The mobile service robots described are designed to operate in dynamics and changing environments together with human beings and other static or moving objects. Sensors that are capable of providing the quality of information that is required for the described scenario are optical sensors, like digital cameras and laser scanners. In this paper the sensor integration and fusion for such sensors is described. Complementary sensor information is transformed into a common representation in order to achieve a cooperating sensor system. Sensor fusion is performed by matching the local perception of the laser scanner and camera system with a global model that is being build incrementally. The Mahalanobis distance is used as matching criterion and a Kalman filter is used to fuse matching features. A common representation including the uncertainty and the confidence is used for all scene features. The system's performance is demonstrated for the task of exploring an unknown environment and incrementally building of the geometrical model.

Different powerful extensions and improvements of the control architecture of an autonomous robot are presented. They are used to increase the reliability of robot assembly and to reach a sufficient behavior. The decision to use autonomous assembly robots in an industrial manufacturing setting depends mainly on the reliability of such a system and the extension of its manipulation capabilities. The Karlsruhe Autonomous Mobile Robot (KAMRO) is a robot system that is able to take on, and to execute, assembly tasks autonomously. Although the robot was able to work without human intervention within a limited scope, the reliability of the system was unfortunately not adequate for large-scale applications. This paper describes how the reliability has been improved and which experiments were performed to evaluate the concept.>

Path generation execution and motion control for an omnidirectional mobile robot (vehicle) are considered. Real-time path generation is based on the polynomial spline-interpolation with prediction of velocities of a spline-function. The mobile vehicle control is performed with the use of its kinematic model and digital PID-controllers of the wheels. The theoretical approach is illustrated by the obtained experimental results.>

Besides the typical use of industrial robots in a manufacturing setting, new application areas for robots have been appearing during the past few years. In these areas, service robots perform general purpose activities without requiring repeated high speed movements or other requirements of industrial robot applications. For the development of service robots, the use and integration of research results obtained in the autonomous robot field is much more necessary than for the development of robots used in manufacturing. Both, high autonomy during service performance and simple system access, which also means flexible programming or user-friendly system control is desired over an easily operated man/machine interface. In this paper, properties of service robots are defined and some similarities and differences between service robots and fully autonomous robots are explained. The enhancement of an existing autonomous assembly robot, which is made to be a flexible service robot for industrial environments, is considered. The paper concludes with a running experiment, which shows how this robot prototype is used for different tasks in a manufacturing line.>

F/sub A/TE, an online task-level planning system for an advanced assembly robot consisting of two manipulators and a set of different sensors such as an overhead camera and force-torque sensors, is presented. The planning system takes an implicit description of the assembly task, plans a sequence of explicit robot commands and monitors the execution by the real-time robot control system. Because it runs completely online, the planning process is highly reactive using sensor information about the robot's present environment. This planning integrates as a key feature a dynamic mapping of assembly subtasks ready for execution onto the manipulators available at the moment. The system was implemented in Prolog on a SUN 4/75 SPARCstation running Unix.>

The design and experimental results for a suspension-shell tactile sensor are described. The sensor uses a suspension-shell mechanism to make the entire surroundings of a finger-body sensitive. The sensor detects the magnitude and the point of application of an external force operating on the shell by measuring the relative displacement of the suspension shell with regard to the finger-body. However, the force distribution is not provided since the sensor has no arrays, and the sensor records the actual force distributed over the surface area of the sensor shell as an integrated force at a single point of action. Sensing at the fingertip is excluded since the prototype sensor is designed for detecting lateral force rather than coaxial force for the first step. The sensor's basic characteristics and how it works in practice are shown.>

As an example of an autonomous assembly robot, the mobile two-arm robot system KAMRO, is described. The system is capable of navigating within an assembly cell, of docking at a work table, and of executing an assembly according to a given plan. A series of successful experiments has demonstrated the completely autonomous operation of the system.>

A proximity sensor is presented in which light is cast from a source point on an object through a slit cut in a rotating disk. The light passing through the slit is reflected onto the object's surface. Some of the reflected light is captured by a photodiode with the time period being recorded. The distance is determined from the function of the slit's shape and the time period when the photodiode captures the reflected light. The light-emitting mechanism makes it possible to measure the distance of an object repetitively. The distance measurement is neither affected by environmental illumination nor by attributes of the object such as diffusibility or reflectivity as far as there is light to reach the photodiode. Two profiles of the slit are discussed. One allows for easy fabrication and the other simplifies signal processing. The validity of the measurement concerning the two profiles is shown by experimental results.>

The architecture and functions of an autonomous mobile assembly system are described. For the operation of such a system, knowledge-based planning, execution, and supervision modules are necessary which are supported by a multisensor system. The individual functions of such a vehicle are explained with the help of an autonomous mobile assembly robot. The vehicle contains a navigator, a docking module, and an assembly planner. Navigation is done with the help of a road map under the direction of the navigator. The docking maneuver is controlled by sensors and the docking supervisor. The assembly of the two robot arms is prepared by the planner and controlled by a hierarchy of sensors. The robot actions are planned and controlled by several expert systems.>

The model of a man - machine - system is the basis of the proposed notation. It consists of the components man and machine. With these (statical) components a (dynamic) process, called man - machine - communication or man - machine - dialog, is realized.