About 40 children a year die from heatstroke, either because they were left behind or became trapped in a car, according to the National Highway Safety Administration (NHSA) That's about one child every 10 days killed in a hot car.
When children are left in a hot car, their major organs start to shut down when body temperature reaches 104 degrees F. At 107 degrees F, a child can die. What’s surprising is that vehicular heatstroke can take place even when the outside temperature is as low as 57 degrees F.
Despite public information campaigns, the incidence of this preventable tragedy is almost unchanged since the 1990s, in contrast to other car-related causes of injury and death. Consumers are relying on their memory or other improvised techniques that are prone to failure.
Congress recognized the shortcomings of the status quo and in 2021 passed the Hot Cars Act, which requires the U.S. Department of Transportation to finalize a rule by November 2023 mandating that new vehicles be equipped with a means to detect the presence of an unattended occupant in the passenger compartment of the vehicle and engage a warning.
The Federal Communications Commission acknowledged the value of RF sensing technology in reducing infant mortality and on May 18, 2023, issued new regulations that establish the use of sensing technology in the 60 GHz band. Cars can now freely use the most appropriate technology for in-cabin sensing, as embodied in the SC1260AR3 device.
Socionext makes a radio-wave ranging sensor, the SC1260AR3, for automotive applications designed to provide car manufacturers with an important new tool in the campaign to reduce infant deaths in cars.
The new 60 GHz sensing technology offers automakers the ability to be able to discriminate between adults, children and pets and determine their heart rate and rate of respiration. It can allow car makers to provide critical information to drivers and emergency response services.
60GHz sensor with TDM-MIMO offering high-precision sensing capabilities
The SC1260AR3 from Socionext uses Time-Division Multiplexing (TDM-MIMO) with multiple transmitting and receiving antennas to detect the position and movement of passengers in a vehicle with high resolution. Radar systems transmit radio frequency signals and receive reflections from objects in their field of view. Solid-state radar sensors typically use an omni-directional transmitter and a receiver array. The radar system uses the differences in frequency and phase in the signals received in the array to determine the direction and travel of the reflections and hence the location of an object.
By increasing the effective angular resolution of the receiver, the location of objects can be more precisely determined. The use of additional physical receivers gives greater angular resolution. However, this comes at the cost of increased size and complexity. An equivalent result is achieved by adding additional transmitters, which, through appropriate placement, can create different virtual receiver configurations. This technique is referred to as multiple-input, multiple-output (MIMO).
The MIMO antenna configuration is influenced by the target sensor application. In the case of automotive in-cabin sensor applications, horizontal (X-axis) resolution is prioritized over vertical resolution (Y-axis). The antenna array of the Socionext device is configured accordingly.
Use case requirements influence antenna array configuration
The Socionext SC1260AR3 is a highly integrated 60GHz CMOS radar device in a compact, 6x9mm package. The antenna array consists of two transmit antennas and four physical receiver antennas, which in combination with a high bandwidth FMCW linear chirp operational mode (up to 6.8GHz BW), result in high resolution sensing.
In addition to low-level signal processing, the SC1260AR3 device has an embedded sensing engine to detect the presence, distance, angle, and clustering. This reduces the processing burden on the in-cabin monitoring system, lowering system power consumption and cost. The device is also AEC-Q100 qualified with a Grade 2 temperature tolerance ranging from -40 degrees F (-40 degree C) to 221 degrees F (105 degrees C).
By using the SC1260AR3 device, car manufacturers can efficiently implement human occupancy and child presence detection as required by the latest regulatory standards, including both the US Hot Cars Act and the European NCAP.
Sensors enable all aspects of our lives
The number of connected IoT devices is growing exponentially and expected to grow from 16.7 billion active endpoints in 2023 to 29.7 billion globally in 2027 (IoT Analytics). Sensors convert physical phenomena into a measurable digital signal, with information which can then be displayed, read, or processed to make our lives easier and safer. Without sensor technology, there would be no IoT at all.
As a global leader in high-precision sensor technology, Socionext is championing new product development for enhancing user experience through its unique lineup of radio-wave ranging sensor devices.etin
Neil Bullock is a marketing manager at Socionext America Inc. He has extensive experience in imaging systems and wireless communications. Socionext is a global leader in high-precision sensor technology with a radio-wave ranging sensor devices that include multi-people detection, vital sensing and even gesture sensing, all based on CMOS.