1. 
 Eidehall, Andreas, et al.
(författare)

A New Approach to Lane Guidance Systems
 2005

Rapport (övrigt vetenskapligt)abstract
 This paper presents a new automotive safety function called Emergency Lane Assist (ELA). ELA combines conventional lane guidance systems with a threat assessment module that tries to activate and deactivate the lane guidance interventions according to the actual risk level of lane departure. The goal is to only prevent dangerous lane departure manoeuvres. Such a threat assessment algorithm is dependent on detailed information about the vehicle surroundings, i.e., positions and motion of other vehicles, but also information about road and lane geometry parameters such as lane width and road curvature. An Extended Kalman Filter for estimating these parameters is used and the performance is improved by introducing a nonlinear model which uses a road aligned, curved coordinate system. The ELA decision algorithm has been tested in a demonstrator and it successfully distinguishes between dangerous and safe lane changes on a small set of test scenarios. It is also able to take control of the vehicle and put it in a safe position in the original lane.


2. 
 Aberger, Martin
(författare)

Effects of Nonlinearities in Black Box Identification of an Industrial Robot
 2000

Rapport (övrigt vetenskapligt)abstract
 This paper discusses effects of nonlinearities in black box identification of one axis of a robot. The used data come from a commercial ABB robot, IRB1400. A threemass flexible model for the robot was built in MathModelica. The nonlinearities in the model are nonlinear friction and backlash in the gear box.


3. 
 Abrahamsson, Tomas, et al.
(författare)

A Study of some Approaches to Vibration Data Analysis
 1993

Rapport (övrigt vetenskapligt)abstract
 Using data from extensive vibrational tests of the new aircraft Saab 2000 three different methods for vibration analysis are studied. These methods are ERA (eigensystem realization algorithm), N4SID (a subspace method) and PEM (prediction error approach). We find that both the ERA and N4SID methods give good initial model parameter estimates that can be further improved by the use of PEM. We also find that all methods give good insights into the vibrational modes.


4. 
 Ahlberg, Jörgen, 1971, et al.
(författare)

Ground Target Recognition in a QueryBased MultiSensor Information System
 2006

Rapport (övrigt vetenskapligt)abstract
 We present a system covering the complete process for automatic ground target recognition, from sensor data to the user interface, i.e., from low level image processing to high level situation analysis. The system is based on a query language and a query processor, and includes target detection, target recognition, data fusion, presentation and situation analysis. This paper focuses on target recognition and its interaction with the query processor. The target recognitionis executed in sensor nodes, each containing a sensor and the corresponding signal/image processing algorithms. New sensors and algorithms are easily added to the system. The processing of sensor data is performed in two steps; attribute estimation and matching. First, several attributes, like orientation and dimensions, are estimated from the (unknown but detected) targets. These estimates are used to select the models of interest in a matching step, where the targetis matched with a number of target models. Several methods and sensor data types are used in both steps, and data is fused after each step. Experiments have been performed using sensor data from laser radar, thermal and visual cameras. Promising results are reported, demonstrating the capabilities of the target recognition algorithms, the advantages of the twolevel data fusion and the querybased system.


5. 
 Akçay, Hüseyin, et al.
(författare)

On the Choice of Norms in System Identification
 1994

Rapport (övrigt vetenskapligt)abstract
 In this paper we discuss smooth and sensitive norms for prediction error system identification when the disturbances are magnitude bounded. Formal conditions for sensitive norms, which give an order of magnitude faster convergence of the parameter estimate variance, are developed. However, it also is shown that the parameter estimate variance convergence rate of sensitive norms is arbitrarily bad for certain distributions. A necessary condition for a norm to be statistically robust with respect to the family F(C) of distributions with support [C, C] for some arbitrary C>0 is that its second derivative does not vanish on the support. A direct consequence of this observation is that the quadratic norm is statistically robust among all lpnorms, p⩽2<∞ for F(C).


6. 
 Akçay, Hüseyin, et al.
(författare)

On the Choice of Norms in System Identification
 1996

Rapport (övrigt vetenskapligt)abstract
 In this paper we discuss smooth and sensitive norms for prediction error system identification when the disturbances are magnitude bounded. Formal conditions for sensitive norms, which give an order of magnitude faster convergence of the parameter estimate variance, are developed. However, it also is shown that the parameter estimate variance convergence rate of sensitive norms is arbitrarily bad for certain distributions. A necessary condition for a norm to be statistically robust with respect to the family F(C) of distributions with support [C, C] for some arbitrary C>0 is that its second derivative does not vanish on the support. A direct consequence of this observation is that the quadratic norm is statistically robust among all lpnorms, p⩽2<∞ for F(C).


7. 
 Akçay, Hüseyin, et al.
(författare)

The LeastSquares Identification of FIR Systems Subject to WorstCase Noise
 1993

Rapport (övrigt vetenskapligt)abstract
 The leastsquares identification of FIR systems is analyzed assuming that the noise is a bounded signal and the input signal is a pseudorandom binary sequence. A lower bound on the worstcase transfer function error shows that the lestsquare estimate of the transfer function diverges as the order of the FIR system is increased. This implies that, in the presence of the worstcase noise, the tradeoff between the estimation error due to the disturbance and the bias error (due to unmodeled dynamics) is significantly different from the corresponding tradeoff in the random error case: with a worstcase formulation, the model complexity should not increase indefinitely as the size of the data set increases.


8. 
 Akçay, Hüseyin, et al.
(författare)

The LeastSquares Identification of FIR Systems Subject to WorstCase Noise
 1994

Rapport (övrigt vetenskapligt)abstract
 The leastsquares identification of FIR systems is analyzed assuming that the noise is a bounded signal and the input signal is a pseudorandom binary sequence. A lower bound on the worstcase transfer function error shows that the leastsquare estimate of the transfer function diverges as the order of the FIR system is increased. This implies that, in the presence of the worstcase noise, the tradeoff between the estimation error due to the disturbance and the bias error (due to unmodeled dynamics) is significantly different from the corresponding tradeoff in the random error case: with a worstcase formulation, the model complexity should not increase indefinitely as the size of the data set increases.


9. 
 Anderson, Kristin, 1977, et al.
(författare)

Broadcast Encryption and Group Codes
 2004

Rapport (övrigt vetenskapligt)abstract
 We consider the subset difference scheme for broadcast encryption and count the number of required transmissions when using this scheme. The subset scheme organizes receivers in a tree structure and we note that isomorphic trees yield the same number of required transmissions. We then study the group properties of isomorphism classes of trees. Finally we formulate some research questions for further study of the performance of the subset difference scheme.


10. 
 Anderson, Kristin, 1977
(författare)

Performance of the Subset Difference Scheme for Broadcast Encryption
 2004

Rapport (övrigt vetenskapligt)abstract
 This report considers the subset difference scheme for broadcast encryption and the number of broadcast transmissions required when using this scheme. For cases where the privileged users are gathered in a few groups we derive the worst case number of transmissions. We also present an upper bound for the number of transmissions based on the number of transitions between privileged and nonprivileged users in the user set.

