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keywords : virtual sensors, generalized car dynamics virtual sensor, non linear dynamic systems modeling, defects detection and recognition, intelligent airbag triggering, statistics for epidemiology, abnormal facts detection, process monitoring, control and regulation, cylinder head quality control, swirl prediction, exhaust estimation,


Pure technical studies


History
NEXYAD main founders, Pierre DA SILVA DIAS and Gérard YAHIAOUI were involved in the 1890's in car industry research studies such as road detection ("Texture-based Image Segmentation for Road Recognition with Neural Networks", G. Yahiaoui, M. de Saint Blancard, Sixth international conference on neural networks and their industrial & cognitive applications NeuroNîmes93, EC2, Nîmes, 1993 ), obstacle detection, or car dynamics modeling. Their know-how was mainly :

 - signal theory

 - artificial vision

 - statistics

 - neural networks

 - applied maths

They also worked for military applications (detection, pattern recognition, tracking, ...).

This explain why there is a strong "on-board " culture at NEXYAD, even if the team also works on other kinds of applications.
We show below some examples of pure technical studies both in technical and in marketing fields.


Technical Applications


Virtual sensors (kalman, luenberger, neural networks, ...)
NEXYAD developed many virtual sensors applications, involving different kinds of applied maths methods such as Kalman filters, extended kalman filters, Luenberger observers, neural nets, fuzzy logic-based ensemblist methods, ...
Example : "true speed" of the car reconstructed from standard on board sensors such as accelarations, wheels speed, ... (for various trajectories and grips)



300 tracks virtual sensor for car dynamics
NEXYAD developed, in partnership with the french research company SERA CD, a 300 tracks virtual sensor for car dynamics. This system is composed of two parts :
 - a model of the car's behaviour (CALLAS software developed by SERA CD) : a 17 mechanical degrees of freedom model,
 - a re-adjustment system (developed by NEXYAD) : re-adjustment of the
model   parameters   presets,   in  real  time,  in order  to fit  into  real  world  observations
The model runs in real time an on-board simulation of the car. The NEXYAD re-adjustment system computes presets of the model in real time in order to let the model and the real car behaviours match.
The 300 internal variables of the CALLAS model are then available in real time as 300 virtual measurement tracks.

Non linear dynamic system modeling
NEXYAD worked on many models for non linear systems :
 - classical differential equations models
 - neural nets
Example : tire model : maximum adherence among depth of water for several speeds

Defects detection and recognition
NEXYAD developed several industrial pattern recognition applications, from occupant recognition in cars (using pressure maps) to defects detection and recognition is glass (for bottles factory), or crack detection in steel materials, ...
Example : defects detection in glass (image processing, eigen vectors analysis, neural networks, bayesian networks, statistics, fuzzy decision arrays, texture analysis - covariance, fractals )
   

Intelligent airbag triggering
NEXYAD developed an intelligent airbag triggering system : from a pressure map and other sensors (such as temperature sensor), NEXYAD developed a pattern recognition system that identifies the kind of seat occupant : children, baby seat, adult, ... From this information, the airbag triggering system can be modulated.
This system is based on fuzzy logic decision arrays.

Statistics for epidemiology
NEXYAD worked on many epidemiological studies such as :
 - influence of air pollutants on health modeling

 - indoor and outdoor pollution quantity estimation
 - biological experimentations results interpretation (statistics)
Example : influence of pollutant on mutation (statistics, pls regression, generalized linear model, bootstrap, ...)

Rare/abnormal facts detection
NEXYAD developed methods (mainly probability-based decision making systems) in order to detect leads for intrusion into computers networks and into computers, defects in process monitoring, ...-
 These methods were applied to many field of application such as :
 - fraud detection
 - instrusion detection in computers

Control and regulation
NEXYAD worked on many advanced process control and regulation applications. In particular, NEXYAD applied maths methods that are given to be "emergent", such as neural networks and fuzzy logic.
One important point is the real-time ability of our methods (even for strongly non linear systems, even in the case of non separable non linearity).

Cylinder head quality control : swirl prediction
NEXYAD worked on an application that consists in analysing the geometric lenghts of a cylinder head : from these geometric lenghts, the swirl characteristics are predicted and cylinder heads that don't have the right estimated swirl are eliminated.
NEXYAD intervention led to save 50% of refused cylinder heads.

Exhaust estimation of a machine element
NEXYAD developed an on-board method that estimates the exhaust of machine elements of a car from regular sensors. Such an application can be used for instance in order to measure the characteristics of a driver during  maintenance check up The driver's use is interpreted into exhaust that may be upper or lower than the average driver's one : this may help for predictive maintenance.


SALES/MARKETING APPLICATIONS :


Turnover forcasting
NEXYAD developed several applications of turnover forecasting and simulation (for big firms).

Pricing
Princing is a very complicated task for big firms that has thousands of products or services items. NEXYAD developped applications of pricing taking into account :
 - the desired marging,
 - the prices of competitors,
  - the previous prices (pricing cannot take customers by surprise : prices often must evolve "slowly"),
 - the public image of the trademark on its market (versus the public image of competitors),
 - the actual costs of products and services,



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