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.

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.

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

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2885
Author(s):  
Pai-Chen Chien ◽  
Chih-Keng Chen
Keyword(s):  
Control Strategy ◽  
Rear Wheel ◽  
Lateral Acceleration ◽  
Slip Angle ◽  
Control Allocation ◽  
Electric Cars ◽  
Integrated Chassis Control ◽  
Wheel Drive ◽  
Chassis Control ◽  
And Control

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.

Steering Analysis of Multi-Axle Vehicle Based on ADAMS/VIEW

2012 ◽  
Vol 538-541 ◽  
pp. 2878-2881
Author(s):  
Yong Qiang Zhu ◽  
Ping Xia Zhang
Keyword(s):  
High Speed ◽  
Large Angle ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Low Speed ◽  
Vehicle Simulation ◽  
Yaw Rate ◽  
Wheel Turning ◽  
Double Phase ◽  
All Wheel Steering

In order to improve low-speed flexibility and high-speed handling and stability of multi-axle vehicle, a double-phase steering system was designed with planetary gear system. An in-phase steering mode is used when steering wheel turning in small angle. A adverse-phase steering mode is used when steering wheel turning in large angle. A five-axle vehicle simulation model was established with software ADAMS/VIEW. The research of all-wheel steering and non-all-wheel steering for high speed and low speed was respectively processed. When running in high speed, the lateral acceleration and yaw rate of the centroid are significantly lower when rear wheels steering in in-phase mode than the rear wheels not turning, which makes the possibility of roll and drift decrease, when vehicle overtaking in high-speed. When running in low speed, compared with rear wheels not steering, when rear wheels sreering, lateral acceleration increased by only 12.8%, yaw rate is 17.3% higher, diameter of the centroid trajectory is reduced by 12.9%, which greatly increases the mobility and flexibility of the multi-axle vehicle when turning at low speed.

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.

A comparison on optimal torque vectoring strategies in overall performance enhancement of a passenger car

2016 ◽  
Vol 230 (4) ◽  
pp. 469-488 ◽  
Author(s):  
Seyed Mohammad Mehdi Jaafari ◽  
Kourosh Heidari Shirazi
Keyword(s):  
Fuel Consumption ◽  
Ride Comfort ◽  
Stability Control ◽  
Electronic Stability Control ◽  
Slip Angle ◽  
Vehicle Model ◽  
Side Slip Angle ◽  
Wheel Drive ◽  
Torque Vectoring ◽  
Four Wheel Drive

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.

Computer Controlled Integrated Steering / Drive System for Vehicles

1996 ◽  
Author(s):  
D. B. Blair ◽  
I. J. Spark
Keyword(s):  
Essential Feature ◽  
Drive System ◽  
Steering Wheel ◽  
Low Speed ◽  
Left Hand ◽  
Right Hand ◽  
Wheel Drive ◽  
Speed Stability ◽  
Computer Controlled ◽  
Four Wheel Drive

Abstract This paper discusses how a computer controlled four-wheel-steering (4WS) system can be used to increase the ability, namely low speed stability and traction as well as increased manoeuvrability of four-wheel-drive (4WD) vehicles. The essential feature of the integrated 4WS/4WD vehicle is that the path of the vehicle is selected via a joy stick or steering wheel, and a computer then controls the drive system of the two right hand wheels independently of the two left hand wheels, along with the positive rotation of the four wheels about vertical axes to the appropriate angles. Previous work by Spark and Besselink (1994a) relating to two wheel steering (2WS) / two wheel drive (2WD) systems will also be discussed briefly and expanded.

An integrated control of front in-wheel motors and rear electronic limited slip differential for high-speed cornering performance

2021 ◽  
pp. 095440702110455
Author(s):  
Hyunsoo Cha ◽  
Youngjin Hyun ◽  
Kyongsu Yi ◽  
Jaeyong Park
Keyword(s):  
High Speed ◽  
Integrated Control ◽  
Rear Wheel ◽  
Target Motion ◽  
Lateral Stability ◽  
Yaw Rate ◽  
Wheel Drive ◽  
Upper Level ◽  
Vehicle Test ◽  
Tire Friction

This paper presents an integrated control of in-wheel motor (IWM) and electronic limited slip differential (eLSD) for high-speed cornering performance. The proposed algorithm is designed to improve the handling performance near the limits of handling. The proposed controller consists of a supervisor, upper-level controller, and lower-level controller. First, the supervisor determines a target motion based on the yaw rate reference with a target understeer gradient. The target understeer gradient is devised to improve the lateral stability with in-wheel motor control based on a nonlinear static map. The yaw rate reference is designed based on the target understeer gradient to track the yaw reference with eLSD control. Second, the upper-level controller calculates the desired yaw moments for IWM and eLSD to generate the target motion. Third, the lower-level controller converts the desired yaw moment to the actuator torque commands for IWMs and eLSD. The tire friction limits are estimated based on the tire model and friction circle model to prevent tire saturation by limiting the torque inputs. The proposed algorithm has been investigated via both simulations and vehicle tests. The performance of the integrated control was compared with those of individual control and uncontrolled case in the simulation study. The vehicle tests have been performed using a rear wheel drive vehicle equipped with two front IWMs and eLSD in the rear axle. The vehicle test has been conducted at a racing track to show that the proposed algorithm can improve the lateral stability near the limits of handling.

Design and Performance Simulation of a Power-Integrated Transmission Mechanism

2013 ◽  
Vol 397-400 ◽  
pp. 388-392
Author(s):  
Chou Mo ◽  
Ji Qing Chen ◽  
Feng Chong Lan
Keyword(s):  
Hybrid Electric Vehicle ◽  
Rear Wheel ◽  
Front Wheel ◽  
Transmission Mechanism ◽  
System Structure ◽  
Performance Simulation ◽  
Operating Modes ◽  
Wheel Drive ◽  
And Performance ◽  
Four Wheel Drive

The power system structure of a hybrid electric vehicle (HEV) critically affects the performance of the vehicle. This study presents a power-integrated transmission mechanism that can provide six basic operating modes that can be further classified into 15 sub-modes. Switching clutch conditions helps transmission achieve speed and torque coupling. The proposed mechanism has CVT capability and an extended range capacity, and it is applicable to front-wheel-drive, rear-wheel-drive, or four-wheel-drive HEVs. A performance simulation on power and economy via Matlab and Cruise software demonstrates that the performance of the proposed transmission mechanism meets the target. Therefore, the mechanism is a feasible candidate for use in HEVs.

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