Small Mobile Robot Research Articles

Clarifying Ideas on Fuzzy Logic by Using Mobile Robots

We report students’ experiments with a small mobile robot Khepera developed in the Microcomputing Laboratory of Swiss Federal Institute of Technology (LAMI‐EPFL). Khepera makes teaching of fuzzy‐control theory easier and more compelling for students. In the experiments, reported in this paper, students learn how to implement a simple fuzzy control algorithm for obstacle avoidance. The students have to build a fuzzy controller step‐by‐step using software package LabVIEW. Although very simple, this experiment focuses on methodology required for building controllers based on fuzzy logic. It allows students to understand basic fuzzy logic concepts, the advantages and drawbacks of fuzzy controllers as well as the difficulties of their practical design.

Video plane robot swarms

This paper proposes a novel and practical method of controlling a very large number of small mobile robots undertaking a cooperative task simply by the use of a TV monitor or projector as the control surface and an overhead camera as an observer and communications receiver. An implementation to test this concept is described to give some indication of the potential of this methodology. Ultimately, many tasks such as carrying, sorting, cleaning, material handling, cutting and assembling could be carried out using such an approach. Specialized robots can be mixed and mathced to meet the task requirements which can themselves change from time to time.

Distributed control of a team of mobile robots

The coordination and control of a team of small mobile robots may be achieved by enforcing both positional and orientational constraint conditions so that the formation is maintained during the process of transporting a large and heavy object by the team. When they travel on the road with uneven surfaces, heights of some grippers of the arms on the mobile robots must be adjusted by moving their joints so that they all are at an even level of the object. Stability of the formation is presented in terms of the bound of the transient response of the team.

Mobile robots for difficult measurements in difficult environments: Application to aging aircraft inspection

This paper describes a systematic approach to using robots to automate making difficult measurements in real-world environments. The approach is illustrated by a detailed description of the architecture's actual application to inspection of commercial aircraft for skin cracks and skin joint delamination. Several robot designs are evaluated; a small mobile robot with suction cup feet is found to be best in the practical context of commercial aircraft maintenance and inspection. Approaches are discussed for primary eddy-current flaw detection sensor signal understanding and for secondary vision-based guidance image understanding. The prospects for vision-based inspection are discussed.

Neural chip for fast pattern matching

The AT&T Bell Labs' neural circuit NET32K is used to increase the speed of image processing in association with a small mobile robot. The neural accelerator was built around an MC68340 microcontroller and the NET32K circuit. Use of field programmable gate arrays minimizes board size and power consumption. Extracting contours, recognizing objects and obtaining a usable measure of distance was achieved with this interface to make robot guidance possible.

A decision-theoretic approach to planning, perception, and control

The application of Bayesian decision theory as a framework for designing high-level robotic control systems is discussed. The approach to building planning and control systems integrates sensor fusion, prediction, and sequential decision making. The system explicitly uses the value of sensor information as well as the value of actions that facilitate further sensing. A stochastic decision model and a model for mobile-target localization used in the control system are described. A control system implemented to drive a small mobile robot equipped with eight sonar transducers with a maximum range of six meters and a visual processing system capable of identifying moving targets in its visual field and reporting their motion relative to the robot is also discussed. >

Development of a Laser Range Sensor for a Mobile Robot

External sensors which can detect environmental information are important for a mobile robot to recognize its surroundings and location. Among external sensors, range sensors are fundamental because they can directly detect the free space in which the mobile robot can move without colliding with the surrounding objects. A laser range sensor provides good spatial resolution, and it is expected to detect characteristic parts of the environment used as landmarks for recognizing robot position. This paper presents the construction of a laser range sensor system which can be implemented in a small mobile robot. The system consists of several components including laser diode, CCD camera, and mark detection hardware. Based on triangulation method, the system can detect the distance to the object's surface on which the beam spot is directed. In order to detect a landmark, such as a wall edge, the sensor system is mounted on a rotary table. By horizontally scanning, the sensor can detect wall edges with an accuracy of approximately 5mm and an orientation accuracy of approximately 1 degree within 3m. This system has been installed in an indoor mobile robot and is used for autonomous navigation control along corridors.

A Study on In-Pipe Insepection Robots. (4th Report. Mechanism and Control Method of Cordless Small In-Pipe Mobile Robots Using Giant Magnetostrictive Alloy).

This paper deals with a small in-pipe mobile robot using the giant magnetostrictive alloy as actuators, which does not require any power supply codes. This cordless mobile robots can be controlled by the magnetic field supplied by the outer side. The mechanisms of the motions are based on the inch worm type of mobile mechanisms. In this paper, two mechanisms are shown: (1) the reversible motion and (2) the one-way motion mechnisms. The sizes of the robots are 21mm in diameter for the reversible motion and 6mm in diameter for the one way motion. The motion is controlled by the regulated motion of the outer electro-magnetic coil, so that the in-pipe mobile robot can follow the outer coil. This small mobile robot has many possible applications for the small pipe inspections, bio-medical fields and others.

Low-level-vision in an autonomous mobile robot

This paper points out the sensor system of a small mobile robot (a so called Micro Mouse), which consists of three CCD line scan cameras. The problem of the maze robot is to find the goal in the center of a maze. In contrast to the existing developments a maze robot with three CCD cameras was designed, which calculates the distance to the walls by the detection of the intensity change from the black floor to the white walls. The whole signal processing is done onboard in the small robot. This development was the base for the later construction of small laser rangefinders and at least a laser scanner, which is used in our autonomous mobile robot (MOBOT-III).