Hardware-in-the-Loop Test Systems to Validate Automotive ECUs

Test & Measurement

Introduction

Germany-based MicroNova develops hardware-in-the-loop (HiL) test systems for electronic control units (ECUs) under the NovaCarts brand. With over 35 years of experience serving the automotive environment and other industries, its ECU testing solutions for, among others, electric vehicles and other e-mobility applications are among the most advanced on the market. By ensuring the seamless exchange of information between people and machines, the company’s 400 highly competent technical experts are shaping the future of mobility. MicroNova uses Enclustra system-on-module (SoM) components to increase the scalability and performance of their modular NovaCarts HiL test systems.

Virtualizing vehicles for HiL testing shortens the time it takes to bring new vehicles to the market by providing a means of validating their ECUs even before all the components are completed. Moreover, it lets vehicle OEMs cut costs and reduce risks by allowing them to comprehensively simulate every conceivable scenario, even those that would involve driving the physical vehicles beyond their operational specifications. Should individual ECUs fail the tests, which run for several days, the root cause of the error can be diagnosed, and the ECU firmware can be corrected and revalidated before it is integrated into the vehicle.

MicroNova’s HiL test systems accelerate testing and validation of the up to 100 ECUs that control modern luxury vehicles. They do so by creating a virtual replica of the vehicle and its environment, simulating the signals and status of the 3000 to 4000 sensors and actuators they comprise. These range from simple analog and digital signals to complex pulse-width modulation (PWM) signals and high-speed sensor protocols. At the same time, they run dynamic models to simulate everything from the vehicles’ electrical motors, batteries, and surrounding physical environment such as the road conditions.

Because they offer extremely high fidelity with the physical vehicle and its environment, testing engineers can use MicroNova’s system to comprehensively validate the normal operation and failure modes of vehicle’s ECUs by integrating them directly into the simulated hardware and software environment it provides . In the best case, the ECUs should be unable to identify whether they are connected to the test system or to a real vehicle.

Customer Challenge

The increasing computational complexity of modern luxury vehicles has ratcheted up technical demands on MicroNova’s solutions to test and validate the ECUs that control them. To precisely replicate the vehicle and its physical environment – to the point that they are indistinguishable from the real systems that they are simulating – their test systems need to constantly stay abreast with this rapid technological evolution.

Simulating all the vehicle’s control units, software and hardware functions, and the electronics in parallel to its environment and outputting data over SPI at the MHz-level with zero latency exceeds the capacity and processing power of today’s standard microcontrollers and software. MicroNova was, therefore, looking for an alternative solution that was both capable of meeting challenging demands in terms of latency and accuracy and that could be customized to address a broad range of highly specific tasks. MicroNova decided to use SoM based solutions to solve all their challenges.

The sheer size of MicroNova’s NovaCarts test benches added an additional challenge. Because they can comprise up to several thousand I/Os, getting all the SoM modules to operate smoothly in concert would necessitate the development of an overlying software architecture. Moreover, because their testing solutions are designed to be long-running products, MicroNova needed a future-proof solution capable not only of providing customers the high performance I/O boards they needed at the time of purchase, but also enabling them to simply scale up their hardware to meet evolving technological environments.

The Solution

After evaluating the cost and effort involved in in-house chip-down development of their own solutions, MicroNova decided to source their FPGAs used to power the I/O boards that make up their solutions externally, freeing up their developers to focus on their core business. In the end, they selected Enclustra’s FPGA-based system-on-module components for the core of their solutions for the high performance and flexibly they offered.

NovaCarts Cell Simulation Board (NC-BEB1000)

Form factor compatibility of modules within the same family offered the scalability that they need without the cost and time required to redesign solutions from scratch. Additionally, the out-of-the-box availability of standard interfaces such as Ethernet simplified solution development.

Initially, MicroNova based their designs on Enclustra’s Mars ZX3 Xilinx® Zynq® 7020 All Programmable SoC Module. They were then able to easily ramp up their performance and capacity by upgrading their designs to the Mars XU3 Xilinx® Zynq® UltraScale+ MPSoC Module. They are currently migrating their designs to the Mercury SoM family to keep up with emerging requirements.

“Form factor compatibility across Enclustra’s device families has made it easy for us to scale solutions up and down without requiring extensive development.”

The Result

«MicroNova has now been using Enclustra’s system-on-module solutions for 8 years to power the input/output (I/O) boards with which they assemble their HiL test systems. Today, Enclustra SoMs are at the heart of every I/O board used in MicroNova’s NovaCarts solution, which offers customers a scalable testing system with up to several thousand I/Os. Building on their experience working with the Enclustra Marx ZX3 and Mars XU3 SoMs, MicroNova is currently developing next-generation I/O boards using the Mercury module family.

«The company’s portfolio currently includes around 15 individual I/O boards featuring Enclustra’s FPGA-based system-on-module components that are optimized to simulate specific types of functions. Their larger testing systems are made up of 40 to 50 I/O boards, illustrated in following block diagram.

«The communication architecture is based on ethernet which is operated in realtime. From an operator PC a realtime computer is controlled where simulation models are running in realtime. The realtime computer reads data from ECU actuators and writes values for simulated sensors to the IO boards. Accuracy in the range of one millisecond is achieved.

«By working with Enclustra, MicroNova has been able to stay ahead of the game in the development of among the most sophisticated hardware-in-the-loop (HiL) test systems for electronic control units (ECUs) for automotive environments and other markets. In addition to their high quality, reliability, and performance, form factor compatibility across Enclustra’s device families proved critical in reducing the cost, effort, and time involved in the developing state-of-the-art solutions for their demanding use cases.

“Enclustra has been a very reliable partner in the development of our solution, despite the challenges presented by the chip crisis. When we encountered issues, they were always there to provide support, not only on the business side, but also on the technical side, to achieve our goals.”