Laser radar signal processing circuit and laser radar

Abstract

The present invention is applicable to the field of radar technology, and provides a laser radar signal processing circuit and a laser radar, wherein the laser radar signal processing circuit comprises: a signal transmitting module, a signal receiving module, a signal integration module and a post-processing module; the signal transmitting module and the signal receiving module are both connected to the signal integration module, and the signal integration module is connected to the post-processing module; the signal transmitting module is used to generate and transmit a laser pulse signal; the signal receiving module is used to receive an echo pulse signal corresponding to the laser pulse signal; the signal integration module is used to integrate the laser pulse signal and the echo pulse signal into an integrated signal; the post-processing module is used to determine the time interval between the time when the laser pulse signal is emitted and the time when the echo pulse signal is received according to the integrated signal. The present invention can effectively improve the measurement accuracy of the time interval between the time when the laser pulse signal is emitted and the time when the echo pulse signal is received, thereby improving the ranging accuracy of the pulse laser radar.

Description

Technical Field

[0001] The present invention belongs to the field of radar technology, and in particular relates to a laser radar signal processing circuit and a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. Among them, pulsed LiDAR is widely used in industry, transportation, robotics and other fields due to its simple technical principles, fast response speed and simple optical structure.

[0003] Pulse laser radar mainly measures distance by emitting laser pulses to the target and receiving the laser pulses reflected from the target. Therefore, the measurement accuracy of the time interval between sending and receiving laser pulses directly affects the ranging accuracy of pulse laser radar. However, in the prior art, when measuring the time interval between sending and receiving laser pulses, different processing circuits are generally used to process the emitted laser pulses and the received laser pulses respectively, and different processing circuits will produce different delays, resulting in a decrease in the measurement accuracy of the time interval between sending and receiving laser pulses, thereby reducing the ranging accuracy of pulse laser radar. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a laser radar signal processing circuit and a laser radar to solve the problem that the prior art cannot accurately measure the time interval between the pulse laser radar and the laser radar, thereby resulting in low ranging accuracy of the pulse laser radar.

[0005] A first aspect of an embodiment of the present invention provides a laser radar signal processing circuit, including:

[0006] Signal transmitting module, signal receiving module, signal integration module and post-processing module;

[0007] The signal transmitting module and the signal receiving module are both connected to the signal integrating module, and the signal integrating module is connected to the post-processing module;

[0008] The signal transmitting module is used to generate and transmit a laser pulse signal; the signal receiving module is used to receive an echo pulse signal corresponding to the laser pulse signal; the signal integration module is used to integrate the laser pulse signal and the echo pulse signal to obtain an integrated signal; the post-processing module is used to determine the time interval between the moment of transmitting the laser pulse signal and the moment of receiving the echo pulse signal based on the integrated signal.

[0009] Optionally, the signal receiving module includes a signal receiving unit, a signal conversion unit and a signal conditioning unit;

[0010] The output end of the signal receiving unit is connected to the signal conversion unit and the signal conditioning unit in sequence, and the output end of the signal conditioning unit is connected to the signal integration module.

[0011] Optionally, the signal integration module includes a first signal processing unit, a second signal processing unit, a third signal processing unit and an integration unit;

[0012] The input end of the first signal processing unit is connected to the signal transmission module, and the output end of the first signal processing unit is connected to the input end of the integration unit through the second signal processing unit;

[0013] The input end of the third signal processing unit is connected to the signal receiving module, and the output end of the third signal processing unit is connected to the input end of the integration unit;

[0014] The output end of the integration unit is connected to the post-processing module.

[0015] Optionally, the first signal processing unit is a resistor or a capacitor for conditioning the laser pulse signal.

[0016] Optionally, the second signal processing unit and the third signal processing unit are both DC blocking capacitors.

[0017] Optionally, the post-processing module includes a post-processing signal processing unit and a timing unit;

[0018] The input end of the post-stage signal processing unit is connected to the signal integration module, and the output end of the post-stage signal processing unit is connected to the timing unit.

[0019] Optionally, the post-stage signal processing unit includes a signal amplification unit and a signal post-stage processing unit;

[0020] The input end of the signal amplifying unit is connected to the signal integrating module, and the output end of the signal amplifying unit is connected to the timing unit through the signal post-processing unit.

[0021] Optionally, the timing unit includes a plurality of signal input channels and a timing sub-unit, and the integrated signal is input into the timing sub-unit through any one of the signal input channels.

[0022] Optionally, determining the time interval between the moment of emitting the laser pulse signal and the moment of receiving the echo pulse signal according to the integrated signal includes:

[0023] Determine the time interval between the time when the laser pulse signal is emitted and the time when the echo pulse signal is received according to the rising edge time of the integrated signal;

[0024] Alternatively, the time interval between the moment of emitting the laser pulse signal and the moment of receiving the echo pulse signal is determined according to the falling edge moment of the integrated signal.

[0025] A second aspect of an embodiment of the present invention provides a laser radar, which includes the laser radar signal processing circuit provided by the first aspect of an embodiment of the present invention.

[0026] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0027] The laser radar signal processing circuit provided by the present invention integrates the laser pulse signal emitted by the laser radar to the target and the echo pulse signal reflected from the target through a signal integration module to obtain an integrated signal, and then the integrated signal is processed by the same post-processing module at the same time, so that the laser pulse signal and the echo pulse signal produce the same circuit delay. At the same time, the laser pulse signal and the echo pulse signal are integrated and passed through the same circuit to eliminate the influence of temperature factors on the delay of different signal paths, thereby avoiding the error caused by the different delays of the laser pulse signal and the echo pulse signal when measuring the time interval. The present invention can effectively improve the measurement accuracy of the time interval between the emission of the laser pulse signal and the reception of the echo pulse signal, thereby improving the ranging accuracy of the pulse laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 A schematic diagram of the overall structure of a laser radar signal processing circuit provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the specific structures of the signal receiving module, signal integration module and post-processing module of the laser radar signal processing circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0032] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0033] A first aspect of an embodiment of the present invention provides a laser radar signal processing circuit, such as Figure 1 As shown, the laser radar signal processing circuit includes:

[0034] A signal transmitting module 11, a signal receiving module 12, a signal integrating module 13 and a post-processing module 14;

[0035] The signal transmitting module 11 and the signal receiving module 12 are both connected to the signal integrating module 13, and the signal integrating module 13 is connected to the post-processing module 14;

[0036] The signal transmitting module 11 is used to generate and transmit a laser pulse signal; the signal receiving module 12 is used to receive an echo pulse signal corresponding to the laser pulse signal; the signal integration module 13 is used to integrate the laser pulse signal and the echo pulse signal to obtain an integrated signal; the post-processing module 14 is used to determine the time interval between the moment of transmitting the laser pulse signal and the moment of receiving the echo pulse signal based on the integrated signal.

[0037] In an embodiment of the present invention, the laser pulse signal output by the signal transmitting module 11 and the echo pulse signal output by the signal receiving module 12 are integrated by the signal integration module 13 to obtain an integrated signal, and then the integrated signal is input into the same post-processing module 13 for processing, so that the laser pulse signal and the echo pulse signal have the same delay, thereby avoiding the error caused by the different delays of the laser pulse signal and the echo pulse signal when measuring the time interval, and improving the measurement accuracy of the time interval between the emission of the laser pulse signal and the reception of the echo pulse signal.

[0038] It should be pointed out that in practical applications, a signal generating device can also be set up to generate a rectangular pulse signal representing the signal emission time at the same time as the laser pulse signal is emitted. The rectangular pulse signal representing the signal emission time is integrated with the echo pulse signal to determine the time interval between the emission of the laser pulse signal and the reception of the echo pulse signal. The present invention is not limited to this.

[0039] Optional, see Figure 2 As shown, as a specific implementation of the laser radar signal processing circuit provided in the first aspect of an embodiment of the present invention, the signal receiving module 12 includes a signal receiving unit 121, a signal conversion unit 122 and a signal conditioning unit 123; the output end of the signal receiving unit 121 is connected to the signal conversion unit 122 and the signal conditioning unit 123 in sequence, and the output end of the signal conditioning unit 123 is connected to the signal integration module 13.

[0040] In the embodiment of the present invention, the signal receiving module 12 first receives the laser signal reflected from the target through the signal receiving unit 121, then converts the laser signal into an electrical signal through the signal conversion unit 122, and finally conditions the electrical signal through the signal conditioning unit 123 to obtain an echo pulse signal whose level value meets the input conditions of the signal integration module 13, and inputs it into the signal integration module 13.

[0041] Optional, see Figure 2 As shown, as a specific implementation of the laser radar signal processing circuit provided by the first aspect of the embodiment of the present invention, the signal integration module 13 includes a first signal processing unit 131, a second signal processing unit 132, a third signal processing unit 133 and an integration unit 134;

[0042] The input end of the first signal processing unit 131 is connected to the signal transmitting module 11, and the output end of the first signal processing unit 131 is connected to the input end of the integration unit 134 through the second signal processing unit 132;

[0043] The input end of the third signal processing unit 132 is connected to the signal receiving module 12, and the output end of the third signal processing unit 133 is connected to the input end of the integration unit 134;

[0044] The output end of the integration unit 134 is connected to the post-processing module 14 .

[0045] Optionally, as a specific implementation of the laser radar signal processing circuit provided in the first aspect of an embodiment of the present invention, the first signal processing unit 131 is a resistor or a capacitor used to condition the laser pulse signal.

[0046] Optionally, as a specific implementation of the lidar signal processing circuit provided in the first aspect of the embodiment of the present invention, the second signal processing unit 132 and the third signal processing unit 133 are both DC blocking capacitors.

[0047] In the embodiment of the present invention, since the laser pulse signal output by the signal transmitting module 11 is a rectangular pulse signal, and the echo pulse signal output by the signal receiving module 12 is a Gaussian signal, the signal integration module 13 first converts the laser pulse signal into a Gaussian signal through the first signal processing unit 131, and adjusts the level of the laser pulse signal to meet the input conditions of the post-processing unit 14, and then the second signal processing unit 132 separates the DC and AC quantities of the laser pulse signal, and outputs the AC quantity of the laser pulse signal, and the third signal processing unit 133 separates the DC and AC quantities of the echo pulse signal, and outputs the AC quantity of the echo pulse signal. After DC isolation processing, the laser pulse signal and the echo pulse signal can be integrated into an integrated signal through the integration unit 134.

[0048] It should be noted that the first signal processing unit 131 may be, but is not limited to, a device such as a resistor or a capacitor, and the second signal processing unit 132 and the third signal processing unit 133 may be DC blocking capacitors. In fact, the laser pulse signal processed by the second signal processing unit 132 and the echo pulse signal processed by the third signal processing unit 133 may be directly integrated into an integrated signal, that is, the integration unit 134 may be a signal channel for merging the laser pulse signal and the echo pulse signal.

[0049] Optionally, the post-processing module 14 includes a post-signal processing unit 141 and a timing unit 142;

[0050] An input end of the post-stage signal processing unit 141 is connected to the signal integration module 13 , and an output end of the post-stage signal processing unit 141 is connected to the timing unit 142 .

[0051] Optionally, the post-stage signal processing unit 141 includes a signal amplifying unit 1411 and a signal post-stage processing unit 1412;

[0052] The input end of the signal amplifying unit 1411 is connected to the signal integrating module 13 , and the output end of the signal amplifying unit 1411 is connected to the timing unit 142 via the signal post-processing unit 1412 .

[0053] In an embodiment of the present invention, after the integrated signal enters the post-processing module 14, it is first amplified by the signal amplification unit 1411. Since the integrated signal is a Gaussian signal, it is not convenient to judge the rising edge moment and the falling edge moment. Therefore, it is necessary to convert the integrated signal into a rectangular pulse signal through the signal post-processing unit 1412, and the signal post-processing unit 1412 also adjusts the level value of the integrated signal to meet the input conditions of the timing unit 142. Finally, the timing unit 142 determines the time interval between emitting the laser pulse signal and receiving the echo pulse signal according to the rising edge time interval or the falling edge time interval of the integrated signal.

[0054] Optionally, the timing unit 142 includes a plurality of signal input channels and timing sub-units, and the integrated signal is input into the timing sub-unit through any one of the signal input channels.

[0055] Optionally, determining the time interval between the moment of emitting the laser pulse signal and the moment of receiving the echo pulse signal according to the integrated signal includes:

[0056] The time interval between the time when the laser pulse signal is emitted and the time when the echo pulse signal is received is determined according to the rising edge time of the integrated signal; or, the time interval between the time when the laser pulse signal is emitted and the time when the echo pulse signal is received is determined according to the falling edge time of the integrated signal.

[0057] In the embodiment of the present invention, the timing unit 142 has multiple signal input channels and timing sub-units, and the integrated signal can be input into the timing sub-unit through any signal input channel, so different integrated signals can be input into the timing sub-unit through different signal input channels, thereby improving the transmission efficiency of the signal, and further improving the working efficiency of the pulse laser radar. At the same time, compared with the traditional method of inputting the laser pulse signal and the echo pulse signal into the timing unit 142 through different signal input channels respectively, this solution integrates the laser pulse signal and the corresponding echo pulse signal into one integrated signal, which can only be transmitted through one signal input channel, thereby reducing the calculation error caused by the signal input into different channels.

[0058] A second aspect of an embodiment of the present invention provides a laser radar, which includes the laser radar signal processing circuit provided in any of the above embodiments of the present invention, and has the beneficial effects brought by the laser radar signal processing circuit provided in any of the above embodiments.

[0059] From the above content, it can be seen that the laser radar signal processing circuit provided by the present invention integrates the laser pulse signal emitted by the laser radar to the target and the echo pulse signal reflected from the target through the signal integration module to obtain an integrated signal, and then inputs the integrated signal into the same post-processing module for processing, so that the laser pulse signal and the echo pulse signal have the same delay, thereby reducing the error caused by the different delays of the laser pulse signal and the echo pulse signal when measuring the time interval. The present invention can effectively improve the measurement accuracy of the time interval between the emission of the laser pulse signal and the reception of the echo pulse signal, thereby improving the ranging accuracy of the pulse laser radar.

[0060] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0061] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A laser radar signal processing circuit, characterized in that: include: Signal transmitting module, signal receiving module, signal integration module and post-processing module; The signal transmitting module and the signal receiving module are both connected to the signal integrating module, and the signal integrating module is connected to the post-processing module; The signal transmitting module is used to generate and transmit a laser pulse signal; the signal receiving module is used to receive an echo pulse signal corresponding to the laser pulse signal; the signal integration module is used to integrate the laser pulse signal and the echo pulse signal to obtain an integrated signal; the post-processing module is used to determine the time interval between the moment of transmitting the laser pulse signal and the moment of receiving the echo pulse signal according to the integrated signal; The signal integration module comprises: A first signal processing unit, a second signal processing unit, a third signal processing unit and an integration unit; The input end of the first signal processing unit is connected to the signal transmission module, and the output end of the first signal processing unit is connected to the input end of the integration unit through the second signal processing unit; The input end of the third signal processing unit is connected to the signal receiving module, and the output end of the third signal processing unit is connected to the input end of the integration unit; The output end of the integration unit is connected to the post-processing module; The post-processing module includes a post-signal processing unit and a timing unit; The input end of the post-stage signal processing unit is connected to the signal integration module, and the output end of the post-stage signal processing unit is connected to the timing unit; The first signal processing unit is a resistor or capacitor used to condition the laser pulse signal; the second signal processing unit and the third signal processing unit are both DC blocking capacitors; the post-stage signal processing unit includes a signal amplification unit and a signal post-stage processing unit; the input end of the signal amplification unit is connected to the signal integration module, and the output end of the signal amplification unit is connected to the timing unit through the signal post-stage processing unit.

2. The laser radar signal processing circuit according to claim 1, characterized in that: The signal receiving module includes a signal receiving unit, a signal conversion unit and a signal conditioning unit; The output end of the signal receiving unit is connected to the signal conversion unit and the signal conditioning unit in sequence, and the output end of the signal conditioning unit is connected to the signal integration module.

3. The laser radar signal processing circuit according to claim 1, characterized in that: The timing unit includes a plurality of signal input channels and a timing sub-unit, and the integrated signal is input into the timing sub-unit through any one of the signal input channels.

4. The laser radar signal processing circuit according to claim 1, characterized in that: The step of determining the time interval between the moment of emitting the laser pulse signal and the moment of receiving the echo pulse signal according to the integrated signal comprises: Determine the time interval between the moment of emitting the laser pulse signal and the moment of receiving the echo pulse signal according to the rising edge moment of the integrated signal; Alternatively, the time interval between the moment when the laser pulse signal is emitted and the moment when the echo pulse signal is received is determined according to the falling edge moment of the integrated signal.

5. A laser radar, characterized in that: A laser radar signal processing circuit comprising any one of claims 1-4.

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