scholarly journals Kinematic analysis of a single-loop reconfigurable 7R mechanism with multiple operation modes

Robotica ◽  
2014 ◽  
Vol 32 (7) ◽  
pp. 1171-1188 ◽  
Author(s):  
Xiuyun He ◽  
Xianwen Kong ◽  
Damien Chablat ◽  
Stéphane Caro ◽  
Guangbo Hao
Keyword(s):  
Kinematic Analysis ◽  
Computer Aided Design ◽  
Operation Mode ◽  
Algebraic Approach ◽  
Single Loop ◽  
Operation Modes ◽  
Translational Mode ◽  
Kinematic Mapping ◽  
Multiple Operation ◽  
Aided Design

SUMMARYThis paper presents a novel one-degree-of-freedom (1-DOF) single-loop reconfigurable 7R mechanism with multiple operation modes (SLR7RMMOM), composed of seven revolute (R) joints, via adding a revolute joint to the overconstrained Sarrus linkage. The SLR7RMMOM can switch from one operation mode to another without disconnection and reassembly, and is a non-overconstrained mechanism. The algorithm for the inverse kinematics of the serial 6R mechanism using kinematic mapping is adopted to deal with the kinematic analysis of the SLR7RMMOM. First, a numerical method is applied and an example is given to show that there are 13 sets of solutions for the SLR7RMMOM, corresponding to each input angle. Among these solutions, nine sets are real solutions, which are verified using both a computer-aided design (CAD) model and a prototype of the mechanism. Then an algebraic approach is also used to analyse the mechanism and same results are obtained as the numerical one. It is shown from both numerical and algebraic approaches that the SLR7RMMOM has three operation modes: a translational mode and two 1-DOF planar modes. The transitional configurations among the three modes are also identified.

scholarly journals Operation Modes Comparison of a Reconfigurable 3-PRS Parallel Manipulator Based on Kinematic Performance

2016 ◽  
Author(s):  
Siddharth Maraje ◽  
Latifah Nurahmi ◽  
Stéphane Caro
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
Operation Mode ◽  
Algebraic Approach ◽  
Transmission Efficiency ◽  
Force Transmission ◽  
Operation Modes ◽  
Transmission Index ◽  
Prismatic Joints ◽  
Kinematic Mapping

The 3-PRS parallel manipulator with different arrangements of prismatic joints is called a reconfigurable 3-PRS parallel manipulator in this paper. The three prismatic joints in PRS limbs are attached to the base with an angle α between the horizontal plane of the base and their directions. Based on [1], the manipulator has identical operation modes, namely x0 = 0 and x3 = 0 for any value of α. Accordingly, this paper presents in more details the performance evaluation of these operation modes by using the output transmission index (OTI) and the constraint transmission index (CTI). The OTI and CTI determine the force transmission efficiency and the constraining ability of the manipulators, respectively. Initially, the determination of the number and types of operation modes of the 3-PRS parallel manipulator is recalled. The computation is carried out by using an algebraic approach, namely the Study kinematic mapping. In each operation mode, the actuation wrenches and the constraint wrenches are obtained based on the Screw theory. Then, the OTI and CTI are traced in the orientation workspace of the manipulator for different values of angle α. Furthermore, the singularity conditions are analysed corresponding to the values of OTI and CTI.

Type Synthesis of Variable Degrees-of-Freedom Parallel Manipulators With Both Planar and 3T1R Operation Modes

2012 ◽  
Author(s):  
Xianwen Kong
Keyword(s):  
Degrees Of Freedom ◽  
Operation Mode ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Operation Modes ◽  
Moving Platform ◽  
Multiple Operation ◽  
Schönflies Motion

Parallel manipulators (PMs) with multiple operation modes are novel reconfigurable PMs which use less number of actuators and can be reconfigured without disassembly. Although several classes of PMs with multiple operation modes that have the same DOF (degrees-of-freedom) in all the operation modes have been proposed, only one class of variable-DOF PMs with multiple operation modes — PMs with multiple operation modes that do not have the same DOF in all the operation modes — have been proposed so far. This paper deals with the type synthesis of variable-DOF PMs with both planar and 3T1R (or Schönflies motion which has three translational DOF and 1 rotational DOF) operation modes. The axes of rotation of the moving platform in the planar operation mode are not parallel to the axes of rotation of the moving platform in the 3T1R operation mode. At first, an approach to the type synthesis of PMs with multiple operation modes is recalled. Based on the results on the type synthesis of planar PMs and 3T1R PMs, the types of variable-DOF PMs with both planar and 3T1R operation modes are then obtained. This work can be extended to the type synthesis of other classes of PMs with multiple operation modes.

Type Synthesis of 2-DOF 3-4R Parallel Mechanisms With Both Spatial Parallelogram Translational Mode and Equal-Diameter Spherical Rotation Mode

2014 ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu
Keyword(s):  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Rotation Mode ◽  
Operation Modes ◽  
Translational Mode ◽  
The Common ◽  
Multiple Operation ◽  
Overconstrained Mechanisms

Parallel manipulators (PMs) with multiple operation modes are novel reconfigurable PMs which use less number of actuators and can be reconfigured without disassembly. This paper deals with the type synthesis of 2-DOF PMs with both spatial parallelogram translational mode and equal-diameter spherical rotation mode. At first, a 2-DOF 3-4R overconstrained PM is proposed based on a 5-DOF US equivalent PM proposed in the literature. From this 2-DOF PM, we further obtain a 3-4R PM for equal-diameter spherical rotation and a 3-4R PM for spatial parallelogram translation. By finding the common conditions for the 2-DOF 3-4R PM for spatial parallelogram translation and 2-DOF 3-4R PM for equal-diameter spherical rotation, the types of 2-DOF 3-4R PMs with both spatial parallelogram translational mode and equal-diameter spherical rotation mode are then obtained. This work enriches the types of PMs with multiple operation modes and overconstrained mechanisms.

Type Synthesis of 3-DOF Parallel Manipulators With Both Planar and Translational Operation Modes

2011 ◽  
Author(s):  
Xianwen Kong
Keyword(s):  
Operation Mode ◽  
Parallel Manipulators ◽  
Planar Motion ◽  
Type Synthesis ◽  
Recent Advances ◽  
Operation Modes ◽  
Open Issue ◽  
Moving Platform ◽  
Multiple Operation ◽  
Planar Parallel Manipulators

Despite recent advances in the type synthesis of parallel manipulators with a mono-operation mode, such as translational parallel manipulators and spherical parallel manipulators, the type synthesis of parallel manipulators with multiple operation modes is still an open issue. This paper deals with the type synthesis of 3-DOF parallel manipulators with both planar and translational operation modes. The type synthesis of planar parallel manipulators, which refer to parallel manipulators in which the moving platform undergoes planar motion, is first dealt with using the virtual chain approach. Then, the types of 3-DOF parallel manipulators with both planar and translational operation modes are obtained. This work can be extended to the type synthesis of other classes of parallel manipulators with multiple operation modes.

Reconfiguration Analysis of a 2-DOF 3-4R Parallel Manipulator With Planar Base and Platform

2015 ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu ◽  
Duanling Li
Keyword(s):  
Parallel Manipulator ◽  
Operation Mode ◽  
Euler Parameter ◽  
Operation Modes ◽  
Minimum Number ◽  
Moving Platform ◽  
Multiple Operation ◽  
Motion Characteristics ◽  
Rolling Mode ◽  
And Control

This paper deals with a 2-DOF 3-4R parallel manipulator (PM) with planar base and platform — a novel PM with multiple operation mode (or disassembly-free reconfigurable PM) with minimum number of actuated joints. At first, a set of constraint equations of the 3-4R PM is derived with the orientation of the moving platform represented using a Euler parameter quaternion (also Euler-Rodrigues quaternion) and then solved using the algebraic geometry method. It is found that this 3-4R PM has six 2-DOF operation modes, including the two expected spherical translation mode and sphere-on-sphere rolling mode when the PM was synthesized. The motion characteristics of the moving platform are obtained using the kinematic interpretation of Euler parameter quaternions with certain number of constant zero components, which was presented in a recent paper by the first author of this paper, instead of the eigenspace based approach in the literature. The transition configurations, which are constraint singular configurations, among different operation modes are also presented. This work provides a solid foundation to the development and control of the 2-DOF 3-4R parallel manipulator (PM) with both 2-DOF spherical translation mode and 2-DOF sphere-on-sphere rolling mode.

scholarly journals Using Heat Pumps to Improve the Efficiency of Combined-Cycle Gas Turbines

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2685
Author(s):  
Vitaly Sergeev ◽  
Irina Anikina ◽  
Konstantin Kalmykov
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Computer Aided Design ◽  
Operation Mode ◽  
Heat Pumps ◽  
Combined Cycle ◽  
Heat Sources ◽  
Cad System ◽  
Winter Operation ◽  
Aided Design

This paper studies the integration of heat pump units (HPUs) to enhance the thermal efficiency of a combined heat and power plant (CHPP). Different solutions of integrate the HPUs in a combined-cycle gas turbine (CCGT) plant, the CCGT-450, are analyzed based on simulations developed on “United Cycle” computer-aided design (CAD) system. The HPUs are used to explore low-potential heat sources (LPHSs) and heat make-up and return network water. The use of HPUs to regulate the gas turbine (GT) intake air temperature during the summer operation and the possibility of using a HPU to heat the GT intake air and replace anti-icing system (AIS), over the winter at high humidity conditions were also analyzed. The best solution was obtained for the winter operation mode replacing the AIS by a HPU. The simulation results indicated that this scheme can reduce the underproduction of electricity generation by the CCGT unit up to 14.87% and enhance the overall efficiency from 40.00% to 44.82%. Using a HPU with a 5.04 MW capacity can save $309,640 per each MW per quarter.

scholarly journals To the problem of computer-aided design of gear-and-leverage mechanisms

2020 ◽  
Vol 329 ◽  
pp. 03063
Author(s):  
Alexey Rivkin ◽  
Alexandr Sobolev ◽  
Alexey Nekrasov ◽  
Michael Arbuzov
Keyword(s):  
Kinematic Analysis ◽  
Computer Aided Design ◽  
Mechanical Engineering ◽  
Practical Application ◽  
Program Module ◽  
Computer Aided ◽  
Aided Design ◽  
Gear Lever

The possibilities of using gear-lever mechanisms in modern mechanical engineering are described on the example of three mechanisms from different areas of industry. For practical application, a method of structural and kinematic analysis of gear-lever mechanisms is proposed, implemented using the program module developed by the authors, and an algorithm for kinematic calculation of a gear-lever three-wheeled articulated four-link, as the most common and used in mechanical engineering, is given.

Dynamic rolling analysis of triangular-bipyramid robot

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 884-897 ◽  
Author(s):  
Yaobin Tian ◽  
Yan-An Yao
Keyword(s):  
Kinematic Analysis ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Step Length ◽  
Computer Aided ◽  
Zero Moment ◽  
Aided Design ◽  
Four Bar Linkage ◽  
Three Degrees Of Freedom ◽  
Rolling Robot

SUMMARYIn this paper a rolling robot resembling the shape of a triangular-bipyramid is proposed. The robot has three degrees of freedom and is formed by connecting two tripod mechanisms with three spherical joints. By kinematic analysis, the robot can be viewed as a planar four-bar linkage. Further, its dynamic rolling ability is discussed by Zero Moment Point (ZMP) analysis. We show that the robot has the capability to roll, adjust its step length, and switch rolling directions. These functions are verified by a series of simulations with a CAD (computer-aided design) model and experiments with a prototype.

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