Challenges and possibilities in variable geometry suspension systems

The variable-geometry suspension system is in the focus of the paper. The advantages of the variable-geometry system are the simple structure, low energy consumption and low cost. During maneuvers the variable-geometry system modifies the camber angle of the front wheels in order to improve road stability. The system affects both the chassis roll angle and the half-track change. Moreover, the tracking error of the reference yaw rate can also be reduced. In the paper the challenges and possibilities of the variable geometry suspension system are analyzed

Adaptive interval type-2 fuzzy logic systems for vehicle handling enhancement by new nonlinear model of variable geometry suspension system

This research examines the emerging role of adaptive interval type-2 fuzzy logic systems (AIT2FLS) versus adaptive type-1 fuzzy logic system (AT1FLS) in vehicle handling by a new nonlinear model of the variable geometry suspension system (VGS) as a vehicle active suspension system. A proper controller is needed in order to have soft response and robustness against challenging vehicle maneuvers. Two controllers, including AT1FLS and AIT2FLS have been used in the paper. The proposed AIT2FLS can efficiently handle system uncertainties, especially in the presence of most difficult challenging vehicle maneuvers in comparison with AT1FLS. The interval type-2 fuzzy adaptation law adjusts the consequent parameters of the rules constructed on the Lyapunov synthesis approach. For this purpose, the kinematic equations are obtained for the vehicle double wishbone suspension system and they are substituted in a nonlinear vehicle handling model with eight degrees of freedoms (8DOFs). Thereby, a new nonlinear model for the analysis of VGS is obtained. The results indicate that between the two controllers, the proposed AIT2FLS has better overall vehicle handling, robustness and soft response

Adaptive suspension strategy for a double wishbone suspension through camber and toe optimization

A suspension system is responsible for the safety of vehicle during its manoeuvre. It serves the dual purpose of providing stability to the vehicle while providing a comfortable ride quality to the occupants. Recent trends in suspension system have focused on improving comfort and handling of vehicles while keeping the cost, space and feasibility of manufacturing in the constraint. This paper proposes a method for improving handling characteristics of a vehicle by controlling camber and toe angle using variable length arms in an adaptive manner. In order to study the effect of dynamic characteristics of the suspension system, a simulation study has been done in this work. A quarter car physical model with double wishbone suspension geometry is modelled in SolidWorks. It is then imported and simulated using SimMechanics platform in MATLAB. The output characteristics of the passive system (without variable length arms) were validated on MSC ADAMS software. The adaptive system intends to improve vehicle handling characteristics by controlling the camber and toe angles. This is accomplished by two telescopic arms with an actuator which changes the camber and toe angle of the wheel dynamically to deliver best possible traction and manoeuvrability. Two PID controllers are employed to trigger the actuators based on the camber and toe angle from the sensors for reducing the error existing between the actual and desired value. The arms are driven by actuators in a closed loop feedback manner with help of a separate control system. Comparison between active and passive systems is carried out by analysing graphs of various parameters obtained from MATLAB simulation. From the results, it is observed that there is a reduction of 58% in the camber and 96% in toe gain. Hence, the system provides the scope of considerable adaptive strategy in controlling dynamic characteristics of the suspension system

Overview of the Applied Aerodynamics Division

A major reorganization of the Aeronautics Directorate of the Langley Research Center occurred in early 1989. As a result of this reorganization, the scope of research in the Applied Aeronautics Division is now quite different than that in the past. An overview of the current organization, mission, and facilities of this division is presented. A summary of current research programs and sample highlights of recent research are also presented. This is intended to provide a general view of the scope and capabilities of the division

KINETO-DYNAMIC PADA VARIABLE GEOMETRY SUSPENSION (VGS)

Suspension technology on the vehicle provides a comforting effect with shock absorbers and a safety effect in driving and reducing the accident rate. The suspension system was developed by changing the construction and mechanism as well as the addition of a control element. Variable Geometry Suspension (VGS) is the development of a suspension system by using an active actuator is Single-link which is used to change the geometry of the suspension. Geometry change can affect the performance of the suspension system, so a modeling approach is needed to analyze the performance of the VGS system. The VGS modeling uses a quarter-vehicle model and a multi-body model with an equation of motion system using a Kineto-dynamic model with a double-wishbone suspension type. The analysis method on the VGS uses input is bumpy-road to obtain system performance in body acceleration, suspension deflection, and tire deformation. The results of the VGS with the Kineto-dynamic model has a range of 2 mm in the variation of the single-link angle, the performance values ​​in the body acceleration and tire deformation between the quarter-vehicle and multi-body models have the same oscillations until steady, while the suspension deflection in the Kineto-dynamic model differs in the first oscillation with a steady time of 1.6 seconds. Therefore, the Kineto-dynamic model can be used to approximate the actual system