Modeling and NC Programming for Free-Form Surfaces by Haptic Interfaces

1996 ◽  
Author(s):  
Satoshi Kanai ◽  
Hidetomo Takahashi
Keyword(s):  
Force Feedback ◽  
Surface Modeling ◽  
Simulation Software ◽  
Free Form ◽  
Operating Efficiency ◽  
Programming System ◽  
Haptic Interfaces ◽  
Passive Force ◽  
Active Force ◽  
Nc Programming

Abstract The haptic interfaces were developed and applied to free-form surface CAD/CAM systems to improve the user interaction with geometric models. Two types of haptic interfaces were designed; a passive force feedback device and an active force feedback device. Two application systems were developed with these devices; the surface modeling system by the passive force feedback device, and the NC programming system by the active force feedback device. In the surface modeling system, the operator can generate the surface geometry by cutting the virtual clay model. In the NC programming system, the operator can directly teach the NC program by tracing the model with active force feedback device. The structure, control method, simulation software and representation of the geometric model in these systems are discussed. The performance and operating efficiency and accuracy of the systems are experimentally examined.

The origin of passive force enhancement in skeletal muscle

2008 ◽  
Vol 294 (1) ◽  
pp. C74-C78 ◽  
Author(s):  
V. Joumaa ◽  
D. E. Rassier ◽  
T. R. Leonard ◽  
W. Herzog
Keyword(s):  
Calcium Concentration ◽  
Force Production ◽  
Primary Source ◽  
Passive Force ◽  
Active Force ◽  
Force Enhancement ◽  
Bridge Formation ◽  
Calcium Dependent ◽  
Cross Bridge ◽  
High Calcium

The aim of the present study was to test whether titin is a calcium-dependent spring and whether it is the source of the passive force enhancement observed in muscle and single fiber preparations. We measured passive force enhancement in troponin C (TnC)-depleted myofibrils in which active force production was completely eliminated. The TnC-depleted construct allowed for the investigation of the effect of calcium concentration on passive force, without the confounding effects of actin-myosin cross-bridge formation and active force production. Passive forces in TnC-depleted myofibrils ( n = 6) were 35.0 ± 2.9 nN/ μm2 when stretched to an average sarcomere length of 3.4 μm in a solution with low calcium concentration (pCa 8.0). Passive forces in the same myofibrils increased by 25% to 30% when stretches were performed in a solution with high calcium concentration (pCa 3.5). Since it is well accepted that titin is the primary source for passive force in rabbit psoas myofibrils and since the increase in passive force in TnC-depleted myofibrils was abolished after trypsin treatment, our results suggest that increasing calcium concentration is associated with increased titin stiffness. However, this calcium-induced titin stiffness accounted for only ∼25% of the passive force enhancement observed in intact myofibrils. Therefore, ∼75% of the normally occurring passive force enhancement remains unexplained. The findings of the present study suggest that passive force enhancement is partly caused by a calcium-induced increase in titin stiffness but also requires cross-bridge formation and/or active force production for full manifestation.

Kinesthetically Augmented Mid-Air Sketching of Multi-Planar 3D Curve-Soups

2018 ◽  
Author(s):  
Ronak R. Mohanty ◽  
Umema H. Bohari ◽  
Vinayak ◽  
Eric Ragan
Keyword(s):  
Force Feedback ◽  
Three Dimensional ◽  
Free Form ◽  
Manual Labor ◽  
3D Design ◽  
Planar Curves ◽  
Kinesthetic Feedback ◽  
Curve Modeling

We present haptics-enabled mid-air interactions for sketching collections of three-dimensional planar curves — 3D curve-soups — as a means for 3D design conceptualization. Haptics-based mid-air interactions have been extensively studied for modeling of surfaces and solids. The same is not true for modeling curves; there is little work that explores spatiality, tangibility, and kinesthetics for curve modeling, as seen from the perspective of 3D sketching for conceptualization. We study pen-based mid air interactions for free-form curve input from the perspective of manual labor, controllability, and kinesthetic feedback. For this, we implemented a simple haptics-enabled workflow for users to draw and compose collections of planar curves on a force-enabled virtual canvas. We introduce a novel force-feedback metaphor for curve drawing, and investigate three novel rotation techniques within our workflow for both controlled and free-form sketching tasks.

scholarly journals Reports of the length dependence of fatigue are greatly exaggerated

2006 ◽  
Vol 101 (1) ◽  
pp. 23-29 ◽  
Author(s):  
M. B. MacNaughton ◽  
B. R. MacIntosh
Keyword(s):  
Muscle Length ◽  
Repetitive Stimulation ◽  
Double Pulse ◽  
Medial Gastrocnemius ◽  
Passive Force ◽  
Active Force ◽  
Rightward Shift ◽  
Length Dependence ◽  
Force Depression ◽  
In Series

Relative force depression associated with muscle fatigue is reported to be greater when assessed at short vs. long muscle lengths. This appears to be due to a rightward shift in the force-length relationship. This rightward shift may be caused by stretch of in-series structures, making sarcomere lengths shorter at any given muscle length. Submaximal force-length relationships (twitch, double pulse, 50 Hz) were evaluated before and after repetitive contractions (50 Hz, 300 ms, 1/s) in an in situ preparation of the rat medial gastrocnemius muscle. In some experiments, fascicle lengths were measured with sonomicrometry. Before repetitive stimulation, fascicle lengths were 11.3 ± 0.8, 12.8 ± 0.9, and 14.4 ± 1.2 mm at lengths corresponding to −3.6, 0, and 3.6 mm where 0 is a reference length that corresponds with maximal active force for double-pulse stimulation. After repetitive stimulation, there was no change in fascicle lengths; these lengths were 11.4 ± 0.8, 12.6 ± 0.9, and 14.2 ± 1.2 mm. The length dependence of fatigue was, therefore, not due to a stretch of in-series structures. Interestingly, the rightward shift that was evident when active force was calculated in the traditional way (subtraction of the passive force measured before contraction) was not seen when active force was calculated by subtracting the passive force that was associated with the fascicle length reached at the peak of the contraction. This calculation is based on the assumption that passive force decreases as the fascicles shorten during a fixed-end contraction. This alternative calculation revealed similar postfatigue absolute active force depression at all lengths. In relative terms, a length dependence of fatigue was still evident, but this was greatly diminished compared with that observed when active force was calculated with the traditional method.

Research on Kinematic Analysis and Post Processing Arithmetic for NC Machine Tool for Bonnet Tool Polishing

2007 ◽  
Vol 364-366 ◽  
pp. 707-712
Author(s):  
Ying Xue Yao ◽  
Shun Zhou Yu ◽  
Da Gang Xie
Keyword(s):  
Machine Tool ◽  
Metal Cutting ◽  
Transformation Method ◽  
Programming System ◽  
Automatic Programming ◽  
Post Processing ◽  
Nc Machine Tool ◽  
Nc Programming ◽  
Nc Machine ◽  
Optical Polishing

Bonnet tool polishing, combined traditional optical polishing technique with modern NC technology, is an novel optical polishing technique. As the motion control and material removal process is different from metal cutting NC machine tool, the NC programming for bonnet tool polishing NC machine tools cannot be carried out with commercial CAM software. This paper analyses the kinematics of feed mechanism and precession mechanism using coordinate transformation method and sets up the feed and precession kinematics equations. The arithmetic of post processing applied to NC automatic programming system is proposed according to kinematics equations and detail bonnet tool polishing technique.

scholarly journals Research on Key Process Technology for Profile Electrolytic Finishing of Large Marine Propeller Impeller

2018 ◽  
Vol 25 (s2) ◽  
pp. 158-163
Author(s):  
Bi-Rong Ding ◽  
Yuan-long Chen ◽  
Ji Zhou ◽  
Pei-xuan Chen
Keyword(s):  
Manufacturing Industry ◽  
Simulation Software ◽  
Free Form ◽  
Surface Finishing ◽  
Motion Path ◽  
Machining Accuracy ◽  
Process Technology ◽  
Blade Machining ◽  
Cathode Structure ◽  
Free Form Surface

Abstract An electrolysis process method for free-form blade surface finishing is proposed for a free-form surface impeller, and a stepwise method is used to process the inter-blade channel of the overall impeller. The forming cathode is then used to finish the blade to meet the blade processing requirements. In the design, the forming cathode structure was improved by using motion simulation software, and the flow field simulation software was used to simulate and analyze the cathode flow channel. The cathode shape and the electrolyte flow rate between the electrodes meet the processing requirements. In the process of processing experiments, the motion path of the cathode was analyzed and optimized. The effect of the feed direction on the uneven distribution of the blade machining gap was reduced through optimization, and high-frequency pulse power processing was used to reduce the machining gap and improve the machining accuracy of the blade. The experimental results show that the process scheme is feasible and the precision of the processed impeller free-form surface is significantly improved. The material is a monolithic turbine disk of high-temperature alloys, and its large twisted blade processing has always been a problem in the manufacturing industry.

Numerical Control Programming System for Mill-Turn Machining

2015 ◽  
Vol 799-800 ◽  
pp. 1154-1157
Author(s):  
Chen Hua She ◽  
Jian Yu Lin ◽  
Shen Yung Lin
Keyword(s):  
Computer Aided Design ◽  
Tool Path ◽  
Geometric Model ◽  
Control Program ◽  
Simulation Software ◽  
Numerical Control ◽  
Programming System ◽  
Nc Program ◽  
Machining System ◽  
The Cost

To develop the numerical control program of mill-turn machine, the traditional method is to apply the computer-aided design and manufacture software to construct the geometric model, then to generate tool path and convert the path to NC program. For complex numerical control program of mill-turn machine, such as the multiple turret synchronized motion machining, because of the need to control time sequence, the NC program is highly required on using of dedicated software system. The objective of this paper is to establish a mill-turn machining system with window interface of via the language of Borland C++ Builder. The developed system can plan the machining path of simple mill-turn features, including turning shape, axial slot milling, and radial packet milling, and generate the corresponding NC program. For the milling functions, after the offset coordinates are calculated along the polygonal angle vector in the center point of cutters, the NC program is generated. For the turning functions, through importing the 2D DXF (Drawing Exchange Format) file and inputting related configurations, the entity coordinates can be retrieved and the corresponding NC program is then converted. By means of the solid cutting simulation software and practical cutting experiment for the generated numerical control program, the accuracy of the tool path generation algorithm is confirmed. Hence, the cost of purchasing commercial software can be saved and the time of generating program can also be decreased so that the working efficiency can be enhanced.

Note: Hybrid active/passive force feedback actuator using hydrostatic transmission

2017 ◽  
Vol 88 (12) ◽  
pp. 126103
Author(s):  
Yea-Seok Park ◽  
Juwon Lee ◽  
Kyung-Soo Kim ◽  
Soohyun Kim
Keyword(s):  
Force Feedback ◽  
Passive Force ◽  
Hydrostatic Transmission

Active Synthesis of Discrete Systems as a Tool for Reduction Vibration

2013 ◽  
Vol 198 ◽  
pp. 427-432 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Force Feedback ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Discrete Systems ◽  
Mechanical Effect ◽  
Active Force ◽  
Active Synthesis ◽  
Proper Selection ◽  
Selection Of

The paper presents the problem of vibration reduction in designed discrete mechanical systems. The method of reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.

Development Research of the End Mills Grinding Programming System Based on MATLAB

2013 ◽  
Vol 422 ◽  
pp. 242-246
Author(s):  
Hong Jun Zhang ◽  
Jian Guang Li ◽  
Tian Wei Zhang
Keyword(s):  
Simulation Software ◽  
Cnc Machining ◽  
Programming System ◽  
Development Research ◽  
Machining Simulation ◽  
Nc Code ◽  
Cnc Grinding ◽  
End Mills ◽  
Five Axis ◽  
Grinding Simulation

Using MATLAB for development tools,we has developed a set of end mills CNC grinding programming system by analysis the end mills grinding craft ,research on cutter location trajectory calculation and post-processing technology. Meanwhile, build a five-axis tool grinder grinding simulation processing by VERICUT(a kind of CNC machining simulation software), through the edge grinding simulation , we confirm the cutter location trajectory and the NC code is errorless.

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