Why ECU Calibration Required

Question

Why ECU Calibration is required in Software Development and testing?

Example would be nice to understand

Answer 1

During the course of my career, several engineers have enquired about why calibration is required. The answers which I provided can range from a simple clarification regarding how calibration was necessary to ensure certain performance based on a set of optimal performance characteristics that guards against defects or poor performance of electronic systems to more elaborate discussions on the actual predictive mechanisms that ensures a desired system performance.

The question asked here was why an ECU calibration should be done in software development and testing. An Electronic Control Unit(ECU) is a module which comprises of several embedded(integrated circuits, microcontrollers etc) hardware and software functioning as a whole system that controls the fuel injection in a car as shown in Figure 1 below. Simplified ECU block diagram Figure 1

As depicted in the diagram, the ECU is connected to other sensors, power, network and other external systems. As such, there is a need to characterise these parameters into external sensory parameters, power parameters, automotive control parameters and network parameters according to the various states that an ECU can be in. An ECU state refers to the behaviour of the ECU i.e. its operation. Hence, this gives rise to a state-machine model that indicates the actual ECU activity together with its configured parameters.

Calibration, thus provides default (known) good values to the various parameters associated with each distinct state of operation. Hence, calibration methodology is adopted during development and testing in order to align an ECU module performance characteristics to an expected set of performance. Such setup ensures the correct processing of observable parameters for accurate prediction of system performance for all available system states.