Hardware in the Loop Simulation of Active Front Wheel Steering control for yaw disturbance rejection

This paper introduces an Active Front Wheel Steering (AFWS) control for the purpose of reducing unwanted yaw motion. Side wind forces are considered to be the sources of yaw disturbance in this study. The proposed control strategy for the AFWS is a lateral directional control with yaw rate feedback. The AFWS controller was implemented on Hardware in the Loop Simulation (HiLS) using an AFWS test rig. From the simulation and experimental results, AFWS control is able to perform the task of yaw disturbance attenuation by providing additional steering correction for maintaining the original direction of the vehicle. Keywords: active front wheel steering; side wind force; yaw cancellation; HiLS; vehicle safety

CONTROLADOR ACTIVO LINEAL APLICADO AL VEHÍCULO EN SOFTWARE SCILAB (LINEAR ACTIVE CONTROLLER APPLIED TO THE VEHICLE IN SCILAB SOFTWARE)

Resumen     En este artículo se muestra un problema clásico en la teoría de control, el cual es el diseño de una ley de retroalimentación, teniendo el propósito de que la salida de cualquier sistema siga asintóticamente una señal de referencia. En este trabajo, se pretende que la velocidad lateral siga a una maniobra del conductor o sensor del volante, pero en sentido contrario. Se propone que el vehículo se encuentra realizando pruebas de manejo conocidas por la norma internacional ISO 7401, por ende el problema de la teoría de regulación lineal vía retroalimentación de estados por medio de una función de Lyapunov es la solución idónea a nuestro problema ya que se supone la medición de la velocidad angular de viraje. Los actuadores que integraremos en este artículo serán los frenos () y el sistema frontal activo (AFS, por sus siglas en inglés), por medio de la simulación del software Scilab.Palabra(s) clave: Retroalimentación de estados, Scilab, velocidad lateral, velocidad angular de viraje. Abstract    This article shows a classic problem of control theory, which is the design of a feedback law, it has the purpose that the output of any system follows a reference signal asymptotically. In this paper we aim that the lateral velocity follows a drivers´s maneuver or steering wheel sensor, but in the opposite direction. It is proposed that the vehicle performs driving test knowed by the ISO 7401 international standard, thus, to solve this problem we are going to use the feedback-state lineal theory by means of a Lyapunov function, because it is supposed to measure the yaw velocity. The actuators that we will be integrating in this paper, will be the brakes () and Front Active System (AFS), through simulations in the software Scilab.Keywords: Feedback state, lateral velocity, Scilab, yaw velocity

PLATAFORMAS PARA CONTROLADOR ACTIVO LINEAL APLICADO A LA DIRECCIÓN ASISTIDA AUTOMOTRIZ (PLATFORMS FOR LINEAR ACTIVE CONTROLLER APPLIED TO THE AUTOMOTIVE ASSISTED STEERING)

En este artículo se muestra un problema clásico en la teoría de control, el cual es el diseño de una ley de retroalimentación, teniendo el propósito de que la salida de cualquier sistema siga asintóticamente una señal de referencia. En este trabajo, se pretende que la velocidad lateral siga a una maniobra del conductor, pero en sentido contrario. Se propone que el vehículo se encuentra realizando pruebas de manejo conocidas por norma internacional ISO 7401, por ende el problema de la teoría de regulación lineal vía retroalimentación de estados por medio de una función de Lyapunov es la solución idónea a nuestro problema ya que se supone la medición de la velocidad angular de viraje. Los actuadores que integraremos en este artículo serán los frenos () y el sistema frontal activo (AFS, por sus siglas en inglés), por medio de la simulación de Matlab-Simulink-CarSim y una plataforma propia.Palabra(s) clave: Retroalimentación de estados, velocidad lateral, velocidad angular de viraje, CarSim. AbstractThis article shows a classic problem of control theory, which is the design of a feedback law, it has the purpose that the output of any system follows a reference signal asymptotically. In this paper we aim that the lateral velocity follows a drivers´s maneuver, but in the opposite direction. It is proposed that the vehicle performs driving test knowed by the ISO 7401 international standard, thus, to solve this problem we are going to use the feedback-state lineal theory by means of a Lyapunov function, because it is supposed to measure the yaw velocity. The actuators that we will be integrating in this paper, will be the brakes () and Front Active System (AFS), through simulations in Matlab- Simulink-CarSim and own platform.Keywords: Feedback state, lateral velocity, yaw velocity, CarSim

Control systems integration for enhanced vehicle dynamics

This paper deals with improving comfort and handling for a ground vehicle through the coordinated control of different active systems available in passenger cars, e.g., electronic stability control, active roll control and engine torque control. The authors first describe separate control systems, each with its logic, showing advantages and limits, then propose various possible integrations, aiming at exploiting the benefits of a coordinated approach. Finally, the proposed control logics are tested on a vehicle model: simulation results prove the effectiveness of the approach in improving vehicle response during typical handling maneuver

Electronic Differential with a Separate Electric Wheel Drive

Import 03/08/2012Diplomová práce je zaměřena na analýzu vlastností vozidel s různou koncepcí diferenciálu. Mechanické diferenciály, které jsou v současnosti nejrozšířenější, výrazně ovlivňují výsledné chování vozidla a schopnosti trakce vozidla. Diplomová práce je tedy zaměřená na rozbor základních mechanických diferenciálu až po současně nejdokonalejší aktivní mechanické diferenciály. Součástí práce je také porovnání možností mechanického diferenciálu a elektronického diferenciálu s odděleným pohonem kol. Závěrečná část se zaměřuje na vylepšení jízdních vlastností laboratorního elektromobilu Kaipan, prostřednictvím matematického modelování v programu Matlab/Simulink. K vylepšení jízdních vlastností je využito výhod odděleného pohonu kol.This thesis is focused on analyzing the properties with various vehicles concepts differential. Mechanical differentials, which are currently the most widely used, strongly influence the resulting behavior of the vehicle and the vehicle's traction capabilities. This thesis is focused on the analysis of basic mechanical differential to the currently ultimate active mechanical differentials. The work is also a comparison between a mechanical differential and an electronic differential with separate drive wheels. The final section focuses on improving the handling of laboratory electric vehicle Kaipan through mathematical modeling in Matlab / Simulink. To improve the driving characteristics to reap the benefits of a separate drive wheels.430 - Katedra elektronikyvýborn

Multi-Actuated Vehicle Control and Path Planning/Tracking at Handling Limits

The increasing requirements for vehicle safety along with the impressive progress in vehicle actuation technologies have motivated manufacturers to equip vehicles with multiple control actuations that enhance handling and stability. Moreover, multiple control objectives arise in vehicle dynamics control problems, such as yaw rate control and rollover prevention, therefore, vehicle control problems can be defined as multi-actuation multi-objective vehicle control problems. Recently, the importance of integrating vehicle control systems has been highlighted in the literature. This integration allows us to prevent the potential conflicting control commands that could be generated by individual controllers. Existing studies on multi-actuated vehicle control offer a coordinated control design that shares the required control effort between the actuations. However, they mostly lack an appropriate strategy for considering the differences among vehicle actuations in their energy usage, capabilities, and effectiveness in any given vehicle states. Therefore, it is very important to develop a cost-performance strategy for optimally controlling multi-actuated vehicles. In this thesis, a prioritization model predictive control design is proposed for multi-actuated vehicles with multiple control objectives. The designed controller prioritizes the control actuations and control objectives based on, respectively, their advantages and their importance, and then combines the priorities such that a low priority actuation will not kick in unless a high priority objective demands it. The proposed controller is employed for several actuations, including electronic limited slip differential (ELSD), front/rear torque shifting, and differential braking. In this design, differential braking is engaged only when it is necessary, thus limiting or avoiding its disadvantages such as speed reduction and maintenance. In addition, the proposed control design includes a detailed analysis of the above-mentioned actuations in terms of modelling, control, and constraints. A new vehicle prediction model is designed for integrated lateral and roll dynamics that considers the force coupling effect and allows for the optimal control of front/rear torque distribution. The existing methods for ELSD control may result in chattering or unwanted oversteering yaw moments. To resolve this problem, a dynamic model is first designed for the ELSD clutch to properly estimate the clutch torque. This ELSD model is then used to design an intelligent ELSD controller that resolves the issues mentioned above. Experimental tests with two different vehicles are also carried out to evaluate the performance of the prioritization MPC controller in real-time. The results verify the capability of the controller in properly activating the control actuations with the designed priorities to improve vehicle handling and stability in different driving maneuvers. In addition, the test results confirm the performance of the designed ELSD model in ELSD clutch torque estimation and in enabling the controller to prevent unwanted oversteering yaw moments. The designed stability controller is extended to use for emergency collision avoidance in autonomous vehicles. This extension in fact addresses a local path planning/tracking problem with control objectives prioritized as: 1) collision avoidance, 2) vehicle stability, and 3) tracking the desired path. The controller combines a conservative form of torque/brake vectoring with front steering to improve the lateral agility and responsiveness of the vehicle in emergency collision avoidance scenarios. In addition, a contingency MPC controller is designed with two parallel prediction horizons - a nominal horizon and a contingency horizon - to maintain avoidance in identified road condition uncertainties. The performance of the model predictive controllers is evaluated in software simulations with high fidelity CarSim models, in which different sets of actuation configurations in various driving and road conditions are assessed. In addition, the effectiveness of the local path planning/tracking controller is evaluated in several emergency and contingency collision avoidance scenarios

Reconfigurable Integrated Control for Urban Vehicles with Different Types of Control Actuation

Urban vehicles are designed to deal with traffic problems, air pollution, energy consumption, and parking limitations in large cities. They are smaller and narrower than conventional vehicles, and thus more susceptible to rollover and stability issues. This thesis explores the unique dynamic behavior of narrow urban vehicles and different control actuation for vehicle stability to develop new reconfigurable and integrated control strategies for safe and reliable operations of urban vehicles. A novel reconfigurable vehicle model is introduced for the analysis and design of any urban vehicle configuration and also its stability control with any actuation arrangement. The proposed vehicle model provides modeling of four-wheeled (4W) vehicles and three- wheeled (3W) vehicles in Tadpole and Delta configurations in one set of equations. The vehicle model is also reconfigurable in the sense that different configurations of control actuation can be accommodated for controller design. To develop the reconfigurable vehicle model, two reconfiguration matrices are introduced; the corner and actuator reconfiguration matrices that are responsible for wheel and actuator configurations, respectively. Simulation results show that the proposed model properly matches the high-fidelity CarSim models for 3W and 4W vehicles. Rollover stability is particularly important for narrow urban vehicles. This thesis investigates the rollover stability of three-wheeled vehicles including the effects of road angles and road bumps. A new rollover index (RI) is introduced, which works for various road conditions including tripped and un-tripped rollovers on flat and sloped roads. The proposed RI is expressed in terms of measurable vehicle parameters and state variables. In addition to the effects of the lateral acceleration and roll angle, the proposed RI accounts for the effects of the longitudinal acceleration and the pitch angle, as well as the effects of road angles. Lateral and vertical road inputs are also considered since they can represent the effects of curbs, soft soil, and road bumps as the main causes of tripped rollovers. Sensitivity analysis is provided to evaluate and compare the effects of different vehicle parameters and state variables on rollover stability of 3W vehicles. A high-fidelity CarSim model for a 3W vehicle has been used for simulation and evaluation of the proposed RI accuracy. As a potentially useful mechanism for urban vehicles, wheel cambering is also investigated in this study to improve both lateral and rollover stability of narrow vehicles. A suspension system with active camber has an additional degree of freedom for changing the camber angle through which vehicle handling and stability can be improved. Conventionally, camber has been known for its ability to increase lateral forces. In this thesis, the benefits of cambering for rollover stability of narrow vehicles are also investigated and compared with a vehicle tilt mechanism. The simulation results indicate that active camber systems can improve vehicle lateral stability and rollover behavior. Furthermore, by utilizing more friction forces near the limits, the active camber system provides more improvement in maneuverability and lateral stability than the active front steering does. The proposed reconfigurable vehicle model leads us to the development of a general integrated reconfigurable control structure. The reconfigurable integrated controller can be used to meet different stability objectives of 4W and 3W vehicles with flexible combinations of control actuation. Employing the reconfigurable vehicle model, the proposed unified controller renders reconfigurability and can be easily adapted to Tadpole and Delta configurations of 3W as well as 4W vehicles without reformulating the problem. Different types and combinations of actuators can be selected for the control design including or combination of differential braking, torque vectoring, active front steering, active rear steering, and active camber system. The proposed structure provides integrated control of the main stability objectives including handling improvement, lateral stability, traction/braking control, and rollover prevention. The Model Predictive Control (MPC) approach is used to develop the reconfigurable controller. The performance of the introduced controller has been evaluated through CarSim simulations for different vehicles and control actuation configurations