• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.293-296
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• 2002

This work presents the reconstruction of impact force produced by the collision between two elastic structures. The 2-DOF impactor was designed. The shape control of impact farce using correlations of the dynamic characteristics and impact force history between two elastic structures is accomplished. The effects of the relative motion between impactor and elastic structure on the impact force shape are studied. Reconstruction characteristics of impact force in cantilever beam are reviewed.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.272-275
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• 1997

When a manipulator makes contact with an object having position uncertainty, performance measures vary considerably with the control law. To achieve the optimal solution for this problem, an unique objective function that weights time and impact force is suggested and is solved with the help of variational calculus. The resulting optimal velocity profile is then modified to define a sliding mode for the impact and force control. The sliding mode control technique is used to achieve the desired performance. Sets of experiments are performed, which show superior performance compared to any existing controller.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.49-58
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• 2003

In this study, the equation of motion of impacting elastic structures was derived through the theory, and the shape control of impact force using correlations of the dynamic characteristics and impact force history between two elastic structures was accomplished. Through numerical analysis and experiments, the classical contact mechanisms were verified, and the effects of the relative motion between impactor and elastic structure on the impact force shape were studied, and then the shape change of impact force depending on the impact position and mode shape of cantilever beam were analyzed. The 2-DOF impactor was designed and used. Reconstruction characteristics of impact force in cantilever beam were reviewed .

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.172-178
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• 1993

This paper deals with the modeling and experiment of a robot system for force/impact control performance. The basic model is composed of a direct drive motor, servo amplifier, link, force sensor and environments. Based on the developed model, the stability of the whole system was analyzed via root locus method. For the force control, integral force compensation with velocity feedback method shows the best performance of all the explicit force control strategies. In dealing with impact, PID position control and the explicit force control method were implemented. Instead of add more damping to the robot system by velocity feedback, we developed a new passive damping method and it was also applied to enhance the damping characteristic of the system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.121-121
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• 2000

This paper presents a design of macro-micro system for high-speed mounting of micro-chips. A macro motion device is driven by DC servomotor and ball screw mechanism. To obtain fast response, a micro motion device utilizes a precision elector magnetic actuator In order to reduce peak impact force, We evaluate the design parameters that have an effect on it. And a characteristic of response is simulated using PID controller in velocity and force control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.949-953
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• 1996

Force shape control for impact test is required in order to simulate dynamic reponse of structures which is subjected to impact force. In this paper, the mechanisms of contact and impact force generation are analyzed and tested with a simple test equipment. It was carried out for the pre-design of impact force reconstruction apparatus.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.388-397
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• 2009

There are many tasks which require robotic manipulators interaction with environment. It consists of three control problems, i.e., position control, impact control and force control. The position control means the way of reaching to the environment. The moment of touching to the environment yields the impact control problem and the force control is to maintain the desired force trajectory after the impact with the environment. These three control problems occur in sequence, so each control algorithm can be developed independently. Especially for redundant manipulators, each of these three control problems has been important independent research topic. For example, joint torque minimization and impulse minimization are typical techniques for such control problems. The three control problems are considered as a single task in this paper. The position control strategy is developed to improve the performance of the task, i.e., minimization of the individual joint torques and impulse. Therefore, initial conditions of the impact control problem are optimized at the previous position control algorithm. Such a control strategy yields improved result of the impact control. Similarly, the initial conditions for the force control problem are indirectly optimized by the previous position control and impact control strategies. The force control algorithm uses the individual joint torque minimization concept. It also minimizes the force disturbances. The simulation results show the proposed control strategy works well.

• Journal of Drive and Control
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• v.19 no.3
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• pp.1-8
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• 2022

In this paper, the design of automatic impact force control mechanism of hydraulic breaker was studied. The control mechanism uses the change of piston upper chamber pressure, when the hydraulic breaker impacts various strength rock. The piston stroke is controlled by rock strength sensing valve, piston stroke switching valve, and piston control valve. It is imperative to denote the area of each valve section, the spring constant of the spring. It provides convenience to users by automatically adjusting the appropriate striking force, according to the strength of the rock. Additionally, by increasing work productivity, it can contribute to reducing greenhouse gas emissions due to fuel efficiency reduction.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.1-7
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• 2005

Excessive pronation and impact force during running are related to various running injuries. To prevent these injuries, three type of running shoes are used, such as cushioning, stability, and motion control. Although there were may studies about the effect of midsole hardness on impact force, no study to investigate biomechanical effect of motion control running shoes. The purpose of this study was to determine biomechanical difference between cushioning and motion control shoes during treadmill running. Specifically, plantar and rearfoot motion, impact force and loading rate, and insole pressure distribution were quantified and compared. Twenty male healthy runners experienced at treadmill running participated in this study. When they ran on treadmill at 3.83 m/s. Kinematic data were collected using a Motion Analysis eight video camera system at 240 Hz. Impact force and pressure distribution data under the heel of right foot were collected with a Pedar pressure insole system with 26 sensors at 360 Hz. Mean value of ten consecutive steps was calculated for kinematics and kinetics. A dependent paired t-test was used to compare the running shoes effect (p=0.05). For most kinematics, motion control running shoes reduced the range of rearfoot motion compared to cushioning shoes. Runners wearing motion control shoe showed less eversion angle during standing less inversion angle at heel strike, and slower eversion velocity. For kinetics, cushioning shoes has the effect to reduce impact on foot obviously. Runners wearing cushioning shoes showed less impact force and loading rate, and less peak insole pressure. For both shoes, there was greater load on the medial part of heel compared to lateral part. For pressure distribution, runners with cushioning shoes showed lower, especially on the medial heel.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1080-1084
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• 1989

The motion of an workpiece to be manipulated is determined by the forces applied to the workpiece. During the contact between the robot hand and the workpiece, impulsive forces may dominate all other forces, and determine the ultimate success or failure of a task. Therefore, one of the important problems in the robot hands is the control of the initial impact force. In this paper, the problem of the force control of robot hand under system with contact force is presented. The principle of energy can be applied in the modelling of the impact force. In order to achieve stable contact and avoid bounces and vibrations, VSS is adopted in the design of the contact force controller. Some simulations are carried out for a pushing operation to control the contact force.