• 한국기계연구소 소보
• /
• s.13
• /
• pp.143-161
• /
• 1984

The mass balancing of rotors is an integral part of the study practice of the rotor dynamics. Any machine with rotating components is considered to be rotating machine. The part of a rotating machine that rotates in normal operation is generally reffered to as a rotor. A rotor is flexible if it deforms when the machine is operating at any speed up to its maximum design speed. Otherwise, the rotor is rigid. The general Purpose of the study of rotor dynamics is to increase understanding of rotor vibration phenomena and thus provide a means for controlling or eliminating these vitrations. As the efficiency of rotating machinery has been increased through reduced weight and increased speed, which implies increasement of rotor flexibility, the control of rotor vibration has become essential. Thus, the study and practice of rotor dynamaics has taken on an increasingly important role in recent years. Therefore many workers have studied about this and introduced a few balancing methods of flexible rotor, which can be classified mainly in following four sorts, 1. Polar plotting methed 2. Modal balancing method 3. Influence coefficient method 4. Unified balancing approach In this paper practical theories of rotor dynamics related to flexible rotor balancing have been reviewed and confirmed the calculation results of flexible balancing of typical rotor, as an example, respectively

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.4
• /
• pp.17-24
• /
• 2017

In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.2
• /
• pp.190-196
• /
• 2014

In this paper, we get state equations based on wheel's rotation, tilt and steering are independent each other in balancing robot. Accordingly, we propose two LQR controllers which are appropriate for rotation and steering control of a balancing robot. And its superiority and appropriateness are demonstrated by a comparison to a PID method. Simulation results verify the possibility of upright balancing, rectilinear motion and position control. Moreover, experimental results show that it guarantees the performance to apply the two LQR controllers to balance the robot.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.6 no.2
• /
• pp.155-160
• /
• 2006

In the paper a robust indirect adaptive fuzzy controller is proposed for balancing and position control of the inverted pendulum system. Because balancing control rules of the pendulum and position control rules of the cart can be opposite, it is difficult to design an adaptive fuzzy controller that satisfy both objectives. To stabilize the pendulum at a specified position, the proposed fuzzy controller consists of a robust indirect adaptive fuzzy controller for balancing and a supervisory fuzzy controller which emulates heuristic control strategy and arbitrate two control objectives. It is proved that the signals in the overall system are bounded. Simulation results are given to verify the proposed adaptive fuzzy control method.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.16 no.3
• /
• pp.188-196
• /
• 2016

For the balancing control of a one-wheel mobile robot, CMG (Control Moment Gyro) can be used as a gyroscopic actuator. Balancing control has to be done in the roll angle direction by an induced gyroscopic motion. Since the dedicated CMG cannot produce the rolling motion of the body directly, the yawing motion with the help of the frictional reaction can be used. The dynamic uncertainties including the chattering of the control input, disturbances, and vibration during the flipping control of the high rotating flywheel, however, cause ill effect on the balancing performance and even lead to the instability of the system. Fuzzy compensation is introduced as an auxiliary control method to prevent the robot from the failure due to leaning aside of the flywheel. Simulation studies are conducted to see the feasibility of the proposed control method. In addition, experimental studies are conducted for the verification of the proposed control.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.18 no.2
• /
• pp.1-22
• /
• 1993

This paper deals with the problem of mixed model assembly line balancing. In mixed model assembly lines, tsks should be assigned to stations in such a manner that all stations have approximately the same amount of work on a production cycle basis. Further in balancing assembly lines, the related tasks, the performing task side and the team tasks should be considered to improve work methods, to give more job satisfaction to workers, and to allow greater flexibility in the design of assembly lines. In this paper, the heuristic dispatch assignment rule is developed to assign evenly tasks of each model to all stations. The heuristic method based on the assignment rule developed is presented for mixed model assembly line balancing with the considerations of the related tasks, the performing task side, and the team tasks. The proposed method is analyzed, and compared with other methods for line balancing.

• The KIPS Transactions:PartD
• /
• v.15D no.1
• /
• pp.73-86
• /
• 2008

Because of its capability of automatic identification of objects, RFID(Radio Frequency Identification) technologies have extended their application areas to logistics, healthcare, and food management system. Load balancing is a basic technique for improving scalability of systems by moving loads of overloaded middlewares to under loaded ones. Adaptive load balancing has been known to be effective for distributed systems of a large load variance under unpredictable situations. There are needs for applying load balancing to RFID middlewares because they must efficiently treat vast numbers of RFID tags which are collected from multiple RFID readers. Because there can be a large amount of variance in loads of RFID middlewares which are difficult to predict, it is desirable to consider adaptive load balancing approach for RFID middlewares, which can dynamically choose a proper load balancing strategy depending on the current load. This paper proposes an adaptive load balancing approach for RFID middlewares and presents its design and implementation. First we decide a performance model by a experiment with a real RFID middleware. Then, a set of proper load balancing strategies for high/medium/low system loads is determined from a simulation of various load balancing strategies based on the performance model.

• Journal of the HCI Society of Korea
• /
• v.13 no.3
• /
• pp.65-73
• /
• 2018

Game balance settings are crucial to game design. Game balancing must take into account a large amount of numerical values, configuration data, and the relationship between elements. Once released and served, a game - even for a balanced game - often requires calibration according to the game player's preference. To achieve sustainability, game balance needs adjustment while allowing for small changes. In fact, from the producers' standpoint, game balance issue is a critical success factor in game production. Therefore, they often invest much time and capital in game design. However, if such a costly game cannot provide players with an appropriate level of difficulty, the game is more likely to fail. On the contrary, if the game successfully identifies the game players' propensity and performs self-balancing to provide appropriate difficulty levels, this will significantly reduce the likelihood of game failure, while at the same time increasing the lifecycle of the game. Accordingly, if a novel technology for game balancing is developed using artificial intelligence (AI) that offers personalized, intelligent, and customized service to individual game players, it would bring significant changes to the game production system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.1
• /
• pp.87-93
• /
• 2014

Conventional two-wheeled balancing robots are limited in terms of turning speed because they lack the lateral motion to compensate for the centrifugal force needed to stop rollover. In order to improve lateral stability, this paper suggests a two-wheeled balancing mobile platform equipped with a tilting mechanism to generate roll motions. In terms of static force analysis, it is shown that the two-body sliding type tilting method is more suitable for small-size mobile robots than the single-body type. For the mathematical modeling, the tilting-balancing platform is assumed as a 3D inverted pendulum and the four-degrees-of-freedom equation of motion is derived. In the velocity/posture control loop, the desired tilting angle is naturally determined according to the changes of forward velocity and steering yaw rate. The efficiency of the developed tilting type balancing mobile platform is validated through experimental results.

• Journal of the Korean Society of Industry Convergence
• /
• v.18 no.2
• /
• pp.67-74
• /
• 2015

Two-wheeled driying mobild robots are precise controlled in terms of linear contol methods without considering the nonlinear dynamical characteristics. However, in the high maneuvering situations such as fast turn and abrupt start and stop, such neglected terms become dominant and heavy influence the overall driving performance. This study describes the nonlinear optimal control method to take advantage of the exact nonlinear dynamics of the balancing robot. Simulation results indicate that the optimal control outperforms in the respect of transient performance and required wheel torques. A design example is suggested for the state matrix that provides design flexibility in the control. It is shown that a well-planned state matrix by reflecting the physics of a balancing robot greatly conrtibutes to the driving performance and stability.