KR20190051462A - Radar system for vehicle and operation method thereof - Google Patents

Abstract

The present invention relates to a radar system for a vehicle, and to an operating method thereof. The radar system for a vehicle comprises: a rainfall information acquisition unit acquiring rainfall information; a road information acquisition unit acquiring road information on a road; a reception unit receiving a reflection signal from a neighboring object with respect to a transmission signal and amplifying the reflection signal in accordance with a reception gain; and a signal processing unit adjusting the reception gain of the reception unit based on the rainfall information acquired by the rainfall information acquisition unit and the road information acquired by the road information acquisition unit.

Description

TECHNICAL FIELD [0001] The present invention relates to a radar system for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar system for a vehicle and a method of operating the same, and more particularly, to a radar system for a vehicle and a method of operating the same.

A typical method used as a vehicle radar is a Frequency Modulated Continuous Wave (FMCW) radar. FMCW radar means a radar that transmits frequency-modulated signals continuously.

The loss due to air and water vapor for the 70 GHz band, which is mainly used as the transmission frequency of a vehicle radar, is about 0.3 to 5 dB / km, which is relatively high as compared to other frequency bands as shown in Fig. When the rainfall per hour is 100 mm / h, the attenuation due to rainfall is approximately 3.0 to 3.3 dB / 0.1 km. When the detection range of the radar is 100 m, as shown in FIG. 2, the attenuation is 6 to 6.6 dB . In order to overcome this propagation loss, the vehicle radar uses a relatively high transmission power, but there is a limitation in raising the transmission output by EIRP (Effective Isotropically Radiated Power) regulation. Therefore, in the operating environment where humid atmosphere and high instantaneous rainfall exist, the maximum detection distance may be shortened and the performance of the vehicle radar may be deteriorated.

In addition, when fixed transmission power and reception gain are used in various road situations such as a tunnel and a high-priced road, a received signal is too large to cause a receiver saturation state, or a received signal is too weak to detect a target signal .

The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 10-2017-0040971 (published on Apr. 14, 2017).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a radar system for a vehicle, which is capable of improving the detection performance of a radar system according to a driving environment of a vehicle, And to provide a radar system for a vehicle and a method of operating the radar system.

According to one aspect of the present invention, a vehicular radar system includes a rainfall information acquisition unit for acquiring rainfall information, a road information acquisition unit for acquiring road information on the road, a reflection signal from a nearby object for a transmission signal, And a signal processing unit for adjusting the reception gain of the receiver based on the rain information obtained by the rain information acquiring unit and the road information acquired by the road information acquiring unit.

In the present invention, the signal processing section performs a primary adjustment of the reception gain based on the rainfall information acquired by the rainfall information acquisition section, and based on the road information acquired by the road information acquisition section, Thereby increasing or decreasing the reception gain.

In the present invention, the signal processing unit may firstly adjust the reception gain so that a higher value is obtained as the rainfall amount determined according to the rainfall information increases.

In the present invention, the rain information acquiring unit may include a rain sensor, the signal processing unit may perform smoothing on the rain information by calculating an average value of output values of the rain sensor obtained during a set period, And the receiving gain is firstly adjusted to have a higher value as the rainfall amount determined according to the smoothed rainfall information increases.

In the present invention, the signal processing unit may reduce the first-order reception gain when the current traveling road determined according to the road information is a tunnel, and decrease the first-order reception gain when the current traveling road is an expensive road, Is increased.

In the present invention, the receiver amplifies the reflection signal using a reception gain of a programmable gain amplifier (PGA), and the signal processor adjusts a reception gain of the PGA through SPI (Serial Peripheral Interface) And the reception gain of the receiver is adjusted.

According to an aspect of the present invention, there is provided a method of operating a radar system for a vehicle, the method comprising: acquiring rain information from a rain information acquiring unit; acquiring road information while the road information acquiring unit is running; Adjusting a reception gain for amplifying a reflection signal from a neighboring object with respect to a transmission signal based on the received rainfall information and the road information acquired by the road information acquisition unit, And amplifying the received signal according to the adjusted reception gain.

According to an aspect of the present invention, there is provided a radar detection system including a radar detection system capable of detecting a radar detection performance that is robust to a driving environment, such as a rainfall condition and a traveling road condition, in which a radar system variably adjusts a reception gain for amplifying a reception signal, Lt; / RTI >

Figs. 1 and 2 are exemplary diagrams showing propagation loss in a conventional radar system. Fig.
3 is a block diagram illustrating a radar system for a vehicle according to an embodiment of the present invention.
4 is a block diagram illustrating a specific embodiment of a radar system for a vehicle according to an embodiment of the present invention.
5 is an exemplary diagram for explaining a process of first adjusting a reception gain in a radar system for a vehicle according to an embodiment of the present invention.
FIGS. 6 and 7 are views for explaining a process of controlling the reception gain of a PGA through SPI communication in a vehicular radar system according to an embodiment of the present invention.
8 is a flowchart illustrating an operation method of a radar system for a vehicle according to an embodiment of the present invention.
FIG. 9 is a flowchart specifically illustrating a step of adjusting a reception gain in an operation method of a radar system for a vehicle according to an embodiment of the present invention.
FIG. 10 is a flowchart specifically illustrating a step of increasing / decreasing a first-order reception gain in an operation method of a radar system for a vehicle according to an embodiment of the present invention.

Hereinafter, a vehicle radar system and an operation method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 3 is a block diagram illustrating a radar system for a vehicle according to an embodiment of the present invention. FIG. 4 is a configuration diagram illustrating a specific example of a radar system for a vehicle according to an embodiment of the present invention. FIGS. 6 and 7 are views illustrating an SPI communication in a radar system for a vehicle according to an exemplary embodiment of the present invention. Referring to FIG. 6 and FIG. 7, FIG. 2 is a diagram illustrating a process of adjusting a reception gain of a PGA through a PGA; FIG.

3, a vehicle radar system according to an embodiment of the present invention includes a rain information acquisition unit 100, a road information acquisition unit 200, a transmission unit 300, a reception unit 400, and a signal processing unit 500 .

The rainfall information acquisition unit 100 may acquire the current rainfall information of the vehicle and transmit it to a signal processing unit 500 to be described later. The rainfall information obtaining unit 100 may include a rain sensor provided inside the windshield glass of the vehicle to detect current rainfall information, that is, rainfall information, and to detect rainfall through the LED and the photo sensor have. Accordingly, the rainfall information obtaining unit 100 can detect the rainfall amount information through the rain sensor and output the 8-bit binary value to the signal processing unit 500. [

The road information obtaining unit 200 may obtain the road information of the vehicle currently traveling and may transmit the road information to the signal processing unit 500. The road information acquisition unit 200 may include a navigation device to acquire road information that is currently being traveled, thereby acquiring road information through the DMB antenna of the navigation device.

Meanwhile, the rainfall information acquisition unit 100 and the road information acquisition unit 200 can transmit rainfall information and road information to the signal processing unit 500 through CAN (Controller Area Network) communication, respectively.

The transmitting unit 300 may transmit a signal for detecting a peripheral object of the vehicle to the outside of the vehicle. When the radar system according to the present embodiment is an FMCW radar system, the transmitter 300 can continuously transmit the frequency-modulated signal to the outside of the vehicle. Accordingly, the transmitter 300 may include a PA (Power Amplifier) and a VCO (Voltage Controlled Oscillator) as shown in FIG.

The receiver 400 may receive a reflection signal from a neighboring object with respect to a transmission signal transmitted from the transmitter 300, amplify the amplified signal according to the reception gain, and transmit the amplified signal to the signal processor 500. 4, the receiving unit 400 includes a low noise amplifier (LNA), a programmable gain amplifier (PGA), a mixer, a high pass filter (HPF), and a low pass filter (LPF) (Low Pass Filter). At this time, the receiver 400 can amplify the received reflection signal using the reception gain of the PGA.

The signal processing unit 500 may transmit a signal for detecting a peripheral object of the vehicle to the outside of the vehicle through the transmitting unit 300 and may perform signal processing of the radar system for receiving the reflected signal through the receiving unit 400 , The signal processing unit 500 may include a micro controller unit, a digital analogue converter (DAC), and an analogue digital converter (ADC), as shown in FIG. 4, when the radar system according to the present embodiment is an FMCW radar system .

The signal processor 500 controls the reception gain of the receiver 400 based on the rainfall information acquired by the rainfall information acquisition unit 100 and the road information acquired by the road information acquisition unit 200 . That is, in order to solve the problem that the detection performance of the radar system deteriorates depending on the driving environment of the vehicle such as the conditions of the rainfall and the running road, as described above, the signal processing unit 500 of the present embodiment detects By adjusting the gain, robust detection performance of the radar system can be maintained.

Specifically, the signal processing unit 500 firstly adjusts the reception gain based on the rain information obtained by the rain information acquiring unit 100, and based on the road information acquired by the road information acquiring unit 200, It is possible to increase or decrease the reception gain adjusted by the difference.

First, a process of the signal processing unit 500 to primarily adjust the reception gain based on the rainfall information will be described.

The signal processing unit 500 can primarily adjust the reception gain to have a higher value as the amount of rainfall to be determined according to the rainfall information increases.

Specifically, as described above, the rainfall information obtaining unit 100 may detect the rainfall amount information through the rain sensor and output an 8-bit binary value to the signal processing unit 500. The output value of the rain sensor may be a given bit, It has a minimum value and a maximum value in the number. For example, if the output value is 8 bits, 00000000b is the minimum value, and 11111111b is the maximum value. When the output value of the rain sensor is minimized, it can be regarded as a state where there is no rainfall at all. When the output value of the rain sensor is maximized, the maximum instantaneous rainfall amount to be sensed by the rain sensor exists. Accordingly, the signal processing unit 500 can primarily adjust the reception gain of the receiver 400 so that the output value from the lane sensor becomes higher.

Meanwhile, the signal processor 500 calculates an average value of the output values of the rain sensor obtained during the set period to perform smoothing on the rain information, and calculates the reception gain (gain) so that the rainfall amount determined according to the smoothed rain information increases, Can be firstly adjusted.

That is, when the output value of the rain sensor instantaneously changes due to noise or the like, it is impossible to normally detect the rainfall amount. Therefore, the smoothing that calculates the average value of the output values of the rain sensor obtained during the set period is applied, Malfunction can be prevented. The period of obtaining the output values of the rain sensor and calculating the average value can be designed based on the designer's and experimental results.

FIG. 5 shows a specific example of first-order adjustment of the reception gain. 5, assuming that the output value of the rain sensor is composed of 8 bits and the reception gain is composed of 4 bits, the signal processing unit 500 outputs the smoothed rainfall information That is, the average value of the output values of the lane sensor obtained during the set period is divided by a value obtained by adding 1 to the maximum value of the reception gain, and the result can be determined as the primary reception gain adjustment value. For example, the maximum value of the reception gain composed of 4 bits is 1111b, and the primary reception gain adjustment value can be determined by dividing the output value of the smoothed lane sensor by 10000b (= 16) by adding 1 to the maximum value of the reception gain.

When the reception gain is firstly adjusted through the above process, the signal processor 500 may increase or decrease the first-order reception gain based on the road information obtained by the road information obtaining unit 200. [

At this time, the signal processor 500 may reduce the first-order reception gain when the current traveling road determined according to the road information is a tunnel, and may increase the first-order reception gain when the current traveling road is a high- have.

That is, when the current traveling road is a tunnel, the reception signal is too large to cause saturation of the reception unit 400, so that the signal processing unit 500 can reduce the primary reception gain. If the current traveling road is an expensive road, since the received signal is too weak to detect the target signal, the signal processing unit 500 can increase the first-order adjusted reception gain. In each case, the amount of increase / decrease to increase or decrease the first-order reception gain can be variously designed based on the designer's intention and experimental results.

The reception gain of the receiver 400 can be optimally adjusted through the process of firstly adjusting the reception gain according to the rain information and increasing or decreasing the first-order reception gain according to the road information.

Meanwhile, as described above, the receiving unit 400 can amplify the received reflection signal using the reception gain of the PGA included therein. At this time, the PGA may exist independently in the receiving unit 400 or may be functionally included in a receiving MMIC (Monolithic Microwave Integrated Circuit). Recently received MMIC includes most of the gain adjustment function through PGA and can control the receiving gain through SPI (Serial Peripheral Interface) communication.

In consideration of this point, the signal processing unit 500 of the present embodiment may adjust the reception gain of the reception unit 400 by adjusting the reception gain of the PGA functionally implemented in the reception MMIC through the SPI communication as shown in FIG. 6 have.

FIG. 7 shows an example of an SPI control message for a receiving MMIC having a receiving gain control function via a PGA. In the example shown in FIG. 7, the number of bits of the SPI control message is 24 bits, one bit for enabling / disabling the PGA is allocated, and four bits for controlling the reception gain of the PGA are allocated. The Control Bit located in the LSB (Least Significant Bit) is for distinguishing SPI message types. To adjust the receive gain through the PGA, the PGA Enable bit may be set to On (1), and the four bits allocated to the PGA Gain may be set to the optimum adjusted receive gain via the procedure described above.

FIG. 8 is a flowchart illustrating a method of operating a radar system for a vehicle according to an embodiment of the present invention. FIG. 9 is a flowchart illustrating a method of operating a radar system for a vehicle according to an exemplary embodiment of the present invention. FIG. 10 is a flowchart specifically illustrating a step of increasing / decreasing a first-order reception gain in an operation method of a radar system for a vehicle according to an embodiment of the present invention.

Referring to FIG. 8, an operation method of a radar system for a vehicle according to an embodiment of the present invention will be described. First, the rainfall information obtaining unit 100 obtains rainfall information (S100). The rainfall information obtaining unit 100 may detect the rainfall amount information through the rain sensor and output an 8-bit binary value to the signal processing unit 500. [

Then, the roadway government obtaining unit 200 obtains road information on the road (S200). The road information obtaining unit 200 may obtain the road information through the DMB antenna of the navigation device and transmit the road information to the signal processing unit 500.

Subsequently, the signal processing unit 500 receives the rain information from the rain information acquiring unit 100 and the road information obtained by the road information obtaining unit 200, The reception gain for amplifying the reflection signal from the surrounding object is adjusted (S300).

9, the signal processing unit 500 firstly adjusts the reception gain based on the rainfall information obtained by the rainfall information obtaining unit 100 (S310), and then the road information obtaining unit 200 (S330) based on the road information obtained in step S310.

In step S310, the signal processing unit 500 may first adjust the reception gain such that the rainfall amount determined according to the rainfall information has a higher value. At this time, the signal processor 500 calculates the average value of the output values of the rain sensor obtained during the set period, performs smoothing on the rain information, and calculates the reception gain (gain) so that the rainfall amount determined according to the smoothed rain information increases. Can be firstly adjusted.

10, in step S330, the signal processor 500 reduces the first-order reception gain (S333) when the current traveling road determined according to the road information is the tunnel (S331) If the road is a high-priced road (S335), the first-adjusted reception gain is increased (S337). If the current road is a general road other than a tunnel or an expensive road, the first-order reception gain can be maintained (S339).

Meanwhile, the receiving unit 400 of this embodiment can amplify the reflection signal using the gain of the PGA (Programmable Gain Amplifier) and consider that the PGA can be functionally included in the receiving MMIC (Monolithic Microwave Integrated Circuit) The signal processing unit 500 of the present embodiment may adjust the reception gain of the receiver 400 by adjusting the reception gain of the PGA functionally implemented in the reception MMIC through the SPI communication.

After step S300, the receiving unit amplifies the received reflection signal according to the reception gain adjusted in step S300 (S400).

As described above, according to the present embodiment, the radar system can maintain robust radar detection performance in a driving environment by varying the reception gain for amplifying the received signal according to the driving environment of the vehicle such as a rainfall condition and a traveling road condition.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

100: Rainfall information acquisition unit
200: Road information obtaining unit
300:
400: Receiver
500: Signal processor

Claims (12)

A rainfall information acquiring unit for acquiring rainfall information;
A road information acquiring unit for acquiring road information while driving;
A receiver for receiving a reflection signal from a neighboring object with respect to a transmission signal and amplifying the reflection signal according to a reception gain; And
A signal processing unit for adjusting the reception gain of the receiver based on the rain information acquired by the rain information acquisition unit and the road information acquired by the road information acquisition unit;
And a radar system for a vehicle.
The method according to claim 1,
Wherein the signal processing unit performs a first adjustment of the reception gain based on the rainfall information acquired by the rainfall information acquisition unit and a second adjustment of the first adjusted reception gain based on the road information acquired by the road information acquisition unit The radar system comprising:
3. The method of claim 2,
Wherein the signal processing unit firstly adjusts the reception gain to have a higher value as the rainfall amount determined according to the rainfall information increases.
The method of claim 3,
The rainfall information obtaining unit includes a rain sensor,
Wherein the signal processing unit performs smoothing on the rainfall information by calculating an average value of the output values of the rain sensor obtained during the set period and outputs the smoothed rainfall information to the receiver so as to have a higher value as the rainfall amount determined according to the smoothed rainfall information increases And the gain is firstly adjusted.
The method of claim 3,
Wherein the signal processing unit reduces the first adjusted reception gain when the current traveling road determined according to the road information is a tunnel and increases the first adjusted reception gain when the current traveling road is an expensive road A radar system for a vehicle.
The method according to claim 1,
The receiver amplifies the reflection signal using a gain of a PGA (Programmable Gain Amplifier)
Wherein the signal processor adjusts a reception gain of the receiver by adjusting a reception gain of the PGA through SPI (Serial Peripheral Interface) communication.
Acquiring rainfall information by the rainfall information acquisition unit;
Obtaining road information while the road information acquisition unit is running;
The signal processing unit adjusts the reception gain for amplifying the reflection signal from the neighboring object with respect to the transmission signal based on the rain information obtained by the rain information acquiring unit and the road information acquired by the road information acquiring unit ; And
Amplifying the received reflection signal according to the adjusted reception gain;
The radar system comprising: a radar system;
8. The method of claim 7,
Wherein the adjusting comprises:
The signal processing unit may include: a first step of adjusting the reception gain based on the rainfall information obtained by the rainfall information obtaining unit; And
And increasing or reducing the first-order received gain based on the road information obtained by the road information obtaining unit.
9. The method of claim 8,
In the primary adjustment step,
Wherein the receiving gain is first adjusted to have a higher value as the rainfall amount determined according to the rainfall information increases.
10. The method of claim 9,
The rainfall information obtaining unit includes a rain sensor,
In the primary adjustment step,
Wherein the average value of the output values of the rain sensor obtained during the setting period is smoothed for smoothing the rainfall information and the reception gain is adjusted to have a higher value as the rainfall amount determined according to the smoothed rainfall information increases, The radar system comprising:
10. The method of claim 9,
In the step of increasing / reducing the first-order adjusted reception gain,
Wherein the control unit decreases the first-order reception gain when the current driving road determined according to the road information is a tunnel and increases the first-order reception gain when the current driving road is an expensive road, Method of operation of the system.
8. The method of claim 7,
The receiver amplifies the reflection signal using a gain of a PGA (Programmable Gain Amplifier)
In the step of adjusting the reception gain,
Wherein the reception gain of the receiver is adjusted by adjusting a reception gain of the PGA through SPI (Serial Peripheral Interface) communication.

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