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.

Input Shaping for Flexible System With Nonlinear Spring and Damper

2017 ◽  
Author(s):  
Withit Chatlatanagulchai ◽  
Ittidej Moonmangmee ◽  
Pisit Intarawirat
Keyword(s):  
Linear System ◽  
Input Shaping ◽  
Destructive Interference ◽  
Impulse Responses ◽  
Residual Vibration ◽  
Energy Principle ◽  
Nonlinear Spring ◽  
Flexible System ◽  
Input Shaper ◽  
Simulation And Experiment

Input shaping suppresses residual vibration by destructive interference of the impulse responses. Because proper destructive interference requires superposition property of the linear system, traditional input shaper only applies to the linear flexible system. In this paper, the work and energy principle is used to derive input shaper for flexible system having nonlinear spring and damper. It was shown via simulation and experiment that this type of shaper performs well with nonlinear systems. Positive, robust, and negative input shapers are discussed.

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.

scholarly journals Vibration Suppression of a 3-DOF Parallel Manipulator Based on Hybrid Negative Impulses Multi-Mode Input Shaping

2011 ◽  
Vol 2-3 ◽  
pp. 372-377 ◽  
Author(s):  
Yan Yan Han ◽  
Bing Li ◽  
Yu Lan Wei ◽  
Shou Xin Zhu ◽  
Ying Jun Dai
Keyword(s):  
Time Delay ◽  
Numerical Simulations ◽  
Parallel Manipulator ◽  
Vibration Suppression ◽  
Input Shaping ◽  
Vibration Modes ◽  
Residual Vibration ◽  
Input Shaper ◽  
Multi Mode

The classic multi-mode negative impulses input shapers can suppress the residual vibration of the multi-mode system effectively. But when these several frequencies bandwidths and amplitudes of vibration modes are greatly different, the time delay and the suppression performances of input shapers are decreased. However, the hybrid multi-mode negative impulses input shapers can overcome the disadvantage. The hybrid double-mode negative impulses input shapers of a 3-DOF parallel manipulator and are constructed and compared with the classic multi-mode negative impulses input shapers. And the numerical simulations are shown out, for different frequencies bandwidths and amplitudes of vibration, and the hybrid multi-mode negative impulses input shapers can increase the total suppression performance of input shaper.

Vibration Control of Flexible Joint Robots Using a Discrete-Time Two-Stage Controller Based On Time-varying Input Shaping and Delay Compensation

2021 ◽  
Author(s):  
Minh-Nha Pham ◽  
Bruce Hazel ◽  
Philippe Hamelin ◽  
Zhaoheng Liu
Keyword(s):  
Disturbance Rejection ◽  
Robot Manipulator ◽  
Rigid Body Dynamics ◽  
Smith Predictor ◽  
Input Shaping ◽  
Delay Compensation ◽  
Two Stage ◽  
Flexible Joint ◽  
Flexible Joint Robots ◽  
Flexible Mode

Abstract Most industrial serial robots use decentralized joint controllers assuming rigid body dynamics. To prevent exciting the flexible mode, gains are kept low, resulting in poor control bandwidth and disturbance rejection. In this paper, a two-stage flexible joint discrete controller is presented, in which the decentralized approach is extended with a stiffness to take into account the dominant coupling mode. In the first-stage, an input shaping feedforward shapes the rigid closed-loop dynamics into desired dynamics that does not produce link vibrations. Robotic dynamic computation based on a recursive Newton-Euler Algorithm is conducted to update the feedforward link inertia parameter during robot motion. A second-stage is added to increase disturbance rejection. A generalized Smith predictor is developed to compensate for delay and feedback sensor filtering. An effective methodology is presented to optimize the control loop gains. Numerical simulations and experiments on a six-joint robot manipulator confirm that the proposed controller improves control performances in terms of bandwidth, vibration attenuation, and disturbance rejection.

Command Shaping Slewing Motions for Tower Cranes

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Jason Lawrence ◽  
William Singhose
Keyword(s):  
Nonlinear Dynamics ◽  
Rotational Motion ◽  
Effective Control ◽  
Input Shaping ◽  
Residual Vibration ◽  
Command Shaping ◽  
Tower Crane ◽  
Control Scheme ◽  
Point To Point ◽  
Gantry Cranes

Input shaping has been shown to be a practical and effective control scheme for reducing payload swing on industrial bridge and gantry cranes. However, when applied to tower cranes, standard input shapers will have degraded performance due to the nonlinear dynamics of rotational motion. To alleviate this problem, two new command generators for tower cranes are developed for a point-to-point slewing motion. It is shown that standard shaping techniques greatly reduce oscillation and the new tower crane command generators cause even less residual vibration. Simulations and experiments verify the results.

Model Reference Control With Command Shaping for a Micro-Electromagnetic Actuator With Input Constraints

2019 ◽  
Author(s):  
Gerald Eaglin ◽  
Joshua Vaughan
Keyword(s):  
Reference Model ◽  
Electromagnetic Actuator ◽  
Input Shaping ◽  
Input Constraints ◽  
Residual Vibration ◽  
Model Reference ◽  
Command Shaping ◽  
Model Reference Control ◽  
Limiting Property ◽  
Nonlinear Plants

Abstract Model Reference Control is used to force a system to track the response of an assigned reference model, where the reference model is often designed to reflect the desired properties of the system. If a linear reference model is used, Model Reference Control has a linearizing effect for nonlinear plants, allowing it to be cascaded with linear controllers. Model Reference Control has been used to force nonlinear flexible systems to behave linearly such that input shaping can be used to limit residual vibration. However, when a system encounters saturation limits, the vibration limiting property of input shaping is degraded. This paper proposes Model Reference Control with an adaptive input shaping method to account for saturation by modifying the input shaper after saturation has been encountered. Simulations are presented to illustrate the effectiveness of this method in canceling residual vibration for a nonlinear electromagnetic actuator subject to input constraints.

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.

Input Shaper Syntheses for Explicit Fractional Derivative Systems Using Nonlinear Optimization

2017 ◽  
Author(s):  
Withit Chatlatanagulchai ◽  
Poom Jatunitanon ◽  
Sirichai Nithi-uthai
Keyword(s):  
Fractional Derivative ◽  
Nonlinear Optimization ◽  
Vibration Suppression ◽  
Oscillatory System ◽  
Input Shaping ◽  
Destructive Interference ◽  
Residual Vibration ◽  
Modeling And Control ◽  
Input Shaper ◽  
Derivative System

Fractional derivative system has gained its popularity in modeling and control because of its long memory property. Only recently, residual vibration suppression for the fractional derivative oscillatory system using input shaping has been studied. Input shaping suppresses residual vibration by using destructive interference of impulse responses. So far, only a few types of input shapers have been proposed for the fractional derivative oscillatory system, using only analytical, closed-form solutions. In this paper, input shaper syntheses for explicit fractional derivative systems using nonlinear optimization have been proposed. This work designs input shapers that have never been used with the fractional derivative system before, which include fixed-interval input shaper and specified-insensitivity input shaper, and extends the type that has already been used to a more general, improved input shaper.

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