Kinematic Performance Analysis for Hexapod Mobile Robot Using Parallel Mechanism

2014 ◽  
Author(s):  
Yang Pan ◽  
Feng Gao
Keyword(s):  
Performance Analysis ◽  
Parallel Mechanism ◽  
Kinematic Model ◽  
Walking Robots ◽  
Walking Robot ◽  
Complex Environments ◽  
Emergency Rescue ◽  
Nuclear Plants ◽  
Parallel Leg Mechanism ◽  
Kinematic Performance

Walking robots have been studied a lot over last several decades due to their good adaptability in different complex environments. The walking robot in this paper is designed for the research on emergency rescue missions in nuclear plants. Unlike other mobile robots, it apply parallel mechanism for its legs. This paper mainly focus on the kinematic performance of the parallel leg mechanism. Section 2 gives a brief introduction of our robot and the kinematic model. Then section 3 analyze the workspace of the leg tip. After that the payload and velocity capability are discussed respectively and it turns out that the mechanism has very good payload performance but the velocity is relatively low. Next the isotropic characteristic is studied in the whole workspace. Then the experiments indicate that the robot can successfully finish walking and manipulating tasks.

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.

Kinematic performance analysis of a parallel mechanism for loading test of hydraulic support

2022 ◽  
Vol 168 ◽  
pp. 104592
Author(s):  
Siyang Peng ◽  
Zhihong Cheng ◽  
Linxian Che ◽  
Yuwei Zheng ◽  
Shuang Cao
Keyword(s):  
Performance Analysis ◽  
Parallel Mechanism ◽  
Loading Test ◽  
Hydraulic Support ◽  
Kinematic Performance

scholarly journals Singularity analysis and dexterity performance on a novel parallel mechanism with kinematic redundancy

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141987264 ◽  
Author(s):  
Fuqun Zhao ◽  
Sheng Guo ◽  
Chengyu Zhang ◽  
Haibo Qu ◽  
Dian Li
Keyword(s):  
Parallel Mechanism ◽  
Large Range ◽  
Kinematic Model ◽  
Design Strategy ◽  
Singularity Analysis ◽  
Kinematic Redundancy ◽  
Spatial Parallel Mechanism ◽  
Virtual Plane ◽  
Kinematic Performance ◽  
Redundant Mechanism

This article presents a novel spatial parallel mechanism with kinematic redundancy. The design strategy and evolution of the proposed mechanism is introduced, and kinematic model of the mechanism is established. To simplify singularity analysis of this kind of mechanism, the virtual plane method which can separate the whole parallel mechanism into two parts is presented. The relative Jacobian matrices are established and illustrated with singularity configurations of three types. Kinematic performance is obtained to see redundancy effects on the mechanism. The orientational workspace is obtained by the regions of orientational angles with varied platform position. It shows the orientational workspace of the redundant mechanism is significantly larger. Evaluation of condition number demonstrates the proposed mechanism can clearly stay away from singularities with a large range of rotational angles. A trajectory example is conducted to further prove the proposed mechanism can produce a large range of rotational angles without meeting with singularities.

scholarly journals A New Metamorphic Parallel Leg Mechanism with Reconfigurable Moving Platform

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yong Xu ◽  
Zheng Liang ◽  
Jiali Liu
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Screw Theory ◽  
Degree Of Freedom ◽  
Walking Robots ◽  
Metamorphic Mechanism ◽  
Parallel Leg Mechanism ◽  
Moving Platform ◽  
Configuration Synthesis

This paper proposes the concept of full configuration state of metamorphic mechanism. Based on the concept, the configuration synthesis principle of metamorphic parallel mechanism is put forward. Firstly, a metamorphic parallel mechanism in full configuration state is synthesized, and then full configuration state evolves into a specific configuration state by increasing constraints or decreasing degrees of freedom. A reconfigurable moving platform based on the triple symmetric Bricard spatial closed-loop mechanism with a single degree of freedom is proposed. Based on this, a new method for switching motion configuration states of the metamorphic parallel mechanism is constructed. According to the configuration synthesis principle presented above, a novel metamorphic parallel mechanism that can switch between three- and four-degree-of-freedom is synthesized, and then the triple symmetric Bricard spatial closed-loop mechanism is used as the reconfigurable moving platform (that is, the reconfigurable foot of a walking robot) of the metamorphic mechanism, and thus, a novel metamorphic parallel leg mechanism is created. The screw theory is used to verify the degrees of freedom of the new type of metamorphic parallel leg. The proposed metamorphic parallel leg mechanism is expected to improve flexibility and adaptability of walking robots in unstructured environment.

Complexity Criteria for the Preliminary Design Stage of Walking Robots

2017 ◽  
Author(s):  
Da Xi ◽  
Feng Gao
Keyword(s):  
Walking Robots ◽  
Design Stage ◽  
Structure Parameters ◽  
Preliminary Design ◽  
Walking Robot ◽  
Type Synthesis ◽  
End Effector ◽  
Iterative Design ◽  
Preliminary Design Stage ◽  
Kinematic Performance

This paper introduces several complexity-based criteria for walking robots at the preliminary design stage. The motivation lies in filtering optimal leg types or body layouts to reduce cost at later iterative-design stage. Several qualitative or semi-quantitative criteria are proposed for walking robot designers. For different type-synthesis results of robot legs, three criteria are proposed named the uncertainty of the end-effector, the complexity of control and the complexity of movement. For different layouts of robot bodies, two kinematic criteria are proposed named the complexity of translation and the complexity of rotation. These criteria could together judge the kinematic performance or potential for a walking robot with the least structure parameters at the conceptual-design stage. Several prototypes in the researchers’ lab are evaluated with the criteria, and the results are compared with the experimental data to proof the validity.

Design and Analysis of the Quadruped Walking Robot Based on 3-RPS Parallel Mechanism

2013 ◽  
Vol 373-375 ◽  
pp. 201-205
Author(s):  
Hong Bo Wang ◽  
Yun Wang ◽  
Ling Feng Sang ◽  
Qi Fang Gu ◽  
Yong Fei Feng
Keyword(s):  
Parallel Mechanism ◽  
Theoretical Foundation ◽  
Virtual Organization ◽  
The Elderly ◽  
Search Method ◽  
Optimum Size ◽  
Walking Robot ◽  
Quadruped Walking Robot ◽  
The Disabled ◽  
Parallel Leg Mechanism

Based on the importance of the robot for the elderly and the disabled, a quadruped walking robot using 3-RPS parallel mechanism as the basic leg mechanism is proposed. The structure of the basic leg is described, and the whole structure of the quadruped walking robot is formed. Then taking the workspace of the basic leg as the standard, the optimum size parameters of the upper platform and the lower platform of the based leg are achieved. Meanwhile the workspace of the basic leg is obtained by the anti-solution search method. Taking the basic leg as analysis object and applying the virtual organization method, the kinematic expression is got. All of these analyses lay a theoretical foundation for the further study on the quadruped walking robot with parallel leg mechanism.

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