Analysis of Fingertip Force Vector for Pinch-Lifting Gripper With Robust Adaptation to Environments

2021 ◽  
pp. 1-17
Author(s):  
Dukchan Yoon ◽  
Youngjin Choi
Keyword(s):  
Force Vector ◽  
Fingertip Force

Activation of intrinsic and extrinsic finger muscles in relation to the fingertip force vector

2002 ◽  
Vol 146 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Theodore E. Milner ◽  
Sukhdeep S. Dhaliwal
Keyword(s):  
Force Vector ◽  
Fingertip Force

Finite Deformation Stiffness of Sliding Elastomeric Bearings

2011 ◽  
Vol 374-377 ◽  
pp. 1858-1862
Author(s):  
Jian Chun Xiao ◽  
Peng Liu ◽  
Ke Jian Ma
Keyword(s):  
Parametric Analysis ◽  
Steel Plates ◽  
Structural Behavior ◽  
Analysis Method ◽  
Force Vector ◽  
Elastomeric Bearings ◽  
Before And After ◽  
Bearing Stiffness ◽  
Vector Formula

Anchor bolts are set in some elastomeric bearings of large-span column-supported spatial steel roofs. Besides helping the bearing in-site assembly, the bolts play the roles of sliding position limitation and vertical anchorage. To analyze the effect of bearings on nonlinear structural behavior, the bearing stiffness change is studied just before and after the elastomer pad is in contact with the bolts. For the bearing that the pad is glued with the top/bottom steel plates, three kinds of relation of pad and bolts are discussed and an approximate horizontal stiffness formula is obtained with parametric analysis method. Based on the analysis results a stiffness expression for sliding elastomeric bearings is deduced. To solve the computational problem caused by the bearing stiffness changes, an improved imbalance force vector formula is proposed. Case study shows that the bolts have influence upon the computed results more significantly.

scholarly journals Associations between hoof shape and the position of the frontal plane ground reaction force vector in walking horses

2015 ◽  
Vol 64 (2) ◽  
pp. 76-81 ◽  
Author(s):  
GR Colborne ◽  
JE Routh ◽  
KR Weir ◽  
JE McKendry ◽  
E Busschers
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Frontal Plane ◽  
Force Vector

scholarly journals SPONTANEOUS CORRECTION OF EXTERNAL TIBIOFEMORAL ROTATION AND TIBIAL TUBEROSITY-TROCHLEAR GROOVE DISTANCE OCCURS AFTER MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION IN FIXED OR OBLIGATORY DISLOCATORS

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0013
Author(s):  
Alexandra H. Aitchison ◽  
Kenneth M. Lin ◽  
Daniel W. Green
Keyword(s):  
Patellar Instability ◽  
Ligament Reconstruction ◽  
Medial Patellofemoral Ligament ◽  
Extensor Mechanism ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Medial Patellofemoral Ligament Reconstruction ◽  
Force Vector ◽  
Tibiofemoral Rotation ◽  
The Mean

Background: Tibial tubercle to trochlear groove distance (TT-TG) and external tibiofemoral rotation (TFR) through the knee joint have been identified potential contributing factors to patellar instability. In patients with a fixed or obligatory lateral patella dislocation (FOD), the normal force vector of the extensor mechanism is altered, so instead of a direct axial pull to cause extension, it exerts a lateralizing and external rotatory force on the tibia via the tibial tubercle. Hypothesis/Purpose: The purpose of this study is to investigate postoperative changes in TT-TG and TFR after medial patellofemoral ligament reconstruction (MPFLR) in two clinical cohorts: standard traumatic patellar instability (SPI) patients and FOD patients. We hypothesized that by surgically relocating the patella in the trochlea, and re-establishing medial sided soft tissue tension, the increased medializing force vector on the patella may exert enough force to alter resting rotation of the tibia in relation to the femur in the FOD group. Methods: A retrospective study was performed from April 2009 to February 2019. FOD and SPI patients under 18 years with available magnetic resonance imaging (MRI) of the knee before and after MPFLR were eligible. All FOD patients in the time frame were analyzed and SPI patients were randomly selected. Exclusion criteria were outside institution MRI, concomitant alignment procedures done at the time of MPFLR, and prior MPFLR or tibial tubercle osteotomy. TT-TG and TFR (using the posterior femoral and tibial condylar lines) were measured blindly on initial axial MRI. Statistical analysis using a paired sample t-test was performed with significance set at p<0.05. Results: A total of 30 patients were included, 14 in the FOD group and 16 in the SPI group. The mean age at time of surgery was 13.9 years (range 10-17 years), 53% of the cohort was female, and the mean time from surgery to follow-up MRI was 2.0 years. Demographics by group are shown in Table 1. TT-TG and TFR were not significantly different preoperatively versus postoperatively in the SPI group (Table 2). In the FOD group, both TT-TG (17.7 vs 13.7, P=.019) and TFR (8.6 vs 3.1, P=.025) decreased significantly on postoperative MRI. Conclusion: The postoperative decrease in TT-TG and TFR in the FOD group suggests that MPFLR in fixed or obligatory dislocators can improve the external rotation deformity through the level of the joint, and thus may help normalize the forces acting through the extensor mechanism. Tables/ Figures [Table: see text][Table: see text]

Design of an optical soft sensor for measuring fingertip force and contact recognition

2017 ◽  
Vol 15 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Haedo Cho ◽  
Hyosang Lee ◽  
Yeongjin Kim ◽  
Jung Kim
Keyword(s):  
Soft Sensor ◽  
Fingertip Force

scholarly journals Responses of hair cells to statocyst rotation.

1975 ◽  
Vol 66 (4) ◽  
pp. 507-530 ◽  
Author(s):  
D L Alkon
Keyword(s):  
Hair Cell ◽  
Centrifugal Force ◽  
Hair Cells ◽  
New Technique ◽  
Force Vector ◽  
Generator Potential ◽  
Recording Apparatus ◽  
Intracellular Potentials ◽  
A New Technique

A new technique is described for stimulating hair cells of the Hermissenda statocyst. The preparation and recording apparatus can be rotated at up to 78 rpm while recording intracellular potentials. Hair cells in front of the centrifugal force vector depolarize in response to rotation. Hair cells in back of the centrifugal force vector hypoerpolarize in response to rotation. Mechanisms by which the hair cell generator potential might arise are examined.

Mechanical power output during running accelerations in wild turkeys

2002 ◽  
Vol 205 (10) ◽  
pp. 1485-1494 ◽  
Author(s):  
Thomas J. Roberts ◽  
Jeffrey A. Scales
Keyword(s):  
Power Output ◽  
Ground Reaction Force ◽  
Center Of Mass ◽  
Reaction Force ◽  
Mechanical Power ◽  
Force Vector ◽  
Instantaneous Power ◽  
Hindlimb Muscle ◽  
Wild Turkeys ◽  
Running Mechanics

SUMMARYWe tested the hypothesis that the hindlimb muscles of wild turkeys(Meleagris gallopavo) can produce maximal power during running accelerations. The mechanical power developed during single running steps was calculated from force-plate and high-speed video measurements as turkeys accelerated over a trackway. Steady-speed running steps and accelerations were compared to determine how turkeys alter their running mechanics from a low-power to a high-power gait. During maximal accelerations, turkeys eliminated two features of running mechanics that are characteristic of steady-speed running: (i) they produced purely propulsive horizontal ground reaction forces, with no braking forces, and (ii) they produced purely positive work during stance, with no decrease in the mechanical energy of the body during the step. The braking and propulsive forces ordinarily developed during steady-speed running are important for balance because they align the ground reaction force vector with the center of mass. Increases in acceleration in turkeys correlated with decreases in the angle of limb protraction at toe-down and increases in the angle of limb retraction at toe-off. These kinematic changes allow turkeys to maintain the alignment of the center of mass and ground reaction force vector during accelerations when large propulsive forces result in a forward-directed ground reaction force. During the highest accelerations, turkeys produced exclusively positive mechanical power. The measured power output during acceleration divided by the total hindlimb muscle mass yielded estimates of peak instantaneous power output in excess of 400 W kg-1 hindlimb muscle mass. This value exceeds estimates of peak instantaneous power output of turkey muscle fibers. The mean power developed during the entire stance phase increased from approximately zero during steady-speed runs to more than 150 W kg-1muscle during the highest accelerations. The high power outputs observed during accelerations suggest that elastic energy storage and recovery may redistribute muscle power during acceleration. Elastic mechanisms may expand the functional range of muscle contractile elements in running animals by allowing muscles to vary their mechanical function from force-producing struts during steady-speed running to power-producing motors during acceleration.

A Prototype of Fingertip Force Sensor Using Small Piezoelectric Element

2021 ◽  
Vol 2021 (0) ◽  
pp. 1P3-I04
Author(s):  
Haruki YAMAMOTO ◽  
Takuma AKIDUKI ◽  
Atsuo HONNA ◽  
Tomoaki MASIMO
Keyword(s):  
Piezoelectric Element ◽  
Force Sensor ◽  
Fingertip Force
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