Handling forklift control system verification and validation

Siemens Experimenter Siemens Experimenter
Siemens Experimenter

Are you wondering how to improve your forklift design while reducing cost and lead-time risks, by avoiding extensive physical prototype testing?

Are you planning to implement a solid verification and validation process for your electronic control systems?


Read this article and learn how Simcenter Amesim supports product innovation and associated control system verification and validation.


Let’s say you’re a forklift manufacturer (OEM) and you want to bring a new, highly efficient, cost effective forklift to the market to improve your customers’ warehouse management profitability.


To do so, you want to opt for a hydraulic recovery braking (HRB) forklift technology in order to:

  • recover braking energy
  • assist the internal combustion engine (ICE) during accelerations over the so-called  VDI test cycle (see picture below).

VDI2198 cycle.jpgVDI2198 cycle


The proposed forklift design is modeled and evaluated using Simcenter Amesim. In order to operate and control the forklift in a fuel efficient and performant way, a basic hydraulic valves controller is built in Simcenter Amesim:


Forklift model with HRB.pngSimcenter Amesim forklift model

A comparison is performed between the reference forklift design and the new design that includes the HRB system. You can see in the below image that a potential fuel consumption reduction of 21% can be reached while still achieving the required performances during the VDI test cycle.


Recovery system benefits.pngHRB versus conventional designThe performances and efficiency of the new forklift design are meeting the high-level requirements. So you take the decision to continue in that direction and build a physical prototype.


While physical parts can be ordered to suppliers, a controller needs to be developed. To start developing this controller, you can provide a Simulink-based executable specification to your software supplier (Internal or external one). During this step, a systems engineer develops a basic Simulink control model which will be used as an executable specification. 

To verify if that specifications make sense, your systems engineer uses Model-in-the-Loop (MiL). He connects the Simulink model to the Simcenter Amesim plant model which has been created earlier in the process:


MIL model.pngSimcenter Amesim model for MiL simulations

You can either develop your controllers internally or outsource them. Therefore, two different tracks can be followed:

  • The internal software development team builds a software release based on the executable specification requirements. This software is compiled in C-code and integrated in the Amesim Plant model in order to verify its implementation through Software-in-the-Loop (SiL):


SIL model.pngSimcenter Amesim model for SiL simulation

  • Or the external software development company (such as Bosch, Continental, Denso and more) has developed and delivered an electronic control unit (ECU) with embedded software based on your executable specification. In that case, you perform system verification and integration on a dSPACE Hardware-in-the-Loop (HiL) test rig (for example), still using the same Simcenter Amesim plant model as before, compiled for HiL target:


Control desik interface.pngdSPACE ControlDesk interface for running HiL simulations

The software verification is performed through scenario-based test cases that are rolled-out automatically or manually, as in the video below:

(view in My Videos)


By following such a process, you can achieve a pre-validated hydro-mechanical design and ECU even before the first forklift prototype has been assembled, and in this way increase the chances to do it right the first time. Hence, you potentially reduce the number of prototypes and so the development cost and time, while ensuring that the product’s efficiency and performances meet your customers’ expectations.


And by the way, the Simcenter Amesim model used here is already real-time compatible. The process for making complex Simcenter Amesim models real-time compatible is not explained in this post. Please refer to this model simplification video for more information on this process.

Siemens Valued Contributor Siemens Valued Contributor
Siemens Valued Contributor

Thanks Romain. This is as great article demonstrating the full capabilities of LMS Imagine.Lab Amesim.