Instability detection of the tire-road contact and torque control for wheel-individual driven vehicles

2018 ◽  
Vol 66 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Peter Speth ◽  
Andreas Hummler ◽  
Michael Buchholz ◽  
Klaus Dietmayer

Abstract Traction control for vehicles with wheel individual drives is a challenging task, since the wheel slips are unknown when each wheel transfers a torque. This contribution presents an approach which deals with this problem especially for electrical vehicles, where the drive torques can be changed very fast in comparison to vehicles with combustion engines. The algorithm is based on two filters. The first filter is an adaptive Kalman filter which is used to detect fast changes in the stability conditions of the wheels. The filter also delivers a valuation for the torque to which the drive torque has to be reduced to get the wheel stable again. The second filter estimates the wheel slip. It is based on a simplified expression of the slip dynamics in combination with a special reset strategy for low slip situations. This filter allows detection of slow changes in the stability conditions. All filters are wheel individual and use only standard sensor information. No tire model is needed for the filters to work. A simple reflexive traction controller, which is based on a state machine, computes the drive torques in dependence on the stability criteria based on the filter outputs.

2018 ◽  
Vol 7 (3.13) ◽  
pp. 22
Author(s):  
Abdelaziz Sahbani ◽  
. .

This paper deals with a detailed dynamic design of traction control strategies based on fuzzy logic controller. The proposed system is motorized by two independent DC motors associated with two static DC converters and an electrical differential. An approach to both longitudinal and lateral controls of two wheels is described. In fact, by using electric motors, it is possible to have a torque control in each wheel drive, enabling the implementation of a traction control. Consequently, the stability and the safety of the vehicle will be improved. Obtained simulation results confirm the efficiency of the proposed controller. 


2020 ◽  
Vol 28 (2) ◽  
pp. 489-504 ◽  
Author(s):  
Elias Reichensdorfer ◽  
Dirk Odenthal ◽  
Dirk Wollherr

2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Kun Yang ◽  
Danxiu Dong ◽  
Chao Ma ◽  
Zhaoxian Tian ◽  
Yile Chang ◽  
...  

Tire longitudinal forces of electrics vehicle with four in-wheel-motors can be adjusted independently. This provides advantages for its stability control. In this paper, an electric vehicle with four in-wheel-motors is taken as the research object. Considering key factors such as vehicle velocity and road adhesion coefficient, the criterion of vehicle stability is studied, based on phase plane of sideslip angle and sideslip-angle rate. To solve the problem that the sideslip angle of vehicles is difficult to measure, an algorithm for estimating the sideslip angle based on extended Kalman filter is designed. The control method for vehicle yaw moment based on sliding-mode control and the distribution method for wheel driving/braking torque are proposed. The distribution method takes the minimum sum of the square for wheel load rate as the optimization objective. Based on Matlab/Simulink and Carsim, a cosimulation model for the stability control of electric vehicles with four in-wheel-motors is built. The accuracy of the proposed stability criterion, the algorithm for estimating the sideslip angle and the wheel torque control method are verified. The relevant research can provide some reference for the development of the stability control for electric vehicles with four in-wheel-motors.


2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Farid Taghinavaz

Abstract In this paper, I study the conditions imposed on a normal charged fluid so that the causality and stability criteria hold for this fluid. I adopt the newly developed General Frame (GF) notion in the relativistic hydrodynamics framework which states that hydrodynamic frames have to be fixed after applying the stability and causality conditions. To do this, I take a charged conformal matter in the flat and 3 + 1 dimension to analyze better these conditions. The causality condition is applied by looking to the asymptotic velocity of sound hydro modes at the large wave number limit and stability conditions are imposed by looking to the imaginary parts of hydro modes as well as the Routh-Hurwitz criteria. By fixing some of the transports, the suitable spaces for other ones are derived. I observe that in a dense medium having a finite U(1) charge with chemical potential μ0, negative values for transports appear and the second law of thermodynamics has not ruled out the existence of such values. Sign of scalar transports are not limited by any constraints and just a combination of vector transports is limited by the second law of thermodynamic. Also numerically it is proved that the most favorable region for transports $$ {\tilde{\upgamma}}_{1,2}, $$ γ ˜ 1 , 2 , coefficients of the dissipative terms of the current, is of negative values.


Author(s):  
Bo Xiao ◽  
Hak-Keung Lam ◽  
Zhixiong Zhong

AbstractThe main challenge of the stability analysis for general polynomial control systems is that non-convex terms exist in the stability conditions, which hinders solving the stability conditions numerically. Most approaches in the literature impose constraints on the Lyapunov function candidates or the non-convex related terms to circumvent this problem. Motivated by this difficulty, in this paper, we confront the non-convex problem directly and present an iterative stability analysis to address the long-standing problem in general polynomial control systems. Different from the existing methods, no constraints are imposed on the polynomial Lyapunov function candidates. Therefore, the limitations on the Lyapunov function candidate and non-convex terms are eliminated from the proposed analysis, which makes the proposed method more general than the state-of-the-art. In the proposed approach, the stability for the general polynomial model is analyzed and the original non-convex stability conditions are developed. To solve the non-convex stability conditions through the sum-of-squares programming, the iterative stability analysis is presented. The feasible solutions are verified by the original non-convex stability conditions to guarantee the asymptotic stability of the general polynomial system. The detailed simulation example is provided to verify the effectiveness of the proposed approach. The simulation results show that the proposed approach is more capable to find feasible solutions for the general polynomial control systems when compared with the existing ones.


2012 ◽  
Vol 220-223 ◽  
pp. 1040-1043
Author(s):  
Hong Cui ◽  
You Qing Gao

High-speed permanent magnet synchronous motor (PMSM) is more and more widely applied in high precision processing and high-performance machines. It is very important to research practical control strategy for the stability operation of the high-speed PMSM. The strategy of sensorless grey prediction fuzzy direct torque control (DTC) is proposed which is suitable for high-speed PMSM control system. The method of prediction fuzzy control based on DTC is used to gain the flux, torque and flux oriented angle through the prediction model of the motor parameters. The best control scheme is gained by fuzzy reasoning to overcome the lag on the system making the adjustment process stable and realizing accurate predictive control. Thereby, the dynamic response of the system, anti-disturbance capability and control accuracy can be improved.


Robotica ◽  
2015 ◽  
Vol 35 (2) ◽  
pp. 463-482 ◽  
Author(s):  
Avinash Siravuru ◽  
Suril V. Shah ◽  
K. Madhava Krishna

SUMMARYThis paper discusses the development of an optimal wheel-torque controller for a compliant modular robot. The wheel actuators are the only actively controllable elements in this robot. For this type of robots, wheel-slip could offer a lot of hindrance while traversing on uneven terrains. Therefore, an effective wheel-torque controller is desired that will also improve the wheel-odometry and minimize power consumption. In this work, an optimal wheel-torque controller is proposed that minimizes the traction-to-normal force ratios of all the wheels at every instant of its motion. This ensures that, at every wheel, the least traction force per unit normal force is applied to maintain static stability and desired wheel speed. The lower this is, in comparison to the actual friction coefficient of the wheel-ground interface, the more margin of slip-free motion the robot can have. This formalism best exploits the redundancy offered by a modularly designed robot. This is the key novelty of this work. Extensive numerical and experimental studies were carried out to validate this controller. The robot was tested on four different surfaces and we report an overall average slip reduction of 44% and mean wheel-torque reduction by 16%.


2014 ◽  
Vol 971-973 ◽  
pp. 454-457
Author(s):  
Gang He ◽  
Li Qiang Jin

Based on the independent design front wheel drive vehicle traction control system (TCS), we finished the two kinds of working condition winter low adhesion real vehicle road test, including homogenous pavement and separate pavement straight accelerate, respectively completed the contrastive experiment with TCS and without TCS. Test results show that based on driver (AMR) and brake (BMR) joint control ASR system worked reliably, controlled effectively, being able to control excessive driving wheel slip in time, effectively improved the driving ability and handling stability of vehicle.


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