• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_1
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• pp.993-999
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• 2023

In this paper, a novel polishing tool mechanism with 3-axis compliance is presented, which consists of 2-axis rotational and 1-axis linear compliances in series. The 2-axis rotational compliance mechanism is made up of four cantilever beams for adjusting rotational stiffness and one flexure universal joint at the center for constraining the z-axis deflection. The 2-axis rotational compliance can mechanically adjust the polishing tool to machined surfaces. The polishing press force can be simply controlled by using a linear spring along the z-axis. The 2-axis rotational and 1-axis linear compliance design is decoupled. The stiffness analysis of the 2-axis compliance mechanism was performed based on link compliance matrix and rigid body transformation. A 3-axis polishing tool was designed by configuring the 2-axis compliance mechanism and one linear spring.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.334-339
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• 1994

In this work, we propose a planar three degree-of-freedom parallel mechanism as another type of assembly device which utilized joint compliances. These joint compliances can be adjusted either by properly replacing the joint compliances or by actively controlling stiffness at joints, in order to generate the desired operational compliance characteristics at RCC point, The operational compliance matrix for this mechanism is explicitly obtained by symbolic manipulation and its operational compliance characteristics are examined, it is found that the RCC point exists at the center of the workspace when the mechanism maintains symmetric configurations. Compliance characteristic and its sensitivity of this mechanism is analyzed with respect to the magnitude of the diagonal compliance components and two different matrix norms measuring compliance sensitivity. It is expected that the analysis results provide the designer with a helpful information to determine a set of optimal parameters of this RCC mechanism.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.531-534
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• 1996

In this work, we investigate the characteristics of output compliance matrix of a planar 3 degree-of-freedom parallel mechanism when joint compliances are attached to the mechanism redundantly. It is shown by simulation that by attaching redundant joint compliances symmetrically to the mechanism, the translational and rotational compliances can be arbitrarily modulated within some ranges. This property could be effectively used in the control of the compliance characteristics of actively adjustable RCC devices.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.06a
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• pp.33-40
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• 2000

To improve the compliance and verification mechanism is one of the important reasons to revise the STCW Convention. The mechanism includes the assessment of competence, control, precision of description of competence, quality standard system, communication of information and so on. Chinese seaman's education an training institute & the organization of evaluating and issuing certificates should enhance realizing the importance of compliance and verification mechanism and carry out it down to earth. The current work that should be reinforced is to control the qualified evaluation effectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.611-616
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• 1994

Most of Commercial Remote Center Compliance(RCC) devices have been designed using deforma ble structures. In this work, we propose another type of assembly devices which generate the compliance effec ts by attaching the compliances (or spring) at the prismatic joints of the griven mechainsm. First, the kinematic analysis for a parallel-type planar 3-degree-of-freedom mechanism is performed using modified transfer method of generalized coordinate. Then, compliance characteristics for the mechanism using prismatic joint compliances are investigated. In particular, when the system maintains its symmetric configuration, the mechanism is show n to have RCC points at the center of the workspace. Finally, sensitivity analysis around RCC points is perfor med.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1534-1541
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• 2005

Unlike industrial manipulators, the manipulators mounted on service robots are interacting with humans in various aspects. Therefore, safety has been one of the most important design issues. Many compliant robot arms have been introduced for safety. It is known that passive compliance method has faster response and higher reliability than active ones. In this paper, a new safety mechanism based on passive compliance is proposed. Passive mechanical elements, specifically transmission angle of the 4-bar linkage, springs and shock absorbing modules are incorporated into this safety mechanism. This mechanism works only when the robot arm exerts contact force much more than the human pain tolerance. Validity of this mechanism is verified by simulations and experiments. It is shown that the manipulator using this mechanism provides higher performance and safety than those using other passive compliance mechanisms or active methods.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.180-185
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• 2004

Unlike industrial manipulators, the manipulators mounted on the service robots are interacting with humans in various aspects. Therefore, safety has been the important design issue. Many compliant robot arm designs have been introduced for safety. It is known that passive compliance method has faster response and higher reliability than active ones. In this paper, a new safe mechanism based on passive compliance has been proposed. Passive mechanical elements, specifically transmission angle of the 4-bar linkage, springs and shock absorbing modules are incorporated into this safe mechanism. This mechanism works only when the robot arm exerts contact force much more than the human pain tolerance. Validity of the safe mechanism is verified by simulations and experiments. In this research, it is shown that the manipulator using this mechanism provides higher performance and safety than those using other passive compliance mechanisms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.793-798
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• 1996

In this paper, output compliance effects at RCC point by both redundant joint compliances and antagonistic torques generated by internal preloading between joints of a spherical 3 degree-of-freedom mechanism are investigated. For this purpose, kinematic analysis is briefly described. Then, output compliance models at RCC point, which is generated by redundant joint compliances and by internal preloading between joints are derived. Finally, ranges of output compliance modulation due to these redundant joint compliances and antagonistic torques are examined through simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.718-721
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• 1996

In this work, an effective stiffness generated by internal loading for a planar 3 degrees of freedom RCC mechanism is investigated. For this purpose, the internal kinematic analysis and antagonistic stiffness modeling for this mechanism are performed. It is shown that the antagonistic stiffness could be effectively created at the center of the mechanism in its symmetric configuration.

• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.168-177
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• 2007

In a number of fields, robots are being used for two purposes: efficiency and safety. Most robots, however, have single-actuator mechanism for each joint, where the tasks are performed with high stiffness. High stiffness causes undesired problems to the environment and robots. This study proposes redundant actuator mechanism as an alternative idea to cope with these problems. In this paper, Double-Actuator Unit (DAU) is implemented at each joint for applications of multi-link manipulators. The DAU is composed of two motors: the positioning actuator and the stiffness modulator, which enables independent control of positioning and compliance. A three-link manipulator with DAUs enables adaptive control of RCC. By modulating the joint stiffness of the manipulator and controlling the position of RCC, we can significantly reduce contact force during assembly tasks and surgical procedures.