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Article
Publication date: 6 September 2011

Cui Hutao, Cheng Xiaojun, Xu Rui and Cui Pingyuan

The purpose of this paper is to propose an attitude control algorithm for spacecraft with geometric constraints.

Abstract

Purpose

The purpose of this paper is to propose an attitude control algorithm for spacecraft with geometric constraints.

Design/methodology/approach

The geometric constraint is reformulated as a quadratic form when quaternion is used as attitude parameter, then the constraint is proved to be nonconvex and is further transformed to a convex one. By designing a new constraint formulation to satisfy the real constraint in the predictive horizon, the attitude control problem is reshaped to a convex planning problem which is based on receding horizon control.

Findings

The proposed algorithm is more effective in handling geometric constraints than previous research which used single step planning control.

Practical implications

With novel improvements to current methods for steering spacecraft from one attitude to another with geometric constraints, great attitude maneuver path can be achieved to protect instruments and meanwhile satisfy mission requirements.

Originality/value

The attitude control algorithm in this paper is designed especially for the satisfaction of geometric constraints in the process of attitude maneuver of spacecraft. By the application of this algorithm, the security of certain optical instruments, which is critical in an autonomous system, can be further assured.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 5
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 17 June 2021

Nigar Ahmed and Mou Chen

The purpose of this research paper is to design a disturbance observer-based control based on the robust model reference adaptive backstepping sliding-mode control for…

Abstract

Purpose

The purpose of this research paper is to design a disturbance observer-based control based on the robust model reference adaptive backstepping sliding-mode control for attitude quadrotor model subject to uncertainties and disturbances.

Design/methodology/approach

To estimate and reject the disturbance, a disturbance observer is designed for the exogenous disturbances with perturbation while a control criterion is developed for the tracking of desired output. To achieve the control performance, backstepping and sliding-mode control techniques are patched together to obtain robust chattering-free controller. Furthermore, a model reference adaptive control criterion is also combined with the design of robust control for the estimation and rejection of uncertainties and unmodeled dynamics of the attitude quadrotor.

Findings

The findings of this research work includes the design of a disturbance observer-based control for uncertain attitude quadrotor system with the ability of achieving tracking control objective in the presence of nonlinear exogenous disturbance with and without perturbation.

Practical implications

In practice, the quadrotor flight is opposed by different kinds of the disturbances. In addition, being an underactuated system, it is difficult to obtain an accurate mathematical model of quadrotor for the control design. Thus, a quadrotor model with uncertainties and disturbances is inevitable. Hence, it is necessary to design a control system with the ability to achieve the control objectives in the presence of uncertainties and disturbances.

Originality/value

Designing the control methods for quadrotor control without uncertainties and disturbances is a common practice. However, investigating the uncertain quadrotor plant in the presence of nonlinear disturbances is rarely taken into consideration for the control design. Hence, this paper presents a control algorithm to address the issues of the uncertainties and disturbances as well as investigate a control algorithm to achieve tracking performance.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 7
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 27 April 2020

Qun Shi, Wangda Ying, Lei Lv and Jiajun Xie

This paper aims to present an intelligent motion attitude control algorithm, which is used to solve the poor precision problems of motion-manipulation control and the…

Abstract

Purpose

This paper aims to present an intelligent motion attitude control algorithm, which is used to solve the poor precision problems of motion-manipulation control and the problems of motion balance of humanoid robots. Aiming at the problems of a few physical training samples and low efficiency, this paper proposes an offline pre-training of the attitude controller using the identification model as a priori knowledge of online training in the real physical environment.

Design/methodology/approach

The deep reinforcement learning (DRL) of continuous motion and continuous state space is applied to motion attitude control of humanoid robots and the robot motion intelligent attitude controller is constructed. Combined with the stability analysis of the training process and control process, the stability constraints of the training process and control process are established and the correctness of the constraints is demonstrated in the experiment.

Findings

Comparing with the proportion integration differentiation (PID) controller, PID + MPC controller and MPC + DOB controller in the humanoid robots environment transition walking experiment, the standard deviation of the tracking error of robots’ upper body pitch attitude trajectory under the control of the intelligent attitude controller is reduced by 60.37 per cent, 44.17 per cent and 26.58 per cent.

Originality/value

Using an intelligent motion attitude control algorithm to deal with the strong coupling nonlinear problem in biped robots walking can simplify the control process. The offline pre-training of the attitude controller using the identification model as a priori knowledge of online training in the real physical environment makes up the problems of a few physical training samples and low efficiency. The result of using the theory described in this paper shows the performance of the motion-manipulation control precision and motion balance of humanoid robots and provides some inspiration for the application of using DRL in biped robots walking attitude control.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 3
Type: Research Article
ISSN: 0143-991X

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Book part
Publication date: 2 December 2019

Frank Fitzpatrick

Abstract

Details

Understanding Intercultural Interaction: An Analysis of Key Concepts
Type: Book
ISBN: 978-1-83867-397-0

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Article
Publication date: 1 May 1983

In the last four years, since Volume I of this Bibliography first appeared, there has been an explosion of literature in all the main functional areas of business. This…

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Abstract

In the last four years, since Volume I of this Bibliography first appeared, there has been an explosion of literature in all the main functional areas of business. This wealth of material poses problems for the researcher in management studies — and, of course, for the librarian: uncovering what has been written in any one area is not an easy task. This volume aims to help the librarian and the researcher overcome some of the immediate problems of identification of material. It is an annotated bibliography of management, drawing on the wide variety of literature produced by MCB University Press. Over the last four years, MCB University Press has produced an extensive range of books and serial publications covering most of the established and many of the developing areas of management. This volume, in conjunction with Volume I, provides a guide to all the material published so far.

Details

Management Decision, vol. 21 no. 5
Type: Research Article
ISSN: 0025-1747

Keywords

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Article
Publication date: 1 March 1985

Through a survey of 200 employees working in five of the thirty establishments analysed in previous research about the microeconomic effects of reducing the working time…

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18202

Abstract

Through a survey of 200 employees working in five of the thirty establishments analysed in previous research about the microeconomic effects of reducing the working time (Cahier 25), the consequences on employees of such a reduction can be assessed; and relevant attitudes and aspirations better known.

Details

International Journal of Manpower, vol. 6 no. 3
Type: Research Article
ISSN: 0143-7720

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Article
Publication date: 2 October 2017

Uzair Ansari and Abdulrahman H. Bajodah

To design a robust attitude control system for the ascent flight phase of satellite launch vehicles (SLVs).

Abstract

Purpose

To design a robust attitude control system for the ascent flight phase of satellite launch vehicles (SLVs).

Design/methodology/approach

The autopilot is based on generalized dynamic inversion (GDI). Dynamic constraints are prescribed in the form of differential equations that encapsulate the control objectives, and are generalized inverted using the Moore-Penrose Generalized Inverse (MPGI) based Greville formula to obtain the control law. The MPGI is modified via a dynamic scaling factor for assuring generalized inversion singularity-robust tracking control. An additional sliding mode control (SMC) loop is augmented to robustify the GDI closed-loop system against model uncertainties and external disturbances.

Findings

The robust GDI control law allows for two cooperating controllers that act on two orthogonally complement control spaces: one is the particular controller that realizes the dynamic constraints, and the other is the auxiliary controller that is affined in the null control vector, and is used to enforce global closed-loop stability.

Practical implications

Orthogonality of the particular and the auxiliary control subspaces ensures noninterference of the two control actions, and thus, it ensures that both actions work toward a unified goal. The robust control loop increases practicality of the GDI control design.

Originality/value

The first successful implementation of GDI to the SLV control problem.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 22 January 2020

Jiangtao Xu, Na Luo, Shaojie Liu, Baoshan Zhao, Fang Qi, Yinjun Lian and Litong Wang

The purpose of this paper is to design a component synthesis method to suppress the vibration of the flexible spacecraft, which has the constant amplitude force/moment actuator.

Abstract

Purpose

The purpose of this paper is to design a component synthesis method to suppress the vibration of the flexible spacecraft, which has the constant amplitude force/moment actuator.

Design/methodology/approach

The authors proposed a method to construct constant amplitude of time delay and composite coefficient sequences based on the principles of the component synthesis vibration suppression (CSVS). The associated design strategy of the CSVS torque control is also developed. The dynamic model consisting of a single axis rotating rigid central body and a fixed flexibility panel is used to validate the proposed method. Constraint modal and free modal method are both tested to analyse the natural frequencies of the panel and dynamic properties of rigid–flexible decoupling system, under the conditions of known and unknown frequencies. The feasibility of constructing CSVS control force based on the constraint modal frequency is also analysed.

Findings

The proposed method can suppress multistage vibration and has arbitrary order robustness for each order frequencies simultaneously. Simulation results show that only the duration time of the actuator has to be set for the proposed method, reasonable vibration suppression effect can be achieved.

Practical implications

The method can be used in spacecraft, especially flexible spacecraft to suppress the vibration; the approach is convenient for engineering application and can be easily designed.

Originality/value

The authors proposed a method to construct constant amplitude of time delay and composite coefficient sequences based on the principles of the CSVS.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 2 October 2017

Li Fan, Min Hu and Mingqi Yang

The purpose of this paper is to develop a theoretical design for the attitude control of electromagnetic formation flying (EMFF) satellites, present a nonlinear controller…

Abstract

Purpose

The purpose of this paper is to develop a theoretical design for the attitude control of electromagnetic formation flying (EMFF) satellites, present a nonlinear controller for the relative translational control of EMFF satellites and propose a novel method for the allocation of electromagnetic dipoles.

Design/methodology/approach

The feedback attitude control law, magnetic unloading algorithm and large angle manoeuvre algorithm are presented. Then, a terminal sliding mode controller for the relative translation control is put forward and the convergence is proved. Finally, the control allocation problem of electromagnetic dipoles is formulated as an optimization issue, and a hybrid particle swarm optimization (PSO) – sequential quadratic programming (SQP) algorithm to optimize the free dipoles. Three numerical simulations are carried out and results are compared.

Findings

The proposed attitude controller is effective for the sun-tracking process of EMFF satellites, and the magnetic unloading algorithm is valid. The formation-keeping scenario simulation demonstrates the effectiveness of the terminal sliding model controller and electromagnetic dipole calculation method.

Practical implications

The proposed method can be applied to solve the attitude and relative translation control problem of EMFF satellites in low earth orbits.

Originality/value

The paper analyses the attitude control problem of EMFF satellites systematically and proposes an innovative way for relative translational control and electromagnetic dipole allocation.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 February 1976

V. LEO BARTLETT

The Pupil Control Ideology (PCI) concept has been used extensively to describe the school organization. Teachers hate been described as either “custodial” or “humanistic”…

Abstract

The Pupil Control Ideology (PCI) concept has been used extensively to describe the school organization. Teachers hate been described as either “custodial” or “humanistic” in their belief orientation to control of pupils. But clarification of the nature of pupil control and the teacher attitudes which lie at the base of control, has not been investigated adequately. The first section of the present investigation indicates the attitudes of teachers which are associated with high levels of custodialism. These attitudes include emphasis on, content to be taught, teacher direction, rigid classroom procedures and social disengagement from pupils. The second part of the study shows that while operational measures of control may be similar, attitudes underlying control may differ. In schools serving higher socio‐economic communities, teachers exhibit an “emotional disengagement—non‐teacher direction” form of ideology. The conclusion is drawn that unless future investigations both identify attitudes and explain the interactions of attitudes of teachers in each school system, Pupil Control Ideology may be an inadequate descriptor of the school as a social system.

Details

Journal of Educational Administration, vol. 14 no. 2
Type: Research Article
ISSN: 0957-8234

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