Aerospace Science and Technology
Seyyed S Moosapour; Amin Keyvan
Abstract
This paper provides an academic insight into the design of a three-dimensional guidance law which can be utilized to reach the maneuvering targets in definite angles. Firstly, the theoretical phenomenon of a conventional dynamic inversion which can be implemented for reaching targets with constant velocity ...
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This paper provides an academic insight into the design of a three-dimensional guidance law which can be utilized to reach the maneuvering targets in definite angles. Firstly, the theoretical phenomenon of a conventional dynamic inversion which can be implemented for reaching targets with constant velocity will be addressed. However, given that this method is not applicable for reaching accelerated targets, a combination of dynamic inversion method and sliding mode control is presented. These mechanisms can impact maneuvering targets with bounded acceleration. Proceeding the discussion of these observations, an improved form of the proposed controller will be introduced as this method guarantees a finite reaching time. Furthermore, the chattering phenomenon, which is the predominant disadvantage of the sliding mode, will be analysed. Given these findings, a second terminal sliding surface will be presented. This approach will be able to generate continuous guidance law whilst effectively eliminating the chattering problem that was evident in the sliding mode mechanism. Finally, through the application of numerical simulations, the effectiveness of the proposed guidance laws against maneuvering targets will be demonstrated.
Reza Soltani Nezhad; Abolqasem Naghash
Abstract
This article examines the fault tolerance control (FTC) system for the Boeing 747. to reach this goal, firstly 6 degrees of freedom equations are simulated and linearized by using dynamic inversion method. Then, the system is controlled by a linear proportional-integral-derivative controller. To control ...
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This article examines the fault tolerance control (FTC) system for the Boeing 747. to reach this goal, firstly 6 degrees of freedom equations are simulated and linearized by using dynamic inversion method. Then, the system is controlled by a linear proportional-integral-derivative controller. To control this system, the angular velocity loop (r, q, p) must be closed and use cascade control to achieve this goal. Faults such as actuator and sensor failure are injected into the system, and by adding an integrated gain to the controller, the system resists these faults. Also, a redundancy system has been used in sensors to prevent sensor faults. Moreover, a linear Kalman filter has been used to eliminate noise in the system. If an actuator is locked in the Boeing 747, the faulty actuator is removed from the control system. Then, a healthy actuator or other remaining actuators will eliminate the effects of this fault.
