SiL: the first step in the real world

SiL testing involves the evaluation and validation of software components within a simulated environment before their integration into the actual hardware.

This methodology allows developers to thoroughly assess the performance, functionality, and reliability of software elements in a controlled virtual setting.

Trying to empower the performance offered by our Corner Brake Actuators, we decided to study and implement a custom ABS logic.

This being the case, we developed 3 different ABS control algorithms, progressively increasing the level of complexity involved.

Then, the effect of each one was assessed on a virtual environment (M42 Hardware and Human in the Loop steering bench) in different cases.

Longitudinal and combined braking conditions, in both low and optimal road-tire adherence circumstances, were examined.

  • Direct use of production-level software
  • Complete traceability of both high and low-level requirements
  • Validation of the specification framework at HW level
  • FuSa/SOTIF assessment at SW level*

*FuSa: Functional Safety

*SOTIF: Safety Of The Intended Functionality

Case study: ABS logic development 

Aim of the activity

 comparison of three different ABS algorithms

Method

assessment on a virtual environment with SiL approach

Results

advantages and drawbacks of each controller was tested in different conditions

  • Longitudinal braking (high ad low adherence)
  • Combined braking (high ad low adherence)

Case study: proprietary ABS logic research

Vehicle model

Multi-degree vehicle model developed in ADAMS environment and implemented in Vi-grade CRT to be co-simulated with Matlab-Simulink

Controls in SiL
  • State estimator with an Unscented Kalman Filter
  • Electronic Stability Control (ESC)
  • Electronic Brake-force Distribution (EBD)
  • ABS

Case study: autonomous vehicles

At limit handling condition autonomous driving controller
Trajectory generation
  • Minimum curvature algorithm
High-level NMPC
  • Computes vehicle velocity profile for the long prediction horizon
  • Feed the start braking point to the low-level controller
  • High-fidelity 7 DOF vehicle model
Sideslip angle estimation
  • Artificial Neural Network (ANN)
  • Unscented Kalman Filter (UKF)
  • Experimental test
Low-level NMPC
  • Determines vehicle action for the short prediction horizon
  • Simple point-mass vehicle model
Hierarchical Robot Controller
  • High-level Non-linear Model Predictive Controller
  • Low-level Non-linear Model Predictive Controller