Design Of Electro-hydraulic System Research Articles

Educational design and modelling of electro-hydraulic control system machine tool motion

Purpose. To present the design and modeling technology of real electrohydraulic systems, for use in the educational process of a higher educational institution, and the prospects of the proposed approach in the training of technical specialists. As an example, the model of the motion control system of the hydraulic cylinder of the device for fixing parts on the working table of a milling machine, created on the basis of components of the Festo company, is considered. The methods. The methodological basis of the work is a systematic approach, which consists in the use of modern FluidSim software - comprehensive software for creating, modeling and studying, including electro-hydraulic circuits and educational equipment of the Festo company, which allows students to acquire and develop practical skills and at the same time simulate a real working environment . Additional advantages of computer and physical modeling in the educational process are the interactive component, which facilitates the visualization of educational material and improves the process of problem solving. Findings. Taking into account the pedagogical features inherent in the world trends in technical education, the application of a comprehensive approach using computer and physical modeling in the training of technical specialists in the design of electrohydraulic systems is justified in the educational process. The sequence and results of the students' work on one of the options for the implementation of the educational project – the control system for the motion of the hydraulic cylinder of the device for fixing parts on the work table of the milling machine – have been demonstrated. The result of the proposed approach is also an increase in students' motivation, the achievement of a higher level of practical knowledge and skills compared to the traditional model of education. The originality. A modified algorithm for the formation of an extended model of mastering educational material from electro-hydraulic devices and systems with the use of modern software and equipment has been developed. Which allows students to acquire and develop practical skills and at the same time simulate a real working environment. Practical implementation. The materials of the work can serve as a basis for using the proposed integrated approach, which will improve the process of learning and teaching electrohydraulics, ensuring a higher level of learning outcomes, especially in terms of acquiring practical knowledge and skills.

Mechanical Design of Lower Extremity Exoskeleton Assisting Walking of Load Carrying Human

Exoskeletons are used in rehabilitation, military, industrial applications and rescuing, heavy-weight lifting and civil defense applications as well. This paper presents to design of a lower-extremity exoskeleton assisting walking of a load carrying human. Proposed exoskeleton system is designed to be appropriate mechanism with human lower extremity and it operates synchronously with the human realizes. The aim of exoskeleton actuator system is to provide forces against to external load carried by user during walking, sitting, and standing motions. Thus, it supports human walking and significant portion of external load carrying by the user. Also it makes possible to user spend less energy, less stress and fatigue. Proposed work involves the following design steps: kinematic synthesis of the exoskeleton, mechanical and electro-hydraulic system design.

An electrohydraulic system for synchronously jacked box tunneling in shallow saturated soft soil cover

Abstract Part of the Central Ring Fast Autoroad in Shanghai, Beihong Vehicular Undercrossing Tunnel is a two-way, eight-lane vehicular tunnel of 126-m long, 34.2-m wide, and 7.85-m high. An electrohydraulic control system for synchronously jacked box tunneling was developed in the project. Estimation of jacking force is essential prerequisite of design of electrohydraulic system. Volume speed-regulating hydraulic circuit rather than throttle circuit was used to adjust flow rate, and the rotating speed of driving motor of main pump is controlled by variable voltage variable frequency (VVVF) technology. Three-level structure of control system was employed. A “double-object synchronization” control scheme enables 112 cylinders to coordinate the extending action, and automatically achieve synchronous motion and posture control of box and uniform load distribution to each pump unit. Differences are controlled within ± 40 mm during the whole jacking process.

The Modelling of Electrohydraulic Control Valves and its Influence on the Design of Electrohydraulic Drives

The modelling of the control valve is shown to be a factor of prime importance in the design of electrohydraulic systems. The process required to model a commercially available valve is described in detail, with equal attention to the production of the experimental data and the identification of the model parameters. The quality of the decisions made in the construction of a model is shown to be most critically evaluated when derivative feedback loops are employed. A study of a system with negative transient acceleration feedback is included to illustrate the effectiveness of a third-order model. It is demonstrated that the use of a digital computer is essential for this type of system design.