Browsing by Author "Cheng, Chun-Kai"

Now showing 1 - 7 of 7

A new single inductor bipolar multi-output (SIBMO) DC-DC converter driven by constant on-time with improved performance
(2016-06-01)
Chao, Paul C. P.
;
Chang, Chun-Kai
;
Cheng, Chun-Kai
;
Trong-Hieu Tran
;
Sauter, Thilo
This study is dedicated to design and realization of a new single inductor bipolar multi-output (SIBMO) DC-DC converter with performance improvement. A bandgap is first designed to offer a stable input bias with capability to work against inevitable input voltage variations for avoiding possible p-n breakdowns. A new drive technique based on constant on-time (COT) is developed for the designed SIBMO with assistance from level shifters and zero current detection circuits to drive MOS devices. The designed circuit is capable of boosting input voltage 2.8 V to four bipolar outputs of +6, -6, +12 and -12 V. The COT proposed herein adopts a new technique of time multiplexing to offer stable multi-outputs with an off-chip inductor for fast switchings. This new COT is different from the conventional pulse width modulation which usually operates with fixed frequencies. The COT is particularly favorable in regards of crossing regulation and high transfer efficiency in cases of unbalanced loads. The proposed SIBMO and COT are applicable to drive systems of organic light-emitting diodes, optical sensors, and portable electronic devices, displays, etc. The designed on-chip SIBMO and COT are fabricated via the TSMC 0.25 A mu m high-voltage CMOS process. Experimental results clearly show the capability of the designed SIBMO chip to offer four bipolar, stabilized output voltages with a total power consumption minimized to 320 mW and the switching frequency varying from 650 to 500 kHz. Most importantly, the maximum efficiency reaches 83.1 %.
A new single inductor bipolar multi-output (SIBMO) DC-DC converter driven by constant on-time with improved performance
(2016-06)
Chao, Paul C. P.
;
Chang, Chun-Kai
;
Cheng, Chun-Kai
;
Trong-Hieu Tran
;
Sauter, Thilo
This study is dedicated to design and realization of a new single inductor bipolar multi-output (SIBMO) DC-DC converter with performance improvement. A bandgap is first designed to offer a stable input bias with capability to work against inevitable input voltage variations for avoiding possible p-n breakdowns. A new drive technique based on constant on-time (COT) is developed for the designed SIBMO with assistance from level shifters and zero current detection circuits to drive MOS devices. The designed circuit is capable of boosting input voltage 2.8 V to four bipolar outputs of +6, -6, +12 and -12 V. The COT proposed herein adopts a new technique of time multiplexing to offer stable multi-outputs with an off-chip inductor for fast switchings. This new COT is different from the conventional pulse width modulation which usually operates with fixed frequencies. The COT is particularly favorable in regards of crossing regulation and high transfer efficiency in cases of unbalanced loads. The proposed SIBMO and COT are applicable to drive systems of organic light-emitting diodes, optical sensors, and portable electronic devices, displays, etc. The designed on-chip SIBMO and COT are fabricated via the TSMC 0.25 A mu m high-voltage CMOS process. Experimental results clearly show the capability of the designed SIBMO chip to offer four bipolar, stabilized output voltages with a total power consumption minimized to 320 mW and the switching frequency varying from 650 to 500 kHz. Most importantly, the maximum efficiency reaches 83.1 %.
Chaos Synchronization between Josephson Junction and Classical Chaotic System Via Iterative Learning Control
(2018-01-01)
Cheng, Chun-Kai
;
Chao, Paul C. -P.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An application of Iterative Learning Control Theory (ILC) for system synchronization exhibited is in this study. The drive system is the Rossler system in this study is a macroscopic system. Another system is a mesoscopic system containing the resistive-capacitive-inductance shunted Josephson junctions (RCL-shunted JJ) to be the response system in this study. The ILC method is important to research for the robotics development in 1984. Many studies, such as image identification, adaptive control, sliding mode control and secure communication are gradually employed. The resistive-capacitive-inductance shunted Josephson junctions (RCL-shunted JJ) and resistive-capacitive shunted Josephson junctions (RCS JJ) are essentially nonlinear dynamical systems in a superconductor device could be used to synchronize drive-response system of chaos and chaos-based secure communication. The iterative error between the drive and response system influences the synchronization of systems. The Lyapunov criteria are still satisfied the mesoscopic, and the tracking error dynamics could be bounded and converged. There are also to exhibit system synchronized will be Lyapunov stable for which based on to designate appropriated learning the law. The simulation results demonstrate the consistent with the concept of proposing the controlled learning law and scheme.
Chaotic Synchronizing Systems with Zero Time Delay and Free Couple via Iterative Learning Control
(2018-02-01)
Cheng, Chun-Kai
;
Chao, Paul C. -P.
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This study aims to orchestrate a less restrictive learning controller by using the iteration-varying function, the so-called iterative learning controller (ILC), to synchronize two nonlinear systems with free time delay and couple free. The mathematical theories are proven rigorously and controllers are developed for system synchronization, and then an example is forged to demonstrate the effectiveness of synchronization by the designed ILC. The ILC is designed with a feed-forward based by the error dynamics between the two considered nonlinear drive and response systems. The stability of the synchronization facilitated by the designed ILC is ensured by rendering the convergence of an error dynamics that satisfied the Lyapunov function. The Lorenz system within a drive-response system is considered as one system that drives another for the demonstration of the effectiveness of the designed ILC to achieve synchronization and verified initial conditions. Simulations are conducted for the controlled Lorenz system, and the results validated well the expected capability of the designed ILC for synchronization and matched the proposed mathematical theory.
Optimizing an on-chip boost DC-DC converter with an on-chip or on-board inductor
(2015-12-01)
Chao, Paul C. -P.
;
Cheng, Chun-Kai
;
Kuan, Ching-Huan
;
電機工程學系
;
Department of Electrical and Computer Engineering
This study is dedicated to develop an on-chip DC-DC boost converter with on-chip or on-board inductors to provide steady high voltage biases from 2.8 to 5 V to drive the gate drivers for advanced liquid crystal displays. Note that the off-chip inductor as compared to the on-chip one inevitably occupies substantial board area and leads to negative effects of electro-magnetic interference (EMI). This study also intends to find optimal design of the on-chip or on-board inductors for an on-chip DC-DC converter in order to provide required large instantaneous currents, while minimizing negative impacts from the off-chip inductance. Parametric studies are conducted to successfully find optimal designs, including optimal switching frequency and duty. The optimization process is further standardized for future commercialization. The optimized DC-DC converters are taped out via the TSMC 0.35 mu m CMOS process technology to validate the proposed design. Experiments are carried out for validating the performance of tape-out chips. The results clearly show the effectiveness of the designs and consistency to expectations.
Trajectory Tracking between Josephson Junction and Classical Chaotic System via Iterative Learning Control
(2018-08-01)
Cheng, Chun-Kai
;
Chao, Paul Chang-Po
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This article addresses trajectory tracking between two non-identical systems with chaotic properties. To study trajectory tracking, we used the Rossler chaotic and resistive-capacitive-inductance shunted Josephson junction (RCLs-JJ) model in a similar phase space. In order to achieve goal tracking, two stages were required to approximate target tracking. The first stage utilizes the active control technique to transfer the output signal from the RCLs-JJ system into a quasi-Rossler system. Next, the RCLs-JJ system employs the proposed iterative learning control scheme in which the control signals are from the drive system to trace the trajectory of the Rossler system. The numerical results demonstrate the validity of the proposed method and the tracking system is asymptotically stable.
Using maximum likelihood to calibrate a six-DOF force/torque sensor
(2018-11-01)
Tran, Trong-Hieu
;
Wang, Yu-Jen
;
Cheng, Chun-Kai
;
Chao, Paul C. -P.
;
Wang, Chun-Chieh
This study presents a new six-DOF force/torque sensor and its calibration method. This calibration method apply the method of so-called maximum likelihood estimation (MLE). MLE is utilized to determine and identify the parameters related to applied torques/forces towards resulted deformations at varied locations of the sensor structure. Formulating such relations in a vector-matrix form, those parameters are captured as coefficients in a matrix related to torques/forces towards angular/linear deformations in different directions. In addition to applying MLE, finite element modeling and analysis are conducted to generate realistic-like empirical data for the afore-mentioned calibration computation. The matrix formed by these coefficients can predict exactly forces and torques by this sensor based on deformations detected by strain gauges. In simulated results the worst sum of error for three forces is less than 0.04% while the worst sum of error for three torques is less than 0.005%. Experiments are also conducted, and the results show that the designed sensor and maximum-likelihood parameter estimation approach achieve favorable performance of predicting forces and torques with error less than 1%. The developed sensor is suitable for real-time sensing of multi-dimensional interactive forces/torques in a robot arm.