scholarly journals Universal Adaptive Neural Network Predictive Algorithm for Remotely Piloted Unmanned Combat Aerial Vehicle in Wireless Sensor Network

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2213
Author(s):  
Hongyang Xu ◽  
Guicai Fang ◽  
Yonghua Fan ◽  
Bin Xu ◽  
Jie Yan

Remotely piloted unmanned combat aerial vehicle (UCAV) will be a prospective mode of air fight in the future, which can remove the physical restraint of the pilot, maximize the performance of the fighter and effectively reduce casualties. However, it has two difficulties in this mode: (1) There is greater time delay in the network of pilot-wireless sensor-UCAV, which can degrade the piloting performance. (2) Designing of a universal predictive method is very important to pilot different UCAVs remotely, even if the model of the control augmentation system of the UCAV is totally unknown. Considering these two issues, this paper proposes a novel universal modeling method, and establishes a universal nonlinear uncertain model which uses the pilot’s remotely piloted command as input and the states of the UCAV with a control augmentation system as output. To deal with the nonlinear uncertainty of the model, a neural network observer is proposed to identify the nonlinear dynamics model online. Meanwhile, to guarantee the stability of the overall observer system, an adaptive law is designed to adjust the neural network weights. To solve the greater transmission time delay existing in the pilot-wireless sensor-UCAV closed-loop system, a time-varying delay state predictor is designed based on the identified nonlinear dynamics model to predict the time delay states. Moreover, the overall observer-predictor system is proved to be uniformly ultimately bounded (UUB). Finally, two simulations verify the effectiveness and universality of the proposed method. The results indicate that the proposed method has desirable performance of accurately compensating the time delay and has universality of remotely piloting two different UCAVs.

2021 ◽  
Author(s):  
Yongjun Pan ◽  
Xiaobo Nie ◽  
Wei Dai ◽  
Feng Xu ◽  
Zhixiong Li

Abstract The vehicle multibody model can be used for accurate coupling dynamics, but it has higher computational complexity. Numerical stability during integration is also very challenging, especially in complicated driving situations. This issue can be substantially alleviated by using a data-driven nonlinear dynamics model owing to its computational speed and robust generalization. In this work, we propose a deep neural network (DNN)-based modeling approach for predicting lateral-longitudinal vehicle dynamics. Dynamic simulations of vehicle systems are performed based on a semirecursive multibody formulation for data acquisition. The data are then used for training and testing the DNN model. The DNN inputs are the torque applied on wheels and the initial vehicle speed that imitates a double lane change maneuver with acceleration and deceleration. The DNN outputs are the longitudinal driving distance, lateral driving distance, final longitudinal velocities, final lateral velocities, and yaw angle. The dynamic responses obtained from the DNN model are compared with the multibody results. Furthermore, the accuracy of the DNN model is investigated in terms of error functions. The DNN model is finally verified via the results of a commercial software package. The results show that the DNN vehicle dynamics model predicts accurate dynamic responses in real time. The DNN model can be used for real-time simulation and preview control in autonomous vehicles.


2011 ◽  
Vol 66-68 ◽  
pp. 933-936
Author(s):  
Xian Jie Meng

A one degree of freedom nonlinear dynamics model of self-excited vibration induced by dry-friction was built firstly, the numerical method was taken to study the impacts of structure parameters on self-excited vibration. The calculation result shows that the variation of stiffness can change the vibration amplitude and frequency of the self-excited vibration, but can not eliminate it, Along with the increase of system damping the self-excite vibration has the weakened trend and there a ritical damping, when damping is greater than it the self-excite vibration will be disappeared.


2010 ◽  
Vol 44-47 ◽  
pp. 1923-1927 ◽  
Author(s):  
Xian Jie Meng

A two degrees of freedom nonlinear dynamics model of self-excited vibration induced by dry-friction of brake disk and pads is built firstly, the stability of vibration system at the equilibrium points is analyzed using the nonlinear dynamics theory. Finally the numerical method is taken to study the impacts of friction coefficient on brake groan. The calculation result shows that with the increase of kinetic friction coefficient /or the decrease of difference value between static friction coefficient and kinetic friction coefficient can prevent or restrain self-excited vibration from happening.


1997 ◽  
Vol 79 (3) ◽  
pp. 447-450 ◽  
Author(s):  
Timothy J. Burns ◽  
Matthew A. Davies

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