Quadrotor Attitude Control using Incremental Nonlinear Dynamics Inversion
Given the large flight envelope of vertical take-off and landing vehicles, and the nonlinear nature of multirotor aircraft, especially in aggressive maneuvering, nonlinear control strategies are often considered. Yet, most available solutions are model dependent and thus require a precise knowledge of the system dynamics, including the hard to model aerodynamics. This paper proposes a sensor-based approach to the problem. It considers a recent strategy based on incremental control and Nonlinear Dynamics Inversion (NDI), the Incremental Nonlinear Dynamics Inversion (INDI), to solve the attitude control problem of quadrotors. The INDI general formulation is presented, and then applied considering the attitude stabilization of a quadrotor. In order to apply the INDI solution to this case study, a linear predictor for the angular acceleration is provided. Simulation results demonstrate the robustness of this sensor-based approach to model-parameter uncertainties and wind disturbances. An analysis is also done regarding the tuning of INDI parameters and its sensitivity to the chosen sampling time.
Altitude Trajectory Control of an Unmanned Airship Using Incremental Nonlinear Dynamic Inversion
This paper presents the application of the incremental nonlinear dynamic inversion (INDI) control approach for the trajectory tracking of an unmanned airship. The proposed vehicle architecture is composed of two main components: a helium envelop with a rigid keel and moving gondola capable of travelling along the keel. This motion significantly alters the location of the centre of gravity and thus the pitch of the airship. The dynamic equations of the airship are derived using the Newton–Euler formulation, and the model was implemented and simulated in Matlab/Simulink to illustrate the effectiveness of the designed controller for translational and longitudinal motions in the presence of wind disturbances. Keywords-component; unmanned airship; trajectory tracking; incremental nonlinear dynamic inversion
ANALYSIS OF BOLT′S ANCHORING QUALITY BASED ON WAVELET NEURAL NETWORK
The dynamic response of bolt achieved by impact-echo method can be effected easily by some factors.It′s difficult to classify bolt′s anchoring quality according to the dynamic response of bolt.In this paper,a new analytical method of bolt′s dynamic response is put forward.The new analytical method combing with advantages of wavelet analysis and artificial neural network is presented.Firstly,the dynamic response of bolt by numerical simulation software FLAC3D is obtained.Secondlyt,he features are extracted from the dynamic response of bolt by wavelet analysis.Thirdlyt,hese features are fed into the artificial neural network for training.Finallyt,his artificial neural network to classify the bolt′s anchoring quality intelligent according to the dynamic response of bolt is employed.In order to validate this new analytical method,some practical signals of bolt′s dynamic response are used for the test.The results indicate that the new analytical method is practicable.