scholarly journals Foot trajectory analysis of a robotic leg

2021 ◽  
Vol 2070 (1) ◽  
pp. 012172
Author(s):  
M J Koushik ◽  
M S Aravind Krishna ◽  
R Rahul ◽  
Pramod Sreedharan
Keyword(s):  
Dynamic Analysis ◽  
Mathematical Analysis ◽  
Degrees Of Freedom ◽  
Trajectory Analysis ◽  
Step Length ◽  
Walking Robots ◽  
Walking Robot ◽  
Theoretical Approaches ◽  
Robotic Leg ◽  
Foot Trajectory

Abstract When it comes to walking robots, foot trajectory is a crucial element that can significantly influence the efficiency of the walking robot. This paper analyses the various foot return trajectories, which can provide higher step length while consuming less power. It is done through mathematical analysis and verified using simulations in software such as MSC Adams and Solidworks. This paper also discusses the kinematic and dynamic analysis of the two degrees of freedom leg using theoretical approaches in MATLAB and verifies the results using the simulation in MSC Adams.

Design of a Four Legged Parallel Mechanism to Improve the Dexterity of Walking Robot

2009 ◽  
Author(s):  
ChiHyo Kim ◽  
KunWoo Park ◽  
TaeSung Kim ◽  
MinKi Lee
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Topology Design ◽  
Condition Numbers ◽  
Walking Robots ◽  
Rough Terrain ◽  
Parallel Mechanisms ◽  
Walking Robot ◽  
Intermediate Mechanism

This paper designs a four legged parallel mechanism to improve the dexterity of three layered parallel walking robot. Topology design is conducted for a leg mechanism composed of four legs, base and ground, which constitute a redundant parallel mechanism. This mechanism is subdivided into four sub-mechanism composed of three legs. A motor vector is adopted to determine the 6×8 Jacobian of the redundant parallel mechanism and the 6×6 Jacobian of the sub-mechanisms, respectively. The condition number of the Jacobian matrix is used as an index to measure a dexterity. We analyze the condition numbers of the Jacobian over the positional and orientational walking space. The analytical results show that a sub-mechanism has lots of singularities within workspace but they are removed by a redundant parallel mechanism improving the dexterity. This paper presents a parallel typed walking robot to enlarge walking space and stability region. Seven types of three layered walking robots are designed by inserting an intermediate mechanism between the upper and the lower legged parallel mechanisms. They provide various types of gaits to walk rough terrain and climb over a wall with small degrees of freedom.

Biped Walking Robot Gait Planning Research

2013 ◽  
Vol 706-708 ◽  
pp. 674-677
Author(s):  
Hai Long Chen ◽  
Xiao Wu ◽  
Jun Du ◽  
Jin Ping Tang
Keyword(s):  
Degrees Of Freedom ◽  
Original System ◽  
System Model ◽  
Walking Robots ◽  
Walking Robot ◽  
Transformation Theory ◽  
Biped Walking ◽  
Gait Planning ◽  
Biped Walking Robot ◽  
Build System

This paper uses biped walking robot as the research object, and designs robots original system, based on the requirements of Biped Walking Robot Competition of China. According to the biped walking robots characteristics of multi-joints, many degrees of freedom, multivariable, strong coupling and nonlinearity [, we can build system model using the Denavi - Hartenberg coordinate, describe the system model by the homogeneous coordinate transformation theory, and then plan on system gait based on ZMP stability . Finally, we can solve for the joint trajectory of the system by using computer-aided software.

Bibot-U6: A Novel 6-DoF Biped Active Walking Robot - Modeling, Planning and Control

2014 ◽  
Vol 11 (02) ◽  
pp. 1450014 ◽  
Author(s):  
Xuefeng Zhou ◽  
Yisheng Guan ◽  
Haifei Zhu ◽  
Wenqiang Wu ◽  
Xin Chen ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
High Energy ◽  
Walking Robots ◽  
Walking Robot ◽  
Biped Robots ◽  
Planning And Control ◽  
Biped Walking Robot ◽  
And Control ◽  
High Energy Consumption

Most of current biped robots are active walking platforms. Though they have strong locomotion ability and good adaptability to environments, they have a lot of degrees of freedom (DoFs) and hence result in complex control and high energy consumption. On the other hand, passive or semi-passive walking robots require less DoFs and energy, but their walking capability and robustness are poor. To overcome these shortcomings, we have developed a novel active biped walking robot with only six DoFs. The robot is built with six 1-DoF joint modules and two wheels as the feet. It achieves locomotion in special gaits different from those of traditional biped robots. In this paper, this novel biped robot is introduced, four walking gaits are proposed, the criterion of stable walking is addressed and analyzed, and walking patterns and motion planning are presented. Experiments are carried out to verify the locomotion function, the effectiveness of the presented gaits and to illustrate the features of this novel biped robot. It has been shown that biped active walking may be achieved with only a few DoFs and simple kinematic configuration.

Quadruped Walking Robot with Reduced Degrees of Freedom

2001 ◽  
Vol 13 (2) ◽  
pp. 190-197 ◽  
Author(s):  
Kan Yoneda ◽  
◽  
Yusuke Ota ◽  
Fumitoshi Ito ◽  
Shigeo Hirose
Keyword(s):  
Experimental Model ◽  
Mechanical Model ◽  
Degrees Of Freedom ◽  
Walking Robots ◽  
Walking Robot ◽  
Arbitrary Angle ◽  
Uneven Terrain ◽  
Quadruped Walking Robot ◽  
Arbitrary Position

We advocate the effectiveness of a walking robot to have a structure with a reduced DOF, not based on a model of real animals, to make the robot lightweight and practical, and discuss a technique for reducing the active degrees of freedom (DOF) of a quadruped walking robot as an example for realizing such objectives. If functions required of a quadruped walking robot are properly organized and the required active DOF is examined, 4 active DOF make it possible to select an arbitrary position on uneven terrain and to move in all directions. We describe a mechanism with 4 active DOF and 2 passive DOF as an example of concrete configurations for quadruped walking robots with 4 active DOF. A robot with a reduced active DOF, namely with 3 active DOF and 2 passive DOF, has a capability to reach an arbitrary position at an arbitrary angle on uneven terrain. An actual mechanical model was manufactured as an experimental model, and a walking experiment was conducted. The mechanical model turned out to be about one-4th in weight compared to a conventional biomimetic model of the same size. Based on the walking experiment, it was confirmed that this mechanical model can carry a load up to 4 times its own weight.

Selection of Degrees of Freedom for Dynamic Analysis

1987 ◽  
Vol 109 (1) ◽  
pp. 65-69 ◽  
Author(s):  
K. W. Matta
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
General Purpose ◽  
Component Mode Synthesis ◽  
Complex Structures ◽  
Large Complex ◽  
Static Condensation ◽  
Basis Vectors ◽  
Selection Of

A technique for the selection of dynamic degrees of freedom (DDOF) of large, complex structures for dynamic analysis is described and the formulation of Ritz basis vectors for static condensation and component mode synthesis is presented. Generally, the selection of DDOF is left to the judgment of engineers. For large, complex structures, however, a danger of poor or improper selection of DDOF exists. An improper selection may result in singularity of the eigenvalue problem, or in missing some of the lower frequencies. This technique can be used to select the DDOF to reduce the size of large eigenproblems and to select the DDOF to eliminate the singularities of the assembled eigenproblem of component mode synthesis. The execution of this technique is discussed in this paper. Examples are given for using this technique in conjunction with a general purpose finite element computer program GENSAM[1].

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.

Accelerometer correction for the dynamic analysis of damped multi-degree of freedom systems

1969 ◽  
Vol 59 (4) ◽  
pp. 1591-1598
Author(s):  
G. A. McLennan
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Exact Method ◽  
Three Degrees Of Freedom

Abstract An exact method is developed to eliminate the accelerometer error in dynamic response calculations for damped multi-degree of freedom systems. It is shown that the exact responses of a system can be obtained from the approximate responses which are conventionally calculated from an accelerogram. Response calculations were performed for two typical systems with three degrees of freedom for an assumed pseudo-earthquake. The results showed that the approximate responses may contain large errors, and that the correction developed effectively eliminates these errors.

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