A General‐Purpose Safety Light Curtain Using ToF Sensor for End Effector on Human Collaborative Robot

2020 ◽  
Vol 15 (12) ◽  
pp. 1868-1874
Author(s):  
Satoshi Tsuji ◽  
Teruhiko Kohama
Keyword(s):  
General Purpose ◽  
End Effector ◽  
Collaborative Robot

scholarly journals Cobot with Prismatic Compliant Joint Intended for Doppler Sonography

Robotics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 14 ◽  
Author(s):  
Juan Sandoval ◽  
Med Amine Laribi ◽  
Saïd Zeghloul ◽  
Marc Arsicault ◽  
Jean-Michel Guilhem
Keyword(s):  
Musculoskeletal Disorder ◽  
Doppler Sonography ◽  
Impact Force ◽  
Variable Stiffness ◽  
Safety Performance ◽  
End Effector ◽  
Force Criterion ◽  
Compliant Joint ◽  
The Impact ◽  
Collaborative Robot

This paper deals with a collaborative robot, i.e., cobot, coupled with a new prismatic compliant joint (PCJ) at its end-effector. The proposed collaborative solution is intended for Doppler sonography to prevent musculoskeletal disorders issues. On one hand, the Doppler sonographer’s postures are investigated based on motion capture use during the arteries examination. This study highlighted that configurations adopted by angiologists lead to the musculoskeletal disorder. On the other hand, the proposed PCJ with variable stiffness gives an intrinsic compliance to the cobot handling the probe. This feature allows preserving the human safety when both human and cobot share a common workspace. The effectiveness of the proposed solution is experimentally validated through a 7-DoF Franka Emika robot virtually coupled with the PCJ, during the execution of a trajectory performed during a Doppler ultrasound exam. The impact force criterion is considered as a safety performance.

Singularities of the Typical Collaborative Robot Arm

2018 ◽  
Author(s):  
Mohammad H. FarzanehKaloorazi ◽  
Ilian A. Bonev
Keyword(s):  
Jacobian Matrix ◽  
Robot Arm ◽  
End Effector ◽  
Collaborative Robot

In this paper, the singularities of the typical 6R collaborative robot (such as the cobots made by Universal Robots) are analytically and geometrically described. Since the axes of the last three joints in such a cobot are not concurrent, the singularities are slightly different from those of the PUMA-style manipulator. It is shown that the determinant of the Jacobian matrix of the typical cobot splits into four factors, three of which can vanish. As in the typical PUMA-style manipulator, the three vanishing factors correspond to shoulder, elbow and wrist singularities. However, in a wrist singularity, the redundant motion associated with no end-effector movement is more complex.

scholarly journals Control Strategy for Direct Teaching of Non-Mechanical Remote Center Motion of Surgical Assistant Robot with Force/Torque Sensor

2021 ◽  
Vol 11 (9) ◽  
pp. 4279
Author(s):  
Minhyo Kim ◽  
Youqiang Zhang ◽  
Sangrok Jin
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Dimensional Space ◽  
Degree Of Freedom ◽  
Torque Sensor ◽  
Motion Generation ◽  
End Effector ◽  
Generation Algorithm ◽  
Direct Teaching ◽  
Collaborative Robot

This paper presents a control strategy that secures both precision and manipulation sensitivity of remote center motion with direct teaching for a surgical assistant robot. Remote center motion is an essential function of conventional laparoscopic surgery, and the most intuitive way a surgeon manipulates a robot is through direct teaching. The surgical assistant robot must maintain the position of the insertion port in three-dimensional space during the four-degree-of-freedom motions such as pan, tilt, spin, and forward/backward. In addition, the robot should move smoothly when controlling it with the hands during the surgery. In this study, a six-degree-of-freedom collaborative robot performs the cone-shaped trajectory with pan and tilt motion of an end-effector keeping the position of the remote center. Instead of the bulky mechanically constrained remote center motion mechanism, a conventional collaborative robot is used to mimic the wrist movement of a scrub nurse. A force/torque sensor that is attached between the robot and end-effector estimates the surgeon’s intention. A direct teaching control strategy based on position control is applied to guarantee precise remote center position maintenance performance. A motion generation algorithm is designed to generate motion by utilizing a force/torque sensor value. The parameters of the motion generation algorithm are optimized so that the robot can be operated with uniform sensitivity in all directions. The precision of remote center motion and the torque required for direct teaching are analyzed through pan and tilt motion experiments.

scholarly journals Human-robot collaboration for surface treatment tasks

2019 ◽  
Vol 20 (1) ◽  
pp. 148-184
Author(s):  
Luis Gracia ◽  
J. Ernesto Solanes ◽  
Pau Muñoz-Benavent ◽  
Jaime Valls Miro ◽  
Carlos Perez-Vidal ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Surface Treatment ◽  
Sliding Mode ◽  
Experimental Results ◽  
Force Sensors ◽  
End Effector ◽  
Mode Control ◽  
Task Priority ◽  
Human Robot Collaboration ◽  
Collaborative Robot

Abstract This paper presents a human-robot closely collaborative solution to cooperatively perform surface treatment tasks such as polishing, grinding, finishing, deburring, etc. The proposed scheme is based on task priority and non-conventional sliding mode control. Furthermore, the proposal includes two force sensors attached to the manipulator end-effector and tool: one sensor is used to properly accomplish the surface treatment task, while the second one is used by the operator to guide the robot tool. The applicability and feasibility of the proposed collaborative solution for robotic surface treatment are substantiated by experimental results using a redundant 7R manipulator: the Sawyer collaborative robot.

Three-finger SMA robot hand and its practical analysis

Robotica ◽  
2002 ◽  
Vol 20 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Savas Dilibal ◽  
Ertan Guner ◽  
Nizami Akturk
Keyword(s):  
Assembly Line ◽  
General Purpose ◽  
Robot Hand ◽  
End Effector ◽  
Industrial Environment ◽  
Different Types ◽  
Robot Hands ◽  
Industrial Operations ◽  
Practical Analysis ◽  
Specific Temperature

Gripping of different types of objects with a multi-finger robot hand is a vital task for robot arms. Grippers, which are end effector elements in robot applications, are employed in various industrial operations such as transferring, assembling, welding and painting. However, if a gripper is considered for handling different jobs or to carry different types of parts in an assembly line, a general-purpose robot hand is going to be required. There are various technological actuators of robot hands such as electrical, hydraulic and pneumatic motors, etc. Besides these conventional actuators, it is possible to include Shape Memory Alloys (SMA) in the category of technological actuators. The SMA can give materials motion by moving to a predetermined position, at a specific temperature. The conversion of this motion to a gripping action of the robot hand is the heart of the matter. In this study, a robot hand is developed using Ni-Ti SMA and a set of experiments were performed in order to check the compatibility of the system in an industrial environment.

scholarly journals Automated Screwing of Fittings in Pneumatic Manifolds

2021 ◽  
Vol 15 (2) ◽  
pp. 140-148
Author(s):  
Michele Gabrio Antonelli ◽  
◽  
Pierluigi Beomonte Zobel
Keyword(s):  
Added Value ◽  
Human Operator ◽  
End Effector ◽  
Collaborative Robotics ◽  
Automated Process ◽  
To Receive ◽  
Collaborative Robot ◽  
Vibrating Feeder

The task of screwing is based on a set of actions with no added value, requiring precision, attention, and repeatability. These set of actions could consist of alienating and demanding activity for a human operator. Collaborative robotics can facilitate the performance of such tasks. This investigation focuses on the development of a smart station for the automated screwing of fittings in pneumatic manifolds. The collaborative robot Sawyer produced by Rethink Robotics is equipped with an appropriate end-effector and was utilized to receive the fittings from a vibrating feeder towards the end-effector. This facilitated centering of the fittings on the threaded holes, and the performance of the screwing task on a set of manifolds placed on a rotating station. The design of the end-effector and its prototype is described. In addition, the proposed automated process was experimentally tested and its effectiveness was validated.

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