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.

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.

An E/H Control Design for a Hydraulic Variable Displacement Axial Piston Motor

2011 ◽  
Author(s):  
Hongliu Du
Keyword(s):  
Adaptive Learning ◽  
Lower Cost ◽  
Learning Algorithm ◽  
Control Design ◽  
Test Results ◽  
Satisfactory Performance ◽  
Control Scheme ◽  
Variable Displacement ◽  
System Uncertainties ◽  
Axial Piston

A simple and novel speed control scheme for variable displacement motors has been developed under the consideration of some system uncertainties. Theoretical analysis and experimental test results have shown that the proposed control strategy is capable of driving the swashplate to track its desired trajectory with robust stability and satisfactory performance. An adaptive learning algorithm enables the controls to automatically adjust for uncertainties in the control bias current. Compared with its hydro-mechanical counterpart, the provided E/H control results in a hydraulic variable displacement motor with lower cost and better performance.

scholarly journals Control design, implementation, and evaluation for an in-field 500 kW wind turbine with a fixed-displacement hydraulic drivetrain

2018 ◽  
Vol 3 (2) ◽  
pp. 615-638 ◽  
Author(s):  
Sebastiaan Paul Mulders ◽  
Niels Frederik Boudewijn Diepeveen ◽  
Jan-Willem van Wingerden
Keyword(s):  
Wind Turbine ◽  
Control Design ◽  
Business Case ◽  
Torque Control ◽  
Offshore Wind ◽  
Pelton Turbine ◽  
Torque Control Strategy ◽  
Control Scheme ◽  
Active Valve ◽  
Electrical Generator

Abstract. The business case for compact hydraulic wind turbine drivetrains is becoming ever stronger, as offshore wind turbines are getting larger in terms of size and power output. Hydraulic transmissions are generally employed in high-load systems and form an opportunity for application in multi-megawatt turbines. The Delft Offshore Turbine (DOT) is a hydraulic wind turbine concept replacing conventional drivetrain components with a single seawater pump. Pressurized seawater is directed to a combined Pelton turbine connected to an electrical generator on a central multi-megawatt electricity generation platform. This paper presents the control design, implementation, and evaluation for an intermediate version of the ideal DOT concept: an in-field 500 kW hydraulic wind turbine. It is shown that the overall drivetrain efficiency and controllability are increased by operating the rotor at maximum rotor torque in the below-rated region using a passive torque control strategy. An active valve control scheme is employed and evaluated in near-rated conditions.

scholarly journals Rollover Mitigation Controller Development for Three-Wheeled Vehicle Using Active Front Steering

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Raja Amer Azim ◽  
Fahad Mumtaz Malik ◽  
Waheed ul Haq Syed
Keyword(s):  
Traffic Safety ◽  
Load Transfer ◽  
Sliding Mode ◽  
Control Design ◽  
Highway Traffic ◽  
Parameter Uncertainties ◽  
National Highway Traffic Safety ◽  
Vehicle Simulation ◽  
Active Front Steering ◽  
Control Scheme

Three-wheeled vehicles are agile, less complex, but relatively more prone to rollover. The current study focuses on the rollover mitigation control design using active front steering for such vehicles. A lateral load transfer ratio (LLTR) adapted for a three-wheeled platform is presented. Sliding mode control design strategy has been devised which results in pseudo-direct control for roll dynamics of the vehicle. The lag in vehicle roll angle response has been managed using adaptive sliding surface. This concept can be extended for other vehicle configurations. The proposed control scheme is investigated for efficacy using a full vehicle simulation model of CarSim software and National Highway Traffic Safety Administration’s proposed Fishhook maneuver. The controller is able to limit the rollover propensity even with vehicle parameter uncertainties.

Minimizing the Effect of Out of Bandwidth Modes in Truncated Structure Models

1998 ◽  
Vol 122 (1) ◽  
pp. 237-239 ◽  
Author(s):  
S. O. Reza Moheimani
Keyword(s):  
Modal Analysis ◽  
Low Frequency ◽  
Control Design ◽  
Higher Order ◽  
Analysis Approach ◽  
Order Model ◽  
Infinite Dimensional ◽  
Higher Order Modes ◽  
Frequency Term ◽  
Zero Frequency

The modal analysis approach to modeling of structures and acoustic systems results in infinite-dimensional models. For control design purposes, these models are simplified by removing higher frequency modes which lie out of the bandwidth of interest. Truncation can considerably perturb the in-bandwidth zeros of the truncated model. This paper suggests a method of minimizing the effect of the removed higher order modes on the low frequency dynamics of the truncated model by adding a zero frequency term to the low order model of the system. [S0022-0434(00)01501-X]

Control of Two-Link Flexible Structures

Volume 1 ◽  
2004 ◽  
Author(s):  
Clarice Wagner-Nachshoni ◽  
Yoram Halevi
Keyword(s):  
Transfer Function ◽  
Time Delays ◽  
Wave Motion ◽  
Controller Design ◽  
Flexible Structures ◽  
Infinite Dimensional ◽  
Second Stage ◽  
Finite Dimensional ◽  
Control Scheme ◽  
Two Stages

A method of noncollocated controller design for non-uniform flexible structures, governed by the wave equation, is proposed. An exact, infinite dimensional, transfer function, relating the actuation and measurement points, with general boundary conditions, is derived for the multi-link case. Three modeling methods are presented and discussed. A key element of the model is the existence of time delays, due to the wave motion, which play a major role in the controller design. The design consists of two stages. First an inner rate loop is closed in order to improve the system dynamic behavior. It leads to a finite dimensional plus delay inner closed loop, which is the equivalent plant for the outer loop. In the second stage an outer noncollocated position loop is closed. It has the structure of an observer–predictor control scheme to compensate for the response delay. The resulting overall transfer function is second order, with arbitrarily assigned dynamics, plus delay.

An Adaptively Controlled Electrohydraulic Servo-Mechanism: Part 1: Adaptive Controller Design

1987 ◽  
Vol 201 (3) ◽  
pp. 175-180 ◽  
Author(s):  
K A Edge ◽  
K R A Figueredo
Keyword(s):  
Adaptive Control ◽  
Controller Design ◽  
Control Design ◽  
Adaptive Controller ◽  
Adaptive Control System ◽  
Sampled Data ◽  
Robust Controller ◽  
Servo Mechanism ◽  
Control Scheme ◽  
Model Reference Adaptive

A systematic model reference adaptive control design scheme is presented. The control scheme is developed and analysed within the framework of a sampled data system with a parameter adaptive algorithm designed on the basis of hyper stability theory. A number of supervisory functions are used to supplement the basic adaptive control system in order to enhance robust controller action.

scholarly journals Numerical study of a control scheme on flow-induced cavity noise

2019 ◽  
Vol 283 ◽  
pp. 09002
Author(s):  
Lulu Liu ◽  
Jin Liu ◽  
Shijin Lyu
Keyword(s):  
Experimental Data ◽  
Cavity Length ◽  
Numerical Study ◽  
Numerical Procedure ◽  
Acoustic Analogy ◽  
Cavity Depth ◽  
Eddy Simulation ◽  
Control Scheme ◽  
Large Eddy ◽  
Flow Induced Noise

A numerical procedure for flow induced cavity noise is established in the paper. The procedure is based on large eddy simulation and FW-H acoustic analogy. The computational scheme is validated by comparing with experimental data. The change of flow induced noise along with cavity length, cavity depth and velocity is studied. A noise control scheme, which includes upright grille and oblique grille, is designed for reducing the flow-induced cavity noise. It turns out that the oblique grille shows superiority in the reduction of cavity noise by modifying the flow structure of the sheat layer.

scholarly journals Motion Detection Enhanced Control of an Upper Limb Exoskeleton Robot for Rehabilitation Training

2017 ◽  
Vol 14 (01) ◽  
pp. 1650031 ◽  
Author(s):  
Wenjun Ye ◽  
Zhijun Li ◽  
Chenguang Yang ◽  
Fei Chen ◽  
Chun-Yi Su
Keyword(s):  
Motion Detection ◽  
Detection Method ◽  
Control Method ◽  
Control Design ◽  
Training Process ◽  
User Intention ◽  
Upper Limb Exoskeleton ◽  
Exoskeleton Robot ◽  
Control Scheme ◽  
Adaptive Control Scheme

The paper studies the control design of an exoskeleton robot based on electromyography (EMG). An EMG-based motion detection method is proposed to trigger the rehabilitation assistance according to user intention. An adaptive control scheme that compensates for the exoskeleton's dynamics is employed, and it is able to provide assistance tailored to the human user, who is supposed to participate actively in the training process. The experiment results verify the effectiveness of the control method developed in this paper.

Optimal Sliding Mode Dual-Stage Actuator Control in Computer Disk Drives

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Seung-Hi Lee
Keyword(s):  
Discrete Time ◽  
Sliding Mode ◽  
Voice Coil Motor ◽  
Disk Drives ◽  
Flexible Mode ◽  
Control Scheme ◽  
Dual Stage ◽  
Actuator Control ◽  
Dual Stage Actuator ◽  
Computer Disk

This paper presents a discrete-time design of a dual-stage actuator control system with sliding mode for computer disk drives. A state estimator based discrete-time boundary layer sliding mode control scheme is developed for a dual-stage actuator, which consists of a voice coil motor and a microactuator. Considering dominant microactuator flexible mode dynamics and the interaction between the two actuators, an optimal sliding hyperplane is designed to maximize their cooperation so as to attain desired responses. An application example demonstrates the utility of the proposed sliding mode dual-stage actuator control scheme for track-seek in the microactuator range, settle, and track-follow.

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