CN111007484A

CN111007484A - Single line laser radar

Info

Publication number: CN111007484A
Application number: CN201911379513.7A
Authority: CN
Inventors: 刘祖文; 金里; 蒋平; 杨伟; 路侑锡; 刘祺鑫; 曹睿; 李同辉; 杨米杰
Original assignee: United Microelectronics Center Co Ltd
Current assignee: United Microelectronics Center Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-14
Anticipated expiration: 2039-12-27
Also published as: CN111007484B

Abstract

The invention provides a single-line laser radar which comprises a first beam expanding collimating lens and a second beam expanding collimating lens which are adjacently arranged, wherein a laser detector is arranged at the focal length position of the first beam expanding collimating lens, and the main detection light path of the laser detector is superposed with the optical axis of the first beam expanding collimating lens; and a semiconductor laser module is arranged at the focal length position of the second beam expanding and collimating lens and deviates from the optical axis of the second beam expanding and collimating lens. The semiconductor laser module integrates a fast axis compression lens and a slow axis compression lens, and can emit round Gaussian beams or nearly round Gaussian beams through reasonable design; the distance between the principal ray of the semiconductor laser module and the optical axis of the second beam expanding and collimating lens is not more than the radius of the detection surface of the laser detector.

Description

Single line laser radar

Technical Field

The invention relates to the field of laser radars, in particular to a single-line laser radar.

Background

The laser radar is one of key core sensors for realizing intelligent sensing of the surrounding environment, has the characteristics of high ranging precision, long distance, quick response, strong anti-interference capability and the like, and is more and more widely applied to the fields of unmanned driving, robots, intelligent security, environment monitoring and the like. At present, the single-line laser radar has the problems that the detection distance is relatively short, the measurement reliability still needs to be further improved, in addition, the precise adjustment of the laser radar is time-consuming and low in efficiency, and in order to solve the problems, deep research is necessary.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the single-line laser radar with longer detection distance and higher reliability.

In order to achieve the purpose, the invention adopts the following technical scheme:

a single line laser radar comprises a first beam expanding and collimating lens and a second beam expanding and collimating lens which are arranged adjacently, wherein a laser detector is arranged at the focal length position of the first beam expanding and collimating lens, and the main detection light path of the laser detector is superposed with the optical axis of the first beam expanding and collimating lens; a semiconductor laser module is arranged at the focal length position of the second beam expanding and collimating lens and deviates from the optical axis of the second beam expanding and collimating lens, and the semiconductor laser module emits multi-pulse laser of round Gaussian beams or nearly round Gaussian beams; the distance between the principal ray of the semiconductor laser module and the optical axis of the second beam expanding and collimating lens is not more than the radius of the detection surface of the laser detector. The design ensures that the spot from which the laser is emitted is always within the field of view of the detector.

Furthermore, the semiconductor laser module comprises a hybrid integrated base plate, and a pulse semiconductor laser packaged by a patch is arranged on the hybrid integrated base plate.

Furthermore, the pulse semiconductor laser emits an elliptical Gaussian beam, and the hybrid integrated baseplate correspondingly comprises a fast-axis lens and a slow-axis lens, so that the light emitted by the pulse semiconductor laser is compressed into a round Gaussian beam or a near-round Gaussian beam after passing through the slow-axis lens and the fast-axis lens.

The semiconductor laser module deviates from the optical axis by a small distance integrally, so that the main ray is parallel to the main detection light path at the edge of the field of view of the receiving end, the light beam is ensured to be always in the field of view of the receiving end at a far distance, and the semiconductor laser module emitting a round Gaussian beam or a nearly round Gaussian beam is combined, so that the subsequent beam expanding collimation is facilitated, and the effective detection distance of the laser radar is increased; meanwhile, compared with other packaging modes (such as a typical TO packaging mode, in the packaging mode, the length of a pin line is difficult TO control, and the position of the laser is difficult TO accurately determine), the surface mount packaging mode of the laser transmitting module can more accurately control the position of the laser, so that the assembly and adjustment precision can be improved, and the assembly and adjustment complexity can be reduced; meanwhile, multi-pulse laser emission is adopted, so that multiple independent measurements can be performed on a detection point, and the measurement reliability is improved; and through SMD encapsulation, the part size is littleer, and parasitic electrical parameter reduces, is convenient for realize narrower pulse compression.

Drawings

Fig. 1 is a schematic structural view of a semiconductor laser module in the embodiment.

Fig. 2 is a schematic diagram of a transmit-receive optical path according to the embodiment.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

A single line laser radar comprises a first beam expanding and collimating lens and a second beam expanding and collimating lens which are arranged adjacently, wherein a laser detector is arranged at the focal length position of the first beam expanding and collimating lens, and the main detection light path of the laser detector is superposed with the optical axis of the first beam expanding and collimating lens; and a semiconductor laser module is arranged at the focal length position of the second beam expanding collimating lens in a manner of deviating from the optical axis of the second beam expanding collimating lens, and the distance between the principal ray of the semiconductor laser module and the optical axis of the second beam expanding collimating lens is not more than the radius of the detection surface of the laser detector. As shown in fig. 1, the semiconductor laser module includes a hybrid integrated base plate 1 (a PCB board may be used), a pulse semiconductor laser 2, a fast axis lens 3, and a slow axis lens 4 packaged by a patch are disposed on the hybrid integrated base plate 1, and the slow axis lens 4 and the fast axis lens 3 are disposed in front of a light outlet of the pulse semiconductor laser 2. The pulse semiconductor laser 2 emits an elliptic Gaussian beam, and the elliptic Gaussian beam is compressed into a round Gaussian beam or a near-round Gaussian beam after passing through the fast axis lens 3 and the slow axis lens 4, so that the difference of the fast axis and the slow axis directions is reduced in a fast axis and slow axis compression mode, good conditions are provided for subsequent further beam expanding collimation, and therefore the effective detection distance can be well extended.

In this embodiment, the laser uses a pulse semiconductor laser with a wavelength of 905nm, the light outlet of the laser is 100um x 1um, and emits a corresponding elliptical gaussian beam, the slow axis divergence angle is 25 degrees, the fast axis divergence angle is 7 degrees, the fast axis uses a 100um focal length cylindrical fast axis lens 3, the slow axis uses a slow axis lens 4 of a 5 mm focal length cylinder as a starting point, and the distance is optimized by zemax, so that a round gaussian beam or an approximately round gaussian beam can be obtained. For a simpler explanation, in terms of designing the transmitting and receiving optical paths, as shown in fig. 2, it is assumed that the first beam expanding and collimating lens 6 and the second beam expanding and collimating lens 5 both use a lens with f being 28mm, and the receiving end uses a laser detector 8 with a receiving area of half 800 um. Therefore, the semiconductor laser module 7 needs to deviate from the optical axis 400um of the second beam expanding and collimating lens 5, and light beams can always fall in the field range of the receiving end after being transmitted to a remote position to detect the object to be detected 9. In the aspect of multi-pulse echo detection, taking double pulses as an example, the scanning frequency of the laser radar scanning speed is assumed to be 15HZ, and the angular resolution is 0.36 degrees. The divergence angle of the laser 2mrad is 0.114 °, the time interval of the double pulses may be set to 2us, and the deviation of the two pulse angles is 0.0108 °, 0.0108/0.114 is 9.5%, the coincidence ratio is greater than 90%, and the two pulses are measured at the same point. The reliability of signal detection is expected to be further enhanced by using a larger number of pulse groups with shorter time intervals. Therefore, the laser pulse is narrower, the beam quality is better, the transmission distance is longer, and the detection result is more reliable.

In practical use, the light-emitting hole of the laser is not limited to 100um × 1um, but may be 100um × 10um, 160um × 8um, and the like; the focal length of the collimation and beam expansion lens is not limited to 28mm, the good light beam expansion and collimation effect can be achieved in the range of 10-80 mm, and meanwhile, the focal length of a lens at a receiving end can be different from that at a transmitting end; the double-pulse distance measurement is not limited to a pulse pair, and may be a pulse pair composed of 3 pulses and 4 pulses.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. A single line laser radar is characterized by comprising a first beam expanding collimating lens and a second beam expanding collimating lens which are arranged adjacently, wherein a laser detector is arranged at the focal length position of the first beam expanding collimating lens, and the main detection light path of the laser detector is superposed with the optical axis of the first beam expanding collimating lens; a semiconductor laser module is arranged at the focal length position of the second beam expanding and collimating lens and deviates from the optical axis of the second beam expanding and collimating lens, and the semiconductor laser module emits multi-pulse laser of round Gaussian beams or nearly round Gaussian beams; the distance between the principal ray of the semiconductor laser module and the optical axis of the second beam expanding and collimating lens is not more than the radius of the detection surface of the laser detector.

2. A singlet lidar according to claim 1 wherein: the semiconductor laser module comprises a hybrid integrated base plate, and a pulse semiconductor laser packaged by a patch is arranged on the hybrid integrated base plate.

3. A singlet lidar according to claim 2, wherein: the pulse semiconductor laser emits an elliptic Gaussian beam, and the hybrid integrated baseplate correspondingly comprises a fast-axis lens and a slow-axis lens, so that the light emitted by the pulse semiconductor laser is compressed into a round Gaussian beam or a near-round Gaussian beam after passing through the slow-axis lens and the fast-axis lens.

4. A singlet lidar according to claim 1 wherein: the ratio of the angle deviation of two adjacent pulse lasers to the divergence angle of the light emitted by the semiconductor laser module is not more than 10%.

5. A singlet lidar according to claim 1 wherein: the focal lengths of the first beam expanding and collimating lens and the second beam expanding and collimating lens are between 10mm and 80 mm.

6. A singlet lidar according to claim 1 wherein: the focal lengths of the first beam expanding and collimating lens and the second beam expanding and collimating lens are the same.