Trajectory Control Of Vehicle Research Articles

Trajectory control of autonomous vehicles via I-O linearization and ISMC through backstepping method

Trajectory control of autonomous vehicles via I-O linearization and ISMC through backstepping method

A mixed traffic speed harmonization model with connected autonomous vehicles

Emerging connected autonomous vehicles (CAV) technologies provide an opportunity to the detailed vehicle trajectory control to reduce adverse impacts of stop-and-go traffic imposed by freeway bottlenecks. This study proposes a CAV-based trajectory-smoothing concept to harmonize traffic, improve fuel-efficiency and reduce environmental impacts. The presented algorithm is applicable to mixed-traffic environments with human-driven vehicles (HVs), connected vehicles (CVs), and CAVs. This algorithm controls CAVs so that they smoothly hedge against the backward deceleration waves and gradually merge into the downstream traffic with a reasonable speed. This model addresses the full spectrum of CV and CAV market penetration rates and various traffic conditions. Numerical experiments are performed to assess the algorithm performance with different traffic conditions and CV and CAV market penetration rates. The results show significant improvements in dampening traffic oscillation and reducing fuel consumption and emissions.

Disturbance observer-based optimal longitudinal trajectory control of near space vehicle

Disturbance observer-based optimal longitudinal trajectory control of near space vehicle

Trajectory control of autonomous vehicles via I-O linearization and backstepping

Trajectory control of autonomous vehicles via I-O linearization and backstepping

Integrated trajectory planning and control for obstacle avoidance manoeuvre using non‐linear vehicle MP algorithm

In the current literature, model-predictive (MP) algorithm is widely applied in autonomous vehicle trajectory planning and control but most of the current studies only apply the linear tyre model, which cannot accurately present the tyre non-linear characteristic. Furthermore, most of these studies separately consider the trajectory planning and trajectory control of the autonomous vehicle and few of them have integrated the trajectory planning and trajectory control together. To fill in above research gaps, this study proposes the integrated trajectory planning and trajectory control method using a non-linear vehicle MP algorithm. To fully utilise the advantages of four-wheel-independent-steering and four-wheel-independent-driving vehicle, the MP algorithm is proposed based on four-wheel dynamics model and non-linear Dugoff tyre model. This study also proposes the mathematical modelling of the static obstacle and dynamic obstacle for the obstacle avoidance manoeuvre of the autonomous vehicle. Finally, simulation results have been presented to show the effectiveness of the proposed control method.

Spatiotemporal intersection control in a connected and automated vehicle environment

Current research on traffic control has focused on the optimization of either traffic signals or vehicle trajectories. With the rapid development of connected and automated vehicle (CAV) technologies, vehicles equipped with dedicated short-range communications (DSRC) can communicate not only with other CAVs but also with infrastructure. Joint control of vehicle trajectories and traffic signals becomes feasible and may achieve greater benefits regarding system efficiency and environmental sustainability. Traffic control framework is expected to be extended from one dimension (either spatial or temporal) to two dimensions (spatiotemporal). This paper investigates a joint control framework for isolated intersections. The control framework is modeled as a two-stage optimization problem with signal optimization at the first stage and vehicle trajectory control at the second stage. The signal optimization is modeled as a dynamic programming (DP) problem with the objective to minimize vehicle delay. Optimal control theory is applied to the vehicle trajectory control problem with the objective to minimize fuel consumption and emissions. A simplified objective function is adopted to get analytical solutions to the optimal control problem so that the two-stage model is solved efficiently. Simulation results show that the proposed joint control framework is able to reduce both vehicle delay and emissions under a variety of demand levels compared to fixed-time and adaptive signal control when vehicle trajectories are not optimized. The reduced vehicle delay and CO2 emissions can be as much as 24.0% and 13.8%, respectively for a simple two-phase intersection. Sensitivity analysis suggests that maximum acceleration and deceleration rates have a significant impact on the performance regarding both vehicle delay and emission reduction. Further extension to a full eight-phase intersection shows a similar pattern of delay and emission reduction by the joint control framework.

Maneuvering Support System for an Amphibian Vehicle – Warning Display to Prevent Rough Maneuvers –

[abstFig src='/00290003/14.jpg' width='300' text='Amphibian vehicle maneuvering simulator' ] This study proposes a maneuvering support system for an amphibian vehicle by applying a nonlinear state feedback control law for vehicle trajectory control. We consider that the vehicle should not drift sideways for good driving performance. To derive a nonlinear state feedback control law, we have defined ‘Maneuvering Trajectory’ as an additional reference trajectory that is generated by the driver’s maneuver. We have constructed a Lyapunov-like function for the trajectory control system. In this paper, we construct a vehicle-maneuvering simulator and set a clockwise circular reference trajectory. The efficiency of the proposed maneuvering support system is shown in the maneuvering simulations. We consider the case where the propulsive forces of the vehicle have limited influence on maneuverability. A new warning display system is proposed so that the driver can recognize if his or her maneuver is not suitable. Then, we examine the feasibility of the proposed warning display system through several simulations.

PD CONTROLLER BASED UNMANNED SHIP NAVIGATION

For the improvement of the performance of track keeping of unmanned water vehicle numerous ship models, wave disturbances models and distinct control algorithms has been proposed. Researchers are using variants of PID controllers, Adaptive controllers and Predictive controllers for accurate trajectory control. Being simpler in nature still PID controller are popular in control domain. In this paper we have implemented PD based controller for trajectory control of unmanned vehicle considering all standard models of sea disturbances. Analysis of result obtained using PD control proved that path tracking is more accurate than open loop controller in terms of computation time, complexity and fuel consumption.

Управление движением беспилотного автомобиля по траектории с использованием метода динамического окна

Управление движением беспилотного автомобиля по траектории с использованием метода динамического окна

Map-Based Positioning Method for Vehicle Trajectory Control

Map-Based Positioning Method for Vehicle Trajectory Control

Trajectory control for autonomous electric vehicles with in‐wheel motors based on a dynamics model approach

The trajectory control of autonomous vehicles is an area which has attracted much research recently because it can prevent accidents caused by driver errors and significantly improve road capacity. Overtaking is one of the most complex and challenging manoeuvres for road vehicles and the autonomous control of the vehicle during this manoeuvre can greatly improve vehicle safety. As the innovative four-wheel independent steering (4WIS) and four-wheel independent driving (4WID) electric vehicle can provide redundant control actuators, this study focuses on utilising 4WIS–4WID techniques and vehicle dynamics control to achieve better control of autonomous vehicles. This study first introduces the traditional two-wheel proportional–integral–derivative (PID) steering control and two-wheel sliding mode controller (SMC) driving control for autonomous vehicle control. Then based on these, the four-wheel PID steering controller and four-wheel SMC steering controller are proposed. A four-wheel SMC driving controller and a four-wheel combined yaw rate and longitudinal velocity SMC driving controller are also proposed. Simulation results prove that the best control performance can be achieved when the four-wheel SMC steering controller and four-wheel combined yaw rate and longitudinal velocity SMC driving controller are used together.

Navier–Stokes predictions of dynamic stability derivatives for air-breathing hypersonic vehicle

Dynamic derivatives are important parameters for designing vehicle trajectory and attitude control system that directly decide the divergence behavior of vibration of the aircraft open-loop system under interference. After calibration model validation, the dynamic behavior of air-breathing hypersonic vehicle WR-A is characterized. The unsteady flow field of aircraft forced simple harmonic vibration (SHV) is simulated using N–S equation. The direct damping derivatives, cross derivatives, acceleration derivatives and rotary derivatives of WR-A under different frequencies, amplitudes and positions of centroid are obtained. Research demonstrates that the proportion of acceleration derivatives, which represents the flow time lag effect, in the direct damping derivatives can be as high as 40% but is opposite to the damping derivative value symbols in some cases, contributing to dynamic instability. Numerical simulation on large-amplitude forced vibration of WR-A indicates that the aerodynamic behavior predicted by the dynamic derivative model agrees well with unsteady calculations. The inlet performance parameter derivatives are solved using the Etkin theory. The inlet performance parameters under large-amplitude vibration are successfully predicted using the dynamic derivative model. This offers a guideline for characterizing the dynamic internal flow field and unsteady inlet performance.

A Controller Framework for Autonomous Drifting: Design, Stability, and Experimental Validation

This paper presents the development of a controller for autonomous, steady-state cornering with rear tire saturation (“drifting”) of a rear wheel drive vehicle. The controller is designed using a three-state vehicle model intended to balance simplicity and sufficient model fidelity. The model has unstable “drift equilibria” with large rear drive forces that induce deep rear tire saturation. The rear tire saturation at drift equilibria reduces vehicle stability but enables “steering” of the rear tire force through friction circle coupling of rear tire forces. This unique stability–controllability tradeoff is reflected in the controller design, through novel usage of the rear drive force for lateral control. An analytical stability guarantee is provided for the controller through a physically insightful invariant set around a desired drift equilibrium when operating in closed-loop. When implemented on a by-wire testbed, the controller achieves robust drifts on a surface with highly varying friction, suggesting that steady cornering with rear tire saturation can prove quite effective for vehicle trajectory control under uncertain conditions.

Nonlinear Trajectory Control of Multi-body Aerial Manipulators

This paper studies trajectory control of aerial vehicles equipped with robotic manipulators. The proposed approach employs free-flying multi-body dynamics modeling and backstepping control to develop stabilizing control laws for a class of underactuated aerial systems. Two control methods are developed: coordinate-based and coordinate-free which are both generally applicable to aerial manipulation tasks. A simulated hexrotor vehicle equipped with a simple manipulator is employed to demonstrate the proposed techniques.

An improved model-based predictive control of vehicle trajectory by using nonlinear function

A new model-based predictive control algorithm for vehicle trajectory control is proposed by using vehicle velocity and sideslip angle. Based on the error function combined with vehicle velocity and side slip of a bicycle model, a predictive control method has been proven to be useful on low velocity. Thus, it could be applied for an autonomous vehicle without a driver. Although an autonomous robot is not necessary to be driven with a high velocity, a commercial vehicle has to be driven at high velocity. Thus the previous predictive control formulation is not enough for a commercial driving system. This study is proposed to enhance the capacity of the predictive controller for rather high speed vehicles.

Predictive control of a vehicle trajectory using a coupled vector with vehicle velocity and sideslip angle

In this paper, a predictive algorithm for vehicle trajectory control using the vehicle velocity and sideslip angle is proposed. Since the driving state of a vehicle generates nonholonomic constraint equations, it is difficult to control the trajectory with a conventional control algorithm. Furthermore, control vectors such as vehicle velocity and sideslip angle are coupled together; hence, a separate control for each variable is not suitable. In this study, a coupled control vector that combines the velocity and sideslip angle is proposed for the predictive control of vehicle trajectory. Since the coupled control vector is derived from the status of the vehicle’s motion, it is easy to generate a feedback control vector for the predictive controller. The coupled vector cannot be directly used as input to the vehicle systems; therefore, the vehicle input vector should be calculated from the control vector using a nonlinear function. Since nonlinear functions are not inserted in the control loop, they are calculated by the controller. Therefore, this method does not require a linearization process in the control logic, which enhances the stability and accuracy of the predictive controller.

Robust trajectory control of underwater vehicles using time delay control law

A new control scheme for robust trajectory control based on direct estimation of system dynamics is proposed for underwater vehicles. The proposed controller can work satisfactorily under heavy uncertainty that is commonly encountered in the case of underwater vehicle control. The dynamics of the plant are approximately canceled through the feedback of delayed accelerations and control inputs. Knowledge of the bounds on uncertain terms is not required. It is shown that only the rigid body inertia matrix is sufficient to design the controller. The control law is conceptually simple and computationally easy to implement. The effectiveness of the controller is demonstrated through simulations and implementation issues are discussed.

Trajectory Control of Autonomous Vehicles in Viscous Media

Problems of motion control of autonomous mobile vehicles in viscous medium are considered. A control law providing motion of the vehicles along smooth and composite analytical curves (trajectories) is designed. The approach is based on nonlinear coordinate change leading to a task-oriented model of the plant and enable one to reduce the complex technological task to simple stabilization problems to be solved by using standards techniques of nonlinear spatial motion control.

Trajectory Control of Aerial Vehicles for Live-line Maintenance Work (1st Report, Control of Derricking Action by the Linearization of Servo Valve)

In this paper, as the first step of trajectory control of aerial vehicles for live-line maintenance work, by servo valve attached to the derricking cylinder, a trajectory control method of bucket in the vertical plane is discussed. Here, we reorganized the equation of motion for the aerial vehicle and linearized the servo value by introducing the current compensation. Based on these equations, we derived the simple model of the controlled variable corresponding to the altitude of the bucket gravity center and the control rule. Simulations demonstrate that current compensation can improve the precision of trajectory control effectively, and good results can be obtained for the changing of the bucket altitude and sinusoidal reference trajectory by using the proposed method.

ＡＣＶの軌道制御実験

In this research, it is considered that the air cushion vehicle should not drift sideways for a good driving performance. A nonlinear state feedback control was proposed previously for the trajectory control of an air cushion vehicle. With this control law, the successful values of the propulsion forces could be calculated. However, the way how to realize these forces was not considered. In the present paper, an algorithm for the generation of these propulsion forces is proposed. An experimental system with a simple air cushion vehicle model is also constructed. Then, the validity of the proposed scheme is verified through several trajectory control experiments.