On the planar stability of rigid-link binary walking robots

Robotica ◽  
2003 ◽  
Vol 21 (6) ◽  
pp. 667-675 ◽  
Author(s):  
Yu Zhou
Keyword(s):  
Simple Model ◽  
Walking Robots ◽  
Walking Robot ◽  
Research Results ◽  
Rigid Link ◽  
Straight Line ◽  
The Stability ◽  
State Nature

A binary walking robot moves as a result of bi-state actuator transitions. Because of the bi-state nature of binary joints, many research results about continuous walking robots cannot be applied to binary walking robots directly. In this paper, a new and simple model of rigid-link binary walking robot is proposed, around which related concepts are introduced, and formulas are derived. Based on this model, general characteristics and limitations of periodic gaits are discussed, and the stability qualities of several straight-line walking periodic gaits are studied in both pitch-greater-than-stroke and stroke-greater-than-pitch cases. Valuable results are obtained from the analysis, which should be followed in the design of rigid-link binary walking robots.

Dynamic Force-Position Control of the Walking Robots Motion on Slope

2012 ◽  
Vol 186 ◽  
pp. 98-104 ◽  
Author(s):  
Luige Vladareanu ◽  
Daniel Octavian Melinte
Keyword(s):  
Position Control ◽  
Dynamic Control ◽  
Open Architecture ◽  
Walking Robots ◽  
Robot Motion ◽  
Dynamic Force ◽  
Walking Robot ◽  
Kinematic Modeling ◽  
Dynamic Hybrid ◽  
The Stability

Abstract. The paper presents a strategy for the dynamic hybrid force-position control of the walking robot motion on slope using the ZMP method for dynamic control and a stable and robust method. Through dynamic and kinematic modeling of the walking robots motion an open architecture system was developed which contains five control interfaces. The stability problem of quadruped walking robots, through extendible segments which are designed to reduce the difficulty of walking on slope, and also by using them to avoid obstacles that may occur during a stepping cycle are presented. The results obtained have led to an improvement in the response time to disturbances, to tracking the motion trajectory with higher precision in conditions of high stability and to development of new technological capabilities, adapting the robot walking to movement over sloped terrain, with obstacles and bumps.

scholarly journals A comparative study of stability margins for walking machines

Robotica ◽  
2002 ◽  
Vol 20 (6) ◽  
pp. 595-606 ◽  
Author(s):  
Elena Garcia ◽  
Joaquin Estremera ◽  
Pablo Gonzalez de Santos
Keyword(s):  
Walking Robots ◽  
Stability Criteria ◽  
Walking Robot ◽  
Stability Margins ◽  
Walking Machines ◽  
Static And Dynamic Stability ◽  
Qualitative Classification ◽  
The Stability ◽  
Stability Measurements

Several static and dynamic stability criteria have been defined in the course of walking robot history. Nevertheless, different applications may require different stability criteria and, to the authors' best knowledge, there is no qualitative classification of such stability measurements. Using the wrong stability criterion to control a robot gait may prevent the task from succeeding. Furthermore, if the optimum criterion is found, the robot gait can also be optimized. In this paper, the stability criteria that have been applied to walking robots with at least four legs are examined in terms of their stability margins in different static and dynamic situations. As a result, a qualitative classification of stability criteria for walking machines is proposed so that the proper criterion can be chosen for every desired application.

Configuration and Motion Simulation of Multi-Legged Walking Robots with Hand-Food-Integrated Mechanism Arm

2010 ◽  
Vol 42 ◽  
pp. 54-58 ◽  
Author(s):  
Xin Jie Wang ◽  
Liang Wen Wang ◽  
Wei Gang Tang ◽  
Xiao Hui Zhang
Keyword(s):  
Three Dimensional ◽  
Characteristic Parameter ◽  
Walking Robots ◽  
Dynamic Parameters ◽  
Motion Simulation ◽  
Walking Robot ◽  
Straight Line ◽  
Solid Works

The paper introduces the configuration of a multi-legged walking robot with hand-food-integrated mechanism arm. In order to study the kinematics and the dynamics of the robot, three-dimensional entity model of the multi-legged walking robot is built up in solid-works based on inner relation of different simulation softwares. And then the model is leaded in ADAMS to simulate the dynamics and the kinematics of the robot. The paper describes the corresponding process. As an example, the robot ZQROT-1 walking along straight line is investigated. Dynamic parameters of the robot are obtained and analyzed by using ADAMS. The results can be used to optimize the robot structure and to determine its characteristic parameter. The methods and the thoughts of the paper can be referenced to solve similar problem in some aspects.

The Stability Control of Soft Soil Foundations of Urban Roads According to the Surface Subsidence Monitoring Data

2013 ◽  
Vol 859 ◽  
pp. 222-227
Author(s):  
Hong Jun Liu ◽  
Jin Hua Tan ◽  
Xue Wen Su ◽  
Hao Wu
Keyword(s):  
Soft Soil ◽  
Stability Control ◽  
Surface Subsidence ◽  
Monitoring Data ◽  
Research Results ◽  
The Road ◽  
Future Design ◽  
Left And Right ◽  
Soil Foundation ◽  
The Stability

Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.

Feasibility Study of Designing a Three Legged Walking Robot: Tribot

1991 ◽  
Author(s):  
Yueh-Jaw Lin ◽  
Aaron Tegland
Keyword(s):  
Feasibility Study ◽  
Legged Robots ◽  
Walking Robots ◽  
Design Parameters ◽  
Optimized Design ◽  
Motion Simulation ◽  
Walking Robot ◽  
Design Considerations ◽  
Simulation Based ◽  
Weight Distributions

Abstract In recent years, walking robot research has become an important robotic research topic because walking robots possess mobility, as oppose to stationary robots. However, current walking robot research has only concentrated on even numbered legged robots. Walking robots with odd numbered legs are still lack of attention. This paper presents the study on an odd numbered legged (three-legged) walking robot — Tribot. The feasibility of three-legged walking is first investigated using computer simulation based on a scaled down tribot model. The computer display of motion simulation shows that a walking robot with three legs is feasible with a periodic gait. During the course of the feasibility study, the general design of the three-legged robot is also analyzed for various weights, weight distributions, and link lengths. In addition, the optimized design parameters and limitations are found for certain knee arrangements. These design considerations and feasibility study using computer display can serve as a general guideline for designing odd numbered legged robots.

Predicting Force Redistributions on Walking Robots for Reliable Locomotion: Modeling and Experiments

1992 ◽  
Author(s):  
Peter V. Nagy ◽  
Subhas Desa ◽  
William L. Whittaker
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Walking Robots ◽  
Ground Contact ◽  
Walking Robot ◽  
Computationally Efficient ◽  
The Face ◽  
Modeling And Experiments ◽  
Stable Gait

Abstract A large number of walking robots walk with a statically-stable gait. A statically-stable walker has at least three feet that are in ground contact at any time. If there are more than three feet in ground contact, the normal (vertical) forces exerted by the ground on the feet of the walker are indeterminate, unless they are measured. Some walking robots may walk with more than three legs in ground contact in order to achieve greater stability. To ensure this stability it is desirable to predict how vertical forces passively redistribute underneath the feet during walker motions. Predictions of future foot forces can be used as a basis for accepting or rejecting any planned walker motion. Two methods — the least-squares method and the compliance method — for predicting this redistribution of forces in the face of static indeterminacy are presented in this work. Both methods are computationally efficient, and give reasonably accurate predictions, as verified by experiments on a walking robot.

scholarly journals Turning Gait Planning Method for Humanoid Robots

2018 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Tianqi Yang ◽  
Weimin Zhang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Libo Meng ◽  
...  
Keyword(s):  
Inverted Pendulum ◽  
Center Of Mass ◽  
Translational Motion ◽  
Humanoid Robots ◽  
Inverted Pendulum Model ◽  
Straight Line ◽  
Pendulum Model ◽  
The Stability ◽  
And Control ◽  
Present Simulation

The most important feature of this paper is to transform the complex motion of robot turning into a simple translational motion, thus simplifying the dynamic model. Compared with the method that generates a center of mass (COM) trajectory directly by the inverted pendulum model, this method is more precise. The non-inertial reference is introduced in the turning walk. This method can translate the turning walk into a straight-line walk when the inertial forces act on the robot. The dynamics of the robot model, called linear inverted pendulum (LIP), are changed and improved dynamics are derived to make them apply to the turning walk model. Then, we expend the new LIP model and control the zero moment point (ZMP) to guarantee the stability of the unstable parts of this model in order to generate a stable COM trajectory. We present simulation results for the improved LIP dynamics and verify the stability of the robot turning.

Walking Robot Leg Design Based on Translatory Straight-Line Generator

2020 ◽  
pp. 264-271
Author(s):  
Sayat Ibrayev ◽  
Nutpulla Jamalov ◽  
Amandyk Tuleshov ◽  
Assylbek Jomartov ◽  
Aidos Ibrayev ◽  
...  
Keyword(s):  
Walking Robot ◽  
Straight Line ◽  
Robot Leg ◽  
Leg Design

scholarly journals Hydraulic Tests and Interpretation of Test Data for Reno Mattresses in Open Channel Flow

2021 ◽  
Vol 930 (1) ◽  
pp. 012025
Author(s):  
P D Pietro ◽  
M Lelli ◽  
A Rahman ◽  
Serkandi
Keyword(s):  
Soil Erosion ◽  
Control Systems ◽  
Soil Layer ◽  
Erosion Control ◽  
Wire Mesh ◽  
Unit Weight ◽  
Research Results ◽  
Colorado State University ◽  
Soil Erosion Control ◽  
The Stability

Abstract The efficacy of erosion control systems depends on preventing soil loss underneath and maintaining its integrity under the effects of the water flow. The paper presents the research results at the Colorado State University on the performance of double twisted wire mesh products, known as Reno Mattresses, used as soil erosion control systems. Mattresses were subjected to various flow conditions on a 10 m long flume placed on a soil layer. The performance against erosion was evaluated by assessing the effect of the stone motion inside the mattress combined with the condition of incipient soil erosion underneath, in relationship to the mattress thickness, the filling stone properties, and under variable hydraulic flow regimes. At the same time, confirming the stability obtained using the conventional tractive force design approach, the research results allowed to introduce a new performance limit based on incipient soil erosion underneath the revetment. Based on the research results, the authors propose to express the shear resistance of mattresses used as soil erosion control systems as a function of the filling stones’ size, uniformity, unit weight, mattress thickness, and the presence of vertical strengthening elements.

scholarly journals Universal modesty in signal-burying games

2018 ◽  
Author(s):  
Tadeg Quillien
Keyword(s):  
Simple Model ◽  
Evolutionary Game ◽  
Costly Signaling ◽  
Positive Information ◽  
Probabilistic Information ◽  
Signaling Dynamics ◽  
The Stability ◽  
Positive Traits ◽  
Shed Light

Why would people hide positive information about themselves? Evolutionary game theorists have recently developed the signal-burying game as a simple model to shed light on this puzzle; they have shown that the game has an equilibrium where some agents are better off deliberately reducing the visibility of the signal by which they broadcast their positive traits. However, their explanation falls short of explaining all modesty norms, since this equilibrium also features individuals who openly brag. This leaves modesty norms that everyone adheres to in want of an explanation. Here we show that the signal-burying framework actually affords such an explanation: the game contains an equilibrium where all agents who send a signal voluntarily reduce its conspicuousness. Surprisingly, the stability of the two kinds of equilibria rely on very different principles. The equilibrium where some agents brag is stable because of costly signaling dynamics. By contrast, the universal modesty equilibrium exists because buried signals contain probabilistic information about a sender's type, and receivers make optimal use of this information. In the latter equilibrium, burying a signal can be understood as a handicap which makes the signal more honest, but honesty is not achieved through standard costly signaling dynamics.

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