Optimal Design of a 4-DOF SCARA Type Parallel Robot Using Dynamic Performance Indices and Angular Constraints

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Songtao Liu ◽  
Tian Huang ◽  
Jiangping Mei ◽  
Xueman Zhao ◽  
Panfeng Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Rigid Body Dynamics ◽  
Performance Indices ◽  
Global Dynamic ◽  
Transmission Angle ◽  
Body Dynamics ◽  
Rigid Design

This paper deals with the optimal design of a 4-DOF SCARA type (three translations and one rotation) parallel robot using dynamic performance indices and angular constraints within and amongst limbs. The architecture of the robot is briefly addressed with emphasis on the mechanical realization of the articulated traveling plate for achieving a lightweight yet rigid design. On the basis of the kinematic singularity analysis, two types of transmission angle constraints are considered to ensure the kinematic performance. A simplified model of rigid body dynamics is then formulated, with which two global dynamic performance indices are proposed for minimization by taking into account both inertial and centrifugal/Coriolis effects. In addition, the servomotor specifications are estimated using the Extended Adept Cycle. The proposed approach has successfully been employed to develop a prototype machine.

Dimensional synthesis of the Delta robot using transmission angle constraintsDimensional synthesis of the Delta robot using transmission angle constraints

Robotica ◽  
2011 ◽  
Vol 30 (3) ◽  
pp. 343-349 ◽  
Author(s):  
LiMin Zhang ◽  
JiangPing Mei ◽  
XueMan Zhao ◽  
Tian Huang
Keyword(s):  
Dynamic Performance ◽  
Volume Ratio ◽  
Dimensional Synthesis ◽  
Performance Constraints ◽  
Global Dynamic ◽  
Design Variables ◽  
Transmission Angle ◽  
Pressure Transmission ◽  
Delta Robot ◽  
And Performance

SUMMARYThis paper deals with dynamic dimensional synthesis of the Delta robot using the pressure/transmission angle constraints. Two types of pressure/transmission angles are defined, with which the direct and indirect singularities can be identified in a straightforward manner. Two novel global dynamic metrics are proposed for minimisation, which are associated respectively with the inertial and centrifuge/Coriolis components of the driving torque. Various geometrical and performance constraints are taken into account in terms of workspace/machine volume ratio, pressure/transmission angles, etc. The effects of pressure/transmission angle constraints on the feasible domain of design variables are investigated in depth via an example, and a set of optimised dimensional parameters is obtained for achieving a good kinematic and dynamic performance throughout the entire task workspace.

scholarly journals Inverse rigid-body dynamic analysis for a 3UPS-PRU parallel robot

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401769319 ◽  
Author(s):  
Yongjie Zhao ◽  
Ziqiang Zhang ◽  
Gang Cheng
Keyword(s):  
Rigid Body ◽  
Parallel Robot ◽  
Rigid Body Dynamics ◽  
Rigid Body Dynamic ◽  
Body Dynamics ◽  
Moving Platform ◽  
Driving Torque ◽  
Joint Acceleration ◽  
Body Dynamic ◽  
Base Platform

Inverse rigid-body dynamic analysis for a 3UPS-PRU parallel robot are conducted in this research. The position, velocity, acceleration, jerk, and singularity are considered in the inverse kinematics analysis. The rigid-body dynamic model is developed by means of the principle of virtual work and the concept of link Jacobian matrices. The driving torque, driving power, and required output work of motors have been computed in the inverse rigid-body dynamics analysis. For the pre-defined trajectory, the required output work generated by the driving motor is achieved by numerical integration technique. The inverse kinematics and rigid-body dynamics have been investigated in an exhaustive decoupled way. The effects of the velocity of the moving platform on the components of the joint acceleration, joint jerk, driving torque, and driving power, which are related to the velocity of the moving platform, are investigated. There are linear relationships between the acceleration of the moving platform and the components of the joint acceleration, joint jerk, driving torque, and driving power, which are related to the acceleration of the moving platform. The total driving torques, the torques related to the acceleration, velocity, and gravity, the torques related to the moving platform, strut connected with the moving platform, strut connected with the base platform, and motor rotor-coupler are calculated. The total driving powers, the powers related to the acceleration component of torque, velocity component of torque, gravity component of torque, and the powers related to the moving platform, strut connected with the moving platform, strut connected with the base platform, and motor rotor-coupler are also achieved.

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.

scholarly journals Integrating Dynamics into Design and Motion Optimization of a 3-PRR Planar Parallel Manipulator with Discrete Time Transfer Matrix Method

2020 ◽  
Vol 2020 ◽  
pp. 1-23 ◽  
Author(s):  
Guoning Si ◽  
Mengqiu Chu ◽  
Zhuo Zhang ◽  
Haijie Li ◽  
Xuping Zhang
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Discrete Time ◽  
Parallel Manipulator ◽  
Robot Manipulators ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Time Transfer ◽  
Performance Indices ◽  
Planar Parallel Manipulator

This paper presents a novel method of dynamic modeling and design optimization integrated with dynamics for parallel robot manipulators. Firstly, a computationally efficient modeling method, the discrete time transfer matrix method (DT-TMM), is proposed to establish the dynamic model of a 3-PRR planar parallel manipulator (PPM) for the first time. The numerical simulations are performed with both the proposed DT-TMM dynamic modeling and the ADAMS modeling. The applicability and effectiveness of DT-TMM in parallel manipulators are verified by comparing the numerical results. Secondly, the design parameters of the 3-PRR parallel manipulator are optimized using the kinematic performance indices, such as global workspace conditioning index (GWCI), global condition index (GCI), and global gradient index (GGI). Finally, a dynamic performance index, namely, driving force index (DFI), is proposed based on the established dynamic model. The described motion trajectory of the moving platform is placed into the optimized workspace and the initial position is determined to finalize the end-effector trajectory of the parallel manipulator by the further optimization with the integrated kinematic and dynamic performance indices. The novelty of this work includes (1) developing a new dynamic model method with high computation efficiency for parallel robot manipulators using DT-TMM and (2) proposing a new dynamic performance index and integrating the dynamic index into the motion and design optimization of parallel robot manipulators.

Geometric Optimization of a Delta Type Parallel Robot Using Harmony Search Algorithm

Robotica ◽  
2019 ◽  
Vol 37 (9) ◽  
pp. 1494-1512
Author(s):  
Mahmood Mazare ◽  
Mostafa Taghizadeh
Keyword(s):  
Optimal Design ◽  
Search Algorithm ◽  
Dynamic Performance ◽  
Harmony Search ◽  
Parallel Robot ◽  
Harmony Search Algorithm ◽  
Geometric Optimization ◽  
Global Error ◽  
Reachable Workspace ◽  
Sensitivity Indices

SummaryThis paper aims to provide an optimal design of geometric parameters of a special architecture of the delta parallel mechanism, in order to improve positioning accuracy, workspace size, and kinematic and dynamic performance characteristics. In the studied 3[P2(US)] robot, the radius of both fixed and moving platforms, length of the connecting rods, and installation angle of the actuators of the manipulator are chosen as the decision variables. These parameters are optimized to maximize the weighted objective function, comprising workspace volume, global dexterity, global mass, global error, and global error sensitivity indices. Optimizations are performed employing two distinct algorithms, Genetic and Harmony Search whose results confirm each other. The optimal design of the robot leads to maximum workspace size, high dexterity, and dynamic performance, with a minimum error of the end-effector position in its reachable workspace.

Analysis and multi-objective optimal design of a planar differentially driven cable parallel robot

Robotica ◽  
2021 ◽  
pp. 1-17
Author(s):  
Ruobing Wang ◽  
Yangmin Li
Keyword(s):  
Optimal Design ◽  
Parallel Robot ◽  
Complex Model ◽  
Design Parameters ◽  
Performance Indices ◽  
Multi Objective

Abstract In this work, a planar cable parallel robot (CPR) driven by four cable-and-pulley differentials is proposed and analyzed. A new cable-and-pulley differential is designed by adding an extra pulley to eliminate the modeling inaccuracies due to the pulley radius and obviate the need of solving the complex model which considers the pulley kinematics. The design parameters of the proposed CPR are determined through multi-objective optimal design for the largest total orientation wrench closure workspace (TOWCW) and the highest global stiffness magnitude index. The proposed differentially driven CPR is evaluated by comparing various performance indices with a fully actuated CPR.

Functional Design and Optimization of a Novel 3-URU Multimodal Reconfigurable Robot

2017 ◽  
Author(s):  
Luca Carbonari ◽  
David Corinaldi ◽  
Matteo-Claudio Palpacelli ◽  
Giacomo Palmieri ◽  
Massimo Callegari
Keyword(s):  
Dynamic Performance ◽  
Parallel Robot ◽  
Complete Characterization ◽  
Functional Design ◽  
Parallel Kinematics ◽  
Performance Indices ◽  
Design And Optimization ◽  
Reconfigurable Robot ◽  
Moving Bodies

This paper presents the functional design and dynamics optimization of a reconfigurable 3-DoF parallel kinematics manipulator conceived for motions of pure rotations and pure translations. The main peculiarity of the device, indeed, is that of allowing changes of the mobility of its moving platform. The kinematic structure of the three identical legs is designed in a way that, when a particular configuration of the manipulator is reached, the transition between the working modes is possible through the reconfiguration of three metamorphic universal joints, which are used to connect each limb to the ground. This configuration allows to limit the weight of the moving bodies of the robot, with a consequent enhancement of the dynamic performance. The kinematics of the parallel robot is introduced in the very first part of the work as a necessary preamble to the optimization of the manipulator geometry, which has been performed in two steps: at first, the Jacobian matrices which characterize the two working modes were used as performance indices for the preliminary functional optimization of the device; subsequently, an optimization of the dynamic behaviour was performed to obtain a complete characterization of the robot in both its modes.

scholarly journals Slipping–rolling transitions of a body with two contact points

2021 ◽  
Author(s):  
Mate Antali ◽  
Gabor Stepan
Keyword(s):  
Rigid Body ◽  
Contact Point ◽  
Static Friction ◽  
Rigid Body Dynamics ◽  
Contact Forces ◽  
Friction Forces ◽  
Contact Points ◽  
Body Dynamics ◽  
Coulomb Model ◽  
Rigid Surfaces

AbstractIn this paper, the general kinematics and dynamics of a rigid body is analysed, which is in contact with two rigid surfaces in the presence of dry friction. Due to the rolling or slipping state at each contact point, four kinematic scenarios occur. In the two-point rolling case, the contact forces are undetermined; consequently, the condition of the static friction forces cannot be checked from the Coulomb model to decide whether two-point rolling is possible. However, this issue can be resolved within the scope of rigid body dynamics by analysing the nonsmooth vector field of the system at the possible transitions between slipping and rolling. Based on the concept of limit directions of codimension-2 discontinuities, a method is presented to determine the conditions when the two-point rolling is realizable without slipping.

Time-Accurate Simulation of Longitudinal Flight Mechanics with Control by CFD/RBD Coupling

2012 ◽  
Vol 226-228 ◽  
pp. 788-792 ◽  
Author(s):  
Dong Guo ◽  
Min Xu ◽  
Shi Lu Chen
Keyword(s):  
Computational Study ◽  
Rigid Motion ◽  
Rigid Body Dynamics ◽  
Flight Mechanics ◽  
Control Surface ◽  
Free Flight ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Coupled Solution ◽  
Surface Deflections

This paper describes a multidisciplinary computational study undertaken to compute the flight trajectories and simultaneously predict the unsteady free flight aerodynamics of aircraft in time domain using an advanced coupled computational fluid dynamics (CFD)/rigid body dynamics (RBD) technique. This incorporation of the flight mechanics equations and controller into the CFD solver loop and the treatment of the mesh, which must move with both the control surface deflections and the rigid motion of the aircraft, are illustrated. This work is a contribution to a wider effort towards the simulation of aeroelastic and flight stability in regions where nonlinear aerodynamics, and hence potentially CFD, can play a key role. Results demonstrating the coupled solution are presented.

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