Thrust Vector Controller Comparison for a Finless Rocket

The paper focuses on comparing applicability, tuning, and performance of different controllers implemented and tested on a finless rocket during its boost phase. The objective was to evaluate the advantages and disadvantages of each controller, such that the most appropriate one would then be developed and implemented in real-time in the finless rocket. The compared controllers were Linear Quadratic Regulator (LQR), Linear Quadratic Gaussian (LQG), and Proportional Integral Derivative (PID). To control the attitude of the rocket, emphasis is given to the Thrust Vector Control (TVC) component (sub-system) through the gimballing of the rocket engine. The launcher is commanded through the control input thrust gimbal angle δ , while the output parameter is expressed in terms of the pitch angle θ . After deriving a linearized state–space model, rocket stability is addressed before controller implementation and testing. The comparative study showed that both LQR and LQG track pitch angle changes rapidly, thus providing efficient closed-loop dynamic tracking. Tuning of the LQR controller, through the Q and R weighting matrices, illustrates how variations directly affect performance of the closed-loop system by varying the values of the feedback gain (K). The LQG controller provides a more realistic profile because, in general, not all variables are measurable and available for feedback. However, disturbances affecting the system are better handled and reduced with the PID controller, thus overcoming steady-state errors due to aerodynamic and model uncertainty. Overall controller performance is evaluated in terms of overshoot, settling and rise time, and steady-state error

Correction to the Euler Lagrange multirotor model with Euler angles generalized coordinates

This technical note proves analytically how the exact equivalence of the Newton-Euler and Euler-Lagrange modeling formulations as applied to multirotor UAVs is achieved. This is done by deriving a correct Euler-Lagrange multirotor attitude dynamics model. A review of the published literature reveals that the commonly adopted Euler-Lagrange multirotor dynamics model is equivalent to the Newton-Euler model only when it comes to the position dynamics, but not in the attitude dynamics. Step-by-step derivations and calculations are provided to show how modeling equivalence to the Newton-Euler formulation is proven. The modeling equivalence is then verified by obtaining identical results in numerical simulation studies. Simulation results also illustrate that when using the correct model for feedback linearization, controller stability at high gains is improved

Evaluation of the ACC Vehicles in Mixed Traffic: Lane Change Effects and Sensitivity Analysis

Almost every automobile company is producing vehicles with Adaptive Cruise Control (ACC) systems that allow a vehicle to do automatic vehicle following in the same lane. The ACC system is designed for driver comfort and safety and to operate with manually driven vehicles. These characteristics of ACC were found to have beneficial effects on the environment and traffic flow characteristics [1, 2, 3] by acting as filters of a wide class of traffic disturbances. It has been argue that the smooth response of ACC vehicles to high acceleration disturbances or large position errors creates large gaps between the ACC vehicle and the vehicle ahead inviting cut -ins and therefore generating additional disturbances that would not have been created if the vehicles were all manually driven. In this report we examine the effect of lane changes on the benefits suggested in [1,2,3] as well as the sensitivity of these benefits with respect to various variables such as ACC penetration, level of traffic disturbances etc. We demonstrate using theory, simulations and experiments that during lane changes, the smoothness of the ACC vehicle response attenuates the disturbances introduced by the cut -in or exiting vehicle in a way that is beneficial to the environment when compared with similar situations where the ACC vehicle is absent. We concluded that the higher number of possible cut-ins that may be present due to the higher gaps created during high accelerations maneuvers by the vehicle in front of the ACC vehicle, will not take away the benefits shown in the absence of such cut -ins when compared with the situation of similar maneuvers but with no cut-ins in the case of 100% manually driven vehicles. Keywords: Adaptive Cruise Control vehicles, manually driven ('manual') vehicles, mixed traffic, vehicle following, lane change, air pollution, fuel consumption

Evaluation of the ACC Vehicles in Mixed Traffic: Lane Change Effects and Sensitivity Analysis

Almost every automobile company is producing vehicles with Adaptive Cruise Control (ACC) systems that allow a vehicle to do automatic vehicle following in the same lane. The ACC system is designed for driver comfort and safety and to operate with manually driven vehicles. These characteristics of ACC were found to have beneficial effects on the environment and traffic flow characteristics [1, 2, 3] by acting as filters of a wide class of traffic disturbances. It has been argue that the smooth response of ACC vehicles to high acceleration disturbances or large position errors creates large gaps between the ACC vehicle and the vehicle ahead inviting cut -ins and therefore generating additional disturbances that would not have been created if the vehicles were all manually driven. In this report we examine the effect of lane changes on the benefits suggested in [1,2,3] as well as the sensitivity of these benefits with respect to various variables such as ACC penetration, level of traffic disturbances etc. We demonstrate using theory, simulations and experiments that during lane changes, the smoothness of the ACC vehicle response attenuates the disturbances introduced by the cut -in or exiting vehicle in a way that is beneficial to the environment when compared with similar situations where the ACC vehicle is absent. We concluded that the higher number of possible cut-ins that may be present due to the higher gaps created during high accelerations maneuvers by the vehicle in front of the ACC vehicle, will not take away the benefits shown in the absence of such cut -ins when compared with the situation of similar maneuvers but with no cut-ins in the case of 100% manually driven vehicles. Keywords: Adaptive Cruise Control vehicles, manually driven ('manual') vehicles, mixed traffic, vehicle following, lane change, air pollution, fuel consumption.

Koopman operator based modeling and control of quadrotors

This book showcases a collection of papers that present cutting-edge studies, methods, experiments, and applications in various interdisciplinary fields. These fields encompass optimal control, guidance, navigation, game theory, stability, nonlinear dynamics, robotics, sensor fusion, machine learning, and autonomy. The chapters reveal novel studies and methods, providing fresh insights into the field of optimal guidance and control for autonomous systems. The book also covers a wide range of relevant applications, showcasing how optimal guidance and control techniques can be effectively applied in various domains, including mechanical and aerospace engineering. From robotics to sensor fusion and machine learning, the papers explore the practical implications of these techniques and methodologies

An Advanced Hexacopter for Mars Exploration: Attitude Control and Autonomous Navigation

Mars exploration has recently witnessed major interest within the scientific community, particularly because unmanned aerial robotic platforms offer reliable alternatives for acquiring and collecting data and information from the Red Planet. However, the specific conditions of the Martian environment result in a restricted flight envelope when flying close to Mars and then landing on the surface of Mars. Therefore, in addition to the requirement to develop an aerial platform suitable for operations on Mars, autonomous navigation strategies and robust controllers are also needed for exploration tasks. It is argued that hexacopters with their relatively compact design represent a promising solution for autonomous exploration tasks on Mars, overcoming at the same time the limitations of wheel-based rovers. This research focuses on the design of a Mars Hexacopter (MHex) for a scouting mission in the Jezero region of Mars. The configuration and architecture of the hexacopter follow NASA conceptual study of the Mars Science Helicopter (MSH). Then, the mission profile for mapping Belva crater is examined, followed by a detailed approach to implement and test observer-based navigation and control strategies. A comprehensive simulated experiments environment based on the integration of ROS and Ardupilot,is also presented, used to validate the overall system architecture and mission parameters considering both the morphological shape of the explored crater and the atmospheric conditions of Mars