CN115407331A - Vehicle-mounted millimeter wave radar with detection angle range larger than 180 degrees and alarm method - Google Patents

Abstract

The invention relates to a vehicle-mounted millimeter wave radar with a detection angle range larger than 180 degrees and an alarm method, and belongs to the field of vehicle detection. The invention aims to provide a vehicle-mounted millimeter wave radar with a detection angle range larger than 180 degrees and an alarm method. The vehicle-mounted millimeter wave radar comprises a radar shell, a first radar circuit board and a second radar circuit board; the first radar circuit board and the second radar circuit board are packaged in the radar shell; the radars on the first radar circuit board and the second radar circuit board share one radar radio frequency chip; connecting at least one transmitting channel and at least one receiving channel of the radar radio frequency chip to a transmitting antenna and a receiving antenna on a second radar circuit board, and connecting the rest transmitting channels and receiving channels of the radar radio frequency chip to a transmitting antenna and a receiving antenna on a first radar circuit board; and the first radar circuit board and the second radar circuit board fuse the respective detected results to generate an alarm.

Description

A vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees and an alarm method

technical field

The invention relates to a vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees and an alarm method, belonging to the field of vehicle detection.

Background technique

Some applications of automotive millimeter-wave radar require that the FOV angle of the millimeter-wave radar is equal to or greater than 180 degrees. Taking the vehicle-mounted angle radar as an example, as shown in Figure 1, the vehicle-mounted millimeter-wave radar needs to cover two alarm areas: the blind spot monitoring on the side of the vehicle body and the rear collision warning function directly behind the vehicle body, resulting in an angular range of the radar detection area greater than 180 degrees. Considering that the angular detection range of the vehicle-mounted millimeter-wave radar is determined by the horizontal lobe angle of the antenna, the lobe angle of the planar antenna made on the printed circuit board is less than 180 degrees. Therefore, the current vehicle-mounted millimeter-wave radar cannot cover such a large-angle alarm area. Radar-based intelligent driver assistance systems perform poorly at the edges of the desired alert area. In the prior art, some schemes use two identical millimeter-wave radars to be installed at a staggered angle to cover the entire area greater than 180 degrees, but the disadvantage of this scheme is that it brings about an increase in cost and poor market acceptance.

Contents of the invention

The purpose of the present invention is to provide a vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees and an alarm method, and to expand a millimeter-wave radar with a simple structure and low cost that can realize a detection angle range greater than 180 degrees. The vehicle-mounted millimeter-wave radar, the extended one-transmit-one-receive millimeter-wave radar is provided with two radar circuit boards inside, and the two radar circuit boards share the design of the shell, power supply, and interface circuit, so that the extended vehicle millimeter-wave radar can The cost of wave radar has increased slightly, but it is still within the acceptable range of the market.

In order to achieve the above object, the present invention provides the following technical solutions:

A vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees, wherein the vehicle-mounted millimeter-wave radar includes a radar housing, a first radar circuit board, and a second radar circuit board;

The first radar circuit board and the second radar circuit board are packaged in the radar housing;

The radar on the first radar circuit board and the second radar circuit board share a radar radio frequency chip; At least one transmitting channel and at least one receiving channel of the radar radio frequency chip are connected to the transmitting antenna and the receiving channel on the second radar circuit board an antenna, connecting the remaining transmit channels and receive channels of the radar radio frequency chip to the transmit antenna and receive antenna on the first radar circuit board;

The transmitting antenna and the receiving antenna of the first radar circuit board are horizontally facing the first radar detection area behind the side of the vehicle, and the transmitting antenna and receiving antenna of the second radar circuit board are horizontally facing the second radar detection area on the side of the vehicle. The first radar detection area and the second radar detection area cover a detection angle range greater than 180 degrees at the rear and sides of the vehicle;

The first radar circuit board and the second radar circuit board generate an alarm after fusing the results detected respectively.

Among them, the first detection distance that needs to be detected in the first radar detection area is greater than 50 meters, and it needs to be able to detect with high angle measurement accuracy; Probing of measurement accuracy.

Wherein, the radar radio frequency chip is a radar radio frequency chip with four transmissions and four receptions; three transmission channels and three reception channels of the radar radio frequency chip with four transmissions and four receptions are used on the first radar circuit board, so that the first The radar circuit board becomes a radar with three transmissions and three receptions; a transmission channel and a reception channel of the radar radio frequency chip of the four transmissions and four receptions are connected to the transmission antenna and the reception antenna on the second radar circuit board, so that the second radar circuit board Become a pitch-and-catch radar.

Wherein, the radar radio frequency chip is a radar radio frequency chip with four transmissions and four receptions; three transmission channels and two reception channels of the radar radio frequency chip with four transmissions and four receptions are used on the first radar circuit board, so that the first radar circuit The board becomes a three-transmit and two-receive radar; one transmit channel and two receive channels of the radar RF chip are connected to the transmit antenna and the receive antenna on the second radar circuit board, so that the second radar circuit board becomes a one-transmit and two-receive radar .

Wherein, the radar radio frequency chip is a radar radio frequency chip with four transmissions and four receptions; two transmission channels and two reception channels of the radar radio frequency chip with four transmissions and four receptions are used on the first radar circuit board, so that the first radar circuit The board becomes a two-transmit and two-receive radar; the two transmit channels and two receive channels of the radar radio frequency chip are connected to the transmit antenna and the receive antenna on the second radar circuit board, so that the second radar circuit board becomes a two-transmit and two-receive radar. radar.

Wherein, a transmitting channel and a receiving channel of the radar radio frequency chip are divided into two transmitting channels and two receiving channels through a power divider, and one transmitting channel and one receiving channel are connected to the second radar circuit board A transmitting antenna and a receiving antenna, another transmitting channel and a receiving channel are connected to the transmitting antenna and the receiving antenna on the first radar circuit board.

An alarm method using the vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees, wherein,

Described warning method comprises the steps:

S1. The first radar circuit board detects continuous stationary objects in the detection area of the first radar;

S2. The first radar circuit board judges whether the lateral distance between the continuous stationary object and the vehicle is less than a predetermined value. If it is lower than the predetermined value, it is determined that the car is driving next to the continuous stationary object. In this case, the second radar is raised The alarm threshold of the circuit board; if it is higher than the predetermined value, the alarm threshold of the second radar circuit board is not changed.

Wherein, the predetermined value is 1 meter.

Wherein, in step S2, the radar threshold value is set as the signal-to-noise ratio and/or signal strength threshold value of the radar signal in the current cycle, when the signal-to-noise ratio and/or signal strength of the radar signal are higher than a certain set value S1, then It thinks that there is a target and needs to call the police;

When the first radar circuit board judges that the lateral distance between the continuous stationary object and the vehicle is less than a predetermined value, it is determined that the car is driving past the continuous stationary object. In this case, the alarm threshold of the second radar circuit board is increased to a certain set value S ₂ , said S ₂ >S ₁ .

Wherein, in step S2, the radar threshold value is set such that in consecutive N radar cycles, the signal-to-noise ratio and/or signal strength threshold value of the radar signal in at least M ₁ radar cycles is higher than a certain set value S ₁ , Then it is considered that there is a target at present, and the alarm needs to be called;

When the first radar circuit board judges that the lateral distance between the continuous stationary object and the vehicle is less than a predetermined value, it is determined that the automobile is running against the continuous stationary object. In this case, the alarm threshold of the second radar circuit board is increased to be at least M The signal-to-noise ratio and/or the signal strength threshold of the radar signal in _two radar cycles is higher than a certain set value S ₂ , wherein, N>M ₂ >M ₁ , and S ₂ >S ₁ .

Compared with prior art, the beneficial effect of the present invention is:

With the development of smart cars, the horizontal angle range that radar needs to detect is getting larger and larger, reaching or exceeding 180 degrees. Considering that the radar antenna gain drops sharply at the boundary of the radar horizontal angle range, the maximum detection range of the radar at the boundary of the radar horizontal angle range is also much lower than the maximum detection range of the radar at the center of the radar. Therefore, it is an inevitable result to use two radars facing different directions to achieve a detection angle range of 180° or greater. However, the use of two radars with one transmission and two receptions or multiple transmissions and multiple receptions will almost double the product cost, and the market acceptance is very low.

The advantage of the present invention is that the use of a simple-structured and low-cost once-send-and-receive millimeter-wave radar expands a vehicle-mounted millimeter-wave radar that can achieve a detection angle range greater than 180 degrees to meet customer and regulatory requirements. Two radar circuit boards are arranged inside the extended one-send-one-receive millimeter-wave radar, and the two radar circuit boards share the shell, power supply, and interface circuit, so that the cost of the expanded vehicle-mounted millimeter-wave radar increases slightly. But it is still within the acceptable range of the market.

Description of drawings

Figure 1 is a schematic diagram of the detection coverage of the vehicle-mounted millimeter-wave radar;

Figure 2 is a schematic diagram of two detection areas that the vehicle-mounted millimeter-wave radar needs to detect;

3 is a schematic diagram of a vehicle-mounted millimeter-wave radar with a detection angle range greater than 180 degrees of the present invention;

Fig. 4 is a schematic diagram of an embodiment in which the first radar circuit board and the second radar circuit board share a radar radio frequency chip;

5 is a schematic diagram of an alarm method for correcting the result of the second radar circuit board by using the detection result of the first radar circuit board to the environment;

Fig. 6 is a schematic diagram of another embodiment in which the first radar circuit board and the second radar circuit board share one radar radio frequency chip.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 2, according to actual needs, the detection area that the vehicle-mounted millimeter-wave radar needs to cover is divided into the first radar detection area behind the vehicle side and the second radar detection area on the side of the vehicle.

As shown in FIG. 3 , the first detection range that needs to be detected in the first radar detection area is greater than 50 meters, and some radars with higher performance requirements need to be able to perform detection with high angle measurement accuracy.

The first radar detection area is covered by the first radar circuit board. Preferably, the first radar circuit board is a conventional medium-distance wide-angle radar circuit board, such as a 24GHz one-transmission and two-reception radar, a 77GHz two-transmission and four-reception radar, three-transmission and four-reception radar, and four-transmission and four-reception radar. Generally, the transmission power of 24GHz radar is greater than 5dBm (decibel milliwatts, 5dBm is about 3.2 milliwatts), and the transmission power of 77GHz radar is greater than 10dBm (10 milliwatts), and has the ability to measure angles, so the detection distance reaches more than 50 meters.

The send-two-receive radar has one transmit antenna and two receive antennas. Similarly, the two-transmit and four-receive radar has two transmitting antennas and four receiving antennas, the three-transmit and four-receive radar has three transmitting antennas and four receiving antennas, and the four-transmit and four-receive radar has four transmitting antennas antenna and four receiving antennas.

Preferably, the second detection distance that needs to be detected by the second radar detection area is less than or equal to 5 meters, which is about the width of a lane, and detection with high angle measurement accuracy is not required. The second radar detection area is covered by the second radar circuit board. The second radar circuit board only measures the distance and speed of the target, but does not measure the angle of the target. Preferably, the second radar circuit board is a send-and-receive millimeter-wave radar circuit board. The pitch-receive radar has a transmit antenna and a receive antenna.

The vehicle-mounted millimeter-wave radar includes a radar housing, a first radar circuit board and a second radar circuit board. The first radar circuit board and the second radar circuit board are packaged in a radar housing, the transmitting antenna and receiving antenna of the first radar circuit board are horizontally facing the first radar detection area behind the side of the vehicle, and the transmitting antenna of the second radar circuit board is The antenna and the receiving antenna are horizontally facing the second radar detection area on the side of the vehicle, and the first radar detection area and the second radar detection area cover a detection angle range greater than 180 degrees behind and side of the vehicle. The first radar circuit board and the second radar circuit board generate an alarm after fusing the results detected respectively.

As shown in FIG. 4 , the radars on the first radar circuit board and the second radar circuit board share one radar radio frequency chip. Connect at least one transmitting channel and at least one receiving channel of the radar radio frequency chip to the transmitting antenna and receiving antenna on the second radar circuit board, and connect the remaining transmitting channels and receiving channels of the radar radio frequency chip to the first radar circuit Transmit and receive antennas on the board.

For example, the radar radio frequency chip is a four-transmission and four-reception radar radio frequency chip. On the first radar circuit board, use three transmission channels and three reception channels of the radar radio frequency chip of the four transmissions and four receptions, so that the first radar circuit board becomes a radar with three transmissions and three receptions; A transmitting channel and a receiving channel of the radar radio frequency chip are connected to the transmitting antenna and the receiving antenna on the second radar circuit board, so that the second radar circuit board becomes a send-and-receive radar.

In addition to connecting a transmitting channel and a receiving channel of the radar radio frequency chip to the transmitting antenna and the receiving antenna on the second radar circuit board, the target detection requirements of the second radar circuit board and the first radar circuit board can also be connected to More than one transmitting channel and receiving channel of the radar radio frequency chip are connected to the antenna on the second radar circuit board. For example, the radar radio frequency chip is a four-transmission and four-receiver radar radio frequency chip, and the second radar circuit board also needs to detect a range of more than 5 meters, and needs to have the ability to measure angles, then the four can be used on the first radar circuit board. The three transmit channels and two receive channels of the radar radio frequency chip that send out four receive, make the first radar circuit board become three transmit two receive radars; One transmit channel and two receive channels of the radar radio frequency chip are connected to the second The transmitting antenna and the receiving antenna on the radar circuit board make the second radar circuit board a radar with one sending and two receiving. Or on the first radar circuit board, use two transmitting channels and two receiving channels of the radar radio frequency chip of four sending and four receiving, so that the first radar circuit board becomes two sending and two receiving radars; The two transmit channels and the two receive channels are connected to the transmit antenna and the receive antenna on the second radar circuit board, so that the second radar circuit board becomes a two-transmit and two-receive radar.

As shown in Figure 6, in one embodiment, a transmit channel and a receive channel of the radar radio frequency chip are divided into two transmit channels and two receive channels through a power divider, and one transmit channel and one receive channel are divided into two One channel is connected to the transmitting antenna and receiving antenna on the second radar circuit board, and the other transmitting channel and one receiving channel are connected to the transmitting antenna and receiving antenna on the first radar circuit board.

In order to reduce the false alarm rate of the send-and-receive radar on the second radar circuit board, the present invention provides an alarm method for correcting the result of the second radar circuit board by using the detection result of the first radar circuit board to the environment.

As shown in Figure 5, if the first radar circuit board detects that the vehicle is driving along continuous stationary objects such as fences and walls, the probability of vehicles appearing in the second radar detection area of the second radar circuit board is very low. Next, increase the alarm threshold of the second radar circuit board. Described warning method comprises the steps:

S1. The first radar circuit board detects continuous stationary objects such as fences and walls in the detection area of the first radar;

S2. The first radar circuit board judges whether the lateral distance from continuous stationary objects such as fences and walls to the vehicle is less than a predetermined value. If it is lower than the predetermined value, it is determined that the car is driving against continuous stationary objects such as fences and walls. In this case, increase the alarm threshold of the second radar circuit board; if it is higher than the predetermined value, then do not change the alarm threshold of the second radar circuit board.

Preferably, the predetermined value is 1 meter.

Preferably, in step S2, the radar threshold value is set as the signal-to-noise ratio and/or signal strength threshold value of the current period radar signal, when the signal-to-noise ratio and/or signal strength of the radar signal are higher than a certain set value S1, Then it is considered that there is a target at present, and the alarm needs to be called.

When the first radar circuit board judges that the horizontal distance from continuous stationary objects such as fences and walls to the vehicle is less than a predetermined value, it is determined that the car is running against continuous stationary objects such as fences and walls. The alarm threshold of the board is a set value S ₂ , where S ₂ >S ₁ .

Preferably, in step S2, the radar threshold value is set such that in consecutive N radar cycles, the signal-to-noise ratio and/or signal strength threshold value of the radar signal in at least M ₁ radar cycles is higher than a certain set value S ₁ , it is considered that there is a target and an alarm is required.

When the first radar circuit board judges that the horizontal distance from continuous stationary objects such as fences and walls to the vehicle is less than a predetermined value, it is determined that the car is running against continuous stationary objects such as fences and walls. The alarm threshold of the board is that the signal-to-noise ratio and/or signal strength threshold value of the radar signal in at least M ₂ radar cycles is higher than a certain set value S ₂ , wherein, said N>M ₂ >M ₁ , S ₂ > S ₁ .

For example, in general, set the current cycle SNR and/or signal strength of the radar signal to be higher than 5 dB, and the SNR and/or signal strength of the radar signal to be higher than 5 dB for at least 4 out of 7 consecutive cycles , it is considered that there is a target and an alarm is required. When the first radar circuit board judges that the horizontal distance from continuous stationary objects such as fences and walls to the vehicle is less than a predetermined value, it is determined that the car is running against continuous stationary objects such as fences and walls. The alarm threshold of the board is that the signal-to-noise ratio and/or signal strength of the radar signal is higher than 8 dB for at least 6 out of 7 consecutive cycles.

Claims (10)

1. The utility model provides a be greater than on-vehicle millimeter wave radar of 180 degrees detection angle scopes which characterized in that: the vehicle-mounted millimeter wave radar comprises a radar shell, a first radar circuit board and a second radar circuit board;

the first radar circuit board and the second radar circuit board are packaged in the radar shell;

the radars on the first radar circuit board and the second radar circuit board share one radar radio frequency chip; connecting at least one transmitting channel and at least one receiving channel of the radar radio frequency chip to a transmitting antenna and a receiving antenna on a second radar circuit board, and connecting the rest transmitting channels and receiving channels of the radar radio frequency chip to a transmitting antenna and a receiving antenna on a first radar circuit board;

the transmitting antenna and the receiving antenna of the first radar circuit board horizontally face a first radar detection area at the lateral rear part of the vehicle, the transmitting antenna and the receiving antenna of the second radar circuit board horizontally face a second radar detection area at the lateral side of the vehicle, and the first radar detection area and the second radar detection area cover detection angle ranges of the lateral rear part and the lateral side of the vehicle, wherein the detection angle ranges are larger than 180 degrees;

and the first radar circuit board and the second radar circuit board fuse the respective detected results to generate an alarm.

2. The vehicle-mounted millimeter wave radar of greater than 180 degrees of detection angle range according to claim 1, wherein: the first detection distance to be detected in the first radar detection area is more than 50 meters, and the detection with high angle measurement precision is required to be carried out; and the second detection distance to be detected in the second radar detection area is less than or equal to 5 meters, and the detection with high angular measurement precision is not required.

3. The vehicle-mounted millimeter wave radar of greater than 180-degree detection angle range according to claim 1 or 2, wherein: the radar radio frequency chip is a four-transmitting four-receiving radar radio frequency chip; three transmitting channels and three receiving channels of the four-transmitting four-receiving radar radio frequency chip are used on the first radar circuit board, so that the first radar circuit board becomes a three-transmitting three-receiving radar; and connecting a transmitting channel and a receiving channel of the four-transmitting and four-receiving radar radio frequency chip to a transmitting antenna and a receiving antenna on the second radar circuit board, so that the second radar circuit board becomes a one-transmitting and one-receiving radar.

4. The vehicle-mounted millimeter wave radar of greater than 180-degree detection angle range according to claim 1 or 2, wherein: the radar radio frequency chip is a four-transmitting four-receiving radar radio frequency chip; three transmitting channels and two receiving channels of the four-transmitting and four-receiving radar radio frequency chip are used on the first radar circuit board, so that the first radar circuit board becomes a three-transmitting and two-receiving radar; and connecting one transmitting channel and two receiving channels of the radar radio frequency chip to a transmitting antenna and a receiving antenna on the second radar circuit board, so that the second radar circuit board becomes a transmitting-receiving radar.

5. The vehicle-mounted millimeter wave radar of greater than 180-degree detection angle range according to claim 1 or 2, wherein: the radar radio frequency chip is a four-transmitting four-receiving radar radio frequency chip; two transmitting channels and two receiving channels of the four-transmitting and four-receiving radar radio frequency chip are used on the first radar circuit board, so that the first radar circuit board becomes a two-transmitting and two-receiving radar; and connecting the two transmitting channels and the two receiving channels of the radar radio frequency chip to a transmitting antenna and a receiving antenna on the second radar circuit board, so that the second radar circuit board becomes a two-transmitting and two-receiving radar.

6. The vehicle-mounted millimeter wave radar of greater than 180-degree detection angle range according to claim 1 or 2, characterized in that: and dividing one transmitting channel and one receiving channel of the radar radio frequency chip into two transmitting channels and two receiving channels through a power divider, connecting one transmitting channel and one receiving channel to a transmitting antenna and a receiving antenna on a second radar circuit board, and connecting the other transmitting channel and one receiving channel to a transmitting antenna and a receiving antenna on a first radar circuit board.

7. An alarm method using the vehicle-mounted millimeter wave radar of which detection angle range is larger than 180 degrees according to any one of claims 1 to 6, characterized in that:

the alarm method comprises the following steps:

s1, a first radar circuit board detects that a continuous static object appears in a first radar detection area;

s2, the first radar circuit board judges whether the transverse distance between the continuous stationary object and the vehicle is smaller than a preset value or not, if the transverse distance is smaller than the preset value, the vehicle is judged to be driving along the continuous stationary object, and under the condition, the alarm threshold of the second radar circuit board is increased; if the alarm threshold is higher than the preset value, the alarm threshold of the second radar circuit board is not changed.

8. The alarm method of claim 7, wherein:

the predetermined value is 1 meter.

9. The alarm method according to claim 7, wherein:

in the step S2, a radar threshold value is set as a signal-to-noise ratio and/or a signal intensity threshold value of a radar signal in the current period, and when the signal-to-noise ratio and/or the signal intensity of the radar signal is higher than a certain set value S1, a target is considered to be present and an alarm is required;

when the first radar circuit board judges that the transverse distance between the continuous stationary object and the vehicle is smaller than a preset value, the fact that the vehicle is driving along the continuous stationary object is judged, and under the condition, the alarm threshold of the second radar circuit board is increased to be a set value S ₂ Said S ₂ ＞S ₁ 。

10. The alarm method according to claim 7, wherein:

in step S2, the radar threshold value is set to be at least M in N continuous radar periods ₁ The signal-to-noise ratio and/or the signal strength threshold value of the radar signal in each radar period are higher than a set value S ₁ If the target is present, the alarm is needed;

when the first radar circuit board judges that the transverse distance between the continuous stationary object and the vehicle is less than a preset value, the vehicle is judged to be running along the continuous stationary object, and under the condition, the alarm threshold of the second radar circuit board is increased to be at least M ₂ The signal-to-noise ratio and/or the signal strength threshold value of the radar signal in each radar period are higher than a set value S ₂ Wherein said N > M ₂ ＞M ₁ ，S ₂ ＞S ₁ 。

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