JP7317539B2 - Radar device and target detection method - Google Patents

Description

The present invention relates to a radar device and a target detection method.

2. Description of the Related Art Radar devices that transmit electromagnetic waves and receive reflected waves from targets (objects to be detected) to detect (recognize the existence of) targets are widely used. In order to improve the sensitivity of a radar device and detect a target existing at a long distance, it is effective to increase the output of the transmitted wave. However, increasing the output of the transmitted wave has the disadvantage that the resolution of targets existing at a short distance (the ability to separately recognize a plurality of targets) decreases.

Therefore, by transmitting a low-power pulse-shaped transmission wave for short-range and a high-power pulse-shaped transmission wave for long-distance transmission with a gap between them, it is possible to improve both short-range resolution and long-range sensitivity. Techniques for doing so are known. However, in a radar device that uses a short-range transmission wave and a long-range transmission wave, when a target exists at an intermediate distance, the reflected wave of the short-range transmission wave and the reflected wave of the long-range transmission wave overlap. As a result, there is a possibility that the target cannot be detected correctly.

On the other hand, in Patent Document 1, by making the frequency of the transmission wave for short distance and the frequency of the transmission wave for long distance different, the reflected wave of the transmission wave for short distance and the reflected wave of the transmission wave for long distance A technique for separating the frequency of the two has been proposed. Further, in Patent Document 2, transmission and reception are repeatedly performed while changing the transmission interval between the short-range transmission wave and the long-range transmission wave, and by removing components existing at different time positions in a plurality of received signals, Techniques for extracting a reflected wave signal of one transmission wave have been proposed.

JP 2011-247776 A JP-A-61-133885

The method described in Patent Literature 1 requires an extremely high-speed IC for switching frequencies, which is disadvantageous in that the radar apparatus becomes expensive. On the other hand, in the method described in Patent Document 2, since it is necessary to perform transmission and reception a plurality of times for one detection, there is an inconvenience that the time required for detection becomes long.

SUMMARY OF THE INVENTION An object of the present invention is to provide a radar apparatus and a target detection method that can reduce interference between a reflected wave of a short-range transmission wave and a reflected wave of a long-range transmission wave with a simple configuration.

A radar apparatus according to the present invention includes a transmission unit that transmits a first transmission wave and a second transmission wave having a higher output than the first transmission wave at predetermined time intervals, a reflected wave of the first transmission wave and the a receiving unit for receiving a reflected wave of the second transmission wave; a detection unit for detecting a target based on the reflected wave of the first transmission wave and the reflected wave of the second transmission wave received by the receiving unit; an index acquisition unit for acquiring an output index having a correlation with an output of a first transmission wave; and an output of the first transmission wave transmitted by at least the transmission unit based on the output index acquired by the index acquisition unit. and an output control unit that controls the

Further, a target detection method according to the present invention includes the step of transmitting a first transmission wave and a second transmission wave having a higher output than the first transmission wave at predetermined time intervals; a step of receiving a wave and a reflected wave of the second transmission wave; and a step of detecting a target based on the reflected wave of the first transmission wave and the reflected wave of the second transmission wave received in the receiving step. , acquiring an output index having a correlation with the output of the first transmission wave; and controlling at least the output of the first transmission wave based on the output index.

ADVANTAGE OF THE INVENTION According to this invention, the radar apparatus and target detection method which can reduce the interference of the reflected wave of the transmission wave for short distances, and the reflected wave of the transmission wave for long distances by simple structure can be provided.

1 is a block diagram showing the configuration of a radar device according to a first embodiment of the present invention; FIG. 2 is a diagram showing an envelope waveform of a transmission wave of the radar device of FIG. 1; FIG. 2 is a graph showing changes in circuit characteristics according to temperature of the radar device of FIG. 1; 2 is a flow chart showing a procedure of target detection by the radar device of FIG. 1; It is a block diagram which shows the structure of the radar apparatus of 2nd Embodiment of this invention. FIG. 6 is a flow chart showing a procedure of target detection by the radar device of FIG. 5; FIG. It is a block diagram which shows the structure of the radar apparatus of 3rd Embodiment of this invention. It is a block diagram which shows the structure of the radar apparatus of 4th Embodiment of this invention.

A radar device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a radar device 1 according to the first embodiment of the invention.

The radar apparatus 1 of the present embodiment has a pulse-shaped first transmission wave P1 and a pulse-shaped second transmission wave P1 having a larger output than the first transmission wave, as shown in FIG. A transmitter 2 that sequentially transmits the transmission wave P2, a receiver 3 that receives the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 and converts them into digital signals, and the receiver 3 receives A detection unit 4 that detects a target based on the digital signals of the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2, and obtains an output index that has a correlation with the output of the first transmission wave P1. an index acquisition unit 5 that measures the internal temperature of the radar device 1; , and a temperature sensor 7 that provides the measured temperature to the index acquisition unit 5 as an output index. The detection unit 4, the index acquisition unit 5, and the output control unit 6 can be configured by executing appropriate programs in a single computing device having a microprocessor, memory, and the like. The detection unit 4, the index acquisition unit 5, and the output control unit 6 are functionally distinguished, and may not be distinguished in terms of physical configuration or program configuration.

The transmission unit 2 includes an original signal generation unit 21 that generates an original signal that determines the reference amplitude and pulse width of the first transmission wave P1 and the second transmission wave P2, and based on the original signal generated by the original signal generation unit 21: a waveform signal forming circuit 22 for forming a waveform signal similar in shape to the envelope waveforms of the first transmission wave P1 and the second transmission wave P2; an offset circuit 23 for offsetting in accordance with an offset circuit 23, an oscillator 24 for generating a local oscillator signal with a predetermined carrier frequency, and the local oscillator signal generated by the oscillator 24 is multiplied by a waveform signal formed by a waveform signal forming circuit 22 for amplification. A configuration including a transmission amplifier 25 and a transmission antenna 26 for converting a signal output from the transmission amplifier 25 into a radio wave and transmitting the radio wave may be employed.

The original signal generation unit 21 generates an original signal for forming an envelope waveform that serves as a reference for the first transmission wave P1 and the second transmission wave P2. This original signal can be, for example, a signal having a rectangular waveform output by a digital circuit or a stepped waveform obtained by superimposing a rectangular waveform. In other words, the original signal generator 21 can be configured to form the original signal using a microprocessor or the like. Therefore, the original signal generator 21 can be implemented as one function of the same arithmetic device as the detector 4 , the index acquisition unit 5 and the output controller 6 .

The waveform signal forming circuit 22 converts the original signal output from the original signal generator 21 into a waveform signal, which is an electrical signal having a waveform similar to the envelope waveforms of the first transmission wave P1 and the second transmission wave P2. . The waveform signal formed by the waveform signal forming circuit 22 is an appropriate electric signal according to the configuration of the transmission amplification unit 25, specifically, an envelope waveform similar to the reference of the first transmission wave P1 and the second transmission wave P2. can be a current signal or a voltage signal having a waveform of Such a waveform signal forming circuit 22 can be configured to have a filter circuit for removing high frequency components from the original signal and an amplifier circuit for amplifying the original signal from which the high frequency components have been removed.

The offset circuit 23 offsets the value of the waveform signal output by the waveform signal forming circuit 22 according to a command signal from the output control section 6, which will be described later. Specifically, for example, when the waveform signal output by the waveform signal forming circuit 22 is a voltage signal including a voltage value, the offset circuit 23 includes a plurality of pull-up resistors and a circuit for digitally controlling their ON/OFF. is provided, and some or all of the pull-up resistors may be turned ON/OFF according to the command signal from the output control unit 6 . As a result, the offset circuit 23 controls the voltage value input from the waveform signal forming circuit 22 according to the command signal from the output control unit 6, thereby increasing the voltage output to the transmission amplification unit 25. offset (increase or decrease) the value or current value (voltage value/current value). Also, the offset voltage/current value can be the same voltage/current value regardless of the output timing of the first transmission wave P1 and the second transmission wave P2. A circuit that converts a voltage signal into a current signal may be used as such an offset circuit 23 . In addition, the offset circuit 23 is an addition circuit for adding the waveform signal from the waveform signal forming circuit 22 and the command signal from the output control unit 6, It can be configured by a multiplier circuit or the like that multiplies signals.

The oscillator 24 can be configured to have a well-known oscillator that generates and oscillates a high-frequency signal. The frequency of the local oscillator signal oscillated by the oscillator 24 can be selected as appropriate, and can be, for example, 1 GHz or more and 100 GHz or less.

The transmission amplifier 25 forms a power signal to be supplied to the transmission antenna 26 by amplifying the local oscillator signal generated by the oscillator 24 with an amplification factor corresponding to the waveform signal formed by the waveform signal forming circuit 22 . A well-known amplifier circuit can be used as the transmission amplifier 25 . In the following example, the transmission amplifier 25 amplifies the local oscillator signal with an amplification factor corresponding to the input current value, and the current value input to the transmission amplifier 25 is offset by the offset circuit 23. and

The transmission antenna 26 converts the power signal supplied from the transmission amplifier 25 into electromagnetic waves, and transmits the first transmission wave P1 and the second transmission wave P2. A well-known antenna can be used as the transmitting antenna 26 .

The receiving unit 3 includes a receiving antenna 31 that receives an electromagnetic wave and converts it into an electrical signal, a receiving amplification unit 32 that amplifies the electrical signal formed by the receiving antenna 31, and an amplitude component ( and an AD converter 34 for converting the intensity signal extracted by the demodulator 33 into a digital signal.

The receiving antenna 31 receives reflected waves of the first transmission wave P1 and the second transmission wave P2 transmitted by the transmission antenna 26 and converts them into electric signals. A well-known antenna can be used as the receiving antenna 31 .

The reception amplifier 32 amplifies the electrical signals of the reflected waves of the first transmission wave P<b>1 and the second transmission wave P<b>2 received by the reception antenna 31 . Further, the reception amplification section 32 may have a filter function (circuit configuration with small gain in the high frequency range) for removing high frequency components remaining in the output of the demodulation section 33, or the like.

The demodulator 33 uses the local oscillator signal generated by the oscillator 24 to remove the frequency component of the carrier wave from the electrical signal amplified by the reception amplifier 32, thereby generating an analog signal representing the strength change of the reflected wave signal. Extract the formation, ie the envelope wave. This demodulator 33 can be configured by a well-known multiplier circuit.

The AD conversion section 34 converts the analog signal amplified by the reception amplification section 32 into a digital signal and provides the detection section 4 with the digital signal. This AD converter 34 can be configured by a well-known AD converter.

The detection unit 4 analyzes the waveform of the received wave provided from the reception unit 3 to perform calculations for detecting the target. Specifically, when there is an intensity peak formed by the reflected wave of the first transmitted wave P1 or the second transmitted wave P2 in the received wave, it can be determined that there is a target reflecting the transmitted wave. can. In this case, by calculating the time from when the transmitting unit 2 transmits the first transmission wave P1 or the second transmitting wave P2 to when the receiving unit 3 receives the reflected wave, the distance from the radar device 1 to the target is calculated. Distance can be estimated.

As the output index acquired by the index acquiring unit 5, any value may be used as long as the output of the first transmission wave P1 can be estimated. In this embodiment, temperature information within the device is used. The output of the first transmission wave P1 transmitted by the transmitter 2 depends on the waveform signal and the temperature. FIG. 3 shows the relationship between the current value of the current (waveform signal) input to the transmission amplifier 25 and the power value of the electromagnetic wave transmitted from the transmission antenna 26 measured at different temperatures. As shown in the figure, in a region where the input current is small, the transmission power of the transmitter 2 decreases as the temperature increases.

The second transmission wave P2 with a large output should be formed so that the transmission power (the output of the transmission amplifier 25) is stable and the temperature sensitivity is small (for example, near I2 as the value of the input current in FIG. 3). can be done. Therefore, the output of the second transmission wave P2 is hardly affected by the temperature. On the other hand, the first transmission wave P1 with a small output needs to be formed so that the output of the transmission amplifier 25 has a high temperature sensitivity region (for example, near I1 as the value of the input current in FIG. 3). . Therefore, even if the same waveform signal is input to the transmission amplifier 25, the actual output of the first transmission wave P1 may greatly deviate from the desired value depending on the temperature inside the device. Conversely, if the temperature characteristics of the transmission amplifier 25 are known, the output of the first transmission wave P1 can be estimated from the temperature information within the apparatus.

The output control section 6 controls the value of the command signal to the offset circuit 23 based on the output index. That is, the output control unit 6 controls the offset amount of the waveform signal input to the transmission amplification unit 25 based on the output index, thereby keeping the outputs of the first transmission wave P1 and the second transmission wave P2 substantially constant. (Control the output that has deviated from the desired value so that it approaches the desired value). That is, as shown in FIG. 3, the output of the first transmission wave P1 varies depending on the current and temperature input to the transmission amplification section 25, but the output of the second transmission wave P2 is input to the transmission amplification section 25. Therefore, by offsetting the current value input to the transmission amplifier 25 according to the temperature by the output controller 6, the output of the first transmission wave P1 and the second transmission wave P2 can be adjusted to the temperature. It can be kept substantially constant against changes. Thereby, the possibility that the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 interfere with each other can be reduced.

Specifically, the output control unit 6 calculates the value of the command signal for the offset circuit 23 as a function of the output index, or creates a reference table in which the correspondence between the output index value and the command signal value is stored in advance. It can be configured to refer to and determine a command signal.

As the temperature sensor 7, any sensor that can detect temperature may be used, and for example, a thermistor or the like can be used. Although the output of the first transmission wave P1 is considered to depend mainly on the temperature of the transmission amplifier 25, if the temperature sensor 7 is arranged to measure the temperature inside the package of the radar device 1, the There is no problem in regarding the measured value as the temperature of the transmission amplifier 25 . Furthermore, even when the temperature sensor 7 is arranged to measure the temperature outside the package of the radar device 1, the corresponding temperature inside the package is determined by a predetermined function or table based on the measured temperature. There is no problem even if it is calculated.

FIG. 4 shows the procedure of the target object detection method according to one embodiment of the present invention. The target detection method of FIG. 4 can be implemented by the radar device 1 of FIG.

As is clear from the description of the radar device 1 in FIG. 1, the target detection method of the present embodiment includes a step of obtaining an output index having a correlation with the output of the first transmission wave P1 (step S01: output index obtaining step); controlling the output of the first transmission wave P1 based on the output index obtained in the output index obtaining step (step S02: output control step); a step of sequentially transmitting (step S03: transmitting step); a step of receiving a reflected wave of the first transmission wave P1 and a reflected wave of the second transmission wave P2 (step S04: receiving step); A step of detecting a target based on the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 (step S05: detection step), and a step of confirming whether or not to end the target detection operation (step S06: end confirmation step).

In the output index acquisition process of step S01, temperature information is acquired from the temperature sensor 7 as an output index.

In the output control process of step S02, a command value for the offset circuit 23 is determined so that the output of the first transmission wave P1 can be kept constant based on the output index.

In the transmission process of step S03, by inputting the waveform signal corrected by the offset circuit 23 in accordance with the command value determined in the output control process to the transmission amplifier 25, the first transmission wave P1 and the second transmission wave P1 having a predetermined output are input to the transmission amplifier 25. Send out wave P2.

In the receiving step of step S04, the receiving unit 3 receives the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 from the target, and the signal indicating the strength of the received wave generated by the receiving unit 3 is input to the detection unit 4 .

In the detection process of step S05, the peak of the reflected wave of the first transmitted wave P1 or the reflected wave of the second transmitted wave P2 is confirmed, and if the peak exists, it is recognized that the target exists. When the peak of the reflected wave is confirmed, the distance to the target is calculated based on the time difference between the transmission and the reception of the peak.

In the end confirmation step of step S06, it is determined based on an external signal or the like whether or not to end the target detection operation (the steps from step S01 to step S05 are executed again).

The radar device 1 that executes the target detection method described above acquires an output index (temperature information) having a correlation with the output of the first transmission wave P1, and the transmission unit 2 transmits based on the acquired output index. By controlling the output of the first transmission wave P1, not only the output of the second transmission wave P2 whose output fluctuation is relatively small, but also the output of the first transmission wave P1 which tends to fluctuate can be held substantially constant. If the time interval T for transmitting the first transmission wave P1 and the second transmission wave P2 is, for example, several hundred ns, it is difficult to individually control the output of each transmission wave at such a time interval. Sometimes. Therefore, by utilizing the difference in the characteristics of the output of the first transmission wave P1 and the output of the second transmission wave P2 with respect to changes in current value and temperature input to the transmission amplification unit 25, the transmission amplification unit 25 may be offset according to the temperature and regardless of the output timings of the first transmission wave P1 and the second transmission wave P2. The offset current value changes (increases or decreases) according to the temperature, but is constant with respect to changes in the waveform signal output by the waveform signal forming circuit 22 (the voltage value output by the waveform signal forming circuit 22). be able to. With such a configuration, it is possible to keep the outputs of the first transmission wave P1 and the second transmission wave P2 substantially constant with a simple configuration. As a result, the radar device 1 can reduce the overlapping of the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 with a simple configuration, so that the target existing in the middle range can be accurately detected. can do. Therefore, the radar device 1 detects a target existing in a short range with a relatively high resolution using the first transmission wave P1, and detects a target existing in a long range with a relatively high sensitivity using the second transmission wave P2. In addition to being able to detect targets in the middle range, it is also possible to detect them with high accuracy.

Next, a radar device according to a second embodiment of the invention will be described. FIG. 5 is a block diagram showing the configuration of a radar device 1A according to the second embodiment of the invention.

The radar device 1A of FIG. 5 includes a transmitter 2A that sequentially transmits a first transmission wave P1 and a second transmission wave P2, and a reflected wave of the first transmission wave P1 and a reflected wave of the second transmission wave P2. a receiving unit 3 for converting into a digital signal; a detecting unit 4 for detecting a target based on the digital signals of the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 received by the receiving unit 3; An index acquisition unit 5A for acquiring an output index having a correlation with the output of one transmission wave P1, and output control for controlling (adjusting) the output of the first transmission wave P1 based on the output index acquired by the index acquisition unit 5A. and a part 6A. The detection unit 4, the index acquisition unit A5, and the output control unit 6A can be configured as different functions of a single arithmetic unit. In the following description, the same reference numerals are given to the same components as in the previously described embodiment, and duplicate descriptions will be omitted.

The transmission unit 2A generates a waveform signal based on the original signal generated by the original signal generation unit 21A, which generates a waveform signal similar in shape to the envelope waveforms of the first transmission wave P1 and the second transmission wave P2, and the original signal generation unit 21A. an oscillator 24 for generating a local oscillator signal of a predetermined carrier frequency; and the local oscillator signal generated by the oscillator 24 is multiplied by the waveform signal output from the waveform signal generator 22A. A configuration including a transmission amplifier 25 and a transmission antenna 26 for converting a signal output from the transmission amplifier 25 into a radio wave and transmitting the radio wave may be employed.

The original signal generation unit 21A takes into account the command value from the output control unit 6A, that is, the change in the gain of the transmission amplification unit 25 due to the temperature. An original signal is generated which causes the waveform signal forming circuit 22A to form a waveform signal having a waveform (especially, a wave height) from which the first transmission wave P1 can be obtained. The original signal generating section 21A can also be implemented as one function of the same computing device as the detecting section 4, the index obtaining section 5A and the output control section 6. FIG.

The waveform signal forming circuit 22A generates a waveform signal to be input to the transmission amplifying section 25 based on the original signal generated by the original signal generating section 21A. 22 A of waveform signal formation circuits can be comprised by a DA converter etc., for example.

The index acquisition unit 5A obtains intensity information (power value, power value, voltage value, current value, etc.). As described above, since the output of the second transmission wave P2 is substantially constant regardless of temperature conditions, the ratio of the power of the first transmission wave P1 to the power of the second transmission wave P2 is It can be considered as a value proportional to the output of the first transmission wave P1. Also, it is considered that the power ratio between the received wave of the first transmission wave P1 and the received wave of the second transmission wave P2 is substantially equal to the power ratio between the first transmission wave P1 and the second transmission wave P2. Therefore, the power of the first transmission wave P1 can be estimated from the strength information of the received waves of the first transmission wave P1 and the second transmission wave P2.

Based on the output index acquired by the index acquisition unit 5A, the output control unit 6A sets parameters for causing the original signal generation unit 21 to generate an original signal that can set the output of the first transmission wave P1 to a predetermined value. A command value that indicates the control amount is calculated. This command value may be feedback-controlled so that the intensity ratio between the received wave of the first transmitted wave P1 indicating the output of the first transmitted wave P1 and the received wave of the second transmitted wave P2 approaches a predetermined target value.

It should be noted that the power ratio of the reflected waves of the first transmission wave P1 and the second transmission wave P2 in the reception unit 3 may vary depending on the characteristics of the target, etc. It may not accurately reflect the power ratio of wave P2. Therefore, the output control unit 6A controls the output of the first transmission wave P1 in accordance with the strength signals of the received waves of the first transmission wave P1 and the second transmission wave P2 directly propagating from the transmission unit 2 to the reception unit 3. You may Furthermore, when the transmitting antenna 26 and the receiving antenna 31 are configured using patch antenna elements on the surface of the same circuit board (arranged on the board), the output control section 6A controls the receiving section 3 from the transmitting antenna 26. The output of the first transmission wave P1 may be controlled according to the intensity signals of the first transmission wave P1 and the second transmission wave P2 received by the reception antenna 31 through the surface of the transmission substrate. Therefore, the output control unit 6A controls the output of the first transmission wave P1, that is, controls the command value for the original signal generation unit 21A only when the target detection result by the detection unit 4 satisfies a predetermined condition. may be configured. As a specific example, the output control unit 6A may control the output of the first transmission wave P1 only when no target is detected within a certain distance range, and the intensity of the reflected wave from the target is The output of the first transmission wave P1 may be controlled only when it is equal to or less than a certain threshold. As a result, the output of the first transmission wave P1 can be more accurately adjusted based on the intensity signals of the reception waves of the first transmission wave P1 and the second transmission wave P2 that propagate directly from the transmission unit 2 to the reception unit 3. can.

FIG. 6 shows the procedure of a target object detection method according to another embodiment of the present invention. The target detection method of FIG. 6 can be implemented by the radar device 1A of FIG.

The target detection method of the present embodiment includes a step of sequentially transmitting a first transmission wave P1 and a second transmission wave P2 (step S11: transmission step), and a reflected wave of the first transmission wave P1 and a second transmission wave P2. A step of receiving the reflected wave (step S12: receiving step), and a step of detecting a target based on the reflected wave of the first transmitted wave P1 and the reflected wave of the second transmitted wave P2 received in the receiving step (step S13 : detection step), a step of confirming whether or not the target detection operation should be terminated (step S14: end confirmation step), and a step of confirming whether or not the detection result indicates that a target exists nearby. (Step S15: target existence confirmation step); obtaining an output index having a correlation with the output of the first transmission wave P1 (step S16: output index obtaining step); and the output obtained in the output index obtaining step. and a step of controlling the output of the first transmission wave P1 based on the index (step S17: output control step).

In the transmission step of step S11, the waveform signal formed by the waveform signal forming circuit 22A based on the original signal generated by the original signal generation unit 21A is input to the transmission amplification unit 25, thereby generating the first transmission wave P1 with a predetermined output. and a second transmission wave P2.

In the receiving step of step S12, the receiving unit 3 receives the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 from the target, and the signal indicating the strength of the received wave generated by the receiving unit 3 is input to the detection unit 4 . It should be noted that steps S11 and S12 may be repeated and the process may proceed to step S13.

In the detection process of step S13, the detection unit 4 confirms the peak of the reflected wave of the first transmission wave P1 or the reflected wave of the second transmission wave P2, and recognizes that the target exists when the peak exists. When the peak of the reflected wave is confirmed, the distance to the target is calculated based on the time difference between the transmission and the reception of the peak.

In the end confirmation step of step S14, it is determined based on an external signal or the like whether or not to end the target detection operation. If the detection operation is to be terminated, the process is immediately terminated, and if the detection operation is not to be terminated, the process proceeds to the next step S15.

In the target object presence confirmation step of step S15, the detection result in the detection step is confirmed, and it is confirmed whether or not the target object exists in a nearby area (for example, a range within 3 m) under a predetermined condition. If the target exists in the vicinity area, the process returns to step S1, and if the target does not exist in the vicinity area, the process proceeds to the next step S16.

In the output index acquisition step of step S16, intensity information of the received waves of the first transmission wave P1 and the second transmission wave P2 is acquired from the detection unit 4 as the output index. When acquiring the strength information of the received waves, if there is no target in the vicinity area, the receiving antenna 31 may Received intensity information may be acquired (actually, there is a minimal time interval corresponding to the distance between the transmitting antenna 26 and the receiving antenna 31, but this case is also included in the "moment" in this paragraph. ). The intensity information thus acquired can be used as intensity information corresponding to intensity signals of the first transmission wave P1 and the second transmission wave P2 received by the reception antenna 31 from the transmission antenna 26 via the surface of the transmission substrate. In addition, a target exists in a region farther than the near region (for example, within a range of several meters), and the peaks of the reflected waves of the first transmission wave P1 and the second transmission wave P2 corresponding to the position of the target are When each of them can be confirmed, the received intensity of both the reflected wave of the first transmitted wave P1 and the reflected wave of the second transmitted wave P2 may be acquired as the intensity information.

In the output control step of step S17, a command value for the original signal generator is determined based on the output index so that the output of the first transmission wave P1 can be kept constant. After executing this output control step, the transmission step of step S11 is performed again using the command value determined here.

Since the radar device 1A of FIG. 5 estimates the output of the first transmission wave P1 based on the intensity ratio between the received wave of the first transmitted wave P1 and the received wave of the second transmitted wave P2, the output of the second transmitted wave P2 is If the output is an appropriate value, the output of the first transmission wave P1 can be kept substantially constant without considering variations in the individual circuit characteristics of the transmission amplifier 25 and the like.

Furthermore, a radar device according to a third embodiment of the present invention will be described. FIG. 7 is a block diagram showing the configuration of a radar device 1B according to the third embodiment of the invention.

The radar device 1B of FIG. 7 includes a transmitter 2 that sequentially transmits a first transmission wave P1 and a second transmission wave P2, and a reflected wave of the first transmission wave P1 and a reflected wave of the second transmission wave P2. a receiving unit 3 for converting into a digital signal; a detecting unit 4 for detecting a target based on the digital signals of the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 received by the receiving unit 3; A first index acquisition unit 5 that acquires temperature information as a first output index that correlates with the output of one transmission wave P1, and a second output index that correlates with the output of the first transmission wave P1: Based on the two types of output indices obtained by the second index obtaining unit 5A for obtaining the intensity information of the received wave of the first transmission wave P1 and the received wave of the second transmission wave P2, and the two types of output indices obtained by the two index obtaining units 5 and 5A and an output control unit 6B that controls the output of the first transmission wave P1. The first index acquisition unit 5 of the radar device 1B of FIG. 7 is the same as the index acquisition unit 5 of the radar device 1 of FIG. 1, and the second index acquisition unit 5A of the radar device 1B of FIG. It is the same as the index acquisition unit 5A of the device 1A.

The output control unit 6B roughly adjusts the output of the first transmission wave P1 based on the output index (temperature information) acquired by the first index acquisition unit 5, and the output index (reflection temperature information) acquired by the second index acquisition unit 5A. wave intensity information), the power of the first transmission wave P1 can be finely adjusted.

In the radar device 1B of FIG. 7, even if the target continues to exist in the vicinity of the radar device 1B, the output of the first transmission wave P1 can be controlled relatively accurately based on the temperature information. When there is no target near 1B, the output of the first transmission wave P1 can be controlled more accurately based on the intensity information of the received waves of the first transmission wave P1 and the second transmission wave P2.

Furthermore, a radar device according to a fourth embodiment of the present invention will be described. FIG. 8 is a block diagram showing the configuration of a radar device 1C according to the third embodiment of the invention.

The radar device 1C of FIG. 7 includes a transmission section 2B that sequentially transmits a first transmission wave P1 and a second transmission wave P2, and receives a reflected wave of the first transmission wave P1 and a reflected wave of the second transmission wave P2. a receiving unit 3 for converting into a digital signal; a detecting unit 4 for detecting a target based on the digital signals of the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 received by the receiving unit 3; A first index acquisition unit 5 that acquires temperature information as a first output index that correlates with the output of one transmission wave P1, and a second output index that correlates with the output of the first transmission wave P1: Based on the two types of output indices obtained by the second index obtaining unit 5A for obtaining the intensity information of the received wave of the first transmission wave P1 and the received wave of the second transmission wave P2, and the two types of output indices obtained by the two index obtaining units 5 and 5A An output control unit 6C for controlling the output of the first transmission wave P1, and an interval for changing the interval between the first transmission wave P1 and the second transmission wave P2 transmitted by the transmission unit 2 according to an instruction from the output control unit 6C. and a changing unit 8 .

Based on the original signal generated by the original signal generation unit 21C, the transmission unit 2 generates an original signal that determines the amplitude and pulse width of the first transmission wave P1 and the second transmission wave P2. an offset circuit 23 for offsetting the current value of the waveform current formed by the waveform signal forming circuit 22 according to a command signal from the output control section 6; and a local oscillator with a predetermined carrier frequency. a transmission amplifier 25 for multiplying the local oscillator signal generated by the oscillator 24 by the waveform signal formed by the waveform signal forming circuit 22; and a transmitting antenna 26 for converting and transmitting.

The original signal generator 21C changes the time interval between the original signal of the first transmission wave P1 and the original signal of the second transmission wave P2 according to the command signal from the interval changer 8. FIG.

The output control unit 6C uses the output control of the first transmission wave P1 and the interval change unit 8 to prevent the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 from overlapping each other. It is combined with the interval change between the first transmission wave P1 and the second transmission wave P2. Therefore, the output control unit 6C only needs to be able to suppress variations in the output of the first transmission wave P1 due to temperature changes.

The interval changer 8 gives a command signal to the original signal generator 21C so that the interval between the first transmission wave P1 and the second transmission wave P2 increases as the output of the first transmission wave P1 increases. After the output control of the first transmission wave P1 by the output control unit 6C reaches the limit, the interval changing unit 8 changes the interval between the first transmission wave P1 and the second transmission wave P2 to reflect the first transmission wave P1. It is also possible to prevent interference between the wave and the reflected wave of the second transmission wave P2. Alternatively, the output control amount of the first transmission wave P1 may be reduced.

In the radar device 1C of FIG. 8, in addition to controlling the output of the first transmission wave P1, the interval between the first transmission wave P1 and the second transmission wave P2 is changed. Even if the ratio is large, it is possible to prevent interference between the reflected wave of the first transmission wave P1 and the reflected wave of the second transmission wave P2 in a relatively wide temperature range. In addition, since the radar device 1C controls the output of the first transmission wave P1, there is no need to excessively increase the interval between the first transmission wave P1 and the second transmission wave P2, and the short-distance It is possible to perform target detection in a long range and target detection in a long range by the second transmission wave P2 in a relatively short time.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various changes and modifications are possible.

For example, in the present invention, one or both of the first transmission wave and the second transmission wave are not limited to pulse waves as used in each embodiment, but may be frequency-modulated continuous waves in which the carrier frequency continuously changes with a constant amplitude. etc.

In the radar device according to the present invention, the transmitter and receiver may have a plurality of channels. That is, the transmitting section and the receiving section may be configured to have a plurality of antennas and a selector for selecting an antenna to be used.

In the radar apparatus according to the present invention, the transmission amplifier section may be configured to amplify the local oscillator signal with an amplification factor corresponding to the input voltage signal (voltage value).

In the radar device according to the present invention, when a target exists in an area other than a nearby area within a predetermined distance range and the first transmission wave and the second transmission wave reflected by the target are received, the The output of the first transmission wave may be controlled based on the output index including intensity information of the received first transmission wave and second transmission wave.

The radar apparatus according to the present invention may be configured to control not only the power of the first transmission wave but also the power of the second transmission wave. For example, the current or voltage signal input to the amplifier includes first and second current values or first and second voltage values corresponding to the outputs of the first and second transmission waves, and the output control unit , similarly increases or decreases each of the first and second current values or each of the first and second voltage values based on the output index obtained by the index obtaining unit (for example, each of the first and second current values is , increasing or decreasing by the same value depending on the temperature).

1, 1A, 1B, 1C Radar device 2, 2A, 2C Transmission unit 3 Reception unit 4 Detection unit 5, 5A Index acquisition unit 6, 6A, 6B, 6C Output control unit 7 Temperature sensor 8 Interval change unit 21, 21C Original signal Generation section 22, 22A Waveform signal forming circuit 23 Offset circuit 24 Oscillation section 25 Transmission amplification section 26 Transmission antenna 31 Reception antenna 32 Reception amplification section 33 Demodulation section 34 AD conversion section P1 First transmission wave P2 Second transmission wave

Claims (8)

a transmission unit that transmits a first transmission wave and a second transmission wave having a higher output than the first transmission wave at predetermined time intervals;
a receiving unit that receives a reflected wave of the first transmission wave and a reflected wave of the second transmission wave;
a detection unit that detects a target based on the reflected wave of the first transmission wave and the reflected wave of the second transmission wave received by the receiving unit;
an index acquisition unit that acquires an output index having a correlation with the output of the first transmission wave;
an output control unit that controls the output of at least the first transmission wave transmitted by the transmission unit based on the output index acquired by the index acquisition unit;
with
The output index includes intensity information of the first transmission wave and the second transmission wave received by the receiving unit,
The output control section is a radar device that controls the output of the first transmission wave when the detection result of the target object by the detection section satisfies a predetermined condition. 2. The radar device according to claim 1, wherein said output index includes temperature information within the device. The transmission unit has a transmission antenna arranged on a substrate,
The receiving unit has a receiving antenna arranged on the substrate,
When the predetermined condition is satisfied, the target does not exist in the neighboring area within the predetermined distance range,
wherein the output index includes intensity information of the first transmission wave and the second transmission wave received by the reception antenna at the moment when the first transmission wave and the second transmission wave are transmitted from the transmission antenna; Item 3. The radar device according to item 1 or 2 . When the predetermined condition is satisfied, a target exists in an area other than the neighboring area within the predetermined distance range, and the first transmission wave and the second transmission wave reflected by the target are received. and
3. The radar device according to claim 1, wherein said output index includes intensity information of said received first transmission wave and said second transmission wave. 5. The apparatus according to any one of claims 1 to 4 , further comprising an interval changing unit that changes an interval between the first transmission wave and the second transmission wave transmitted by the transmission unit based on the output index acquired by the index acquisition unit. 1. Radar device according to claim 1. The transmission unit
an oscillator that generates and oscillates a high-frequency signal;
an amplification unit that amplifies and outputs the high-frequency signal input from the oscillation unit according to an input current or voltage signal;
with
The radar device according to any one of claims 1 to 5 , wherein the output control section controls the current or voltage signal input to the amplification section based on the output index obtained by the index obtaining section. the current or voltage signal input to the amplifying unit includes first and second current values or first and second voltage values corresponding to outputs of the first and second transmission waves;
The output control unit is configured to similarly increase or decrease each of the first and second current values or each of the first and second voltage values based on the output index obtained by the index obtaining unit. 7. The radar installation according to claim 6 , wherein the A transmitting unit that transmits radio waves, a receiving unit that receives radio waves, a detecting unit that detects a target based on the radio waves received by the receiving unit, an index acquiring unit that acquires an output index of the radio waves transmitted by the transmitting unit, and a method of detecting a target using a radar device comprising an output control unit that controls the output of radio waves transmitted by the transmission unit,
a step of transmitting a first transmission wave and a second transmission wave having a higher output than the first transmission wave by the transmission unit at predetermined time intervals;
a step of receiving a reflected wave of the first transmission wave and a reflected wave of the second transmission wave by the transmission unit;
a step of detecting a target based on the reflected wave of the first transmission wave and the reflected wave of the second transmission wave received in the receiving step by the receiving unit;
obtaining an output index having a correlation with the output of the first transmission wave by the index obtaining unit;
controlling the output of at least the first transmission wave by the output control unit based on the output index;
with
The output index includes intensity information of the first transmission wave and the second transmission wave received by the receiving unit,
The target detection method, wherein the output control unit controls the output of the first transmission wave when the detection result of the target by the detection unit satisfies a predetermined condition.

Images