Radar technology is changing the three trends in the cockpit sensing market

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Radar technology is changing the three trends in the cockpit sensing market [Copy link]

Radar sensors not only change the way vehicles perceive their surroundings, but also how they perceive objects and occupants. Imagine a car that can detect a forgotten child or a sick driver in the back seat and design a system to take action to mitigate the situation.

Radar’s ability to detect through solid materials enables it to detect unattended children, monitor occupant status and estimate driver vital signs with greater accuracy than ever before.

In this technical article, I’ll explore three trends in the automotive in-cabin perception market as more automakers turn their attention to radar sensors.

Trend 1: Functions beyond child presence detection

To comply with regulatory requirements such as the European New Car Assessment Program, automakers are turning to radar sensors for child presence detection. But they are finding that they don’t have to stop there.

In this video (click this link to view the video: https://v.qq.com/x/page/o096612i40f.html), you can see how a single radar sensor detects and determines the position of all occupants in the car, classifies occupants in the rear seats as adults or children, and tracks the occupants' vital signs.

Radar’s capabilities for in-cabin sensing continue to grow, improving the accuracy of systems such as seatbelt reminders and airbag deployment, and better serving vehicle occupants. Heavy objects placed on seats will no longer trigger seatbelt reminders. When children are in the vehicle, airbags can deploy at different speeds, reducing the risk of impact injuries.

Radar sensors can also accurately detect a driver’s drowsiness or an occupant’s breathing and heart rate, which the vehicle can then use to identify abnormal situations. Once alerted, the driver can take appropriate action, such as taking a break after driving for a while or stopping the car if a physical condition occurs.

Trend 2: Using 60 GHz radar sensors for in-cockpit perception

Automotive Tier 1 suppliers have explored different operating frequency bands for radar in-cabin perception applications. For example, 24 GHz radar sensors are not suitable for these applications because their poor range and velocity resolution do not provide accurate results. The large sensor size makes vehicle integration very difficult. Finally, due to FCC and ETSI mandates, 24 GHz ultra-wideband will not be available for automotive applications after 2022.

For more accurate speed detection and angular resolution, it is better to use higher frequencies such as 60 GHz or 77 GHz. Depending on the region, in-cabin sensing applications can use 60 or 77 GHz sensors. Most regions are choosing 60 GHz sensors, but Tier 1 suppliers should work with the region’s regulator for further clarification.

Texas Instruments offers a scalable radar portfolio with TI mmWave sensors in the 60-GHz (AWR6843) and 77-GHz (AWR1843) bands. These single-chip devices are pin-to-pin compatible and software compatible—features that enable designers to build sensors for deployment in different regions because they can build a common printed circuit board (except for antenna tuning) and develop algorithms and software that can run on both platforms.

Trend 3: Scalable sensor architecture for vehicles of any size

The integration of the sensor inside the vehicle affects its design (form factor, antenna) and functionality. Since radar can penetrate solid materials such as plastics and fabrics, automotive designers can place radar sensors in many different locations within the vehicle.

As shown in Figure 1, when the sensor is integrated into the roof canopy facing the center of a two-row vehicle, a single radar sensor such as the (AWR6843) can detect a child in a rear-facing child seat or standing in the footwell, and can detect and classify other occupants throughout the vehicle. This is possible due to the on-chip processing and memory capabilities of the AWR6843 chipset. The integrated digital signal processor and microcontroller on the AWR6843 implement complex algorithms and the Automotive Open System Architecture (AUTOSAR) stack for host communications.

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Figure 1: Detection and classification of occupants in a double-row vehicle using TI radar (Source: Azcom Technologies)

In a large three-row vehicle, two AWR6843 sensors can detect all occupants. Because the AWR6843 has two controller area networks (CAN) with flexible data-rate interfaces, the two sensors can easily synchronize and communicate with the vehicle's CAN network, making the solution scalable to any size car and any number of seats.

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Figure 2: Detecting five occupants in a vehicle using TI radar (Source: Smart Radar Systems)

The sensor can also be placed in the overhead console or B-pillar, which is a challenge for the size of the sensor. TI radar enables a very small form factor sensor, which helps to achieve easy vehicle integration.

TI's scalable portfolio of radar sensors includes single chips and imaging radar chipsets. With cross-device compatible software, portability has never been easier, allowing you to start designing your next in-cockpit perception system today.