Proof of Concept of Electronic Differential for Electric Car with Independent Drives

Abstract

The goal of the project is to prove the concept of the electronic differential of the electric car with minimal two
independent drives, i.e. one motor per each driven wheel. The goal of the electronic differential is, based on the
current state of the vehicle and command from the driver(angle of the steering wheel and accelerator and brake
pedals), to determine torque reference to be set to the individual motor, in such a way to achieve car movement
that corresponds to the driver’s expectations. The proper torque distribution is achieved by Traction Control
System (TCS), electronic stability program (ESP), and in the case of regenerative braking, the Anti-lock Braking
System (ABS). All those elements make a torque vectoring (TV) system. The goal of the PoC project is to verify
concept investigated during HRZZ (Croatian Science Foundation) research project “Electronic differential of a
small city electric car”, when the control algorithms were developed, and later some of them tested on the electric
car using general purpose control unit (microcontroller). Main activities of the project are based on the testing of
the electronic differential on Vehicle Control Unit (VCU) specialized for automotive industry. Those activities
include specification based parametrization of the car model, testing car dynamics and parameter correction,
implementation of the electronic differential algorithms in VCU using CODESYS software, that represent a
standard in automotive industry, verification of the dynamics estimation, verification and correction of the traction
control system, verification and correction of electronic stability system and verification and correction of the antilock
braking system. Besides testing, there is a plan to determine a possibility for protection of intellectual
property. Proof of concept is necessary, because the algorithms created in the research project have a great
potential, but there is no point to begin product development phase, before testing their functionality in realistic
conditions. The outcome of the project is the proof of functionality of described systems with real car and in
realistic conditions, tested on the safe driving polygon and on track with different surface types.

Project duration:
July 2016 – July 2017

Principal investigator:
Prof.dr.sc. Stjepan Bogdan