scholarly journals Design of a Spatial RPR-2SS Valve Mechanism

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Peter L. Wang ◽  
Ulrich Rhem ◽  
J. Michael McCarthy
Keyword(s):  
Tunnel Boring Machine ◽  
Degree Of Freedom ◽  
Valve Mechanism ◽  
Kinematic Synthesis ◽  
Soil Conditioning ◽  
Spatial Mechanism ◽  
Tunnel Boring ◽  
Serial Chain ◽  
Smooth Movement ◽  
Cylindrical Array

This paper applies kinematic synthesis theory to obtain the dimensions of a constrained spatial serial chain for a valve mechanism that cleans and closes a soil conditioning port in a tunnel boring machine. The goal is a smooth movement that rotates a cylindrical array of studs into position and then translates it forward to clean and close the port. The movement of the valve is defined by six positions of the revolute-prismatic-revolute (RPR) serial chain. These six positions are used to compute the dimensions of the two spherical spherical (SS) dyads that constrain the RPR chain to obtain a one degree-of-freedom spatial mechanism. An example design of this valve mechanism is provided in detail.

Design Considerations for an Articulated Leg-Wheel Locomotion Subsystem

2004 ◽  
Author(s):  
Seung Kook Jun ◽  
Venkat N. Krovi
Keyword(s):  
Sagittal Plane ◽  
Degree Of Freedom ◽  
Kinematic Synthesis ◽  
Ground Clearance ◽  
Uneven Terrain ◽  
Design Considerations ◽  
Serial Chain ◽  
Vehicle Systems ◽  
Lower Pair ◽  
Adequate Ground

In this paper, we examine and evaluate candidate articulated leg-wheel subsystem designs for use in vehicle systems with enhanced uneven-terrain locomotion capabilities. The leg-wheel subsystem designs under consideration consist of disk wheels attached to the chassis through an articulated linkage containing multiple lower-pair joints. Our emphasis is on creating a design that permits the greatest motion flexibility between the chassis and wheel while maintaining the smallest degree-of-freedom (d.o.f.) within the articulated chain. In particular, we focus our attention on achieving two goals: (i) obtaining adequate ground clearance by designing the desired/feasible motions of the wheel axle, relative to the chassis, using methods from kinematic synthesis; and (ii) reducing overall actuation requirements by a judicious mix of structural equilibration design and spring assist. We examine this process in the context of two candidate designs — a coupled-serial-chain configuration and four-bar-configuration — for the articulated-leg-wheel subsystem. The performance of planar variants of these designs, operating in the sagittal plane, is evaluated and representative results are presented to highlight the process.

Kinetostatic Design Considerations for an Articulated Leg-Wheel Locomotion Subsystem

2005 ◽  
Vol 128 (1) ◽  
pp. 112-121 ◽  
Author(s):  
Seung Kook Jun ◽  
Glenn D. White ◽  
Venkat N. Krovi
Keyword(s):  
Degree Of Freedom ◽  
Kinematic Synthesis ◽  
Design Synthesis ◽  
Single Degree Of Freedom ◽  
Uneven Terrain ◽  
Serial Chain ◽  
Vehicle Systems ◽  
Lower Pair ◽  
Adequate Ground

Our long-term goal is one of designing land-based vehicles to provide enhanced uneven-terrain locomotion capabilities. In this paper, we examine and evaluate candidate articulated leg-wheel subsystem designs for use in such vehicle systems. The leg-wheel subsystem designs under consideration consist of disk wheels attached to the chassis through an articulated linkage containing multiple lower-pair joints. Our emphasis is on creating a design that permits the greatest motion flexibility between the chassis and wheel while maintaining the smallest degree-of-freedom (DOF) within the articulated chain. We focus our attention on achieving two goals: (i) obtaining adequate ground clearance by designing the desired/feasible motions of the wheel axle, relative to the chassis, using methods from kinematic synthesis; and (ii) reducing overall actuation requirements by a judicious mix of structural equilibration design and spring assist. This process is examined in detail in the context of two candidate single-degree-of-freedom designs for the articulated-leg-wheel subsystems—a coupled-serial-chain configuration and a four-bar configuration. We considered the design synthesis of planar variants of the two candidate designs surmounting a representative obstacle profile while supporting a set of end-effector loads and highlight the key benefits in the presented results.

Dimensional Synthesis of CRR Serial Chains

2003 ◽  
Author(s):  
Alba Perez ◽  
J. M. McCarthy
Keyword(s):  
Degree Of Freedom ◽  
Dimensional Synthesis ◽  
Dual Quaternion ◽  
Kinematic Synthesis ◽  
Revolute Joints ◽  
Serial Chain ◽  
In Series ◽  
Synthesis Methodology ◽  
Serial Chains

This paper presents the kinematic synthesis of a CRR serial chain. This is a four-degree-of-freedom chain constructed from a cylindric joint and two revolute joints in series. The design equations for this chain are obtained from the dual quaternion kinematics equations evaluated at a specified set of task positions. In this case, we find that the chain is completely defined by seven task positions. Furthermore, our solution of these equations has yielded 52 candidate designs, so far; there may be more. This synthesis methodology shows promise for the design of constrained serial chains.

Transient Property Improvement of Hydraulic Cylinder Control for Tunnel Boring Machine Using Opposite Reference Filter

2020 ◽  
Vol 140 (3) ◽  
pp. 320-325
Author(s):  
Yoshihiro Ohnishi ◽  
Takahisa Shigematsu ◽  
Takuma Kawai ◽  
Shinichi Kawamura ◽  
Noboru Oda
Keyword(s):  
Tunnel Boring Machine ◽  
Hydraulic Cylinder ◽  
Tunnel Boring

Integral hoisting technology of tunnel boring machine in limited space

2016 ◽  
Vol 33 (3) ◽  
pp. 317
Author(s):  
Fei Wang ◽  
Mengbo Liu ◽  
Long Chen ◽  
Wen Liu ◽  
Linmeng Tang
Keyword(s):  
Tunnel Boring Machine ◽  
Tunnel Boring ◽  
Limited Space

A Newly Developed State-of-the-Art Full-Scale Excavation Testing Apparatus for Tunnel Boring Machine (TBM)

2021 ◽  
Author(s):  
Gi-Jun Lee ◽  
Hee-Hwan Ryu ◽  
Tae-Hyuk Kwon ◽  
Gye-Chun Cho ◽  
Kyoung-Yul Kim ◽  
...  
Keyword(s):  
State Of The Art ◽  
Tunnel Boring Machine ◽  
Full Scale ◽  
Testing Apparatus ◽  
Tunnel Boring

scholarly journals A New System to Evaluate Comprehensive Performance of Hard-Rock Tunnel Boring Machine Cutterheads

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Ye Zhu ◽  
Wei Sun ◽  
Junzhou Huo ◽  
Zhichao Meng
Keyword(s):  
Stability Index ◽  
Tunnel Boring Machine ◽  
Efficiency Index ◽  
Structure Design ◽  
Cutting Efficiency ◽  
Evaluation Indexes ◽  
Average Value ◽  
Tunnel Boring ◽  
Rock Tunnel ◽  
Thrust And Torque

AbstractThe accurate performance evaluation of a cutterhead is essential to improving cutterhead structure design and predicting project cost. Through extensive research, this paper evaluates the performance of a tunnel boring machine (TBM) cutterhead for cutting ability and slagging ability. This paper propose cutting efficiency, stability, and continuity of slagging as the evaluation indexes of comprehensive cutterhead performance. On the basis of research of true TBM engineering applications, this paper proposes a calculation method for each index. A slagging efficiency index with a ratio of the maximum difference between the slagging amount and average slagging is established. And a slagging stability index with a ratio of the maximum slagging fluctuation and average slagging is presented. Meanwhile, a cutting efficiency index by the weighed average value of multistage rock fragmentation of a cutter’s specific energy is established. The Robbins and China Railway Construction Corporation (CRCC) cutterheads are evaluated. The results show that under the same thrust and torque, the slagging stability of the CRCC scheme is worse, but the slagging continuity of the CRCC scheme is better. The cutting ability index shows that the CRCC cutterhead is more efficient.

Seven-Position Synthesis of a Spatial Eight-Bar Linkage by Constraining a TRS Serial Chain

2009 ◽  
Author(s):  
Gim Song Soh ◽  
J. Michael McCarthy
Keyword(s):  
Degree Of Freedom ◽  
Upper Arm ◽  
End Effector ◽  
Serial Chain ◽  
Position Synthesis ◽  
Two Degree Of Freedom ◽  
Puma Robot

In this paper, we use seven-position synthesis to add four TS constraints to a TRS serial chain robot and obtain a two degree-of-freedom spatial eight-bar linkage. The TRS chain is an elbow manipulator, similar to a PUMA robot. We synthesize a TS dyad to connect the base of the robot to its forearm, and then we synthesize three TS dyads that connect the upper arm of the robot to its end-effector. The result is a two degree-of-freedom spatial eight-bar linkage that moves through seven prescribed positions. It consists of a TRST loop supporting a 3TS-RS platform, which we denote as a TS-TRS-3TS spatial linkage. We formulate and solve the design equations for the TS dyads, and analyze the resulting eight-bar linkage. An example demonstrates our results.

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