Performance Portrait Research Articles

Performance Portrait Method: Robust Design of Predictive Integral Controller

The performance portrait method (PPM) can be characterized as a systematized digitalized version of the trial and error method—probably the most popular and very often used method of engineering work. Its digitization required the expansion of performance measures used to evaluate the step responses of dynamic systems. Based on process modeling, PPM also contributed to the classification of models describing linear and non-linear dynamic processes so that they approximate their dynamics using the smallest possible number of numerical parameters. From most bio-inspired procedures of artificial intelligence and optimization used for the design of automatic controllers, PPM is distinguished by the possibility of repeated application of once generated performance portraits (PPs). These represent information about the process obtained by evaluating the performance of setpoint and disturbance step responses for all relevant values of the determining loop parameters organized into a grid. It can be supported by the implementation of parallel calculations with optimized decomposition in the high-performance computing (HPC) cloud. The wide applicability of PPM ranges from verification of analytically calculated optimal settings achieved by various approaches to controller design, to the analysis as well as optimal and robust setting of controllers for processes where other known control design methods fail. One such situation is illustrated by an example of predictive integrating (PrI) controller design for processes with a dominant time-delayed sensor dynamics, representing a counterpart of proportional-integrating (PI) controllers, the most frequently used solutions in practice. PrI controllers can be considered as a generalization of the disturbance–response feedback—the oldest known method for the design of dead-time compensators by Reswick. In applications with dominant dead-time and loop time constants located in the feedback (sensors), as those, e.g., met in magnetoencephalography (MEG), it makes it possible to significantly improve the control performance. PPM shows that, despite the absence of effective analytical control design methods for such situations, it is possible to obtain high-quality optimal solutions for processes that require working with uncertain models specified by interval parameters, while achieving invariance to changes in uncertain parameters.

Transforming community-based primary health care delivery through comprehensive performance measurement and reporting: examining the influence of context

BackgroundCommunity-based primary health care represents various community-based health care (CBPHC) models that incorporate health promotion and community development to deliver first-contact health services. Learning health systems (LHSs) are essential for improving CBPHC in which feedback from relevant stakeholders is used to continuously improve health systems with the goal of achieving population health and health equity. Performance reporting is one way to present data to clinicians and decision makers to facilitate a process of reflection, participation, and collaboration among partners to improve CBPHC.MethodsOur objective was to obtain feedback on a regional CBPHC performance portrait through key informant interviews. We used purposive convenience sampling to recruit participants who were clinicians in primary care and/or decision-makers in primary care at a regional level. The performance portrait summarized results of survey questions asked of patients, providers, and primary care organizations. The portrait was organized by the 10 pillars of the Patient’s Medical Home (PMH) model. Interview questions specifically asked about portrait content, formatting, interpretability, utility, and dissemination strategies. Content analysis was used to analyze interview data.ResultsWe completed 19 interviews with key informants from the Canadian provinces of Nova Scotia (n = 8), Ontario (n = 6) and British Columbia (n = 5). We coded transcripts into four content areas: (1) Usability as influenced by content and interpretability, (2) Formatting, (3) Utility, and (4) Dissemination. Using data and reporting back to clinicians and decision-makers about how their practices and jurisdictions are performing in primary care in meaningful ways is important. Our results suggest having available methodology notes, including the analysis used to develop any scoring, sampling and sample sizes, and interpretation of the statistics is necessary.ConclusionsThis research was the first to create a comprehensive performance portrait using data driven by factors that are important to primary care partners. We obtained important feedback on the portrait in the context of usability, formatting, utility, and dissemination. This data needs to be used to provide feedback in continuous cycles to evaluate and improve CBPHC models as part of a LHS.

Modeling of farmers’ production performance portrait based on GASA-WFCM clustering

To identify the typical characteristics of farmers with different production performance, this paper constructs a farmer portrait model from the perspective of production performance segmentation. Firstly, we constructed the evaluation index system of production performance and quantified grape farmers’ production performance. Then, an optimized clustering algorithm (GASA-WFCM) was proposed to cluster the grape farmers based on their production performance, which was based on fuzzy C-mean algorithm, and incorporating the genetic simulated annealing algorithm to overcome the problem of sensitive initial clustering centers and tendency to fall into local optimum, and the ReliefF algorithm was also integrated to strengthen the contribution ability of effective features to clustering. Finally, we designed a labeling system and feature transformation quantification method, and combined with the visualization effects to realize the description of grape farmers’ portraits. The results of models training indicated that the convergence speed and division accuracy of the optimized clustering algorithm were significantly improved. By comparing the clustering results on the typical UCI datasets, it was demonstrated that GASA-WFCM algorithm improved the accuracy, NMI and ARI by 3.0%, 7.2% and 6.1%, respectively. Moreover, the segmentation method was applied in grape farmers dataset, and the findings revealed that Chinese fresh grape farmers may be clustered into three groups, namely high-yield-driven grape farmers, high-input-driven grape farmers and high -income grape farmers, respectively. This paper provided a set of methods of users clustering analysis and portrait from a theoretical point of view. The findings and suggestions can help provide accurate and focused decision support for improving the effect of agricultural technology promotion and farmers’ production performance.

Series PIDA Controller Design for IPDT Processes

This paper discusses optimal design of the series proportional–integral–derivative–accelerative (PIDA) controller for integral-plus-dead-time (IPDT) plants. The article starts with the design of disturbance reconstruction and compensation based on proportional-derivative-accelerative (PDA) stabilizing controllers. It shows that by introducing positive feedback by a low-pass filter from the (limited) output of the stabilizing PDA controller, one gets disturbance observer (DOB) for the reconstruction and compensation of input disturbances. Thereby, the DOB functionality is based on evaluating steady-state controller output. This DOB interpretation is in full agreement with the results of the analysis of the optimal setting of the stabilizing PDA controller and of its expanded PIDA version with positive feedback from the controller output. By using the multiple real dominant pole (MRDP) method, it confirms that the low-pass filter time constant in positive feedback must be much longer than the dominant time constant of the stabilized loop. This paper also shows that the constrained PIDA controller with the MRDP setting leads to transient responses with input and output overshoots. Experimentally, such a constrained series PIDA controller can be shown as equivalent to a constrained MRDP tuned parallel PIDA controller in anti-windup connection using conditional integration. Next, the article explores the possibility of removing overshoots of the output and input of the process achieved for MRDP tuning by interchanging the parameters of the controller transfer function, which was proven as very effective in the case of the series PID controller. It shows that such a modification of the controller can only be implemented approximately, when the factorization of the controller numerator, which gives complex conjugate zeros, will be replaced by a double real zero. Neglecting the imaginary part and specifying the feedback time constant with a smaller approximative time constant results in the removal of overshoots, but the resulting dynamics will not be faster than for the previously mentioned solutions. A significant improvement in the closed-loop performance can finally be achieved by the optimal setting of the constrained series PIDA controller calculated using the performance portrait method. This article also points out the terminologically incorrect designation of the proposed structure as series PIDA controller, because it does not contain any explicit integral action. Instead, it proposes a more thorough revision of the interpretation of controllers based on automatic reset from the controller output, which do not contain any integrator, but at the same time represent the core of the most used industrial automation. In the end, constrained structures using automatic reset of the stabilizing controller output can ensure a higher performance of transient responses than the usually preferred solutions based on parallel controllers with integral action that, in order to respect the control signal limitation, must be supplemented with anti-windup circuitry. The excellent properties of the constrained series PIDA controller are demonstrated by an example of controlling a thermal process and proven by the circle criterion of absolute stability.

Performance Portrait Method: An Intelligent PID Controller Design Based on a Database of Relevant Systems Behaviors.

The article deals with a computer-supported design of optimal and robust proportional-integral-derivative controllers with two degrees of freedom (2DoF PID) for a double integrator plus dead-time (DIPDT) process model. The particular design steps are discussed in terms of intelligent use of all available information extracted from a database of control tracking and disturbance rejection step responses, assessed by means of speed and shape-related performance measures of the process input and output signals, and denoted as a performance portrait (PP). In the first step, the performance portrait method (PPM) is used as a verifier, for whether the pilot analytical design of the parallel 2DoF PID controller did not omit practically interesting settings and shows that the optimality analysis can easily be extended to the series 2DoF PID controller. This is important as an explicit observer of equivalent input disturbances based on steady-state input values of ultra-local DIPDT models, while the parallel PID controller, allowing faster transient responses, needs an additional low-pass filter when reconstructed equivalent disturbances are required. Next, the design efficiency and conciseness in analyzing the effects of different loop parameters on changing the optimal processes are illustrated by an iterative use of PPM, enabled by the visualization of the dependence between the closed-loop performance and the shapes of the control signals. The main contributions of the paper are the introduction of PPM as an intelligent method for controller tuning that mimics an expert with sufficient experience to select the most appropriate solution based on a database of known solutions. In doing so, the analysis in this paper reveals new, previously undiscovered dimensions of PID control design.

Tuning of PID Control for the Double Integrator Plus Dead Time Model by Modified Real Dominant Pole and Performance Portrait Methods

The paper discusses the proportional-integral-derivative (PID) controller from the viewpoint of (a) the analytical tuning of the PID controller for the double integrator plus dead time (DIPDT) model and (b) the numerical tuning using the performance portrait method (PPM). In the first case, the already published tuning with multiple real dominant pole, extended by integrated tuning procedures, which incorporate the inevitable low-pass filters by delay equivalences, is elaborated for modified sets of real poles. By considering several such modified sets of real poles, resulting in several new sets of controller parameters, the design can be better adapted to the requirements of the control tasks solved and to the limitations of the existing control loop hardware. In a noisy and uncertain environment, the balance between speed of setpoint and disturbance responses and acceptable excessive controller effort can thus be improved. The effectiveness of the analytical design can be evaluated using the numerical performance portrait method (PPM). For an already generated performance portrait (PP), it can offer a broad spectrum of controller settings that satisfy various design constraints. However, the results of the analytical design are still important as they facilitate the initial steps in the elaboration of the PPM and in explaining the nature of PID control. The developed controller tuning are compared using a new interpretation of PID controller as an extension of the stabilising PD controller by disturbance observer (DOB). The input disturbances reconstructed by DOB by evaluating the controller output of an integral process model in steady-state, can be estimated by a low-pass filter with a sufficiently long (integral) time constant. All analysed results are in full agreement with the proposed DOB interpretation, which furthermore contributes significantly to the explanation of the problems related to the optimal design of PID controllers.

PID Tuning for DIPDT System by Web Application

The article discusses basic features of a web application for the optimal proportional-integral-derivative (PID) controller design for the double-integrator-plus-dead-time (DIPDT) system by the performance portrait method. It is the only optimization method whose main part, generating a performance portrait, is solved only once. Solving a new assignment then just requires selecting the best matching solution by browsing the database of relevant dimensionless solutions related to the solved task. For the identified process model parameters, it is then possible to derive controller optimal for the considered application. The article describes all theoretical aspects of the created web application, which aims to make available this often solved task of optimal setting of PID controllers for DIPDT system control to a wide community of users without requiring deeper knowledge in the field of optimization methods and optimal control of time-delayed systems.

BANDURIST CAPELLA “THE SUN” OF I. P. KOTLYAREVSKY KhNUA: DEVELOPMENT AND SPECIFICS OF EVOLUTION (for the 20th anniversary of the artistic life of the capella and the 50th anniversary of its leader Nadezhda Melnik)Background. The present of the national

Background. The present of the national musical culture is characterized by a kind of synthesis between imitation of the original folk-instrumental traditions with the latest ideological models and performing means. The art of bandura players also occupies a proper place in the development of academic folk instruments of Ukraine. A prominent place in the diversity of ensemble groups of large forms is occupied by the bandura band “Sun” of Kharkiv I. P. Kotlyarevsky National University of Arts, whose artistic director and conductor is a famous and talented bandura player, senior lecturer at the Department of Folk Instruments of Ukraine, Kharkiv National University of Arts Nadiya Melnik. The band has a unique performance portrait, relatively long creative path and its own genre and style specifics of development. Today the band is the only large educational bandura ensemble in Kharkiv, which presents the performing traditions of Sloboda Ukraine but, unfortunately, in the musicological discourse there are no studies on the creative activity of this artistic association, analysis of development specifics and its role in the development of bandura performance of Ukraine, which determines the relevance of the article. Many scholars such as: L. Yashchenko, V. Umanets, R. Kiyanovska, A.Ivanysh, T. Cherneta and others studied the development, the stages of formation and the specifics of activities of large bandura groups in Ukraine. The main attention of musicologists and bandura practitioners is devoted to the activities of powerful and leading large ensembles and bandura groups. Among them there are National Honored Bandura Band of Ukraine named after G. I. Mayboroda, bandura choir “Magician” of the Dnipro Academy of Music named after M. Glinka, bandura choir “Lyubava” of Poltava College of Arts named after M. V. Lysenko and others. However, the study of the creative activity of the bandura band “Sun” of Kharkiv I. P. Kotlyarevsky National University of Arts under the direction of N. V. Melnyk, which today has a strong potential and vividly represents the bandura performance not only of Kharkiv, but of Ukraine as a whole remains unnoticed. The purpose and objectives of the article are to highlight the main stages of formation and specifics of the creative activity of the bandore band “Sun” as a bright representative of modern bandura performance in Kharkov. To achieve this goal, the following tasks must be completed: – to identify the main stages of development of the bandura band “Sun”; – to analyze the performance and repertoire of the bandura band “Sun”; – to determine the specifics of the development of creative activity of the bandura band “Sun”. Methods. To achieve this goal and solve the main tasks of the article, the method of artistic and scientific research was used. Results. Basing on the method of art research, it was found that at the present stage the band is the only large group that represents the bandura performance not only of Kharkiv but also in the Sloboda region. Significant events in the artistic life of the participants are marked, which characterize the main milestones in the history of formation and development of the band: the period of the band, the first state recognition of bandura conductors as a professional artists, creation of a bandore band for the first time, winning the laureate title (I place at the all-Ukrainian competition which is called “Ring, bandura” (Dnepropetrovsk, 2004)). The synthesis of traditional performance forms with modern elements of music, combination of vocal and instrumental material and dramatization, melodic recitation, artistic experiments etc. is characteristic for the work of the artistic team. Conclusions. Summarizing all what is written above, we can say that the bandura band “Sun” is a powerful highly professional team with its own performance and drama approach, genre and style features and specific development features: combination of vocal-instrumental material and theatrical performance, melodic, etc. The high appreciation of the bandura players’ creative activity by the leading musicologists of Ukraine and the popularity of the famous artistic group testifies to its recognition in the musicological circle and among the fans of bandura performance in Kharkiv and in Ukraine as a whole.

Research on Students’ Performance Portrait Method Based on Multidimensional Data

With the construction and operation of the university’s intelligent application system, it also accumulates a large amount of data for colleges and universities. Many of these data are student performance data. It is of certain significance to analyze its performance characteristics through data mining technology, to realize teaching in accordance with the aptitude, intelligent management, improve the quality of education and teaching, and work efficiency. We collect data such as wireless user trajectory data, card data, and book borrowing data to analyze student performance. Construct a classification model of student performance based on cluster analysis, and analyze the performance indicators to find the rules between performance and achievement, and improve the learning efficiency of students.

A web based support for the performance portrait based controller design

The Performance Portrait Method enables to visualize influence of chosen control parameters on the loop performance of the selected dynamical system with given interval parameter uncertainties. The knowledge of this behavior can help to analyze and tune control algorithm and to fulfill expected requirements as far as robustness and control quality. The presented paper introduces a new web tool that in an interactive way enables to design filtered 2DOF PI controller for the integral plus dead time system models on the base of the performance portrait method. For a performance portrait calculated once in the 3-5D parameter space it enables to find optimal robust controller tuning. For given plant parameter uncertainties it yields the fastest possible transient responses satisfying with chosen tolerances the shape related constraints at the plant input and output. A web application developed to illustrate the problem offers much richer visual information than it is possible to offer by standard publications, interactivity and dynamical effects. The backend of the application is driven by Matlab software. This environment is used both for calculation of the performance portrait and for simulation of transients of the considered feedback control structure.

Performance Measures and the Robust and Optimal Control Design

The paper discusses performance measures used dominantly in the robust and optimal control design. By simple examples of the first order time delayed (FOTD) system control it illustrates that the usually prescribed levels of the maximal and complementary sensitivity functions indeed define situations with interesting loop properties, but may not be universally applied to the robust and optimal design of systems with an uncertain feedback variable in a broader range. For this purpose the shape related measures based on deviations from monotonicity yield results matching the technological requirements of practice in a much more appropriate way. It is also shown that in an optimal nominal controller design the monotonicity based performance measures nearly coincide with the multiple real dominant pole (MRDP) method. For the loop optimization using a broader spectrum of different performance measures, the performance portrait method may be recommended. It avoids the problems of convergence to the absolute optimum and, once generated, the performance portrait may repeatedly be used with a limited effort for a broader spectrum of different cost function specifications.

Multi-job production systems: definition, problems, and product-mix performance portrait of serial lines

This paper pursues two goals: (a) Define a class of widely used in practice flexible manufacturing systems, referred to as Multi-Job Production (MJP) and formulate industrially motivated problems related to their performance. (b) Provide initial results concerning some of these problems pertaining to analysis of the throughput and bottlenecks of MJP serial lines as functions of the product-mix. In MJP systems, all job-types are processed by the same sequence of manufacturing operations, but with different processing time at some or all machines. To analyse MJP with unreliable machines, we introduce the work-based model of production systems, which is insensitive to whether single- or multi-job manufacturing takes place. Based on this model, we investigate the performance of MJP lines as a function of the product-mix. We show, in particular, that for the so-called conflicting jobs there exists a range of product-mixes, wherein the throughput of MJP is larger than that of any constituent job-type manufactured in a single-job regime. To characterise the global behaviour of MJP lines, we introduce the Product-Mix Performance Portrait, which represents the system properties for all product-mixes and which can be used for operations management. Finally, we report the results of an application at an automotive assembly plant.

Web Application for the Analysis of One Type of Disturbance Observer Based PI Control by the Performance Portrait Method

One type of the disturbance observer (DO) based controller has been proposed by extending the traditional PI control loop for a velocity servo control by DO for reconstruction and compensation of input disturbances. This solution has significantly improved the disturbance response and attracted attention of many subsequent papers. On the other hand, the structure has led to problems that have limited achievable improvements of transients. Thus, this structure takes a unique position in understanding features of the DO based control and in all associated courses. The application should yield open access to an interactive analysis of such a solution by the performance portrait method and to its comparison with another possible modification of the DO based filtered PI control.

Performance portrait - a 3D approach

The paper deals with a comparison of two possible approaches to the performance portrait method application for an optimal nominal tuning of an integral plus dead time (IPDT) plant. The first one relies on a more compact 2D approach used by Huba et al. [2009] inspired by the triple real dominant pole method [Víteček and Vítečková, 2008]. The second approach is a simpler but, at the same time, in some aspects a computationally more demanding 3D method. Pros and cons of both approaches are analyzed and discussed.

Comparing 2DOF PI and predictive disturbance observer based filtered PI control

This paper analyses the optimal nominal tuning of a new modification of predictive disturbance observer (PDO) based filtered PI control (PDO FPI) applied to a first order plus dead time (FOPDT) plant with exactly known parameters.The impacts of applied filters on optimal controller tuning and on achievable closed loop performance are evaluated first of all. The limits of achievable performance are compared with those of traditional two degree of freedom (2DOF) PI control, with both controllers tuned by the multiple real dominant pole method. This comparison shows the potential of PDO FPI control to improve tracking and regulatory dynamics significantly, permitting the Pareto-like servo/regulator trade-off of 2DOF PI control to be removed.Two PDO FPI tuning approaches are proposed, allowing optimal filter degree and time constants to be evaluated.The first tuning scenario considers optimization of closed loop performance expressed in terms of the Integral of the Absolute Error (IAE) weighted alternatively by the relative total variance TV1 of the control signal. This is carried out by changing the filter order n under the constraint that a constant position of the dominant closed loop pole is maintained. This keeps the dynamics of the setpoint step responses almost unchanged. In the second tuning scenario the optimization is carried out under a constraint on constant speed of disturbance step responses.All the main results are then numerically checked for the integral first order plant with dead time by the performance portrait (PP) method.The analysis presented here shows that the new PDO FPI structure substantially enriches the spectrum of controllers applicable to simple control tasks.

Performance measures, performance limits and optimal PI control for the IPDT plant

This paper considers PI controller tuning for the Integral Plus Dead Time (IPDT) plant subject to constraints on tolerable deviations from ideal shapes and guaranteeing minimal combined IAE (Integral of Absolute Error) measure composed of weighted IAE values of the setpoint and disturbance step responses. As the ideal responses at the plant output, monotonic (MO) transients are chosen. This implies one-pulse (1P) responses consisting of two monotonic intervals at the plant input. Optimal nominal tunings for the most important situations regarding the servo/regulation trade-off are determined by the newly developed Matlab/Simulink tool based on the performance portrait (PP) method. Generated results confirm Pareto-like limits of performance achievable under PI control and are used in classifying traditional tuning approaches into the setpoint and disturbance oriented ones. Principles of robust PP based tuning are briefly illustrated and conditions of invariance of the closed loop performance against the dead time uncertainty are formulated and checked by simulation.

Performance Portrait Method: a new CAD Tool

The Performance Portrait Method opens new possibilities for analysis and design of the optimal and robust control. In different settings and in a simple and graspable way it allows to visualize influence of chosen control parameters on the loop performance, no matter how a peculiar dynamics is considered (with a long dead time, parameter uncertainties, constraints, etc.). Its use in design of the PI control for a single integrator + dead time is considered.

Setpoint Versus Disturbance Responses of the IPDT Plant

This paper considers PI controller tuning for Integral Plus Dead Time plant (IPDT) by new Matlab/Simulink tool based on the performance portrait method. It enables to guarantee transient responses with specified deviations from ideal shapes at the plant output and input and to fulfill additional optimality specification, defined in terms of the minimal IAE (Integral of Absolute Error) values weighted for the setpoint and disturbance steps. As the ideal step responses at the plant output monotonic transients are considered, whereas at the plant input one-pulse responses consisting of two monotonic intervals are required. As an introduction to new generation of robust tuning approaches, optimal nominal tuning is firstly treated.

Computer Design of Robust I-controller

AbstractThis paper shows new possibility of the robust design of simple controllers based on computer analysis of closed loop transient responses achieved over predefined grid of possibly normalized loop parameters by simulation, or by measurement. Evaluation of the collected transients according to chosen performance measures related to monotonicity and time yields the so called Performance Portrait (PP). Based on the PP, controller tuning satisfying desired robust performance may be derived what is illustrated by tuning simple integral (I) controllers for the simplest uncertain 2-parameter plant model. Achieved results that extend the simple tuning proposed by Skogestad (2003) to a broader spectrum of nearly monotonic shapes are compared with the analytical controller tuning based on the double real dominant closed loop pole and then, on an example of a higher order dead-time dominant plant, with the results achieved by the Filtered Smith Predictor. Possible extension to PI control is briefly mentioned.

Robust Controller Tuning for Integral Dead Time Systems

By using newly developed method of the performance portrait (PP) for achieving as fast as possible transients in the closed loops with the Integrator Plus Dead Time (IPDT) and Second Order Integrator Plus Dead Time (SOIPDT) plants this paper discusses optimality of the traditional controller tuning corresponding to the Multiple Real Dominant Pole (MRDP) and shows potential of the new method for arbitrarily shaping the close loop properties of time delayed systems.