Heading Angle Control Research Articles

Enhanced Conflict Avoidance and Dynamic Path Replanning for Multi-UAVs through MILP with Real-time Speed and Heading Angle Control

Enhanced Conflict Avoidance and Dynamic Path Replanning for Multi-UAVs through MILP with Real-time Speed and Heading Angle Control

DDPG based LADRC trajectory tracking control for underactuated unmanned ship under environmental disturbances

Realizing trajectory tracking control of underactuated unmanned ships is critical for safe and stable navigation during offshore operations. The principal difficulties of this task lie in the coupling problem caused by the underactuated system and the uncertainty caused by the modeling error, internal parameter perturbations, and external environment. In this paper, a three-degree-of-freedom ship model is first built based on the manipulative modeling group equation. Then, a trajectory tracking line-of-sight guidance law is proposed to achieve the desired heading angle and forward speed during trajectory tracking, and the Lyapunov function is used to analyze its stability. Furthermore, the heading angle controller and forward speed controller are designed based on the linear active disturbance rejection control framework. In addition, to solve the challenging problem of controller parameter tuning and further improve the controller’s robustness, the Deep Deterministic Policy Gradient algorithm is applied to adjust the controller parameters. Finally, the effectiveness of the proposed method is verified by the simulation results of sinusoidal, circular, and square trajectories with wind and current disturbances.

ОБОСНОВАНИЕ ЭЛЕКТРОННОЙ КОМПОНЕНТНОЙ БАЗЫ ДЛЯ АВТОГЕНЕРАТОРОВ ПРИ НАВИГАЦИОННОМ ОБЕСПЕЧЕНИИ БЕСПИЛОТНЫХ ЛЕТАТЕЛЬНЫХ АППАРАТОВ

The study analyzes the tasks of air objects navigation support. The authors conducted a synthesis of a flight route of an unmanned aerial vehicle with the choice of heading angles of flight at turning points using the direction finding signals received from a stationary ground source. The root-mean-square errors are estimated based on the flying tests. These errors determine a location of emitters during multiple estimation of angular coordinates at points separated in space by direction-finding receivers placed on board of unmanned aerial vehicles “Orlan-10”, “Phoenix”, and “Grant-M”. Methods for correcting autonomous flight with increasing and decreasing accuracy in estimating signal arrival directions are studied, which make it possible to minimize positioning errors for a fixed observation time. The study proposes a scheme of a self-excited oscillator on a field-effect transistor for backup command control with automatic heading angle control. A rule is substantiated for constructing a model of a selfexcited oscillator that meets the requirements for a minimum standard deviation calculated using an electrical circuit and a given heading angle with a restriction on the physical feasibility of the layout parameters of a given structure. Recommendations for the implementation of the electronic circuit are formulated and the modes of self-excitation of the oscillator are determined.

Three-Dimensional Path-Following Control of an Autonomous Underwater Vehicle Based on Deep Reinforcement Learning

Abstract In this article, a deep reinforcement learning based three-dimensional path following control approach is proposed for an underactuated autonomous underwater vehicle (AUV). To be specific, kinematic control laws are employed by using the three-dimensional line-of-sight guidance and dynamic control laws are employed by using the twin delayed deep deterministic policy gradient algorithm (TD3), contributing to the surge velocity, pitch angle and heading angle control of an underactuated AUV. In order to solve the chattering of controllers, the action filter and the punishment function are built respectively, which can make control signals stable. Simulations are carried out to evaluate the performance of the proposed control approach. And results show that the AUV can complete the control mission successfully.

High-Accuracy Driving Control of a Stone-Throwing Mobile Robot for Curling

In this study, a novel mobile robot that can throw precisely a stone in a curling match is introduced. This mobile robot plays alongside a human team. Several requirements for developing the mobile robot are defined so that it follows the game rules and operates on an ice field. A static force analysis considering the operating conditions of the mobile robot is conducted to derive the required motor torque and the optimal mechanical design. For a successful stone-throwing, the mobile robot must present a high driving performance on an ice surface with a target velocity and an angle provided by an autonomous strategy generator. To achieve the target velocity on an icy surface, a velocity control algorithm based on slip ratio control (SRC) is proposed. Moreover, to precisely achieve heading angle control, a heading angle controller including a steering angle disturbance observer (SA-DOB) is introduced. The mathematical model of the SA-DOB is derived by a dynamic analysis of the mobile robot. Several experimental results verify the proposed motion control algorithm and the feasibility of the mobile robot as a curling robot to compete with a human team. This study is motivated by the challenge of driving a mobile robot on an extremely slippery surface with high-accuracy motion for curling. To prevent slippage, a slip ratio controller is adopted based on the difference between the wheel and robot speeds. To maintain a desired heading angle of the mobile robot during driving, orientation control based on the yaw dynamics is developed. Moreover, the robot does not require any positioning information from external sources, such as sensors and cameras. In addition to playing an actual game, this curling robot can be utilized for training athletes. Furthermore, the developed algorithms for high-accuracy driving on ice in an indoor stadium can be applied to various mobile robots that drive on other slippery environments (such as sand and dust) and sealed spaces (such as underground warehouses) where external positioning signals cannot be received. The proposed robot is limited to straight driving, and the possibility of extending it to circular motion is still under development. Note to Practitioners—This study is motivated by the challenge of driving a mobile robot on an extremely slippery surface with high-accuracy motion for curling. To prevent slippage, a slip ratio controller is adopted based on the difference between the wheel and robot speeds. To maintain a desired heading angle of the mobile robot during driving, orientation control based on the yaw dynamics is developed. Moreover, the robot does not require any positioning information from external sources, such as sensors and cameras. In addition to playing an actual game, this curling robot can be utilized for training athletes. Furthermore, the developed algorithms for high-accuracy driving on ice in an indoor stadium can be applied to various mobile robots that drive on other slippery environments (such as sand and dust) and sealed spaces (such as underground warehouses) where external positioning signals cannot be received. The proposed robot is limited to straight driving, and the possibility of extending it to circular motion is still under development.

Potential risk assessment for safe driving of autonomous vehicles under occluded vision

This study aimed to explore how autonomous vehicles can predict potential risks and efficiently pass through the dangerous interaction areas in the face of occluded scenes or limited visual scope. First, a Dynamic Bayesian Network based model for real-time assessment of potential risks is proposed, which enables autonomous vehicles to observe the surrounding risk factors, and infer and quantify the potential risks at the visually occluded areas. The risk distance coefficient is established to integrate the perception interaction ability of traffic participants into the model. Second, the predicted potential risk is applied to vehicle motion planning. The vehicle movement is improved by adjusting the speed and heading angle control. Finally, a dynamic simulation platform is built to verify the proposed model in two specific scenarios of view occlusion. The model has been compared with the existing methods, the autonomous vehicles can accurately assess the potential danger of the occluded areas in real-time and can safely, comfortably, and effectively pass through the dangerous interaction areas.

A Post Impact Stability Control for Four Hub-Motor Independent-Drive Electric Vehicles

This article presents a post-impact lateral stability control strategy integrated for Four Hub-Motor Independent-Drive Electric Vehicles (4MIDEV) to address the issue of loss of vehicle stability control due to vehicle skidding and saturated tire forces upon light vehicle collision using active front steering (AFS) and direct yaw moment control (DYC). Upon a light vehicle collision, vehicle experiences lateral and yaw motions due to collision impact-induced yaw moment. A multiple-objective hierarchical control strategy to attenuate vehicle yaw moment and regain stability control is proposed. Two potential sets of control reference states for the control strategy motion control are considered: desired DYC states and the drift equilibrium. A direct yaw moment controller based on sliding mode control (SMC) theory is designed to track the desired yaw rate. For the AFS, the tracking of desired DYC sideslip angle is performed using a SMC based controller, whereas the tracking of drift equilibrium state values employs a state feedback controller. An SMC longitudinal controller is designed for deceleration control of the vehicle after collision. Upon compensation of the yaw moment, a multiple sliding surface control theory-based lane controller is employed for lateral path deviation and heading angle control. The effectiveness of the proposed control strategy is validated on Carsim and Matlab/Simulink joint simulation platform. Simulation results showed that the proposed control strategy is effective in improving the post-impact stability control of the 4MIDEV on a high-velocity condition, and the control strategy that tracks the drift equilibrium showed better control performance on low adhesion coefficient surface.

Output-Based Tracking Control for a Class of Car-Like Mobile Robot Subject to Slipping and Skidding Using Event-Triggered Mechanism

This paper presents an output-based tracking controller for a class of car-like mobile robot (CLMR) subject to slipping and skidding. The slipping and skidding are regarded as external disturbances, and an event-triggered extended state observer (ET-ESO) is utilized to recover the velocities as well as to estimate the uncertainties and disturbances. The constrained longitudinal velocity is established, conforming to the traffic flow theory on the kinematic level. The velocity control law and heading angle control law are developed on the dynamic level, respectively. The input to state stability (ISS) of the closed-loop system is analyzed via cascade theory. Simulation results are given to demonstrate the effectiveness of the proposed tracking controller for CLMR subject to slipping and skidding.

Iterative Self-Tuning Minimum Variance Control of a Nonlinear Autonomous Underwater Vehicle Maneuvering Model

This paper addresses the problem of control design for a nonlinear maneuvering model of an autonomous underwater vehicle. The control algorithm is based on an iteration technique that approximates the original nonlinear model by a sequence of linear time-varying equations equivalent to the original nonlinear problem and a self-tuning control method so that the controller is designed at each time point on the interval for trajectory tracking and heading angle control. This work makes use of self-tuning minimum variance principles. The benefit of this approach is that the nonlinearities and couplings of the system are preserved, unlike in the cases of control design based on linearized systems, reducing in this manner the uncertainty in the model and increasing the robustness of the controller. The simulations here presented use a torpedo-shaped underwater vehicle model and show the good performance of the controller and accurate tracking for certain maneuvering cases.

Tracking moving mesoscale eddies with underwater gliders under autonomous prediction and control

A heading angle control method is proposed for controlling underwater gliders to follow a straight line sampling path relative to the center of a dynamically moving mesoscale eddy. The constant velocity and constant acceleration kinematic models are employed as motion models of eddy center movements. The model parameters are identified from historical data of eddy tracks. A Kalman filter is developed based on the models and real-time satellite imaging data to estimate and predict the movement of eddy centers. Performance of the two modeling approaches are compared based on historical data, results show that the constant velocity model is preferred for eddy movement prediction when used for glider heading control. Both simulation and field experiments confirm that underwater gliders under the heading control, when used with the Kalman filter, are able to follow the sampling path autonomously with acceptable level of tracking error.

Lane Departure Assistance Coordinated Control System for In-Wheel Motor Drive Vehicles Based on Dynamic Extension Boundary Decision

Aiming at the advantages in active safety control of in-wheel motor drive vehicles, the classified decision-control-execution is proposed to the lane departure assistance system under the premise of ensuring the stability of the vehicle. The dynamic extension boundaries which vary with vehicle speed, road curvature and road adhesion coefficient are designed in the decision layer by using the neural network algorithm, which divides different dangerous degrees into different decision regions. The active differential steering controller, the electronic differential controller and their coordinated control strategy are designed in the control layer, and the corresponding control is carried out among different decision regions. In order to avoid the dangerous situation of secondary deviation caused by the existence of drift angle when the vehicle is rectified to the lane centerline, the heading angle controller is then designed in the control layer. The different torque distribution modes are divided according to the current vehicle speed, road adhesion coefficient and lateral acceleration in the execution layer, and the economic distribution, stability distribution, joint distribution are correspondingly executed among different torque distribution modes. Finally, Carsim and Matlab/Simulink are used for simulation verification.

Autopilot Design for an Autonomous Sailboat Based on Sliding Mode Control

This paper deals with the design of an autopilot based on sliding mode control combined with feedback linearization method for an autonomous sailing vessel. This autopilot is developed using a model with four degrees of freedom, which represents the dynamic of a sailboat. Due to the high nonlinearity of the developed dynamic model, heading and sail opening angle controller were developed to steer the sailboat toward a specific target position. The nonlinear four degrees of freedom dynamic model for the sailing vessel is first described. Then, an autopilot is designed using both sliding mode control and feedback linearization method. Finally, some simulations are carried out to illustrate the behavior of the overall system.

Hybrid Locomotion Evaluation for a Novel Amphibious Spherical Robot

We describe the novel, multiply gaited, vectored water-jet, hybrid locomotion-capable, amphibious spherical robot III (termed ASR-III) featuring a wheel-legged, water-jet composite driving system incorporating a lifting and supporting wheel mechanism (LSWM) and mechanical legs with a water-jet thruster. The LSWM allows the ASR-III to support the body and slide flexibly on smooth (flat) terrain. The composite driving system facilitates two on-land locomotion modes (sliding and walking) and underwater locomotion mode with vectored thrusters, improving adaptability to the amphibious environment. Sliding locomotion improves the stability and maneuverability of ASR-III on smooth flat terrain, whereas walking locomotion allows ASR-III to conquer rough terrain. We used both forward and reverse kinematic models to evaluate the walking and sliding gait efficiency. The robot can also realize underwater locomotion with four vectored water-jet thrusters, and is capable of forward motion, heading angle control and depth control. We evaluated LSWM efficiency and the sliding velocities associated with varying extensions of the LSWM. To explore gait stability and mobility, we performed on-land experiments on smooth flat terrain to define the optimal stride length and frequency. We also evaluated the efficacy of waypoint tracking when the sliding gait was employed, using a closed-loop proportional-integral-derivative (PID) control mechanism. Moreover, experiments of forward locomotion, heading angle control and depth control were conducted to verify the underwater performance of ASR-III. Comparison of the previous robot and ASR-III demonstrated the ASR-III had better amphibious motion performance.

Target Tracking Based on a Nonsingular Fast Terminal Sliding Mode Guidance Law by Fixed-Wing UAV

This paper proposes a modified nonsingular fast terminal sliding mode (NFTSM) guidance law to solve the problem of ground moving target tracking for fixed-wing unmanned aerial vehicle (UAV) in a planar environment. Firstly, the loitering algorithm is analysed, which can steer the UAV to follow and circle around a ground moving target with the desired distance by heading angle control. Secondly, the effects of different parameters on the convergence time of sliding manifold is presented which is helpful for the designing of sliding manifold. Singularity can be avoided by using a modified saturation function which is obtained through a small range around the null point. Moreover, the NFTSM sliding manifold is used in the loitering algorithm. By using the Lyapunov theory, the finite-time convergence of the proposed method has been proved in the the reaching phase and the sliding phase. In order to verify the approach’s feasibility and benefits, numerical simulations are performed by using a moving target with three different motion states in comparison with the conventional sliding model control method. Simulation results indicate that, under the proposed NFTSM guidance law, the UAV can reach the desired distance in a short time.

Autonomous Landing Control of Fixed-wing UAVs: from Theory to Field Experiment

This paper describes our work on autonomous landing control of fixed-wing unmanned aerial vehicles (UAVs). A hierarchical control structure is developed for autonomous landing of fixed-wing UAVs. In the hierarchical control structure, active disturbance rejection controllers are designed for attitude control. A proportional guidance law is proposed for height tracking. Other controllers, such as flight path angle controller, heading angle controller and taxiing controller, are designed using proportion integration differentiation technique. A test system is developed to validate the hierarchical structure and narrow the gap between the theory and practice. The test system includes an X-Plane based hardware-in-the-loop(HIL) simulation subsystem and a flight test subsystem. The interface and protocol between the autopilot and X-plane are designed same with that of the flight test platform. Consequently, the autopilot passed the validation in the HIL simulation can be directly moved on to the flight test platform. Finally, results of the HIL simulation and field experiment are presented to demonstrate the performance of the proposed approach and the entire test system.

Evaluation of the transient response and implementation of a heading-angle controller for an autonomous ground vehicle

In this paper, a dynamic mathematical model of an autonomous ground vehicle was used to analyse its transient response and to design a heading-angle controller for the vehicle. A suitable ‘control-oriented model’ that could accurately characterize the phenomenon of interest was used to design the controller. The efficacy of this model was evaluated by corroborating its results with experimental data. This model included the cornering stiffness of the tyres as an unknown parameter, and two approaches were attempted to estimate its value. The dynamics of the actuator were included in the analysis since the response time to steer the front wheel is of the same order as that of the heading-angle dynamics of the vehicle. The performance of two controllers (namely a classical transfer-function-based controller and an optimal linear quadratic regulator) were evaluated using the IPG: CarMaker® simulation platform over a range of speeds. The transfer-function-based controller was also implemented on the experimental test vehicle at low speeds (high-speed experimental implementation was not possible because of safety concerns). It was found that control gain scheduling helped to track the desired heading angles of the vehicle at various speeds. Subsequently, a lane-change manoeuvre using the test vehicle was performed to evaluate the controller further. It was found that the transfer-function-based heading-angle controller could provide a comparable performance with that of the linear quadratic regulator, while keeping the sensing requirements to a minimum; thus, it was suitable for real-time implementation in an autonomous ground vehicle.

Design and development of a heading angle controller for an unmanned ground vehicle

This paper describes the design and implementation of a controller to track the desired heading angle for an unmanned ground vehicle (UGV) considering the limits on rotation of steering wheel and steering motor rate. The well-known “bicycle model” approximation, that considers the vehicle slip angle and ground-wheel interaction, has been used. In this work, combined closed loop control for steering motor and heading angle of the vehicle has been considered for better accuracy. The challenge in designing this control system is to include the actuator dynamics as the response time to steer the front wheel is in the same order as that of the heading angle dynamics of the vehicle. Experiments have been conducted, analysis of data collected is presented and the resulting mathematical representation is explained in detail. Results from both simulation and experimental implementation are also compared. It has been found that the vehicle controller can be tuned effectively to achieve the desired heading angle changes up to twenty degrees within three seconds when the vehicle is moving at a speed of 1.4 m/sec.

A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins

This study aims to develop a waypoint-tracking control system for a biomimetic underwater vehicle (BUV). The BUV is propelled by wide paired pectoral foils, and each pectoral foil is driven by three independent fin rays. To simplify the control strategy, the maximum flapping amplitude of the pectoral fin is used to control the forward velocity, and a turning factor is defined for the manoeuvre control. Several swimming experiments are carried out to investigate the influence of the control parameters on the swimming performance of the prototype. Based on the results of the swimming experiments, a waypoint-tracking control system is proposed, which contains two layers: the velocity control layer and the heading angle control layer. A subdivision control method is adopted by the velocity control layer to get the maximum flapping amplitude. The fuzzy control method is employed by the heading angle control layer to obtain the turning factor for steering motion. Several waypoint-tracking experiments are carried out to verify effectiveness of the control system. The results show that the prototype can automatically reach the target area with the designed control system, even though the waypoints are arranged or randomly given.

Design, Implementation and Navigation Test of Manta-type Unmanned Underwater Vehicle

This paper describes the mathematical modeling, control algorithm, system design, hardware implementation and experimental test of a Manta-type Unmanned Underwater Vehicle (MUUV). The vehicle has one thruster for longitudinal propulsion, one rudder for heading angle control and two elevators for depth control. It is equipped with a pressure sensor for measuring water depth and Doppler Velocity Log for measuring position and angle. The vehicle is controlled by an on-board PC, which runs with the Windows XP operating system. The dynamic model of 6DOF is derived including the hydrodynamic forces and moments acting on the vehicle, while the hydrodynamic coefficients related to the forces and moments are obtained from experiments or estimated numerically. We also utilized the values obtained from PMM (Planar Motion Mechanism) tests found in the previous publications for numerical simulations. Various controllers such as PID, Sliding mode, Fuzzy and H∞ are designed for depth and heading angle control in order to compare the performance of each controller based on simulation. In addition, experimental tests are carried out in a towing tank for depth keeping and heading angle tracking.

A path tracking control algorithm for underwater mining vehicles

In this paper, a path tracking control algorithm is formulated for the use of tracked underwater mining vehicles. The algorithm consists of two parts, the forward velocity control and the heading angle control. The control algorithm is designed based on kinematics, and it considers the track slips and the longitudinal and yaw dynamic models of the tracked vehicle including the soil-track interaction force model. The desired heading angle is obtained by the so-called “Line of Sight” method. The suggested algorithm is tested by numerical simulations using the TRACSIM software developed by MOERO/KORDI, Korea. After the control gains are tuned by a series of numerical simulations, the algorithm is verified on a scale vehicle on air on a soil bin test bed containing the cohesive soil of the Bentonite-water mixture.