• Title/Summary/Keyword: Pitch Command

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The Pitch/Turning Control Driver Design Modeling of Permanent Magnet Synchronous Motor (영구자석형 동기전동기의 고저/선회 제어용 드라이버 설계 모델링)

  • Lee, Chun-Gi;Hwang, Jeong-Won;Lee, Joung-Tae;Yang, Bin;Lim, Dong-Keun;Park, Seung-Yub
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.4
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    • pp.219-225
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    • 2014
  • The purpose of this paper is to control of the low-speed, high-precision PMSM 2-axes pitch/turning. In this paper, apply the PAM-PWM inverter for it. However, The PAM-PWM inverter, control algorithms and hardware is complex. But it is possible to improve the performance in the low-speed operation can reduce the effect of the PWM ripple and Dead Time of inverter by applying suitable DC-bus voltage control. The direct driver PMSM(Permanent Magnet Synchronous Motor) configured to vector control part, PAM control part and the other controller. The vector control part includes PI current, speed control, additional space vector modulation. PAM control part has to have PI voltage controller and P current controller for DC-bus voltage control. Besides, the motor position estimator, the speed estimator and the counter electromotive force and Dead Time Compensation are added. With this arrangement, PMSM was driven with a low pole pitch/turning by performing the current control to the current command or torque command is the paper. As a result, it was possible to minimize the disturbance component that appears in the drive in proportion to the DC voltage magnitude. The use of a hydraulic drive method for a two-axis bubble column is a typical tank. When using the PWM PAM inverter driver is in the turret can be driven by high-precision, low vibration, low noise compared to the hydraulic drive may contribute to the computerization of the turret.

A Novel Two-Level Pitch Detection Approach for Speaker Tracking in Robot Control

  • Hejazi, Mahmoud R.;Oh, Han;Kim, Hong-Kook;Ho, Yo-Sung
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.89-92
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    • 2005
  • Using natural speech commands for controlling a human-robot is an interesting topic in the field of robotics. In this paper, our main focus is on the verification of a speaker who gives a command to decide whether he/she is an authorized person for commanding. Among possible dynamic features of natural speech, pitch period is one of the most important ones for characterizing speech signals and it differs usually from person to person. However, current techniques of pitch detection are still not to a desired level of accuracy and robustness. When the signal is noisy or there are multiple pitch streams, the performance of most techniques degrades. In this paper, we propose a two-level approach for pitch detection which in compare with standard pitch detection algorithms, not only increases accuracy, but also makes the performance more robust to noise. In the first level of the proposed approach we discriminate voiced from unvoiced signals based on a neural classifier that utilizes cepstrum sequences of speech as an input feature set. Voiced signals are then further processed in the second level using a modified standard AMDF-based pitch detection algorithm to determine their pitch periods precisely. The experimental results show that the accuracy of the proposed system is better than those of conventional pitch detection algorithms for speech signals in clean and noisy environments.

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A study on the 3-axis attitude stabilization of Koreasat (무궁화 방송통신 위성의 3축 자세 안정화 장치에 관한 연구)

  • 진익민;백명진;김진철
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.793-798
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    • 1993
  • In this study the attitude control of the KOREASAT is investigated. The KOREASAT is a geostationary satellite and its 3 attitude angles, namely, roll, pitch and yaw angles, are stabilized by using the 3-axis stabilization technique. In the pitch control loop, the pitch attitude angle received from the earth sensor is processed in the attitude processing electronics by using PI type control logic, and the control command is sent to the momentum wheel assembly to generate the control torque by varying the wheel rate. The roll/yaw attitude control is performed by activating a magnetic torquer or by firing appropriate thrusters. The magnetic torquer interacts with the earth magnetic field to produce the control torque, and the thrusters are used to control the larger roll attitude errors. In this study dynamic modelling of the satellite is performed. And the earth sensor, the momentum wheel, and the magnetic torquer are mathematically modelled. The 3-axis attitude control logic is implemented to make the closed-loop system and simulations are carried out to verify the implemented control laws.

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A Study on the Improvement of the Control Circuit Design of Controllable Pitch Propeller (가변피치프로펠러의 제어회로 설계 개선에 관한 연구)

  • Kim, Dong-Young;Kang, Gu-Heon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.52-60
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    • 2019
  • The control circuit of the CPP applied to FFX Batch-I and LST-II may be capable of generating a backward pitch even when the grounding phenomenon occurs in the other system. The purpose of this study was to improve the CPP control circuit to maintain the pitch even in the event of grounding. Since the CPP control circuit changes the propeller angle with the voltage difference input, it has a design structure that can be vulnerable if the input voltage fluctuates instantaneously. In order to solve the above problem, a terminating resistor is applied to the end of the control wire and a signal converter is applied between the control wires, as a way to improve the CPP control circuit design. In order to verify that there is no problem in improving the CPP control circuit design, the CPP pitch change control was tested in the actual sailing commissioning with LST-II. Since the command pitch value and the feedback pitch value are very similar to each other, it is confirmed that the CPP control circuit is suitable for the control signal transmission because there is no problem in transmitting the control signal.

A Study on Polar Converting Logic of BTT Missiles (BTT 유도탄의 하중계수 분배논리 연구)

  • Lee, Yong-In;Kim, Eul-Gon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.10
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    • pp.77-82
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    • 2004
  • This paper presents polar converting logic(PCL) of BTT missiles against slowly moving or stationary targets. A guidance commands expressed in rectangular coordinates must be converted in the form of polar coordinates for BTT control. Since conventional PCL has nonlinear and discontinuous function, the missiles may lose controllability when pitch acceleration command equals to zero. Further, roll coupling may have a serious unstabilizing influence on homing guidance with two gimbals seeker. In this paper, a linear homotopy equation is introduced to improve the controllability and a command following performance at midcourse phase. We also design a PCL which is less sensitive to pitch acceleration command so that it may improve the stability of the homing loop. To substantiate our conclusion, results of the computer simulation have been illustrated.

A Study on the Design and Validation of Automatic Pitch Rocker for the Aircraft Deep Stall Recovery (항공기의 실속 회복을 위한 자동 회복 장치 설계 및 검증에 관한 연구)

  • Hahn, Seong-Ho;Hwang, Byung-Moon;Lee, Young-Ho;Lee, Dong-Kyu;Ahn, Sung-Jun;Kim, Chong-Sup
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.1
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    • pp.6-14
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    • 2007
  • Modem version of supersonic jet fighter aircraft must have been guaranteed appropriate controllability and stability in HAoA(High Angle of Attack). Limit value of aircraft entering into the departure in HAoA is related to aircraft configuration design. But, the control law such as AoA and yaw-rate limiter is implemented in digital Fly-By-Wire flight control system of supersonic jet fighter to guarantee the aircraft's safety in HAoA. The HAoA flight control law have two parts, one is control law of departure prevention and the other is control law of departure recovery support. The control laws of departure prevention for advanced jet trainer consist AoA limiter, roll command limiter and rudder fader. The control laws of departure recovery support are consist yaw-rate limiter and MPO(Manual Pitch Override) mode. The guideline of pitch rocking using MPO mode is simple, but operating skill of pitch rocking is very difficult by the pilot with inexperience of departure situation. This paper addresses the design and validation of APR(Automatic Pitch Rocker) control law instead of MPO in order to automatic recovery without manual pitch rocking by the pilot. And, recovery characteristic with APR verifies by the nonlinear analysis and pilot evaluation.

Numerical Study about Initial Behavior of an Ejecting Projectile for Varying Flight Conditions (비행 조건 변화에 따른 사출 운동체의 초기 거동에 관한 수치적 연구)

  • Jo, Sung Min;Kwon, Oh Joon;Kwon, Hyuck-Hoon;Kang, Dong Gi
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.4
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    • pp.517-526
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    • 2019
  • In the present study, unsteady flows around a projectile ejected from an aircraft platform have been numerically investigated by using a three dimensional compressible RANS flow solver based on unstructured meshes. The relative motion between the platform and projectile was described by six degrees of freedom(6DOF) equations of motion with Euler angles and a chimera technique. Initial behavior of the projectile for varying conditions, such as roll and pitch-yaw command on the control surface of the projectile, flight Mach number, and platform pitch angle, was investigated. The ejection stability of the projectile was degraded as Mach number increases. In the transonic condition, the initial behavior of the projectile was found to be unstable as increase of platform pitch angle. By applying the command to control surfaces of the projectile, initial stability was highly enhanced. It was concluded that the proposed simulation data are useful for estimating the ejection behavior of a projectile in design phase.

Experimental Study on the Control for a Randomly Disturbing Dynamic System (불규칙한 교란을 받는 동적 시스템의 제어에 관한 실험적 연구)

  • Lee, Jong-Bok;Cho, Yun-Hyun;Yang, In-Beom;Park, Sung-Man;Heo, Hoon
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1120-1125
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    • 2007
  • Experimental study on the control of randomly disturbing system is conducted. External and internal disturbances are imposed to the system in combined manner. A vertical propeller system exposed horizontal weak turbulent air flow is chosen as an experimental model. The aim of the control system is to maintain the angular position of vertical propeller in parallel to air flow. Trajectory Tracking Stochastic Controller (TTSC) is designed to ensure system's stability while following system command. The Trajectory Tracking Stochastic Controller is composed of two controller, one is stochastic controller to suppress internal random noise and the other one is trajectory-tracking controller to follow the command having random noise. The proposed hybrid controller, TTSC, shows remarkable performance in pitch control of vertical propeller system in wind-tunnel test

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Trajectory Optimization and Optimal Explicit Guidance Algorithm Design for a Satellite Launch Vehicle (위성발사체의 궤적최적화와 최적 유도 알고리듬 설계)

  • Roh, Woong-Rae;Kim, Yodan;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.2
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    • pp.173-182
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    • 2001
  • Ascent trajectory optimization and optimal explicit guidance problems for a satellite launch vehicle in a 2-dimensional pitch plane are studied. The trajectory optimization problem with boundary conditions is formulated as a nonlinear programming problem by parameterizing the pitch attitude control variable, and is solved by using the SQP algorithm. The flight constraints such as gravity-turn are imposed. An optimal explicit guidance algorithm in the exoatmospheric phase is also presented, the guidance algorithm provides steering command and time-to-go value directly using the current states of the vehicle and the desired orbit insertion conditions. To verify the optimality and accuracy of the algorithm simulations are performed.

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A Control Scheme for Stabilizing a Two-Axes Antenna System (이축 안테나 시스템의 안정화를 위한 제어 기법)

  • Lim, Joong-Soon;Lyou, Joon
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.209-212
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    • 1987
  • This paper presents a control scheme to stabilize a two-axes microwave antenna system which is located on a ship and is subject to roll, pitch and yaw(RPY) motions. The scheme first computes the compensated angular positions of the antenna for RPY disturbances through coordinate transformations, and then use a servo con roller of PID type for each axis to track the compensated position command with a good transient behavior.

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