Mueller, S. and Langjahr, P., "Efficient Testing and Cost Awareness: Low-Cost versus HIL-System," SAE Technical Paper 2012-01-0933, 2012, doi:10.4271/2012-01-0933.
Developments for innovative systems in engines, hybrid and electrical vehicles are strongly affected by a high pressure on costs, short development cycles and high quality requirements.Therefore within the business unit Powertrain Systems of Bosch Engineering GmbH (BEG) test environments for SW functions in engine control units (ECU) are selected according to cost and efficiency aspects as well as availability. Prototype vehicles are very expensive and cannot always be provided in time by vehicle manufacturers. Closed-loop test systems like hardware-in-the-loop systems (HIL) are alternatives to perform system tests of ECUs in a vehicle simulation. We propose to consider the usage of low-cost solutions with reduced costs in many cases. At the same time due to these saving effects the number of test systems in an organization can be increased significantly. This enhances the availability of testing equipment for engineers.The low-cost approach is equipped with an 8-bit microcontroller that governs a small number of analog and digital inputs and outputs and provides basic CAN functionalities. Test systems like the proposed μLabCar cover a large part of the use cases for testing of systems and software. Tests can be performed either manually using a graphical user interface or automatically using a commercial tool or a scripting language. The μLabCar could also be controlled remotely via the company network - an advantage that is very useful for distributed development teams, e.g., for cooperation with subsidiaries in Europe, Asia and the US.The authors discuss why, when and under which boundary conditions simple low-cost test systems are a good alternative in terms of economy and quality compared to other test systems like full HIL systems.