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Keysight’s Virtual Test Kit Propels Autonomous Driving
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ecent research showed the automotive semiconductor industry grew to a value of nearly US$42 billion in 2018 and is likely to be US$65.5 billion in 2025, while the semiconductor content per car is estimated to double from a value of US$312 in 2013 to US$652 in 2025. Chipmakers have become involved in the manufacture of automotive sensor, wireless and power management chips for the connected car, which now comes loaded with electronics to run onboard safety and comfort features, and communicate with its surroundings for vehicle-to-everything (V2X) applications.

The road to full autonomous driving sees the modern car having an increasing number of advanced driver-assistance systems (ADAS), with wireless connectivity providing the low-latency V2X connectivity needed for mission-critical safety functions.

Cellular vehicle-to-everything (C-V2X) technologies are one of the fastest evolving parts of the market, but it is impractical to road test an early-stage vehicle to measure its response to other vehicles, GPS, and pedestrians. At the same time, automakers can no longer rely on late-stage road tests as a means of ensuring that inbuilt V2X safety systems work seamlessly on the road.

These technologies present new design verification and functional test challenges. Even at the early stage of chip development, the automotive designer’s goal is to ensure perfect performance for when the car eventually hits the road.

To ensure performance and safety, developers must navigate the many existing communications standards and protocols, and bridge the gap between current and new technologies, such as the transition from LTE to the next-generation fifth-generation (5G) communications standard.

Developers now need to grapple with growing test complexity for wireless connectivity (see Figure 1).

Test complexity
Fig. 1: Test complexity rises as connectivity expands.
Test Complexity with Emulation Systems
With test complexity rising as connectivity expands, emulation systems are increasingly pivotal in enabling engineers to validate their designs, verify performance, and identify potential problems at an early stage.

Emulators are able to imitate the behavior of a single component, or a system. While simulation creates a synthetic environment that tests a chip’s performance in all states, emulation uses hardware to simulate chip performance at near real-time speeds. The hardware allows this process to be sped up by the designer, over and above the capabilities of traditional simulation software.

An emulator can therefore mimic the behavior of a system identically. Games console emulators are good examples, as they can emulate an old or damaged console and allow fans to play their favorite retro games on modern equipment. Other examples are the classic early Macintosh computers, which fans can emulate on Mac OS, Windows and Linux platforms.

In the past, emulation technology was costly and cumbersome, and took days to set up before testing could commence. However, improvements in hardware power and advances in software capability, allow engineers to adjust test parameters quickly to emulate different test scenarios.

In enabling the connected car for instance, engineers use emulators to design and test 5G and over-the-air (OTA) applications used in ADAS systems and in autonomous driving features.

Faster, More Flexible Chip Design, Development
The use of emulators in chip design verification has grown significantly in the last 10 years, with engineers adopting emulators in their electronic design automation process.

Manufacturers of automotive ICs must adhere to various safety standards, like ISO 26262 for functional safety for instance. Testing for this standard will include repeatable, systematic failures, and random environmental failures such as those caused by heat and vibration.

With the proliferation of system-on-chip (SoC) designs with embedded software, the use of emulation as a means of chip verification has increased in proportion. Furthermore, emulation systems have become more capable and affordable, increasing their viability and use as part of the design and test strategy.

Emulating C-V2X for the Connected Car
By using emulation to verify the design and function of C-V2X systems, actual operations of the elements within the complex C-V2X formula can be simulated during the development phase. These include testing communication scenarios by emulating onboard units (OBUs), roadside units (RSUs), and global navigation satellite systems (GNSS).

A further upside is that developers can adapt the same emulation solution to test products for different markets, each having their own C-V2X communications protocols and standards (see Table 1).

Table 1: Regional C-V2X policies
Table
Another example of emulators at work is in testing vehicle emergency call (e-Call) systems. Engineers use benchtop equipment to emulate components that make up the real-world environment in such systems: the car, satellite systems, cellular networks, and public safety answering points. Regardless of regional standards, designers can test the conformity of the e-Call system to the various national standards and protocols, right in their lab.

As communication platforms transition from LTE to 5G, automakers need to confront the new conformance standards. They must also gear up as autonomous driving becomes a broader reality. Engineers from Keysight Technologies have built a 5G network emulation solution using their UXM 5G signaling test platform. The extensive RF resource palette allows engineers to create and test 5G communications, establishing quick fault analysis and debug for different automotive devices under test.

Emulating Drive Tests to Cut Prototyping Costs
When it comes to new test methodologies, the automotive industry is conservative. The carmakers’ priority is to weed out potential life-threatening situations or manufacturing defects, and to avoid costly recalls.

However, the recent acceleration of innovation in the industry challenges manufacturers to find new test methodologies that are not only cost-effective, but offer comprehensive test coverage.

The design and production of physical prototypes are costly parts of the development process. By using emulators, verification and debug cycle times can be reduced, and these prototyping costs greatly reduced. Emulators are therefore increasingly being used for drive testing, reducing the overheads in building test stands and fixtures.

Solutions such as Keysight’s Virtual Drive Testing toolkit allow manufacturers to capture and record parameters, like network settings, as well as signalling to, and responses from the car module. Developers can also test the RF environment in and around the car based on various factors such as traffic, reflections from other cars, buildings and trees, and satellite signals.

Engineers can use field data to create virtual test environments. RF network conditions emulated in the laboratory can resolve issues found in the field during the early stages of product development, as seen in Figure 2.

Drive Testing
Fig. 2: Virtual Drive Testing toolkit
Emulating Over-the-Air (OTA) Performance
When a radio wave interacts with an object, the wave is scattered, diffracted, reflected, or absorbed. Radio channel emulation can replicate these scenarios. Replicated radio frequency (RF) network conditions include: multipath propagation, Doppler effect, angles of departure, angles of arrival, and noise/interference, as well as all the typical channel conditions between the base station or access point, and the vehicle antenna cluster.

With the inevitable rollout of 5G, automotive and wireless device manufacturers need to ensure their systems are compliant with standards like CTIA OTA Test Plan v3.8.1 and CTIA MIMO OTA Test Plan v1.2 in different environments. The use of anechoic chambers and emulation can simulate rural, suburban, urban, and indoor environments within the laboratory.

It is increasingly likely that, as the car of the future becomes more connected and intelligent, the self-driving car will have emulated millions of sub-processes long before it hits the road. In this time, the erratic human behaviours that cause accidents will have been preempted by emulation, and circumvented by the design and test verification processes.

About This Article:
The author is Hwee-Yng Yeo, Industry Solutions Marketing Manager, Automotive and Energy Industry Solutions, Keysight Technologies.