Event-Driven Prescribed-Time Tracking Control for Multiple UAVs with Flight State Constraints

The purpose of this research is to realize precise straight motion. The straight motion system used in the paper has an ability to control five degrees of freedom of a moving table; vertical and horizontal positions, and roll, pitch and yaw angles. For the purpose, two references are introduced; motion reference and absolute reference. Table motions are controlled relatively to the motion reference. A solid master is used for the motion reference because of its stability against changes of environment. A geometrical error of the motion reference causes motion errors of the table. To compensate these errors, motion errors relative to the absolute reference are measured. The paper proposes the liquid surface for the absolute reference. The liquid surface is used only to measure motion errors caused by the geometrical error because the liquid surface is not robust enough. After the compensation, straight motion accuracies of 0.2μm in vertical position, 0.1arc sec in roll angle and 0.3arc sec in pitch angle were achieved.

Quadrotor is one type of unmanned aerial vehicle that has the ability to vertical takeoff and landing. In this research, a system designed to stabilize quadrotor during flight condition by maintaining at angle of roll, pitch, yaw, and x, y, and z axis position using LQR full state feedback with artificial neural network (ANN).The LQR full state feedback method uses 12 states with each K constant being tuned with ANN. This research implements ANN method to change feedback constant at angle of roll, pitch, and yaw and x, y, and z axis. The artificial neural network method uses 12 input layers, 12 hidden layers, and 1 output layer.Testing with ANN improved the rise time to ± 2.18 seconds at the roll angle, ± 1.23 seconds at the pitch angle, and ± 0.31 seconds at the yaw angle. Improved settling time value up to ± 2.41 seconds at roll angle, ± 1.23 seconds at pitch angle, and ± 1.07 seconds at yaw angle. Improved steady state eror value of ± 0.61% at roll angle, ± 4.88% at pitch angle, and ± 0.82% at the yaw angle.

Adaptive fault-tolerant control for the ascent phase of hypersonic vehicle with time-varying full state constraints

Dynamic responses of a floating dock under corrosion-induced accidents are studied using a numerical method. The numerical model is proposed to calculate the dynamic responses of the floating dock during operations. It includes a six-degree-of-freedom (6-DOF) model, a hydrostatic force model, a hydrodynamic force model, and a hydraulic model. The effects of the corrosion-induced holes on the stability of the floating dock are investigated and the results show that the maximum pitch and roll angles are 0.18° and 0.69° respectively when there is one hole located at one tank. The maximum pitch and roll angles become 0.42° and 2.04° respectively when there are two holes located at different tanks. The results indicate that situations involving more than one corroded hole result in large roll and pitch angles, which ultimately increase the risk of the vessel capsizing. This analysis not only emphasizes potential hazards but also presents an opportunity for the maritime sector to enhance safety, operational efficiency, and environmental responsibility.

Event-triggered adaptive control for multiple high-speed trains with deception attacks in bottleneck sections

This paper proposes new concepts of configuration and attitude control of underwater towed vehicle to perform operation in both vertical and horizontal axis with stable attitude.The principal configuration composed of fuselage, main wing, horizontal tail, vertical canard, upper and lower vertical tails designed taking into account stability and manoeuvrability in vertical and horizontal planes. The manoeuvrability was estimated by use of lamped mass method for equilibrium equations of motion of towed cable and vehicle. The dynamic stability was analysed by use of eigenvalue analysis based on linear equations of motion.CCV (Control Configured Vehicle) technology was adopted to perform the attitude control. Three types of decoupled mode were considered, i) pitch angle and vertical velocity, ii) pitch angular velocity and vertical velocity, iii) roll angle, yaw angle and side slip velocity. Fuzzy algorithm was applied to CCV attitude control.The effect of motion of towing mother ship in waves was simulated numerically based on non-linear equations of motion of cable and vehicle to examine the effectiveness of attitude control in vertical axis. Not only drifts of velocity components and pitch angle, but also oscillation of pitch angle are remarkably suppressed.The effect of tidal current was simulated numerically to examine the attitude control in horizontal axis. Oscillations of side slip velocity, roll angle and yaw angle are almost eliminated.

In several motion control applications, e.g. in precise pointing devices and navigation systems, an accurate estimate of the attitude of a device in the world coordinate system is required. Readily available sensors used to estimate the attitude suffer from drift, magnetic disturbances, or a lack of information about the direction of the geodetic north. In this paper, an algorithm which estimates the attitude of a camera using camera images and a Digital Surface Model (DSM) referenced by GPS is proposed. The algorithm uses shape features of a skyline extracted from a camera image and synthetic skylines rendered from a DSM in order to estimate the roll and pitch angles, while the yaw angle is estimated using grid search. The algorithm was evaluated using roughly 600 camera images captured with varying pitch and yaw angles. The standard deviations from the ground truth, provided by a high precision pointing device, are 0.037° ,0.015°, and 0.018° for roll, pitch, and yaw respectively. The results indicate a higher precision than current camera attitude estimation algorithms using a DSM, while also providing a robust yaw estimate.

Standard helicopters use the propeller angle to alter the aerodynamic force and have been shown to be feedback linearizable with the pitch, yaw and roll angles being the flat outputs. In this work, a-two-degree-of-freedom, laboratory-scale helicopter-like system (termed the toycopter), where the aerodynamic force is manipulated using the propeller speed, is considered. For such a system the yaw and pitch angles are not flat outputs contrarily of the real helicopters. Moreover, the system does not seem to be flat and is shown to admit at most a one dimensional defect. Various properties of this system are investigated to illustrate the difficulties that arise in the control of the toycopter.

We have been developing a rice-duck farming robot. The robot has functions of cackling, wing flapping, and feeding for gathering and leading real ducks. Our previous research results showed that these functions effectively gather and lead real ducks for weed areas in a paddy field. The robot has a tilt sensor and an acceleration sensor for measuring pitch, roll, and yaw angles of the robot's body, and has a front view camera for autonomous locomotion control. We designed and implemented a pitch angle control system and a roll angle control system for the robot. By using the roll angle of the robot's body, control parameters for crawlers are revised for stabilization of autonomous locomotion. By using the pitch angle of the robot's body, pitch angle of the front view camera is revised for stabilization of appropriate image processing and autonomous locomotion. The stabilization of autonomous locomotion in marshy paddy fields was verified through experiments in an indoor rice paddy.

The installation conditions of fluidic oscillators embedded in a hump surface were numerically investigated to improve the separation control of the flow over the hump. Unsteady flow analysis was performed using three-dimensional Reynolds-averaged Navier–Stokes equations with a modified shear stress transport model. The numerical results were validated by comparing them to experimental data. Five geometric parameters were studied in a parametric study: the installation location, staggered location, pitch angle, roll angle, and yaw angle of the fluidic oscillators. The highest flow control performance was obtained when in-line fluidic oscillators were located just downstream of the separation point. Nonzero roll and yaw angles had favorable effects on the separation control, and the flow control was most sensitive to the pitch angle among the installation parameters.

The gyroscope deterministic error can be estimated through laboratory test using rate table. However, the setting misalignment, if exists, degrade the estimation accuracy severely. To solve this problem, for the simple error model which contains sensor misalignment and bias, a setting misalignment error compensation method is proposed in this paper. This method based on the fact that the setting misalignment can be represented by Euler angle: roll, pitch, and yaw angles. The identification of the three angles is performed step by step. For each pitch and yaw angle, we use the fact that the one specific element of misalignment matrix multiplied by roll matrix is exactly 1 and find pitch and yaw angle which make the estimate of the specific element closely 1. Next, we estimate roll angle with the same procedure. Finally, we estimate the sensor misalignment matrix using the estimated Euler angles. Thorough simulation, the proposed method is verified

We consider autonomous control for micro UAV. The direction of movement is controlled using holonomy. The model airplane is difficult to be controlled due to nonholonomic system. It is effective to use the holonomy that is the response for the periodic input signal. Holonomy is displacement of state quantity by cycle input. At steady flight, short cycle block impulse is input to rudder. Yaw angle and roll angle change. However roll angle returns to 0 [deg] by attitude stabilizing apparatus and UAV’s stability, and yaw angle converges to a certain value. In this study, position, bank angle, and direction angle of the model airplane are controlled by the rudder only. Also, the altitude is controlled using delayed feedback control (DFC) at steady flight. The role of DFC is to make the state converge to unknown equilibrium position. During landing control, the thrust is fixed to 30% of the max thrust. We show that the direction control using holonony and landing control without gust wind are succeeded. International standard atmosphere, steady wind and continuous gust are considered in the numerical simulation.

Quasi-static and dynamic roof crush simulations have been carried out successfully on a small European car that was loaded at different pitch/roll angles. The results obtained were validated against the MIRA experimental dynamic roof crush outputs and against the Bolton experiments performed under FMVSS 216. Overall, the outcomes show that bonded windscreens contribute to nearly 30 per cent of the roof strength, thus confirming similar results obtained by a number of other researchers. Furthermore, these results show that roof strength is a function of roll and pitch angles which also greatly influence the overall intrusion rate. The new findings illustrate that, having a fixed loading pitch angle, the roof strength decreases when the roll angles are between 15 and 45°. If the pitch angle is increased, the same phenomenon of reduced strength is observed. However, this does not signify that the roof becomes weaker with increasing pitch angle, because there are limits within which this can occur, and hence the worst-case loading that yields the smallest strength is found at pitch 10° and roll 45. Therefore, it is recommended in this paper that an update be made to the FMVSS 216, where a roll angle of 45° (not 25°) and a pitch angle of 10° (not 5°) be used as they constitute the worst-case loading condition. As a result, a more realistic test configuration with angles that replicate real-world accident data can be represented.

We developed a signal processing algorithm to determine three components of the velocity vector of a highly maneuverable aircraft. We developed an equation of the distance from an aircraft to an underlying surface. This equation describes a general case of random spatial aircraft positions. Particularly, this equation considers distance changes according to an aircraft flight velocity variation. We also determined the relationship between radial velocity measured within the radiation pattern beam, the signal frequency Doppler shift, and the law of the range changing within the irradiated surface area. The models of the emitted and received signals were substantiated. The proposed equation of the received signal assumes that a reflection occurs not from a point object, but from a spatial area of an underlying surface. It fully corresponds to the real interaction process between an electromagnetic field and surface. The considered solution allowed us to synthesize the optimal algorithm to estimate the current range and three components {Vx,Vy,Vz} of the aircraft’s velocity vector V→. In accordance with the synthesized algorithm, we propose a radar structural diagram. The developed radar structural diagram consists of three channels for transmitting and receiving signals. This number of channels is necessary to estimate the full set of the velocity and altitude vector components. We studied several aircraft flight trajectories via simulations. We analyzed straight-line uniform flights; flights with changes in yaw, roll, and attack angles; vertical rises; and landings on a glide path and lining up with the correct yaw, pitch, and roll angles. The simulation results confirmed the correctness of the obtained solution.

Quadcopter requires monitoring to determine the position and attitude of the object when flying. Attitude consists of roll, pitch, and yaw angles. In quadcopter monitoring is difficult when the object is flying away and outside the operator's viewing range. Monitoring requires a monitoring system to monitor objects further. One way that can be used to determine the position and motion of a quadcopter is by combining GPS technology and Inertial Sensor. This study discusses data acquisition to monitor the position, attitude, and value of reading the sulfur gas sensor in the quadcopter by combining GPS and Inertial Sensor. The communication module used is 433 MHz radio frequency with STM32F103 and the main microcontroller using STM32F4DISCOVERY. Data about accepted objects is then displayed through Visual C # in real time. Testing of latitude and longitude is done by tracking the path of the object, while testing roll, pitch, and yaw angles is done by placing the object in accordance with the reference angle.