Model-Based Design of an Improved Electric Drive Controller for High-Precision Applications Based on Feedback Linearization Technique

This paper presents the design flow of an advanced non-linear control strategy, able to absorb the effects that the main causes of torque oscillations, concerning synchronous electrical drives, cause on the positioning of the end-effector of a manipulator robot. The control technique used requires an exhaustive modelling of the physical phenomena that cause the electromagnetic torque oscillations. In particular, the Cogging and Stribeck effects are taken into account, whose mathematical model is incorporated in the whole system of dynamic equations representing the complex mechatronic system, formed by the mechanics of the robot links and the dynamics of the actuators. Both the modelling procedure of the robot, directly incorporating the dynamics of the actuators and the electrical drive, consisting of the modulation system and inverter, and the systematic procedure necessary to obtain the equations of the components of the control vector are described in detail. Using the Processor-In-the-Loop (PIL) paradigm for a Cortex-A53 based embedded system, the beneficial effect of the proposed advanced control strategy is validated in terms of end-effector position control, in which we compare classic control system with the proposed algorithm, in order to highlight the better performance in precision and in reducing oscillations.

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A Robust Approach to Dynamic Feedback Linearization for a Steerable Nips Mechanism

ASME 2008 Dynamic Systems and Control Conference, Parts A and B ◽

10.1115/dscc2008-2134 ◽

2008 ◽

Cited By ~ 2

Author(s):

Edgar I. Ergueta ◽

Robert Seifried ◽

Roberto Horowitz

Keyword(s):

Control Strategy ◽

Feedback Linearization ◽

Position Control ◽

Control Strategies ◽

Successful Implementation ◽

Experimental Setup ◽

Dynamic Feedback ◽

Robust Approach ◽

Internal Loops ◽

Steerable Nips

This paper presents two different control strategies for paper position control in printing devices. The first strategy is based on feedback linearization plus dynamic extension (dynamic feed-back linearization). Even though this controller is very simple to design, we show that it is not able to handle actuator multiplicative uncertainties, and therefore it fails when it is implemented on the experimental setup. The second strategy we present uses similar concepts, but it is more robust since feedback linearization is used only to linearize the kinematics of the system and internal loops are used to locally control the actuator’s positions and velocities. Not only do we prove the robustness of the second control strategy, but we also show its successful implementation.

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Cogging Torque Reduction in Brushless Motors by a Nonlinear Control Technique

Energies ◽

10.3390/en12112224 ◽

2019 ◽

Vol 12 (11) ◽

pp. 2224 ◽

Cited By ~ 8

Author(s):

Pierpaolo Dini ◽

Sergio Saponara

Keyword(s):

Permanent Magnet ◽

Electric Drive ◽

Feedback Linearization ◽

Permanent Magnets ◽

Position Control ◽

Angular Position ◽

Control Technique ◽

Electrical Machine ◽

Brushless Motors ◽

Cogging Torque

This work addresses the problem of mitigating the effects of the cogging torque in permanent magnet synchronous motors, particularly brushless motors, which is a main issue in precision electric drive applications. In this work, a method for mitigating the effects of the cogging torque is proposed, based on the use of a nonlinear automatic control technique known as feedback linearization that is ideal for underactuated dynamic systems. The aim of this work is to present an alternative to classic solutions based on the physical modification of the electrical machine to try to suppress the natural interaction between the permanent magnets and the teeth of the stator slots. Such modifications of electric machines are often expensive because they require customized procedures, while the proposed method does not require any modification of the electric drive. With respect to other algorithmic-based solutions for cogging torque reduction, the proposed control technique is scalable to different motor parameters, deterministic, and robust, and hence easy to use and verify for safety-critical applications. As an application case example, the work reports the reduction of the oscillations for the angular position control of a permanent magnet synchronous motor vs. classic PI (proportional-integrative) cascaded control. Moreover, the proposed algorithm is suitable to be implemented in low-cost embedded control units.

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A Control Strategy of Actively Actuated Eccentric Mass System for Imbalance Rotor Vibration

Actuators ◽

10.3390/act9030069 ◽

2020 ◽

Vol 9 (3) ◽

pp. 69

Author(s):

DaeYi Jung

Keyword(s):

Power Consumption ◽

Centrifugal Force ◽

Control Strategy ◽

Vibration Isolation ◽

Position Control ◽

Angular Position ◽

Fine Tuning ◽

Control Technique ◽

Mass System ◽

Rotor Imbalance

This paper explores the new control strategy of an actively actuated eccentric mass system (AAEMS) for cancelling the rotor imbalance vibration. The AAEMS consists of an eccentric mass with an actuator that actively moves around the circular guided track attached to the rotating rotor thus can generate an effective centrifugal force perpendicular to any tangential direction of the guided circular trajectory. Therefore, once the magnitude and angular position of the inherited static imbalance of the rotor are identified, this actively controlled system can be dispatched to the target angular position(s) where the effective centrifugal force due to rotor imbalance is completely or partially removed. This novel device is currently available and widely used in the vibration isolation problem. However, the study of its control strategy is quite limited, thus, herein, we proposed a new possible control technique, guaranteeing both the robust vibration isolation performance and less control power consumption. To meet such needs, three primary functions of AAEMS are addressed here. First, two (Extended) Kalman filters were employed to sequentially estimate the unknown imbalance of the rotor and the unknown coulomb friction induced between the contact surface of the circular track and the counter-contacted parts of AAEMS. Second, the position control of the AAEMS is achieved by a linear quadratic regulator (LQR)-based optimal control law, simultaneously minimizing the imbalance vibration of the rotor as well as the power consumption of its own actuator. Third, for the situation where the estimation and control errors are presented, thus causing the failure to an acceptable threshold for imbalance vibration, the trial-error-based fine-tuning angular position control was proposed. The effectiveness of the proposed control strategy was evaluated via the simulations and this study shows the practical potential for addressing the AAEMS-based imbalance vibration elimination.

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Control Strategy for Direct Teaching of Non-Mechanical Remote Center Motion of Surgical Assistant Robot with Force/Torque Sensor

Applied Sciences ◽

10.3390/app11094279 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4279

Author(s):

Minhyo Kim ◽

Youqiang Zhang ◽

Sangrok Jin

Keyword(s):

Control Strategy ◽

Position Control ◽

Dimensional Space ◽

Degree Of Freedom ◽

Torque Sensor ◽

Motion Generation ◽

End Effector ◽

Generation Algorithm ◽

Direct Teaching ◽

Collaborative Robot

This paper presents a control strategy that secures both precision and manipulation sensitivity of remote center motion with direct teaching for a surgical assistant robot. Remote center motion is an essential function of conventional laparoscopic surgery, and the most intuitive way a surgeon manipulates a robot is through direct teaching. The surgical assistant robot must maintain the position of the insertion port in three-dimensional space during the four-degree-of-freedom motions such as pan, tilt, spin, and forward/backward. In addition, the robot should move smoothly when controlling it with the hands during the surgery. In this study, a six-degree-of-freedom collaborative robot performs the cone-shaped trajectory with pan and tilt motion of an end-effector keeping the position of the remote center. Instead of the bulky mechanically constrained remote center motion mechanism, a conventional collaborative robot is used to mimic the wrist movement of a scrub nurse. A force/torque sensor that is attached between the robot and end-effector estimates the surgeon’s intention. A direct teaching control strategy based on position control is applied to guarantee precise remote center position maintenance performance. A motion generation algorithm is designed to generate motion by utilizing a force/torque sensor value. The parameters of the motion generation algorithm are optimized so that the robot can be operated with uniform sensitivity in all directions. The precision of remote center motion and the torque required for direct teaching are analyzed through pan and tilt motion experiments.

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A Robust Approach to Dynamic Feedback Linearization for a Steerable Nips Mechanism

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4003261 ◽

2011 ◽

Vol 133 (2) ◽

Author(s):

Edgar I. Ergueta ◽

Robert Seifried ◽

Roberto Horowitz

Keyword(s):

Control Strategy ◽

Feedback Linearization ◽

Position Control ◽

Control Strategies ◽

Successful Implementation ◽

Experimental Setup ◽

Dynamic Feedback ◽

Robust Approach ◽

Internal Loops ◽

Steerable Nips

This paper presents two different control strategies for paper position control in printing devices. The first strategy is based on standard feedback linearization plus dynamic extension (dynamic feedback linearization). Even though this controller is very simple to design, we show that it is not able to handle actuator multiplicative uncertainties, and therefore, it fails when it is implemented on the experimental setup. The second strategy we present uses similar concepts, but it is more robust since feedback linearization is used only to linearize the kinematics of the system and internal loops are used to locally control the actuator’s positions and velocities. In this paper, not only do we formally prove the robustness of the second control strategy but we also show its successful implementation.

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An LVRT Scheme for Grid Connected DFIG Based WECS Using State Feedback Linearization Control Technique

Electronics ◽

10.3390/electronics8070777 ◽

2019 ◽

Vol 8 (7) ◽

pp. 777 ◽

Cited By ~ 3

Author(s):

Ghulam Kaloi ◽

Mazhar Baloch ◽

Mahesh Kumar ◽

Dur Soomro ◽

Sohaib Chauhdary ◽

...

Keyword(s):

Wind Energy ◽

Control Strategy ◽

Feedback Linearization ◽

State Feedback ◽

Low Voltage ◽

Mechanical Energy ◽

Control Technique ◽

Minimal Amount ◽

Stator Current ◽

Fault Clearance

This paper primarily focuses on an advance control strategy to enhance the low voltage ride through (LVRT) capability in doubly fed induction generator (DFIG) based wind energy conversion system (WCES). In the proposed control strategy, the captured wind energy during grid faults circumstances is stored timidly in the rotor’s inertia kinetic energy. Though a minimal amount of energy is available in the grid, stator current and DC-link voltage are set beneath the perilous levels. However, both the required stator voltage and stator current are kept within a tolerable range of rotor side converter (RSC), through state feedback linearization technique for maintaining the accurate control to suppress the overvoltage and overcurrent. Furthermore, stator current oscillations are significantly suppressed during fault transient. The input mechanical energy from the wind turbine can be resumed after the fault clearance. In spite of being dissipated in the resistors of crowbar circuit, as in the conventional LVRT assemblies, torque balancing among electrical and mechanical measures is attained; DC-link voltage instabilities and rotor speed inconsistencies are substantially reduced. As a result, a noticeable reduction in the requirement of reactive power and swift restoration of terminal voltage on fault clearance is acquired successfully. Correspondingly, several tests are conducted to validate the effectiveness and enhancement in the performance of the DFIG based wind farms, when the proposed control strategy is implemented over it during numerous fault ride-through circumstances.

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Nonlinear Maximum Power Point Tracking Control of Wind Turbine Based on Two-Mass Model Without Anemometer

Frontiers in Energy Research ◽

10.3389/fenrg.2021.753718 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jian Chen ◽

Qun Lu ◽

Libing Chen ◽

Xiaohui Duan ◽

Boping Yang ◽

...

Keyword(s):

Wind Speed ◽

Nonlinear Control ◽

Wind Turbine ◽

Control Strategy ◽

Feedback Linearization ◽

Maximum Power ◽

Control Technique ◽

Speed Ratio ◽

Rotor Speed ◽

Mass Model

A nonlinear control without using anemometer is proposed to achieve the maximum power of the wind turbine (WT) based on two-mass model in this paper. To track the maximum power points, the optimal tip speed ratio control strategy requiring to know the optimal rotor speed of the WT (ORS) is employed. To achieve the ORS, a torque observer is designed to estimate the aerodynamic torque, then the ORS can be obtained by the corresponding calculations based on the estimated torque. Due to the high nonlinearities of the WT and time-varying wind speed, a nonlinear control based on feedback linearization control (FLC) is adopted to track the ORS. In the FLC, the WT is linearized firstly, then the rotor speed controller is designed via linear control technique. The effectiveness of the proposed control strategy is verified by simulation studies. The simulation results show that, compared with the traditional PI control based on torque estimation and FLC based on wind speed estimation, the proposed control strategy provides better dynamic performances and higher power conversion efficiency.

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A Novel Control Strategy of Indirect Matrix Converter Using Space Vector Modulation

International Journal of Power Electronics and Drive Systems (IJPEDS) ◽

10.11591/ijpeds.v7.i3.pp926-935 ◽

2016 ◽

Vol 7 (3) ◽

pp. 926

Author(s):

Kuldeep Behera ◽

Subrat Behera

Keyword(s):

Embedded System ◽

Control Strategy ◽

Matrix Converter ◽

Control Technique ◽

Space Vector Modulation ◽

Switching Loss ◽

Space Vector ◽

Complete Control ◽

Matlab Simulink ◽

Vector Modulation

This paper introduces a control scheme of Indirect Matrix Converter which includes space vector modulation to stabilize the frequency variations. The terminal voltage and frequency of any synchronous machine can be controlled easily with this scheme. Further the control strategy is proposed and implemented in Matlab/Simulink Embedded system which gives significant better performance compared to conventional control technique like better Total Harmonic Distortion (THD), more output voltage with same Modulation Index, less switching stress and less switching loss. This method might prove effective for wind energy conversion system using DFIG as the DFIG speed is close to synchronous speed. The complete control strategy is verified using MATLAB/Simulink.

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