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Much research has been done on the subject of collision avoidance (COLAV). However, few results are presented that consider vehicles with second-order nonholonomic constraints, such as autonomous underwater vehicles (AUVs). This paper considers the dynamic window (DW) algorithm for reactive horizontal COLAV for AUVs, and uses the HUGIN 1000 AUV in a case study. The DW algorithm is originally developed...
Motion planning for service robots used for human assistance in complex environments is a challenging task with multifaceted requirements. On the one hand, the generated path has to avoid obstacles and satisfy the user requirements. On the other, the generated path has to be perceived as comfortable by the user. An efficient solution to this difficult problem is based on a separation of concerns between...
A distributed control strategy for leader-follower synchronization of agents with generic linear dynamics affected by constant unknown disturbances is presented. In particular, we consider a group of N + 1 agents, where we have a leader and N followers. The leader's behavior is independent of the followers'. Furthermore, the leader will influence the behavior of all the followers, through consensus...
In this paper, we propose a central coordination system to compute optimized trajectories of intelligent vehicles in a double lane road with traffic lights. The focus is to decrease travel time when comparing to human drivers traffic. First, we predict the waiting line formation order when vehicles approach traffic lights. Then, we compute a global motion plan in order to force trajectories result...
The main objective of this paper is to develop an Eco-Traffic Signal System (Eco-TSS) that can improve fuel consumption and delays at an isolated intersection under Connected Vehicle environment. The proposed system consists of an eco-driving algorithm and a traffic signal optimization process to find an optimal solution minimizing fuel consumption and delays. We designed a bi-level optimization method...
This paper aims to develop a modeling framework for optimizing the timing of a set of traffic signals by considering individual vehicle characteristics (such as fuel consumption and travel time). Through the Vehicle to Infrastructure (V2I) communications, such individual vehicle information is available for the infrastructure center to produce optimal signal timing. The proposed strategy applies the...
We examine the problem of jointly determining the positions of multiple underwater vehicles based on a set of pairwise range and bearing measurements taken over time. This extends prior work on the so-called (static) collaborative localization paradigm where a hybrid approach was proposed for seamless instantaneous fusion (i.e., no time dependence) of range and bearing measurements. To incorporate...
This paper proposes an efficient hybrid positioning method for land vehicles in urban area. As widely known, any single satellite positioning system suffers from the lack of satellite visibility in urban area. To improve positioning availability in urban area, the proposed method integrates a GPS/BeiDou receiver, an OBD-II (On-Board Diagnostics-II) device, and a MEMS IMU (Micro Electro Mechanical...
With the rapid development of GPS devices, satellite and wireless communications technologies, many trajectory data is generated. Consequently, processing and analyzing trajectory data have become a hot topic. In this paper, an improved noise filtering, trajectory compression and trajectory segmentation method based on Kalman filter and Douglas-Peucker algorithm and corner is proposed. Firstly, the...
Boosting trajectory planning is the basis of the gliding trajectory planning for land-launch hypersonic vehicle. Its terminal states are essential to subsequence flight. Besides, mobile launch is an important means to promote the survivability of hypersonic vehicle. To plan the boosting trajectory for hypersonic vehicle and satisfy the strict terminal constraints, firstly we analyzed and established...
One approach to reduce energy consumption in railway systems is to implement optimised train trajectories. These are speed profiles that reduce energy consumption without foregoing customer comfort or running times. This is achieved by avoiding unnecessary braking and running at reduced speed whilst maintaining planned arrival times. An optimised train trajectory can be realised using a driver advisory...
In this paper, the complicated motion equations are established based on the dynamic characteristics of the return flying vehicle. This model is incorporated into an optimal control formulation that includes constraints on both the vehicle and mission parameters, such as the height, velocity, range, heat rate, aerodynamic load and dynamic pressure capability. How these models are appropriately employed...
We develop a robust, unsupervised vehicle tracking system for videos of very congested road intersections in urban environments. Raw tracklets from the standard Kanade-Lucas-Tomasi tracking algorithm are treated as sample points and grouped to form different vehicle candidates. Each tracklet is described by multiple features including position, velocity, and a foreground score derived from robust...
Distraction during driving is a growing concern for global road safety. Different activities impertinent to driving hinder the concentration of driver on road and often cause substantial damage to life and property. For making driving safe, an algorithm is proposed in this paper that is capable of detecting distraction during driving. The proposed algorithm tracks key body parts of the driver in video...
Multiple objective navigation is commonly found in practice, where a path for an autonomous vehicle needs to be generated to simultaneously optimize a number of different objectives such as distance, safety, and visibility. Objectives can be weighted to solve a single objective optimization problem but appropriate weights may not be known a priori. In this paper, we formulate a series of missions...
We present a motion planning algorithm for autonomous aggressive vehicle maneuvers. The motion planner takes advantages of the sparse stable trees (SST), the RRT* algorithm and the model predictive control (MPC) design. The use of the sparsity property helps to reduce the computational burden of the RRT* method by removing non-useful nodes in each iteration (i.e., rewiring) and therefore to quickly...
In this paper, a simplified dynamic vehicle model is established to accurately describe the dynamics of Unmanned Ground Vehicle (UGV) in trajectory tracking, while meeting the real-time computing requirement. And a modified model predictive control (MPC) algorithm with soft constraint for UGV trajectory tracking is proposed to improve the tracking stability and rapidity. The optimal control problem...
This paper studies the hypersonic reentry trajectory optimization problem considering waypoints and no-fly zones constraints. This problem is difficult to solve because of (1) the poor damping phugoid oscillations, (2) the constraints on waypoints and no-fly zones, and (3) the rapid changes in part of the trajectory. To suppress the oscillations, we establish a novel reentry dynamic model by embedding...
In this paper, a real-time laser based gap finding obstacle avoidance algorithm is presented. This algorithm layers on top of a global planner to maintain the overall goal of a given task. In the presence of an unknown obstacle, the algorithm computes a trajectory toward a gap that is wide enough and is closest to the path pre-planned by the global planner. In order to achieve this result, a four-stage...
This paper introduces a new approach for designing a simplified control law, which controls an autonomous underwater vehicle (AUV) to track a given 3D trajectory. To get a Linear Time Variant (LTV) state space model, the 6 degrees of freedom (6DOF) dynamics and kinematics model of the AUV is linearized about the given desired 3D trajectory it needs to track. A linear quadratic regulator (LQR) is designed...
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