scholarly journals Trajectory Generation for High Speed Pick and Place Robots

2012 ◽  
Author(s):  
Cornelius J. Barnard ◽  
Sébastien Briot ◽  
Stéphane Caro
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Vibration Reduction ◽  
Parallel Robots ◽  
Short Cycle ◽  
Cycle Times ◽  
Smooth Motion ◽  
Pick And Place

Currently parallel robots are finding more and more acceptance in high-speed pick-and-place operations. As for all high-speed mechanisms, vibratory phenomena appear and deteriorate accuracy and dynamic performance at the terminal positions of the pick-and-place path. This paper aims to evaluate the effectiveness of several pick-and-place trajectories in terms of vibration reduction. To address this problem, an elastodynamic model of a five bar mechanism is developed and its behaviour is simulated as it traverses each trajectory. Spectral analysis of the vibrations allows the quality of the vibration reduction to be quantified. The results show that the first and second natural frequencies of the system are excited. It is also shown that long cycle times with smooth motion profiles improve residual error norms, but are outperformed by their discontinuous counterparts when short cycle times are imposed.

Dynamic Analysis of a Parallel Pick-and-Place Robot With Flexible Links

2008 ◽  
Author(s):  
Haihong Li ◽  
Zhiyong Yang
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Lithium Ion ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Modeling And Analysis ◽  
Flexible Links ◽  
Pick And Place ◽  
Floating Frame ◽  
Pick And Place Operation

The dynamic modeling and analysis of a 2-DOF translational parallel robot for high-speed pick-and-place operation was presented. Considering the flexibility of all links, the governing equation of motion of a flexible link is formulated in the floating frame of reference using Euler-Lagrange method. A kineto-elasto dynamic model of the system is achieved, ready for modal analysis. Simulation in FEM software showed the similar modes with above computational result in typical location and rotation. The dynamic experiment presented the dominant modes and proved the theoretical analysis and simulation. The Diamond robot used in Lithium-ion battery sorting was taken as an example to demonstrate how to finish above studies. The result shows that the mechanism has good dynamic performance. The work is available for all parallel robots with flexible links.

A Novel Parameter Optimization Method for the Driving System of High-Speed Parallel Robots

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Xin-Jun Liu ◽  
Gang Han ◽  
Fugui Xie ◽  
Qizhi Meng ◽  
Sai Zhang
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Optimization Method ◽  
Parallel Robots ◽  
Parameters Optimization ◽  
Driving System ◽  
System Parameters ◽  
Driving Torque ◽  
Instantaneous Acceleration

Driving system parameters optimization, especially the optimal selection of specifications of motor and gearbox, is very important for improving high-speed parallel robots' performance. A very challenging issue is parallel robots' performance evaluation that should be able to illustrate robots' performance accurately and guide driving system parameters optimization effectively. However, this issue is complicated by parallel robots' anisotropic translational and rotational dynamic performance, and the multiparameters of motors and gearboxes. In this paper, by separating the influence of translational and rotational degrees-of-freedom (DOFs) on robots' performance, a new dynamic performance index is proposed to reflect the driving torque in instantaneous acceleration. Then, the influence of driving system's multiparameters on robots' driving torque in instantaneous acceleration and cycle time in continuous motion is investigated. Based on the investigation, an inertia matching index is further derived which is more suitable for minimizing the driving torque of parallel robots with translational and rotational DOFs. A comprehensive parameterized performance atlas is finally established. Based on this atlas, the performance of a high-speed parallel robot developed in this paper can be clearly evaluated, and the optimal combination of motors and gearboxes can be quickly selected to ensure low driving torque and high pick-and-place frequency.

Kinematics and Stiffness Modeling of a 4-DOF Parallel Robot for Schönflies Motion Generation

2014 ◽  
Author(s):  
Shaoping Bai ◽  
Lasse Køgs Andersen ◽  
Carsten Rebbe Mølgaard
Keyword(s):  
Dynamic Performance ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Motion Generation ◽  
Stiffness Modeling ◽  
Pick And Place ◽  
Fea Simulation ◽  
Schönflies Motion ◽  
Pick And Place Operation ◽  
Good Agreement

This work deals with the design of parallel robots for the generation of pick-and-place operation, or Schönflies motion. The aim is to develop a robot with workspace optimized for fast pick-and-place operations, namely, a robot with a superellipsoidal reachable volume, which suits best for the pick-and-place operations on conveyers, where robots’ working areas are nearly rectangular. In this paper, the kinematics and stiffness modeling of the new robot are presented. A method of stiffness modeling by means of Castigliano’s Theorem is developed. Using the new method, the stiffness of the robot is analyzed. The results are compared with FEA simulation, which shows a good agreement between the results. The method is finally applied to the engineering design of the new robot for enhanced static and dynamic performance.

Vibration Characteristic Analysis and Research of High Speed Dynamic Balancing Machine

2012 ◽  
Vol 529 ◽  
pp. 180-185
Author(s):  
Qing Lei Zhang ◽  
Hai Ou Shen ◽  
Bai Yu Zhao ◽  
Jing Kuan Guo
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Frame Structure ◽  
Structure Model ◽  
Vibration Characteristic ◽  
Characteristic Analysis ◽  
Dynamic Balancing ◽  
Calculation Results

Dynamic performance of high speed dynamic balancing machine directly affects the accuracy and safety of dynamic balancing machine. ANSYS 12.0 was used to establish the frame structure model in this paper. The four models of dynamic balancing machine were calculated respectively. The calculation results show that additional stiffness can greatly improve the natural frequencies of dynamic balancing machine. In addition, as the base is large, we can ignore the influence on natural frequencies caused by the base.

Modal Analysis of Ballooning Strings With Small Sag

1999 ◽  
Author(s):  
Rongjun Fan ◽  
Sushil K. Singh ◽  
Christopher D. Rahn
Keyword(s):  
Steady State ◽  
High Speed ◽  
Natural Frequencies ◽  
Rotation Speed ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Theoretical Predictions ◽  
Nonlinear Equations Of Motion

Abstract During the manufacture and transport of textile products, yarns are rotated at high speed and form balloons. The dynamic response of the balloon to varying rotation speed, boundary excitation, and disturbance forces governs the quality of the associated process. Resonance, in particular, can cause large tension variations that reduce product quality and may cause yarn breakage. In this paper, the natural frequencies and mode shapes of a single loop balloon are calculated to predict resonance. The three dimensional nonlinear equations of motion are simplified via small steady state displacement (sag) and vibration assumptions. Axial vibration is assumed to propagate instantaneously or in a quasistatic manner. Galerkin’s method is used to calculate the mode shapes and natural frequencies of the linearized equations. Experimental measurements of the steady state balloon shape and the first two natural frequencies and mode shapes are compared with theoretical predictions.

The Optimization of the Beam of High-Speed Computerized Embroidery Machine

2013 ◽  
Vol 470 ◽  
pp. 381-384
Author(s):  
Jun Rong Zhou
Keyword(s):  
Performance Analysis ◽  
High Speed ◽  
Dynamic Performance ◽  
New Model ◽  
Breakage Rate ◽  
The Future ◽  
Dynamic Performance Analysis ◽  
A Company

The beam of embroidery machine vibrates more intensely and breakage rate goes higher when the spindle rotates at 850rpm and then the quality of product reduces drastically. One high-speed computerized embroidery machine with 20 heads manufactured by a company in Jiangmen was studied for the problem mentioned above. Dynamic performance analysis was conducted to the beam by analytical experiment and computation based on FEM through ANSYS. One improvement solution was proposed and theoretical verification to the optimized beam was processed. It provides a reference for the improvement on embroiderys structure and the development of new model in the future.

Investigation on the Vibration of High Speed Cable Robot Manipulation due to Tension Around Drum

2019 ◽  
Author(s):  
Jinwoo Jung ◽  
Jinlong Piao ◽  
Eunpyo Choi ◽  
Jong-Oh Park ◽  
Chang-Sei Kim
Keyword(s):  
High Speed ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Rigid Base ◽  
Robot System ◽  
Vibration Problem ◽  
Cable Robot ◽  
Pick And Place ◽  
Flexible Cables ◽  
Pick And Place Operation

Abstract A cable-driven parallel robot (CDPR) consists of an end-effector, flexible lightweight cables, pulleys, winches, and a rigid base frame. As opposed to the rigid links of the traditional serial robots and parallel robots, the flexible lightweight cables allow the CDPR to easily achieve the high speed, heavy payload manipulation, and scalable workspace. Especially, the conventional high-speed pick and place operation can be realized due to the lightweight of its flexible cables. However, the flexibility of the lightweight cables can introduce a considerable vibration problem to the high speed cable robot system. One of main causes can be a cable tension difference between initial pre-tension and winding tension around a drum of the winch-motor actuator. To effectively investigate the effect of the tension around the drum on the high speed manipulation of the cable robot system, the spatial eight-cable high speed cable robot was reduced to the horizontal two cable system. The reduction of the number of the cable enables us to minimize the influences from the other factors such as the cable sagging and the geometric errors. A series of experiments was conducted using the combinations of the low and high initial pre-tensions and low and high tensions around the drum. The experimental results clearly show that the low tension around the drum can cause the vibration problem during the high speed pick and place operation. Also, it demonstrates that securing the drum tension similar to the initial pre-tension can effectively reduce the magnitude of the vibration.

A Method for Estimating Servomotor Parameters of a Parallel Robot for Rapid Pick-and-Place Operations

2004 ◽  
Vol 127 (4) ◽  
pp. 596-601 ◽  
Author(s):  
Tian Huang ◽  
Jiangping Mei ◽  
Zhanxian Li ◽  
Xueman Zhao ◽  
Derek G. Chetwynd
Keyword(s):  
High Speed ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Rechargeable Battery ◽  
Quality Inspection ◽  
Effective Manner ◽  
Pick And Place ◽  
The Moment ◽  
Object Of Study ◽  
Value Decomposition

By taking a 2-DOF high-speed translational parallel manipulator as an object of study, this paper presents an approach that enables the servomotor parameters of parallel robots for pick-and-place operations to be estimated in an effective manner using the singular value decomposition. These parameters include the moment of inertia, speed, torque, and power of the motor required for producing the specified velocity and acceleration of the end effector. An example is given to determine these parameters of a device for the rechargeable battery quality inspection.

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