Precise force control for hydraulic and pneumatic press system

Abstract

Design and layout:University of Maribor Press No. of Copies 120Published in: September 2017 © University of Maribor PressAll rights reserved. No part of this book may be reprinted or reproduced or utilized in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publisher. The International Fluid Power Conference is a two day event, intended for all those professionally-involved with hydraulic or pneumatic power devices and for all those, wishing to be informed about the 'state of the art', new discoveries and innovations within the field of hydraulics and pneumatics. CIP -Kataložni zapis o publikacijiThe gathering of experts at this conference in Maribor has been a tradition since 1995, and is organised by the Faculty of Mechanical Engineering at the University of Maribor, in Slovenia. Fluid Power conferences are organised every second year and cover those principal technical events within the field of fluid power technologies in Slovenia, and throughout this region of Europe. This year's conference is taking place on the 14th and 15th September in Maribor.We wish all participants at the International Conference-Fluid Power 2017 continued successful professional work, and hope that we have yet again added another small piece within the mosaic of fluid power. 1The role of pneumatics in digital systems Industry 4.0 represents a future where intelligent machines are self-aware and automation challenges can be solved by the machinery itself. In the factory of tomorrow, cyber-physical systems will communicate with one another using the Internet of Things. Microsystems will make decisions autonomously and highly sensitive robots will support employees so that they can continue to work, even in their later years.Pneumatic applications are sturdy and reliable, which from an Industry 4.0 perspective might also be interpreted as inflexible. For pneumatics, this concept seems to leave only peripheral tasks. Simple, repetitive tasks might remain under the control of some intelligent sub-system. The "natural" motion for intelligent cyberphysical systems seems to be driven electrically.For machine builders and machine operators pneumatic controls come with some additional challenges, since every logical function comes encapsulated in a physical valve. Changing the functionality means exchanging the valve. This also means that potentially a lot of valves and other pneumatic function elements such as throttles are kept on stock resulting in costs. Pneumatic valve terminal with controller and multiple functions, where any combination of functions can be implemented, but changing functions requires physical changes is shown in Figure 1. Digital pneumaticsAs a response to above mentioned challenges, Festo has developed the Festo Motion Terminal, the world's first standardised platform that will develop into a "cyber-physical system" thanks to its intelligent fusi...

Uniformly ultimately bounded tracking control of sandwich systems with nonsymmetric sandwiched dead-zone nonlinearity and input saturation constraint

“…Note To structure the sandwich system in Figure 1, the actuator piston with load is represented by the S2 subsystem, the moving direction of the pilot valve piston on the fluid orifice represented by the dead-zone nonlinearity , and the S1 subsystem represents the dynamic equations of the motor and pilot valve piston. The force balance equation for the hydraulic actuator can be obtained as below (Benić et al, 2017). where M and xp represent the mass of load and its displacement, respectively.…”

Control of a Pneumatic System for Material Strength Testing

“…The dynamic model of the pneumatic cylinder is obtained using the expression for the balance of forces of the mechanical system, assuming that air is an ideal gas. From [9], the reaction force of the test specimen is represented as a spring force. Given that dynamic testing of materials is primarily conducted within the elastic region of the material, such a representation of the reaction force is valid.…”

Simulative investigation of hybrid force and position control for electromechanical feed axes in production machines

“…A fuzzy controller in combination with a mixed force output control structure was designed in order to achieve precision force control. Benic et al 18 present approaches of force control methods for a pneumatic press and a hydraulic press. Practical use and effectiveness of proportional-integral (PI) and proportional-integral-derivative control algorithms for precise force control, which is required in modern industrial plants, are investigated.…”