Optimum Design of Serial Robots

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Vinay Gupta ◽  
Subir Kumar Saha ◽  
Himanshu Chaudhary
Keyword(s):  
Optimum Design ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Minimum Weight ◽  
Serial Robots ◽  
Equimomental System ◽  
Inertia Properties ◽  
Simplified Algorithm ◽  
Save Energy ◽  
Puma Robot

An optimum design of an industrial robot can be achieved from different point of views. For example, a robot can be conceived from the standpoint achieving maximum workspace or minimum weight, etc. In this paper, the objective is to arrive at a robot design that will require optimum driving torques/forces at its joints to perform tasks within its workspace. Such a design will automatically save energy. Note that these torques/forces at the joints are highly dependent on the mass and the inertia properties of the robot’s links. Therefore, these quantities were minimized by determining the optimum masses and optimum mass centers and finding out the corresponding inertia properties of the moving links. Such an approach was briefly introduced earlier by the authors with the help of a simple two-link planar arm. In this paper, the concept is generalized and demonstrated with the help of a complex robot, a 6-degrees-of-freedom PUMA robot. To achieve the design for optimum driving torques/forces at the joints, the concept of equimomental system of point masses was introduced, which helped to obtain the optimum locations of the mass centers of each link quite conveniently. However, to compute the driving torques/forces recursively for such equivalent point mass systems, the decoupled natural orthogonal complement matrices for point masses (DeNOC-P) was derived. It has led to a simplified algorithm for obtaining driving torques/forces. The proposed algorithm for optimization is illustrated with the help of a PUMA robot.

Contributions to the Constructive Optimization of an Orientation Module in the Structure of the TRR Industrial Robot

2012 ◽  
Vol 245 ◽  
pp. 267-273
Author(s):  
Silviu Mihai Petrişor ◽  
Ghiţă Bârsan
Keyword(s):  
Optimum Design ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Dynamic Modelling ◽  
3D Modelling ◽  
Robotic Arm ◽  
Lagrangian Formalism ◽  
Mechanical Structure ◽  
Constructive Version ◽  
Selection Of

The author of the present paper proposes a constructive version, selected on the grounds of dynamic and organological equations, which enables an optimum design and operation of the (MO Sil) orientation module that possesses two degrees of freedom, to which the prehension device is attached, in the mechanical structure of the TRR-type serial modular industrial robot. This paper aims at highlighting the dynamic modelling of the mechanical structure of the TRR-type robot by using Lagrangian formalism, with aspects regarding the MO Sil module’s organological construction as well as with the 3D modelling of the orientation module in the mechanical structure of the robotic arm. Another important issue that this paper deals with is the mathematical-organological algorithm used for the selection of the servomotors actuating the orientation movable system in the mechanical structure of the robot.

Functional and Constructive Optimization of a Serial-Modular Industrial Robot Implemented within a Single Purpose Flexible Manufacturing Cell

2012 ◽  
Vol 186 ◽  
pp. 239-246
Author(s):  
Silviu Mihai Petrişor ◽  
Ghiţă Bârsan
Keyword(s):  
Flexible Manufacturing ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Kinematic Chain ◽  
Chain Structure ◽  
Calculation Algorithm ◽  
Flexible Manufacturing Cell ◽  
Manufacturing Cell ◽  
Lagrangian Equations ◽  
Selection Of

The authors of this paper aim to highlight the basic design of a flexible manufacturing cell destined for the final processing of water radiators used for AAVs, cell serviced by a serial modular industrial robot possessing in its kinematic chain structure three degrees of freedom, RRT SIL type. The paper outlines the concept, calculation and design of the (MRB) rotation module at the studied industrial robot’s base and of the (MT) translation module of the prehension device attached to the robotic arm. Depending on the organological elements that are part of the MRB rotation module and based on a rigorous dynamic study performed on robotic modules, modeling conducted with the help of Lagrangian equations of the second kind, a dynamic-organological calculation algorithm was obtained for the selection of the appropriate driving servomotor necessary to putting the rotation movable system into service. The last part of the paper deals with the flexible manufacturing cell, together with the calculations related to profitability, economy and investment return duration, following the implementation of the RRT SIL-type industrial robot.

Analysis of Five-Degree-of-Freedom Robot Arms

1983 ◽  
Vol 105 (1) ◽  
pp. 23-27 ◽  
Author(s):  
K. Sugimoto ◽  
J. Duffy
Keyword(s):  
Arc Welding ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Industrial Robot ◽  
Degree Of Freedom ◽  
Numerical Example ◽  
Robot Arms ◽  
Special Cases ◽  
Computer Controlled ◽  
Five Axes

Many kinds of robot arms with five degrees of freedom are widely used in industry for arc welding, spray painting, assembling etc. It is necessary to be able to compute joint displacements when such devices are computer controlled. A solution to this problem is presented and the analysis is illustrated by a numerical example using the most common industrial robot with five axes. Further, special cases are discussed using screw theory.

Precision Evaluation of NeXus, a Custom Multi-Robot System for Microsystem Integration

2021 ◽  
Author(s):  
Danming Wei ◽  
Alireza Tofangchi ◽  
Andriy Sherehiy ◽  
Mohammad Hossein Saadatzi ◽  
Moath Alqatamin ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Sensor Arrays ◽  
Industrial Robots ◽  
Element Analysis ◽  
Product Packaging ◽  
Precision Evaluation ◽  
High Efficient ◽  
Supporting Frame ◽  
Microsystem Integration

Abstract Industrial robots, as mature and high-efficient equipment, have been applied to various fields, such as vehicle manufacturing, product packaging, painting, welding, and medical surgery. Most industrial robots are only operating in their own workspace, in other words, they are floor-mounted at the fixed locations. Just some industrial robots are wall-mounted on one linear rail based on the applications. Sometimes, industrial robots are ceiling-mounted on an X-Y gantry to perform upside-down manipulation tasks. The main objective of this paper is to describe the NeXus, a custom robotic system that has been designed for precision microsystem integration tasks with such a gantry. The system tasks include assembly, bonding, and 3D printing of sensor arrays, solar cells, and microrobotic prototypes. The NeXus consists of a custom designed frame, providing structural rigidity, a large overhead X-Y gantry carrying a 6 degrees of freedom industrial robot, and several other precision positioners and processes. We focus here on the design and precision evaluation of the overhead ceiling-mounted industrial robot of NeXus and its supporting frame. We first simulated the behavior of the frame using Finite Element Analysis (FEA), then experimentally evaluated the pose repeatability of the robot end-effector using three different types of sensors. Results verify that the performance objectives of the design are achieved.

Application of non-linear H∞ control to the Tetrabot robot manipulator

1998 ◽  
Vol 212 (6) ◽  
pp. 459-465 ◽  
Author(s):  
I Postlethwaite ◽  
A Bartoszewicz
Keyword(s):  
Degrees Of Freedom ◽  
Robot Manipulator ◽  
Industrial Robot ◽  
External Disturbances ◽  
Six Degrees Of Freedom ◽  
Control Scheme ◽  
Non Linear ◽  
Modelling Uncertainties ◽  
Real Robot ◽  
Robotic Application

In this paper, an application of a non-linear H∞ control law for an industrial robot manipulator is presented. Control of the manipulator motion is formulated into a non-linear H∞ optimization problem, namely optimal tracking performance in the presence of modelling uncertainties and external disturbances. Analytical solutions for this problem are implemented on a real robot. The robot under consideration is the six-degrees-of-freedom GEC Tetrabot. Investigations are made into the selection of weights for the H∞ controller and it is shown how different selections of weights affect the Tetrabot performance. The authors believe this to be the first robotic application of nonlinear H∞ control. Comparisons of the proposed control strategy with conventional proportional-derivative and proportional-integral-derivative controllers show favourable performance of the Tetrabot under the new non-linear H∞ control scheme.

Robot Collision Detection Without External Sensors Based on Time-Series Analysis

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Tie Zhang ◽  
Peizhong Ge ◽  
Yanbiao Zou ◽  
Yingwu He
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Collision Detection ◽  
Degrees Of Freedom ◽  
Detection Method ◽  
Industrial Robot ◽  
Detection Algorithm ◽  
Detection Accuracy ◽  
External Torque ◽  
Series Analysis

Abstract To ensure the human safety in the process of human–robot cooperation, this paper proposes a robot collision detection method without external sensors based on time-series analysis (TSA). In the investigation, first, based on the characteristics of the external torque of the robot, the internal variation of the external torque sequence during the movement of the robot is analyzed. Next, a time-series model of the external torque is constructed, which is used to predict the external torque according to the historical motion information of the robot and generate a dynamic threshold. Then, the detailed process of time-series analysis for collision detection is described. Finally, the real-machine experiment scheme of the proposed real-time collision detection algorithm is designed and is used to perform experiments with a six degrees-of-freedom (6DOF) articulated industrial robot. The results show that the proposed method helps to obtain a detection accuracy of 100%; and that, as compared with the existing collision detection method based on a fixed symmetric threshold, the proposed method based on TSA possesses smaller detection delay and is more feasible in eliminating the sensitivity difference of collision detection in different directions.

scholarly journals Crack Assessment of Wheel Hubs via an Ultrasonic Transducer and Industrial Robot

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4336 ◽  
Author(s):  
Hanming Zhang ◽  
Chunguang Xu ◽  
Dingguo Xiao
Keyword(s):  
Crack Growth ◽  
Ultrasonic Testing ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Ultrasonic Transducer ◽  
Robot Assisted ◽  
Six Degrees Of Freedom ◽  
Crack Location ◽  
Critical Areas ◽  
Growth Assessment

Crack assessment when making fitness-for-service decisions requires a thorough examination of crack location and size in critical areas. An ultrasonic transducer is used for such assessments, but traditional methods cannot cope with complex rotators, such as wheel hubs. We present a model of robot-assisted crack growth assessment in wheel hubs. We integrate a six-degrees-of-freedom (DOF) industrial robot and a turntable to form a robot-assisted ultrasonic testing (UT) system that does not use traditional UT equipment. Ultrasonic beams are focused at certain depths appropriate for achieving maximum sensitivity. We quantitatively analysed wheel hubs with longitudinal and transverse series of pre-cracks, and concluded that our system autonomously detected cracks.

An Optimization Analysis of Prestressed Space Grid Structures Based on System Reliability

2010 ◽  
Vol 97-101 ◽  
pp. 3294-3298
Author(s):  
Chun Yu Zhang ◽  
Zhen Qing Wang ◽  
Mu Qiao
Keyword(s):  
Optimum Design ◽  
System Reliability ◽  
Failure Modes ◽  
Minimum Weight ◽  
Structural Systems ◽  
Control Parameters ◽  
Improved Genetic Algorithm ◽  
Optimization Analysis ◽  
Structure System ◽  
Space Grid

The system reliability of prestressed space grid structures were using as control parameters. Branch-bound method was used to determine main failure modes. The reliability of system was calculated by PNET method. Improved genetic algorithm was used in the minimum weight optimum design of the structure system under reliability constraint. Using this method, the complex sensitivity analysis of structural systems could be avoided and made optimum design of the structure system easy. The result of an example showed that the effectiveness of the method.

General inverse solution of six-degrees-of-freedom serial robots based on the product of exponentials model

2018 ◽  
Vol 38 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Haixia Wang ◽  
Xiao Lu ◽  
Wei Cui ◽  
Zhiguo Zhang ◽  
Yuxia Li ◽  
...  
Keyword(s):  
Design Methodology ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Complex Problem ◽  
Content Type ◽  
Geometrical Properties ◽  
Closed Form Solutions ◽  
Six Degrees Of Freedom ◽  
Serial Robots ◽  
Six Dof

Purpose Developing general closed-form solutions for six-degrees-of-freedom (DOF) serial robots is a significant challenge. This paper thus aims to present a general solution for six-DOF robots based on the product of exponentials model, which adapts to a class of robots satisfying the Pieper criterion with two parallel or intersecting axes among its first three axes. Design/methodology/approach The proposed solution can be represented as uniform expressions by using geometrical properties and a modified Paden–Kahan sub-problem, which mainly adopts the screw theory. Findings A simulation and experiments validated the correctness and effectiveness of the proposed method (general resolution for six-DOF robots based on the product of exponentials model). Originality/value The Rodrigues rotation formula is additionally used to turn the complex problem into a solvable trigonometric function and uniformly express six solutions using two formulas.

Estimation Local Strength of Bow Structure for High Tensile Steel Yacht Based on Optimum Design

2006 ◽  
Vol 326-328 ◽  
pp. 1463-1466
Author(s):  
Joo Shin Park ◽  
Yun Young Kim ◽  
Tetsuya Yao
Keyword(s):  
Optimum Design ◽  
Minimum Weight ◽  
Analysis Model ◽  
Element Analysis ◽  
Stress Criterion ◽  
Local Strength ◽  
The Finite Element Analysis ◽  
Small Craft ◽  
Weight Design

The optimum design for bow structure of high tensile steel yacht belongs to the nonlinear constrained optimization problem. The determination of scantlings for the bow structure is a very important matter out of whole structural design process of a yacht. The optimum design results are produced with the use of Real-coded Micro-Genetic Algorithm including evaluation LR small craft guideline, so that they can satisfy the allowable stress criterion. In this study, the minimum weight design of bow structure on the HTS yacht was carried out based on the finite element analysis. An analysis model is a bow structure of HTS yacht with structural scantling derived from the minimum weight optimization. The weight of bow structure and the main dimensions of structural members are chosen as an objective function and design variable, respectively. Optimization results were compared with a pre-existing design. From the FE analysis results, bow structure with high tensile steel (AH40) designed by using RμGA has a volume efficiency of 19% than the design of the actual mild yacht.

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