Parking sensors how do they work

They are mounted most commonly on the rear bumper for reverse assistance and the front bumper from forward-clearance in some cars.

But, in theory, they all work in the same manner. The Ultrasonic sensors — just like bats — use high-frequency sound waves to detect objects. These sensors emit sound pulses that reflect off of nearby objects.

A receiver detects the reflected waves and calculates the distance from your vehicle to the object. As ultrasonic systems use sound waves, they can suffer from interferences. They might not work that well with small, narrow objects such as poles. They are also affected by rain and wind. These types of sensors use Electromagnetic frequencies to detect the objects nearby. Electromagnetic Parking Sensors can identify more types of objects and without the limitations of ultrasonic proximity sensors.

This is because they function in a wide range of wavelengths on the electromagnetic spectrum. Electromagnetic sensors can also be paired with a camera to help the driver better visualize her car and the space around it.

As opposed to ultrasonic sensors that are mounted onto the bumpers, Electromagnetic Sensors are mounted inside the bumper. Another plus point with EPS is that they are discreet. One of the most intelligent parking systems of the time thanks to technology is the Park Assist. This is about as close as can we get to a fully automated parking system. Park Assist is employed as a feature in various high-end cars. Combining the cameras and sensors, park assist systems can find and judge the size of a parking space, and with the driver controlling the speed, it can steer its way into it.

Most of these systems are now capable of both reverse and parallel parking manoeuvres. The parking sensor also called "parking aid", is mainly composed of ultrasonic sensors, controllers, and displays. It helps the driver "see" the invisible things in the rearview mirror, and inform the driver of the obstacles around the driver by sound or a more intuitive display.

The parking sensor removes the trouble caused by the driver's front, rear, left, and right visits when parking, reversing, and starting the vehicle, and helps the driver to eliminate the defects of blind spots and blurred vision.

The parking sensor also has certain blind spots, including too low and too thin obstacles and ridges. When backing the car, the parking sensor uses the principle of ultrasonic waves. The ultrasonic sensor installed on the rear bumper sends ultrasonic waves to the obstacle and reflects the sound wave, calculates the actual distance between the car body and the obstacle, and then prompts the driver to stop. Working of the parking sensor. When the car is in R gear, the parking sensor will automatically start.

Through the controller, the ultrasonic sensor at the rear bumper controls the ultrasonic emission. The ultrasonic wave is reflected by obstacles, and the ultrasonic sensor receives the reflected ultrasonic wave and sends it to the amplifier circuit.

The ultrasonic sensor calculates the propagation speed in the medium by using the time from the transmission of the ultrasonic signal to the reception of the echo signal. The data is processed by the single-chip microcomputer, and then the distance and direction of the obstacle are displayed on the display to remind the driver to operate in time. The parking sensor is a safety auxiliary device when the car is parking or reversing. It can notify the driver of the obstacles around the driver by sound or a more intuitive display, eliminating the troublesome when parking, reversing, and starting the vehicle.

It helps the driver to eliminate the defects of blind spots and blurred vision. The parking sensor is mainly composed of ultrasonic sensors, controllers and displays or buzzers, etc. The main function of the ultrasonic sensor is to send and receive ultrasonic signals, then input the signals into the host, and display them through the display device.

Working of the ultrasonic sensor. When the controller sends an electrical signal to the ultrasonic sensor, the piezoelectric sheet of the ultrasonic sensor vibrates to generate ultrasonic waves.

It is common to use a transmitter-receiver integrated sensor, that is to say, both transmitting and receiving ultrasonic waves are completed by the same ultrasonic sensor. In this integrated sensor system, there are generally only two wires connected between the ultrasonic sensor and the controller. The transmitted electrical signal and the returned electrical signal are input to the controller through these two wires. Both the transmitted signal of the ultrasonic sensor and the after-vibration signal will cover or interfere with the echo signal, thus causing the parking sensor system to lose its detection function after being below a certain distance.

This is one of the reasons why the detection range of the general parking sensor must be greater than 0. If the distance is less than this distance, the parking sensor cannot distinguish the signal and can only sound a long warning. In theory, the smaller the aftershock, the smaller the minimum detection distance. The best case is that there are no aftershocks so that the ultrasonic sensor can cover a larger range.

However, it is impossible to determine whether the ultrasonic sensor is working normally during the system self-test. Therefore, people use the aftershock characteristics of the ultrasonic sensor to determine whether the ultrasonic sensor is intact by detecting the aftershock signal of the ultrasonic sensor itself through the controller. Therefore, in actual production, the ultrasonic sensor has a certain range of aftershocks, and the controller checks the detection results according to the pre-set range value, so as to determine whether the ultrasonic sensor meets the requirements.

It reminds the driver whether the system is normal by the buzzer sound. In short, due to the directivity of the ultrasonic beam emitted by the ultrasonic sensor and the existence of the after-vibration of the ultrasonic sensor itself, the parking sensor system is not foolproof in practice. It has detection blind spots, so more and more parking sensor systems integrate the reversing imaging system, which can more intuitively and accurately judge the situation behind the vehicle.

The controller processes the signal to calculate the distance and orientation between the vehicle body and the obstacle. The controller transmits a sine wave pulse to the sensor, processes the received signal, and obtains the corresponding distance value, and then communicates with the display.

The main function of the controller is filtering and calculation. The controllers of different brands of parking sensor systems may be different, but the principles are basically the same. In automobiles, the controller is generally installed around the dashboard, while the ultrasonic sensor is installed on the front and rear bumpers, and transmits signals through long wires.

The long line will inevitably produce some noise, so the controller must filter these noises. The beam of the ultrasonic sensor is not regular, but a directional beam with a cross-section that is approximately elliptical. In the process, the beam will inevitably have some misjudgments. For example, the ultrasonic sensor may occasionally "sweep the floor" when there is no obstacle behind the car, it always detects a fixed distance between cm, that is, the distance between the ultrasonic sensor and the ground.

Therefore, in practice, the control circuit will use technical means to process the echo signal of the ultrasonic sensor to ensure that the system has sufficient sensitivity, but will not cause false alarms.

When the sensor detects that the distance between the car and the obstacle reaches a dangerous distance, the system will send an alarm through the display and buzzer to remind the driver. The display provides corresponding distance alarm sound according to the distance. After years of development, the parking sensor system has been upgraded with technology and improved performance, and applied to various models, such as trucks, buses, school buses, combine harvesters, corn harvesters, passenger cars, construction machinery, etc.

No matter in terms of structure and appearance, or in terms of performance and price, today's products have their own characteristics.

Digital display, screen display, and multi-function mirror display are more commonly used. Vehicle reverse image. The car backup camera system makes the situation behind the car more intuitive when reversing. It is one of the most practical configurations for reversing safety. When the reverse gear is engaged, the system will automatically turn on the high-definition reversing camera located at the rear of the car, and clearly display the rear status on the reversing LCD screen, allowing you to accurately grasp the rear road conditions, and reversing is as confident as forward.

The reversing image system can be seen clearly even through infrared rays at night. The antimagnetic, shockproof, waterproof, and dustproof performance of professional vehicle ultrasonic sensors has been further improved. The car display adopts TFT true color and has no signal interference and no flicker after anti-magnetic treatment. At the same time, it has the functions of reversing visual automatic level conversion and automatic switch. The dashboard and endoscope display can clearly display the information behind the car through the on-board camera at the rear of the car.

Two reversing rear-view cameras can also be installed at the same time to achieve no blind spots when reversing. These sensors use frequencies to create an electromagnetic field which can detect anything that enters it. Even though parking sensors are great assistance tools that significantly ease the task of parking, they can be considered lacking to some.

As such, some manufacturers offer alternative assistance tools that can work in isolation or in conjunction with parking sensors to greater simplify and improve the parking experience.

Rather than relying on sensors and guessing the unknown, reversing cameras clearly show your surroundings. This allows you to determine whether or not the curb is too high for example, or if you can swing around that wall on the left-hand side. Unlike sensors, there are no warnings with reversing cameras and while they may provide the driver with more information, there is no alert should the driver have misread that information.

As such, most manufacturers pair reversing cameras with parking sensors so that you have both visual and audial cues while parking. For example, choosing one of the door mirrors can help you judge whether or not you are too close to the kerb or if you are within the lines of a parking bay.