Cascaded Predictive Control of Tire Force Saturation Levels for Vehicle Stability

2014 ◽  
Author(s):  
Justin Sill ◽  
Beshah Ayalew
Keyword(s):  
Predictive Control ◽  
Longitudinal Direction ◽  
Stability Control ◽  
Vehicle Stability ◽  
Optimal Management ◽  
Torque Distribution ◽  
Tire Force ◽  
Lateral Vehicle Dynamics ◽  
Braking Torque ◽  
Upper Level

This paper proposes and demonstrates a cascaded predictive control strategy that quantifies and uses longitudinal and lateral tire force saturation for directional stability control of road vehicles. Saturation is explicitly defined and computed as the deficiency of a tire to generate a linearly increasing force in either the lateral or longitudinal direction. The optimal management of lateral saturation levels is set as the objective for an upper level controller, while the optimal management of longitudinal saturation among all tires is set as the objective for a lower level driving/braking torque distribution controller. This cascaded predictive scheme exploits prevailing time scale separations between the lateral vehicle dynamics and the tire/wheel dynamics. The performance of the approach is illustrated using simulations of a medium-duty truck undergoing a transient handling maneuver.

Vehicle Stability Control Through Predictive and Optimal Tire Saturation Management

2012 ◽  
Author(s):  
Justin Sill ◽  
Beshah Ayalew
Keyword(s):  
Stability Control ◽  
Vehicle Stability ◽  
Distribution Problem ◽  
Scale Separation ◽  
Torque Distribution ◽  
Hydraulic Hybrid ◽  
Time Scale Separation ◽  
Vehicle Stability Control ◽  
Natural Time ◽  
Set Up

This paper presents a predictive vehicle stability control (VSC) strategy that distributes the drive/braking torques to each wheel of the vehicle based on the optimal exploitation of the available traction capability for each tire. To this end, tire saturation levels are defined as the deficiency of a tire to generate a force that linearly increases with the relevant slip quantities. These saturation levels are then used to set up an optimization objective for a torque distribution problem within a novel cascade control structure that exploits the natural time scale separation of the slower lateral handling dynamics of the vehicle from the relatively faster rotational dynamics of the wheel/tire. The envisaged application of the proposed vehicle stability strategy is for vehicles with advanced and emerging pure electric, hybrid electric or hydraulic hybrid power trains featuring independent wheel drives. The developed predictive control strategy is evaluated for, a two-axle truck featuring such an independent drive system and subjected to a transient handling maneuver.

Adaptive Vehicle Stability Control With Optimal Tire Force Allocation

2012 ◽  
Author(s):  
Mustafa Ali Arat ◽  
Kanwar Bharat Singh ◽  
Saied Taheri
Keyword(s):  
Stability Control ◽  
Crash Risk ◽  
Slip Angle ◽  
Vehicle Stability ◽  
Successful Implementation ◽  
Tire Force ◽  
Vehicle Stability Control ◽  
Saturation Region ◽  
Road Friction ◽  
Tire Forces

Vehicle stability control systems have been receiving increasing attention, especially over the past decade, owing to the advances in on-board electronics that enables successful implementation of complex algorithms. Another major reason for their increasing popularity lies in their effectiveness. Considering the studies that expose supporting results for reducing crash risk or fatality, organizations such as E.U. and NHTSA are taking steps to mandate the use of such safety systems on vehicles. The current technology has advanced in many aspects, and undoubtedly has improved vehicle stability as mentioned above; however there are still many areas of potential improvements. Especially being able to utilize information about tire-vehicle states (tire forces, tire-slip angle, and tire-road friction) would be significant due to the key role tires play in providing directional stability and control. This paper presents an adaptive vehicle stability controller that makes use of tire force and slip-angle information from an online tire monitoring system. Solving the optimality problem for the tire force allocation ensures that the control system does not push the tires into the saturation region where neither the driver nor the controller commands are implemented properly. The proposed control algorithm is implemented using MATLAB/CarSim® software packages. The performance of the system is evaluated under an evasive double lane change maneuver on high and low friction surfaces. The results indicate that the system can successfully stabilize the vehicle as well as adapting to the changes in surface conditions.

The Research of Wheel Drive Vehicle Yaw Stability Controller Based on Model Predictive Control

2014 ◽  
Vol 998-999 ◽  
pp. 735-740 ◽  
Author(s):  
Chen Guo Zou ◽  
Hong Liang Zhou ◽  
Zhen He
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Control Method ◽  
Stability Control ◽  
Safety Control ◽  
Yaw Rate ◽  
Wheel Drive ◽  
Yaw Stability ◽  
Braking Torque ◽  
Driving Torque

As an important active safety control method, vehicle yaw stability control guarantees the dynamic stability of vehicle. A wheel drive vehicle yaw stability controller based on model predictive control theory is designed to plan the longitudinal forces of the four wheels online to control the driving torque or braking torque of each wheel. With the designed controller, the vehicle is able to track the desired yaw rate in the process of turning. The yaw stability and longitudinal characteristics of the vehicle are guaranteed at the same time.

Handling Delays in Yaw Rate Control of Electric Vehicles Using Model Predictive Control With Experimental Verification

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Milad Jalali ◽  
Amir Khajepour ◽  
Shih-ken Chen ◽  
Bakhtiar Litkouhi
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Rear Wheel ◽  
Stability Control ◽  
Vehicle Stability ◽  
Control Loop ◽  
Yaw Rate ◽  
Vehicle Stability Control ◽  
Wheel Drive ◽  
Rear Wheel Drive

In this paper, a new approach is proposed to deal with the delay in vehicle stability control using model predictive control (MPC). The vehicle considered here is a rear-wheel drive electric (RWD) vehicle. The yaw rate response of the vehicle is modified by means of torque vectoring so that it tracks the desired yaw rate. Presence of delays in a control loop can severely degrade controller performance and even cause instability. The common approaches for handling delays are often complex in design and tuning or require an increase in the dimensions of the controller. The proposed method is easy to implement and does not entail complex design or tuning process. Moreover, it does not increase the complexity of the controller; therefore, the amount of online computation is not appreciably affected. The effectiveness of the proposed method is verified by means of carsim/simulink simulations as well as experiments with a rear-wheel drive electric sport utility vehicle (SUV). The simulation results indicate that the proposed method can significantly reduce the adverse effect of the delays in the control loop. Experimental tests with the same vehicle also point to the effectiveness of this technique. Although this method is applied to a vehicle stability control, it is not specific to a certain class of problems and can be easily applied to a wide range of model predictive control problems with known delays.

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