There have been many cases of children being accidentally left in cars and in some cases, tragic consequences have resulted. Since such incidents do occur, Volvo has looked for solutions that can alert the driver to such situations, even if the child is accidentally locked in the boot. The technology is being tested in the SecureCar and uses a heartbeat sensor to detect a living person inside the car.
The heartbeat sensor was originally developed for use in high-security installations to detect people hiding in cars getting in or out. Special operations law enforcement and military units are also known to have such equipment for their covert operations.
In the SecureCar, the technology has been adapted and miniaturised to work with an electric key fob. Two super-sensitive micro-accelerometers measure minute vibrations in the car’s structure and match them against known sonic patterns of the human heartbeat (including some variations for those with irregular heartbeats). The meters are so sensitive that they can detect a human body – and even small animals – anywhere in the car or even someone touching the car body.
To use the system, all the driver has to do is press the button on the key fob. After a pause, the system will have picked up any human heartbeats and an alarm will emanate from the key fob. Extensive programming is being carried out to screen out other types of vibrations like those caused by construction works or wind. The system is not on all the time and only works on application.
“It’s not just for alerting drivers to kids left inside but can also offer peace of mind when returning to the car. There may be times when an intruder has entered the car and is hiding out of sight. With the heartbeat sensor, a quick scan can be done before entry,” said Sam Ebenstein, a staff technical specialist at Ford working on the project.
Another feature of the SecureCar is the automatic boot release. Two approaches are taken; one uses a CO2 (carbon dioxide) sensor to set off an alarm and pop open the bootlid and the other is a touchpad which does the same thing.
The C02 sensor measures the level of the gas, which is exhaled by humans, inside the boot. A microprocessor then compares the level with what is normally found in the atmosphere and if it is high, the boot will be unlocked. A lot of work has gone into calibrating the sensor to cover humans of many sizes and ages and also to work if a person is unconscious.
The touchpad sensor is intended for situations where a person is intentionally or unintentionally locked in the boot. It has a capacitive switch which sense tiny electrical pulses in skin and will trigger the lock. This means that non-human items like luggage or groceries will not cause the switch to work. For children who may be too young to understand what to do, a small illuminated image of a rabbit or some attractive character can be put on the touchpad to attract them to touch it.
This feature will also solve the problem of people who are unfortunate to be dumped in the boot by robbers and can’t get away, as what is often seen in movies but also happens in real life.
“All these technologies will be compared in rigorous real-world testing to determine which single system or combination of sensors will offer the safest result, while screening out false positives that could hinder effectiveness,” said Mr Ebenstein.