CN117930193A

CN117930193A - Bias control system, bias control method, electronic equipment and laser radar

Info

Publication number: CN117930193A
Application number: CN202410095211.1A
Authority: CN
Inventors: 杨子龙; 梁宁忠; 张弛
Original assignee: Shenzhen North Wake Technology Co ltd
Current assignee: Shenzhen North Wake Technology Co ltd
Priority date: 2024-01-23
Filing date: 2024-01-23
Publication date: 2024-04-26

Abstract

The embodiment of the invention provides a bias control system, a bias control method, electronic equipment and a laser radar, which belong to the technical field of control, key information of an input bias signal of a photoelectric detector is acquired through a monitoring module, and a control processing module adjusts a trigger control signal and/or a target control signal according to the key information, so that the control processing module adjusts the bias signal input to the photoelectric detector according to the starting time and period designated by the trigger control signal and a voltage signal designated by the target control signal. Therefore, the period and the voltage of the bias signal input to the photoelectric detector can be repeatedly corrected, the bias signal input to the photoelectric detector can be effectively monitored, the control precision of the photoelectric detector is greatly improved, the measurement precision of the laser radar where the photoelectric detector is located can be further improved, and the performance of the laser radar is optimized.

Description

Bias control system, bias control method, electronic equipment and laser radar

Technical Field

The invention relates to the technical field of control, in particular to a bias voltage control system, a bias voltage control method, electronic equipment and a laser radar.

Background

The silicon photomultiplier (Sipm, silicon photomultiplie) is a novel photodetection device, and is composed of a plurality of pixel arrays which are mutually connected in parallel and work in a geiger mode and are mutually connected in parallel, and each pixel array is composed of a photodiode and a quenching resistor which are connected in series. Sipm is a device that is highly sensitive to bias voltage, when Sipm is in operation, the gain of sipm (the ratio of the amount of charge output by Sipm to the amount of single electron charge when a pixel array detects a photon) increases by 50000 units for every 1v increase in bias voltage.

Currently, sipm are commonly used in a receiver of a lidar: during the near ranging, a smaller bias voltage is provided for Sipm, so that the near strong reflected light can not enter the saturated and supersaturated state of Sipm; when distance measurement is carried out on a distance, a larger bias voltage is provided for Sipm, so that Sipm is ensured to have enough gain to capture weak reflection light at the distance, and a longer distance measurement range is obtained. However, the bias signal input Sipm is easily interfered by factors such as temperature drift, device variability and the like, and the accuracy is low, so that the measurement effect of the laser radar is poor.

Disclosure of Invention

Accordingly, the present invention is directed to a bias control system, a bias control method, an electronic device, and a laser radar, which can effectively monitor a bias curve of a photodetector, and greatly improve the bias control accuracy of the photodetector.

In order to achieve the above object, the technical scheme adopted by the embodiment of the invention is as follows:

in a first aspect, an embodiment of the present invention provides a bias control method, including a monitoring module, a bias control module, a power module, and a control processing module;

the input end of the bias control module is respectively connected with the trigger control end of the control processing module and the voltage output end of the power supply module, the reference control end of the control processing module is connected with the input end of the power supply module, the output end of the bias control module and the monitoring end of the monitoring module are both connected with the input end of the photoelectric detector, and the output end of the monitoring module is connected with the input end of the control processing module;

The control processing module is used for outputting a trigger control signal to the bias control module and outputting a target control signal to the power supply module;

the power supply module is used for inputting a voltage signal appointed by the target control signal to the bias voltage control module when the target control signal is received;

The bias control module is used for inputting a bias signal to the photoelectric detector according to the starting time and period designated by the trigger control signal and the voltage signal;

the monitoring module is used for collecting key information of the bias signal in at least one period and inputting the key information into the control processing module; wherein the key information comprises information of at least two sampling key points;

and the control processing module is used for adjusting the trigger control signal and/or the target control signal according to the key information so as to adjust the bias voltage signal input to the photoelectric detector.

Based on the bias control system provided in the first aspect, key information of an input bias signal of the photodetector is collected through the monitoring module, and the control processing module adjusts the trigger control signal and/or the target control signal according to the key information, so that the control processing module adjusts the bias signal input to the photodetector according to the starting time and period designated by the trigger control signal and the voltage signal designated by the target control signal. Therefore, the period and the voltage of the bias signal input to the photoelectric detector can be repeatedly corrected, the bias signal input to the photoelectric detector can be effectively monitored, the control precision of the photoelectric detector is greatly improved, the measurement precision of the laser radar where the photoelectric detector is located can be further improved, and the performance of the laser radar is optimized.

Optionally, the information of the sampling key point includes a sampling time and a sampling voltage corresponding to the sampling time;

the control processing module is used for carrying out curve fitting by combining the information of the starting point and the information of the sampling key point to obtain a fitting bias voltage curve, comparing the fitting bias voltage curve with a preset standard bias voltage curve, and adjusting a trigger control signal and/or the target control signal according to a comparison result; wherein the information of the starting point includes a starting time and a starting voltage value of the bias signal.

Therefore, the control processing module fits the starting point and the sampling key point of the bias voltage signal acquired by the monitoring module to form a bias voltage curve, the trigger control signal and/or the reference control signal are adjusted according to the comparison result of the bias voltage curve and the standard bias voltage curve, and the bias voltage signal input into the photoelectric detector is subjected to system global adjustment, so that the problem that the adjustment is wrong due to single-point abrupt change errors or single-point data delay and the like is avoided to a certain extent, for example, the voltage value cannot be transmitted to the control processing module at a certain moment, the adjustment precision is greatly improved, and the accuracy of the bias voltage signal input into the photoelectric detector is further improved.

Optionally, the number of the monitoring modules is at least two, the bias control system further comprises a reference output module, a reference control end of the control processing module is connected with a control end of the reference output module, a voltage control end of the reference output module is connected with an input end of the power supply module, and a reference output end of the reference output module is connected with a reference input end of the monitoring module one to one;

The reference output module is used for outputting a reference signal to each monitoring module according to a preset reference value of each monitoring module when the target control signal is received; the reference value is a voltage value of a standard bias curve at a plurality of moments, and the reference signal of each monitoring module is unique;

The monitoring module is used for collecting the voltage value of the bias signal, and outputting the current moment and the voltage value as information of sampling key points to the control processing module when the comparison result of the voltage value and the reference signal meets the sampling condition.

Therefore, when the comparison result of the collected voltage value and the unique reference signal meets the sampling condition, each monitoring module collects the voltage value and the current moment as information of sampling key points, and ensures that the information of each sampling key point corresponds to different moments and voltage values, so that the bias voltage curve fitted by the control signal is more accurate, and the control precision of the input bias voltage signal of the photoelectric detector can be further improved.

Optionally, each monitoring module includes a comparator and a TDC unit, where a first input end of the comparator is connected to an input end of the photodetector, a second input end of the comparator is connected to a reference output end of the reference output module, an output end of the comparator is connected to an input end of the TDC unit, and an output end of the TDC unit is connected to an input end of the control processing module;

The comparator is used for comparing the acquired sampling voltage value of the bias signal with a reference signal input by the reference output module, and sending a sampling instruction to the TDC unit when the comparison result meets the sampling condition;

And the TDC unit is used for outputting the sampling voltage value and the moment of obtaining the sampling voltage value to the control processing module as sampling key points when the sampling instruction is received.

Therefore, the comparator compares the sampling voltage value with the reference signal, under the condition that the sampling condition is met, the TDC unit immediately samples to obtain the sampling key point, and the used TDC unit has high precision and speed, so that the precision of the sampling key point can be improved, and further the control precision of the photoelectric detector can be further improved.

Optionally, when the trigger control signal is a signal indicating a start time of a falling edge, the reference value is a voltage value of a standard bias curve at a plurality of times of a falling edge, a first input end of the comparator is a positive end, and a second input end of the comparator is a negative end;

and the comparator is used for sending a sampling instruction to the TDC unit when the sampling voltage value is smaller than the reference signal input by the reference output module.

When the trigger control signal is a signal indicating the start time of the falling edge, each reference value is made to be the voltage value of a plurality of times of one falling edge of the standard bias curve, so that when the comparator judges that the sampling voltage value is smaller than the reference signal, the TDC unit immediately samples, each sampling key point is the state information of different times of the falling edge of the bias curve of the input photoelectric detector, sampling disorder can be avoided, the precision of the fitted bias curve can be improved, and further control precision is improved.

Optionally, when the trigger control signal is a signal indicating a start time of a rising edge, the reference value is a voltage value of a standard bias curve at a plurality of times of a rising edge, a first input end of the comparator is a negative end, and a second input end of the comparator is a positive end;

And the comparator is used for sending a sampling instruction to the TDC unit when the sampling voltage value is larger than the reference signal input by the reference output module.

When the trigger control signal is a signal indicating the starting moment of the rising edge, each reference value is made to be the voltage value of a plurality of moments of one rising edge of the standard bias curve, so that when the comparator judges that the sampling voltage value is larger than the reference signal, the TDC unit immediately samples, each sampling key point is state information of different moments of the rising edge of the bias curve of the input photoelectric detector, sampling disorder can be avoided, the precision of the fitted bias curve can be improved, and further control precision is improved.

Optionally, the control processing module, the monitoring module and the reference output module are integrated in a field programmable gate array.

Therefore, the control processing module, the monitoring module and the reference output module are realized through the field programmable gate array, so that the cost and the power consumption of the control of the photoelectric detector can be reduced.

Optionally, the bias control system further includes a plurality of filtering modules, an input end of each filtering module is connected with one reference output end of each reference output module, and an output end of each filtering module is connected with a reference input end of each monitoring module;

the filtering module is used for converting the reference signal output by the reference output module from a pulse width modulation signal to a direct current reference signal.

In this way, the reference signal output by the reference output module is converted from the pulse width modulation signal to the direct current reference signal by using the filtering unit, so that the comparator can directly compare the sampling voltage value with the reference signal.

Optionally, the bias control module is configured to generate a bias signal by using a time when the trigger control signal is received as a starting point and a duration indicated by the trigger control signal as a period, and combine a voltage provided by the voltage signal, and output the bias signal to the photodetector.

Therefore, the bias control module takes the moment of receiving the trigger control signal as a starting point, takes the duration indicated by the trigger control signal as a period, and combines the voltage signal to generate and output the bias signal, so that the period and the starting moment of the bias signal can be precisely controlled, and the control precision of the photoelectric detector can be further improved.

Optionally, the bias control system further includes an operational amplifier, an input end of the operational amplifier is connected with an input end of the photodetector, and an output end of the operational amplifier is connected with an input end of the monitoring module;

The operational amplifier is used for attenuating the bias signal and inputting the attenuated bias signal into the monitoring module.

Therefore, the bias signal is attenuated by the operational amplifier and then is input into the monitoring module for sampling, the condition that the monitoring module is damaged due to overlarge voltage can be avoided to a certain extent, the safety of a bias control system can be improved, and the service life of the monitoring module is prolonged.

In a second aspect, an embodiment of the present invention provides a bias control method, including:

the control processing module outputs a trigger control signal to the bias control module and outputs a target control signal to the power supply module;

when the power supply module receives the target control signal, the power supply module inputs a voltage signal appointed by the target control signal to the bias voltage control module;

the bias control module inputs a bias signal to the photoelectric detector according to the trigger control signal and the voltage signal;

The monitoring module collects key information of the bias signal in at least one period and inputs the key information into the control processing module; wherein the key information comprises information of at least two sampling key points;

And the control processing module adjusts the trigger control signal and/or the target control signal according to the key information so as to adjust the bias voltage signal input to the photoelectric detector.

The key information of the input bias voltage signal of the photoelectric detector is collected through the monitoring module, and the control processing module adjusts the trigger control signal and/or the target control signal according to the key information, so that the control processing module adjusts the bias voltage signal input to the photoelectric detector according to the starting time and period designated by the trigger control signal and the voltage signal designated by the target control signal. Therefore, the period and the voltage of the bias signal input to the photoelectric detector can be monitored and regulated, the control precision of the photoelectric detector is greatly improved, the measurement precision of the laser radar where the photoelectric detector is located can be improved, and the performance of the laser radar is optimized.

The step of adjusting the trigger control signal and/or the target control signal by the control processing module according to the key information comprises the following steps:

The control processing module performs curve fitting by combining the information of the starting point and the information of all the sampling key points to obtain a fitting bias voltage curve, compares the fitting bias voltage curve with a preset standard bias voltage curve, and adjusts a trigger control signal and/or the target control signal according to the comparison result; wherein the information of the starting point includes a starting time and a starting voltage value of the bias signal.

Optionally, the step of the monitoring module collecting key information of the bias signal and inputting the key information into the control processing module includes:

When receiving the target control signal, the reference output module outputs a reference signal to each monitoring module according to a preset reference value of each monitoring module; the reference value is a voltage value of a standard bias curve at a plurality of moments, and the reference signal of each monitoring module is unique;

The monitoring module collects the voltage value of the bias signal, and when the comparison result of the voltage value and the reference signal meets the sampling condition, the current moment and the voltage value are used as sampling key points to be output to the control processing module.

Therefore, when the comparison result of the collected voltage value and the unique reference signal meets the sampling condition, each monitoring module collects the voltage value and the current moment as sampling key points, and ensures that each sampling key point corresponds to different moments and voltage values, so that the bias voltage curve fitted by the control signal is more accurate, and the control precision of the input bias voltage signal of the photoelectric detector can be further improved.

In a third aspect, an embodiment of the present invention provides an electronic device, including a bias control system according to any one of the possible embodiments of the first aspect.

Technical effects of the electronic device according to the third aspect may refer to technical effects of the system according to any implementation manner of the first aspect, which are not described herein.

In a fourth aspect, embodiments of the present invention provide a lidar comprising a transmitter and a receiver, the receiver comprising a photodetector and a bias control system as described in any of the possible embodiments of the first aspect.

Technical effects of the lidar according to the fourth aspect may refer to technical effects of the system according to any implementation manner of the first aspect, which are not described here again.

In order to make the above objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows one of schematic structural diagrams of a bias control system according to an embodiment of the present invention.

Fig. 2 shows a second schematic configuration of the bias control system according to the embodiment of the invention.

FIG. 3 is a timing diagram showing the relationship among the trigger control system, the bias signal and the comparator output signal according to the embodiment of the present invention.

Fig. 4 is a schematic flow chart of a bias control method according to an embodiment of the invention.

Reference numerals illustrate: 10-a monitoring module; 20-a bias control module; 30-a power module; 40-a control processing module; 50-a reference output module; 501-a comparator; 502-TDC unit; a 60-filtering module; 70-operational amplifier.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.

It is noted that relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Referring to fig. 1, a bias control system is provided, which includes a monitor module 10, a bias control module 20, a power module 30, and a control processing module 40.

The input end of the bias control module 20 is respectively connected with the trigger control end of the control processing module 40 and the voltage output end of the power supply module 30, the reference control end of the control processing module 40 is connected with the input end of the power supply module 30, the output end of the bias control module 20 and the monitoring end of the monitoring module 10 are both connected with the input end of the photoelectric detector, and the output end of the monitoring module 10 is connected with the input end of the control processing module 40.

The control processing module 40 is configured to output a trigger control signal to the bias control module 20 and a target control signal to the power module 30.

The power module 30 is configured to input a voltage signal specified by the quasi-control signal to the bias control module 20 when receiving the target control signal.

The bias control module 20 is used for inputting a bias signal to the photodetector according to the starting time and period designated by the trigger control signal and the voltage signal.

The monitoring module 10 is configured to collect key information of the bias signal in at least one period, and input the key information to the control processing module 40.

Wherein the key information may include information of at least two sampling key points.

The control processing module 40 is configured to adjust the trigger control signal and/or the target control signal according to the key information, so as to adjust the bias signal input to the photodetector.

The photodetectors may be silicon photomultipliers (Sipm, silicon photomultiplie), photodiodes (APD, AVALANCHE PHOTODIODE), and single photon avalanche diodes (SPAD, single Photon Avalanche Diode), among others.

In the above bias control system, the monitoring module 10 collects key information of the input bias signal of the photodetector, and the control processing module 40 adjusts the trigger control signal and/or the target control signal according to the key information, so that the control processing module 40 adjusts the bias signal input to the photodetector according to the starting time and period designated by the trigger control signal and the voltage signal designated by the target control signal. Therefore, the period and the voltage of the bias signal input to the photoelectric detector can be corrected, the bias signal input to the photoelectric detector can be effectively monitored, the control precision of the photoelectric detector is greatly improved, the measurement precision of the laser radar where the photoelectric detector is located can be improved, and the performance of the laser radar is optimized.

In addition, the adjusted bias signal is sampled by the monitoring module 10 again, and the control processing module 40 adjusts the bias signal according to the resampling result, that is, repeatedly corrects and adjusts the bias signal until the adjusted bias signal is consistent with the preset standard bias curve.

The bias control module 20 may be configured to generate a bias signal by using a time when the trigger control signal is received as a starting point, and a duration indicated by the trigger control signal as a period, in combination with a voltage provided by the voltage signal, and output the bias signal to the photodetector.

The voltage provided by the voltage signal is generally two voltages with different voltage values, and can be positive voltages with two different voltage values, negative voltages with two different voltage values, positive voltages with different voltage values and negative voltages.

Based on the above setting, by using the time when the bias control module 20 receives the trigger control signal as a starting point and using the duration indicated by the trigger control signal as a period, and combining the voltage signal to generate and output the bias signal, the period and the starting time of the bias signal can be precisely controlled, and the control precision of the photodetector can be further improved.

The manner in which the control processing module 40 adjusts the trigger control signal and/or the target control signal according to the key information may be flexibly set. For example, the key information may be a voltage difference value and a period difference value between the sampled voltage collected by the monitoring module 10 and a preset standard voltage, and the trigger control signal and the target control signal are adjusted according to the voltage difference value and the period difference value. The key information can also be input into a preset machine learning model to obtain an adjustment value. In the present embodiment, there is no particular limitation.

The information of the sampling key points comprises sampling time and sampling voltage values corresponding to the sampling time.

In addition, the control processing module 40 may use the time when the trigger control signal is output as the start time, the initial voltage value designated by the target control signal as the start voltage value, and the start time and the start voltage value as the start point information.

On the basis of the above, the control processing module 40 may be configured to perform curve fitting by combining the information of the starting point and the information of all the sampling key points, obtain a fitted bias voltage curve, compare the fitted bias voltage curve with a preset standard bias voltage curve, and adjust the trigger control signal and/or the target control signal according to the comparison result.

The standard bias curve is a target control signal of the photodetector, and corresponds to one detection capability of the photodetector. The abscissa of the fitted bias curve and the standard bias curve may both represent time, and the ordinate represents voltage value.

When the comparison result shows that the fitted bias curve generates longitudinal translation relative to the standard bias curve, but the periods are consistent, the periods are not deviated, and the voltage is deviated, at this time, the control processing module 40 can adjust the target control signal to reduce or increase the voltage. When the comparison result shows that the fitting bias curve generates lateral translation relative to the standard bias curve, but the voltages are consistent, the voltage is not deviated, and the period generates deviation, at this time, the control processing module 40 can adjust the trigger control signal to adjust the occurrence time of the rising and falling edges of the trigger signal. Similarly, if the longitudinal translation and the transverse translation occur simultaneously, the trigger control signal and the target control signal are adjusted simultaneously.

Therefore, the trigger control signal and/or the reference control signal are/is adjusted through the comparison result of the fitted bias curve and the standard bias curve, the bias signal of the input photoelectric detector is subjected to system global adjustment, the problem of adjustment errors caused by single-point abrupt change errors or acquired data delay and the like is avoided to a certain extent, for example, the voltage value cannot be transmitted to the control processing module 40 at a certain moment, the adjustment precision is greatly improved, and the accuracy of the bias signal of the input photoelectric detector is further improved.

In order to acquire information of at least two sampling keypoints without occurrence of sampling disorder, a concept of one-to-one acquisition may be introduced in monitoring, and a reference value for indicating each sampling keypoint. Based on this, referring to fig. 2, the bias control system may further include a reference output module 50, and at least two monitoring modules 10.

The reference control end of the control processing module 40 is connected with the control end of the reference output module 50, the voltage control end of the reference output module 50 is connected with the input end of the power module 30, and the reference output end of the reference output module 50 is connected with the reference input end of the monitoring module 10 one to one.

The reference output module 50 is configured to output a reference signal to each monitoring module 10 according to a preset reference value of each monitoring module 10 when receiving the target control signal.

The reference value is a voltage value of a standard bias curve at a plurality of moments, and the reference signal of each monitoring module 10 is unique. It should be appreciated that the reference signal is equal to the reference value, with each monitoring module 10 corresponding to a single reference signal.

The monitoring module 10 is configured to collect a voltage value of the bias signal, and output information of a current time and the voltage value as a sampling key point to the control processing module 40 when a comparison result of the voltage value and the reference signal meets a sampling condition.

The number of the monitoring modules 10 can be adaptively adjusted according to actual needs, for example, the number of the monitoring modules 10 can be appropriately increased when the period is longer according to the period length of the bias voltage curve, the number of the monitoring modules 10 can be set according to a target precision value, and more monitoring modules 10 can be set when the precision requirement is high.

In this way, when the comparison result of the collected voltage value and the unique reference signal meets the sampling condition, each monitoring module 10 collects the voltage value and the current moment as sampling key points, and ensures that each sampling key point corresponds to different moments and voltage values, so that the obtained information of the bias voltage signal input to the photoelectric detector is richer and more accurate, and the control precision of the input bias voltage signal of the photoelectric detector can be further improved.

In order to enable the trigger control signal and the voltage signal to be input into the bias control module synchronously, so as to improve the accuracy of inputting the bias signal into the photodetector, the reference output module 50 is further configured to initiate a voltage control signal to the power module 30 when receiving the target control signal, and after receiving the voltage control signal, the power module 30 outputs the voltage signal to the bias control module 20 at a voltage value specified by the voltage control signal.

The voltage value specified by the voltage control signal is inherited from the target control signal.

The control processing module 40, the monitoring module 10 and the reference output module 50 may be formed of independent devices, for example, may be an MCU chip, a single chip microcomputer, or the like.

In order to reduce the cost and power consumption of the bias control system, in one possible embodiment, the bias control signal may comprise a field programmable gate array (FPGA, field Programmable GATE ARRAY), and the control processing module 40, the monitoring module 10, and the reference output module 50 are all implemented by, i.e., integrated with, the FPGA.

To obtain information of various sampling keypoints with higher accuracy and higher speed, referring to fig. 2, each monitoring module 10 may include a comparator 501 and a TDC unit 502.

A first input terminal of the comparator 501 is connected to an input terminal of the photodetector, a second input terminal of the comparator 501 is connected to a reference output terminal of the reference output module 50, an output terminal of the comparator 501 is connected to an input terminal of the TDC unit 502, and an output terminal of the TDC unit 502 is connected to an input terminal of the control processing module 40.

The comparator 501 is configured to compare the sampled voltage value of the collected bias signal with the reference signal input by the reference output module 50, and send a sampling instruction to the TDC unit 502 when the comparison result meets the sampling condition.

The TDC unit 502 is configured to output, when receiving the sampling command, the sampled voltage value and the time when the sampled voltage value is obtained as a sampling key point to the control processing module 40.

Through the above arrangement, the comparator 501 compares the sampled voltage value with the reference signal, under the condition that the sampling condition is met, the TDC unit 502 immediately samples to obtain the sampling key point, and the used TDC unit 502 has high precision and speed, so that the precision of the sampling key point can be improved, and further the precision of the control of the photodetector can be further improved.

The bias signal for controlling the photodetector (i.e., the bias signal input to the photodetector by the bias control module 20) is typically a square wave signal or a triangular wave signal, and the same value as the reference value is repeated, for example, both in the rising edge and in the falling edge, due to the periodicity of the bias signal, and the same value as the reference value is repeated multiple times in different periods.

Therefore, in order to avoid sampling disturbance caused by the fact that each monitoring module obtains information of two or more sampling key points in one period due to the simultaneous existence of the reference values of the rising edge and the falling edge, the reference signals of the plurality of monitoring modules 10 may be set to be the reference value of the falling edge at the same time or the reference value of the rising edge at the same time.

Based on the above concept, when the trigger control signal is a signal indicating a start time of a falling edge, the reference value may be voltage values at a plurality of times of one falling edge of the standard bias curve, the first input terminal of the comparator 501 is a positive terminal, and the second input terminal of the comparator 501 is a negative terminal.

The comparator 501 is configured to issue a sampling instruction to the TDC unit 502 when the sampling voltage value is smaller than the reference signal input by the reference output module 50.

With the above arrangement, when the trigger control signal is a signal indicating the start time of the falling edge, by making each reference value be the voltage values at a plurality of times of one falling edge of the standard bias curve, and when the comparator 501 determines that the sampled voltage value is smaller than the reference signal, the TDC unit 502 immediately samples, so that each sampling key point is the state information of the falling edge of the bias curve of the input photodetector at different times, thereby avoiding the sampling disorder, improving the precision of the fitted bias curve, and further helping to improve the control precision.

Conversely, when the trigger control signal is a signal indicating the start time of the rising edge, the reference value is the voltage values at a plurality of times of one rising edge of the standard bias curve, the first input terminal of the comparator 501 is the negative terminal, and the second input terminal of the comparator 501 is the positive terminal.

The comparator 501 is configured to issue a sampling instruction to the TDC unit 502 when the sampling voltage value is greater than the reference signal input by the reference output module 50.

With the above arrangement, when the trigger control signal is a signal indicating the start time of the rising edge, each reference value is made to be the voltage value of the plurality of times of the rising edge of the standard bias curve, so that when the comparator 501 determines that the sampled voltage value is greater than the reference signal, the TDC unit 502 immediately samples, so that each sampling key point is the state information of the rising edge of the bias curve of the input photodetector at different times, thereby avoiding the sampling disorder, improving the precision of the fitted bias curve, and further helping to improve the control precision.

When the monitoring module 10 is implemented by an FPGA, the comparator 501 may be implemented by an LVDS interface of the FPGA, the reference value is taken as a voltage value during a falling edge period, and when the comparators 501 are 4, a timing diagram of signals (sampling instructions), bias curves and trigger control signals output by the comparators 501 may be as shown in fig. 3, where t1, t2, t3, and t4 represent timings at which different comparators 501 output sampling instructions.

When the reference output module is implemented by the FPGA, the output reference signal and the voltage control signal are both pulse width modulation signals (i.e., PWM signals). In order to facilitate the comparator to directly compare the sampled voltage value with the reference signal, a concept of converting the pulse width modulated signal into a direct current signal may be introduced. Based on this, referring to fig. 2, the bias control system may further include a plurality of filter modules 60, and the number of filter modules 60 is equal to the sum of the monitor modules 10 and the power modules 30, for example, 4 monitor modules 10,1 power module 30, and 5 filter modules 60. The filtering module 60 may be divided into a monitoring filtering module 60 and a power filtering module 60.

The input of the monitoring filter module 60 is connected to a reference output of the reference output module 50, and the output of the monitoring filter module 60 is connected to a reference input of the monitoring module 10.

The monitoring filtering module 60 is configured to convert the reference signal output by the reference output module 50 from a pulse width modulation signal to a dc reference signal.

An input terminal of the power filtering module 60 is connected to a voltage control terminal of the reference output module 50, and an output terminal of the power filtering module 60 is connected to an input terminal of the power module 30.

Similarly, the power filtering module 60 is configured to convert the voltage control signal output by the reference output module 50 from a pulse width modulation signal to a dc voltage control signal.

In some implementations, the filtering module 60 may be RC low pass filtering.

With the above arrangement, the reference signal output from the reference output module 50 is converted from a pulse width modulated signal to a direct current reference signal using the filtering module 60 so that the comparator directly compares the sampled voltage value with the reference signal.

In addition, safety protection is performed on the monitoring module 10 and the power module 30, and the service life is prolonged.

It should be appreciated that the duty cycle of the pulse width modulated signal (i.e., PWM signal) is different for different voltage values of the dc reference signal and the dc voltage control signal. Therefore, the voltage value of the direct current control signal or the reference signal can be controlled by adjusting the duty ratio so as to be suitable for controlling the photoelectric detector in different scenes.

In the working engineering of the photoelectric detector, different detection ranges are generally involved, and at this time, the requirements for the bias signals input to the photoelectric detector are different. In order to adapt to the requirements of different detection ranges, the control processing module 40 may store a plurality of standard bias curves and reference values corresponding to each bias curve in advance.

When in use, a user can designate a corresponding detection range to the control processing module 40 through modes of key selection, information input, voice input and the like, and after the control processing module 40 obtains the input detection range (can be an index value), the control processing module 40 selects a standard bias curve corresponding to the detection range and a reference value corresponding to the bias curve, and outputs a trigger control signal and a target control signal according to the standard bias curve and the reference value.

In order to improve the safety of the monitoring module 10, in one possible embodiment, referring to fig. 2, the bias control system may further include an operational amplifier 70, an input terminal of the operational amplifier 70 being connected to an input terminal of the photodetector, and an output terminal of the operational amplifier 70 being connected to an input terminal of the monitoring module 10.

The operational amplifier 70 is used for attenuating the bias signal and inputting the attenuated bias signal into the monitoring module 10.

Through the arrangement, the bias signal is attenuated by the operational amplifier 70 and then enters the monitoring module 10, so that the condition that the monitoring module 10 is damaged due to overlarge voltage can be avoided to a certain extent, the safety of a bias control system can be improved, and the service life of the monitoring module 10 can be prolonged.

The bias control system can be applied to control of the photoelectric detector in any scene, the comparator 501 function and the TDC function provided by the FPGA are adopted, the sampling rate of the TDC unit 502 is the same as that of the comparator 501 interface of the FPGA, and can reach more than 500Msps, so that key point data on a bias curve can be extracted more effectively and more accurately, the bias curve of the photoelectric detector can be monitored more effectively, the voltage precision of the bias curve of the photoelectric detector is improved, and the influence of factors such as device consistency and temperature drift on the bias curve is reduced.

In addition, a bias curve is fitted according to sampling key points of the bias signals collected by the monitoring module 10, and the trigger control signals and/or the reference control signals are adjusted according to comparison results of the bias curve and the standard bias curve, so that the bias signals input into the photoelectric detector are integrally considered and integrally adjusted, the adjustment precision is greatly improved, and the accuracy of the bias signals input into the photoelectric detector is further improved.

Based on the same concept as the bias control system described above, in one possible embodiment, there is also provided a bias control method, referring to fig. 4, which may include the following steps. The bias control method provided in this embodiment may be implemented based on the bias control system provided above.

S11, the control processing module outputs a trigger control signal to the bias control module and outputs a target control signal to the power supply module.

S13, when the power supply module receives the target control signal, the voltage signal designated by the target control signal is input to the bias control module.

And S15, the bias control module inputs a bias signal to the photoelectric detector according to the trigger control signal and the voltage signal.

S17, the monitoring module collects key information of the bias voltage signal in a period and inputs the key information into the control processing module.

And S19, the control processing module adjusts the trigger control signal and/or the target control signal according to the key information so as to adjust the bias voltage signal input to the photoelectric detector.

Through the above steps S11 to S19, the monitoring module 10 collects the key information of the input bias signal of the photodetector, and the control processing module 40 adjusts the trigger control signal and/or the target control signal according to the key information, so that the control processing module 40 adjusts the bias signal input to the photodetector according to the starting time and period specified by the trigger control signal and the voltage signal specified by the target control signal. Therefore, the period and the voltage of the bias signal input to the photoelectric detector can be monitored and regulated, the control precision of the photoelectric detector is greatly improved, the measurement precision of the laser radar where the photoelectric detector is located can be improved, and the performance of the laser radar is optimized.

In some possible embodiments, step S17 may comprise the following steps.

S171, when receiving the target control signal, the reference output module outputs a reference signal to each monitoring module according to a preset reference value of each monitoring module.

The reference value is a voltage value of a standard bias curve at a plurality of moments, and the reference signal of each monitoring module 10 is unique.

And S172, the monitoring module collects the voltage value of the bias signal, and when the comparison result of the voltage value and the reference signal meets the sampling condition, the current moment and the voltage value are used as sampling key points to be output to the control processing module.

In some possible embodiments, step S19 may be implemented as: the control processing module 40 performs curve fitting by combining the information of the starting point and the information of the sampling key point to obtain a fitted bias voltage curve, compares the fitted bias voltage curve with a preset standard bias voltage curve, and adjusts the trigger control signal and/or the target control signal according to the comparison result.

The specific implementation and effects of the bias control method can be referred to the above description of the implementation of the bias system, and will not be repeated here. The various steps in the bias control method described above may be implemented in whole or in part by software, hardware, and combinations thereof.

Based on the same concept as the bias control system described above, in one possible embodiment, an electronic device is also provided, which may include the bias control system provided by the above embodiment.

The electronic device may be a laser radar, a control system of the laser radar, a receiver of the laser radar, a control system of the receiver of the laser radar, a computer device, a controller, or the like which is communicatively connected to the laser radar, or a chip or other component provided on the laser radar, the receiver, or the like, which is not limited in this invention.

Based on the same concept as the bias control system described above, in one possible embodiment there is also provided a lidar comprising a transmitter and a receiver, the receiver comprising a photodetector and the bias control system as provided in any of the embodiments described above.

An embodiment of the present invention provides a computer program product comprising: a computer program (also referred to as code, or instructions), when executed, causes a computer to perform the bias control method of any one of the possible implementations of the method embodiments of the invention.

The embodiment of the application provides a chip system, which comprises: a processor and a memory for storing one or more programs; when the one or more programs are executed by the processor, a bias control method as described in any one of the possible implementations of the method embodiments of the present application is implemented.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The apparatus embodiments described above are merely illustrative, for example, of the flowcharts and block diagrams in the figures that illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, functional modules in the embodiments of the present invention may be integrated together to form a single part, or each module may exist alone, or two or more modules may be integrated to form a single part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The bias control system is characterized by comprising a monitoring module, a bias control module, a power supply module and a control processing module;

2. The bias control system of claim 1 wherein the information of the sampling key point includes a sampling time and a sampling voltage corresponding to the sampling time;

The control processing module is used for carrying out curve fitting by combining the information of the starting point and the information of all the sampling key points to obtain a fitting bias voltage curve, comparing the fitting bias voltage curve with a preset standard bias voltage curve, and adjusting a trigger control signal and/or the target control signal according to a comparison result; wherein the information of the starting point includes a starting time and a starting voltage value of the bias signal.

3. The bias control system of claim 1, wherein the number of the monitoring modules is at least two, the bias control system further comprises a reference output module, a reference control end of the control processing module is connected with a control end of the reference output module, a voltage control end of the reference output module is connected with an input end of the power supply module, and a reference output end of the reference output module is connected with a reference input end of the monitoring module in a one-to-one manner;

4. The bias control system of claim 3 wherein each of said monitor modules includes a comparator and a TDC unit, a first input of said comparator being connected to an input of said photodetector, a second input of said comparator being connected to a reference output of said reference output module, an output of said comparator being connected to an input of said TDC unit, an output of said TDC unit being connected to an input of said control processing module;

5. The bias control system of claim 4, wherein when said trigger control signal is a signal indicating a start time of a falling edge, said reference value is a voltage value at a plurality of times of a falling edge of a standard bias curve, a first input terminal of said comparator is a positive terminal, and a second input terminal of said comparator is a negative terminal;

6. The bias control system of claim 4, wherein when said trigger control signal is a signal indicating a start time of a rising edge, said reference value is a voltage value at a plurality of times of a rising edge of a standard bias curve, a first input terminal of said comparator is a negative terminal, and a second input terminal of said comparator is a positive terminal;

7. The bias control system of claim 4 wherein said control processing module, said monitor module and said reference output module are integrated in a field programmable gate array.

8. The bias control system of claim 5 further comprising a plurality of filter modules, an input of the filter modules being connected to a reference output of a reference output module, an output of the filter modules being connected to a reference input of one of the monitor modules;

9. The bias control system of any one of claims 1-8 wherein,

The bias control module is used for generating a bias signal by taking the moment of receiving the trigger control signal as a starting point and the duration indicated by the trigger control signal as a period and combining the voltage provided by the voltage signal, and outputting the bias signal to the photoelectric detector.

10. The bias control system of claim 9 further comprising an operational amplifier having an input coupled to the input of the photodetector and an output coupled to the input of the monitor module;

11. A method of bias control, the method comprising:

12. The bias control method according to claim 11, wherein the information of the sampling key point includes a sampling timing and a sampling voltage corresponding to the sampling timing;

13. The bias control method of claim 11, wherein the step of the monitor module collecting key information of the bias signal and inputting the key information to the control processing module comprises:

14. An electronic device comprising the bias control system of any of claims 1-10.

15. A lidar comprising a transmitter and a receiver, the receiver comprising a photodetector and the bias control system of any of claims 1 to 10.