Cascade control for heterogeneous multirotor UAS

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ayaz Ahmed Hoshu ◽  
Liuping Wang ◽  
Alex Fisher ◽  
Abdul Sattar
Keyword(s):  
Control System ◽  
Disturbance Rejection ◽  
Unmanned Aircraft ◽  
Cascade Control ◽  
Underactuated System ◽  
Content Type ◽  
Control Approach ◽  
Robust Control System ◽  
And Control ◽  
Stable Control

PurposeDespite of the numerous characteristics of the multirotor unmanned aircraft systems (UASs), they have been termed as less energy-efficient compared to fixed-wing and helicopter counterparts. The purpose of this paper is to explore a more efficient multirotor configuration and to provide the robust and stable control system for it.Design/methodology/approachA heterogeneous multirotor configuration is explored in this paper, which employs a large rotor at the centre to provide majority of lift and three small tilted booms rotors to provide the control. Design provides the combined characteristics of both quadcopters and helicopters in a single UAS configuration, providing endurance of helicopters keeping the manoeuvrability, simplicity and control of quadcopters. In this paper, rotational as well as translational dynamics of the multirotor are explored. Cascade control system is designed to provide an effective solution to control the attitude, altitude and position of the rotorcraft.FindingsOne of the challenging tasks towards successful flight of such a configuration is to design a stable and robust control system as it is an underactuated system possessing complex non-linearities and coupled dynamics. Cascaded proportional integral (PI) control approach has provided an efficient solution with stable control performance. A novel motor control loop is implemented to ensure enhanced disturbance rejection, which is also validated through Dryden turbulence model and 1-cosine gust model.Originality/valueRobustness and stability of the proposed control structure for such a dynamically complex UAS configuration is demonstrated with stable attitude and position performance, reference tracking and enhanced disturbance rejection.

A nonlinear control approach for a hypersonic vehicle

2017 ◽  
Vol 89 (2) ◽  
pp. 320-329 ◽  
Author(s):  
Chao Tao ◽  
Jing Wan ◽  
Jianliang Ai
Keyword(s):  
Control System ◽  
Robust Control ◽  
Nonlinear Control ◽  
Hypersonic Vehicle ◽  
Open Loop ◽  
Parametric Uncertainties ◽  
Content Type ◽  
Control Approach ◽  
Robust Control System ◽  
Dynamic Inverse

Purpose The purpose of the paper is to design a robust control system for a generic hypersonic vehicle which includes dynamic nonlinear, open loop unstable and parametric uncertainties. Design/methodology/approach For a complex longitudinal model of a generic hypersonic vehicle which includes dynamic nonlinear, open loop unstable and parametric uncertainties, a nonlinear dynamic inverse (NDI) approach combined with proportional differential (PD) control is used to design a strong robust control system to deal with the sensitivity to changes of atmosphere condition. In this way, a simple genetic algorithm is used to search a group of parameters of the control system to satisfy the specific performance indices. Then parametric uncertainties are considered to verify the robustness of the control system. Findings The PD hypersonic vehicle control system using NDI approach can satisfy the specific flight performance. And it has strong robustness under the parametric uncertainties. Originality/value The paper fulfills a complete process of the nonlinear control system design for a generic hypersonic vehicle. And, the simulation results show the efficiency and robustness of the control system.

Real-time modeling of retractable self-launching glider using spreadsheets

2017 ◽  
Vol 89 (6) ◽  
pp. 791-796
Author(s):  
Yasser A. Nogoud ◽  
Attie Jonker ◽  
Shuhaimi Mansor ◽  
A.A.A. Abuelnuor
Keyword(s):  
Control System ◽  
High Performance ◽  
Cost Effective ◽  
Visual Presentation ◽  
Content Type ◽  
Spreadsheet Model ◽  
Time Modeling ◽  
Model Complex ◽  
Effective Development ◽  
And Control

Purpose This paper aims to propose a spreadsheet method for modeling and simulation of a retraction system mechanism for the retractable self-launching system for a high-performance glider. Design/methodology/approach More precisely, the method is based on parametric link design using Excel spreadsheets. Findings This method can be used for kinematic and dynamic analysis, graphical plotting and allows simulation of control kinematics with the ability to make quick and easy parametric changes to a design. It also has the ability to calculate the loads imposed on each component in the control system as a function of input loads and position. Practical implications This paper shows that it is possible to model complex control systems quickly and easily using spreadsheet programs already owned by most small companies. The spreadsheet model is a parametric model, and it gives a simple visual presentation of the control system with interactive movement and control by the user. Originality/value This spreadsheet model in conjunction with a simple CAD program enables the rapid and cost-effective development of control system components.

scholarly journals A Control Approach Based on Observers of State and Uncertainty for a Class of Takagi–Sugeno Fuzzy Models

2021 ◽  
Vol 25 (3) ◽  
pp. 317-325
Author(s):  
Jun Zhao ◽  
Hugang Han ◽  
◽  
Keyword(s):  
Control System ◽  
Control Systems ◽  
Fuzzy Model ◽  
State Observer ◽  
The State ◽  
State Information ◽  
Control Approach ◽  
Fuzzy Models ◽  
Takagi Sugeno ◽  
Stable Control

Although the Takagi–Sugeno fuzzy model is effective for representing the dynamics of a plant to be controlled, two main questions arise when using it just as other models: 1) how to deal with the gap, which is referred to as uncertainty in this study, between the model and the concerned plant, and how to estimate the state information when it cannot be obtained directly, especially with the existence of uncertainty; 2) how to design a controller that guarantees a stable control system where only the estimated state is available and an uncertainty exists. While the existing studies cannot effectively observe the state and the resulting control systems can only be managed to be uniformly stable, this study first presents a state observer capable of precisely estimating the state regardless of the existence of uncertainty. Then, based on the state observer, an uncertainty observer is derived, which can track the trajectory of uncertainty whenever it occurs in a real system. Finally, a controller based on both observers is presented, which guarantees the asymptotic stability of the resulting control system.

Adaptive Identification and Control for Small Modular Reactors

2011 ◽  
Author(s):  
Daniel G. Cole
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Adaptive System ◽  
Operating Conditions ◽  
System Stability ◽  
Peak Performance ◽  
Model Matching ◽  
Adaptive Identification ◽  
Control Approach ◽  
And Control

This paper discusses adaptive identification and control (AID&C) techniques to enable automated online identification and control of SMRs. Adaptive system ID allows engineers to rapidly measure system dynamics, calibrate sensors channels, determine loop processes, and quantify actuator authority for the various reactor control loops. Adaptive control can automatically tune these loops and adjust plant processes to optimize conditions for peak performance and power production. Another advantage of the adaptive ID and control approach is that these tools can be used during reactor operation to monitor active and passive components. Adaptive system ID techniques are used to measure loop-transfer characteristics. Presented is a practical approach that uses adaptive model-matching tools to identify the coprime factors of the local loops. This has the advantage over model based approaches since coprime factors can be identified on the real system using real data. Adaptive control enables auto-tuning of controller parameters to meet operational specifications. Using the coprime factors, all controllers that stabilize the plant can be parametrized by a free Q-parameter that can be changed to meet control system objectives and improve performance, and the tuning is performed using adaptive techniques. The controller architecture presented provides several desirable and necessary features: e.g., a default fail-safe mode of operation, stability in the presence of communications failures, guaranteed stability, and robustness. An advantage of the adaptive structure presented here is that control system stability can be guaranteed, even during adaptation by ensuring certain norm conditions on the Q-parameter and estimated plant uncertainty. More importantly, the Q-parameter can be monitored during operation, providing a real-time estimate of the changes in the plant resulting from changes in the reactor itself. This signal monitors the dynamics of each loop, providing information about the reactor from the perspective of the control process. Online monitoring using AID&C can be used to better track control system transients that result in reactor trip, thus avoiding undesirable reactor trips and diversion events. And, there is a potential that the system can better adapt to changing operating conditions during plant transients including load following procedures.

Design and analysis of a feedback loop to regulate the basic parameters of the unmanned aircraft

2018 ◽  
Vol 92 (3) ◽  
pp. 318-328
Author(s):  
Marcin Chodnicki ◽  
Katarzyna Bartnik ◽  
Miroslaw Nowakowski ◽  
Grzegorz Kowaleczko
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Rapid Prototyping ◽  
Unmanned Aerial Vehicle ◽  
Pid Controller ◽  
Control Object ◽  
Unmanned Aircraft ◽  
Feedback Control System ◽  
Content Type ◽  
Aerial Vehicle

Purpose The motivation to perform research on feedback control system for unmanned aerial vehicles, a fact that each quadrocopter is unstable. Design/methodology/approach For this reason, it is necessary to design a control system which is capable of making unmanned aerial vehicle vertical take-off and landing (UAV VTOL) stable and controllable. For this purpose, it was decided to use a feedback control system with cascaded PID controller. The main reason for using it was that PID controllers are simple to implement and do not use much hardware resources. Moreover, cascaded control systems allow to control object response using more parameters than in a standard PID control. STM32 microcontrollers were used to make a real control system. The rapid prototyping using Embedded Coder Toolbox, FreeRTOS and STM32 CubeMX was conducted to design the algorithm of the feedback control system with cascaded PID controller for unmanned aerial vehicle vertical take-off and landings (UAV VTOLs). Findings During research, an algorithm of UAV VTOL control using the feedback control system with cascaded PID controller was designed. Tests were performed for the designed algorithm in the model simulation in Matlab/Simulink and in the real conditions. Originality/value It has been proved that an additional control loop must have a full PID controller. Moreover, a new library is presented for STM32 microcontrollers made using the Embedded Coder Toolbox just for the research. This library enabled to use rapid prototyping while developing the control algorithms.

Cascade controllers design based on model matching in frequency domain for stable and integrating processes with time delay

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohd Atif Siddiqui ◽  
Md Nishat Anwar ◽  
Shahedul Haque Laskar
Keyword(s):  
Time Delay ◽  
Frequency Domain ◽  
Disturbance Rejection ◽  
Low Frequency ◽  
Cascade Control ◽  
Model Matching ◽  
Content Type ◽  
Proportional Integral ◽  
Load Disturbance ◽  
Wide Range

Purpose This paper aims to present an efficient and simplified proportional-integral/proportional-integral and derivative controller design method for the higher-order stable and integrating processes with time delay in the cascade control structure (CCS). Design/methodology/approach Two approaches based on model matching in the frequency domain have been proposed for tuning the controllers of the CCS. The first approach is based on achieving the desired load disturbance rejection performance, whereas the second approach is proposed to achieve the desired setpoint performance. In both the approaches, matching between the desired model and the closed-loop system with the controller is done at a low-frequency point. Model matching at low-frequency points yields a linear algebraic equation and the solution to these equations yields the controller parameters. Findings Simulations have been conducted on several examples covering high order stable, integrating, double integrating processes with time delay and nonlinear continuous stirred tank reactor. The performance of the proposed scheme has been compared with recently reported work having modified cascade control configurations, sliding mode control, model predictive control and fractional order control. The performance of both the proposed schemes is either better or comparable with the recently reported methods. However, the proposed method based on desired load disturbance rejection performance outperforms among all these schemes. Originality/value The main advantages of the proposed approaches are that they are directly applicable to any order processes, as they are free from time delay approximation and plant order reduction. In addition to this, the proposed schemes are capable of handling a wide range of different dynamical processes in a unified way.

scholarly journals Stability Control of a Rotational Inverted Pendulum Using Augmentations with Weighting Functions Based Robust Control System

2020 ◽  
Author(s):  
Mustefa Jibril ◽  
Messay Tadese ◽  
Eliyas Alemayehu Tadese
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Inverted Pendulum ◽  
Stability Control ◽  
Control Methods ◽  
Feedback Control System ◽  
Weighting Functions ◽  
Robust Control System ◽  
And Control ◽  
Optimal Control Methods

This paper mainly analyzes the design and control of the rotational inverted pendulum, and presents a state space expression. Since the system is highly unstable a feedback control system is used. Augmentations with weighting functions based mixed sensetivity and H2 optimal control methods are used to make the system stable for uprise position. The rotational inverted pendulum have been simulated and compared with the proposed controllers and a promising results have been analyzed sussesfuly.

scholarly journals Structuring social and environmental management control and accountability

2018 ◽  
Vol 31 (3) ◽  
pp. 993-1023 ◽  
Author(s):  
Lee D. Parker ◽  
Lai Hong Chung
Keyword(s):  
Environmental Management ◽  
Control System ◽  
Environmental Control ◽  
Local Level ◽  
Structuration Theory ◽  
Management Control ◽  
Financial Control ◽  
Bottom Up ◽  
Content Type ◽  
And Control

Purpose The purpose of this paper is to investigate the construction of social and environmental strategies and the related implementation of management control by a key organisation located in a pivotal Asian location in the global hospitality industry. In doing so, it sets out to elucidate the forms and processes of strategic social and environmental control as well their relationship to the traditional financial control system. Design/methodology/approach The study employs field-based case study of a single case operating in both regional and global context. Drawing upon documentary, survey and interview sources, the study employs structuration theory to inform its design and analysis. Findings The findings reveal the interaction of top-down global corporate framing and bottom-up local-level staff initiatives that combine to develop a locally focussed and differentiated social and environmental programme and expedite an associated management control and accountability system. The study also reveals the dominance of the traditional financial control system over the social and environmental management control system and the simultaneously enabling and constraining nature of that relationship. Practical implications Signification and legitimation structures can be employed in building social and environmental values and programmes which then lay the foundations for related discourse and action at multiple levels of the organisation. This also has the potential to facilitate modes of staff commitment expressed through bottom-up initiatives and control, subject to but also facilitated by the dominating influence of the organisation’s financial control system. Social implications This study reveals the importance of national and regional governmental, cultural and social context as both potential enablers and beneficiaries of organisational, social and environmental strategy and control innovation and implementation. Originality/value The paper offers an intra-organisational perspective on social and environmental strategising and control processes and motivations that elucidates forms of action, control and accountability and the relationship between social/environmental control and financial control agendas. It further reveals the interaction between globally developed strategic and control frameworks and locally initiated bottom-up strategic initiatives and control.

Analysis and Control of Once-Through Boiler-Turbine Unit

2013 ◽  
Vol 805-806 ◽  
pp. 678-681
Author(s):  
Wei Jian Huang ◽  
Yu Zhong Wu ◽  
Wei Min Kan ◽  
Xi Zhang
Keyword(s):  
Control System ◽  
Disturbance Rejection ◽  
Turbine Unit ◽  
Control Structure ◽  
Pi Control ◽  
Control System Design ◽  
Output Variable ◽  
Unit Model ◽  
Study Results ◽  
And Control

A nonlinear once-through coal-fired boiler-turbine unit model is introduced and analyzed for the purpose of control system design. Firstly, input-output variable pairing configurations for this 3×3 system are obtained based on static relative gain array and row-Gershgorin band analysis using its linearization model at 100% load. A decentralized PI control system is then deployed and tuned to explore its control system performance as the basis of further study. Results show that the decentralized control structure has good setpoint tracking performance, while the disturbances between loops are still notable due to non-diagonal dominance, thus control strategy of decoupling or disturbance rejection is necessary.

Sign in / Sign up

Export Citation Format

Share Document