Baeksuk Chu

Bio: Baeksuk Chu is an academic researcher from Kumoh National Institute of Technology. The author has contributed to research in topics: Robot & Mecanum wheel. The author has an hindex of 12, co-authored 42 publications receiving 612 citations. Previous affiliations of Baeksuk Chu include Korea University & University of California, Davis.

A survey of climbing robots: Locomotion and adhesion

Abstract: Climbing robots are robotic systems to move over 2D or complex 3D environments such as walls, ceilings, roofs, and geometric structures and to conduct various tasks. They will not only replace human workers for carrying out risky tasks in hazardous environments, but also increase operational efficiency by eliminating the costly erection of scaffolding and staffing costs. Climbing robots have special characteristics and the ability to adhere to different types of 2D or 3D surfaces, move around, and carry appropriate tools and sensors to work, while self-sustaining their bodies. Therefore, the most significant criterion for designing a climbing robot is to equip it with an appropriate locomotive and adhesion mechanism for adapting to the given environmental requirements. In this paper, a classification of climbing robots and proper examples with a brief outline are presented with considerations of the locomotive and adhesion mechanisms. Also, a list of climbing robots is provided with respect to fields of application that range from cleaning tasks in the construction industry to human care systems in the biomedical service industry.

Kinematics and Efficiency Analysis of the Planetary Roller Screw Mechanism

Abstract: This paper analyzes the kinematics and the efficiency of the planetary roller screw mechanism (RSM) to provide a fundamental basis to support its various applications. The mechanical structure and practical advantages are presented in comparison with the conventional ball screw mechanism (BSM). Kinematic analysis involves derivation of the angular and axial motions, as well as the development of the slip pattern between the contacting components. Results show that for any motion of the RSM slip always occurs. Kinematic analysis including elastic deformation is also presented. The load carrying capacity and efficiency of the RSM are derived based on geometric and equilibrium conditions, and the results are compared with the BSM.

Optimal Cross-Coupled Synchronizing Control of Dual-Drive Gantry System for a SMD Assembly Machine

Abstract: The present paper deals with the development of synchronizing controller for dual-drive servo system that is often used for SMD (Surface Mount Device) assembly machine. Instead of coordinating the commands to the individual feed drives and implementing closed position loop control for each axis, this work is achieved by the evaluation of an optimal cross-coupled compensator aimed specifically at improving synchronous accuracy in dual feed drives. The optimal control formulation explicitly includes the synchronous error in the performance index to be minimized. In this paper, surface chip mounter is used for experiment. It demands to synchronize the positions of its two primary driving axes. The system is modeled as the first order approximation and cross-coupled optimal synchronizing controller is designed. The synchronizing control is simulated and experimented with actual system for various velocity profiles. The results show that the proposed controller reduces the synchronous error considerably, compared to the conventional uncoupled control for the dual-drive system.

Synchronizing dual-drive gantry of chip mounter with LQR approach

Abstract: The present paper deals with the development of synchronizing controller for a dual-drive servo system that is often used for high speed and precision gantry system. The dual-drive mechanism has been used to increase the system bandwidth of precision gantry systems. This work is achieved by the evaluation of an synchronizing control with LQR scheme aimed specifically at improving synchronous accuracy in dual feed drives. The performance index for the optimal control formulation explicitly includes the synchronizing errors both in position and velocity, which is to be minimized. An assembly machine for surface mount devices is used for simulations and experiments. The system is modeled as the first order approximation and cross-coupled optimal synchronizing controller is designed. The design parameters are obtained by multi-variable frequency domain analysis. Simulations and experiments are carried about various gains and mismatched dynamics. The results show that the proposed controller reduces the synchronous error considerably, compared to the conventional uncoupled control for the dual-drive system.

Optimum design of hybrid renewable energy systems: Overview of different approaches

Abstract: Public awareness of the need to reduce global warming and the significant increase in the prices of conventional energy sources have encouraged many countries to provide new energy policies that promote the renewable energy applications. Such renewable energy sources like wind, solar, hydro based energies, etc. are environment friendly and have potential to be more widely used. Combining these renewable energy sources with back-up units to form a hybrid system can provide a more economic, environment friendly and reliable supply of electricity in all load demand conditions compared to single-use of such systems. One of the most important issues in this type of hybrid system is to optimally size the hybrid system components as sufficient enough to meet all load requirements with possible minimum investment and operating costs. There are many studies about the optimization and sizing of hybrid renewable energy systems since the recent popular utilization of renewable energy sources. In this concept, this paper provides a detailed analysis of such optimum sizing approaches in the literature that can make significant contributions to wider renewable energy penetration by enhancing the system applicability in terms of economy.

Swarmanoid: A Novel Concept for the Study of Heterogeneous Robotic Swarms

Abstract: Swarm robotics systems are characterized by decentralized control, limited communication between robots, use of local information, and emergence of global behavior. Such systems have shown their potential for flexibility and robustness [1]-[3]. However, existing swarm robotics systems are by and large still limited to displaying simple proof-of-concept behaviors under laboratory conditions. It is our contention that one of the factors holding back swarm robotics research is the almost universal insistence on homogeneous system components. We believe that swarm robotics designers must embrace heterogeneity if they ever want swarm robotics systems to approach the complexity required of real-world systems.