Many tracking and guidance problems may be formulated as a terminating stochastic game in which the distribution of outcomes is affected by the intermediate actions. Traditional techniques ignore this interaction. In ...
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ISBN:
(纸本)0819428221
Many tracking and guidance problems may be formulated as a terminating stochastic game in which the distribution of outcomes is affected by the intermediate actions. Traditional techniques ignore this interaction. In this paper we develop an information gathering strategy which maximises the expected gain of the outcome (ie engagement). For example, the objective could be a function of the terminal miss distance and target identity with penalties for missing a valid target or attacking a friendly one. Several trade-offs are addressed: the increased information available from taking more measurements, the fact that an increased number of measurements may adversely affect chance of success (due to alerting target for example) and the fact that later measurements may be more informative but also may be of little use since there may not be enough time available for reaction to this extra information. The problem is formulated so that we are required to choose, under uncertainty, an alternative from a set of possible decisions. This set has a discrete uncertainty as to the number of measurements to be taken and a continuous uncertainty as to where and when the measurements should be taken. Preferences over consequences are modelled with a utility function. We propose to choose as optimal the alternative which maximises expected utility. A simulation based approximation to the solution of this stochastic optimization problem is outlined. This relies on recent developments in dimension swapping Markov Chain Monte Carlo (MCMC) techniques. The use of MCMC methodology allows us to explore the expected utility surface and thus select a measurement strategy. The resulting algorithm is demonstrated on a simple guidance problem.
Parametric Mapping (PM) lies midway between older and proven artificial landmark (target) based guidance systems and yet to be realised vision based guidance system. It is a simple yet effective natural landmark recog...
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ISBN:
(纸本)0819426423
Parametric Mapping (PM) lies midway between older and proven artificial landmark (target) based guidance systems and yet to be realised vision based guidance system. It is a simple yet effective natural landmark recognition system offering freedom from the need for enhancements to the environment. Development of PM systems can be inexpensive and rapid and they are starting to appear in commercial and industrial applications. Together with a description of the structural framework developed to generically describe robot mobility, this paper illustrates clearly the parts of any mobile robot navigation and guidance system and their interrelationships. Among other things, the importance of the richness of the reference map, and not necessarily the sensor map, is introduced the benefits of dynamic path planners to alleviate the need far separate object avoidance, and the independence of the PM system to the type of-sensor input is shown.
Perspective flightpath displays and the depiction of 3-D terrain are regarded as a potential means to increase safety. Although the technology to generate such presentations in real-time is available, other issues whi...
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ISBN:
(纸本)0819428132
Perspective flightpath displays and the depiction of 3-D terrain are regarded as a potential means to increase safety. Although the technology to generate such presentations in real-time is available, other issues which are required for a safe introduction must still be resolved. This paper focuses on some of the major obstacles which are still present. It discusses several objections against perspective flightpath displays and shows why most of them are no longer justified. The potential for an increase in safety is related to navigation, guidance, and control task requirements, and potential implementations, ranging in complexity, to satisfy these requirements are discussed. This classification allows a gradual transition from today's 2-D symbolic displays to future spatial displays. The paper proposes an approach which supports an evolutionary introduction of 3-D navigation displays into the cockpit.
The increasing use of computer controlled mobile robots in various tasks has created a growing technological need for efficient low cost means and methods for mobile robot guidance. This work presents a robot navigati...
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ISBN:
(纸本)0819429783
The increasing use of computer controlled mobile robots in various tasks has created a growing technological need for efficient low cost means and methods for mobile robot guidance. This work presents a robot navigation and guidance system that consists of a directional light sensor and a set of at least three uniquely coded light sources, The three light sources provide distinct light fields in the operating area of the robot. The light sensor, mounted on a mobile robot, is used to measure the angle of the direction of origin of each of the three light: sources with respect to the robot reference frame. The local room coordinates of the robot can then be determined by an on-board microprocessor system. The planar position and orientation of the robot can be used to control the drive and steering mechanisms to reach a given target position or track a prescribed trajectory. Control methods for robot guidance are discussed.
Carl McDaniels has made contributions to professional counseling for nearly 40 years. He is well known for practical applications of career development theory such as the Virginia Tech Employee Career Development Prog...
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Carl McDaniels has made contributions to professional counseling for nearly 40 years. He is well known for practical applications of career development theory such as the Virginia Tech Employee Career Development Program and the Virginia Career Information Delivery System, and for his theoretical formula "Career = Work + Leisure." In this interview, he reflects on transitions in his career as a counselor and a counselor educator.
Polar satellite launch vehicle PSLV is an optimally guided and controlled vehicle that has several fault tolerant and in flight retargetting features. Several flights have proven the soundness of control and guidance ...
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Polar satellite launch vehicle PSLV is an optimally guided and controlled vehicle that has several fault tolerant and in flight retargetting features. Several flights have proven the soundness of control and guidance design. Features of Control & guidance system of PSLV are described.
The method of the air-combat evaluation only by computer simulations is presented The mathematical models of the vehicles; aircraft, missile and bullet, their dynamics and guidance and control system are explained As ...
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The method of the air-combat evaluation only by computer simulations is presented The mathematical models of the vehicles; aircraft, missile and bullet, their dynamics and guidance and control system are explained As the preciseness of simulation models depends on the purpose of evaluation, the difference between the six cEgrees-of-freedom rigid body model and the point mass model, the analytical function model is explained Some tactics of the aircraft in air-combat are also explained and combat simulation examples are shown.
Midcourse guidance laws are developed for a short-range, bank-to-turn attack missile with a high thrust-to-weight ratio, The trajectory optimization formulation is to minimize the flight time from a low-altitude, subs...
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Midcourse guidance laws are developed for a short-range, bank-to-turn attack missile with a high thrust-to-weight ratio, The trajectory optimization formulation is to minimize the flight time from a low-altitude, subsonic launch to a fixed target 100-300 n mile from the launch aircraft at any azimuth. After the thrust phase, the missile coasts in a vertical plane at zero angle of attack. For guidance, optimal guidance is selected, and two guidance laws are developed by formulating an equivalent optimal control problem over the thrust phase. The analytical guidance law is obtained by making approximations in the optimal control problem. It performs well for midcourse guidance but needs terminal guidance to hit the target. The error compensation (EC) guidance law is obtained by replacing the approximation terms by bounded controls, where the bounds are handled indirectly by adding penalty terms to the performance index. The EC weights are determined by using the EC control in the trajectory optimization problem and minimizing the flight time with respect to the weights. On board, weights can be stored for an array of target ranges and azimuths and obtained at launch by table lookup. The EC guidance law enables the missile to hit the target without terminal guidance.
During the guidance process of an antiradiation missile (ARM), the target radar is often switched off in order to avoid being attacked. This will cause the passive seeker in ARM disabled, so the guidance system of the...
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During the guidance process of an antiradiation missile (ARM), the target radar is often switched off in order to avoid being attacked. This will cause the passive seeker in ARM disabled, so the guidance system of the missile will stop working. To solve this problem, a scheme called LOS angles optimal estimation, has been put forward,based on the fault-tolerant design method of system reconstruction. The effectiveness of the proposed scheme has been proved by the simulations.
Observability is analyzed for the target tracking with bearings-only measurements (BOM) applied to a passive homing missile system using augmented proportional navigation guidance (APNG). Based on the analysis, a prac...
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Observability is analyzed for the target tracking with bearings-only measurements (BOM) applied to a passive homing missile system using augmented proportional navigation guidance (APNG). Based on the analysis, a practical homing guidance law is proposed to enhance observability for tactical missile applications. The new guidance law is tailored to provide oscillation of line-of-sight (LOS) angle induced by initial missile heading errors without sacrificing terminal effectiveness. Simulation studies indicate that the proposed guidance law provides convergence of the state estimates essential to homing guidance applications as well as terminal effectiveness.
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