Pre-Bending Motion Strategy Analysis of a 3-DOF UACT Robotic Finger

2021 ◽  
Author(s):  
Shangling Qiao ◽  
Yichen Wang ◽  
Hongwei Guo ◽  
Hong Xiao ◽  
Zongquan Deng
Keyword(s):  
Driving Force ◽  
Driving Forces ◽  
Virtual Work ◽  
Linkage Mechanism ◽  
Strategy Analysis ◽  
Single Motor ◽  
Motion Models ◽  
And Control ◽  
Underactuated Finger ◽  
Motion Strategy

Abstract Motion strategy analysis at the pre-bending stage is a fundamental component of underactuated finger grasp research. This study presents the pre-bending motion strategy and corresponding analysis of cable driving forces a 3-DOF underactuated finger comprising cable truss units. This robotic finger uses a tendon-pulley transmission and parallel four-linkage mechanism to realize the grasp capability. The structure and four motion strategies at the pre-bending stage are illustrated. The equivalent joint-driven and quasi-static motion models are established in the case where one or two cable driving forces drive the finger. In accordance with the virtual work principle, the tendon-pulley transmission is transformed into an equivalent joint-driven system. On the basis of the constraints of maximum motion space of the finger, the joint spring stiffness distributions are discussed and the finger quasi-static motion space is analyzed under the condition of single motor driving force. The unique coupled motion process and corresponding cable driving force of the finger driven by a single motor are assessed. Furthermore, three other typical quasi-static motion strategies and their corresponding cable driving forces are discussed. Valid simulation experiments are conducted to verify the accuracy of the quasi-static motion strategy. The analysis of this study can provide guidance and a theoretical reference for the design of cable-driven underactuated hands and control of the couple-driven underactuated mechanism.

scholarly journals Natural driving force

2020 ◽  
Author(s):  
ruiyu zhu
Keyword(s):  
Human Body ◽  
Driving Force ◽  
Driving Forces ◽  
Natural Evolution ◽  
Objective World ◽  
And Control ◽  
Inside Out

We seem to be able to think about everything and imagine everything. However, we are just a higher form of natural evolution and cannot escape the shackles of nature. Our world is moving and changing. We inevitably feel that a force beyond our control drives everything and pushes everything forward. This artical discusses the natural driving force hidden in the objective world and the human body. There are five basic points: 1) Natural driving forces are everywhere and control everything; 2) the natural driving force from the inside out; 3) expectations about the outcome of human-related matters, determine the choice of cause; 4) the natural driving force for society moves from individual to society and therefore only a full realization of everyone's life will produce a better society; and, 5) the foundation of life's growth is to face reality and pain by acknowledging the driving forces.

Dynamic modeling of the Stewart platform for the NanShan Radio Telescope

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094007
Author(s):  
Guljaina Kazezkhan ◽  
Binbin Xiang ◽  
Na Wang ◽  
Aili Yusup
Keyword(s):  
Radio Telescope ◽  
Driving Forces ◽  
Virtual Work ◽  
Dynamic Performance ◽  
Stewart Platform ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Passive Rotation ◽  
Precise Analysis ◽  
And Control

The NanShan Radio Telescope is a 26-m fully steerable radio telescope, and it adopts a 6-UPU Stewart platform with electric motors to adjust and align the position of the subreflector. In order to analyze the actual dynamic performance and control the Stewart platform of the NanShan Radio Telescope, this article models the inverse dynamic of the Stewart platform using the virtual work approach. The model improves the accuracy of the dynamic equations and considered the pitching motion of the base platform in the practical application of the radio telescope. Dynamic simulations of the Stewart platform are implemented, the conditions of the passive rotation of the piston of actuators are considered, and the results show that the effect of the passive rotation of the pistons of the actuators is important to obtain more accurate result. The conditions of the system under the different elevation angles of the radio telescope are also considered, and the results show that the change of the elevation angles of the radio telescope has a great impact on the driving forces of the Stewart platform. It is known from the analysis that the passive rotation of pistons of actuators and the elevation movement of the primary reflector of the radio telescope are not ignorable for the precise analysis and control of the Stewart platform of the NanShan Radio Telescope.

scholarly journals Development of Underactuated Prosthetic Fingers with Joint Locking and Electromyographic Control

2013 ◽  
Vol 3 (1) ◽  
pp. 130 ◽  
Author(s):  
Bart Peerdeman ◽  
Stefano Stramigioli ◽  
Edsko E. G. Hekman ◽  
Dannis M. Brouwer ◽  
Sarthak Misra
Keyword(s):  
Control Systems ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Single Motor ◽  
Hand Prosthesis ◽  
And Control ◽  
Electromyographic Signals ◽  
Underactuated Finger

Modern hand prostheses possess a large number of degrees of freedom. These degrees of freedom cannot simply be actuated by a single motor each, since their combined size and weight would exceed the limitations of an anthropomorphic prosthesis. Some hand prostheses try to remedy this by way of underactuation of the fingers or addition of entirely passive fingers, but this reduces the hand's ability to execute different grasp types. We present a joint locking system, allowing certain degrees of freedom to be fixed during actuation of an underactuated finger. These locks are actuated by miniature solenoids, and allow the fingers to support a variety of grasp types. In this paper, these locks are implemented in a two-fingered prosthesis prototype, which is able to perform several grasping motions important for prosthesis users. This prototype is controlled by pre-recorded electromyographic signals, which control different grasp types and their opening/closing. Various grasping experiments show that the prototype is able to execute three essential grasp types for daily living with a single main actuator, and can be intuitively controlled by means of six different electromyographic signals. This prototype demonstrates new joint locking mechanisms and control systems that can provide an anthropomorphic, myoelectric hand prosthesis with minimal actuation and intuitive control.

scholarly journals Coupled Bending Inwards Motion and Control Strategy Analysis of a Cable-Driven Underactuated Finger

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 133902-133913
Author(s):  
Shangling Qiao ◽  
Lianqing Zhang ◽  
Bingyan Li ◽  
Rongqiang Liu ◽  
Hongwei Guo ◽  
...  
Keyword(s):  
Control Strategy ◽  
Strategy Analysis ◽  
And Control ◽  
Underactuated Finger

scholarly journals Driving forces on dislocations: finite element analysis in the context of the non-singular dislocation theory

2021 ◽  
Author(s):  
Xiandong Zhou ◽  
Christoph Reimuth ◽  
Peter Stein ◽  
Bai-Xiang Xu
Keyword(s):  
Finite Element ◽  
Dislocation Loop ◽  
Driving Force ◽  
Complex Geometry ◽  
Driving Forces ◽  
Singular Solutions ◽  
Dislocation Model ◽  
Configurational Force ◽  
Element Analysis ◽  
Dislocation Configuration

AbstractThis work presents a regularized eigenstrain formulation around the slip plane of dislocations and the resultant non-singular solutions for various dislocation configurations. Moreover, we derive the generalized Eshelby stress tensor of the configurational force theory in the context of the proposed dislocation model. Based on the non-singular finite element solutions and the generalized configurational force formulation, we calculate the driving force on dislocations of various configurations, including single edge/screw dislocation, dislocation loop, interaction between a vacancy dislocation loop and an edge dislocation, as well as a dislocation cluster. The non-singular solutions and the driving force results are well benchmarked for different cases. The proposed formulation and the numerical scheme can be applied to any general dislocation configuration with complex geometry and loading conditions.

Driving forces and structural changes of China as a market provider for Korea

2018 ◽  
Vol 22 (3) ◽  
pp. 194-211 ◽  
Author(s):  
Yongqi Feng ◽  
Tianshu Zhang
Keyword(s):  
Steady State ◽  
Driving Force ◽  
Design Methodology ◽  
Structural Changes ◽  
Driving Forces ◽  
Consumption Expenditure ◽  
Input Output ◽  
Content Type ◽  
Fixed Capital Formation ◽  
The Impact

Purpose The purpose of this paper is to provide a better understanding of the driving forces and structural changes of China as a market provider for Korea. This paper gives the answers for the following questions: How do China’s final demands trigger the growth of its imports from Korea? And what’s the impact of China’s final demands on the import in different industries? Design/methodology/approach Based on the Multi-Regional Input-Output model and World Input-Output Table database, this paper constructs the non-competitive imports input-output (IO) table of China to Korea. According to this table, we can calculate the induced imports coefficient and comprehensive induced import coefficients of China’s four final demands for imports from Korea in the 56 industries in China. Findings Among the four driving forces, the strongest one is changes in inventories and valuables. The impact of final consumption expenditure and fixed capital formation is much lower than that of changes in inventories and valuables, but they have a broader impact for the 56 industries. This paper finds out the China’s import induction of the final demands to Korea peaked in 2005 and 2010 and decreased greatly in 2014, so the position of China as market provider for Korea will no longer rise substantially, contrarily it will be in a steady state. Originality/value First, this paper constructs the non-competitive IO table to analyze the market provider issues between two countries and provides practical ways and methods for studies on the issues of imports and market provider. Second, this paper investigates the different roles of four final demands on driving force of China as market provider for Korea and the structural changes of China as a market provider for Korea among 56 industries from 2000 to 2014.

Study on the Steering Performance of Dual-Motor Drive Track Bulldozer

2013 ◽  
Vol 427-429 ◽  
pp. 133-136
Author(s):  
Qiang Song ◽  
Pu Zeng
Keyword(s):  
Simulation Model ◽  
Dynamic Characteristics ◽  
Driving Force ◽  
Driving Forces ◽  
Small Radius ◽  
Motor Drive ◽  
Matlab Simulink ◽  
Simulation Results ◽  
Two Sides

The driving theory and the dynamic characteristics of small radius steering, medium radius steering and big radius steering is analyzed, and the simulation model is established under Matlab/Simulink. Then the track bulldozers steering performance of the three sheerings is simulated. The results show that, at different steering modes, the running states of the two sides driving motors are not the same, and the track driving forces of the two sides vary widely. The track driving force is great in the small radius steering model, while small in the medium and big radius steering models. The simulation results lay the foundation for dual-motor drive track bulldozers steering performance matching.

Study on the Motion Generation Method of Gun Training Simulator

2012 ◽  
Vol 182-183 ◽  
pp. 1673-1680
Author(s):  
Yu Wang ◽  
Ri Na Su
Keyword(s):  
Real Time ◽  
Driving Force ◽  
Motion Simulation ◽  
Motion Generation ◽  
Motion Platform ◽  
Training Simulator ◽  
Simulation Experiments ◽  
Optimize Design ◽  
Homogeneous Matrix ◽  
And Control

A kind of 3-RPS and 3-DOF parallel robotic mechanisms is used as motion-sensible-platform of gun training simulator to implement the motion simulation. Its dynamics is analyzed and driving force of joint is gained. This paper introduces the study on motion generation of gun training simulator. The moving model of gun is established on the basis of the model of vehicle. We solve the pose of gun by applying the theory of homogeneous matrix. In order to ensure actuators moving at a preset speed and enable the motion-sensible-platform to perform a real-time moving posture simulation of a wheeled gun vehicle in running, the speed equation of actuator is given. The feasibility of models was tested through the simulation experiments. All of these works are beneficial to optimize design and control realization of motion platform structure.

scholarly journals Range Automatic Adjusted Current Transformer Primary Winning

2021 ◽  
Vol 12 (3) ◽  
pp. 3142-3147
Author(s):  
Amirov Sultan Fayzullayevich Et.al
Keyword(s):  
Correction Factor ◽  
Driving Forces ◽  
Operating Mode ◽  
Current Transformer ◽  
Measuring Range ◽  
Secondary Current ◽  
Measuring Devices ◽  
The Difference ◽  
Protection And Control ◽  
And Control

The article discusses the issue of introducing a correction factor for protection and control devices, as the value of the secondary current in a certain range of the auto-adjustable current transformer does not correspond to the value of the secondary current in another range determined by the difference of magnetic driving forces generated by the components of the primary current. Alternatively, an algorithm has been developed to account for the measurement error in this condition in an automatic system that controls the operating mode of the current transformer. It was also found that the output data should be transmitted taking into account the correction factor in order to ensure the proper operation of the protection and measuring devices when the current transformer is switched to another measuring range in the measuring range.

scholarly journals The Formation of Deposits on the Walls of the Pores in the Filtering Process

2019 ◽  
Vol 14 (2) ◽  
pp. 15-22
Author(s):  
Yu. A. Taran ◽  
A. V. Kozlov ◽  
A. L. Taran
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Driving Force ◽  
Nonequilibrium Thermodynamics ◽  
Driving Forces ◽  
Solid Particles ◽  
Original Structure ◽  
Small Particles ◽  
Filtration Process ◽  
Filter Unit

The aim of the work is to consider the mechanism of clogging the pores of the filter unit by small particles from the flow of filtrate inside them. Theoretical ideas about the process of filtering with the deposition of small particles from the filtrate on the pore walls and attribution of its fundamentals to restructuring from the original structure to the final structure allow to describe the process of clogging the pores using well studied concepts of known processes with phase transformations (in particular, crystallization). Based on this analogy and the approach to the description of the transformation of the "old" structure into a "new" one in time, using experimental data and their processing we calculated the rate of nucleation of the sediment centers (ωnucl), the linear (υlin) and volumetric rates of sediment plaques growth in the pores of the filter unit at different values of the process driving force, at different pressure difference in the system, and at different concentrations of solid particles in the suspension. Interpolation and extrapolation dependences were obtained for analyzing the mechanisms of sediments formation and growth for determining and calculating these (ωnucl, υlin) rates. Using the concepts of nonequilibrium thermodynamics to assess the influence of the driving forces we studied their influence (changes in the concentration of solid particles in the filtrate suspension and pressure drop across the filtering layer) on the dynamics of the filtration process. Using the data obtained it is possible to find the degree of clogging of through pores, which determines the filtration conditions, the filter septum type, and the filter overall dimensions.

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