Research on Configuration-Complete Dynamic Modeling of Metamorphic Mechanism Based on Screw Theory

2013 ◽  
Vol 655-657 ◽  
pp. 531-536 ◽  
Author(s):  
Sheng Hai Hu ◽  
Hong Guang Wang ◽  
Xiu Lian Liu ◽  
Xiao Dong Zhang
Keyword(s):  
Dynamic Modeling ◽  
Screw Theory ◽  
Constraint Equation ◽  
Complex Surface ◽  
Cutting Machine ◽  
Metamorphic Mechanism

Kane dynamics equations of metamorphic mechanism based on screw theory is built, and the constraint equation with cut-off joint is completed by introducing exponentials formula. The configuration-complete dynamics equations of metamorphic mechanism is established with this two equations combined. The configuration-complete dynamics equations of the metamorphic mechanism in cutting machine for complex-surface is built using this method.

Research on Configuration Transformation of Cutting Machine for Complex-Surface for Metamorphic Mechanism

2013 ◽  
Vol 655-657 ◽  
pp. 1286-1290
Author(s):  
Sheng Hai Hu ◽  
Xiu Lian Liu ◽  
Hong Guang Wang ◽  
Xiao Dong Zhang
Keyword(s):  
Graph Theory ◽  
Complex Surface ◽  
Genetic Evolution ◽  
Cutting Mechanism ◽  
Cutting Machine ◽  
Metamorphic Mechanism ◽  
Cutting Equipment

Through the research and analysis on the metamorphic cutting mechanism of cutting equipment for complex-surface, the configuration transformation of metamorphic cutting mechanism based on genetic evolution principles is analyzed, and the solution of the first structure is completed. the structures and configuration transformation of the metamorphic cutting mechanism is researched based on graph theory and adjacent matrix.

An efficient method for the dynamic modeling and analysis of Stewart parallel manipulator based on the screw theory

2019 ◽  
Vol 234 (3) ◽  
pp. 808-821
Author(s):  
Yulei Hou ◽  
Guoxing Zhang ◽  
Daxing Zeng
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Parallel Manipulator ◽  
Inverse Dynamics ◽  
Screw Theory ◽  
Parallel Manipulators ◽  
Force Balance ◽  
Constraint Matrix ◽  
Scheme Design ◽  
Control Scheme

Dynamic modeling serves as the fundamental basis for dynamic performance analysis and is an essential aspect of the control scheme design of parallel manipulators. This report presents a concise and efficient solution to the dynamics of Stewart parallel manipulators based on the screw theory. The initial pose of these manipulators is described. Then the pose matrix of each link of the Stewart parallel mechanism is obtained using an inverse kinematics solution and an exponential product formula. Considering the constraint relationship between joints, the constraint matrix of the Stewart parallel manipulator is deduced. In addition, the Jacobian matrix and the twist of each link are obtained. Moreover, by deriving the differential form of the constraint matrix, the spatial acceleration of each link is obtained. Based on the force balance relationship of each link, the inverse dynamics and the general form of the dynamic model of the Stewart parallel manipulator is established and the process of inverse dynamics is summarized. The dynamic model is then verified via dynamic simulation using the ADAMS software. A numerical example is considered to demonstrate the feasibility and effectiveness of this model. The proposed dynamic modeling approach serves as a fundamental basis for structural optimization and control scheme design of the Stewart parallel manipulators.

Topology and Constraint Analysis of Phase Change in the Metamorphic Chain and Its Evolved Mechanism

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Ketao Zhang ◽  
Jian S. Dai ◽  
Yuefa Fang
Keyword(s):  
Phase Change ◽  
Parallel Mechanism ◽  
Screw Theory ◽  
Evolutionary Process ◽  
Geometric Constraints ◽  
Structure Evolution ◽  
Kinematic Pair ◽  
Motion Patterns ◽  
Metamorphic Mechanism ◽  
Topological State

This paper presents a metamorphic kinematic pair extracted from origami folds in the context of mechanisms, its evolved metamorphic chain, and the novel metamorphic parallel mechanism. This paper starts from the generic issues of topological representation for metamorphic mechanism, leading to unified elementary matrix operation for presentation of topological variation. Phase matrix and augmented adjacency matrix are developed to present the topological state and geometry of metamorphic mechanism in an evolutionary process. The metamorphic kinematic pair has the ability of changing mobility to generate different motion patterns based on mobility change correlated with the link annex induced topological phase change. This paper then investigates topological variation of the metamorphic chain and the topological subphases are enumerated in accordance with structure evolution. Using the metamorphic chain as chain-legs, a multiloop metamorphic mechanism with ability of performing phase change and orientation switch is constructed. The disposition of constraints and geometric constraints induced bifurcated motion are analyzed based on screw theory. The topological variation of the metamorphic parallel mechanism is addressed and the foldability is verified by physical device.

scholarly journals Whole-body kinematic and dynamic modeling for quadruped robot under different gaits and mechanism topologies

2021 ◽  
Vol 7 ◽  
pp. e821
Author(s):  
Wei Yan ◽  
Yang Pan ◽  
Junjie Che ◽  
Jiexian Yu ◽  
Zhuchen Han
Keyword(s):  
Dynamic Modeling ◽  
Screw Theory ◽  
Control Strategies ◽  
Quadruped Robot ◽  
The Body ◽  
Joint Torque ◽  
Sensor Data ◽  
Whole Body ◽  
Measurement Unit ◽  
Body Kinematic

Dynamic locomotion plays a crucial role for legged robots to fulfill tasks in unstructured environments. This paper proposes whole-body kinematic and dynamic modeling method s based on screw theory for a quadruped robot using different gaits and mechanism topologies. Unlike simplified models such as centroid or inverse pendulum models, the methods proposed here can handle 10-dimensional mass and inertia for each part. The only simplification is that foot contact models are treated as spherical joints. Models of three different mechanism topologies are formulated: (1) Standing phase: a system consisting of one end-effector, the body, and four limbs, the legs; (2) Walking phase: a system consisting of one or two lifting legs (depending on the chosen gait), two or three supporting legs; (3) Floating phase: a system in which all legs detach from the ground. Control strategies based on our models are also introduced, which includes walk and trot gait plans. In our control system, two additional types of information are provided: (1) contacting forces are given by force sensors installed under feet; (2) body poses are determined by an inertial measurement unit (IMU). Combined with the sensor data and calibrated mass, inertia, and friction, the joint torque can be estimated accurately in simulation and experiment. Our prototype, the “XiLing” robot, is built to verify the methods proposed in this paper, and the results show that the models can be solved quickly and leads to steady locomotions.

scholarly journals Dynamic Modeling of the Feed Drive System of a CNC Metal Cutting Machine

2021 ◽  
Vol 55 (4) ◽  
pp. 19-30
Author(s):  
H. Heydarnia ◽  
I. A. Kiselev ◽  
M. M. Ermolaev ◽  
S. Nikolaev
Keyword(s):  
Dynamic Modeling ◽  
Metal Cutting ◽  
Drive System ◽  
Metal Cutting Machine ◽  
Feed Drive ◽  
Cutting Machine ◽  
Feed Drive System

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.

Stability Research on Configuration Transformation of the Complex-Surface Cutting Metamorphic Mechanism

2013 ◽  
Vol 655-657 ◽  
pp. 421-424
Author(s):  
Sheng Hai Hu ◽  
Xiu Lian Liu ◽  
Hong Guang Wang ◽  
Xiao Dong Zhang
Keyword(s):  
Complex Surface ◽  
Metamorphic Mechanism ◽  
The Stability ◽  
The Impact ◽  
Impact Problem

The impact problem is analyzed when the complex-surface cutting metamorphic mechanism changes the configuration through ADAMS, assuring that the impact is decreased to minimum by changing the motion law of driving joint. The effectiveness of this method is verified through simulation, ensuring the stability of metamorphic mechanism in configuration transformation.

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