CN108732552A - A kind of method and laser radar for realizing that the probe of laser radar is detached with cabinet - Google Patents

Abstract

The invention discloses a method for realizing the separation of a laser radar probe and a chassis, and relates to the technical field of laser radar, which includes that the laser radar probe is an optical lens exposed and installed in an external environment, and the laser radar chassis is internally installed to generate laser signals The components of the components, the components that receive the laser signal, and the electronic components that process the laser signal are isolated from the outside world, and the optical fiber bundle connecting the two; this method can realize the space between the probe and the chassis in the laser radar Separation, so that the laser, detector, electronics, etc. are placed in a chassis that is relatively isolated from the outside world, and it is easier to achieve temperature control, vibration reduction, and dust isolation. The exposed probe part is only an optical lens, and its surface is easy to clean and chemically resistant. Strong corrosion performance, resistant to environmental temperature changes.

Description

A method for realizing the separation of laser radar probe and chassis and laser radar

technical field

The invention relates to the technical field of laser radar, in particular to a method for realizing the separation of a laser radar probe and a chassis and the laser radar.

Background technique

LiDAR is a key sensor for intelligent driving cars, and has huge market potential and has attracted widespread attention. LiDAR currently on the market is a mechanical scanning type, which is composed of lasers, detectors, optical lenses, scanning mechanisms, electronics, etc., and uses the principle of time-of-flight ranging, which belongs to direct ranging. In the mechanical scanning lidar for intelligent driving, in order to adapt to the distance image acquisition when the car is moving at high speed, multi-point laser lighting is generally used, and multiple lasers are arranged in a line array. One-dimensional scanning in the vertical direction of the line array can obtain the entire image of the space around the car, which is faster than single-point lighting. At present, lidar technology has not yet been finalized. People are developing non-scanning lidar based on flood lighting, and lidar using new principles of amplitude or frequency modulation light sources. No matter what kind of lidar, it is a whole of opto-mechanical integration, and it is not fully suitable for the requirements of autonomous driving of cars.

At present, in the application fields such as intelligent driving cars, since the lidar must meet the strict requirements of the car regulations before it can be officially installed on the car, the existing lidar still has defects in adapting to harsh environments such as high temperature and bumps, so it is necessary to improve it.

Contents of the invention

For the defects existing in the prior art, the object of the present invention is to provide a method for realizing the separation of the laser radar probe and the chassis, the method realizes the spatial separation of the laser radar probe and the chassis through the optical fiber, so that the laser, the detector , electronics, etc. are placed in a chassis that is relatively isolated from the outside world, and it is easier to achieve temperature control, vibration reduction, and dust isolation. The exposed probe part is just an optical lens. Its surface is easy to clean, with strong chemical corrosion resistance and environmental temperature resistance. Variety.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

A method for realizing the separation of the lidar probe and the chassis, the lidar probe is an optical lens exposed and installed in the external environment, the lidar chassis is internally installed with components for generating laser signals, components for receiving laser signals, and processing The chassis structure of the electronic components of the laser signal is isolated from the outside world, in which the laser pulse generated by the components in the chassis forms a divergent laser beam through the optical fiber, and the divergent laser beam forms a collimated laser beam through the laser radar probe and irradiates the target Above, dot matrix lighting is formed on the target object, and the laser spot is formed after the target object is illuminated. The formed laser spot generates a reflected laser beam, and the reflected laser beam forms a converged laser beam through the laser radar probe, and the converged laser beam is transmitted back through the optical fiber Go to the components in the lidar chassis for analysis and processing.

At the same time, this solution also provides a laser radar according to the method for separating the laser radar probe from the chassis. The laser radar includes a chassis, a probe, and an optical fiber bundle, and the chassis includes M×N+1 lasers. , a laser power supply, a trigger signal generator for generating a pulse trigger control signal for the laser, M×N incident fiber connectors in the two-dimensional emitting fiber array, a pair of optical fibers arranged at both ends of the first optical fiber The connector, the microlens, and the M×N fiber connectors at the exit end in the two-dimensional emitting fiber array respectively receive the first photodetector of the start signal and the second photodetector of the stop signal, and are used to give the first A photodetector and a second photodetector provide a detector power supply for bias voltage, an amplification circuit for amplifying the signals in the first photodetector and the second photodetector in turn, and a time discrimination circuit and a time-to-digital conversion circuit, the M×N incident end optical fiber connectors are respectively coupled to the M×N lasers, the other laser is coupled to one of the optical fiber connectors, and the M×N output ports The optical fiber connectors are respectively coupled with the second photodetectors, wherein M and N are both natural integers ≥ 1; the probes include an exit end face of a two-dimensional emitting fiber array, and an exit end face arranged on the exit end face M×N laser side fiber cores, a laser emitting lens, a divergent laser beam formed between the laser side fiber cores and the laser emitting lens, a narrow band filter, a laser receiving lens, a two-dimensional receiving fiber array end face, M×N detector-side fiber cores arranged on the end face of the two-dimensional receiving fiber array and a converging laser beam formed between the detector-side fiber cores and the laser receiving lens; the fiber bundle includes M×N transmitting fibers, M×N receiving fibers and first optical fibers, wherein the emitting ends of the M×N transmitting fibers are connected to the M×N laser side on the emitting end face of the two-dimensional transmitting fiber array Optical fiber cores, the incident ends of the M×N receiving optical fibers are connected to the M×N detector-side optical fiber cores on the outgoing end face of the two-dimensional transmitting optical fiber array.

Further, the laser is one of a laser diode, a solid-state laser or a fiber laser.

Further, the exit end face of the two-dimensional emitting fiber array is provided with two-dimensionally arranged M×N openings, each opening is equipped with one optical fiber core, wherein M and N are both ≥ 1 natural integer.

Further, the end face of the two-dimensional receiving optical fiber array is provided with two-dimensionally arranged M×N openings, and each opening is equipped with one of the optical fiber cores, wherein M and N are natural integers ≥ 1 .

Further, the opening is a small hole structure formed by adopting microfabrication technology.

Further, the first photodetector and the second photodetector are one of avalanche photodiode detectors or diode detectors composed of P-type-intrinsic-N-type semiconductors.

Further, the microlens is a microlens structure for coupling the signal from the optical fiber to the first photodetector and the second photodetector.

Further, the laser emitting lens is composed of one lens or a lens group composed of several lenses.

Further, the laser power supply is a power supply structure that can provide fast pulse driving capability.

Compared with the prior art, the beneficial technical effect of this scheme is:

1. The spatial separation of the probe and the chassis is realized, so that the laser, detector, electronics, etc. are placed in a chassis that is relatively isolated from the outside world, making it easier to achieve temperature control, vibration reduction, and dust isolation. The exposed probe part is only the optical lens , the surface is easy to clean, has strong chemical corrosion resistance, and is resistant to environmental temperature changes;

2. The size of the probe after space separation is small, and the restriction on the placement position is small, which is beneficial to the overall design of the car shape.

3. The separation between the probe and the chassis is realized through the fiber optic bundle, and the size and direction of the separation space can be adjusted at will by using the flexibility of the fiber optic bundle.

Description of drawings

FIG. 1 is a schematic diagram of the structure and principle of the lidar in this embodiment.

Explanation of the reference signs in the figure:

1-Laser power supply, 2-Trigger signal generator, 3-Laser, 4-Incidence end fiber connector, 5-Laser fiber, 6-Exit end face, 7-Laser side fiber core, 8-Divergent laser beam, 9- Laser emission lens, 10-collimated laser beam, 11-object, 12-laser spot, 13-first optical fiber, 14-first optical fiber A-end connector, 15-microlens, 16-first photodetector, 17-detector power supply, 18-signal amplification circuit, 19-time discrimination circuit, 20-time digital conversion circuit, 21-reflected laser beam, 22-narrow band filter, 23-laser receiving lens, 24-converging laser beam, 25-incidence end face, 26-detector side fiber core, 27-optical fiber, 28-fiber optic connector at exit end, 29-second photodetector, 30-probe, 31-fiber bundle, 32-chassis, 33-the first A B-end connector of an optical fiber.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

This solution is aimed at the current application fields such as intelligent driving cars. Since the laser radar must meet the strict requirements of the car regulations before it can be officially installed on the car, the existing laser radar still has defects in adapting to harsh environments such as high temperature and bumps. A method for separating the laser radar probe from the chassis is proposed. This method can realize the spatial separation of the laser radar probe and the chassis, so that the laser, detector, electronics, etc. are placed in the chassis that is relatively isolated from the outside world. , and it is easier to achieve temperature control, vibration reduction, and dust isolation. The exposed probe part is just an optical lens. Its surface is easy to clean, has strong chemical corrosion resistance, and is resistant to environmental temperature changes.

This embodiment firstly provides a method for separating the probe on the lidar from the chassis. The method is that the probe of the lidar is an optical lens exposed and installed in the external environment, and the lidar chassis is installed with components that generate laser signals inside. , The components that receive laser signals and the electronic components that process laser signals are isolated from the outside world. The laser pulses generated by the components in the chassis form divergent laser beams through optical fibers, and the divergent laser beams are formed by laser radar probes. Collimate the laser beam and irradiate the target object to form a dot matrix illumination on the target object. After the target object is illuminated, a laser spot is formed. The formed laser spot generates a reflected laser beam, and the reflected laser beam passes through the laser radar probe to form a converged laser beam. The converged laser beams are transmitted back to the components in the lidar chassis through optical fibers for analysis and processing.

In the above method, the lidar is mainly composed of three parts: a probe, a chassis, and an optical fiber bundle. Compared with the current lidar, there are more fiber bundles with a certain length and free bending. The probe is composed of a laser emitting lens, a laser detecting lens, a fiber connector of a two-dimensional emitting fiber array, and a fiber connector of a two-dimensional receiving fiber array. The optical fiber bundle is composed of the transmitting optical fiber bundle, the receiving optical fiber bundle and the first optical fiber. The transmitting and receiving optical fiber bundles are part of the fiber array, one end of which enters the probe, and the other end enters the chassis to be coupled with the laser or detector respectively. The rest of the laser radar is completely inside the chassis.

The working principle is that the laser is coupled to the incident end of the two-dimensional emitting fiber array, and after being transmitted through the fiber bundle, at the output end of the two-dimensional emitting fiber array, the laser is irradiated onto the target through the laser emitting lens to form a laser lattice spot. After the reflected light on the target passes through the laser detection lens, the laser is irradiated to the incident end of the two-dimensional receiving fiber array, and after being transmitted through the fiber bundle, it is coupled with the detector at the output end of the two-dimensional receiving fiber array, which is equivalent to high performance Multi-pixel detector array. Here, using the soft and easy-to-bend characteristics of optical fibers, the spatial separation of lasers, detectors, electronics, etc. from the laser emitting lens and laser receiving lens is realized, so that the delicate lasers, detectors, electronics, etc. are placed in relatively isolated In the environment, temperature control, vibration reduction, and dust isolation become easier, so that the lidar can pass the car regulations smoothly. At the same time, the laser dot matrix illumination and detection method is adopted here, which has the characteristics of no scanning or reduced scanning requirements.

Referring to FIG. 1 , it is a schematic diagram of the structure and principle of the laser radar in this embodiment. The laser radar in this embodiment includes a housing 32 , a probe 30 and an optical fiber bundle 31 . The chassis 32 includes M×N+1 lasers 3, a laser power supply 1, a trigger signal generator 2 for generating pulse trigger control signals for the lasers 3, and M×N incident-end optical fiber connections in the two-dimensional emitting fiber array. Head 4, a pair of first optical fiber A-end connectors 14 and first optical fiber B-end connectors 33 arranged at both ends of the first optical fiber 13, microlenses 15, and M×N output end optical fibers in the two-dimensional emitting optical fiber array are connected The head 28, the first photodetector 16 receiving the start signal and the second photodetector 29 receiving the stop signal respectively, the detector for providing bias voltage to the first photodetector 16 and the second photodetector 29 The power supply 17, the amplifying circuit 18, the time discrimination circuit 19 and the time-to-digital conversion circuit 20, which are successively used to amplify the signals in the first photodetector 16 and the second photodetector 29, respectively, the above-mentioned M×N incident terminals The optical fiber connectors 4 are respectively coupled to M×N lasers 3, and the other laser 3 is coupled to the connector 14 at the A end of the first optical fiber. The photodetector 29 is coupled, wherein both M and N are natural integers ≥ 1; the probe 30 includes an exit end face 6 of a two-dimensional emitting fiber array, and M×N laser-side fiber cores 7 arranged on the exit end face 6 , a laser emitting lens 9, a divergent laser beam 8 formed between the laser side fiber core 7 and the laser emitting lens 9, a narrow band filter 22, a laser receiving lens 23, a two-dimensional receiving fiber array incident end face 25, arranged on two M×N detector side fiber cores 26 on the incident end face 25 of the fiber receiving fiber array and the converging laser beam 24 formed between the detector side fiber cores 26 and the laser receiving lens 23; the fiber bundle 31 includes M×N N transmitting optical fibers 5, M×N receiving optical fibers 27 and the first optical fiber 13 for transmitting the initial signal laser, wherein the incident ends of the M×N transmitting optical fibers 5 are connected to M×N incident-end optical fiber connectors 4, The exit end is connected to the M×N laser side fiber cores 7 on the exit end face 6 of the two-dimensional emitting fiber array, and the incident end of the M×N receiving fibers 27 is connected to M on the incident end face 25 of the two-dimensional receiving fiber array. ×N detector-side optical fiber cores 26 , the output ends of which are connected to M×N optical fiber connectors 28 at the output ends.

When working, the laser power supply 1 provides fast driving pulses for the laser 3, the trigger signal generator 2 generates a trigger electrical signal, and simultaneously controls M×N+1 lasers 3 to generate laser pulses, and the incident fiber in the two-dimensional emitting fiber array is connected to Each optical fiber connector in the head 4 is efficiently coupled with a laser 3 respectively, and there are M×N optical fiber connectors in total. After the laser pulse is coupled into the optical fiber connector 4 at the emitting end, it is transmitted along the emitting fiber 5 to the emitting end face 6 of the two-dimensional emitting fiber array. M×N laser pulses leave the laser-side fiber core 7 on the exit end face 6 of the two-dimensional emitting fiber array and enter free space to form a divergent laser beam 8 . The divergent laser beam 8 becomes a collimated laser beam 10 after passing through the laser emitting lens 9 . The collimated laser beam 10 is transmitted in free space, and is irradiated on the target object 11 to form M×N laser spots, thereby completing the dot matrix illumination.

The A-end connector 14 of the first optical fiber is coupled with the laser 3, and the coupled laser light is transmitted along the first optical fiber 13, and after being transmitted to the B-end connector 33 of the first optical fiber, it enters the first photodetector after being focused by the microlens 15 16. Generate a starting signal in the form of analog quantity. The first photodetector 16 is powered by a detector power supply 17 . The start signal in analog form is amplified by the subsequent signal amplifying circuit 18 , enters the time discrimination circuit 19 to be shaped and becomes a digital start signal, and finally enters the time-to-digital conversion circuit 20 .

The target object 11 is illuminated by the laser illumination system to generate a laser spot 12 . The reflected laser beam 21 produced by the laser spot 12 enters the laser receiving lens 23 through the narrow-band filter 22 to generate a converged laser beam 24, which is incident on the incident end face 25 of the two-dimensional receiving optical fiber array at the focal plane position of the laser receiving lens 23 Inside the fiber core 26 at the detector side. The received laser light is transmitted through the receiving optical fiber 27 and comes out from the fiber connector 28 at the output end of the two-dimensional receiving optical fiber array. The laser light coming out of the optical fiber connector enters the second photodetector 29 receiving the stop signal after passing through the microlens 15 . The detector power supply 17 provides a bias voltage to the second photodetector 29 to make it work normally. The second photodetector 29 generates a stop signal in analog form. The weak signal is amplified by the signal amplifying circuit 18, and then passes through the time discrimination circuit 19 to become a digital stop signal related to the distance information, and enters the time-to-digital conversion circuit 20 from different input terminals. The time-to-digital conversion circuit 20 generates the time of flight by comparing the time difference between the start signal and the stop signal. The time-of-flight related to the distance of the laser spot 12 is output in the form of a digital signal, which is entered into the computer for processing. The distances of different laser spots 12 are aggregated to form the desired distance image, which can be carried out in an appropriate form. Display, such as the well-known laser point cloud, or send the control system to control the actuator. What needs to be explained here is that the computer and the like belong to the information processing system of the laser radar, which are not shown here and are prior art.

In addition, the above-mentioned signal amplifying circuit 18 is a circuit for amplifying the weak signal generated by the photodetector through photoelectric conversion, and is generally composed of a preamplifier and a main amplifier, which is a prior art; the same time discrimination circuit 19 is the circuit that gives the start signal or the stop signal by the time discriminator after filtering the pulse signal after the amplification; the time-digital conversion circuit 20 measures the time difference between the input start signal and the stop signal, and uses the output circuit in the form of This time difference is the distance-related time-of-flight, multiplied by the speed of light to provide the detected distance. It can be composed of a special time-to-digital conversion chip equipped with an auxiliary circuit, or it can be composed of a field programmable gate array FPGA circuit.

The laser power supply 1 in this embodiment is a power supply structure that provides fast pulse driving capability for the laser 3 . The laser 3 can be a laser diode, a solid-state laser, or a fiber laser. These lasers are powered by the power supply 1. Under the control of the same trigger signal generated by the trigger signal generator 2, multiple lasers 3 simultaneously generate multiple trigger signals. beam of laser pulses. The microlens is a microlens structure used to couple the signal from the optical fiber to the first photodetector 16 and the second photodetector 29; the laser emitting lens 9 is a lens composed of one lens or formed by several lenses Composition; the first photodetector 16 and the second photodetector 29 are one of avalanche photodiode detectors or diode detectors composed of P-type-intrinsic-N-type semiconductors, usually avalanche photodiodes are more common. Avalanche photodiodes can work in Geiger mode with a bias voltage slightly higher than the avalanche threshold voltage, or in linear mode with a bias voltage slightly lower than the avalanche threshold voltage. The first photodetector 16 is used to detect the start signal. The second photodetector 29 is used to detect the stop signal.

Two-dimensional arrays of M×N openings are respectively arranged on the outgoing end face 6 of the two-dimensional transmitting fiber array and on the incident end face 25 of the two-dimensional receiving optical fiber array, and an optical fiber core is installed in each opening, wherein M and N are natural integers ≥ 1. In actual production, M×N small holes are precisely processed on silicon wafers and other materials through microfabrication technology, and the optical fibers are stably fixed in the small holes to form a precisely arranged two-dimensional optical fiber array. Here, the arrangement period in the X direction and the arrangement period in the Y direction may be the same, or may take different values according to design requirements. M may or may not be equal to N.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. a kind of method realized the probe of laser radar and detached with cabinet, it is characterised in that：The probe of laser radar is exposed Optical lens in external environment, laser radar cabinet are that inside is equipped with the component for generating laser signal, reception The casing structure of the component of laser signal and the electronics component of processing laser signal being isolated with the external world, wherein machine The laser pulse that component generates in case forms divergent laser beam, the probe shape that divergent laser beam passes through laser radar by optical fiber It at collimated laser beam and is irradiated on object, forms dot matrix illumination on object, object forms laser light after being illuminated The laser facula of spot, formation generates reflection laser beam, and reflection laser beam forms convergence laser beam by the probe of laser radar, converges Poly- laser beam is by fiber pass-back to the component in laser radar cabinet, carrying out analyzing processing.

2. a kind of laser radar for the method that the probe of realization laser radar as described in claim 1 is detached with cabinet, special Sign is：The laser radar includes cabinet, probe and fiber optic bundle, includes to have M × N+1 laser in the cabinet Device, laser power supply, the trigger signal generator for generating Pulse-trigger control signal to the laser, two dimension transmitting light The fiber connector at the first optical fiber both ends, lenticule, two are arranged in M × N number of incidence end fiber connector, a pair in fibre array M × N number of exit end fiber connector in launching fiber array is tieed up, the first photodetector of initial signal is received respectively and connects Receive the second photodetector of stop signal, for providing biased electrical to first photodetector and the second photodetector The detector power supply of pressure is orderly used to is put to the signal in first photodetector and the second photodetector respectively Amplifying circuit, time-discriminating circuit and the time-to-digital conversion circuit handled greatly, M × N number of incidence end optical fiber jointing Correspondence is coupled with M × N number of laser respectively, another described laser is coupled with first fiber connector, and M × Correspondence is coupled N number of exit end fiber connector with second photodetector respectively, wherein M and N all for >=1 nature Integer；The probe includes the outgoing end face of two-dimentional launching fiber array, is arranged and swashs in the M × N items being emitted on end face Light device optical fiber fibre core, Laser emission lens, the hair being formed between the laser side fiber core and Laser emission lens Laser beam, spike filter, laser pick-off lens, two-dimentional reception optical fiber array end face, setting are dissipated in the two-dimentional reception optical fiber M × N detector side fiber core on array end face and it is formed in the detector side fiber core and laser pick-off is saturating Convergence laser beam between mirror；The fiber optic bundle includes M × N launching fiber, M × N reception optical fiber and the first optical fiber, The exit end of wherein launching fiber described in M × N items is connected to M × N items on the outgoing end face of the two-dimentional launching fiber array Laser side fiber core, the incidence end of reception optical fiber described in M × N items are connected to the exit end of the two-dimentional reception optical fiber array M × N detector side fiber core on face.

3. a kind of laser radar according to claim 2, it is characterised in that：The laser is laser diode, solid One kind in laser or optical fiber laser.

4. a kind of laser radar according to claim 2, it is characterised in that：The exit end of two-dimentional launching fiber array It is provided with the M in two-dimensional arrangements × N number of trepanning on face, a fiber core is installed, wherein M and N are in each trepanning For >=1 natural integer.

5. a kind of laser radar according to claim 4, it is characterised in that：It is set on the two dimension reception optical fiber array end face It is equipped with M × N number of trepanning in two-dimensional arrangements, a fiber core is installed in each trepanning, wherein M and N are >=1 Natural integer.

6. a kind of laser radar according to claim 4 or 5, it is characterised in that：The trepanning is to add by using fine The small structure that work technology is formed.

7. a kind of laser radar according to claim 2, it is characterised in that：First photodetector and the second photoelectricity Detector be using avalanche photodiode detector or p-type-it is intrinsic-N-type semiconductor constitute diode detector in one Kind.

8. a kind of laser radar according to claim 2, it is characterised in that：The lenticule is for will be from optical fiber Signal is coupled to the fine lens arrangement in first photodetector and the second photodetector.

9. a kind of laser radar according to claim 2, it is characterised in that：The Laser emission lens are by a lens It constitutes or is made of the lens group of several lens forming.

10. a kind of laser radar according to claim 2, it is characterised in that：The laser power supply is that can provide quickly The power supply architecture of pulsed drive ability.