MEMS Application of ultrasonic Sensor Solution in CPD System

With the implementation of Euro NCAP requirements, MEMS ultrasonic sensor solutions may become the mainstream sensing solution for future CPD systems.

With the widespread popularity of cars, self-driving travel has gradually become the main choice for family travel. Children travel frequently, injury accidents involving children forgotten in cars are frequently reported due to various reasons or negligence, should pay attention to the safety issue of children staying in cars.

Euro NCAP, one of the world's most authoritative automotive safety certification bodies, has proposed more stringent standards in this regard. From January 2023, new car CPD systems should have three major functions: sensing, warning, and intervention. From 2025, the system should have life functions. It can detect physical signs, and the sensing range needs to cover all seats in the cabin to ensure the safety of children stranded in the car.

*CPD system (Child Presence Detection, children’s car legacy monitoring function)

Introduction to CPD system

The core function of the CPD system is to use sensors to monitor seat conditions, mainly detects whether there are children's movements. After the driver locks the car and leaves, if the system detects the movement of children, it will immediately send an alarm. At the same time, the body flashlight lights up and an alarm message can be sent to the owner's mobile phone through the in-car intelligent system. In addition, dashboard will also display a message to remind the car owner to check the seat before getting off the car. If the child in the car is not rescued, further will proceed rescue intervention.

Currently, the sensing functions of CPD systems on the market mainly use ultrasonic and millimeter wave solutions. However, as Euro NCAP requirements are implemented, MEMS ultrasonic sensor solutions may become mainstream with their good vital sign detection functions, wider sensing range, smaller size and hidden installation advantages.

Good Vital Sign Detection Function

The MEMS sensor solution includes two MEMS ultrasonic sensors with integrated transceivers. The ultrasonic signals sent and received by the sensors are integrated with dynamic detection algorithms and modules to achieve life monitoring functions. 
The movement, breathing and environmental status of the test target are different, and the reflection amplitude and phase detected by the MEMS ultrasonic sensor change accordingly. The sensor can achieve respiratory level detection by transmitting and receiving panoramic ultrasonic waves.

Wider Sensing Range

MEMS ultrasonic sensor has a field of view angle of ±90°, which can reach 180°, and a wide detection range. It can be installed throughout the cabin of passenger cars and commercial vehicles to meet the sensing needs of all seats in the cabin.

Smaller Size

The size of the MEMS ultrasonic sensor is 30*20*5mm, which is much smaller than the open ultrasonic sensor module (size: 45*55*20mm) and millimeter wave radar module (size: 54*64*16.7mm).

Concealed Installation

The MEMS ultrasonic solution can be installed in a concealed manner without affecting the interior design of the car at all, maintaining the integrity and beauty of the car interior design.