Development of a Compliant Rotary-to-Translational Transmission Mechanism for a Micro-Parallel Kinematic Mechanism

2008 ◽  
Author(s):  
Jessica R. Bronson ◽  
Gloria J. Wiens ◽  
Irene Fassi
Keyword(s):  
Translational Motion ◽  
Integrated Design ◽  
Flexible Beams ◽  
Embedded Sensing ◽  
Rotary Actuator ◽  
Straight Line ◽  
Parallel Kinematic ◽  
Kinematic Mechanisms ◽  
Straight Line Mechanism ◽  
Crank Mechanism

This paper presents the integrated design of an electrostatic comb-drive rotary actuator and a compliant slider-crank mechanism to transmit the motion from a rotary actuator into translational motion. This integrated design yields a transmission exhibiting minimal sliding contact with supporting substrate. This design is applicable to micro-Parallel Kinematic Mechanisms (PKM) for micro/nano positioning and manipulation of optical components including lenses and mirrors. For a 3 degree of freedom micro-PKM, the rotational motion of three electrostatic torsion actuators is converted into translational motion through a compliant transmission device. The compliant transmission is based on a slider-crank mechanism that uses flexible beams for the linkages. The input of the rotary motion through the transmission’s crank yields translational motion of the slider component. The slider is supported via a Roberts straight-line mechanism which yields a suspended slider design and therefore reduced friction and wear within the transmission. Furthermore, the slider component of the transmission provides a linear force-displacement relationship beneficial for embedded sensing. This paper describes the design of the actuation and transmission system and its integration into the kinematics of the micro PKM motion.

scholarly journals Kinematic Synthesis Using Reinforcement Learning

2018 ◽  
Author(s):  
Kaz Vermeer ◽  
Reinier Kuppens ◽  
Justus Herder
Keyword(s):  
Reinforcement Learning ◽  
Path Generation ◽  
Two Dimensional ◽  
Kinematic Synthesis ◽  
Prior Art ◽  
Straight Line ◽  
Feature Based ◽  
Kinematic Mechanisms ◽  
Straight Line Mechanism ◽  
Kinematic Simulations

The presented research demonstrates the synthesis of two-dimensional kinematic mechanisms using feature-based reinforcement learning. As a running example the classic challenge of designing a straight-line mechanism is adopted: a mechanism capable of tracing a straight line as part of its trajectory. This paper presents a basic framework, consisting of elements such as mechanism representations, kinematic simulations and learning algorithms, as well as some of the resulting mechanisms and a comparison to prior art. Series of successful mechanisms have been synthesized for path generation of a straight line and figure-eight.

scholarly journals Turning Gait Planning Method for Humanoid Robots

2018 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Tianqi Yang ◽  
Weimin Zhang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Libo Meng ◽  
...  
Keyword(s):  
Inverted Pendulum ◽  
Center Of Mass ◽  
Translational Motion ◽  
Humanoid Robots ◽  
Inverted Pendulum Model ◽  
Straight Line ◽  
Pendulum Model ◽  
The Stability ◽  
And Control ◽  
Present Simulation

The most important feature of this paper is to transform the complex motion of robot turning into a simple translational motion, thus simplifying the dynamic model. Compared with the method that generates a center of mass (COM) trajectory directly by the inverted pendulum model, this method is more precise. The non-inertial reference is introduced in the turning walk. This method can translate the turning walk into a straight-line walk when the inertial forces act on the robot. The dynamics of the robot model, called linear inverted pendulum (LIP), are changed and improved dynamics are derived to make them apply to the turning walk model. Then, we expend the new LIP model and control the zero moment point (ZMP) to guarantee the stability of the unstable parts of this model in order to generate a stable COM trajectory. We present simulation results for the improved LIP dynamics and verify the stability of the robot turning.

Design and Development of a Novel Infant Surgical Table for 4-DOF Patient Manipulation

2007 ◽  
Author(s):  
Kimberly Ryland ◽  
Carl A. Nelson ◽  
Thomas Hejkal
Keyword(s):  
Premature Infants ◽  
Laser Photocoagulation ◽  
Occupational Injury ◽  
Quality Care ◽  
Blood Vessel Development ◽  
Locking Mechanism ◽  
Straight Line ◽  
Vessel Development ◽  
Straight Line Mechanism ◽  
Standard Table

Retinopathy of Prematurity, caused by abnormal blood vessel development in the retina of premature infants, is a leading cause of childhood blindness. It is treated using laser photocoagulation. Current methods require the surgeon to assume awkward standing positions, which can result in injury to the surgeon if repeated often. To assist surgeons in providing quality care and prevent occupational injury, a new infant surgical table was designed. The engineered solution is an attachment to a standard surgical table, saving cost and space. This takes advantage of the adjustable height and tilt provided by the standard table, while 360° rotation designed into the attachment allows the surgeon to sit during surgery. The critical cords and tubes are routed through the attachment to avoid pulling and kinking. A four-bar locking mechanism allows easy attachment to standard medical railing. Finally, a straight line mechanism provides positive locking of the rotation, allowing precise positioning of the infant.

Mathematical Model for Face-Hobbed Straight Bevel Gears

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Yi-Pei Shih
Keyword(s):  
Mathematical Model ◽  
Bevel Gear ◽  
Tooth Contact Analysis ◽  
Rolling Circle ◽  
High Productivity ◽  
Bevel Gears ◽  
Straight Line ◽  
Base Circle ◽  
Straight Line Mechanism ◽  
Straight Lines

Face hobbing, a continuous indexing and double-flank cutting process, has become the leading method for manufacturing spiral bevel gears and hypoid gears because of its ability to support high productivity and precision. The method is unsuitable for cutting straight bevel gears, however, because it generates extended epicycloidal flanks. Instead, this paper proposes a method for fabricating straight bevel gears using a virtual hypocycloidal straight-line mechanism in which setting the radius of the rolling circle to equal half the radius of the base circle yields straight lines. This property can then be exploited to cut straight flanks on bevel gears. The mathematical model of a straight bevel gear is developed based on a universal face-hobbing bevel gear generator comprising three parts: a cutter head, an imaginary generating gear, and the motion of the imaginary generating gear relative to the work gear. The proposed model is validated numerically using the generation of face-hobbed straight bevel gears without cutter tilt. The contact conditions of the designed gear pairs are confirmed using the ease-off topographic method and tooth contact analysis (TCA), whose results can then be used as a foundation for further flank modification.

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