On-Off Control With Specified Fuel Usage

1999 ◽  
Vol 121 (2) ◽  
pp. 206-212 ◽  
Author(s):  
William Singhose ◽  
Tarunraj Singh ◽  
Warren Seering
Keyword(s):  
Flexible Systems ◽  
Residual Vibration ◽  
Command Generation ◽  
Modeling Errors ◽  
Command Signals

A method for generating on-off command profiles for flexible systems is presented. The command profiles move a system without residual vibration while using a specified amount of actuator fuel. Robustness to modeling errors can be incorporated into the design of the command signals. Techniques are presented that facilitate implementation and indicate prudent choices for the amount of fuel to be used. The method is compared to other command generation techniques that balance fuel usage and slew time.

Hybrid input shaping to suppress residual vibration of flexible systems

2011 ◽  
Vol 18 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Hakan Yavuz ◽  
Selçuk Mıstıkoğlu ◽  
Sadettin Kapucu
Keyword(s):  
Input Shaping ◽  
Flexible Systems ◽  
Residual Vibration

Reducing Trajectory Tracking Error of Flexible Mobile Robots Using Command Shaping With Error-Limiting Constraints

2017 ◽  
Author(s):  
Gerald Eaglin ◽  
Joshua Vaughan
Keyword(s):  
Mobile Robots ◽  
Trajectory Tracking ◽  
Tracking Error ◽  
Input Shaping ◽  
Flexible Systems ◽  
Command Shaping ◽  
Modeling Errors ◽  
Temporal Tracking ◽  
Point Motion ◽  
Point To Point

The ability to track a trajectory without significant error is a vital requirement for mobile robots. Numerous methods have been proposed to mitigate tracking error. While these trajectory-tracking methods are efficient for rigid systems, many excite unwanted vibration when applied to flexible systems, leading to tracking error. This paper analyzes a modification of input shaping, which has been primarily used to limit residual vibration for point-to-point motion of flexible systems. Standard input shaping is modified using error-limiting constraints to reduce transient tracking error for the duration of the system’s motion. This method is simulated with trajectory inputs constructed using line segments and Catmull-Rom splines. Error-limiting commands are shown to improve both spatial and temporal tracking performance and can be made robust to modeling errors in natural frequency.

Performance Measures For Input Shaping and Command Generation

2005 ◽  
Vol 128 (3) ◽  
pp. 731-736 ◽  
Author(s):  
Kris Kozak ◽  
William Singhose ◽  
Imme Ebert-Uphoff
Keyword(s):  
Performance Measures ◽  
Input Shaping ◽  
Residual Vibration ◽  
Command Generation ◽  
Multimode System

Many performance measures for input shaping and command generation have appeared in the literature, but very rarely have these measures been critically evaluated or thoroughly discussed. In this paper we review and discuss a number of key measures of residual vibration. These measures are clarified, and mathematical and graphical interpretations of these measures are developed. In addition, a set of energy-based vibration measures are presented for use in even the most general situations, such as measuring the vibration of a nonlinear, multimode system in response to an arbitrary command.

New Command Shaping Methods for Reduced Vibration of a Suspended Payload With Constrained Trolley Motion

2007 ◽  
Author(s):  
Aaron R. Enes ◽  
Timothy Y. Hsu ◽  
Angela A. Sodemann
Keyword(s):  
System Modeling ◽  
Small Scale ◽  
Residual Vibration ◽  
Conveyor System ◽  
Command Shaping ◽  
Common Task ◽  
Modeling Errors ◽  
Point To Point ◽  
Manufacturing Environments ◽  
Command Signal

In manufacturing environments, a common task is to quickly move a suspended payload point-to-point along a fixed overhead conveyor track without inducing significant payload vibration. Recent research in command shaping has shown remarkably effective ways to reduce the swing of a suspended payload providing the motion of the trolley is not constrained. However, the development of a command shaper where the trajectory of the trolley is constrained to follow a fixed curvilinear path has not been explored. This paper will present the development of a simple feedforward command shaper for fast, low vibration, point-to-point movement of a payload suspended from a trolley constrained to follow a fixed generalized path. The command shaping method involves modifying the command signal by convolving it with a series of impulses. Prior work has suggested command shaping to be very effective for fast, low-vibration movement of flexible systems. In this paper, command shaping methods are applied to an overhead conveyor system constrained to move along a fixed curvilinear path. Two new command shapers are presented for canceling payload vibration induced by motion of the trolley along the path. The designed Tangential Vibration (TV) shaper reduces payload vibrations induced by tangential accelerations of the trolley along the path, while the Centripetal-Tangential Vibration (CTV) shaper reduces vibrations induced by both tangential and centripetal accelerations. A key result of this study is that a command shaper having at least three impulses is required to yield zero residual vibration for motion along a curvilinear path. A simple pendulum payload attached to an actual small-scale overhead trolley following a constrained path is used to evaluate the performance of the designed command shapers. It is shown that the designed shapers significantly reduce payload swing compared to unshaped performance. An experimental sensitivity analysis shows the designed shapers are robust to system modeling errors and variations in path parameters.

Comparison of Polynomial Cam Profiles and Input Shaping for Driving Flexible Systems

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Brice Pridgen ◽  
William Singhose
Keyword(s):  
Rise Time ◽  
Laplace Transforms ◽  
Experimental Results ◽  
Input Shaping ◽  
Flexible Systems ◽  
Residual Vibration ◽  
Alternative Method ◽  
Cam Follower ◽  
Low Pass ◽  
Polynomial Profiles

Polynomial profiles can be used as reference commands to limit induced vibration in flexible systems. Due to their ease of design and low-pass filtering effects, polynomial profiles are often found in cam-follower systems. Polynomial profiles have also been used as smooth reference commands for automated machines. However, despite extensive work to develop and improve such profiles, inherent tradeoffs still exist between induced vibration, rise time, and ease of design. Input shaping is an alternative method for generating motion commands that reduce residual vibration. This paper compares polynomial profiles to input-shaped commands for the application of reducing vibration in flexible systems. Analyses using Laplace transforms reveal that input shapers suppress vibration at regularly spaced frequencies. However, polynomial profiles do not share this property. Simulations and experimental results show that input shaping improves rise time and reduces residual vibration in comparison to polynomial profiles.

Residual Vibration Reduction Using Vector Diagrams to Generate Shaped Inputs

1994 ◽  
Vol 116 (2) ◽  
pp. 654-659 ◽  
Author(s):  
W. Singhose ◽  
W. Seering ◽  
N. Singer
Keyword(s):  
Natural Frequency ◽  
Upper Bound ◽  
Vibration Amplitude ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
System Model ◽  
Input Shaping ◽  
Flexible Systems ◽  
Residual Vibration ◽  
Performance Predictions

This paper describes a method for limiting vibration in flexible systems by shaping the input to the system. Unlike most previous input shaping strategies, this method does not require a precise system model or lengthy numerical computation; only estimates of the system natural frequency and damping ratio are required. The effectiveness of this method when there are errors in the system model is explored and quantified. Next, an algorithm is presented, which, given an upper bound on acceptable residual vibration amplitude, determines a shaping strategy that is insensitive to errors in the estimate of the natural frequency. Finally, performance predictions are compared to hardware experiments.

Performance Measure of Residual Vibration Control

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Chul-Goo Kang
Keyword(s):  
Vibration Control ◽  
Vibration Amplitude ◽  
Performance Measure ◽  
Input Shaping ◽  
Residual Vibration ◽  
Modeling Errors ◽  
Experimental Works ◽  
A Performance

The robustness of residual vibration control, such as input shaping, has conventionally been evaluated from the ratio of residual vibration amplitude with input shaping to that without input shaping at the time of the final impulse. However, in that robustness evaluation, vibration-suppressing speed due to each residual vibration control has not been considered, which is also an important aspect of residual vibration control. In this paper, a performance measure including robustness to modeling errors and the effect of vibration-suppressing speed is defined, and the validity of the performance measure is demonstrated by simulations and experimental works.

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