Safe operating envelope for electric semi-trailer: On safe driving conditions with electric trailer propulsion for heavy truck combinations using coordinated vehicle motion control
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
With higher demands on electrification of the transport sector comes new challenges
regarding the range of battery electric heavy vehicles. Installing batteries in
the trailers of a heavy vehicle combination allows for an increase in range and also
gives the opportunity of adding electric motors to the trailer. However using an
electric trailer for propulsion may introduce stability issues which, if found, must be
accounted for and controlled in order to not decrease the performance of the electric
vehicle compared to the conventional tractor semi-trailer vehicles.
This thesis presents an investigation on when and how an electric trailer can be
used for propulsion and coordination of a heavy tractor semi-trailer vehicle combination.
Definitions of what is regarded as safe motion of the vehicle is defined and a
limiting operating envelope for the electric trailer is developed using data attained
from simulations. Control systems which include control allocation are developed to
coordinate the two vehicle units and to distribute forces among each of the available
motion and steering actuators on the vehicle. The systems are verified and tested
in a high fidelity simulation environment for two test cases, the first of which is to
travel through an S-curve consisting of two opposing 90° turns and the second is the
standardized "Sine with dwell" test (ISO 18375:2016).
The proposed control systems perform well for the two presented test cases with
some limitations regarding the scenario parameters. Additional predictive control
systems are proposed as a possible improvement to the current systems. In the thesis,
electric trailers are proven to, in concept, be a viable way of propelling, braking
and controlling a two-unit vehicle combination using a safe operating envelope and
control allocators.
Beskrivning
Ämne/nyckelord
Heavy trucks, control theory, control allocation, vehicle safety, semitrailer, electric vehicle, operating envelope, actuator coordination, simulation