Robust position control and disturbance rejection of an industrial plant emulator system using the feedforward-feedback control

Jeyasenthil, R.,Choi, S.B.,Purohit, Harsh,Jung, D. Elsevier 2019 Mechatronics Vol.57 No.-

<P><B>Abstract</B></P> <P>An important class of electromechanical system known as the industrial plant emulator system which represents the many practical systems used in the industry. The motion control of the emulator system is challenging and important one as it mimics the system class of conveyors, machine tools, spindle drives, and automated assembly machines. In this paper, a new quantitative feedback-feedforward approach is proposed to address both tracking and the disturbance (measurable, uncertain) rejection problem. The proposed methodology is centered on the design of feedback controller with the inversion based feedforward control. The proposed method converts the problem on the uncertain system into a nominal sensitivity problem which is simple, less conservative and easier to solve for a large number of uncertain parameter system such as the emulator plant. The unknown dynamic of the disturbance (motor) is identified practically by a step response (three parameter model) for integrating system. The proposed feedforward/feedback control is experimentally demonstrated to meet the tracking and reject the disturbance with the less demand on the feedback control as compared to the existing methods under different loading condition.</P>

Robust Air-to-Fuel Ratio and Boost Pressure Controller Design for the EGR and VGT Systems Using Quantitative Feedback Theory

Inseok Park,Seungwoo Hong,Myoungho Sunwoo Institute of Electrical and Electronics Engineers 2014 IEEE transactions on control systems technology Vol. No.

<P>This paper describes robust multi-input, multi-output controller for the exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) systems of passenger car diesel engines. The air-to-fuel ratio of the exhaust gas and boost pressure of the intake manifold were selected as performance indicators in this paper. To enable the online calibration of the controller, proportional-integral-derivative (PID) was used as a feedback controller. Using quantitative feedback theory (QFT), two control loops for air-to-fuel ratio and boost pressure were independently designed with linearized models and parameter uncertainties. The prefilters and PID gains of two control loops were designed for satisfying required robust stability and tracking performance using the QFT design framework. Furthermore, the problems originated from the cross-coupled dynamics between the EGR and VGT systems were mitigated by a static decoupler. Using the proposed design steps, PID and decoupler gains of the representative 15 engine operating points which are mainly used in New European Driving Cycle were obtained. The proposed controller was validated through various test conditions of engine experiments. From the step responses and transient experiments, it was demonstrated that the required robustness and tracking performance were successfully achieved.</P>

QFT를 이용한 유압 로드 시뮬레이터에 관한 힘 제어계 설계

김진완(Jin Wan Kim),현동길(Dong Ji Xuan),남양해(Yang Hai Nan),김영배(Young Bae Kim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

This paper presents the road simulator control technology for reproducing the road input signal to implement the real road data. The simulator consists of the hydraulic pump, servo valve, hydraulic actuator and its control equipment. The QFT is utilized to control the simulator effectively. The control system illustrates a tracking performance of the closed-loop controller with low order transfer function G(s) and pre-filter F(s) for a parametric uncertain model. A force controller is designed to communicate the control signal between simulator and digital controller. The efficacy of the QFT force controller is verified through the numerical simulation, in which combined dynamics and actuation of the hydraulic servo system are tested. The simulation results show that the proposed control technique works well under uncertain hydraulic plant system. The conventional software (Labview) is used to make up for the real controller in the real-time basis, and the experimental works show that the proposed algorithm works well for a single road simulator.

정량적 피드백 이론을 이용한 유압 로드 시뮬레이터에 관한 힘 제어계 설계

김진완(Jin Wan Kim),현동길(Dong Ji Xuan),김영배(Young Bae Kim) 대한기계학회 2007 大韓機械學會論文集A Vol.31 No.11

This paper presents the road simulator control technology for reproducing the road input signal to implement the real road data. The simulator consists of the hydraulic pump, servo valve, hydraulic actuator and its control equipment. The QFT(Quantitative Feedback Theory) is utilized to control the simulator effectively. The control system illustrates a tracking performance of the closed-loop controller with low order transfer function G(s) and pre-filter F(s) for a parametric uncertain model. A force controller is designed to communicate the control signal between simulator and digital controller. Tracking specification is satisfied with upper and lower bound tolerances on the steep response of the system to the reference signal. The efficacy of the QFT force controller is verified through the numerical simulation, in which combined dynamics and actuation of the hydraulic servo system are tested. The simulation results show that the proposed control technique works well under uncertain hydraulic plant system. The conventional software (Labview) is used to make up for the real controller in the real-time basis, and the experimental works show that the proposed algorithm works well for a single road simulator.

Robust Controls of a Galvanometer : A Feasibility Study

Park, Myoung-Soo,Kim, Young-Chol,Lee, Jae-Won Institute of Control 1999 Transaction on control, automation and systems eng Vol.1 No.2

Optical scanning systems use glavanometers to point the laser beam to the desired position on the workpiece. The angular speed of a galvanometer is typically controlled using Proportional+Integral+Derivative(PID) control algorithms. However, natural variations in the dynamics of different galvanometers due to manufacturing, aging, and environmental factors(i.e., process uncertainty) impose a hard limit on the bandwidth of the galvanometer control system. In general, the control bandwidth translates directly into efficiency of the system response. Since the optical scanning system must have rapid response, the higher control bandwidth is required. Auto-tuning PID algorithms have been accepted in this area since they could overcome some of the problems related to process uncertainty. However, when the galvanometer is attached to a larger mechanical system, the combined dynamics often exhibit resonances. It is well understood that PId algorithms may not have the capacity to increase the control bandwidth in the face of such resonances. This paper compares the achieable performance and robustness of a galvanometer control system using a PID controller tuned by the Ziegler-Nichols method and a controller designed by the Quantitative Feedback Theory(QFT) method. The results clearly indicate that-in contrast to PID designs-QFT can deliver a single, fixed controller which will supply high bandwidth design even when the dynamics is uncertain and includes mechanical resonances.

Robust Common Rail Pressure Control for Diesel Engines using a Quantitative Feedback Theory

Jaewook Shin,Seungwoo Hong,Inseok Park,Minkwang Lee,Myoungho Sunwoo 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

This paper proposes a common rail pressure controller for passenger car diesel engines. The common rail system of diesel engine has some difficulties to control rail pressure. The rail pressure is influenced by interaction between a metering unit (MeUn) and a pressure control valve (PCV). The interaction increases complexity of control algorithm. In order to solve this problem, we present a common rail pressure controller based on the quantitative feedback theory (QFT). For the controller design, a plant model of the common rail system is approximated by a first order transfer function, and the PCV driving current and the rail pressure are used as input/output variables of this model. The rail pressure variation by MeUn is represented as parametric uncertainty. Then, requirement specifications for stability and reference tracking are defined, and the control algorithm is designed to satisfy these requirements using the QFT method. In order to validate the proposed controller, engine experiments are performed. The QFT based rail pressure controller successfully satisfies the tracking performance. Furthermore, the control robustness is evaluated when the MeUn driving current is abruptly changed.

Robust force control of a hybrid actuator using quantitative feedback theory

Kyoung Kwan Ahn,Nguyen Huynh Thai Chau,Dinh Quang Truong 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.12

The use of hydraulic systems in industrial applications has become widespread due to their advantages in efficiency. In recent years, hybrid actuation systems, which combine electric and hydraulic technology into a compact unit, have been adapted to a wide variety of force, speed and torque requirements. A hybrid actuation system resolves energy consumption and noise problems characteristic of conventional hydraulic systems. A new, low-cost hybrid actuator using a DC motor is considered to be a novel linear actuator with various applications such as robotics, automation, plastic injection-molding, and metal forming technology. However, this efficiency gain is often accompanied by a degradation of system stability and control problems. In this paper, to satisfy robust performance requirements, tracking performance specifications, and disturbance attenuation requirements, the design of a robust force controller for a new hybrid actuator using Quantitative Feedback Theory (QFT) is presented. A family of plant models is obtained from measuring frequency responses of the system in the presence of significant uncertainty. Experimental results show that the hybrid actuator can achieve highly robust force tracking even when environmental stiffness set-point force varies. In addition, it is understood that the new system reduces energy use, even though its response is similar to that of a valve-controlled system.

정량적 궤환 이론을 이용한 4-회전익 비행체의 자세 제어

이병석,허문범,이준화 한국항공우주학회 2012 한국항공우주학회 학술발표회 논문집 Vol.2012 No.11

본 논문은 정량적 궤환 이론(QFT)을 이용한 제어기에 의한 4-회전익 비행체(QRV)의 자세제어를 소개하고 있다. 정량적 궤환 이론은 플랜트의 파라미터와 외란의 불확실성에 대해 주파수 영역에서 설계사양의 강인성을 보장하는 설계기법이다. 정량적 궤환 이론에 의한 4-회전익 비행체의 자세 제어를 위해 4-회전익 비행체의 동역학 모델을 구하고, 플랜트인 4-회전익 비행체의 파라미터 변동 범위와 플랜트의 동작 범위를 고려한 전필터(pre-filter) 설계를 통하여 4-회전익 비행체의 자세제어를 구현하였다. 이러한 작업을 위해 본 논문에서는 MATLAB에서 정량적 궤환 이론에 의한 제어기를 설계할 수 있는 QFT control toolbox인 QFTCT를 사용하였다. This paper presents an attitude control of a Quad Rotor Vehicle(QRV) by a controller using the Quantitative Feedback Theory(QFT). The QFT is the design methodology guaranteeing the robustness of design specifications for parameter uncertainty of the plant and disturbance in the frequency domain. A dynamics model of a QRV was derived for an attitude control of a QRV by the QFT. An attitude control of a QRV was implemented through the range of a parameter fluctuation and a pre-filter design considering an operating range of a QRV(that is the plant). In this paper, QFTCT, that is the QFT Control Toolbox which is designed a controller by the QFT in MATLAB, was used.

Precision Control for Ionic Polymer Metal Composite Actuator Based on Quantitative Feedback Theory

Doan Ngoc Chi Nam,Dinh Quang Truong,Yoon Jong Il,Ahn Kyoung Kwan 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

An ion polymer metal composite (IPMC) is an Electro-Active Polymer (EAP) that bends in response to a small applied electrical field as a result of mobility of cations in the polymer network and vice versa. Recently, IPMC is widely applied in many fields such as biometric, biomedical and micro manipulator fields. This paper proposes a robust position controller for IPMCs which is based on the quantitative feedback theory (QFT). Firstly, the IPMC actuation was investigated. The PRBS input voltage signals were applied to the IPMC in order to identify the system characteristic. Consequently, the QFT controller for the IPMC was designed from the identified IPMC model. Experiments were carried out to validate the effectiveness of proposed controller applied to the IPMC.

QFT 를 이용한 디젤엔진의 커먼레일 압력 제어알고리즘 설계 연구

신재욱(Jaewook Shin),홍승우(Seungwoo Hong),박인석(Inseok Park),선우명호(Myoungho Sunwoo) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.2

이 연구에서는 Quantitative Feedback Theory(QFT) 기법을 이용한 승용디젤엔진의 커먼레일 압력제어 알고리즘을 제안하였다. 커먼레일 압력모델의 입력과 출력은 각각 Pressure Control Valve(PCV) 구동전류와 커먼레일 압력으로 정의하였고, Metering Unit(MeUn)이 커먼레일 압력에 미치는 영향은 모델 파라미터 불확실성으로 정의하였다. QFT 기법은 이러한 모델의 불확실성에 대하여 강건하면서도 정량적 요구사항을 만족할 수 있는 제어알고리즘 설계방법을 제시한다. 제안된 커먼레일 압력제어기는 목표 레일압력 추종성능과 안정성능이 확보되었으며, 인젝터에 의한 연료분사가 커먼레일 압력에 미치는 영향을 줄이기 위하여 외란제거성능(Disturbance Rejection)이 고려되었다. 설계된 제어 알고리즘은 엔진 동력계 실험을 통하여 검증하였으며, MeUn 구동전류와 연료분사량의 급격한 변화에 따른 제어알고리즘의 강건성과 외란제거성능을 검증하였다. This paper proposes a common rail pressure control algorithm for passenger car diesel engines. For handling the parameter-varying characteristics of common rail systems, the quantitative feedback theory (QFT) is applied to the design of a robust rail pressure control algorithm. The driving current of the pressure control valve and the common rail pressure are used as the input/output variables for the common rail system model. The model parameter uncertainty ranges are identified through experiments. Rail pressure controller requirements in terms of tracking performance, robust stability, and disturbance rejection are defined on a Nichols chart, and these requirements are fulfilled by designing a compensator and a prefilter in the QFT framework. The proposed common rail pressure control algorithm is validated through engine experiments. The experimental results show that the proposed rail pressure controller has a good degree of consistency under various operating conditions, and it successfully satisfies the requirements for reference tracking and disturbance rejection.