Guidance Problem Research Articles

CACLA-Based Trajectory Tracking Guidance for RLV in Terminal Area Energy Management Phase.

This paper focuses on the trajectory tracking guidance problem for the Terminal Area Energy Management (TAEM) phase of the Reusable Launch Vehicle (RLV). Considering the continuous state and action space of this guidance problem, the Continuous Actor–Critic Learning Automata (CACLA) is applied to construct the guidance strategy of RLV. Two three-layer neuron networks are used to model the critic and actor of CACLA, respectively. The weight vectors of the critic are updated by the model-free Temporal Difference (TD) learning algorithm, which is improved by eligibility trace and momentum factor. The weight vectors of the actor are updated based on the sign of TD error, and a Gauss exploration is carried out in the actor. Finally, a Monte Carlo simulation and a comparison simulation are performed to show the effectiveness of the CACLA-based guidance strategy.

A Study of Educational Problem and Need of Guidance in Graduate Students

Aims of this paper to find out the Education Problems and Need of Guidance in graduate students. Here 2 x 3 factorial designs were used. In this study total 120 (60 boys and 60 girls) were randomly selected from Surat city (Gujarat, India). Out of 60 (20 first birth order, 20 second birth order and 20 third birth order) graduate students selected. Education Problems scale created by Prof. Beena Shah and Dr. S. K. Lakhera and Need of Guidance scale created by Dr. J. S. Grewal was used to collect the required data, F- test and correlation method was used for analysis of data. The Result of the study evaluated that there is no significance difference in gender variable on Education Problems and Need of Guidance in graduate students. Also there is no significance difference in birth order variable on Education Problems and Need of Guidance in graduate students. Education problems and need of guidance found 0.09 positive correlation.

PSO-Based Soft Lunar Landing with Hazard Avoidance: Analysis and Experimentation

The problem of real-time optimal guidance is extremely important for successful autonomous missions. In this paper, the last phases of autonomous lunar landing trajectories are addressed. The proposed guidance is based on the Particle Swarm Optimization, and the differential flatness approach, which is a subclass of the inverse dynamics technique. The trajectory is approximated by polynomials and the control policy is obtained in an analytical closed form solution, where boundary and dynamical constraints are a priori satisfied. Although this procedure leads to sub-optimal solutions, it results in beng fast and thus potentially suitable to be used for real-time purposes. Moreover, the presence of craters on the lunar terrain is considered; therefore, hazard detection and avoidance are also carried out. The proposed guidance is tested by Monte Carlo simulations to evaluate its performances and a robust procedure, made up of safe additional maneuvers, is introduced to counteract optimization failures and achieve soft landing. Finally, the whole procedure is tested through an experimental facility, consisting of a robotic manipulator, equipped with a camera, and a simulated lunar terrain. The results show the efficiency and reliability of the proposed guidance and its possible use for real-time sub-optimal trajectory generation within laboratory applications.

Distributed observer-based cooperative guidance with appointed impact time and collision avoidance

The problem of cooperative guidance is considered with appointed impact time and collision avoidance for the leader-following flight vehicles, which consist of one leader with the target seeker and the other seeker-less followers. A fixed-time convergent guidance law is presented for the leader to achieve appointed impact time. To guarantee the simultaneous arrival of all the flight vehicles, a cooperative guidance law is proposed to make the follower-leader ranges keep proportional consensus with the range-to-go of leader. A distributed observer is put forward for the followers to estimate the range-to-go of leader. Moreover, the collision avoidance can be reliably fulfilled by the collaborative action of the direction-based and distance-based means.

Optimal Q-laws via reinforcement learning with guaranteed stability

Closed-loop feedback-driven control laws can be used to solve low-thrust many-revolution trajectory design and guidance problems with minimal computational cost. Lyapunov-based control laws offer the benefits of increased stability whilst their optimality can be increased by tuning their parameters. In this paper, a reinforcement learning framework is used to make the parameters of the Lyapunov-based Q-law state-dependent, increasing its optimality. The Jacobian of these state-dependent parameters is available analytically and, unlike in other optimisation approaches, can be used to enforce stability throughout the transfer. The results focus on GTO–GEO and LEO–GEO transfers in Keplerian dynamics, including the effects of eclipses. The impact of the network architecture on the behaviour is investigated for both time- and mass-optimal transfers. Robustness to navigation errors and thruster misalignment is demonstrated using Monte Carlo analyses. The resulting approach offers potential for on-board autonomous transfers and orbit reconfiguration.

Robust spline-line energy management guidance algorithm with multiple constraints and uncertainties for solid rocket ascending

For the solid rocket with depletion shutdown system, effective energy management is significant to meet terminal constraints by exhausting excess energy. Several traditional energy management algorithms cannot satisfy the altitude constraint and path constraints are not sufficiently considered. The velocity adjustment capability of these algorithms is limited and the uncertainties are not considered. Based on the on-line programming of velocity capability curve, Spline-Line Energy Management (SLEM) guidance algorithm is proposed. It introduces lateral maneuvers to further consume the available velocity on the basis of longitudinal energy management. After expressing the constraints as several algebraic equations, the closed-loop guidance problem is converted to solving a system of nonlinear equations about the curve parameters in real time. The advantage is that the altitude constraint can be satisfied theoretically. The overload and control variable change rate and amplitude constraints are also considered during the flight by constructing the feasible boundary of velocity capability curve. To improve the robustness, it is further extended by estimating the actual uncertainties. The effectiveness and advantages of SLEM are demonstrated by simulations and comparisons with other energy management algorithms. Simulation results show that the proposed approach can satisfy multiple constraints with high precision under the condition of uncertainties.

Distributed adaptive cooperative time-varying formation tracking guidance for multiple aerial vehicles system

Distributed adaptive cooperative time-varying formation tracking guidance problems of multiple aerial vehicles system against a maneuvering target are investigated. Different from the former results, the proposed cooperative guidance strategies are based on distributed time-varying formation tracking theories. Firstly, the leader aerial vehicle is designed to achieve interception with desired terminal attack angle, which provides a reference trajectory. The uncertain dynamic items and target's uncertain maneuver have been compensated. For the follower aerial vehicles, the distributed cooperative time-varying formation tracking guidance laws are raised. Adaptive distributed extended state observers are introduced to estimate the leader vehicle's states and input information. Then, an algorithm is shown for determining guidance parameters of cooperative guidance laws. Thirdly, the properties and the stabilities of the algorithm are discussed in detail. Finally, a simulation experiment is performed for showing the feasibility and effectiveness of achieved results.

Problematika Pelayanan Bimbingan Manasik Haji Sepanjang Tahun di Pusat Layanan Haji dan Umrah Terpadu kota Padang

This research describes information on various issues of Hajj Manasik Guidance activities throughout the year at the Integrated Hajj and Umrah Service Center (PLHUT) Padang City. This activity is an innovation from the Ministry of Religion of the Republic of Indonesia since 2019 which aims to meet the achievement of the objectives of organizing the Hajj, providing guidance, service and protection for pilgrims in accordance with sharia, as well as realizing independence and resilience in the implementation of the Hajj and Umrah pilgrimages. The Facts show that this new innovation creates some problems for PLHUT that require solutions. The research aims to find out the problems and solutions provided in dealing with the problem of guidance. This research is a field research with a descriptive qualitative approach. The data source is taken from the Head of the Hajj and Umrah Organizing Section of the Ministry of Religion of the city of Padang, implementing officers, supervisors and prospective pilgrims as well, by using purposive technique. The instruments that used are observation and interview. The results are as following : 1) The problems faced by PLHUT were budget issues, guidance materials, Jamaat do not have the maximum time to follow the guidance, the available time allocation and limited facilities. Presentation of guidance material and its schedule are less systematic and module are ineffective. 2) PLHUT provides a solution by increasing the guidance time in “Ramadan” every day, the committee will provide a schedule and guidance module.

Computational Missile Guidance: A Deep Reinforcement Learning Approach

This paper aims to examine the potential of using the emerging deep reinforcement learning techniques in missile guidance applications. To this end, a Markovian decision process that enables the application of reinforcement learning theory to solve the guidance problem is formulated. A heuristic way is used to shape a proper reward function that has tradeoff between guidance accuracy, energy consumption, and interception time. The state-of-the-art deep deterministic policy gradient algorithm is used to learn an action policy that maps the observed engagements states to a guidance command. Extensive empirical numerical simulations are performed to validate the proposed computational guidance algorithm.

Instantaneous Impact Point Guidance with Coast Arcs for Solid Rockets

This paper proposed an analytical iterative guidance method with the desired instantaneous impact point constraint for solid rockets in “burn-coast-burn” trajectory mode. Solid rocket motors expect to remove the thrust termination mechanism to increase the structural strength and launch reliability, which induce new difficulties and challenges to the guidance problems. In terms of the “Hohmann transfer” principle, a pointing algorithm is deduced in depth to establish the theoretical relations among the ignition time, the required velocity vector, and the orbital element constraints and provides the analytical expression of the ignition time. Then, an analytic solution of the required velocity vector is derived based on orthogonal and nonorthogonal velocity vectors, and a complete guidance logic is used to solve the target orbit elements satisfying the desired instantaneous impact point. Finally, the application of the developed theoretical algorithm in this paper is conducted using a two-stage solid rocket. The proposed guidance method is verified by Monte Carlo simulations, and the testing results demonstrate the adaptability, strong robustness, and excellent performance for different desired impact point missions.

Time-Fixed Glideslope Guidance for Approaching the Proximity of an Asteroid

The guidance and control problem of spacecraft approaching an asteroid using constant continuous thrust is studied in this work. The range of interest is from hundreds of kilometers to several kilometers, in which relative measurements of much higher accuracy than based on Earth can be used to facilitate further hovering or landing operations. Time-fixed glideslope guidance algorithm is improved by introducing a substitute of an existing control parameter and combined with elliptical relative orbital dynamics to rendezvous the spacecraft with a prescribed location in the proximity of a given asteroid. A vast range of values for the control parameters are explored and suitable combinations are found. To fully validate the robustness and accuracy of the proposed control algorithm, Monte Carlo simulations are done with the navigational error and implementation error considered.

Cooperative Docking Guidance and Control with Application to Civil Autonomous Aerial Refueling

This paper proposes a novel concept for automatic docking of a boom-receptacle aerial refueling system adequate for civil aerial transportation. The receiving aircraft is assumed to keep straight and steady flight, and the docking maneuver is performed exclusively by the tanker and its boom system. As opposed to the conventional approach, the docking maneuver consists in a coordinated and guided motion of the tanker and the boom arm that is simultaneous with the extension of the nozzle tip. To achieve this, a cooperative guidance algorithm is derived in a systematic manner. The first step is to reduce the docking problem to a planar kinematic guidance problem. Subsequently, the cooperative guidance law algorithm is derived and applied to generate commands for the inner-loop controllers of the tanker aircraft and the boom. The ability to achieve successful docking is demonstrated using numerical simulations, and advantages of this concept are highlighted using a comparison with a baseline controller that uses separated control of the tanker and the boom in a sequential manner.

Nonlinear Optimal Impact-Angle-Constrained Guidance with Large Initial Heading Error

This paper investigates the problem of impact-angle-constrained guidance law design against maneuvering target with large initial heading error. The guidance problem is first formulated in the range domain by leveraging a relative reference frame. Based on optimal control theory and optimal error dynamics, the proposed guidance law is derived analytically without using any linearization assumptions. The approximate closed-form solution and exact numerical solution are presented to analyze the characteristics and physical meaning of the proposed guidance law. The key feature of the proposed guidance law lies in its simple implementation and exact nonlinear nature. Hence, the tolerable initial heading error of the proposed approach is larger than that of conventional linear optimal guidance laws. Numerical simulations are conducted to support the analytical findings.

Early Career Guidance for Older Preschoolers Through Story-Related Didactic Games

The article deals with the problem of early career guidance for preschool children. Currently, one of the areas of social and communicative development of children is the development of their focus on human labour, orientation in the world of professions in demand in the modern world. This work is organized in preschool educational institutions in accordance with the Federal State Educational Standard of Preschool Education. The article presents the results of identifying orientation of preschoolers in the world of professions, reveals indicators and research methods. The experimental data show the narrowness of preschoolers’ ideas about professions, superficial knowledge of some professions in the immediate environment, reduced interest in the world of professions and the reflection of labor actions in play activities. The logic of work on early career guidance of preschoolers through plot-didactic games is described: features of the plot-didactic games’ development, the content of work stages, methods and techniques. Potential possibilities of plot-didactic games are reflected, which allow solving other educational tasks: development of independent game activity, ability to interact in a team, and increasing motor activity. Keywords: preschool education, early career guidance, plot-didactic game, game activity, social development

Trajectory Tracking Control in Real-Time of Dual-Motor-Driven Driverless Racing Car Based on Optimal Control Theory and Fuzzy Logic Method

To improve the accuracy and timeliness of the trajectory tracking control of the driverless racing car during the race, this paper proposes a track tracking control method that integrates the rear wheel differential drive and the front wheel active steering based on optimal control theory and fuzzy logic method. The model of the lateral track tracking error of the racing car is established. The model is linearized and discretized, and the quadratic optimal steering control problem is constructed. Taking advantage of the differential drive of dual-motor-driven racing car, the dual motors differential drive fuzzy controller is designed and integrated driving with active steering control. Simulation analysis and actual car verification show that this integrated control method can ensure that the car tracks different race tracks well and improve the track tracking control accuracy by nearly 30%.

Singular-Perturbation-Based Guidance of Pulse Motor Interceptors with Look Angle Constraints

This paper addresses the problem of midcourse guidance of dual-pulse rocket motor interceptors with seeker field-of-view constraints using singular perturbation technique. The guidance law considers a combination of terminal velocity and flight time as a performance measure. In addition to the seeker field-of-view limit, constraints in the optimization problem include minimum dynamic pressure limit arising due to aerodynamic controllability. Using the time scale separation between the state variables, the full-order problem is reduced into lower-order subproblems, and a closed-form solution for guidance law is derived. It is shown that the performance of the interceptor is not very sensitive to perturbation of pulse firing time, and an offline generated lookup table is used to time the second thrust pulse firing. The proposed guidance law is computationally efficient, and its performance is benchmarked with that of pseudospectral-based feedback guidance with much lower computational cost. Simulation studies with point mass and six-degree-of-freedom model are presented highlighting the accuracy and efficacy of the proposed guidance law.

Closed-Form Impact-Angle-Control Guidance of Nose-Dive Missiles for Maximum Terminal Speed

This paper addresses an impact angle control guidance problem for nose-dive missiles to achieve the maximum terminal speed against a fixed target in the same vertical plane. By modeling the aerodynamic drag as a drag polar, we set up the nonlinear system equations needed to pursue an analytic closed-form solution. This paper shows that maximizing the terminal speed is equivalent to minimizing a weighted quadratic cost of the curvature of trajectory, and can be used as an equivalent problem to the original problem. Applying Pontryagin’s maximum principle to the equivalent problem, we obtained a closed-form optimal guidance law, described in terms of air density parameters as well as heading error angle, flight path angle, range-to-go, and time-varying speed.

Construction of Rural Primary School Teachers’ Professional Ability Promotion System based on Cloud Platform

At present, primary school teachers often face the problems of insufficient resources and guidance. Under the cloud platform learning, teaching and research are more efficient. In this paper, based on the cloud platform of rural primary school teachers’ professional ability improvement system as the research object, through the current situation of primary school teachers’ ability, combined with the current intelligent technology, the ability improvement of primary school teachers is studied. The results show that 75% of the respondents believe that their decision-making in the department actually relies on data analysis. 40% of the people think that using the results of data analysis to make decisions improves the importance of their work and their position in the enterprise. Decision making based on data has become the new normal, and the efficiency of primary school teachers’ ability improvement has increased by more than 45%. Similarly, education big data also has a profound impact on teaching decision-making. Cloud platform is the fundamental direction and key focus of teacher leadership in the new era. As a kind of dynamic leadership, teacher leadership has changed due to cloud platform learning. The impact of cloud platform learning on teachers’ leadership is omni-directional. Under cloud platform learning, teachers’ post requirements are higher, cooperation among teachers will be enhanced, teaching improvement will be strong, and teaching improvement and change behavior will be more active.

DESIGN CONTROL OF SURFACE MARINE VEHICLE USING DISTURBANCE COMPENSATING MODEL PREDICTIVE CONTROL (DC-MPC)

This research studied ship motion control by considering four degrees of freedom (DoF): yaw, roll, sway, and surge in which comprehensive mathematical modeling forming a nonlinear differential equation. Furthermore, this research also investigated solutions for fundamental yet challenging steering problems of ship maneuvering using advanced control method: Disturbance Compensating Model Predictive Control (DC-MPC) method, which based on Model Predictive Control (MPC). The DC-MPC allows optimizing a compensated control then consider sea waves as the environmental disturbances. Those sea waves influence the control and also becomes one of the constraints for the system. The simulation compared the varying condition of Horizon Prediction (Np) and another method showing that the DC-MPC can manage well the given disturbances while maneuvering in certain Horizon Prediction. The results revealed that the ship is stable and follows the desired trajectory

Optimal Guidance and Control of a Low-Altitude Skid-to-Turn Vehicle

The problem of optimal guidance of a low-altitude skid-to-turn vehicle is considered. In particular, the skid-to-turn vehicle is both guided and controlled using a recently developed computational optimal guidance and control method that employs Gaussian quadrature collocation. First, this recently developed method is used to re-solve the optimal control problem on a shrinking horizon at constant guidance cycles. The performance of this computational guidance and control method is then analyzed and compared against a classical LQ follower. It is found that, although the computational efficiencies of both methods are comparable, the computational method for optimal guidance and control is significantly more accurate than that of the LQ follower. The results of this study show that the recently developed computational method for optimal guidance and control has the potential to improve performance over traditional methods when solving an optimal control problem in real time.