Determination of the Safe Working Zone of a Parallel Manipulator

Author(s):  
Rangaprasad Arun Srivatsan ◽  
Sandipan Bandyopadhyay
Author(s):  
Dhruvesh Patel ◽  
Rohit Kalla ◽  
Halil Tetik ◽  
Gökhan Kiper ◽  
Sandipan Bandyopadhyay

Robotica ◽  
2019 ◽  
Vol 38 (5) ◽  
pp. 861-885 ◽  
Author(s):  
Murali K. Karnam ◽  
Aravind Baskar ◽  
Rangaprasad A. Srivatsan ◽  
Sandipan Bandyopadhyay

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.


Author(s):  
Parth Y. Patel ◽  
Gemunu Happawana ◽  
Vladimir V. Vantsevich ◽  
David Boger ◽  
Chris Harned

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.


2017 ◽  
Vol 107 ◽  
pp. 396-399 ◽  
Author(s):  
Sean M. Barber ◽  
Zain Boghani ◽  
William Steele ◽  
J. Bob Blacklock ◽  
Todd Trask ◽  
...  

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.


Author(s):  
C. Gosselin

Abstract This paper presents an algorithm for the determination of the workspace of parallel manipulators. The method described here, which is based on geometrical properties of the workspace, leads to a simple graphical representation of the regions of the three-dimensional Cartesian space that are attainable by the manipulator with a given orientation of the platform. Moreover, the volume of the workspace can be easily computed by performing an integration on its boundary, which is obtained from the algorithm. Examples are included to illustrate the application of the method to a six-degree-of-freedom fully-parallel manipulator.


2020 ◽  
Vol 177 ◽  
pp. 03017
Author(s):  
Victor Shestakov ◽  
Pavel Bezkorovainyy ◽  
Tatyana Franz

The relevance of the work is due to the need of the design departments involved in the design of hydraulic excavators in techniques that reduce the mass of excavators while providing the required technological capabilities. Existing methods are aimed at determining the size of working equipment on the condition of providing a given working area. The methods are based on an algorithm for calculating the boundaries of the working area for the input dimensions of the boom, stick and bucket, if the obtained boundaries do not correspond to the specified ones, then the dimen-sions of the equipment are adjusted and the calculations are repeated. The boundaries of the working zone determined by these algorithms do not take into account the power capabilities - the bucket can be at a given point, but the realized forces on the teeth do not ensure separation of the rock. The article discusses the methodology in which possible digging efforts are calculated at all points where the bucket can be located. Results. For a hydraulic excavator with working equipment “direct shov-el”, a mathematical model for calculating digging forces, an algorithm and a program in algorithmic language have been developed to determine possible forces in the elements of the working equipment.


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