Fereydoon Diba

Innovative Active Vehicle Safety Using Integrated Stabilizer Pendulum and Direct Yaw Moment Control

Basically, there are two main techniques to control the vehicle yaw moment. First method is the indirect yaw moment control, which works on the basis of active steering control (ASC). The second one being the direct yaw moment control (DYC), which is based on either the differential braking or the torque vectoring. An innovative idea for the direct yaw moment control is introduced by using an active controller system to supervise the lateral dynamics of vehicle and perform as an active yaw moment control system, denoted as the stabilizer pendulum system (SPS). This idea has further been developed, analyzed, and implemented in a standalone direct yaw moment control system, as well as, in an integrated vehicle dynamic control system with a differential braking yaw moment controller. The effectiveness of SPS has been evaluated by model simulation, which illustrates its superior performance especially on low friction roads.

Optimized robust cruise control system for an electric vehicle

Besides environmental advantages and fuel efficiency, electric motors are a suitable choice for powertrain of vehicles due to appropriate similarity between their torque–speed characteristics and the required vehicle torque for longitudinal performance. An applicable robust control system for the cruise controller of a DC motor-driven electric vehicle is proposed. The robust controller is tuned using a numerical optimization design method to compensate the disturbances from the road grade and changes in the vehicle weight. In this study, the vehicles powertrain model is developed and details of the controller design process are described. The robustness and performance of the designed controller is evaluated by performing computer simulations. The results demonstrate adequate robustness and disturbance rejection of the designed control system.

Integrated momentum wheel and differential braking control to improve vehicle dynamic performance

Recent studies showed that active yaw moment control is the most effective method to improve the stability and road handling of vehicles. Corrective yaw moment action should be applied to a vehicle in order to improve the vehicle dynamic performance. The corrective yaw moment is directly related to the interaction between the tires and road, which could either be generated directly or indirectly. Subsequently, the performance of the yaw moment control system, in low-friction road conditions, would noticeably be reduced. An innovative method is proposed to generate the corrective yaw moment by utilizing a momentum wheel that works independent of the tire/road interaction. A comprehensive dynamic analysis of this model, when is integrated with a direct yaw moment control system, has been carried out. Computer simulation results for the vehicle model combined with an integrated momentum wheel and differential braking, under different road conditions, are presented.

Handling and safety enhancement of race cars using active aerodynamic systems

A methodology is presented in this work that employs the active inverted wings to enhance the road holding by increasing the downward force on the tyres. In the proposed active system, the angles of attack of the vehicles wings are adjusted by using a real-time controller to increase the road holding and hence improve the vehicle handling. The handling of the race car and safety of the driver are two important concerns in the design of race cars. The handling of a vehicle depends on the dynamic capabilities of the vehicle and also the pneumatic tyres’ limitations. The vehicle side-slip angle, as a measure of the vehicle dynamic safety, should be narrowed into an acceptable range. This paper demonstrates that active inverted wings can provide noteworthy dynamic capabilities and enhance the safety features of race cars. Detailed analytical study and formulations of the race car nonlinear model with the airfoils are presented. Computer simulations are carried out to evaluate the performance of the proposed active aerodynamic system.

Experimental investigation of active yaw moment control system using a momentum wheel

ABSTRACT Active yaw moment control is one of the most effective methods to improve the lateral stability and safety of vehicle. In this method, the overall yaw moment of the vehicle is modified by applying the corrective yaw moment generated by the systems that are mostly dependent on the tyre and road interaction. A unique technique to generate the corrective yaw moment has been considered and experimentally analysed in this work. This system utilizes a momentum wheel to generate the corrective yaw moment, which is independent of the tyre/road interaction, and is not limited by the adhesion between the tyre and road. A prototype model has been designed and developed to conduct the experimental tests and also to analyse the vehicle dynamics responses and examine the effectiveness of the designed controller. A microcontroller along with the essential sensors has been employed in the prototype to execute the embedded control system, which consists of the control algorithms, states estimator and the Kalman filter. This system provides a better vehicle performance and improves the responses of vehicle on low-friction roads. Experimental results also confirmed that the momentum wheel performance is not limited by the tyre/road adhesion condition.

A new parallel-series configuration for hybridization of a line-haul truck

The hybridization of the articulated line-haul heavy duty truck with self-propelled trailer is investigated. In this innovative configuration, the tractor electric hybrid powertrain is arranged in series with the trailer electric motor that provides a share of total traction efforts of the vehicle. This configuration could provide a regenerative braking capability in the trailer and improves the vehicle longitudinal handling and enhances the vehicle lateral stability. Detailed mathematical modeling of the drivetrain components is developed and the energy consumption analyses for typical driving cycles are performed. Simulation results showed the worthwhile capability of the proposed hybrid drivetrain to improve the regenerative braking and enhance the fuel efficiency of the line-haul trucks.

Active Aerodynamic System to Improve the Safety and Handling of Race Cars in Lane Change and Wet Road Maneuvers

Motor vehicle racing is usually supported by advanced engineering technologies considering every attempt to improve the performance of the car. A major objective of the engineering support is to enhance the handling and safety of race cars. The normal force on every tire has important effects on the handling properties, longitudinal dynamic and the safety of vehicle. Therefore, developing technologies to control and adjust these forces is highly desirable. The capability of active aerodynamic system to compensate the overall downward force of the vehicle has been widely published in literature. This paper shows the effectiveness of an actively controlled aerodynamic system to improve the handling and safety of a small-size race car in a lane-change maneuver and driving on wet roads. The analyses of a nonlinear vehicle model with active aerodynamic system, the controller structure and the control law have been presented. Computer simulations were carried out to verify the model and evaluate the performance of the control system.Copyright

Down Force Control of the Low Velocity Racing Car Using Active Aerodynamic Inverse Wings

A common denominator in all types of racing cars is the need for more traction and road holding, which is limited in traction to the capability of the dynamics of the vehicle, and its tires. Accurate modeling and formulation of the vehicle behavior helps to determine its cornering limits, road stability and handling. A design solution, based on the properties of an aerodynamic system, is developed to study the dynamic performance of a small size racing car. It is shown that the aerodynamic system increases the capability by algorithmic supply of the desired down-forces. The real-time adjustment of the airfoil combinations requires detailed analysis and formulation of the dynamic properties of the vehicle. Also the aerodynamic properties of the configuration of airfoils’ system should be considered. In this paper, implementation of an active aerodynamics inverted wings is investigated for a low-speed, high-down-force application in a typical Formula racing vehicle and detailed analysis and formulation are presented.Copyright