• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.620-625
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• 2013

Mammals such as dogs and cheetahs change their gait from trot to gallop as they run faster. However, lizards always trot for various speeds of running. When mammals run slowly with trot gait, their fore leg and hind leg generate the required force for acceleration or deceleration such that the yaw moments created by these forces cancel each other. On the other hand, when lizards run slowly, their fore legs and hind legs generate the forces for deceleration and acceleration, respectively. In this paper, the yaw motion of a lizard model is controlled by the movement of their waist and tail, and the reaction moment from the ground produced by the hind legs in simulation. The simulation uses the whole body dynamics of a lizard model, which consists of 4 links based on the Callisaurus draconoides. The results show that the simulated trotting of the model is similar to that of a real lizard when the movement of the model is optimized to minimize the reaction moment from the ground. It means that the body of a lizard moves in such a way that the reaction moment from the ground is minimized. This demonstrates our hypothesis on how lizards trot using body motion.

• Journal of IKEEE
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• v.16 no.3
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• pp.235-243
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• 2012

In this study, we developed two legged multi-joint robot by using wireless servo motor that was applied by wireless sensor network technology, which is widely used recently, and performed an experiment of walking method of two legged multi-joint robot. We constructed the star network with servo motors which were used at each joint of two-legged robot. And we designed the robot for operation by transmission of joint control signal from main control system or by transmission of the status of each joint to the main control system, so it operates with continuously checking the status of joints at same time. We developed the humanoid robot by using wireless digital servo motor which is different from existing servo motor control system, and controlled it by transmitting the information of angles and speeds of robot joints to the motor(node) as a feedback through main control system after connecting power and setting up the IDs to each joint. We solved noisy problem generated from wire and wire length to connection point of the control device by construction of the wireless network instead of using existing control method of wiring, and also solved problem of poor real time response to gait motion by controlling the position with continuous transmission of control signals to each joint. And we found that the effective control of robot is able by performing the simulation on walking motion in advance with the developed control algorithm which was downloaded into installed memory. Also we performed the stable walking with two-legged robot by attaching pressure sensor to robot sole. And we examined the robot gait operated by application of calculated algorithm on robot movement to each joint. In this study, we studied the method of controlling robot gait motion by using wireless servo motors and measured the torque applied to each joint, and found that the developed wireless servo motor by ZigBee sensor network offers easier control of two legged robot gait and better circuit configuration of it than the existing wired control system could do.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.843-848
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• 2007

Quadruped robot is very useful mechanism for a various area. Recently, home entertainment and military robots adapted quadruped platform and useful function have been introduced. Our goal is the development of quadruped robot locomotion for any type of ground included to sloping one and irregular terrain. This paper, as a first step, deals with design and construction of quadruped robot walking on the flat ground. The most important factor of quadruped robot is stability of locomotion. At first, we introduce the developed quadruped robot based on dynamic simulation and experimental study of general gait algorithm. Finally, propose unique locomotion proper to our mechanism. Future work of this study is the performance test and analysis on the ground of various conditions and proposes the improved mechanism and gait algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1934-1937
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• 2005

This paper proposes suitable gait generation for dynamic walking of biped robot with varying load in real time. Author proposes the relationship between ZMP(Zero Moment Point) and measurement from FSR(Force Sensing Register). Simplifying this relationship, it is possible to reduce the computational time and control the biped robot in real time. If the weight of the biped robot varies in order to move some object, then joint trajectories of the the biped robot must be changed. When some object is loaded on the biped robot in it's home position, FSRs can measure the variation of weight. Evaluating the relations between varying load and stable gait of the biped robot, it can walk adaptively. This relation enables the biped robot to walk properly with varying load. The simulation is also represented in this paper which shows proposed relationships.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.424-426
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• 2005

We propose an analytic trajectory planning method using a wavelet neural network (WNN) for a natural and stable locomotion of the 9-link biped robot. We design a appropriate locomotion, which have a kick-action, by means of a ballastic walking model condition. In this paper, a WNN is used to interpolate the trajectory planed by the analytic method. Finally, we show the proposed trajectories through the computer simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.347.2-347
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• 2002

This paper presented a design and a Vibration control of a biped walking RGO(Robotic Gait Orthosis) and walking simulation by this system. The vibration evaluation of the Knee Joint Mechanism on the biped walking RGO(Robotic Galt Orthosis) was used to access by the 3-axis accelerometer with a low frequency vibration for the spinal cord injuries. It will be expect that the spinal cord injury patients are able to recover effectively by a biped walking RGO. (omitted)

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.2
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• pp.83-88
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• 2006

This paper proposes a method that minimizes the consumed energy by searching the optimal locations of the mass centers of the biped robot's links using Genetic Algorithm. This paper presents a learning controller for repetitive gait control of the biped robot. The learning control scheme consists of a feedforward learning nile and linear feedback control input for stabilization of learning system. The feasibility of learning control to the biped robotic motion is shown via computer simulation and experimental results with 24 DOF biped walking robot.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.163-169
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• 2015

This study proposes a sports simulation device with various harmonics generation. The proposed system is composed of 6 degrees of freedom simulator devices and three types of sports simulation such as walking, snowboard, and jet-ski. In this research, every joint movement is designed with a crank-and-slider mechanism, which is efficient for generating continuous curvature smoothly. Contrary to the conventional spatial simulator with linear actuators, harmonics generation and its spatial combinations become the crucial issue in this research. The harmonic pattern in each joint is modelled for generating smooth curvatures that are also superposed for achieving overall motions. In addition, the targeted motions of sports simulations have different physical factors of periodic gait motion, frictionless surface, and buoyant effects, which are respectively designed by integrating three dimensional graphics information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.989-992
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• 2004

In general, it is known that walking stability of a quadruped is determined by its COG(Center of Gravity). In this paper, in order to know whether our virtual quadruped robot is applicable to the real quadruped robot, we simulated our virtual model using the data from the real robot‘s walking. We were able to evaluate the stride of quadruped based on direct and inverse kinematics and compared the stride of the simulation with real robot’s it. During the simulation we calculated the COG of the virtual model and evaluated the walking stability of real model.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.117-121
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• 2023

Research on walking assistance exoskeletons that provide optimized torque to individuals has been conducted steadily, and these studies aim to help users feel stable when walking and get help that suits their intentions. Because exoskeleton auxiliary efficiency evaluation is based on metabolic cost savings, experiments on real people are needed to evaluate continuously evolving control algorithms. However, experiments with real people always require risks and high costs. Therefore, in this study, we intend to actively utilize human musculoskeletal simulation. First, to improve the accuracy of musculoskeletal models, we propose a body segment mass distribution algorithm using body composition analysis data that reflects body characteristics. Secondly, the efficiency of most exoskeleton torque control algorithms is evaluated as the reduction rate of Metabolic Cost. In this study, we assume that the torque minimizing the Metabolic Cost is the optimal torque and propose a method for obtaining the torque.