Guidance Principle Research Articles

A model-based kinematic guidance method for control of underactuated autonomous underwater vehicles

In this work, a novel guidance principle for underactuated autonomous underwater vehicles is introduced. This new method relies on the kinematic coupling between non-actuated and actuated degrees of freedom. It uses a newly introduced matrix called the Handy Matrix denoted H. The method allows reassigning unused degrees of freedom of the task to useful non-actuated DOF. The algorithm and design rules leading to the construction of H are also provided. Two different solutions based on matrix H are compared on a standard seabed scanning task.

Rational design of MXene-based vacancy-confined single-atom catalyst for efficient oxygen evolution reaction

Two-dimensional transition metal carbides (MXenes) have been demonstrated to be promising supports for single-atom catalysts (SACs) to enable efficient oxygen evolution reaction (OER). However, the rational design of MXene-based SACs depends on an experimental trial-and-error approach. A theoretical guidance principle is highly expected for the efficient evaluation of MXene-based SACs. Herein, high-throughput screening was performed through first-principles calculations and machine learning techniques. Ti3C2(OH)x, V3C2(OH)x, Zr3C2(OH)x, Nb3C2(OH)x, Hf3C2(OH)x, Ta3C2(OH)x, and W3C2(OH)x were screened out based on their excellent stability. Zn, Pd, Ag, Cd, Au, and Hg were proposed to be promising single atoms anchored in MXenes based on cohesive energy analysis. Hf3C2(OH)x with a Pd single atom delivers a theoretical overpotential of 81 mV. Both moderate electron-deficient state and high covalency of metal–carbon bonds were critical features for the high OER reactivity. This principle is expected to be a promising approach to the rational design of OER catalysts for metal-air batteries, fuel cells, and other OER-based energy storage devices.

A Ship Path Tracking Control Method Using a Fuzzy Control Integrated Line-of-Sight Guidance Law

A fuzzy control improvement method is proposed with an integral line-of-sight (ILOS) guidance principle to meet the needs of autonomous navigation and high-precision control of ship trajectories. Firstly, a three-degree-of-freedom ship motion model was established with the battery-powered container ship ZYHY LVSHUI 01 built by the COSCO Shipping Group. Secondly, a ship path-following controller based on the ILOS algorithm was designed. To satisfy the time-varying demand of the look-ahead distance parameters during the following process, especially under different navigation conditions, fuzzy logic controllers were designed for different navigation conditions to automatically adjust the look-ahead distance parameters. Thirdly, a controller was applied that uses a five-state extended Kalman filter (EKF) to estimate the heading, speed, and heading rate based on the ship’s motion model with the assistance of Global Navigation Satellite System (GNSS) position measurements. This provides the necessary navigational information, reduces the algorithm’s dependence on sensors, and improves its generalizability. Finally, path-following experiments were carried out in the MATLAB experimental platform, and the results were compared with different following algorithms. The simulation results showed that the new algorithm has a better following performance, and it can maintain a smooth rudder angle output. The research results provide a reference for the path-following control of ships.

LPVS guidance and adaptive event-triggered control for an underactuated surface vessel with the prevention of obstacle’s vicious maneuvering

This paper investigates the adaptive neural event-triggered control for an underactuated surface vessel (USV), considering constraints of the obstacle’s vicious maneuvering and the limited communication channel. In the algorithm, a novel logical phantom virtual ship (LPVS) guidance principle is developed to generate the global path following reference and the obstacle avoidance order in the simulation results, where the corresponding operation comply to the suggestion in international regulations for prevention collision at sea (COLREGs). The improved design of velocity obstacle (VO) method can guarantee its predictive capability to prevent the obstacle’s vicious maneuvering. As for the control module, the adaptive event-triggered control algorithm is proposed by employing the robust neural damping technique and the input event-triggered mechanism. And the derived adaptive law can effectively solve perturbations from the gain uncertainty and the external disturbances. Through the theoretical analysis, all signals of the closed-loop control system are with the semi-globally uniform ultimate bounded (SGUUB) stability. The simulation experiments have been presented to verify the obstacle avoidance effectiveness and the burden-some superiority of the algorithm.

Finite-time adaptive event-triggered control for USV with COLREGS-compliant collision avoidance mechanism

This paper focuses on the real time intelligent navigation scheme for unmanned surface vehicle (USV) subject to collision avoidance regulations. The proposed approach is formulated as two segments: the real time guidance principle with COLREGS-compliant collision avoidance mechanism and the finite-time adaptive event-triggered control algorithm. The pointed improvement for the artificial potential field (APF) can guarantee USV possess the excellent avoidance function in accordance with COLREGS regulations. Especially, when the obstacle makes dangerous actions, the emergency obstacle avoidance operation (EOAO) is implemented according to the real time position of obstacles. Based on the proposed guidance principle, a finite-time robust neural control algorithm is developed by fusion of the finite-time stability theory and event-triggered mechanism. The intermittent computing and communication can effectively reduce the energy and resource consumption of the control system. Moreover, the finite-time adaptive controller design contributes to smaller computation load and facilitates the implementation of the algorithm in ocean engineering. The semi global finite-time uniformly boundedness (SGFTUB) of the closed-loop system is guaranteed through the Lyapunov theory. Finally, the numerical simulation and comparison experiment are illustrated to verify the guidance and control performance of the proposed algorithm.

Intervehicle Security-Based Robust Neural Formation Control for Multiple USVs via APS Guidance

This paper focuses on the intervehicle security-based robust formation control of unmanned surface vehicles (USVs) to implement the formation switch mission. In the scheme, a novel adaptive potential ship (APS)-based guidance principle is developed to prevent intervehicle collisions, which is common and threatening when maneuvering a formation switch. By employing the artificial potential field (APF), the APS can program the real-time attitude reference for USVs by using the security intervehicle distance while achieving the path-following task. As for the control part, a robust adaptive formation control algorithm is proposed to effectively stabilize the USVs to the APS via the fusion of the disturbance observer (DOB) and by using the robust neural damping technique. Regarding the merits of the improved design of the DOB, the weight compression of the neural networks can effectively simplify the structure of the DOB and enhance the observation accuracy of the external disturbance. This can facilitate the avoidance of intervehicle collisions and guarantee the application of the theoretical algorithm in engineering practice. Considerable effort has been made to obtain the semiglobally uniform ultimate bounded (SGUUB) stability via theoretical analysis. Finally, with the sailing scene in a narrow channel, the simulated experiment is illustrated to verify the security performance of the proposed strategy.

Research on Angular Motion Characteristics and Stability of Trajectory‐Corrected Rocket Projectile with Isolated Rotating Tail Rudder

A trajectory‐corrected rocket projectile with an isolated rotating tail rudder provides a new concept for a low‐cost trajectory correction and guidance due to its simplified guidance principle. To study the angular motion characteristics of a trajectory‐corrected rocket projectile with an isolated rotating tail rudder under the action of a periodic control force, the angular motion differential equation described in the complex plane is derived based on the rigid body trajectory equation. Furthermore, the effects of the initial conditions, gravity, and an asymmetric tail on the flight stability of the projectile in an uncorrected trajectory state are studied. The critical rotational speed of the tail rudder, which makes the projectile unstable due to the Magnus moment, and the rotational speed of the tail rudder, which causes projectile resonance, are derived. The transient and steady‐state solutions of the angular motion of the projectile under trajectory correction and the variation law of the velocity direction for the projectile centroid are obtained. Finally, an example is given to verify the conclusions of this study. This research has important guiding significance for trajectory analysis, guidance control, and guidance law designs for isolated rotating rudder trajectory‐corrected rocket projectiles.

Design and Analysis of Guidance Function of Permanent Magnet Electrodynamic Suspension

Inspired by the guidance principle in the electromagnetic levitation system, a new permanent magnet electrodynamic suspension (PM EDS) structure with ferromagnetic guidance track is proposed and analyzed in this paper. Considering the lack of effective guidance ability for the PM EDS system, we adopted the ferromagnetic guidance track as being mounted under the conductor plate. The guidance principle is studied and the implementation of the guidance function is also introduced, and the finite element method (FEM) is employed and its accuracy is confirmed via the PM EDS high-speed rotating experimental platform fabricated in our laboratory. The influence of longitudinal speed on the guidance force is taken into account, which shows that the guidance performance is enhanced more obviously at low speeds. Moreover, the influence of the guidance track parameters on the guidance performance is also analyzed, including the geometric parameters, section shape, installation position and material. The equivalent small-scale PM EDS system experimental prototype is carried out to validate the effectiveness of the ferromagnetic guidance. The proposed ferromagnetic guidance structure is demonstrated to improve the guidance performance of the PM EDS system effectively, which will offer a technical reference for the practical engineering application of the PM EDS system.

Event-Triggered Cooperative Formation Control for Autonomous Surface Vehicles Under the Maritime Search Operation

To improve the autonomy of maritime search and rescue (SAR) operation, this paper concentrates on the formation control problem for autonomous surface vehicles (ASVs) with the limited communication resource. A novel parallel search guidance, considering the maneuvering characteristics of ASVs, is developed to guide the formation to execute the automatic SAR operation. That can guarantee that the corresponding guidance law is highly efficient, self-driving and suitable for the large-scale formation. Combined with the guidance principle, a formation control algorithm is proposed by fuse of the event-triggered control and neural networks (NNs). In the proposed scheme, the gain uncertainty of actuators is effectively compensated requiring no prior information around the model structure. Unlike the existing results, the proposed event-triggered mechanism can activate synchronously both the controller and the NNs weight estimator. Considerable effort has been made to guarantee the semi-global uniform ultimate bounded (SGUUB) stability. Finally, two examples are illustrated to verify the effectiveness of the algorithm.

Finite time PAILOS based path following control of underactuated marine surface vessel with input saturation

In this article, the line-of-sight (LOS)-based on the control principle of path following is presented to apply to a marine surface vessel (MSV) with an unknown time-varying sideslip angle. The input saturation and the uncertain model are taken into account. The presented finite-time predictor-based adaptive integral line-of-sight (FPAILOS) guidance principle can estimate the unknown time-varying sideslip angle while compensating for the drift force. The FPAILOS guidance law offers the desired yaw angle. The drift force can be caused by the ocean currents, which are taken into account in the kinematic model for the MSV. For the input saturation problem, we select the finite-time auxiliary system to limit inputs. Designing path following control signals adopts the finite-time dynamic surface control (FDSC) method. The finite-time low-frequency learning-based fuzzy system is designed to solve the uncertain model problem for the MSV. Finally, the stability of the system is demonstrated and numerical simulations are performed, where the objective is to evaluate the proposed theoretical results. With the presented control strategy, the track errors can converge into arbitrary small neighborhoods around zero in finite time.

Is it Reasonable to Demand Reasons in Pediatric Decision-Making?

In 1989, Allen Buchanan and Dan Brock published their groundbreaking work on surrogate decision-making entitled: Deciding for Others: The Ethics of Surrogate Decision Making in which they developed a decision making framework that could apply to adults and children. 1 Buchanan A.E. Brock D.W. Deciding for others: the ethics of surrogate decision making. Cambridge University Press, New York1990 Crossref Google Scholar It entailed 4 principles: (1) underlying ethical values, (2) authority principle, (3) guidance principle, and (4) intervention principle. Whereas the underlying ethical values in adult decision-making are self-determination and well-being, in pediatrics they placed greater priority on well-being followed by self-determination and then added a third value—parental interests—because they understood that parents are not fiduciaries who always act in their child’s best interest, but must balance the child’s needs and interests with the needs and interests of other family members (including themselves). 2 Ross L.F. Children, families and health care decision making. Oxford University Press, Oxford UK1996 Google Scholar In fact, for each principle, Buchanan and Brock distinguished how the framework applied for adults vs pediatrics. Whereas adults could choose who would speak for them (authority principle), parents were presumed the decision-makers for their children. Surrogate decision-makers for adults were supposed to act (guidance principle) following the patient’s preferences (living will or advance directive) when available. If not, the surrogate was supposed to act according to the principle of substituted judgment, as if the surrogate were to walk in the other person’s shoes. If those preferences were not known, they were to make a best interest determination. In contrast, in pediatrics, the only guidance principle was to act in the child’s best interest, although Buchanan and Brock quickly stated that this was only “a regulative ideal.” The only principle in which Buchanan and Brock did not distinguish between adults and minors was when the state should intervene. They limited the intervention principle to 3 types of cases: (1) conditions that disqualify the family, (2) certain classes of cases deserving special scrutiny, and (3) decisions outside the range of medically sound alternatives. 1 Buchanan A.E. Brock D.W. Deciding for others: the ethics of surrogate decision making. Cambridge University Press, New York1990 Crossref Google Scholar

Practical multiport event-triggered control for ASV via the intervened LVS guidance

A crucial and challenging issue in path following control of the autonomous surface vehicle (ASV) is input constraint and communication burden. In this paper, an intervened logic virtual ship (ILVS) guidance is developed to generate the reference signal, and further to tackle the input saturation constraint by employing the dynamic feedback evaluation rule. The main superiority of this design is to intervene the logic virtual ship (LVS) guidance principle to avoid the persistent large stabilization error. Associated with ILVS guidance framework, a robust adaptive neural event-triggered algorithm is proposed for the ASV by fusing the adaptive technique and the multiport event-triggered approach. The constrains of the model nonlinear term and the uncertain actuators gain are released by constructing online learning parameters. Furthermore, the channel resource from the sensor to the controller (SC) as well as the controller to the actuator (CA) is reduced for merits of the multiport event-triggered approach. The feedback error signals and the control inputs will be updated while the triggered condition is occurred. That also can eliminate the low frequency disturbance, caused by marine environment, to improve the robustness of the closed-loop system. Through the Lyapunov stability criterion, all state variables in the triggered point and triggered interval are achieved semi-global uniform ultimate bounded (SGUUB) stability. Finally, the control performance of the proposed method is evaluated on simulation platform, showing the satisfied tracking accuracy with the low transmission load.

APF-based intelligent navigation approach for USV in presence of mixed potential directions: Guidance and control design

This paper investigates the real-time intelligent navigation approach for unmanned surface vehicle (USV), considering constraints of the randomly moving target and multiple static or moving obstacles. In the scheme, an intelligent guidance principle is developed by employing the traditional dynamic virtual ship (DVS) structure and the artificial potential field (APF) technique. The improved design for repulsive potential field can guarantee the reasonable obstacle avoidance capability. Especially, the amended repulsive terms are derived by the velocity and orientation factors of moving obstacles. Combining with the APF-based guidance, the robust neural path following control algorithm is proposed by employing the minimal learning parameter (MLP) and the nonlinear disturbance observer (DOB) technique. For merit of the improved design of DOB, the attitude of USV can be effectively stabilized to that of virtual ship. That can derive the state-of-art trade-off between the complicated control law and the hardware computing burden. Through the Lyapunov synthesis, all states of USV are with the semi-globally uniform ultimate bounded (SGUUB) stability. Two experiments have been illustrated to verify the obstacle avoidance and dynamic tracking performance of the proposed strategy.

ZOH-based composite neural event-triggered control of underactuated cable-laying vehicle in presence of varying depth

To achieve the autonomous cable-laying operation under the varying depth, this note investigates the path-following problem of underactuated cable-laying vehicles with constraints of the unknown actuator gain. A double-stage logical (DSL) guidance principle is developed to realize the practical laying path programming for the cable-laying vehicle. In the guidance law, the catenary model is incorporated to derive the towing distance, i.e., the horizontal projection distance between the cable landing point and the vehicle’s gravity center. That can guarantee the cable-laying operation is solidly implemented in the condition of the varying depth. As for the control part, the composite neural event-triggered control algorithm is proposed by fusing the zero-order holder (ZOH) to stabilize the track error between the target position and the actual one. The event-triggered mechanism is employed to effectively reduce the occupancy of the communication channel between sensors and controllers. Moreover, for the merits of robust neural damping and composite learning techniques, the gain uncertainty of actuators can be compensated by updating two adaptive laws online. The stability analysis of the closed-loop system is rigorously performed via Lyapunov criterion and simulation results are provided to verify the performance of the proposed scheme.

Robust Composite Dynamic Event-Triggered Control for Multiple USVs with DLLOS Guidance

In this paper, a robust composite dynamic event-triggered formation control scheme is proposed for multiple underactuated surface vehicles (USVs) from two aspects, i.e., guidance and control. In the guidance module, a novel dual-layer line-of-sight (DLLOS) guidance principle is incorporated into the leader–follower framework to generate the reference path. To overcome the problem of unavailable leader velocity information, an adaptive speed controller is designed to adjust the navigational speed of followers. As for the control part, by utilizing the dynamic event-triggered method, the operational frequency of actuators can be reduced in a flexible manner. That can effectively avoid the excessive wear and chattering phenomenon of actuators. Furthermore, by the fusing of the radial basis function neural networks (RBF NNs) and the robust neural damping technique, the model uncertainty, environmental disturbances and some unknown parameters can be remodeled, and only two gain-related adaptive laws need to be updated online. The serial–parallel estimation model (SPEM) is established to predict the velocity variables, and the approximation performance of NNs can be enhanced by virtue of the derived prediction error. Through the Lyapunov stable theorem, all control signals in the closed-loop system are guaranteed semi-globally uniformly ultimately bounded (SGUUB) stability. Finally, digital simulations are illustrated to verify the effectiveness and superiority of the proposed algorithm.

Robust Adaptive Neural Cooperative Control for the USV-UAV Based on the LVS-LVA Guidance Principle

Around the cooperative path-following control for the underactuated surface vessel (USV) and the unmanned aerial vehicle (UAV), a logic virtual ship-logic virtual aircraft (LVS-LVA) guidance principle is developed to generate the reference heading signals for the USV-UAV system by using the “virtual ship” and the “virtual aircraft”, which is critical to establish an effective correlation between the USV and the UAV. Taking the steerable variables (the main engine speed and the rudder angle of the USV, and the rotor angular velocities of the UAV) as the control input, a robust adaptive neural cooperative control algorithm was designed by employing the dynamic surface control (DSC), radial basic function neural networks (RBF-NNs) and the event-triggered technique. In the proposed algorithm, the reference roll angle and pitch angle for the UAV can be calculated from the position control loop by virtue of the nonlinear decouple technique. In addition, the system uncertainties were approximated through the RBF-NNs and the transmission burden from the controller to the actuators was reduced for merits of the event-triggered technique. Thus, the derived control law is superior in terms of the concise form, low transmission burden and robustness. Furthermore, the tracking errors of the USV-UAV cooperative control system can converge to a small compact set through adjusting the designed control parameters appropriately, and it can be also guaranteed that all the signals are the semi-global uniformly ultimately bounded (SGUUB). Finally, the effectiveness of the proposed algorithm has been verified via numerical simulations in the presence of the time-varying disturbances.

Data-driven model identification and predictive control for path-following of underactuated ships with unknown dynamics

With the trends towards autonomous shipping, advanced ship motion control methods have received increased attention in recent years. The validity of ship models is crucial in designing motion controllers and directly affects their performances. However, accurate models that could reflect true ship dynamics are highly nonlinear, complex and complicated to identify, especially in situations when the experimental conditions are limited. This paper proposes a data-driven predictive control method for path-following of under-actuated cargo ships with unknown dynamics, which makes use of data gathered during operation to improve the model and the path-following performance. Based on the ship navigation data set, the relations between the heading angle and the rudder angle of the ship are fitted with seven typical regression algorithms, which acts as the prediction model in the path-following controller. Simulation study is carried out to choose the most suitable regression algorithm, among which elastic net regression is selected. The Antenna Mutation Beetle Swarm Predictive (AMBS-P) algorithm is introduced to find the optimal weights in the model identification process. A Line-of-Sight (LOS) algorithm is used as the guidance law to transform reference way-points into reference heading angles, and the path-following controller is designed also based on and the AMBS-P algorithm. Simulation results show that the proposed data-driven control method performs well in the path-following task without having prior knowledge regarding the hydrodynamic coefficients and ship parameters. • The proposed data-driven control strategy allows the users to exploit the advantage of the predictive control scheme, as well as exploiting the approximate model knowledge captured from data without having prior knowledge regarding the hydrodynamic coefficients and ship parameters. • A quantitative analysis of the model identification performances of seven typical regression algorithms is carried out. • The Antenna Mutation Beetle Swarm Predictive (AMBS-P) algorithm is proposed and applied in finding the optimal weights in the model identification process and in designing the path-following controller with a LOS guidance principle. This could save the efforts spend in weight selection and controller parameter adjustments. It is also fast and easy to implement, which could facilitate its use in practice.

LVS guidance principle and adaptive neural fault-tolerant formation control for underactuated vehicles with the event-triggered input

This paper presents a novel adaptive neural event-triggered formation control strategy for underactuated surface vehicles (USVs) in the presence of marine practical constraints, i.e. the waypoints-based planned path and actuator failures. The proposed strategy is composed of the guidance model and the control one. For the guidance part, the logic virtual ship (LVS) guidance principle is developed to implement the reference path programming for the formation pattern. For merit of the adaptive virtual ship, the smooth reference can be produced for followers without using the velocity information of leader. Furthermore, the proposed adaptive neural fault-tolerant control algorithm is to guarantee that the followers can maintain their pattern and converge to the corresponding reference path. In the algorithm, the neural networks (NNs)-based observer is designed to estimate the unmeasurable velocities of followers online. With the input event-triggered mechanism, two adaptive parameters are derived to compensate for the gain uncertainty and actuator failure. And that could effectively reduce the communication burden for the channel from controller to actuator. The derived closed-loop system has been proved to be with the semi-global uniform ultimate bounded (SGUUB) stability. Finally, the superiority of the proposed strategy can be verified by the simulation experiments.

Studying sporty positive behavior for Iraqi universities teams players in some sports

The present study aims at: Building a standard of sporty positive behavior for the teams players of Iraqi universities in some sports.(volleyball- footb fences) Knowing the standard of sporty positive behavior study for the players of Iraqi universities teams in some sports. (volleyball-futsal) imbose of the Research: eamt is a good level of positive behavior for the teams players of Iraqi universities in some sports. (volleyball- futsal) Researchers used descriptive method in scanning style for the suitability the nature of research, the research contains teams players of Iraqi universities in some sports(volleyball- footb fences ( 889 players ), but the sample of the research contains ( 433 players ) who represent teams players of the Iraqi universities in some sports(volleyball- footb fences . Researchers ued the following statistic procedures: To get results in the present research, researchers used the statistic model ( spss ) and ( Excel ) spreadsheet to get the ( percentages and chi square ) and Mean , Median and ( T ) test for one sample and Pearson Correlation Coefficient , Spearman- brown equation , and Cronbach's Alpha Correlation Coefficient. The results are : Building a scale for the sport positive behavior which consists of ( 42 ) points and contains ( 5 ) basic cores. Teams players of Iraqi universities in some sports(volleyball- futsal) can have very good degree in sporty positive behavior. According to the results, the two researchers made the following results: effectineness of standard sporty positive behavior which was built by the researchers to apply on the teams players of Iraqi universities in some sports, and its ability to recognize between players through axes which are relied by the researchers in the present research. Teams players of Iraqi universities in choral games can have a very good degree in positive behavior. Recommendations made by the two researchers based on the research results Making use of the sporty positive behavior scale in order to make comparisons between other mass sports. Making similar studies on different sporty activities. Using direction and guidance principle which plays important role to sustain the positive behavior in individuals. Requesting social institutions including the university to immerse moral values and positive behaviors in students.

COLREGs-Constrained Adaptive Fuzzy Event-Triggered Control for Underactuated Surface Vessels With the Actuator Failures

This article investigates the adaptive fuzzy event-triggered control for the underactuated surface vessels (USVs), considering constraints of the International Regulations for Preventing Collisions at Sea (COLREGs) and the actuator failures. The proposed scheme can be divided into the guidance module and the control module. An improved logic virtual ship guidance principle, considering the ship-to-ship collision avoidance, is developed to generate the real-time reference signal for USVs. The main characteristic of the guidance principle is to ensure USVs sailing in the path following mode and collision avoidance mode. Especially for the collision avoidance mode, the collision avoidance guidance is targetedly designed for three sailing situations (the head-on situation, the overtaking situation, and the crossing situation), which is consistent with the COLREGs. Furthermore, an adaptive fuzzy event-triggered law is designed to control the USVs to converge to the desired path. The model unknown terms and the basic fault of the actuator are identified by the fuzzy logic system, and the fuzzy logic state observer is designed to estimate the unmeasured states of the USVs. Unlike the existing results, the communication burden from the controller to the actuators is reduced for the merits of the input event-triggered rule. Through the Lyapunov theory, it is proved that all the signals of the closed-loop control system are the semiglobal uniform ultimate bounded. Finally, the simulated examples are provided to illustrate the validity of the proposed control approach.