Mooncheol Won

Design and control of a marine satellite antenna

A three axes marine satellite antenna has been developed. As a design step, a CAD model for the antenna has been created according to the design requirements. Kinematic analyses are carried out to insure design specification and to check collision detection of the CAD model. Marine satellite antennas experience base motions, and a relevant control system should control the three antenna axis to point to the satellites accurately. A sensor fusion algorithm and a PIDA (Proportional, Integral, Derivative, Acceleration) control algorithm are designed and implemented to control the yaw, level, and cross-level angle of a small size satellite marine antenna. Antenna stabilization control experiments are performed using a test simulator which gives the antenna base motions. Experimental results show small pointing errors, which is less than 0.2 degree for the level, cross-level, and yaw axis

A Joystick Driving Control Algorithm with a Longitudinal Collision Avoidance Scheme for an Electric Vehicle

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver’s joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

A joystick driving algorithm with a collision stop feature on an electric vehicle (Cycab)

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication between the five processors. The developed algorithm consists of a torque distribution algorithm for the traction motors neglecting the joystick command and two automatic vehicle speed control algorithms for normal and emergency situations, that override the drivers Joystick command. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the developed algorithm.

The Development of a Real-Time Multibody Vehicle Dynamics and Control Model for a Low Cost Virtual Reality Vehicle Simulator: An Application to Adaptive Cruise Control

The concept of the ACC (Adaptive Cruise Control) system is shown in Fig. 1. ACC system controls the throttle valve and the brake master cylinder to maintain a desired space between the preceding vehicle and the ACC vehicle. To evaluate performance of the ACC system and driver’s responses to the intelligent vehicles, a vehicle simulator with a virtual reality feature can be a very effective tool. For such a vehicle simulator, a real-time vehicle dynamics and control model is essential.

Development of Algorithm for Measuring Oscillating Angles and Periods of Ships in a Seaway

It is essential to find oscillating angles and periods in a seaway when designing and manufacturing stabilizers. It is difficult to find oscillating angles and periods in high speed turning and they vary with ship speed and wave heading angles, therefore, proper algorithm to measure oscillating periods in a seaway. In the present study, three kinds of algorithms are developed to measure oscillating angles periods in a seaway. Dual axis tilt sensor of low price is used to measure oscillating angles, and the effect of lateral accelerations on tilt sensor have been reduced by the fusion algorithm using the gyro sensor signals. Analog and digital filters are applied to minimize the noise of the signals. Three kinds of algorithms, zero crossing, peak to peak and moving zero crossing algorithm, are developed to measure oscillating periods in a seaway. It is found that the moving zero algorithm showed the best results in the sea trials.

Assembly and Characterization of Nanodevice using Carbon Nanotubes and Nanowires

We report the assembly and characterization of three types of Ag, SnO2, and Ga2O3 nanowires (NWs) and two types of carbon nanotubes (NTs) using dielectrophoresis. The NWs and NTs were individually assembled using an experimental approach based on the dielectrophoretic force equation. After depositing a Pt top electrode using a focused ion beam, we investigated the I-V curves of NW and NT devices.