Laser radar circuit and laser radar equipment

Abstract

The utility model provides a laser radar circuit and laser radar equipment, and relates to the technical field of laser radars. The laser radar circuit comprises a controller, a receiving module, a transmitting module and a digital processing module. The control module is electrically connected with the receiving module, the transmitting module and the digital processing module. The receiving module comprises a receiver and a matching capacitor. The capacitance value of a parasitic capacitor of the receiver is equal to the capacitance value of the matching capacitor. In the laser radar circuit provided by the invention, the capacitance value of the parasitic capacitor of the receiver is equal to the capacitance value of the matching capacitor, so that impedance matching can be more effectively realized, signal reflection and transmission loss can be reduced, noise in the circuit can be reduced, the signal-to-noise ratio of signals can be improved, electromagnetic interference can be effectively reduced, and the reliability of the laser radar circuit can be improved. The background noise of the optical receiver is effectively reduced, and the overall performance of the laser radar system is improved.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and more specifically, to a lidar circuit and lidar device. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a radar system that uses emitted laser beams to detect the position, velocity, and other characteristics of targets. Its working principle involves emitting a detection signal (laser beam) towards the target, then comparing the received signal reflected back from the target (target echo) with the emitted signal. After appropriate processing, information about the target can be obtained, such as its distance, azimuth, altitude, velocity, attitude, and even shape. This allows for the detection, tracking, and identification of targets such as aircraft and missiles.

[0003] A lidar system mainly consists of a laser transmitter, an optical receiver, and a data processing system. The laser transmitter converts electrical pulses into light pulses and emits them. The optical receiver then converts the light pulses reflected back from the target back into electrical pulses. The data processing system determines relevant information based on the received electrical pulses.

[0004] The optical receiver plays a crucial role in the entire lidar system, and the quality of the signal it receives directly affects the overall performance of the lidar system. However, current optical receivers generally suffer from high noise levels, leading to suboptimal overall performance of the lidar system. Summary of the Invention

[0005] The purpose of this application is to provide a lidar circuit and lidar system to solve the problem of high noise floor in existing optical receivers.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] On one hand, this application provides a lidar circuit, which includes a controller, a receiving module, a transmitting module, and a digital processing module. The control module is electrically connected to the receiving module, the transmitting module, and the digital processing module, respectively.

[0008] The receiving module includes a receiver and a matching capacitor, wherein the parasitic capacitance of the receiver is equal to the capacitance of the matching capacitor.

[0009] Optionally, when the transmitter is model SFH2701, the capacitance of the matching capacitor is 2.2pF;

[0010] When the transmitter model is SFH2400, the capacitance of the matching capacitor is 3.6pF.

[0011] Optionally, the lidar circuit further includes a temperature sensor, which is integrated into the digital processing module.

[0012] Optionally, the lidar circuit further includes a power supply module, which includes a first power supply unit and a second power supply unit. The first power supply unit and the second power supply unit are both connected to the same power supply terminal, and the first power supply unit is electrically connected to the controller and the digital processing module respectively, and supplies power to the controller and the digital processing module.

[0013] The second power supply unit is electrically connected to the transmitting module and supplies power to the transmitting module.

[0014] Optionally, the transmitting module includes a light-emitting diode, a first filter capacitor, and a second filter capacitor. The anode of the light-emitting diode is electrically connected to the second power supply unit, and the cathode of the light-emitting diode is electrically connected to one end of the first filter capacitor, one end of the second filter capacitor, and the controller, respectively. The other ends of the first filter capacitor and the second filter capacitor are grounded.

[0015] Optionally, the capacitance of the first filter capacitor is 22pF, and the capacitance of the second capacitor is 8pF.

[0016] Optionally, the first power supply unit includes a first voltage regulator, a first ferrite bead, and a second ferrite bead. The input terminal of the first voltage regulator is connected to the power supply terminal, and the output terminal of the first voltage regulator is electrically connected to the first ferrite bead and the second ferrite bead, respectively.

[0017] The first magnetic bead is electrically connected to the controller and provides analog power to the controller;

[0018] The second magnetic bead is electrically connected to the controller and the digital processing module respectively, and provides digital power to the controller and the digital processing module.

[0019] Optionally, the second power supply unit includes a second voltage regulator, a feedback component, a third ferrite bead, and a filter component. The input terminal of the second voltage regulator is connected to the power supply terminal, and the output terminal of the second voltage regulator is connected to one end of the third ferrite bead and the feedback component. The other end of the feedback component is grounded, and the feedback component is also electrically connected to the feedback port of the second voltage regulator. The other end of the third ferrite bead is electrically connected to the filter component and the transmitting module, and the filter component is also grounded.

[0020] Optionally, the lidar circuit further includes a connector, and the digital processing module is electrically connected to the connector;

[0021] The digital processing module is used to filter the controller's data and then output it through the connector.

[0022] On the other hand, embodiments of this application also provide a lidar device, which includes the lidar circuit described above.

[0023] Compared with the prior art, this application has the following advantages:

[0024] This application provides a lidar circuit and a lidar system. The lidar circuit includes a controller, a receiving module, a transmitting module, and a digital processing module. The control module is electrically connected to the receiving module, the transmitting module, and the digital processing module. The receiving module includes a receiver and a matching capacitor, where the parasitic capacitance of the receiver is equal to the capacitance of the matching capacitor. Because the parasitic capacitance of the receiver in the lidar circuit provided by this application is equal to the capacitance of the matching capacitor, impedance matching can be achieved more effectively, reducing signal reflection and transmission loss. Furthermore, it can reduce noise in the circuit, improve the signal-to-noise ratio, effectively reduce electromagnetic interference, and thus effectively reduce the noise floor of the optical receiver, improving the overall performance of the lidar system.

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a lidar circuit provided in an embodiment of this application.

[0028] Figure 2 The circuit diagrams for the controller, receiving module, and transmitting module provided in the embodiments of this application are shown.

[0029] Figure 3 This is a circuit diagram of a digital processing module provided in an embodiment of this application.

[0030] Figure 4 A circuit diagram of the first power supply unit provided in an embodiment of this application.

[0031] Figure 5 A circuit diagram of the second power supply unit provided in an embodiment of this application.

[0032] Figure 6 A circuit diagram of the connector provided in an embodiment of this application.

[0033] In the picture:

[0034] 110 - Controller; 120 - Receiver module; 130 - Transmitter module; 140 - Digital processing module. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0039] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] As described in the background section, current lidar systems generally suffer from high noise floor in the optical receivers, leading to poor overall system performance.

[0041] To address this issue, this application provides a lidar circuit that reduces background noise and improves system performance by setting a matching capacitor value.

[0042] The lidar circuit provided in this application is illustrated below:

[0043] Please adopt this as one implementation method. Figure 1 The lidar circuit includes a controller 110, a receiver module 120, a transmitter module 130, and a digital processing module 140. The controller module is electrically connected to the receiver module 120, the transmitter module 130, and the digital processing module 140, respectively. The receiver module 120 includes a receiver and a matching capacitor. The parasitic capacitance of the receiver is equal to the capacitance of the matching capacitor.

[0044] By setting the parasitic capacitance to be equal to that of the matching capacitor, impedance matching can be achieved more effectively, reducing signal reflection and transmission loss. Simultaneously, for signal integrity, the matching capacitor can compensate for the effects of parasitic capacitance, thereby improving signal integrity and reducing signal distortion. Of course, matching parasitic capacitance can also reduce noise in the circuit and improve the signal-to-noise ratio. Furthermore, good impedance matching can reduce electromagnetic interference and improve circuit stability.

[0045] Please see Figure 2 In one implementation, pin 24 of the controller provided in this application is connected to a matching capacitor C12, and pin 25 is connected to a receiver. The receiver provided in this application can be a photodiode D5, with the anode of the photodiode D5 grounded and the cathode connected to pin 25 of the controller 110.

[0046] Based on this, the parasitic capacitance of the photodiode D5 is equal to the capacitance of the matching capacitor C12. The applicant verified that when the photodiode D5 is model SFH2701, the capacitance of the matching capacitor is 2.2pF; and when the photodiode D5 is model SFH2400, the capacitance of the matching capacitor is 3.6pF.

[0047] The transmitting module 130 includes a light-emitting diode D2, a first filter capacitor C5, and a second filter capacitor C23. The anode of the light-emitting diode is connected to the power supply, and the cathode of the light-emitting diode is electrically connected to one end of the first filter capacitor C5, one end of the second filter capacitor C23, and pin 7 of the controller 110, respectively. The other ends of the first filter capacitor C5 and the second filter capacitor C23 are grounded.

[0048] By setting the first filter capacitor C5 and the second filter capacitor C12, EMI filtering of the light-emitting diode D2 can be achieved. Furthermore, the applicant's research found that the filtering effect is optimal when the capacitance of the first filter capacitor C5 is 22pF and the capacitance of the second capacitor C23 is 8pF.

[0049] Please see Figure 3The digital processing module 140 provided in this application is a 32-bit MCU. Furthermore, the lidar circuit also includes a temperature sensor, which is integrated within the digital processing module 140. That is, compared to the prior art method of setting up a separate temperature sensor, this application's method of integrating the temperature sensor into the digital processing module 140 eliminates the need for an additional I / O port, thus saving I / O ports. Simultaneously, it reduces the overall footprint of the lidar circuit.

[0050] Of course, in order to achieve effective power supply, the lidar circuit also includes a power supply module. In order to ensure the independence of power supply and avoid mutual interference between power supplies, in this application, the power supply module includes a first power supply unit and a second power supply unit. The first power supply unit and the second power supply unit are both connected to the same power supply terminal. The first power supply unit is electrically connected to the controller 110 and the digital processing module 140 respectively, and supplies power to the controller 110 and the digital processing module 140. The second power supply unit is electrically connected to the transmitting module 130 and supplies power to the transmitting module 130.

[0051] Please see Figure 4 The first power supply unit includes a first voltage regulator U1, a first ferrite bead FB1, and a second ferrite bead FB2. The input terminal of the first voltage regulator U1 is connected to the power supply terminal VIN. To achieve a stable power input, the first power supply unit also includes capacitors C26 and C4. One end of capacitors C26 and C4 is connected to the power supply, and the other end is grounded, thus filtering the input power supply. Furthermore, the enable terminal EN of the first voltage regulator U1 is also directly connected to the power supply terminal VIN.

[0052] The output of the first voltage regulator U1 is electrically connected to the first ferrite bead FB1 and the second ferrite bead FB2. The first ferrite bead FB1 is electrically connected to the controller 110 and provides analog power to the controller 110. The second ferrite bead FB2 is electrically connected to both the controller 110 and the digital processing module 140, providing digital power to both. In the diagram, AVDD_DUT_3P3V represents the port used to provide analog power, and IOVDD_DUT represents the port used to provide digital power. Furthermore, the output of the first voltage regulator U1 is grounded through capacitor C7.

[0053] Please see Figure 5 The second power supply unit includes a second voltage regulator U2, a feedback component, a third ferrite bead FB3, and a filter component. The input terminal of the second voltage regulator U2 is connected to the power supply terminal VIN. Naturally, the input terminal of the second voltage regulator U2 is also grounded through capacitor C1, thus achieving the effect of filtering the input power supply.

[0054] The output of the second voltage regulator U2 is connected to one end of the third ferrite bead FB and the feedback component. The other end of the feedback component is grounded, and the feedback component is also electrically connected to the feedback port NR / FB of the second voltage regulator U2. The other end of the third ferrite bead FB is electrically connected to the filter component and the transmitter module 130, and the filter component is also grounded.

[0055] The feedback component includes resistors R14 and R16. One end of resistors R14 and R16 connected in series is connected to the output terminal of the second voltage regulator U2, and the other end is grounded. The connection node of resistors R14 and R16 is also connected to the feedback port NR / FB of the second voltage regulator U2, so that the second voltage regulator U2 can obtain the output voltage in real time and adjust the output in real time according to the voltage of the feedback port NR / FB to achieve the purpose of voltage regulation.

[0056] Meanwhile, the second power supply unit provided in this application also includes capacitor C2, capacitor C14, and a fourth ferrite bead FB4. One end of capacitor C2 is connected to the output terminal of the second voltage regulator U2, and the other end is connected to the connection node of resistor R14 and resistor R16. One end of capacitor C14 is connected to the output terminal of the second voltage regulator U2, and the other end is grounded. The third ferrite bead FB3 is connected to one end of the filter component, and the fourth ferrite bead FB4 is connected to the other end of the filter component.

[0057] The filtering component includes capacitors C15, C16, and C17 connected in parallel. Capacitors C15, C16, and C17 are connected to the anode of LED D2. The first filtering capacitor C5 and the second filtering capacitor C23 are connected to the cathode of LED D2. By filtering both the anode and cathode of LED D2 simultaneously, the light emission performance of LED D2 can be improved.

[0058] As one implementation method, the capacitance values ​​of capacitors C15, C16, and C17 connected in parallel gradually decrease. Specifically, capacitor C15 has a capacitance of 10uF, capacitor C16 has a capacitance of 1uF, and capacitor C17 has a capacitance of 100nF. By setting these specific capacitance values, the filtering effect of LED D2 can be improved.

[0059] In addition, for easier signal input and output implementation, please refer to [link / reference needed]. Figure 6 The lidar circuit also includes a connector, and the digital processing module 140 is electrically connected to the connector; the digital processing module 140 is used to filter the data from the controller 110 and output it through the connector.

[0060] The following is combined Figures 2-6 The working principle of the lidar circuit provided in this application is explained in detail below:

[0061] Both the first power supply unit and the second power supply unit are connected to the VIN port of the connector, allowing for independent power supply through the first and second power supply units respectively after power input. Specifically, the first power supply unit outputs 3.3V analog and digital power to power the controller 110 and the digital processing module 140; while the second power supply unit is directly connected to the light-emitting diode D2 to power it.

[0062] Furthermore, pins 11 and 12 of controller 110 are connected to pins 10 and 9 of digital processing module 140, respectively; pins 13 and 14 of controller 110 are connected to pins 6 and 7 of digital processing module 140, respectively; and pin 16 of controller 110 is connected to pin 8 of digital processing module 140, thereby enabling signal transmission between controller 110 and digital processing module 140. Simultaneously, pins 27 and 28 of digital processing module 140 are also connected to pins 1 and 2 of connector, enabling signal input and output.

[0063] Based on this, when the lidar circuit needs to operate, the digital processing module 140 sends a signal to the controller 110, which in turn enables the controller 110 to control the light-emitting diode D2 to emit light. Simultaneously, the controller 110 can also acquire the signal received through the photodiode D5 and send the received signal to the digital processing module 140. After filtering and other processing, the digital processing module 140 outputs the signal through the connector, completing the lidar detection.

[0064] Based on the above implementation, this application embodiment also provides a lidar device, which includes the lidar circuit described above.

[0065] In summary, this application provides a lidar circuit and a lidar system. The lidar circuit includes a controller, a receiving module, a transmitting module, and a digital processing module. The control module is electrically connected to the receiving module, the transmitting module, and the digital processing module. The receiving module includes a receiver and a matching capacitor, where the parasitic capacitance of the receiver is equal to the capacitance of the matching capacitor. Because the parasitic capacitance of the receiver in the lidar circuit provided by this application is equal to the capacitance of the matching capacitor, impedance matching can be achieved more effectively, reducing signal reflection and transmission loss. Furthermore, it can reduce noise in the circuit, improve the signal-to-noise ratio, effectively reduce electromagnetic interference, and thus effectively reduce the noise floor of the optical receiver, improving the overall performance of the lidar system.

[0066] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0067] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A lidar circuit, characterized in that, The lidar circuit includes a controller, a receiving module, a transmitting module, and a digital processing module, wherein the controller is electrically connected to the receiving module, the transmitting module, and the digital processing module respectively. The receiving module includes a receiver and a matching capacitor, wherein the parasitic capacitance of the receiver is equal to the capacitance of the matching capacitor.

2. The lidar circuit as described in claim 1, characterized in that, When the transmitting module is model SFH2701, the capacitance of the matching capacitor is 2.2pF; When the transmitting module is model SFH2400, the capacitance of the matching capacitor is 3.6pF.

3. The lidar circuit as described in claim 1, characterized in that, The lidar circuit also includes a temperature sensor, which is integrated into the digital processing module.

4. The lidar circuit as described in claim 1, characterized in that, The lidar circuit also includes a power supply module, which includes a first power supply unit and a second power supply unit. The first power supply unit and the second power supply unit are both connected to the same power supply terminal. The first power supply unit is electrically connected to the controller and the digital processing module respectively, and supplies power to the controller and the digital processing module. The second power supply unit is electrically connected to the transmitting module and supplies power to the transmitting module.

5. The lidar circuit as described in claim 4, characterized in that, The transmitting module includes a light-emitting diode, a first filter capacitor, and a second filter capacitor. The anode of the light-emitting diode is electrically connected to the second power supply unit, and the cathode of the light-emitting diode is electrically connected to one end of the first filter capacitor, one end of the second filter capacitor, and the controller, respectively. The other ends of the first filter capacitor and the second filter capacitor are grounded.

6. The lidar circuit as described in claim 5, characterized in that, The first filter capacitor has a capacitance of 22pF, and the second capacitor has a capacitance of 8pF.

7. The lidar circuit as described in claim 4, characterized in that, The first power supply unit includes a first voltage regulator, a first ferrite bead, and a second ferrite bead. The input terminal of the first voltage regulator is connected to the power supply terminal, and the output terminal of the first voltage regulator is electrically connected to the first ferrite bead and the second ferrite bead, respectively. The first magnetic bead is electrically connected to the controller and provides analog power to the controller; The second magnetic bead is electrically connected to the controller and the digital processing module respectively, and provides digital power to the controller and the digital processing module.

8. The lidar circuit as described in claim 4, characterized in that, The second power supply unit includes a second voltage regulator, a feedback component, a third ferrite bead, and a filter component. The input terminal of the second voltage regulator is connected to the power supply terminal. The output terminal of the second voltage regulator is connected to one end of the third ferrite bead and one end of the feedback component. The other end of the feedback component is grounded, and the feedback component is also electrically connected to the feedback port of the second voltage regulator. The other end of the third ferrite bead is electrically connected to the filter component and the transmitting module, and the filter component is also grounded.

9. The lidar circuit as described in claim 1, characterized in that, The lidar circuit also includes a connector, and the digital processing module is electrically connected to the connector. The digital processing module is used to filter the controller's data and then output it through the connector.

10. A lidar device, characterized in that, The lidar device includes the lidar circuit as described in any one of claims 1 to 9.

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