Peter Tapak

New Thermo-Optical Plants for Laboratory Experiments

Abstract This paper explains motivation and gives a brief development history of a laboratory model of thermo-optical plant. Then it continues with a short description of linear and nonlinear identification and control experiments that may be carried out with the recently innovated model directly in a classroom from the Matlab/Simulink environment, or remotely via Internet.

Experimenting with the Modified Filtered Smith Predictors for FOPDT Plants

Abstract This paper deals with experimental verification of new modified Filtered Smith Predictor with primary 2DOF P-controller that simplifies treatment of the control constraints. Testing the traditional and the new solutions with different disturbance filters by real time experiments on a stable plant fully confirms superiority of the new controllers in constrained control. It also shows that despite to the formal input-to-output equivalence of the new and the traditional solutions, due to different implementation schemes and the plant-model mismatch they give responses to the setpoint and disturbance steps that are slightly different in terms of the speed, monotonicity, as well as noise attenuation. As a by-product of this paper it is shown that both the new and the traditional solutions with the 2 nd order disturbance filter are much more sensitive than those with the 1st order one, what may be crucial for their practical use.

Experimenting with Modified Smith Predictors Using B&R Automation Studio Target for Simulink

This paper deals with experimental verification of the new modified Filtered Smith Predictor with primary 2DOF P-controller that simplifies treatment of the control constraints carried out on a physical model of a stable optical plant using a PLC. Testing the traditional and the new solutions with different disturbance filters by real time experiments fully confirms superiority of the new controllers in constrained control. The paper simultaneously analyzes advantages of using Simulink Target for B&R Automation studio. It allows to use Matlab/Simulink environment with a PLC.

One degree of freedom copter

The paper presents laboratory model of aerial vehicle. The plant design, construction and building was a part of a project in the course on autonomous mechatronic systems. The goal was to make an exercise in mechatronics, resulting in plants which could be used in other project or classes.

Intelligent P controller and disturbance observer based PI controller comparison

The paper shows analogies between two separately evolved areas of PID control, the disturbance observer based controllers and the “intelligent” PID controllers. The simplest “intelligent” PID controller is represented by the “intelligent P” controller denoted as iP. It is designed for the simplified “ultra-local” integral plant models neglecting all internal plant feedbacks. These are included and compensated by an equivalent input disturbance. The performance of the iP controller is compared with the controllers employing disturbance observers based on inverted plant model. It is shown that both these solutions may represent an alternatives to the same control strategy.

Supporting new control paradigm by new technologies

This paper discusses needs on flexible learning provision in control engineering courses and confronts them with more than three decades long experience of the author team in developing and delivering control courses in the automatic control area.

Combining model based and data-driven approaches: First order nonlinear plants control

The paper deals with a data-based robust tuning of a controller for nonlinear first order plants combining exact linearization based nonlinearity compensation with a nonlinear disturbance observer (NDOB) based integral action. A two-step experimental control design is carried out with the aim of the fastest possible monotonic setpoint step responses and of a well damped control signal courses. The first stage of an optimal and robust tuning procedure focuses on collecting and processing data about the process by a sequence of step responses. It is used for determining appropriate parameters of the stabilizing P control extended by a fixed offset. This may be extended by a second stage, when the proposed controller is used to generate new data sets for an optimal robust disturbance observer tuning. All procedures are illustrated by an electrical fan speed control example carried out in a Matlab/Simulink environment.

Disturbance observer based controller in object tracking

Object tracking is large and important area in the field of computer vision. In this paper the pan/tilt camera is used to track objects. The paper focuses on the control algorithms for the camera which are chosen and tuned to yield fast transients without overshooting. The image processing algorithms are realized using open computer vision library. Two setups are presented in the paper. The first one shows the case when the pan/tilt system is placed on the ground. In other words, the goal is to keep the centroid of the moving object in the middle of the picture by the rotation of the camera. The second case demonstrates the performance of the system when the camera is mounted to a flying quadcopter. In this scenario, the noise reduction is a much bigger issue. The P controller with constrained rate of change of the output, in other words the speed of the camera rotation, expanded by the disturbance observer to guarantee the zero steady state error was used. This controllers performance benefits from the low pass filters used in the disturbance observer. The real experiments were performed with the sampling time of 60ms.

Interactive tool for dynamical class zero controller tuning by performance portrait method

The paper shows Matlab based interactive tool for integral disturbance observer based controller performance analyses and design. The user can set several control loop parameters such as plant parameters and their uncertainties, model parameters etc. and evaluate various performance measures.

Automated marking in constrained PID control course

The paper describes the marking aids used in the constrained PID control course. The exercises are based on experimenting with the real plants which increases the difficulty of marking of the assignments. Several scripts are used to support the marking of the assignments. Originally the scripts were meant to be used by the teachers. The paper shows how the availability of these aids for the students influenced the quality of their work.