Integrated Chassis Control and Control Allocation for All Wheel Drive Electric Cars with Rear Wheel Steering

This study investigates a control strategy for torque vectoring (TV) and active rear wheel steering (RWS) using feedforward and feedback control schemes for different circumstances. A comprehensive vehicle and combined slip tire model are used to determine the secondary effect and to generate desired yaw acceleration and side slip angle rate. A model-based feedforward controller is designed to improve handling but not to track an ideal response. A feedback controller based on close loop observation is used to ensure its cornering stability. The fusion of two controllers is used to stabilize a vehicle’s lateral motion. To increase lateral performance, an optimization-based control allocation distributes the wheel torques according to the remaining tire force potential. The simulation results show that a vehicle with the proposed controller exhibits more responsive lateral dynamic behavior and greater maximum lateral acceleration. The cornering safety is also demonstrated using a standard stability test. The driving performance and stability are improved simultaneously by the proposed control strategy and the optimal control allocation scheme.

Download Full-text

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

Volume 13: Design, Reliability, Safety, and Risk ◽

10.1115/imece2018-87609 ◽

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.

Download Full-text

Analysis of Vehicle Lateral Response During Regenerative Braking in a Turn

Volume 12: Transportation Systems ◽

10.1115/imece2016-66355 ◽

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.

Download Full-text

Design of an Integrated Vehicle Chassis Control System with Driver Behavior Identification

Mathematical Problems in Engineering ◽

10.1155/2015/954514 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Bing Zhu ◽

Yizhou Chen ◽

Jian Zhao ◽

Yunfu Su

Keyword(s):

Control System ◽

Control Strategy ◽

Driver Behavior ◽

Stability Performance ◽

Integrated Chassis Control ◽

Yaw Moment Control ◽

Chassis Control ◽

Lane Change Test ◽

Behavior Characteristics ◽

Vehicle Chassis

An integrated vehicle chassis control strategy with driver behavior identification is introduced in this paper. In order to identify the different types of driver behavior characteristics, a driver behavior signals acquisition system was established using the dSPACE real-time simulation platform, and the driver inputs of 30 test drivers were collected under the double lane change test condition. Then, driver behavior characteristics were analyzed and identified based on the preview optimal curvature model through genetic algorithm and neural network method. Using it as a base, an integrated chassis control strategy with active front steering (AFS) and direct yaw moment control (DYC) considering driver characteristics was established by model predictive control (MPC) method. Finally, simulations were carried out to verify the control strategy by CarSim and MATLAB/Simulink. The results show that the proposed method enables the control system to adjust its parameters according to the driver behavior identification results and the vehicle handling and stability performance are significantly improved.

Download Full-text

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

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/09544070jauto662 ◽

2008 ◽

Vol 222 (3) ◽

pp. 293-304 ◽

Cited By ~ 5

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.

Download Full-text

Attitude Blended Control for Aerospace Vehicle with Lateral Thrusters and Aerodynamic Fins

Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University ◽

10.1051/jnwpu/20193730532 ◽

2019 ◽

Vol 37 (3) ◽

pp. 532-540

Author(s):

Aijun Li ◽

Yu Wang ◽

Yong Guo ◽

Changqing Wang

Keyword(s):

Control Strategy ◽

Finite Time ◽

Attitude Control ◽

Sliding Mode ◽

Control Allocation ◽

Sliding Mode Controller ◽

Attitude Error ◽

The Neural Network ◽

And Control ◽

Attitude Model

A finite-time blended control strategy is proposed for the reentry phase attitude control of the aerospace vehicle (ASV) based on the neural network, sliding mode control theory and control allocation. Firstly, a finite-time neural networks sliding mode controller is designed based on the attitude model of the ASV in the reentry phase to obtain the virtual control moments which can make the attitude error converge to the equilibrium point in finite time. Secondly, the desired control moments are mapped into the control commands on the aerodynamic deflectors and the reaction control system (RCS) by using the control allocation. Finally, simulation results are provided to demonstrate the effectiveness of the attitude blended control strategy proposed.

Download Full-text