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Journal Article

3D Coverage Control and Target Orientation Alignment Using Unmanned Ground Vehicle with Onboard Camera Sensor

2023-04-11
2023-01-0693
This paper addresses a three dimensional (3D) mission domain coverage control problem combined with camera pose control to align towards specific objects of interest. We consider an unmanned ground vehicle (UGV) based on a unicycle kinematics model with an onboard camera sensor based on a visual perspective sensor model. The coverage control problem has been researched in large part for planar domains, which is however not sufficient for real world applications for UGV navigation. Furthermore, in contrast to coverage control of points in the environment, when dealing with objects of interest, it is more amicable to consider that there exist certain orientations to which the camera must align itself to properly cover the object and make ‘sense’ of it. Hence, we seek to derive both UGV coverage control law for 3D mission domains and onboard camera pose control considering target orientation.
Technical Paper

Actively Articulated Wheeled Architectures for Autonomous Ground Vehicles - Opportunities and Challenges

2023-04-11
2023-01-0109
Traditional ground vehicle architectures comprise of a chassis connected via passive, semi-active, or active suspension systems to multiple ground wheels. Current design-optimizations of vehicle architectures for on-road applications have diminished their mobility and maneuverability in off-road settings. Autonomous Ground Vehicles (AGV) traversing off-road environments face numerous challenges concerning terrain roughness, soil hardness, uneven obstacle-filled terrain, and varying traction conditions. Numerous Active Articulated-Wheeled (AAW) vehicle architectures have emerged to permit AGVs to adapt to variable terrain conditions in various off-road application arenas (off-road, construction, mining, and space robotics). However, a comprehensive framework of AAW platforms for exploring various facets of system architecture/design, analysis (kinematics/dynamics), and control (motions/forces) remains challenging.
Technical Paper

An Integrated Energy Management and Control Framework for Hybrid Military Vehicles based on Situational Awareness and Dynamic Reconfiguration

2022-03-29
2022-01-0349
As powertrain hybridization technologies are becoming popular, their application for heavy-duty military vehicles is drawing attention. An intelligent design and operation of the energy management system (EMS) is important to ensure that hybrid military vehicles can operate efficiently, simultaneously maximize fuel economy and minimize monetary cost, while successfully completing mission tasks. Furthermore, an integrated EMS framework is vital to ensure a functional vehicle power system (VPS) to survive through critical missions in a highly stochastic environment, when needed. This calls for situational awareness and dynamic system reconfiguration capabilities on-board of the military vehicle. This paper presents a new energy management and control (EMC) framework based on holistic situational awareness (SA) and dynamic reconfiguration of the VPS.
Journal Article

Data Reduction Methods to Improve Computation Time for Calibration of Piston Thermal Models

2023-04-11
2023-01-0112
Fatigue analysis of pistons is reliant on an accurate representation of the high temperatures to which they are exposed. It can be difficult to represent this accurately, because instrumented tests to validate piston thermal models typically include only measurements near the piston crown and there are many unknown backside heat transfer coefficients (HTCs). Previously, a methodology was proposed to aid in the estimation of HTCs for backside convection boundary conditions of a stratified charge compression ignition (SCCI) piston. This methodology relies on Bayesian inference of backside HTC using a co-simulation between computational fluid dynamics (CFD) and finite element analysis (FEA) solvers. Although this methodology primarily utilizes the more computationally efficient FEA model for the iterations in the calibration, this can still be a computationally expensive process.
Technical Paper

Decomposition and Coordination to Support Tradespace Analysis for Ground Vehicle Systems

2022-03-29
2022-01-0370
Tradespace analysis is used to define the characteristics of the solution space for a vehicle design problem enabling decision-makers (DMs) to evaluate the risk-benefit posture of a vehicle design program. The tradespace itself is defined by a set of functional objectives defined by vehicle simulations and evaluating the performance of individual design solutions that are modeled by a set of input variables. Of special interest are efficient design solutions because their perfomance is Pareto meaning that none of their functional objective values can be improved without decaying the value of another objective. The functional objectives are derived from a combination of simulations to determine vehicle performance metrics and direct calculations using vehicle characteristics. The vehicle characteristics represent vendor specifications of vehicle subsystems representing various technologies.
Technical Paper

Effects of Framing on Tradespace Exploration Decision-Making for Vehicle Design

2024-04-09
2024-01-2660
Tradespace exploration (TSE) describes the activity occurring early in the design process through which stakeholders explore a broad solution space in search of more-optimal alternatives. In doing so, these stakeholders attempt to maximize the utility inherent in the chosen solution while understanding the tradeoffs and compromises that may be required to find an acceptable solution. In the field of vehicle design, tradespaces are often comprised of vast amounts of alternatives which increases the complexity of the decision-making process. Additionally, the number of stakeholders has grown, as decision-makers seek to include more variety in both perspectives and expertise. As such, decision-making stakeholders can often find themselves working at odds and attempting to maximize vastly different objectives in the process. One way to rectify these contrasting viewpoints can be to intentionally introduce a group framing prior to the start of decision making.
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