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International audience; Paved shoulders have long been used to create "forgiving" roads where drivers can maintain control of their vehicles even when as they drift out of the lane. While the safety benefits of shoulders have been well documented, their effects on driver behavior around curves have scarcely been examined. The purpose of this paper is to fill this gap by assessing whether the addition of shoulders affects driver behavior differently as a function of bend direction. Driver behavior in a driving simulator was analyzed on left and right curves of two-lane rural roads in the presence and absence of 0.75-m and 1.25-m shoulders. The results demonstrated significant changes in drivers' lateral control when shoulders were provided. In the absence of oncoming traffic, the shoulders caused participants to deviate more toward the inner lane edge at curve entry, at the apex and at the innermost position on right bends but not left ones. In the presence of oncoming traffic, this also occurred at the apex and the innermost position, leading participants to spend more time off the lane on right curves. Participants did not slow down in either traffic condition to compensate for steering farther inside, thereby increasing the risk of lane departure on right curves equipped with shoulders. These findings highlight the direction-specific influence of shoulders on a driver's steering control when driving around bends. They provide arguments supporting the idea that drivers view paved shoulders as a new field of safe travel on right curves. Recommendations are made to encourage drivers to keep their vehicle within the lane on right bends and to prevent potential interference with cyclists when a shoulder is present.

A control strategy based on H∞-type static output feedback combined with dynamic feed-forward is proposed to improve the high-speed lateral performance of an A-double combination vehicle(tractor–se...

Alcohol-impairment of drivers has significant influence on road traffic safety; however, no experimental research has been conducted on the lateral driving control of Indian drivers. Therefore, the present study investigates the effects of different Blood Alcohol Concentration (BAC) levels (0%, 0.03%, 0.05% and 0.08%) and driver attributes on the lane positioning and steering control of Indian drivers.A driving simulator experiment was designed where 82 adult licensed drivers (62 males, 20 females) completed driving on the simulated urban arterial road environment under the influence of varying BACs. Lateral driving performance measures associated with lane positioning (lane position variability) and steering control of drivers (steering angle variability and steering reversal rates (SRR)) were analyzed.The findings reported that lane position variability was significantly influenced only at 0.08% BAC (5.8% increment); no significant influence was observed at 0.03% and 0.05% BACs. Compared to 0% BAC, steering angle variability increased by 0.105 degrees or 15.7%, 0.142 degrees or 21.4%, and 0.176 degrees or 25.7% at 0.03%, 0.05% and 0.08% BACs respectively. No significant differences were observed between the sober-state driving and alcohol-impaired driving at 1In conclusion, the outcomes of this study provide novel insights into the alcohol-impaired lateral vehicle control of Indian drivers which can assist in policy interventions aiming to reduce crashes with alcohol as a major crash causation factor.

Keeping a vehicle in its current lane without veering into adjacent lanes is important in hard-braking manoeuvres on split- μ roads. Whether the emergency braking is initiated by a human driver or ...

The lateral position control of the vehicle is analyzed in the presence of time delay. To compensate the negative effects of dead time, the predictor control approach called finite spectrum assignment is applied. This controller includes a linear model of the plant and uses the solution of this model over the delay interval to predict the current system states. The focus of the article is whether to include tire dynamics in the predictive model of the controller. Although the more detailed model should improve control performance, the additional parameters (e.g., tire stiffnesses and yaw moment of inertia) are difficult to determine accurately. The effects of parameter mismatches are analyzed in detail, and recommendations are given to ensure safe control of the vehicle. It is shown that the inclusion of tire dynamics in the predictive model vastly improves control performance even in the presence of large parameter errors, but in certain cases, the inaccuracies may lead to instability.

Differential steering is an emerging steering concept based on traction force differences between left and right sides of vehicles equipped with independently actuated wheels. Actually, this concep...

Motorcycles are a primary mode of daily transportation in many developing countries, especially in towns and cities. The increased traffic congestion constrains the average speed of the motorcycle, causing stability and safety concerns for the riders. A controller that assists the riders can improve this scenario. This paper presents a new controller developed using an experimental study that improves the low-speed stability of a motorcycle. The experiments were conducted on a motorcycle with the riders of three experience levels: beginner, intermediate and expert. The input parameters: steering angle and steering torque; the output parameters: roll angle, yaw angle, roll rate and yaw rate were measured. Critical input and output parameters were identified statistically from the experimental measurements and used for the controller modelled in Simulink. The controller model was co-simulated with a multi-body dynamics model of the motorcycle. The co-simulation results showed the controller developed herein stabilises the motorcycle model at low speeds.

Automated steering technology offers significant benefits to the safety and efficiency of vehicles, but desire to keep the human driver in the loop requires better understanding of the interaction between driver and vehicle. An existing noncooperative-game-theoretic framework for modelling such interaction is revisited in this paper, leading to the development of two alternative driver steering control models. Both models bears Nash-equilibrium properties but involve different assumptions about driver steering control behaviour. A simulation study is performed to demonstrate the difference between the two driver models in terms of their simulated driver steering angles and vehicle lateral motions. An experiment using a fixed-base driving simulator is conducted to measure six test subjects’ steering control behaviour in response to the lane- change manoeuvres generated by an automated steering control system. The two proposed driver models are fitted to the measured driver steering angle data to investigate their capabilities for representing individual driver’s steering control behaviour. Key model parameters are identified following a system identification procedure. It is found that the two driver models have equivalent capability for capturing the trend exhibited in all the six test subjects’ steering angle histories, but less good at reproducing the severe overshoot or oscillation involved in two subjects’ measured steering angles. It is found that the inclusion of an arm neuromuscular system model can improve the performance of the proposed driver models on representing human driver steering control behaviour.

Various driving assistance systems have been developed to reduce the number of automobile accidents. However, the control laws of these assistance systems differ based on each situation, and the discontinuous control command value may be input instantaneously. Therefore, a seamless and unified control law for driving assistance systems that can be used in multiple situations is necessary to realize more versatile autonomous driving. Although studies have been conducted on four-wheel steering that steers the rear wheels, these studies considered the role of the rear wheels only to improve vehicle dynamics and not to contribute to autonomous driving. Therefore, in this study, we define the risk potential field as a uniform control law and propose a rear-wheel steering control system that actively steers the rear wheels to contribute to autonomous driving, depending on the level of the perceived risk in the driving situation. The effectiveness of the proposed method is verified by a double lane change test, which is performed assuming emergency avoidance in simulations, and subject experiments using a driving simulator. The results indicate that actively steering the rear wheels ensures a safer and smoother drive while simultaneously improving the emergency avoidance performance.

As demands increase for goods transportation services, long articulated vehicles are introduced as a viable alternative to conventional heavy-duty vehicles. Nowadays, steering control systems are commonly used for enhancing the stability and handling of articulated vehicles. As situations become more difficult for the movement of a vehicle, the ability of the steering actuators decreases and it will not be possible to use this controller alone in critical maneuvers. Another effective way to adjust the directional dynamics of a long articulated vehicle is the simultaneous application of the braking and steering systems. In a situation where the vehicle is close to the ultimate steering limit, it is desirable to reduce the speed, and the steering system can be strengthened through the intervention of the braking system. In this article, a 23 degree of freedom dynamic model of the long articulated vehicle has been developed in MATLAB software. After determining the reference control variables, we will design a sliding mode controller to steer the tractor’s front axle and the semi-trailer’s rear axles. After defining and setting the weight coefficients using a performance indicator, we will design an integrated controller in a way that if maneuvers become more difficult to perform and the efficiency of the steering actuators decreases, the braking forces exerted on the tractor’s rear axle and the semi-trailer’s rear axles will take a share in regulating the vehicle’s movement. The main achievement of this article is the introduction of a new method to integrate braking and steering control systems in long articulated vehicles. The paper aims to prove that only if manoeuvres become more difficult to perform and the performance of steering actuators decreases, then braking forces can take part in regulating the vehicle’s movement.

This paper describes steering returnability by analyzing forces applied to kingpin axis in limit cornering conditions. The steering returnability is related to forces applied to kingpin axis. These forces are classified by its source: Tire force and steering force. Tire force is generated from tire such as longitudinal, lateral, vertical force, and residual self-aligning torque. Steering force consists of friction force and assist force. These forces are vectorized by suspension geometry and calculated with respect to kingpin axis. The simulation results are compared with measurement data and verifies that steering returnability can be formulated by tire forces and steering forces. Using these relations, this paper proposes new steering control logics at limit driving conditions. This logic is verified by simulation model to check performance and confirmed in various test conditions for robustness.

Recent research efforts on automated driving reveal the need to address driver’s interaction with vehicle automation. This paper focuses on the design of an override mode for automated driving systems, a topic little studied in literature. In this paper, a shared control framework for driver’s override of automatic steering control is proposed. This framework formulates the control transfer between the driver and the system as a constrained optimization problem which is solved online by a model predictive controller. At a higher level in the framework, the system detects driver’s lane-change intention so that the low-level controller can actively assist the driver in a lane-change maneuver. The whole framework was evaluated in a user test based on a driving simulator. The test results show that the proposed shared control framework has the advantage of allowing the driver to regain control with ease while ensuring the smoothness of control transition.

This paper aims to investigate the drivetrain load response caused by induction and wake steering control on two floating wind turbines (FWTs) in a wind farm. In this study, two DTU 10 MW turbines, supported on the nautilus floater, are modelled using FAST.Farm. The downstream turbine is placed at the distance of seven rotor diameters (D) from the upstream turbine in the positive wind direction. Partial wake shading is considered for wake steering control and full wake shading is considered for induction control. An ambient wind speed of 8m/s is used and a representative sea state is selected. The test cases are defined based on different blade pitch and yaw angles of the upstream turbine. Power generation of the offshore wind farm is studied under different test cases. A decouped analysis approach is used to investigate drivetrain response. Global responses are obtained from FAST.Farm. These loads are used as input of the 10 MW wind turbine drivetrain model for the gears and bearings load response analysis. Results show that both induction and wake steering control lead to a limited increase in power generation of the wind farm. Additionally, both control methods affect the drivetrain response statistics, while the features are different. This study facilitates a better understanding on drivetrain dynamic behaviour in a wind farm perspective, which serves as a reference for the wind farm optimizaton in the future. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

As a significant threat to vehicle stability and road safety, tire blowout, which is still inevitable nowadays as an emergent situation, needs to be properly controlled for vehicle stabilization. This paper proposes a novel shared control strategy to stabilize vehicles with active safety systems (e.g. SAE driving automation Level 2 and 3) after a tire blowout event, which enables a human driver to cooperate with a normal automatic controller for path following under a dynamic control authority allocation strategy. Driver-related and safety-related factors in the event of tire blowout are explicitly considered in a dynamic control authority allocation function. Matlab/Simulink and CarSim ® co-simulation results validate that the proposed shared control is promising in enhancing vehicle directional stability and driving safety after tire blowout even with a bad (panicked) driver input.

The steering system in autonomous vehicles is an essential issue that must be addressed. Appropriate control will result in a smooth and risk-free steering system. Compared to other types of controls, type-2 fuzzy logic control has the advantage of dealing with uncertain inputs, which are common in autonomous vehicles. This paper proposes a novel method for the steering control of autonomous vehicles based on type-2 fuzzy logic control combined with PI control. The primary control, type-2 fuzzy logic control, has three inputs—distance, navigation, and speed. The fuzzy system’s output is the steering angle value. This was used as input for the secondary control, PI control. This control is in charge of adjusting the motor’s position as a manifestation of the steering angle. The study results applied to the EPS system of autonomous vehicles revealed that type-2 fuzzy logic control and PI control produced better and smoother control than type-1 fuzzy logic control and PI. The slightest disturbance in the type-1 fuzzy logic control showed a significant change in steering, while this did not occur in the type-2 fuzzy logic control. The results indicate that type-2 fuzzy logic control and PI control could be used for autonomous vehicles by maintaining the comfort and safety of the users.

An active steering system was developed to solve problems such as severe wheel, rail wear, noise and dust generation due to insufficient steering performance of EMU running on an urban railroad section with a large number of curved sections. An electromechanical type active steering system for EMU was designed and a prototype was manufactured. As a result of the performance test of the components for the active steering system, the target design specification was satisfied. Prior to the performance test with test vehicle equipped with the active steering system on test track, the steering control test simulating real track running was conducted, excellent steering performance was noted. The thrust force of the driving unit was also shown to be below the maximum thrust force of the prototype throughout most parts of the track. These results confirm that the simulation test can predict the feasibility of the steering control on the test track for the active steering test vehicle through this simulation test.

In the past decade, several publications have shown that it is advisable to design an advanced driver assistance system using a shared control structure. This paper is concerned with the modelling ...

The article offers an algorithm for the operation of the steering and active drive control system of a saddle-type tractor – trailer combination. The algorithm allows reducing the width of the cornering corridor when maneuvering at low speeds. In the combination vehicle under study, all the wheels of the tractor and semi-trailer are driving and steered. The algorithm of the steering control system takes into account the current values of the folding angle and speed of the combination vehicle. The active drive control is based on the analysis of the forces in the coupling device. The efficiency and effectiveness of the proposed algorithm has been proved using computational experiments.

This paper presents a new application of active rear-wheel steering control to improve the lateral vehicle behaviour. In the state of the art, yaw or lateral velocity is used as control variable th...

Due to the growing environmental pollution, methods are being sought to improve this situation. One of the main factors influencing this pollution is passenger vehicles. This paper will analyze a new approach to vehicles with in-wheel electric motors as well as the steering of all four wheels, which will increase the efficiency of the vehicles and at the same time the driving safety. Driving operation modes of vehicles as well as applications of 4-wheel steering (4WS) with steer-by-wire (SBW) system shall be analyzed. Specially, the steering geometry and the vehicle dynamics equations of this vehicle type will be reported. Finally, the proposed 4WS SBW control system will be presented and simulated with New European Driving cycle (NEDC).

The adaptation of high capacity vehicles (HCVs) into existing commercial vehicle fleets have been considered a potential solution for reducing emissions, operational costs and infrastructure damages. However, due to increased length and number of articulations, there are challenges associated with HCVs with regard to their manoeuvrability at low-speeds and stability at high-speeds. This paper presents a Virtual Rigid Axle Command Steering control strategy for dolly steering, due to which both low- and high-speed performance of HCVs may be improved significantly compared to their conventional version with non-steered dolly. To demonstrate this, two HCVs, namely, A-double (tractor-semitrailer-dolly-semitrailer) and LHV-D (truck-dolly-semitrailer) are considered in this work.

This paper illustrates the potential of a gyroscopic stabiliser for the stabilisation of single-track vehicles, at low and high speed as well as during braking. Alternative systems are considered, including single and twin counter-rotating gyroscopes, spinning and precessing with respect to different axes, either freely (passive stabilisers) or in a controlled way (active stabilisers). A suitable mathematical model has been developed and stability has been investigated both by eigenvalue calculation and time domain simulations. It has been found that the most effective configuration is one where the gyroscope(s) spin with respect to an axis parallel to the wheels' spin axis and swing with respect to the vehicle yaw axis. Passive systems may effectively stabilise both weave and wobble at medium and high speed, but cannot stabilise the vehicle at low and zero speed. On the contrary, actively controlled gyroscopes are capable of stabilising the vehicle in its whole range of operating speed, as well as during braking. The alteration of the original vehicle handling characteristics is negligible when active counter-rotating gyroscopes are used, and still acceptable if a single gyroscope is adopted instead.

A practical approach on remote monitoring of axle loads for heavy commercial vehicles with mechanical suspension was presented. At present, there are motor vehicles act implemented in most of the countries against operating commercial with overload. The major root cause for many truck accidents is overloading. When a truck is loaded more than its rated load, it will increase the risk of affecting vehicle stability while driving. Due to overloading of trucks, the driver will loss the steering control during turning and braking, and this loss of control leads to major accidents on roads. In some cases, even when the cargo load is within the rated load, any one of the individual vehicle axle will get overloaded due to non-uniform distribution of payload. Uniform distribution of loads is important for safe vehicle operation. Overloading of trucks will reduce the life of tires and parts related to suspension from their actual service life, which leads to increase in service cost for the vehicle. The best way to overcome these problem is to monitor each axle loads by avoiding traditional method of weigh bridge measurement. Axle load monitoring system presented in this paper works under the technique of capturing axle load with respect to the deflection of mechanical spring suspension. In addition, the system supports remote data capturing using telematics device. This will avoid the physical presence for measuring.

Electric vehicles are the new target for researchers from many fields to find new innovation to reduce the usage of fossil fuel which currently almost finished. This paper presents a strategy of independent speed steering control for four in-wheel direct drive type by using brushless direct current (BLDC) motors. The hybrid Fuzzy-PI speed controller has been proposed to control the speed of each motor. Hysteresis current controller is introduced to generate the switching signal for each switch in inverter. Ackermann-Jeantand steering model is combined to determine the reference speed each wheel of vehicle during turn in a curve road. By using GUI's interface controlling in MATLAB/SIMULINK, the results of simulation each motor are demonstrated. Four different cases are simulated and given satisfy performance.

Taking the steering performance of all-wheel steering system for the three-wheel forklift as the research object, based on a 2-dof model of three-wheel steer-by-wire system, two kinds of control strategies are proposed in this paper, one with front and rear isometric reverse rotation, and the other with yaw rate feedback. According to actual data of the forklift TFC20, the simulation analyses of the steering performance of all-wheel steering system for the three-wheel forklift is given. Compared with the conventional steering control method, the simulation results show that the first control strategy improved the steering flexibility, and the second control strategy improved the steering stability.

In this paper, a complete analysis of the influence of a look-ahead distance and the longitudinal vehicle velocity on the vehicle lateral dynamics is made in order to choose an adequate control str...

In recent years, researchers from both academia and industry have worked on connected and automated vehicles and they have made great progress toward bringing them into reality. Compared to automated cars, bicycles are more affordable to daily commuters, as well as more environmentally friendly. When comparing the risk posed by autonomous vehicles to pedestrians and motorists, automated bicycles are much safer than autonomous cars, which also allows potential applications in smart cities, rehabilitation, and exercise. The biggest challenge in automating bicycles is the inherent problem of staying balanced. This paper presents a modified electric bicycle to allow real-time monitoring of the roll angles and motor-assisted steering. Stable and robust steering controllers for bicycle are designed and implemented to achieve self-balance at different forward speeds. Tests at different speeds have been conducted to verify the effectiveness of hardware development and controller design. The preliminary design using a control moment gyroscope (CMG) to achieve self-balancing at lower speeds are also presented in this work. This work can serve as a solid foundation for future study of human-robot interaction and autonomous driving.

Many of vehicle crash related fatalities are caused by run-off-road crashes and failures of the drivers to avoid obstacles in front of them. This can happen in near collision encounters, where the driver should steer in order to avoid a crash. In these situations, some drivers steer too much and go off the road, and some do not steer enough and collide with the obstacle. In this study, the authors developed a steering control collision avoidance system (SCCAS) to help drivers to safely perform severe manoeuvres and avoid such crashes. This system is activated by the driver's steering input, and was implemented in a car driving simulator to study human interactions. Testing the subjects with no collision avoidance feature resulted in collision with the obstacles in 61 out of 63 encounters; whereas, using the implemented SCCAS, the subjects avoided 44 out of 60 near collision encounters in a new scenario with the same level of difficulty as the original tests. The post-experiment surveys revealed that besides the effectiveness of the system in reducing the crashes, it was acceptable to the drivers and they found the activation type intuitive.

Reportedly the fatality rate from secondary collision is six times higher than the average fatality rate from all traffic accidents. So prevention of the secondary collision is attracting significant attention from automotive industries. However, the secondary collision prevention systems that have been developed are not considering possibility of brake actuator failure that can occur by the impact during the initial collision. In this paper, a new system has been developed that could prevent secondary collision even in case of brake actuator failure by taking advantage of still operating actuators. In this system, a steering control is performed for maintaining a lane by using linear quadratic regulator. Additionally, the system attempts differential brake control with the remaining braking capability to stop the vehicle in the shortest distance. Through simulation in various collision scenarios, the system has demonstrated significant potential of preventing secondary collision that could otherwise have resulted in severe fatality.

One of the important properties of road transport vehicles is maneuverability, which directly affects the performance and safety of transportation, as well as the total cost of freight and passenger traffic. The paper discusses the design features of various steering control systems and their effect on the maneuverability of vehicles.

As the number of automobiles in worldwide increases, the number of associated serious environmental and safety problems also increases. A solution to these problems is an autonomous platooning system for trucks, which is expected to have various effects such as reduction in carbon dioxide emissions and increase in traffic capacity. Although various control laws have been proposed for automated driving, control gains are typically tuned manually. The optimal values change owing to the freight or over a period of several years. Therefore, when the control performance decreases, gain tuning is again required. In this study, as additional evaluations of the proposed self-tuning method, we newly examine if the method can adjust gain to the change of a freight weight by simulation and evaluate the convergence property of the method experimentally.

This paper focuses on designing a controller to enhance the traction and handling of an Independent-Wheel-Drive Electric Vehicle (IWD-EV). It presents a traction torque distribution controller for an IWD-EV in order to maintain vehicle handling and stability during critical maneuvers. The proposed controller is based on the Direct Yaw-moment Control (DYC) and Active Front Steering control (AFS) which intended to increase the handling and stability of the vehicle respectively by applying the yaw rate and the lateral acceleration as the control variables. The performance of the controller is evaluated by numerical simulations of two standard high speed maneuvers which are the double lane change (DLC) and J-Curve. The proposed scheme presents a new controller design for IWD-EV which can effectively improved the vehicle handling and stability.