Communication circuit and laser radar

Abstract

The invention discloses a communication circuit and a laser radar, and relates to the technical field of communication. The communication circuit comprises a first current source, a second current source and a first optical unit. The first current source is configured to output a direct current. The second current source is configured to receive the first digital signal and output a pulse current based on the first digital signal. The first optical unit is connected with the first current source and the second current source. The first optical unit is configured to obtain and emit a first optical signal according to the direct current and the pulse current. In this way, the transmission rate of data and the anti-interference capability of signals can be improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication circuit and a laser radar. Background Art

[0002] Mechanical lidar usually consists of a base and a rotator. The base mainly realizes functions such as external interface, motor drive, wireless power supply and wireless communication, while the rotator mainly realizes functions such as ranging and wireless communication.

[0003] In mechanical lidars, wireless communication initially employed magnetic ring wireless communication, which achieved wireless communication through electromagnetic coupling between inner and outer magnetic rings. Due to drawbacks such as bulk, difficult processing, and low data rates, magnetic ring wireless communication is gradually being replaced by optical communication. However, optical communication currently still offers relatively low data transmission rates. Summary of the Invention

[0004] The present application aims to provide a communication circuit and a laser radar capable of improving the data transmission rate.

[0005] To achieve the above-mentioned objectives, in a first aspect, the present application provides a communication circuit, comprising: a first current source, configured to output a direct current; a second current source, configured to receive a first digital signal and output a pulse current based on the first digital signal; a first optical unit, the first optical unit being connected to the first current source and the second current source, respectively, and the first optical unit being configured to obtain and emit a first optical signal based on the direct current and the pulse current.

[0006] In an optional manner, the first optical unit includes a vertical cavity surface emitting laser or a light emitting diode.

[0007] In an optional manner, the first optical unit includes a first emitter and a second emitter, wherein the first emitter is a vertical cavity surface emitting laser or a light emitting diode, and the second emitter is a vertical cavity surface emitting laser.

[0008] In an optional manner, both the first emitter and the second emitter are vertical cavity surface emitting lasers.

[0009] The first optical unit includes two emitters that increase the amplitude of the first optical signal, thereby enhancing the signal's anti-interference capability, reducing the risk of bit errors, and extending the data transmission distance. Furthermore, compared to light-emitting diodes, vertical-cavity surface-emitting lasers (VCSELs) shorten the rise and fall times of the first optical signal, thereby achieving a higher communication rate. The first and second emitters are of the same type and have the same characteristics, making them easier to manage and maintain, and reducing compatibility issues caused by component differences.

[0010] In an optional embodiment, the communication circuit also includes: a second optical unit, configured to receive the first optical signal and obtain a first current signal based on the first optical signal; a voltage signal acquisition unit, the voltage signal acquisition unit is connected to the second optical unit, and the voltage signal acquisition unit is configured to obtain a first voltage signal based on the first current signal; a first signal conversion unit, the first signal conversion unit is connected to the voltage signal acquisition unit, and the first signal conversion unit is configured to obtain the second digital signal based on a reference voltage signal and the first voltage signal.

[0011] In an optional manner, the first signal conversion unit is a low voltage differential signal transmission unit in a field programmable logic gate array, and the second digital signal is obtained by differential processing of the reference voltage signal and the first voltage signal.

[0012] By performing differential processing, the effects of signal attenuation and distortion are reduced, improving anti-interference capabilities and enabling long-distance data transmission. Furthermore, by reducing signal waveform distortion during transmission, the reliability and stability of data transmission are ensured. Furthermore, compared to using high-speed comparators, this approach can also reduce costs.

[0013] In a second aspect, the present application provides a laser radar comprising a main board, a base board and the communication circuit as described above; the first optical unit is arranged at the center of the main board, and the second optical unit is arranged at the center of the base board.

[0014] The first optical unit and the second optical unit are both arranged at a central position, which is beneficial to improving the signal transmission rate between the first optical unit and the second optical unit and extending the communication distance.

[0015] In an optional manner, the first emitter is arranged at the center of the mainboard, and the second emitter is arranged on one side of the first emitter.

[0016] By setting up two transmitters and placing one of them at the center of the mainboard, not only can the signal amplitude of the first optical signal be increased to increase the signal's anti-interference ability and reduce the risk of bit errors, but the data transmission distance and communication rate can also be improved.

[0017] In an optional embodiment, the communication circuit also includes a third optical unit provided on the base plate, a fourth optical unit provided on the main board, and a second signal conversion unit; the third optical unit is used to receive a third digital signal and output a second optical signal based on the third digital signal; the fourth optical unit is used to receive the second optical signal and convert the second optical signal into a second current signal; the second signal conversion unit is connected to the fourth optical unit, and the second signal conversion unit is used to output a fourth digital signal based on the second current signal.

[0018] In one optional embodiment, the third optical unit is provided on one side of the second optical unit, and the fourth optical unit is provided on one side of the first optical unit. This configuration prioritizes downlink data transmission. Furthermore, by staggering the wavelength of the optical signal used in the uplink communication process with the wavelength of the signal used in the downlink communication process, i.e., by having different wavelengths for the first and second optical signals, uplink and downlink data transmissions can be prevented from interfering with each other.

[0019] In an optional embodiment, the laser radar also includes a radar front-end device and an upper-level application device; the radar front-end device is configured to output the first digital signal and receive the fourth digital signal; the upper-level application device is configured to receive the second digital signal and output the third digital signal.

[0020] The beneficial effects of the present application are as follows: the communication circuit provided by the present application includes a first current source, a second current source and a first optical unit. The first current source outputs a direct current, and the second current source outputs a pulse current based on a first digital signal. Both the direct current and the pulse current are input to the first optical unit, so that the first optical unit obtains and emits a first optical signal based on the direct current and the pulse current. On the one hand, the pulse current is related to the first digital signal, and the first optical signal is related to the pulse current. It can be determined that the first optical signal is related to the first digital signal, and the data transmission process can be realized by emitting the first optical signal related to the first digital signal. On the other hand, the direct current can keep the first optical unit in a conductive state. During the data transmission process, when the first digital signal changes, it will only cause the size of the driving current to change, without the need to execute the process of starting the first optical unit. Therefore, during the data transmission process, the first optical signal can maintain a faster level switching speed, which is conducive to improving the data transmission rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0022] Figure 1Schematic diagram of the structure of the communication circuit provided in the embodiment of the present application Figure 1 ;

[0023] Figure 2 A schematic diagram of a pulse current and a binary number corresponding to a first digital signal provided in an embodiment of the present application;

[0024] Figure 3 For Figure 1 Schematic diagram of circuit structure corresponding to the structure shown;

[0025] Figure 4 Schematic diagram of the structure of the communication circuit provided in the embodiment of the present application Figure 2 ;

[0026] Figure 5 For Figure 4 Schematic diagram of circuit structure corresponding to the structure shown;

[0027] Figure 6 Schematic diagram of the structure of the communication circuit provided in the embodiment of the present application Figure 3 ;

[0028] Figure 7 For Figure 6 A schematic diagram of the circuit structure corresponding to the portion receiving the first optical signal in the structure shown;

[0029] Figure 8 Schematic diagram of the structure of the laser radar provided in the embodiment of this application Figure 1 ;

[0030] Figure 9 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 1 ;

[0031] Figure 10 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 2 ;

[0032] Figure 11 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 3 ;

[0033] Figure 12 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 4 ;

[0034] Figure 13 Schematic diagram of the structure of the laser radar provided in the embodiment of this application Figure 2 ;

[0035] Figure 14 A schematic diagram of a portion of the structure of a communication circuit provided in an embodiment of the present application;

[0036] Figure 15 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 5 ;

[0037] Figure 16 Schematic diagram of some structures of the laser radar provided in the embodiment of this application Figure 6 ;

[0038] Figure 17 Schematic diagram of the structure of the laser radar provided in the embodiment of this application Figure 3 .

[0039] Description of reference numerals:

[0040] 1000, laser radar; 500, upper application device; 400, radar front-end device; 300, baseboard; 200, mainboard; 100, communication circuit; 90, second signal conversion unit; 80, fourth optical unit; 70, third optical unit; 60, first signal conversion unit; 50, voltage signal acquisition unit; 40, second optical unit; 30, first optical unit; 31, first transmitter; 32, second transmitter; 20, second current source; 10, first current source; I1, DC current; I 2. Pulse current; I3, drive current; DS1, first digital signal; DS2, second digital signal; DS3, third digital signal; DS4, fourth digital signal; LD1, light emitting diode; VL1, vertical cavity surface emitting laser; VL2, vertical cavity surface emitting laser; VREF, reference voltage signal; V1, first voltage; PD1, photodiode; PD2, photodiode; U1, transimpedance amplifier; U2, low voltage differential signal transmission unit in field programmable logic gate array. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the communication circuit provided in the embodiment of the present application. Figure 1 As shown, the communication circuit 100 includes a first current source 10 , a second current source 20 and a first optical unit 30 .

[0043] The first current source 10 is configured to output a direct current I1. Direct current I1 represents a current whose magnitude remains constant for a predetermined period of time. In one embodiment, the first current source 10 is controlled by a first control signal. When the first current source 10 receives the first control signal, the first current source 10 is enabled and maintains outputting the direct current I1. In one embodiment, the magnitude of the direct current I1 is configured to remain constant to simplify the subsequent demodulation of the first optical signal.

[0044] The second current source 20 is configured to receive a first digital signal DS1 and output a pulse current I2 based on the first digital signal DS1. The first digital signal DS1 is a digital signal corresponding to the data to be transmitted. For example, in one embodiment, the communication circuit 100 is applied to a laser radar and is used to transmit an echo signal, wherein the echo signal is formed by the detection light emitted by the laser radar to the target object and reflected by the target object. In this embodiment, the digital signal corresponding to the echo signal is the first digital signal DS1. The pulse current I2 is composed of a current signal that is suddenly generated in the circuit and has a short duration, that is, the pulse current I2 is composed of one or more pulses, and each pulse has a certain amplitude, width and interval. The shape of these pulses can be a square wave, a sine wave or a sawtooth wave, etc. The specific shape of the pulse can be set based on the actual application scenario, and the embodiment of the present application does not impose specific restrictions on this.

[0045] In one embodiment, the first digital signal DS1 corresponds to a binary number consisting of 0 and 1. Thus, the pulse current I2 corresponds to the binary number corresponding to the first digital signal DS1, thereby enabling data transmission. In one embodiment, the correspondence between the pulse current I2 and the binary number corresponding to the first digital signal DS1 is configured such that each time the binary number corresponding to the first digital signal DS1 is 1, the pulse current I2 generates a pulse. Conversely, each time the binary number corresponding to the first digital signal DS1 is 0, the pulse current I2 does not generate a pulse.

[0046] Please refer to Figure 2 , Figure 2 An exemplary implementation of the binary number corresponding to the pulse current I2 and the first digital signal DS1 is shown, wherein the pulse shape of the pulse current I2 is a square wave as an example. In some embodiments, as Figure 2 As shown, the binary number corresponding to the first digital signal DS1 is 10101010010101011010. Each time the binary number is 1, a pulse occurs in the pulse current I2. For example, the first 1 in the binary number (counted from left to right) corresponds to a pulse in the pulse current I2. This approach enables the pulse current I2 to correspond to the first digital signal DS1, thereby enabling data transmission.

[0047] Please refer back to Figure 1 The first light unit 30 is connected to the first current source 10 and the second current source 20 respectively. The first current source 10 and the second current source 20 are used to provide a driving current I3 for the first light unit 30. The driving current I3 includes a direct current I1 and a pulse current I2, that is, I3=I1+I2.

[0048] The first optical unit 30 is configured to generate a first optical signal based on a drive current I3 and transmit the first optical signal. In some embodiments, parameters of the first optical signal (such as level switching speed and response time) are related to the drive current I3. The drive current I3 comprises a direct current I1 and a pulse current I2. Therefore, the parameters of the first optical signal are determined by the direct current I1 and the pulse current I2. The pulse current I2 is derived from the first digital signal DS1, and the first optical signal is derived from the pulse current I2. This ensures that the first optical signal necessarily carries information corresponding to the first digital signal DS1, thus enabling data transmission via the first optical signal. The direct current I1 keeps the first optical unit 30 in a conductive state. During data transmission, changes in the first digital signal DS1 only cause changes in the drive current I3, without requiring the first optical unit 30 to start up. This allows the first optical signal to maintain a relatively fast level switching speed. Level switching speed includes the speed of switching from a high level to a low level and the speed of switching from a low level to a high level, also known as the speed of the falling edge and the speed of the rising edge. Faster level switching speeds translate to higher system response speeds and higher data transmission rates. In summary, by providing the first current source 10 and the second current source 20 to power the first optical unit 30 , a higher data transmission rate can be achieved while ensuring data transmission.

[0049] In one embodiment, if Figure 3 As shown, the first light unit 30 includes a light emitting diode (LED) LD1, which is used to convert electrical energy into light energy. The anode of the LED LD1 is connected to a terminal of the first current source 10 outputting a direct current I1 and a terminal of the second current source 20 outputting a pulsed current I2. The cathode of the LED LD1 is connected to ground GND. Specifically, a driving current I3, which is a combination of the direct current I1 and the pulsed current I2, is input to the anode of the LED LD1. The LED LD1 converts the driving current I3 into a first light signal and emits the first light signal.

[0050] In related technologies, logic circuits such as inverters or buffers are typically used to drive light-emitting diodes. This approach results in longer rise and fall times for the optical signal, leading to lower data transmission rates. However, in the embodiments of the present application, by providing a first current source 10 and a second current source 20 to power the light-emitting diode LD1, the light-emitting diode LD1 can be kept in an operating state during data transmission, thereby shortening the rise and fall times of the optical signal and thereby increasing the data transmission rate.

[0051] In one embodiment, the first optical unit 30 includes a vertical cavity surface emitting laser (denoted as VL1), which is used to obtain a first optical signal according to the driving current I3. The vertical cavity surface emitting laser (VCSEL) VL1 is a semiconductor laser with a vertical structure. The vertical cavity surface emitting laser VL1 can reflect the laser beam in the vertical direction so that the laser beam is emitted perpendicular to the surface of the chip. The specific connection method between the vertical cavity surface emitting laser VL1 and the first current source 10 and the second current source 20 is the same as Figure 3 The light emitting diodes LD1 shown are identical.

[0052] Specifically, compared to the light-emitting diode LD1, the rise time and fall time of the optical signal emitted by the vertical cavity surface emitting laser VL1 are shorter, which is conducive to achieving a higher communication rate. In some embodiments, due to the speed limitation of the device itself, the rise time and fall time of the optical signal emitted by the light-emitting diode LD1 are more than 10ns, making it difficult to achieve a communication rate of more than 100Mbps. The rise time and fall time of the optical signal emitted by the vertical cavity surface emitting laser VL1 can be reduced to less than 1ns, which can support a communication rate of more than 1G. Secondly, the light beam generated by the vertical cavity surface emitting laser VL1 is more concentrated and directional, with high beam quality. It not only has a longer communication distance and higher practicality, but also has a lower risk of bit errors during the optical communication process and higher data transmission reliability.

[0053] In some embodiments, by simultaneously supplying power from the first and second current sources 10 and 20 and combining them with a vertical-cavity surface-emitting laser (VL1) to achieve electro-optical conversion, the rise and fall times of the optical signal can be shortened, thereby increasing the data transmission rate. Furthermore, the enhanced optical signal can support longer-distance communication and improve the optical signal's anti-interference capability, thereby reducing the risk of bit errors.

[0054] In the above embodiment, the first optical unit 30 includes one emitter, which is a light emitting diode LD1 or a vertical cavity surface emitting laser VL1. In other embodiments, more emitters may be configured to achieve a longer data transmission distance.

[0055] In one embodiment, if Figure 4 As shown, the first light unit 30 includes a first emitter 31 and a second emitter 32 .

[0056] The first emitter 31 and the second emitter 32 are both input with the driving current I3, and then the first emitter 31 and the second emitter 32 jointly emit the first optical signal. The optical signal emitted by the first emitter 31 is recorded as the first sub-optical signal, and the optical signal emitted by the second emitter 31 is recorded as the second sub-optical signal. At this time, the first optical signal emitted by the first optical unit 30 includes the first sub-optical signal and the second sub-optical signal. That is, the first optical signal is obtained by combining the first sub-optical signal and the second sub-optical signal, and the first sub-optical signal and the second sub-optical signal partially overlap, so that the signal amplitude of the first optical signal is greater than both the first sub-optical signal and the second sub-optical signal. At this time, the signal amplitude of the first optical signal in this embodiment is greater than the signal amplitude of the first optical signal when the first optical unit 30 includes only one emitter.

[0057] In this embodiment, the first optical unit 30 includes two transmitters, which can increase the signal amplitude of the first optical signal, thereby increasing the signal's anti-interference ability and reducing the risk of bit errors, while also extending the data transmission distance, that is, increasing the communication distance.

[0058] Please refer to Figure 5 , Figure 5 An example is shown with Figure 4 An implementation method corresponding to the structure shown in FIG. Figure 5 As shown, the first emitter 31 and the second emitter 32 are both vertical cavity surface emitting lasers VL1.

[0059] In some embodiments, the anodes of the two VCSELs VL1 are connected to one end of the first current source 10 outputting the DC current I1 and one end of the second current source 20 outputting the pulse current I2, and the cathodes of the two VCSELs VL1 are grounded GND.

[0060] Specifically, the process of realizing optical communication by a vertical cavity surface emitting laser VL1 alone can refer to the description of the above embodiment and will not be repeated here. In this embodiment, one vertical cavity surface emitting laser VL1 can be used as the main transmitter, and the other vertical cavity surface emitting laser VL1 can be used as the auxiliary transmitter. Then, the vertical cavity surface emitting laser VL1 as the main transmitter is used to realize data transmission, and the vertical cavity surface emitting laser VL1 as the auxiliary transmitter is used to realize signal amplitude enhancement to extend the communication distance.

[0061] In this embodiment, both the first emitter 31 and the second emitter 32 are configured as vertical cavity surface emitting lasers (VL1). This allows for a high communication rate based on the characteristics of the VCSL VL1. Furthermore, the identical type and characteristics of the first and second emitters facilitate management and maintenance, and help reduce compatibility issues caused by component differences.

[0062] In another embodiment, both the first emitter 31 and the second emitter 32 may be configured as a light emitting diode LD1 to increase the communication rate and extend the communication distance. Of course, in other embodiments, one of the first emitter 31 and the second emitter 32 may be configured as a vertical cavity surface emitting laser VL1 and the other may be configured as a light emitting diode LD1.

[0063] In addition, in other embodiments, reference may be made to Figure 4 The method shown in FIG. 1 is to increase the number of transmitters to correspondingly increase the communication rate and extend the communication distance. For example, in one embodiment, the first optical unit 30 includes three or more transmitters. Furthermore, each transmitter can be configured as a vertical cavity surface emitting laser (VCSEL) or a light emitting diode (LED). In some embodiments, when the first optical unit 30 includes three or more transmitters, at least one of the transmitters can be configured as a vertical cavity surface emitting laser (VCSEL) to maintain a high communication rate.

[0064] The above embodiments all describe the portion of the communication circuit 100 related to transmitting the first optical signal, and subsequent embodiments of the present application further provide the portion of the communication circuit 100 related to receiving the first optical signal.

[0065] Please refer to Figure 6 , Figure 6 FIG. 1 is a block diagram of a communication circuit 100 including a circuit for receiving an optical signal. Figure 6 As shown, the communication circuit 100 further includes a second optical unit 40 , a voltage signal acquiring unit 50 and a first signal converting unit 60 .

[0066] In some embodiments, the second optical unit 40 is configured to receive the first optical signal and obtain the first current signal according to the first optical signal. The second optical unit 40 is a unit that converts light energy into electrical energy. Figure 7 As shown, the second optical unit 40 includes a photodiode (PD1). The photodiode PD1 is a semiconductor device composed of a PN junction and has a unidirectional conductive characteristic. The photodiode PD1 can generate a current under the illumination of the first light signal, and the current is the first current signal.

[0067] Please refer back to Figure 6, the voltage signal acquisition unit 50 is connected to the second optical unit 40. The voltage signal acquisition unit 50 is configured to obtain a first voltage signal V1 according to the first current signal. Figure 7 As shown, the voltage signal acquisition unit 50 includes a trans-impedance amplifier (TIA) U1. The TIA U1 can convert an input first current signal into an output first voltage signal V1 using a feedback resistor. Furthermore, by adjusting the feedback resistor, the conversion gain of the TIA U1 can be varied to accommodate varying input signal strengths.

[0068] Please refer back to Figure 6 , the first signal conversion unit 60 is connected to the voltage signal acquisition unit 50. In some embodiments, the first signal conversion unit 60 is configured to obtain the second digital signal DS2 based on the reference voltage signal VREF and the first voltage signal V1. Specifically, the first signal conversion unit 60 is used to convert the analog signal (i.e., the first voltage signal V1) into a corresponding digital signal (the second digital signal DS2). By processing the second digital signal DS2, the first digital signal DS1 can be determined, and the information corresponding to the first digital signal DS1 can be further obtained to realize the communication process. For example, in one embodiment, the communication circuit 100 is applied to a laser radar, and the first digital signal DS1 corresponds to the echo signal obtained after the detection light emitted by the laser radar to the target object is reflected by the target object. Based on the processing of the second digital signal DS2, the first digital signal DS1 and its corresponding echo signal can be determined, and then the parameters related to the target object (such as the distance to the target object, etc.) can be determined.

[0069] In one embodiment, the first signal conversion unit 60 includes a comparator. The reference voltage signal VREF and the first voltage signal V1 are respectively input to two input terminals of the comparator. The comparator outputs a second digital signal DS2 based on the comparison result between the reference voltage signal VREF and the first voltage signal V1. For example, in one embodiment, the first voltage signal V1 is input to the non-inverting input terminal of the comparator, and the reference voltage signal VREF is input to the inverting input terminal of the comparator. When the first voltage signal V1 is greater than the reference voltage signal VREF, the comparator outputs a high level (corresponding to the binary number 1); when the first voltage signal V1 is less than or equal to the reference voltage signal VREF, the comparator outputs a low level (corresponding to the binary number 0). As a result, the signal output by the comparator is a digital signal composed of 0s and 1s, which is the second digital signal DS2.

[0070] In another embodiment, Figure 7As shown, the first signal conversion unit 60 includes a low voltage differential signaling (LVDS) unit U2 in a field-programmable gate array (FPGA). A reference voltage signal VREF and a first voltage signal V1 are respectively input to two input terminals of the LVDS unit U2. The LVDS unit U2 performs differential processing based on the reference voltage signal VREF and the first voltage signal V1 and outputs a second digital signal DS2. That is, the LVDS unit U2 simultaneously transmits the reference voltage signal VREF and the first voltage signal V1 via a pair of signal lines to achieve differential signal transmission. Simultaneously, the LVDS unit U2 can also implement the function of a comparator as in the above-mentioned embodiment to output the second digital signal DS2. In summary, the process of obtaining the second digital signal DS2 by differential processing the reference voltage signal VREF and the first voltage signal V1 is implemented. It is understood that when the first voltage signal V1 is interfered with, resulting in an abnormality such as signal attenuation, the reference voltage signal VREF will also be interfered with in the same manner, resulting in an abnormality such as signal attenuation. In this case, since this embodiment adopts a differential processing method, the abnormalities of the first voltage signal V1 and the reference voltage signal VREF can be offset to ensure that the second digital signal DS2 output by the LVDS unit U2 is normal.

[0071] In some embodiments, by using the LVDS unit U2 to perform a differential processing on the reference voltage signal VREF and the first voltage signal V1 and then outputting the second digital signal DS2, the effects of signal attenuation and distortion can be reduced, the anti-interference capability can be improved, and long-distance data transmission can be achieved. Moreover, since the signal waveform distortion during the transmission process is reduced, the reliability and stability of the data transmission can also be guaranteed. It can be seen that compared with the above-mentioned embodiment using a comparator, this embodiment using the LVDS unit U2 can achieve a longer data transmission distance and can make data transmission more reliable and stable. In addition, in order to meet the demand for fast data transmission, the communication circuit 100 usually needs to use a high-speed comparator, which is relatively expensive. Replacing the high-speed comparator with the LVDS unit U2 is conducive to reducing costs.

[0072] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the structure of the laser radar provided in the embodiment of this application. Figure 8 As shown, the laser radar 1000 includes the communication circuit 100, the main board 200 and the base board 300 in any embodiment of the present application.

[0073] In some embodiments, the mainboard 200 and the bottom plate 300 are arranged parallel and opposite to each other. The straight line between the center of the mainboard 200 and the center of the bottom plate 300 is the central axis. The mainboard 200 can rotate around the central axis, while the bottom plate 300 remains relatively stationary.

[0074] In some embodiments, a portion of the communication circuit 100 is disposed on the mainboard 200, and another portion is disposed on the baseboard 300. Specifically, at least a portion of the first optical unit 30 of the communication circuit 100 is disposed at the center of the mainboard 200, and at least a portion of the second optical unit 40 is disposed at the center of the baseboard 300. That is, at least a portion of the first optical unit 30 and at least a portion of the second optical unit 40 are located on a central axis. When the mainboard 200 rotates, the portion of the first optical unit 30 disposed at the center of the mainboard 200 and the portion of the second optical unit 40 disposed at the center of the baseboard 300 remain aligned without shifting. Data transmission between the portion of the first optical unit 30 disposed at the center of the mainboard 200 and the portion of the second optical unit 40 disposed at the center of the baseboard 300 is most efficient and produces the strongest signal, thus facilitating extended communication distances.

[0075] In some embodiments, the first light unit 30 and the second light unit 40 each include only one emitter. The entire first light unit 30 is located at the center of the main board 200 , and the entire second light unit 40 is located at the center of the bottom board 300 .

[0076] Please refer to Figure 9 , Figure 9 Schematic diagram showing a first optical unit 30 including a vertical cavity surface emitting laser VL1 and a second optical unit 40 including a photodiode PD1. Figure 9 As shown, the VCSEL VL1 is positioned at the center of the mainboard 200 (corresponding to the first optical unit 30 being positioned at the center of the mainboard 200), and the photodiode PD1 is positioned at the center of the baseboard 300 (corresponding to the second optical unit 40 being positioned at the center of the mainboard 200). In this configuration, both the VCSEL VL1 and the photodiode PD1 are positioned on the central axis. Consequently, when the mainboard 200 rotates, the VCSEL VL1 and the photodiode PD1 maintain positive alignment without shifting. This maximizes communication efficiency and the strongest signal between the VCSEL VL1 and the photodiode PD1.

[0077] In some embodiments, the first optical unit 30 includes two or more emitters, one of which is located at the center of the mainboard 200, and the remaining lasers are located on one side of the centrally located emitter (which may be on the same side or different sides). In some embodiments, when the second optical unit 40 includes two or more receivers, one of which is located at the center of the mainboard 300, and the remaining receivers are located on one side of the centrally located device (which may be on the same side or different sides).

[0078] Please refer to Figure 10 , Figure 10 The first optical unit 30 includes two emitters (including a first emitter and a second emitter) and the second optical unit 40 includes a photodiode PD1. In some embodiments, the first emitter is located at the center of the mainboard 200, and the second emitter is located on one side of the first emitter. For example, if both the first emitter and the second emitter are vertical cavity surface emitting lasers VL1, Figure 10 As shown, one of the two VCSELs VL1 (assuming it is the first emitter) is located at the center of the mainboard 200 (corresponding to the placement of a portion of the first optical unit 30 at the center of the mainboard 200), and the other (assuming it is the second emitter) is located to one side of the first emitter. A photodiode PD1 is located at the center of the base plate 300 (corresponding to the placement of the entire second optical unit 40 at the center of the mainboard 200). When the mainboard 200 rotates, the VCSEL VL1 (i.e., the first emitter) and the photodiode PD1 located on the central axis can maintain positive alignment and will not shift in position. The communication rate and signal strength between the VCSEL VL1 and the photodiode PD1 located on the central axis are the highest, while the VCSEL VL1 (i.e., the second emitter) not located on the central axis can enhance the signal amplitude of the optical signal (i.e., enhance the signal strength of the optical signal), which helps to extend the communication distance.

[0079] It should be noted that, in this embodiment, the second transmitter is set on the left side of the first transmitter as an example, and in other embodiments, the second transmitter can also be set at other positions, as long as it is set on the side of the first transmitter and can play the role of enhancing the signal amplitude of the optical signal. Figure 11 As shown, in another embodiment, the second transmitter is arranged on the upper side of the first transmitter, which can achieve Figure 10 The same effect as shown in the structure is within the scope that can be easily understood by those skilled in the art and will not be described in detail here.

[0080] In some embodiments, please refer to Figure 12 , Figure 12The following schematic diagram illustrates a first optical unit 30 including three emitters (including a first emitter, a second emitter, and a third emitter) and a second optical unit 40 including a photodiode PD1. In one embodiment, the first emitter is located at the center of the mainboard 200, and the second emitter and the third emitter are both located on one side of the first emitter. For example, the first emitter, the second emitter, and the third emitter are all vertical cavity surface emitting lasers VL1. Figure 12 As shown, the first of the three vertical cavity surface emitting lasers VL1 (assuming it is the first emitter) is located at the center of the mainboard 200, the second (assuming it is the second emitter) is located on one side of the first emitter, and the third (assuming it is the third emitter) is located on the other side of the first emitter. A photodiode PD1 is located at the center of the base plate 300. When the mainboard 200 rotates, the vertical cavity surface emitting laser VL1 (i.e., the first emitter) and the photodiode PD1 located on the central axis can maintain positive alignment and will not shift in position. The communication rate between the vertical cavity surface emitting laser VL1 located on the central axis and the photodiode PD1 is the highest and the signal is also the strongest. The vertical cavity surface emitting lasers VL1 not located on the central axis (i.e., the second emitter and the third emitter) can both enhance the signal amplitude of the optical signal, which is beneficial to extend the communication distance.

[0081] It should be noted that in this embodiment, the second and third emitters are located on different sides of the first emitter. This allows the second and third emitters to be closer to the first emitter, thereby more effectively enhancing the amplitude of the optical signal. Of course, in other embodiments, the second and third emitters can also be located on the same side of the first emitter, for example, by arranging the second and third emitters sequentially from the left side of the first emitter.

[0082] Please refer to Figure 13 and Figure 14 ,in, Figure 14 Only a portion of the structure of the communication circuit 100 including the third optical unit 70, the fourth optical unit 80 and the second signal conversion unit 90 is shown. Figure 13 and Figure 14 As shown, the communication circuit 100 further includes a third optical unit 70 disposed on the base plate 300 , a fourth optical unit 80 disposed on the main board 200 , and a second signal conversion unit 90 .

[0083] In some embodiments, the third optical unit 70 is configured to receive a third digital signal DS3 and output a second optical signal based on the third digital signal. The third optical unit 70 can be powered by a single current source, or, similar to the first optical unit 30, by using two current sources to increase the communication rate. Furthermore, the third optical unit 70 can include one or more emitters, each of which can be a light-emitting diode or a vertical-cavity surface-emitting laser. The above implementation process is similar to that of the first optical unit 30, and details can be found in the description of the first optical unit 30. In one embodiment, the third optical unit 70 is driven by a logic circuit such as an inverter or a buffer.

[0084] In some embodiments, the fourth optical unit 80 is configured to receive the second optical signal and convert the second optical signal into a second current signal. The fourth optical unit 80 is a unit that converts optical energy into electrical energy. In one embodiment, the fourth optical unit 80 includes a photodiode, and the current generated by the second optical signal is the second current signal.

[0085] In some embodiments, the second signal conversion unit 90 is connected to the fourth optical unit 80. The second signal conversion unit 90 is used to output the fourth digital signal DS4 based on the second current signal. In one embodiment, the second signal conversion unit 90 first converts the second current signal into a second voltage signal, and then converts the second voltage signal into the fourth digital signal DS4. Based on this, in one embodiment, the second signal conversion unit 40 includes a transimpedance amplifier and a comparator (or a low voltage differential signal transmission unit in a field programmable logic gate array). The transimpedance amplifier can convert the second current signal into a second voltage signal, and the comparator or the low voltage differential signal transmission unit in the field programmable logic gate array can convert the second voltage signal into the fourth digital signal DS4. The above implementation process is similar to that of the voltage signal acquisition unit 50 and the first signal conversion unit 60. For details, please refer to the description of the voltage signal acquisition unit 50 and the first signal conversion unit 60, which will not be repeated here.

[0086] In one embodiment, when at least a portion of the first optical unit 30 is disposed on the main board 200 and at least a portion of the second optical unit 40 is disposed on the bottom board, the third optical unit 70 is disposed on one side of the second optical unit 40 and the fourth optical unit 80 is disposed on one side of the first optical unit 30 to ensure that the uplink data transmission process and the downlink data transmission process do not interfere with each other. Figure 6 The data transmission process shown is a downlink data transmission process. Figure 14 The data transmission process shown is an uplink data transmission process.

[0087] In some embodiments, please refer to Figure 15 , Figure 15The embodiment exemplifies a structure in which the first optical unit 30 includes a vertical cavity surface emitting laser VL1 ; the second optical unit 40 includes a photodiode PD1 ; the third optical unit 70 includes a light emitting diode LD2 ; and the fourth optical unit 80 includes a photodiode PD2 .

[0088] The vertical-cavity surface-emitting laser (VL1) and photodiode (PD1) are located in the center of the mainboard 200 and the baseboard 300, respectively. The light-emitting diode (LD2) is located on one side of the photodiode (PD1), and the photodiode (PD2) is located on the other side of the vertical-cavity surface-emitting laser (VL1). The vertical-cavity surface-emitting laser (VL1) and photodiode (PD1) are used to implement downlink data transmission, which has a low bit error rate, a high transmission rate, and a long transmission distance. The light-emitting diode (LD2) and photodiode (PD2) are used to implement uplink data transmission.

[0089] In some embodiments, please refer to Figure 16 , Figure 16 The example shows a structure in which the first optical unit 30 includes two emitters, namely a vertical cavity surface emitting laser VL1 and a vertical cavity surface emitting laser VL2; the second optical unit 40 includes a photodiode PD1; the third optical unit 70 includes a light emitting diode LD2; and the fourth optical unit 80 includes a photodiode PD2.

[0090] In some embodiments, a vertical cavity surface emitting laser (VL1) and a photodiode (PD1) are located at the center of the mainboard 200 and the baseboard 300, respectively. A light-emitting diode (LED) LD2 is located on one side of the photodiode (PD1), and the photodiode (PD2) and the vertical cavity surface emitting laser (VL2) are located on one side of the VCSL (VL1). The VCSL (VL1), VCSL (VL2), and photodiode (PD1) are used to implement downlink data transmission. The LED (LD2) and photodiode (PD2) are used to implement uplink data transmission.

[0091] It should be noted that Figure 15 and Figure 16 Only two structures are shown as examples. In other embodiments, when the number of devices included in each optical unit is Figure 15 and Figure 16 At different times, just refer to Figure 15 and Figure 16 The corresponding settings are made in a manner that is easily understood by those skilled in the art and will not be described in detail here.

[0092] In one embodiment, if Figure 17 As shown, the laser radar 1000 also includes a radar front-end device 400 and an upper-level application device 500.

[0093] The radar front-end device 400 is configured to output a first digital signal DS1 and receive a fourth digital signal DS4 , and the upper-level application device 500 is configured to receive a second digital signal DS2 and output a third digital signal DS3 .

[0094] In some embodiments, the upper application device 500 can be any type of terminal device with user interaction function and computing capability, for example, a smart car terminal, a drone terminal, or other terminal device that can be installed on a smart car or a drone.

[0095] In some embodiments, the process of transmitting downlink data is as follows: the radar front-end device 400 emits a laser toward a target object, receives an echo signal reflected by the target object, and outputs a first digital signal DS1 based on the echo signal. The first digital signal DS1 is input into the second current source 20 to generate a pulse current I2 corresponding to the first digital signal DS1. At the same time, the direct current I1 and the pulse current I2 output by the first current source 10 are input into the first optical unit 30, causing the first optical unit 30 to emit a first optical signal. Subsequently, the second optical unit 40 generates a first current signal under the illumination of the first optical signal. The first current signal is converted into a second digital signal DS2 by the voltage signal acquisition unit 50 and the first signal conversion unit 60. The second digital signal DS2 is transmitted to the upper application device 500. Based on processing the second digital signal DS2, the upper application device 500 can determine the first digital signal DS1 and its corresponding echo signal, thereby obtaining information related to the target object.

[0096] In some embodiments, the process of transmitting uplink data is as follows: the upper application device 500 receives control instruction information, converts the received control instruction information into a third digital signal DS3, and outputs the third digital signal DS3. Subsequently, the third digital signal DS3 is received by the third optical unit 70. The third optical unit 70 converts the third digital signal DS3 into a second optical signal and transmits the second optical signal. The fourth optical unit 80 generates a second current signal under the irradiation of the second optical signal. The second current signal is converted into a fourth digital signal DS4 by the second signal conversion unit 90. The fourth digital signal DS4 is transmitted to the radar front-end device 400. The radar front-end device 400 performs corresponding operations in response to the fourth digital signal DS4.

[0097] The above approach enables both downlink and uplink data transmission in a lidar. First, during downlink data transmission, configuring two current sources to power the first optical unit 30 enables the first optical signal to maintain a relatively fast level switching speed, thereby maintaining a high system response speed and data transmission rate. Second, using a vertical-cavity surface-emitting laser (VCSEL) as the first optical unit 30 shortens the rise and fall times of the optical signal, further increasing the data transmission rate. Furthermore, differential processing of the voltage signal VREF and the first voltage signal V1 reduces the effects of signal attenuation and distortion, improves the signal's anti-interference capability, and thus enables long-distance data transmission. Furthermore, the first optical unit 30 can utilize two or more transmitters to increase the signal amplitude of the first optical signal, thereby enhancing the signal's anti-interference capability during communication, reducing the risk of bit errors, and increasing the communication distance. Furthermore, configuring the first signal conversion unit 60 to perform differential processing reduces the effects of signal attenuation and distortion, improves the signal's anti-interference capability, and thus enables long-distance data transmission. This also reduces costs compared to using a high-speed comparator. In addition, disposing at least a portion of the first optical unit 30 at the center of the main board 200 and disposing at least a portion of the second optical unit 40 at the center of the base board 300 can improve communication efficiency and signal strength, thereby increasing communication distance.

[0098] In other implementations, the specific implementation scheme for downlink data transmission may also be referred to during uplink data transmission to achieve the same beneficial effects.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication circuit, characterized in that: include: a first current source configured to output a direct current; a second current source configured to receive a first digital signal and output a pulse current based on the first digital signal; A first optical unit is connected to the first current source and the second current source respectively, and the first optical unit is configured to obtain and emit a first optical signal according to the direct current and the pulse current.

2. The communication circuit according to claim 1, wherein: The first optical unit includes a vertical cavity surface emitting laser or a light emitting diode.

3. The communication circuit according to claim 1 or 2, characterized in that: The first optical unit includes a first emitter and a second emitter, wherein the first emitter is a vertical cavity surface emitting laser or a light emitting diode, and the second emitter is a vertical cavity surface emitting laser.

4. The communication circuit according to claim 1, wherein: Also includes: a second optical unit, configured to receive the first optical signal and obtain a first current signal according to the first optical signal; a voltage signal acquisition unit, connected to the second optical unit, and configured to obtain a first voltage signal according to the first current signal; A first signal conversion unit is connected to the voltage signal acquisition unit, and the first signal conversion unit is configured to obtain a second digital signal according to a reference voltage signal and the first voltage signal.

5. The communication circuit according to claim 4, characterized in that The first signal conversion unit is a low voltage differential signal transmission unit in a field programmable logic gate array, and the second digital signal is obtained by differential processing of the reference voltage signal and the first voltage signal.

6. A laser radar, characterized in that: comprising a main board, a base board and the communication circuit according to claim 4 or 5; The first light unit is arranged at the center of the main board, and the second light unit is arranged at the center of the bottom board.

7. The laser radar according to claim 6, characterized in that The first emitter is arranged at the center of the mainboard, and the second emitter is arranged at one side of the first emitter.

8. The laser radar according to claim 6, characterized in that The communication circuit further includes a third optical unit provided on the bottom plate, a fourth optical unit provided on the main plate, and a second signal conversion unit; The third optical unit is configured to receive a third digital signal and output a second optical signal based on the third digital signal; The fourth optical unit is used to receive the second optical signal and convert the second optical signal into a second current signal; The second signal conversion unit is connected to the fourth optical unit, and the second signal conversion unit is configured to output a fourth digital signal based on the second current signal.

9. The laser radar according to claim 8, characterized in that The third light unit is disposed on one side of the second light unit, and the fourth light unit is disposed on one side of the first light unit.

10. The laser radar according to claim 6, characterized in that The laser radar also includes a radar front-end device and an upper application device; The radar front-end device is configured to output the first digital signal and receive the fourth digital signal; The upper application device is configured to receive the second digital signal and output the third digital signal.

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