Incorporating the information and uncertainties of loop-detector and floating car data in freeway traffic state estimation

Traffic state estimation is an important element in traffic management systems. In this research a freeway traffic state estimation methodology is proposed which allows to incorporate the information and uncertainties of heterogeneous data-types, namely loop-detector data and floating car data. The loop-detector data provides estimation of speed...

Real Time Traffic Models, Decision Support for Traffic Management

Reliable and accurate short-term traffic state prediction can improve the performance of real-time traffic management systems significantly. Using this short-time prediction based on current measurements delivered by advanced surveillance systems will support decision-making processes on various control strategies and enhance the performance of...

Nonlinear State Estimation for a Bipedal Robot

Humanoid robots could perform a large variety of tasks, ranging from helping the elderly and entertainment to carrying out repairs in hazardous environments such as nuclear power plants. Therefore, they are an important topic of research. However, controlling the balance of two-legged robots still proves to be a challenge, especially during more...

Real time traffic models, decision support for traffic management

Reliable and accurate short-term traffic state prediction can improve the performance of real-time traffic management systems significantly. Using this short-time prediction based on current measurements delivered by advanced surveillance systems will support decision-making processes on various control strategies and enhance the performance of...

Identification of multiple localized forces on a footbridge

An existing joint input-state estimation algorithm is extended for applications in structural dynamics. The estimation of the input and the system states is performed in a minimum-variance unbiased way, based on a limited number of response measurements and a system model. An additional method is proposed to identify the noise statistics, which...

Lagrangian Multi-Class Traffic State Estimation

Road traffic is important to everybody in the world. People travel and commute everyday. For those who travel by cars (or other types of road vehicles), traffic congestion is a daily experience. One essential goal of traffic researchers is to reduce traffic congestion and to improve the whole traffic system operation and the environment. To...

Fastlane: Traffic flow modeling and multi-class dynamic traffic management

Dynamic Traffic Management (DTM) aims to improve traffic conditions. DTM usually consists of two steps: first the current traffic is estimated, then appropriate control actions are determined based on that estimate. In order to estimate and control the traffic, a suitable traffic flow model that reproduces the properties of traffic well must be...

Bayesian Data Assimilation for Improved Modeling of Road Traffic

This thesis deals with the optimal use of existing models that predict certain phenomena of the road traffic system. Such models are extensively used in Advanced Traffic Information Systems (ATIS), Dynamic Traffic Management (DTM) or Model Predictive Control (MPC) approaches in order to improve the traffic system. As road traffic is the result...

Model-Based Control of Industrial Batch Crystallizers: Experiments on Enhanced Controllability by Seeding Actuation

Crystallization is one of the oldest separation and purification techniques. Batch crystallizers are widely used in production of fine chemicals, food ingredients, specialty chemicals, and active pharmaceutical ingredients. Control of the crystalline material properties is a challenging task due to complexity and nonlinearity of batch...

Modeling of indoor thermal conditions for comfort control in buildings

Some aerospace applications of estimation theory

In this report, the application of estimation theory to three problems from aerospace research is described. The applications considered deal with spacecraft attitude estimation, software reliability modelling and estimation, and with a satellite-based navigation algorithm. Maximum likelihood estimation is used in the software reliability case...

Bayesian estimation for decision-directed stochastic control

Stochastic processes with a decision-directed control are considered as controlled Markov processes, the state space of which is hybrid; i.e. a product of a discrete set and a Euclidean space. This approach yields a mathematical model for many problems of decision-directed stochastic control. In general, the observations made from the "past" and...

Two-dimensional flight-path reconstruction by means of spline approximation

In this report, a method is developed to reconstruct the flight-path of an aircraft in symmetric, non-steady flight by representing this path by a set of splines. That set of splines is chosen, for which the flighttest data are best explained in some weighted least squares sense. This leads to a large, sparse, nonlinear, overdetermined system,...

Processing of Meteosat attitude measurement flight data and evaluation of the performance of an adaptive filtering technique

The attitude measurement data of the ESA geosynchronous spacecraft METEOSAT have been analyzed using an adaptive recursive filtering technique developed at NLR. The mathematical models of spacecraft dynamics and sensors have been kept very simple. Modelling errors are such that, without adaptive feed-back, strong divergence of the filtering...

Accurate spacecraft attitude estimation with the ESA starmapper

The ESA starmapper is an optical-electronic instrument with an array of photo-sensitive slits, to "be strapped down to spinning spacecraft. Recorded times of passage of known stars over these slits, together with mathematical models for spacecraft dynamics and starmapper instrument, provide the basis for recursive estimation of the spacecraft...

Survey of modern control and observation theory for disturbed, target following aerospace systems. Part one: Basic theory

The document contains a general theory towards the observation and optimal control of disturbed, target following aerospace systems. Disturbed, target following aerospace systems eire defined as aerospace systems that are designed to track a moving target system, while they are subjected to external, time-varying disturbances. The first five...