JP5479761B2 - In-vehicle monopulse radar system - Google Patents

Description

  The present invention relates to an on-vehicle monopulse radar device that is mounted on a vehicle and detects an object.

  Conventionally, in an in-vehicle radar device, a noise level with respect to a reflected wave greatly varies depending on a road condition during traveling, a state of surrounding buildings, and environmental conditions such as weather. As a result, the object could not be detected and could be overlooked, or could be erroneously determined as the object. In order to solve such a problem, Patent Document 1 discloses a mechanism for periodically estimating and updating a threshold used for vehicle detection from a received signal.

  In addition, the beam scanning radar of Patent Document 2 includes a motor and a reflector for controlling the beam direction, and the motor is operated to sequentially change the direction of the reflector to perform scanning. It describes that an object in an area is detected, and the distance and speed of the object are measured. The radar of Patent Document 2 includes an interference detection means for detecting an interference wave. A direction in which the interference wave is detected is determined in advance, and a beam is emitted when the receiving antenna is in a predetermined direction. It describes stopping and detecting the interference wave received from that direction.

Japanese Patent Laid-Open No. 05-323014 JP 2004-163340 A

  However, the above conventional technique has the following problems. In the radar apparatus described in Patent Document 1, a noise level is updated by comparing a noise level stored so far with a reception level, and a value obtained by adding a predetermined value is used as a threshold value. However, since the transmission wave is output from the radar device also when the noise level is measured, there is a problem that the transmission wave is mixed into the reception wave and the noise level cannot be measured correctly.

  Further, in the radar device described in Patent Document 2, interference waves are detected using a highly directional antenna only in a predetermined direction, but in-vehicle radar devices generate noise and the like. The external environment such as the position of the external device that is the source and the topography of the tunnel and the road shoulder that cause unnecessary reflected waves constantly change as the vehicle travels. For this reason, in a vehicle-mounted radar device, there is no suitable direction for measuring unnecessary signals. Further, Patent Document 2 uses a highly directional receiving antenna, but such a receiving antenna can receive only unnecessary signals propagating from a limited range in a predetermined direction, and correctly measures the noise level. It is not possible. As a result, an inappropriate threshold value is used, and there is a problem that it is impossible to appropriately detect an object.

  Furthermore, in the radar apparatus of Patent Document 2, since the direction of the scanning beam is controlled using a reflector that mechanically operates, the direction of the scanning beam cannot be changed in a short time. For this reason, it is extremely difficult to measure and update the noise level in a short cycle such as 100 ms. As a result, it is not possible to respond quickly to changes in unnecessary waves that are affected by sudden changes in the surrounding environment, such as tunnel changes, changes in shoulder topography, and changes in weather such as rain and snow. There are problems such as oversight of objects and false detection.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an in-vehicle monopulse radar apparatus that can remove an unnecessary signal contained in a received wave and correctly detect an object. .

  In order to solve the above-described problem, a first aspect of the in-vehicle monopulse radar device according to the present invention includes a transmission processing unit that generates a pulse and generates a transmission signal by up-converting the pulse to a predetermined frequency band. A transmission antenna that receives and radiates the transmission signal from the transmission processing unit, a reception antenna that receives a reflected wave reflected by an object from the transmission antenna, and a reception from the reception antenna A reception processing unit that inputs a signal, down-converts the signal to convert it to a voltage signal, an AD conversion unit that receives the voltage signal from the reception processing unit, converts the signal into an analog signal, and outputs a digital value; An arithmetic processing unit for detecting the object by inputting the digital value from an AD conversion unit, a storage unit for storing unnecessary signal measurement values, and inputting the unnecessary signal measurement values from the storage unit, An unnecessary signal determining unit that determines an unnecessary signal correction value, and the arithmetic processing unit operates the transmission processing unit to radiate the transmission signal from the transmitting antenna, and the unnecessary signal determining unit. The object detection step for detecting the object by subtracting the unnecessary signal correction value from the digital value input from the AD converter and inputting the unnecessary signal correction value from the AD conversion unit, and the object detection step Every time the first predetermined number of times is performed, the transmission processing unit is stopped, the digital value is input from the AD conversion unit, and an unnecessary signal measurement step is performed in which the digital value is stored in the storage unit as an unnecessary signal measurement value. Features.

  In the in-vehicle monopulse radar device of the present invention, the digital value converted from the received signal is corrected with the unnecessary signal correction value updated every first predetermined number of times in the object detection step, and the object is detected. Therefore, it becomes possible to detect an object with high accuracy by reducing the influence of unnecessary signals.

  Another aspect of the on-vehicle monopulse radar device according to the present invention is characterized in that the arithmetic processing unit calculates a distance, an angle, and a relative speed to the object when detecting the object. By calculating the distance to the object, the angle, and the relative speed when the object is detected, advanced operation control is possible.

  In another aspect of the on-vehicle monopulse radar device according to the present invention, the first predetermined number of times is 2 times or more and 50 times or less. Thus, the updated unnecessary signal measurement value is used to detect the object two or more times, and the unnecessary signal correction value is updated by performing an unnecessary signal measurement step at an appropriate time interval.

  In another aspect of the in-vehicle monopulse radar device according to the present invention, the storage unit has a capacity for storing the unnecessary signal measurement value for a second predetermined number of times, and exceeds the second predetermined number of times. When an unnecessary signal measurement value is input, the digital value input from the arithmetic processing unit is discarded in order from the oldest one, and the digital value is stored. By configuring the capacity of the storage unit in this way, it is possible to increase the accuracy of the unnecessary signal correction value calculated by the unnecessary signal determination unit.

  In another aspect of the in-vehicle monopulse radar device according to the present invention, the unnecessary signal determination unit reads the unnecessary signal measurement values for the second predetermined number of times from the storage unit, and averages the read values to determine the unnecessary signal. A correction value is calculated. By calculating an unnecessary signal correction value by averaging a plurality of unnecessary signal measurement values, it becomes possible to reduce the variation of the unnecessary signal correction value and to detect the object with higher accuracy.

  In another aspect of the on-vehicle monopulse radar device according to the present invention, the storage unit is configured by a non-volatile memory, stores the unnecessary signal measurement value even after the power is turned off, and determines the unnecessary signal when the power is turned on again. The unit reads the unnecessary signal measurement value from the storage unit and calculates the unnecessary signal correction value. Thereby, even before the unnecessary signal is measured after the power is turned on, it is possible to correct the received signal and detect the object.

  Another aspect of the on-vehicle monopulse radar device according to the present invention is characterized in that the object detection step and the unnecessary signal measurement step are each performed within a time of 20 ms. By detecting the object and measuring the unnecessary signal within such a short time, it becomes possible to update the unnecessary signal correction value in response to a change in environmental conditions quickly and detect the object with high accuracy. It becomes possible to do.

  According to the on-vehicle monopulse radar device of the present invention, an unnecessary signal included in a received wave is measured at a predetermined time interval, and when detecting an object, an unnecessary signal measured in advance is removed from the received signal. Since the object is determined, the object can be detected with high accuracy.

1 is a block diagram showing a configuration of a vehicle-mounted monopulse radar device according to a first embodiment of the present invention. It is a flowchart which shows the flow of the whole process performed with the vehicle-mounted monopulse radar apparatus of this embodiment. It is a flowchart which shows the flow of the process in measurement of an unnecessary signal. It is a flowchart which shows the flow of the process in the detection of the normal target object.

  An in-vehicle monopulse radar device according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Each component having the same function is denoted by the same reference numeral for simplification of illustration and description.

  A configuration of a vehicle-mounted monopulse radar apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a vehicle-mounted monopulse radar device 100 according to the present embodiment. The on-vehicle monopulse radar device 100 according to the present embodiment includes an arithmetic processing unit 101 that controls the operation of each processing unit and detects an object, a transmission unit 110 that performs processing for transmitting a transmission signal, and reception. And a receiving unit 120 that performs signal processing. Further, the in-vehicle monopulse radar apparatus 100 includes an unnecessary signal determination unit 102 and a storage unit 103 so that unnecessary signals can be appropriately processed.

  The transmission unit 110 includes a transmission processing unit 111 and a transmission antenna 112. When the transmission processing unit 111 receives a transmission instruction as the control signal 11 from the arithmetic processing unit 101, the transmission processing unit 111 generates a pulse signal for detecting an object at a predetermined cycle. The pulse signal is up-converted with a carrier wave having a predetermined frequency to convert it to a transmission signal 12, and the transmission signal 12 is output to the transmission antenna 112.

  When the transmission signal 112 is input from the transmission processing unit 111, the transmission antenna 112 radiates it in the air. In the present embodiment, the in-vehicle monopulse radar device 100 is configured to be able to measure an angle in a wide angle range, and in response to this, the transmitting antenna 112 is, for example, about − to the left and right about the traveling direction of the vehicle. It is assumed that the transmission signal is radiated in the air in the range of 60 degrees to +60 degrees.

  The reception unit 120 on the reception side includes two sets of reception antennas 121a / b, two sets of reception processing units 122a / b, and two sets of AD conversion units 123a / b. The radar apparatus 100 according to the present embodiment is configured to include two systems of reception systems including a reception antenna, a reception processing unit, and an AD conversion unit in order to measure an angle using a monopulse method. Similarly to the transmitting antenna 112, the receiving antenna 121a / b is configured to be able to receive within a range of about −60 degrees to +60 degrees with the traveling direction of the vehicle as the center. Each reception signal 21a / b received by the reception antenna 121a / b is transmitted to the reception processing unit 122a / b to which each reception antenna is connected.

  The reception processing unit 122a / b performs the following processing upon receiving a processing start instruction based on the control signal 24a / b from the arithmetic processing unit 101. That is, the reception processing unit 122a / b first receives each reception signal 21a / b from the reception antenna 121a / b, down-converts each of the reception signals 21a / b, and converts them into voltage signals 22a / b. The voltage signals 22a / b converted by each are output to the AD conversion units 123a / b connected to the respective reception processing units 122a / b.

  Similarly to the reception processing unit 122a / b, the AD conversion unit 123a / b also starts the following processing based on the control signal 25a / b from the arithmetic processing unit 101. That is, the AD conversion unit 123a / b AD-converts the voltage signal 22a / b input from the reception processing unit 122a / b to obtain a digital value 23a / b, and outputs this to the arithmetic processing unit 101. The control signal 25a / b output from the arithmetic processing unit 101 is output almost simultaneously with the control signal 24a / b output to the reception processing unit 122a / b.

  The arithmetic processing unit 101 receives the digital value 23a / b from the AD conversion unit 123a / b and determines the presence / absence of an object. As a result, when the object is detected, position information and relative speed of the object are calculated. In the in-vehicle monopulse radar device 100 according to the present embodiment, the receiving unit 120 includes two systems of receiving antennas 121a / b, a reception processing unit 122a / b, and an AD conversion unit 123a / b. Two digital values 23 a / b processed by the above system are output to the arithmetic processing unit 101. Thereby, in the arithmetic processing unit 101, in addition to the distance to the object, the position angle of the object (shift angle from the traveling direction) is obtained from the two digital values 23a / b according to the monopulse method as the position information of the object. It becomes possible to detect. In addition, when it is not necessary to measure the position angle of the target object, the receiving unit 120 can be configured with one system of receiving antenna, reception processing unit, and AD conversion unit.

  As described above, the in-vehicle monopulse radar device 100 according to the present embodiment includes a transmission antenna 112 that can transmit at a wide angle and a reception antenna 121a / b that can receive a signal radiated from a wide angle direction. Thus, the object can be detected in a wide angle range. On the other hand, since the wide-angle receiving antenna 121a / b is used, the receiving antenna 121a / b receives an unnecessary signal other than the reflected wave from the object from a wide-angle direction. In order to reduce the influence of such unnecessary signals, the in-vehicle monopulse radar device 100 of this embodiment includes an unnecessary signal determination unit 102 and a storage unit 103 in addition to the above configuration. Below, the structure for processing an unnecessary signal in the vehicle-mounted monopulse radar apparatus 100 will be described.

  The on-vehicle monopulse radar apparatus 100 measures an unnecessary signal every predetermined number of times (first predetermined number of times) of detection of an object separately from the detection of the object that is normally performed. The value is stored in the storage unit 103. The predetermined number of times (first predetermined number of times) is preferably 2 times or more and 50 times or less from the viewpoint of performing efficient object detection and updating the unnecessary signal correction value at an appropriate time interval. When detecting a normal object, the unnecessary signal measurement value is read from the storage unit 103 to calculate an unnecessary signal correction value and subtracted from the received signal to reduce the influence of the unnecessary signal. Has been. In this embodiment, in order to prevent the unnecessary signal including the reflected wave of the transmission signal 12 from being measured, when measuring the unnecessary signal, the transmission unit 110 is stopped and only the reception unit 120 side is operated. ing. As a result, only unnecessary signals can be measured and stored in the storage unit 103.

  The unnecessary signal determination unit 102 reads the unnecessary signal measurement value from the storage unit 103 and calculates the unnecessary signal correction value from the storage unit 103 when the request signal 31 is input from the calculation processing unit 101 during normal object detection. The data is output to the processing unit 101. The storage unit 103 stores the two digital values 23a / b input from the AD conversion unit 123a / b during measurement of the unnecessary signal as unnecessary signal measurement values, and the unnecessary signal determination unit 102 stores the two unnecessary signal measurement values. Is read from the storage unit 103. Then, the two unnecessary signal measurement values that have been read out are averaged to determine an unnecessary signal correction value, which is output to the arithmetic processing unit 101. Alternatively, a result of measuring unnecessary signals for a predetermined number of times (second predetermined number) is stored in the storage unit 103, and the unnecessary signal determination unit 102 reads unnecessary signal measurement values for the second predetermined number of times. It is also possible to calculate the unnecessary signal correction value using. In addition, in order to separately correct the two systems of digital values 23a / b, it is possible to average the unnecessary signal measurement values stored in the storage unit 103 and output the averaged values to the arithmetic processing unit 101. is there.

  When the arithmetic processing unit 101 controls the reception unit 120 to measure an unnecessary signal, the arithmetic processing unit 101 inputs the digital value 23a / b from the AD conversion unit 123a / b and stores it in the storage unit 103. The storage unit 103 inputs and stores two digital values 23a / b from the arithmetic processing unit 101 every time an unnecessary signal is measured, and allows this to be stored up to a predetermined number of times (second predetermined number). Is preferred. When the digital values 23a / b for the predetermined number of times are stored, it is preferable that the latest measurement results are stored by sequentially discarding the oldest ones thereafter. The storage unit 103 is preferably a non-volatile memory. As a result, since the data of the past unnecessary signal is stored in the storage unit 103 even immediately after the start, the unnecessary signal determination unit 102 uses the past data stored in the storage unit 103 to correct the unnecessary signal correction value. The initial value of can be determined.

  When the unnecessary signal is measured, the arithmetic processing unit 101 outputs a control signal 11 for stopping the processing to the transmission processing unit 111, while the reception processing unit 122a / b and the AD conversion unit 123a / b. Outputs control signals 24a / b and 25a / b for starting the processing. Thereby, the reception processing unit 122a / b and the AD conversion unit 123a / b process the reception wave that does not include the reflected wave of the transmission signal from the transmission unit 110, and the arithmetic processing unit 101 receives the signal from the AD conversion unit 123a / b. The input digital value 23a / b can be stored in the storage unit 103 as an unnecessary signal measurement value.

  On the other hand, when performing normal object detection, the arithmetic processing unit 101 outputs a control signal 11 for causing the transmission processing unit 111 to start processing, and also outputs an unnecessary signal correction value to the unnecessary signal determining unit 102. The request signal 31 for requesting is output. When the unnecessary signal determination unit 102 calculates the unnecessary signal correction value 32 in response to the request signal 31 and outputs it to the arithmetic processing unit 101, the arithmetic processing unit 101 outputs the digital value 23a input from the AD conversion unit 123a / b. Used to correct / b. That is, when the transmission processing unit 111 starts processing and a transmission signal is emitted from the transmission antenna 112, the digital value 23a / b input by the arithmetic processing unit 101 from the AD conversion unit 123a / b In addition to reflected waves reflected by objects, unnecessary signals are also included. Therefore, the arithmetic processing unit 101 corrects the digital value 23a / b input from the AD conversion unit 123a / b by subtracting the unnecessary signal correction value 32 input from the unnecessary signal determination unit 102. Thereby, it becomes possible to detect the position, relative speed, and angle of an object with high accuracy by reducing the influence of unnecessary signals.

  In the on-vehicle monopulse radar device 100 according to the present embodiment, the transmission processing unit 111 can be stopped or started only by the control signal 11 from the arithmetic processing unit 101, and therefore the transmission signal 12 is transmitted from the transmission antenna 112. Control to radiate and stop can be performed at high speed. As a result, unnecessary signals can be measured at extremely short time intervals, for example, 100 ms. In this case, for example, when the vehicle speed is set to 100 km / h, an unnecessary signal is measured for every travel distance of less than 3 m, and a change in the unnecessary signal accompanying a change in the surrounding environment can be immediately reflected in the detection of the object. It becomes possible.

  Next, processing performed by the on-vehicle monopulse radar device 100 of the present embodiment will be described in more detail using the flowcharts shown in FIGS. In the following, as an example of a cycle for performing measurement, it is assumed that measurement of an unnecessary signal is performed once every 100 ms, and normal object detection is performed four times during that time. That is, the reception unit 120 processes the reception signal at a cycle of 20 ms, and the transmission unit 110 also processes the transmission signal at a cycle of 20 ms. However, the transmission unit 110 stops normal transmission by stopping transmission at a rate of once every five times. Stop detecting the object and measure unnecessary signals.

  FIG. 2 is a flowchart showing the overall flow of processing performed by the in-vehicle monopulse radar device 100. When the vehicle-mounted monopulse radar apparatus 100 is turned on (step S0), the measurement number N is set to 0 and initialization is performed (step S1). The number of times of measurement N is used to determine whether to perform unnecessary signal measurement or object detection. After the measurement count N is initialized to 0, an unnecessary signal is measured in step S2. Here, immediately after the power is turned on, the unnecessary signal is first measured unconditionally, and the unnecessary signal measurement value stored in the storage unit 103 is updated to the latest one. Thereby, in the detection of the normal object performed after the next time, the reception signal can be corrected using the unnecessary signal correction value calculated from the latest unnecessary signal measurement value.

  When the measurement of the unnecessary signal in step S2 ends, the process waits until the next cycle is reached. When the next period of 20 ms is reached, it is first determined in step S3 whether the number of measurements N has reached 4. Since the number of times of measurement N is 0 in the next cycle in which the unnecessary signal is measured in step S2, the determination in step S3 is “NO” and the process proceeds to the next step S4. In step S4, normal object detection is performed. When the detection of the normal object in step S4 is completed, 1 is added to the number N of times of measurement in the next step S5 to update it. The number N of times of measurement is the number of times that a normal object is detected after measuring an unnecessary signal. After that, it waits again until the next cycle is reached.

  Hereinafter, when the number of times N is incremented by 1 in step S5 and the value of N reaches 4 (first predetermined number), the determination in step S3 is “YES” for the first time in the next cycle, and the process proceeds to step S1. The number of measurements N is initialized again to 0, and unnecessary signals are measured again in the next step S2. In this way, in the on-vehicle monopulse radar device 100 according to the present embodiment, a normal object is detected at a predetermined period (for example, 20 ms), and at the same time, unnecessary signals are measured at another period (for example, 100 ms). Configured to do. As a result, the unnecessary signal measurement values stored in the storage unit 103 are appropriately updated to the latest ones corresponding to changes in the surrounding environment and the like. It is possible to correct with the unnecessary signal correction value. As a result, it is possible to prevent an object from being overlooked or erroneously detected.

  Next, measurement of unnecessary signals in step S2 in FIG. 2 will be described in detail with reference to FIG. FIG. 3 is a flowchart showing a flow of processing in measurement of unnecessary signals. When measurement of the unnecessary signal is started, first, in step S11, the arithmetic processing unit 101 outputs a control signal 11 for stopping the processing to the transmission processing unit S111. Thereby, the transmission process part 111 stops the process (step S12). In step S13, control signals 24a / b and 25a / b for starting processing are output from the arithmetic processing unit 101 to the reception processing unit 122a / b and the AD conversion unit 123a / b. Thereby, in step S14, the reception processing unit 122a / b receives the reception signal 21a / b from the reception antenna 121a / b, down-converts it, and outputs the voltage signal 22a / b. In the next step S15, the AD conversion unit 123a / b receives the voltage signal 22a / b from the reception processing unit 122a / b, AD converts this, and outputs a digital value 23a / b. Further, in step S16, when the arithmetic processing unit 101 inputs the digital value 23a / b from the AD conversion unit 123a / b, it is stored in the storage unit 103 as an unnecessary signal measurement value.

  Furthermore, the normal detection of the object in step S4 in FIG. 2 will be described in detail with reference to FIG. FIG. 4 is a flowchart showing a flow of processing in normal object detection. When detection of a normal object is started, first, in step S21, the control processing unit 101 outputs a control signal 11 for starting processing to the transmission processing unit 111. Thereby, the transmission processing unit 111 generates a pulse signal for detecting the object, up-converts the pulse signal, and outputs the pulse signal as the transmission signal 12 to the transmission antenna 112 (step S22). In step S23, the radio wave of the transmission signal 12 is emitted from the transmission antenna 112 into the air.

  In the next step S24, the arithmetic processing unit 101 outputs control signals 24a / b and 25a / b for starting processing to the reception processing unit 122a / b and the AD conversion unit 123a / b. Thereby, in step S25, the reception signal received by the reception antenna 121a / b is output to the reception processing unit 122a / b. In step S26, the reception processing unit 122a / b down-converts the reception signal 21a / b input from the reception antenna 121a / b and outputs a voltage signal 22a / b. In the next step S27, the AD conversion unit 123a / b receives the voltage signal 22a / b from the reception processing unit 122a / b, AD converts this, and outputs a digital value 23a / b. In step S28, the arithmetic processing unit 101 inputs the digital value 23a / b from the AD conversion unit 123a / b. In step S <b> 29, the arithmetic processing unit 101 outputs an unnecessary signal correction value request signal 31 to the unnecessary signal determination unit 102.

  In step 30, when the unnecessary signal determination unit 102 receives a request for the unnecessary signal correction value from the arithmetic processing unit 101, the unnecessary signal measurement value is read from the storage unit 103 and averaged to calculate the unnecessary signal correction value 32. The unnecessary signal correction value 32 is output to the arithmetic processing unit 101. In step S31, the arithmetic processing unit 101 subtracts the unnecessary signal correction value 32 input from the unnecessary signal determination unit 102 from the digital value 23a / b input from the AD conversion unit 123a / b, and detects the object. Further, when the object is detected in step S31, the position (distance, angle) and relative speed of the object are calculated in step S32.

  The description in the present embodiment shows an example of a vehicle-mounted monopulse radar device according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the on-vehicle monopulse radar device according to the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Vehicle-mounted monopulse radar apparatus 101 Operation processing part 102 Unnecessary signal determination part 103 Storage part 110 Transmission part 111 Transmission processing part 112 Transmission antenna 120 Reception part 121 Reception antenna 122 Reception processing part 123 AD conversion part

Claims (7)

An in-vehicle monopulse radar device configured to emit a monopulse transmission signal at a predetermined period and detect the target object by receiving and processing a reflected wave reflected by the target object. There,
A transmission processing unit that generates a pulse and up-converts the pulse to a predetermined frequency band to generate a transmission signal;
A transmission antenna that receives and radiates the transmission signal from the transmission processing unit;
A receiving antenna for receiving external radio waves ,
A reception processing unit that receives a reception signal from the reception antenna, down-converts it, and converts it into a voltage signal;
An AD converter that inputs the voltage signal from the reception processing unit, AD converts the voltage signal, and outputs a digital value;
An arithmetic processing unit that inputs the digital value from the AD conversion unit and performs predetermined arithmetic processing ;
A storage unit for storing unnecessary signal measurement values;
An unnecessary signal determination unit that inputs the unnecessary signal measurement value from the storage unit and determines an unnecessary signal correction value therefrom,
The arithmetic processing unit includes:
While operating the transmission processing unit to radiate the transmission signal from the transmission antenna and input a digital value obtained by processing the reception signal received by the reception antenna by the reception processing unit and the AD conversion unit , An object detection process for determining and inputting the unnecessary signal correction value in the unnecessary signal determination unit , and subtracting the unnecessary signal correction value from the digital value to detect the object ;
Input a digital value obtained when the reception signal received by the reception antenna without operating the transmission processing unit is subjected to the same processing as the object detection processing by the reception processing unit and the AD conversion unit, And performing unnecessary signal measurement processing for storing a value in the storage unit as the unnecessary signal measurement value,
The vehicle-mounted monopulse radar apparatus, wherein the unnecessary signal measurement process is performed once every time the object detection process is performed a first predetermined number of times in the predetermined cycle . The in-vehicle monopulse Doppler radar device according to claim 1, wherein the arithmetic processing unit calculates a distance, an angle, and a relative speed to the object when detecting the object. The on-vehicle monopulse Doppler radar device according to claim 1 or 2, wherein the first predetermined number of times is 2 times or more and 50 times or less. The storage unit has a capacity to store the unnecessary signal measurement value for a second predetermined number of times, and when the unnecessary signal measurement value is input beyond the second predetermined number of times, the oldest one is discarded in order. 4. The in-vehicle monopulse Doppler radar device according to claim 1, wherein the digital value input from the arithmetic processing unit is stored. 5. The said unnecessary signal determination part reads the said unnecessary signal measured value for the said 2nd predetermined number of times from the said memory | storage part, averages this, and calculates the said unnecessary signal correction value, It is characterized by the above-mentioned. Monopulse Doppler radar device for in-vehicle use. The storage unit is configured by a non-volatile memory, stores the unnecessary signal measurement value even after the power is turned off, and when the power is turned on again, the unnecessary signal determination unit reads the unnecessary signal measurement value from the storage unit and The in-vehicle monopulse radar device according to any one of claims 1 to 5, wherein an unnecessary signal correction value is calculated. The on-vehicle monopulse Doppler radar device according to any one of claims 1 to 6, wherein the object detection process and the unnecessary signal measurement process are each performed within a time period of 20 ms.

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