Output Saturation in Electric Motor Systems: Identification and Controller Design

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Kyoungchul Kong ◽  
Helge C. Kniep ◽  
Masayoshi Tomizuka
Keyword(s):  
Electric Motor ◽  
Controller Design ◽  
Input Saturation ◽  
System Response ◽  
Maximum Speed ◽  
State Variables ◽  
Motor Systems ◽  
Maximum Acceleration ◽  
Brushless Dc Motors ◽  
Brushless Dc

Input saturation is a well-known nonlinearity in mechanical control systems; it constrains the maximum acceleration, which results in the limitation of the system response time. Input saturation has been considered in controller design in various ways, e.g., antiwindup control. In addition to the input, the state variables of mechanical systems are often subjected to saturation. For example, the maximum angular velocity of electric motor systems is limited by the maximum voltage provided to the motor windings. In the case of electronically commutated motors (i.e., brushless dc motors), the maximum speed is additionally constrained by limitations of the servo amplifier output. If gears are utilized, further constraints are introduced due to resonances in ball bearings and/or velocity dependent friction. Although such factors are significant in practice, they have not been fully considered in controller design. This paper investigates the input and output saturations, and presents how they may be considered in the controller design; a Kalman filter, a PID controller, and a disturbance observer are designed, taking input/output saturations into consideration. A case study is provided to verify the proposed methods.

Control of Electric Motor Systems Considering Input/Output Saturation

2009 ◽  
Author(s):  
Kyoungchul Kong ◽  
Helge C. Kniep ◽  
Masayoshi Tomizuka
Keyword(s):  
Electric Motor ◽  
Controller Design ◽  
Input Saturation ◽  
System Response ◽  
Maximum Speed ◽  
State Variables ◽  
Input Output ◽  
Motor Systems ◽  
Maximum Acceleration ◽  
Brushless Dc Motors

Input saturation is a well-known nonlinearity in mechanical control systems; it constrains the maximum acceleration, which results in a limitation of the system response time. Input saturation has been considered in controller design in various ways, e.g., anti-windup control. In addition to the input, the state variables of mechanical systems are often subject to saturation. For example, the maximum angular velocity of electric motor systems is limited by the maximum voltage provided for the motor. In the case of electronically commutated motors (i.e. brushless DC motors) the maximum speed is additionally constrained by limitations of the servo amplifier output. If gears are utilized, further constraints are introduced due to resonances in ball bearings and/or velocity dependent friction. Although such factors are significant in practice, they have not been fully considered in controller design. This paper investigates the input and output saturations and presents how they may be considered in the controller design; a Kalman filter, a PID controller, and a disturbance observer are designed in view of input/output saturations. A case study is provided to verify the proposed methods.

Robust Control of Automotive Active Seat-Suspension System Subject to Actuator Saturation

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Zhou Gu ◽  
Shumin Fei ◽  
Yaqin Zhao ◽  
Engang Tian
Keyword(s):  
Controller Design ◽  
Actuator Saturation ◽  
Input Saturation ◽  
Output Feedback Control ◽  
Suspension System ◽  
Linear Matrix ◽  
Control Input ◽  
State Variables ◽  
Sampled Data ◽  
Seat Suspension

This paper deals with the problem of robust sampled-data control for an automotive seat-suspension system subject to control input saturation. By using the nature of the sector nonlinearity, a sampled-data based control input saturation in the control design is studied. A passenger dynamic behavior is considered in the modeling of seat-suspension system, which makes the model more precisely and brings about uncertainties as well in the developed model. Robust output feedback control strategy is adopted since some state variables, such as, body acceleration and body deflection, are unavailable. The desired controller can be achieved by solving the corresponding linear matrix inequalities (LMIs). Finally, a design example has been given to demonstrate the effectiveness and advantages of the proposed controller design approach.

scholarly journals Adaptive Observer of Resistance in Sensorless Estimation of Speed and Position in Brushless DC Electric Motor

2019 ◽  
Vol 19 (1) ◽  
pp. 165-176
Author(s):  
Danail Slavov
Keyword(s):  
Electric Motor ◽  
Adaptive Algorithm ◽  
Adaptive Observer ◽  
Motor Speed ◽  
Electrical Parameters ◽  
Brushless Dc Motors ◽  
Brushless Dc ◽  
Dc Motors ◽  
Dependent Change ◽  
Stator Resistance

Abstract Estimating the speed and position using measurable electrical parameters would allow establishment of sensorless control systems for brushless DC motors, without the need to use expensive sensors for the rotor position and speed. When the motor is running, it heats up and the stator resistance rises. This heat-dependent change needs to be reflected in the observer, as it would produce an error in rated speed and position. An adaptive algorithm can compensate for the change of resistance as a disturbing effect of the motor heating. The adaptive algorithm for estimating the resistance is synthesized using the function of Lyapunov. This article is useful for estimation of brushless electric motor speed and position with observer. It contains simulations with an adaptive observer of resistance for sensorless estimation of speed and position in brushless DC motor through measurement of voltage and current.

Adaptive Control of Brushless DC Motors without Model Reduction

2013 ◽  
Vol 278-280 ◽  
pp. 1409-1412
Author(s):  
Chen Yu, Kai ◽  
An Chyau Huang
Keyword(s):  
Adaptive Control ◽  
Controller Design ◽  
Reduced Model ◽  
Brushless Dc Motors ◽  
Practical Applications ◽  
Brushless Dc ◽  
Dc Motors ◽  
Internal Parameters ◽  
Considerable Simplification ◽  
Almost All

Various applications of brushless DC motors (BLDCM) can be found in the industrial environment. However, almost all controllers designed for BLDCM are based on reduced models where a first order dynamics is regarded as the internal model. This way a second order dynamics is considered with considerable simplification in the controller design. Since the reduced model may not reflect the entire dynamics of the motor, some deterioration in the control outcome can be observed. To improve the performance, this paper considers the adaptive control of a BLDCM without using reduced model. Some unknown time-varying payloads are applied to ensure its effectiveness in practical applications. Rigorous mathematics proof of closed loop stability is provided together with the boundedness of the internal parameters. Simulation cases are given to show efficacy of the proposed scheme.

scholarly journals An Efficient Position Tracking Smoothing Algorithm for Sensorless Operation of Brushless DC Motor Drives

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Surya Susan Alex ◽  
Asha Elizabeth Daniel
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Estimation Accuracy ◽  
Smoothing Algorithm ◽  
State Variables ◽  
Present Measurement ◽  
Brushless Dc Motors ◽  
Rotor Position ◽  
Brushless Dc ◽  
Dc Motors

This paper presents a new position sensorless scheme in which a smoothing filter algorithm is proposed to improve the results obtained through Extended Kalman Filter (EKF) algorithm in tracking the rotor position for sensorless control of brushless DC motors. The rotor position and speed are estimated from the input voltage and current using the Extended Kalman Filter. States obtained through filtering in each sampling instant are refined, using the new smoothing algorithm, giving much better results. In the proposed method, the estimated state in previous instant is enhanced using the present measurement sample by the smoothing algorithm which is then used to improve the present estimated state variables. The complete system is modelled and simulated in MATLAB to verify the merit of the proposed smoothing algorithm. A comparison with conventional EKF is done for various load torque and speed conditions to establish the performance of the new sensorless algorithm. Simulation results show that the proposed smoothing technique offers better estimation accuracy. The peak error in the estimated speed and rotor position is considerably reduced when compared with EKF. The improved state estimate can be used as feedback for speed control of brushless DC motors in variable speed drives.

Recent Challenges and Advances in the Sensorless Commutation of Brushless DC Motors

2020 ◽  
Vol 13 ◽  
Author(s):  
Umesh Kumar Soni ◽  
Ramesh Kumar Tripathi
Keyword(s):  
Initial Position ◽  
Position Estimation ◽  
Current Response ◽  
Flux Linkage ◽  
Brushless Dc Motors ◽  
Position Sensing ◽  
Brushless Dc ◽  
Dc Motors ◽  
Reverse Torque ◽  
Position Detection

Background: Brushless DC motors are highly efficient motors due to its high torque to weight ratio, compact design, high speed operating capability and higher power density. Conventional Hall sensor based rotor position sensing is affected by the heating, vibration, interference and noise. Objective: The innovative, cost effective and easily implementable sensorless techniques are essential in order to achieve high efficiency, reduced current and reduced torque pulsations. Further, a delay free, high load fast startup is also important issue. Methods: In this paper an extensive review of various techniques based on the detection of freewheeling diode current, phase back EMF zero crossoing point detection, back EMF integration method and third harmonic back EMF was done. The study and effect of various PWM strategies on back EMF detection was studied. Later on the sensorless schemes based on flux linkage estimation and flux linkage increment were introduced. The load torque observers, unknown input observers, sliding mode observers, L∞-induced observers, H ∞ - deconvolution filter for back EMF estimation were also reviewed. As the brushless DC motors have no back EMF at starting and for back EMF based commutation a minimum speed is required for sufficient back EMF. Therefore various strategies of open and close-loop reduced current startup have been studied to achieve effective commutation without reverse torque. Initial position detection (IPD) schemes, which are mostly based on saliency and current response to inductance variation, is effective where reverse torque is strictly prohibited. A detailed review of these initial position detection techniques (IPD) has also been presented. Results: The detailed mathematical and graphical analysis has been presented here in order to understand the working of the state-of-art sensorless techniques. Conclusion: The back EMF detection using direct and indirect methods of terminal voltage filtering have the problem of delay and attenuation, PWM noise, freewheeling diode spikes and disturbance in detected back EMFs is a drawback. The parameter detuning, underestimation and overestimation, offset problem, system noise and observer gain variation etc. limit the applicability of observer based technique. Therefore, a more robust and precise position estimation scheme is essential.

scholarly journals A Robust Observer—Based Adaptive Control of Second—Order Systems with Input Saturation via Dead-Zone Lyapunov Functions

Computation ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 82
Author(s):  
Alejandro Rincón ◽  
Gloria M. Restrepo ◽  
Fredy E. Hoyos
Keyword(s):  
Lyapunov Functions ◽  
Dead Zone ◽  
Tracking Error ◽  
Input Saturation ◽  
Chemical Reactor ◽  
Second Order ◽  
Control Law ◽  
Compact Set ◽  
State Variables ◽  
Robust Observer

In this study, a novel robust observer-based adaptive controller was formulated for systems represented by second-order input–output dynamics with unknown second state, and it was applied to concentration tracking in a chemical reactor. By using dead-zone Lyapunov functions and adaptive backstepping method, an improved control law was derived, exhibiting faster response to changes in the output tracking error while avoiding input chattering and providing robustness to uncertain model terms. Moreover, a state observer was formulated for estimating the unknown state. The main contributions with respect to closely related designs are (i) the control law, the update law and the observer equations involve no discontinuous signals; (ii) it is guaranteed that the developed controller leads to the convergence of the tracking error to a compact set whose width is user-defined, and it does not depend on upper bounds of model terms, state variables or disturbances; and (iii) the control law exhibits a fast response to changes in the tracking error, whereas the control effort can be reduced through the controller parameters. Finally, the effectiveness of the developed controller is illustrated by the simulation of concentration tracking in a stirred chemical reactor.

Regional stabilization and H∞ congestion control with input saturation

2021 ◽  
pp. 014233122199273
Author(s):  
Sadek Belamfedel Alaoui ◽  
El Houssaine Tissir ◽  
Noreddine Chaibi ◽  
Fatima El Haoussi
Keyword(s):  
Linear Systems ◽  
Controller Design ◽  
Input Saturation ◽  
Domain Of Attraction ◽  
Queue Management ◽  
Variable Delay ◽  
Challenging Problem ◽  
Regional Stabilization ◽  
Small Gain ◽  
Improved Performance

Designing robust active queue management subjected to network imperfections is a challenging problem. Motivated by this topic, we addressed the problem of controller design for linear systems with variable delay and unsymmetrical constraints by the scaled small gain theorem. We designed two mechanisms: robust enhanced proportional derivative; and robust enhanced proportional derivative subjected to input saturation. Discussion of their practical implementations along with extensive comparisons by MATLAB and NS3 illustrate the improved performance and the enlargement of the domain of attraction regarding some literature results.

New Observer-Based Controller Design for Delayed Systems Subject to Input Saturation and Disturbances

2019 ◽  
Vol 44 (3) ◽  
pp. 1081-1092 ◽  
Author(s):  
Nabil El Fezazi ◽  
Ouarda Lamrabet ◽  
Fatima El Haoussi ◽  
El Houssaine Tissir
Keyword(s):  
Controller Design ◽  
Input Saturation ◽  
Delayed Systems
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