• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.315-319
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• 2006

Support vector machines in biped humanoid robot are presented in this paper. The trajectory of the ZMP in biped walking robot poses an important criterion for the balance of the walking robots but complex dynamics involved make robot control difficult. We are establishing empirical relationships based on the dynamic stability of motion using SVMs. SVMs and kernel method have become very popular method for learning from examples. We applied SVM to model the practical humanoid robot. Three kinds of kernels are employed also and each result has been compared. As a result, SVM based on kernel method have been found to work well. Especially SVM with RBF kernel function provides the best results. The simulation results show that the generated ZMP from the SVM can be improve the stability of the biped walking robot and it can be effectively used to model and control practical biped walking robot.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2405-2407
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• 2003

This study deals with the gait optimization of via points on biped robot. ZMP(Zero Moment Point) is most important index in a biped robot's dynamic walking stability. To stable walking of a biped robot, legs's trajectory and a desired ZMP trajectory is required, balancing weight's movement is solved by FDM(Finite Difference Method). In this study, optimal index is defined to dynamically static walking of a biped robot, and optimization of via points is applied by GA(Genetic Algorithm).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.311-314
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• 1995

Biped locomotion can be simply modeled as a linear inverted pendulum mode. This model considers only the CG (center of gravity) of the entire system. But in real biped robot systems, the free-leg motion dynamics is not negligible. So if its dynamics is not considered in designing the reference CG motion, it is badly influence to the ZMP(zero moment point) position of the biped robot walking in the sagittal plane. Therefore, we modeled the biped locomotion similar to the linear inverted pendulum mode but considered the predetermined free-leg dynamics. To verify that the proposed biped locomotion is more stable than the linear inverted pendulum mode, we constructed a biped robot simulator and designed a serco controller to track both the reference motion of the free leg and the reference motion of CG of the biped robot using the computed torque control low. And through simulations, we verified that the proposed walking is better in stability than the one based on the linear inverted pendulum mode.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.344-351
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• 2014

In order to accomplish complex navigational commands, humanoid robot should be able to modify its walking period, step length and direction independently. In this paper, a novel walking pattern generation algorithm is proposed to satisfy these requirements. Modification of the walking pattern can be considered as a transition between two periodic walking patterns, which follows each navigational command. By assuming the robot as a linear inverted pendulum, the equations of motion between ZMP(Zero Moment Point) and CM(Center of Mass) state is easily derived and analyzed. After navigational command is translated into the desired CM state, corresponding CM motion is generated to achieve the desired state by using simple ZMP functions. Moreover, when the command is not feasible, feasible command is alternated by using binary search algorithm. Subsequently, corresponding CM motion is generated. The effectiveness of the proposed algorithm is verified by computer simulation.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.138-140
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• 2004

This paper mainly deals with the dynamic walking of a biped robot. At first, in order to walk in various environments, it is desirable to adapt to such ground conditions with a suitable foot motion, and maintain the stability of the robot by a smooth hip motion. A method to plan a walking pattern consisting of a foot trajectory and a hip trajectory is presented. The effectiveness of the proposed method is illustrated by simulation results. Secondly, the paper brings forward a balance control technique based on off-line walking pattern with real-time modification. At last, the concept of Zero Moment Point (ZMP) is used to evaluate dynamic stability.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1971-1972
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• 2006

본 논문에서는 휴머노이드 로봇의 예기치 않은 불규칙한 지면 환경 하에서 안정성을 확보하기위한 보행 전략을 제시한다. 휴머노이드 로봇의 안정성에 관한 지표로 널리 사용되는 ZMP(Zero Moment Point)나 COG(Center Of Gravity)를 이용한 방법은 많은 양의 연산을 필요로 하고, 주로 외부에서 가해지는 임의의 힘에 대처하는데 초점을 맞추고 있다. 휴머노이드 로봇의 불안정성을 유발하는 또 다른 주요한 원인으로 예기치 못한 지면 환경을 꼽을 수 있는데, 본 논문에서는 이러한 불규칙한 지형을 보행하는 휴머노이드 로봇의 실시간 안정성을 확보하는데 있어 ZMP나 COG가 아닌 지면으로부터의 반발력을 이용한 직관적인 알고리즘을 제시하며, 자체 개발된 휴머노이드 로봇 ISHURO II를 이용한 시뮬레이션으로 제시된 알고리즘을 검증한다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.162.2-162
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• 2001

This paper presents the stability analysis of a biped robot IWR-III. We use a foot-rotation indicator(FRI) concept to reveal the degree of stability. The foot rotation can be a barometer of postural instability, which should be carefully treated in implementing a dynamically stable walk and avoided altogether in performing a statically stable walk. The conventionally mentioned zero moment point(ZMP) criterion may not be sufficient to express the stability of a biped robot. ZMP equation needs an assumption that the supporting foot is fixed firmly to the ground during the walking. Therefore, applying the FRI concept is more desirable when a biped robot is falling down ...

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.890-897
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• 2002

This paper deals with the reduction of trajectory tracking error by changing the initial postures of a biped robot. Gait of a biped robot depends on the constraints of mechanical kinematics and the initial states including the posture. Also the dynamic walking stability in a biped robot system is analyzed by zero moment point(ZMP) among the stabilization indices. Path trajectory, in which knee joint is bent forward like human's cases, is applied to most cases considered with above conditions. A new initial posture, which is similar to bird's gait, is proposed to decrease trajectory tracking error and it is verified through real experimental results.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.197-202
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• 2006

We present the synergy effect of humanoid robot walking down on a slope and support vector machines in this paper. The biped robot architecture is highly suitable for the working in the human environment due to its advantages in obstacle avoidance and ability to be employed as human substitutes. But the complex dynamics in the robot and ground makes robot control difficult. The trajectory of the zero moment point (ZMP) in a biped walking robot is an important criterion used for the balance of the walking robots. The ZMP trajectory as dynamic stability of motion will be handled by support vector machines (SVM). Three kinds of kernels are also employed, and each result from these kernels is compared to one another.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.456-459
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• 2003

This paper deal with the biped walking stability by inverted pendulum type balancing joints. This model is hard to interpretation for the nonlinearity caused by upper direction movement then conventional model which have roll and prismatic joints. We can interpret this model by a linear approximation or interpolation method. This paper use a linear approximation method that can decide a movement of upper direction. Inverted pendulum type balancing joints have a advantage of less movement for keep stability and similar with human than conventional model and this model can be used for humanoid robot. We can see a stability of biped by ZMP(Zero Moment Point). Genetic algorithm is used for trajectory planning that is important for stable walking of biped.