Obstacle Filtering Alogrithm for Control of an Autonomous Road Vehicle in Public Highway Traffic

This paper presents an obstacle filtering algorithm that mimics human driver-like grouping of objects within a model predictive control scheme for an autonomous road vehicle. In the algorithm, a time to collision criteria is first used as risk assessment indicator to filter the potentially dangerous obstacle object vehicles in the proximity of the autonomously controlled vehicle. Then, the filtered object vehicles with overlapping elliptical collision areas put into groups. A hyper elliptical boundary is regenerated to define an extended collision area for the group. To minimize conservatism, the parameters for the tightest hyper ellipse are determined by solving an optimization problem. By excluding undesired local minimums for the planning problem, the grouping alleviates limitations that arise from the limited prediction horizons used in the model predictive control. The computational details of the proposed algorithm as well as its performance are illustrated using simulations of an autonomously controlled vehicle in public highway traffic scenarios involving multiple other vehicles

Vehicle Suspension Including a Link

A link of a vehicle suspension is elastic and includes three suspension points. A first point is adapted to be pivotally connected to a wheel carrier of the corresponding vehicle. A second point is adapted to be pivotally connected to a rigid chassis of the corresponding vehicle. The third point is adapted to be pivotally connected to a shackle, the shackle pivotally connecting the third point to the rigid chassis of the vehicle

Broadcast performance analysis and improvements of the LTE-V2V autonomous mode at road intersection

An autonomous V2V communication mode (also known as side-link mode 4), which facilitates V2V communication in out of eNB coverage areas, has recently been introduced into the Long term evolution (LTE) standard. Recent research has studied the performance of this LTE-V2V autonomous mode for a highway use case. However, performance analysis for a highway use case cannot be easily applied to an intersection use case as it may contain non-line-of-sight (NLOS) communication links. In this paper, we analyze and evaluate the safety message broadcasting performance of LTE-V2V autonomous mode in an urban intersection scenario. Considering practical path loss models, we present the impact of NLOS communication link on the overall message dissemination performance. Through the analytical and simulation results, we show that the overall message dissemination performance degrades drastically with increasing vehicle density and increasing distance of the transmitting vehicle from the intersection. To improve the performance, we propose a vehicle-assisted relaying scheme in which the relaying vehicle is selected in an autonomous manner. We also present two resource allocation strategies for the relaying vehicle. For low to medium vehicle density along the street, we observe significant improvement in message dissemination through relaying compared to the scheme without relaying

Optimal Melting Interface Tracking in Laser-Aided Powder Deposition Processes

This paper presents a systematic control inputs optimization method for melting interface tracking in laser-aided powder deposition (LAPD) processes. Using a proposed interface approximation and a coordinate system moving with the laser source, and adopting the enhanced thermal conductivity method, the process model is first reduced to a set of coupled partial differential equations (PDEs) in fixed spatial domains. Then, the control problem of achieving process target properties is formulated as one of optimizing the control inputs to track a prescribed melting interface which is approximated from required process target parameters. This proposed optimization scheme is solved by the adjoint-based gradient method for which an algorithm is provided. A weighting scheme is also proposed to overcome feasibility issues with poor interface specifications and still achieve improved tracking of target parameters. The proposed scheme is illustrated through a simulation-based case study on a laser cladding process.Mechanical Engineerin