Contact sensor uses sound to detect low-speed impacts

Most of us have had the unpleasant experience of coming back to our unattended vehicle, only to find some unsightly scratches or dents from another vehicle entering or leaving a neighboring parking spot, or causing damage from making a careless maneuver. Automotive technology company Continental has introduced sensors that can pick up the sound signal of low-speed vehicle impacts to detect such scratches and damages.

Unveiled Monday at the Consumer Electronics Show (CES) in Las Vegas, the miniaturized Contact Sensor System (CoSSY) could provide an added safety margin for automated parking systems. Based on the sound signal CoSSY picks up, the detected low-speed impact brings the vehicle to an immediate emergency stop. By differentiating between airborne sound, knocks, dents, and scratches the new sensor system can be deployed in multi-purpose applications, including vandalism detection

The sensor system provides a redundant signal path required by functional safety. It detects objects which may be located outside the short-range detection cone of other sensor types. The scalable CoSSy solution will typically include two to twelve sensors installed at relevant locations on the vehicle. Once installed, the CoSSy sensor signals can cover many more use-cases, such as the detection of vandalism (scratching) or low-speed parking incidents, because these types of touch are each characterized by a particular sound signature.

The sensor system can be designed to support other functions such as sensing specific road conditions, identifying the driver via voice recognition, or detecting approaching emergency vehicles. Even communication with the vehicle via touch could be enabled by CoSSy: A tap at the door by an authenticated driver would suffice to activate an automated door opening.

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“Structure-borne and airborne sound are signals which provide valuable information about the immediate vehicle surrounding. CoSSy is specially developed to pick up the sound patterns of a number of types of contact. Structure-borne sound, for instance, warns when hitting an obstacle at the low speed level of automated parking,” said Laurent Fabre, head of the Passive Safety & Sensorics business unit within Continental, in a statement. “However, once CoSSy is on board, its detection principle can be used to add many more functions, thus adding to the safety and comfort of a ride.”

Sensing sound in structures is not new, according to Continental, as the concept has been used for many years in passive safety system architectures, such a crash impact sound sensor detecting the sound of a physical impact. “Low-speed contacts are characterized by a different pattern of the structure-borne sound signal,” added Andreas Forster, Manager Next Generation Technology at the Continental business unit Passive Safety & Sensorics.

The first generation of the CoSSy solution can utilize structure-borne sound as an indicator of contact with an object during automated parking. “This could apply to a situation when a person approaches the car without entering the detection cones of other sensors such as ultrasonic or radar. Even though this would be a rare thing to happen, the remaining risk must not be ignored for reasons of safety, especially at the beginning of an autonomous parking maneuver,” Forster explained.

Should a parked car get dented or scratched, the CoSSy sensors can give the incident a time stamp. The sensor signal could also be used to wake up the appropriate camera to take a photo of the situation or to make the other driver aware of the contact by sounding an alarm or sending information to a known smartphone. This would help to deter people from vandalism and to avoid unintentional hit-and-run situations. Rental car companies could easily check the car status as “undamaged” when the vehicles are returned.