4 research outputs found
Autonomous driving of trucks in off-road environment
Off-road driving operations can be a challenging environment for human
conductors as they are subject to accidents, repetitive and tedious tasks,
strong vibrations, which may affect their health in the long term. Therefore,
they can benefit from a successful implementation of autonomous vehicle
technology, improving safety, reducing labor costs and fuel consumption, and
increasing operational efficiency. The main contribution of this paper is the
experimental validation of a path tracking control strategy, composed of
longitudinal and lateral controllers, on an off-road scenario with a
fully-loaded heavy-duty truck. The longitudinal control strategy relies on a
Non-Linear Model Predictive Controller (NMPC), which considers the path
geometry and simplified vehicle dynamics to compute a smooth and comfortable
input velocity, without violating the imposed constraints. The lateral
controller is based on a Robust Linear Quadratic Regulator (RLQR), which
considers a vehicle model subject to parametric uncertainties to minimize its
lateral displacement and heading error, as well as ensure stability.
Experiments were carried out using a fully-loaded vehicle on unpaved roads in
an open-pit mine. The truck followed the reference path within the imposed
constraints, showing robustness and driving smoothness.Comment: Paper accepted at Journal of Control, Automation and Electrical
System
Autonomous Driving of Trucks in Off-Road Environment
Off-road driving operations can be a challenging environment for human conductors as they are subject to accidents, repetitive and tedious tasks, strong vibrations, which may affect their health in the long term. Therefore, they can benefit from a successful implementation of autonomous vehicle technology, improving safety, reducing labor costs and fuel consumption, and increasing operational efficiency. The main contribution of this paper is the experimental validation of a path tracking control strategy, composed of longitudinal and lateral controllers, on an off-road scenario with a fully loaded heavy-duty truck. The longitudinal control strategy relies on a nonlinear model predictive controller, which considers the path geometry and simplified vehicle dynamics to compute a smooth and comfortable input velocity, without violating the imposed constraints. The lateral controller is based on a robust linear quadratic regulator, which considers a vehicle model subject to parametric uncertainties to minimize its lateral displacement and heading error, as well as ensure stability. Experiments were carried out using a fully loaded vehicle on unpaved roads in an open-pit mine. The truck followed the reference path within the imposed constraints, showing robustness and driving smoothness.Funding Agencies|Vale S.A.; Coordenacaode Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) [001, 88887.136349/2017-00]; Brazilian National Research Council (CNPq) [465755/2014-3]; Sao Paulo Research Foundation (FAPESP) [2014/50851-0]</p
Treating cancer with selective CDK4/6 inhibitors.
Uncontrolled cellular proliferation, mediated by dysregulation of the cell-cycle machinery and activation of cyclin-dependent kinases (CDKs) to promote cell-cycle progression, lies at the heart of cancer as a pathological process. Clinical implementation of first-generation, nonselective CDK inhibitors, designed to inhibit this proliferation, was originally hampered by the high risk of toxicity and lack of efficacy noted with these agents. The emergence of a new generation of selective CDK4/6 inhibitors, including ribociclib, abemaciclib and palbociclib, has enabled tumour types in which CDK4/6 has a pivotal role in the G1-to-S-phase cell-cycle transition to be targeted with improved effectiveness, and fewer adverse effects. Results of pivotal phase III trials investigating palbociclib in patients with advanced-stage oestrogen receptor (ER)-positive breast cancer have demonstrated a substantial improvement in progression-free survival, with a well-tolerated toxicity profile. Mechanisms of acquired resistance to CDK4/6 inhibitors are beginning to emerge that, although unwelcome, might enable rational post-CDK4/6 inhibitor therapeutic strategies to be identified. Extending the use of CDK4/6 inhibitors beyond ER-positive breast cancer is challenging, and will likely require biomarkers that are predictive of a response, and the use of combination therapies in order to optimize CDK4/6 targeting