Analysis of a misalignment-insensitive spur gear transmission using a Rzeppa joint

2020 ◽  
pp. 095440622095035
Author(s):  
Zhaksylyk Galym ◽  
Christos Spitas
Keyword(s):  
Real Time ◽  
Contact Stress ◽  
Spur Gear ◽  
Joint Interface ◽  
The Novel ◽  
Mesh Stiffness ◽  
Internal Interface ◽  
Trade Off ◽  
Constant Stiffness ◽  
Novel Design

The design of a novel gear system based on a Rzeppa joint internal interface is presented and analysed. The joint allows the transmission of torque loads while allowing real-time re-alignment of the gear to eliminate non-torque loads arising from misalignment. This gear, when part of a misaligned pair, is shown by means of quasi-static FE simulations to remain essentially under the same stress conditions, even when under considerable misalignment, and to outperform crowned gears. The trade-off is increased contact stress at the ball elements of the joint interface. In addition, the mesh stiffness for the conventional and the novel design are estimated, showing that the proposed design produces a lower but nearly constant stiffness throughout the mesh cycle.

Design, Modeling, and Integration of a Flexible Universal Spatial Robotic Tail

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
William S. Rone ◽  
Wael Saab ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Feedback Control ◽  
Real Time ◽  
Dynamic Model ◽  
Joint Angle ◽  
The Novel ◽  
Joint Angles ◽  
Experimental Prototype ◽  
Continuous Deformation ◽  
Serial Chain ◽  
Novel Design

This paper presents the novel design of a bioinspired robot capable of generating spatial loading relative to its base. By looking to nature at how animals utilize their tails, a bioinspired structure is developed that utilizes a redundant serial chain of rigid links to mimic the continuous deformation of a biological tail. Individual links are connected by universal joints to enable a spatial robot workspace capable of generating spatial loading comprised of pitch, yaw, and roll direction contributions. Two sets of three cables are used to create two actuated segments along the robot. A dynamic model of the robot is derived using prescribed cable displacement trajectories as inputs to determine the resulting joint angle trajectories and cable tensions. Sensors are integrated on-board the robot to calculate joint angles and joint velocities in real-time for use in feedback control. The loading capabilities of the robot are analyzed, and an experimental prototype is integrated and demonstrated.

Sky Segmentation for Enhanced Depth Reconstruction and Bokeh Rendering with Efficient Architectures

2020 ◽  
Vol 2020 (14) ◽  
pp. 378-1-378-7
Author(s):  
Tyler Nuanes ◽  
Matt Elsey ◽  
Radek Grzeszczuk ◽  
John Paul Shen
Keyword(s):  
Real Time ◽  
Mobile Device ◽  
Computational Cost ◽  
False Positives ◽  
Compact Model ◽  
High Quality ◽  
False Negatives ◽  
Trade Off ◽  
Depth Reconstruction ◽  
Binary Classifiers

We present a high-quality sky segmentation model for depth refinement and investigate residual architecture performance to inform optimally shrinking the network. We describe a model that runs in near real-time on mobile device, present a new, highquality dataset, and detail a unique weighing to trade off false positives and false negatives in binary classifiers. We show how the optimizations improve bokeh rendering by correcting stereo depth misprediction in sky regions. We detail techniques used to preserve edges, reject false positives, and ensure generalization to the diversity of sky scenes. Finally, we present a compact model and compare performance of four popular residual architectures (ShuffleNet, MobileNetV2, Resnet-101, and Resnet-34-like) at constant computational cost.

Influence of simultaneous time-varying bearing and tooth mesh stiffness fluctuations on spur gear pair vibration

2019 ◽  
Vol 97 (2) ◽  
pp. 1403-1424 ◽  
Author(s):  
Guanghui Liu ◽  
Jun Hong ◽  
Robert G. Parker
Keyword(s):  
Spur Gear ◽  
Time Varying ◽  
Gear Pair ◽  
Mesh Stiffness

scholarly journals Increased Delay Discounting on a Novel Real-Time Task among Girls, but not Boys, with ADHD

2015 ◽  
Vol 22 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Keri S. Rosch ◽  
Stewart H. Mostofsky
Keyword(s):  
Real Time ◽  
Delay Discounting ◽  
Diagnostic Group ◽  
Group Differences ◽  
The Novel ◽  
Typically Developing ◽  
Subjective Ratings ◽  
Time Discounting ◽  
Children With Adhd ◽  
Girls With Adhd

AbstractThe aim of this study was to examine delay discounting in girls and boys with ADHD-Combined type (ADHD-C) relative to typically developing (TD) children on two tasks that differ in the extent to which the rewards and delays were experienced by participants. Children ages 8–12 years with ADHD-C (n=65; 19 girls) and TD controls (n=55; 15 girls) completed two delay discounting tasks involving a series of choices between smaller, immediate and larger, delayed rewards. The classic delay discounting task involved choices about money at delays of 1–90 days and only some of the outcomes were actually experienced by the participants. The novel real-time discounting task involved choices about an immediately consumable reward (playing a preferred game) at delays of 25–100 s, all of which were actually experienced by participants. Participants also provided subjective ratings of how much they liked playing the game and waiting to play. Girls with ADHD-C displayed greater delay discounting compared to boys with ADHD-C and TD girls and boys on the real-time discounting task. Diagnostic group differences were not evident on the classic discounting task. In addition, children with ADHD-C reported wanting to play the game more and liking waiting to play the game less than TD children. This novel demonstration of greater delay discounting among girls with ADHD-C on a discounting task in which the rewards are immediately consumable and the delays are experienced in real-time informs our understanding of sex differences and motivational processes in children with ADHD. (JINS, 2016, 22, 12–23)

Calculation and Measurement of the Stiffness and Damping Coefficients for a Low Impedance Hydrodynamic Bearing

1997 ◽  
Vol 119 (1) ◽  
pp. 57-63 ◽  
Author(s):  
M. J. Goodwin ◽  
P. J. Ogrodnik ◽  
M. P. Roach ◽  
Y. Fang
Keyword(s):  
Experimental Data ◽  
Dynamic Stiffness ◽  
Perturbation Technique ◽  
The Novel ◽  
Oil Film ◽  
Hydrodynamic Bearing ◽  
Damping Coefficients ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Novel Design

This paper describes a combined theoretical and experimental investigation of the eight oil film stiffness and damping coefficients for a novel low impedance hydrodynamic bearing. The novel design incorporates a recess in the bearing surface which is connected to a standard commercial gas bag accumulator; this arrangement reduces the oil film dynamic stiffness and leads to improved machine response and stability. A finite difference method was used to solve Reynolds equation and yield the pressure distribution in the bearing oil film. Integration of the pressure profile then enabled the fluid film forces to be evaluated. A perturbation technique was used to determine the dynamic pressure components, and hence to determine the eight oil film stiffness and damping coefficients. Experimental data was obtained from a laboratory test rig in which a test bearing, floating on a rotating shaft, was excited by a multi-frequency force signal. Measurements of the resulting relative movement between bearing and journal enabled the oil film coefficients to be measured. The results of the work show good agreement between theoretical and experimental data, and indicate that the oil film impedance of the novel design is considerably lower than that of a conventional bearing.

Modified Posicast Control Design Method Based on the Parameters of a Fractional Order System

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Erhan Yumuk ◽  
Müjde Güzelkaya ◽  
İbrahim Eksin
Keyword(s):  
Real Time ◽  
Fractional Order ◽  
Control Method ◽  
Design Method ◽  
Order System ◽  
Half Cycle ◽  
Empirical Formulas ◽  
Real Time System ◽  
Novel Design ◽  
Better Than

Abstract In this study, a novel design method for half-cycle and modified posicast controller structures is proposed for a class of the fractional order systems. In this method, all required design variable values, namely, the input step magnitudes and their application times are obtained as functions of fractional system parameters. Moreover, empirical formulas are obtained for the overshoot values of the compensated system with half-cycle and modified posicast controllers designed utilizing this method. The proposed design methodology has been tested via simulations and ball balancing real-time system. It is observed that the derived formulas are in coherence with outcomes of the simulation and real-time application. Furthermore, the performance of modified posicast controller designed using proposed method is much better than other posicast control method.

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