JP7557978B2 - Radar device, radar device control method, and program - Google Patents

Description

The present invention relates to a radar device, a method for controlling a radar device, and a program.

There is known an object detection radar system that detects an object by radiating (transmitting) electromagnetic waves from a transmitting antenna and receiving (receiving) the electromagnetic waves reflected by the object with a receiving antenna. For example, Patent Document 1 discloses an imaging device that transmits a transmission signal toward the object and obtains an image of the object from the reflected signal reflected by the object. Patent Document 2 discloses an active sensor in which the transmitting antenna and the receiving antenna are arranged in different directions. According to the active sensor of Patent Document 2, the transmitting antenna is scanned in a first direction and the receiving antenna is scanned in a second direction, thereby moving the position of the intersection of the transmitting beam and the receiving beam and obtaining information on the position.

JP 2008-145230 A JP 2015-132474 A

In object detection radar systems like those described above, to detect the size, shape, etc. of a target object with higher accuracy, it was necessary to narrow the beam width of the transmitting antenna and the receiving antenna. This could result in the antenna structure becoming more complex and larger.

The present invention provides a radar device that enables highly accurate object detection while preventing the antenna structure from becoming too complicated or large.

A radar device according to an aspect of the present invention includes the following configuration:
A transmitting antenna having directionality and radiating electromagnetic waves;
a receiving antenna having directivity and receiving a reflected wave of the electromagnetic wave reflected by an object ;
a control means for controlling the transmitting antenna and the receiving antenna so that, within a range in which the beam width of the transmitting antenna and the beam width of the receiving antenna overlap, an angular difference between a transmitting beam direction corresponding to a direction in which the beam of the transmitting antenna is maximized and a receiving beam direction corresponding to a direction in which the beam of the receiving antenna is maximized becomes a predetermined angle greater than 0;
Equipped with
The control means controls the transmitting antenna and the receiving antenna so that the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a first beam direction is different from the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a second beam direction different from the first beam direction .

The present invention makes it possible to achieve highly accurate object detection while preventing the antenna structure from becoming too complicated or large.

FIG. 2A is a diagram showing an example of the configuration of an object detection radar system, FIG. 2B is a diagram explaining a transmitting antenna beam, and FIG. 2C is a diagram explaining a receiving antenna beam. FIG. 4A is a diagram showing an example of scanning for object detection by an object detection radar system, and FIG. 4B is a diagram explaining the half-width. 3A to 3C are diagrams for explaining the operation of the object detection radar system according to the first embodiment. 10 is a flowchart showing a process of a control unit according to a second embodiment. FIG. 11 is a diagram showing an example of an operation for detailed object detection according to the second embodiment. 1A and 1B are diagrams showing examples of changes in radiation patterns depending on the beam direction of a directional antenna; 13A to 13C are diagrams for explaining the operation of the object detection radar system according to the third embodiment.

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe multiple features, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicate explanations are omitted.

In the following embodiment, an object detection radar system using millimeter waves in the 60 GHz band is exemplified, but the frequency band used is not necessarily limited to this. For example, a frequency band from 200 GHz to 500 GHz, which is an even higher frequency band than the 60 GHz band, may be used.

First Embodiment
FIG. 1A is a diagram showing an example of the configuration of an object detection radar system using a radar device according to the first embodiment. The object detection radar system 10 includes a transmitting antenna 101, a receiving antenna 102, an analyzing unit 103, and a control unit 104. The transmitting antenna 101 emits a transmission wave 112 under the control of the control unit 104. As shown in FIG. 1B, the transmitting antenna 101 has a directivity (radiation pattern) shown as a transmitting antenna beam 111, and the control unit 104 can change the transmitting beam direction 113. Here, the transmitting beam direction 113 corresponds to, for example, the direction of maximum radiation intensity (main beam direction) of the transmitting antenna 101. Also, the beam width T is the radiation width of an electromagnetic wave effective for object detection in the transmitting antenna 101.

The receiving antenna 102 receives the reflected wave 122 under the control of the control unit 104. As shown in FIG. 1(c), the receiving antenna 102 has a directivity shown as a receiving antenna beam 121, and the control unit 104 can change the receiving beam direction 123. Here, the receiving beam direction 123 corresponds to the direction of maximum radiation intensity of the receiving antenna (main beam direction). Also, the beam width R is the radiation width of the electromagnetic wave effective for object detection in the receiving antenna 102.

The transmitting antenna 101 and the receiving antenna 102 are shared antennas and are the same antenna. The control unit 104 can individually control the transmitting antenna beam 111 (transmitting beam direction 113) during transmission and the receiving antenna beam 121 (receiving beam direction 123) during reception. In this embodiment, the shape of the transmitting antenna beam 111 and the shape of the receiving antenna beam 121 are the same, and the beam width T and beam width R are also the same. Figure 1(a) shows a state in which the transmitting beam direction and the receiving beam direction are aligned. Below, a method for the object detection radar system to detect the size, shape, etc. of an object 131 will be described.

In this embodiment, the transmitting antenna 101 and the receiving antenna 102 are the same shared antenna, and an example is described in which an array antenna capable of controlling the direction of the antenna beam is used, but this is not limited to this. For example, the transmitting antenna 101 and the receiving antenna 102 may be configured as different antennas, or may be a directional antenna other than an array antenna that has directivity (beam) in a specific direction. In addition, the transmitting antenna beam 111 and the receiving antenna beam 121 do not have to be the same.

The method by which the object detection radar system 10 detects an object will be described with reference to FIG. 1. The transmitting antenna 101 transmits a transmission wave 112 in a direction and with a radiation intensity indicated by a transmitting antenna beam 111. The transmitting wave 112 is an electromagnetic wave, and in this embodiment, it is a millimeter wave in the 60 GHz band. A part of the transmitting wave 112 is reflected by an object 131, and a reflected wave 122 is generated. The receiving antenna 102 can receive the arriving reflected wave 122 in a direction and with a radiation intensity indicated by a receiving antenna beam 121. As shown in FIG. 1(a), the control unit 104 controls the transmitting antenna 101 and the receiving antenna 102 so that the transmitting antenna beam 111 and the receiving antenna beam 121 are in the same direction. When the receiving antenna 102 receives a part of the electromagnetic wave transmitted by the transmitting antenna 101 as a reflected wave, it means that an object exists in that direction, and it becomes possible to detect the size, shape, etc. of the object.

Next, a method for detecting the size, shape, etc. of an object with higher accuracy will be described. In FIG. 2(a), objects 131, 132, and 133 are objects detected by the object detection radar system 10. Here, the control unit 104 controls the transmitting antenna 101 and the receiving antenna 102 so that the transmitting antenna beam 111 and the receiving antenna beam 121 are scanned at a constant angle θ. The transmitting antenna beam 111 and the receiving antenna beam 121 have beam widths T and R. As shown in FIG. 2(b), the angle X between the point 201 where the radiation intensity of the electromagnetic wave radiated from the antenna is maximum and the point 202 where the radiation intensity is 3 dB lower is called the half-width, half-value angle, or 3 dB beam width (hereinafter referred to as the half-width). If the half-width X of the transmitting antenna beam 111 and the receiving antenna beam 121 is wide, the beam widths T and R are also wide. As a result, for example, as shown in FIG. 2(a), when objects 132 and 133 exist within the range of beam widths T and R, it becomes impossible to separate and recognize these objects.

In general, to avoid such false detection and detect the target with higher accuracy, it is possible to narrow the half-width X, which is the radiation characteristic of the transmitting antenna 101 and the receiving antenna 102. That is, by narrowing the half-width, the area (beam width T) where the electromagnetic wave transmitted from the transmitting antenna is incident on the target is narrowed. In addition, the area (beam width R) of the range where the reflected wave reflected from the target is received is also narrowed. This makes it possible to further improve the resolution of detecting the target. However, when the half-width, which is the radiation characteristic of the transmitting antenna and the receiving antenna, is narrowed as described above, the antenna configuration generally becomes complex. For example, in the case of an array antenna, in order to obtain a radiation characteristic with a narrower half-width, it is necessary to increase the number of antennas, which leads to an increase in the size of the target detection system.

Therefore, below, we will explain a method that enables more accurate detection of an object without narrowing the half-value angle, which is the radiation characteristic of the transmitting antenna 101 and the receiving antenna 102.

In the object detection radar system 10 shown in FIG. 3, the transmission beam direction 113 of the transmission antenna beam 111 by the transmission antenna 101 and the reception beam direction 123 of the reception antenna beam 121 by the reception antenna 102 are shifted by an angle δ (δ>0). As described above, object detection is performed when the transmission wave transmitted from the transmission antenna 101 is incident on the object 131 and the reflected wave reflected by the object 131 is received by the reception antenna 102. As can be seen from FIG. 1 and FIG. 3, this is possible in the overlapping range W of the range (beam width T) in which the transmission antenna 101 can transmit the transmission wave 112 and the range (beam width R) in which the reception antenna 102 can receive the reflected wave 122.

1 and 3 are compared with respect to the width (area) of the extension of the region where the beam width T of the transmitting antenna beam 111 and the beam width R of the receiving antenna beam 121 overlap. In FIG. 1, the transmitting beam direction 113 and the receiving beam direction 123 are aligned, and the width of the overlapping region is equal to the beam width T or R. In contrast, in FIG. 3, the transmitting beam direction 113 and the receiving beam direction 123 are shifted by an angle δ, so the width of the region where the beam widths of the transmitting antenna 101 and the receiving antenna 102 overlap is W, which is clearly narrower than the state in FIG. 1. In this way, the control unit 104 controls the beam directions of the transmitting antenna 101 and the receiving antenna 102 to shift, thereby making it possible to narrow the range in which an object can be detected. This makes it possible for the object detection radar system 10 to recognize, for example, objects 132 and 133, which could not be recognized as separate objects in the state of FIG. 2(a), as separate objects.

As described above, according to the first embodiment, by shifting the transmission beam direction 113 and the reception beam direction 123, the area in which the transmission wave and the reflected wave can be transmitted and received (object detectable range) is set to a predetermined narrowness (area), and the accuracy (resolution) of object detection is improved. In addition, by scanning the surroundings centered on the transmission antenna 101 and the reception antenna 102 while maintaining the angular difference between the transmission beam direction 113 and the reception beam direction 123 at a predetermined value, it is possible to detect the presence of an object more accurately. For example, by appropriately setting the angle between the transmission beam direction 113 and the reception beam direction 123, it becomes possible to detect that the objects 132 and 133 shown in FIG. 2(a) are separate objects.

Second Embodiment
In the first embodiment, a configuration has been described in which the beam directions of the transmitting antenna 101 and the receiving antenna 102 are controlled so that the width (area) in which the transmitted wave 112 and the reflected wave 122 can be transmitted and received becomes a predetermined narrowness (area), thereby improving the accuracy of object detection. That is, in the first embodiment, it has been described that the range (area) in which an object can be detected can be changed by controlling the antenna beam directions of the transmitting antenna 101 and the receiving antenna 102. In the second embodiment, a configuration will be described in which the object detection time is shortened and the size, shape, etc. of the target object are detected in more detail by utilizing a configuration that changes the detectable range.

Figure 4 is a flowchart explaining antenna control by the control unit 104 and the analysis unit 103 in the second embodiment. The control unit 104 has, for example, one or more processors and memory, and executes the process shown in Figure 4 by the one or more processors executing a program stored in the memory. First, the control unit 104 controls the transmission beam direction 113 and the reception beam direction 123 so that the overlapping area of the transmission antenna beam 111 and the reception antenna beam 121 is widened, that is, so that the range (area) in which an object can be detected is widened. In this embodiment, the control unit 104 controls the transmission beam direction 113 of the transmission antenna 101 and the reception beam direction 123 of the reception antenna 102 to be the same so that the range (area) in which an object can be detected is widened (S401). This state is as shown in Figure 1.

The control unit 104 performs scanning by the transmitting antenna 101 and the receiving antenna 102, for example, as shown in FIG. 2(a), with the transmitting beam direction 113 and the receiving beam direction 123 aligned (S402). The control unit 104 rotates the beam directions of the transmitting antenna 101 and the receiving antenna 102 so that the ranges in which an object can be detected do not overlap as much as possible. For example, in FIG. 2(a), the transmitting beam direction 113 and the receiving beam direction 123 are rotated by the beam width T (=R) (θ=T), or by the half-value angle X (θ=X). This allows the analysis unit 103 to determine the presence or absence of an object around the transmitting antenna 101 and the receiving antenna 102 in a short time. If the analysis unit 103 detects an object before the scanning is completed (while NO is returned in S405), the control unit 104 stores the detectable range at that time as a specific range in memory (not shown) (YES in S403, S404).

When an object is detected in a specific range, there may be one object or multiple objects in the specific range. Therefore, after the above-mentioned scanning is completed, the specific range in which the object was detected is analyzed in more detail. Therefore, if the specific range is stored in memory (YES in S406), the control unit 104 executes the processing from S407 onwards. If the specific range is not stored (NO in S406), no object has been detected, and this processing is terminated.

First, as described in the first embodiment (FIG. 3), the control unit 104 shifts the beam directions of the transmitting antenna 101 and the receiving antenna 102 as shown in FIG. 3 so that the detectable range (area) of the object becomes a predetermined size (S407). Then, while maintaining this state (while maintaining the angle between the transmitting beam direction 113 and the receiving beam direction 123 at δ), the control unit 104 scans the above-mentioned specific range using the transmitting antenna 101 and the receiving antenna 102 (S408). In scanning the specific range, for example, the beam direction is rotated so that the narrowed detectable range (range W) does not overlap as much as possible. The analysis unit 103 recognizes the size and shape of the object based on the object detection result obtained by scanning (S409). Note that in S404, the beam direction when the object is detected as the specific range may be held. In this case, the control unit 104 determines the specific range in S408 based on the beam direction held in the memory and the beam width (=T) of the above-mentioned scan.

According to the above process, precise scanning is performed with a narrower object detectable range, so it is possible to determine whether multiple objects exist within the specific range. In addition, the size and shape of the object present within the specific range can be identified with a precision according to the object detectable range. In addition, such precise scanning is performed for the specific range in which the object was detected in S403, so that processing speed can be increased. If it is desired to detect the presence or absence of an object within an even finer area, scanning may be performed by narrowing the object detectable area even further within the area in which the object was detected. In other words, the determination of the specific range and more precise scanning of the determined specific range may be repeated while increasing the shift amount of the beam direction of the transmitting antenna 101 and the receiving antenna 102.

As described above, by scanning a specific range where it has been determined that an object exists with the beam directions of the transmitting antenna 101 and the receiving antenna 102 shifted, it is possible to more accurately determine how many objects are contained in the detected object.

Next, we will explain how to more precisely determine the size and shape of each object detected in S409 above.

Figure 5 is a diagram for explaining a method for precisely identifying the size and shape of an object according to the second embodiment. When the object 131 is detected to be present in the narrowed area by the above method, the control unit 104 controls the transmitting antenna 101 and the receiving antenna 102 so that the beam direction faces the direction of the area where the object 131 is present, as shown in Figure 5 (a). Then, the control unit 104 changes the receiving beam direction 123 of the receiving antenna 102 clockwise by a predetermined angle while keeping the transmitting beam direction 113 of the transmitting antenna 101 fixed. Figure 5 (b) shows a state in which the receiving beam direction 123 is rotated clockwise by an angle δ1. Figure 5 (c) shows a state in which the receiving beam direction 123 is further rotated clockwise by an angle δ1 from the state of Figure 5 (b). In Figure 5 (c), the angle between the transmitting beam direction 113 and the receiving beam direction 123 is δ2 (= δ1 x 2).

The analysis unit 103 judges whether the reflected wave 122 can be detected each time the angle between the transmission beam direction 113 and the reception beam direction 123 changes, that is, whether the object 131 has been detected in the object detectable range (area) at each angle. If the angle between the transmission beam direction 113 and the reception beam direction 123 is increased, there should be an area where the object cannot be detected somewhere, and the analysis unit 103 can specify the size and shape of one side of the object 131 from that information. Similarly, the control unit 104 changes the reception beam direction 123 of the reception antenna 102 counterclockwise by a predetermined angle at a time. The analysis unit 103 can specify the size and shape of the other side of the object 131 by judging whether the reflected wave can be detected at each angle, that is, whether the object 131 has been detected in the object detectable range (area) at each angle.

The above method makes it possible to identify the size and shape of the object 131 in a short time with high accuracy. Note that in the second embodiment, the beam direction of the transmitting antenna 101 is fixed and the beam direction of the receiving antenna 102 is rotated clockwise and counterclockwise, but the relationship between the transmitting antenna and the receiving antenna may be reversed. In other words, the control unit 104 may fix the receiving beam direction 123 of the receiving antenna 102 and control the transmitting beam direction 113 of the transmitting antenna 101 to rotate clockwise and counterclockwise.

Third Embodiment
In the above embodiment, the transmitting antenna 101 and the receiving antenna 102 are shared antennas, and are directional antennas having a strong beam (directivity) in a specific direction. In general, the radiation pattern of such a directional antenna changes depending on the beam direction, as shown in FIG. 6. That is, the beam width (half width, etc.) changes depending on the beam direction of the antenna. Therefore, as the transmitting beam direction 113 (receiving beam direction 123) of the transmitting antenna 101 (receiving antenna 102) changes as shown in states 6a, 6b, and 6c, the beam width of the transmitting antenna beam 111 (receiving antenna beam 121) changes. In FIG. 6, a state 6b rotated by a rotation angle θ from the beam direction of the transmitting antenna beam 111 (receiving antenna beam 121) shown in state 6a, and a state 6c rotated by a rotation angle θ'(θ'>θ) are shown. In the example of FIG. 6, the beam width increases as the rotation angle increases. In such a case, if the shift amount (angle difference) between the transmission beam direction 113 of the transmission antenna 101 and the reception beam direction 123 of the reception antenna 102 is constant, the object detectable range will change depending on the beam direction. For example, if the reception beam direction is shifted by the same angle in state 6b and state 6c, the object detectable range in state 6c will be larger. In the third embodiment, a method of controlling the transmission antenna and the reception antenna to set a predetermined object detectable range (area) even when the beam direction changes will be described.

As shown in FIG. 7(a), when an object detectable range (area) is to be obtained as indicated by width W, the angle between the transmitting beam direction 113 of the transmitting antenna 101 and the receiving beam direction 123 of the receiving antenna 102 is set to δ. On the other hand, when the transmitting beam direction 113 radiated from the transmitting antenna 101 is set as shown in FIG. 7(b), in order to obtain the object detectable range (area) indicated by width W, the angle between the transmitting beam direction 113 and the receiving beam direction 123 must be set to δ'. In this way, the angle difference between the transmitting beam direction 113 and the receiving beam direction 123 to obtain the same object detectable range (area) differs between when the beam width is narrow and when the beam width is wide. In other words, the angle difference δ' when the beam width is wide is larger than the angle difference δ when the beam width is narrow.

Based on the above characteristics, the control unit 104 changes the angle difference between the transmission beam direction 113 and the reception beam direction 123 based on the transmission beam direction 113 or the reception beam direction 123 in order to keep the object detectable range (area) constant. For example, the control unit 104 holds a table in which the "angle and beam width of the transmission beam direction of the transmission antenna" and the "angle and beam width of the beam direction of the reception antenna" are stored in association with each other. As described above, the object detectable range (area) is the area where the beam widths of the transmission antenna and the reception antenna overlap. Based on the beam direction and beam width obtained from the held table, the control unit 104 calculates the angle of the beam direction of the transmission antenna 101 and the reception antenna 102 required to obtain a predetermined object detectable range (area). The control unit 104 controls the beam direction of the transmission antenna 101 and the reception antenna 102 based on the calculated beam direction angle.

Alternatively, a table may be held in which the "range (area) in which an object can be detected", the "angle and beam width of the beam direction of the transmitting antenna", and the "angle and beam width of the beam direction of the receiving antenna" are stored in association with each other. In this case, the control unit 104 can directly obtain the angle of the beam direction of the transmitting antenna 101 and the receiving antenna 102 to obtain a specified range (area) in which an object can be detected from the table.

As described above, according to the third embodiment, a stable range in which objects can be detected can be obtained regardless of the beam direction.

Fourth Embodiment
In the first to third embodiments, it has been explained that by shifting the directions of the antenna beams of the transmitting antenna and the receiving antenna, it is possible to narrow the range (area) in which an object can be detected, and thus it is possible to detect the object with higher accuracy. That is, as shown in FIG. 3, the width W (area) of the area where the beam width T of the transmitting antenna beam 111 and the beam width R of the receiving antenna beam 121 overlap is the range in which an object can be detected. However, the direction of the range W is shifted from the transmitting beam direction 113 and the receiving beam direction 123, and the antenna gain of the transmitting antenna 101 and the receiving antenna 102 in the range W is low. Therefore, there is a possibility that the energy of the electromagnetic wave reflected from the object 131 cannot be sufficiently received by the receiving antenna 102. In that case, the reflected wave received by the receiving antenna 102 is mixed up with noise, and the object detection radar system 10 cannot accurately detect the object.

In the fourth embodiment, when the range (area) in which an object can be detected is narrowed by shifting the beam directions of the transmitting antenna 101 and the receiving antenna 102, the receiving antenna 102 is able to receive reflected waves from an object with greater energy.

When the transmission beam direction 113 and the reception beam direction 123 are shifted, the control unit 104 increases the energy of the electromagnetic waves transmitted from the transmission antenna 101 so that the receiving antenna 102 can receive the reflected waves from the object with greater energy. That is, the control unit 104 changes the transmission power of the electromagnetic waves output from the transmission antenna 101 according to the angular difference between the transmission beam direction 113 and the reception beam direction 123. For example, the larger the angular difference, the greater the transmission power is. Through such control, the energy of the reflected waves reflected by the object increases, and the energy of the reflected waves received by the receiving antenna 102 also increases. As a result, the object detection radar system 10 can detect objects more accurately.

For example, when executing the control described in the second embodiment (FIG. 4), the narrower the overlapping beam width W (the larger the angular difference between the transmission beam direction 113 and the reception beam direction 123), the lower the antenna gain. Therefore, the control unit 104 controls the transmission power of the transmission antenna 101 to be increased.

For example, the memory of the control unit 104 holds the table described in the third embodiment as a first table, and also holds a second table that associates the "angular difference between the transmission beam direction and the reception beam direction" with the "transmission power of the transmission antenna." After the control unit 104 determines the transmission beam direction and the reception beam direction using the first table by the method described in the third embodiment, it determines the transmission power of the transmission antenna 101 by referring to the second table based on the angular difference between the determined transmission beam direction and reception beam direction.

As described above, according to the fourth embodiment, the decrease in detection capability caused by the decrease in gain due to shifting the transmission beam direction and the reception beam direction is suppressed.

As described above, according to each of the above embodiments, in an object detection radar system, the accuracy of object detection can be improved by only controlling the antenna beam direction, without changing the half-width of the transmitting antenna and the receiving antenna. In other words, it is possible to achieve highly accurate object detection while suppressing the complexity and size of the antenna structure.

The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-mentioned embodiments to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

The present invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present invention. Therefore, in order to publicize the scope of the present invention, the following claims are appended.

101: transmitting antenna, 102: receiving antenna, 103: analyzing device, 104: control unit, 111: transmitting antenna beam, 121: receiving antenna beam, 112: transmitting wave, 122: reflected wave, 131: object

Claims (15)

A transmitting antenna having directionality and radiating electromagnetic waves;
a receiving antenna having directivity and receiving a reflected wave of the electromagnetic wave reflected by an object ;
a control means for controlling the transmitting antenna and the receiving antenna so that, within a range in which the beam width of the transmitting antenna and the beam width of the receiving antenna overlap, an angular difference between a transmitting beam direction corresponding to a direction in which the beam of the transmitting antenna is maximized and a receiving beam direction corresponding to a direction in which the beam of the receiving antenna is maximized becomes a predetermined angle greater than 0;
Equipped with
The control means controls the transmitting antenna and the receiving antenna so that the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a first beam direction is different from the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a second beam direction different from the first beam direction . 2. The radar device according to claim 1, further comprising an analyzing means for analyzing the reflected wave received by the receiving antenna. The radar device according to claim 2, characterized in that the control means controls the transmission beam direction and the reception beam direction separately. The radar device according to claim 2 or 3, characterized in that the control means rotates the transmission beam direction and the reception beam direction while maintaining the angular difference in order to detect an object by the analysis means. the control means rotates the transmission beam direction and the reception beam direction while maintaining the angular difference at a first angle in order to perform a first object detection by the analysis means;
5. The radar device according to claim 2, wherein when an object is detected in the first object detection, the transmitting beam direction and the receiving beam direction are rotated while maintaining the angular difference at a second angle larger than the first angle in order to perform a second object detection by the analysis means. The radar device according to claim 5, characterized in that the first angle is 0. The radar device according to claim 5 or 6, characterized in that the control means controls the rotation of the transmission beam direction and the reception beam direction so that the second object detection is performed within a range set based on the direction in which the object detected in the first object detection exists. The radar device according to claim 4, characterized in that the control means rotates the receiving beam direction without rotating the transmitting beam direction after orienting the transmitting beam direction and the receiving beam direction in a direction in which the detected object is present, in order to detect the shape or size of the object detected by the object detection. The radar device according to claim 4, characterized in that the control means rotates the transmission beam direction without rotating the reception beam direction after orienting the transmission beam direction and the reception beam direction in a direction in which the detected object is present in order to detect the shape or size of the object detected by the object detection. The radar device according to claim 2, characterized in that the control means changes the angle difference according to the transmission beam direction or the reception beam direction so that the size of the overlapping area of the beam width of the transmission antenna and the beam width of the reception antenna becomes the same. a table storing a relationship between a transmission beam direction and a beam width of the transmitting antenna and a relationship between a reception beam direction and a beam width of the receiving antenna;
11. The radar device according to claim 10, wherein the control means changes the angular difference by referring to the table. 11. The radar device according to claim 10, wherein the control means controls the transmission power of the transmission antenna based on the angular difference . The radar device according to claim 12, characterized in that the control means increases the transmission power as the angular difference increases. A transmitting antenna having directionality and radiating electromagnetic waves;
a receiving antenna having directivity and receiving a reflected wave of the electromagnetic wave reflected by an object,
a step of controlling the transmitting antenna and the receiving antenna so that, within a range in which the beam width of the transmitting antenna and the beam width of the receiving antenna overlap, an angular difference between a transmitting beam direction corresponding to a direction in which the beam of the transmitting antenna is maximized and a receiving beam direction corresponding to a direction in which the beam of the receiving antenna is maximized becomes a predetermined angle greater than 0;
and rotating the transmission beam direction and the reception beam direction while maintaining the angular difference, thereby performing object detection .
A method for controlling a radar device, characterized in that, in the controlling step, the transmitting antenna and the receiving antenna are controlled so that the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a first beam direction is different from the angular difference between the transmitting beam direction and the receiving beam direction when the transmitting beam direction is a second beam direction different from the first beam direction . A program for causing a computer to execute the radar device control method described in claim 14.

Images