CN210155331U - Laser radar - Google Patents
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- CN210155331U CN210155331U CN201920631078.1U CN201920631078U CN210155331U CN 210155331 U CN210155331 U CN 210155331U CN 201920631078 U CN201920631078 U CN 201920631078U CN 210155331 U CN210155331 U CN 210155331U
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Abstract
The utility model discloses a laser radar. This laser radar includes: the device comprises a light generating unit, a light transmitting and receiving unit and a control processing unit; the light generating unit is used for generating frequency-modulated continuous waves; the light transmitting and receiving unit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam, transmitting the detection beam and receiving an echo beam reflected by a target object; the control processing unit is used for determining the related information of the target object according to the reference beam and the echo beam; wherein the related information of the target object comprises at least one of the azimuth, the speed magnitude and the motion direction. The embodiment of the utility model provides a technical scheme can realize the accurate measurement to the target object to can avoid making mistakes to the information judgment of target object.
Description
Technical Field
The embodiment of the utility model provides a relate to laser detection technical field, especially relate to a laser radar.
Background
The laser radar is a radar system that emits a laser beam to detect a characteristic quantity such as a position and a velocity of a target object. The working principle of the laser radar is as follows: the method comprises the steps of transmitting a detection signal (laser beam) to a target object, comparing a received signal (target echo or echo signal) reflected from the target object with the transmitted signal, and carrying out appropriate processing to obtain relevant information of the target object, such as parameters of target distance, direction, height, speed, posture, even shape and the like, so as to detect, track and identify the target object.
Currently, lidar systems are typically pulsed lidar which determine the range of a target object by measuring the time of pulse propagation. However, the pulse lidar has poor interference rejection, and cannot identify whether the detected pulse is emitted by the pulse lidar or is emitted by other laser radar systems. When a plurality of laser radars work simultaneously, a plurality of false targets appear in the output point cloud picture, so that the information of the target object is judged wrongly.
SUMMERY OF THE UTILITY MODEL
An embodiment of the utility model provides a laser radar can realize the accurate measurement to the target to can avoid the information judgement of target object to make mistakes.
An embodiment of the utility model provides a laser radar, this laser radar includes: the device comprises a light generating unit, a light transmitting and receiving unit and a control processing unit;
the light generating unit is used for generating frequency-modulated continuous waves;
the light transmitting and receiving unit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam, transmitting the detection beam and receiving an echo beam reflected by a target object;
the control processing unit is used for determining the related information of the target object according to the reference beam and the echo beam;
wherein the related information of the target object comprises at least one of orientation, speed magnitude and moving direction.
Furthermore, the light generating unit comprises a laser subunit, an intensity modulating subunit, a continuous frequency modulation signal source and a signal amplifying subunit;
the laser subunit is used for emitting a single-frequency light beam, and the single-frequency light beam is incident to the intensity modulation subunit;
the intensity modulation subunit is used for carrying out amplitude modulation on the single-frequency light beam under the driving of the continuous frequency modulation signal source to form an initial frequency modulation continuous wave;
the signal amplification subunit is used for increasing the power of the initial frequency modulation continuous wave to form the frequency modulation continuous wave.
Further, the laser subunit includes a single-frequency polarization-maintaining laser, the intensity modulation subunit includes a polarization-maintaining lithium niobate intensity modulator, the continuous frequency modulation signal source includes a chirp signal source, and the signal amplification subunit includes a polarization-maintaining fiber amplifier.
Furthermore, the light transmitting and receiving unit comprises a beam splitting subunit, a detection signal transmitting subunit, an echo signal receiving subunit and a reference signal processing subunit;
the beam splitting subunit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam according to a preset intensity ratio; wherein the intensity of the probe beam is greater than the intensity of the reference beam;
the detection signal transmitting subunit is used for transmitting and transmitting the detection light beam;
the echo signal receiving subunit is used for receiving the echo light beam;
the reference signal processing subunit is used for frequency shifting the reference beam;
the control processing unit is used for determining the related information of the target object according to the echo light beam and the reference light beam after frequency shift.
Further, the optical axis of the probe signal transmitting subunit and the optical axis of the echo signal receiving subunit are coaxially arranged.
Further, the beam splitting sub-unit comprises a polarization-preserving beam splitter, and the reference signal processing sub-unit comprises a polarization-preserving acousto-optic frequency shifter;
the polarization-maintaining circulator comprises a first port, a second port and a third port; the detection signal transmitting subunit comprises an optical path between the first port and the second port, and the echo signal receiving subunit comprises an optical path between the second port and the third port.
Furthermore, the detection signal transmitting subunit further comprises a beam expanding and collimating subunit and a two-dimensional scanning subunit;
the beam expanding and collimating subunit is used for expanding and collimating the detection beam emitted by the second port;
the two-dimensional scanning subunit is used for deflecting the expanded and collimated detection beam on a first plane and a second plane; the first plane intersects the second plane.
Further, the two-dimensional scanning subunit includes a combination of a horizontal prism and a vertical prism, a combination of a rotating prism and a mechanical micro-vibration mirror, a combination of a rotating prism and a one-dimensional MEMS scanning mirror, a combination of a one-dimensional MEMS scanning mirror and a one-dimensional mechanical micro-vibration mirror, a two-dimensional MEMS scanning mirror or a two-dimensional mechanical vibration mirror.
Furthermore, the control processing unit comprises a coherent processing subunit, a photoelectric conversion subunit, an analog-to-digital conversion subunit and an information acquisition subunit;
the coherent processing subunit is used for mixing the echo light beam with the reference light beam and outputting a light beam to be processed;
the photoelectric conversion subunit is used for converting the light beam to be processed into an analog electric signal;
the analog-to-digital conversion subunit is used for converting the analog electric signal into a digital electric signal;
the information acquisition subunit is used for acquiring the related information of the target object according to the digital electric signal.
Further, the coherent processing subunit includes a polarization maintaining coupler, the photoelectric conversion subunit includes a balanced detector, and the information acquisition subunit includes a field programmable gate array.
The laser radar provided by the embodiment of the utility model comprises a light ray generating unit, a light ray transmitting and receiving unit and a control processing unit; the light ray generating unit is used for generating frequency-modulated continuous waves; the light transmitting and receiving unit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam, transmitting the detection beam and receiving an echo beam reflected by a target object; the control processing unit is used for determining the related information of the target object according to the reference beam and the echo beam; the polarization states of the detection light beam, the reference light beam and the echo light beam are the same as the polarization state of the frequency modulation continuous wave; the related information of the target object includes at least one of an orientation, a velocity magnitude, and a moving direction. The relevant information of the target object can be calculated and determined only by using the detection beam emitted by the laser radar, the echo beam reflected by the target object by the detection beam and the reference beam corresponding to the detection beam, and the influence of the detection beam or the echo beam of other laser radars is not easy to influence, so that the accurate measurement of the target object is favorably realized; meanwhile, the movement direction and the speed of the target object can be accurately obtained by combining a coherent detection mode and utilizing a Doppler principle, so that the detection precision can be improved, and the target object can be accurately measured.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a laser radar according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another laser radar provided in an embodiment of the present invention;
fig. 3 is a schematic diagram of a frequency of a chirp continuous signal source according to an embodiment of the present invention changing with time;
fig. 4 is a schematic structural diagram of another laser radar provided by an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another laser radar according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of another laser radar according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of another laser radar according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Fig. 1 is a schematic structural diagram of a laser radar according to an embodiment of the present invention. Referring to fig. 1, the laser radar 10 includes: a light generating unit 110, a light transmitting and receiving unit 120, and a control processing unit 130; the light generating unit 110 is used for generating frequency-modulated continuous waves; the light transmitting and receiving unit 120 is configured to split the frequency-modulated continuous wave into a probe beam and a reference beam, transmit the probe beam, and receive an echo beam reflected by the target object 20; the control processing unit 130 is used for determining the relevant information of the target object 20 according to the reference beam and the echo beam; wherein the related information of the target object 20 includes at least one of the azimuth, the speed magnitude and the moving direction.
Wherein, the frequency modulated continuous wave generated by the light generating unit 110 is transmitted to the light transmitting and receiving unit 120; the light receiving and emitting unit 120 divides the frequency modulated continuous wave into two beams, wherein one beam is used as a probe beam, and the other beam is used as a reference beam; the detection beam is emitted by the laser radar 10 and irradiates a target area, the target area comprises a plurality of target objects 20, the beam reflected by the target objects 20 is called an echo beam, and the control processing unit 130 can determine the relevant information of the target objects according to the echo beam and the reference beam; by scanning the probe beam in a spatial range, information on the spatial range around the laser radar 10 can be obtained. The information of the spatial range includes at least one of the number, size, orientation, speed magnitude and moving direction of the target object 20.
The laser radar 10 provided by the embodiment of the utility model detects based on the frequency modulated continuous wave, and can realize the accurate measurement of the relevant information of the target object 20; meanwhile, the velocity and the moving direction of the target object 20 can be accurately measured in real time by combining a coherent detection mode and utilizing a Doppler principle. When the laser radar is applied to a vehicle-mounted system, the safety guarantee is favorably improved.
Optionally, fig. 2 is a schematic structural diagram of another laser radar provided in the embodiment of the present invention. Referring to fig. 2, in the laser radar 10, the light generating unit 110 includes a laser subunit 111, an intensity modulating subunit 112, a continuous frequency modulation signal source 113, and a signal amplifying subunit 114; the laser subunit 111 is configured to emit a single-frequency light beam, and the single-frequency light beam is incident to the intensity modulation subunit 112; the intensity modulation subunit 112 is configured to perform amplitude modulation on the single-frequency light beam under the driving of the continuous frequency modulation signal source 113, so as to form an initial frequency modulation continuous wave; the signal amplification subunit 114 is configured to increase the power of the initial frequency-modulated continuous wave to form a frequency-modulated continuous wave.
Wherein, the laser subunit 111 emits a single-frequency laser beam; the single-frequency laser beam is incident to the intensity modulation subunit 112, and the parameters such as the light intensity and the phase of the single-frequency laser beam incident to the intensity modulation subunit 112 are modulated by using the continuous frequency modulation signal source 113 to obtain an initial frequency modulation continuous wave; the initial frequency-modulated continuous wave is incident to the signal amplification subunit 114, and the signal amplification subunit 114 further increases the intensity of the initial frequency-modulated continuous wave to meet the detection requirement. It should be noted that the amplitude, power and intensity are all in positive correlation.
The light generating unit 110 of the laser radar 10 employs an external modulation mode, that is, a modulation signal is loaded after a single-frequency laser beam is formed, and since the external modulation mode does not have additional frequency modulation of the laser subunit 111, combined secondary distortion can be effectively overcome.
Wherein, intensity modulation subunit 112 can modulate single-frequency laser beam based on electro-optic effect, magneto-optic effect, acousto-optic effect or other effects, the embodiment of the utility model provides a do not limit to this.
Fig. 3 is a schematic diagram of a frequency of a chirped continuous signal source changing with time according to an embodiment of the present invention, wherein a horizontal axis X represents time, a vertical axis Y represents frequency, a first signal L41 represents a local oscillator signal (i.e., a signal of a reference beam), a second signal L42 represents an echo signal (i.e., a signal of an echo beam), a time difference △ t is a time delay of the echo signal relative to the local oscillator signal, and a distance of a target object can be correspondingly analyzed.
It should be noted that fig. 3 only shows three frequency variation cycles by way of example, and only illustrates the variation rule of the chirp continuous signal, and does not constitute a limitation on the chirp continuous signal provided by the embodiment of the present invention. In other embodiments, the duration of the continuous fm signal source 113 may be set according to the actual requirement of the laser radar 10, which is not limited by the embodiment of the present invention.
Optionally, with continued reference to fig. 2, the laser subunit 111 includes a single-frequency polarization-maintaining laser, the intensity modulation subunit 112 includes a lithium polarization-maintaining niobate intensity modulator, the continuous frequency modulation signal source 113 includes a chirp signal source, and the signal amplification subunit 114 includes a polarization-maintaining fiber amplifier.
With such an arrangement, it is favorable to ensuring that the polarization states of the light beams of the transmission nodes in the laser radar 10 are all consistent, and it is favorable to ensuring the detection accuracy.
The single-frequency polarization-maintaining laser generates a single-frequency polarization-maintaining laser beam, the chirp signal source drives the polarization-maintaining lithium niobate intensity modulator to modulate the single-frequency polarization-maintaining laser beam to form an initial frequency modulation continuous wave, and the initial frequency modulation continuous wave with a narrow line width and high power is formed after passing through the polarization-maintaining optical fiber amplifier.
For example, the single-frequency polarization maintaining laser may be a single-frequency polarization maintaining fiber laser, a single-frequency polarization maintaining semiconductor laser, or other types of single-frequency polarization maintaining lasers known to those skilled in the art, and the embodiment of the present invention is not limited thereto.
For example, the wavelength band of the single-frequency polarization maintaining laser may be 1.064 μm, 1.55 μm, 2 μm, or other wavelength bands known to those skilled in the art, and the embodiment of the present invention is not limited thereto.
Illustratively, the frequency of the signal of the chirp signal source varies with time, and the frequency variation due to modulation at the leading and trailing edges of the pulse causes the signal to be spectrally broadened, and is described by a chirp coefficient (also called a line width broadening factor), and the variation can be linear (as in fig. 3) or non-linear.
Illustratively, the lithium-polarization-maintaining niobate intensity modulator employs an electro-optic effect to amplitude modulate a single-frequency light beam.
The polarization maintaining fiber amplifier can amplify the power of the initial frequency modulation continuous wave to form a narrow-linewidth high-power frequency modulation continuous wave. Illustratively, the polarization maintaining Fiber Amplifier may be an Erbium-Doped Fiber Amplifier (EDFA), a praseodymium-Doped Fiber Amplifier (PDFA), a Niobium-Doped Fiber Amplifier (NDFA), an Ytterbium-Doped Fiber Amplifier (YDFA), or other types of Fiber amplifiers, which are not limited in this respect.
Thus, the light generating unit 110 can generate and amplify the frequency modulated continuous wave.
Optionally, with reference to fig. 2, the light transmitting and receiving unit 120 includes a beam splitting subunit 121, a detection signal transmitting subunit 122, an echo signal receiving subunit 123, and a reference signal processing subunit 124; the beam splitting subunit 121 is configured to split the frequency-modulated continuous wave into a probe beam and a reference beam according to a preset intensity ratio; wherein the intensity of the probe beam is greater than the intensity of the reference beam; the probe signal transmitting subunit 122 is configured to transmit and transmit a probe beam; the echo signal receiving subunit 123 is configured to receive an echo light beam; the reference signal processing subunit 124 is configured to shift the frequency of the reference beam; the control processing unit 130 is used for determining the relevant information of the target object 20 according to the echo light beam and the frequency-shifted reference light beam.
The laser radar 10 uses a coherent detection method to accurately measure the speed and the moving direction of the target object 20.
For example, the predetermined intensity ratio of the probe beam to the reference beam may be 9:1, 8:2 or other suitable ratios, which may be satisfied with the detection and signal processing requirements, and the embodiment of the present invention does not limit this.
Optionally, the optical axis of the probe signal transmitting subunit 122 is coaxially arranged with the optical axis of the echo signal receiving subunit 123.
With this arrangement, the structure of the light transmitting and receiving unit 120 is simplified, the number of optical elements is reduced, and the space is saved, thereby reducing the space occupied by the entire laser radar 10.
Optionally, fig. 4 is a schematic structural diagram of another laser radar provided in the embodiment of the present invention. With reference to fig. 2 and 4, the splitting subunit 121 comprises a polarization-preserving splitter 1211, and the reference signal processing subunit 124 comprises a polarization-preserving acousto-optic frequency shifter 1241; also included is a polarization maintaining circulator 125, the polarization maintaining circulator 125 including a first port 1251, a second port 1252, and a third port 1253; the probe signal transmitting subunit 122 includes an optical path between the first port 1251 and the second port 1252, and the echo signal receiving subunit 123 includes an optical path between the second port 1252 and the third port 1253.
The polarization maintaining beam splitter 1211 splits the frequency-modulated continuous wave into two beams according to a preset intensity ratio, the probe beam with higher intensity is emitted after passing through the first port 1251 and the second port 1252 of the polarization maintaining circulator 125, and the echo beam reflected by the target object 20 is incident to the polarization maintaining circulator 125 through the second port 1252 and is output through the third port 1253. The reference beam with a lower intensity is passed through the polarization-preserving acousto-optic frequency shifter 1241 (in an exemplary embodiment, the polarization-preserving acousto-optic frequency shifter 1241 is controlled by the driver 1242), and then compared with the echo beam in the control processing unit 130 to obtain the related information of the target object 20.
For example, the polarization maintaining circulator 125 may be a polarization maintaining fiber circulator, or may be a polarization maintaining circulator having a spatial structure formed by a polarization splitting prism, an 1/4 wave plate, and a 1/2 wave plate, or may be another type of polarization maintaining circulator, which is not limited in this embodiment of the present invention.
Optionally, with continued reference to fig. 2 and 4, the probe signal emitting subunit 122 further includes a beam expanding and collimating subunit 1261 and a two-dimensional scanning subunit 1262; the beam expanding and collimating subunit 1261 is configured to expand and collimate the probe beam emitted from the second port; the two-dimensional scanning subunit 1262 is configured to deflect the expanded and collimated probe beam on a first plane and a second plane; the first plane intersects the second plane.
The beam expanding and collimating subunit 1261 and the two-dimensional scanning subunit 1262 can be collectively referred to as an optical system unit 126. The light beam emitted from the second port 1252 of the polarization maintaining circulator 125 passes through the beam expanding and collimating subunit 1261 and the two-dimensional scanning subunit 1262 and is then emitted.
For example, the beam expanding and collimating subunit 1261 may include a beam expanding lens, a collimating lens, or other optical elements known to those skilled in the art, and the embodiments of the present invention are not limited thereto.
Optionally, the two-dimensional scanning subunit 1262 includes a combination of a horizontal prism and a vertical prism, a combination of a rotating prism and a mechanical micro-galvanometer, a combination of a rotating prism and a one-dimensional MEMS scanning mirror, a combination of a one-dimensional MEMS scanning mirror and a one-dimensional mechanical micro-galvanometer, a two-dimensional MEMS scanning mirror or a two-dimensional mechanical galvanometer.
The horizontal prism, the vertical prism, the rotating prism, the mechanical micro-vibration mirror and the one-dimensional MEMS scanning mirror can be regarded as one-dimensional scanning mirrors, and the two one-dimensional scanning mirrors are combined to realize scanning of a two-dimensional space; or the two-dimensional scanning mirror is directly utilized to realize the scanning of the two-dimensional space so as to obtain the three-dimensional space coordinate of the target object 20; based on the coherent detection and the doppler principle, the velocity and the moving direction of the target object 20 can be obtained. Therefore, the five-dimensional information detection of the target object 20 can be realized, and the five-dimensional information detection system is strong in anti-interference performance, accurate in detection and high in sensitivity, and is favorable for providing higher safety guarantee for unmanned driving when being applied to a vehicle-mounted system.
In addition, the optical scanning system of the laser radar 10 only needs to rotate the prism or the MEMS micro-vibrating mirror or the mechanical vibrating mirror, the laser transmitting and receiving lens and various control circuits do not need to rotate, and power is directly supplied to the circuits without other modes.
Exemplarily, fig. 5 is a schematic structural diagram of another laser radar provided by the embodiment of the present invention, fig. 6 is a schematic structural diagram of another laser radar provided by the embodiment of the present invention, and fig. 7 is a schematic structural diagram of another laser radar provided by the embodiment of the present invention, which all shows an optical scanning system of the laser radar 10, and this optical scanning system adopts a coaxial system.
The optical scanning system comprises, among other things, an optical fiber 301 (which can be understood as the second port 1252 of the polarization-maintaining circulator 125 in fig. 4), a collimating and receiving lens 302, and a two-dimensional scanning sub-unit, which comprises, in fig. 5 and 6, a first scanning mirror 303 and a second scanning mirror 304, and, in fig. 7, a two-dimensional scanning sub-unit, which comprises a two-dimensional scanning mirror 305. The collimating and receiving lens 302 collimates the output beam of the polarization-maintaining circulator 125 and transmits and converges the received echo beams into the polarization-maintaining circulator 125.
Illustratively, in FIG. 5, first scanning mirror 303 is a first rotating prism and second scanning mirror 304 is a second rotating prism. The first rotating prism is rotated, laser is scanned in the vertical direction through a rotating corner and is shot on the side face (working face) of the second rotating prism, the second rotating prism reflects a laser beam out according to a set angle through rotation, the laser beam is scanned in the horizontal direction, and scanning in a certain angle in the vertical direction and the horizontal direction is realized through the two rotating prisms to form a planar array.
Illustratively, in fig. 6, the first scanning mirror 303 is a MEMS micro-galvanometer or a one-dimensional mechanical galvanometer, and the second scanning mirror 304 is a rotating prism. The laser is irradiated on the MEMS micro-vibrating mirror or the one-dimensional mechanical vibrating mirror, so that the laser scans in the vertical direction and is irradiated on the side surface (working surface) of the rotating prism, the rotating prism reflects the laser beam out according to a set angle through rotation, and the laser scans in the horizontal direction, so that the scanning in certain angles in the vertical direction and the horizontal direction is realized, and an area array is formed.
Illustratively, the two-dimensional scanning mirror 305 in fig. 7 is a two-dimensional MEMS scanning mirror, a two-dimensional mechanical galvanometer, or other types of two-dimensional scanning mirrors known to those skilled in the art, and the two-dimensional scanning mirror 305 can simultaneously scan in the horizontal and vertical directions to form an area array in the detection area.
Fig. 5 and 6 only show an exemplary combination of two one-dimensional scanning mirrors, but do not limit the laser radar 10 according to the embodiment of the present invention. In other embodiments, other types of one-dimensional scanning mirror combinations known to those skilled in the art may be further provided according to the actual requirements of the laser radar 10 to implement two-dimensional scanning, which is not limited by the embodiments of the present invention.
Optionally, with continued reference to fig. 2 or fig. 4, the control processing unit 130 includes a coherent processing subunit 131, a photoelectric conversion subunit 132, an analog-to-digital conversion subunit 133, and an information acquisition subunit 134; the coherent processing subunit 131 is configured to mix the echo beam with the reference beam and output a beam to be processed; the photoelectric conversion subunit 132 is configured to convert the light beam to be processed into an analog electrical signal; the analog-to-digital conversion subunit 133 is configured to convert the analog electrical signal into a digital electrical signal; the information acquiring subunit 134 is configured to acquire information related to the target object according to the digital electrical signal.
Thus, the reference signal and the echo signal are mixed, and after photoelectric conversion and analog-to-digital conversion, the information acquisition subunit 134 is used to perform corresponding algorithm processing, so that information such as two-dimensional coordinates, distance, motion direction, speed and the like of the target object can be output, and five-dimensional detection is realized.
It should be noted that the laser radar 10 may further include other components or assemblies known to those skilled in the art, such as a signal output unit 135, for outputting the five-dimensional information of the target object to a total control system or to a display interface, which is not limited by the embodiment of the present invention.
Optionally, with continued reference to fig. 2 or fig. 4, the coherent processing subunit 131 includes a polarization maintaining coupler, the photoelectric conversion subunit 132 includes a balanced detector, and the information acquisition subunit 134 includes a field programmable gate array.
The echo signal and the frequency-shifted reference signal are mixed in the polarization-preserving coupler and then output, and the noise can be reduced by utilizing the balance detector, so that the detection precision and the sensitivity can be improved; then sampling by A/D (analog-to-digital conversion), and carrying out algorithm processing by using a field programmable gate array to obtain the related information of the target object.
It should be noted that fig. 1, fig. 2, and fig. 4 only exemplarily show the signal transmission relationship among the components in the lidar 10, but do not constitute a limitation on the spatial relative position. In other embodiments, the relative positions between the components of the laser radar 10 may be set according to the actual requirements of the laser radar, which is not limited by the embodiment of the present invention.
The embodiment of the utility model provides a laser radar 10 realizes the accurate measurement to the relevant information of target object based on frequency modulation continuous wave laser coherent detection and Doppler principle; meanwhile, the five-dimensional information detection of the target object can be realized by combining a two-dimensional optical scanning system.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (10)
1. A lidar, comprising: the device comprises a light generating unit, a light transmitting and receiving unit and a control processing unit;
the light generating unit is used for generating frequency-modulated continuous waves;
the light transmitting and receiving unit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam, transmitting the detection beam and receiving an echo beam reflected by a target object;
the control processing unit is used for determining the related information of the target object according to the reference beam and the echo beam;
wherein the related information of the target object comprises at least one of orientation, speed magnitude and moving direction.
2. The lidar of claim 1, wherein the light generating unit comprises a laser subunit, an intensity modulating subunit, a continuous frequency modulation signal source, and a signal amplifying subunit;
the laser subunit is used for emitting a single-frequency light beam, and the single-frequency light beam is incident to the intensity modulation subunit;
the intensity modulation subunit is used for carrying out amplitude modulation on the single-frequency light beam under the driving of the continuous frequency modulation signal source to form an initial frequency modulation continuous wave;
the signal amplification subunit is used for increasing the power of the initial frequency modulation continuous wave to form the frequency modulation continuous wave.
3. The lidar of claim 2, wherein the laser subunit comprises a single frequency polarization-maintaining laser, the intensity modulation subunit comprises a lithium polarization-maintaining niobate intensity modulator, the continuous frequency modulation signal source comprises a chirp signal source, and the signal amplification subunit comprises a polarization-maintaining fiber amplifier.
4. The lidar of claim 1, wherein the light transmitting and receiving unit comprises a beam splitting subunit, a probe signal transmitting subunit, an echo signal receiving subunit, and a reference signal processing subunit;
the beam splitting subunit is used for splitting the frequency-modulated continuous wave into a detection beam and a reference beam according to a preset intensity ratio; wherein the intensity of the probe beam is greater than the intensity of the reference beam;
the detection signal transmitting subunit is used for transmitting and transmitting the detection light beam;
the echo signal receiving subunit is used for receiving the echo light beam;
the reference signal processing subunit is used for frequency shifting the reference beam;
the control processing unit is used for determining the related information of the target object according to the echo light beam and the reference light beam after frequency shift.
5. The lidar of claim 4, wherein an optical axis of the probe signal transmitting subunit is disposed coaxially with an optical axis of the echo signal receiving subunit.
6. The lidar of claim 5, wherein the beam splitting sub-unit comprises a polarization-preserving beam splitter, and the reference signal processing sub-unit comprises a polarization-preserving acousto-optic frequency shifter;
the polarization-maintaining circulator comprises a first port, a second port and a third port; the detection signal transmitting subunit comprises an optical path between the first port and the second port, and the echo signal receiving subunit comprises an optical path between the second port and the third port.
7. The lidar of claim 6, wherein the probe signal transmitting subunit further comprises a beam expanding collimating subunit and a two-dimensional scanning subunit;
the beam expanding and collimating subunit is used for expanding and collimating the detection beam emitted by the second port;
the two-dimensional scanning subunit is used for deflecting the expanded and collimated detection beam on a first plane and a second plane; the first plane intersects the second plane.
8. The lidar of claim 7, wherein the two-dimensional scanning subunit comprises a combination of a horizontal prism and a vertical prism, a combination of a rotating prism and a mechanical galvanometer, a combination of a rotating prism and a one-dimensional MEMS scanning mirror, a combination of a one-dimensional MEMS scanning mirror and a one-dimensional mechanical galvanometer, a two-dimensional MEMS scanning mirror, or a two-dimensional mechanical galvanometer.
9. The lidar of claim 1, wherein the control processing unit comprises a coherent processing subunit, a photoelectric conversion subunit, an analog-to-digital conversion subunit, and an information acquisition subunit;
the coherent processing subunit is used for mixing the echo light beam with the reference light beam and outputting a light beam to be processed;
the photoelectric conversion subunit is used for converting the light beam to be processed into an analog electric signal;
the analog-to-digital conversion subunit is used for converting the analog electric signal into a digital electric signal;
the information acquisition subunit is used for acquiring the related information of the target object according to the digital electric signal.
10. The lidar of claim 9, wherein the coherent processing subunit comprises a polarization maintaining coupler, the photoelectric conversion subunit comprises a balanced detector, and the information acquisition subunit comprises a field programmable gate array.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109991622A (en) * | 2019-04-30 | 2019-07-09 | 深圳市镭神智能系统有限公司 | A kind of laser radar |
| WO2023005716A1 (en) * | 2021-07-30 | 2023-02-02 | 北京万集科技股份有限公司 | Motion direction measurement method and laser radar system |
| CN117347980A (en) * | 2023-12-04 | 2024-01-05 | 深圳市镭神智能系统有限公司 | Large-view-field laser radar and carrier |
-
2019
- 2019-04-30 CN CN201920631078.1U patent/CN210155331U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109991622A (en) * | 2019-04-30 | 2019-07-09 | 深圳市镭神智能系统有限公司 | A kind of laser radar |
| WO2023005716A1 (en) * | 2021-07-30 | 2023-02-02 | 北京万集科技股份有限公司 | Motion direction measurement method and laser radar system |
| CN117347980A (en) * | 2023-12-04 | 2024-01-05 | 深圳市镭神智能系统有限公司 | Large-view-field laser radar and carrier |
| CN117347980B (en) * | 2023-12-04 | 2024-03-12 | 深圳市镭神智能系统有限公司 | Large-view-field laser radar and carrier |
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