Steering Control Strategy Research Articles

Active front steering control strategy based on estimation of vehicle state and mass identification

Active front steering control strategy based on estimation of vehicle state and mass identification

Robust model referenced control for vehicle rollover prevention with time-varying speed

In this paper, an active steering control strategy is proposed to prevent rollover of a vehicle with a time-varying forward speed. The controller is designed with the aim of reducing the rollover index (RI) from an initial dangerous status to an absolutely safe status by active steering. The controller consists of two parts. The nominal control is firstly designed on the basis of the fundamental equation of constrained motion (FECM) of the vehicle, which will guarantee the nominal vehicle to track the desired states and thus rollover is prevented. To handle system uncertainties, compensatory sliding mode control (SMC) is proposed, by which the actual states are forced to track the desired ones. In the controller, the chattering problem can be alleviated by selecting a suitable performance function. To indicate the merits of the designed controller, simulation is conducted. Simulation results demonstrate that compared to conventional controllers, the proposed controller can prevent the vehicle from rollover with stronger robustness and without system chattering.

Active front steering control strategy based on estimation of vehicle state and mass identification

Active front steering control strategy based on estimation of vehicle state and mass identification

Design and error compensation of active mechanically automated guided vehicle

To reduce the navigation control cost, this paper proposes a mechanical guidance control scheme that uses a cam-link mechanism as a steering control mechanism for an automated guided vehicle with a fixed driving path. According to the steering principle, a mathematical model of the steering system and the driving trajectory are established. By setting the boundary conditions, the vehicle trajectory is modeled using a quintic polynomial. The contour of the directional control cam is obtained based on the equation of the vehicle trajectory. Because errors occur in actual machining and assembly processes, errors will be classified based on their impact on the trajectory. The effects of various errors on the trajectory are quantitatively determined by using simulation methods with different parameters. Furthermore, an error compensation approach is designed to reduce the influence of the error on the trajectory directly or indirectly. Finally, experiment results illustrate that the adjustment accuracy of the proposed automated guided vehicle trajectory is 2 mm.

Robust Stochastic Observer-Based Attack-Tolerant Missile Guidance Control Design Under Malicious Actuator and Sensor Attacks

In this study, the robust H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> stochastic observer-based attack-tolerant guidance control strategy is designed for the nonlinear stochastic missile guidance control system under the external disturbance and measurement noise as well as actuator attack signal and sensor attack signal. To simplify the attack signal estimation, a novel nonsingular smoothed dynamic model is introduced to efficiently describe the actuator and sensor attack signals. Consequently, the state/attack signal estimation can be easily achieved by using conventional Luenberger observer. Next, to attenuate the effect of external disturbance, measurement noise and approximation errors of attack signal on the missile guidance control system, the robust H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> attack-tolerant guidance control performance is considered and the design condition is derived in terms of nonlinear Hamilton-Jacobi inequality (HJI) constrained problem. Since HJI cannot be easily solved analytically or numerically, the Takagi-Sugeno (T-S) fuzzy modelling method is utilized to facilitate the robust H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> attack-tolerant guidance control strategy design. Thereafter, the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> observer-based attack-tolerant control design problem is transformed into linear matrix inequalities problem (LMIP) which can be solved very efficiently by using the convex optimization techniques. Simulation example, with the comparison between the proposed method and conventional robust missile guidance strategy, is given to illustrate the design procedures and validate the performance of the proposed method.

An Emergency Hierarchical Guidance Control Strategy for Autonomous Vehicles

This paper introduces a vehicle guidance control architecture capable of autonomously resolving emergency situations due to a steering system failure. This situation requires a safe stop in the emergency lane by means of differential braking. The proposed approach is based on a three-level hierarchical architecture composed, from the highest to the lowest, by a reference generation, a guidance control, and a control allocation level. The reference generation function computes the trajectory and the speed profile to be tracked by the vehicle according to the active mode of operation: normal or emergency. Switching mode information are received by the fault detection and isolation (FDI) supervisor. The guidance control function generates the steering angle and the braking/accelerating wheels’ torques commands based on longitudinal and lateral tracking errors. At the lowest level of hierarchy, the control allocation function dynamically redistributes the control commands to the available set of actuators, according to FDI information. For instance, in the proposed study, promoting differential braking in case of a steering system failure, guaranteeing acceptable tracking performance both in longitudinal and lateral directions. Simulation results prove the efficacy of the proposed approach.

Theoretical and experimental investigation of driver noncooperative-game steering control behavior

This paper investigates two noncooperative-game strategies which may be used to represent a human driver's steering control behavior in response to vehicle automated steering intervention. The first strategy, namely the Nash strategy is derived based on the assumption that a Nash equilibrium is reached in a noncooperative game of vehicle path-following control involving a driver and a vehicle automated steering controller. The second one, namely the Stackelberg strategy is derived based on the assumption that a Stackelberg equilibrium is reached in a similar context. A simulation study is performed to study the differences between the two proposed noncooperative-game strategies. An experiment using a fixed-base driving simulator is carried out to measure six test driver's steering behavior in response to vehicle automated steering intervention. The Nash strategy is then fitted to measured driver steering wheel angles following a model identification procedure. Control weight parameters involved in the Nash strategy are identified. It is found that the proposed Nash strategy with the identified control weights is capable of representing the trend of measured driver steering behavior and vehicle lateral responses. It is also found that the proposed Nash strategy is superior to the classic driver steering control strategy which has widely been used for modeling driver steering control over the past. A discussion on improving automated steering control using the gained knowledge of driver noncooperative-game steering control behavior was made.

Active Front Steering-Based Electronic Stability Control for Steer-by-Wire Vehicles via Terminal Sliding Mode and Extreme Learning Machine

In this article, a novel active front steering (AFS) control strategy including the upper controller and the lower controller is proposed to improve the yaw stability and maneuverability for steer-by-wire (SbW) vehicles. The adaptive recursive integral terminal sliding mode (ARITSM) control is adopted in the upper controller for guaranteeing the convergence performance of both the actual sideslip angle and the yaw rate with strong robustness and fast convergence rate. Then, a fast nonsingular terminal sliding mode (FNTSM) control with extreme learning machine (ELM) estimator to estimate its equivalent control is designed in the lower controller to track the desired front wheel steering angle calculated from the upper controller for driving the sideslip angle and the yaw rate to converge ideal value. It is shown that the upper controller takes two controlled variables (vehicle sideslip angle and yaw rate) and only one control input (front steering angle) into consideration, which can obtain a better performance compared with the case of using only one of these values. Since using the ELM technique in the lower controller to estimate the equivalent control of the FNTSM, not only the dependence of SbW system dynamics can be alleviated in the process of designing controller but also the excellent steering control performance can be achieved. Comparative simulations are carried out by utilizing Carsim and Matlab software to validate the excellent performance of the proposed control strategy for different steering maneuvers.

Wake steering strategies for combined power increase and fatigue damage mitigation: an LES study

The impact of wake steering control strategy on power production and loads for a cluster of two wind turbines is analysed in this work. The power and loads data base are generated by means of high resolution simulations using an ALM-LES model along with an aeroelastic code for multibody analysis, while the optimal yaw misalignment values are obtained, for different wind directions and performance requirements, using a weighted cost function that accounts for both power production and fatigue damage on main wind turbine components. The sensitivity of the results regarding the inflow conditions, in terms of turbulence intensity, is also analysed. The overall results show that when accounting for both power production and fatigue damage, greater values of optimal yaw misalignment are obtained. This indicates that standard yaw misalignment strategies that accounts only for power production reduce at the same time the loading damage on the wind turbine, compared to greedy configuration.

Controlling tractor‐semitrailer vehicles in automated highway systems: Adaptive robust and Lyapunov minimax approach

AbstractIn this paper, we design a coordinated steering and braking control scheme to ensure the tractor‐semitrailer vehicle system is practically stable. The tractor's steering input is designed to realize lane tracking and the semitrailer's differential braking torque is designed to improve the stability of the semitrailer. This control methodology is developed in two steps. Firstly, the expected steering input and the expected differential braking force are derived by introducing a set of given tracking constraints and considering the possible initial condition derivation from the constraints based on the Udwadia‐Kalaba approach. Secondly, we develop an adaptive robust control law to tackle the parameter uncertainty, which may be (possibly) time‐varying, and design the required braking torques, which are the actual inputs, to generate the desired braking forces. Furthermore, this control methodology can deal with nonlinear mechanical systems with both holonomic constraints and nonholonomic constraints. Numerical simulations demonstrate that the control algorithm could guarantee the vehicle dynamics are practically stable and achieve lane following maneuvering.

Three-dimensional neural network tracking control of autonomous underwater vehicles with input saturation

This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties, environmental disturbances and input saturation. First, a virtual guidance control strategy is established on the basis of tracking error kinematics, which resolves the overall control system into two cascade subsystems. Then, a first-order sliding mode differentiator is introduced in the derivation to avoid tedious analytic calculation, and a Gaussian error function-based continuous differentiable symmetric saturation model is explored to tackle the issue of input saturation. Combined with backstepping design techniques, the neural network control method and an adaptive control approach are used to estimate composite items of the unknown uncertainty and approximation errors. Meanwhile, Lyapunov-based stability analysis guarantees that control error signals of the closed-loop system are uniformly ultimately bounded. Finally, simulation studies are conducted for the trajectory tracking of a moving target and a spiral line to validate the effectiveness of the proposed controller.

Active steering control strategy for rail vehicle based on minimum wear number

ABSTRACT Active steering technology is an effective method to solve the contradiction between curving performance and running stability of traditional bogie. In this study, an integrated active steering device was developed to integrate wheelset constraints and actuators. In addition, to study the minimum wear number control strategy, the existence of an optimal steering level that minimises the wear number was corroborated by a theoretical derivation based on the single wheelset model. Later, this research method was extended to the complete vehicle lateral dynamics model and steady-state solutions at different active steering levels were analysed. The results demonstrate that at optimal steering control, wear number is the lowest. This state is less affected by the running velocity, stiffness of the primary suspension, tread taper, and creep state, which are determined by the wheelbase and track curvature. The lateral forces of rail-vehicle wheels with an active steering function at different steering levels were measured using instrumented wheelsets. Furthermore, the accuracy of the simulation model was verified by comparing the experimental data with simulation results. Finally, the wear number of test vehicles at different steering levels were predicted using this model, and the control strategy proposed in this investigation was validated.

Effects of motorcycle simulator configurations on steering control and gaze behavior in bends.

The recent development of motorcycle simulators has made it possible to study rider behavior in safe conditions. However, their use still raises validity issues. Our study examined how riders' steering and gaze behaviors and subjective experience are influenced by motorcycle roll tilt and reverse steering, which are considered to be essential factors in real-life motorcycle riding. The results revealed that tilting the motorcycle in the roll plane did not lead to significant changes in rider behavior, gaze sampling, or perceived realism. The steering control strategy adopted by riders did, however, significantly influence these results. A direct steering control strategy meant that riders took a racing path and scanned the road far in advance. When reverse steering was implemented, however, riders chose to take a "safety path", as recommended by training manuals. Reverse steering also received the highest realism score. However, steering control was more difficult, as shown by the larger number of lane departures recorded and a change in the trade-off between guiding and look-ahead fixations. This suggests that although reverse steering matches riders' real control behavior and improves the subjective experience of simulator riding, it is hindered by an inadequate internal model of vehicle dynamics. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Precise Discrete-Time Steering Control for Robotic Fish Based on Data-Assisted Technique and Super-Twisting-Like Algorithm

In this article, a novel dynamic model of robotic fish with the data-assisted method is established and a discrete-time super-twisting-like controller (DTSTC) is proposed to effectively control the steering for a robotic fish. Although the thrust of the robotic fish is generated by the body motion in surrounding water environment, it is rather difficult to model the hydrodynamics in practice. Therefore, the data-assisted modeling method is applied where the reaction force generated by the yawing of fish head is also considered to obtain a more accurate model. The DTSTC is, then, designed to achieve robust steering control performance against system uncertainties. The experimental results are presented in support of the effectiveness and excellent performance of the proposed steering control scheme of the robotic fish.

Integrated active steering control strategy for autonomous articulated vehicles

An integrated active steering control strategy for tractor and trailer unit of articulated vehicles is presented in order to achieve both autonomous and safe motion. The tractor and trailer controllers are designed to preview and follow the demanded path automatically and safely. Based on model predictive control (MPC) theory, the integrated active steering controller of the tractor and trailer is designed to minimise path-tracking deviation while taking lateral stability into account. The manoeuvrability and stability of the articulated vehicle under the proposed control strategy are verified by simulations at low speed and high speed, respectively. The results confirm that the proposed integrated active steering system is capable of keeping the articulated vehicle automatically following the demanded path with high stability. The lateral stability and path-tracking of both tractor and trailer are significantly improved.

Integrated active steering control strategy for autonomous articulated vehicles

Integrated active steering control strategy for autonomous articulated vehicles

Guidance control for parallel parking tasks

Parking into small berths remains difficult for unskilled drivers. Researchers had proposed different automatic parking systems to solve this problem. The first kind of strategies &#x0028 called parking trajectory planning &#x0029 designs a detailed reference trajectory that links the start and ending points of a special parking task and let the vehicle track this reference trajectory so as to park into the berth. The second kind of strategies &#x0028 called guidance control &#x0029 just characterizes several regimes of driving actions as well as the important switching points in certain rule style and let the vehicle follows the pre-selected series of actions so as to park into the berth. Parking guidance control is simpler than parking trajectory planning. However, no studies thoroughly validated parking guidance control before. In this paper, a new automatic parking method is presented, which could characterize the desired control actions directly. Then the feasibility is examined carefully. Tests show that a simple parking guidance control strategy can work in most parallel parking tasks, if the available parking berth is not too small. This finding helps to build more concise automatic parking systems that can efficiently guide human drivers.

Research On Differential Steering Control Strategy Of Distributed Electric Drive Vehicle

Research On Differential Steering Control Strategy Of Distributed Electric Drive Vehicle

Robust control of a bevel-tip needle for medical interventional procedures

In minimally invasive surgery, one of the main objectives is to ensure safety and target reaching accuracy during needle steering inside the target organ. In this research work, the needle steering approach is determined using a robust control algorithm namely the Integral sliding mode control &#x0028 ISMC &#x0029 strategy to eliminate the chattering problem associated with the general clinical scenario. In general, the discontinuity component of feedback control input is not appropriate for the needle steering methodology due to the practical limitations of the driving actuators. Thus in ISMC, we have incorporated the replacement of the discontinuous component using a super twisting control &#x0028 STC &#x0029 input due to its unique features of chattering elimination and disturbance observation characteristics. In our study, the kinematic model of an asymmetric flexible bevel-tip needle in a soft-tissue phantom is used to evaluate stability analysis. A comparative study based on the analysis of chattering elimination is executed to determine the performance of the proposed control strategy in real-time needle steering with conventional sliding mode control using vision feedback through simulation and experimental results. This validates the efficacy of the proposed control strategy for clinical needle steering.

An approach to develop haptic feedback control reference for steering systems using open-loop driving manoeuvres

In this paper, a methodology to capture the model-based haptic feedback control reference for closed-loop steering systems is demonstrated. The parameterisation is based on the measurements of open-loop driving manoeuvres for the inertia-spring-damper-friction reference model. The steady-state and transient manoeuvres are used to identify the model parameters. The reference model is limited to the haptic feedback of driver excitation in the linear vehicle handling range and intended to be used in closed-loop steering control strategies. The model parameters have an intuitive interpretation that allows to be used in both admittance and impedance control setting. The feasibility of the proposed model is demonstrated in a validated simulation environment for electric power assisted steering and on a real hardware for the steer-by-wire force-feedback case.