Operator-Based Robust Nonlinear Control Design of a Robot Arm with Micro-Hand

2016 ◽  
Vol 28 (4) ◽  
pp. 568-578 ◽  
Author(s):  
Zhengxiang Ma ◽  
◽  
Aihui Wang ◽  
Tiejun Chen ◽  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Nonlinear Control ◽  
Angular Position ◽  
Control Design ◽  
Robot Arm ◽  
Robust Nonlinear Control ◽  
Precise Position ◽  
Control Scheme ◽  
Loop Feedback

[abstFig src='/00280004/14.jpg' width='300' text='Robot arm with micro-hand system' ] This work focuses on a robust nonlinear control design of a robot arm with micro-hand (RAMH) by using operator-based robust right coprime factorization (RRCF) approach. In the proposed control system, we can control the endpoint position of robot arm and obtain the desired force of micro-hand to perform a task, and a miniature pneumatic curling soft (MPCS) actuator which can generate bidirectional curling motions in different positive and negative pressures is used to develop the fingers of micro-hand. In detail, to control successively the precise position of robot arm and the desired force of three fingers according to the external environment or task involved, this paper proposes a double-loop feedback control architecture using operator-based RRCF approach. First, the inner-loop feedback control scheme is designed to control the angular position of the robot arm, the operator controllers and the tracking controller are designed, and the robust stability and tracking conditions are derived. Second, the complex stable inner-loop and micro-hand with three fingers are viewed as two right factorizations separately, a robust control scheme using operator-based RRCF approach is presented to control the fingers forces, and the robust tracking conditions are also discussed. Finally, the effectiveness of the proposed control system is verified by experimental and simulation results.

Operator-based robust nonlinear control and its realization for a multi-tank process by using a distributed control system

2011 ◽  
Vol 34 (7) ◽  
pp. 891-902 ◽  
Author(s):  
Shengjun Wen ◽  
Mingcong Deng ◽  
Shuhui Bi ◽  
Dongyun Wang
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Nonlinear Control ◽  
Distributed Control ◽  
Control Design ◽  
Distributed Control System ◽  
Nonlinear Feedback Control ◽  
Nonlinear Feedback ◽  
Robust Nonlinear Control ◽  
Coprime Factorization

In this paper, a robust nonlinear control design method using an operator-based robust right coprime factorization approach and its realization based on a distributed control system (DCS) device are considered for a multi-tank process. In detail, for the multi-tank process, consisting of a water-level process and a water-flow process, theoretical models are developed according to the Bernoulli theorem. Based on the obtained models, a robust nonlinear feedback control design is presented by using robust right coprime factorization for the multi-tank process. Further, from a large-scale industrial application viewpoint, the realization of the designed operator-based robust right coprime factorization controllers is considered by using a DCS device. Because there are some nonlinear functions in the designed controllers which cannot be realized straightforwardly in the DCS device such that the designed controllers need to be realized approximately. That is, there exist some parasitic terms for the approximated realization of the controllers in the real system. As a result, the parasitic terms and processes’ unknown uncertainties should be considered simultaneously. In this paper, a robust condition is derived to guarantee robust stability of the nonlinear feedback control system with the parasitic terms and the uncertainties. Moreover, tracking controller design problem for the multi-tank process is discussed. Finally, by using a DCS device (CENTUM CS3000), experimental results are given to confirm the effectiveness of the proposed design scheme.

scholarly journals A Control Design Technique for Grinding Systems with Feedforward Undercompensation and Feedback Control

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
C. R. Costea ◽  
E. Gergely ◽  
G. Husi ◽  
Laura Coroiu ◽  
Helga Silaghi ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Controller Design ◽  
Control Design ◽  
Industrial Processes ◽  
Control Algorithms ◽  
Design Technique ◽  
Best Value ◽  
Control Scheme ◽  
Systems Control

Abstract Feedforward and feedback control are new control algorithms used in industrial processes control and very suitable for grinding systems control. The purpose of this paper is to provide a design technique for a control system of a grinding circuit using the feedforward and feedback control. The control scheme is based on the undercompensation of the milling feed flow. The best value of the undercompensation is chosen after analyzing several scenarios. The controller design based on this value proves to provide improved productivity.

A Robust Nonlinear Control Scheme for a Sag Compensator Active Multilevel Rectifier Without Sag Detection Algorithm

2012 ◽  
Vol 27 (8) ◽  
pp. 3576-3583 ◽  
Author(s):  
Jesus Lira ◽  
Nancy Visairo ◽  
Ciro Nunez ◽  
Adrian Ramirez ◽  
Hebertt Sira-Ramirez
Keyword(s):  
Nonlinear Control ◽  
Detection Algorithm ◽  
Robust Nonlinear Control ◽  
Control Scheme

Stability analysis in machining process by using adaptive closed-loop feedback control system in turning process

2020 ◽  
pp. 107754632095261
Author(s):  
Kashfull Orra ◽  
Sounak K Choudhury
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Closed Loop ◽  
Machining Process ◽  
Feedback Control System ◽  
Turning Process ◽  
Tool Vibration ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
The Stability

The study presents model-based mechanism of nonlinear cutting tool vibration in turning process and the strategy of improving cutting process stability by suppressing machine tool vibration. The approach used is based on the closed-loop feedback control system with the help of electro–magneto–rheological damper. A machine tool vibration signal generated by an accelerometer is fed back to the coil of a damper after suitable amplification. The damper, attached under the tool holder, generates counter forces to suppress the vibration after being excited by the signal in terms of current. The study also discusses the use of transfer function approach for the development of a mathematical model and adaptively controlling the process dynamics of the turning process. The purpose of developing such mechanism is to stabilize the machining process with respect to the dynamic uncut chip thickness responsible for the type-II regenerative effect. The state-space model used in this study successfully checked the adequacy of the model through controllability and observability matrices. The eigenvalue and eigenvector have confirmed the stability of the system more accurately. The characteristic of the stability lobe chart is discussed for the present model-based mechanism.

Surface Texture Improvement in the Turning Process Via Application of a Magnetostrictively Actuated Tool Holder

1998 ◽  
Vol 120 (2) ◽  
pp. 193-199 ◽  
Author(s):  
D. Liu ◽  
J. W. Sutherland ◽  
K. S. Moon ◽  
T. J. Sturos ◽  
A. R. Kashani
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Dynamic Response ◽  
Vibration Control ◽  
Surface Texture ◽  
Turning Process ◽  
Tool Holder ◽  
Rate Feedback ◽  
Control Scheme ◽  
Surface Profiles

An active vibration control system for a turning process is presented. The system employs a magnetostrictive actuator and a rate feedback control scheme to suppress the vibration caused by random excitation in the turning process. A specially designed tool holder is developed to implement the actuation and the control scheme effectively. A model which accounts for both the dynamic response of the cutting process and the control system is described. The effectiveness of the vibration control system is studied via simulation and a series of experiments. A disturbance force is applied to the system by a shaker and the dynamic response of the system is observed. The experimental data shows that the rate feedback control scheme adds additional damping to the system and reduces the vibration. A complete set of 24 factorial design cutting experiments were also conducted using the tool holder and experimentally obtained surface profiles were compared to surface profiles obtained without the vibration control. It is shown that the system can improve the surface texture generated by the turning process.

Underwater Flexible Manipulator Double-Loop Feedback Control Based on Built-in Binocular Vision and Displacement Sensor

2020 ◽  
Author(s):  
Chen Yang ◽  
He Xu ◽  
Xin Li ◽  
Haihang Wang ◽  
Fengshu Yu
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Binocular Vision ◽  
Hydraulic Drive ◽  
Flexible Manipulator ◽  
Displacement Sensor ◽  
Double Loop ◽  
Interior Space ◽  
Displacement Sensors ◽  
Loop Feedback

Abstract A real-time and effective double-loop feedback control system for underwater flexible manipulators is raised in this paper. The research object is a kind of underwater flexible manipulator driven by McKibben water hydraulic artificial muscle (WHAM) that can grasp, swallow, and disgorge target objects in its interior space. To make up for the lack of flexibility, an underwater flexible manipulator collaborative working strategy is proposed. A more flexible and smaller flexible manipulator is placed inside the flexible manipulator to assist it in performing difficult underwater works. The control system feeds back the position of internal objects through a built-in binocular camera and the working state of the manipulator through displacement sensors. The control system setups including underwater flexible manipulator subsystem, hydraulic drive subsystem, PLC control subsystem, displacement sensor subsystem, built-in binocular vision subsystem, and upper computer subsystem is built. PYTHON-based built-in binocular vision software and C++-based underwater flexible manipulator control software are also developed to facilitate observation and recording. The underwater flexible manipulator collaborative experiment is designed to verify the performance of the control system and the control algorithm.

Control Design With Inverse Feedback Shaper for Quadcopter With Suspended Load

2018 ◽  
Author(s):  
Jaroslav Bušek ◽  
Matěj Kuře ◽  
Martin Hromčík ◽  
Tomáš Vyhlídal
Keyword(s):  
Numerical Study ◽  
Control Design ◽  
Suspended Load ◽  
Oscillatory Mode ◽  
Infinite Dimensional ◽  
Positive Effects ◽  
Flexible Mode ◽  
Control Scheme ◽  
Distributed Time Delay ◽  
Loop Feedback

A control design and numerical study is presented for the problem of maneuvering a quadcopter with suspended load. An inverse shaper with a distributed time delay is applied to the feedback path in order to pre-compensate the oscillatory mode of the two-body system. As the first step, the mode to be targeted by the inverse shaper is determined, which is neither the oscillatory mode of the overall system dynamics, nor the oscillatory mode of the suspended load. Next, the established cascade control scheme for UAVs with slave PD pitch angle controller and master PID velocity controller is adopted and supplemented by the inverse shaper tuned to the isolated flexible mode. The numerical and simulation based analysis reveals the key design aspects and dynamics features — due to including the inverse shaper with time delays, the closed loop system becomes infinite dimensional. As the main result, the positive effects of including the inverse shaper in the loop feedback are demonstrated. First of all, the oscillatory mode is well compensated when excited by both the set-point and disturbance changes. Besides, it is shown that the mode compensation is preserved even when reaching the saturation limits at the control actions.

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