Proximity Sensor

What is a proximity sensor on a car

A proximity sensor is a device that detects the presence of nearby objects, usually people or animals. Proximity sensors use an electrical signal and can detect an object without touching it. Proximity sensors are often used in security systems to detect when someone is trying to break into a car or tamper with it. They can also automatically unlock doors when the owner is nearby or park a car by detecting available space. We sometimes use them by approximating distance to ensure no damage to the car, individual, or animal. 

Table of Contents

Define proximity

Proximity refers to the physical closeness of two or more things. Proximity sensors detect the presence of nearby objects. Security, keyless entry, and automated parking systems all use proximity when an object is close to an opening door, hatch, or simply the presence of a person or part of a person’s body.

  1. Proximity sensors can detect approaching vehicles and trigger an automated garage door opener.
  2. They can also detect people or animals approaching your car and trigger an alarm. 
  3. Unlock your car doors when you are nearby automatically with Proximity sensors.
  4. Proximity sensors detect available space when parking a car or the vehicle get’s close enough to the wall or another vehicle. Automatic car parking works by detecting and computing distances from the car to the obstruction.
  5. Proximity sensors can be used in car security systems to detect when someone is trying to break into the car or tamper with its contents.

Proximity Meaning

The word proximity derives from the Latin proximitas, which means “closeness.” Proximity refers to the physical closeness of two or more things. Proximity sensors detect the presence of nearby objects in security systems, keyless entry systems, and automated parking systems. Proximity describes objects close to an opening door, hatch, or simply the presence of a person or part of a person’s body.

Proximity Sensor for a car

How do car proximity sensor work?

Car proximity sensors detect the presence of nearby objects without making physical contact with them. They use electromagnetic fields, sound waves, or light to detect the object’s existence.

Proximity sensor range

The proximity sensor range is the distance that the sensor can detect an object. The range of a proximity sensor depends on the sensor type, the object’s size, and the environment in which it is used. 

What are proximity sensors used for?

Proximity sensors detect nearby objects without making physical contact with them. These sensors detect and present information to occupants about items in and around the car.

Prevent car injuries with proximity sensors

Smart Close® is a device that helps to prevent injuries by detecting a change in the electric field and instantly reversing the powered closure element. The device is best in class when considering the angle / scissor action and FMVSS118 S5 requirement for an autonomous vehicle or when remote activation is required. The Smart Close® also interfaces with all power closure systems, power windows, sunroofs, and power liftgates. By sensing the human presence and reversing, even when holding the switch in the closed position, the Smart Close® system helps to create a safe environment while also providing the potential NCAP benefit.

Regarding safety, nothing is more important than ensuring that power closure systems are correctly functioning. That’s why ascencioné has developed a unique solution that uses electric field sensing to detect obstacles and reverse the power closure element. This innovative technology offers many benefits, including faster closure speeds, zero-force detection and reversal, and the ability to interface with all power closure systems. The Smart Close® system can help make power closure systems safer for everyone by providing injury-free, no-trap protection.

Proximity sensors for cars prevent damage to your automobile.

Along with protecting people from injury, proximity Sensors will also protect against damage to your vehicle. It’s nice to know that your car door will not open if an object is in its way. Or you won’t be able to drive a car into an object without a warning alarm. In the age of auto opening and closing doors, proximity sensors are a blessing.

Unlock Car Door with Brite®

Actual operation of Brite® Keyless unlocking system for a car door.

Inductive proximity sensors

Inductive proximity sensors use an electromagnetic field. This field detects nearby metal objects. Inductors are coils of wire which has inductance. The coil generates a magnetic field on the front area of the sensor. The LC Oscillator produces a radio frequency that generates an electromagnetic field. The trigger circuit determines the change in oscillation amplitude and gives the output circuit information. Once the circuit receives a signal, it switches on and provides an output. 

Capacitive proximity sensor

Capacitive proximity sensors use an electric field to detect the presence of nearby objects. Most sensors have two parallel plates separated with a dielectric material such as plastic, glass, or porcelain. These materials do not conduct electricity well. However, the plates are conductive and made of Aluminum Tantalum or other metal materials. 

The plates usually are electrically neutral; however, if you connect the plate to a battery, the plate on the negative side with have a net negative charge while the one connected to the right will have a net positive charge. The ability to store an electric charge when voltage is applied is called capacitance. Quantity measuring the strength of a dielectric material to store charge is called the dielectric constant. The distance between the both plates and the material determines the capacitance of a capacitor.

Two types of capacitive sensors

First, the dielectric type can detect an object with a dielectric constant greater than air. Dielectric types of capacitive proximity sensors will sense both metallic and non-metallic objects.

Secondly, the conductive type of sensor has one plate inside the sensor, and the air between the sensor and the object becomes the dielectric medium. The target acts as the second plate of the capacitor. As this distance decreases, the capacitance increases and increases oscillation amplitude. Once the sensor detects a predetermined value, a generated signal is produced. This signal indicates that the object has reached the sensor’s zone. The target is an electrically conductive material.

 They are often used in keyless entry systems to automatically detect when the owner is nearby and unlock the doors. Capacitive proximity sensors can also be used in car security systems to detect when someone is trying to break into the car or tamper with it.

Radar capacitive proximity sensor

The capacitive radar sensor can reach long distances. In general, the proximity sensor range is limited to a certain distance. However, some proximity sensors – such as capacitive radar sensors – have a more extended range and can detect objects farther away, up to several feet. 

Ultrasonic proximity sensor

An ultrasonic proximity sensor uses two transducers to transmit and receive ultrasonic pulses, which bounce off from objects, relaying information about an object’s proximity. Ultrasonic sensors determine if there is anything in front of the sensor and how far away it is. 

Micro proximity sensor

A micro proximity sensor is a type of proximity sensor that has a concise range. The microsensor detects objects too close to the car that may cause a collision. The range of a micro proximity sensor is typically just a few inches.

Laser proximity sensor

Another type of sensor, is Laser sensors emit a laser beam and detect the object’s presence by the reflection of the beam. They are mounted on all four corners of the car and measure the distance to the obstacle. The laser sensor is ideal for small to medium-sized objects. The laser proximity sensor can reach a distance of up to 10 feet.

Proximity Sensors for cars in development for 2022

We currently work with two OEMs on radar proximity sensors in-car products. Both use Smart Open® in conjunction with proximity testing and calculations to make the motors function. We will be announcing these products next year, hopefully along with your ideas for this fantastic technology!

Field Capacitive

One of the safety features of many newer vehicles is the Smart Close®, non-contact obstacle detection and reversal system for powered closure elements such as doors, windows, sunroofs, and liftgates. The system uses sensors to detect a change in the electric field around the vehicle, which indicates the presence of a human or object. The system then instantly reverses the powered closure element, preventing it from trapping or injuring anyone. The Smart Close® has several advantages over traditional obstacle detection systems. It can detect obstacles without coming into contact with them, making it much faster and more accurate. Obstacale detections allows for a much smoother and safer operation. Finally, all power closure systems should have the Smart Close® system integrated.

Prevent injuries

Finally, Smart Close® is a device that helps to prevent injuries by detecting a change in the electric field and instantly reversing the powered closure element. The device is best in class when considering the angle / scissor action and FMVSS118 S5 requirement for an autonomous vehicle or when remote activation is required. The Smart Close® also interfaces with all power closure systems, power windows, sunroofs, and power liftgates. By sensing the human presence and reversing, even when holding the switch in the closed position, the Smart Close® system helps to create a safe environment while also providing the potential NCAP benefit. 

Ascencioné has developed a unique solution that uses electric field sensing to detect obstacles and reverse the power closure element. This innovative technology offers many benefits, including faster closure speeds, zero-force detection and reversal, and the ability to interface with all power closure systems. The Smart Close® system can help make power closure systems safer for everyone by providing injury-free, no-trap protection.