Quadruped Robot Omni-Directional Walking on a Slope Based on Static Balance

2012 ◽  
Vol 591-593 ◽  
pp. 1436-1440
Author(s):  
Wen Yu Zhang ◽  
Lei Zhang
Keyword(s):  
Computer Simulation ◽  
Structural Stability ◽  
Stability Criterion ◽  
Quadruped Robot ◽  
Static Balance ◽  
Gait Transition ◽  
Uneven Terrain ◽  
Transition Problem ◽  
Walking Environment ◽  
The Stability

Quadruped robot is widely developed on the basis of bionic technology and has good structural stability and flexibility in uneven terrain. It is required of the quadruped robot to keep static balance while transportation task is executed. In this paper, first, the unstable problems during static walking on a slope have been analyzed in detail, and the stability criterion which considering affections of slope walking environment has been proposed. Based on static balance, the falling over problem and tumbling around the line connecting two support feet during gait transition problem have been solved. The gaits are planned to ensure omni-directional stable walking on a slope. Through walking experiments by computer simulation, the validity of the proposed method has been verified.

Gait Planning of Quadruped Robot Walking on a Slope Based on Static Balance

2013 ◽  
Vol 373-375 ◽  
pp. 282-286 ◽  
Author(s):  
Wen Yu Zhang ◽  
Lei Zhang
Keyword(s):  
Center Of Pressure ◽  
Quadruped Robot ◽  
Joint Torque ◽  
Static Balance ◽  
Gait Transition ◽  
Gait Planning ◽  
Motion Speed ◽  
Walking Environment ◽  
Movement Parameters ◽  
The Stability

Gait planning affects stability, motion speed, and joint torque of quadruped robot etc. Also, it is necessary to consider movement parameters of slope walking environment such as the inclination angle, the movement area of feet and so on. The stability criterion on the basis of center of pressure is chosen to analyze the stability during the movement. Based on static balance, the omni-directional walking of quadruped robot on a slope is planned. CFP is set in order to reduce the transition steps. Then the start and end positions of swinging leg and supporting leg is calculated. The process of gait transition is planned to make sure stable and continuous movement. The experiment verifies the validity of the proposed method.

Normalized Energy Stability Margin Based Analysis of Omni-Directional Static Walking of a Quadruped Robot on Rough Terrain

2011 ◽  
Vol 383-390 ◽  
pp. 7401-7405
Author(s):  
Lei Zhang ◽  
Shan Gao
Keyword(s):  
Stability Criterion ◽  
Simulation Experiment ◽  
Stability Margin ◽  
Quadruped Robot ◽  
Center Of Gravity ◽  
Energy Stability ◽  
Rough Terrain ◽  
The Stability

With Normalized Energy Stability Margin(Sne ) as stability criterion, this paper studies the tumbles of omni-directional static walking of a quadruped robot around the line connecting two adjacent supporting legs on rough terrain, proposes the method to improve the stability of quadruped robot by increasing the (Sne ) value, which is realized by lowering the height of center of gravity(COG), and finally substantiates the feasibility of the method through a simulation experiment.

scholarly journals Dynamic Imbalance Analysis and Stability Control of Galloping Gait for a Passive Quadruped Robot

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Chunlei Wang ◽  
Ting Zhang ◽  
Xiaohui Wei ◽  
Yongjun Long ◽  
Shigang Wang
Keyword(s):  
Stability Criterion ◽  
Center Of Mass ◽  
Zero Point ◽  
Stability Control ◽  
Quadruped Robot ◽  
Peak Time ◽  
Flight Phase ◽  
Trunk Posture ◽  
The Stability ◽  
Necessary And Sufficient

Some imbalance and balance postures of a passive quadruped robot with a simplified mathematical model are studied. Through analyzing the influence of the touchdown angle of the rear leg on the posture of the trunk during the flight phase, the stability criterion is concluded: the closer are the two moments which are the zero time of the pitching angle and the peak time of the center of mass, the better is the stability of the trunk posture during the flight phase. Additionally, the validity of the stability criterion is verified for the cat, greyhound, lion, racehorse, basset hound, and giraffe. Furthermore, the stability criterion is also applicable when the center of the mass of body is shifted. Based on the stability criterion, the necessary and sufficient condition of the galloping stability for the quadruped robot is proposed to attain a controlled thrust. The control strategy is designed by an optimization dichotomy algorithm for seeking the zero point of the balance condition. Through the control results, it is demonstrated that the imbalance posture of the trunk could be stabilized by adjusting the stiffness of four legs.

scholarly journals Stability Criterion for Dynamic Gaits of Quadruped Robot

2018 ◽  
Vol 8 (12) ◽  
pp. 2381 ◽  
Author(s):  
Yan Jia ◽  
Xiao Luo ◽  
Baoling Han ◽  
Guanhao Liang ◽  
Jiaheng Zhao ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Stability Criterion ◽  
Quadruped Robot ◽  
Stability Criteria ◽  
Irregular Terrain ◽  
Quadruped Robots ◽  
Simulation Results ◽  
Zero Moment ◽  
The Stability ◽  
Dynamic Gait

Dynamic-stability criteria are crucial for robot’s motion planning and balance recovery. Nevertheless, few studies focus on the motion stability of quadruped robots with dynamic gait, none of which have accurately evaluated the robots’ stability. To fill the gaps in this field, this paper presents a new stability criterion for the motion of quadruped robots with dynamic gaits running over irregular terrain. The traditional zero-moment point (ZMP) is improved to analyze the motion on irregular terrain precisely for dynamic gaits. A dynamic-stability criterion and measurement are proposed to determine the stability state of the robot and to evaluate its stability. The simulation results show the limitations of the existing stability criteria for dynamic gaits and indicate that the criterion proposed in this paper can accurately and efficiently evaluate the stability of a quadruped robot using such gaits.

Straight Walking and Stair Climbing Gait of Quadruped Robot Based on Static Balance

ROBOT ◽  
2010 ◽  
Vol 32 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Bo HUANG ◽  
Jianwen ZHAO ◽  
Lining SUN
Keyword(s):  
Quadruped Robot ◽  
Stair Climbing ◽  
Static Balance

Intrinsic Thermal Stability of Anisotropic Thin-Film Superconductors

1990 ◽  
Vol 112 (1) ◽  
pp. 10-15 ◽  
Author(s):  
M. I. Flik ◽  
C. L. Tien
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Stability Criterion ◽  
High Temperature Superconductors ◽  
Stability Criteria ◽  
Anisotropic Thermal Conductivity ◽  
Operating Current ◽  
Released Energy ◽  
The Stability ◽  
Thermal Stability Of

Intrinsic thermal stability denotes a situation where a superconductor can carry the operating current without resistance at all times after the occurrence of a localized release of thermal energy. This novel stability criterion is different from the cryogenic stability criteria for magnets and has particular relevance to thin-film superconductors. Crystals of ceramic high-temperature superconductors are likely to exhibit anisotropic thermal conductivity. The resultant anisotropy of highly oriented films of superconductors greatly influences their thermal stability. This work presents an analysis for the maximum operating current density that ensures intrinsic stability. The stability criterion depends on the amount of released energy, the Biot number, the aspect ratio, and the ratio of the thermal conductivities in the plane of the film and normal to it.

The flow of a micropolar liquid layer down an inclined plane

1968 ◽  
Vol 64 (2) ◽  
pp. 513-526 ◽  
Author(s):  
A. J. Willson
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Liquid Layer ◽  
Stability Criterion ◽  
Long Waves ◽  
Inclined Plane ◽  
The Stability ◽  
Micropolar Liquid

AbstractConsideration is given to the flow of a micropolar liquid down an inclined plane. The steady state is analysed and Yih's technique is employed in an investigation of the stability of this flow with respect to long waves. Detailed calculations are given for thin films and it is shown that the micropolar properties of the liquid play an important role in the stability criterion.

Efficient Dynamic Computer Simulation of Simple-Closed Spatial Linkages

1990 ◽  
Author(s):  
L. T. Wang
Keyword(s):  
Computer Simulation ◽  
Computational Algorithm ◽  
Equations Of Motion ◽  
Joint Space ◽  
Kinematic Chains ◽  
Spatial Linkages ◽  
Dynamic Computer Simulation ◽  
The Stability ◽  
Coordinate Partitioning ◽  
Generalized Coordinate

Abstract A new method of formulating the generalized equations of motion for simple-closed (single loop) spatial linkages is presented in this paper. This method is based on the generalized principle of D’Alembert and the use of the transformation Jacobian matrices. The number of the differential equations of motion is minimized by performing the method of generalized coordinate partitioning in the joint space. Based on this formulation, a computational algorithm for computer simulation the dynamic motions of the linkage is developed, this algorithm is not only numerically stable but also fully exploits the efficient recursive computational schemes developed earlier for open kinematic chains. Two numerical examples are presented to demonstrate the stability and efficiency of the algorithm.

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