As part of the laboratory exercises on the subject "Analog Control", students perform the following six laboratory exercises:
- Identification of analog industrial process models,
- Study of quality and accuracy of control,
- Stabilization and correction of linear control systems,
- Application of PID controllers in DC servos,
- Study of relays control systems,
- Computer aided analysis and synthesis of control systems.
The organization of the laboratory classes is as follows:
- introduction – 2 hours
- exercise # 1 – 2 hours
- exercise # 2 – 2 hours
- exercise # 3 – model identification (2 hours) and implementation of control algorithms (2godz.)
- exercise # 4 – model identification (2 hours) and implementation of control algorithms (2godz.)
- exercise # 5 – 2 hours
- exercise # 6 – 2 hours
- exercise # 7 – project task.
The lab (room 530) is equipped with 7 laboratory stations for exercises 1 and 2, 2 laboratory stations for exercise 4, and 3 laboratory stations for exercises 3, 5 and 6.
Exercise 1 is an illustration of the frequency and time-domain methods of identifying dynamic objects. In the identification process, the following models of dynamic objects are tested: first order inertial system, first order inertial system with transport delay, second order system, non-minimum phase system and integrator.
In Exercise 2, steady states and transition states in the control system are investigated in which the objects identified in Exercise 1 are controlled by a proportional controller. The study therefore deals with the influence of the gain of such a controller on the indicators describing the accuracy of the control and the quality of the step response. In addition, a simple synthesis of proportional controllers is performed to provide a closed system with imposed control indicator values for stability, accuracy, or speed.
The lab station for exercises 1 and 2 is equipped with:
- A set of analog industrial process models (ZAMPP), containing dynamic objects and a phase shift meter;
- METEX MS-9140 or MS-9150 multifunction measuring set composed of periodic signal generator, frequency meter, universal meter and power supply;
- Dual-channel oscilloscope model GW GOS-622 20MHz or LG OS-9020 20MHz or
- Agilent InfiniiVision X 2004 digital oscilloscope.
Exercise 3 deals with the correction of control (control) systems using PID controllers. The study, in its basic scope, concerns the steady state and transient states in the control systems of integrating and inertial objects and two-divisions. These models thus represent two important classes of objects found in many industrial fields. In addition, the use of an auxiliary static correction coupling incorporates a control object. Simple PID tuning rules are considered, however, to ensure that the closed system meets the assumed design requirements set by the specifications for stability, accuracy and control speed. The purpose of the exercise is to study simple methods for the identification of controlled dynamic objects based on the measured frequency parameters and the time characteristics of the respective closed control systems using a proportional controller of known gain. These methods are based on analytic formulas describing the properties of second order dynamic members (see Exercise 1).
The lab station for exercise 3 is equipped with:
- a model of a regulation system that contains a dynamic object, each of which can be closed by an individual feedback loop with adjustable feedback coefficients;
- PID type controllers, described as transmittance, with variable proportional gain and integral gain and derivative gain;
- SEUNG JI SJ-9300 multifunction measuring set consisting of a periodic signal generator, a frequency meter, a universal meter and a power supply;
- oscilloscope type GW GOS-622 20MHz.
The purpose of Exercise 4 is to illustrate the essential activities involved in the design and start-up of control systems such as:
- the identification (determination of the mathematical model) of the controlled object, the design of the controller algorithm and the simulation of the control system for the identification of the object model obtained,
- Implementation of the designed control algorithm (physical implementation), commissioning of the real object control system, quality analysis of the control process, to assess the conformity of the process quality indicators with the relevant specifications.
The right object is controlled in this laboratory exercise DC motor; Controlled quantities are the position of the controlled axle (see below) or the rotational speed of the axle.
The lab station for exercise 4 is equipped with:
- universal feedback system, including the mechanical block containing the controlled object, along with the relevant measuring and control elements, and an analogue block, is a universal electronic system that enables the implementation of various versions of the PID algorithm.
- GoldStar OS-3020 20MHz dual-channel oscilloscope with digital memory;
- two digital voltmeters;
- ZU-154 stabilized power supply;
- PC computer with software for simulating the control system.
Exercise 5 deals with two- and three-position relays with hysteresis, as well as systems in which corrective feedback is applied. In such a solution there is a possibility of sliding motion. This exercise allows you to observe this movement both in the phase plane and in the time domain.
The lab station for exercise 5 is equipped with:
- regulatory model, containing an integrative object,
- two- and three-position regulator with constant step amplitude, variable hysteresis zone width and smoothly adjustable dead zone of three-position regulator
- correction system, incorporated into the feedback loop around the regulator,
- differential system, which allows analysis of the error signal "e" on the phase plane.
- SEUNG JI SJ-9300 multifunction measuring set consisting of a periodic signal generator, a frequency meter, a universal meter and a power supply;
- two IWATSU SS-5702A dual-channel oscilloscopes 20MHz.
The purpose of Exercise 6 is to design and commission basic control systems using the ACs-1000 modules. The materials include sample layouts and exercises:
The basic purpose of Exercise 7 is to consolidate the knowledge of the design (synthesis and simulation) of control systems of single- and multi-dimensional objects, described by the corresponding continuous time linear models. The following issues are considered:
- synthesis of drivers (equalizers) based on integral quality criteria, including tuning PID drivers using Ziegler-Nichols rules,
- pole positioning of the closed control system,
- synthesis of state observers (full observers and reduced observers);
- control synthesis with feedback from state estimation,
- optimal control synthesis due to square quality indicators.
The exercise consists in executing the project (determining the structure and parameters of the system and simulating the controlled processes) based on the data (model of the controlled object and the control objective) prepared by the instructor. Calculations and simulation experiments are carried out using the CC program. Secondary, although also important, the purpose of the exercise is, therefore, to familiarize yourself with the advanced capabilities of this computer-aided design program for automatic control systems.
The lab station for exercise 5 is equipped with PC computer
Additional support materials:
- script to the lab
- software supporting the identification of the studied models of dynamic objects
- a description of operating a digital oscilloscope
Support for the Agilent InfiniiVision X2004 digital oscilloscope::
