ZMP Based Motion Stability Analysis of a Wheeled Humanoid Robot with Bending Torso

2016 ◽  
Vol 851 ◽  
pp. 497-502
Author(s):  
Si Yu Xia ◽  
Qiang Zhan ◽  
Ahmed Rahmani
Keyword(s):  
Stability Analysis ◽  
Humanoid Robot ◽  
Center Of Gravity ◽  
Chain Rule ◽  
Point Method ◽  
Zero Moment Point ◽  
Motion Stability ◽  
Simulation Results ◽  
Zero Moment ◽  
High Center

Motion stability is the most important issue to be considered when designing a wheeled humanoid robot with bending torso, as it’s easy to capsize because of its high center of gravity. With ZMP (Zero Moment Point) method the motion stability of a wheeled humanoid robot with bending torso was analyzed. At first, the chain rule was used to model the kinematics of the wheeled humanoid robot, and then the process of calculating the ZMP of the robot was presented. With MATLAB the motion stability of the humanoid robot in three typical conditions is simulated and analyzed, and the simulation results were used to optimize some parameters of a wheeled humanoid robot we are designing.

Dynamical Model of Walking Transition Considering Nonlinear Friction with Floor

2016 ◽  
Vol 20 (6) ◽  
pp. 974-982 ◽  
Author(s):  
Xiang Li ◽  
◽  
Hiroki Imanishi ◽  
Mamoru Minami ◽  
Takayuki Matsuno ◽  
...  
Keyword(s):  
Humanoid Robot ◽  
Dynamical Equation ◽  
Control Method ◽  
Dynamical Model ◽  
Reliable Control ◽  
Biped Locomotion ◽  
Nonlinear Friction ◽  
View Point ◽  
Zero Moment Point ◽  
Zero Moment

Biped locomotion created by a controller based on Zero-Moment Point (ZMP) known as reliable control method looks different from human’s walking on the view point that ZMP-based walking does not include falling state, and it’s like monkey walking because of knee-bended walking profiles. However, the walking control that does not depend on ZMP is vulnerable to turnover. Therefore, keeping the event-driven walking of dynamical motion stable is important issue for realization of human-like natural walking. In this research, a walking model of humanoid robot including slipping, bumping, surface-contacting and line-contacting of foot is discussed, and its dynamical equation is derived by the Extended NE method. In this paper we introduce the humanoid model which including the slipping foot and verify the model.

scholarly journals CYCLOIDAL GAIT WITH DOUBLE SUPPORT PHASE FOR THE NAO HUMANOID ROBOT

2019 ◽  
Vol 6 ◽  
pp. 83-94
Author(s):  
Jesus E. Fierro P. ◽  
J. Alfonso Pamanes G. ◽  
Victor De-Leon-Gomez
Keyword(s):  
Humanoid Robot ◽  
Experimental Tests ◽  
Zero Moment Point ◽  
Double Support ◽  
Revolute Joints ◽  
Zero Moment ◽  
The Stability ◽  
Reduced Mobility ◽  
Support Phase ◽  
Double Support Phase

The commercial Nao humanoid robot has 11 DOF in legs. Even if these legs include 12 revolute joints, only 11 actuators are employed to control the walking of the robot. Under such conditions, the mobility of the pelvis and that of the oscillating foot are mutually constrained at each step. Besides, the original gait provided by the manufacturer company of the Nao employs only single support phases during the walking. Because of both issues, the reduced mobility in legs and the use of only single support phases, the stability of the walking is affected. To contribute to improving such stability, in this paper an approach is proposed that incorporates a double support phase and a gait based on cycloidal time functions for motions of the pelvis and those of the oscillating foot. To assess the stability of the walking an index is applied, which is based on the notion of zero-moment point (ZMP) of the static foot at each step. Results of experimental tests show that the proposed gait enhances the stability of the robot during the walking.

Design of a Biped Toy Robot with an Automatic Center of Gravity Shifting Mechanism

2010 ◽  
Vol 118-120 ◽  
pp. 670-674
Author(s):  
Pai Shan Pa ◽  
Jinn Bao Jou
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
Center Of Gravity ◽  
Biped Robots ◽  
Zero Moment Point ◽  
Single Motor ◽  
Mechanical Products ◽  
Zero Moment ◽  
Crank Mechanism

The design of the biped toy robot in this study, presents a brand new concept compared to that of the conventional mechanical biped robots on the market. These conventional mechanical products rely mainly on a large sole area to stabilize the wobbling movement during walking. In this design walking stability is not achieved by large sole areas, but by having more degrees of freedom and automatically shifting the center of gravity as the robot walks. A single motor is used to drive the biped toy robot trunk so that the center of gravity is automatically shifted to achieve walking stability. The two feet are driven by four connecting rods for striding and leg-lifting action. More particularly, an equal parallel crank mechanism is provided that uses a single motor to drive the connecting rods, thereby swinging the center of gravity of the toy robot in time with striding frequency. In addition, the concept of the zero moment point is utilized in the shifting of the center of gravity allowing the biped robot to lift its legs, change step, and move forward in balance. This study also discusses the use of the four connecting rods, and the shifting of the center of gravity of the robot, as an alternative to the servomotors commonly used in conventional robots which are bulky, expensive and hard to control.

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