Real-Time Attitude Control Algorithm for Fast Tumbling Objects under Torque Constraint-Feedback Controller Using Conservative State Variables-

An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC) of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE) method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

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An intelligent method for solar flare observation

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313003050 ◽

2012 ◽

Vol 8 (S294) ◽

pp. 503-504

Author(s):

Jia Ben Lin ◽

Juan Guo ◽

Yuan Yong Deng

Keyword(s):

Fine Structure ◽

Solar Flare ◽

Real Time ◽

Structure Data ◽

Control Algorithm ◽

Simulation Experiment ◽

Hard Disk ◽

Solar Observatory ◽

Explosive Phase

AbstractTo capture the fine structure of the flare kernel during it's explosive phase, we design a real time flare onset detecting algorithm named Near Saturation Area Threshold(NSAT), And an automatic CCD parameters control algorithm for the observing software. All the data from CCD, 48f/s, could be saved to the hard disk, and the GPS time of the flare onset also be saved in the log. These methods could avoid the data overflow and grab the fine structure data of the flare kernel. The simulation experiment works well and the software will be put into use in Huairou Solar Observatory soon.

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Design of Semi-Physical Simulation for Small Satellite by Virtual Display

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.130-134.2684 ◽

2011 ◽

Vol 130-134 ◽

pp. 2684-2687 ◽

Cited By ~ 1

Author(s):

Kai Xu ◽

Yan Lv ◽

Guang Jin

Keyword(s):

Control System ◽

Real Time ◽

Attitude Control ◽

Physical Simulation ◽

Simulation System ◽

Space Environment ◽

Small Satellite ◽

Attitude Control System ◽

Actual Environment ◽

Virtual Display

Semi-physical simulation of attitude control system is the more synthetically test and verify for designing of small satellite control system. It is an important means of small satellite development. However, the results of current semi-physical simulation system have a lot of non-intuitive. Compare with the actual environment, the simulation environment still has striking disparity. So the shortcomings affect precision of simulation. Based on the virtual display technology, the group semi-physical simulation system has been constructed for attitude control of small satellite due to the combination with xPC real-time environment, the simulation computer, high-precision single-axis air-bearing turntable, reaction wheel, air thrust device, fiber gyroscopes, sensors synchronizer, power subsystem and wireless devices virtual display computer etc. Semi-physical simulation achieved the visual simulation in orbit and tracked new information of virtual environment of space into real-time simulation computer. Simulation results show that the simulation system for real-time attitude and orbit position of small satellite semi-physical simulation has an excellent display effect. At the same time, Real-time transfuse of orbit information provides a more accurate space environment simulation. The simulation system of small satellite attitude control to design and evaluate the more direct and convenient.

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Robust active disturbance attenuation control of an uncertain quadrotor

International Journal of Intelligent Unmanned Systems ◽

10.1108/ijius-11-2020-0064 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Nigar Ahmed ◽

Ajeet kumar Bhatia ◽

Syed Awais Ali Shah

Keyword(s):

Control Algorithm ◽

Sliding Mode ◽

The State ◽

Disturbance Attenuation ◽

State Variables ◽

Pass Filter ◽

Low Pass Filter ◽

Content Type ◽

Highly Nonlinear ◽

The Stability

PurposeThe aim of this research is to design a robust active disturbance attenuation control (RADAC) technique combined with an extended high gain observer (EHGO) and low pass filter (LPF).Design/methodology/approachFor designing a RADAC technique, the sliding mode control (SMC) method is used. Since the standard method of SMC exhibits a chattering phenomenon in the controller, a multilayer sliding mode surface is designed for avoiding the chattering. In addition, to attenuate the unwanted uncertainties and disturbances (UUDs), the techniques of EHGO and LPF are deployed. Besides acting as a patch for disturbance attenuation, the EHGO design estimates the state variables. To investigate the stability and effectiveness of the designed control algorithm, the stability analysis followed by the simulation study is presented.FindingsThe major findings include the design of a chattering-free RADAC controller based on the multilayer sliding mode surface. Furthermore, a criterion of integrating the LPF scheme within the EHGO scheme is also developed to attenuate matched and mismatched UUDs.Practical implicationsIn practice, the quadrotor flight is opposed by different kinds of the UUDs. And, the model of the quadrotor is a highly nonlinear underactuated model. Thus, the dynamics of the quadrotor model become more complex and uncertain due to the additional UUDs. Hence, it is necessary to design a robust disturbance attenuation technique with the ability to estimate the state variables and attenuate the UUDs and also achieve the desired control objectives.Originality/valueDesigning control methods to attenuate the disturbances while assuming that the state variables are known is a common practice. However, investigating the uncertain plants with unknown states along with the disturbances is rarely taken in consideration for the control design. Hence, this paper presents a control algorithm to address the issues of the UUDs as well as investigate a criterion to reduce the chattering incurred in the controller due to the standard SMC algorithm.

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Altitude Controller Design for Quadcopter UAV

Jurnal Teknologi ◽

10.11113/jt.v74.3993 ◽

2015 ◽

Vol 74 (1) ◽

Cited By ~ 2

Author(s):

Muhammad Zaki Mustapa

Keyword(s):

Real Time ◽

Attitude Control ◽

Controller Design ◽

Design Method ◽

Time Windows ◽

The Real ◽

Data Acquisition Card ◽

Aerial Vehicle ◽

Hovering Control ◽

Real Time Application

This paper discusses on attitude control of a quadcopter unmanned aerial vehicle (UAV) in real time application. Newton-Euler equation is used to derive the model of system and the model characteristic is analyzed. The paper describes the controller design method for the hovering control of UAV automatic vertical take-off system. In order to take-off the quadcopter and stable the altitude, PID controller has been designed. The scope of study is to develop an altitude controller of the vertical take-off as realistic as possible. The quadcopter flight system has nonlinear characteristics. A simulation is conducted to test and analyze the control performance of the quadcopter model. The simulation was conducted by using Mat-lab Simulink. On the other hand, for the real time application, the PCI-1711 data acquisition card is used as an interface for controller design which routes from Simulink to hardware. This study showed the controller designs are implemented and tuned to the real system using Real Time Windows Target approach by Mat-Lab Simulink.

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