Classical Guidance Law Research Articles

VECTOR FIELD GUIDANCE LAW FOR CURVED PATH FOLLOWING OF AN UNDERACTUATED AUTONOMOUS SHIP MODEL

A vector field guidance law and control system for curved path following of an underactuated surface ship model is presented in this paper. In order to obtain the curved path, continuous derivatives piecewise cubic Hermite interpolation is applied for path generation based on the predefined waypoints. A heading autopilot controller is designed based on 2nd order Nomoto’s model and its stability is guaranteed by the Diagram of Vyshnegradsky method. The parameters of Nomoto model are estimated using least square support vector machine based on the manoeuvring tests. The vector field guidance law is applied for both straight and curved path-following control of an underactuated surface ship model. In order to demonstrate the performance, the classical guidance law based on line-of-sight, is adopted for comparison. The results show that the vector field method is capable to solve the guidance problem of underactuated surface ships.

A Combined Linear–Quadratic/Bounded Control Differential Game Guidance Law

A new guidance law, based on the solution of a combined linear–quadratic and norm-bounded differential game, is proposed. It hinges on the insight that the hard constraints on the lateral acceleration are critical in the last part of the flight, and in contrast, at the early stages of the flight, it is important to avoid excessive speed loss due to induced drag. This yields a linear–quadratic differential game formulation for the initial stage and a norm-bounded differential game formulation for the last stage of the engagement. In an important particular case of players with ideal dynamics, the proposed guidance law is shown to be biased proportional navigation guidance with a deadzone. Due to its simple structure, the proposed guidance law is easy to implement in practice. The performance of the guidance law is illustrated using numerical simulations, and it is shown to perform better than comparable classical guidance laws.

Vector Field Guidance Law for Curved Path Following of an Underactuated Autonomous Ship Model

A vector field guidance law and control system for curved path following of an underactuated surface ship model is presented in this paper. In order to obtain the curved path, continuous derivatives piecewise cubic Hermite interpolation is applied for path generation based on the predefined waypoints. A heading autopilot controller is designed based on 2nd order Nomoto’s model and its stability is guaranteed by the Diagram of Vyshnegradsky method. The parameters of Nomoto model are estimated using least square support vector machine based on the manoeuvring tests. The vector field guidance law is applied for both straight and curved path-following control of an underactuated surface ship model. In order to demonstrate the performance, the classical guidance law based on line-of-sight, is adopted for comparison. The results show that the vector field method is capable to solve the guidance problem of underactuated surface ships.

A finite-time 3D guidance law based on fixed-time convergence disturbance observer

In order to achieve accurate interception of high-speed maneuvering targets, this paper presents a relative Line-of-Sight (LOS) velocity based finite-time three-dimensional guidance law design framework, and discusses the application of fixed-time convergence disturbance observer in this framework. Firstly, a simple Lyapunov function is provided to show that the coupled terms in the relative kinematics can be ignored in the proposed guidance law design framework. Secondly, the realizations of several classical guidance laws are analyzed with the proposed framework, including TPN guidance law, finite-time Input-to-State Stability (ISS) guidance law, and sliding mode guidance law. Thirdly, fixed-time convergence disturbance observers are introduced to design the composite finite-time 3D guidance law, and Lyapunov method is employed to show the stability of the guidance system. Numerical simulations with different scenarios show that the proposed generalized guidance law performs high interception accuracy.

Hawks steer attacks using a guidance system tuned for closepursuit of erratically manoeuvring\xa0targets

Aerial predators adopt a variety of different hunting styles, withdivergent flight morphologies typically adapted either to high-speed interception ormanoeuvring through clutter, but how are their sensorimotor systems tuned inrelation to habitat structure and prey behavior? Falcons intercept prey athigh-speed using the same proportional navigation guidance law as homing missiles.This classical guidance law works well in the open, but performs sub-optimallyagainst highly-manoeuvrable targets, and may not produce a feasible path through thecluttered environments frequented by hawks and other raptors. Here we identify theguidance law of n = 5 Harris’ Hawks Parabuteo unicinctus chasing erratically manoeuvringartificial targets. Harris’ Hawks use a mixed guidance law, coupling low-gainproportional navigation with a low-gain proportional pursuit element. This guidancelaw promotes tail-chasing and is not thrown off by erratic manoeuvres, making itwell suited to the hawks’ natural hunting style, involving close pursuit of agileprey through clutter.

Cooperative Nonlinear Guidance Strategies for Aircraft Defense

This paper presents nonlinear guidance strategies for scenarios where an aircraft launches a defender missile as a countermeasure against an incoming attacking missile. The guidance system offers an additional degree of freedom due to two available controls, the lateral accelerations of defender and aircraft. This extra degree of freedom is used in various ways to design guidance strategies. These guidance strategies, in addition to each ensuring interception of missile, also individually allow: 1) to reduce sensitivity of guidance law to erroneous time-to-go estimates, 2) the aircraft to perform optimal evasive maneuvers, and 3) either of the aircraft or the defender to maneuver independently with their maximum limit small as compared to that of missile. The design of guidance strategies is performed in a nonlinear framework, using sliding-mode control technique, with relevant zero-effort miss variables as switching surfaces. For reduction of sensitivity against time-to-go, an additional zero-effort velocity switching surface is proposed. Simulations are presented to validate the efficacy of the proposed guidance strategies and their superior performance compared to existing classical guidance laws. The protection envelopes, which depict the variations of minimum aircraft–missile distance with respect to heading angle of missile, to ensure successful interception, are also obtained.

Terminal guidance strategy for a hybrid thrust-tether lunar landing scheme

A hybrid thrust-tether lunar landing scheme and its terminal guidance strategy are proposed in this paper, which has potential application in avoiding the dusts aroused by the plume of thrusters. The combined lander is made up of a descent stage and a rover, which are connected by a tethered device. An innovative combination of fuzzy and variable-structure controllers is introduced to guide the terminal landing, which is more robust than some classical guidance laws derived from the linearized dynamics. At the beginning of this phase, the combined lander carries out the targeting guidance law from the height of 250m to the desired landing site. When the combined lander arrives at the height of about 20m, the tethered device is triggered to release the rover which is controlled by the tensioning force provided by the motor and windlass. In releasing the rover, the descent stage is required to hover above the lunar surface at a certain height until the rover meets safe landing conditions. After the rover cuts off the tether, the descent stage will be driven by the deputy thrusters as far away from the rover as possible. A typical scenario is implemented numerically to demonstrate the stabilization of the horizontal initial velocity even in nonzero azimuth angle case. To investigate the robustness of the closed-loop guidance law, a Monte-Carlo simulation is performed to create all the scenarios parameterized by the errors in initial position and velocity which is the result of last powered descent phase.

Retro-PN Based Simultaneous Salvo Attack Against Higher Speed Nonmaneuvering Targets

One of the biggest challenges in current defence scenario is significant improvement in countermeasure, which essentially leads to the degradation of classical guidance laws that are most widely used in practice. To improve the odds of intercepting an intelligent target and destroying its warhead, a salvo attack of two or more interceptors could be considered as a viable option since it is more difficult to create an effective countermeasure against a group of interceptors attacking at the same time, even though each of them may follow some conventional guidance strategy. Moreover, this simultaneous salvo attack can also be further improved in efficiency by incorporating the shoot-look- shoot approach in making decision about launching of interceptors. This can be considered as the first step towards a layered defence system, which has been described in literature as a potentially effective strategy against short range or long range ballistic threat. Thus, in strategic defence scenario, cooperative salvo of interceptors has a great role to play. Also, ballistic and cruise threat is a present day reality. This paper discusses a cooperative strategy for lower speed interceptors guided by Retro-PN guidance law to perform salvo attack against a higher speed target. The effectiveness of this cooperative strategy is justified with simulation results.

Research on High Accuracy Guidance Law for Reentry Vehicles

The problem of low accuracy for classic guidance law is considered in this paper. Based on the mature theory used in missiles, this paper presents an integrated guidance law for reentry vehicles. At the initial stage of reentry flight, standard trajectory guidance law is employed, and then converts to 3dof proportional guidance law when this vehicle is close to the target. Simulation results are provided to demonstrate the accuracy of the proposed integrated guidance law.

Sampling-based path planning: a new tool for missile guidance

A new missile midcourse guidance algorithm is proposed in this paper. It is a combination of sampling based path planning, Dubins’ curves and classical guidance laws. Moreover, a realistic interceptor missile model is used. It allows to anticipate the future changes of flight conditions along the trajectory, especially the loss of maneuverability at high altitude. Simulation results are presented to demonstrate the substantial performance improvements over classical midcourse guidance laws.

Control-based fault detection and isolation for autonomous aircraft

This article describes a new method to perform fault detection and isolation for a closed-loop-controlled autonomous aircraft. This vehicle is equipped with standard sensors and actuators, and its dynamics is non-linear. It is assumed that a guidance law and a control loop have been designed to achieve a given mission. The diagnosis method uses the resulting control objectives to generate residuals indicative of the presence of faults. Two classical guidance laws are considered, leading to different control constraints and diagnosis signals. A structural sensitivity analysis shows that all sensor and actuator faults can be detected and all sensor faults isolated, for both laws. The fault diagnosis procedure does not require the costly integration of the model of the system, and the closed-loop scheme makes it robust to model uncertainty. Realistic simulation results with strong model and measurement uncertainty demonstrate the potential of the approach. A theoretical analogy with observer-based fault diagnosis is also derived.

ROBOT FORMATION MODELLING AND CONTROL BASED ON THE RELATIVE KINEMATICS EQUATIONS

This paper deals with the problem of modeling, initialization, and control of mobile robots formation. We suggest to use a new family of methods that consists of a combination between classical guidance laws and kinematics rules. These methods allow modeling and controlling a dynamic robotic formation using sets of differential equations that give the relative motion between the robots. These differential equations give the range rate and the visibility angle between leaders and followers. Graph theory is used to store the relationship leader-follower and plan the formation by using three different matrices. The configuration of the formation is based on these matrices. Initialization of formation is also considered, where different approaches are suggested. Because of the nature of the kinematics laws, it is easy to model, initialize, and keep any formation shape. Simulation is provided to illustrate the method.

Current Trends in Tactical Missile Guidance

The problem of tactical missile guidance is very challenging and has been treated using several basic metlfodologies in the past four decades. Major techniques can be grouped under classical guidance laws, modern guidance laws, l'aws for manoeuvring targets, predictive guidance for endgame scenario, and guidance laws based on intelligent control methods. Each technique has some advantages and disadvantages while implementing in a practical system. Guidance law selection is dictated by nature of flight profile like boost, midcourse, terminal homing, etc, and also miss-distance and a single-shot kill probability. This paper presents a brief survey of the existing techniques and current trends in tactical missile guidance.

Guidance and control in a Josephson charge qubit

In this paper we propose a control strategy based on a classical guidance law and consider its use for an example system: a Josephson charge qubit. We demonstrate how the guidance law can be used to attain a desired qubit state using the standard qubit control fields.

Extensive Comparison Between Quantitative Pursuit Evasion Game Guidance Law and PNS

A horizontal pursuit-evasion game of degree (with capture time as criterion) between a coasting missile and a maneuvering target of constant speed is considered. This game is the quantitative version of a qualitative one (game of kind with capture or no capture as binary criterion) previously studied by J. Shinar and Co-authors. The optimal strategies are used in an algorithm to synthesize a feedback guidance law and to perfonn a comparison with classical guidance laws as True Proportional Navigation (TPN) and Augmented Proportional Navigation (APN) (Zarchan, 1997)

Fuzzy logic control — application to the guidance of a re-entry space capsule

A closed loop re-entry guidance law for a space capsule has been synthetized with the help of fuzzy logic concept. In order to make an assessment, this guidance law has been obtained by introducing two fuzzy logic layers in a classical guidance law used as a reference for comparisons. Those two layers are a “fuzzy PID” which ensures the respect of a specified drag acceleration value, and a range correction which adjusts the level of the specified drag acceleration according to the remaining longitudinal range down to landing. Comparisons have been made in the presence of air density, aerodynamic coefficient and deorbit impulse deviation along with static winds statistically combined for a Monte-Carlo analysis. Results showed that the fuzzy guidance law is robust, with very close performances to the classical reference guidance law, with overall a great facility for tuning.