• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.875-881
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• 2014

The redundancy resolution of the seven DOF (Degree of Freedom) upper limb exoskeleton is key to the synchronous motion between a robot and a human user. According to the seven DOF human arm model, positioning and orientating the wrist can be completed by multiple arm configurations that results in the non-unique solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and its effect on the redundancy resolution of the seven DOF human arm model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing two cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid of the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each of two consecutive points along the task space trajectory. The contribution of each criterion on the redundancy was verified by the post processing of experimental data collected with a motion capture system. Results indicate that the bimodal redundancy resolution approach improved the accuracy of the predicted swivel angle. Statistical testing of the dynamic constraint contribution shows that under moderate speeds and no load, the dynamic component of the human arm is not dominant, and it is enough to resolve the redundancy without dynamic constraint for the realtime application.

• 드라이브 ㆍ 컨트롤
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• 제17권3호
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• pp.33-46
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• 2020

We introduce a piece of special-purpose equipment for responding to disasters that has a dual-arm manipulator consisting of six-axis multi joints, and a master-slave operating system controlled by a wearable joystick for intuitive and convenient operation. However, due to the complexity and diversity of a disaster environment, training and suitable training means are needed to improve the interaction between the driver and equipment. Therefore, in this paper, a system that can improve the operator's immersion in the training simulation is proposes, this system is implemented in a virtual environment. The implemented system consists of a cabin installed with the master-slave operation system, a motion platform, visual and sound systems, as well as a real-time simulation device. This whole system was completed by applying various techniques such as a statistical mapping method, inverse kinematics, and a real-time physical model. Then, the implemented system was evaluated from a point of view of the appropriateness of the mapping method, inverse kinematics, the feasibility for real-time simulations of the physical environment through some task mode.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.434-441
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• 2004

In this paper, an exoskeleton-type motion capturing system is designed and implemented. The device is designed to have 12 degree-of-freedom entirely to represent human arm motions. Forward and inverse kinematics of the device are analyzed to make sure of its singular positions. With the designed model parameters, simulation studies are conducted to verify that the designed motion capturing system is effective to represent human motions within the workspace. As a counterpart of the exoskeleton system, a mobile robot is built to follow human motion restrictively. Experimental studies of teleoperation from the exoskeleton device to control the mobile robot are carried out to show feasible application of wireless man-machine interface.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.998-1004
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• 2008

In this paper, a visual servoing control technique of humanoid robot arms is implemented for tracking a moving object. An embedded time-delayed controller is designed on an FPGA(Programmable field gate array) chip and implemented to control humanoid robot arms. The position of the moving object is detected by a stereo vision camera and converted to joint commands through the inverse kinematics. Then the robot arm performs visual servoing control to track a moving object in real time fashion. Experimental studies are conducted and results demonstrate the feasibility of the visual feedback control method for a moving object tracking task by the humanoid robot arms called the ROBOKER.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.679-685
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• 2006

In this paper, development of an omni-directional mobile robot with rocker-bogie link structure is addressed. The overall mobile robot system consists of the robot mechanism with embedded control architecture, wireless communication with host graphic monitoring system, and the joy stick tole-controller. In the cluttered environment with various sizes of obstacles, the omni-directionality and the traversality are required for a mobile robot, so that the robot call go around or climb over the obstacles according to the size. The mobile robot mechanism developed in this paper has both of the omni-directionality and the traversality by 4 steerable driving wheels and the 2 additional passive omni-directional wheels linked with the rocker-bogie structure. The kinematic modeling for the mobile robot is described based on the well-known Sheth-Uicker convention and the instantaneous coordinate system.

• 제어로봇시스템학회논문지
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• 제8권3호
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• pp.233-242
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• 2002

A kinematic modeling method is proposed which models the sliding and skidding at the wheels as pseudo joints and utilizes those pseudo joint variables as augmented variables. Kinematic models of various type of wheels are derived based on this modeling method. Then, the transfer method of augmented generalized coordinates is applied to obtain inverse and forward kinematic models of mobile robots. The kinematic models of five different types of planar mobile robots are derided to show the effectiveness of the proposed modeling method.

• International Journal of Control, Automation, and Systems
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• 제4권3호
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• pp.318-324
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• 2006

The mobile manipulator is expected to work in partially defined or unstructured environments. In our global/local approach to path planning, joint trajectories are generated for a desired Cartesian space path, designed by the global path planner. For a local path planner, inverse kinematics for a redundant system is used. Joint displacement limit for the manipulator links is considered in the motion planner. In an event of failure to obtain feasible trajectories, the task cannot be accomplished. At the point of failure, a deviation in the Cartesian space path is obtained and a replanner gives a new path that would achieve the goal position. To calculate the deviation, a nonlinear optimization problem is formulated and solved by standard Sequential Quadratic Programming (SQP) method.

• 제어로봇시스템학회논문지
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• 제12권5호
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• pp.464-472
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• 2006

This paper presents the two degree-of-freedom (DOF) planar parallel mechanism, called the $2{\underline{R}}RR-RP$ manipulator, whose degree-of-freedom is dependent on an additional passive constraining leg connecting the base and the platform. First, the kinematic analysis of the mechanism is performed: the inverse and forward kinematic problems are analytically solved, the workspace is systematically derived, and all of the singular configurations are examined. Then, in order to determine the geometric parameters the optimization of the mechanism is performed considering its dexterity, stiffness, and space utilization. Finally, the kinematic performances of the optimized mechanism are evaluated through the comparison study to the conventional 5-bar parallel manipulator.

• 한국기계가공학회지
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• 제16권4호
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• pp.113-118
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• 2017

As the demand for industrial robots and Automated Guided Vehicles (AGVs) increases, higher performance is also required from them. Fuzzy controllers, as part of an intelligent control system, are a direct control method that leverages human knowledge and experience to easily control highly nonlinear, uncertain, and complex systems. This paper uses a $LabVIEW^{(R)}-based$ fuzzy controller with gain scheduling to demonstrate better performance than one could obtain with a fuzzy controller alone. First, the work area was set based on forward kinematics and inverse kinematics programs. Next, $LabVIEW^{(R)}$ was used to configure the fuzzy controller and perform the gain scheduling. Finally, the proposed fuzzy gain scheduling controller was compared with to controllers without gain scheduling.

• 한국CDE학회논문집
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• 제12권6호
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• pp.429-440
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• 2007

The purpose of this research is to develop the Human-centered CAD system in which human factors can be considered during the design stage. For this system there are several issues to research, like the digital human modeling technology, the definition of interactions between human and product, the simulation of human motion when using the product, and the bio-mechanical analysis of human, etc. This paper introduces how to construct the kinematical structure of the digital human model. For our digital human model H-ANIM, the international specification of humanoid animation is referenced. And we added the skeleton geometry and the skin surfaces to our model. And it can manipulate its joints by forward kinematics. Also the IKAN inverse kinematics algorithm is adopted to support the posture prediction of the digital human model in the product environment. All of these ideas are implemented using CAD API so that we can apply these functions to the current commercial CAD systems. In this manner, the human factor issues can be effectively taken into account at the early design phase and the costs of bio-mechanical evaluation will be significantly reduced.