Experimental Verification of Time-Varying Impulse Shaping for a Two-Link Flexible Manipulator

1995 ◽  
Author(s):  
Jung-Keun Cho ◽  
Youn-sik Park
Keyword(s):  
Vibration Reduction ◽  
Vertical Plane ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Time Varying ◽  
Flexible System ◽  
Revolute Joints ◽  
Point Motion ◽  
Time Varying Systems ◽  
Point To Point

Abstract Input shaping is a method to reduce the motion-induced vibration in a flexible system. A kind of input shaping method (time-varying impulse shaping) has been proposed previously which is applicable to vibration reduction of time-varying systems. This paper presents experimental results of time-varying impulse shaping with a two-link flexible manipulator. The flexible manipulator has two revolute joints and moves on a vertical plane under gravity. A dynamic model was developed to provide a basis for the shaping, and the model was proved through some experiments. The reference trajectories commanded to the system are shaped by using the suggested time-varying impulse shaping. Implemented to the two-link flexible manipulator, test results demonstrate that the link vibration can be greatly suppressed during and after a point-to-point motion, and the residual vibration reduction was observed more than 90% with this shaping.

Experimental evaluation of time-varying impulse shaping with a two-link flexible manipulator

Robotica ◽  
1996 ◽  
Vol 14 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Jung-Keun Cho ◽  
Youn-Sik Park
Keyword(s):  
Vibration Reduction ◽  
Vertical Plane ◽  
Joint Stiffness ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Time Varying ◽  
Modal Properties ◽  
Revolute Joints ◽  
Point Motion ◽  
Point To Point

SUMMARYIn the authors' previous paper,10 an input shaping method was presented to reduce motion-induced vibrations effectively for various classes of flexible systems. In this paper, the effectiveness of the shaping method is experimentally demonstrated with a two-link flexible manipulator systemThe manipulator for experiments includes two revolute joints and two flexible links, and moves on a vertical plane under gravity. An analytic model is developed considering the flexibility of the system and its joint stiffness in order to derive an appropriate estimation of dynamic modal properties. The input shaping method used in this work utilizes time-varying modal properties obtained from the model instead of the conventional input shaping method which employs time-invariant modal properties. A point-to-point motion is tested in order to show the effectivess of the proposed shaping method in vibration reduction during and after a given motion. The given reference trajectories are shaped to suppress the motion induced vibration. The test results demonstrate that the link vibration can be greatly suppressed during and after a motion, and the residual vibration reduction was observed more than 90% by employing this time-varying impulse shaping technique.

Residual vibration reduction for a flexible structure using a modified input shaping technique

Robotica ◽  
2002 ◽  
Vol 20 (5) ◽  
pp. 553-561 ◽  
Author(s):  
Ki-Seong Lee ◽  
Youn-sik Park
Keyword(s):  
Linear Time ◽  
Vibration Reduction ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Fast Time ◽  
Time Varying ◽  
Residual Vibration ◽  
Shaping Technique ◽  
Time Varying Systems ◽  
Special Case

SummaryThis paper presents a modified input shaping method to reduce the motion-induced vibration of a linear time-varying system after a rest-to-rest motion. Shaping parameters were obtained using the concept of modal-filtered impulse response. The conventional shaping method can be said just a special case of the proposed shaping method. The effectiveness of this proposing method was checked using some examples of both moderate and considerably fast time-varying systems. With a rest-to-rest motion control of a two-link flexible manipulator, this study also demonstrates that this method can be expanded to nonlinear cases.

Friction-Compensating Command Shaping for Vibration Reduction

2004 ◽  
Vol 127 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Jason Lawrence ◽  
William Singhose ◽  
Keith Hekman
Keyword(s):  
Steady State ◽  
Coulomb Friction ◽  
Vibration Reduction ◽  
Input Shaping ◽  
Residual Vibration ◽  
Command Shaping ◽  
Point Motion ◽  
Common Operation ◽  
Point To Point ◽  
Theoretical Developments

Fast and accurate point-to-point motion is a common operation for industrial machines, but vibration will frequently corrupt such motion. This paper develops commands that can move machines without vibration, even in the presence of Coulomb friction. Previous studies have shown that input shaping can be used on linear systems to produce point-to-point motion with no residual vibration. This paper extends command-shaping theory to nonlinear systems, specifically systems with Coulomb friction. This idea is applied to a PD-controlled mass with Coulomb friction to ground. The theoretical developments are experimentally verified on a solder cell machine. The results show that the new commands allow the proportional gain to be increased, resulting in reduced rise time, settling time, and steady-state error.

Variable-Velocity Exponential Input Shaping for Position Controlled Robotic Systems

2010 ◽  
Author(s):  
P. Iravani ◽  
M. N. Sahinkaya
Keyword(s):  
Inverse Dynamics ◽  
Vibration Reduction ◽  
Robotic Systems ◽  
Input Shaping ◽  
Control Input ◽  
End Effector ◽  
Flexible System ◽  
Flexible Loads ◽  
New Form ◽  
Point To Point

This paper demonstrates a new form of Input Shaping for vibration reduction applied to robotic systems that manipulate flexible loads. The method is based on using an exponential function to define asymptotic and vibration-free trajectories for the flexible system. The required control input is calculated analytically by using inverse dynamics which ensures the desired end-effector trajectory. The method is demonstrated experimentally on the control of point-to-point movements of a robotic manipulator.

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.

Joint input shaping and feedforward for point-to-point motion: Automated tuning for an industrial nanopositioning system

Mechatronics ◽  
2014 ◽  
Vol 24 (6) ◽  
pp. 572-581 ◽  
Author(s):  
Frank Boeren ◽  
Dennis Bruijnen ◽  
Niels van Dijk ◽  
Tom Oomen
Keyword(s):  
Input Shaping ◽  
Point Motion ◽  
Point To Point ◽  
Automated Tuning

Fuzzy logic–based decision support system for selection of optimum input shaping techniques in point-to-point motion systems

2020 ◽  
pp. 095965182096570
Author(s):  
Hasan Huseyin Bilgic ◽  
Caglar Conker ◽  
Hakan Yavuz
Keyword(s):  
Fuzzy Logic ◽  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Input Shaping ◽  
Advantages And Disadvantages ◽  
Shaping Technique ◽  
Point Motion ◽  
Point To Point ◽  
Selection Of

In this study, a novel fuzzy logic–based decision support system approach to provide assistance in the selection of suitable input shaping techniques is presented. The proposed approach selects the suitable input shaping technique for point-to-point motion type of systems such as precise positioning, crane operations, flexible robotic systems and so on. The problem solution addressed is the selection of the input shaping technique and the settings for the selection of the input shaper. Some of these design issues require extensive expertise in command shaping and system modeling studies. To overcome these problems and the necessity for such an expertise in these application areas, the proposed technique is provided as a solution. The presented study also provides a review of input shaping methods as well as their advantages and disadvantages in terms of vibration elimination performance, traveling time and robustness features. In the final section of the study, the details of the simulations, as well as experimental results, are provided to validate the achieved high performance of the proposed technique. The experimental studies are conducted on a Quanser IP02 Gantry Crane experimental setup.

Iterative learning identification and control for point-to-point tracking of linear time-varying systems with unknown parameters and stochastic noise

2017 ◽  
Vol 40 (13) ◽  
pp. 3834-3845 ◽  
Author(s):  
Yan Geng ◽  
Xiaoe Ruan
Keyword(s):  
Linear Time ◽  
Tracking Error ◽  
Iterative Learning ◽  
Time Varying ◽  
Unknown Parameters ◽  
Point Tracking ◽  
Time Varying Systems ◽  
System Output ◽  
Point To Point ◽  
And Control

In this paper, an interactive iterative learning identification and control (ILIC) scheme is developed for a class of discrete-time linear time-varying systems with unknown parameters and stochastic noise to implement point-to-point tracking. The identification is to iteratively estimate the unknown system parameter matrix by adopting the gradient-type technique for minimizing the distance of the system output from the estimated system output, whilst the control law is to iteratively upgrade the current control input with the current point-to-point tracking error scaled by the estimated system parameter matrix. Thus, the iterative learning identification and the iterative learning control are scheduled in an interactive mode. By means of norm theory, the boundedness of the discrepancy between the system matrix estimation and the real one is derived, whilst, by the manner of the statistical technique, it is conducted that the mathematical expectation of the tracking error monotonically converges to nullity and the variance of the tracking error is bounded. Numerical simulations exhibit the validity and effectiveness of the proposed ILIC scheme.

Vibration reduction in flexible systems using a time-varying impulse sequence

Robotica ◽  
1995 ◽  
Vol 13 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Jung-Keun Cho ◽  
Youn-Sik Park
Keyword(s):  
Vibration Suppression ◽  
Linear Time ◽  
Robot Manipulator ◽  
Input Shaping ◽  
Time Varying ◽  
Vibrational Modes ◽  
Flexible Systems ◽  
Overhead Crane ◽  
Shaping Technique ◽  
Time Varying Systems

SummaryAn input shaping technique using a time-varying impulse sequence is presented to reduce the motion-induced vibration of flexible systems in a feedforward way.The decoupled modal responses for a general linear time-varying system are firstly approximated. Upon this approximation, the time-varying impulse sequences to suppress the vibrational modes are found. The reference inputs to the systems are shaped by convolving with the time-varying impulse sequence to suppress the multimode vibrations. This technique can be also applied to suppress the vibration of nonlinear time-varying systems.The performance of this method is demonstrated with two practical examples: a moving overhead crane and a two-link robot manipulator. Consequently, this study provides an input shaping technique applicable to the vibration suppression of broader classes of flexible systems.

Quantitative Feedback Input Shaping for Flexible-Joint Robot Manipulator

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Withit Chatlatanagulchai ◽  
Dumrongsak Kijdech ◽  
Takat Benjalersyarnon ◽  
Supparat Damyot
Keyword(s):  
Reference Model ◽  
Robot Manipulator ◽  
Simple Zero ◽  
Input Shaping ◽  
Residual Vibration ◽  
Flexible Joint ◽  
Input Shaper ◽  
Time Varying Systems ◽  
Shaping System ◽  
Point To Point

Input shaping technique has been applied to flexible-joint robot to suppress its residual vibration from fast point-to-point movement. Input shaping performance deteriorates when the knowledge of the mode parameters of the robot is not accurate. Several robust input shapers were proposed at the expense of longer move time. A novel input shaping system, consisting of a quantitative feedback controller, a feed-forward reference model, and a simple zero-vibration (ZV) input shaper, is proposed in this paper. Advantages over the existing robust input shapers include toleration of substantially larger amount of uncertainty in the mode parameters, shorter move time that does not increase with insensitivity, application to nonlinear and time-varying systems, and suppression of vibration induced by disturbance and noise.

Sign in / Sign up

Export Citation Format

Share Document