scholarly journals Sensitivity Analysis and Flight Tests Results for a Vertical Cold Launch Missile System

Aerospace ◽  
2020 ◽  
Vol 7 (12) ◽  
pp. 168
Author(s):  
Robert Głębocki ◽  
Mariusz Jacewicz
Keyword(s):  
Vision System ◽  
Flight Test ◽  
Measurement Unit ◽  
Flight Tests ◽  
Test Range ◽  
Roll Rate ◽  
Six Degree Of Freedom ◽  
Main Engine ◽  
Missile Test ◽  
Missile System

In vertical cold launch the missile starts without the function of the main engine. Over the launcher, the attitude of the missile is controlled by a set of lateral thrusters. However, a quick turn might be disturbed by various uncertainties. This study discusses the problem of the influences of disturbances and the repeatability of lateral thrusters’ ignition on the pitch maneuver quality. The generic 152.4 mm projectile equipped in small, solid propellant lateral thrusters was used as a test platform. A six degree of freedom mathematical model was developed to execute the Monte-Carlo simulations of the launch phase and to prepare the flight test campaign. The parametric analysis was performed to investigate the influence of system uncertainties on quick turn repeatability. A series of ground laboratory trials was accomplished. Thirteen flight tests were completed on the missile test range. The flight parameters were measured using an onboard inertial measurement unit and a ground vision system. It was experimentally proved that the cold vertical launch maneuver could be realized properly with at least two lateral motors. It was found that the initial roll rate of the projectile and the lateral thrusters ‘igniters’ uncertainties could affect the pitch angle achieved and must be minimized to reduce the projectile dispersion.

scholarly journals Development of Non Expensive Technologies for Precise Maneuvering of Completely Autonomous Unmanned Aerial Vehicles

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 391
Author(s):  
Luca Bigazzi ◽  
Stefano Gherardini ◽  
Giacomo Innocenti ◽  
Michele Basso
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Degrees Of Freedom ◽  
Vision System ◽  
Video Stream ◽  
Measurement Unit ◽  
Absolute Position ◽  
Light Load ◽  
Aerial Vehicles ◽  
Angular Velocities ◽  
Custom Hardware

In this paper, solutions for precise maneuvering of an autonomous small (e.g., 350-class) Unmanned Aerial Vehicles (UAVs) are designed and implemented from smart modifications of non expensive mass market technologies. The considered class of vehicles suffers from light load, and, therefore, only a limited amount of sensors and computing devices can be installed on-board. Then, to make the prototype capable of moving autonomously along a fixed trajectory, a “cyber-pilot”, able on demand to replace the human operator, has been implemented on an embedded control board. This cyber-pilot overrides the commands thanks to a custom hardware signal mixer. The drone is able to localize itself in the environment without ground assistance by using a camera possibly mounted on a 3 Degrees Of Freedom (DOF) gimbal suspension. A computer vision system elaborates the video stream pointing out land markers with known absolute position and orientation. This information is fused with accelerations from a 6-DOF Inertial Measurement Unit (IMU) to generate a “virtual sensor” which provides refined estimates of the pose, the absolute position, the speed and the angular velocities of the drone. Due to the importance of this sensor, several fusion strategies have been investigated. The resulting data are, finally, fed to a control algorithm featuring a number of uncoupled digital PID controllers which work to bring to zero the displacement from the desired trajectory.

scholarly journals Implementasi Sensor Inertial Meansurenment Unit (IMU) untuk Monitoring Perilaku Roket

AVITEC ◽  
2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Mudarris Mudarris ◽  
Satria Gunawan Zain
Keyword(s):  
User Interface ◽  
Graphical User Interface ◽  
Inertial Measurement Unit ◽  
Flight Test ◽  
Flight Speed ◽  
Functional Test ◽  
Measurement Unit ◽  
Vibration Testing ◽  
Baud Rate ◽  
Inertial Measurement

This paper examines the Implementation of the Inertial Measurement Unit (IMU) Sensor for Monitoring Rocket Attitude. The monitored rocket attitude data is in the form of vibration which is generated by the payload during the functional test and flight speed, acceleration and direction flight test. The rocket payload device is mounted in the rocket compartment for the function of measuring rocket behavior. Data is sent to ground stations via telemetry devices use baud rate of 57600. Based on the results of G-Shock, G-Force and Vibration testing shows that the payload can work well. In accordance with the results of reading the data on the Graphical user Interface (GUI) can be displayed and shows the rocket payload works well. This rocket payload can transmit data remotely. 

scholarly journals Opportunistic In-Flight INS Alignment Using LEO Satellites and a Rotatory IMU Platform

Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 280
Author(s):  
Farzan Farhangian ◽  
Hamza Benzerrouk ◽  
Rene Landry
Keyword(s):  
Kalman Filter ◽  
State Space Model ◽  
Flight Test ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Measurement Unit ◽  
Starting Point ◽  
Leo Satellites ◽  
Positioning Method ◽  
Global Navigation Satellite

With the emergence of numerous low Earth orbit (LEO) satellite constellations such as Iridium-Next, Globalstar, Orbcomm, Starlink, and OneWeb, the idea of considering their downlink signals as a source of pseudorange and pseudorange rate measurements has become incredibly attractive to the community. LEO satellites could be a reliable alternative for environments or situations in which the global navigation satellite system (GNSS) is blocked or inaccessible. In this article, we present a novel in-flight alignment method for a strapdown inertial navigation system (SINS) using Doppler shift measurements obtained from single or multi-constellation LEO satellites and a rotation technique applied on the inertial measurement unit (IMU). Firstly, a regular Doppler positioning algorithm based on the extended Kalman filter (EKF) calculates states of the receiver. This system is considered as a slave block. In parallel, a master INS estimates the position, velocity, and attitude of the system. Secondly, the linearized state space model of the INS errors is formulated. The alignment model accounts for obtaining the errors of the INS by a Kalman filter. The measurements of this system are the difference in the outputs from the master and slave systems. Thirdly, as the observability rank of the system is not sufficient for estimating all the parameters, a discrete dual-axis IMU rotation sequence was simulated. By increasing the observability rank of the system, all the states were estimated. Two experiments were performed with different overhead satellites and numbers of constellations: one for a ground vehicle and another for a small flight vehicle. Finally, the results showed a significant improvement compared to stand-alone INS and the regular Doppler positioning method. The error of the ground test reached around 26 m. This error for the flight test was demonstrated in different time intervals from the starting point of the trajectory. The proposed method showed a 180% accuracy improvement compared to the Doppler positioning method for up to 4.5 min after blocking the GNSS.

Flight tests with enhanced/synthetic vision system for rescue helicopter

2011 ◽  
Author(s):  
Hiroka Tsuda ◽  
Kohei Funabiki ◽  
Tomoko Iijima ◽  
Kazuho Tawada ◽  
Takashi Yoshida
Keyword(s):  
Vision System ◽  
Flight Tests ◽  
Rescue Helicopter ◽  
Synthetic Vision

Flight test of fault-tolerant flight control system using simple adaptive control with PID controller

2018 ◽  
Vol 90 (1) ◽  
pp. 210-218 ◽  
Author(s):  
Hidenobu Matsuki ◽  
Taishi Nishiyama ◽  
Yuya Omori ◽  
Shinji Suzuki ◽  
Kazuya Masui ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Flight Control ◽  
Pid Controller ◽  
Control Method ◽  
Fault Tolerant ◽  
Flight Test ◽  
Static Stability ◽  
Flight Tests ◽  
Content Type ◽  
Sudden Reduction

Purpose This paper aims to demonstrate the effectiveness of a fault-tolerant flight control method by using simple adaptive control (SAC) with PID controller. Design/methodology/approach Numerical simulations and flight tests are executed for pitch angle and roll angle control of research aircraft MuPAL-α under the following fault cases: sudden reduction in aileron effectiveness, sudden reduction in elevator effectiveness and loss of longitudinal static stability. Findings The simulations and flight tests reveal the effectiveness of the proposed SAC with PID controller as a fault-tolerant flight controller. Practical implications This research includes implications for the development of vehicles’ robustness. Originality/value This study proposes novel SAC-based flight controller and actually demonstrates the effectiveness by flight test.

INS/GPS fusion architectures for unmanned aerial vehicles

2014 ◽  
Vol 2 (3) ◽  
pp. 154-167 ◽  
Author(s):  
Sanketh Ailneni ◽  
Sudesh K. Kashyap ◽  
N. Shantha Kumar
Keyword(s):  
Flight Test ◽  
Vital Role ◽  
Open Loop ◽  
Measurement Unit ◽  
Data Logger ◽  
Content Type ◽  
Loosely Coupled ◽  
Black Kite ◽  
Aerial Vehicle ◽  
Split Architecture

Purpose – The purpose of this paper is to present fusion of inertial navigation system (INS) and global positioning system (GPS) for estimating position, velocities, attitude and heading of an unmanned aerial vehicle (UAV). Design/methodology/approach – A 15-state extended Kalman filter (EKF) and a split architecture consisting of six-state nonlinear complementary filter (NCF) and nine-state EKF are investigated in detail. In both these fusion architectures GPS and inertial measurement unit consisting of three axis accelerometers, three axis rate gyros and three axis magnetometer have been fused in open loop fashion (loosely coupled) to estimate the navigation states. Findings – These architectures have been implemented in MATLAB/SIMULINK environment and evaluated in closed loop guidance of Black-Kite MAV with software-in-the-loop-simulation (SILS) setup. Furthermore, both the algorithms are validated with flight test data obtained from on-board data logger using an off-the shelf autopilot board (Ardupilot Mega APM-2.5) on SLYBIRD UAV. Originality/value – The proposed architectures are of high value to accomplish INS/GPS fusion, which plays a vital role in autonomous guidance and navigation of an UAV.

3D Coordinate Measurement System Using Single Camera and IMU

2011 ◽  
Vol 308-310 ◽  
pp. 351-355
Author(s):  
Syed Ghafoor Shah ◽  
Gui Li Xu ◽  
Wei Ji Ni ◽  
Yong Qiang Ye
Keyword(s):  
Inertial Measurement Unit ◽  
Vision System ◽  
Contact Point ◽  
Measurement Unit ◽  
Single Camera ◽  
Inertial Measurement ◽  
Coordinate Measurement ◽  
Improve Accuracy ◽  
Continuous Scanning ◽  
Feature Calculation

This paper proposes a new method for measuring 3D coordinates of a point using a single camera vision system. The contact point is determined by using 3D force sensors. In addition, the force limiting system has also been incorporated to improve accuracy of the results. 3D point is captured when the touching probe senses the force up to certain limit and subsequently recording of that point is initiated. The points being recorded are then processed for the required feature calculation such as distance between planes, angle, radius etc. The IMU (inertial measurement unit) initially estimates the target plane position which enables the whole system to perform the required task quickly. Hence, this system can be used for continuous scanning of any surface.

scholarly journals Implementation of a Potential Field-Based Decision-Making Algorithm on Autonomous Vehicles for Driving in Complex Environments

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3318 ◽  
Author(s):  
Carlos Martínez ◽  
Felipe Jiménez
Keyword(s):  
Autonomous Vehicles ◽  
Vision System ◽  
Autonomous Driving ◽  
Road User ◽  
Measurement Unit ◽  
Maximum Speed ◽  
The Road ◽  
Planning Algorithm ◽  
High Level ◽  
Path Planning Algorithm

Autonomous driving is undergoing huge developments nowadays. It is expected that its implementation will bring many benefits. Autonomous cars must deal with tasks at different levels. Although some of them are currently solved, and perception systems provide quite an accurate and complete description of the environment, high-level decisions are hard to obtain in challenging scenarios. Moreover, they must comply with safety, reliability and predictability requirements, road user acceptance, and comfort specifications. This paper presents a path planning algorithm based on potential fields. Potential models are adjusted so that their behavior is appropriate to the environment and the dynamics of the vehicle and they can face almost any unexpected scenarios. The response of the system considers the road characteristics (e.g., maximum speed, lane line curvature, etc.) and the presence of obstacles and other users. The algorithm has been tested on an automated vehicle equipped with a GPS receiver, an inertial measurement unit and a computer vision system in real environments with satisfactory results.

Visual servoing applied to real-time stabilization of a multi-rotor UAV

Robotica ◽  
2012 ◽  
Vol 30 (7) ◽  
pp. 1203-1212 ◽  
Author(s):  
Hugo Romero ◽  
Sergio Salazar ◽  
Rogelio Lozano
Keyword(s):  
Real Time ◽  
Inertial Measurement Unit ◽  
Visual Servoing ◽  
Vision System ◽  
Measurement Unit ◽  
Translational Velocity ◽  
Inertial Measurement ◽  
Second Stage ◽  
Yaw Angle ◽  
Flying Robot

SUMMARYIn this paper we address the problem of stabilization and local positioning of a four-rotor rotorcraft using computer vision. Our approaches to estimate the orientation and position of the rotorcraft combine the measurements from an Inertial Measurement Unit (IMU) and a vision system composed of a single camera. In the first stage, the vision system is used to estimate the position and yaw angle of the rotorcraft, while in the second stage the vision system is used to estimate the translational velocity of the flying robot. In both cases the IMU gives the pitch and roll angles at a higher rate. The technique used to estimate the position of the rotorcraft in the first stage combines the homogeneous transformation approach for the camera calibration process with the plane-based pose method for estimating the position. In the second stage, a navigation system using the optical flow is also developed to estimate the translational velocity of the aircraft. We present real-time experiments of stabilization and location of a four-rotor rotorcraft.

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