EV, Powertrain and Embedded Systems: Questions Answered by Skill-Lync Experts

• Lithium batteries use primary cell construction. They are single-use and not rechargeable.
• Lithium-ion batteries use secondary cell construction. They can be recharged and reused many times before they degrade.

Lithium batteries were invented first. Because they could not be recharged safely or easily, companies developed the rechargeable lithium-ion alternative.

Why lithium (primary) batteries still exist

• They have higher energy density, so they last longer on a single charge, even if they only ever get one.
• They are easier to make and cheaper, because they use lithium metal in the anode, while lithium-ion cells use several materials in the anode.
• They can sit on the shelf for many years without degrading, while lithium-ion cells lose capacity with age.

AUTOSAR has a layered architecture. Software components (SWCs) in the application layer communicate with each other, within one ECU and also with SWCs on other ECUs.

The Virtual Function Bus (VFB) is the concept for this communication, and it is implemented in the RTE layer. It is called "virtual" because there is no direct physical connection between SWCs. SWCs on different ECUs actually talk through a low-level bus such as CAN or FlexRay, and AUTOSAR handles those low-level matters so the ECUs communicate as if there were a virtual link. Because of this, an SWC is independent of the underlying hardware, and the same SWC can be relocated to any ECU on any hardware platform.

In short, the VFB is the conceptual foundation for communication between SWCs and for the use of basic software (BSW) services. The RTE controls the actual connections between SWCs and from SWCs to the BSW.

Spark timing directly affects the burn rate, so it comes under predictive combustion modelling (input: P-theta curve, output: burn rate).

The tutorial model uses an SI Wiebe combustion model, which is non-predictive (input: burn rate, output: P-theta curve). So it has no spark timing attribute to tune.

The predictive SI model in GT-SUITE is SI-Turb. In GT's example files, go to 1-D Gas combustion, then Gasoline, then CCV. That model uses SI-Turb to compute cycle-to-cycle variation (CCV) by running a finite number of cycles after an explicit engine reaches steady state. Under the SI-Turb model there is a spark timing object where you can specify spark timing against engine speed and BMEP.