Constantin Bucşan

Hardware Structures for High Precision Pneutronic Systems

Pneutronic systems come with a series of advantages that are natural to working with compressed air, such as the large power/weight ratio of pneumatic actuators, easy and affordable installation and maintenance as well as being clean working systems. However, due to working with compressed air, there are a series of issues, such as static and transient nonlinear behavior, mostly due to the high compressibility of air. Thus, the behavior of such systems is hard to control, especially in terms of precision positioning. The paper deals with proposing three hardware configurations of pneutronic positioning systems in order to assure the imposed positioning accuracy in the presence of disturbances and the preservation in time of the obtained position.

PWM Controlled Proportional Equipment

The paper presents an experimental model of PWM controlled proportional pneumatic direction control valve developed by the authors, as well as the functioning of a pneumatic system that incorporates the original solution of valve. The main parameters that control the system can be settled using a software application developed for that purpose.

Hardware structures of hydronic systems for speed control

Most hydraulic actuating systems use constant flow pumps, for economic reasons. The resistive method is then used to control the speed of the actuated load. In the case of high performance systems the flow area is modified using analogical or numeric electric commands applied to proportional flow control devices. In the first part of the paper some hardware structures of hydronic actuating systems used for speed control are presented, and in the second part two experimental models of such systems are presented. Some aspects regarding the output improvement of such a system are also considered.

Hydraulic Control of Speed and Position of a Pneumatic Actuator

The paper presents an original pneumo-hydraulic system that controls the speed and the position of the actuated load by using a hydraulic circuit containing a hydraulic proportional throttle. A mathematical model of the solution is developed and numerical simulations are performed. The experimental results obtained on the built model confirm the theoretical ones.

Influence of the Flow Section Geometry on the Static Characteristic Curves of Proportional Hydraulic Throttle Valves

Various constructive versions of hydraulic units found in the structure of proportional hydraulic equipment are analysed in the paper. For each version, the authors establish the variation law of the flow section in function of the position of the adjusting element in relation to the reference position. The approach is useful when a theoretical analysis of a proportional equipment is needed, as well as when the characteristic diagrams of the equipment are theoretically established.

Gripper System for Handling the Book on the Library Shelf Out

The paper deals with a method applied for handling the book on the library shelf out by using a specialized gripper. The main advantage is the gripper positioning along the symmetry axis of the founded book spine, so that the fingers controlled with high accuracy could retrieve it. The vision camera has been used for processing the information, so that we have written the software using Microsoft Visual Studio. The proposed method may find out the room existing between nearby books as well as the one needed along the vertical axis. The required room for movement has the minimum value due to the bottom finger thickness and the vertical displacement is proposed mainly.

Proportional Hydraulic Flow Control Valves with Simple and Differential Command

The paper brings in an original solution of proportional hydraulic flow control valve, which can function with both simple and differential command. The static adjustment characteristic of this equipment is analyzed. Also, two systems that integrate the discussed equipment are taken into account.

Incremental Pneumo-Hydraulic Positioning Unit

The paper describes the construction of an original linear pneumo-hydraulic positioning unit developed by the authors. The mathematical model that describes the functioning of the unit and the simulation results are also presented.

On Mechanical Amplification of the Piezoelectric Actuators Displacements

The paper deals with improving the mechanical characteristics of piezoelectric actuators. This type of actuators can be found in many mechatronic systems, but they have a great disadvantage consisting in the small displacements they produce. The paper presents five mechanical structures designed and manufactured to amplify the displacements produced by piezoelectric actuators.

Mechatronic Designed Hydraulic Positioning System

The paper presents the hardware structure of an original hydraulic positioning system based on a mechatronic approach. Dedicated control algorithms are also presented.