XiL testing to support the introduction of a new powertrain platform

Case Study Overview

HORIBA MIRA was brought in to support the integration of a new powertrain on Tevva’s 7.5-tonne battery electric trucks.

Having previously carried out cell characterisation to assist with Tevva’s choice of battery pack for the new powertrain, a team of consultants from HORIBA MIRA developed an x-in-the-loop (XiL) simulation environment (both physical and virtual) that was used to fast-track and de-risk the integration of the new systems.



The traditional approach to integrating a new powertrain would be to build a proof-of-concept vehicle. Waiting for such a prototype vehicle to be designed, built, made safe, and finally become available, is a time consuming and expensive exercise. De-bugging such a prototype on a proving ground or on a dyno then adds to this burden. HORIBA MIRA therefore proposed using an XiL approach in combination with physical testing.

A complete Tevva powertrain was assembled on the test bench at HORIBA MIRA’s Propulsion Test and Development Centre (PTDC) in Nuneaton, including a physical battery pack, thermal emulation and motor/invertor/gearbox linked to a 1e Dyno. This was then combined with HORIBA MIRA’s own vehicle model of the Tevva truck.

The combination of hardware and software in the loop provided a complete digital sandbox that could be used for shake-down testing, fault-finding, and initial calibration.

Physical testing was then carried out on the same site with the prototype vehicle. Any issues identified could then be recreated under laboratory or simulated conditions on the test rig, providing total repeatability.

Successes and benefits

By leveraging a highly efficient simulation-led engineering approach, HORIBA MIRA was able to slash the time and risk involved in Tevva’s new powertrain integration. Highlights of the project included:

  • Implementing a whole-vehicle simulation model with a complete powertrain, including both hardware, software, and modelling elements, in the loop.
  • Providing a totally controlled environment for repeatable testing and debugging.
  • Flexibility to bring in additional engineering and test services as required.
  • Fast-track approach, enabling the vehicle to be delivered in a heavily compressed time scale compared to traditional methods.

HORIBA MIRA has a vast array of engineering competencies in one place, which we can combine to make projects like this as low-risk as possible. There’s nowhere else in the world that gives access to the same spectrum of expertise in one place.
 Ben Gale. Solution Leader for Automotive Energy Efficiency, HORIBA MIRA

Project Information

Project Information

  • Battery Management
  • Virtual Validation
  • De-risk vehicle trials
  • LCV & HCV
  • Location – UK



  • Cell characterisation & cell supplier shortlisting
  • Vehicle modelling
  • Drive cycle analysis
  • Cell/module/pack validation
  • Battery optimisation (BMS algorithms)
  • Powertrain verification

A key focus was the use of hardware, software and model in the loop development – hence the ‘X’ In XiL – to de-risk the interface between the vehicle VCU and a newly developed BMS system utilising HORIBA MIRA optimisation algorithms.

Engineering team deployed: Five UK-based subject matter experts formed thecore of a team that numbered up ten at times.