Since Hyundai Motor Group introduced the world’s first Rear Occupant Alert system to mass-produced cars in 2018, the system has been applied to various mass-produced models. The upcoming Genesis GV70 will also house a rear occupant alert. However, the ‘advanced’ rear occupant alert of the GV70 uses a high-performance radar rather than an ultrasonic sensor to leap forward from the previous system. What has changed? Eung-Hwan Kim, Senior Researcher of Electronics Convenience Control Development Team explained the necessity of the rear occupant alert and the world’s first advanced rear occupant alert applied to the GV70.
Q. Why is the rear occupant alert necessary?
A cabin in a closed car can reach high temperatures depending on the external environment. Therefore, it can be very dangerous if infants, children, and pet animals who cannot open the car door by themselves are left inside for a long time. According to statistics released by ‘Kids and Cars,’ the national nonprofit child safety organization in the United States, an average of 39 infants and children per year die after being left in locked cars. The rear occupant alert is a technology developed to prevent such accidents. I think it is valuable that the advanced technology of automobiles can prevent accidents caused by the driver’s carelessness.
Q. Does the global automobile industry agree on the need for a rear occupant alert?
In the United States, it is already illegal to leave infants unattended in vehicles. Furthermore, in order to prevent such accidents, the Hot Car Act has been proposed and is pending in the Senate, allowing automakers to equip vehicles to prevent infants and toddlers from being unattended. Euro NCAP, a new vehicle evaluation program in Europe, announced that from 2023, it will establish and apply Child Presence Detection (CPD) in the child protection category. This means that additional points are given to cars equipped with technologies to monitor young passengers, such as the rear occupant alert.
Global automakers are applying safety measures such as prompting the cluster to check the rear seat when the driver is leaving the vehicle, by utilizing the use of the rear seat door without attaching a separate sensor to prevent neglect of infants in the vehicle. However, this method can be overlooked by the driver. Therefore, in recent years, automobiles are shifting toward mounting sensors that can directly detect living organisms. Hyundai Motor Group was known as an exemplary case of automobile manufacturers that carefully take care of the safety by applying a system that recognizes passengers in rear seats with ultrasonic sensors for the first time in the world. The rear occupant alert system applied to the upcoming Genesis GV70 is more advanced than before.
Q. How is the GV70’s rear occupant alert different from the existing system?
The rear occupant alert, first applied in 2018, used an ultrasonic sensor that recognizes living organisms indoors. On the other hand, a high-precision radar sensor was used for this Genesis GV70. Both systems transmit the signal from the sensor and analyze the changes in the return signal after reflected by living organisms to determine whether there is motion. However, in the case of a high-precision radar sensor, a very high frequency can be used to detect minute movements of an object. In addition, there is an advantage in that it is not significantly affected by external vibration or noise, and thus can be analyzed more precisely.
Q. What are the technical advantages of high-performance radar?
The high-performance radar sensor installed in the Genesis GV70 is equipped with a high-performance microchip to efficiently perform complex signal processing such as size setting of the object to be detected, movement pattern, movement change, and noise component removal. This makes it possible to detect not only the general movement of the rear passenger but also the minute movements that occur even when the body is not moving, such as breathing. It is said that it is even possible to detect the minute movements of the belly and chest of a baby when sleeping quietly in the car seat.
Another improvement is that the sensors can detect broader areas. Thanks to this, the detection range has been extended not only to the rear seats where infants, children, and pet animals are mainly located, but also to the cargo space. This is because there are cases where companion animals are boarded in the cargo space. In the cargo space, like the rear seat, a high-performance radar sensor determines the movement, breathing, and fine movement of animals and alert the driver. However, it is impossible to detect tiny pets; the size, movement, and physical characteristics should be similar to those of infants, at least.
Q. How does the Genesis GV70’s rear occupant alert notifies the driver when it detects infants or pets in the rear seat or cargo space?
The Genesis GV70 sends a message on the cluster first right before the driver gets out of the driver’s seat. If the driver closes the car door without dismissing this notification, a high-performance radar scans the rear seat and cargo space from then on. It takes about 20 seconds for the sensor to detect a passenger in the rear seat, and if it does, it notifies the driver of the danger with a warning sound, emergency light, and a text message. In the event of a warning, the driver can stop the alarm by pressing the Unlock button on the remote control, but the sensor can be reactivated to protect any living organism in the rear seat – that is, to induce the driver to check directly just in case.
Q. The GV70 is the world’s first rear occupant alert system using high-performance radar. It seems that there was no existing case for reference, so there must have been difficulties when developing such a system.
Radar has long been used in the field of aviation and defense vehicles. However, the Genesis GV70 rear occupant alert was the first to be applied to a car’s cabin. For that reason, we have undergone numerous trials and errors, such as changing the frequency to meet the regulations for radio waves around the world, adjusting the whole system structure in accordance with those regulations, or conducting repeated evaluations. In some cases, there are no relevant laws or regulations, and in this case, we met directly with the certification agency to discuss the matter.
In addition, in order to check the detection performance of the radar sensor, numerous tests were conducted with the test team, such as making the models pose differently in the rear seat or shaking the vehicle. In fact, adults with infants and pets were invited to conduct tests, and when a child was asleep, we checked if the radar could detect his or her movements while being careful not to wake him or her up during the test.
Q. What is your development plan to improve the performance, utilization, and safety of the rear occupant alert in the future?
The rear occupant alert installed on the Genesis GV70 can be seen as just the beginning of the vehicle interior monitoring technology. Currently, we are developing additional functions to improve customer utility and sync with connected services. For example, it would provide services such as checking passenger information through a high-performance radar and interacting with the air conditioning system to block the heating or cooling system when unnecessary, or it could offer a checking service through a smartphone. In the future, it is expected that the utilization of indoor radars that can accurately recognize the location and information of passengers in various types of mobility environments will increase. Just as the rear occupant alert was introduced through the GV70, it plans to introduce a safer and more convenient intelligent indoor service by advancing the technology using high-performance radar.