The robust adaptive control algorithm - DACDM

W artykule przedstawiono studium przypadku nad nową, autorską metodą odpornego sterowania adaptacyjnego - DACDM. Celem proponowanego algorytmu jest wyznaczenie regulatora odpornego na niepewność parametryczną, pracującego w układzie adaptacyjnym. Novum w syntezie regulatora stanowi wykorzystanie trójstopniowej kontroli odporności układu. Przeprowadzone badania numeryczne potwierdzają skuteczność proponowanego rozwiązania.The paper presents a case study on a new, original, robust adaptive control method - DACDM [1]. The design of a controller robust to parametric uncertainty and working in the adaptive system is an aim of proposed algorithm. The DACDM procedure combines advantages of both control techniques - robust and adaptive. A novelty in the controller synthesis is the use of three stage system robustness control (by the use of coefficient diagram [2], optional step of the robustness index optimization [3], the use of adaptation mechanisms [4]). The case study is performed for the linear model SMFNO (stable, minimum-phase, non-oscillatory) described by equation 1 in the structure of the control system of Figure 1. The proposed algorithm from Figure 2 uses table 2 [5] for the selection of controller structure and design specifications [2] specified by equations 4 and 6. The use of the equation 16 enables to introduce the averaged model to the adaptive control system and the change of parametric uncertainty vector. The case study highlights the clarity of the design procedure. The coefficient diagram analysis (Fig.3) and results of conducted numerical studies (Fig. 4, Fig. 5, Fig. 8) confirm the effectiveness of the proposed solution in relation to the selected SMFNO model

The designing of a robust control system supported by CDM algorithm

W pracy przedstawiono nową metodę syntezy układu regulacji odpornej. Scharakteryzowano podstawy metody diagramu współczynnikowego (ang. Coefficient Diagram Method) w kontekście projektowania układu oraz analizy jego właściwości. Omówiono sposoby poprawy jakości regulacji z wykorzystaniem diagramu współczynnikowego - narzędzia umożliwiającego kompleksową kontrolę odporności, stabilności i dynamiki układu. Zamieszczono przykład syntezy układu regulacji odpornej z obiektem stabilnym minimalnofazowym oscylacyjnym przy użyciu algorytmu CDM i analizę właściwości układu w oparciu o diagram współczynnikowy. Wyniki badań symulacyjnych potwierdziły skuteczność proponowanego rozwiązania.In a paper a new method of synthesis of robust control system is presented. Basis of Coefficient Diagram Method in the system designing context and its properties analysis, were characterized. Methods of control quality improvement on the basis of the coefficient diagram - a tool which the complex control of robustness, stability and system's dynamics enables, were discussed. The example of robust control system synthesis for oscillatory minimum-phase plant by CDM algorithm and system properties analysis by coefficient diagram, were placed. The results of simulations confirmed the effectiveness of the proposed solution

The influence of drive unit on measurement error of ultrasonic sensor in multi - rotor flying robot

The article describes the impact of the drive units on the data obtained from ultrasonic sensors. These sensors are mounted on the multi-rotor flying robot. In experiments, previously designed ultrasonic sensor was used. On purpose of this study special testbed, consisted of a dynamometer and manipulator from KUKA company was created. In the research the influence of the location of the drive unit on the aforementioned sensor was measured. For this purpose, the sensor was placed in front, behind and in the line of the rotating propeller. The obtained results allowed to identify places where there are the least interference from the drive units that affect the ultrasonic sensor. Thanks to this, the results of measurements of the obstacles distance from a flying robot were improved

An adequate mathematical model of four-rotor flying robot in the context of control simulations

In this paper a model of the dynamics of four-rotor flying robot is described in details. Control design must be preceded by the modeling and subsequent analysis of the robot behavior in simulator. It is therefore necessary to develop the mathematical model as accurate as it is possible. The paper contains a detailed derivation of the mathematical model in the context of physics laws affecting the quadrocopter. The novelty of presented notation is an extention of Coriolis forces in linear acceleration and the gyroscopic effect on angular acceleration. In the validation phase, the mathematical model was verified with the use of proposed control algorithms. Simulation studies have demonstrated the adequacy of a MATLAB model to properly reflect the real quadrocopter dynamics. This would allow for its use in the simulator and afterwards to implement and verify of control laws on the real fourrotor flying robot

Influence of time delay on fractional-order PI-controlled system for a second-order oscillatory plant model with time delay

The paper aims at presenting the influence of an open-loop time delay on the stability and tracking performance of a second-order open-loop system and continuoustime fractional-order PI controller. The tuning method of this controller is based on Hermite- Biehler and Pontryagin theorems, and the tracking performance is evaluated on the basis of two integral performance indices, namely IAE and ISE. The paper extends the results and methodology presented in previous work of the authors to analysis of the influence of time delay on the closed-loop system taking its destabilizing properties into account, as well as concerning possible application of the presented results and used models

UAV Propulsion Analysis System with Reconfigurable Controller Feature

In this paper, a custom measuring system for propulsion units of multi-rotor UAV is presented. Designed solution provides measurements of thrust, rotational speed and power consumption of popular electric propulsion systems consisting of BLDC motor, electronic speed controller (ESC) and various propellers. The method is applicable to both single and twin (coaxial) configurations of rotors. Thanks to the use of a precision 6-axis force/torque sensor and sensorless method of speed measurement it is possible to record performance of propulsion with convenient PC software. The system is equipped with complete galvanic isolation between power and sensory circuits. A unique feature of presented solution is the possibility of remote reconfiguration of various controllers, governing speed or thrust of the propeller. Possible applications of the presented test rig are: estimating the performance of UAV design (flight time, power consumption, payload capabilities), mathematical modelling of electric propulsion and analysis of faulty states of rotor operation