O'Neill, Simon James
Control of vehicle lateral dynamics based on longitudinal wheel forces.
MSc(R) thesis, University of Glasgow.
Full text available as:
Trends show that on board vehicle technology is becoming increasingly complex and that
this will continue to be the case. This complexity has enabled both driver assistance systems
and fully automatic systems to be introduced. Driver assistance systems include anti-lock
braking and yaw rate control, and these diﬀer from fully automatic systems which include
collision avoidance systems, where control of the car may be taken away from the driver.
With this distinct diﬀerence in mind, this work will focus on driver assist based systems,
where emerging technology has created an opportunity to try and improve upon the systems
which are currently available.
This work investigates the ability to simultaneously control a set of two lateral dynamics
using primarily the longitudinal wheels forces. This approach will then be integrated with
front wheel steering control to assess if any beneﬁts can be obtained.
To aid this work, three diﬀerent vehicle models are available. A linear model is derived for
the controller design stage, and a highly nonlinear validated model from an industrial partner
is available for simulation and evaluation purposes. A third model, which is also nonlinear,
is used to integrate the control structures with a human interface test rig in a Hardware in
the Loop (HiL) environment, which operates in real-time.
Frequency based analysis and design techniques are used for the feedback controller design,
and a feedforward based approach is used to apply a steering angle to the vehicle model.
Computer simulations are initially used to evaluate the controllers, followed by evaluation via
a HiL setup using a test rig. Using a visualisation environment in Matlab, this interface device
allows driver interaction with the controllers to be analysed. It also enables driver reaction
without any controllers present to be compared directly with the controller performance
whilst completing the test manoeuvres.
Results show that during certain manoeuvres, large variations in vehicle velocity are
required to complete the control objective. However, it can be concluded from both the
computer simulation and HiL results that simultaneous control of the lateral dynamics, based
on the longitudinal wheel forces can be achieved using linear control methods.
Actions (login required)