Identifying the Optimal Controller Strategy for DC Motors

2017 ◽  
Vol 6 (4) ◽  
pp. 252
Author(s):  
M. R. Qader
Keyword(s):  
Transfer Function ◽  
Angular Rate ◽  
Linear Quadratic Regulator ◽  
System Stability ◽  
Step Response ◽  
Phase Lag ◽  
Linear Quadratic ◽  
Loop Control ◽  
Dc Motors ◽  
Tuning Methods

<p class="Default"><span>The aim of this study is to design a control strategy for the angular rate (speed) of a DC motor by varying the terminal voltage. This paper describes various designs for the control of direct current (DC) motors. We derive a transfer function for the system and connect it to a controller as feedback, taking the applied voltage as the system input and the angular velocity as the output. Different strategies combining proportional, integral, and derivative controllers along with phase lag compensators and lead integral compensators are investigated alongside the linear quadratic regulator. For each controller transfer function, the step response, root locus, and bode plot are analysed to ascertain the behaviour of the system, and the results are compared to identify the optimal strategy. It is found that the linear quadratic controller provides the best overall performance in terms of steady-state error, response time, and system stability. The purpose of the study that took place was to design the most appropriate controller for the steadiness of DC motors. Throughout this study, analytical means like tuning methods, loop control, and stability criteria were adopted. The reason for this was to suffice the preconditions and obligations. Furthermore, for the sake of verifying the legitimacy of the controller results, modelling by MATLAB and Simulink was practiced on every controller.</span></p>

scholarly journals Synthesis of A Digital PID/LQR Control System for Duty-Cycle Modulation Buck Converters

2020 ◽  
pp. 185-189
Author(s):  
Paul Owoundi Etouke ◽  
Jean Mbihi ◽  
Leandre Nneme Nneme
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Duty Cycle ◽  
Linear Quadratic Regulator ◽  
Buck Converter ◽  
Step Response ◽  
Buck Converters ◽  
Linear Quadratic ◽  
Lqr Control ◽  
Digital Pid

<p>This research paper presents a synthesis approach of a digital optimal PID/LQR control system for DCM (duty-cycle cycle modulation) Buck converters. The step response of the DCM Buck converter is obtained under Multisim virtual simulation framework. The related data file is saved as *.SCP format, and imported into EditPad Lite7 editor, then exported as Matlab file to be processed. The transfer function of the DCM Buck converter is computed from the imported step response data. Then, using the zoh (zero order holder) discretization method with 100 ms resampling period, the z-transfer function of the DCM Buck converter is computed, and that of the analog optimal PID/LQR(linear quadratic regulator) controller is calculated using Tustin’s discretization technique. Furthermore, the step response of the related closed loop digital PID control system is simulated and compared to that of the original analog PID/LQR control system. The simulation results obtained are presented in order to show the high precision as well as the reliability of Matlab-based synthesis of digital optimal PID/LQR control systems for DCM Buck converters.</p>

Comparison of Control Methods for Two-Link Planar Flexible Manipulator

2017 ◽  
Author(s):  
Joseph Bowkett ◽  
Rudranarayan Mukherjee
Keyword(s):  
Position Control ◽  
Linear Quadratic Regulator ◽  
Flexible Manipulator ◽  
Linear Quadratic ◽  
Large Space ◽  
Loop Control ◽  
Command Shaping ◽  
Aerospace Applications ◽  
Control Command ◽  
Low Stiffness

While the majority of terrestrial multi-link manipulators can be considered in a purely kinematic sense due to their high stiffness, the launch mass restrictions of aerospace applications such as in-orbit assembly of large space structures result in low stiffness links being employed, meaning dynamics can no longer be ignored. This paper seeks to investigate the suitability of several different open and closed loop control techniques for application to the problem of end effector position control with minimal vibration for a low stiffness space based manipulator. Simulations of a representative planar problem with two flexible links are used to measure performance and sensitivity to parameter variation of: model predictive control, command shaping, and command shaping with linear quadratic regulator (LQR) feedback. An experimental testbed is then used to validate simulation results for the recommended command shaped controller.

Optimal attitude trajectory planning method for CMG actuated spacecraft

2017 ◽  
Vol 232 (1) ◽  
pp. 131-142 ◽  
Author(s):  
Lijun Zhang ◽  
Chunmei Yu ◽  
Shifeng Zhang ◽  
Hong Cai
Keyword(s):  
Trajectory Planning ◽  
Closed Loop ◽  
Pseudospectral Method ◽  
Linear Quadratic Regulator ◽  
Fixed Time ◽  
Open Loop ◽  
Planning Method ◽  
Global Perspective ◽  
Linear Quadratic ◽  
Loop Control

This paper presents an optimal attitude trajectory planning method for the spacecraft equipped with control moment gyros as the actuators. Both the fixed-time energy-optimal and synthesis performance optimal cases are taken into account. The corresponding nonsingular attitude maneuvering trajectories (i.e. open-loop control trajectories) with the consideration of a series of constraints are generated via Radau pseudospectral method. Compared with the traditional steering laws, the optimal steering law designed by this method can explicitly avoid the singularity from the global perspective. A linear quadratic regulator closed-loop controller is designed to guarantee the trajectory tracking performance in the presence of initial errors, inertia uncertainties and external disturbances. Simulation results verify the validity and feasibility of the proposed open-loop and closed-loop control methods.

A Vertical Seismometer With Build-in Retroreflector for Absolute Gravimetry

2018 ◽  
Author(s):  
Meiying Guo ◽  
Kang Wu ◽  
Jiamin Yao ◽  
Jin Qian ◽  
Lijun Wang
Keyword(s):  
Transfer Function ◽  
Ground Vibration ◽  
Free Fall ◽  
Correction Method ◽  
Step Response ◽  
Broadband Seismometer ◽  
Loop Control ◽  
Modified Method ◽  
Absolute Gravimetry ◽  
Feedback Voltage

A free-fall absolute gravimeter uses a Mach-Zehnder interferometer to track the free-falling object. Theoretically, it needs an inertial reference point, which is a reference retroreflector keeping static in inertial frame for an accurate absolute gravimetry. Practically, the reference retroreflector is always disturbed by the ground vibration. Traditionally, a vibration correction method with a broadband seismometer is used to reduce the effect of the ground vibration. The transfer function between the reference retroreflector and the seismometer is hypothesized as a proportional element with time delay. The difference between the hypothesized and the real transfer function limits the effect of the vibration correction. On this basis, a modified method, replacing the sensitive element of a seismometer with the reference retroreflector, is proposed. The motion of the reference retroreflector is measured directly by differential parallel plate capacitance detection. A closed-loop control circuit produces feedback voltage to make the reference retroreflector track the ground vibration. The feedback voltage represents the reference retroreflector’s motion directly. Experiments show the capacitance detecting circuit detects the displacement of the reference retroreflector relative to the ground with a resolution of 0.6 nm at 500 Hz. The acceleration resolution of the homemade vertical seismometer is about 10 mGal. The sensitivity of the seismometer is 316 V/g. The damp ratio of the homemade seismometer is little, and the natural frequency of the homemade seismometer is 104 Hz by analyzing the step response of the system. The bandwidth of the system is around 175 Hz. In the future, the homemade seismometer will be applied in absolute gravimeters for hostile measurement.

Real Time Modeling and Control of Three Tank Hybrid System

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
K. Sathishkumar ◽  
V. Kirubakaran ◽  
T. K. Radhakrishnan
Keyword(s):  
Real Time ◽  
Controller Design ◽  
Linear Quadratic Regulator ◽  
Estimation Model ◽  
Linear Quadratic ◽  
Loop Control ◽  
Modeling And Control ◽  
Time Modeling ◽  
Lqr Controller ◽  
Servo Tracking

AbstractThis study discusses the modeling and linear quadratic regulator (LQR) controller based closed loop control of a three tank hybrid (TTH) process. A pseudo random binary signal (PRBS) based excitation data obtained from a real time TTH setup is utilized in validating its first principle model (FPM). Based on top and bottom interactions, various modes prevalent are considered based on steady state physical reachability analysis of the TTH for a given input range for controller design. The FPM is linearized using nominal values of process parameters using Jacobians from each existing mode. LQR controllers are designed for each mode. A supervisory structure is designed for selecting estimation model and controller for each appropriate mode. Results from real time servo tracking and disturbance rejection experiments are discussed.

Event triggered non-inverting chopper fed networked DC motor speed synchronization

2018 ◽  
Vol 37 (2) ◽  
pp. 911-929 ◽  
Author(s):  
Suhaib Masroor ◽  
Chen Peng
Keyword(s):  
Electrical Power ◽  
Single Agent ◽  
Network Connectivity ◽  
Linear Quadratic Regulator ◽  
Lyapunov Stability Theory ◽  
System Stability ◽  
Motor Speed ◽  
Linear Quadratic ◽  
Content Type ◽  
Theoretical Concepts

PurposeThis paper aims to provide a new approach to address the problem of reaching the synchronous speed in the network connected multiple motors. Design/methodology/approachPractically, all the control approaches require continuous monitoring of the system thereby consuming extra energy. The method proposed in this paper uses an event-based approach with the multi-agent system (MAS) consensus control alongside with linear quadratic regulator control, thus saving a larger amount of energy. The proposed system is developed by using non-inverting buck boost chopper to provide necessary electrical power for the direct current motor, hence creating a single agent of bigger MAS with identical dynamics. The system stability is formulated by using Lyapunov stability theory. The proposed system is simulated via MATLAB. FindingsThe acquired simulated results validate that the proposed methodology and the multi-motor system worked successfully, thereby achieving common speed, i.e. consensus. The proposed system also validates the energy-saving concept. Practical implicationsPresently, the multiple motor synchronous speed system found application in paper-making machines, textile printing machines, offset printing, etc. The proposed study will contribute greatly to the existing methodologies and overcome their deficiencies by making the system more flexible and error-free due to the presence of network connectivity. Originality/valueThe system is simulated to verify theoretical concepts.

Modular estimation of lateral vehicle dynamics and application in optimal AFS control

2021 ◽  
pp. 095440702110143
Author(s):  
Shouvik Chakraborty ◽  
Ashoke Sutradhar ◽  
Anindita Sengupta
Keyword(s):  
Linear Quadratic Regulator ◽  
Estimation Algorithm ◽  
Vehicle Model ◽  
Linear Quadratic ◽  
Loop Control ◽  
Lateral Vehicle Dynamics ◽  
Estimation Scheme ◽  
Tire Dynamics ◽  
Stable Performance ◽  
Tire Forces

The paper introduces a novel modular estimation approach for lateral vehicle and tire dynamics using a simplified vehicle model and a non-linear estimation algorithm. A dynamics-oriented representation of lateral tire forces with a single track lateral vehicle model (STVM) has been introduced. Subsequently, extended Kalman filter (EKF) based distributed observer modules for each dynamical parameter has been designed and combined into a Unified Estimation Scheme (UES). Finally, a linear quadratic regulator (LQR) based Active Front Steering (AFS) control system has been designed using the estimated parameters. The accuracy and computational efficiency of the designed scheme has been analyzed and compared to non-modular UKF, EKF, and Particle Filter (PF) algorithms, through Monte-Carlo Simulations using the CarSim dataset for both high and low [Formula: see text] surfaces, followed by further validation using real-time dataset. The results show that the proposed system significantly improve the accuracy and speed of estimation, as well as stable performance in closed loop control.

scholarly journals Performance Evaluation of Pole Placement and Linear Quadratic Regulator Strategies Designed for Mass-Spring-Damper System Based on Simulated Annealing and Ant Colony Optimization

2021 ◽  
Vol 27 (11) ◽  
pp. 15-31
Author(s):  
Huthaifa Al-Khazraji ◽  
Luay T. Rasheed
Keyword(s):  
Performance Evaluation ◽  
Simulated Annealing ◽  
State Feedback ◽  
Linear Quadratic Regulator ◽  
The State ◽  
Ant Colony ◽  
System Stability ◽  
Pole Placement ◽  
Linear Quadratic ◽  
Mass Spring

This paper investigates the performance evaluation of two state feedback controllers, Pole Placement (PP) and Linear Quadratic Regulator (LQR). The two controllers are designed for a Mass-Spring-Damper (MSD) system found in numerous applications to stabilize the MSD system performance and minimize the position tracking error of the system output. The state space model of the MSD system is first developed. Then, two meta-heuristic optimizations, Simulated Annealing (SA) optimization and Ant Colony (AC) optimization are utilized to optimize feedback gains matrix K of the PP and the weighting matrices Q and R of the LQR to make the MSD system reach stabilization and reduce the oscillation of the response. The Matlab software has been used for simulations and performance analysis. The results show the superiority of the state feedback based on the LQR controller in improving the system stability, reducing settling time, and reducing maximum overshoot. Furthermore, AC optimization shows significant advantages for optimizing the parameters of PP and LQR and reducing the fitness value in comparison with SA optimization

CONTROL OF TWO-WHEELED INVERTED PENDULUM ROBOT USING ROBUST PI AND LQR CONTROLLERS

2020 ◽  
pp. 1-15
Author(s):  
Nguyen Hoai Nam
Keyword(s):  
Inverted Pendulum ◽  
Linear Quadratic Regulator ◽  
Pi Controller ◽  
Linear Quadratic ◽  
Control Loops ◽  
Dc Motors ◽  
Wheeled Inverted Pendulum ◽  
Control Scheme ◽  
Lqr Controller ◽  
Heading Angle

In this paper, a robust PI controller in combination with a linear quadratic regulator (LQR) is proposed to control a two-wheeled inverted pendulum robot (TWIPR) such that it is kept balanced while moving. The proposed TWIPR control system consists of two control loops. The inner loop has two PI controllers for two DC motors’ currents, which are separately designed based on a robust PI controller structure. The outer loop contains a LQR controller for the tilt angle, heading angle and position of the TWIPR. The proposed PI controller is compared to the existing method such as the magnitude optimum (MO) and genetic algorithm (GA) methods. The proposed control scheme is verified through simulations and practical tests, and it is also compared to the MO-LQR and GA-LQR strategies.

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