• International Journal of Control, Automation, and Systems
• /
• v.6 no.4
• /
• pp.596-606
• /
• 2008

In this paper, we present a co-design methodology of dynamic optimal network-bandwidth allocation (ONBA) and adaptive control for networked control systems (NCSs) to optimize overall control performance and reduce total network-bandwidth usage. The proposed dynamic co-design strategy integrates adaptive feedback control with real-time scheduling. As part of this co-design methodology, a "closed-loop" ONBA algorithm for NCSs with communication constraints is presented. Network-bandwidth is dynamically assigned to each control loop according to the quality of performance (QoP) information of each control loop. As another part of the co-design methodology, a network quality of service (QoS)-adaptive control design approach is also presented. The idea is based on calculating new control values with reference to the network QoS parameters such as time delays and packet losses measured online. Simulation results show that this co-design approach significantly improves overall control performance and utilizes less bandwidth compared to static strategies.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.681-686
• /
• 2006

In order to protect the environment from the refrigerant pollution, the $CO_2$ may be regarded as one of the most attractive alternative refrigerants for an automotive air-conditioning system. Control methods for a $CO_2$ system should be different because of $CO_2's$ unique propel-ties as a refrigerant. Especially, the high-side pressure of a $CO_2$ system should be controlled for the effective operation of the system. In this study, dynamic models of a $CO_2$ air-conditioning system were developed by using experimental data. Control algorithms for a high-side pressure control and an indoor air temperature control were developed and analysed by using the dynamic simulation program of a $CO_2$ system.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.366-368
• /
• 1994

This paper deals with the vector control that control of torque and speed of the induction motor using field-oriented control method. Rotor flux is estimated using the indirect sensing method based on the rotor circuit equation in the synchronously rotation reference frame, and slip angle and rotor position are caculated from rotor angular velocity and stator current. Through modeling and digital simulation with a voltage source inverter, it is shown that the proposed scheme gives good static and dynamic performance to the induction motor drive.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.2
• /
• pp.110-115
• /
• 2014

The reconfigurability of FPGA devices allows designers to evaluate, test and validate a new control algorithm; a new component or prototypes without damaged the real system with the so-called hardware co-simulation. The present paper uses the Xilinx System Generator (XSG) environment to establish and validate a new nonlinear estimator for the rotor time constant inverse that will be exploited to improve the indirect rotor field control of induction motor.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1430-1439
• /
• 2019

In Functional Mockup Interface(FMI)-based co-simulation, a bisectional algorithm can be used to find the zerocrossing point as a way to improve the accuracy of the simulation results. In this paper, the proposed master algorithm(MA) analyzes the repeated interval graph and predicts the next interval by applying the Markov Chain to the step size. In the simulation, we propose an algorithm to minimize the rollback by storing the step size that changes according to the graph type as an array and applying it to the next prediction interval when the rollback occurs in the simulation. Simulation results show that the proposed algorithm reduces the simulation time by more than 20% compared to the existing algorithm.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.328-333
• /
• 2007

The purpose of this study is modelling of system air-conditioner for TRNSYS. System air-conditioner is operated by a variable capacity compressor and accommodated by multiple evaporators. By reason of these feature, realizing performance of system air-conditioner for TRNSYS was incomplete. In this study performance data of system air-conditioner and control logics are used to make system air-conditioner module for TRNSYS. Performance data contains total capacity, power input and capacity index of system air-conditioner. The simulation was carried out in a mode of temperature level control using TRNSYS 16. The simulation shows that the system air-conditioner model operate variable capacity and can compute capacity index and power input of system.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.5 no.4
• /
• pp.17-25
• /
• 2008

This study presents an analytical model of the pneumatic circuit of an air suspension system to analyze the characteristics of vehicle height control. The analytical model was developed through the co-simulation of Simulink(air spring) and HyPneu(pneumatic circuit). Variant effective area of air spring and flow coefficients of pneumatic valves were estimated experimentally prior to the system test, and utilized in simulation. One-comer test apparatus was established using the components of commercial air suspension products. The results of simulation and experiment were so close that the proposed analytical model in this study was validated. However the frictional loss of conduit and heat dissipation which were ignored in this study need to be considered in future study. As an application example of proposed analytical model, an alternative pneumatic circuit of air suspension to conventional WABCO circuit was evaluated. The comparison of simulation results of WABCO circuit and alternative circuit show that proposed analytical model of co-simulation in this study is useful for the study of pneumatic system of automotive air suspension.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.5
• /
• pp.277-286
• /
• 2017

This paper introduces mathematical modelling and control algorithm of expendable mine disposal vehicle. This vehicle has two longitudinal thrusters, one vertical thruster and internal mass moving system which can control pitch rate. Also, the vehicle has an optical camera and forward looking sonar for underwater mine detection and classification. The vehicle is controlled via an optical cable connected with operating console on the mother ship. We describe the vehicle's 6DOF dynamic model and controller which can track the desired trajectory for the way-point tracking. These simulation results shows guidance and maneuvering performance which has other sensor data or not.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.11a
• /
• pp.245-246
• /
• 2008

The Correlation FXLMS (Co-FXLMS) algorithm was developed to improve the control performance. The Co-FXLMS algorithm is realized by using an estimate of the cross correlation between the adaptation error and the filtered input signal to control the step size. In this paper, the performance of the Modified Co-FXLMS is presented in comparison with that of the CO-FXLMS algorithm. Simulation results show that active noise control using Modified Co-FXLMS is effective to control performance of algorithm and prevent divergence.

• 한국전산유체공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.134-134
• /
• 2003