Strong international competition forces enterprises to reduce organizational overhead and cost. Today's industrial practices allow, in general, only the selection of whole planning and control systems for CIM (e.g...
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Strong international competition forces enterprises to reduce organizational overhead and cost. Today's industrial practices allow, in general, only the selection of whole planning and control systems for CIM (e.g., CAD systems, PP&C systems,...). These systems can be adapted only in a limited range to the user requirements. With the introduction of executable enterprise models to the industrial environment, it is expected that it will be possible to design tailored CIM systems built of standardized software modules which will lead to higher complexity of the planning process for software systems. Thus, today's planning and selection approaches will face more and more problems. In order to master the increasing complexity of the planning of software systems for enterprises, new planning methods and tools are required. An integrated approach to software system planning and selection based on CIMOSA enterprise models was developed. The underlying idea of the approach is the conversion of the planning problem into an equivalent constraint satisfaction problem. The conversion process can be accomplished fully automatically.
The use of manipulator systems with many degrees of freedoms is essential to expand the field of potential applications. This paper presents a distributed approach for executing task-level programs for cooperating man...
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The use of manipulator systems with many degrees of freedoms is essential to expand the field of potential applications. This paper presents a distributed approach for executing task-level programs for cooperating manipulators or one-arm systems with many degrees of freedom. At task level, only the movement of the objects to be manipulated is specified. The according manipulator motions are then calculated by assigning local intelligence to each joint. The local intelligence enables the joint agents to calculate in parallel their appropriate movements to make the end effector reach the desired position. During execution, each joint evaluates sensor data to compensate for execution errors, to react on unexpected obstacles and to provide the manipulator coordination. Therefore, a distributed fuzzy rule base has been developed. As this local evaluation may lead to non-optimal overall behavior of the manipulator, the joint agents communicate to provide global suboptimality.
A mobile robot that navigates in an unknown or changing environment needs to maintain a dynamic model of its environment in order to update existing knowledge about the world. This paper addresses the problem of how t...
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A mobile robot that navigates in an unknown or changing environment needs to maintain a dynamic model of its environment in order to update existing knowledge about the world. This paper addresses the problem of how to update a local model of the perceivable environment of a mobile robot and how to produce a description of newly perceived obstacles. A new hybrid concept is presented which combines the advantages of parameter- and grid-based modelling techniques. By introducing local grids that only cover areas where new obstacles are expected, the complexity of the map building process is significantly reduced. Local grids can be used in dynamic environment which was not possible with earlier grid-modelling approaches. The information, grids are constructed from, is provided by ultrasonic range sensors and an active stereo-vision system, Fusing information of both sensor systems is advantageous, especially due to their complementary error characteristics concerning range and angular resolution.
Intelligent control architecture of autonomous robot systems must be modular, scaleable, extendible, and adaptable to the available capacity of computercontrol systems. For the support of these properties, the concep...
Intelligent control architecture of autonomous robot systems must be modular, scaleable, extendible, and adaptable to the available capacity of computercontrol systems. For the support of these properties, the concept of adaptive control structure, ACS, is presented in this paper. Experiments with small autonomous assembly robot show the successful use of ACS.
Programming by Demonstration (PbD) is an intuitive method to program a robot. The user, acting as a teacher or programmer, shows how a particular task should be carried out. The demonstration is monitored using an int...
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Programming by Demonstration (PbD) is an intuitive method to program a robot. The user, acting as a teacher or programmer, shows how a particular task should be carried out. The demonstration is monitored using an interface device that allows the measurement and recording of both the applied commands as well as the data simultaneously perceived by robot’s sensors. This paper identifies the kind of knowledge that the robot can actually acquire from the human user through demonstrations and the requirements that must be met in order to be able to interpret what has been demonstrated. Finally, it presents and experimentally evaluates an approach to integrated acquisition, evaluation, tuning, and execution of elementary skills and task-level programs for robots based on human demonstrations.
This paper discusses the design of neural networks to solve specific problems of adaptive control. In particular, it investigates the influence of typical problems arising in real-world control tasks as well as techni...
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This paper discusses the design of neural networks to solve specific problems of adaptive control. In particular, it investigates the influence of typical problems arising in real-world control tasks as well as techniques for their solution that exist in the framework of neurocontrol. Based on this investigation, a systematic design method is developed. The method is exemplified for the development of an adaptive force controller for a robot manipulator.
Performing fine manipulations with multifingered robot hands makes high demands on the control algorithms and the speed of the controlcomputer. Mainly non-linear friction problems and plant uncertainties require inte...
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A good map of its environment is essential for efficient task execution of a mobile robot. realtime map update, especially in dynamic scenes is a difficult problem due to noisy sensor data and limited observation tim...
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A good map of its environment is essential for efficient task execution of a mobile robot. realtime map update, especially in dynamic scenes is a difficult problem due to noisy sensor data and limited observation time. The paper describes a mapping procedure which identifies new obstacles in a scene and constructs a 3D surface model of it. This description is included in the geometrical map which robot navigation relies on. The mapping procedure is based on sonar range information and scenes reconstructed from stereo vision. The combination of sonar and stereo vision is advantageous, due to a complementary error characteristic concerning range and angular resolution. For sonar data integration the idea of local probability grids is proposed. Local grids which only cover areas where new obstacles are expected, reduce the complexity of grid based sonar data integration and can be applied to a dynamic environment. The partial models of an object that has been observed from different viewpoints are fused to a homogeneous description in a later step. A complex example shows the mapping procedure work robustly in dynamic indoor environments.
This paper presents a new approach for on-line collision-free path planning of a two-arm manipulator system, integrated in an on-line task-level planning system. For service and assembly tasks, pick and place operatio...
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This paper presents a new approach for on-line collision-free path planning of a two-arm manipulator system, integrated in an on-line task-level planning system. For service and assembly tasks, pick and place operations are requested asynchronously by the action sequence planning. Collision-free paths for independent tasks are planning using a 2D geometric model in consideration of the swept regions by the robot arms and the pay loads during their motions. A dynamic, deadlock-free scheduling concept coordinates the robot motions in the case that a collision-free path for one arm can not be found at moment. The on-line path planning for two-arm cooperations for exchanging and regrasping parts incorporates an off-line connectivity analysis, avoiding both collisions and kinematic restrictions. The implemented on-line planning system can generate collision-free path for one manipulator while the other is moving. The time needed for motion planning is in the average case shorter and in the worst case comparable with that needed for motion execution. Experiments have been successfully conducted with the mobile two-arm robot KAMRO at the author's institute.
With high speed control applications it is often very difficult to achieve the aspired timing of the control algorithm using just one processor. This is true especially if the system is complex or very large. In this ...
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With high speed control applications it is often very difficult to achieve the aspired timing of the control algorithm using just one processor. This is true especially if the system is complex or very large. In this paper we discuss advantages and disadvantages of a new system architecture using many processors of which each one is specialised for one part of the algorithm. A tailorable parallel computer architecture which we developed to cope with the problems of parallelisation of control algorithms is presented. Finally examples from the field of robotics and the performance of the prototype computer is presented.
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