JP2005077288A - Radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar device enabling a stable target recognition by detecting the absolute value of the maximum swing angle of a scanner to keep an amount of amplitude constant. <P>SOLUTION: The radar device includes a laser diode 22, a two-dimensional scanner 21 two-dimensionally scanning by using the signals transmitted from the laser diode 22 with lengthwise and breadthwise vibration, and a receiving section 3 for signals for receiving the reflected signals transmitted via the two-dimensional scanner 21, optically measuring the position of the swing angle of the two-dimensional scanner 21 by a measuring apparatus for an amplitude angle. As an optical measurement approach, a structure reflecting the front and rear of the reflecting surface of the two-dimensional scanner 21 is formed, and then a photodiode or a two-dimensional PSD as a light receiving element for measuring an amplitude angle reflected is arranged at a predetermined position on the projection face of a two-dimensional scanning region formed with the beams of light-emitting element 23 for measuring the amplitude angle reflected by a reflecting surface. Then, the maximum amplitude angle on the reflecting surface of the two-dimensional scanner 21 is measured by the presence on the measuring element for the amplitude angle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radar apparatus that detects a distance and a shape to a target existing around using a two-dimensional scanner.

  As a conventional radar apparatus, there is one that uses a two-dimensional scanner such as a micro scanner and performs two-dimensional scanning by reflecting laser light from a laser diode on a mirror surface of the two-dimensional scanner. For example, as shown in FIG. 12, the radar apparatus using the two-dimensional scanner includes a two-dimensional scanner 221 in which the mirror surface vibrates in two vertical and horizontal directions, and from the laser diode 222 according to a light emission command from the transmission pulse generator 241. The transmitted laser light is incident on the mirror surface of the two-dimensional scanner 221, and the mirror surface of the two-dimensional scanner 221 is vibrated in the vertical and horizontal directions by the two-dimensional scanner driving unit 224 based on the frequency control of the signal processing unit 204. Two-dimensional scanning is performed by scanning light. In the target recognition, the distance to the target is detected based on the time difference between the transmitted laser beam and the laser beam reflected back to the target, and the laser beam is transmitted based on the displacement angle information of the two-dimensional scanner 221. The direction is detected, and two-dimensional observation data is generated based on the detected distance and direction.

Here, as a method of detecting the amount of displacement of the scanner deflection angle of the two-dimensional scanner 221, a permanent magnet is fixed to the mirror movable portion as in “Vibration state detection device” disclosed in Japanese Patent Laid-Open No. 2002-350754. A piezoelectric element is bonded to a beam portion of a vibrating mirror, such as one that detects a deflection angle by a magnetic sensor, or an “optical scanner device” disclosed in Japanese Patent Laid-Open No. 9-101474, and its bending motion There is one that detects the amount of voltage displacement due to.
JP 2002-350754 A JP-A-9-101474

  However, the method using the magnetic sensor disclosed in Patent Document 1 has a problem that it cannot be applied to a two-dimensional scanner because it mainly corresponds to a one-dimensional scanning motion.

  Further, in the method using the piezoelectric element disclosed in Patent Document 2, it is necessary to secure a certain size and thickness in the beam portion to be bonded due to physical restrictions of the element, and a large amplitude deflection angle can be obtained. Can not. On the other hand, there is a method for detecting a back electromotive force signal when a two-dimensional scanner is pulse-driven by an electromagnetic method, but even when this method is used, only a relative displacement amount can be obtained, and the surrounding environment changes. Even if the maximum deflection angle of the scanner fluctuates due to disturbance or the like, the absolute value cannot be detected, so that there is a problem that a constant amplitude cannot be maintained. The present invention has been made to solve such a conventional problem, and an object of the present invention is to detect a distance and a shape to a target existing around by using a two-dimensional scanner. In other words, it is desirable to provide a radar apparatus that detects the absolute value of the maximum deflection angle of the scanner, maintains the amplitude amount constant, and enables stable target recognition.

  In order to solve the above-described object, the present invention provides a signal transmission device that transmits a signal, a two-dimensional scanner that performs two-dimensional scanning using the signal transmitted from the signal transmission device by vibrating vertically and horizontally, A signal receiving device that receives a reflection signal of the signal transmitted through the two-dimensional scanner, and an amplitude angle measuring device that optically measures a deflection angle position of the two-dimensional scanner. .

  According to the present invention, in a radar apparatus using a two-dimensional scanner that performs two-dimensional scanning by vertical and horizontal vibrations by optically measuring a deflection angle position of the two-dimensional scanner by an amplitude angle measuring apparatus, The maximum amplitude angle can be obtained, and by combining with the phase of the vibration waveform obtained by the back electromotive force signal, the angle of the scanner reflection surface can be accurately obtained, and the amplitude amount is kept constant and stable. Target recognition is possible.

  Hereinafter, embodiments of a radar apparatus according to the present invention will be described in detail in the order of [first embodiment] and [second embodiment] with reference to the drawings. In the following description, it is assumed that the radar device is applied to an on-vehicle system, and it is assumed that an obstacle existing around the vehicle and the distance and shape to a preceding vehicle are detected using a two-dimensional scanner. Needless to say, the scope of application of the radar device and the target recognition method of the invention is not limited to this.

  Examples of radar devices include laser radar using infrared light and radio wave radar using electromagnetic waves. The radar system also includes a pulse system that transmits a short-time pulse signal, calculates the distance by measuring the time it takes to receive the pulse signal reflected back to the target, and frequency modulation with a triangular wave. There is a CW system that transmits a continuous wave that is amplitude-modulated and calculates a distance by frequency displacement or phase displacement of a reflected signal. Hereinafter, a method using a pulse method using an optical scanner in an infrared laser radar apparatus will be described.

First embodiment

  FIG. 1 is a configuration diagram of a radar apparatus according to a first embodiment of the present invention. In FIG. 1, the radar apparatus according to this embodiment includes a signal transmission unit 2, a signal reception unit 3, and a signal processing unit 4.

  The signal transmission unit 2 includes a laser diode 22, a beam scanning unit 26, and a two-dimensional scanner driving unit 24 (a 2D scanner driving unit in the figure). The laser diode 22 sends out infrared laser light (hereinafter referred to as laser light) based on the light emission command from the signal processing unit 4. The beam scanning unit 26 scans the laser beam forward, but as will be described in detail later (see FIG. 5), the beam scanning unit 26 reflects on the front and back of the reflecting surface, and the reflecting surface is vertically and horizontally. A two-dimensional scanner 21 that oscillates two-dimensionally, a photodiode 25a, 25b as a light-receiving element for amplitude angle measurement that measures the maximum amplitude angle of the reflecting surface of the two-dimensional scanner 21, or a two-dimensional PSD 27; The light emitting element 23 is provided. Further, the two-dimensional scanner driving unit 24 controls the resonance operation of the two-dimensional scanner 21 based on amplitude control and frequency control from the signal processing unit 4.

  Next, the signal receiving unit 3 includes a photodiode 31 and an optical lens 32.

  Further, the signal processing unit 4 includes a transmission pulse generation unit 41, a transmission direction detection unit 42, a drive signal adjustment unit 43, a distance detection unit 44, and a target recognition logic unit 46. Specifically, the signal processing unit 4 is realized by a CPU, a ROM, a RAM, and the like, and each unit in the signal processing unit 4 is embodied by a program executed on the CPU, a circuit around the CPU, and the like. .

  First, the transmission pulse generator 41 outputs a light emission command to the laser diode 22. The drive signal adjustment unit 43 outputs a control command to the two-dimensional scanner drive unit 24 to adjust the frequency and amplitude for driving the two-dimensional scanner 21. The transmission azimuth detecting unit 42 detects the transmission azimuth of the laser beam. The transmission azimuth calculation by the transmission azimuth detecting unit 42 is calculated by the two-dimensional scanner 21 obtained from the beam scanning unit 19 when the laser beam is transmitted. This is performed by detecting the transmission direction of the laser light from the maximum amplitude angle of the inner mirror surface and the deflection angle position of the mirror surface in the two-dimensional scanner 21 obtained from the two-dimensional scanner drive unit 24.

  The distance detection unit 44 detects the distance to the target. The distance detection unit 44 detects the distance from the transmission pulse generation unit 41 by sending a light emission command for sending the laser light to the laser diode 22 of the signal transmission unit 2. Laser light that has been reflected and reflected back by the target at the photodiode 31 of the signal receiving unit 3 is received and calculated based on the time difference from when the received signal is sent to the signal processing unit 4. . At this time, correction is performed in consideration of the delay time of signal transmission / reception in the circuit.

  Further, the target recognition logic unit 46 performs two-dimensional scanning within a predetermined observation time, and generates two-dimensional observation data based on the distance detected by the distance detection unit 44 and the direction detected by the transmission direction detection unit 42. Then, the preceding vehicle is identified using vehicle recognition logic or the like. The obtained preceding vehicle information, obstacle information, and the like are transmitted to an ACC controller (Adaptive Cruise Control) that performs preceding vehicle following control so that the distance to the preceding vehicle becomes the set inter-vehicle distance.

  Next, the configuration of the two-dimensional scanner 21 will be described with reference to FIG. FIG. 2 is a configuration diagram illustrating a double gimbal type microscanner. In the figure, 51 is a mirror, 52 is a horizontal beam, 52 'is a vertical beam, 53 is a mirror support, 54 is a scanner base board, and 55 and 55' are permanent magnets.

  In FIG. 2, the mirror 51 is supported by a cross beam 52 from a mirror support 53. Further, the mirror support 53 is supported by a vertical beam 52 ′ from the scanner base substrate 54. Two pairs of permanent magnets 55 and 55 ′ are arranged outside the scanner base substrate 54, and a vertical and horizontal magnetic field is applied to the entire scanner base substrate 54.

  In addition, a coil (not shown) is wired between the rear outer frame of the mirror 51 and the rear outer frame of the mirror support 53. A Lorentz force is generated at the end of the mirror 51 and the end of the mirror support 53 by the amount of current flowing through the coil and the magnetic field applied from the permanent magnets 55 and 55 '. Resonance vibration of vibration and lateral vibration occurs. As a result, the laser beam reflected by the mirror 51 performs two-dimensional scanning.

  FIG. 3 is a configuration diagram specifically showing the configuration of the two-dimensional scanner driving unit 24. In the figure, the two-dimensional scanner drive unit 24 includes a vertical drive signal generator 61, a horizontal drive signal generator 62, and variable gain amplifiers 63 and 63 '. Hereinafter, the rectangular vibration signal generated by the longitudinal drive signal generator 61 is referred to as a longitudinal drive signal, and the rectangular vibration signal generated by the lateral drive signal generator 62 is referred to as a lateral drive signal.

  The rectangular wave of the vertical drive signal and the horizontal drive signal oscillated by the vertical drive signal generator 61 and the horizontal drive signal generator 62 is adjusted to a frequency according to the control signal input from the signal processing unit 4 and gained respectively. It is output to the variable amplifiers 63 and 63 ′. In the variable gain amplifiers 63 and 63 ′, the input drive signal is amplified based on the adjustment values (longitudinal vibration amplitude control signal and lateral vibration amplitude control signal) from the signal processing unit 4, and then the longitudinal drive signal and the lateral drive are amplified. A signal is sent to the two-dimensional scanner 21. Further, the vertical and horizontal counter electromotive force signals obtained from the two-dimensional scanner 21 in operation are amplified and digital waveform processed, and sent to the signal processing unit 4 as deflection angle position information of the two-dimensional scanner 21.

  Note that the vertical drive signal and the horizontal drive signal are initially set to frequencies near the resonance frequency of the two-dimensional scanner 21. This resonance frequency may be any resonance frequency such as primary resonance or secondary resonance of the two-dimensional scanner 21.

  Next, a specific operation of the radar apparatus of this embodiment, that is, a target recognition method will be described.

  FIG. 4 is a timing chart of each part signal in the radar apparatus of the present embodiment. FIG. 4A shows a trigger signal transmitted from the signal processing unit 4 in order to send a laser beam from the laser diode 22. b) A transmission signal transmitted from the laser diode 22, and FIG. 4C shows a reception signal when the photodiode 31 receives the reflected light.

When a trigger signal is sent from the signal processing unit 4 to the signal transmission unit 2 in order to send out the laser beam, the laser diode 22 of the signal transmission unit 2 synchronizes with the trigger signal and emits infrared pulsed light having a pulse width τ (hereinafter referred to as a pulse signal τ). , Called pulsed light) toward the target. The transmitted pulse light is reflected by the target and is received by the photodiode 31 through the optical lens 32 of the signal receiving unit 3. The distance D between the laser device and the target is calculated by the following equation (1), where Δt is the time from when the pulsed light is transmitted until the reflected light is received, and C is the speed of light.

(Equation 1)
D = C · Δt / 2 (1)
When calculating the actual distance, the error to the target is calculated by correcting the error in consideration of the measurement distance error caused by circuit delay or the like.

  Next, the beam scanning unit 26 will be described in detail with reference to FIGS. FIG. 5 is a schematic view of the beam scanning unit 26 viewed from the upper surface direction of the radar apparatus. 6 to 8 are explanatory views illustrating the arrangement of the light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21. FIG. 6 shows the first form, FIG. 7 shows the second form, and FIG. Three forms are shown. Further, FIG. 9 is a timing chart for explaining the detection timing for measuring the maximum amplitude angle of the two-dimensional scanner 21.

  In FIG. 5, the beam scanning unit 26 irradiates the laser beam from the laser diode 22 on the surface of the reflection surface of the two-dimensional scanner 21 arranged obliquely, while the amplitude angle is applied to the back surface of the reflection surface of the two-dimensional scanner 21. In this structure, light is emitted from the light-emitting element 23 for measurement. The laser light transmitted from the laser diode 22 is used for measuring the distance to the front target, and the light transmitted from the light emitting element 23 is used for measuring the maximum amplitude angle of the two-dimensional scanner 21. Here, the type of the light emitting element 23 is not limited to laser light, and may be an inexpensive one such as a visible LED as long as it can be detected by a light receiving element.

  Next, FIG. 6 illustrates a first form of the light receiving element arrangement for measuring the maximum amplitude angle of the two-dimensional scanner 21. In the first embodiment, a total of twelve photodiodes 25 a are arranged on each of four vertical and horizontal sides in the two-dimensional scanning region of the two-dimensional scanner 21. As shown in the timing chart of FIG. 9, the amount of fluctuation of the maximum amplitude angle (FIG. 9) can be seen by observing the output state of the three photodiodes 25a arranged (see FIGS. 9B, 9C, and 9D). For example, the amount of change from timing T11 to timing T12) can be measured.

  That is, it can be seen that when the output values of all the photodiodes 25a are ON, the maximum amplitude angle is larger than the predetermined angle, and when the output values of all the photodiodes 25a are OFF, it is smaller than the predetermined angle. Understand. Therefore, the predetermined maximum amplitude angle is satisfied when the inner and central photodiodes 25a are turned on and the outer photodiode 25a is turned off for all four sides (as at timing T12 in FIG. 9). Further, by combining with the phase of the vibration waveform obtained from the back electromotive force signal (see FIG. 9E), the scanner reflection (as in the detected value in FIG. 9F with respect to the actual amplitude in FIG. 9A). The angle of the surface can be obtained accurately.

  In addition, since the four edge portions of the two-dimensional scanning region can be detected, even if the center of the two-dimensional scanning region is offset in the vertical and horizontal directions, the maximum amplitude angle can be measured within the detection range of the photodiode 25a. Can do. For this reason, when the center of the two-dimensional scanning region is constant without being offset, a total of six photodiodes 25a are arranged, three on each of one vertical side and one horizontal side of the two-dimensional scanning region. The maximum amplitude angle can be detected.

  Next, FIG. 7 illustrates a second form of the light receiving element arrangement for measuring the maximum amplitude angle of the two-dimensional scanner 21. In the second embodiment, a total of ten photodiodes 25b are arranged at five diagonal positions in a two-dimensional scanning region by the two-dimensional scanner 21. By comparing the output values of the photodiode 25b, the edge portion of the two-dimensional scanning region can be identified, and the maximum amplitude angle of the two-dimensional scanner 21 can be measured.

  Even if the center of the two-dimensional scanning region is offset, the same measurement can be performed. From this, when the center of the two-dimensional scanning region is constant without being offset, the maximum amplitude angle can be detected by arranging three photodiodes 25b at one corner of the two-dimensional scanning region. .

  Further, FIG. 8 illustrates a third form of the light receiving element arrangement for measuring the maximum amplitude angle of the two-dimensional scanner 21. In the third embodiment, one two-dimensional PSD 27 is arranged at each of two diagonal positions of a two-dimensional scanning area by the two-dimensional scanner 21. Based on the output value of the two-dimensional PSD 27, the edge portion of the two-dimensional scanning region can be determined linearly, and the maximum amplitude angle of the scanner 6 can be measured.

  Even if the center of the two-dimensional scanning region is offset, the same measurement can be performed. From this, when the center of the two-dimensional scanning region is constant without being offset, the maximum amplitude angle can be detected by arranging one two-dimensional PSD 27 at one corner of the two-dimensional scanning region. .

  As described above, in the radar apparatus according to the present embodiment, two-dimensional scanning is performed using the laser diode 22 (signal transmission apparatus) that transmits a signal and the signal transmitted from the laser diode 22 by vibrating vertically and horizontally. In a radar apparatus including a two-dimensional scanner 21 to be performed and a signal receiving unit 3 (signal receiving apparatus) that receives a reflection signal of a signal transmitted through the two-dimensional scanner 21, the amplitude angle measuring apparatus uses the two-dimensional scanner. The deflection angle position is optically measured. As an optical measurement method of the deflection angle position by the amplitude angle measuring device, in this embodiment, the reflection surface of the reflection surface of the two-dimensional scanner 21 is reflected on the front and back, and the light of the light emitting element 23 for measuring the amplitude angle is reflected on the reflection surface. A photodiode 25a, 25b or a two-dimensional PSD 27 is arranged as a light-receiving element for measuring the amplitude angle at a predetermined position on the projection surface projected on the two-dimensional scanning area formed by reflecting the light depending on whether light is received by the amplitude angle measuring element. The maximum amplitude angle of the reflection surface of the two-dimensional scanner 21 is measured.

  As a result, in a radar apparatus using a two-dimensional scanner that performs two-dimensional scanning by vertical and horizontal vibrations, the maximum amplitude angle of the two-dimensional scanning region can be obtained, and the phase of the vibration waveform obtained from the back electromotive force signal can be obtained. By combining with, the angle of the scanner reflection surface can be accurately obtained, and stable target recognition is possible with the amplitude amount kept constant (effect of claim 1). In the first embodiment of the arrangement of the light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21, the photodiodes 25 a are arranged on the four sides in the two-dimensional scanning region of the two-dimensional scanner 21. By measuring the maximum amplitude angle of the entire two-dimensional scanning region with the light receiving elements arranged in this way, it is possible to correct even if the amplitude of the scanner changes due to the influence of disturbance or the like, and to keep the amount of amplitude of the scanner constant. (Effect of claim 4).

  In the modification of the first embodiment of the light receiving element arrangement, the photodiodes 25a are arranged on one vertical side and one horizontal side of the two-dimensional scanning region. By measuring the maximum amplitude angle from the center of the two-dimensional scanning region with the light receiving elements arranged in this way, the amount of amplitude of the scanner can be kept constant (effect of claim 2). This is particularly effective when the center of the two-dimensional scanning region is constant without being offset.

  In the second embodiment of the arrangement of the light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21, the photodiodes 25 b are arranged at two diagonal positions in the two-dimensional scanning region by the two-dimensional scanner 21. In the third embodiment, two-dimensional PSDs 27 are arranged at two diagonal positions in the two-dimensional scanning area by the two-dimensional scanner 21. By measuring the maximum amplitude angle of the entire two-dimensional scanning region with the light receiving elements arranged in this way, it is possible to correct even if the amplitude of the scanner changes due to the influence of disturbance or the like, and to keep the amount of amplitude of the scanner constant. (Effect of claim 5).

  In the modification of the second embodiment of the light receiving element arrangement, the photodiode 25b is arranged at one corner of the two-dimensional scanning region, and in the modification of the third embodiment of the light receiving element arrangement, two photodiodes are arranged at one corner of the two-dimensional scanning region. A dimension PSD 27 is arranged. By measuring the maximum amplitude angle from the center of the two-dimensional scanning region with the light receiving elements arranged in this way, the amount of amplitude of the scanner can be kept constant (effect of claim 3). This is particularly effective when the center of the two-dimensional scanning region is constant without being offset.

Second embodiment

  Next, a radar apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a schematic view of the beam scanning unit in the radar apparatus according to the second embodiment as viewed from the upper surface of the radar apparatus. FIG. 11 is a flowchart of a routine for performing scanner amplitude correction in the radar apparatus according to the second embodiment. The configuration other than the beam scanning unit of the radar apparatus of this embodiment is the same as that of the first embodiment (see FIG. 1).

  The beam scanning unit of the present embodiment includes a two-dimensional scanner 21 that reflects on a reflecting surface, a half mirror 28 that distributes laser light reflected by the two-dimensional scanner 21 in front of the radar apparatus and in the direction of the amplitude angle measuring element, and two-dimensional Photodiodes 25a and 25b or two-dimensional PSDs 27 serving as light receiving elements for amplitude angle measurement for measuring the maximum amplitude angle of the reflecting surface of the scanner 21 are provided. As for the arrangement of the light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21, the first, second and third embodiments of the first embodiment and their modifications can be applied as they are.

  In FIG. 10, the beam scanning unit of the present embodiment has a structure in which the reflection surface of the two-dimensional scanner 21 arranged obliquely is irradiated with the laser light from the laser diode 22 and the half mirror 28 is placed in the path after reflection. is there. The laser light incident on the half mirror 28 is irradiated in front of the radar apparatus for measuring the distance to the target, and at the same time for measuring the maximum amplitude angle of the two-dimensional scanner 21 (downward in the figure). Also irradiated. By doing so, two types of measurement items can be shared by one laser diode 22, and the number of parts of the apparatus can be reduced.

  By the way, the maximum amplitude angle of the two-dimensional scanner 21 may change due to surrounding environmental changes and disturbances. In order to keep a predetermined two-dimensional scanning region constant, amplitude control is performed according to the maximum amplitude angle of the two-dimensional scanner 21. This control method will be described with reference to the flowchart of FIG. This control is appropriately performed after the distance measurement is started. Therefore, it may be performed every predetermined time, or may be performed before or after predetermined control. Hereinafter, description will be made in order from step S10.

  First, in step S10, it is determined whether or not the maximum amplitude angle of the two-dimensional scanner 21 is within a predetermined allowable range. If it is determined that the maximum amplitude angle is appropriate, the amplitude operation is continued with the current amplitude command value. If it is determined that the maximum amplitude angle is not appropriate, the process proceeds to step S11.

  Next, in step S11, it is determined whether or not the maximum amplitude angle is larger than a predetermined allowable range. If it is determined that the maximum amplitude angle is larger than the predetermined allowable range, the process proceeds to step S12. If it is determined that the maximum amplitude angle is smaller than the predetermined allowable range, the process proceeds to step S13.

  Next, in step S12, the current amplitude command value is decreased by a certain amount, and the process returns to step S10. On the other hand, in step S13, the current amplitude command value is increased by a certain amount, and the process returns to step S10.

  According to the above-described control, even if the maximum amplitude angle of the two-dimensional scanner 21 fluctuates after the amplitude operation, the amplitude amount of the two-dimensional scanner 21 is adjusted at any time, so that two-dimensional scanning is always performed with a constant amplitude amount. Can do. Therefore, it is possible to replace the relative shake angle position information obtained from the two-dimensional scanner drive unit 24 with the actual angle information of the amplitude angle.

  As described above, the radar apparatus according to the present embodiment includes the half mirror 28 (signal distribution unit) that distributes the signal transmitted through the two-dimensional scanner 21 to the transmission signal and the second signal, and receives the signal. The unit 3 (signal receiving device) receives the reflection signal of the transmission signal transmitted through the half mirror 28, and the amplitude angle measuring means uses the second signal transmitted through the half mirror 28 to perform a two-dimensional operation. The deflection angle position of the scanner 21 is optically measured.

  As a result, in a radar apparatus using a two-dimensional scanner that performs two-dimensional scanning by vertical and horizontal vibrations, the maximum amplitude angle of the two-dimensional scanning region can be obtained, and the phase of the vibration waveform obtained from the back electromotive force signal can be obtained. By combining with, the angle of the scanner reflecting surface can be obtained accurately, and stable target recognition is possible with the amplitude amount kept constant. Also, two types of measurement can be shared by one laser diode 22, and the number of parts of the apparatus can be reduced (effect of claim 6).

  While the first and second embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in addition to laser radar using infrared light, it can also be used for laser radar using visible light, radio wave radar using radio waves, ultrasonic radar using ultrasonic waves, and other radar devices.

  As described above, according to the present invention, in a radar apparatus using a two-dimensional scanner in which only the relative deflection angle of the scanner can be obtained, the light receiving element is arranged at the edge portion of the two-dimensional scanning region. The amplitude angle can be detected, and even if the deflection angle of the scanner fluctuates due to disturbance or the like, a constant amplitude amount can be maintained, and the distance detection performance can be improved.

1 is a configuration diagram of a radar apparatus according to a first embodiment of the present invention. It is a block diagram which illustrates a double gimbal type micro scanner. 3 is a configuration diagram specifically showing the configuration of a two-dimensional scanner driving unit 24. FIG. It is a timing chart of each part signal in a radar apparatus of the 1st example. It is the schematic diagram which looked at the beam scanning part 26 from the upper surface direction of the said radar apparatus. FIG. 6 is an explanatory diagram illustrating the arrangement (first form) of light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21. FIG. 5 is an explanatory diagram illustrating the arrangement (second form) of light receiving elements for measuring the maximum amplitude angle of the two-dimensional scanner 21. It is explanatory drawing which illustrates arrangement | positioning (3rd form) of the light receiving element for measuring the maximum amplitude angle of the two-dimensional scanner. 4 is a timing chart illustrating detection timing for measuring the maximum amplitude angle of the two-dimensional scanner 21. It is the schematic diagram which looked at the beam scanning part in the radar apparatus of 2nd Example from the upper surface of the radar apparatus. It is a flowchart of the routine which performs scanner amplitude correction | amendment in the radar apparatus of 2nd Example. It is a block diagram of a radar apparatus using a conventional two-dimensional scanner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radar apparatus 2 ... Signal transmission part 3 ... Signal receiving part 4 ... Signal processing part 21 ... Two-dimensional scanner 22 ... Laser diode 23 ... Light emitting element for amplitude angle measurement 24 ... Two-dimensional scanner drive part 25a, 25b ... Photodiode 26: Beam scanning unit 27: Two-dimensional PSD
DESCRIPTION OF SYMBOLS 28 ... Half mirror 31 ... Photodiode 32 ... Optical lens 41 ... Transmission pulse generation part 42 ... Transmission direction detection part 43 ... Drive signal adjustment part 44 ... Distance detection part 46 ... Target recognition logic part 51 ... Mirror 52 ... Cross beam 52 ' ... Vertical beam 53 ... Mirror support 54 ... Scanner base board 55, 55 '... Permanent magnet 61 ... Vertical drive signal generator 62 ... Horizontal drive signal generator 63, 63' ... Variable gain amplifier

Claims (6)

A signal transmission device for transmitting a signal;
A two-dimensional scanner that performs two-dimensional scanning using the signal sent from the signal sending device by vibrating vertically and horizontally;
A signal receiving device for receiving a reflected signal of the signal transmitted through the two-dimensional scanner;
An amplitude angle measuring device for optically measuring a deflection angle position of the two-dimensional scanner;
A radar apparatus comprising:   2. The radar apparatus according to claim 1, wherein the amplitude angle measuring device includes receiving elements respectively disposed at one longitudinal side and one lateral side in a two-dimensional scanning region of the two-dimensional scanner. .   The radar apparatus according to claim 1, wherein the amplitude angle measurement unit includes a receiving element arranged at one corner in a two-dimensional scanning region of the two-dimensional scanner.   The radar apparatus according to claim 1, wherein the amplitude angle measuring unit includes receiving elements respectively arranged at four vertical and horizontal sides in a two-dimensional scanning region of the two-dimensional scanner.   The radar apparatus according to claim 1, wherein the amplitude angle measuring unit includes receiving elements respectively disposed at two corner portions that are diagonal in the two-dimensional scanning region of the two-dimensional scanner. Signal distribution means for distributing the signal transmitted through the two-dimensional scanner into a transmission signal and a second signal;
The signal receiving device receives a reflection signal of the transmission signal transmitted through the signal distribution means;
6. The amplitude angle measuring unit optically measures a deflection angle position of the two-dimensional scanner by using a second signal sent through the signal distributing unit. The radar device according to any one of the above.

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