Dynamic Trajectory Planning and Geometric Design of a Two-DOF Translational Cable-Suspended Planar Parallel Robot Using a Parallelogram Cable Loop

2018 ◽  
Author(s):  
Jordan M. Longval ◽  
Clément Gosselin
Keyword(s):  
Trajectory Planning ◽  
Parallel Robot ◽  
Geometric Design ◽  
Rotational Stability ◽  
Design Parameters ◽  
Sensitivity Index ◽  
General Elliptic ◽  
Planning Approach ◽  
Kinematic Sensitivity ◽  
Dynamic Trajectory

This paper presents a trajectory planning approach and an analysis of the geometric design parameters for a planar cable-suspended translational parallel robot based on a parallelogram cable loop. The cable robot produces purely translational movements in a planar workspace. Furthermore, this special architecture only requires two actuators which makes it fully actuated. From the dynamic model of the robot, general algebraic inequalities are obtained that ensure that the cables remain taut. A general elliptic trajectory is then defined and substituted into the algebraic inequalities to obtain conditions on the geometrical design parameters that ensure that the cables are always in tension. In addition, a special trajectory-specific oscillation frequency emerges and enables the end-effector to dynamically move beyond the boundaries of the static workspace, thus expanding the workspace of the mechanism. Finally, a kinematic sensitivity index is studied in order to assess the influence of the parallelogram structure on the rotational stability of the mechanism.

Dynamic Trajectory Planning and Geometric Analysis of a Two-Degree-of-Freedom Translational Cable-Suspended Planar Parallel Robot Using a Parallelogram Cable Loop

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Jordan M. Longval ◽  
Clément Gosselin
Keyword(s):  
Trajectory Planning ◽  
Geometric Analysis ◽  
Parallel Robot ◽  
Design Parameters ◽  
Sensitivity Index ◽  
General Elliptic ◽  
Planning Approach ◽  
Kinematic Sensitivity ◽  
Two Degree Of Freedom ◽  
Dynamic Trajectory

This paper presents a trajectory planning approach and an analysis of the geometric design parameters for a planar cable-suspended translational parallel robot based on a parallelogram cable loop. The cable robot produces purely translational movements in a planar workspace. Furthermore, this special architecture only requires two actuators, which make it fully actuated. From the dynamic model of the robot, general algebraic inequalities are obtained that ensure that the cables remain taut. A general elliptic trajectory is then defined and substituted into the algebraic inequalities to obtain conditions on the geometrical design parameters that ensure that the cables are always in tension. In addition, a special trajectory-specific oscillation frequency emerges and enables the end effector to dynamically move beyond the boundaries of the static workspace, thus expanding the workspace of the mechanism. Finally, a kinematic sensitivity index is studied in order to determine if the parallelogram structure has any influence on the rotational sensitivity of the mechanism.

Optimal Synthesis of a Planar Reactionless Three-Degree-of-Freedom Parallel Mechanism

2010 ◽  
Author(s):  
Jean-Francois Collard ◽  
Cle´ment Gosselin
Keyword(s):  
Power Consumption ◽  
Interesting Property ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Sensitivity Index ◽  
Optimization Approach ◽  
Counter Rotation ◽  
Kinematic Sensitivity ◽  
Global Moment ◽  
Three Degree Of Freedom

A reactionless mechanism is one in which no reaction forces nor moments are transmitted to the base for any arbitrary motion. This interesting property often requires to increase the total mass and the moments of inertia, leading to reduced dynamical performances. Therefore, this paper presents an optimization approach to synthesize and improve the dynamical performance of a reactionless three-degree-of-freedom planar mechanism. The three legs of this original mechanism are composed of reactionless four-bar mechanisms dynamically balanced with only one counter-rotation at the base. The optimization variables are the geometric and inertial parameters, while the goal is to minimize the global moment of inertia of each leg. This will reduce the power consumption of the three actuators and increase the agility. To meet physical and realistic requirements, the optimization problem is also constrained with bounds on the parameters, with the reachability of a given workspace and with a given range on a kinematic sensitivity index. Since different initial guesses of the optimization lead to similar objective results, it is proposed to search for several local solutions (morphologies) in the design space. The final choice among these solutions is made using additional design criteria based on the sensitivity in terms of dynamic balancing and power consumption with respect to the design parameters.

Optimal Synthesis of a Planar Reactionless Three-Degree-of-Freedom Parallel Mechanism

2011 ◽  
Vol 3 (4) ◽  
Author(s):  
Jean-François Collard ◽  
Clément Gosselin
Keyword(s):  
Power Consumption ◽  
Interesting Property ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Sensitivity Index ◽  
Optimization Approach ◽  
Counter Rotation ◽  
Kinematic Sensitivity ◽  
Global Moment ◽  
Three Degree Of Freedom

A reactionless mechanism is one in which no reaction forces nor moments are transmitted to the base for any arbitrary motion. This interesting property often requires to increase the total mass and the moments of inertia, leading to reduced dynamical performances. Therefore, this paper presents an optimization approach to synthesize and improve the dynamical performance of a reactionless three-degree-of-freedom planar mechanism. The three legs of this original mechanism are composed of reactionless four-bar mechanisms dynamically balanced with only one counter-rotation at the base. The optimization variables are the geometric and inertial parameters, whereas the goal is to minimize the global moment of inertia of each leg. This will reduce the power consumption of the three actuators and increase the agility. To meet physical and realistic requirements, the optimization problem is also constrained with bounds on the parameters, with the reachability of a given workspace and with a given range on a kinematic sensitivity index. Since different initial guesses of the optimization process lead to similar objective results, it is proposed to search for several local solutions (morphologies). A methodology is therefore developed to explore the design space and group the results after refinement. The final choice among the obtained solutions is made using additional design criteria based on the sensitivity in terms of dynamic balancing and power consumption with respect to the design parameters.

scholarly journals Social spider optimization algorithm for tuning parameters in PD-like Interval Type-2 Fuzzy Logic Controller applied to a parallel robot

2021 ◽  
Vol 54 (3-4) ◽  
pp. 303-323
Author(s):  
Amjad J Humaidi ◽  
Huda T Najem ◽  
Ayad Q Al-Dujaili ◽  
Daniel A Pereira ◽  
Ibraheem Kasim Ibraheem ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Trajectory Tracking ◽  
Fuzzy Logic Controller ◽  
Optimization Technique ◽  
Parallel Robot ◽  
Design Parameters ◽  
Social Spider ◽  
Social Spider Optimization ◽  
Interval Type

This paper presents control design based on an Interval Type-2 Fuzzy Logic (IT2FL) for the trajectory tracking of 3-RRR (3-Revolute-Revolute-Revolute) planar parallel robot. The design of Type-1 Fuzzy Logic Controller (T1FLC) is also considered for the purpose of comparison with the IT2FLC in terms of robustness and trajectory tracking characteristics. The scaling factors in the output and input of T1FL and IT2FL controllers play a vital role in improving the performance of the closed-loop system. However, using trial-and-error procedure for tuning these design parameters is exhaustive and hence an optimization technique is applied to achieve their optimal values and to reach an improved performance. In this study, Social Spider Optimization (SSO) algorithm is proposed as a useful tool to tune the parameters of proportional-derivative (PD) versions of both IT2FLC and T1FLC. Two scenarios, based on two square desired trajectories (with and without disturbance), have been tested to evaluate the tracking performance and robustness characteristics of proposed controllers. The effectiveness of controllers have been verified via numerical simulations based on MATLAB/SIMULINK programming software, which showed the superior of IT2FLC in terms of robustness and tracking errors.

scholarly journals Geometric Design-based Dimensional Synthesis of a Novel Metamorphic Multi-fingered Hand with Maximal Workspace

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Wei An ◽  
Jun Wei ◽  
Xiaoyu Lu ◽  
Jian S. Dai ◽  
Yanzeng Li
Keyword(s):  
Geometric Design ◽  
Practical Significance ◽  
Design Parameters ◽  
Control Algorithms ◽  
Discretization Method ◽  
Dimensional Synthesis ◽  
Symmetrical Structure ◽  
Design And Optimization ◽  
Total Length

AbstractCurrent research on robotic dexterous hands mainly focuses on designing new finger and palm structures, as well as developing smarter control algorithms. Although the dimensional synthesis of dexterous hands with traditional rigid palms has been carried out, research on the dimensional synthesis of dexterous hands with metamorphic palms remains insufficient. This study investigated the dimensional synthesis of a palm of a novel metamorphic multi-fingered hand, and explored the geometric design for maximizing the precision manipulation workspace. Different indexes were used to value the workspace of the metamorphic hand, and the best proportions between the five links of the palm to obtain the optimal workspace of the metamorphic hand were explored. Based on the fixed total length of the palm member, four nondimensional design parameters that determine the size of the palm were introduced; through the discretization method, the influence of the four design parameters on the workspace of the metamorphic hand with full-actuated fingers and under-actuated fingers was analyzed. Based on the analysis of the metamorphic multi-fingered hand, the symmetrical structure of the palm was designed, resulting in the largest workspace of the multi-fingered hand, and proved that the metamorphic palm has a massive upgrade for the workspace of underactuated fingers. This research contributed to the dimensional synthesis of metamorphic dexterous hands, with practical significance for the design and optimization of novel metamorphic hands.

Dynamic trajectory planning for unmanned ship under multi-object environment

2021 ◽  
Author(s):  
Mengxia Li ◽  
Junmin Mou ◽  
Yixiong He ◽  
Xiaohan Zhang ◽  
Qinqiong Xie ◽  
...  
Keyword(s):  
Trajectory Planning ◽  
Unmanned Ship ◽  
Dynamic Trajectory
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