Torsten Schönberg

Motion control of a spherical mobile robot

The paper deals with dynamics and control of a special type of mobile robot designed to act as a small platform to carry sensing devices or actuators in an environment where stability of the platform is critical, like in surveying unstructured hostile industrial environment exploring other planets, or simply being a part of a human place, like office or home, which has not been designed for mobile machines. The spherical construction offers extraordinary motion properties in cases where turning over or falling down are risks for the robot to continue its motion. Also it has full capability to recover from collisions with obstacles or another robots traveling in the environment.

Positioning an autonomous off-road vehicle by using fused DGPS and inertial navigation

This paper deals with a positioning system for an autonomous vehicle ARSKA. Localization of the vehicle is based on fusion of internal dead reckoning navigation and periodic absolute position measurements. Fusion is performed by using a Kalman-type filtering technique. A similar kind of approach is used in correcting the heading measurement. This is important because the position error is mostly the result of the accumulated heading error. The resulting accuracy depends on the accuracy of the dead reckoning estimation and on the accuracy and frequency of the absolute position measurement. As an absolute position measurement system, several alternatives can be used. Two different systems have been used with the vehicle: an external optical measurement device, tachymeter, and different combinations of DGPS. A real guarding application will be discussed in the paper.

The concept of robot society and its utilization

Societies are formed as collaborative structures to execute tasks which are not possible or are difficult for individuals alone. There are many types of biological societies, but societies formed by machines or robots are still rare. The concept offers, however, interesting possibilities especially in applications where a long term fully autonomous operation is needed and/or the work to be done can be executed in a parallel way by a group of individuals. The paper introduces the basic control and communication structures of robot societies by using a model society. Also, a mini-scaled mobile robot which is under construction to be multiplied for the corresponding physical society demonstrator is introduced. Simulation results illustrating the behaviour of the model society are given. Possible applications in waste treatment and process monitoring and cleaning are considered.<<ETX>>

An Application Concept of an Underwater Robot Society

Cooperation as a mean to adapt to dynamic environments is well known in animal world from the social insects up to primates. But similar behavior seems to exist also in simple unicellular microbes. In this paper a novel approach for a very application oriented multi-agent system is taken. The principles of this robot society are derived from bacteria, which are here considered as multicellurar organisms. The analogy from Nature includes bacteria’s ability to communicate through chemical substances, to form a colony (a society) and to act as a predator hunting for food. The concept is tested in simulations, where the behavior of the society is used to demonstrate how the extensive use of chemical in a closed water circuit for algae removal could be minimized with a collective cooperation of mobile underwater robots. Additionally, some early tests with the first generation society member will be shown in order to validate some of the simulation results including a simple topological mapping and navigation method.

Bacterium Robot Society-A biologically inspired multi-agent concept for internal monitoring and controlling of processes

Societies are formed as collaborative structures to execute tasks that are not possible or are difficult for individuals alone. There are many types of biological societies formed by animals, but societies formed by machines or robots are still rare. This paper introduces the concept of an application oriented robot society formed by autonomous underwater robots. The Bacterium Robot Society is a generic concept with many potential applications. As an example of such application a scenario, where robot society serves as a mobile distributed sensor instrument inside a process plant, is presented.

Positioning an Autonomous Off-Road Vehicle by Using Fused DGPS and Inertial Navigation

Abstract The paper deals with positioning system for an autonomous vehicle ARSKA. Localization of the vehicle is based on fusion of internal dead reckoning navigation and periodic absolute position measurements. Fusion is done by using Kalman-filtering technique. Similar kind of approach is used in correcting the heading measurement. This is important because the position error is mostly result of the accumulated heading error. The resulting accuracy depends on the accuracy of the dead reckoning estimation and on the accuracy and frequency of the absolute position measurement. As an absolute position measurement system several alternatives can be used. Two different systems have been used with the vehicle; an external optical measurement device, tachymeter, and different combinations of DGPS. Also a real guarding application will be discussed in the paper.

Optimizing the Performance of a Robot Society in Structured Environment Through Genetic Algorithms

Societies are formed as collaborative structures to execute tasks that are not possible or are otherwise difficult for individuals alone. There are many types of biological societies, but societies formed by machines or robots are still rare. The concept offers, however, interesting possibilities especially in applications where a long term fully autonomous operation is needed and/or the work to be done can be executed in a parallel way by a group of individuals. To explore these features a foraging society formed by several autonomous mobile robots working in structured environment was defined. The society members have restricted communication properties and their work is evaluated and controlled when needed by an outside operator. So far the problems for the societys functional optimization with a simulator have been caused by the large number of parameters with built-in cross relations and by the strong dependence on a given environment. To deal with these problems and to provide the society ways to adapt itself to changing circumstances Genetic Algorithms were applied. The concept was tested with simulations, which indicated the existence of adaptation both at the individual member level and at the higher society level.

Group Behavior of a Mobile Underwater Robot Society Destroying Distributed Targets in a Closed Process Environment

Abstract In this paper a group behavior of a novel underwater robotic system is considered. The society maps an initially unknown process environment and then collectively removes distributed targets. The operation of robots is based on FSA representation combined with task performance evaluation and inter-robot communication.

Underwater robot society doing internal inspection and leak monitoring of water systems

In the field of civil engineering an effective internal monitoring of pipes and water storage is very problematic. Normally the sensors used for the task are either fixed or manually movable. Thus they will only provide locally and temporally restricted information. As a solution an underwater robotic sensor/actuator society is presented. The system is capable of operating inside a fluid environment as a kind of distributed sensory system. The value of the system emerges from the interactions between the members. Through a communication system the society fuses information from individual members and provides a more reliable estimate of the conditions inside water systems. Tests results in a transparent demo process consisting of tanks and pipes with a volume of 700 liters are presented.

Evolving of a Fitness Based Operation Strategy for a Robot Society

Abstract An evolving fitness based foraging and exploration strategy for a robot society formed by cooperative autonomous mobile robots in a spatially and temporally dynamic environment is presented. The operation of multiple behaviour-based robots is controlled by an outside operator through modifications in members’ fitness functions. With a certain type of function formulation a collective society behavior will emerge and improve the society’s operation. The suggested concept is verified with simulations and some near future physical realizations are also presented.