Suchergebnisse

Parts 3-5, 7, reproduced from type-written copy. ; pt. 1.--Introduction to earth.--pt. 2. Introduction to navigation.--pt. 3. Dead reckoning and lines of position.--pt. 4. Navigation instruments.--pt. 5. Relative movement.--pt. 6. Contact flying.--pt. 7. Nautical astronomy and celestial navigation. ; Mode of access: Internet.

Bugis Navigation. Gene Ammarell. New Haven: Yale University Southeast Asia Studies, 1999. 299 pp.

Robotter vil om få år blive en del af vores daglige liv. Inden for produktionsindustrien har det allerede være tilfældet i mange år, men anvendelsen af mobile robotter har hidtil været henvist til isolerede områder som græsslåning, overvågning, landbrugsproduktion og militære funktioner. Fremskridt i forskningen gør, at robotter vil kunne assistere os i mange af vore daglige gøremål i en ikke så fjern fremtid. En af de teknologier, der skal gøre dette muligt, er navigation, og navigation er emnet for denne afhandling. Navigation for autonome robotter handler om robottens evne til autonomt at manøvrere fra den nuværende position til et ønsket bestemmelsessted. Denne afhandling præsenterer og validerer eksperimentelt løsninger til detektering af farbar vej, omgåelse af forhindringer og gennemførelse af missioner. Vejklassifikationen er baseret på laserscanner-målinger og assisteret med vision for længere rækkevidde. Vejklassifikationen er tilstrækkelig selektiv til at kunne adskille selv flade vejrabatter fra selve vejen og kan isolere asfaltveje fra grusveje. Vejgenkendelse ud fra kamerabilleder tager udgangspunkt i klassifikationen fra laserscanneren og bruger en kombination af farve og kantdetektering til at estimere farbar vej på længere afstande. Resultatet af disse to sensorer anvendes under planlægning af en farbar rute, og her er det især robottens evne til at følge vejens kanter, der er undersøgt. Navigationen i en mission er styret af et sekventielt manuskript. Manuskriptsproget giver mulighed for detektering af vejkryds, for beregninger til brug under passagen af disse kryds og til valg a styringsmetode i øvrigt. Det samlede system er testet på en kombination af asfalt- og grusveje, med et antal forgreninger og vejkryds. Missioner på op til 3km længde er gennemkørt autonomt med det beskrevne system. Fokus i afhandlingen har været den eksperimentelle validering af de implementerede metoder og metodernes evne til at løse problemer i en virkelig verden. Der skal en betydelig mængde software til for at styre en autonom robot, emner som software genbrug og distribueret udvikling er derfor essentielle. Denne afhandling beskriver yderligere en komponentbaseret arkitektur for robotter, som kan fremme software genbrug og distribueret udvikling og vedligeholdelse. ; Abstract Robots will soon take part in everyone's daily life. In industrial production this has been the case for many years, but up to now the use of mobile robots has been limited to a few and isolated applications like lawn mowing, surveillance, agricultural production and military applications. The research is now progressing towards autonomous robots which will be able to assist us in our daily life. One of the enabling technologies is navigation, and navigation is the subject of this thesis. Navigation of an autonomous robot is concerned with the ability of the robot to direct itself from the current position to a desired destination. This thesis presents and experimentally validates solutions for road classification, obstacle avoidance and mission execution. The road classification is based on laser scanner measurements and supported at longer ranges by vision. The road classification is sufficiently sensitive to separate the road from flat roadsides, and to distinguish asphalt roads from gravelled roads. The vision-based road detection uses a combination of chromaticity and edge detection to outline the traversable part of the road based on a laser scanner classified sample area. The perception of these two sensors are utilised by a path planner to allow a number of drive modes, and especially the ability to follow road edges are investigated. The navigation mission is controlled by a script language. The navigation script controls route sequencing, junction detection, junction crossing calculations and drive mode selection. The entire system is tested on a combination of narrow asphalt and gravelled roads connected by a number of junctions. Missions of up to 3km in length have been successfully completed using the described system. The main focus of the thesis has been the experimental validation of the implemented solutions and the ability of the methods to solve real world problems. The amount of software needed by an autonomous robot can be overwhelming. Software reuse and distributed development are therefore important issues. The thesis describes a new component architecture for robotics software that promotes software reuse and distributed development and maintenance.

In the case of one car following another to a destination, it is very effective at getting the second vehicle to the destination quickly; however, the driver of the second car may not learn the route. Yet, for individuals, such as firefighters, law enforcement, and military personnel, it is imperative that a route be learned quickly and accurately and that an awareness of the situation is maintained while they traverse the given route. This leads to three questions, (a) will navigation aids affect initial route navigation; (b) will navigation aids affect retention; and (c) will navigation aids affect situation awareness while en route? The hypotheses of this study were that navigation aids would significantly increase the speed at which a person can initially navigate a route, but the use of the aids would significantly decrease the retention of the route navigated. The findings of this study support the hypotheses. The results suggest that participants that followed a confederate and participants that were given verbal directions were quicker and made fewer errors than participants that reviewed a map or initially figured the route out on their own (control group). The study also showed that as the participants navigated the route for a second time with no navigational assistance, the ones that reviewed a map or that were in the control group outperformed participants that initially had a confederate to follow or were given verbal directions their first time through. Finally, no real effects were found on the participants' situation awareness during the retention portion of the study. ; 2005-05-01 ; Ph.D. ; Engineering and Computer Science, Other ; Doctorate ; This record was generated from author submitted information.