338-0506/03 – Hydraulic Mechanisms Control (Řízhy)
Gurantor department | Department of Hydromechanics and Hydraulic Equipment | Credits | 5 |
Subject guarantor | Ing. Adam Bureček, Ph.D. | Subject version guarantor | Ing. Adam Bureček, Ph.D. |
Study level | undergraduate or graduate | Requirement | Compulsory |
Year | 2 | Semester | winter |
| | Study language | Czech |
Year of introduction | 2013/2014 | Year of cancellation | 2022/2023 |
Intended for the faculties | FS | Intended for study types | Follow-up Master |
Subject aims expressed by acquired skills and competences
Students will be acquainted with three qualitative grades of hydraulic mechanism control: classical control technique, proportional control technique, and servo technique. Students will learn to distinguish two basic methods of hydraulic mechanisms control: valve control and volumetric control. They are able to analyze both of these methods especially in terms of control accuracy, dynamic characteristics, energy performance, and price. In the case of proportional control are able to perform design the control system (synthesis) for a specific application. In the case of servomechanisms, they will be able to do the same for simpler applications.
Teaching methods
Lectures
Tutorials
Experimental work in labs
Project work
Summary
In the subject of Hydraulic Mechanisms Control, the students will learn about volumetric control and variable resistance control, dynamics of the controlled system, thermal balance of controlled hydrostatic drive and applications of control technique in hydrostatic mechanisms. Proportional control technique and servo technique are discussed in detail, where the knowledge of the subject of Fundamentals of Automation and Dynamics of Fluid Mechanisms is used. Students will learn the composition of speed and position servomechanisms. Furthermore, they will learn the principles of commissioning and maintenance of hydraulic proportional components and electrohydraulic servo valves and the issues of filtration of hydraulic devices with servo valves and proportional valves.
Compulsory literature:
[1] EWALD, R. et al. Proportional and Servo-valve Technology. Lohr am Main, Germany: Bosch Rexroth AG, 2003. 300 p.
[2] GÖTZ, W. Hydraulics. Theory and Applications. Ditzingen, Germany: OMEGON, 1998. 291 s. ISBN 3-980-5925-3-7.
Recommended literature:
Additional study materials
Way of continuous check of knowledge in the course of semester
E-learning
Other requirements
Additional requirements for the student are not.
Prerequisities
Subject has no prerequisities.
Co-requisities
Subject has no co-requisities.
Subject syllabus:
The program of lectures
Week Lectures
1 The definition of a control term. Hydraulic mechanisms control: controlled variables, methods of control - classification. Control by variable resistor, one-edge depending on the pressure gradient on engine. Sources of constant pressure.
2 Control by variable resistor, one-edge depending on the pressure gradient on engine. Throttling valves with two-way pressure weight. Throttling valves independent on viscosity. Throttling valves with a three-way pressure weight.
3 Control by variable resistor, two-edge. Four-edge control valve. Proportional valve controlled mechanically.
4 Electrically operated proportional valve. The control electronics. Proportional valve with two-way and three-way pressure weight, LS (load sensing) systems.
5 Design of circuits with a proportional directional valve.
6 Servovalves.
7 Servodrives. Application of servo-drives in aviation, robotics, machine tools, thermal and nuclear power.
8 Dynamics of servodrivers. Ways of describing the regulatory circuit components. Mathematical and physical models of the regulatory circuit components.
9 Rotary servodrivers: a mathematical description of dynamic behavior, the ways of control, dynamic stability.
10 Positional servomechanisms with mechanical feedbacks. Electro-hydraulic positional servomechanism. Mathematical description of dynamic behavior, ways of control, dynamic stability.
11 Stabilization of positional servomechanisms.
12 Volume control.
13 Secondary control of motors. Control of pressure, force, torque.
14 Principle of installation, operation and maintenance of the servomechanisms. Filtration and temperature stabilization.
Program of exercises and seminars + individual students' work
Week Contents of exercises and seminars
1 Repetition of basic terms of fluid mechanisms.
2 Control by variable resistance: the circuits with throttle valves.
3 Control by variable resistance: the circuits with throttle valves.
4 Measurement 1: The measurement of the throttle valve vs. temperature. Measurement of characteristics throttle valve with of two-way pressure weight.
5 Measurement 2: Measurement of M-n characteristics of drive with control by variable
resistance.
6 Program 3: Design of the circuit with a proportional valve.
7 Design of the circuit with a proportional valve - completion.
8 Design of hydrostatic transducer with control of pump and motor geometric volume.
9 Transient response, transfer, frequency response.
10 Mathematical and physical models of the regulatory circuit elements.
11 Program 4: Design of a rotary servo-drive. An example of the lifting device.
12 Measurement of rotary servo-drive - to program No.4.
13 Design of positional servomechanism. An example from the field of nuclear energy.
14 Demonstration of operation of positional servomechanism in a laboratory. Credits.
Exam questions:
1 Control by variable resistor, one-edge: principles of control, static M-n and F-v
characteristics of drive.
2 Throttling valves depending on the pressure gradient. Throttling valves dependent
and independent on viscosity. Location of throttle valves at the inlet and outlet of hydraulic motor.
3 Energy balance of drive controlled by variable resistor.
4 Throttling valves with two-way pressure weight: function, construction, use, energy balance.
5 Throttling valves with a three-way pressure weight: function, construction, use, energy balance.
6 Implementation of a constant pressure source.
7 Proportional distributors directly controlled: design, properties, applications. Types of
valves. i-Q-flow characteristics.
8 Proportional distributors indirectly controlled: design, properties, applications.
9 Proportional pressure valves. Proportional distributors with two-way and
three-way pressure weight.
10 Design of a proportional distributor with respect to the dynamics of the system.
11 Volume control of drive. Regulatory pumps and methods of
geometric volume control: mechanical, electrical, hydraulic direct and indirect,
electro-hydraulic.
12 Regulatory pump with regulation on constant flow. Pump with LS regulation.
13 Servomechanisms: definitions, types, characteristic features, a general block diagram.
Example of a copy machine.
14 Dynamic properties of servodrives: the response properties of simple blocks.
15 Transient response, frequency response, a logarithmic magnitude and phase frequency response of simple blocks.
16 Servo-valves: controlling valve, static characteristics, the mathematical description.
17 Servo-valves: 1st stage of servo.valves, feedback performance. Three-stage servo-valves.
18 Servo-valves: mathematical models of dynamic behavior. Dynamic characteristics.
19 Motors of servo-drives: design, mathematical models of dynamic behavior.
20 Regulators, position and speed sensors.
21 Velocity servomechanism: hydraulic diagram, block diagram of the control, properties, dynamic stability.
22 Positional servomechanism: hydraulic diagram, block diagram of the control, dynamic stability.
23 Stabilization of positional servomechanisms.
24 Secondary regulation of motors.
Conditions for subject completion
Occurrence in study plans
Occurrence in special blocks
Assessment of instruction