The classical
automobile drivetrain is composed of a single
Internal combustion engine providing torque to one or more driving wheels. The most common solution is to use a mechanical device to distribute torque to the wheels. This
mechanical differential allows different wheel speeds when cornering. With the emergence of
electric vehicles new drive train configurations are possible. Multi-drive systems become easy to implement due to the large power density of
electric motors. These systems, usually with one motor per driving wheel, need an additional top level controller which performs the same task as a mechanical differential. The ED scheme has several advantages over a mechanical differential: • simplicity - it avoids additional mechanical parts such as a
gearbox or
clutch; • independent torque for each wheel allows additional capabilities (e.g.,
traction control,
stability control); • reconfigurable - it is reprogrammable in order to include new features or tuned according to the driver’s preferences; • allows distributed
regenerative braking; • the torque is not limited by the wheel with least traction, as it is with a mechanical differential. • faster response times; • accurate knowledge of traction torque per wheel. However, the ED scheme also come with many disadvantages and drawbacks: • errors and glitches are prone to happen, thus giving inaccurate reading and output as compared to conventional differential. These result in the wheels either receiving too much or little power and torque. • increased premature tyre wear due to the inaccurate reading and output as compared to conventional differential. • higher cost to manufacture and maintain the electronic systems. ==Applications==