Development of a Hardware-in-the-Loop Test Bench for Validation of an ABS System on an e-Bike

Type of the Paper: Extended Abstract

Development of a Hardware-in-the-Loop Test Bench for Validation of an ABS System on an e-Bike

N. Ramosaj¹, E. Viennet^1,*

¹HES-SO University of Applied Sciences and Arts, Western Switzerland; nicolas.ramosaj@hefr.ch; emmanuel.viennet@hefr.ch ORCID 0009-0004-0922-2934

*corresponding author.

Name of Editor: Jason Moore

Submitted: 27/02/2023

Accepted: 14/04/2023

Published: 26/04/2023

Citation: Viennet, E. & Ramosaj, N. (2023). Development of a Hardware-in-the-Loop Test Bench for Validation of an ABS System on an e-Bike. The Evolving Scholar - BMD 2023, 5th Edition.

This work is licensed under a Creative Commons Attribution License (CC-BY).

Abstract:

Electrically assisted bicycles (e-bikes) have become increasingly popular and may facilitate active commuting but this comes at the price of safety since e-bikers have a higher risk of traffic accident than conventional cyclists (Haufe et al. 2022). However, the availability of electric energy on-board allows the emergence of active safety systems like antilock braking systems (ABS) that could help reducing the accident rate in the same way it was observed in the last decades for cars and motorcycles (Maier, 2018). ABS is a mechatronic device involving multi-domain expertise (electronics, mechanics, software) and conflicting objectives (cost, performance, perceived quality, safety of operation, safety of testing). This makes a model-based system engineering (MBSE) methodology the best suited approach to develop such a device. In the MBSE context, simulation models are deployed all along the development cycle, from requirements down to testing phases (both verification and validation).

This paper presents the development of a test-bench that can be leveraged to validate an e-bike ABS for multiple bicycle geometry/loading and various test scenarios. The approach consists in reproducing the dynamics of an e-bike thanks to a simulation model and interfacing it with a physical brake and the ABS hardware under test, thus obtaining a hardware in the loop (HiL) test bench as mentioned in (Heidrich et al., 2013) and (Pfeiffer et al., 2019). Figure 1 presents an overview of the installation; the core part is the real-time target machine where the simulation model is uploaded onto, and the hardware is interfaced as input of target machine to interact during the scenario. It allows the test engineer to first test and evaluate the ABS behavior in a safe place, before starting tests on the track.

Figure 1. Concept of the developed hardware-in-the-loop test-bench. The ABS hardware under test is interfaced to the real-time target machine that runs the virtual bike model.

The developed dynamic model represents an e-bike with a semi-rigid frame (front suspension only). The simulation model considers 6 degrees of freedom: longitudinal, vertical and pitch motion of the bike frame; front and rear wheel rotation; front suspension travel. The parameters of the model are either directly measured when feasible or reproduced from literature or identified indirectly from bicycle measurements. A fixed step solver is used for numerical integration with a time step of 0.2 ms, allowing the model to communicate real-time with the ABS and its control unit.

The fidelity of the model is assessed by comparing its results against measurements conducted on a physical test bike. The test bike is a Flyer Goroc 2 instrumented with various sensors including force at front brake lever, longitudinal and vertical acceleration (X axis and Z axis), pitch rate (Y axis), front and rear wheel speeds, suspension travel. The test apparatus used is listed and the implementation on the test bike is presented. The obtained comparisons between measures and simulations are discussed in details. The parameters values used for the model validation are published.

References

Haufe S, Boeck HT, Häckl S, et al., (2022), Impact of electrically assisted bicycles on physical activity and traffic accident risk: a prospective observational study. BMJ Open Sport & Exercise Medicine 2022.

Heidrich L. et al., (2013), Hardware-in-the-loop test rig for integrated vehicle control systems, IFAC Proceedings Volumes, 46, 21, 683-688.

Maier, O. (2018), Modellbasierte Entwicklung eines aktiven Sicherheitssystems für elektrifizierte Fahrräder, PhD thesis, Otto-von-Guericke-Universität Magdeburg.

Pfeiffer, M., Wrede, J., Steeb, S., (2020), Validation of a Dynamics Assistance System Using Hardware-in-the-Loop Simulation. Symposium on the Dynamics and Control of Single Track Vehicles.