Guidance system

About: Guidance system is a research topic. Over the lifetime, 4282 publications have been published within this topic receiving 45964 citations.

Guidance of a Forage Harvester with GPS

Abstract: Precision agriculture requires automatic control of agricultural machinery in order to cope with the large amount of information which has to be applied during site specific field work. The driver is occupied with operating and supervising the controlled and non-controlled implements as well as with vehicle guidance. Steering, in particular, is monotonous and tiring. This can result in reduced operation quality. This was the motivation to develop a concept of a guidance system for agricultural vehicles. A self-propelled forage harvester was the test vehicle for this research. The harvester was equipped with an automatic steering system. Real Time Kinematic Global Positioning System (RTK-GPS) was used as the only positioning sensor due to high absolute accuracy within the field and its high reliability. The system performance was investigated under various test conditions. Additionally a guidance-path-planning for swath harvesting operations was developed. Both the automatically steered forage harvester and the path planner could be examined under real field conditions. The standard deviation of the driving performance was better than 100 mm under all conditions. The swaths could be collected reliably with the automatically steered forage harvester.

Design, Implementation and Evaluation of an Indoor Navigation System for Visually Impaired People

Abstract: Indoor navigation is a challenging task for visually impaired people. Although there are guidance systems available for such purposes, they have some drawbacks that hamper their direct application in real-life situations. These systems are either too complex, inaccurate, or require very special conditions (i.e., rare in everyday life) to operate. In this regard, Ultra-Wideband (UWB) technology has been shown to be effective for indoor positioning, providing a high level of accuracy and low installation complexity. This paper presents SUGAR, an indoor navigation system for visually impaired people which uses UWB for positioning, a spatial database of the environment for pathfinding through the application of the A* algorithm, and a guidance module. The interaction with the user takes place using acoustic signals and voice commands played through headphones. The suitability of the system for indoor navigation has been verified by means of a functional and usable prototype through a field test with a blind person. In addition, other tests have been conducted in order to show the accuracy of different relevant parts of the system.

Evaluating the benefits of a combined route guidance and road pricing system in a traffic network with recurrent congestion

Abstract: When drivers do not have complete information on road travel time and thus choose their routes in a stochastic manner or based on their previous experience, separate implementations of either route guidance or road pricing cannot drive a stochastic network flow pattern towards a system optimum in a Wardropian sense It is thus of interest to consider a combined route guidance and road pricing system A road guidance system could reduce drivers' uncertainty of travel time through provision of traffic information A driver who is equipped with a guidance system could be assumed to receive complete information, and hence be able to find the minimum travel time routes in a user-optimal manner, while marginal-cost road pricing could drive a user-optimal flow pattern toward a system optimum Therefore, a joint implementation of route guidance and road pricing in a network with recurrent congestion could drive a stochastic network flow pattern towards a system optimum, and thus achieve a higher reduction in system travel time In this paper the interaction between route guidance and road pricing is modeled and the potential benefit of their joint implementation is evaluated based on a mixed equilibrium traffic assignment model The private and system benefits under marginal-cost pricing and varied levels of market penetration of the information systems are investigated with a small and a large example It is concluded that the two technologies complement each other and that their joint implementation can reduce travel time more efficiently in a network with recurrent congestion

Simulation and flight control of an aeroelastic fixed wing micro aerial vehicle

Abstract: Micro aerial vehicles have been the subject of continued interest and development over the last several years. The majority of current vehicle concepts rely on rigid fixed wings or rotors. An alternate design based on an aeroelastic membrane wing has also been developed that exhibits desired characteristics in flight test demonstrations, competition, and in prior aerodynamics studies. This paper presents a simulation model and an assessment of flight control characteristics of the vehicle. Linear state space models of the vehicle associated with typical trimmed level flight conditions and which are suitable for control system design are presented as well. The simulation is used as the basis for the design of a measurement based nonlinear dynamic inversion control system and outer loop guidance system. The vehicle/controller system is the subject of ongoing investigations of autonomous and collaborative control schemes. The results indicate that the design represents a good basis for further development of the micro aerial vehicle for autonomous and collaborative controls research.

Integrated Sliding Mode Guidance and Control for Missile with On-Off Actuators

Abstract: A sliding mode controller was recently introduced for integrated guidancecontrol loops of agile missiles. The sliding surface was chosen to be the zeroeffort miss-distance. The current work extends this result to address nonlinear on-off actuators commonly used in such interceptors. The performance of the integrated design is compared with a two-loop design, i.e., separate guidance and autopilot loops. The simulation includes a detailed pneumatic model of the aerodynamic surface actuators. Compared to the results obtained with a linear first order actuation system, it is shown that the advantages of the integrated design are more significant when tested with the on-off actuator. The proposed integrated algorithm is effective especially for the endgame phase of the interception. However, its high interception accuracy can be attained only if engaged from a limited range of initial conditions within the so called region of attraction, thus posing performance requirements to the midcourse guidance system. The paper presents the regions of attraction for a sample interception setup.