Improving the B-Spline Method of Dynamically-Compensated Cam Design by Minimizing or Restricting Vibrations in High-Speed Cam-Follower Systems

This paper presents an improved method for dynamically-compensated (tuned) cam design by minimizing or restricting vibrations in high-speed cam-follower systems. Using this approach, cams can be synthesized with a variety of design requirements and reduced residual vibrations. An example of the dynamically-compensated B-spline method illustrates the application process and demonstrates the improvement effect. While preserving the features of the B-spline method, the improved design method allows the cams to satisfy requirements, such as pressure angle, radius of curvature, and contact stress, and also reduces the residual vibrations caused by deviations in actual cam speed or system damping ratio from their design values.

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An Experimental and Analytical Investigation of the Dynamic Response of a High-Speed Cam-Follower System. Part 1: Experimental Investigation

Journal of Mechanisms Transmissions and Automation in Design ◽

10.1115/1.3258538 ◽

1983 ◽

Vol 105 (4) ◽

pp. 692-698 ◽

Cited By ~ 31

Author(s):

A. P. Pisano ◽

F. Freudenstein

Keyword(s):

Dynamic Response ◽

High Speed ◽

Dynamic Models ◽

Analytical Investigation ◽

System Response ◽

Pathological System ◽

Cam Design ◽

Cam Follower ◽

System Part ◽

Basic Experiments

This paper is concerned with filling two gaps in the cam design field: (a) the absence of adequate measurements of the dynamic response of cam-follower systems, and (b) the need for the development of a predictive dynamic model for both normal and pathological system behavior. Part 1 presents the results of basic experiments on the dynamic response of a modern, high-speed cam-follower system. These data, which we believe to be the most comprehensive available in the open literature, and which are described more fully in [11], can be used by research investigators both in understanding system response and in developing and evaluating predictive dynamic models.

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A Simple Procedure for Modifying High-Speed Cam Profiles for Vibration Reduction

Journal of Mechanical Design ◽

10.1115/1.1798231 ◽

2004 ◽

Vol 126 (6) ◽

pp. 1105-1108 ◽

Cited By ~ 11

Author(s):

Ulf Andresen ◽

William Singhose

Keyword(s):

Real Time ◽

High Speed ◽

Simple Procedure ◽

Vibration Reduction ◽

Operating Costs ◽

Input Shaping ◽

Cam Design ◽

Experimental Apparatus ◽

Cam Follower ◽

Computer Controlled

Unwanted vibration in cam-follower systems causes increased forces, noise, wear, and operating costs. This paper investigates the use of input shaping on cam profiles to reduce vibration. Input shaping is a real-time command modification algorithm developed for computer-controlled machines. In order to apply the concept to cam design, some modifications to the algorithm must be made. To test the validity of high-speed input-shaped cam profiles, an experimental apparatus was constructed with variable operating speeds and follower dynamics. The experimental results demonstrate the effectiveness of the proposed solution.

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Polydyne Cam Mechanisms for Typehead Positioning

Journal of Engineering for Industry ◽

10.1115/1.3428119 ◽

1972 ◽

Vol 94 (1) ◽

pp. 250-254 ◽

Cited By ~ 18

Author(s):

K. Kanzaki ◽

K. Itao

Keyword(s):

Boundary Conditions ◽

High Speed ◽

Design Method ◽

Polynomial Equations ◽

Cam Design ◽

Wide Range ◽

Theoretical Results

This paper describes a cam design method for typehead positioning in high-speed teleprinters. By this method, residual vibrations are extinguished at plural adjacent rise times and reduced over a comparatively wide range of rise times. The polynomial equations for the cam followers are determined upon consideration of the boundary conditions and the characteristics of the residual vibrations. The theoretical results are verified by the experiments.

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A design method for selecting the physical parameters of a free piston Stirling engine

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216634120 ◽

2016 ◽

Vol 231 (13) ◽

pp. 2441-2450 ◽

Cited By ~ 1

Author(s):

Seon-Jun Jang ◽

Michael J Brennan ◽

Fadi Dohnal ◽

Yoon-Pyo Lee

Keyword(s):

Design Method ◽

Damping Ratio ◽

Feedback Mechanism ◽

Stirling Engine ◽

Physical Parameters ◽

Operation Condition ◽

Free Piston ◽

Design Values ◽

Nyquist Stability ◽

Free Piston Stirling Engine

A new design method for selecting the physical parameters of a free piston Stirling engine (FPSE) is presented. The dynamics of FPSE are described in the form of a transfer function including the inherent feedback mechanism. The simplified Nyquist stability criterion is used to derive the operation condition, where the indices of the magnitude amplification factor (MAF) and the operation limit factor (OLF) are introduced in terms of the physical parameters. Further, a measure for the efficiency of the engine is defined as the damping ratio of the power piston system (DRP). Parametric studies of these quantities are carried out as well as benchmarking against the design values of the standard RE-1000 engine. A design method is presented that defines the physical parameters of an FPSE which is working at a given operation frequency.

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Design of high-speed cam profiles for vibration reduction using command smoothing technique

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406214528321 ◽

2014 ◽

Vol 228 (18) ◽

pp. 3322-3328 ◽

Cited By ~ 7

Author(s):

Zan Liang ◽

Jie Huang

Keyword(s):

High Speed ◽

Damping Ratio ◽

Vibration Reduction ◽

Control Plant ◽

Operating Costs ◽

Operating Speed ◽

Smoothing Technique ◽

Vibration Properties ◽

Cam Follower ◽

Novel Method

Unwanted vibration in cam-follower systems causes increased forces, noise, wear, and operating costs. This paper proposes a novel method to design high-speed cam profiles for vibration reduction by using command smoothing technique. Using system natural frequency and damping ratio, the technique reduces vibrations by intelligently smoothing any basic profiles. Furthermore, an example is given to express the design process and to verify the effectiveness of the method. The displacement, velocity, acceleration, and jerk properties of the proposed profile are demonstrated to show the excellent smoothness, which benefits high-speed cam follower systems. The comparisons of vibration properties between the smoothed profile and 3-4-5 polynomial profile are explored and quantified. The smoothed profile will induce zero vibration at the design operating speed and produce a low level of vibration around it. Experimental results obtained from a rectilinear control plant validate the simulated dynamic behavior and the effectiveness of the profile created by using command smoothing.

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Simultaneous Optimization of Damping and Tracking Controller Parameters Via Selective Pole Placement for Enhanced Positioning Bandwidth of Nanopositioners

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4030723 ◽

2015 ◽

Vol 137 (10) ◽

Cited By ~ 11

Author(s):

Douglas Russell ◽

Andrew J. Fleming ◽

Sumeet S. Aphale

Keyword(s):

High Speed ◽

Design Method ◽

Damping Ratio ◽

Simultaneous Optimization ◽

Pole Placement ◽

Control Scheme ◽

Optimal Damping ◽

Tracking Controllers ◽

Tracking Controller ◽

Resonant Systems

Positive velocity and position feedback (PVPF) is a widely used control scheme in lightly damped resonant systems with collocated sensor actuator pairs. The popularity of PVPF is due to the ability to achieve a chosen damping ratio by repositioning the poles of the system. The addition of a tracking controller, to reduce the effects of inherent nonlinearities, causes the poles to deviate from the intended location and can be a detriment to the damping achieved. By designing the PVPF and tracking controllers simultaneously, the optimal damping and tracking can be achieved. Simulations show full damping of the first resonance mode and significantly higher bandwidth than that achieved using the traditional PVPF design method, allowing for high-speed scanning with accurate tracking. Experimental results are also provided to verify performance in implementation.

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Shape Optimization of Cam Profiles Using a B-Spline Representation

Journal of Mechanisms Transmissions and Automation in Design ◽

10.1115/1.3258983 ◽

1989 ◽

Vol 111 (2) ◽

pp. 195-201 ◽

Cited By ~ 19

Author(s):

E. Sandgren ◽

R. L. West

Keyword(s):

Combustion Engine ◽

Control Point ◽

Radius Of Curvature ◽

Flow Area ◽

B Spline ◽

Design Variables ◽

Spline Representation ◽

Cam Follower ◽

Gradient Based ◽

Acceleration Profile

An arbitrary acceleration profile for the cam follower acceleration is generated using a B-spline representation. The control point locations for the B-spline become the design variables in the nonlinear programming problem. The B-spline representation provides for local control of the acceleration profile which is required in order to generate reliable optimization results. Constraints are imposed in order to place appropriate limits on the contact stress, lift, duration, acceleration, jerk, radius of curvature, manufacturing requirements, and to avoid cam-follower separation. The objective function may take on a number of forms depending upon the design requirements. The optimization is carried out with a gradient based penalty function algorithm. A specific example is presented in which the flow area is maximized for an internal combustion engine.

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Laser Lens Size Measurement Using Swept-Source Optical Coherence Tomography

Applied Sciences ◽

10.3390/app10144936 ◽

2020 ◽

Vol 10 (14) ◽

pp. 4936

Author(s):

Pingping Jia ◽

Hong Zhao ◽

Yuwei Qin

Keyword(s):

Optical Coherence Tomography ◽

High Speed ◽

Wave Number ◽

Radius Of Curvature ◽

Optical Coherence ◽

Swept Source ◽

Laser Focusing ◽

Fitting Algorithm ◽

Laser Confocal Microscope ◽

Focusing Lens

A high-speed, high-resolution swept-source optical coherence tomography (SS-OCT) is presented for focusing lens imaging and a k-domain uniform algorithm is adopted to find the wave number phase equalization. The radius of curvature of the laser focusing lens was obtained using a curve-fitting algorithm. The experimental results demonstrate that the measuring accuracy of the proposed SS-OCT system is higher than the laser confocal microscope. The SS-OCT system has great potential for surface topography measurement and defect inspection of the focusing lens.

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