Safe joint mechanism using passive compliance method for collision safety

2013 ◽  
Author(s):  
O. Zebardast ◽  
H. Moradi ◽  
F. Najafi
Keyword(s):  
Collision Safety ◽  
Passive Compliance ◽  
Joint Mechanism

scholarly journals Safe Joint Mechanism using torsion springs for Collision Safety and Positioning Accuracy of a Robot Arm

2020 ◽  
Author(s):  
Adel Belharet ◽  
Jae-Bok Song
Keyword(s):  
Service Robots ◽  
Robot Arm ◽  
Positioning Accuracy ◽  
External Torque ◽  
High Stiffness ◽  
Collision Safety ◽  
Passive Compliance ◽  
Joint Mechanism ◽  
Mechanical Elements ◽  
Torsion Springs

In recent years, the potential for collision between humans and robots has drawn much attention since service robots are increasingly being used in the human environment. A safe robot arm can be achieved using either an active or passive compliance method. A passive compliance system composed of purely mechanical elements often provides faster and more reliable responses to dynamic collision than an active system involving sensors and actuators. Since positioning accuracy and collision safety of a robot arm are equally important, a robot arm should have very low stiffness when subjected to a collision force capable of causing human injury. Otherwise, it should maintain a very high stiffness. To implement these requirements, a novel safe joint mechanism (SJM-IV) consisting of a CAM, rotational links with rollers, and torsion springs is proposed. The SJM-IV has the advantage of nonlinear stiffness, which can be achieved only with passive mechanical elements. Various analyses and experiments on static and dynamic collisions show high stiffness of the SJM-IV against an external torque less than a predetermined threshold torque, with an abrupt drop in stiffness when the external torque exceeds this threshold. The safe joint mechanism enables a robot manipulator to guarantee positioning accuracy and collision safety, and which is simple to install between an actuator and a robot link without a significant change in the robot’s design.

A Nonlinear Stiffness Safe Joint Mechanism Design for Human Robot Interaction

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Jung-Jun Park ◽  
Jae-Bok Song
Keyword(s):  
Human Robot Interaction ◽  
Service Robots ◽  
Robot Arm ◽  
Positioning Accuracy ◽  
External Torque ◽  
High Stiffness ◽  
Collision Safety ◽  
Passive Compliance ◽  
Joint Mechanism ◽  
Mechanical Elements

Service robots used in human environments must be designed to avoid collisions with humans. A safe robot arm can be designed using active or passive compliance methods. A passive compliance system composed of purely mechanical elements often provides faster and more reliable responses for dynamic collision than an active one involving sensors and actuators. Because positioning accuracy and collision safety are equally important, a robot arm should have very low stiffness when subjected to a collision force that could cause human injury but should otherwise maintain very high stiffness. A novel safe joint mechanism (SJM) consisting of linear springs and a double-slider mechanism is proposed to address these requirements. The SJM has variable stiffness that can be achieved with only passive mechanical elements. Analyses and experiments on static and dynamic collisions show high stiffness against an external torque less than a predetermined threshold value and an abrupt drop in stiffness when the external torque exceeds this threshold. The SJM enables the robotic manipulator to guarantee positioning accuracy and collision safety and it is simple to install between an actuator and a robot link without a significant change in the robot’s design.

scholarly journals ABENICS: Active Ball Joint Mechanism With Three-DoF Based on Spherical Gear Meshings

2021 ◽  
pp. 1-20
Author(s):  
Kazuki Abe ◽  
Kenjiro Tadakuma ◽  
Riichiro Tadakuma
Keyword(s):  
Ball Joint ◽  
Joint Mechanism ◽  
Spherical Gear

A joint mechanism for singlet oxygen generation by diketone-anchored MIL-101: Exciton-mediated energy transfer and photosensitization

2021 ◽  
pp. 118360
Author(s):  
Wentao Zhang ◽  
Kunrui Wei ◽  
Wenguang Huang ◽  
Jianghua Yang ◽  
Yonghai Gan ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Singlet Oxygen ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Joint Mechanism
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