CN110018486A - A kind of multi-beam laser range sensor based on TOF - Google Patents

Abstract

The present invention provides a kind of multi-beam laser range sensor based on TOF, including digital processing element, laser emission element, optical system unit and laser pick-off unit；The laser firing signals that the laser emission element is used to be sent according to the digital processing element emit at least three Lu Jiguang；The optical system unit is used to every road laser focusing to testee, and will focus to the laser pick-off unit through the reflected laser of the testee；The laser pick-off unit is used to generate laser pick-off signal based on the laser received, and is sent to the digital processing element；The digital processing element is used for the distance based on the laser firing signals and the corresponding laser of the laser pick-off signal acquisition to the testee.Multi-beam laser range sensor based on TOF of the invention solves the problems, such as that existing laser measurement frequency and resolution ratio are low, contour of object is unintelligible, the detection visual field is narrow by multi-beam laser ranging.

Description

A TOF-based multi-beam laser ranging sensor

technical field

The present invention relates to the technical field of laser ranging sensors, in particular to a multi-beam laser ranging sensor based on time of flight (TOF).

Background technique

TOF technology means that the sensor emits modulated near-infrared light, which reflects after encountering an object. The sensor calculates the time difference or phase difference between light emission and reflection, and converts the distance of the object according to the time difference or phase difference to generate depth information. In addition, combined with the object The intensity of the reflected echo energy, combined with the distance of the measured distance, can present the three-dimensional outline of the object in the form of a topographic map with different colors representing different distances.

In the prior art, most of the TOF-based laser ranging sensors use single-beam laser emission as the measurement core. Among them, the single-beam laser ranging sensor projects the surface of the object with a laser point to measure the distance from the current object to the ranging center, which is more used in security engineering and so on. With the development of the lidar field, single-line laser ranging can no longer meet operational needs, such as automated guided vehicle (AGV) navigation and obstacle avoidance, unmanned aerial vehicle (UAV) altitude determination and mapping , security monitoring, automotive unmanned driving and other applications. These applications all require the laser ranging sensor to respond to the environment ahead and the state of the object in real-time and high-speed with three-dimensional or more details.

SUMMARY OF THE INVENTION

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a multi-beam laser ranging sensor based on TOF, which solves the problem of low frequency and resolution of existing laser measurement and unclear object contour through multi-beam laser ranging. , Detect the problem of narrow field of view.

In order to achieve the above purpose and other related purposes, the present invention provides a multi-beam laser ranging sensor based on TOF, including a digital processing unit, a laser emission unit, an optical system unit and a laser receiving unit; the laser emission unit and the digital The processing unit is connected to transmit at least three lasers according to the laser emission signal sent by the digital processing unit; the optical system unit is connected to the laser transmitting unit and the laser receiving unit, and is used to focus each laser to the measured object, and focus the laser reflected back by the measured object to the laser receiving unit; the laser receiving unit is connected with the optical system unit and the digital processing unit, and is used for receiving The laser generates a laser receiving signal and sends it to the digital processing unit; the digital processing unit is configured to obtain the distance from the corresponding laser to the measured object based on the laser transmitting signal and the laser receiving signal.

In an embodiment of the present invention, the digital processing unit includes an FPGA module and a TOF time-of-flight measurement circuit; the TOF time-of-flight measurement circuit is used to calculate the time difference between the laser emission signal and the laser received signal; the FPGA The module is used to generate a laser emission signal and send it to the laser emission unit, and calculate the distance between the corresponding laser and the measured object according to the time difference.

In an embodiment of the present invention, the laser emitting unit includes a laser drive circuit and an array laser diode; the array laser diode includes at least three laser diodes arranged in parallel up and down; the laser drive circuit is configured to emit light based on the laser The signal generates the driving signal of the laser diode, so as to drive each laser diode to emit laser light in time division;

The laser receiving unit includes an array of APD diodes and a laser receiving circuit; the array of APD diodes includes at least three APD diodes arranged in parallel up and down, and the APD diodes are in one-to-one correspondence with the laser diodes; each APD diode It is used for receiving the laser light emitted by the corresponding laser diode, and the laser receiving circuit is used for generating a laser receiving signal and outputting it to the digital processing unit.

In an embodiment of the present invention, the laser drive circuit includes a single high-speed drive circuit and a laser diode control circuit corresponding to the laser diodes one-to-one; the high-speed drive circuit is used to generate a laser diode drive based on the laser emission signal. The laser diode control circuit is used to control the on-off of the corresponding laser diodes, so as to realize the time-sharing conduction of the plurality of laser diodes.

In an embodiment of the present invention, the laser receiving circuit includes an I/V circuit, a gain amplifier circuit, a constant ratio timing circuit and a digital shaping circuit; the I/V circuit is used to convert the current signal output by the APD diode. is a voltage signal; the gain amplifying circuit is used to amplify the voltage signal; the constant-ratio timing circuit and the digital shaping circuit are respectively used to perform constant-ratio timing and digital shaping on the amplified voltage signal.

In an embodiment of the present invention, the laser diodes in the array of laser diodes are arranged up and down at a predetermined angle; the APD diodes in the array of APD diodes are arranged up and down at the predetermined angle.

In an embodiment of the present invention, the number of the laser diodes and the APD diodes is 3-16.

In an embodiment of the present invention, the optical system unit includes an emission mirror and a reception mirror; the emission mirror is used to focus the laser light emitted by the laser diode to the object to be measured; the reception mirror is used to The laser light reflected from the measured object is focused to the APD diode corresponding to the laser diode.

In an embodiment of the present invention, it further includes a system compensation unit, which is connected to the laser receiving unit and the digital processing unit, and includes a temperature compensation circuit and an APD high voltage compensation circuit; the temperature compensation circuit is used for collecting the array APD. The temperature information of the diode is output to the digital processing unit; the APD high voltage compensation circuit is used to generate a DC high voltage to drive the array APD diode, and collect the voltage information on the array APD diode and output it to the digital processing unit; the digital processing unit is further configured to perform temperature compensation and high voltage compensation on the array APD diodes based on the temperature information, and correct the DC high voltage according to the voltage information.

In an embodiment of the present invention, the laser emission signal is a narrow pulse signal, and the frequency of the narrow pulse signal is equally distributed to each laser diode as the driving frequency of the laser diode.

As mentioned above, the TOF-based multi-beam laser ranging sensor of the present invention has the following beneficial effects:

(1) Using the optical structure and circuit design, the laser emitting unit will only drive one laser diode at the same time. At the same time, based on the receiving angle between the avalanche photodiode (APD) of the receiving unit and the laser diode (LD) of the transmitting unit, Ensure that the APD energy of the receiving unit is the largest at the same time, and multiple APD outputs are connected in parallel, which increases the sensitivity of the receiving end; and based on the algorithm to determine whether the received signal is valid at this time, to ensure the usefulness of the signal;

(2) It has the characteristics of three-dimensional space measurement, and can realize multi-beam laser emission and multi-beam laser reception. Each laser transmitting circuit corresponds to a laser receiving circuit, and the laser transceiver devices correspond one-to-one and are arranged at a certain angle up and down. can form three-dimensional graphics;

(3) It has the characteristics of wide field of view detection, and the target distance detection can be carried out within a maximum field of view of 30 degrees, the center angle is 0, and the maximum angle range of up and down is 15 degrees;

(4) With the characteristics of ultra-high-speed ranging, multiple laser beams can drive each laser diode at a frequency of 20khz at a frequency of 320kz, and the laser diodes do not interfere with each other, and the maximum number of ranging times can reach 3,200,000 times per second. ;

(5) Compared with the traditional multi-wire receiving circuit, the circuit is simple, the cost is low, the reliability is high, and the volume is small;

(6) The high-speed FPGA module is used as the control core unit, and there are multiple TOF measurement channels externally. The high-speed FPGA module controls its measurement and data output respectively. It is suitable for 3-16 time difference measurement channels, and can measure multi-channel laser time-of-flight at the same time. , with the characteristics of multi-channel high-speed measurement;

(7) Suitable for high-speed multi-line lidar industry.

Description of drawings

FIG. 1 is a schematic structural diagram of a TOF-based multi-beam laser ranging sensor in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a laser emitting unit of the present invention in an embodiment;

3 is a schematic diagram showing the timing of the narrow pulse signal and the clock signal in an embodiment of the present invention;

FIG. 4 is a timing diagram illustrating the narrow pulse signal and the driving signal on each laser diode in an embodiment of the present invention;

5 is a schematic diagram showing the working principle of the optical system unit of the present invention in an embodiment;

FIG. 6 is a timing diagram of the laser flight start measurement signal and the time difference flight signal in an embodiment of the present invention.

Component label description

1 digital processing unit

11 FPGA module

12 TOF time-of-flight measurement circuit

2 Laser transmitter unit

21 Laser drive circuit

211 High-speed drive circuit

212 Laser Diode Control Circuit

22 Array Laser Diodes

3 Optical system unit

31 emitting mirror

32 Receiver mirror

4 Laser receiver unit

41 Array APD Diodes

42 Laser receiver circuit

5 System compensation unit

51 Temperature compensation circuit

52 APD high voltage compensation circuit

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other under the condition of no conflict.

It should be noted that the drawings provided in the following embodiments are only used to illustrate the basic concept of the present invention in a schematic way, so the drawings only show the components related to the present invention rather than the number, shape and number of components in actual implementation. For dimension drawing, the type, quantity and proportion of each component can be changed at will in actual implementation, and the component layout may also be more complicated.

The TOF-based multi-beam laser ranging sensor of the present invention solves the problems of low frequency and resolution of existing laser measurement, unclear object outline and narrow detection field through multi-beam laser ranging, and can realize ultra-high-speed ranging, and only Using a single receiving circuit, the structure is simple, the cost is low, and it is very practical.

As shown in FIG. 1 , in an embodiment, the TOF-based multi-beam laser ranging sensor of the present invention includes a digital processing unit 1 , a laser emitting unit 2 , an optical system unit 3 and a laser receiving unit 4 .

The laser emission unit 2 is connected to the digital processing unit 1 , and is configured to emit at least three lasers according to the laser emission signal sent by the digital processing unit 1 .

Specifically, the digital processing unit 1 sends a narrow pulse signal to the laser emitting unit 2 as a laser emitting signal. In an embodiment of the present invention, as shown in FIG. 2 , the laser emitting unit 2 includes a laser driving circuit 21 and an array laser diode 22 , so as to realize time-sharing and continuous emission of multiple laser diodes. Wherein, the array laser diode 22 includes at least three laser diodes arranged in parallel up and down; the laser driving circuit 21 is configured to generate a driving signal of the laser diode based on the laser emission signal, so as to drive each laser diode to emit time-divisionally laser. Preferably, the array laser diode 22 includes 3-16 SMD chip-type pulsed laser diodes, which are arranged at a certain acute angle up and down, and the field of view angle (that is, the angle of the two laser diodes at the upper and lower edges) is at most 30 degrees. The center angle is 0 degrees, and the field of view is arranged up and down plus or minus 15 degrees. According to the number of laser diodes, the angular resolution of each adjacent two laser diodes is 1°-10°.

In an embodiment of the present invention, the laser driving circuit 21 includes a single high-speed driving circuit 211 and a laser diode control circuit 212 corresponding to the laser diodes one-to-one; the high-speed driving circuit 211 is used for transmitting signals based on the laser light. A laser diode driving signal is generated; the laser diode control circuit 212 is used to control the on-off of the corresponding laser diodes, so as to realize the time-sharing conduction of the plurality of laser diodes. With the cooperation of multiple laser diode control circuits, the time-sharing conduction of multiple laser diodes is realized, and each channel generates a certain phase time difference, so that multiple laser diodes continuously emit laser signals in turn without interfering with each other; The narrow pulse signal is connected to the PWM port of the laser emitting unit 2, and its frequency is 60khz-320khz. The specific frequency is determined according to the number of laser diodes, and it is necessary to ensure that the driving frequency of each laser diode after frequency division is 20khz. The 60-320khz narrow pulse signal is amplified by the high-speed driving circuit, and the output signal is connected to the anode of the array laser diode 22 . At the same time, the digital processing unit 1 generates 3-16 channels of clock signals, and each channel is 20khz, the high level time is longer than the narrow pulse time, and the output end is connected to the G1G2G3....Gn of the laser emitting unit 2. The output time of each channel of the clock signal is different, and the interval between the rising edges of the adjacent time difference is Ta, and the control sequence is shown in Figure 3. Among them, Tz1 is the narrow pulse width, ts is the time interval between the rising edge of the clock signal and the rising edge of the PWM, ta is the time interval between the rising edges of adjacent clock signals, and Tz2 is the high level time of the clock signal. The clock signals on G1-Gn control the conduction of the array laser diodes 22 through 3-16 laser diode control circuits in turn, so that the switching frequency of each laser diode reaches 20khz. The final drive frequency on each laser diode is shown in Figure 4.

The laser receiving unit 4 is connected to the optical system unit 1 and the digital processing unit 2 , and is used for generating a laser receiving signal based on the received laser light and sending it to the digital processing unit 1 . Specifically, the laser receiving unit 4 includes an array of APD diodes 41 and a laser receiving circuit 42; the array of APD diodes includes at least three APD diodes arranged in parallel, and the APD diodes are in one-to-one correspondence with the laser diodes ; Each APD diode is used for receiving the laser light emitted by the corresponding laser diode, and the laser receiving circuit 42 is used for generating a laser receiving signal and outputting it to the digital processing unit 1 . Preferably, the array of APD diodes 41 includes 3-16 SMD APD diodes, which are arranged up and down at a certain angle, the arrangement angle is the same as that of the laser diodes in the laser emitting unit 2, and the maximum receiving field of view angle is 30°, the maximum angular resolution of adjacent APD diodes is 2°, and the arrangement angle error is guaranteed to be accurate to ±0.05°. The multiple APD diodes are arranged in parallel, and the output ends of the multiple APD diodes intersect in parallel and then connect to the laser receiving circuit 42 . After the laser beam from the laser emitting unit 2 is reflected by the measured object, part of the signal is received by the array APD diodes, and each APD diode can guarantee to receive the laser signal emitted by the corresponding laser diode. Multiple APD diodes are connected in parallel, which can also increase the sensitivity of the received signal, so that it has good stability.

In an embodiment of the present invention, the laser receiving circuit 42 includes an I/V circuit, a gain amplifier circuit, a constant-ratio timing circuit, and a digital shaping circuit; the I/V circuit is used to convert the current signal output by the APD diode. Converted into a voltage signal; the gain amplifying circuit is used for amplifying the voltage signal; the constant ratio timing circuit and the digital shaping circuit are respectively used to perform constant ratio timing and digital shaping on the amplified voltage signal. Specifically, the weak current signal from the array APD diode is converted into a identifiable voltage signal through I/V, and then amplified enough to identify a stable voltage signal available, and finally through constant ratio timing and shaping to make the signal more stable and useful. input to the digital processing unit 1.

The optical system unit 3 is connected with the laser emitting unit 1 and the laser receiving unit 4, and is used to focus each laser beam to the object to be measured, and to focus the laser reflected back by the object to be measured to the object to be measured. Laser receiver unit 4.

As shown in FIG. 5, in an embodiment of the present invention, the optical system unit 3 includes an emission mirror surface 31 and a reception mirror surface 32; the emission mirror surface 31 is used for focusing the laser light emitted by the laser diode to the target object. The object to be measured; the receiving mirror 32 is used to focus the laser light reflected from the object to be measured to the APD diode corresponding to the laser diode. Specifically, the emitting mirror surface 31 is composed of a high-precision optical collimating lens, which can focus the scattered laser light of 3-16 channels into 3-16 small dots of the same size and arranged at a certain angle up and down. Can project in a range of 100-200 meters. When a plurality of lasers emit laser light, part of the signal after diffuse reflection returns to the receiving mirror surface 32 . The receiving mirror 32 projects various lasers on the APD diodes corresponding to the laser diodes, thereby realizing one-to-one laser reception.

Specifically, as shown in FIG. 6 , the laser diode LD1 emits a 20khz pulse signal and generates a laser flight start measurement signal START1, which is focused into a laser spot through the emitting mirror 31 and projected onto the surface of the measured object at a certain angle. Part of the energy is focused on the receiving mirror surface 32 through the diffuse reflection of the measured object. Since the laser diode LD1 and the APD diode APD1 are installed at the same angle and are parallel to each other, the APD diode APD1 can ensure that the APD diode APD1 can receive sufficient return energy after the laser is reflected from the measured object. Since the anodes of multiple APD diodes are connected in parallel, according to the diffuse reflection and optical characteristics of the object, the APD diodes APD2, APD3...APDn can also receive a very small amount of energy. The set energy is expressed in dB, then dBapd1>dBapd2>dBapd3...>dBapdn. Therefore, the final output current of the array APD diode is I=Iapd1+Iapd2+Iapd3...+Iapdn, thereby increasing the output current and improving the sensitivity. The above formula can be expressed as In=IAPDn+IAPDe, where In is the current output by the array APD diode when the laser diode LDn emits, IADPn is the current received by the APDn after the laser diode LDn emits and returns, and IAPDe is the output of other adjacent APD diodes. Current signal, ideally this current is 0.

The current In input is amplified by the laser receiving circuit 4, and finally the time difference flight signal STOP is output, so as to obtain the flight time difference t1 for the digital processing unit 1 to calculate the distance D1; Similarly, when the laser diode LD2 is emitted, it is guaranteed that the APD diode APD2 can receive the laser signal to obtain the flight time difference t2 and calculate the distance D2.

The digital processing unit 1 is configured to obtain the distance from the corresponding laser to the measured object based on the laser emission signal and the laser reception signal.

In an embodiment of the present invention, the digital processing unit 1 includes an FPGA module 11 and a TOF time-of-flight measurement circuit 12 . The TOF flight time difference measurement circuit 12 is used to calculate the time difference between the laser emission signal and the laser received signal; the FPGA module 11 is used to generate the laser emission signal and send it to the laser emission unit, and according to the time difference Calculate the distance between the corresponding laser and the measured object.

Specifically, the TOF time-of-flight measurement circuit includes multiple or multi-channel high-speed time-of-flight measurement ICs and peripheral circuits for calculating the time-of-flight according to the laser flight start measurement signal START and the time difference flight signal STOP. The output end of the laser receiving circuit 4 is directly connected to the TDC time-of-flight measurement circuit 12, and the laser receiving circuit 4 outputs 20k-320k measurement pulses per second. Measure 3-16 laser echo signals at a time.

Specifically, the FPGA module 11 calculates the distance between the corresponding laser and the measured object according to the time-of-flight difference. The FPGA module 11 includes an ultra-high-speed FPGA core controller and other peripheral circuits, and is mainly responsible for generating 60khz-320khz high-precision narrow pulse signals and outputting them to the laser emitting unit 2, so that the The laser diode control circuit of 2 controls the opening and closing of a single laser diode; at the same time, the time difference result from the TDC time-of-flight measurement circuit is read in a high-speed state, and data processing is performed according to an algorithm. Preferably, the FPGA module 11 adopts ACTEL's unique SmartFusion series controller, which has an efficient Cortex-M3 core, the internal M3 operating frequency is up to 100Mhz, and the internal has 2M RAM, including rich AD/DA interfaces. The M3 is closely connected with the FPGA control logic, which makes the data throughput rate higher and enhances the confidentiality of the system software algorithm.

In an embodiment of the present invention, the TOF-based multi-beam laser ranging sensor of the present invention further includes a system compensation unit 5, which is connected to the laser receiving unit 4 and the digital processing unit 1, and includes a temperature compensation circuit 51 and an APD. High voltage compensation circuit 52 . The temperature compensation circuit 51 is used to collect the temperature information of the array APD diode 41 and send it to the digital processing unit 1; the APD high voltage compensation circuit 52 is used to generate a DC high voltage to drive the array APD diode 41, and collect the voltage information on the array APD diode 41 and send it to the digital processing unit 1; the digital processing unit 1 is also used to perform temperature compensation and high voltage compensation on the array APD diode 22 based on the temperature information, and The DC high voltage is corrected according to the voltage information.

Specifically, the temperature compensation circuit 51 is connected to the digital processing unit 1 for detecting temperature changes of the array APD diodes 41 and the system, and transmitting the detected temperature information to the digital processing unit 1 in real time. The temperature sensor in the temperature compensation circuit 51 is close to the array APD diode 41 to accurately detect the temperature change on the array APD diode 41 , and can also detect the overall temperature change of the laser receiving unit 4 in real time. The output of the temperature compensation circuit 51 is connected to the ADC unit inside the FPGA module 11, and the temperature information is sent to the FPGA module 11, so that the FPGA module 11 uses a software algorithm to perform temperature algorithm compensation.

The APD high-voltage compensation circuit 52 is connected to the digital processing unit 1, and is used to generate a 50V-200V high-voltage DC power supply to drive the APD array diode 41; The collected high-voltage information is fed back to the FPGA module 11, and the FPGA module 11 performs high-voltage compensation on the array APD diode 41 according to the temperature information transmitted by the temperature detection circuit, and according to the APD high-voltage compensation circuit The high-voltage information fed back by 52 controls the output size of the high-voltage DC, so that the array APD diode 41 can maintain the best working state under various ambient temperatures, and can have the best gain under different ambient temperatures, thereby Better reception of echoes to ensure signal stability. Specifically, the APD high-voltage compensation circuit 52 can output a DC high-voltage 50V-200V, 10mA driving capability, as low as 50mV power supply ripple, and the output high voltage is adjustable, its adjustment resolution can reach 0.3V, and its output terminal is directly connected to The reverse ends of the array APD diodes 41 are connected, and 3-16 APD diodes can be driven to work at the same time.

In the present invention, the APD high-voltage compensation circuit 52 and the temperature compensation circuit 51 are interlinked. When the temperature sensor in the temperature compensation circuit 51 detects the temperature change of the laser receiving unit 4, The temperature information is transmitted to the FPGA module 11 , and the FPGA module 11 controls the APD high voltage compensation circuit 52 to perform high voltage compensation on the array APD diodes 41 .

To sum up, the multi-beam laser ranging sensor based on TOF of the present invention adopts optical structure and circuit design. At the same time, the laser emitting unit will only drive one laser diode. It ensures that the APD energy of the receiving unit is the largest at the same time, and multiple APD outputs are connected in parallel, which increases the sensitivity of the receiving end; and based on the algorithm to judge whether the received signal is valid at this time, to ensure the usefulness of the signal; With the characteristics of three-dimensional space measurement, it can realize multi-beam laser emission and multi-beam laser reception. Each laser emitting diode corresponds to a laser receiving diode, and the laser transceiver devices correspond one-to-one and are arranged at a certain angle up and down. It forms a three-dimensional figure; it has the characteristics of wide field of view detection, and can detect the target distance within a maximum field of view of 30 degrees. Its center angle is 0, and the maximum angle range of vertical arrangement is 15 degrees. It can drive each laser diode at a frequency of 20khz at a frequency of 320kz, and the laser diodes do not interfere with each other, and the maximum number of ranging times can reach 3,200,000 times per second; compared with the traditional multi-line receiving circuit, the circuit is simple and the cost Low, high reliability, small size and other characteristics; high-speed FPGA module is used as the control core unit, and there are multiple TOF measurement channels externally. It can measure multi-channel laser time-of-flight at the same time, and has the characteristics of multi-channel high-speed measurement; it is suitable for high-speed multi-line laser radar industry. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be covered by the claims of the present invention.

Claims (10)

1. a kind of multi-beam laser range sensor based on TOF, it is characterised in that: including digital processing element, Laser emission Unit, optical system unit and laser pick-off unit；

The laser emission element is connected with the digital processing element, swashs for what is sent according to the digital processing element Light emission signal emits at least three Lu Jiguang；

The optical system unit is connected with the laser emission element and the laser pick-off unit, for gathering every road laser Coke will focus to the laser pick-off unit through the reflected laser of the testee to testee；

The laser pick-off unit is connected with the optical system unit and the digital processing element, for based on receiving Laser generates laser pick-off signal, and is sent to the digital processing element；

The digital processing element is used to be based on the laser firing signals and the corresponding laser of the laser pick-off signal acquisition To the distance of the testee.

2. the multi-beam laser range sensor according to claim 1 based on TOF, it is characterised in that: at the number Managing unit includes FPGA module and TOF jet lag measuring circuit；The TOF jet lag measuring circuit is described sharp for calculating The time difference of light emission signal and the laser pick-off signal；The FPGA module is for generating laser firing signals and being sent to institute Laser emission element is stated, and the distance between corresponding laser and the testee are calculated according to the time difference.

3. the multi-beam laser range sensor according to claim 1 based on TOF, it is characterised in that:

The laser emission element includes laser drive circuit and array laser diode；The array laser diode includes extremely The laser diode of few three parallel arrangeds；The laser drive circuit is used to generate based on the laser firing signals described sharp The driving signal of optical diode, to drive each laser diode time division emission laser；

The laser pick-off unit includes array APD diode and laser pick-off circuit；The array APD diode includes at least The APD diode of three parallel arrangeds, and the APD diode and the laser diode put in order one-to-one correspondence；Each APD diode is used to receive the laser that corresponding laser diode issues, and the laser pick-off circuit is for generating laser pick-off Signal is simultaneously exported to the digital processing element.

4. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the laser drives Dynamic circuit include single high-speed driving circuit and with the one-to-one laser diode control circuit of the laser diode；It is described High-speed driving circuit is used to generate laser diode driving signal based on the laser firing signals；The laser diode control Circuit is for controlling cut-offfing for corresponding laser diode, to realize the timesharing conducting of multiple laser diodes.

5. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the laser connects Receiving circuit includes I/V circuit, gain amplifying circuit, constant fraction discriminator circuit and digital shaping circuit；The I/V circuit is used for institute The current signal for stating the output of APD diode is converted to voltage signal；The gain amplifying circuit is for amplifying the voltage signal； The constant fraction discriminator circuit and the digital shaping circuit are respectively used to carry out constant fraction discriminator sum number to amplified voltage signal Word shaping.

6. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the array swashs Laser diode in optical diode is in predetermined angle arrangement up and down；It is in above and below APD diode in the array APD diode The predetermined angle arrangement.

7. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the laser two Pole pipe and the number of the APD diode are 3-16.

8. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the optical system Unit of uniting includes transmitting mirror surface and reception mirror surface；The laser that the transmitting mirror surface is used to launch the laser diode focuses To the testee；The reception mirror surface is for focusing to and the laser two the reflected laser of the testee The corresponding APD diode of pole pipe.

9. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: further include system Compensating unit is connected with the laser pick-off unit and the digital processing element, including temperature-compensation circuit and APD high pressure are mended Repay circuit；The temperature-compensation circuit is used to acquire the temperature information of the array APD diode, and exports to the number Manage unit；The APD high pressure compensation circuit drives the array APD diode for generating high direct voltage, and described in acquisition Information of voltage on array APD diode is exported to the digital processing element；The digital processing element is also used to based on institute It states temperature information and temperature-compensating and high pressure compensation is carried out to the array APD diode, and institute is corrected according to the information of voltage State high direct voltage.

10. the multi-beam laser range sensor according to claim 3 based on TOF, it is characterised in that: the laser hair Penetrating signal is narrow pulse signal, and the frequency averaging of the narrow pulse signal is distributed to each laser diode, as the laser The driving frequency of diode.