Measurement & Calibration of ECUs
In embedded software development, microcontroller settings are adjusted to meet specific requirements.
In the industry, this adjustment is often called calibration:
It is an iterative process in which parameters are changed during runtime.
This allows for flexible changes without modifying the source code. Measurements are used to capture the changed system behavior.
Highlights
- Optimized Process: One solution covering everything from functional development, software-in-the-loop, and rapid prototyping to test bench applications, functional tests, and road tests.
- Flexible Scaling: In addition to ECU data, synchronously acquire data from ADAS sensors or physical measurement values.
- Efficient workflows: Standardized data formats, support for various hardware, and the integration of cloud-based applications simplify processes and facilitate collaboration in large teams.
Interfaces to Busses and ECUs
High-performance hardware solutions are available for accessing control units and vehicle networks: In addition to communication via CAN, CAN FD, LIN, or Ethernet, specialized measurement and calibration interfaces enable direct access to internal parameters via debug and microcontroller interfaces.
To this end, customizable adapter solutions are used that are designed for different microcontroller architectures. The result is effective access to measurement and calibration data with minimal impact on the ECU’s runtime performance.
Measurement and Calibration of HPCs and Zone ECUs
The transition from traditional vehicle architectures to software-defined vehicles is changing the way next-generation control units are measured and calibrated. Zone ECU/HPC architecture has a direct impact on measurement and calibration. It involves accessing data in controllers, in processors, and in inter-process communication. The measurement concepts required for this differ significantly from those used in typical AUTOSAR-based ECUs.
Data Description for ECU Access
A2L description files allow access to internal ECU variables by symbolic names. They are a fundamental component of every measurement and adjustment operation via XCP protocol. An ASAP2 description file (also known as A2L) contains all information about the relevant data objects in the ECU, such as parameters, maps, real and virtual measured variables, structures, and variant dependencies. For each of these objects, information such as memory address, storage structure, data type, and conversion rules for conversion to physical units are required. In addition, an A2L file contains the parameters for communication between CANape and the ECU.
Rapid Prototyping
Use Rapid Control Prototyping to test control algorithms quickly and efficiently without having to replace the entire ECU software. This applies not only to real control units but also to virtual ECUs. To achieve this, parts of the control algorithm (bypassing) or the entire ECU code (full passing) can be processed on additional hardware.
Diagnostics and Flashing
Diagnostic testing plays a significant role in the development of diagnostic functions in the control unit. The functions are easily accessed via the diagnostic windows in CANape. Output parameters can be captured like measurement signals and displayed over time in the corresponding display windows. Input parameters can be entered and modified like calibration parameters. When parameters are changed, the corresponding diagnostic function is executed in the ECU. During control unit calibration, flashing serves both to update the application and to adjust the parameters.
