JP2010256133A - Interference prevention radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference prevention radar device capable of preventing more surely radio wave interference with another device for transmitting a radio wave. <P>SOLUTION: This interference prevention radar device 10 including a radar sensor 1 for transmitting a millimeter wave and receiving a reflected wave relative to the millimeter wave, for detecting a peripheral environment by the received reflected wave includes: a synchronous signal acquisition part 42 for receiving a time synchronous signal used for transmitting the millimeter wave by the radar sensor 1, synchronously with another radar device for transmitting the millimeter wave; and a time-sharing driving control part 41 for controlling the radar sensor 1 so that the millimeter wave is transmitted toward a direction corresponding to the time synchronous signal received by the synchronous signal acquisition part 42. Radio wave interference with another device for transmitting the millimeter wave can be prevented more surely by the interference prevention radar device 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an interference prevention radar apparatus that includes a radar sensor that transmits an electromagnetic wave and receives a reflected wave with respect to the electromagnetic wave, and detects an ambient environment based on the received reflected wave.

  Conventionally, a radar device installed in a vehicle is known. For example, Patent Document 1 below discloses a radar device that is mounted on a moving body such as a vehicle, transmits a transmission wave, receives a reflected wave, and detects the surrounding environment of the vehicle. This radar apparatus is provided with a receiving unit that receives a radio signal related to a common time, and is assigned a radio wave transmission cycle. And, in a predetermined first time zone, only radiation of radio waves in a predetermined first direction seen from the vehicle is permitted, and in a predetermined second time zone, a predetermined second time seen from the vehicle Only emission of radio waves in the direction is permitted. As a result, when a plurality of vehicles on which this radar device is mounted are traveling in the same course direction, synchronized radio waves are not transmitted in the opposite directions, so that mutual radio wave interference Is prevented.

JP 2007-187632 A

  However, when a plurality of vehicles equipped with the radar device described in Patent Document 1 are traveling while facing each other, the radiated radio waves have a certain angle width and intersect with each other by millimeter waves. Since the possibility increases, especially when the road on which these vehicles are traveling is curved, there is a problem that radio wave interference that may cause millimeter wave detection failure may occur. .

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide an interference prevention radar device that can more reliably prevent radio wave interference with other devices that transmit radio waves. And

  An interference prevention radar apparatus according to the present invention is an interference prevention radar apparatus that includes a radar sensor that transmits an electromagnetic wave and receives a reflected wave with respect to the electromagnetic wave, and detects an ambient environment by the received reflected wave. Receiving means for receiving a synchronization signal used for transmitting an electromagnetic wave by a radar sensor in synchronization with another radar device for transmitting the electromagnetic wave, and the electromagnetic wave is transmitted in a direction corresponding to the synchronization signal received by the receiving means. And a control means for controlling the radar sensor.

  According to this interference prevention radar apparatus, a radar signal is received so that a synchronization signal used for transmitting an electromagnetic wave in synchronization with another radar apparatus is received, and the electromagnetic wave is transmitted in a direction corresponding to the synchronization signal. The sensor is controlled. For this reason, even when a vehicle equipped with this interference prevention radar device is traveling and moving opposite to another vehicle equipped with another interference prevention radar device, the above-mentioned synchronization signal Since electromagnetic waves are transmitted toward the same direction corresponding to, radio wave interference does not occur. As a result, it is possible to more reliably prevent radio wave interference with other devices that transmit radio waves.

  In addition, it is preferable that detection means for detecting a transmission direction in which electromagnetic waves are transmitted by the radar sensor is further provided, and the control means controls the radar sensor based on the transmission direction detected by the detection means.

  Thereby, since the radar sensor is controlled based on the detected transmission direction, the direction in which the electromagnetic wave is transmitted can be more accurately controlled.

  ADVANTAGE OF THE INVENTION According to this invention, the interference prevention radar apparatus which can prevent more reliably radio wave interference with the other apparatus which transmits a radio wave can be provided.

1 is a schematic configuration diagram of an interference prevention radar apparatus according to an embodiment. It is explanatory drawing for demonstrating an example of a time synchronizing signal. It is explanatory drawing for demonstrating the direction used in an example of a time synchronizing signal. It is explanatory drawing for demonstrating the direction from which a millimeter wave is transmitted. It is explanatory drawing for demonstrating the direction from which a millimeter wave is transmitted. It is explanatory drawing for demonstrating the direction from which a millimeter wave is transmitted. It is explanatory drawing for demonstrating the direction from which a millimeter wave is transmitted. It is a flowchart for demonstrating the process sequence of the millimeter wave transmission control performed with an interference prevention radar apparatus.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(1) Configuration of Interference Prevention Radar Device First, the configuration of the interference prevention radar device according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an interference prevention radar apparatus 10 according to the present embodiment. The interference prevention radar device 10 is mounted on a mobile vehicle such as an automobile (hereinafter, referred to as an own vehicle), and transmits an electromagnetic wave to receive a reflected wave, thereby allowing the surrounding environment (for example, other vehicles, people, roads) This is an in-vehicle sensing device that detects an object or an obstacle.

  The interference prevention radar apparatus 10 according to the present embodiment includes a radar sensor 1, a GPS 2 (Global Positioning System), a geomagnetic compass 3, and a control unit 4 (control means). The control unit 4 includes a time-division drive control unit 41 (control unit), a synchronization signal acquisition unit 42 (reception unit), and a direction information acquisition unit 43 (detection unit).

  One or a plurality of radar sensors 1 are installed outside the host vehicle, and millimeter waves (radars) are directed toward regions in a predetermined direction as viewed from the host vehicle (for example, a front region, a rear region, a right region, and a left region). This is an FM-CW sensor that senses the presence of a reflector, the distance to the reflector, and the like by transmitting the electromagnetic wave as a wave), receiving the reflected wave with respect to the millimeter wave, and analyzing the signal. The use frequency band of the millimeter wave transmitted by the radar sensor 1 is 76 to 77 GHz in Japan.

  The GPS 2 is a system that detects latitude and longitude information related to the current position of the host vehicle based on radio signals transmitted from GPS satellites. The GPS 2 includes a gyro mechanism, and angular velocity information is detected by the gyro mechanism. Then, the latitude and longitude information is finely corrected based on the detected angular velocity information. Note that a radio timepiece capable of receiving a time synchronization signal described later may be used instead of the GPS 2.

  The geomagnetic compass 3 is an instrument that measures and indicates a direction by using geomagnetism. The geomagnetic compass 3 indicates the direction of the traveling direction of the host vehicle, for example. Instead of the geomagnetic compass 3, navigation information including direction information that can be acquired by a conventionally used navigation system may be used.

  The synchronization signal acquisition unit 42 extracts and acquires a time synchronization signal used for transmitting a millimeter wave in synchronization with another radar transmission device that transmits the millimeter wave from the latitude / longitude information acquired by the GPS 2. Thus, the time information is shared with other radar transmitters. A millimeter wave is transmitted by the radar sensor 1 based on the received time synchronization signal. Details of the time synchronization signal will be described later.

  The direction information acquisition unit 43 is a part that detects and acquires the transmission direction, which is the direction in which the millimeter wave is transmitted by the radar sensor 1, based on the direction measured by the geomagnetic compass 3. In addition, the direction information acquisition part 43 can also detect and acquire not only this transmission direction but the direction which the advancing direction of the own vehicle faces.

  The time-division drive control unit 41 drives the radar sensor 1 so that the millimeter wave is transmitted only in the direction (orientation) corresponding to the time synchronization signal received by the synchronization signal acquisition unit 42, whereby the radar sensor 1 is a time division synchronization part that controls the direction in which the millimeter wave is transmitted and schedules the transmission timing. The direction corresponding to the time synchronization signal is stored in the time division drive control unit 41. Details of the time synchronization signal will be described later.

  In addition, the time division drive control unit 41 can control the radar sensor 1 based on the transmission direction detected by the direction information acquisition unit 43. Accordingly, only when the direction corresponding to the time synchronization signal received by the synchronization signal acquisition unit 42 matches the transmission direction detected by the direction information acquisition unit 43, the millimeter wave is transmitted only to this direction. Thus, the radar sensor 1 is controlled. As a result, the direction in which the millimeter wave is transmitted can be controlled more accurately.

(2) Example of Time Synchronization Signal Next, an example of the time synchronization signal will be described with reference to FIGS. FIG. 2 is an explanatory diagram for explaining an example of a time synchronization signal indicating a millimeter-wave transmission timing scheduled in time division, and FIG. 3 is a diagram for explaining a direction used in this example of the time synchronization signal. It is explanatory drawing.

  First, as shown in FIG. 2, the transmission is performed when the elapsed time T from a predetermined time (for example, noon) is 0 (for example, “second”; hereinafter, description of the unit is omitted) or more and less than 1. "East" is assigned as a direction by the time synchronization signal, and "North" is assigned as a direction by the time synchronization signal transmitted when the elapsed time T is 1 or more and less than 2, and the elapsed time T is 2 or more and 3 “West” is assigned as the direction by the time synchronization signal transmitted when the time is less than 3, and “South” is assigned as the direction by the time synchronization signal transmitted when the elapsed time T is 3 or more and less than 4.

  Similarly, “northeast” is assigned as a direction by the time synchronization signal transmitted when the elapsed time T is 4 or more and less than 5, and by the time synchronization signal transmitted when the elapsed time T is 5 or more and less than 6. “NW” is assigned as the direction, and “SW” is assigned as the direction according to the time synchronization signal transmitted when the elapsed time T is 6 or more and less than 7, and the elapsed time T is 7 or more and 8 (the second “ “Southeast” is assigned as the direction by the time synchronization signal transmitted when the value is less than 0). The same cycle is repeated again, with the period of elapsed time T from 0 to 8 as one cycle.

  Next, as shown in FIG. 3, the directions used in the example of the time synchronization signal include “east”, “north”, “west”, “south”, “north”, “northwest”, “southwest”, A region divided into eight corresponding to the eight directions “southeast” is used. More specifically, the range from the boundary of 22.5 degrees north of true east to the boundary of 22.5 degrees south of true east is defined as “east”, and the boundary of 22.5 degrees east of true south To the boundary of 22.5 degrees west of true south is defined as “south”, from the boundary of 22.5 degrees south of true west to the boundary of 22.5 degrees north of true west The range is defined as “west”, and the range from the boundary of 22.5 degrees west of true north to the boundary of 22.5 degrees east of true north is defined as “north”.

  And the range between the “North” range and the “East” range is defined as “Northeast”, the range between the “East” range and the “South” range is defined as “Southeast”, The range between the “south” range and the “west” range is defined as “southwest”, and the range between the “west” range and the “north” range is defined as “northwest”.

(3) An example of a method for transmitting a millimeter wave toward the direction corresponding to the time synchronization signal Next, an example of a method for transmitting a millimeter wave toward the direction corresponding to the time synchronization signal will be described with reference to FIGS. To do. FIG. 4 is an explanatory diagram for explaining the direction in which the millimeter wave is transmitted when the elapsed time T from the predetermined time is 0 or more and less than 1, and FIG. 5 is the elapsed time T from the predetermined time. FIG. 6 is an explanatory diagram for explaining a direction in which a millimeter wave is transmitted in a case where is 5 or more and less than 6, and FIG. 6 illustrates a case where the millimeter wave is transmitted when the elapsed time T from a predetermined time is 6 or more and less than 7. FIG. 7 is an explanatory diagram for explaining a direction in which a millimeter wave is transmitted when an elapsed time T from a predetermined time is 7 or more and less than 8. is there.

  First, as shown in FIG. 4, it is assumed that vehicles C1 to C4 on which the interference prevention radar device 10 is mounted are traveling on a curved road R, and an elapsed time from a predetermined time (for example, noon) at the present time. It is assumed that T is 0 (for example, “seconds”; hereinafter, description of units is omitted) or more and less than 1. At this time, when the time synchronization signal is received in the vehicles C1 to C4, “east” is assigned as the direction in which the millimeter wave is transmitted. And in vehicles C1-C4, direction information acquisition part 43 judges whether radar sensor 1 which can transmit a millimeter wave exists in the direction of "east" field, and, as a result of judgment, this "east" field The millimeter wave W is transmitted only from the vehicle C3 having the radar sensor 1 capable of transmitting the millimeter wave in the direction of. On the other hand, as a result of the determination, the millimeter wave W is not transmitted from the vehicles C1, C2, and C4 that do not have the radar sensor 1 capable of transmitting the millimeter wave to “east”.

  Next, as shown in FIG. 5, it is assumed that a period of time has elapsed and the elapsed time T from a predetermined time (here, noon) is in a state of 5 or more and less than 6. At this time, when a new time synchronization signal is received in the vehicles C1 to C4, “northwest” is assigned as the direction in which the millimeter wave is transmitted. Then, in the vehicles C1 to C4, the direction information acquisition unit 43 determines whether or not the radar sensor 1 capable of transmitting a millimeter wave exists in the direction of the “north-west” region. The millimeter wave W is transmitted only from the vehicle C4 having the radar sensor 1 capable of transmitting the millimeter wave in the direction of. When the millimeter wave W is transmitted from the vehicle C4, the presence of the vehicle C3 is detected in the vehicle C4. On the other hand, as a result of the determination, the millimeter wave W is not transmitted from the vehicles C1, C2, and C3 that do not have the radar sensor 1 capable of transmitting the millimeter wave “northwest”.

  Next, as shown in FIG. 6, it is assumed that a certain time has elapsed and the elapsed time T from a predetermined time (noon here) is 6 or more and less than 7. At this time, when a new time synchronization signal is received in the vehicles C1 to C4, “southwest” is assigned as a direction in which the millimeter wave is transmitted. And in vehicles C1-C4, direction information acquisition part 43 judges whether radar sensor 1 which can transmit a millimeter wave exists in the direction of a "southwest" area, and as a result of judgment, this "southwest" area The millimeter wave W is transmitted only from the vehicles C1 and C2 having the radar sensor 1 capable of transmitting the millimeter wave in the direction of. When the millimeter wave W is transmitted from the vehicle C2, the presence of the vehicle C1 is detected in the vehicle C2. On the other hand, as a result of the determination, the millimeter wave W is not transmitted from the vehicles C3 and C4 that do not have the radar sensor 1 capable of transmitting the millimeter wave “southwest”.

  Next, as shown in FIG. 7, it is assumed that a period of time has elapsed and an elapsed time T from a predetermined time (noon here) is 7 or more and less than 8. At this time, when a new time synchronization signal is received in the vehicles C1 to C4, “southeast” is assigned as the direction in which the millimeter wave is transmitted. And in vehicles C1-C4, direction information acquisition part 43 judges whether radar sensor 1 which can transmit a millimeter wave exists in "southeast", and transmits a millimeter wave to "southeast" as a result of determination. The millimeter wave W is not transmitted from the vehicles C1 to C4 that do not have the possible radar sensor 1. In this case, the radar sensors 1 in the vehicles C1 to C4 may temporarily stop the millimeter wave reception process (that is, the time division control may be performed), or by continuing the reception process. You may be in the state which can detect presence by receiving the millimeter wave from another vehicle.

  Here, when the reception process is continued without time division control, it is determined whether the received millimeter wave is a millimeter wave transmitted from another vehicle, and is a millimeter wave transmitted from another vehicle. Is a process based on the determination result (for example, a process for determining that the received millimeter wave is not adopted or a positional relationship in which the other vehicle is facing the host vehicle, then the millimeter wave in this direction. When the transmission schedule is reached, control is performed using an algorithm that performs a process of deciding to carefully scan.

(4) Processing Procedure of Millimeter Wave Transmission Control Next, a processing procedure of millimeter wave transmission control executed by the interference prevention radar apparatus 10 will be described with reference to FIG. FIG. 8 is a flowchart for explaining a processing procedure of millimeter wave transmission control executed by the interference prevention radar apparatus 10. The process shown in the flowchart of FIG. 8 is repeatedly executed at predetermined time intervals from when the power of the interference prevention radar apparatus 10 is turned on until the process is started and then turned off.

  First, the synchronization signal acquisition unit 42 extracts and receives the time synchronization signal used to synchronize with other interference prevention radar devices that transmit millimeter waves from the latitude and longitude information acquired by the GPS 2 (step S01). ).

  Next, based on the direction measured by the geomagnetic compass 3, the direction information acquisition unit 43 detects and acquires a transmission direction that is a direction from which the millimeter wave is transmitted by the radar sensor 1 (step S02).

  Then, only when the direction corresponding to the time synchronization signal received by the synchronization signal acquisition unit 42 and the transmission direction detected by the direction information acquisition unit 43 coincide with each other, the time division drive control unit 41 matches this direction. In order to transmit the millimeter wave, the millimeter wave is transmitted by controlling to switch to the radar sensor 1 capable of transmitting the millimeter wave in the direction (step S03). As a result, a series of processing ends, and the process proceeds to step S01 again.

(5) Operational effects of the present embodiment Next, the operational effects of the present embodiment will be described. According to this embodiment, a time synchronization signal used for transmitting a millimeter wave in synchronization with another interference prevention radar apparatus is received, and the millimeter wave is transmitted only in the direction corresponding to the time synchronization signal. Thus, the radar sensor 1 is controlled. Thus, the millimeter wave transmission timing is limited by the timing indicated by the time synchronization signal and the millimeter wave transmission possible direction determined by a predetermined time zone as shown in FIG.

  Therefore, as shown in FIG. 5, even when the vehicle C4 equipped with the interference prevention radar device 10 is traveling and facing the other vehicle C3 equipped with another interference prevention radar device, Each of the vehicles C3 and C4 is transmitted only from a vehicle (here, the vehicle C4) capable of transmitting the millimeter wave W only in the same direction (here, “northwest”) corresponding to the time synchronization signal. No radio wave interference. As a result, radio wave interference with other devices that transmit millimeter waves can be prevented more reliably, and the ambient environment can be detected more accurately by millimeter waves.

  In addition, since the millimeter wave W is transmitted only in the same direction corresponding to the time synchronization signal (here, “northwest”), the number of radar sensors 1 installed outside one vehicle is larger. Even in this case, radio wave interference can be more reliably prevented without changing the scheduling in each radar sensor 1.

  Further, since the radar sensor 1 is controlled based on the transmission direction detected by the direction information acquisition unit 43, the direction in which the millimeter wave is transmitted can be more accurately controlled.

(6) Modified Example Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, as shown in FIG. 3, an area divided into eight directions is used, but the number of directions is not particularly limited, and “east-northeast”, “east-southeast” , “South-southeast”, “south-south-west”, “west-south-west”, “west-north-west”, “north-north-west”, “north-north-east” can be used together, or they may not be equally divided.

  In the above embodiment, as shown in FIG. 2, until the elapsed time T reaches 8 (described as the second “0”) after the time synchronization signal is received at a predetermined time (for example, noon). Although the time synchronization signal is received seven times by the synchronization signal acquisition unit 42, the reception frequency of the time synchronization signal may be reduced. In this case, for example, until the elapsed time T reaches 8 after the time synchronization signal is received at a predetermined time (for example, noon), the radar sensor 1 is based on the elapsed time information managed by the interference prevention radar apparatus 10. Can be switched.

  Moreover, in said embodiment, although the millimeter wave transmission possible direction is made into the aspect determined by a time slot | zone, it can also be set as the aspect which determines a millimeter wave transmission possible direction by the present position of the own vehicle. More specifically, on a highway or the like, since the traveling direction of a running vehicle is almost constant with no curves and no intersections, scheduling is performed in a relatively small number of directions such as two or four as possible millimeter wave transmission directions. In general roads, it is possible to switch to scheduling in a relatively large number of directions such as eight.

  In this case, the above scheduling may be incorporated in the interference prevention radar apparatus 10 in advance, or may be defined in advance as local scheduling information corresponding to each region, and the interference prevention radar apparatus 10 communicates with the outside. Thus, the scheduling information corresponding to each area of the destination can be acquired.

  ADVANTAGE OF THE INVENTION According to this invention, the interference prevention radar apparatus which can prevent more reliably radio wave interference with the other apparatus which transmits a radio wave can be provided.

DESCRIPTION OF SYMBOLS 1 ... Radar sensor, 2 ... GPS, 3 ... Geomagnetic compass, 4 ... Control part, 10 ... Interference prevention radar apparatus, 41 ... Time division drive control part, 42 ... Synchronization signal acquisition part, 43 ... Direction information acquisition part, C1- C4 ... vehicle, R ... roadway, W ... millimeter wave.

Claims (2)

An interference prevention radar device that has a radar sensor that transmits an electromagnetic wave and receives a reflected wave with respect to the electromagnetic wave, and detects an ambient environment based on the received reflected wave,
Receiving means for receiving a synchronization signal used for transmitting an electromagnetic wave by the radar sensor in synchronization with another radar device for transmitting an electromagnetic wave;
Control means for controlling the radar sensor so that an electromagnetic wave is transmitted in a direction corresponding to the synchronization signal received by the receiving means;
An interference prevention radar apparatus comprising: It further comprises detection means for detecting a direction of transmission in which electromagnetic waves are transmitted by the radar sensor,
The control means controls the radar sensor based on the transmission direction detected by the detection means;
The interference prevention radar apparatus according to claim 1.

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