• Journal of Power Electronics
• /
• v.4 no.1
• /
• pp.28-38
• /
• 2004

In this paper, the position control of a detuned indirect field oriented control (IFOC) induction motor drive is studied. A proposed Simple-Neuro-Controllers (SNCs) are designed and analyzed to achieve high-dynamic performance both in the position command tracking and load regulation characteristics for robotic applications. The proposed SNCs are trained on-line based on the back propagation algorithm with a modified error function. Four SNCs are developed for position, speed and ｄ-ｑ axes stator currents respectively. Also, a synchronous proportional plus integral-derivative (PI-D) two-degree-of-freedom (2DOF) position controller and PI-D speed controller are designed for an ideal IFOC induction motor drive with the desired dynamic response. The performance of the proposed SNCs and synchronous PI-D 2DOF position controllers for detuned field oriented induction motor servo drive is investigated. Simulation results show that the proposed SNCs controllers provide high-performance dynamic characteristics which are robust with regard to motor parameter variations and external load disturbance. Furthermore, comparing the SNC position controller with the synchronous PI-D 2DOF position controller demonstrates the superiority of the proposed SNCs controllers due to attain a robust control performance for IFOC induction motor servo drive system.

• The Journal of Korea Robotics Society
• /
• v.19 no.2
• /
• pp.139-148
• /
• 2024

In this paper, we propose a two-degree-of-freedom snake robot head system and an I-PID (Intelligent Proportional-Integral-Derivative)-based controller utilizing RBF (Radial Basis Function) neural network and adaptive robust terms as a control strategy to reduce rotation occurring in the snake robot head. This study proposes a two-degree-of-freedom snake robot head system to avoid complex snake robot dynamics. This system has a control system independent of the snake robot. Subsequently, it utilizes an I-PID controller to implement a control system that can effectively manage rotation at the snake robot head, the robot's nonlinearity, and disturbances. To compensate for the time delay estimation errors occurring in the I-PID control system, an RBF neural network is integrated. Additionally, an adaptive robust term is designed and integrated into the control system to enhance robustness and generate control inputs responsive to signal changes. The proposed controller satisfies stability according to Lyapunov's theory. The proposed control strategy was tested using a 9-degreeof-freedom snake robot. It demonstrates the capability to reduce rotation in Lateral undulation, Rectilinear, and Sidewinding locomotion.

• Smart Structures and Systems
• /
• v.14 no.6
• /
• pp.1151-1172
• /
• 2014

This paper presents a user programmable computational/control platform developed to conduct real-time hybrid simulation (RTHS). The architecture of this platform is based on the integration of a real-time controller and a field programmable gate array (FPGA).This not only enables the user to apply user-defined control laws to control the experimental substructures, but also provides ample computational resources to run the integration algorithm and analytical substructure state determination in real-time. In this platform the need for SCRAMNet as the communication device between real-time and servo-control workstations has been eliminated which was a critical component in several former RTHS platforms. The accuracy of the servo-hydraulic actuator displacement control, where the control tasks get executed on the FPGA was verified using single-degree-of-freedom (SDOF) and 2 degrees-of-freedom (2DOF) experimental substructures. Finally, the functionality of the proposed system as a robust and reliable RTHS platform for performance evaluation of structural systems was validated by conducting real-time hybrid simulation of a three story nonlinear structure with SDOF and 2DOF experimental substructures. Also, tracking indicators were employed to assess the accuracy of the results.

• Wind and Structures
• /
• v.24 no.5
• /
• pp.481-500
• /
• 2017

A novel three-degree-of-freedom (DOF) forced vibration system has been developed for identification of aeroelastic (self-excited) load parameters used in time-domain response analysis of wind-excited flexible structures. This system is capable of forcing sinusoidal motions on a section model of a structure that is used in wind tunnel aeroelastic studies along all three degrees of freedom - along-wind, cross-wind, and torsional - simultaneously or in any combination thereof. It utilizes three linear actuators to force vibrations at a consistent frequency but varying amplitudes between the three. This system was designed to identify all the parameters, namely, aeroelastic- damping and stiffness that appear in self-excited (motion-dependent) load formulation either in time-domain (rational functions) or frequency-domain (flutter derivatives). Relatively large displacements (at low frequencies) can be generated by the system, if required. Results from three experiments, airfoil, streamlined bridge deck and a bluff-shaped bridge deck, are presented to demonstrate the functionality and robustness of the system and its applicability to multiple cross-section types. The system will allow routine identification of aeroelastic parameters through wind tunnel tests that can be used to predict response of flexible structures in extreme and transient wind conditions.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.6
• /
• pp.169-174
• /
• 2019

Flexure joints are recently used in the ultra-precision mechanism for a telecommunication mirror stage. Flexure joints have several advantages coming from their monolithic characteristics. They can be used to reduce the size of manipulators or to increase the precision of motion. In our research, 6 dof(degree of freedom) mechanism is suggested for micrometer repeatability using a flexure mechanism. To design the 6-dof motion, the 2-dof planar mechanism are designed and assembled to make the 6-dof motion. To achieve a certain performance, it is necessary to define the performance of mechanism that quantifies the characteristics of flexure joints. This paper addresses the analysis and design of the 6-dof parallel manipulator with a flexure joint using a finite element analysis tool. To obtain experimental result, CCD laser displacement sensor is used for the total displacement and the stiffness for the 6-dof flexure mechanism.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.474-479
• /
• 2004

This paper presents an economical solution of the control system of robot, which is widely applied to sophisticated robots. The proposed control system is built on a foundation that is combined between driver motor, PC controlled servo-motor control card, and driver software. The solution had been applied to design hardware of controlled 6-DOF (Degree Of Freedom) robot. The controlled system is used to control VML Robot (Vehicle Mechatronic Lab). Addition, because of flexibility of the solution, the controller can be suit with widely robots at used servo-moto.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.805-808
• /
• 1991

In this paper, dynamical model and control architecture are developed for the closed chain motion of two N-joint manipulators holding a rigid object. Controller consist of forward controller which is reduced order model and compensator that compensates for modeling error. Control laws are determined so as to decouple the force and position controlled degree of freedom(DOF) during motion of the system.

• 연구논문집
• /
• s.22
• /
• pp.21-26
• /
• 1992

Dynamic analysis is important in structural design of SCARA or articulated type industrial robots and is' usually done to main three axes. In this paper, robot arm dynamics was analyzed using FBD(free body diagram). Though the proposed scheme becomes complex as DOF(degree of freedom)increases, it allows to see types and directions of forces and moments acting on the body. Therefore, the strength analysis of robot arm can be done relatively easy in a case of either closed or open loop chain. This method can be used for obtaining dynamic simulation at off-line programming system and calculating required torques at joints at on-line system.

• 한국전산유체공학회:학술대회논문집
• /
• 2006.10a
• /
• pp.136-141
• /
• 2006

A prediction of store separation trajectory using grid survey method has been conducted. For the grid survey method, store's aerodynamic flowfield data such as freestream and grid data is needed to solve 6 degree of freedom(6-DOF) equations of motion. In the presented study, aerodynamic flowfield data was generated by Euler solver instead of CTS wind tunnel test. The predicted trajectories shows good agreement with CTS test results.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.84.1-84
• /
• 2002

A Human-Robot-Interface(HRI) for the disabled Person is developed. $\textbullet$ HRI consists of the laser pointer '||'&'||' USB camera and pressure sensor. $\textbullet$ HRI makes three degree of freedom. $\textbullet$ Three robot position control method with the Interface is presented. $\textbullet$ Experimental results show that user control the 6 DOF robot with the interface and control method.