• International Journal of Precision Engineering and Manufacturing
• /
• v.3 no.2
• /
• pp.15-21
• /
• 2002

A control-structure combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these farms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. A numerical example shows the validity of combined optimal design of structure and control systems. We also consider the validity of sensor-actuator collocation for control system design in this paper.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.2
• /
• pp.192-196
• /
• 2004

A combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only the minimum weight design problem for the structure, but also the suppression problem of the effect of disturbances for the control system as the purpose of the design. A numerical example shows the validity of combined optimal design of the structure and control systems. We also consider the validity of the sensor-actuator collocation for the control system design in this paper.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.3
• /
• pp.267-272
• /
• 2004

In this Paper, we present analysis on the dynamics of human swing and its realization by a miniaturized humanoid robot. Since the motion of legs is the most important in the swing, the swing system can be approximated as a double pendulum. Based on Lagrangian analysis, the leg motion is designed to make the swing motion as sustained oscillation. In order to detect the peak instant of the swing and to synchronize the leg motion with the swing, we use ADXL acceleration/inclination sensor. The miniaturized humanoid in this paper has total 20 DOFs including 6 DOFs in each leg, 34cm in height, and 2kg in weight. As a result of realization of the swing by the humanoid, the sustained oscillation is verified through experiments.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.139-142
• /
• 1990

A gas sensor, comprised of both ZnO and $PdCl_2$ powders, has been developed to sense the CO gas of low concentration (100 ppm). When the weight ratio of ZnO/$PdCl_2$ element sintered at $600^{\circ}C$ was 99.5/0.5, the maximum sensitivity to CO gas was obtained at the operating temperature of $200^{\circ}C$. Also, the response characteristics of this element were examined, and then the response time was decreased from 90 to 45 sees, with operating temperature increase in the range of $100-400^{\circ}C$.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.3
• /
• pp.266-272
• /
• 2014

This study proposes a closed-loop shaping control method with $H_{\infty}$ optimization for optical image stabilization (OIS) in mobile phone cameras. The image stabilizer is composed of a horizontal stage constrained by ball bearings and actuated by the magnetic force from voice coil motors. The displacement of the stage is measured by Hall effect sensors. From the OIS frequency response experiment, the transfer function models of the stage and Hall effect sensor were identified. The weight functions were determined considering the tracking performance, noise attenuation, and stability with considerable margins. The $H_{\infty}$ optimal controller was executed using closed-loop shaping and limiting the controller order, which should be less than 6 for real-time implementation. The control algorithm was verified experimentally and proved to operate as designed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11c
• /
• pp.684-689
• /
• 2000

In harvesting rice and barley using combine, the inclination of the body caused by the irregular surface condition of the field and the soil sinking from the unbalanced weight during the grain collection used to make harvesting operation difficult and even impossible. To overcome such a problem, automatic leveling control system for a combine has been developed and tested. The system was composed of the sensor for measuring left and right inclination of the combine chassis and the hydraulic control system. The adaptability of the control system was investigated by analyzing system response in time domain. And the limit angle of the leveling control was set up to be +/- 7$^{\circ}$. The proposed control and hydraulic power system was implemented to the prototype combine. The prototype combine was designed and built as a separable structure with chassis and track. This paper shows results of the leveling performance tested in the laboratory and the grain field.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2000.11a
• /
• pp.39-45
• /
• 2000

In recent years, composite materials such as fiber reinforced plastics (FRP) have gained considerable attention in the aircraft and automobile industries due to their light weight, high modulus and specific strength. In practice, control of chip formation appears to be the most serious problem since chip formation mechanism in composite machining has significant effects on the finished surface ［1,2,3,4,5］. Current study will discuss frequency analysis based on autoregressive (AR) time series model and process characterization in orthogonal cutting of a fiber-matrix composite materials. A sparsely distributed idealized model composite material, namely a glass reinforced polyester (GFRP) was used as workpiece. Analysis method employs a force sensor and the signals from the sensor are processed using AR time series model. The experimental correlation between the different chip formation mechanisms and model coefficients are established.(omitted)

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.11
• /
• pp.79-90
• /
• 2003

In this paper, we propose a multisensor-based navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments using multi-ultrasonic sensor. Instead of using “sensor fusion” method which generates the trajectory of a robot based upon the environment model and sensory data, “command fusion” method by fuzzy inference is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor using fuzzy inference is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we performed simulations in PC as well as experiments with IRL-2002. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.7
• /
• pp.592-598
• /
• 2013

In this paper, a small, lightweight smartphone-controlled riding robot is developed. Also, in this study, a smartphone with a jog shuttle mode for consideration of user convenience is proposed to make a small, lightweight riding robot. As well, a compass sensor is used to compensate for the mechanical characteristics of motors mounted on the riding robot. The riding robot is controlled by the interface of a drag-based jog shuttle in the smartphone, instead of a mechanical controller. For a personal riding robot, if the smartphone is used as a controller instead of a handle or a pole, it reduces its size, weight, and cost to a great extent. Thus, the riding robot can be used in indoor spaces such as offices for moving or a train or bus station and an airport for scouting, or hospital for disabilities. Experimental results show that the riding robot is easily and conveniently controlled by the proposed smartphone interface based on Android.

• Journal of Industrial Technology
• /
• v.15
• /
• pp.83-91
• /
• 1995

This paper presents the design of a smart A/D conversion interface used for measuring the load of a truck. Since the load-cell sensor to be used is very sensitive for weight variation, the interface board must have the low-drift and the A/D conversion for accuracy. A new integrator and comparator has been developed to reduce the offset voltage and the drift current of operational amplifiers and has been adapted into the interface board. Also, a software algorithm has been developed to obtain the stable and accrurate A/D conversion. This software includes a RS-485 communication program to control the interface, which gives a capability of backing-up the calibration data and transferring control data. The test and evaluation of the designed interface has been shown as having the better performance compared to the other types of existing weighing systems and sensor instruments.