Future vehicles are expected to have more features, lower emissions, greater fuel economy, and higher safety ratings. To meet this challenge, car makers are adopting ECU architectures because they are more reliable, more efficient, add less weight to a vehicle, and can offer more functionality. By the end of this decade, it is expected that electronics will represent close to 40 % of a vehicle's value.
The increased complexity inherent in these systems works against business pressures to reduce time-to-market and development cost. Fortunately, HIL simulation has proven to be a practical solution to these diverging challenges. While HIL simulation does not replace the need for physical testing, it does help engineers accomplish the following by enabling tests earlier in the development cycle and eliminating the need for a physical system during test:
Make educated design decisionsevaluate specific design alternatives early in the development process based on test data
Test earlier in the development processidentify design errors earlier when they are less expensive to correct and have a smaller impact on time-to-market
Reduce testing costreduce capital, repair, and maintenance expenses for test fixtures without the need for a physical system
Achieve greater testing capacityenable "lights-out" testing of systems where unmonitored physical testing is not possible
Increase test coveragetest ECUs under extreme conditions that might not be practical for physical testing due to safety or equipment damage concerns
Increase test flexibilitysimulate winter road conditions for a vehicle under test even in the heat of summer
Increase test repeatabilityisolate deficiencies in an ECU even if they occur only under certain circumstances
Considerations when choosing a HIL system
There are many options for implementing HIL simulation as part of a test system. However, to ensure the short- and long-term success of the investment, the simulation must be both flexible and open.
With the drive to continually reduce the cost of test, a flexible solution is essential to making HIL simulation practical in the development process. The ability to test a variety of ECU configurations without downtime or the need for specialized services keeps the cost of ownership low. Furthermore, an effective HIL simulation should be able to rapidly adapt to changes encountered during and between development cycles. A small change in the test process or configuration should not require a major renovation of the HIL simulator.
As technologies advance and converge in the automobile, new communication buses, vision inspection systems, RF instrumentation, and other specialized instruments make implementation of HIL simulation test systems necessary. At the current rate of innovation, it is not practical to expect a single vendor to simultaneously meet the time-to-market, quality, and cost expectations for all the latest technologies. An open HIL simulation solution ensures that you will always be able to integrate the technologies required to test your ECU.
Business and technical challenges will continue to grow in the automotive industry. As technology evolves to address these challenges, the role of HIL simulation in vehicle development will become increasingly important. By enabling tests earlier in the development cycle and removing the limitations of physical test, HIL simulation is helping to reduce development cost and increase the quality of vehicles in the face of these challenges.
For help in HIL simulation, the HIL Simulation Checklist provides a comprehensive list of topics you should consider when specifying a HIL simulation test system.
Chris Washington is HIL product manager at National Instruments.