László Vajta

Micromanipulation Sensor Structure: A New Approach

Abstract This paper presents robot vision sensors that can be used in a micromanipulation working cell. The cell includes a piezoelectric microrobot capable of moving over long distances and manipulating in the range of few micrometers. The transport sensor consists of a laser tracking unit in order to follow the movements of the microrobot. The manipulation sensor uses image processing methods to determine the position and the orientation of the micromanipulator in the field of sight of a microscope.

Design of an Internet-Based Tele-Microrobotical Laboratory Assignment

This paper describes the design of a distributed laboratory exercise intended for M.Sc. level students of Technological Educational Institute of Piraeus in Athens and the Budapest University of Technology and Economics. M.Sc. students with specialization in control of autonomous systems have to design, implement and test a sensor-coupled robot control algorithm via Internet.

Simultaneous localization and mapping using adaptive appearance based loop-closing detection

Visual appearance based scene recognition has been widely studied in the past decade. However, such systems still present failures in dynamic, heterogeneous urban environments. This paper presents a methodology in order to integrate an advanced Adaptive Appearance Based Loop-Closing Detection algorithm into a graph optimization based Simultaneous Localization and Mapping algorithm. The system described uses stereo visual data, captured in discrete locations in order to detect loop-closure situations and to build, respectively update the topological map of a large, complex environment.

Optical Speed Measurement and Applications

Mobile robot navigation is a well researched discipline, looking back to a relatively long history however it is still a rich, active area for research and development. The ultimate goal for robots and intelligent vehicles seems to be autonomous navigation in complex real life scenarios. In order to achieve higher levels of autonomy sophisticated sensors and a sound understanding of the robot and its interaction with the environment is needed. The tasks involved can be divided to two basic categories; internal tasks involve keeping track of internal dynamic parameters, like speed accelerations, internal states etc. On the other hand the vehicle needs to be aware of external factors like obstacles, points of interest, possible routes from a to b and the respective costs. This is generally called robotic mapping. Intelligent Vehicle stands for a vehicle that senses the environment and provides information or control to assist the driver in optimal vehicle operation. Intelligent Vehicle systems operate at the tactical level of driving (throttle, brakes, steering) as contrasted with strategic decisions such as route choice, which might be supported by an on-board navigation system. (Bishop, 2005) Optical sensors supply by far the most information and as greater and greater processing capabilities become readily available their use becomes more widespread. Many researchers and companies have made more or less successful attempts at creating optical sensors for speed measurement, however to the knowledge of the authors no accurate high speed solution exist at the low price range. The aim of this article is to introduce a novel method for optical speed measurement and put it into perspective by summarizing other navigation methods and reviewing recent related work and possible applications. Also an introduction to optical flow calculation is given and practical considerations on texture analysis and sensor parameters are discussed backed up with simulation results.

Vision guided mobile platform for outdoor use in unstructured environment

This paper presents a mobile robot system with vision based teleoperation for the use in unstructured outdoor environment. Our system makes use of a camera-laser combined sensor system, which gives suitable information for the operator in such unstructured environments with homogenous reflection, as the surface of the frozen Lake Balaton. The role of the human vision is essential in visual guided teleoperation. A comprehensive overview of the humans 3D sensing, and the role of the different vision cues is introduced. The need for the combined 2D-3D vision, our approach for that and the first experimental results in teleoperation are presented.

Unknown object localization and identification in shallow water environment at Lake Balaton

This paper addresses a particular detection problem related to the largest freshwater lake of Central and Western Europe, namely the Lake Balaton. The bed-silt of this shallow water lake (its average depth is 3.3 meters) contains several type of objects: industrial debris, historical vestiges, and in particular, an unknown quantity of unexploded ordnance from the second World War. It is important to localize and classify these objects for precise risk assessment and eventual later removal (not addressed in the paper). The bed-silt of the lake can be characterized as a mud having a light and constantly changing structure. It follows that the shallow water is almost always mixed with the mud. This admixture is constantly maintained by winds and navigating boats, hence the underwater visibility is close to zero during the most part of the year, especially in the depth range close to the bottom. Since the climate makes it possible, the authors propose a special way to explore the bed-silt of the lake, namely the use an autonomous vehicle on the frozen lake. Note that the ice prevents the wind and navigating boats to generate water movement and thus the mud is sedimented. This autonomous vehicle is equipped with a GPS based onboard localization system, with multiple sensor and recording equipment, and with a radio link to its command post. More details about the nature of objects to be detected as well as about the architecture of the detection and localization system are presented in the paper.