New repetitive motion planning scheme with cube end-effector planning precision for redundant robotic manipulators

Robotica ◽  
2021 ◽  
pp. 1-22
Author(s):  
Limin Shen ◽  
Yuanmei Wen
Keyword(s):  
Theoretical Analysis ◽  
Motion Planning ◽  
Robotic Manipulators ◽  
Robotic Manipulator ◽  
Repetitive Motion ◽  
End Effector ◽  
Difference Formula ◽  
Planning Scheme ◽  
Simulation Results ◽  
The Difference

Abstract Repetitive motion planning (RMP) is important in operating redundant robotic manipulators. In this paper, a new RMP scheme that is based on the pseudoinverse formulation is proposed for redundant robotic manipulators. Such a scheme is derived from the discretization of an existing RMP scheme by utilizing the difference formula. Then, theoretical analysis and results are presented to show the characteristic of the proposed RMP scheme. That is, this scheme possesses the characteristic of cube pattern in the end-effector planning precision. The proposed RMP scheme is further extended and studied for redundant robotic manipulators under joint constraint. Based on a four-link robotic manipulator, simulation results substantiate the effectiveness and superiority of the proposed RMP scheme and its extended one.

On-the-Fly Substrate Eccentricity Recognition for Robotized Manufacturing Systems

2005 ◽  
Vol 127 (1) ◽  
pp. 206-216 ◽  
Author(s):  
Martin Hosek ◽  
Jan Prochazka
Keyword(s):  
Optical Sensors ◽  
Semiconductor Manufacturing ◽  
Manufacturing Systems ◽  
Robotic Manipulator ◽  
End Effector ◽  
Transfer Path ◽  
The Difference ◽  
Manufacturing Applications ◽  
Actual Location

This paper describes a method for on-the-fly determination of eccentricity of a circular substrate, such as a silicon wafer in semiconductor manufacturing applications, carried by a robotic manipulator, where eccentricity refers to the difference between the actual location of the center of the substrate and its desired position on the end-effector of the robotic manipulator. The method utilizes a pair of external optical sensors located along the substrate transfer path. When moving a substrate along the transfer path, the robotic manipulator captures the positions and velocities of the end-effector at which the edges of the substrate are detected by the sensors. These data along with the expected radius of the substrate and the coordinates of the sensors are used to determine the eccentricity of the substrate. This information can be used by the robotic manipulator to compensate for eccentricity of the substrate when performing a place operation, resulting in the substrate being placed centered regardless of the amount and direction of the initial eccentricity. The method can also be employed to detect a defect, such as breakage, of a circular substrate and report an error condition which can abort or otherwise adjust operation of the robotic manipulator.

LENGTH-OPTIMIZED SMOOTH OBSTACLE AVOIDANCE FOR ROBOTIC MANIPULATORS

2011 ◽  
Vol 35 (4) ◽  
pp. 505-514 ◽  
Author(s):  
Soheil S. Parsa ◽  
Juan A. Carretero ◽  
Roger Boudreau
Keyword(s):  
Harmonic Function ◽  
Obstacle Avoidance ◽  
Robotic Manipulators ◽  
Joint Space ◽  
Displacement Velocity ◽  
End Effector ◽  
Smooth Path ◽  
Simulation Results

This paper presents a novel optimized smooth obstacle avoidance algorithm for robotic manipulators. First, a 3-4-5 interpolating polynomial is used to plan a smooth trajectory between initial and final positions in the joint space without considering any obstacles. Then, a simple harmonic function, which is smooth and continuous in displacement, velocity and acceleration, is applied to generate a new smooth path avoiding collisions between the robot links and an obstacle. The obstacle avoidance portions on the path are optimized such that the length of the path traversed by the end-effector is minimized. Simulation results for a 6 DOF serial manipulator demonstrate the efficiency of the proposed method.

Gateway Configuration for Rapid Pick-and-Place Operations of 2-Degrees-of-Freedom Parallel Robots

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Andrea Martin-Parra ◽  
David Rodriguez-Rosa ◽  
Sergio Juarez-Perez ◽  
Guillermo Rubio-Gomez ◽  
Antonio Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Parallel Robots ◽  
End Effector ◽  
Joint Coordinates ◽  
Pick And Place ◽  
Low Energy Consumption ◽  
Simulation Results ◽  
The Difference

Abstract This article presents a new assembling for 2 degrees-of-freedom (DOFs) parallel robots for executing rapid pick-and-place operations with low energy consumption. A conventional design of 2-DOF parallel robots is based on five-bar mechanisms. Collisions between links are highly possible, restricting the end-effector workspace and/or increasing the trajectory time to avoid collisions. In this article, an alternative assembling for preventing collisions is presented. This novel assembling allows exploring the difference between the four five-bar mechanism configurations for the same position of the end-effector. Some of these configurations yield to lower time and/or lower energy consumption for the same motorization. First, a dynamic model of the robot has been developed using matlab® and simulink® and validated by comparison with the results obtained by adams® software. A robust cascade PD regulator for controlling joint coordinates has been tuned providing a high accurate end-effector positioning. Finally, simulation results of four configurations are presented for executing controlled maneuvers. The obtained results demonstrate that the conventional configuration is the worst one in terms of trajectory time or energy consumption and, conversely, the best one corresponds to an uncommonly used configuration. A workspace map where all configurations provide faster maneuvers has been obtained in terms of Jacobian matrix and mechanism elbows distance. The results presented here allow designing a rapid manipulator for pick-and-place operations.

Substrate Centering Method for Robotized Semiconductor Manufacturing Systems

Manufacturing ◽  
2003 ◽  
Author(s):  
Martin Hosek ◽  
Jan Prochazka
Keyword(s):  
Optical Sensors ◽  
Semiconductor Manufacturing ◽  
Manufacturing Systems ◽  
Robotic Manipulator ◽  
End Effector ◽  
Transfer Path ◽  
The Difference ◽  
Manufacturing Applications ◽  
Actual Location

This paper describes a method for on-the-fly determination of eccentricity of a circular silicon substrate carried by a robotic manipulator in semiconductor manufacturing applications, where eccentricity refers to the difference between the actual location of the center of the substrate and its desired position on the end-effector of the robotic manipulator. The method utilizes a pair of external optical sensors located along the substrate transfer path. When moving a substrate along the transfer path, the robotic manipulator captures the positions and velocities of the end-effector at which the edges of the substrate are detected by the sensors. These data along with the expected radius of the substrate and the coordinates of the sensors are used to determine the eccentricity of the substrate. This information can be used by the robotic manipulator to compensate for eccentricity of the substrate when performing a place operation, resulting in the substrate being placed centered regardless of the amount and direction of the initial eccentricity. The method can also be employed to detect a defect, such as breakage, of a substrate and report an error condition which can abort or otherwise adjust operation of the robotic manipulator.

Fault Tolerant Motion Planning With Avoidance of the Sudden Change of Joint Velocity for Two Coordinating Redundant Manipulators

2005 ◽  
Author(s):  
Jing Zhao ◽  
Kailiang Zhang ◽  
Xuebin Yao
Keyword(s):  
Motion Planning ◽  
Fault Tolerant ◽  
Dynamic Properties ◽  
Sudden Change ◽  
Redundant Manipulators ◽  
Motion Stability ◽  
Planning Algorithm ◽  
Simulation Results ◽  
The Difference ◽  
Joint Velocity

The sudden change of joint velocity in fault tolerant operation of two coordinating manipulators for joint-locking failures is studied. First, the difference between the joint velocity of original manipulator and that of reduced manipulator is defined as the sudden change in joint velocity. Then, a corresponding fault tolerant planning algorithm based on this criterion is proposed. At last, a simulation example of fault tolerant operations is implemented with two planar 3R manipulators. Simulation results show that this algorithm can effectively avoid the sudden change of joint velocity occurring in fault tolerant operation of two coordinating manipulators, strengthen their motion stability and so improve their kinematical and dynamic properties in fault tolerant operations.

Path planning of the hybrid parallel robot for ankle rehabilitation

Robotica ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 173-184 ◽  
Author(s):  
Hamid Rakhodaei ◽  
Mozafar Saadat ◽  
Alireza Rastegarpanah ◽  
Che Zulkhairi Abdullah
Keyword(s):  
Theoretical Analysis ◽  
Path Planning ◽  
Dynamic Analysis ◽  
Parallel Robot ◽  
Degree Of Freedom ◽  
End Effector ◽  
Ankle Rehabilitation ◽  
Series Of Experiments ◽  
Linear Actuators ◽  
Simulation Results

SUMMARYThis paper presents a new configuration for ankle rehabilitation using a 9-DOF (degree of freedom) hybrid parallel robot. The robot contains nine linear actuators serially connecting two movable platforms and one stationary platform. The optimization is based on the singularity and dynamic analysis of the robot. The obtained data of the ankle motions from a series of experiments were applied to the model in order to investigate the motion of the end-effector and the force required for each actuator in a particular path. The end-effector tracking simulation results validated the proposed theoretical analysis of the required rehabilitation path of the foot.

scholarly journals An Exponential Varying-Parameter Neural Network for Repetitive Tracking of Mobile Manipulators

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ying Kong ◽  
Qingqing Tang ◽  
Jingsheng Lei ◽  
Ruiyang Zhang
Keyword(s):  
Neural Network ◽  
Trajectory Planning ◽  
Matrix Equation ◽  
Mobile Manipulator ◽  
Mobile Manipulators ◽  
Time Varying ◽  
Repetitive Motion ◽  
End Effector ◽  
The Matrix ◽  
Simulation Results

A novel exponential varying-parameter neural network (EVPNN) is presented and investigated to solve the inverse redundancy scheme of the mobile manipulators via quadratic programming (QP). To suspend the phenomenon of drifting free joints and guarantee high convergent precision of the end effector, the EVPNN model is applied to trajectory planning of mobile manipulators. Firstly, the repetitive motion scheme for mobile manipulators is formulated into a QP index. Secondly, the QP index is transformed into a time-varying matrix equation. Finally, the proposed EVPNN method is used to solve the QP index via the matrix equation. Theoretical analysis and simulations illustrate that the EVPNN solver has an exponential convergent speed and strong robustness in mobile manipulator applications. Comparative simulation results demonstrate that the EVPNN possesses a superior convergent rate and accuracy than the traditional ZNN solver in repetitive trajectory planning with a mobile manipulator.

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