Optimal tuning of the lateral-dynamics parameters for aerial vehicles with bounded lateral force

This letter shows for the first time why it is important and how to optimize the gains of a position controller on board of a fully-actuated aerial vehicle with bounded lateral force, via an auto-tuning approach. In such vehicles, most of the control authority is expressed along a principal thrust direction, while along lateral directions smaller forces can be exploited to achieve full-pose tracking. The nonlinear and hard to model interplay between the constraint imposed on the lateral force and the gains of the position controller is overcome by employing the OPTIM-tune calibration method. Several experimental tests, performed fully autonomously during flight, clearly show the practicability and benefits of the approach

Directional change in multivariable LQG control with actuator failure

The paper presents the phenomenon of directional change in LQG control of multivariable systems with amplitude constraints, as well as the impact of the latter on control performance. The interplay of directional change of the computed control vector with control performance has been thoroughly investigated, and is a result of the presence of constraints imposed on the applied control vector for different proportions of the number of control inputs to plant outputs. The impact of directional change phenomenon on the control performance has been defined, stating that performance deterioration is not tightly coupled with preservation of direction of the computed control vector. The statement has been supported by numerous simulation results for different types of plants with different LQG controller parameters

Directional change and windup phenomena in LQR-controlled systems with actuator failure

The paper presents a phenomenon of directional change in the case of a LQR controller applied to multivariable plants with amplitude and rate constraints imposed on the control vector, as well as the impact of the latter on control performance, with the indirect observation of the windup phenomenon effect via frequency of consecutive resaturations. The interplay of directional change of the computed control vector with control performance has been thoroughly investigated, and it is a result of the presence of constraints imposed on the applied control vector for different ratios of the number of control inputs to plant outputs. The impact of the directional change phenomenon on the control performance (and also on the windup phenomenon) has been defined, stating that performance deterioration is not tightly coupled with preservation of direction of the computed control vector. This conjecture has been supported by numerous simulation results for different types of plants with different LQR controller parameters

Pole - Placement Adaptive Control for a Plant with Unknown Structure and Parameters - a Simulation Study

Adaptive pole-placement control for the plant with unknown orders and coefficients of its model is presented in the paper, in an on-line approach. In order to adapt to the plant, the considered controller changes its structure and parameters, along with the identification process. In order to combine structural and parametric identification, the approach presented in [5] has been used, with the simulation runs performed for continuous plant and a discrete-time controller and identification algorithms

Robust Performance of Sampled-data Adaptive Control. From Simulation to Experimental Results

The paper considers robustness aspects of adaptive control in application to sampled-data systems with poleplacement controller subject to plant-model mismatch, in the sense of mistuning to model parameters with respect to their „true” values. The paper extends the results presented in author’s previous work respecting comparison of sampled-data and discrete-time control systems to experimental results obtained from the control system of a servo drive. Firstly, the adaptive sampleddata controller is introduced and is applied by means of simulation, secondly, it is implemented in real-time control system to extend robust performance issues to realworld control systems. Finally, the regions of robust performance are shown on parameter surface, i.e. visualisation of parameters? span for which there is no severe performance degradation in comparison to the best plantmodel matching, as a function of sampling interval

On directional change and anti-windup compensation in multivariable control systems

The paper presents a novel description of the interplay between the windup phenomenon and directional change in controls for multivariable systems (including plants with an uneven number of inputs and outputs), usually omitted in the literature. The paper also proposes a new classification of anti-windup compensators with respect to the method of generating the constrained control signal

LQG/LTR control of input-delayed discrete-time systems

A simple robust cheap LQG control is considered for discrete-time systems with constant input delay. It is well known that the full loop transfer recovery (LTR) effect measured by error function ∆(z) can only be obtained for minimum-phase (MPH) systems without time-de-lay. Explicit analytical expressions for ∆(z) versus delay d are derived for both MPH and NMPH (nonminimum-phase) systems. Obviously, introducing delay deteriorates the LTR effect. In this context the ARMAX system as a simple example of noise-correlated system is examined. The robustness of LQG/LTR control is analyzed and compared with state prediction control whose robust stability is formulated via LMI. Also, the robustness with respect to uncertain time-delay is considered including the control systems which are unstable in open-loop. An analysis of LQG/LTR problem for noise-correlated systems, particularly for ARMAX system, is included and the case of proper systems is analyzed. Computer simulations of second-order systems with constant time-delay are given to illustrate the performance and recovery error for considered systems and controllers

Robustness of adaptive discrete-time LQG control for first-order systems

The discrete-time adaptive LQG control of first-order systems is considered from robustness point of view. Both stability and performance robustness are analyzed for different control system structures. A case of amplitude-constrained control is presented, and application of certainty equivalence for self-tuning implementation is also discussed

Analysis of simple anti-windup compensation in pole-placement control of a second order oscillatory system

The main aim of the paper is to present the analysis of anti-windup compensation impact on tracking performance for a second-order plant and continuous-time PID controller and five different simple anti-windup compensators. The performance of the system is compared on the basis of computing differences between the integrals of absolute and squared tracking errors for the system with and without compensation, as well as observing the excess of windup phenomena taking place. Parameters of the controller are computed according to pole-placement scheme. The control system quality is described on the basis of two quality indices for a stable oscillatory second-order plant and a square reference signal

Quality analysis of the tracking systems with anti-windup compensators for oscillatory plant models

Artykuł dotyczy analizy wpływu kompensacji zjawiska windup na jakość śledzenia w układach z regulatorem PID i ograniczeniem amplitudy sygnału sterującego dla obiektów oscylacyjnych. Jakość śledzenia oceniano na podstawie różnic między wartościami całkowych wskaźników (modułu i kwadratu błędu śledzenia) dla układu bez i z kompensatorem. Nastawy parametrów regulatora dla rozpatrywanych modeli symulacyjnych dobrano wykorzystując blok NCD pakietu Matlab. Wyniki numeryczne analiz symulacyjnych uzyskano dla stabilnych obiektów oscylacyjnych i prostokątnego sygnału śledzonego.The paper discusses influence of anti+windup compensator on tracking operation of szstems with PID controllers and control amplitude constraints for oscillatorz plants. Tracking performance has been evaluated according to differencies between intregal indexes (of absolute and squared tracking error) for szstems with ang without compensation Controller parapeters for considered plants have been chosen according to NCD block from MATLAB. The results of numerical analzsis have been obtained for stable oscillatorz plants and square reference signal