dc.description.abstract |
Due to noise and bias in the Inertial Navigation System (INS), vehicle dynamics
measurements using the INS are inaccurate. Although alternative methods involving
the integration of INS with accurate Global Positioning System (GPS) exist and
are accurate, this kind of system is far too expensive to become value-adding to
production vehicles. This thesis therefore considers two aspects: 1) the possibility
of estimating vehicle dynamics using low-cost INS and GPS, and 2) the importance
of vehicle dynamics in terms of handling in the eyes of customers upon vehicle
purchase. The former aspect is considered from an engineering perspective and the
latter is studied in a marketing context.
From an engineering point of view, knowledge of vehicle dynamics not only improves
existing safety control systems, such the Anti-lock Braking System (ABS)
and Electronic Stabilising Program (ESP), but also allows the development of new
systems. Based on modelling and simulation in MATLAB/Simulink, low-cost GPS
and in-car INS (such as accelerometers, gyroscopes and wheel speed sensors) measurements
are fused using Kalman Filters (KFs) to estimate the vehicle dynamics.
These estimations are then compared with the simulation results from IPG Car-
Maker. For most simulations, the speed of the vehicle is kept between 15 to 55kph.
It is found that while triple KF designs are able to estimate the tyre radius, the
longitudinal velocity and the heading angle accurately, an integrated KF design
with known vehicle parameters is also able to estimate the lateral velocity precisely.
Apart from studying and comparing different KF designs with restricted sensors
quality, the effects and benefits of different sensor qualities in dynamic estimations
are also studied via the variation of sensor sampling rates and accuracies. This investigation
produces a design procedure and estimation error analyses (theoretical
and graphical) which may help future engineers in designing their KFs.
From a marketing perspective, it is important to understand customers’ purchase
reasons in order to allocate resources more efficiently and effectively. As GPS/INS
KF designs are able to enhance vehicle handling, it is vital to understand the relative
importance of vehicle handling as a consumer purchase choice criterion. Based on two surveys, namely the New Vehicle Experience Survey in the US (NVES US)
and the New Car Buyer Survey in the UK (NCBS UK), analyses are performed in a
computer program called the Predictive Analytics SoftWare (PASW), which is formerly
known as the Statistical Package for the Social Sciences (SPSS). The number
of purchase reasons are first reduced with factor analysis, the latent factors produced
are then used in the SPSS Two Step Cluster analysis for customer segmentation.
With the customer segments and the latent factors defined, a discriminant analysis
is carried out to determine customer type in the automobile sector, in particular for
Jaguar Cars. It is found that customers in general take vehicle handling for granted
and often underrate its importance in their purchase. New vehicle handling-aided
systems therefore need to be marketed in terms of the value they add to other benefits
such as reliability and performance in order to increase sales and stakeholder
value. |
en_UK |