Enhanced braking and steering yaw motion controllers with a non-linear observer for improved vehicle stability

2008 ◽  
Vol 222 (3) ◽  
pp. 293-304 ◽  
Author(s):  
Jeonghoon Song
Keyword(s):  
Load Transfer ◽  
Rear Wheel ◽  
Front Wheel ◽  
Driver Model ◽  
Lateral Acceleration ◽  
Slip Angle ◽  
Vehicle Stability ◽  
Motion Controller ◽  
Non Linear ◽  
Linear Observer

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.

Paper 5: Vehicle Behaviour in Combined Cornering and Braking

1968 ◽  
Vol 183 (8) ◽  
pp. 19-34 ◽  
Author(s):  
A. J. Harris ◽  
B. S. Riley
Keyword(s):  
Steady State ◽  
Load Transfer ◽  
Equations Of Motion ◽  
Rear Wheel ◽  
Front Wheel ◽  
Slip Angle ◽  
Vehicle Model ◽  
Force Coefficient ◽  
Wheeled Vehicle ◽  
Non Linear

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.

Analysis of Vehicle Lateral Response During Regenerative Braking in a Turn

2016 ◽  
Author(s):  
C. S. Nanda Kumar ◽  
Shankar C. Subramanian
Keyword(s):  
Rear Wheel ◽  
Front Wheel ◽  
Lateral Acceleration ◽  
Regenerative Braking ◽  
Steering Wheel ◽  
Slip Angle ◽  
Lateral Response ◽  
Wheel Drive ◽  
Reference Track ◽  
The Impact

Regenerative braking is applied only at the driven wheels in electric and hybrid vehicles. The presence of brake force only at the driven wheels reduces the lateral traction limit of the corresponding tires. This impacts the vehicle lateral response, particularly while applying the regenerative brake in a turn. In this paper, a detailed study was made on the impact of regenerative brake on the vehicle lateral response in front wheel drive and rear wheel drive configurations on dry and wet asphalt road surfaces. Simulations were done considering a typical set of vehicle parameters with the IPG CarMaker® software for different drive conditions and braking configurations along the same reference track. The steering wheel angle, yaw rate, lateral acceleration, vehicle slip angle, and tire forces were obtained. Further, they were compared against the conventional all wheel friction brake configuration. The regenerative braking configuration that had the most impact on vehicle lateral response was analyzed and response variations were quantified.

Measurement of Vehicle Handling by Tethered Testing

1969 ◽  
Vol 184 (1) ◽  
pp. 219-231 ◽  
Author(s):  
N. F. Barter
Keyword(s):  
Steady State ◽  
Front Wheel ◽  
Lateral Acceleration ◽  
Slip Angle ◽  
Vehicle Stability ◽  
Centrifugal Acceleration ◽  
Vehicle Handling ◽  
Centre Of Gravity ◽  
Stability Derivatives ◽  
Method Of Measurement

The technique of tethered testing is introduced as a method of measurement of vehicle steady state handling, where the vehicle under test is attached to a large parent vehicle by means of an arm attached at its centre of gravity, and the tyre forces, which in the normal free vehicle situation produce a centrifugal acceleration, are simply reacted by this arm. The tethered testing rig built at M.I.R.A. is described. It is shown that the concept of tethered testing leads naturally to the idea of describing vehicle steady state handling by means of a quantity which depends only on lateral acceleration, and suitable quantities are shown to be static margin and the slope of a curve of mean front wheel steer angle against vehicle slip angle. These quantities are defined and their derivation in terms of vehicle stability derivatives is outlined in an appendix. Some examples of tethered test measurements are given in the form of plots of static margin against lateral acceleration, and a tentative set of criteria for good steady state handling is given in terms of the behaviour of static margin with lateral acceleration.

Slip parameter estimation of a single wheel using a non-linear observer

Robotica ◽  
2008 ◽  
Vol 27 (6) ◽  
pp. 801-811 ◽  
Author(s):  
Z. B. Song ◽  
L. D. Seneviratne ◽  
K. Althoefer ◽  
X. J. Song ◽  
Y. H. Zweiri
Keyword(s):  
Sliding Mode ◽  
Kinematic Model ◽  
Variable Structure ◽  
Lyapunov Stability Theory ◽  
Sliding Mode Observer ◽  
Slip Angle ◽  
Wheel Slip ◽  
Variable Structure System ◽  
Non Linear ◽  
Linear Observer

SUMMARYSliding mode observer is a variable structure system where the dynamics of a nonlinear system is altered via application of a high-frequency switching control. This paper presents a non-linear sliding mode observer for wheel linear slip and slip angle estimation of a single wheel based on its kinematic model and velocity measurements with added noise to simulate actual on-board sensor measurements. Lyapunov stability theory is used to establish the stability conditions for the observer. It is shown that the observer will converge in a finite time, provided the observer gains satisfy constraints based on a stability analysis. To validate the observer, linear and two-dimensional (2D) test rigs are specially designed. The sliding mode observer is tested under a variety of conditions and it is shown that the sliding mode observer can estimate wheel slip and slip angle to a high accuracy. It is also shown that the sliding mode observer can accurately predict wheel slip and slip angle in the presence of noise, by testing the performance of the sliding mode observer after adding white noise to the measurements. An extended Kalman filter is also developed for comparison purposes. The sliding mode observer is better in terms of prediction accuracy.

Test Results: Vehicle Responses to Simulated Drag Caused by Front Tire Tread Detachment — The Effect of Scrub Radius and Speed

2018 ◽  
Author(s):  
Mark W. Arndt ◽  
Stephen M. Arndt
Keyword(s):  
Lateral Displacement ◽  
Rear Wheel ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Slip Angle ◽  
Yaw Rate ◽  
Wheel Drive ◽  
Steady State Responses ◽  
Four Wheel Drive ◽  
Left Front

The effects of reduced kingpin offset distance at the ground (scrub radius) and speed were evaluated under controlled test conditions simulating front tire tread detachment drag. While driving in a straight line at target speeds of 50, 60, or 70 mph with the steering wheel locked, the drag of a tire tread detachment was simulated by applying the left front brake with a pneumatic actuator. The test vehicle was a 2001 dual rear wheel four-wheel-drive Ford F350 pickup truck with an 11,500 lb. GVWR. The scrub radius was tested at the OEM distance of 125 mm (Δ = 0) and at reduced distances of 49 mm (Δ = −76) and 11 mm (Δ = −114). The average steady state responses at 70 mph with the OEM scrub radius were: steering torque = −24.5 in-lb; slip angle = −3.8 deg; lateral acceleration = −0.47 g; yaw rate = −8.9 deg/sec; lateral displacement after 0.75 seconds = 3.1 ft and lateral displacement after 1.5 seconds = 13.1 ft. At the OEM scrub radius, responses that increased linearly with speed included: slip angle (R2 = 0.84); lateral acceleration (R2 = 0.93); yaw rate (R2 = 0.73) and lateral displacement (R2 = 0.59 and R2 = 0.87, respectively). At the OEM scrub radius, steer torque decreased linearly with speed (R2 = 0.76) and longitudinal acceleration had no linear relationship with speed (R2 = 0.09). At 60 mph and 70 mph for both scrub radius reductions, statistically significant decreases (CI ≥ 95%) occurred in average responses of steer torque, slip angle, lateral acceleration, yaw rate, and lateral displacement. At 50 mph, reducing the OEM scrub radius to 11 mm resulted in statistically significant decreases (CI ≥ 95%) in average responses of steer torque, lateral acceleration, yaw rate and lateral displacement. At 50 mph the average slip angle response decreased (CI = 87%) when the OEM scrub radius was reduced to 11 mm.

Determination of the Vehicle Body Side Slip Angle with Non-Linear Observer Strategies

2005 ◽  
Author(s):  
Marcus Hiemer ◽  
Anne Von Vietinghoff ◽  
Uwe Kiencke ◽  
Takanori Matsunaga
Keyword(s):  
Vehicle Body ◽  
Slip Angle ◽  
Side Slip Angle ◽  
Body Side ◽  
Non Linear ◽  
Linear Observer

scholarly journals Improving Handling Stability Performance of Four-Wheel Steering Vehicle Based on the H2/H∞ Robust Control

2019 ◽  
Vol 9 (5) ◽  
pp. 857 ◽  
Author(s):  
Fei-Xiang Xu ◽  
Xin-Hui Liu ◽  
Wei Chen ◽  
Chen Zhou ◽  
and Bing-Wei Cao
Keyword(s):  
Robust Control ◽  
System Performance ◽  
Rear Wheel ◽  
Stability Control ◽  
Driver Model ◽  
Vehicle Stability ◽  
Vehicle Model ◽  
Stability Performance ◽  
Vehicle Stability Control ◽  
Modeling Uncertainties

Considering the demand for vehicle stability control and the existence of uncertainties in the four-wheel steering (4WS) system, the mixed H2/H∞ robust control methodology of the 4WS system is proposed. Firstly, the linear 2DOF vehicle model, the nonlinear 8DOF vehicle model, the driver model, and the rear wheel electrohydraulic system model were constructed. Secondly, based on the yaw rate tracking strategy, the mixed H2/H∞ controller was designed with the optimized weighting functions to guarantee system performance, robustness, and the robust stability of the 4WS vehicle stability control system. The H∞ method was applied to minimize the effects of modeling uncertainties, sensor noise, and external disturbances on the system outputs, and the H2 method was used to ensure system performance. Finally, numerical simulations based on Matlab/Simulink and hardware-in-the-loop experiments were performed with the proposed control strategy to identify its performance. The simulation and experimental results indicate that the handling stability of the 4WS vehicle is improved by the H2/H∞ controller and that the 4WS system with the H2/H∞ controller has better handling stability and robustness than those of the H∞ controller and the proportional controller.

Vehicle Braking Stability Analysis in Turn Condition

2014 ◽  
Vol 607 ◽  
pp. 604-607 ◽  
Author(s):  
Ling Zhao
Keyword(s):  
Stability Analysis ◽  
Dynamic Model ◽  
Load Transfer ◽  
Rear Wheel ◽  
Front Wheel ◽  
Vertical Load ◽  
Steering Angle ◽  
Braking Distance ◽  
Simulation Results

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.

A study on an anti-lock braking system controller and rear-wheel controller to enhance vehicle lateral stability

2007 ◽  
Vol 221 (7) ◽  
pp. 777-787 ◽  
Author(s):  
Jeonghoon Song ◽  
Heungseob Kim ◽  
Kwangsuck Boo
Keyword(s):  
Sliding Mode ◽  
Dynamic Performance ◽  
Rear Wheel ◽  
Slip Angle ◽  
Lateral Stability ◽  
Motion Controller ◽  
Wheel Slip ◽  
Stopping Distance ◽  
Braking System ◽  
The Stability

This paper presents a mathematical vehicle model that is designed to analyse and improve the dynamic performance of a vehicle. A wheel slip controller for anti-lock braking system (ABS) brakes is formulated using a sliding mode controller and a proportional-integral-derivative (PID) controller for rear wheel steering is also designed to enhance the stability, steerability, and driveability of the vehicle during transient manoeuvres. The braking and steering performances of controllers are evaluated for various driving conditions, such as straight and J-turn manoeuvres. The simulation results show that the proposed full car model is sufficient to predict vehicle responses accurately. The developed ABS reduces the stopping distance and increases the longitudinal and lateral stability of both two-and four-wheel steering vehicles. The results also demonstrate that the use of a rear wheel controller as a yaw motion controller can increase its lateral stability and reduce the slip angle at high speeds.

The Control of the Braking Stability of Active Rear Wheel Steering Vehicle Based on LQR

2013 ◽  
Vol 416-417 ◽  
pp. 909-913
Author(s):  
Qi Jia Liu ◽  
Si Zhong Chen
Keyword(s):  
Slip Rate ◽  
Linear Quadratic Regulator ◽  
Rear Wheel ◽  
Front Wheel ◽  
Slip Angle ◽  
Linear Quadratic ◽  
Wheel Slip ◽  
Side Slip Angle ◽  
Braking Distance ◽  
Lock Mode

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.

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