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Presents a robot control system dedicated to grinding large Francis turbines. The control system is based on an active force feedback system using a three‐axes force sensor attached to the robot’s end effector. This system offers high flexibility and robustness against workpiece positioning and grinding tool wear. It provides control of the grinding process parameters ensuring high productivity in addition to good grinding performance and grinding tool economy. The system was experimentally tested out on a MultiCraft 560 grinding robot.

The third in a series giving suggestions for laboratory work on the various types of machine tool

IN modern machining practice, precision grinding (the operation known in France as “rectification” is carried out on a limited number of parts and the use of the term immediately suggests the type of component usually subjected to this method of working—the gear wheel.

The purpose of this paper is to propose a robot constant grinding force control algorithm for the impact stage and processing stage of robotic grinding.

The robot constant grinding force control algorithm is based on a grinding model and iterative algorithm. During the impact stage, active disturbance rejection control is used to plan the robotic reference contact force, and the robot speed is adjusted according to the error between the robot’s real contact force and the robot’s reference contact force. In the processing stage, an RBF neural network is used to construct a model with the robot's position offset displacement and controlled output, and the increment of control parameters is estimated according to the RBF neural network model. The error of contact force and expected force converges gradually by iterating the control parameters online continuously.

The experimental results show that the normal force overshoot of the robot based on the grinding model and iterative algorithm is small, and the processing convergence speed is fast. The error between the normal force and the expected force is mostly within ±3 N. The normal force based on the force control algorithm is more stable than the normal force based on position control, and the surface roughness of the processed workpiece has also been improved, the Ra value compared with position control has been reduced by 24.2%.

As the proposed approach obtains a constant effect in the impact stage and processing stage of robot grinding and verified by the experiment, this approach can be used for robot grinding for improved machining accuracy.

Grinding cutting tools is usually done dry because of the need to watch the zone of contact of tool and wheel, but dry grinding can cause cracking of the tool and the use of atomized coolants is more acceptable since the worker can observe the contact zone. Work on this has been done at the Gor'kov plant in Russia and it was found that the best design of nozzle and mixer for this work was as illustrated, and this was used in these tests as shown in the diagrammatic arrangement.

This paper discusses research on machining and repairing of turbomachinery components which are generally complex geometries and made up of difficult to machine materials (nickel super alloys or titanium alloys).

The approaches, methods and methodologies used for machining and repairing of blades are reviewed as well as the comparisons between them are made.

Particularly, the most recent blade machining and repair techniques using high flexible machine tools and industrial robots, are mentioned.

The limitation of the approaches, methods and methodologies are given and supported by real practical application examples.

This paper presents a state of the art review of research in machining and repairing of turbomachinery components, which have been mainly done in the last decade. The paper act as a reference, gathering the works about turbomachinery components from a manufacturing point of view.

In this paper a Virtual Reality (VR) based interactive system for specifying robotic tasks using virtual tools is described. This environment allows an operator to reach into a live video scene and direct robots to use corresponding real tools in complex scenarios that involve integrating a variety of otherwise autonomous technologies. The attribute‐rich virtual tool concept provides a human‐machine interface that is robust to unanticipated developments and tunable to the specific requirements of a particular task. This interactive specification concept is applied to intermediate manufacturing processes such as robotic based grinding and polishing. Further, in this research, when the operator selects a virtual tool by “clicking” on an icon of the desired tool in a virtual toolbox, a representation of the real‐world tool, laden with associated attributes is displayed. A new flavor of tool is created from the parent class when desired. According to operating constraints, new subclasses, which are offspring of the parent tool class, are derived. A specific instance of a tool can be evoked from any of the derived subclasses. Such attribute laden virtual tools enable easy control of otherwise complicated manufacturing task planning. This paper also explores the use of JAVA applet based interface for using these tools over the Internet. Successful implementation of such a Web‐based system will open the door to the use of robots in many other human intensive manufacturing processes.