Vehicle Braking Stability Analysis in Turn Condition

2014 ◽  
Vol 607 ◽  
pp. 604-607 ◽  
Author(s):  
Ling Zhao

Considering the influence of wheel vertical load transfer and Steering angle, the paper establishes a dynamic model of 7 degrees freedom for vehicle under Braking in Turn Condition. Based on this model, wheel lock braking and ABS braking were researched and simulated. The simulation results show directly that first lock of front wheel loses vehicle steering performance, first lock the rear wheel sideslips, ABS braking can prevent loss of vehicle steering performance and sideslip, but slightly long braking distance.

Robotica ◽  
2011 ◽  
Vol 30 (4) ◽  
pp. 517-535 ◽  
Author(s):  
Maciej Michałek ◽  
Krzysztof Kozłowski

SUMMARYThe paper introduces a novel general feedback control framework, which allows applying the motion controllers originally dedicated for the unicycle model to the motion task realization for the car-like kinematics. The concept is formulated for two practically meaningful motorizations: with a front-wheel driven and with a rear-wheel driven. All the three possible steering angle domains for car-like robots—limited and unlimited ones—are treated. Description of the method is complemented by the formal stability analysis of the closed-loop error dynamics. The effectiveness of the method and its limitations have been illustrated by numerous simulations conducted for the three main control tasks, namely, for trajectory tracking, path following, and set-point regulation.


Author(s):  
Jeonghoon Song

This study proposes two enhanced yaw motion controllers that are modified versions of a braking yaw motion controller (BYMC) and a steering yaw motion controller (SYMC). A BYMC uses an inner rear-wheel braking pressure controller, while an SYMC uses a rear-wheel steering controller. However, neither device can entirely ensure the safety of a vehicle because of the load transfer from the rear to front wheels during braking. Therefore, an enhanced braking yaw motion controller (EBYMC) and an enhanced steering yaw motion controller (ESYMC) are developed, which contain additional outer front-wheel controllers. The performances of the EBYMC and ESYMC are evaluated for various road conditions and steering inputs. They reduce the slip angle and eliminate variation in the lateral acceleration, which increase the controllability, stability, and comfort of the vehicle. A non-linear observer and driver model also produce satisfactory results.


2011 ◽  
Vol 338 ◽  
pp. 236-240
Author(s):  
Ren Cai Zhao ◽  
Xu Ma ◽  
Long Qi ◽  
Rui Chuan Li

When tractor steers in the same rut, it can not only improve its flexibility in steering, but also reduce soil compaction and crop rolling. In this paper , the concept of tractor steering in the same rut was proposed on the basis of four-wheel-steering (4WS) theory, and the angle relationship between front wheel and rear wheel, which can achieve the same-rut-steering, was established. A three dimensional parameterized model of tractor’s same-rut-steering mechanism was established by the Pro/E software, and its running tracks were simulated in the ADAMS environment. Simulation results show that the same-rut-steering accuracy was affected to some extent when tractor’s speed or steering wheel deflection rate was changed. At last, methods for improving the same-rut-steering accuracy were put forward.


2013 ◽  
Vol 416-417 ◽  
pp. 909-913
Author(s):  
Qi Jia Liu ◽  
Si Zhong Chen

The aim of this article is to improve the brake stability of active rear wheel steering vehicle. The optimal theory of linear quadratic regulator is used to construct a controller, and the aim of the controller is to maintain the side slip angle is zero, and the control parameter is set according to the change of velocity when braking. An antilock brake model based on the door limit of wheel slip rate is constructed. The analysis is carried on a front wheel steering vehicle, which has two kinds of unti-lock mode. Meanwhile, an active rear wheel steering vehicle with two kinds of unti-lock mode is performed, also. All tests are performed on the bisectional road. The results of analysis show that the active rear wheel steering vehicle using the anti-lock mode of four wheels independent control can give the shortest braking distance, the smaller side slip angle and the smaller deviation from the lane. So it can give more contribution to the braking safety.


2012 ◽  
Vol 241-244 ◽  
pp. 2019-2022
Author(s):  
Yu Zhuo Men ◽  
Hai Bo Yu ◽  
Xian Sheng Li

In order to research the influence of lateral load transfer on the roll stability of passenger vehicle, the dynamics simulation model is established. Pass through simulation, the influence of the passenger vehicle structural parameters and speed on its roll stability is analyzed. The research result shows that, the passenger vehicle rear wheel drive axle is risky for roll stability; it will first lift off when the speed is too high or the front wheel angle is too big. The roll stability of passenger vehicle can be effectively improved by increasing the wheel spread and wheelbase, lowering sprung mass center height, and improving the passenger vehicle suspension roll stiffness.


Author(s):  
A. J. Harris ◽  
B. S. Riley

This paper considers first the steady-state motions of a simple two-wheeled vehicle model having non-linear sideway force relationships with respect to tyre slip angle. It is shown that any steady-state conditions may be represented and their solutions found by simple graphical means, using only the non-linear curves. The curves can be modified to take into account the influence of vehicle parameters such as compliance, roll steer, wheel camber, and load transfer. Stability boundaries are discussed and criteria are presented showing that stability of the motion depends only on the slopes of the curves and the speed of the manoeuvre at the cornering acceleration being considered. A more involved four-wheeled vehicle model is then considered when subjected to braking while cornering on a fixed radius path of 45·8 m on a wet Bridport macadam surface. Actual sideway force–slip angle curves for combined braking and cornering, as presented by Holmes and Stone (see reference (6))†, are used with the equations of motion derived for the quasi-steady state conditions of decelerating while cornering. The effects of front wheel steered angle and body slip angle on the forces necessary for the manoeuvre are also considered. An envelope of maximum cornering acceleration at various braking decelerations is presented. This shows that for those particular conditions up to about 70 per cent of maximum deceleration may be obtained before there is more than about 10 per cent loss in maximum cornering ability. Outside the envelope the vehicle fails to maintain the path. At the lower deceleration the car spins, and at higher values it continues tangentially to its original path without spinning. It is also shown that the total sideway force–slip angle curve for a pair of front or rear wheels, when one or both wheels have a high braking force coefficient, can have a sharp peak, such that for small increase in slip angle there is a rapid fall in sideway force. It is suggested that this is why a rear wheel skid which occurs while braking and cornering is more difficult to correct than one which occurs when only cornering.


Author(s):  
Yan Ti ◽  
Kangcheng Zheng ◽  
Wanzhong Zhao ◽  
Tinglun Song

To improve handling and stability for distributed drive electric vehicles (DDEV), the study on four wheel steering (4WS) systems can improve the vehicle driving performance through enhancing the tracking capability to desired vehicle state. Most previous controllers are either a large amount of calculation, or requires a lot of experimental data, these are relatively time-consuming and laborious. According to the front and rear wheel steering angle of DDEV can be distributed independently, a novel controller named internal model controller with fractional-order filter (IMC-FOF) for 4WS systems is proposed and studied in this paper. The IMC-FOF is designed using the internal model control theory and compared with IMC and PID controller. The influence of time constant and fractional-order parameters which is optimized using quantum genetic algorithms (QGA) on tracking ability of vehicle state are also analyzed. Using a production vehicle as an example, the simulation is performed combining Matlab/Simulink and CarSim. The comparison results indicated that the proposed controller presents performance to distribute the front and rear wheel steering angle for ensuring better tracking capability to desired vehicle state, meanwhile it possesses strong robustness.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1291
Author(s):  
Balázs Németh

The paper proposes a novel learning-based coordination strategy for lateral control systems of automated vehicles. The motivation of the research is to improve the performance level of the coordinated system compared to the conventional model-based reconfigurable solutions. During vehicle maneuvers, the coordinated control system provides torque vectoring and front-wheel steering angle in order to guarantee the various lateral dynamical performances. The performance specifications are guaranteed on two levels, i.e., primary performances are guaranteed by Linear Parameter Varying (LPV) controllers, while secondary performances (e.g., economy and comfort) are maintained by a reinforcement-learning-based (RL) controller. The coordination of the control systems is carried out by a supervisor. The effectiveness of the proposed coordinated control system is illustrated through high velocity vehicle maneuvers.


2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.


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