scholarly journals Computing the Safe Working Zone of a 3-RRS Parallel Manipulator

2016 ◽  
pp. 113-120 ◽  
Author(s):  
Dhruvesh Patel ◽  
Rohit Kalla ◽  
Halil Tetik ◽  
Gökhan Kiper ◽  
Sandipan Bandyopadhyay
Keyword(s):  
Parallel Manipulator ◽  
Working Zone ◽  
Safe Working Zone ◽  
Safe Working

Computation of the safe working zones of Planar and Spatial Parallel Manipulators

Robotica ◽  
2019 ◽  
Vol 38 (5) ◽  
pp. 861-885 ◽  
Author(s):  
Murali K. Karnam ◽  
Aravind Baskar ◽  
Rangaprasad A. Srivatsan ◽  
Sandipan Bandyopadhyay
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Working Zone ◽  
Three Degrees Of Freedom ◽  
Safe Working Zone ◽  
Safe Working

SUMMARYThis paper presents the computation of the safe working zone (SWZ) of a parallel manipulator having three degrees of freedom. The SWZ is defined as a continuous subset of the workspace, wherein the manipulator does not suffer any singularity, and is also free from the issues of link interference and physical limits on its joints. The proposed theory is illustrated via application to two parallel manipulators: a planar 3-R̲RR manipulator and a spatial manipulator, namely, MaPaMan-I. It is also shown how the analyses can be applied to any parallel manipulator having three degrees of freedom, planar or spatial.

Morphing Capabilities and Safe Operation Zone of the Utility Truck Boom Equipment

2020 ◽  
Author(s):  
Parth Y. Patel ◽  
Gemunu Happawana ◽  
Vladimir V. Vantsevich ◽  
David Boger ◽  
Chris Harned
Keyword(s):  
Rigid Body ◽  
Static Analysis ◽  
Severe Weather ◽  
Normal Reaction ◽  
Safe Operation ◽  
Force Vector ◽  
Numerical Illustration ◽  
Working Zone ◽  
Safe Working Zone ◽  
Safe Working

Abstract Utility trucks are the first responders in extreme climate and severe weather situations, for saving people’s lives to restoring traffic on the roads. However, such trucks can create dangerous situations on the roads, and off-road conditions, while moving, and performing tasks. Trucks equipped with large booms for reaching elevated heights can become unstable due to their geometry change, which can cause a drastic variation of the truck-boom system’s moment of inertia, and the extreme weight re-distribution among the wheels. Morphing capabilities of the utility trucks need to be investigated together with the vehicle-road forces in order to hold the vehicle safe on the roads. In this research paper, static analysis and range of the normal reaction at the wheel of the utility truck is performed to characterize a safe working zone of the boom equipment when the truck is in the flat and titled surface. The analysis is performed for 5-degree of freedom boom equipment with revolute and translational joints in a complex constrained space given by the truck design using 3D moment and force-vector analysis. The possible morphing configuration of the boom equipment is examined in order to define static normal reactions at the wheel-road interaction. Further, the morphing of the boom equipment is investigated to determine limiting configurations that can be reached without rolling over the truck. In this analysis, it is assumed that the wheels provide enough friction between the tires and road so that tire slippage does not extensively occur, and the utility truck is assumed as a rigid body. In this study, utility truck equipped with boom equipment is utilized in this study for numerical illustration.

Variation in Psoas Muscle Location Relative to the Safe Working Zone for L4/5 Lateral Transpsoas Interbody Fusion: A Morphometric Analysis

2017 ◽  
Vol 107 ◽  
pp. 396-399 ◽  
Author(s):  
Sean M. Barber ◽  
Zain Boghani ◽  
William Steele ◽  
J. Bob Blacklock ◽  
Todd Trask ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Interbody Fusion ◽  
Psoas Muscle ◽  
Working Zone ◽  
Safe Working Zone ◽  
Safe Working

scholarly journals Experimental Study of Ultrasonic Vibration Effects on Punch Radial in Sheet Hydroforming Process

2021 ◽  
Author(s):  
Reza Ghasemi ◽  
Majid Elyasi ◽  
Hamid Baseri ◽  
Mohammad Javad Mirnia
Keyword(s):  
Ultrasonic Vibration ◽  
Deep Drawing ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Maximum Height ◽  
Sheet Hydroforming ◽  
Working Zone ◽  
Hydroforming Process ◽  
Vibration Assistance ◽  
Safe Working

Abstract Nowadays, one of the metal forming processes that are widely used in industries is sheet hydroforming. Because of high complexity and sensitivity, this process needs precise calculations in the die and method to control metal flow correctly and prevent defects. Therefore recently, new processes were combined to this process to increase precision and effectiveness. For example, ultrasonic vibration assistance forming. Using hydroforming and ultrasonic vibration as new methods were studied in several research types separately, and each of them redounded to different analyses and improvements in the process. Even synchronic use of these two methods was studied in some metal forming processes such as tube hydroforming, but it has not been studied in sheet hydroforming. Therefore the aim of this research is the experimental study of St14 sheet hydroforming ultrasonic vibration assistance. For this purpose, ultrasonic vibration (with 20 KHz frequency and 4μm amplitude) was applied to a hydromechanical deep drawing die into punch radial in the hydroforming process. Then process parameters consisting of LDR, maximum height, forming force, safe working zone, and thickness distribution were determined and compared in four case states conventional deep drawing(CDD), hydroforming deep drawing(HDD), ultrasonic vibration assistance deep drawing(UDD) and ultrasonic vibration assistance hydroforming deep drawing(UHDD). Results indicated that applying ultrasonic vibration into the sheet hydroforming process increases LDR and the maximum height of the cup, decreases forming force and develops a safe working zone. Also was very effective in thickness distribution and decrease of sheet thinning in critical sections.

An experience of elaboration and implementation of systems of slag-forming mixtures mechanized feeding into CCM moulds

2020 ◽  
Vol 76 (10) ◽  
pp. 994-1003
Author(s):  
S. P. Eron’ko ◽  
M. Yu. Tkachev ◽  
E. V. Oshovskaya ◽  
B. I. Starodubtsev ◽  
S. V. Mechik
Keyword(s):  
Economic Effect ◽  
Three Dimensional ◽  
Movable Part ◽  
High Quality ◽  
Working Zone ◽  
Fine Material ◽  
Mixing Chamber ◽  
Field Samples ◽  
Technical Solutions ◽  
Feeding Systems

Effective application of slag-forming mixtures (SFM), being fed into continuous castingg machine (CCM) moulds, depends on their even distribution on the melt surface. Manual feeding of the SFM which is widely usedd does not provide this condition, resulting in the necessity to actualize the work to elaborate systems of SFM mechanized feedingg into moulds of various types CCM. A concept of the designing of a system of SFM feeding into CCM moulds presented with the ratte strictly correspondent to the casting speed and providing formation of an even layer of fine material of given thickness on the whoole surface of liquid steel. The proposed methods of designing of the SFM mechanized feeding systems based on three-dimensional computer simulation with the subsequent verification of the correctness of the adopted technical solutions on field samples. Informattion is presented on the design features of the adjusted facilities intended for continuous supply of finely granulated and powder mixtuures on metal mirror in moulds at the production of high-quality billets, blooms and slabs. Variants of mechanical and pneumo-mechaanical SFM supply elaborated. At the mechanical supply the fine material from the feeding hopper is moved at a adjusted distance bby a rigid horizontally located screw. At the pneumo-mechanical supply the metered doze of the granular mixture is delivered by a sshort vertical screw, the lower part of which is located in the mixing chamber attached from below to the hopper and equipped with ann ejector serving for pneumatic supply of the SFM in a stream of transporting gas. It was proposed to use flexible spiral screws in the ffuture facilities of mechanical SFM feeding. It will enable to eliminate the restrictions stipulated by the lack of free surface for locatiion of the facility in the working zone of the tundish, as well as to decrease significantly the mass of its movable part and to decreaase the necessary power of the carriage moving mechanism driver. The novelty of the proposed technical solutions is protected by thhree patents. The reduction of 10–15% in the consumption of slag-forming mixtures during the transition from manual to mechanizeed feeding confirmed. The resulting economic effect from the implementation of technical development enables to recoup the costs inncurred within 8–10 months.

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