R. Dindorf

Indirect Method of Leakage Flow Rate Measurement in Compressed Air Pipelines

The paper deals with new indirect methods of leakage flow rate measurement in compressed air pipelines. In this method the measurement equipment has branch connection to the pipeline. The measurement method consists in determining the relation between air leakage flow rate in pipeline and the controlled air flow rate through adjustable throttle valve. Compressed air leakage flow rate in pipeline is calculated on the basis of pressure ratio measurements in two time intervals - during leakage without the controlled flow and with the controlled flow in branch line. The controlled air flow through the throttle valve is directly measured by flow meter.

Contour Error of the 3-DoF Hydraulic Translational Parallel Manipulator

The paper deals with a selected problem of contour error for the desired tracking trajectory of the spatial 3-DoF hydraulic translational parallel manipulator (TPM). The prototype hydraulic TPM consists of a fixed base and a moving platform connected by the joints with three hydraulic linear axes. The closed-loop kinematic chains of the hydraulic TPM create a 3-RRPRR structure in which revolute joints R and prismatic joints P step out. The three equal integrated electro-hydraulic axes are prismatic joints P in which hydraulic cylinders are integrated with position measuring systems and proportional directional control valves.

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

Modeling and Analysis of the Hydraulic Servo Drive System

In the hydraulic servo drive appear structural nonlinearities which cause that designing nonlinear control of the position and power system is hampered. In the article a mathematical model of the servo drive hydraulic control was described. It is useful for the synthesis algorithms in the simulation model. The calculation diagram of the hydraulic servo drive model consisting of the double-acting cylinder with one-sided piston rod and directional control valve was presented. There were presented characteristics of: displacement, velocity, acceleration and pressures as well as the displacement of spool valve at mass load. An algorithm of control the nonlinear object was adapted by using the linearization method of the model process. Simulation examinations will serve for developing the control algorithm which will enable the compensation influences of disruptions such as: friction and changeable load powers mass.

Synchronized Trajectory Tracking Control of 3-DoF Hydraulic Translational Parallel Manipulator

The paper deals with a cross-coupled control approach to the spatial 3-DoF hydraulic translational parallel manipulator. The control system of the cross-coupling control (CCC) has been proposed in order to reduce the contour error for three electro-hydraulic axes. Control of the manipulator takes into account not only the position errors for each drive axis but also synchronization errors of neighboring axes. Cascade control system with inner and outer loop was proposed. Decentralized tracking system allows to adjust the trajectory of disturbances in the internal loops it is based on the defined synchronization of errors for each axis drive. There was specified the synchronization function for the control system which takes account of the errors positioning of each axis. The experiments were performed on a prototype parallel manipulator (3-DoF). The prototype hydraulic manipulator consists of a fixed base and a moving platform, that are connected by the joints with three hydraulic linear axes. They demonstrated improvement in the positioning accuracy of the movement of end effector manipulator. The aim of the research was to examine the effectiveness of synchronous control method with a simplified structure of the control system for the electro-hydraulic manipulator both theoretically and experimentally.

Virtual prototyping of electro-hydraulic parallel manipulator control systems

Abstract The paper presents the process of virtual prototyping of a parallel manipulator which uses electro-hydraulic servo-mechanisms to drive active elements. A mechatronic solution of tasks of forward and inverse kinematics with the use of a virtual model of the manipulator, as well as a control system for the virtual machine were presented herein. The solution presented in the article makes it possible to study the functions of the control system before its merger with a real manipulator. At the same time, the design process is significantly accelerated.

Modeling and Control of Motion Systems for an Electro-Hydraulic Tripod Manipulator

The paper presents the results of theoretical considerations, experimental studies and control of electro-hydraulic servo control of manipulator. The structure of the device together with an analysis of its kinematic structure is described. The structure of dynamic manipulator model is derived from each axis dynamic model. The issue that has been discussed, focused on providing robust of electro-hydraulic servo controller to change the dynamic properties. The results of simulation and experimental tests data are presented and analyzed.

Pneumatyczne semiaktywne zawieszenie siedziska maszyny roboczej

Presented are issues related to improvement of the vibration isolating properties of semi-active seat suspension. It shows the practical implementation of the force control system for pneumatic spring which was mounted in mass-produced seat suspension. Output control function for pressure valve of pneumatic supply system was proposed. The developed solution allowed to carry out the research of air spring applied to a semi-active suspension system.

Rozwój energooszczędnych napędów hydrostatycznych z odzyskiem energii

For many years, the search for energy-efficient solutions in hydrostatic drives of passenger vehicles, municipal and military vehicles, buses, work and construction machinery, lifting equipment and others has been ongoing. These solutions include: vehicle weight reduction, aerodynamic body design, use of electronic ignition or injection equipment, energy recovery and accumulator systems and hybrid drives. Such solutions lead to reduced noise and reduced fuel consumption and emissions to the environment: NOx, carbon monoxide and hydrocarbons (CO/HC) and particulate matter (PM). In conventional vehicle drives, braking energy is irretrievably lost and the internal combustion engine must cover the power demand throughout the entire vehicle cycle. This clearly indicates the need to include in the vehicle movement recovery (recovery) and storage (accumulation) of braking energy, and then use it to accelerate the vehicle. In such drives, an internal combustion engine can be used to cover the average power requirement during traffic. This reduces the power of the engine cooling system. The main goal of hybrid vehicles is to improve fuel efficiency and reduce emissions for the benefit of the environment. After the tightening of emission standards in 2000 and fuel price increases, the advantages of such drives have been recognized. Hybrid vehicles are classified based on the configuration of the power transmission system and the method of energy accumulation. The first hybrid electric vehicle, the Lohnerporsche (HEV), was built in 1900. Originally, the hybrid technology was designed for military vehicles, lorries, vans and buses. The Hydro-Bus concept was introduced in Hanover in the early 1980’s and was subsequently researched at the Technical University of Lodz [16]. Loading and unloading equipment and construction machinery for short runs (with frequent stoppages), Bosch Rexroth has developed a hybrid hydrostatic regenerative braking system (HRB) [13]. The history of modern hybrid technology in cars began about 30 years ago – examples are hybrid drives used in the Toyota Prius (1997) and Honda Insight (1999). The research also included hydraulic hybrid drives in SUVs such as the Hummer H3, Nissan Titan, Pathfinder, Dodge Durango, Ford Explorer and GMC Yukon. One of the first hybrid parallel hybrid drives introduced into urban vehicles was the Parked Hannifin CBED (cumulo brake energy drive) system. On the other hand, the company’s first hybrid hydrostatic drive was the CHD (cumulo hydrostatic drive) system. The latest hybrid hydraulic drive solution was developed by Bosch Rexroth with PSA Peugeot Citroën. This system, called hybrid air, was used in the Peugeot 2008 car, which was presented at the Geneva Motor Show in 2013. The use of a hybrid drive (HHD) in vehicles is most appropriate when the vehicle is moving in a repetitive cycle (acceleration – fixed travel – braking – stopping), while high power instantaneous power with high energy efficiency is possible. little energy loss. In many cases the traffic of urban, municipal and commercial vehicles is characterized by such cyclic driving. In energy-efficient hydrostatic drive systems, the pump is used as the primary source of energy, and the battery as a secondary power source and reverse drive unit with secondary control, which, depending on the direction of transmission, operates like a motor or pump. In such systems there is a two-way flow of energy: the energy is transferred from the pump and the battery to the reversible motor as the engine, and the energy recovered from the braking (during so-called regenerative braking) is transferred from a reversible drive unit operating as a pump to a hydraulic accumulator, where * Prof. dr hab. inż. Ryszard Dindorf (dindorf@tu.kielce.pl), dr inż. Piotr Woś (wos@tu.kielce.pl) – Katedra Technologii Mechanicznej i Metrologii, Wydział Mechatroniki i Budowy Maszyn Politechniki Świętokrzyskiej ARTYKUŁ PRZEKROJOWY

Remote control of the electro-pneumatic servo drive using biosignals

Machines and devices control can be held using keyboard, joystick, touch interface, gesture recognition interface or speech. Completely different control form is biosignals use, such as electromyogram, electrooculogram or electroencephalogram. In the article presented the controller construction of electro-pneumatic servo drive, which control is backed up by biosignals generated by activity patterns in muscles, brain and eye.