Optimal Trajectory Resolution for the Coordination of Two Robots in Contact Operations

1992 ◽  
Author(s):  
E. Tabarah ◽  
B. Benhabib ◽  
R. G. Fenton ◽  
G. Hexner
Keyword(s):  
Optimal Trajectory ◽  
Coordinate Frame ◽  
Polynomial Functions ◽  
Optimal Layout ◽  
Robot System ◽  
The World ◽  
Specific Contact ◽  
Tool Trajectory ◽  
Optimal Coordination ◽  
Simulation Results

Abstract A new method is presented for the optimal coordination of a two-robot system performing contact operations. One of the robots carries a tool and performs the specific contact operation on a workpiece which is grasped and maneuvered by the second robot. The two robots move simultaneously relative to each other so that the tool maintains contact with the workpiece while moving along its prescribed trajectory at a constant speed. This prescribed trajectory, which is specified with respect to the workpiece frame, is thus resolved into a pair of conjugate trajectories, one for each robot, and specified in the world coordinate frame. This resolution process does not yield a unique solution, i.e. there exist an infinity of conjugate-trajectory pairs corresponding to a given tool trajectory. This paper presents a technique for resolving the original tool trajectory, where the robots’ conjugate trajectories are parameterized using polynomial functions. A method is then developed for selecting the optimal pair of conjugate trajectories on the basis of minimizing a given choice of cost function. This optimization is further enhanced by coupling it to a procedure for selecting the optimal layout of the robots within the workcell, resulting in the best possible solutions. Numerical simulation results support the validity of the proposed technique.

scholarly journals Cheating at Craps

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Modeling And Simulation ◽  
Analytical Model ◽  
Quantitative Evaluation ◽  
Mathematical Analysis ◽  
Simulation Modeling ◽  
Analytical Modeling ◽  
The World ◽  
Simulation Results

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.

scholarly journals A New Rotor Position Measurement Method for Permanent Magnet Spherical Motors

2018 ◽  
Vol 8 (12) ◽  
pp. 2415 ◽  
Author(s):  
Yin Lu ◽  
Cungang Hu ◽  
Qunjing Wang ◽  
Yi Hong ◽  
Weixiang Shen ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Measurement Method ◽  
Coordinate Frame ◽  
Feature Points ◽  
Position Measurement ◽  
Experimental Platform ◽  
Rotor Position ◽  
Straight Line ◽  
The World

This paper proposes a new high-precision rotor position measurement (RPM) method for permanent magnet spherical motors (PMSMs). In the proposed method, a LED light spot generation module (LSGM) was installed at the top of the rotor shaft. In the LSGM, three LEDs were arranged in a straight line with different distances between them, which were formed as three optical feature points (OFPs). The images of the three OFPs acquired by a high-speed camera were used to calculate the rotor position of PMSMs in the world coordinate frame. An experimental platform was built to verify the effectiveness of the proposed RPM method.

An optimal trajectory planning method for path tracking of industrial robots

Robotica ◽  
2018 ◽  
Vol 37 (3) ◽  
pp. 502-520 ◽  
Author(s):  
Xianxi Luo ◽  
Shuhui Li ◽  
Shubo Liu ◽  
Guoquan Liu
Keyword(s):  
Trajectory Planning ◽  
Optimal Trajectory ◽  
Optimal Path ◽  
Path Tracking ◽  
Industrial Robots ◽  
Planning Method ◽  
Coordinate Frame ◽  
Optimization Approach ◽  
Cartesian Coordinate ◽  
Optimal Trajectory Planning

SUMMARYThis paper presents an optimal trajectory planning method for industrial robots. The paper specially focuses on the applications of path tracking. The problem is to plan the trajectory with a specified geometric path, while allowing the position and orientation of the path to be arbitrarily selected within the specific ranges. The special contributions of the paper include (1) an optimal path tracking formulation focusing on the least time and energy consumption without violating the kinematic constraints, (2) a special mechanism to discretize a prescribed path integration for segment interpolation to fulfill the optimization requirements of a task with its constraints, (3) a novel genetic algorithm (GA) optimization approach that transforms a target path to be tracked as a curve with optimal translation and orientation with respect to the world Cartesian coordinate frame, (4) an integration of the interval analysis, piecewise planning and GA algorithm to overcome the challenges for solving the special trajectory planning and path tracking optimization problem. Simulation study shows that it is an insufficient condition to define a trajectory just based on the consideration that each point on the trajectory should be reachable. Simulation results also demonstrate that the optimal trajectory for a path tracking problem can be obtained effectively and efficiently using the proposed method. The proposed method has the properties of broad adaptability, high feasibility and capability to achieve global optimization.

scholarly journals Design of Automatic Operated Modular Underwater Vehicle System for Marine Ranch BreedingDesign of Automatic Operated Modular Underwater Vehicle System for Marine Ranch Breeding

2021 ◽  
Author(s):  
ZhongRen Zhang ◽  
FengBao Xu ◽  
PeiJun Li ◽  
XinBao Wang ◽  
FuXiang Liu ◽  
...  
Keyword(s):  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Marine Resources ◽  
Main Body ◽  
Robot System ◽  
Vehicle System ◽  
The World ◽  
Development And Utilization ◽  
Dead Fish ◽  
Root Module

Abstract As terrestrial resources gradually cannot meet people's needs, Countries around the world gradually increase the development and utilization of marine resources. The emergence of marine ranching overcomes many disadvantages of traditional fishery, but there is still a distance from unattended intelligent marine ranch. In this paper, designed a kind of unattended modular underwater robot system which used in marine ranch, including the main body for cage monitoring, the robot module for cleaning and repairing of net clothes and recycling of dead fish, while designed a underwater interfacing apparatus for the main body and root module,This paper introduces the underwater vehicles system of marine ranching, and designs the main body and working module in detail. This paper simply describes the interfacing process of the underwater workstation with the main body and modules.The research results of this paper compensate for the gaps in marine ranch engineering equipment and technology, and meantime proposed an underwater vehicle for cage repairing and dead fish recycling, which uses modular ideas, it can reduces costs and this paper strongly promotes the development of intelligence and automation level of marine ranching.

scholarly journals A New Approach to the Solution of Robot Kinematics Based on Relative Transformation Matrices

2016 ◽  
Vol 5 (3) ◽  
pp. 213
Author(s):  
Mohammad Reza Elhami ◽  
Iman Dashti
Keyword(s):  
Robot Manipulator ◽  
Robot Kinematics ◽  
Coordinate Frame ◽  
End Effector ◽  
New Approach ◽  
Transformation Matrices ◽  
The World ◽  
Convenient Approach ◽  
Position And Orientation ◽  
Relative Transformation

In analyzing robot manipulator kinematics, we need to describe relative movement of adjacent linkages or joints in order to obtain the pose of end effector (both position and orientation) in reference coordinate frame. Denavit-Hartenberg established a method based on a 4×4 homogenous matrix so called “A” matrix. This method used by most of the authors for kinematics and dynamic analysis of the robot manipulators. Although it has many advantages, however, finding the elements of this matrix and link/joint’s parameters is sometimes complicated and confusing. By considering these difficulties, the authors proposed a new approach called ‘convenient approach’ that is developed based on “Relative Transformations Principle”. It provides a very simple and convenient way for the solution of robot kinematics compared to the conventional D-H representation. In order to clarify this point, the kinematics of the world known Stanford manipulator has been solved through D-H representation as well as convenient approach and the results are compared.

Organizational Machines Layout and the Application of Individual Features on the Specific Production Respectively Assembly through the Simulation

2012 ◽  
Vol 479-481 ◽  
pp. 508-511
Author(s):  
Katarína Krajčová ◽  
František Pecháček ◽  
Karol Velíšek
Keyword(s):  
Great Emphasis ◽  
Specific Production ◽  
Optimal Layout ◽  
Part Type ◽  
Production Logistics ◽  
Assembly Cell ◽  
The World ◽  
Basic Features ◽  
Plant Simulation ◽  
Vega 1

The great emphasis is currently placed on the optimal layout of individual workplaces and machines in the issue of production and production logistics. It is possible to achieve by the selecting an appropriate organizational layout form of machines and devices. There are several layout forms – technological, subject, free, modular and cellular. The paper is focused on clarifying the basic features and differences of individual machines layout and on the application these features on the specific production of certain part type through the simulation in the simulation program. There are several programs, which are used on the production simulation, for example: Plant Simulation, Simul 8, Witness etc. Witness program is the world recognized program. The utilization of individual machines layout is possible to determine by the using of this program. The simulation of production system is possible to use in the assembly system. The similar problem is solving in a project VEGA 1/0206/09 / Intelligent assembly cell.

Optimal trajectory planning for a hexapod machine tool during contour machining

2002 ◽  
Vol 216 (12) ◽  
pp. 1247-1257 ◽  
Author(s):  
S Pugazhenthi ◽  
T Nagarajan ◽  
M Singaperumal
Keyword(s):  
Machine Tool ◽  
Trajectory Planning ◽  
Machine Tools ◽  
Optimal Trajectory ◽  
Computational Algorithm ◽  
End Milling ◽  
Optimum Location ◽  
Simulation Results ◽  
Contour Machining ◽  
Optimal Trajectory Planning

This paper addresses the problem of optimal trajectory planning for Stewart platform based machine tools. The objectives are to maximize the stiffness of the structure and to minimize the force requirement of the actuators while satisfying the constraints of workspace and singularity. A computational algorithm for searching the optimum location of machining trajectory is developed. The algorithm is applied to two contour machining examples involving end milling. The simulation results of contour machining along the optimal trajectory are discussed.

Dynamic Modeling and Analysis of a Fruit and Vegetable Picking Robot

2012 ◽  
Vol 241-244 ◽  
pp. 1845-1849
Author(s):  
Yan Wang ◽  
Yun Wang Ge ◽  
Xiao Li Wang
Keyword(s):  
Dynamic Modeling ◽  
Trajectory Planning ◽  
Dynamic Models ◽  
Lagrange Equation ◽  
Angular Displacement ◽  
Fruit And Vegetable ◽  
Robot System ◽  
Modeling And Analysis ◽  
Abrupt Changes ◽  
Simulation Results

According to characteristics of the fruit and vegetable picking operations, an articulated picking robot with four degree-of-freedom is developed. And in order to perform an expected motion of picking work, the kinematic and dynamic models have to be constructed firstly. Kinematics is established based on Denavit-Hartenberg notation. Then, the explicit expressions of dynamic models are presented through Lagrange equation. Finally, trajectory planning from one point to another point is carried out with cycloidal motion, and the angular displacement, velocity, acceleration and torque curves of each joint are analyzed. Simulation results show that the torque curves are quite smooth and with no abrupt changes, which indicates that the motions of each joint won’t result vibrations and can ensure stability of the robot system.

scholarly journals Shape adaptive IRS Enhanced SAG IoT Network

2021 ◽  
Author(s):  
Fei Qi ◽  
Wenjing Li ◽  
Peng Yu ◽  
Lei Feng ◽  
Fanqin Zhou
Keyword(s):  
Future Development ◽  
Functional Requirements ◽  
Integrated Network ◽  
Flexible Materials ◽  
The World ◽  
Physical Shape ◽  
Simulation Results ◽  
Radiation Beams

Abstract 6G technology connects physical and digital, and ubiquitous 6G services will provide convenience to users around the world. The concept of the world-earth integrated network is to seamlessly integrate these three subnets to better adapt to future development. This article introduces the world-earth integrated network and shapeadaptive IRS antenna technology. The shape-adaptive IRS antenna described in this article is made of flexible materials, and the physical shape of the antenna can be changed according to different situations, and specific radiation beams can be generated according to functional requirements. And the effectiveness of the shape-adaptive IRS antenna technology has been proven in the simulation results.

scholarly journals Alignment Method of Combined Perception for Peg-in-Hole Assembly with Deep Reinforcement Learning

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yongzhi Wang ◽  
Lei Zhao ◽  
Qian Zhang ◽  
Ran Zhou ◽  
Liping Wu ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Visual Perception ◽  
Simulation Training ◽  
Tactile Perception ◽  
Visual Feature ◽  
Alignment Method ◽  
Torque Sensor ◽  
Robot System ◽  
Contact State ◽  
Simulation Results

The method of tactile perception can accurately reflect the contact state by collecting force and torque information, but it is not sensitive to the changes in position and posture between assembly objects. The method of visual perception is very sensitive to changes in pose and posture between assembled objects, but they cannot accurately reflect the contact state, especially since the objects are occluded from each other. The robot will perceive the environment more accurately if visual and tactile perception can be combined. Therefore, this paper proposes the alignment method of combined perception for the peg-in-hole assembly with self-supervised deep reinforcement learning. The agent first observes the environment through visual sensors and then predicts the action of the alignment adjustment based on the visual feature of the contact state. Subsequently, the agent judges the contact state based on the force and torque information collected by the force/torque sensor. And the action of the alignment adjustment is selected according to the contact state and used as a visual prediction label. Whereafter, the network of visual perception performs backpropagation to correct the network weights according to the visual prediction label. Finally, the agent will have learned the alignment skill of combined perception with the increase of iterative training. The robot system is built based on CoppeliaSim for simulation training and testing. The simulation results show that the method of combined perception has higher assembly efficiency than single perception.

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