79,332 research outputs found

    Design of Self-tuning PID Controller Parameters Using Fuzzy Logic Controller for Quad-rotor Helicopter

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    This paper presents the design of a Fuzzy PID controller (FPID) based on fuzzy logic with a PID structure with many valued logic and reasoning. The self-turning Fuzzy PID control take in an error and the rate of change of error of the altitude and attitude of the quadrotor as the input to the fuzzy controller and use the fuzzy rules to adjust the PID parameter automatically. Simulations have been conducted to observe the differences in controlling the quadrotor in flight using the new FPID controller instead of using PID controller. The effectiveness of the developed FPID is verified using the dSPACE platform whereby the Simulink model of the controller is converted to a real time system to generate the control signals for the control of quad rotor helicopter

    controller. The result shows that the proposed controller reduced the overshoot and steady state error of the pneumatic actuator system to no overshoot and 0.025mm respectively. Index terms: System identification, recursive least square, ARX, dead zone compensator, pneumatic actuator

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    In this paper, a nonlinear mathematical modeling based on fundamental physical derivation is presented. The mass flow rate, pressure dynamic and equation of motion are derived referring to the previous research. Simulation work is done to confirm the model based on this derivation. Cascade control based on PID and P controller is designed through simulation in SIMULINK where the parameters of the controller are obtained through PID with optimization toolbox. The results reveal that both step and sinusoidal response test, the cascade controller consistently indicates outperform performance compared to classical PID method. In future, it is recommended to apply this technique to the real-time implementation

    Automated and dynamic extrusion pressure adjustment based on real-time flow rate measurements for precise ink dispensing in 3D bioprinting

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    Extrusion-based printing relying on pneumatic dispensing systems is the most widely employed tool in bioprinting. However, standardized and reliable methods for process development, monitoring and control are still not established. Suitable printing parameters are often determined in a trial-and-error approach and neither process monitoring nor real-time adjustments of extrusion pressure to environmental and process-related changes are commonly employed. The present study evaluates an approach to introduce flow rate as a main process parameter to monitor and control extrusion-based bioprinting. An experimental setup was established by integrating a liquid flow meter between the cartridge and nozzle of a pneumatically driven bioprinter to measure the actual flow of dispensed ink in real-time. The measured flow rate was fed to a Python-based software tool implementing a proportional-integral-derivative (PID) feedback loop that automatically and dynamically adapted the extrusion pressure of the bioprinter to meet a specified target flow rate. The performance of the employed experimental setup was evaluated with three different model inks in three application examples. a) Continuous dispensing: Several runs of continuous dispensing showed that the PID-based pressure control was able to generate a steady flow rate more consistently and precisely than constant pressure settings. b) Adaptation to ink inhomogeneities: Deliberately created ink inhomogeneities were successfully compensated for by real-time pressure adjustments which profoundly enhanced the printing quality compared to printing without adaptive pressure. c) Process transfer to other nozzle types: Experiments with different nozzle types demonstrated the potential of the established setup to facilitate and accelerate process transfer and development. The present study provides an alternative approach for process design, monitoring and control by introducing flow rate as a main process parameter. We propose bioprinting processes to be based on flow rate specifications instead of constant pressure settings. This approach has the potential to save time by avoiding tedious parameter screenings and to introduce an active, real-time control over the printing process. Subjective influences by individual users during process development can be reduced and the process transfer between different devices and experimental setups can be facilitated and accelerated

    A novel intelligent adaptive control of laser-based ground thermal test

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    AbstractLaser heating technology is a type of potential and attractive space heat flux simulation technology, which is characterized by high heating rate, controlled spatial intensity distribution and rapid response. However, the controlled plant is nonlinear, time-varying and uncertainty when implementing the laser-based heat flux simulation. In this paper, a novel intelligent adaptive controller based on proportion–integration–differentiation (PID) type fuzzy logic is proposed to improve the performance of laser-based ground thermal test. The temperature range of thermal cycles is more than 200K in many instances. In order to improve the adaptability of controller, output scaling factors are real time adjusted while the thermal test is underway. The initial values of scaling factors are optimized using a stochastic hybrid particle swarm optimization (H-PSO) algorithm. A validating system has been established in the laboratory. The performance of the proposed controller is evaluated through extensive experiments under different operating conditions (reference and load disturbance). The results show that the proposed adaptive controller performs remarkably better compared to the conventional PID (PID) controller and the conventional PID type fuzzy (F-PID) controller considering performance indicators of overshoot, settling time and steady state error for laser-based ground thermal test. It is a reliable tool for effective temperature control of laser-based ground thermal test

    A packet-based dual-rate PID control strategy for a slow-rate sensing Networked Control System

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    [EN] This paper introduces a packet-based dual-rate control strategy to face time-varying network-induced delays, packet dropouts and packet disorder in a Networked Control System. Slow-rate sensing enables to achieve energy saving and to avoid packet disorder. Fast-rate actuation makes reaching the desired control performance possible. The dual-rate PID controller is split into two parts: a slow-rate PI controller located at the remote side (with no permanent communication to the plant) and a fast-rate PD controller located at the local side. The remote side also includes a prediction stage in order to generate the packet of future, estimated slow-rate control actions. These actions are sent to the local side and converted to fast-rate ones to be used when a packet does not arrive at this side due to the network-induced delay or due to occurring dropouts. The proposed control solution is able to approximately reach the nominal (no-delay, no-dropout) performance despite the existence of time-varying delays and packet dropouts. Control system stability is ensured in terms of probabilistic Linear Matrix Inequalities (LMIs). Via real-time control for a Cartesian robot, results clearly reveal the superiority of the control solution compared to a previous proposal by authors. (C) 2018 ISA. Published by Elsevier Ltd. All rights reserved.This work is funded by European Commision as part of Project H2020-SEC-2016-2017 Topic: SEC-20-BES-2016 Id: 740736 C2 Advanced Multi-domain Environment and Live Observation Technologies (CAMELOT). Part WP5 supported by Tekever ASDS, Thales Research & Technology, Viasat Antenna Systems, Universitat Politècnica de València, Fundação da Faculdade de Ciências da Universidade de Lisboa, Ministério da DefesaNacional Marinha Portuguesa, Ministério da Administração Interna Guarda Nacional Republicana.Cuenca, Á.; Alcaina-Acosta, JJ.; Salt Llobregat, JJ.; Casanova Calvo, V.; Pizá, R. (2018). A packet-based dual-rate PID control strategy for a slow-rate sensing Networked Control System. ISA Transactions. 76:155-166. https://doi.org/10.1016/j.isatra.2018.02.022S1551667

    Positional control of rotary servo cart system using generalized dynamic inversion

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    This paper presents the design approach of Generalized Dynamic Inversion (GDI) for angular position control of SRV02 rotary servo base system. In GDI, linear first order constraint differential equations are formulated based on the deviation function of angular position and its rate, and its inverse is calculated using Moore-Penrose Generalized Inverse to realize the control law. The singularity problem related to generalized inversion is solved by the inclusion of dynamic scaling factor that will guarantee the boundedness of the elements of the inverted matrix and stable tracking performance. Numerical simulations and real-time experiment are performed to evaluate the tracking performance and robustness capabilities of the proposed control law considering nominal and perturbed model dynamics. For comparative analysis, the results of GDI is compared with conventional PID control. Simulation and experimental results demonstrate better angular position tracking for the square-wave and sinusoidal waveforms, which reveals the superiority, and agility of GDI control over conventional PID

    Performance comparison of optimal fractional order hybrid fuzzy PID controllers for handling oscillatory fractional order processes with dead time

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Fuzzy logic based PID controllers have been studied in this paper, considering several combinations of hybrid controllers by grouping the proportional, integral and derivative actions with fuzzy inferencing in different forms. Fractional order (FO) rate of error signal and FO integral of control signal have been used in the design of a family of decomposed hybrid FO fuzzy PID controllers. The input and output scaling factors (SF) along with the integro-differential operators are tuned with real coded genetic algorithm (GA) to produce optimum closed loop performance by simultaneous consideration of the control loop error index and the control signal. Three different classes of fractional order oscillatory processes with various levels of relative dominance between time constant and time delay have been used to test the comparative merits of the proposed family of hybrid fractional order fuzzy PID controllers. Performance comparison of the different FO fuzzy PID controller structures has been done in terms of optimal set-point tracking, load disturbance rejection and minimal variation of manipulated variable or smaller actuator requirement etc. In addition, multi-objective Non-dominated Sorting Genetic Algorithm (NSGA-II) has been used to study the Pareto optimal trade-offs between the set point tracking and control signal, and the set point tracking and load disturbance performance for each of the controller structure to handle the three different types of processes

    Analysis of a Near Real-Time Optimal Attitude Control for Satellite Simulators

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    Dynamic optimization of spacecraft attitude reorientation maneuvers can result in significant savings in attitude determination and control system size, mass, and power. Optimal control theory is generally applied using an open loop trajectory which is vulnerable to disturbances. A closed loop implementation of optimal control has been difficult to achieve due to the computational requirements needed to quickly compute solutions to the optimal control problem. This research focuses on evaluating a near real-time optimal control (RTOC) system for large angle slew maneuvers on the Air Force Institute of Technology\u27s spacecraft simulator called SimSat. A near RTOC algorithm computes optimal control solutions at a rate of 0.4 Hz using a pseudospectral-based solver. The solutions or trajectories are then resampled at a fixed time step of 100 Hz and fed forward to a closed loop on SimSat. This algorithm is developed and tested on the hardware and compared to simulated and hardware results of a proportional-integral-derivative (PID) controller and an open loop optimal control controller for 90 degree and 180 degree Z-axis rotations. The benefits of decreased time to complete the maneuver and increased accuracy at the end of the optimal maneuver are shown to be improvements over traditional over PID control and open loop optimal control

    A simulation-based comparative analysis of PID and LQG control for closed-loop anesthesia delivery

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    Closed loop anesthesia delivery (CLAD) systems can help anesthesiologists efficiently achieve and maintain desired anesthetic depth over an extended period of time. A typical CLAD system would use an anesthetic marker, calculated from physiological signals, as real-time feedback to adjust anesthetic dosage towards achieving a desired set-point of the marker. Since control strategies for CLAD vary across the systems reported in recent literature, a comparative analysis of common control strategies can be useful. For a nonlinear plant model based on well-established models of compartmental pharmacokinetics and sigmoid-Emax pharmacodynamics, we numerically analyze the set-point tracking performance of three output-feedback linear control strategies: proportional-integral-derivative (PID) control, linear quadratic Gaussian (LQG) control, and an LQG with integral action (ILQG). Specifically, we numerically simulate multiple CLAD sessions for the scenario where the plant model parameters are unavailable for a patient and the controller is designed based on a nominal model and controller gains are held constant throughout a session. Based on the numerical analyses performed here, conditioned on our choice of model and controllers, we infer that in terms of accuracy and bias PID control performs better than ILQG which in turn performs better than LQG. In the case of noisy observations, ILQG can be tuned to provide a smoother infusion rate while achieving comparable steady-state response with respect to PID. The numerical analyses framework and findings, reported here, can help CLAD developers in their choice of control strategies. This paper may also serve as a tutorial paper for teaching control theory for CLAD.Comment: Accepted in the IFAC2020 Conferenc
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