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Safety is a necessity in any case, as is driving. Many motorists today ignore safety in driving. Based on this innovation is needed in driving safety, automatic steering cars can be one of the driving safety solutions. This is because the automatic steering car uses a technological approach from various aspects ranging from deep learning, computer vision, sensor fusion, localization, control, unit path planning. In this discussion, the implementation of the line detection algorithm uses the hough transform and power steering methods. The results of the application of this method require a method to recognize the road markings with other things that are symmetrical in shape like a line, can be a shadow of a pole, a road divider, and so forth. Because the parameters of this method can only be used in ideal conditions. The overall application of this method successfully detects road markings with an accuracy of 75%

This paper presents low frequency ripple power steering control strategies for a power conversion topology that comprises of a high frequency linked three port converter (HFL-TPC) and a voltage source inverter (VSI) for PV-BESS/EV applications. The proposed topology has three interfaces which can be connected with a photovoltaic (PV) port, battery energy storage systems (BESS) and/or electric vehicles (EVs) port, and a four-quadrant ac port. The proposed topology inherently exhibits double line frequency (DLF) power fluctuation that needs to be decoupled and steered away from the PV port. In this paper, we have developed and demonstrated two control strategies to deal with the DLF ripple. The first control strategy utilizes loop gain of the closed loop control system to decouple the DLF power, however a residual DLF power still exists at the ac port. To completely decouple the DLF fluctuations, an improved sequence based control strategy is proposed where the DLF voltage components are converted into positive and negative sequence components and controlled separately on their respective synchronous reference frames. To verify the practical feasibility of the proposed low frequency ripple power steering control strategies, a 40 V, 400 W HFL-TPC is built and tested. Experimental results show that the proposed ripple power steering control strategies can decouple the DLF power fluctuation and selectively steer it to the BESS/EV port as DLF power fluctuation is undesirable at the PV port. A comparative results reveal that sequence based control strategy show higher degree of DLF ripple suppression.

Electric power steering (EPS) is widely used in tractor automatic driving because of its good operation stability. However, there is a lack of research about solving robust problems and response ability simultaneously when the tractor encounters emergency steering in harsh fields. The traditional robust controller has poor tracking performance and antidisturbance ability when encountering emergency steering. This paper proposes to add the corresponding mixed sensitivity operator to the corresponding performance index in the controller. By adjusting the amplitude of the mixed sensitivity operator, the tracking performance and the speed of disturbance attenuation can be both adjusted for the tractor EPS system. Simulation and hardware in the loop experiments verify the antidisturbance ability of the controller and the torque tracking performance. The results show that the control method has strong robustness and robust stability, which can meet the practical requirements. Also, the power steering characteristic of the H∞ controller with hybrid sensitivity design method is better than that of an unoptimized one, and its robustness is better, and under external pavement interference, the following ability is stronger for the ideal hand torque and the steering is more stable.

Since heavy vehicles need all-terrain adaptability and large load drive capability, the dual hydraulic cylinders symmetrically arranged and connected in series are widely used in their steering system, which is quite different from the traditional electrohydraulic power steering systems. Accurate steering control for this dual hydraulic system is challenged due to its complicated structure and a wide range of steering loads. To solve this issue, an improved integral sliding-mode control (ISMC) is presented in this article. Specifically, a hyperbolic tangent function is integrated into the controller to mitigate the chattering caused by the sliding mode. A stability analysis is then conducted based on the finite-time Lyapunov stability theory, revealing the proposed controller's capability of achieving the asymptotic convergence of the tracking error within a finite time. A test bench is also established to experimentally validate the controller's effectiveness through multiple test scenarios, including various tire loads, supply pressures, and command signals frequencies. The results show that the tracking error of ISMC is kept within 0.5°, which is significantly superior to PID control. In addition, the ISMC can achieve high-precision control under lower supply pressure, showing the energy-saving potential of nonlinear control for the steering system in heavy vehicles.

This work deals with the stress analysis of a shaft used in hydraulic steering pump, which helps to transmit motion between two gears used in the pump. Suitable material (20NiCrMo2) with a greater tensile strength and similar chemical composition is also recommended. This suitable material thus found out is also being used for making the high speed shaft of steering pumps used in an automobile. This material is also being suggested to the industry as an alternate material used for making high speed shafts. Step by step process performed by us is explained in detail. The analysis of the shaft and the outcomes are also given. By observing these values, the material of the shaft can be analyzed properly. The conclusion of the report shows that the given objective has been achieved and parameters necessary to improve the endurance life is also given. With the help of the linear model, relevant transfer functions and the underlying control structure of the power steering system have been derived and analysed [1]

Permanent Magnet Synchronous Motors (PMSMs) have been replacing conventional DC motors in numerous automotive applications. One of which is Electrically Power Assisted Steering Systems (EPAS). PMSMs offer better performance and a longer lifetime while slightly increasing the system’s cost and complexity. In a vector-controlled PMSM drive system, the rotor position sensor’s resolution plays a vital role in the overall system performance. The better the resolution, the higher the cost. Although numerous sensor-less control algorithms currently exist, machine startup and operation with dynamically changing set-points and loads still impose a challenge for such an approach. For this reason, inexpensive Hall-Effect sensors have been recently used along with a proper position estimation algorithm to provide high-resolution rotor position. In this paper, an implementation of a vector-controlled drive system is applied to an EPAS using only low-resolution Hall-Effect sensors. Additionally, an improved rotor position estimation algorithm based on speed integration is developed to decrease estimation errors and torque ripples in the case of direction reversal. This is to cater to the dynamically changing commands encountered during the normal power assist operation. Comparisons of the proposed rotor position estimation system with the conventional technique are introduced. A complete representation of the proposed system is built using MATLAB/Simulink. An experimental setup is developed and built around a Motor-Driven Power Steering (MDPS) unit which is a column-assist type EPAS system made by Hyundai Mobis. The simulation and experimental results are presented to verify and evaluate the effectiveness of the proposed algorithm.

The power-assisted steering system is the advancement in vehicle dynamics to enhance the comfort of the driver by reducing the steering effort and also its response is quicker than the conventional manual steering system. Consider a situation of failure of a powering steering system due to its pump failure in a heavy truck/buses which are running in high-speed on highways or running in slow speeds in hill stations which is having more bends and grades which is more severe than the high-speed since it requires more steering effort, it makes huge loss of lives or valuables which are carried in the bus/trucks. Thus, with this background the following research focuses to safeguard the guiding framework in such circumstances which is constrained by a reasonable back-up framework. The concept of emergency power steering systems ensures the functioning of the steering system without compromising its performance when the primary system fails to respond. In this system, a secondary electrical pump introduced in addition to the present engine-driven pump. The pressurized hydraulic line which goes to the steering gear is also routed through this electrical pump and both the lines are combined with double check valve arrangement. Double-check valve allows the fluid flow through one direction, either the engine-driven pump line or electrical driven pump line. By introducing a pressure sensor to monitor the engine line outlet pressure the functioning of power steering through the engine-driven pump ensured. Whenever the engine-driven pump fails the pressure sensor reads pressure drop on that line and immediately provides a signal to the electrically driven pump to operate to continue power steering mode. With this system, the accidents due to power steering is avoided and the driver comfort is retained without any compromise.

Expedition truck is a vehicle that serves to transfer goods from one place to another. Previously maintenance policy was periodic, depending on the run distance and Run To Failure, maintain the trucks after the occurrence of component damage then system failure. Analysis in maintenance management based on system and critical components do optimize truck performance by using RCM (Reliability Centered Management) method. There are 5 systems in a truck: electrical system, power steering system, cooling machine system, coupling system, and brake system. Interaction and function of the components from each system are analyzed, evaluated the failure mode (FMEA method), and categorized the level of critical damage and adjusted the maintenance time (LTA method). The results of the RCM method for 16 component functions from the 5 systems are 5 component functions with Time Directed (TD), 6 Condition Directed (CD), 3 Failure Finding (FF), and 2 component functions by Run To Failure (RTF).

This paper conducts the front wheel angle tracking compensation control of the electro-hydraulic coupling power steering system (EHCPS) of the intelligent heavy vehicle (IHV). It has been found from the results of mathematic analysis, simulation and open-loop frequency test of the EHCPS that front wheel angle slightly lags behind handwheel angle at low frequencies. In this paper, a kind of fuzzy neural network controller (FNNC) based on model reference adaptive control (MRAC) is designed. Fuzzy neural network is also used to identify the EHCPS on-line. Membership function and inference rules of the FNNC and fuzzy neural network identification (FNNI) are renewed by the self-learning function of neural network to achieve on-line regulation of controller’s parameters. Reference model with certain bandwidth and control algorithm are designed to ensure that actual front wheel angle follows desired front wheel angle. Finally, the hardware-in-the-loop experiment and simulation results indicate that the control strategy presented in this paper is effective in compensating front wheel angle tracking within certain bandwidth of EHCPS.

The tie rod is one of the key components affecting the steering stability and reliability in the steering system of heavy vehicles. In order to meet the heavy load steering requirements of heavy vehicles, the steering system is universally the electro-hydraulic power steering system (EHPSS). The hydraulic actuators used in the EHPSS are double hydraulic cylinders, which are connected in series and symmetrically installed in this study. The hydraulic drive system in the steering system will affect the steering mechanism of stress state, leading to the tension of the tie rod in most working conditions. The tie rod be compressed only in extremely unequal loading of dual-tires. The tie rod force model is established based on Lagrange equation and verified by the tie rod test platform. Three key parameters describing the force rule of tie rod are obtained by adopting quasi-steady state analysis method, including pump pressure, difference value and sum value of left and right tires steering resistance torque. Pump pressure is the key factor affecting the tie rod force. The higher the pump pressure is, the greater the pull force of tie rod is. The steering resistance torque will further affect the variation law of the tie rod force. In the analysis when the tire at middle position, with the increase of difference value of steering resistance torque, the tie rod force offset between loading conditions and no-load conditions increases. When the tire turns from the middle to both sides, the increase of sum value of steering resistance torque will result in the rising of tie rod force change rate. This study reveals the variation law and key parameters of the tie rod force of heavy vehicles. It can provide basis for stability and reliability design of steering system.

The article presents a developed embedded system for control of electrohydraulic power steering based on multivariable uncertain plant model and advanced control techniques. The plant model is obtained by identification procedure via “black box” system identification and takes into account the deviations of the parameters that characterize the way that the control signal acts on the state of the model. Three types of controller are designed: Linear-Quadratic Gaussian (LQG) controller, H∞ controller and μ-controller. The main result is a performed comparative analysis of time and frequency domain properties of control systems. The results show the better performance of systems based on µ-controllers. Also the robust stability and robust performance are investigated. All three systems achieved robust stability which guarantees their workability, but only the system with µ-controller has robust performance against prescribed uncertainties. The control algorithms are implemented in specialized 32-bit microcontroller. A number of real world experiments have been executed, which confirm the quality of the electrohydraulic power steering control system.

Aiming at the problem of nonlinear power steering in the automobile electric power steering system, an advanced control algorithm is required for the practical system. This paper introduces back propagation neural network arbitrary nonlinear approximations to discretize the vehicle’s power assistance characteristic. Steering power is also realized in the whole range of speed, which overcomes the steering blind zone and lays a foundation for the design of subsequent controllers. In addition, considering the nonlinear frictional resistance problem of the electric power steering system, the traditional proportional–integral–derivative remote control algorithm will result in poor dynamic performance or system instability. Therefore, this paper proposes a control algorithm based on back propagation neural network proportional–integral–derivative parameter self-tuning. Using the error between the expected current and the actual motor current, the back propagation neural network algorithm is used to learn and realize the adaptive adjustment of proportional–integral–derivative parameters. Simulation results show that the proposed control system effectively realizes the nonlinear steering assistance in the whole vehicle range speed, eliminates the influence of nonlinear friction in the electric power steering system, and improves the robustness of the control system.

As a novel power steering technology, Differential Drive Assisted Steering (DDAS) technology for the independent-wheel-drive electric vehicle has gradually appealed to researcher's attention. However, the previous experimental results show that its assistance quality cannot be fully accepted due to its caused sensitive steering wheel torque fluctuation in actual work environment. According to the working principle of the DDAS system, it is founded that the road roughness, the front wheel alignment parameters and sensor noise are the main factors that influence the quality of assisted steering and driver's road feel. Hence the three factors are added as interference into the ideal vehicle model. The simulation results and its comparison with the previous real vehicle tests confirm this causality between these factors considered and the steering wheel torque fluctuation of the DDAS system. Then a robust H∞ loop-shaping controller is designed to solve the issue caused by these inner interferences and outer noises. Simulations results validate the proposed controller and show better steering wheel torque performance than the traditional anti-windup PID controller published in the literature earlier. The proposed robust controller is further verified via real vehicle tests and the results are similar to the simulation results which can effectively suppress the steering wheel torque ripple, improve the anti-interference ability of DDAS system and greatly improve the driver's road feel.

To bridge the gap between autonomous and normal steering during low lateral acceleration maneuvers, a steering-wheel torque controller is developed. It consists of three controllers in series, a high-gain feedback steering-wheel torque controller, a nonlinear steering-angle controller, and a linear yaw-rate controller. A validated two degrees of freedom steering-system model, in combination with a single-track vehicle model, is used to determine the controller parameters. Driving tests with different drivers have been executed to find a comfortable steering-wheel torque/angle relation. This relation is maintained throughout the lane change by specifying the steering-wheel torque as a function of the steering-wheel angle tracking error. Experiments show promising results regarding the driver/vehicle interaction, but also show that a system to detect the lanes and the vehicle position on the road is required for further improvement.

Dual three-phase permanent magnet synchronous motors (DTPMSM) are used in the steer-by-wire system of electric vehicles that require high reliability. Multiple faults should be considered for the steering system, such as open-circuit faults and speed sensor faults. However, the current speed sensorless control methods of the dual three-phase motor are mainly derived from the promotion of the three-phase motor. They fail when an open-circuit fault occurs, leading to the failure of fault-tolerant control. Researchers have noticed this problem and proposed many methods, but they are very complicated and computationally intensive. This paper proposes one type of improved model reference adaptive system (MRAS). By adding certain fault-related restraints to the output of the adjustable model, speed sensorless control can automatically fit the open-circuit fault and estimate accurately even if an open-circuit fault occurs, which makes sure the whole system continues to operate. Simulation results are presented that contain normal operation, open-circuit fault operation, fault-tolerant control operation, and the whole process from start to fault-tolerant operation. The results show that no matter what period the motor is in, the improved speed sensor can accurately estimate the motor speed and position. The improved model reference adaptive system is significant for improving the reliability of the motor steering system and ensuring the safety of people and property.

Electric motors are widely used in modern vehicles to drive various mechanisms (power steering, generators, starters, etc.). Normal operation and traffic safety depend on their reliability. Modern repairing technologies make it possible to obtain 70-80% of the secondary resource of the car electric equipment. The solution to the problem of the electric motor cylindrical casing panel homogenous strain is obtained. It showed that in the repair conditions by flattering or expansion-reduction, the casing diameter does not significantly affect the circumferential deformations equality. The workpiece diameter invariability does not affect the high accuracy of the grooves and flanges zones planned final dimensions. Since the tool is a roll-roller, it is universal for flattening and strain of various diameters of the casing cylinders. This is a feature of this repair method and its adaptability to the conditions of single-piece manufacture. To align the casing cylinders out-of-roundness and the dents on them, it is enough to make the operating stroke of the driven roller by 0.5-1 mm of radial infeed, which will lead to plastic tangential and meridional workpiece strain and its flattening. This process does not require large energy costs, since the strain is carried out by the tool locally, in the roll contact zone, which is of great importance in the conditions of repair workshops.

Electric Power-Assisted Steering system (EPAS) is a new power steering technology for vehicles especially for Electric Vehicles (EV). It has been applied to displace conventional Hydraulic Power-Assisted Steering system (HPAS) due to space efficiency, environmental compatibility, and engine performance. An EPAS system is a driver-assisting feedback system designed to boost the driver input torque to the desired output torque causing the steering action to be undertaken at much lower steering efforts. In this chapter, the Particle Swarm Optimization (PSO) algorithm is implemented as a tuning mechanism for Fractional-Order PID (FOPID) controller. The aim of this controller is to track the assisted current generated by the lookup table. The results show the performance and efficiency of using the PSO algorithm for FOPID tuning.

With the broad prospects of the electrohydraulic power steering system (EHPS) for the development and application in the field of commercial electric vehicles, noise study of EHPS has become a significant part of the research on vehicle noise, vibration, and harshness. In this study, with the essential component of EHPS—the electric hydraulic pump, which is the integration of oil pump, electric motor and controller, as the research object, the pulsed resonance noise was explored and noise reduction measures were proposed. Main research topics of this study included: (1) testing and analyzing the noise of the electric hydraulic pump to trace the source of noise; (2) analyzing the mechanism of noise generation, and proposing two noise reduction schemes, i.e., adding vibration damping pads to block vibration transmission and increasing the shell thickness to suppress surface vibration; and (3) manufacturing improved prototypes for different noise reduction schemes, and conducting further tests to verify the effectiveness of the proposed noise optimization schemes. The test results reveal that after adding the vibration damping pads, the vibration of the electric hydraulic pump increased instead of decreasing; and when the shell thickness of the electric hydraulic pump was increased from 8 to 12 mm, the noise in all directions was significantly reduced. The aforementioned findings indicate that increasing the shell thickness is an effective way to reduce the noise of the electric hydraulic pump. The present research can provide a reference for noise testing, optimization and control of the vehicle steering system.

The article presents the design, implementation and experimental investigation of linear-quadratic Gaussian controller for load-sensing electro-hydraulic servo system, which is applicable to power steering system of modern mobile machines. In previous studies, the authors have investigated the workability and control performance of the electro-hydraulic power steering (EHPS) system without load-sensing function, which is powered by a fixed displacement pump and an external priority valve. The possibility to develop EHPS with higher energy efficiency motivates the authors to begin series of studies of embedded control systems for load-sensing EHPS, in which the performance strongly depend on the embedded controller. In contrast to the EHPS studied in previous works, this system uses feedback on the piston position of the steering cylinder and on the position of the proportional valve (measured by LVDT). In addition the flow rate is measured but it is not directly involved in the control task. It allows to perform an energy analysis of the entire electrohydraulic steering system.

Automotive pumps have two forms either hydraulic or centrifugal one. Hydraulic pumps areusually positive displacement pumps. In the automotive industry, vane pumps have wide rangeof applications including fuel pumping, power steering system and automatic transmissionsystem. Fluid behavior costs a lot to be seen inside the pump during operation experimentallyhowever, predictive tools based on Computational Fluid Dynamics (CFD), has become a validalternative approach to pump design and optimization. In this paper, CFD analysis for oil vanepump will be shown including different (number of vanes) models and different gap heights.The numerical model was built up with ANSYS (Fluent) using dynamic mesh code and it wasvalidated by comparing the obtained numerical results with the experimental data of (fourvanes) pump. The model gave a good agreement with the experiment results, with maximumdeviation mm gave the largest flow-rate and best performance as well.

Due to parametric uncertainties, unknown nonlinearities, and dynamic external disturbances, it is a challenging and valuable task for heavy vehicle electro-hydraulic power steering systems to realize high-precision tracking control. To cope with this complex nonlinear tracking control problem, the integral sliding mode control is an extremely potential control method, which has strong robustness to model uncertainties and unknown disturbances, and can effectively reduce the steady-state error in tracking control process. However, the inherent chattering phenomenon of integral sliding mode control seriously affects its control performance. In order to suppress the chattering while ensuring robustness, adaptive fuzzy technique is adopted as an effective auxiliary means, which can not only deal with the inherent chattering problem of integral sliding mode control and a priori knowledge of the disturbance upper bound in controller design but also dynamically adjust the parameters in the fuzzy rules. Moreover, the designed adaptive fuzzy–integral sliding mode control scheme still needs the precise mathematical models of the control systems. But it is difficult to obtain the model for heavy vehicle electro-hydraulic power steering systems with highly complex and coupling properties. Therefore, to further improve the method, this paper presents a novel adaptive fuzzy–radial basis function neural network–integral sliding mode control method for the complex systems to achieve timely and accurate steering angle tracking control. In addition to the advantages of adaptive fuzzy–integral sliding mode control, the modified controller no longer requires the precise mathematical models of heavy vehicle electro-hydraulic power steering systems and realizes the continuous adaptive updating of weights. Finally, the effectiveness and superiority of the proposed control scheme is illustrated by comparisons and extensive simulations.

The permanent-magnet motors are widely used especially in traction and power steering motor drive applications in automotive. Accurate knowledge of machine parameters, such as the inductance, is essential for efficient and optimal control of the machine. There are numerous methods proposed in the literature for online as well as off-line learning of machine parameters. They differ in accuracy and measurement techniques. This paper proposes an online measurement of inductance using the relationship with the current derivative. An adaptive observer is used to calculate the inductance parameters from the current measured. The proposed method uses no external injection but relies on the pulsewidth modulation excitation used for normal motor drive control. The simulation and experimental results show the feasibility and performance of the proposed technique.

To investigate the unknown (uncertain) tire steering resistance moment and model uncertainties in a multi-axle vehicle electro-hydraulic power steering system (EHPSS), including the steering mechanisms, valve-controlled double hydraulic actuators, and heavy-duty tires, an adaptive robust control algorithm is developed to estimate the tire steering resistance moment online and compensate for the model uncertainties of EHPSS. The proposed control strategy consists of an adaptive control law and a robust controller which are based on a Lyapunov function. The adaptive control law is employed to update estimated values of the (unknown) tire steering resistance moment and parameter uncertainties in the EHPSS, whereas complicated nonlinearities are addressed by the robust controller. All adaptive laws of the EHPSS and controller, which can impede parametric uncertainties and stabilize the EHPSS, are synthesized by backstepping techniques. The comparative simulation results demonstrate that the proposed adaptive robust control scheme can achieve the desired performance for feasible tracking trajectories despite the existence of an uncertain tire steering resistance moment and external disturbance in the EHPSS.

Column type of motor driven power steering(C-MDPS) system has been developed for driving convenience and fuel efficiency. Nowadays, it requires agile vehicle response when driver tries to steer the steering wheel. So rack type MDPS(R-MDPS) system is often considered to improve vehicle response, but it is difficult to apply due to package problem and high cost. This paper proposes a design methodology about C-MDPS vehicle in terms of maximizing vehicle response. Among various design parameters which affect vehicle response, this paper deals with steering and suspension system design factors. The main parameters in the steering system are component characteristics such as friction level or torsion bar stiffness. The main parameters in the suspension system are kinematic and compliance (K&C) characteristics such as lateral force stiffness or kinematic displacement. In this paper, influence analysis method and optimization process for these factors are suggested.

The article introduces a robust stability and robust performance investigation of two embedded systems for control of electrohydraulic power steering in mobile machinery . They are based on advanced control techniques - linear-quadratic Gaussian (LQG) controller and H-infinity controller . The synthesis of the two controllers is performed via experimentally estimated SIMO state space model. The 30% input multiplicative uncertainty is introduced in estimated model. In this manner, a dead-band of proportional spool valve position is taken into account. This dead-band is constructively implemented to provide safety requirements of electrohydraulic steering. The robust stability and robust performance analysis are done by determining a structured singular value (μ) of the both closed-loop control systems, which are represented in M-Δ structure. The workability of the both systems are verified through simulation and real world experiments on laboratory test rig.

The main purpose of this article is to present the design, optimal setting and experimental study of a multivariable PID controller supposed for electrohydraulic power steering system with load-sensing function. The set of the controller is performed through an optimization procedure based on a genetic algorithm. The PID controller is embedded into a microcontroller for mobile machinery used in laboratory test rig for investigation of an electrohydraulic servo steering system. Results obtained in conditions of physical experiment and numerical simulation with the optimally tuned PID controller are presented. An analysis of the control performance, as well as some features of the used method for setting the PID controller.

The control of the driver’s steering torque of electromechanical power steering systems is state of the art. However, due to nonlinear characteristics and degrees of freedom of the plant which are unconsidered in the control design, the challenge still is the robust implementation of this control approach. Therefore, a new control approach was presented in previous papers that solves this robustness problems. In this paper, the control approach is analyzed in an augmented simulation environment. It is demonstrated that this control approach ensures a high robustness even when simulating critical driving situations. In addition, the control approach allows a nearly unconstrained design of the steering feel.

Aiming at the functions and characteristics of the EPS power steering system, power model of electric power steering is established, the ideal power-assisted characteristic curve is analyzed, the EPS steering system test is designed based on the bench, and the driving simulator hardware-in-loop test is carried out. The effects of EPS power steering in stationary and motion state are tested. The results show that the experimental results are accord with the ideal assist characteristic curve, and the designed driving simulator hardware-in-loop EPS experiment has a good assist effect, which is beneficial to improve the operating sensitivity and steering stability of electric vehicles.

Plenty electrical machines are used in modern vehicles due to the strong electrification of car auxiliaries required by the intensifying awareness about their safety and comfort features. A typical trend is to replace the classical hydraulic steering systems with those actuated by electrical machines (the so-called electric power steering systems). For such applications, two permanent magnet synchronous machines (with surface and interior permanent magnets) were proposed. In the paper, their design and comparative numerical analysis is detailed.

Terrain conditions of road are a determining factor for the driver's feel of driving. But, power steering is a boon to all the drivers of all classes of vehicles. This paper presents a novel control strategy for an electric power assisted steering system that would help in reducing the undesirable vibration and the driver effort in both the parking and driving state of the vehicle. The performance of steering system depends on the assist torque map. The proposed methods use the assist torque map. Since, a high amount of steering assist gain and nonlinearity of the torque map can have a negative effect in Electric power assisted steering (EPAS) system causing instability; the approach uses a properly designed new law that can circumvent the issues of nonlinearity. Here the modeling of EPAS system has been carried out and model parameters are identified. Based on the available EPAS model, a PID - Sliding Mode controller is designed to control this system. The evaluated performance of designed controllers showed that is successfully improved by the desired controller.

Feedback through the steering wheel is known as the most important source of information to the driver. The so-called steering feeling, composed of self-aligning actions coming from tyres and suspension geometry all the way through mechanical linkages to the driver&rsquo, s hands, provides vital communication for intuitive driving, and it is therefore utterly important for safety and for a pleasant driving experience as well. Subtle forces and vibrations, due to the interaction between the tyre contact patch and the road surface texture, also play a role, provided they are not heavily filtered or cancelled by the power steering system. Human perception is guided by experience in order to establish correlations between steering feedback and vehicle motion in terms of straight-line stability, cornering speed, tyre adhesion and available friction, vehicle balance, and so on. A front-wheel drive car is potentially a critical vehicle from this point of view, especially when the powertrain can deliver large torque figures, and even more so if a limited-slip differential (LSD) or a similar active device is present in order to improve traction capabilities. Any difference between the two wheels in terms of tractive force can result into the so-called torque steer issue, that is to say, a &ldquo, pulling&rdquo, sensation on the steering wheel or a shifting of the vehicle from the desired trajectory. This paper analyses the torque steer phenomenon on an all-wheel-drive, full electric sportscar where a significant portion of the torque is transferred to the front axle. The effects of suspension kinematics and the load variation at tyre contact patch level are taken into account. For evaluating the impact of steering feedback, the VI-grade&reg, simulation software is adopted and a test campaign on the professional driving simulator available at the University of Brescia has been carried out in order to understand the impact of steering feedback on driver perception and performance.

Background Nowadays, electric vehicle development takes a great attention in vehicle industry and researches, due to demising supplies of fuel, less pollution, and developing many resources of generating electricity as renewable energy and clean resources. Results This research is a part of the Autotronics Research Lab (ARL), applying researches on autonomous and electric vehicles. The main aim of the research is to apply vector control method on traction control system of electric vehicle (mini golf cart) by using two hub motors on the rear wheels while the two front wheels are used for steering; it is assumed that the controlled vehicle is fitted with some equipment which can used in autonomous driving. Simulation results show the output response of speed and torque of the vehicle motors and vehicle speed while the vehicle is moving in a straight line or during steering and also show the fusion between vector control and power steering algorithm. Conclusions The system preforms the efficiency, safety, accuracy, and more controllability of electric vehicle traction system, leading to more stability in vehicle speed, lower troubleshoots, and less error in unstable surfaces and bad roads.

The electronic control plays an important role in the modern automotive world. As more software is embedded in the vehicle electronics, software quality and reliability becomes essential to the vehicle reliability. This paper summarizes the embedded software reliability and testing performed at Dare Auto, Inc. for an automotive EHPS (Electro-Hydraulic Power Steering) pump. The ASPICE (Automotive Software Process Improvement and Capability Determination) process has been used during the design and development. The component, subsystem and vehicle level testing have been conducted before releasing for production. The lessons learned and the issues have been identified.

The conventional hydraulic steering system of the wheel loader suffers large energy consumption and significant heating issues caused by the relief and throttling losses during operation. To solve the problems, a novel flow matching principle is proposed, where a fixed displacement hydraulic pump driven by a servo motor is used to supply oil for steering system independently, and the supplied oil is fully consistent with the demanded flow for steering operation. In the study, the rotational speed and angle of the servo motor are determined by the angular velocity and rotational angle of the steering wheel. Thus, both the steering speed and angle of the wheel loader can be controlled. To enhance the safety and reliability of the steering operation, the original steering system is still retained. When the oil supply unit of the new system is out of order, the original system is automatically switched on through a solenoid valve. Based on the simulation and experimental results, by using the proposed system, the energy consumption of the proposed steering system can be reduced by 16% as compared to the conventional steering system, owing to the reduction of throttling loss and elimination of relief loss. In addition, the pressure fluctuation can be reduced from 2 to 1 MPa as compared to the conventional system, indicating an improvement in the stability of the steering operation. Furthermore, the safety and reliability enhancement strategy is also verified experimentally.

This paper presents a coupling control strategy of force and displacement for an electric differential power steering (EDPS) system to improve steering maneuverability and handling stability of electric vehicles with motorized wheels. In order to investigate mutual influences between vehicles and drivers, models of the EDPS system, the vehicle, the tire as well as the actuate motor are introduced. Then, by analyzing key factors that affect the interaction between vehicles and drivers, the optimum hand wheel torque of the EDPS system is developed and actualized by torque difference between two front wheels based on the ${\text{H}}_{2}{\text{/ H}}_{{{\infty }}}$ control method. In addition, a yaw rate control method is schemed to diminish the yaw moment interference to vehicles caused by the torque difference between two front wheels, and μ-synthesis theory is applied here to improve the yaw rate tracking performance as well as attenuate influences of system uncertainties and disturbances. Finally, simulations by MATLAB/Simulink and hardware-in-the-loop experiments based on dSPACE are conducted and effectiveness of the proposed control strategy is demonstrated by simulation and experiment results and numerical analyses.

The paper introduces a comprehensive mathematical model for power steering systems mounted on cars. Dynamic modelling for the steering system is studied in consideration of nonlinear friction forces in the system such as friction in the steering column, friction in the steering mechanism (gear and rack), friction between tires with road. The dynamic modelling for both the mechanism subsystems and the hydraulic subsystem is provided. Simulations were conducted to show the accuracy of the research model which can support further research on design for safer and more efficient driving systems.

Paper presents results of the laboratory tests concerning with measurements of the acoustic emission of the power steering column equipped with a modified composite gear body juxtaposed with the production version of the power steering column with the gear body made of aluminium alloy. The new, developed power steering column worm gear housing is made of a polymer called polydicyclopentadiene (PDCPD) and the Reaction-Injection-Moulding technology was used to produce it (the shortcut of the technology name is RIM technology). Both types of the worm power steering housings were tested to analyse their properties of acoustic emission. Results of the tests are very important considering noise generated during exploitation of a car’s power steering system.

As one of the hot spots and advanced technology for the development of automotive electronic control technologies, electric power steering system has broad application prospects. Due to the variety of driving conditions for heavy vehicles, a reasonable power steering system is critical to heavy vehicles, and the design and development of EPS system of heavy vehicles has a very large development space. According to characteristics of heavy vehicle steering and driving, combining with the steering power characteristic of electric power steering system, the control strategy technology of heavy vehicle’s electric power steering system is analyzed and studied in depth. Aiming at the change of the control mode of the EPS system of heavy vehicles under different driving speed, the strategy of power compensation control, damping control and returnable control are designed. A comprehensive control strategy for the electric power steering system for heavy vehicles is established. Finally, the feasibility is verified by simulation, which provides a theoretical reference for the follow-up development and design of the heavy vehicles EPS system.

An accurate electro-hydraulic power steering system (EHPSS) model is essential to analyze dynamic steering performance and advanced nonlinear control. The main obstacle to establish an accurate model is the complex structure, including steering mechanism, valve controlled dual hydraulic-actuator, and heavy duty tires. This paper constructs a suitable model incorporating these parts, based on a Lagrange equation describing the steering trapezoid mechanism and dual cylinder hydraulic dynamics, regarding steering resisting moment as an external load. A simplified tire model is used to represent the tire basic steering load characteristics. Due to the complexity of the kinematic relationship in the model, several expressions are fitted using back propagation neural networks to significantly reduce calculation difficulty. Experimental measurements and simulation using Matlab/Simulink and experiment are realized for the case of in situ steering, and the results validate the proposed model accuracy. Thus, the proposed model is suitable to analyze the system and design advanced controllers.

In the paper, the method of measuring and assessing of steering systems with the help of test benches with HILS technology implementation is justified in part of the adaptive algorithms of the regulation of the assistant steering torque. In the article, overall principal of creating virtual – physical system using as a physical part the rack and pinion steering system with electromechanical assistant is described. Interaction of the physical and virtual parts and fields of usage are described. Development, calibration and tweaking of the newly designed ECU and adaptive algorithms suppose a lot of testing. Time consumption and difficultness can be reduced only by the way of carrying out bench tests with usage of HILS technology.

Hydraulic spool valve, pilot operated with bi-state switching micro valves is a low-cost alternative to the conventional proportional and high-response valves. However, high-frequency switching causes variations in the control flow which limits achievable spool tracking error. This paper presents the design of a robust μ-controller for the spool position reference tracking synthesized with D-K iterative procedure. Furthermore, in order to reduce wind-up effects in the closed-loop, the μ-controller is decomposed to a canonical observer and state feedback components which allows explicit introduction of the saturated control signal in the controller equations. The uncertainty model required for the μ-synthesis is inferred from the nonlinear hydraulic model by identification of a Box–Jenkins model set characterized by its parameter covariance matrix. The regulator is implemented in a 32-bit programmable logic controller (PLC) and its performance is experimentally verified on a laboratory test bench of electro-hydraulic power steering system.

Thermal depositions are very wide spread in the industry of coating techniques. The materials used as coatings for several applications must have the ability to produce a stable, slow-growing surface coating, in order to provide good service behavior. This paper presents a method to increase the wear resistance of steering pump cam, strongly stressed having premature wear effects. The method that the authors use is atmospheric plasma deposition with Ni-Cr-Fe and Ni-Cr-B-Fe powders on steel substrate. It was investigated the morphology and physico-mechanical properties (scratch and micro-indentation analysis). Results showed a comparison between those two coatings with the metallic substrate. It has been found that the deposited coatings have an adherent, dense and uniform layer with a typically molten morphology. By increasing the coefficient of friction we can obtain higher wear resistance and recommend the optimum solution for further researches.