scholarly journals Vehicle Dynamic Control with 4WS, ESC and TVD under Constraint on Front Slip Angles

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6306
Author(s):  
Jaewon Nah ◽  
Seongjin Yim

To enhance vehicle maneuverability and stability, a controller with 4-wheel steering (4WS), electronic stability control (ESC) and a torque vectoring device (TVD) under constraint on the front slip angles is designed in this research. In the controller, the control allocation method is adopted to generate yaw moment via 4WS, ESC and TVD. If the front steering angle is added for generating yaw moment, the steering performance of the vehicle can be further deteriorated. This is because the magnitude of the lateral tire forces are limited and the required yaw moment is insufficient. Constraint is imposed on the magnitude of the front slip angles in order to prevent the lateral tire forces from saturating. The driving simulation is performed by considering the limit of the front slip angle proposed in this study. Compared to the case that uses the existing 4WS, the results of this study are derived from the actuator combination that enhances performance while maintaining stability.

Author(s):  
Avesta Goodarzi ◽  
Amir Soltani ◽  
Ebrahim Esmailzadeh

Active variable wheelbase (AVW) has been introduced here as an innovative vehicle dynamic control method in which, the position of the front or rear axle relative to the vehicle C.G. can be actively varied. An attempt has been made to show the potential capabilities of this method in improving the road handling and stability of vehicles regardless of its embedded technical difficulties. For this purpose the proposed method has been conceptually studied in the first step and has been shown that one can generate the stabilizing yaw moment by changing the distance of the vehicle C.G. from the front or rear axles. Then the proposed concept has been theoretically studied using a simple vehicle dynamic model incorporated with the Magic Formula tire model. A comprehensive nonlinear 8 DOF vehicle model and a ‘model following control strategy’ have been used to evaluate the performance of AVW systems. The vehicle dynamic behavior when it is either uncontrolled or equipped with an AVW system has been simulated. Simulation results show that AVW can be considered as an innovative method for vehicle dynamic control in future.


Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1934
Author(s):  
Jaewon Nah ◽  
Seongjin Yim

This paper presents a method to design a vehicle stability controller with four-wheel independent braking (4WIB), drive (4WID) and steering (4WIS) for electric vehicles (EVs) adopting in-wheel motor (IWM) system. To improve lateral stability and maneuverability of vehicles, a direct yaw moment control strategy is adopted. A control allocation method is adopted to distribute control yaw moment into tire forces, generated by 4WIB, 4WID and 4WIS. A set of variable weights in the control allocation method is introduced for the application of several actuator combinations. Simulation on a driving simulation tool, CarSim®, shows that the proposed vehicle stability controller is capable of enhancing lateral stability and maneuverability. From the simulation, the effects of actuator combinations on control performance are analyzed.


Author(s):  
Ozan Temiz ◽  
Melih Cakmakci ◽  
Yildiray Yildiz

This paper presents an integrated fault-tolerant adaptive control allocation strategy for four wheel frive - four wheel steering ground vehicles to increase yaw stability. Conventionally, control of brakes, motors and steering angles are handled separately. In this study, these actuators are controlled simultaneously using an adaptive control allocation strategy. The overall structure consists of two steps: At the first level, virtual control input consisting of the desired traction force, the desired moment correction and the required lateral force correction to maintain driver’s intention are calculated based on the driver’s steering and throttle input and vehicle’s side slip angle. Then, the allocation module determines the traction forces at each wheel, front steering angle correction and rear steering wheel angle, based on the virtual control input. Proposed strategy is validated using a non-linear three degree of freedom reduced two-track vehicle model and results demonstrate that the vehicle can successfully follow the reference motion while protecting yaw stability, even in the cases of device failure and changed road conditions.


Author(s):  
Yaqi Dai ◽  
Jian Song ◽  
Liangyao Yu

By analyzing the key safety problems under the front-outside-tire burst steering condition, a vehicle stability control strategy is proposed in this paper, which is based on active front steering and differential braking systems. Taken both the handling stability and safety into account, we divided the whole control strategy into two layers, which are yaw moment control layer and the additional steering angle & tire force distribution layer. To solve the similar linear problem concisely, the LQR control is adopted in the yaw moment control layer. To achieve the goal of providing enough additional lateral force and yaw moment while keeping the burst tire in appropriate condition, the additional steering angle provided by active front steering system and the tire force distribution was adjusted step by step. To test the proposed control strategy performance, we modelling a basic front-outside-tire burst steering condition, in which the tire blows out once the vertical pressure reach the predefined critical value. Through simulation on different adhesion coefficient road, the control strategy proposed in this paper performance quite better compare with the uncontrolled one in aspect of movement, burst tire protection, handling stability.


2017 ◽  
Vol 50 (1) ◽  
pp. 13854-13859 ◽  
Author(s):  
Arya Senna Abdul Rachman ◽  
Adem Ferad Idriz ◽  
Shiqian Li ◽  
Simone Baldi

Author(s):  
Seyed Mohammad Mehdi Jaafari ◽  
Kourosh Heidari Shirazi

In this paper, a comparison is made on different torque vectoring strategies to find the best strategy in terms of improving handling, fuel consumption, stability and ride comfort performances. The torque vectoring differential strategies include superposition clutch, stationary clutch, four-wheel drive and electronic stability control. The torque vectoring differentials are implemented on an eight-DOF vehicle model and controlled using optimized fuzzy-based controllers. The vehicle model assisted with the Pacejka tyre model, an eight-cylinder dynamic model for engine, and a five-speed transmission system. Bee’s Algorithm is employed to optimize the fuzzy controller to ensure each torque vectoring differential works in its best state. The controller actuates the electronic clutches of the torque vectoring differential to minimize the yaw rate error and limiting the side-slip angle in stability region. To estimate side-slip angle and cornering stiffness, a combined observer is designed based on full order observer and recursive least square method. To validate the results, a realistic car model is built in Carsim package. The final model is tested using a co-simulation between Matlab and Carsim. According to the results, the torque vectoring differential shows better handling compared to electronic stability control, while electronic stability control is more effective in improving the stability in critical situation. Among the torque vectoring differential strategies, stationary clutch in handling and four-wheel drive in fuel consumption as well as ride comfort have better operation and more enhancements.


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