Enhancement of Vibration Suppression for Multi-Link Flexible Robots Using Direct Parameter Adaptation

2001 ◽  
Author(s):  
Joono Cheong ◽  
Wan Kyun Chung ◽  
Youngil Youm
Keyword(s):  
Adaptive Control ◽  
Vibration Suppression ◽  
Simplified Model ◽  
Robot Dynamics ◽  
Flexible Robot ◽  
Parameter Mismatch ◽  
Parameter Adaptation ◽  
Flexible Robots ◽  
Control Schemes ◽  
On Line

Abstract The precise modeling of multi-link flexible robot is hard to obtain and even if we can get it, it is difficult to use in on-line control tasks. Due to these reasons, a simplified model is often used to describe the robot dynamics instead of using complex dynamic model. In the simplified model, however, parameter mismatch and structural modeling error are inevitable. To compensate these uncertainties, an adaptive control is formulated in this paper after separating the system into rigid and flexible subsystems. A simple direct parameter update rule is presented considering the flexible subsystem. Different from most of adaptive control schemes in multi-link flexible robots, which is indirect model-independent approach, the proposed adaptive control is a direct one and good for fast suppression of vibration of uncertain and untuned systems. We verify the effectiveness of the proposed algorithm through experiments.

Adaptive Control of Flexible-Link Robots Based on a V-Shape Lyapunov Function

1999 ◽  
Author(s):  
Ho-Hoon Lee
Keyword(s):  
Adaptive Control ◽  
Lyapunov Function ◽  
Matching Condition ◽  
Robot Dynamics ◽  
Flexible Link ◽  
Flexible Robot ◽  
Model Based Control ◽  
New Model ◽  
Model Based ◽  
Flexible Link Robots

Abstract This paper proposes a new model-based control for flexible-link robots based on Lyapunov stability theorem, where a V-shape Lyapunov function is introduced for the flexible robot dynamics that do not satisfy the so-called matching condition. First, a new model-based nonlinear control is proposed based on a V-shape Lyapunov function, where the global exponential stability of the control is obtained. The model-based control is then extended to a model-based adaptive control to cope with parametric uncertainties in the dynamics, where the global asymptotic stability of the control is attained. The effectiveness of the proposed approach has been shown by computer simulation.

scholarly journals The Study of Dynamic Modeling and Multivariable Feedback Control for Flexible Manipulators with Friction Effect and Terminal Load

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1522
Author(s):  
Fuli Zhang ◽  
Zhaohui Yuan
Keyword(s):  
Dynamic Model ◽  
Vibration Suppression ◽  
Control Method ◽  
Coupling Effect ◽  
Flexible Manipulator ◽  
Flexible Beam ◽  
Robot Dynamics ◽  
Joint Friction ◽  
Balance Principle ◽  
Multivariable Feedback

The flexible manipulato is widely used in the aerospace industry and various other special fields. Control accuracy is affected by the flexibility, joint friction, and terminal load. Therefore, this paper establishes a robot dynamics model under the coupling effect of flexibility, friction, and terminal load, and analyzes and studies its control. First of all, taking the structure of the central rigid body, the flexible beam, and load as the research object, the dynamic model of a flexible manipulator with terminal load is established by using the hypothesis mode and the Lagrange method. Based on the balance principle of the force and moment, the friction under the influence of flexibility and load is recalculated, and the dynamic model of the manipulator is further improved. Secondly, the coupled dynamic system is decomposed and the controller is designed by the multivariable feedback controller. Finally, using MATLAB as the simulation platform, the feasibility of dynamic simulation is verified through simulation comparison. The results show that the vibration amplitude can be reduced with the increase of friction coefficient. As the load increases, the vibration can increase further. The trajectory tracking and vibration suppression of the manipulator are effective under the control method of multi-feedback moment calculation. The research is of great significance to the control of flexible robots under the influence of multiple factors.

A Survey on Brachiation Robots: An Energy-Based Review

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Sibyla Andreuchetti ◽  
Vinícius M. Oliveira ◽  
Toshio Fukuda
Keyword(s):  
Special Class ◽  
Control Strategies ◽  
Underactuated Systems ◽  
Decision Variable ◽  
Robot Dynamics ◽  
Technical Literature ◽  
Control Schemes

SUMMARY Many different control schemes have been proposed in the technical literature to control the special class of underactuated systems, the- so-called brachiation robots. However, most of these schemes are limited with regard to the method by which the robot executes the brachiation movement. Moreover, many of these control strategies do not take into account the energy of the system as a decision variable. To observe the behavior of the system’s, energy is very important for a better understanding of the robot dynamics while performing the motion. This paper discusses a variety of energy-based strategies to better understand how the system’s energy may influence the type of motion (under-swing or overhand) the robot should perform.

Design, Construction and Control of a Remotely Operated Vehicle (ROV)

2011 ◽  
Author(s):  
Alireza Marzbanrad ◽  
Jalil Sharafi ◽  
Mohammad Eghtesad ◽  
Reza Kamali
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Remotely Operated Vehicle ◽  
Six Degrees Of Freedom ◽  
Depth Sensors ◽  
Control Schemes ◽  
On Line ◽  
Operation Unit ◽  
And Control ◽  
Design Construction

This is report of design, construction and control of “Ariana-I”, an Underwater Remotely Operated Vehicle (ROV), built in Shiraz University Robotic Lab. This ROV is equipped with roll, pitch, heading, and depth sensors which provide sufficient feedback signals to give the system six degrees-of-freedom actuation. Although its center of gravity and center of buoyancy are positioned in such a way that Ariana-I ROV is self-stabilized, but the combinations of sensors and speed controlled drivers provide more stability of the system without the operator involvement. Video vision is provided for the system with Ethernet link to the operation unit. Control commands and sensor feedbacks are transferred on RS485 bus; video signal, water leakage alarm, and battery charging wires are provided on the same multi-core cable. While simple PI controllers would improve the pitch and roll stability of the system, various control schemes can be applied for heading to track different paths. The net weight of ROV out of water is about 130kg with frame dimensions of 130×100×65cm. Ariana-I ROV is designed such that it is possible to be equipped with different tools such as mechanical arms, thanks to microprocessor based control system provided with two directional high speed communication cables for on line vision and operation unit.

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