CN111007484B

CN111007484B - Single-line laser radar

Info

Publication number: CN111007484B
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: 2023-08-25
Anticipated expiration: 2039-12-27
Also published as: CN111007484A

Abstract

The invention provides a single-line laser radar, which comprises a first beam expanding and collimating lens and a second beam expanding and collimating lens which are adjacently arranged, wherein a laser detector is arranged at the focal length position of the first beam expanding and collimating lens, and a main detection light path of the laser detector is overlapped 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 and collimating lens and deviated from the optical axis of the second beam expanding and collimating lens. The semiconductor laser module is integrated with a fast axis compression lens and a slow axis compression lens, and can emit a round Gaussian beam or a near-round Gaussian beam through reasonable design; the distance between the principal ray of the semiconductor laser module and the optical axis of the second beam expansion 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 core key sensors for realizing intelligent perception of surrounding environment, has the characteristics of high ranging precision, long distance, quick response, strong anti-interference capability and the like, and is increasingly widely applied to the fields of unmanned operation, 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 is still to be further improved, in addition, the accurate adjustment of the laser radar is time-consuming and low-efficient, and in order to solve the problems, intensive research is necessary.

Disclosure of Invention

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

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

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

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

Furthermore, the pulsed semiconductor laser emits an elliptical gaussian beam, and correspondingly, the hybrid integrated bottom plate further comprises a fast axis lens and a slow axis lens, and the light emitted by the pulsed semiconductor laser is compressed into a circular gaussian beam or a near-circular gaussian beam after passing through the slow axis lens and the fast axis lens.

Because the semiconductor laser module is wholly deviated from the optical axis by a small distance, the main light ray is parallel to the main detection light path at the edge of the receiving end view field, the light beam is ensured to be always in the range of the receiving end view field at a distance, and the semiconductor laser module which emits a round Gaussian light beam or a near-round Gaussian is combined, so that the subsequent beam expansion 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 which the pin wire length is difficult TO control and the position of the laser is difficult TO accurately determine), the chip packaging mode of the laser emitting module can more accurately control the position of the laser, so that the adjustment precision can be improved and the adjustment complexity can be reduced; meanwhile, the multi-pulse laser emission is adopted, so that the detection point can be independently measured for multiple times, and the measurement reliability is improved; and through the SMD encapsulation, the part size is smaller, and parasitic electrical parameter reduces, is convenient for realize narrower pulse compression.

Drawings

Fig. 1 is a schematic structural diagram of a semiconductor laser module in an embodiment.

Fig. 2 is a schematic diagram of a transceiving optical path according to an embodiment.

Detailed Description

The technical scheme of the invention is further described below with reference to the accompanying drawings and examples.

A single line laser radar comprises a first beam expansion collimating lens and a second beam expansion collimating lens which are adjacently arranged, wherein a laser detector is arranged at the focal length position of the first beam expansion collimating lens, and a main detection light path of the laser detector is coincident with the optical axis of the first beam expansion collimating lens; and a semiconductor laser module is arranged at the focal length position of the second beam expanding and collimating lens and deviated from the optical axis of the second beam expanding and collimating lens, and 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. As shown in fig. 1, the semiconductor laser module includes a hybrid integrated chassis 1 (a PCB board may be used), a pulse semiconductor laser 2, a fast axis lens 3 and a slow axis lens 4, which are packaged by a patch, are disposed on the hybrid integrated chassis 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 elliptical Gaussian beam, the elliptical Gaussian beam is compressed into a circular Gaussian beam or a nearly circular Gaussian beam after passing through the fast axis lens 3 and the slow axis lens 4, the difference in the directions of the fast axis and the slow axis is reduced in a fast axis compression mode, good conditions are provided for subsequent further beam expansion collimation, and therefore the effective detection distance can be better extended.

In this embodiment, the laser uses a pulsed semiconductor laser with a wavelength of 905nm, the light outlet of the laser is 100um gamma 1um, a corresponding elliptical gaussian beam is emitted, the slow axis divergence angle is 25 degrees, the fast axis divergence angle is 7 degrees, the fast axis uses a cylindrical fast axis lens 3 with a focal length of 100um, the slow axis uses a slow axis lens 4 with a focal length of 5 mm as a starting point, and the distance is optimized by zemax, so that a circular gaussian beam or an approximately circular gaussian beam can be obtained. In terms of the design of the transceiver optical path, for the sake of simplicity, 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 are lenses with f=28mm, and the receiving end adopts a half 800um receiving area of the laser detector 8. Therefore, the semiconductor laser module 7 is required to deviate from the optical axis 400um of the second beam expansion collimating lens 5, so that the light beam can always fall in the range of the receiving end view field after being transmitted to the far distance to detect the detected object 9. In the multi-pulse echo detection, taking double pulses as an example, the laser radar scanning speed is assumed to be 15HZ, and the angular resolution is assumed to be 0.36 degrees. The divergence angle of the laser is 2 mrad=0.114°, the double pulse time interval can be set to 2us, the angle deviation of the two pulses is 0.0108 degrees, 0.0108/0.114=9.5%, and the overlap ratio is greater than 90%, so that the two pulses can be considered to be measured as the same point target. A greater number of pulse sets with shorter time intervals is expected to further enhance the reliability of signal detection. 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 can be 100um×10um,160 um×8um, etc.; the focal length of the collimating and beam expanding lens is not limited to 28mm, the collimating and beam expanding lens has a good beam expanding and collimating effect in 10 to 80mm, and meanwhile, the focal length of the lens at the receiving end can be different from that of the lens at the transmitting end; the double pulse distance measurement is not limited to pulse pairs, but may be pulse pairs composed of 3 pulses and 4 pulses.

Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and 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 and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention.

Claims

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

2. A single-wire lidar as defined in claim 1, wherein: the semiconductor laser module comprises a hybrid integrated bottom plate, and a pulse semiconductor laser packaged by a patch is arranged on the hybrid integrated bottom plate.

3. A single-wire lidar as defined in claim 2, wherein: the pulse semiconductor laser emits elliptical Gaussian beams, and correspondingly, the hybrid integrated bottom plate also comprises a fast axis lens and a slow axis lens, and the light emitted by the pulse semiconductor laser passes through the slow axis lens and the fast axis lens and then is compressed into circular Gaussian beams or nearly circular Gaussian beams.

4. A single-wire lidar as defined in claim 1, wherein: the ratio of the angular 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 single-wire lidar as defined in claim 1, wherein: the focal length of the first beam expanding collimating lens and the second beam expanding collimating lens is between 10mm and 80 mm.

6. A single-wire lidar as defined in claim 1, wherein: the focal length of the first beam expansion collimating lens is the same as that of the second beam expansion collimating lens.