Real-time appearance-based Monte Carlo localization
A new technique for vision processing is presented which lets a mobile robot equipped with an omnidirectional camera perform appearancebased global localization in real time. The technique is applied directly to the omnidirectional camera images, producing low-dimensional rotation invariant feature vectors without any training or set-up phase. Using the feature vectors, particle filters can accurately estimate the location of a continuously moving real robot, processing 5000 simultaneous localization hypotheses on-line. Estimated body positions overlap the actual ones in over 95% of the time steps. The feature vectors show a graceful degradation against increasing levels of simulated noise and occlusion.
Robot localization in indoor environments, using long-range distance sensors like laser range finders [56], millimeter-wave radar [12] or sonars [32,7,54], is now generally considered as a solved problem. Localization using vision is however still an open problem. Besides being an interesting area of research relating to neuroscience and cognition, vision as a primary sensor has a number of advantages. Cameras have a virtually unlimited range and can cover large fields of view at high update rates. Due to the passive nature, multiple cameras do not interfere with each other when operating even in the same area. Information like color and texture is readily available in the images, and camera systems are available at relatively low cost and have a limited power consumption.
いやーありがとうございます！ 助かります＾＾たまりません！！！ これも助けてください！！続きです＾＾； In this article, we present a novel technique for image processing which enables a mobile robot equipped with an omnidirectional camera to perform localization in real time. The technique extracts features from camera images based on higher-order local auto-correlations, enabling storage of a large set of visited locations in the form of feature vectors. The key idea is a novel polar higher-order local auto-correlation (PHLAC) feature extractor. The PHLAC was outlined in [33]; we present here the details behind the design and a larger set of experiments, including results on orientation estimation and robustness against noise and occlusion. The PHLAC is based on HLAC, which is known to be translation invariant. It is also to be noted that translation invariance on a panoramic view is equivalent to rotation invariance on an omnidirectional view. The combination of these properties gives rotation invariance of the polar HLAC directly on the omnidirectional view. As the PHLAC vectors are also low dimensional, the image matching is substantially simplified, enabling a large set of localization hypotheses to be matched on-line in real time. As the localization space is continuous, but computation is to take place on-line using limited resources, particle filters are here used for estimating the approximate position and orientation of the robot. Our system lets a mobile robot perform global localization and recover from kidnappings based on only visual data and odometry readings.
Hardly one mature adult in a thousand, or ten thousand, could in any three years of his life learn as much and grow as much in his understanding of the world around him, as every infant learns and frows in his first three years.
As previously discussed, two clients can have the same identification. If the identification is a user-supplied text string (for example, a host name), a collision occurs when two users choose the same name. For example, if The Lord of the Rings (a popular fantasy trilogy) has a lot of fans at any given site, several users may choose the name Gandalf for their computer.
In Section 2, existing works on vision-based localization are reviewed, with focus on appearance-based techniques. Section 3 introduces polar higher-order local auto-correlation (PHLAC) which is then used for probabilistic localization based on Sequential Monte Carlo, described in Section 4. Results from experiments using a real robotic system are then presented in Section 5, along with an analysis of the PHLAC vectors and their robustness against noise and occlusion. Section6 deliberates on how the extracted vectors can be made more distinct for different locations and how invariance against illumination can be introduced directly into the extraction process. Finally, in Section 7, main contributions and results are summarized, and major strengths and weaknesses of our current system are discussed. 2. Vision-based localization A camera-based equivalent of a typical distance-based localization system would be acquiring a detailed threedimensional model of the environment [39]. This 3D model can then be used during localization to generate the expected 2D projections (camera images) at different locations. Instead of being able to internally generate complete camera images, the system could settle for being able to predict what features [49] would be detected at each location. The features in this case make up a sort of sparse 3D map of the environment. However, the 3D model-based approaches regularly depend on auxiliary distance sensors like stereo [8] and trinocular [10] cameras. An alternative to the Cartesian 3D models is to use an appearance-based approach [22]. Appearance-based localization, in its simplest form, involves taking raw snapshots at various locations and storing them along with positioning information. The current camera image can then subsequently be matched against these memorized images to find the most probable current location. お願いします＾＾；
As we alluded to earlier, Perl is also a mathematical language. This is true at several levels, from low-level bitwise logical operations, up through number and set manipulation, on up to larger predicates and abstractions of various sorgs. And as we all know from studying math in school, mathematicians love strange symbols.
特にThis is true...からの文が、上手く訳せませんorz
318 名前：317 mailto:sage [2006/07/03(月) 23:47:02 ]
しかも間違ってるorz × abstractions of various sorgs. ○ abstractions of various sorts.
Needless to say,it is impossible to predict with any precision the degree of success that we will have in dealing with the above challenges in the near future. However,one thing is certain:even if we can deal successfully with these issues and related problems, new problems will arise. It has always been the case that the problems one generation has been able to solve lead to difficulties that another must face, and this, without question, will not change.
言うまでもない事だが、 近い未来に行うだろう上記のチャレンジが成功する度合いは、 どんな精度ででも予言する事は不可能である。 しかしながら、１つだけ確かな事がある。 それは、これらの問題や関連する問題が解決したとしても、 新しい問題が発生するだろうということだ。 It has always been the case that the problems one generation has been able to solve ← この部分がよく分からん。It って何を指してるんだろ。前の何か？ それとも that 以下？ lead to difficulties that another must face, そしてこのことは、疑うまでもなく、これからも変わらないだろう。
If one messenger or pathway is blocked _____ is likely to take its place as the body tries to protect itself against starvation． (A)another (B)the other (C)other (D)others 当てはめて訳すやつなんですが｢体を飢餓から守ろうとして…｣くらいの部分的な訳しかわかりませんorz 助けてください…('A`)
Visual Studio .NET includes a number of additional windows that you might find useful on occasion. You can display each of these windows by choosing Other Windows from the View menu and selectiong the window you want Visual Studio .NET to show.
>>344>>345 同じ本のはしがきより ActiveX, Authenticode, .(中略), Win32, Windows, Windows NT and Xbox are either registered trademarks ortrademarks of Microsoft Corporation in the United States and/or other countries. Other product and company names mentioned herein may be the trademarks of their respective owners .
As a results of the trilateral trade of slaves-raw cotton-cotton textiles and the trade between the West Coast of Africa and South America, a large black population moved to South and North America.
