Data Requierments for a Look-Ahead System
Look ahead cruise control deals with the concept of using recorded topographic
road data combined with a GPS to control vehicle speed. The purpose of this
is to save fuel without a change in travel time for a given road. This thesis
explores the sensitivity of different disturbances for look ahead systems. Two
different systems are investigated, one using a simple precalculated speed trajectory
without feedback and the second based upon a model predictive control
scheme with dynamic programming as optimizing algorithm.
Defect input data like bad positioning, disturbed angle data, faults in mass
estimation and wrong wheel radius are discussed in this thesis. Also some
investigations of errors in the environmental model for the systems are done.
Simulations over real road profiles with two different types of quantization
of the road slope data are done. Results from quantization of the angle data in
the system are important since quantization will be unavoidable in an implementation
of a topographic road map.
The results from the simulations shows that disturbance of the fictive road
profiles used results in quite large deviations from the optimal case. For the
recorded real road sections however the differences are close to zero. Finally
conclusions of how large deviations from real world data a look ahead system
can tolerate are drawn.
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Last updated: 2019-12-12