrified and more intelligent in terms of sensing, actuation and processing; a number of interesting possibilities arise in controlling vehicle dynamics and driving behavior. Over-actuation with in- wheel motors, all wheel steering and active camber is one such possibility, which facilitate the control strategies that push boundaries in energy consumption and safety. Optimal control can be used to investigate the best combinations of control inputs to an over-actuated system. This paper shows how an optimal control problem can be formulated and solved for an over-actuated vehicle case, and highlights the translation of this optimal solution to a real-world scenario, enabling intelligent means to improve vehicle efficiency. This paper gives an insight into Dynamic Programming (DP) as an offline optimal control method that guarantees the global optimum. Therefore the optimal control allocation to minimize an objective function and simultaneously fulfill the defined
Bhat, Sriharsha, Davari, Mohammad Mehdi, Nybacka, Mikael
Investigation of the Behavior of Three-Wheel Vehicles When They Pass Over a Low μ Road Surface2016-32-005111/08/2016
In recent years three-wheel camber vehicles, with two wheels in the front and a single rear wheel, have been growing in popularity. We call this kind of vehicle A “Leaning Multi Wheel category Vehicle” (hereinafter referred to as a “LMWV”). A LMWV has various characteristics, but one of them stands out in particular. When a LMWV is cornering, if one of the front wheels passes over a section of road surface with a low friction coefficient, there is very little disturbance to the vehicle’s behavior and can continue to be driven as normal. However, there has been no investigation into why these vehicles have this particular characteristic. Consequently, in this paper an investigation was carried out in order to determine the behavior of a LMWV in this situation. First, measurements were taken using an actual vehicle to confirm the situation described above. As a result, it was confirmed that there is only a small change in the vehicle’s posture and also that the other front tire generates
Terada, Keisuke, Sano, Takayuki, Watanabe, Kenichi, Kaieda, Takashi, Takano, Kazuhisa
Self-Latching Piezocomposite ActuatorTBMG-2517908/01/2016
NASA’s Langley Research Center has developed a self-latching piezocomposite actuator. The self-latching nature of this invention allows for piezo actuators that do not require constant power draw. Among other applications, the invention is well suited for use in aerodynamic control surfaces and engine inlets. The technology is a self-latching piezoelectric actuator with power-off, set-and-hold capability. Integrated into an aerodynamic control surface or engine inlet, the self-latching piezocomposite actuator may function as a trim tab, variable camber airfoil, vortex generator, or winglet with adjustable shapes. Deflections could be made in-flight, and set and maintained (latched) without a constant power draw. Current piezo actuators require constant power to control and manage their electric fields. The control device leverages the shape memory behavior (specifically, the remnant stress-strain behavior) to create a morphing actuator that changes and holds the new shape with no
Effect of Three Controls (Camber Angle Control, Derivative Steering Assistance Control, and Inside-Outside Wheel Braking Force and Driving Force Control in Body Slip Angle Area2016-01-166604/05/2016
In this research, we examine the three controls inside-outside wheel braking force and driving force, camber angle, and the derivative steering assistance to determine how angle differences affect cornering performance and controllability. This is accomplished by comparing body slip angle area differences in a closed loop examination of the grip to drift area using a driving simulator. The results show that inside-outside wheel braking force and driving force control in the area just before critical cornering occurs has a significant effect on vehicle stability. We also clarified that controlling the camber angle enhances grip-cornering force, and confirmed that the sideslip limit could be improved in the vicinity of the critical cornering area. Additionally, when the counter steer response was improved by the use of derivative steering assistance control in the drift area exceeding the critical cornering limit, corrective steering became easier. Moreover, the effect could be achieved
Yamaguchi, Ryo, Nozaki, Hiromichi
Mathematical Model for Kinematic Analysis of McPherson Strut Suspension2016-28-018402/01/2016
Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input. Suspension characteristics which can be derived by using proposed mathematic model are curves for camber, caster, toe change &curves for bump and rebound steer
Patil, Aditya Anant
Suspension and Mass Parameter Measurements of Wheeled Vehicles2015-01-275109/29/2015
The United States Army Tank Automotive Research, Development and Engineering Center (TARDEC) built systems to measure the suspension parameters, center of gravity, and moments of inertia of wheeled vehicles. This is part of an ongoing effort to model and predict vehicle dynamic behavior. The new machines, the Suspension Parameter Identification and Evaluation Rig (SPIdER) and the Vehicle Inertia Parameter Evaluation Rig (VIPER), have sufficient capacity to cover most heavy, wheeled vehicles. The SPIdER operates by holding the vehicle sprung mass nominally fixed while hydraulic cylinders move an “axle frame” in bounce or roll under each axle being tested. Up to two axles may be tested at once. Vertical forces at the tires, displacements of the wheel centers in three dimensions, and steer and camber angles are measured. Contact patch can move in lateral, longitudinal and steer motions of the suspension and the small deflections of the vehicle sprung mass resulting from the contact patch
Baseski, Igor, Norman, Kenneth, Ryan, David, Stahara, Stefanie
Tailplane with Positive Camber for Reduced Elevator Hinge Moment2015-01-256609/15/2015
The Learjet 85 is a business jet with an unpowered manual elevator control and is designed for a maximum dive Mach number of 0.89. During the early design, it was found that the stick force required for a 1.5g pull-up from a dive would exceed the limit set by FAA regulations. A design improvement of the tailplane was initiated, using 2D and 3D Navier-Stokes CFD codes. It was discovered that a small amount of positive camber could reduce the elevator hinge moment for the same tail download at high Mach numbers. This was the result of the stabilizer forebody carrying more of the tail download and the elevator carrying less. Consequently, the elevator hinge-moment during recovery from a high-speed dive was lower than for the original tail. Horizontal tails are conventionally designed with zero or negative camber since a positive camber can have adverse effects on tail stall and drag. The tailplane sections for the Learjet 85 were tailored to minimize these adverse effects while achieving
Chandrasekharan, Reuben, Iarocci, Nick, Vafa, Sherry, Akel, Iyad
Elastokinematic Characteristics of Torsion Beam Suspensions2015-01-149704/14/2015
Torsion beam suspensions are lightweight and low in cost, and they are therefore frequently used as the rear suspensions of small front-wheel drive vehicles. However, it is difficult to predict their characteristics and to satisfy performance targets in the early stages of development in particular, because the various aspects of performance required of a suspension must be achieved by a single structure. A great deal of research has been conducted into the cross-sectional shape of the beam section; however, this paper focuses on the effect of the properties of the trailing arms on suspension characteristics. Two similar test torsion beam suspensions differing only in the rigidity of the trailing arms were fabricated, and kinematics and compliance (K&C) tests were conducted using a 3D measurement system. The lateral compliance test showed the anticipated result that change in toe and camber is greater in the suspension with lower rigidity trailing arms. On the other hand, the roll
Shibue, Hideaki, Srivastava, Devesh
A Comparison between Caster and Lean Angle in Generating Variable Camber2015-01-006703/10/2015
A variation in the camber of an automotive wheel is desired to compensate a side-slip force change owing to normal load transfer when the car is cornering. The camber of a steered wheel can be varied by adjusting caster or lean angle which are the representations of steering axis orientation. Thus, a smart camber can be created by a variable caster or lean angle. Choosing which parameter among the two angles to be variable is very important and dependent on its different effects. Here, homogeneous transformation is employed to establish camber as a function of caster, lean angle, and steering angle in the general case. A comparison between caster and lean angle based on different criteria is then made. The comparison shows that a variable caster is much better and more feasible than a variable lean angle in generating a smart camber.
Vo, Dai Q, Jazar, Reza N., Fard, Mohammad
Effect of Direct Yaw Moment Control Based on Steering Angle Velocity and Camber Angle Control2014-01-238609/30/2014
It has been reported that steering systems with derivative terms have a heightened lateral acceleration and yaw rate response in the normal driving range. However, in ranges where the lateral acceleration is high, the cornering force of the front wheels decreases and hence becomes less effective. Therefore, we applied traction control for the inner and outer wheels based on the steering angle velocity to improve the steering effectiveness at high lateral accelerations. An experiment using a driving simulator showed that the vehicle's yaw rate response improved for a double lane change to avoid a hazard; this improves hazard avoidance performance. Regarding improved vehicle control in the cornering margins, traction control for the inner and outer wheels is being developed further, and much research and development has been reported. However, in the total skid margin, where few margin remains in the forward and reverse drive forces on the tires, spinout is unavoidable. Therefore, we
Yoshino, Takahiko, Nozaki, Hiromichi
About the Effect of Camber Control on Vehicle Dynamics2014-01-238309/30/2014
In recent years, the conversion of vehicles to electric power has been accelerating, and if a full conversion to electric power is achieved, further advancements in vehicle kinematic control technology are expected. Therefore, it is thought that kinematic performance in the critical cornering range could be further improved by significantly controlling not only the steering angle but also the camber angle of the tires through the use of electromagnetic actuators. This research focused on a method of ground negative camber angle control that is proportional to the steering angle as a technique to improve maneuverability and stability to support the new era of electric vehicles, and the effectiveness thereof was clarified. As a result, it was found that in the critical cornering range as well, camber angle control can control both the yaw moment and lateral acceleration at the turning limit. It was also confirmed that both stability and the steering effect in the critical cornering range
Yoshino, Takahiko, Nozaki, Hiromichi
Cutting Edge - Double Bevel Cross SectionsJ738_201401 (Historical)01/08/2014
This standard is for cutting edge sections typically used in earth-moving machinery defined in SAE J1116 and ISO 6165: a Scrapers as defined in ISO 7133. b Dozers as described in ISO 6747. c Loaders as described in ISO 7131. d Graders as described in ISO 7134. Hole spacing is defined ISO 7129. Hole conformation is defined in SAE J740.
MTC1, Earthmoving Machinery
Detailed Analysis of Variables Affecting Wing Kinematics of Bat Flight2013-01-900312/20/2013
Body motions of flying animals can be very complex, especially when the body parts are greatly flexible and they interact with the surrounding fluid. The wing kinematics of an animal flight is governed by a large number of variables and thus the measurement of complete flapping flight is not so simple, making it very complex to understand the contribution of each parameter to the performance and hence, to decide the important parameters for constructing the kinematic model of a bat is nearly impossible. In this paper, the influence of each parameter is uncovered and the variables that a specified reconstruction of bat flight should include in order to maximally reconstruct actual dimensional complexity, have been presented in detail. The effects of the different kinematic parameters on the lift coefficient are being resulted. The computation analysis of the lift coefficient for different camber thicknesses and various wing areas is done by unsteady thin airfoil theory and vortex
Bindal, Gaurav, Sharma, Sparsh, Janser, Frank, Neu, Eugen
Computational Analysis of 3D Unsteady Flow Over Flapping Wing2013-01-209809/17/2013
This paper summarizes the complex unsteady, 3-D viscous flow aerodynamics (dominantly laminar) developed in flapping wing generating vortices and intersecting with them. Different flying creatures, (Insects, Birds, and Bats) flapping wing mechanisms are studied and hence being compared based on their wing kinematics and aerodynamic efficiency. The performance of low Reynolds number flyers is highly influenced by the wing shape, wing size, wing camber, aspect ratio, % camber thickness, elastic deformation, wing-beat frequency and wing twisting. The Computation technique used to analyze the wake characteristics of a flapping motion shows that the generation and shedding of vortices dominate the aerodynamic loading on the wing. The periodicity of the wing motion and the resultant vortices leads to conclude that any quantitative model must be based on unsteady aerodynamics and vortex dynamics. The preliminary assessment of the plan form and the airfoils are performed using Modified Blade
Sharma, Sparsh, Bindal, Gaurav
Active Kinematics Suspension for a High Performance Sports Car2013-01-068404/08/2013
The challenge to design the rear suspension of a rear wheel drive sports car has always been one of optimizing the position of both wheels and therefore the contact patch of the tires in order to obtain the maximum possible limit acceleration. This project takes the active kinematics idea a step further, and for the first time, we present an active system which allows complete control of the wheel by controlling the toe and camber angles on the fly. This allows a more complete control of the contact patch condition which can then further optimize the overall dynamics of the vehicle. This system, called Active Kinematics Suspension (AKS), is realized by four electromechanical actuators (two per side) in a sophisticated multilink axle. This allows direct manipulation of the camber and toe angles of the rear wheels by changing the length of two of the links. A high level vehicle dynamics controller then drives this system based on achieving two measurable targets; 1 Improvement of the
Ramirez Ruiz, Isabel
High Performance Electromechanical Actuator for Active Rear Axle Kinematics of a Sports Car2012-01-097404/16/2012
An electromechanical actuator is presented for the active control of a sports car's rear axle kinematics with a high performance-to-size ratio not available on the market up to now. Toe and camber values of both rear wheels are controlled independently to reach the optimum position of the tire contact patch on the ground for each driving situation. The complete system utilizes 4 actuators and is known as Active Kinematics Suspension (AKS). The actuators substitute the camber and toe links in a multilink suspension, without major modifications, on the prototype of an existing car. The actuators are capable of covering the high axial forces seen in the links and can rapidly alter the wheel position. The heart of the actuator is a hollow-shaft brushless DC motor running efficiently in field control. It drives a recirculating ball-screw which transfers the motor's rotational motion to a translational displacement of a central rod. Packaging and manufacturing checks are performed in a 3D
Ramirez Ruiz, Isabel
A Study of the Ditch Fall-over Test Method Using Numerical Simulation2012-01-009404/16/2012
Rollover tests are performed to design the algorithms for deployment of countermeasures to mitigate occupant ejection in rollover situations. The ditch fall-over test is one of the rollover test methods in which a vehicle on a steep slope, representing a ditch embankment, is subjected to a forced steering operation that results in a turnover. An accurate prediction method is needed to determine the specifications of the ditch fall-over test equipment and test conditions because a test-based trial-and-error process involves high cost of performing repeated experiments and preperation for various types of related test equipment. This paper presents a newly developed numerical simulation method for simulating vehicle behavior in ditch fall-over tests. The vehicle model used in the simulation incorporates a finite element tire model for calculating the contact forces to a steep slope in a rollover situation characterized by large contact patch deformation with very large camber angles
Fukushima, Tatsuya, Shitamichi, Masafumi, Nishikata, Osamu, Mori, Masamitsu, Hatano, Keiji, Torigaki, Toshikazu, Nishi, Masato, Miyachi, Takahiko
A 3D Semi-Empirical On-Road Transient Tire Model2010-01-191610/05/2010
To realistically predict the dynamics of a vehicle, the forces and moments in the contact patch must be accurately computed. A two-dimensional semi-empirical transient tire model was previously developed in the Advanced Vehicle Dynamics Lab (AVDL) at Virginia Tech, and extended the capabilities of the steady-state tire model also developed at AVDL. In this paper, a three-dimensional semi-empirical transient tire model is presented. The tire structure is modeled by an elastic ring supported on a spring and damper system. The elastic ring represents the belt ring and the spring and damper system represents the sidewall and the tread element. The analysis of the deformation of the tire structure with camber angle is performed on a flat surface to obtain the geometry of the contact patch and the normal pressure distribution. The forces and the moments are formulated using empirical data and based on theoretical mechanics. Illustrative simulations were performed for two scenarios: a driving
Umsrithong, Anake, Sandu, Corina
Parametric Study of Three - Wheeler Directional Stability using MBD Simulations2010-32-010209/28/2010
Directional stability is an important parameter in high speed as well as in low speed maneuvering. A three - wheeled vehicle has a tendency to pull one side resulting in poor directional stability. This pulling requires continuous steering correction for improving directional stability. Driver needs to apply more force on handle bar to stabilize the vehicle. This causes the driver to experience shoulder pain and inferior maneuverability. A vehicle one side pull problem is directly related to safety and comfort. Also, during riding external disturbances from road generate lateral forces in tyre leading to sudden path deviation of vehicle. This path deviation deteriorates handling and it becomes difficult for the rider to control it to its original position. The aim of this work is to understand the influence of various parameters on three wheeled vehicle directional stability. Different parameters such as front steering CG offset, uneven mass distribution, wheel camber, caster angle
GSG, Ravikanth, D, Gangi Reddy, Gawade, Tushar.R., Santosh, K.V., Reddy, M.Nagarjun
Synthesis of a Vehicle Suspension with Constrained Lateral Space using a Roll-plane Kineto-dynamic Model2010-01-064104/12/2010
The larger chassis space requirements of hybrid vehicles necessitates considerations of the suspension synthesis with limited lateral space, which may involve complex compromises among performance measures related to vehicle ride and handling. This study investigates the influences of suspension linkage geometry on the kinematic and dynamic responses of the vehicle including the wheel load in order to facilitate synthesis of suspension with constrained lateral space. A kineto-dynamic half-car model is formulated incorporating double wishbone suspensions with tire compliance, although the results are limited to kinematic responses alone. An optimal synthesis of the suspension is presented to attain a compromise among the different kinematic performance measures with considerations of lateral space constraints. In the kineto-dynamic model, the struts comprising linear springs and viscous dampers are introduced as force elements. Kinematic formulations of the proposed model are derived
Balike, Krishna Prasad, Rakheja, Subhash, Stiharu, Ion
Normalization of the Pacejka Tire Model2004-01-352811/30/2004
This paper reviews the Pacejka tire performance model that relates the slip to the tire adhesion forces at various normal forces and camber. This model is then presented in a normalized form so the degradation in the coefficient of friction and the value of slip that results in a peak force can be expressed as a function of normal load and camber. With this form of expression, μ and the maximizing slip can be identified directly. Knowing how these factors vary with load and other parameters will allow engineers to determine the best suspension settings.
Woods, Robert L.
Use of Genetic Algorithms with Multiple Metrics Aimed at the Optimization of Automotive Suspension Systems2004-01-352011/30/2004
Suspension models are highly multivariate and require a nonlinear system to model the movements and interaction of the parameters within the suspension system. Multiple metrics must be considered to determine an optimal result. This paper describes a system for the use of a Genetic Algorithm for the optimization of automotive suspension geometries, a description of the suspension model, and the scoring mechanism. The results of this model evaluate the impact of multiple independent metrics. A combined objective function score is determined with the assistance of a user selectable weighting of metrics. The optimization algorithm is also compared to a discrete grid search.
Mitchell, Scott A., Smith, Stephen, Damiano, Alberto, Durgavich, Joel, MacCracken, Rosalyn
Parameterizing Shape Perturbations for Multidisciplinary Design OptimizationTBMG-676602/01/2000
A recently developed method of parameterizing complex shapes that one seeks to optimize differs from prior such methods in two major respects: (1) instead of entirely parameterizing the shapes, one parameterizes only shape perturbations (deformations of initial or baseline shapes) and (2) the deformations are computed by soft-objects animation (SOA) algorithms commonly used in computer graphics. This method is suitable for multidisciplinary design-optimization processes, in which shapes of structures are optimized along with other aspects of design (e.g., aerodynamics). This method can be applied, for example, to the shapes of both exterior aerodynamic surfaces and internal structural components of aircraft.
Study of Tire Model Consisting of Theoretical and Experimental Equations for Vehicle Dynamics Analysis - Part 2: Under the Condition of Various Velocity on the Asphaltic Road Surface96099602/01/1996
As the progress is made in vehicle dynamics analysis, tire models for vehicle dynamics analysis that are broadly applicable have been increasingly sought. Therefore, following the previous paper, the method to formulate a tire model consisting of theoretical and experimental equations, that represents, with high accuracy, the experimental characteristics of a tire, based on relatively simple theoretical equations - by obtaining the coefficients through experiments and further adding to them appropriate collections - is investigated in this paper. In the previous paper, the procedure to formulate a model that shows the changes in lateral force, driving-braking force and aligning moment, generated on a tire running at a constant velocity, due to slip angle, slip ratio, camber angle and load was presented. However, the change due to velocity was not taken into consideration. Therefore, the model in the previous paper is further developed into the one that also shows the change due to
Araki, Kazuo, Sakai, Hideo
New Multi - link Suspension91256711/01/1991
The recent trend of higher-efficiency, higher-grade automobiles appearing on the market is causing the growing demand for better handling/stability and ride quality. To respond to such needs, Mazda has developed a new multi-link suspension and installed it on a new model. This suspension has five links: longitudinally high-mounted upper leading link (or trailing link), lower-trailing link, transversely-mounted upper lateral link, lower lateral link, and two lower lateral links. It is constructed for optimal control of toe change, camber angle change, roll-center height, anti-dive, and anti-squat, while performing independently geometry control, compliance control, etc. required of the suspension. With the new model, we have succeeded to derive full potential benefits of the suspension with handling/stability and ride balanced at high levels.
Ushio, Kouichi
AFTI/F-111 Performance Flight Test Summary87188110/01/1987
The AFTI/F-111 Mission Adaptive Wing (MAW) incorporates a smooth variable contour wing system in order to maintain optimum camber throughout all flight regimes. The aircraft has completed its initial phase of flight testing at Edwards AFB CA. The purpose of this paper is to briefly summarize the aerodynamic and performance results. Comparisons of MAW flight test data are made against full-scale wind tunnel predictions and flight test data from a fixed camber wing of similar geometry. Wing pressure plots are presented to show the effectiveness of both the supercritical and the variable camber airfoils. Point performance plots show improvements in aerodynamic efficiency and maneuverability. Turn performance gains of as much as 38% are attainable. Range improvements of 25% are shown for a high altitude supersonic combat mission. The AFTI/F-111 is demonstrating aerodynamic improvements achieved by using a smooth variable contour wing system. This paper documents these improvements and
Smith, Francis R., Harshberger, Glenn W., Ujcik, Vaclav G.
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