Sideslip Motion Research Articles

The Effect of Nonlinear Feature of Tire on the Control of Active Rear Steering at High Speed

The two-degree-of-freedom model of the vehicle is more accurate with considering of the nonlinear feature of tire. Based on the model, the active rear steering control strategy for achieving zero sideslip angle is yielded. Simulation results show that both of the two cases, constant and variable cornering stiffness, are useful in the control of sideslip motion, and using the variable stiffness due to the effect of load transfer in control strategy is more effective.

Aircraft wing rock oscillations suppression by simple adaptive control

Roll angular motion of the modern aircraft operating in non-linear flight modes with a high angle of attack often demonstrates the limit cycle oscillations, which is commonly known as the wing rock phenomenon. Wing rock dynamics are represented by a substantially non-linear model, with parameters varying over a wide range, depending on the flight conditions (altitude, Mach number, payload mass, etc.) and angle of attack. A perspective approach of the wing rock suppression lies in the adaptation methods. In the present paper an application of the simple adaptive control approach with the Implicit Reference Model (IRM) is proposed and numerically studied. The IRM adaptive controller is applied to ensure smooth tracking the roll angle of the reference (desired) trajectory with the simultaneous wing rock prevention. As compared with the previous authors' work, in the present paper more complex and realistic model is employed, where interdependence between aircraft roll and sideslip motions and the limitations on the aileron deflection angle are explicitly taken into account at the stage of the controller design. To this aim, the modification of the IRM control scheme is suggested and numerically studied. The simulation results obtained demonstrate high efficiency of the proposed method.

Research on Roll Attitude Control of UAV Based on Active Disturbance Rejection Control

The roll attitude control of small high-speed unmanned aerial vehicle (UAV) is very difficult compared to the conventional low-speed UAV. The dynamic pressure is large and the moment of inertia is too small, which cause the aileron is sensitive to manipulation. The roll attitude may oscillate due to the actuator rate limiting. In response to this feature, the active disturbance rejection control (ADRC) is added to compensate the nonlinear part of the system, so that the system is close to an integral link. The problem of the actuator rate limiting can be solved by tuning the gain of the angular rate control to change the system bandwidth. On the other hand, the rolling motion is, in general, coupled from the yawing and sideslip motions. ADRC can decouple the roll channel and the yaw channel, solving the nonlinear problem of control. Combination with the requirements of frequency and time domain, design the roll attitude controller. The UAV nonlinear simulation results show that the roll attitude control based on ADRC meets the flight control requirements.

Development and evaluation with MIL and HIL simulations of a LQR-based upper-level electronic stability control

This paper proposes an electronic stability control and shows MIL and HIL simulations performed for evaluation. Two designs are presented, one based on two-degrees-of-freedom linear model that includes side-slip and yaw motion and other based on three-degrees-of-freedom linear model that includes roll motion. Model-in-the-loop and Hardware-in-the-loop simulations were performed to test ESC on vehicle represented by a nonlinear model that considers lateral, yaw and roll motions and an intelligent driver model to generate the steering wheel command as driver reaction to vehicle motion in respect with desired path. It’s found from simulations for double lane change maneuver that the proposed controller is effective in reducing of side-slipping, rolling and yaw rate errors, keeping the steering stable in scenarios where the driver loses control of the vehicle, even in presence of disturbances in vehicle response in relation with response predicted by linear model used for control design.

Direct Yaw Moment Control for Enhancing Handling Quality of Lightweight Electric Vehicles with Large Load-To-Curb Weight Ratio

In this paper a vehicle dynamics control system is designed to compensate the change in vehicle handling dynamics of lightweight vehicles due to variation in loading conditions and the effectiveness of the proposed design is verified by simulations and an experimental study using a fixed-base driving simulator. Considering the electrification of future mobility, the target vehicle of this research is a lightweight vehicle equipped with in-wheel motors that can generate an additional direct yaw moment by transverse distribution of traction forces to control vehicle yawing as well as side slip motions. Previously, the change in vehicle handling dynamics for various loading conditions have been analyzed by using a linear two-wheel vehicle model in planar motion and a control law of the DYC system based on feed-forward of front steering angular velocity and feedback of vehicle yaw rate. The feed-forward controller is derived based on the model following control with approximation of the vehicle dynamics to 1st-order transfer function. To make the determination of the yaw rate feedback gain model-based and adaptable to various vehicle velocity conditions, this paper selects a method where the yaw rate feedback gain in the DYC system is determined in a way that the steady-state yaw rate gain of the controlled loaded vehicle matches the gain of the unloaded vehicle. The DYC system is simulated in a single lane change maneuver to confirm the improved responsiveness of the vehicle while simulations of a double-lane change maneuver with a driver steering model confirms the effectiveness of the DYC system to support tracking control. Finally, the effectiveness of the proposed DYC system is also verified in an experimental study with ten human drivers using a fix-based driving simulator.

Stability and Control of Tailless Aircraft Using Variable-Fidelity Aerodynamic Analysis

The purpose of this study is to evaluate the stability and control characteristics of the tailless aircraft using a hierarchy of variable-fidelity aerodynamics analysis methods, including unsteady linear potential flow, Euler, and Reynolds-averaged Navier–Stokes solvers as low-, medium-, and high-fidelity analysis, respectively. Contributions of the study are numerous. First, derivations of the equations of motion for the tailless aircraft and stability criteria using system matrices in longitudinal and lateral motions were carried out. Second, an efficient time-spectral Reynolds-averaged Navier–Stokes computational fluid dynamics method, which is based on the solution approximation of a discrete Fourier series, and the steady form of a corresponding adjoint solution approach can compute dynamic derivatives at computational cost considerably less than that of the conventional time-marching method without deterioration in solution accuracy. The innovative control effector 101 configuration was chosen, and the validation of the variable-fidelity computation results was made with wind tunnel data for forces, moments, and their derivative values in static and dynamic motions. Finally, example flight conditions of trim, climb, and side slip motions were analyzed by the Reynolds-averaged Navier–Stokes solver for the stability analysis. It is concluded that the weak instabilities observed in some of the dynamic modes can be easily controlled by appropriate control inputs.

Observer-based decentralised fuzzy control design for nonlinear interconnected systems: an application to vehicle dynamics

ABSTRACTIn this study, a decentralised output learning control strategy for a class of nonlinear interconnected systems is studied. Based on Takagi-Sugeno fuzzy (TS) model to approximate the considered interconnected nonlinear systems, a decentralised observer-based control scheme is designed to override the external disturbances such that the performance is achieved. The appealing attributes of this approach include: (1) the closed-loop system exhibits a robustness against nonlinear interconnections and external disturbance, (2) by one-step procedure, the gain matrices of observer and controller are obtained on a single step. In simulation results, the controller design is evaluated on the steering stability of a car where the nonlinear model describes the side slip, roll and yaw motions of the automotive vehicle equipped with four-wheel-steering and active suspension.

Effects of the lateral compliance of the suspension on the vehicle-handling responses

In the current work the yawing and side-slip motion of a two-mass vehicle is studied. The vehicle is divided into an upper rigid mass and a lower rigid mass pivoted on one another on a vertical axis through the centre of mass. The vehicle body constitutes the upper rigid body, and the suspension axles represent the lower rigid body. A yawing stiffness and damping package is acting between the two rigid bodies. The equations of motion of the two-body yawing vehicle are developed, and the handling behaviour of the vehicle is compared with that of a basic two-degree-of-freedom vehicle-handling model. The steady-state yaw responses of the two systems are equal but the side-slip angles are different. The results show considerable differences in the transient response properties of the two systems. With regard to the stability of motion, at situations where the two-degree-of-freedom model is stable, the three-degree-of-freedom yaw stiff model is also stable.

Closed-loop design for decoupling control of a four-wheel steering vehicle

In this paper, a four–wheel–steering (4WS) system with multiple inputs is introduced. This multiple–input 4WS system provides the driver with the ability to control the sideslip motion and yaw motion of the vehicle simultaneously and independently. The decoupling control of these two independent motions is accomplished by a steering controller which translates the steering commands into the steer angles of the front and rear wheels. A method to find the inverse transfer matrix of the vehicle in a simple symbolic form is introduced to design the steering controller. By the design method introduced in this paper, the decoupling control of the sideslip and yaw motion can be achieved by three types of controllers for a stable vehicle plant without any signal fed back. The performance of the system under the variations of the vehicle parameters is also investigated via computer simulation.

Steering vehicle control and road bank angle estimation: application for diagnosis of vehicle limits in bend

This paper deals with the diagnosis of the critical driving situations. This work is divided into three parts: the first one presents two steering controllers using the sliding mode and the switched H∞ controllers, the second one describes an unknown input sliding mode observer, while the last one presents an approach to the diagnosis of critical driving situations. All existence conditions are established using the Lyapunov approach. Simulations are conducted to highlight the efficiency of the proposed approach using the experimental data recorded by an instrumented Peugeot 307 laboratory car. The diagnosis of the critical driving situations is achieved by the speed extrapolation concept using simultaneously a non–linear model, a steering control and road bank observer. The speed extrapolation concept is used in order to evaluate situations under high dynamic loads on a bend, using stability of the sideslip motion.

Sliding mode control to design a driver model for vehicle steering: Experimental validation and stability evaluation of sideslip motion

This paper presents a driver model based on first-order sliding mode control for the steering control of the vehicle. This strategy calculates the steering angle which must be applied to a nonlinear 4-wheel model under high lateral accelerations. Sliding mode control has limitations due to the phenomenon of chattering which damages the actuator; this problem is overcome using a continuous function. Part of this work focuses on the synthesis of the nonlinear control using a linear parameter-variant model. Another part is devoted to experimental validation using real data acquired using a Peugeot 307 vehicle developed by INRETS-MA. Speed extrapolation tests of this control law, coupled with a nonlinear 4-wheel model, were also performed in order to evaluate situations under high dynamic loads on a bend, using stability criteria on the vehicle sideslip motion.

A fuzzy logic controlled Anti-lock Braking System (ABS) for improved braking performance and directional stability

A simple and effective fuzzy logic controller is designed for an Anti-Lock Braking System (ABS) to improve the braking performance and directional stability of an automobile during braking, and steering-braking manoeuvres on uniform and nonuniform (µ-split) friction surfaces. The system consists of two controllers working in tandem. The first controller works on the longitudinal slip, and the second controller is responsible for the side-slip motion control of the vehicle. The fuzzy logic controller is implemented on a four-wheel nonlinear vehicle model with nonlinear tyre behaviour. Simulations are carried out and comparisons are made using the vehicle model with and without the fuzzy logic controlled ABS to assess controller performance.

2204 操舵・制駆動力配分の統合制御による前方障害物回避の解析(乗り心地・操舵性,OS3 交通・物流システムのダイナミクスと制御)

This paper investigates the vehicle dynamics performance when the desired vehicle responses are improved by using Active Front Steering and Direct Yaw moment control. This paper introduces an integrated control algorithm which can arbitrarily determine the desired vehicle responses, i.e. side slip angle and yaw rate, independently. The proposed control algorithm is composed of feedforward and feedback compensators for yaw and side slip motion. Finally, the effect of the desired responses on obstacle avoidance performances are analyzed by computer simulations

Stability Versus Maneuverability in Aquatic Locomotion

The dictionary definition of stability as "Firmly established, not easily to be changed" immediately indicates the conflict between stability and maneuverability in aquatic locomotion. The present paper addresses several issues resulting from these opposing requirements. Classical stability theory for bodies moving in fluids is based on developments in submarine and airship motions. These have lateral symmetry, in common with most animals. This enables the separation of the equations of motion into two sets of 3 each. The vertical (longitudinal) set, which includes motions in the axial (surge), normal (heave) and pitching directions, can thus be separated from the lateral-horizontal plane which includes yaw, roll and sideslip motions. This has been found useful in the past for longitudinal stability studies based on coasting configurations but is not applicable to the analysis of turning, fast starts and vigorous swimming, where the lateral symmetry of the fish body is broken by bending motions. The present paper will also examine some of the aspects of the stability vs. maneuverability tradeoff for these asymmetric motions. An analysis of the conditions under which the separation of equations of motions into vertical and horizontal planes is justified, and a definition of the equations to be used in cases where this separation is not accurate enough is presented.

Application of Aerodynamic Actuators to Improve Vehicle Handling

This exploratory study considers applications of active aerodynamic devices for suppressing parasitic motion and for improving the response of vehicles to steering, within the scope of the linear dynamic behaviour. A three DOF linear model is chosen to describe the side slip, yaw and roll motion of a baseline front-wheel steered vehicle. The improvements in performance of the base-line vehicle that are achievable by the application of direct yaw and roll moments are determined when either an open loop control pre-filter or a state feedback control law based on LQR design is applied. Unlike the former control, the state feedback control is unable to make the body side-slip angle vanish. The feedback control performance of each of the two moment actuators has been examined separately and then jointly. The advantages of combining the open loop and feedback dual actuator configurations are demonstrated using the two-degree of freedom control scheme. It is found that the scheme yields a spectacular performance but demands unreasonably large moments from the actuators in the context of available aerodynamic forces. On the other hand, the demand on direct yaw and roll moment of actuators is modest when the actuators are controlled using the LQR feedback only and if the control design is used to track a desired yaw rate trajectory and simultaneously to reduce the parasitic rolling motion. Significant improvements in handling and dynamic stability of a base-line vehicle can be achieved by aerodynamically generated direct yaw and roll actuator moments provided the target control performance is reasonable. The configurations of aerodynamic actuators considered are feasible for improving vehicle handling in cornering on motorways but more work remains to be done to explore alternative aerodynamic configurations that give rise to less side effects and higher lift coefficients.

Control of High-Incidence Vortical Flow on Double-Delta Wings Undergoing Sideslip

An experimental study of the vortical flow over a baseline double-delta wing model and a diamond-fillet double-delta wing model, both with sharp leading edges, was conducted in a water tunnel using the dye-injection technique at a nominal flow Reynolds number of 1.875 x 10 4 . The diamond fillets at the strake/wing junction increased the wing area of the baseline model by 1%. The main focus of this study was to evaluate the effect of juncture fillets on the vortex core trajectory and the vortex burst location at high angles of attack with sideslip angle. Comparison of the test results between the baseline and the diamond-fillet models indicates a clear delay for the latter model in terms of both the vortex core trajectory, and the breakdown location at high angle of attack, with sideslip angles. The vortex breakdown data for the diamond-fillet model implies lift augmentation during sideslip motion, thus supporting the concept of flow control using fillets. From the maneuvering viewpoint, the data suggest that the diamond-fillet model has a better operational envelope.

Experimental validation of a tractor overturning simulation

In 30 experiments under different conditions a tractor with an instrumented experimental safety frame was overturned down a simulated bank about 2 m high. Dynamic behaviour and energy absorbed in the safety frame showed good agreement with the predictions of a computer simulation. The simulations provided valuable insight into the relationships between tyre side slip and tyre bounce motions that had considerable effects on roll velocity as the tractor slid down the bank. The experiments confirmed predicted effects on behaviour due to bank angle and limiting tyre friction. The effects of other parameters studied were small and could not be confidently established from the experimental results alone. Taking account of their complexity, the experiments showed adequate repeatability and control of conditions.