阅读说明：本技术 一种全固态形式的LiDAR传感系统 (All-solid-state LiDAR sensing system ) 是由 余崇圣 李梦 陈方圆 董子乐 于 2020-07-06 设计创作，主要内容包括：本发明公开了一种全固态形式的LiDAR传感系统,包括：光束控制模块分别与激光调制模块和MEMS控制模块连接,激光调制模块与MEMS控制模块连接,MEMS控制模块与MEMS光束操纵传感器连接；光束控制模块与激光发射阵列控制模块连接,激光发射阵列控制模块与激光发射阵列模块连接,激光发射阵列模块与MEMS光束操纵传感器连接；光探测器与信号放大模块连接,信号放大模块与信号处理与控制模块连接,信号处理与控制模块与识别显示模块连接。本发明提供的LiDAR传感系统稳定性高、体积小、功耗低,具有更好的角度分辨率。(The invention discloses an all-solid-state LiDAR sensing system, comprising: the beam control module is respectively connected with the laser modulation module and the MEMS control module, the laser modulation module is connected with the MEMS control module, and the MEMS control module is connected with the MEMS beam control sensor; the beam control module is connected with the laser emission array control module, the laser emission array control module is connected with the laser emission array module, and the laser emission array module is connected with the MEMS beam control sensor; the optical detector is connected with the signal amplification module, the signal amplification module is connected with the signal processing and control module, and the signal processing and control module is connected with the identification display module. The LiDAR sensing system provided by the invention has the advantages of high stability, small volume, low power consumption and better angular resolution.)

1. An all-solid-state form of LiDAR sensing system, characterized by: the device comprises a light beam control module, a laser modulation module, an MEMS control module, a laser emission array module, an MEMS light beam manipulation sensor, a light detector, a signal amplification module, a signal processing and control module and an identification display module; the beam control module is respectively connected with the laser modulation module and the MEMS control module, the laser modulation module is connected with the MEMS control module, and the MEMS control module is connected with the MEMS beam control sensor; the beam control module is connected with the laser emission array control module, the laser emission array control module is connected with the laser emission array module, and the laser emission array module is connected with the MEMS beam control sensor; the optical detector is connected with the signal amplification module, the signal amplification module is connected with the signal processing and control module, and the signal processing and control module is connected with the identification display module.

2. The all-solid-state form of LiDAR sensing system of claim 1, wherein: the signal amplification module comprises a main amplifier and a preamplifier; the optical detector is connected with the preamplifier, the preamplifier is connected with the main amplifier, and the main amplifier is connected with the signal processing and control module.

3. The all-solid-state form of LiDAR sensing system of claim 1, wherein: the MEMS light beam manipulation sensor comprises a spring type MEMS cantilever structure, a tunable grating and an optical coupling waveguide cone; the spring type MEMS cantilever structure is provided with an MEMS comb-shaped driver; one end of the tunable grating is connected with the MEMS comb driver, and the other end of the tunable grating is connected with the optical coupling waveguide cone.

4. The all-solid-state form of LiDAR sensing system of claim 3, wherein: an MEMS suspension structure is arranged on the spring type MEMS cantilever structure; the MEMS suspended structure comprises a graphene layer, a silicon dioxide layer and a silicon layer, wherein the silicon dioxide layer is attached to the silicon layer, and the graphene layer is attached to the silicon dioxide layer; patterning the graphene layer to enable the graphene layer to form an electrode plate; the MEMS comb drive stretches the spring type MEMS cantilever structure through the electrode plate.

5. The all-solid-state form of LiDAR sensing system of claim 4, wherein: the thickness of the silicon layer is 220 nm; the thickness of the silicon dioxide layer is 2 um; the thickness of the graphene layer is less than or equal to 1 nm.

6. The all-solid-state form of LiDAR sensing system of claim 1, wherein: the laser emitting array module comprises 905nm, 1550nm or vertical cavity surface emitting lasers.

Technical Field

The invention relates to the technical field of laser radars, in particular to an all-solid-state LiDAR sensing system.

Background

In recent years, the laser radar has wide application fields and plays an important role in the fields of intelligent robots, three-dimensional modeling, unmanned driving and the like. The existing laser radar sensor technology is mainly divided into electromechanical rotary laser radar, MEMS micro-vibration mirror technology mixed solid laser radar and OPA optical phased array laser radar according to the existence of mechanical rotating parts. The mechanical laser radar is provided with a rotating part for controlling the laser emission angle, such as a motor, the hybrid solid-state laser radar integrates the rotating part of a device into a micro-vibrating mirror chip through an MEMS (micro-electro-mechanical systems) process, and the solid-state laser radar controls the laser emission angle by means of electronic parts without mechanical or micro-vibrating mirror parts. At present, no matter a mechanical technology or a solid-state technology is adopted, a laser radar system in the prior art is large in size, large in power consumption, poor in reliability, high in cost, small in working temperature range, difficult to pass vehicle specification authentication and the like, and application and popularization of the laser radar technology are directly restricted.

Disclosure of Invention

The invention provides an all-solid-state LiDAR sensing system, aiming at the problems that the existing laser radar system is large in size, large in power consumption, poor in reliability, high in cost, small in working temperature range and difficult to pass vehicle specification authentication.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a full solid-state LiDAR sensing system comprises a light beam control module, a laser modulation module, an MEMS control module, a laser emission array module, an MEMS light beam manipulation sensor, a light detector, a signal amplification module, a signal processing and control module and an identification display module; the beam control module is respectively connected with the laser modulation module and the MEMS control module, the laser modulation module is connected with the MEMS control module, and the MEMS control module is connected with the MEMS beam control sensor; the beam control module is connected with the laser emission array control module, the laser emission array control module is connected with the laser emission array module, and the laser emission array module is connected with the MEMS beam control sensor; the optical detector is connected with the signal amplification module, the signal amplification module is connected with the signal processing and control module, and the signal processing and control module is connected with the identification display module.

Preferably, the large assembly comprises a main amplifier and a preamplifier; the optical detector is connected with the preamplifier, the preamplifier is connected with the main amplifier, and the main amplifier is connected with the signal processing and control module.

Preferably, the MEMS beam steering sensor comprises a spring type MEMS cantilever structure, a tunable grating, and an optical coupling waveguide taper; the spring type MEMS cantilever structure is provided with an MEMS comb-shaped driver; one end of the tunable grating is connected with the MEMS comb driver, and the other end of the tunable grating is connected with the optical coupling waveguide cone.

Preferably, an MEMS suspension structure is arranged on the spring type MEMS cantilever structure; the MEMS suspended structure comprises a graphene layer, a silicon dioxide layer and a silicon layer, wherein the silicon dioxide layer is attached to the silicon layer, and the graphene layer is attached to the silicon dioxide layer; patterning the graphene layer to enable the graphene layer to form an electrode plate; the MEMS comb drive stretches the spring type MEMS cantilever structure through the electrode plate.

Preferably, the thickness of the silicon layer is 220 nm; the thickness of the silicon dioxide layer is 2 um; the thickness of the graphene layer is less than or equal to 1 nm.

Preferably, the laser emitting array module comprises 905nm, 1550nm or vertical cavity surface emitting lasers.

Compared with the prior art, the invention has the beneficial effects that:

the beam control module controls the MEMS beam steering sensor to modulate the emergent angle of the laser beam through the MEMS control module, the modulated beam reaches a target detection object, is reflected back to be detected by the optical detector, is amplified and processed, and finally displays a three-dimensional live-action image on the identification display module after multiple measurements;

the MEMS beam control sensor replaces a traditional rotating motor or MEMS micro-oscillating mirror structure, avoids the defects of short service life and small scanning angle of devices in the traditional technical scheme, and has high reliability and stability, small volume, low power consumption and low cost;

according to the invention, the MEMS suspension type structure containing the graphene material is adopted, so that the sensitivity and reliability of the micro-electromechanical structure on light beam manipulation are improved, the service life of the device is prolonged, and the better angle resolution of laser radar sensing is provided.

Of course, it is not necessary for any one product that embodies the invention to achieve all of the above-described advantages at the same time.

Drawings

FIG. 1 is a block diagram of an all solid state form of LiDAR sensing system of the present invention;

FIG. 2 is a block diagram of a MEMS beam steering sensor of the present invention;

fig. 3 is a schematic view of a MEMS suspension structure according to the present invention.

In the figure, 1-beam steering module; 2-a laser modulation module; 3-a MEMS control module; 4-laser emission array control module; 5-laser emission array module; 6-MEMS beam steering sensors; 7-a light detector; 8-a signal amplification module; 9-a signal processing and control module; 10-identifying a display module; 11-a target probe; 61-spring MEMS cantilever structure; 62-tunable grating; 63-optical coupling waveguide taper; 81-a preamplifier; 82-a main amplifier; 611-MEMS comb drive; 612-MEMS suspended structures; 6121-graphene layer; 6122-a silicon dioxide layer; 6123-silicon layer.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to FIG. 1, an all solid state form of LiDAR sensing system includes a beam control module 1, a laser modulation module 2, a MEMS control module 3, a laser emitting array control module 4, a laser emitting array module 5, a MEMS beam steering sensor 6, a photodetector 7, a signal amplification module 8, a signal processing and control module 9, and an identification display module 10; the beam control module 1 is respectively connected with the laser modulation module 2 and the MEMS control module 3, the laser modulation module 2 is connected with the MEMS control module 3, and the MEMS control module 3 is connected with the MEMS beam control sensor 6; the beam control module 1 is connected with the laser emission array control module 4, the laser emission array control module 4 is connected with the laser emission array module 5, and the laser emission array module 5 is connected with the MEMS beam control sensor 6; the optical detector 7 is connected with the signal amplification module 8, the signal amplification module 8 is connected with the signal processing and control module 9, and the signal processing and control module 9 is connected with the identification display module 10.

In this embodiment, the light beam control module 1 controls the laser emission array module 5 to emit laser through the laser emission array control module 4, the light beam control module 1 wakes up the MEMS control module 3, then controls the MEMS control module 3 to output voltage through the laser modulation module 2, controls the MEMS light beam manipulation sensor 6 to modulate laser through voltage, the MEMS light beam manipulation sensor 6 modulates the laser emission direction, the modulated light beam reaches the target detection object 11, is reflected back, receives a light beam signal through the light detector 7, converts the light beam signal into an electrical signal, amplifies the electrical signal through the signal amplification module 8, processes the electrical signal through the signal processing and control module 9, and controls the electrical signal to be displayed on the identification display module 10 in the form of an image. The invention can control the sensor 6 to modulate the laser emitting direction through the MEMS light beam, and obtains the surrounding three-dimensional real scene under the condition of consistent measuring point positions.

In one embodiment, the signal amplification module 8 includes a main amplifier 82 and a preamplifier 81; the photodetector 7 is connected to a preamplifier 81, the preamplifier 81 is connected to a main amplifier 82, and the main amplifier 82 is connected to the signal processing and control module 9.

In this embodiment, the optical detector 7 converts the detected optical signal into an electrical signal, the pre-amplifier 81 pre-processes the electrical signal, performs a preliminary amplification without distortion, and then performs a secondary amplification by the main amplifier 82, and finally the electrical signal is processed by the signal processing and control module 9 and is controlled to be displayed in the form of an image on the recognition module.

Referring to fig. 2, the MEMS beam steering sensor 6 includes a spring-loaded MEMS cantilever structure 61, a tunable grating 62, and an optical coupling waveguide taper 63; the spring type MEMS cantilever structure 61 is provided with an MEMS comb-shaped driver 611; one end of the tunable grating 62 is connected to the MEMS comb drive 611 and the other end is connected to the optically coupled waveguide taper 63.

In this embodiment, when the MEMS comb actuator 611 loads a voltage on the spring-type MEMS cantilever structure 61, the spring-type MEMS cantilever structure 61 deforms and stretches, so as to change the distance between grating teeth of the tunable grating 62, thereby causing a change in the out-of-plane angle light emission angle of the tunable grating 62, i.e. achieving beam steering.

Referring to fig. 3, a MEMS suspension structure 612 is provided on the spring type MEMS cantilever structure 61; the MEMS suspension structure 612 includes a graphene layer 6121, a silicon dioxide layer 6122, and a silicon layer 6123, where the silicon dioxide layer 6122 is attached to the silicon layer 6123, and the graphene layer 6121 is attached to the silicon dioxide layer 6122; patterning the graphene layer 6121 to enable the graphene layer 6121 to form an electrode plate; the MEMS comb drive 611 stretches the spring-loaded MEMS cantilever structure 61 through the electrode plates.

In this embodiment, the MEMS suspension structure 612 forms positive and negative electrode plates on the spring-type MEMS cantilever structure 61, and the MEMS comb driver 611 loads a voltage on the positive and negative electrode plates, so that the spring-type MEMS cantilever structure 61 deforms and stretches, thereby changing the size of the tunable grating 62 and implementing beam steering.

The process of the MEMS suspension structure 612 is:

the method comprises the following steps: transferring a single-layer graphene film on the surface of the 2um silicon dioxide layer 6122 without damage to form a graphene layer 6121;

step two: exposing the graphene layer 6121 by using a 250nm deep ultraviolet band to complete the patterning of the micro-nano structure of the graphene layer 6121;

step three: the silicon layer 6123 is patterned by using two electron beam lithography thinning silicon etching methods, and then the silicon dioxide layer 6122 is etched into the MEMS suspension structure 612 by using hydrofluoric acid aqueous solution with the concentration of 50% and critical point drying.

In one embodiment, the silicon layer 6123 is 220nm thick; the thickness of the silicon dioxide layer 6122 is 2 um; the thickness of the graphene layer 6121 is less than or equal to 1 nm.

In one embodiment, the lasing array module 5 comprises 905nm, 1550nm or vertical cavity surface emitting lasers.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.