Real-Time Windows Target Research Articles

Real-time application of IMC-PID-FO multi-loop controllers on the coupled tanks process

The coupled tanks process is a two input-two output system. It presents a nonlinear behavior and interactions characteristic. After the nonlinear model is obtained, it is linearized around an operating point. A fractional-order proportional–integral–derivative based on the internal model control paradigm (1DOF-IMC-PID-FO) multi-loop controller is determined without considering the interactions, and a fractional-order proportional–integral–derivative based on the 2-degree-of-freedom internal model control structure (2DOF-IMC-PID-FO) multi-loop controller is determined by considering the interactions. Thus, an interactions reduction effect controller is calculated. Both controllers are implemented on a real-time process using the Real Time Windows Target of MATLAB. The objective of the control is to maintain the water level in the lower tanks at desired values. In the experiment, setpoint tracking and disturbance rejection tests are carried out to assess the performance of both 1DOF and 2DOF-IMC-PID-FO multi-loop controllers.

Real-Time-Simulation of IEEE-5-Bus Network on OPAL-RT-OP4510 Simulator

The Real-Time Simulator tools have high computing technologies, improved performance. They are widely used for design and improvement of electrical systems. The advancement of the software tools like MATLAB/SIMULINK with its Real-Time Workshop (RTW) and Real-Time Windows Target (RTWT), real-time simulators are used extensively in many engineering fields, such as industry, education, and research institutions. OPAL-RT-OP4510 is a Real-Time Simulator which is used in both industry and academia. In this paper, the real-time simulation of IEEE-5-Bus network is carried out by means of OPAL-RT-OP4510 with CRO and other hardware. The performance of the network is observed with the introduction of fault at various locations. The waveforms of voltage, current, active and reactive power are observed in the MATLAB simulation environment and on the CRO. Also, Load Flow Analysis (LFA) of IEEE-5-Bus network is computed using MATLAB/Simulink power-gui load flow tool.

Real-Time Digital Simulators: A Comprehensive Study on System Overview, Application, and Importance

The multifarious improvements in computational and simulation tools have brought tremendous progress in the field of designing, testing and analyzing technologies. In this paper, the technological aspects and the concept of modern real-time digital simulators are presented. The real-time simulator functions in real time, thus it produces continuous output that realistically represents the conditions of a real system. Also, in a real-time simulator the user can test physical devices. Therefore, it is of great importance to understand the features and roles of the advanced simulator technologies. Also, User-friendly system interface, easy application in system design and testing, and most importantly cost effectiveness are the most desire features for implying these simulator into a research. Therefore, this paper summarizes all significant features by considering the above-mentioned facts of some most popular, globally, and commercially available simulator technologies. Real Time Digital Simulators (RTDS), OPAL-RT, Network Torsion Machine Control (NETOMAC), dSPACE, Real-Time solution by MathWorks (xPC target, Real-Time Windows target), Power_system Online_simulation Unveil Your Analysis (POUYA) Simulator and Typhoon HIL Simulator are discussed in this review paper based on the accessibility of information. A summarization of these simulators’ background, hardware, software and communication protocols are presented. Applications of these above-mentioned simulators are also added to understand the potentials of these simulators.

Altitude Controller Design for Quadcopter UAV

This paper discusses on attitude control of a quadcopter unmanned aerial vehicle (UAV) in real time application. Newton-Euler equation is used to derive the model of system and the model characteristic is analyzed. The paper describes the controller design method for the hovering control of UAV automatic vertical take-off system. In order to take-off the quadcopter and stable the altitude, PID controller has been designed. The scope of study is to develop an altitude controller of the vertical take-off as realistic as possible. The quadcopter flight system has nonlinear characteristics. A simulation is conducted to test and analyze the control performance of the quadcopter model. The simulation was conducted by using Mat-lab Simulink. On the other hand, for the real time application, the PCI-1711 data acquisition card is used as an interface for controller design which routes from Simulink to hardware. This study showed the controller designs are implemented and tuned to the real system using Real Time Windows Target approach by Mat-Lab Simulink.

WORKBENCH FOR CONTROL SYSTEMS TRIALS BASED ON VIPA 300 CONTROLLER AND ADVANTECH INPUT/OUTPUT CARD

The topic is about workbench creation for control systems trials based on VIPA 300 industrial PLC and model of control object which is implemented in MatLab Simulink program on PC. Connection between controller and the PC is provided by the Advantech PCI-1711 input/output card of discrete and analog signals. Object identification, control system synthesis, creation of control device structure and its parametrical identification, as a rule, is done on a PC in a modelling environment, e.g. in MatLab. But often, using this PC modelling, the hardware and software features of algorithms which were obtained during system synthesis are not considered in a specific industrial PLC. It is considered a good idea to use a composite version where obtained algorithms are tested in a real industrial PLC and control object is substituted by a model which is working on a PC in real time scale. In this case software realization of algorithms in a specific PLC are fully taken into account and substitution of real control object by its model considerably reduces the costs for carrying out experiments and allows to study the system behavior when control object parameters and modes of operation vary greatly. The creation of workbench stipulates several stages: configuration and programming of industrial PLC VIPA 313 SC, installation and configuration of Advantech PCI1711 input/output card, tuning of Simulink modelling environment for working in real time scale using Real-Time Windows Target Library, testing of workbench by using constant and harmonic signals of different frequencies. Work results of virtual stabilization system are compared with combined version. In virtual stabilization system PID governor and control object are implemented in Simulink. In combined version control object is still implemented in Simulink and PID governor - in VIPA 313 SC controller (using functional block FB58 from Step7 standard library).

Photovoltaic Panel Emulators, Design and Implementation Using Rapid Prototyping Technique

Photovoltaic emulators (PVE) are power electronic systems that are able to reproduce the output Current-Voltage characteristics of photovoltaic panels in various operating conditions. They are indispensable for the design and evaluation of the operational components of a photovoltaic energy system, such as battery chargers and Maximum Power Point Tracking (MPPT). Those emulators prevent the experimental testing process on a site and ensure considerable savings in time and cost. In this article, we adopt the rapid prototyping technique incorporating an acquisition board and the toolbox Real Time Windows Target of Matlab. For that, we propose to use direct blocs schemes in Simulink in order to simulate and control a hardware target emulating a photovoltaic panel. The experimental platform's obtained results show that the characteristics of the designed emulator output are in good agreement with those of a real photovoltaic panel, under different conditions of temperature, irradiation and load.

Design and Realization of a Digital PV Simulator with a Push-Pull Forward Circuit

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with <TEX>$k_i$</TEX> and <TEX>$R_L$</TEX> as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of <TEX>$R_L$</TEX> and the operating point of the PV simulator to match the controller parameters with <TEX>$R_L$</TEX>. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

Research on Performance of Two Real-Time Simulation Environments: RTWT and xPC Target

RTWT (Real-Time Windows Target) and xPC Target are two developing environments based on Matlab/RTW for hardware-in-loop real-time simulation and rapid control prototype. Some error messages which lead to program stop often occur in their practical applications, such as CPU overload, buffer too small, and so on. In this paper, performance of the two simulation environments were studied by analyzing their working mechanism and conducting a lot of experiments, including signal data logging capability, sampling period and system stability. And the reasons which cause error running messages were analyzed. The following conclusions have been drawn. For RTWT data logging capability is not limited by buffer size because the data in buffer are saved to file in real-time during operating. While for xPC Target data logging capability is not limited by buffer size because the data in buffer are uploaded to the host computer and stored in file at the end of run. As long as the sampling period is slightly larger than the task execution time, xPC Target can run stably. RTWT can run stably only when the sampling period is far larger than the task execution time. The proposed conclusions can provide reference for selection between RTWT and xPC Target and their application.

Development and evaluation of a prototype tracking system using the treatment couch

Tumor motion increases safety margins around the clinical target volume and leads to an increased dose to the surrounding healthy tissue. The authors have developed and evaluated a one-dimensional treatment couch tracking system to counter steer respiratory tumor motion. Three different motion detection sensors with different lag times were evaluated. The couch tracking system consists of a motion detection sensor, which can be the topometrical system Topos (Cyber Technologies, Germany), the respiratory gating system RPM (Varian Medical Systems) or a laser triangulation system (Micro Epsilon), and the Protura treatment couch (Civco Medical Systems). The control of the treatment couch was implemented in the block diagram environment Simulink (MathWorks). To achieve real time performance, the Simulink models were executed on a real time engine, provided by Real-Time Windows Target (MathWorks). A proportional-integral control system was implemented. The lag time of the couch tracking system using the three different motion detection sensors was measured. The geometrical accuracy of the system was evaluated by measuring the mean absolute deviation from the reference (static position) during motion tracking. This deviation was compared to the mean absolute deviation without tracking and a reduction factor was defined. A hexapod system was moving according to seven respiration patterns previously acquired with the RPM system as well as according to a sin(6) function with two different frequencies (0.33 and 0.17 Hz) and the treatment table compensated the motion. A prototype system for treatment couch tracking of respiratory motion was developed. The laser based tracking system with a small lag time of 57 ms reduced the residual motion by a factor of 11.9 ± 5.5 (mean value ± standard deviation). An increase in delay time from 57 to 130 ms (RPM based system) resulted in a reduction by a factor of 4.7 ± 2.6. The Topos based tracking system with the largest lag time of 300 ms achieved a mean reduction by a factor of 3.4 ± 2.3. The increase in the penumbra of a profile (1 × 1 cm(2)) for a motion of 6 mm was 1.4 mm. With tracking applied there was no increase in the penumbra. Couch tracking with the Protura treatment couch is achievable. To reliably track all possible respiration patterns without prediction filters a short lag time below 100 ms is needed. More scientific work is necessary to extend our prototype to tracking of internal motion.

Design of Networked Control System with Discrete-Time State Predictor over WSN

 Abstract—We design a networked control system (NCS) with discrete-time state predictor where the communication between the controller output and the plant input takes place over a wireless sensor network (WSN). In order to measure time delays between the controller output and the plant input in real time, we design an algorithm to measure round trip time (RTT) between WSN nodes, and implement it into TinyOS of WSN. By using the measured time delays, we construct the discrete-time state predictor to compensate the time delays between the controller output and the plant input in real-time. For the real time experiment, we simulate the dynamic plant model, the controller, and WSN interface using Real-Time Windows Target provided in MATLAB. The WSN interface in the Simulink model consists of serial ports, which connect the controller output and the plant input with WSN nodes. The experiment results show that the time delays between the controller output and the plant input are precisely measured in real time; the discrete-time state predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS. In this paper, we design an NCS with discrete-time state predictor where the communication between the controller output and the plant input takes place over WSNs. In order to measure time delays between the controller output and the plant input in real time, we design an algorithm to measure round trip time (RTT) between WSN nodes, and implement it into TinyOS of WSN. By using the measured time delays as a parameter, we construct the discrete-time state predictor (6), (7) to compensate the time delays between the controller output and the plant input in real time. The discrete-time state predictor suitably compensates measured time delays in the feedback loop. The experiment results show that the time delays between the controller output and the plant input are precisely measured in real time; the discrete-time state predictor appropriately compensates the time delays; and the closed-loop of the NCS is made to be stable.

RTT 측정을 이용하는 USN 기반 Networked Control System

We design a NCS (Networked Control System) where the communication between sensors and controllers takes place over a USN (Ubiquitous Sensor Network). In order to measure time delays between sensors and controllers in real time, we design an algorithm to measure RTT (Round Trip Time) between USN nodes, and implement it into TinyOS of USN. By using the measured time delays, we construct the Smith predictor to compensate the time delays between sensors and controllers in real-time. For the real time experiment, we simulate the dynamic plant model, controller, and USN interface using Real-Time Windows Target provided in MATLAB. The USN interface in the Simulink model consists of serial ports, which connect the plant output and controller with USN nodes. The experiment results show that the time delays between sensors and controllers are precisely measured in real time; the Smith predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS.

Mechatronic Aeropendulum: Demonstration of Linear and Nonlinear Feedback Control Principles With MATLAB/Simulink Real-Time Windows Target

This paper presents a low-cost hands-on experiment for a classical undergraduate controls course for non-electrical engineering majors. The setup consists of a small dc electrical motor attached to one of the ends of a light rod. The motor drives a 2-in propeller and allows the rod to swing. Angular position is measured by a potentiometer attached to the pivot point. A custom-designed circuit board produces the controlled voltage input to the motor. The target board is powered and communicates with the PC through its USB port using a virtual RS-232 port. A simple MATLAB/Simulink module has been created to read the pendulum angle and send a command signal to the motor. The module is based on Real-time Windows Target software, which allows a sampling rate of up to 200 Hz. Students are able to design and test classical PID and phase lead-lag controllers, as well as modern controllers, including state-space controller design combined with feedback linearization. A semester-long series of assignments is described that can be carried out without the need for a specialized laboratory or teaching assistants. The project was tested in a classical control systems design class of senior-level mechanical engineering students. Student feedback and survey data on the effectiveness of the modules are also presented.

Real-time application of shunt active power filter dynamic compensation using real-time windows target

SUMMARY In this contribution, a control strategy in phase coordinates abc is proposed as the reference current generator to be used by the shunt active power filter (APF) compensation device. The development of the proposed reference current generator is described in detail. Its control design is kept simple, and transformation between different frameworks is not needed, thus allowing the control strategy to be applicable for both three-phase and single-phase electric systems maintaining theoretical and practical advantages. The proposed control strategy for the reference current generator is tested using Matlab/Simulink® with the incorporation of the Real-Time Workshop® for the simulation of the shunt APF compensation in real time. Based on the reported real-time application, it is possible to obtain simulation conditions that are close to the true real-time environment under study using only a single computer, giving accurate results with relatively low-cost hardware and providing a more complete evaluation of the applied control strategy. The dynamic behavior and performance of the shunt APF, using the proposed reference current calculator, have shown remarkable results. Copyright © 2012 John Wiley & Sons, Ltd.

Fuel cell emulator for oxygen excess ratio estimation on power electronics applications

This paper proposes a real-time fuel cell emulator based on the Real-Time Windows Target from Matlab and a controlled power source. The emulator accurately reproduces both static and dynamic fuel cell behaviors, and its main features are the estimation of the oxygen excess ratio and its ability to safely interact with electrical loads such as switching converters. Consequently, the proposed emulator can be used to design and test devices prior to their connection to real fuel cells, preventing undesired phenomena. The emulator was adjusted to the Ballard NEXA 1.2 kW fuel cell, obtaining a satisfactory experimental validation. Finally, the emulator was used to design a hardware-in-the-loop test system to analyze the oxygen starvation effect generated by a DC/DC power converter.

Human control of an inverted pendulum: Is continuous control necessary? Is intermittent control effective? Is intermittent control physiological?

Human motor control is often explained in terms of engineering 'servo' theory. Recently, continuous, optimal control using internal models has emerged as a leading paradigm for voluntary movement. However, these engineering paradigms are designed for high band-width, inflexible, consistent systems whereas human control is low bandwidth and flexible using noisy sensors and actuators. By contrast, engineering intermittent control was designed for bandwidth-limited applications. Our general interest is whether intermittent rather than continuous control is generic to human motor control. Currently, it would be assumed that continuous control is the superior and physiologically natural choice for controlling unstable loads, for example as required for maintaining human balance. Using visuo-manual tracking of an unstable load, we show that control using gentle, intermittent taps is entirely natural and effective. The gentle tapping method resulted in slightly superior position control and velocity minimisation, a reduced feedback time delay, greater robustness to changing actuator gain and equal or greater linearity with respect to the external disturbance. Control was possible with a median contact rate of 0.8±0.3 s(-1). However, when optimising position or velocity regulation, a modal contact rate of 2 s(-1) was observed. This modal rate was consistent with insignificant disturbance-joystick coherence beyond 1-2 Hz in both tapping and continuous contact methods. For this load, these results demonstrate a motor control process of serial ballistic trajectories limited to an optimum rate of 2 s(-1). Consistent with theoretical reasoning, our results suggest that intermittent open loop action is a natural consequence of human physiology.

Modeling and Controller Design for the VVS-400 Pilot Scale Heating and Ventilation System

Abstract In this paper, a heating and ventilation model VVS-400 from Instrutek, Larvik, Norway is modeled using ARX model structure and linear black-box technique. The conventional PID controller and artificial Fuzzy controller are designed based on the approximated plant model and real plant model. The approximated plant model is estimated using System Identification approach while the real plant model is developed by interfacing the Real-time Windows Target toolbox in Matlab with real VVS-plant by using data acquisition (DAQ) card PCI-1711. An artificial Fuzzy controller approach is incorporated in two ways which are conventional Fuzzy logic controller (FLC) and a replacement of conventional fuzzy controller known as Single input fuzzy logic controller (SIFLC). Simulations and experiment validate the equivalency of both controllers. Results reveal that SIFLC found to be better than FLC due to its less computation time compared to conventional FLC.

Real-Time Shunt Active Power Filter Compensation

This letter presents the application of a real-time simulation technique to shunt active power filter compensation of the harmonic currents and reactive power in the power system. Available literature details several techniques developed and implemented to perform real-time simulations on the power system analysis. This paper will focus on the following technique: real-time windows target (RTWT) using Matlab/Simulink. Based on the obtained results of the RTWT application, it is possible to obtain simulation conditions that are close to the true real-time environment under study using only a single computer (e.g., the same computer is used as a host and as a target), giving accurate results with relatively low-cost hardware.

A local active noise control system based on a virtual-microphone technique for railway sleeping vehicle applications

Low-frequency broadband noise generated on a railway vehicle by the wheel–rail interaction could be a big annoyance for passengers in sleeping cars. Low-frequency acoustic radiation is extremely difficult to attenuate by using passive devices. In this article, an active noise control (ANC) technique has been proposed for this purpose. A three-dimensional cabin was built in the laboratory to carry out the experiments. The proposed scheme is based on a Filtered-X Least Mean Square (FXLMS) control algorithm, particularised for a virtual-microphone technique. Control algorithms were designed with the Matlab-Simulink tool, and the Real Time Windows Target toolbox of Matlab was used to run in real time the ANC system. Referring to the results, different simulations and experimental performances were analysed to enlarge the silence zone around the passenger's ear zone and along the bed headboard. Attenuations of up to 20 and 15 dB(A) (re:20 μPa) were achieved at the passenger's ear in simulations and in experimental results, respectively.

Investigation of the micro-step control positioning system performance affected by random input signals

This paper gives the results of simulation and experimental investigation on the effects of random signals on the accuracy of micro-stepping control positioning. For studying and simulation of the effect of random noise signals on performance of the accurate position control systems, such as Hybrid Stepper Motors (HSMs), a micro-step driver and controlling unit using PID controller has been designed and constructed. Several parametric studies have been carried out including different white noise power and micro-step per revolution. Tracking problem for a HSM model has been simulated, and the experimental study for similar cases has been carried out by implementing the designed controller in real-time operation by using Real Time Windows Target Toolbox of Matlab software and Simulink. Simulation and experimental results show that random noise source changes current profile and affects the accuracy of positioning. Performance of the proposed PID controller under the implementation of random noise on phases one and two of stepper motor has been proved to be accurate enough even under disturbance load currents, on the system. Experimental and simulation results show the good performance of designed controller in tracking problem, affected by various random noise powers and motor speeds in different micro-step positions. Moreover there is an excellent agreement between experimental and simulation results.

A MATLAB-based control systems laboratory experience for undergraduate students: toward standardization and shared resources

This paper seeks to begin a discussion with regard to developing computer aided control system design (CACSD) tools to promote undergraduate controls laboratory development. The advocated CACSD design tools are based on the popular, commercially available MATLAB environment, the Simulink toolbox, and the Real-Time Workshop toolbox. This paper describes how these tools can be utilized to address several issues that are confronted by control systems educators including: standardization, budget constraints, and limited resources. Specifically, by confronting the standardization issue, the following advantages are realized for laboratory development: (1) the required computer hardware will be low cost; (2) commercially available plants from different manufacturers can be supported under the same CACSD environment with no hardware modifications; (3) both the Windows and Linux operating systems can be supported via the MATLAB based Real-Time Windows Target and the Quality Real-Time Systems (QRTS) based Real-Time Linux Target; and (4) the Simulink block diagram approach can be utilized to prototype control strategies, thereby, eliminating the need for low level programming skills. The advantages related to standardization of the CACSD design tools will enable educators to confront the additional budget constraint and limited teaching resources issue by facilitating: (1) the sharing of laboratory resources within each university (i.e., between departments); (2) the development of Internet laboratory experiences for students (i.e., between universities); and (3) the initiation of an Internet-based archive of laboratory tutorials and Simulink files for in-house developed plants and commercially available plants.