Road Feeling Research Articles

Design and development of networked real-life cycling training system based on mixed reality technology

The intelligent riding platform cooperates with the PC-side riding training system to simulate the effect of outdoor riding with a certain sense of reality. With the rapid development of information technology, users have also put forward higher requirements for cycling training systems. The 3D virtual scene riding mode provided by the existing intelligent riding training system does not meet the user's preference for real riding, and the domestic riding platform cannot simulate the real road feeling, lacking realism and fun. Therefore, developing a richer and more interesting new cycling training mode and creating a more realistic and accurate real cycling experience based on mixed reality are the new demands of users for the cycling training system. At the same time, the calculation and development of rider power based on the platform is the core of it. In the original single-person riding training mode, the server framework and client-side functional modules are constructed by using the principle of network communication and related technologies such as the production of online game rooms to realize the multi-player competitive function.

Analysis on the research method of road sense feedback in steer-by-wire system

Nowadays, the automobile industry is gradually developing towards the trend of electrification and intelligence. Compared with the traditional steering system, the steer-by-wire system cancels the mechanical transmission structure, reduces the space utilization, reduces the probability of damage to the driver caused by the steering system in the collision accident, and improves the driving portability and enhances the driver’s handling experience. The road feeling feedback of steer-by-wire system has the greatest impact on the driver’s driving experience. This paper discusses the research methods of road feeling feedback of steer-by-wire system, introduces the basic structure of road feeling feedback of steer-by-wire system, the basic idea of dynamic modeling, the establishment of simulation model of road feeling feedback, and the establishment method of control strategy and simulation platform of road feeling feedback. Finally, it summarizes and prospects in order to provide basic information and perspectives for the development and research of steer-by-wire system.

Active Disturbance Rejection Control of Differential Drive Assist Steering for Electric Vehicles

The differential drive assist steering (DDAS) system makes full use of the advantages of independent control of wheel torque of electric vehicle driven by front in-wheel motors to achieve steering assistance and reduce the steering effort of the driver, as the electric power steering (EPS) system does. However, as an indirect steering assist technology that applies steering system assistance via differential drive, its linear control algorithm, like existing proportion integration differentiation (PID) controllers, cannot take the nonlinear characteristics of the tires’ dynamics into account which results in poor performance in road feeling and tracking accuracy. This paper introduces an active disturbance rejection control (ADRC) method into the control issue of the DDAS. First, the third-order ADRC controller of the DDAS is designed, and the simulated annealing algorithm is used to optimize the parameters of ADRC controller offline considering that the parameters of ADRC controller are too many and the parameter tuning is complex. Finally, the 11-DOF model of the electric vehicle driven by in-wheel motors is built, and the standard working conditions are selected for simulation and experimental verification. The results show that the ADRC controller designed in this paper can not only obviously reduce the steering wheel effort of the driver like PID controller, but also have better nonlinear control performance in tracking accuracy and smooth road feeling of the driver than the traditional PID controller.

Matching Analysis and Optimization Design of Energy-saving Intelligent Electro-hydraulic Hybrid Steering System

Based on the modeling of 2DOF vehicle, energysaving intelligent EHHS system and controller, the influence of different parameters on the vehicle steering performance is studied and then the most important parameters are determined. To establish the stability criteria, the road feeling and steering sensitivity transfer function are derived. Next, the optimization model is put forward, and the genetic algorithm is used to optimize the important parameters of EHHS system. The simulation results show that the optimization design improves the steering performance of the steering system while ensuring the stability of the system.

Energy analysis and optimization design of vehicle electro-hydraulic compound steering system

In order to reduce the vehicle steering energy consumption and improve the steering road feeling, this work proposes an electro-hydraulic compound steering (EHCS) system, which combines the functions of electric power steering (EPS) and electro-hydraulic power steering (EHPS). For this novel steering system, there is a complex mechanical-electro-hydraulic coupling relationship that affects the steering performance. Thus, how to choose the appropriate parameters to ensure the system of good energy-saving characteristics and steering road feeling is one of the key issues. The power flow of mechanical, electrical and hydraulic subsystems is used to test the coupling relationship between the parameters of the motor, hydraulic pipe, hydraulic valve, power cylinder, and mechanical steering structure, and analyze their influence on the steering energy consumption. According to the results of energy consumption sensitivity analysis, the main coupling parameters are selected as design variables, and the steering energy consumption, steering road feeling and steering wheel return error are taken as optimization objectives. To add population diversity and accelerate convergence velocity, the improved competitive multi-objective particle swarm optimization (CMOPSO) algorithm is proposed and used for optimization. The optimization results illustrate that the CMOPSO has better convergence compared with the basic MOPSO, and the EHCS system optimized by CMOPSO has a better steering economy, with better steering road feeling and smaller steering wheel return error. To verify the comprehensive steering performance, the optimized EHCS system is installed on the vehicle for an on-field road test. Compared with original EHPS, the road test results show that the energy consumption of the modified vehicle under the steering condition significantly decreases, and can also meet the steering assistance and driver road feeling requirements. Furthermore, the real road traffic scene around Nanjing University of Aeronautics and Astronautics is reconstructed to analyze the relationship between the whole vehicle energy consumption and energy characteristics of the EHCS system in the intelligent traffic environments, which verifies the steering energy consumption is reduced by 51.7% under the 15 km test road.

Dual-Motor Full-Weight Electric Power Steering System for Commercial Vehicle

In order to study the electric power steering system (EPS) which is suitable for the steering characteristics of commercial vehicles, the effect of weight on steering performance is analyzed, and a dual-motor full-weight EPS system is proposed. Firstly, the full-weight assist characteristics are studied, and two current distribution schemes and corresponding fault-tolerant control strategies are proposed according to the structural characteristics of dual-motor EPS system. By comparing with the traditional single-weight EPS system, it is proved that the full-weight EPS system improves the control stability and makes the driver get a better road feeling. Through the double line change test and step test, the effectiveness of the two current distribution schemes are verified, and it has better fault-tolerance performance. By comparison, the fault-tolerance performance of scheme two is better than that of scheme one.

The Fractional Order PID Method with a Fault Tolerant Module for Road Feeling Control of Steer-by-Wire System

To improve the road feeling of the steer-by-wire (SBW) system, a fractional order PID (proportion-integral-derivative) method with a fault tolerant module is proposed in this paper. Firstly, the overall road feeling control strategy of the SBW system is introduced, and then the mathematical model of road feeling control is established. Secondly, a fractional order PID (FOPID) controller is designed to control torque of the road feeling motor. Furthermore, genetic algorithm (GA) is applied to tune the FOPID controller’s parameters. Thirdly, a fault tolerant module aiming at potential failures of the motor’s torque sensor is studied to improve the reliability of the system. Kalman Filter (KF) algorithm is utilized in the fault tolerant module so as to detect failures of the motor’s torque sensor, and then fault tolerant module reconfigures the motor’s torque estimated by KF as a substitute when the torque sensor fails. Finally, simulations based on MATLAB are performed with the proposed control strategy to identify its performance, and the results demonstrate that the proposed control method is feasible and accurate.

Parametric optimization of novel electric–hydraulic hybrid steering system based on a shuffled particle swarm optimization algorithm

Abstract The on-board battery is the primary energy storage device of the electric vehicle that provides power to drive all actuators of the chassis, i.e., the energy consumption of each actuator has a direct impact on the vehicle’s energy management system. To reduce energy consumption while steering and improve the handling stability of electric vehicles, a novel electric–hydraulic hybrid steering (E–HHPS) system with multiple steering modes is presented herein. The electric power mode is used to reduce the overall energy consumption of the system by adaptive intervention, whereas the hybrid power mode is responsible for the steering portability in conditions of increased steering torque. To further improve the performance of the E–HHPS system, the structural parameter optimization model of the E-HHPS system is established based on the consideration of the steering economy, steering road feeling, and steering sensitivity. To solve the multi-objective optimization problem with characteristics of increased dimensions, a shuffled particle swarm optimization algorithm (SPSO) is proposed to realize a combination of a local search and global information exchange. The simulation results demonstrate that compared with the EHPS system, the E–HHPS system has a better steering economy at low vehicular speeds. In addition, the E–HHPS system optimized by the SPSO algorithm can considerably reduce the steering energy consumption and noticeably improve the handling performance of the vehicle.

Displacement and force coupling control design for automotive active front steering system

Abstract A displacement and force coupling control design for active front steering (AFS) system of vehicle is proposed in this paper. In order to investigate the displacement and force characteristics of the AFS system of the vehicle, the models of AFS system, vehicle, tire as well as the driver model are introduced. Then, considering the nonlinear characteristics of the tire force and external disturbance, a robust yaw rate control method is designed by applying a steering motor to generate an active steering angle to adjust the yaw stability of the vehicle. Based on mixed H2/H∞ control, the system robustness and yaw rate tracking performance are enforced by H∞ norm constraint and the control effort is captured through H2 norm. In addition, based on the AFS system, a planetary gear set and an assist motor are both added to realize the road feeling control in this paper to dismiss the influence of extra steering angle through a compensating method. Evaluation of the overall system is accomplished by simulations and experiments under various driving condition. The simulation and experiment results show the proposed control system has excellent tracking performance and road feeling performance, which can improve the cornering stability and maneuverability of vehicle.

Optimal design of variable assist characteristics of electronically controlled hydraulic power steering system based on simulated annealing particle swarm optimisation algorithm

In order to ensure that bus drivers have superior manipulation and good road feeling at different speeds, variable assist characteristics of electronically controlled hydraulic power steering system (ECHPS) were optimally designed based on simulated annealing particle swarm optimisation (SA-PSO) algorithm. First of all, characteristic points of assist characteristics curves were deduced via bus drivers' preferred steering torque and steering resistance moment at different speeds. Then the optimisation model of rotary valve parameters was built, with the minimum root of quadratic sum of the difference between hydraulic pressure at typical speeds and characteristic hydraulic pressure defined as objective function. The optimisation problem was solved by SA-PSO algorithm. To verify the design method, low-speed lemniscate and high-speed in-between steering simulations and experiments were carried out. The results showed that the low-speed steering portability and high-speed steering road feeling of optimised steering system were significantly enhanced.

Evaluations of road information and stiffness feeling by mean of the steering vibration

Evaluations of road information and stiffness feeling by mean of the steering vibration

A theoretical model of speed-dependent steering torque for rolling tyres

ABSTRACTIt is well known that the tyre steering torque is highly dependent on the tyre rolling speed. In limited cases, i.e. parking manoeuvre, the steering torque approaches the maximum. With the increasing tyre speed, the steering torque decreased rapidly. Accurate modelling of the speed-dependent behaviour for the tyre steering torque is a key factor to calibrate the electric power steering (EPS) system and tune the handling performance of vehicles. However, no satisfactory theoretical model can be found in the existing literature to explain this phenomenon. This paper proposes a new theoretical framework to model this important tyre behaviour, which includes three key factors: (1) tyre three-dimensional transient rolling kinematics with turn-slip; (2) dynamical force and moment generation; and (3) the mixed Lagrange–Euler method for contact deformation solving. A nonlinear finite-element code has been developed to implement the proposed approach. It can be found that the main mechanism for the speed-dependent steering torque is due to turn-slip-related kinematics. This paper provides a theory to explain the complex mechanism of the tyre steering torque generation, which helps to understand the speed-dependent tyre steering torque, tyre road feeling and EPS calibration.

Novel electric power steering control strategies of commercial vehicles considering adhesion coefficient

The steering resistance torque of commercial vehicles on low adhesion pavement is greatly reduced. Therefore, while driving on low adhesion pavement, the use of traditional EPS control strategies without considering adhesion coefficient will lead to driver’s road feeling being reduced or even lost, endangering driving safety. In this paper, the relationship between adhesion coefficient and steering resistance torque is researched through theoretical analysis and simulation. Two novel EPS control strategies of commercial vehicles considering adhesion coefficient are designed. The first control strategy calculates assist coefficient through steering resistance torque under different working conditions, and assist coefficient is used to adjust the assist torque on the pavements with different adhesion coefficients. The second control strategy applies a compensation current related to adhesion coefficient on the basis of traditional EPS control strategy to improve the road feeling of low adhesion roads. Finally, a joint simulation model of TruckSim/Simulink is established, the two novel control strategies are simulated and verified. The simulation results show that both the two novel control strategies can improve the road feeling of the driver and improve the driving safety on low-adhesion road while ensuring the steering portability.

Integrated control of lateral and vertical vehicle dynamics based on multi-agent system

The existing research of the integrated chassis control mainly focuses on the different evaluation indexes and control strategy. Among the different evaluation indexes, the comprehensive properties are usually not considered based on the non-linear superposition principle. But, the control strategy has some shortages on tyre model with side-slip angle, road adhesion coefficient, vertical load and velocity. In this paper, based on belief, desire and intention(BDI)-agent model framework, the TYRE agent, electric power steering(EPS) agent and active suspension system(ASS) agent are proposed. In the system(SYS) agent, the coordination mechanism is employed to manage interdependences and conflicts among other agents, so as to improve the flexibility, adaptability, and robustness of the global control system. Due to the existence of the simulation demand of dynamic performance, the vehicle multi-body dynamics model is established by SIMPACK. And then the co-simulation analysis is conducted to evaluate the proposed multi-agent system(MAS) controller. The simulation results demonstrate that the MAS has good effect on the performance of EPS and ASS. Meantime, the better road feeling for the driver is provided considering the multiple and complex driving traffic. Finally, the MAS rapid control prototyping is built to conduct the real vehicle test. The test results are consistent to the simulation results, which verifies the correctness of simulation. The proposed research ensures the driving safety, enhances the handling stability, and improves the ride comfort.

Research on Control Strategy of Differential Assisted Steering of Distributed Drive Electric Vehicle

The distributed drive electric vehicle was studied in this paper. According to the advantages of the controllable and accurate wheel speed and torque the ideal differential assisted characteristic curve was designed under different vehicle speed as well as a control strategy for differential power steering, a vehicle dynamics model based on CarSim/Simulink and simulation experiments were conducted. The experimental results indicated that on the premise to guarantee the road feeling, the control strategy for differential power steering decreased the steering wheel torque, angle and reduced driver's work-load , improved markedly the steering portability of the distributed drive electric vehicle.

Modeling and Characteristics Research of Proportional-Valve Hydraulic Power Steering of Commercial Vehicle

Dynamics model of mechanical system and hydraulic system inclued electro-hydraulic proportional valve of Proportional-Valve Hydraulic Power Steering were established.and simulation model of assisted characteristic of PVHPS system was build .Response characteristic of proportional valve bypass flow was analyzed at different speed, and higher of the speed, greater of the flow in the bypass flow is . Steering wheel torque increases gradually as vehicle speed increases at the same wheel angle, and driver's better steering road feeling can be ensured. As wheel steering torque increases, assisted oil pressure increases and higher the speed is , slowly oil pressure increases, and assisted oil pressure increases quickly at low-speed steering condition, and increases slowly at high-speed condition,which meet the requirement of low-speed steering agility and high-speed road feeling.

H∞ control of novel active steering integrated with electric power steering function

Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric power steering. In view of the interference from road random signal and sensor noise in the novel active steering system, the H∞ control model of the novel active steering system was built. With satisfying steering feel, good robust performance and steering stability being the control objectives, the H∞ controller for the novel active front steering (AFS) system was designed. The simulation results show that the novel AFS system with H∞ control strategy can attenuate the road interference quickly, and there is no resonance peak in the bode diagram. It can make the driver obtain more useful information in the low frequency range, and attenuate the road interference better in the high frequency range, thus the driver can get more satisfying road feeling. Therefore, the designed H∞ controller can synthesize the advantages of both robust performance and robust stability, and has certain contribution to the design of novel AFS system.

Tracking Performance of Electric Power Steering System Based on the Mixed H2/H∞ Strategy

The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system's robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system's robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers.

Computer-Aided Design of Curved Assistance Characteristic of EPS System

The control strategy is one of the key technologies of EPS system, and the assistance characteristic has great importance to the vehicle handiness and road feeling. Based on the EPS dynamic model, the curved assistance characteristic is designed. The curved assistance characteristic has the superiority to find the better balance between handiness and road feeling. It has engineering significance to the overall design, function enhancement and optimization and steering manipulation and safety improvement.

Road Feeling of Electric Power Steering System Based on Mixed H2/H∞ Control

In view of the existence of uncertainties such as system model and disturbance signal in the electric power steering(EPS) system, and the demand for system dynamic performance, the mixed H2/H∞ controller is proposed.For the driver to obtain a good steering feeling and for the system to have good robustness and small torque fluctuation, the models of EPS system and the two-freedom car are set up, and the state space model and augmented matrixes are built.The H∞ method is introduced to minimize the effect of disturbances on outputs, and the H2 method is applied to optimizing the system performance.The simulation results of steering feeling show that the controller, which synthesizes the advantage of H2 control and H∞ control, has better robust performance and robust stability.The controller can attenuate the noises and disturbances caused by road random motivation, torque sensor measurement and model parameter uncertainty, and enable the driver to obtain a satisfactory road feeling.