A Procedure for Measuring Planar Cam Profiles and Their Follower Motions

2005 ◽  
Vol 128 (3) ◽  
pp. 697-704 ◽  
Author(s):  
Der-Min Tsay ◽  
Kuo-Shu Tseng ◽  
Hsin-Pao Chen
Keyword(s):  
Contact Point ◽  
Coordinate Measuring Machine ◽  
Displacement Velocity ◽  
Displacement Curve ◽  
Practical Application ◽  
Test Bed ◽  
Traditional Methods ◽  
Theoretical Design ◽  
Cam Profile ◽  
Measuring Machine

A procedure that can be used to inspect planar cam contours and to evaluate their follower displacement, velocity, and acceleration curves with a higher degree of accuracy, without the aid of approximating follower displacements in traditional methods, is constructed. Based on the geometric relationships at the contact point between a planar cam profile and its follower, analytical descriptions that can be utilized to determine the follower displacement curve and its derivatives are first identified. To verify the feasibility and accuracy of the proposed procedure, analytical results generated from a theoretical design are compared to those obtained by the application of the procedure. To demonstrate the effectiveness and usefulness of the developed procedure, a measuring test bed has been constructed for a practical application example. Furthermore, the results obtained by using the developed procedure with the built measuring test bed are also compared to those obtained by using a coordinate measuring machine with the proposed algorithms.

Development of a Measuring System for Planar Cam Profiles and Their Follower Motions

2004 ◽  
Author(s):  
Der-Min Tsay ◽  
Kuo-Shu Tseng ◽  
Hsin-Pao Chen
Keyword(s):  
Contact Point ◽  
Coordinate Measuring Machine ◽  
Measuring System ◽  
Displacement Curve ◽  
Practical Application ◽  
Test Bed ◽  
Theoretical Design ◽  
Cam Profile ◽  
Computing Procedure ◽  
Measuring Machine

A measuring system that can be used to inspect planar cam contours and to evaluate their follower displacement, velocity, and acceleration curves with a higher degree of accuracy without the aid of approximating follower displacements in traditional methods is constructed. Based on the geometric relationships at the contact point between a planar cam profile and its follower, analytical descriptions that can be utilized to determine the follower displacement curve and its derivatives are first identified. To verify the feasibility and accuracy of the algorithms proposed for the measuring system, analytical results generated from a theoretical design are compared to those obtained by the application of the computing procedure. To demonstrate the effectiveness and usefulness of the developed procedure, a measuring test bed has been constructed for a practical application example. Furthermore, the results obtained by using the built measuring system are also compared to those obtained by using a coordinate measuring machine (CMM) with the proposed algorithms.

Data Process for Reverse Engineering Technology

2012 ◽  
Vol 549 ◽  
pp. 1012-1016
Author(s):  
Hui Guo ◽  
Yan Hui Hu ◽  
Xiao Jing Li
Keyword(s):  
Reverse Engineering ◽  
Coordinate Measuring Machine ◽  
Complex Data ◽  
Practical Application ◽  
Engineering Technology ◽  
Data Process ◽  
Surface Data ◽  
Data Points ◽  
Measuring Machine ◽  
Fitting In

Reverse engineering has become an important tool for CAD model construction from the data points, measured by a coordinate measuring machine (CMM), of an existing part. However, due to special structure and complex topology relation, obtaining full surface data of a prototype is not an easy thing and should carry out complex data process procedure to get global model. The paper presents a method for pre-processing data points for curve fitting in reverse engineering. The proposed method has been developed to process the measured data points before fitting into a B-spline form. The method is implemented and used for a practical application in reverse engineering. The result of the reconstruction proves the viability of the proposed method for integration with current commercial CAD systems.

A Simplified Method for Examining Profile Deviations of Conjugate Disk Cams

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Wen-Tung Chang ◽  
Long-Iong Wu
Keyword(s):  
Analytical Approach ◽  
Coordinate Measuring Machine ◽  
Measuring Instrument ◽  
Angle Variation ◽  
Cam Mechanism ◽  
Simplified Method ◽  
Cam Profile ◽  
Measuring Machine ◽  
Profile Errors ◽  
Dial Indicator

The profile errors of conjugate disk cams can be indirectly examined by means of measuring the conjugate condition of the assembled conjugate cam mechanism. This paper demonstrates how to measure the conjugate condition of the assembled conjugate cam mechanism to reveal the cam profile errors and also develops an analytical approach for relating the variation of the conjugate condition with the cam profile errors. For the machined conjugate cams with profile errors, if the subtending angle of the oscillating follower arms is intentionally changed to be variable, the variation of the subtending angle of the follower arms may indicate the variation of profile errors when the cams rotate. According to the magnitude of the subtending angle variation, the profile deviations of conjugate disk cams can be analyzed analytically. The profile errors of a pair of conjugate cams can be evaluated by means of the corresponding motion variation of the indicator reading. For such an examining method, the only required measuring instrument is a dial indicator. A pair of conjugate cams were examined by the method and also measured using a coordinate measuring machine to test the accuracy and efficiency of the method.

Parametric Design and Motion Simulation of Disc Cam Profile Curve Based on the UG NX

2013 ◽  
Vol 753-755 ◽  
pp. 1423-1426
Author(s):  
Li Wang
Keyword(s):  
Motion Analysis ◽  
Parametric Design ◽  
Design Method ◽  
Velocity Curve ◽  
Displacement Curve ◽  
Profile Curve ◽  
Motion Simulation ◽  
Theoretical Design ◽  
Cam Profile ◽  
Continuity Analysis

This paper presents a parametric design method of the cam profile curve with UG NX, created the cam curves with law of the curve command, conducted curve continuity analysis with Curve Continuity Analysis command, and the results show that all adjacent curves are tangent continuous. This ensures the design accuracy. The velocity curve and the displacement curve were got through the cam motion simulation, and the motion analysis is consistent with the results of theoretical design. Expressions were changed, and the motion analysis show that the parametric design of the cam contour is reasonable.

scholarly journals Enhanced measurement of high aspect ratio surfaces by applied sensor tilting

ACTA IMEKO ◽  
2014 ◽  
Vol 3 (3) ◽  
pp. 22
Author(s):  
Alexander Schuler ◽  
Albert Weckenmann ◽  
Tino Hausotte
Keyword(s):  
Contact Point ◽  
Coordinate Measuring Machine ◽  
Test Stand ◽  
Local Surface ◽  
Dynamic Surface ◽  
Surface Measurements ◽  
Measuring Machine ◽  
Measurement Deviation ◽  
Compensation Field ◽  
Surface Angle

During tactile surface measurements the contact point between probing tip and surface varies depending on the local surface angle. To reduce the resulting measurement deviation on high slopes a probing principle is investigated that applies a dynamic surface dependent sensor tilt. This probing process and the logics for the angle determination have been evaluated by simulation. A test stand based on a nanometer coordinate measuring machine is developed and fitted with a rotation kinematic based on stacked rotary axes. Systematic positioning deviations of the kinematic are reduced by a compensation field. The test stand has been completed and results are presented.

DIMENSIONAL INSPECTION OF TRANSLATING CAMS BY CNC COORDINATE MEASURING MACHINE

2012 ◽  
Vol 36 (3) ◽  
pp. 259-270
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Least Square ◽  
Normal Vector ◽  
Transformation Theory ◽  
Fitting Method ◽  
Cam Profile ◽  
Measuring Machine ◽  
Normal Vectors ◽  
Nc Data

In this paper, a simple and analytical method is proposed for accomplishing the inspection procedure. In the proposed approach, a kinematic model of the cam profile is derived using homogenous coordinate transformation theory. The normal vectors and principal curvature of the designed translating cam are then derived from the analytical expression for the cam profile. Based on the coordinates and normal vector of each specified point on the cam profile, the NC data required to move the CMM inspection probe to the surface of the cam are then obtained. A least-square fitting method is proposed to minimize the inspection error caused by a misalignment of the actual evaluation frame relative to the ideal frame.

Inspecting Profile Errors of Conjugate Disk Cams With Coordinate Measurement

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Wen-Tung Chang ◽  
Long-Iong Wu ◽  
Kuang-Hua Fuh ◽  
Chen-Chou Lin
Keyword(s):  
Interpolation Method ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Measurement ◽  
Numerical Interpolation ◽  
Radial Dimension ◽  
Cam Profile ◽  
Measuring Machine ◽  
Profile Errors ◽  
Coordinate Data

To inspect cam profile errors, a coordinate measuring machine (CMM) is frequently employed. The coordinate data of discrete points at the cam surface are measured by a CMM in order to further evaluate the actual cam profile with complicated interpolation algorithms, and then the cam contour approximated by these algorithms may be compared with the theoretical one. In this paper, a direct and simple analytical method, instead of a numerical interpolation algorithm, is proposed for inspecting the profile deviations of conjugate disk cams with coordinate measurement data. The method is based on the derived correlation between the radial-dimension errors and the normal-direction errors of conjugate cam profiles. To verify the proposed method, an experiment of inspecting a pair of conjugate disk cam profiles was conducted. The experimental results obtained from the proposed method were compared with those obtained by using the Hermite interpolation method. It shows that this method is accurate and more efficient for inspecting the profile errors of conjugate disk cams.

Development of virtual coordinate measuring machines incorporating probe errors

1998 ◽  
Vol 212 (7) ◽  
pp. 533-548 ◽  
Author(s):  
H J Pahk ◽  
M Burdekin ◽  
G N Peggs
Keyword(s):  
Computer Model ◽  
Coordinate Measuring Machine ◽  
Error Model ◽  
Coordinate Measuring Machines ◽  
Practical Application ◽  
Volumetric Error ◽  
Measuring Machine ◽  
Virtual Coordinate

In this paper, a comprehensive computer model is described which can be used to predict the volu- metric errors from the parametric errors of the coordinate measuring machine (CMM) and its probing system, for most configurations of CMMs. Several sets of previously unpublished rules have been derived to transform the CMM parametric errors into a corresponding volumetric error map. Thus a virtual CMM has been developed, implementing the integrated volumetric error model. The developed system has been applied to two practical configurations of CMM, in order to demonstrate the performance and practical application of the system.

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