scholarly journals An approach for smooth trajectory planning of high-speed pick-and-place parallel robots using quintic B-splines

2018 ◽  
Vol 126 ◽  
pp. 479-490 ◽  
Author(s):  
Yuhang Li ◽  
Tian Huang ◽  
Derek G. Chetwynd
Keyword(s):  
Trajectory Planning ◽  
High Speed ◽  
Parallel Robots ◽  
B Splines ◽  
Pick And Place

Dynamic Trajectory Planning for a Three Degrees-of-Freedom Cable-Driven Parallel Robot Using Quintic B-Splines

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Sen Qian ◽  
Kunlong Bao ◽  
Bin Zi ◽  
W. D. Zhu
Keyword(s):  
Trajectory Planning ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Planning Method ◽  
End Effector ◽  
B Spline ◽  
B Splines ◽  
Pick And Place ◽  
Two Factors ◽  
Three Degrees Of Freedom

Abstract This paper presents a new trajectory planning method based on the improved quintic B-splines curves for a three degrees-of-freedom (3-DOF) cable-driven parallel robot (CDPR). First, the conditions of positive cables’ tension are expressed in terms of the position and acceleration constraints of the end-effector. Then, an improved B-spline curve is introduced, which is employed for generating a pick-and-place path by interpolating a set of given via-points. Meanwhile, by expressing the position and acceleration of the end-effector in terms of the first and second derivatives of the improved B-spline, the cable tension constraints are described in the form of B-spline parameters. According to the properties of the defined pick-and-place path, the proposed motion profile is dominated by two factors: the time taken for the end-effector to pass through all the via-points and the ratio between the nodes of B-spline. The two factors are determined through multi-objective optimization based on the efficiency coefficient method. Finally, experimental results on a 3-DOF CDPR show that the improved B-spline exhibits overall superior behavior in terms of velocity, acceleration, and cables force compared with the traditional B-spline. The validity of the proposed trajectory planning method is proved through the experiments.

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.

scholarly journals A hierarchical approach for rigid-body dynamics model simplification of a high-speed parallel robot by considering kinematics performance

2021 ◽  
Vol 104 (4) ◽  
pp. 003685042110630
Author(s):  
Jinlu Ni ◽  
Jiangping Mei ◽  
Weizhong Hu
Keyword(s):  
Rigid Body ◽  
Trajectory Planning ◽  
High Speed ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Rigid Body Dynamics ◽  
Model Simplification ◽  
Hierarchical Approach ◽  
Dynamics Model ◽  
Body Dynamics

Considering the real-time control of a high-speed parallel robot, a concise and precise dynamics model is essential for the design of the dynamics controller. However, the complete rigid-body dynamics model of parallel robots is too complex for online calculation. Therefore, a hierarchical approach for dynamics model simplification, which considers the kinematics performance, is proposed in this paper. Firstly, considering the motion smoothness of the end-effector, trajectory planning based on the workspace discretization is carried out. Then, the effects of the trajectory parameters and acceleration types on the trajectory planning are discussed. But for the fifth-order and seventh-order B-spline acceleration types, the trajectory will generate excessive deformation after trajectory planning. Therefore, a comprehensive index that considers both the motion smoothness and trajectory deformation is proposed. Finally, the dynamics model simplification method based on the combined mass distribution coefficients is studied. Results show that the hierarchical approach can guarantee both the excellent kinematics performance of the parallel robot and the accuracy of the simplified dynamics model under different trajectory parameters and acceleration types. Meanwhile, the method proposed in the paper can be applied to the design of the dynamics controller to enhance the robot's performance.

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.

Conceptual Design and Dimensional Synthesis of a Novel 2-DOF Translational Parallel Robot for Pick-and-Place Operations

2003 ◽  
Vol 126 (3) ◽  
pp. 449-455 ◽  
Author(s):  
Tian Huang ◽  
Zhanxian Li ◽  
Meng Li ◽  
Derek G. Chetwynd ◽  
Clement M. Gosselin
Keyword(s):  
Conceptual Design ◽  
High Speed ◽  
Parallel Robot ◽  
Rechargeable Batteries ◽  
Parallel Robots ◽  
Dimensional Synthesis ◽  
Long Distance ◽  
Conceptual Design Phase ◽  
Pick And Place ◽  
Index Subject

This paper deals with the conceptual design and optimal dimensional synthesis of a novel 2-DOF translational parallel robot for pick-and-place operations. In a conceptual design phase, the conditions for generating such kinds of parallel robots are investigated, leading to the invention of a 2-D version of the Delta robot. Combining this robot with a 1-DOF feed mechanism, a hybrid robot can be created which is particularly suitable for transporting objects at very high speed in a plane plus a relatively slow or step-by-step, yet long distance motion, normal to the plane. The kinematic optimality of the 2-DOF translational parallel robot is achieved by minimizing a global and comprehensive conditioning index subject to a set of appropriate constraints. The application of this robot to the development of a device for quality inspection of rechargeable batteries is used to demonstrate its applicability.

scholarly journals Increasing Energy Efficiency of High-Speed Parallel Robots by Using Variable Stiffness Springs and Optimal Motion Generation

2018 ◽  
Author(s):  
Rafael Balderas Hill ◽  
Sébastien Briot ◽  
Abdelhamid Chriette ◽  
Philippe Martinet
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
High Speed ◽  
Variable Stiffness ◽  
Parallel Robots ◽  
Motion Generation ◽  
Suggested Approach ◽  
Pick And Place ◽  
Lightweight Structure ◽  
Parallel Configuration

The classical approach to decrease the energy consumption of high-speed robots is by lowering the moving elements mass in order to have a lightweight structure. Even if this allows reducing the energy consumed, the lightweight architecture affects the robot stiffness, worsening the accuracy of the mechanism. Recently, variable stiffness actuators (VSAs) have been used in order to reduce the energy consumption of high-speed pick-and-place robots. The idea is to smartly tune online the stiffness of VSA springs so that the robot is put in near a resonance mode, thus considerably decreasing the energy consumption during fast pseudo-periodic pick-and-place motions. However, the serial configuration of springs and motors in the VSA leads to uncontrolled robot deflections at high-speeds and, thus, to a poor positioning accuracy of its end-effector. In order to avoid these drawbacks and to increase the energy efficiency while ensuring the accuracy, this paper proposes the use of parallel arrangement of variable stiffness springs (VSS) and motors, combined with an energy-based optimal trajectory planner. The VSS are used as energy storage for carrying out the reduction of the energy consumption and their parallel configuration with the motors ensure the load balancing at high-speed without losing the accuracy of the robot. Simulations of the suggested approach on a five-bar mechanism are performed and show the increase on energy efficiency.

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