Pawel Andrzej Laski

A fuzzy logic controller for the positioning control of an electro-pneumatic servo-drive

The main objective of our research project was to design an electro-pneumatic servo-drive positioning control system, which involved applying a fuzzy logic controller. A proportional–derivative fuzzy logic controller was selected to perform position changeover, follow-up, and teach/playback control. These methods of control are essential in automation equipment, such as pick-and-place machines, manipulators, and robots. Compared to the smart positioning controller SPC200, the proportional–derivative fuzzy logic controller demonstrated superior accuracy required for industrial pneumatic manipulators.

Design of a 3-DOF tripod electro-pneumatic parallel manipulator

The objective of the research project was to design and construct a 3DOF tripod-type electro-pneumatic parallel manipulator that could be used for pick-and-place tasks in municipal waste recycling facilities. The fundamental requirement was that the manipulator be simple and cheap to construct, operate and maintain as well as robust and resistant to damage. The forward and inverse kinematic problem as well as working space and strength analysis issues were used for construction of manipulator. The prototype was tested using different payloads and velocities to establish its positioning accuracy and repeatability. The robot behavior was controlled with a commercially available industrial controller, which was reported insufficient for point-to-point operations required during solid waste handling. Conclusions have been drawn on how to optimize the robot structure and control. Conceptual design and analysis of the 3-UPRR parallel manipulator are performed.Kinematics analysis are carried out for the proposed 3-DOF robot.Electro-pneumatic parallel manipulator.

Determining the Static Characteristics of Pneumatic Muscles

This paper discusses a test stand and methods used to determine static—isobaric, isotonic and isometric—characteristics of two pneumatic muscles: a Festo Fluidic Muscle MAS and a Shadow Air Muscle. The data obtained from the experiments were applied to analytically determine the equations of static characteristics of the pneumatic muscles. The equations were then employed to obtain simulated static characteristics. The experimental characteristics were compared with the simulated ones.

Fuzzy Logic Positioning System of Electro-Pneumatic Servo-Drive

Development of automation and robotization in manufacturing process stimulates interest in pneumatic servo-systems whose advantages include low manufacturing costs, high dynamics and reliability (Situm et al., 2004). Unsatisfactory positioning accuracy of multiaxis pneumatic servosytems considerably reduces their application in manipulating machines, manipulators and robots. Rapid advance in parallel pneumatic manipulators imposes a lot of demands on controllers of pneumatic servo-drive concerning positioning accuracy, resistance to alternating parameters of state and disturbing signals (Dindorf et al., 2005; Takosoglu & Dindorf, 2005; Schulte & Hahn, 2004). The problem of positioning accuracy of servo-pneumatic systems is difficult to solve when no sufficient information on the process of conversion of the compressed gas energy into mechanical energy of pneumatic cylinder is available (Zhu, 2006; Takosoglu, 2005). Because of that, new control methods based on artificial intelligence, for example, fuzzy logic are introduced (Schulte & Hahn, 2004; Renn & Liao, 2004; Dindorf & Takosoglu, 2005). In traditional control systems of pneumatic servo-drives control algorithms are designed intuitively on the basis of operator’s experience. In fuzzy control the knowledge coded in knowledge base is the result of experience, intuition as well as theoretical and practical understanding of control system dynamics which in this case is the dynamics of pneumatic servosystems. Thanks to fuzzy logic the operator’s knowledge can be represented by means of mathematical operations. Fuzzy control enables moving from qualitative to quantitative control of pneumatic servodrive. Application of fuzzy controller makes control of multiaxial pneumatic sevosystems possible in manipulators and robots of various kinematic structures: series, parallel or hybrid series/parallel. Advancements in software for rapid prototyping in real time and in hardware-in-the-loop simulations enable to construct and test positioning fuzzy control (Bucher & Balemi, 2006) of pneumatic servo-drives in laboratory conditions. Such an approach minimizes the design costs of control systems of pneumatic servo-drives. Pneumatic servo-drives with teaching/playback control system have considerable practical significance, especially in the control of manipulating machines, manipulators, industrial robots as well as rehabilitation and physiotherapy manipulators. 13

Design of a Test Stand for Rolling Bearing Durability Testing

The paper presents a design basis adopted for the construction of a test bench for rolling bearing durability testing. This article presents preliminary engineering requirements and the design of a special test rig for the examination of rolling bearings without the necessity of mounting the bearings in a specific machine component unit. The rig testing is widely used in consideration of numerous good points of such a method. The on test rigs consists in reproducing as accurately as possible the real conditions of operation of the bearings when mounted in the device for which they are intended. The device allows is capable of testing the running characteristics of bearings under varying test conditions and loads, speeds, lubrication conditions and temperatures. In addition they allow to test the service life under the set operating conditions.

Acquisition of Measurement Data on a Stand for Durability Tests of Rolling Bearings

A stand for durability testing of rolling bearings is presented in this paper. The project assumptions of the stand, mechanical construction and architecture of data acquisition and analysis system (hardware and software) are described in this paper. Finally, there are conclusions about stand’s capabilities included. The device allows is capable of testing the running characteristics of bearings under varying test conditions and loads, speeds, lubrication conditions and temperatures. This stand provides precise measurements and autonomic work which is necessary in long-term researches. Compact construction of the stand containing overload protection system and automatic turn off system, activated after exceeding limit values of operating parameters or diagnostic signals, allows autonomic work without frequent human supervision. The data obtained from the stand will be used in future researches. In addition, they allow to test the service life under the set operating conditions.