Simulation of working procedures in a distribution centre

This simulation study has been developed to assess a set of realistic proposals of a new distribution centre to a pharmaceutical company, with a focus on the sorting operation. Different sorting strategies, establishing dynamic assignment of the lanes to destinations and lanes to operators are proposed. Also different packing procedures have been presented according to the operator way of working. New qualitative criterions have been defined to evaluate the strategies. The results show some interesting non-linear behaviour in the sorting operation, and give the number of required operators, length of the lanes, and working procedures to be used in this application. The simulation experiments show that the improvement in the overall productivity by choosing a specific sorting strategy can be significant. The study has helped the management of the involved company to make a decision about the supplier and actually, the suggested proposals are being implemented in practice

The non-parametric Parzen's window in stereo vision matching

This paper presents an approach to the local stereovision matching problem using edge segments as features with four attributes. From these attributes we compute a matching probability between pairs of features of the stereo images. A correspondence is said true when such a probability is maximum. We introduce a nonparametric strategy based on Parzen's window to estimate a probability density function (PDF) which is used to obtain the matching probability. This is the main finding of the paper. A comparative analysis of other recent matching methods is included to show that this finding can be justified theoretically. A generalization of the proposed method is made in order to give guidelines about its use with the similarity constraint and also in different environments where other features and attributes are more suitable

Local stereovision matching through the ADALINE neural network

This paper presents an approach to the local stereovision matching problem using edge segments as features with four attributes. Based on these attributes we compute a matching probability between pairs of features of the stereo images. A correspondence is said to be true when this probability is maximum. The probability value is a weighted sum of the attributes. We use two combined ADALINE neural networks to compute the weight for each attribute. A comparative analysis among other recent matching methods is illustrated

A probabilistic neural network for attribute selection in stereovision matching

The key step in stereovision is image matching. This is carried out on the basis of selecting features, edge points, edge segments, regions, corners, etc. Once the features have been selected, a set of attributes (properties) for matching is chosen. This is a key issue in stereovision matching. This paper presents an approach for attribute selection in stereovision matching tasks based on a Probabilistic Neural Network, which allows the computation of a mean vector and a covariance matrix from which the relative importance of attributes for matching and the attribute interdependence can be derived. This is possible because the matching problem focuses on a pattern classification problem. The performance of the method is verified with a set of stereovision images and the results contrasted with a classical attribute selection method and also with the relevance concept

Unified fusion system based on bayesian networks for autonomous mobile robots

A multisensor fusion system that is usedfor estimating the location of a robot and the state of the objects around is presented. The whole fusion system has been implemented as a Dynamic Bayesian Networks (DBN) with the purpose of having a homogenous and formalized way of capturing the dependencies that exist between the robot location, the state of the environment, and all the sensorial data. At this stage of the research it consists of two independent DBNs, one for estimating the robot location and another for building an occupancy probabilistic map of the environment, which are the basis of a unified fusion system. The dependencies of the variables and information in the two DBN will be captured by a unique DBN constructed by adding arcs (and nodes if necessary) between the two DBN. The DBN implemented so far can be used in robots with different sets of sensors

Multiobjective path planner for UAVs based on genetic algorithms

This paper presents a path planner for Unmanned Air Vehicles (UAVs) based on Genetic Algorithms (GA) that obtains a feasible and optimal 3-D path for the UAV. It uses 9 different objective values which are calculated with a realistic model of the UAV and the environment and which are structured with 3 levels of priorities. Our planner works globally offline as well as locally online, which means that the algorithm can recalculate parts of the generated path in order to avoid unexpected risks. Finally, the effectiveness of the solutions given by this planner has been successfully tested against a simulator that contains the complete model of the UAV and the environment

Multisensor fusion of environment measures using Bayesian Networks

Autonomous mobile robots usually require a large number of sensor types and sensing modules. There are different sensors, some complementary and some redundant. Integrating the sensor measures implies several multisensor fusion techniques. These techniques can be classified in two groups: low level fusion, used for direct integration of sensory data; and high level fusion, which is used for indirect integration of sensory data. We have developed a system to integrate indirect measures of different sensors. This system allows us to use any type of sensor which provides measures of the robot's environment It Is designed as a Belief Bayesian Network. The method needs that the user creates a low level fusion module and an interface between that module and our fusion system

Application of a robust QFT linear control method to the course changing manoeuvring of a ship

This paper describes in detail the design methodology of a robust QFT (Quantitative Feedback Theory) controller for the control of the course changing of a ship. A linear model is used with uncertainty in the parameters. The system is designed to fulfil the specifications of robust stability and robust tracking of a reference system