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We propose the structured two-loop flight control system of a novel tandem ducted fan vehicle for near hover flight in consideration of actuator saturations on its dynamics. The prescribed controller architecture consists of static output feedback inner loop and four PI outer loop, which is a desirable and intuitive structure for practical implementation. The effect of a limited control activity on...
A robust control method is proposed for quadrotor systems. The designed controller is developed based upon the quaternion representation model, which is subject to multiple uncertainties. A feedback controller is proposed to restrain the effects of nonlinearities and uncertainties on the closed-loop system. These uncertainties are considered as input equivalent disturbances and their effects are proven...
We demonstrate trajectory control of the tip of an inverted pendulum atop a small unmanned aerial vehicle. In this paper we discuss how exploiting the differential flatness of combined systems provides a realization of adequate control. A differential flatness controller is derived for trajectory control of a pendulum tip. Simulation results are presented for tip trajectory tracking with and without...
Detecting an abandoned object in crowded scenes of surveillance videos becomes more complex task due to occlusions, lighting changes, and other factors. In this paper, a new framework to detect abandoned object using dual background model subtraction is presented. In our system, the adaptive background model is generated based on statistical information of pixel intensity that robust against lighting...
A robust control is developed for the system of aerospace vehicle via variable robustness control (VRC) algorithm. Aerospace vehicle dynamics contain uncertainties due to cross coupling between longitudinal and lateral dynamics. The proposed scheme makes the system of aerospace vehicle impervious of uncertainties ensuring high performance. The variable robustness control technique is based upon scenario...
This paper reports on a fast multiresolution scan matcher for vehicle localization in urban environments for self-driving cars. State-of-the-art approaches to vehicle localization rely on observing road surface reflectivity with a three-dimensional (3D) light detection and ranging (LIDAR) scanner to achieve centimeter-level accuracy. However, these approaches can often fail when faced with adverse...
This paper reports on an underwater cooperative localization algorithm for faulty low-bandwidth communication channels based on a factor graph estimation framework. Vehicles measure the one-way-travel-time (OWTT) of acoustic broadcasts to obtain a relative range observation to the transmitting vehicle. We present a method to robustly share locally observed sensor data across the network by exploiting...
Metamodeling techniques using computational intelligence have been used in Uncertainty-based Design Optimization (UDO) to reduce the high computational cost of the uncertainty analysis and improve the performance of stochastic optimization problems with computationally expensive simulation models. Optimal trajectory generation is a major part of Space Launch Vehicle (SLV) design and if it is robust...
Vehicle pose estimation with respect to the road plays a critical role in the advances of autonomous vehicle navigation and guidance. Vision-based road lane line detection provides a feasible and low cost solution as the vehicle pose can be derived from the detection. While good progress has been made, the lane line detection has remained an open one, given challenging road appearances. In this paper,...
In this paper, a robust traffic sign recognition system is introduced for driver assistance applications and/or autonomous cars. The system incorporates two major operations, traffic sign detection and classification. The sign detection is based on color segmentation and incorporates hue detection, morphological filter and labeling. A nearest neighbor classifier is introduced for sign classification...
The adoption of fault detection and isolation (FDI) techniques is fundamental to ensure high levels of safety and productivity, especially in critical and expensive applications like Autonomous Underwater Vehicles (AUV). This paper describes a comparison between different techniques available in the literature, applied to over-actuated AUVs under single fault condition (SFC) and considering only abrupt...
A mathematical model of agent-based decision-making of Autonomous Surface Vehicles (ASVs) is presented with extensive path planning and abstraction capabilities of the environment. The aim is to enable the ASV to pass through heavy harbour traffic to an intended destination safely and efficiently. While predicting the future path of other vehicles and path planning can be carried out by known methods,...
Vehicle stability control system has evolved significantly over the past three decades. Several control strategies have been implemented to enhance the vehicle stability control performance. However, most of these control strategies have not been focused on improving the transient response for vehicle yaw rate and sideslip angle tracking controller in the presence of uncertainties and disturbance...
This paper addresses a synchronization problem that arises when a team of aerial robots (ARs) need to communicate while performing assigned tasks in a cooperative scenario. Each robot has a limited communication range and flies within a previously assigned closed path. When two robots are close enough, a communication link may be established allowing the robots to share information. The goal is to...
This paper presents a method for stabilizing the attitude of a Hybrid Unmanned Aerial Underwater Vehicle. Firstly, we present aerodynamic and hydrodynamic models for the angular motion of our robot, discussing effects like buoyancy force and added inertia. Next, we apply robust control techniques for both environment, aerial and underwater, based on linear uncertain models with only four vertices...
Scaling down the size and mass of micro aerial vehicles (MAVs) increases their agility and their ability to operate in tight formations. In addition, smaller robots are safer and, as we will show in this paper, more robust to collisions. This paper addresses the development of a pico quadrotor measuring 11 cm from tip to tip, with a mass of 25g. To increase the robustness of the robot to collisions,...
Steering and braking control is applied to avoid rollover of road vehicles. The control concept presented is composed of three feedback loops: Continuous operation steering control, emergency steering control and emergency braking control. In continuous operation the roll rate and the roll acceleration are fed back by velocity scheduled gains to the front wheel steering angle. Thereby, the vehicle's...
This paper generalizes the pole placement method to the case of improper transfer. In that case, the minimal order solution may be non unique. After some illustrating examples, the problem of active control of a vehicle drivetrain is investigated. The control design is based on a simplified model including a non proper approximation of the delay. A methodic choice of the closed loop poles leads to...
This paper is concerned with the use of active brake systems in order to decrease the rollover risk of heavy vehicles. Since the forward velocity of the vehicle changes in time, the combined yaw-roll dynamic model has a nonlinear structure. Selecting the forward velocity and the so-called normalized lateral load transfer at the rear side as scheduling parameters, a Linear Parameter Varying (LPV) model...
In this paper the problem of vehicle lateral control in highway experimental conditions is addressed. The vehicle under consideration is equipped with an electric motor acting on the steering angle (the command input) and a vision system providing two measurements (the two outputs): the lateral displacement and the angular orientation of the vehicle with respect to the lane centerline. We show how,...
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