CN117691977A - Comparator threshold adjusting method, system, laser radar, device and medium - Google Patents
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Abstract
The invention discloses a method, a system, a laser radar, a device and a medium for adjusting a threshold value of a comparator, and relates to the field of laser radars. In the method for determining the threshold value of the comparator, the photoelectric device with the avalanche effect receives the ambient light reflected by the target under the condition that the photoelectric device with the avalanche effect works in a non-avalanche area, and the ambient light only reflected by the target is collected under the condition that the photoelectric device with the avalanche effect works in the non-avalanche area and is not influenced by noise, so that the influence of noise is eliminated without multiple collection, the sampling frequency is reduced, the cost is greatly reduced, and the power consumption is reduced; in addition, the ambient light reflected by the target is not influenced by noise when being collected, so that the ambient light reflected by the target is accurately collected, and the target threshold value to be adjusted by the comparator can be accurately determined according to the ambient light reflected by the target.
Description
Technical Field
The invention relates to the field of laser radars, in particular to a method, a system, a laser radar, a device and a medium for adjusting a threshold value of a comparator.
Background
In recent years, with the rapid popularization and application of unmanned equipment, the laser radar is more and more focused, and the laser radar performs distance detection and point cloud imaging by means of laser beams emitted at high speed, and has the characteristics of high precision, strong penetrating power, long acting distance, high instantaneity and the like. The method has very high development prospect in the fields of unmanned driving, robot navigation, road monitoring, topographic mapping and the like at present, and the market demand is increased.
The main technical route of the laser radar is that a vibrator or a turning mirror replaces the scheme of integral rotation, so that the main cost contradiction point is that a high-speed analog-digital converter (Analog Digital Converter, ADC) required for timing is converted into a common 1Ghz. To reduce costs, most manufacturers use a comparator plus time to digital converter (Time to Digital Converter, TDC) scheme instead of the ADC scheme. The current technical pain points are as follows: for the photoelectric devices (silicon photomultiplier (Silicon Photomultiplier, siPM), single photon avalanche diode (Single Photon Avalanche Diode, SPAD) and the like) with the avalanche effect, the quantum uncertainty of the ambient light is expressed, so that the magnitude of the ambient light directly influences the magnitude of the comparison threshold value of the comparator, and some manufacturers realize the collection of the environment by adding an ambient light sensor, but the magnitude of the actual influence on the threshold value of the comparator is determined by the reflectivity of an object, and the threshold value of the comparator cannot be obtained well only by collecting the energy of the ambient light.
In order to account for the effect of the reflectivity of the target, most schemes use the output of a linear optoelectronic device over a period of time to obtain the reflected ambient light re-dynamically adjusted threshold of the target by calculating the uncertainty. For linear photoelectric devices, the uncertainty of direct current component of ambient light plus ambient light noise is expressed, so that the noise needs to be collected for multiple times, and then the noise and the ambient light are fitted to determine the ambient light reflected by a target. Because of the multiple acquisitions, the ADC is required to perform high-speed sampling, for example, one hundred megabytes of ADC may be required to perform the acquisitions, which ultimately results in high cost and power consumption.
It can be seen how to obtain the ambient light reflected by the target with low cost and low power consumption, so that determining the threshold value of the comparator is a technical problem that needs to be solved by those skilled in the art.
Disclosure of Invention
The invention aims to provide a method, a system, a laser radar, a device and a medium for adjusting the threshold value of a comparator, which are used for acquiring the ambient light reflected by a target with low cost and low power consumption so as to determine the threshold value of the comparator.
In order to solve the above technical problems, the present invention provides a method for adjusting a threshold of a comparator, including:
receiving an ambient light signal reflected by a target in the case of an optoelectronic device having an avalanche effect operating in a non-avalanche region;
determining a target threshold of the comparator from the ambient light signal;
acquiring a current threshold of the comparator;
and in the case that the current threshold value is different from the target threshold value, adjusting the threshold value of the comparator from the current threshold value to the target threshold value.
Preferably, before the receiving the ambient light signal reflected by the target, the method further comprises:
controlling the bias voltage of the optoelectronic device to increase from a preset value until the optoelectronic device operates in the non-avalanche region, and entering the step of receiving the ambient light signal reflected by the target.
Preferably, after said adjusting the threshold of the comparator from the current threshold to the target threshold, the method further comprises:
acquiring the current bias voltage of the photoelectric device;
controlling laser emission in the event that the current bias voltage is less than the avalanche voltage of the optoelectronic device.
Preferably, after said adjusting the threshold of the comparator from the current threshold to the target threshold, the method further comprises:
acquiring the current bias voltage of the photoelectric device;
reducing the current bias voltage to the preset value, and controlling the bias voltage of the photoelectric device to increase from the preset value;
during the increase of the bias voltage of the optoelectronic device, laser emission is controlled.
In order to solve the above technical problem, the present invention further provides a comparator threshold adjustment system, including: the controller, the comparator threshold value adjustment module still includes: the device comprises a photoelectric device with an avalanche effect, an adjustable power supply module and an ambient light acquisition module;
the adjustable power supply module is connected with the photoelectric device;
the controller is connected with the adjustable power supply module and is used for adjusting bias voltage provided by the adjustable power supply module for the photoelectric device so that the photoelectric device can receive an ambient light signal reflected by a target and convert the ambient light signal into an ambient light analog electric signal under the condition that the photoelectric device works in a non-avalanche region under the action of the bias voltage;
the ambient light acquisition module is connected with the photoelectric device and used for converting the ambient light analog electric signal into an ambient light digital signal;
the controller is respectively connected with the ambient light acquisition module, the comparator threshold adjustment module and the comparator and is used for acquiring the current threshold of the comparator and receiving an ambient light digital signal output by the ambient light acquisition module; determining a target threshold of the comparator according to the ambient light digital signal; and in the case that the current threshold value is not the same as the target threshold value, adjusting the threshold value of the comparator from the current threshold value to the target threshold value through the comparator threshold value adjusting module.
Preferably, the adjustable power supply module is a voltage conversion device, wherein the voltage conversion device at least comprises one of a digital-to-analog converter, a potentiometer and an operational amplifier;
the ambient light acquisition module is an analog-to-digital converter;
the comparator threshold adjustment module is a digital-to-analog converter or potentiometer.
In order to solve the technical problem, the invention also provides a laser radar which comprises the comparator threshold adjusting system.
In order to solve the above technical problem, the present invention further provides a comparator threshold adjusting device, including:
a receiving module for receiving an ambient light signal reflected by a target in a case where the photoelectric device having an avalanche effect operates in a non-avalanche region;
a determining module, configured to determine a target threshold of the comparator according to the ambient light signal;
an acquisition module for acquiring a current threshold of the comparator;
and the adjusting module is used for adjusting the threshold value of the comparator from the current threshold value to the target threshold value under the condition that the current threshold value is different from the target threshold value.
In order to solve the above technical problem, the present invention further provides a comparator threshold adjusting device, including:
a memory for storing a computer program;
and the processor is used for realizing the steps of the comparator threshold value adjusting method when executing the computer program.
In order to solve the above technical problem, the present invention further provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor, implements the steps of the above-mentioned comparator threshold adjustment method.
The invention provides a comparator threshold adjusting method, which comprises the following steps: receiving an ambient light signal reflected by a target in the case of an optoelectronic device having an avalanche effect operating in a non-avalanche region; determining a target threshold of the comparator according to the ambient light signal; acquiring a current threshold of a comparator; in the case that the current threshold is not the same as the target threshold, the threshold of the comparator is adjusted from the current threshold to the target threshold. Compared with the prior method for acquiring the output of a linear photoelectric device within a period of time, acquiring noise through multiple times, then fitting the noise and the ambient light to determine the ambient light reflected by a target and further determine the threshold value of the comparator, the method for determining the threshold value of the comparator provided by the invention has the advantages that the ambient light reflected by the target is received under the condition that the photoelectric device with the avalanche effect works in a non-avalanche area, and the ambient light only reflected by the target is acquired under the non-avalanche area due to the fact that the photoelectric device with the avalanche effect works in the non-avalanche area, so that the influence of the noise is not influenced, the influence of the noise is eliminated without multiple times of acquisition, the sampling frequency is reduced, the cost is greatly reduced, and the power consumption is reduced; in addition, the method is not influenced by noise when the ambient light reflected by the target is collected, so that the collected ambient light reflected by the target is more accurate, and the target threshold value to which the comparator is to be adjusted can be accurately determined according to the ambient light reflected by the target.
In addition, the invention also provides a comparator threshold value adjusting system, a laser radar, a comparator threshold value adjusting device and a computer readable storage medium, and the comparator threshold value adjusting system and the laser radar have the same or corresponding technical characteristics and effects as the comparator threshold value adjusting method.
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For a clearer description of embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described, it being apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.
FIG. 1 is a flowchart of a method for adjusting a threshold of a comparator according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an ambient light collection time, a time for completing threshold adjustment of a comparator, and a laser emission time according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another embodiment of the present invention for providing an ambient light collection time, a time for completing a threshold adjustment of a comparator, and a laser emission time;
FIG. 4 is a block diagram of a comparator threshold adjustment system according to an embodiment of the present invention;
fig. 5 is an output schematic diagram of an adjustable power supply module according to an embodiment of the present invention;
FIG. 6 is a block diagram of an apparatus for comparator threshold adjustment in accordance with an embodiment of the present invention;
FIG. 7 is a schematic diagram of an embodiment of the present invention for ambient light acquisition using an 8bit wide ADC;
FIG. 8 is a block diagram of a comparator threshold adjustment device according to an embodiment of the present invention;
fig. 9 is a block diagram of a comparator threshold adjusting device according to another embodiment of the present invention.
The reference numerals are as follows: the device comprises a controller 1, a comparator 2, a threshold value adjusting module of the comparator 3, a photoelectric device 4, an adjustable power supply module 5, an ambient light collecting module 6, an ADC 7, a DAC 8, an operational amplifier 9, a receiving module 10, a determining module 11, an acquiring module 12, an adjusting module 13, a memory 20, a processor 21, a display screen 22, an input/output interface 23, a communication interface 24, a power supply 25, a communication bus 26, a computer program 201, an operating system 202 and data 203.
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. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making any inventive effort are within the scope of the present invention.
The invention aims at providing a method, a system, a laser radar, a device and a medium for adjusting the threshold value of a comparator, which are used for acquiring the ambient light reflected by a target with low cost and low power consumption so as to determine the threshold value of the comparator.
Along with the rapid popularization and application of unmanned equipment, the laser radar is more and more focused by more people, and the laser radar performs distance detection and point cloud imaging by means of laser beams emitted at high speed, and has the characteristics of high precision, strong penetrating power, long acting distance, high instantaneity and the like. The method has very high development prospect in the fields of unmanned driving, robot navigation, road monitoring, topographic mapping and the like at present, and the market demand is increased. In the application process, if the threshold value of the comparator in the laser radar is not adjusted, when the photoelectric device works above the avalanche voltage, the laser is received by the photoelectric device after being internally reflected by the structural member, the output energy is very high, the duration of echo can reach tens of ns or hundreds of ns, and the object cannot be detected and the distance measurement can not be achieved, so that the threshold value of the comparator needs to be adjusted before laser emission in order to avoid forming a dead zone.
In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. Fig. 1 is a flowchart of a method for adjusting a threshold of a comparator according to an embodiment of the present invention, as shown in fig. 1, where the method includes:
s10: receiving an ambient light signal reflected by a target in the case of an optoelectronic device having an avalanche effect operating in a non-avalanche region;
s11: determining a target threshold of the comparator according to the ambient light signal;
s12: acquiring a current threshold of a comparator;
s13: in the case that the current threshold is not the same as the target threshold, the threshold of the comparator is adjusted from the current threshold to the target threshold.
The main function of the optoelectronic device is to implement photoelectric conversion, converting an ambient light signal into an ambient light analog electrical signal, specifically, an ambient light analog electrical signal refers to a current signal or a voltage signal. The noise performance of the optoelectronic device is not uniform under different ambient light. For an avalanche effect optoelectronic device, it appears as a quantum uncertainty of ambient light. For the photoelectric device with the avalanche effect, the photoelectric device is a pure linear device in a bias voltage range which is generally smaller than the working voltage of the photoelectric device, and the uncertainty of the ambient light is very low, so that the photoelectric device adopted in the embodiment of the invention is a photoelectric device with the avalanche effect. The photoelectric device with avalanche effect is not limited, such as SiPM, SPAD, etc., which is represented by the uncertainty of the quanta of the ambient light, and the magnitude of the ambient light directly influences the magnitude of the comparison threshold of the comparator. When the voltage of the photoelectric device with the avalanche effect is smaller than the avalanche voltage, the photoelectric device with the avalanche effect is a linear device and is not affected by noise when collecting ambient light. Thus, in this embodiment, ambient light reflected by the target is received with the optoelectronic device operating in the non-avalanche region. Objects within the field angle of the imaging system are called targets, which are not limited and are determined according to practical situations. It should be noted that the imaging system has a small angle of view, and thus, if the target is located within the angle of view, the received ambient light signal is almost simply reflected by the target. Preferably, the photovoltaic device having an avalanche effect operates in a linear region in the non-avalanche region.
In practice, in order to collect the ambient light reflected by the target, the preferred embodiment further comprises, before receiving the ambient light signal reflected by the target: the bias voltage of the photovoltaic device is controlled to increase from a preset value until the photovoltaic device is operated in a non-avalanche region, and the step of receiving the ambient light signal reflected by the target is entered. The preset value is not limited and is determined according to actual conditions. In practice, the bias voltage controlling the photovoltaic device is stepped up from a very small voltage. Since the photovoltaic device will have small fluctuations (pulse signals) across the non-avalanche region, the collected pulse signals represent the acquisition of ambient light reflected by the target.
After the ambient light signal reflected by the target is acquired, a target threshold of the comparator is determined according to the ambient light signal. The stronger the ambient light signal, the greater the target threshold; the smaller the ambient light signal, the smaller the target threshold. And calibrating the threshold value corresponding to the ambient light according to the sensitivity of different systems, so as to select an appropriate threshold value as a target threshold value. Comparing the target threshold value with the current threshold value of the comparator, if the target threshold value and the current threshold value are the same, the threshold value of the current comparator is reasonable, and adjustment is not needed; if the two are different, the threshold value of the comparator needs to be adjusted from the current threshold value to the target threshold value.
The method for adjusting the threshold value of the comparator provided by the embodiment comprises the following steps: receiving an ambient light signal reflected by a target in the case of an optoelectronic device having an avalanche effect operating in a non-avalanche region; determining a target threshold of the comparator according to the ambient light signal; acquiring a current threshold of a comparator; in the case that the current threshold is not the same as the target threshold, the threshold of the comparator is adjusted from the current threshold to the target threshold. Compared with the previous method for acquiring the output of a linear photoelectric device within a period of time, the method for determining the threshold of the comparator provided by the embodiment acquires noise through multiple acquisitions, then fits the noise with ambient light to determine the ambient light reflected by the target, and then determines the threshold of the comparator; in addition, the method is not influenced by noise when the ambient light reflected by the target is collected, so that the collected ambient light reflected by the target is more accurate, and the target threshold value to which the comparator is to be adjusted can be accurately determined according to the ambient light reflected by the target.
In order to avoid reflection in the structural member during laser emission and form a larger response on the photoelectric device, the embodiment performs laser emission when the photoelectric device is not completely in avalanche, thereby reducing the response of the photoelectric device and detecting the position of an object. In practice, after adjusting the threshold of the comparator from the current threshold to the target threshold, the preferred determination of the time to fire the laser light includes the following two ways:
mode one: acquiring the current bias voltage of the photoelectric device;
in the case where the current bias voltage is smaller than the avalanche voltage of the optoelectronic device, the laser emission is controlled.
Mode two: acquiring the current bias voltage of the photoelectric device;
reducing the current bias voltage to a preset value, and controlling the bias voltage of the photoelectric device to increase from the preset value;
during the bias voltage of the optoelectronic device increases, the laser emission is controlled.
The preset value is determined by taking the sensitivity of the system, and the lower the sensitivity is, the lower the threshold is, and the higher the sensitivity is, the higher the threshold is. Fig. 2 is a schematic diagram of an ambient light collection time, a time for completing threshold adjustment of a comparator, and a laser emission time according to an embodiment of the present invention. Fig. 3 is a schematic diagram of another embodiment of the present invention for providing an ambient light collection time, a time for completing a threshold adjustment of a comparator, and a laser emission time. As shown in fig. 2, the time when the photoelectric device works in the non-avalanche region is the ambient light collection time, the time period corresponding to the time period t 1-t 2 in fig. 2 and 3, and the bias voltage of the photoelectric device corresponding to the time period t 1-t 2 is the ambient light collection voltage; before laser emission, the threshold adjustment of the comparator is completed, and the time for completing the threshold adjustment of the comparator corresponds to the time t3 in fig. 2 and 3; meanwhile, in order to avoid forming a dead zone, laser is emitted before the bias voltage of the photoelectric device is smaller than the avalanche voltage of the photoelectric device, and the photoelectric device reaches the avalanche voltage and corresponds to the time t5 in fig. 2 and 3, that is, the laser is emitted before the time t 5.
The process of increasing the bias voltage of the photoelectric device from a preset value is called a first round; the process of decreasing the bias voltage of the photovoltaic device obtained in the first round to a preset value and then increasing the bias voltage of the photovoltaic device from the preset value is called the second round. The ambient light collection and lasing may or may not be performed in the same wheel (e.g., mode one). When the ambient light collection and the laser emission are performed in the same wheel, and at the moment, after the threshold adjustment of the comparator is completed at the moment t3 in fig. 2, the laser is emitted at the moment t4 when the bias voltage of the photoelectric device does not reach the voltage when the photoelectric device completely avalanche; when the ambient light collection and the laser emission are not carried out in the same wheel, namely, the ambient light is collected first in the first wheel, the threshold value is adjusted, then the bias voltage of the photoelectric device is reduced to a preset value, if the bias voltage is reduced to 0, the second wheel is carried out, the bias voltage of the photoelectric device is increased from 0, and in the process, the laser emission is directly carried out without collecting the ambient light again and adjusting the threshold value. As in fig. 3, the laser emission time t6 may be earlier than the ambient light collection time t1. The environment light collection and the laser emission are carried out on the same wheel, so that the echo can be prevented from being collected; the ambient light collection and lasing do not take place on the same wheel, so that the optoelectronic device does not respond to the laser at all. It should be noted that, before each laser is emitted, an ambient light acquisition and a comparator threshold adjustment are required, that is, the laser emission frequency is the same as the frequency of the ambient light acquisition.
The above describes a method for adjusting the threshold of a comparator, and this embodiment also provides a system for adjusting the threshold of a comparator. Fig. 4 is a block diagram of a comparator threshold adjustment system according to an embodiment of the present invention, as shown in fig. 4, where the system includes: the controller 1, the comparator 2 and the comparator threshold value adjusting module 3 further comprise: the photoelectric device 4 with avalanche effect, the adjustable power supply module 5 and the ambient light acquisition module 6;
the adjustable power supply module 5 is connected with the photoelectric device 4;
the controller 1 is connected with the adjustable power supply module 5, and is used for adjusting the bias voltage provided by the adjustable power supply module 5 for the photoelectric device 4 so that the photoelectric device 4 can receive the ambient light signal reflected by the target and convert the ambient light signal into an ambient light analog electric signal under the condition that the photoelectric device 4 works in a non-avalanche region under the action of the bias voltage;
the ambient light acquisition module 6 is connected with the photoelectric device 4 and is used for converting an ambient light analog electric signal into an ambient light digital signal;
the controller 1 is respectively connected with the ambient light acquisition module 6, the comparator threshold value adjusting module 3 and the comparator 2 and is used for acquiring the current threshold value of the comparator 2 and receiving an ambient light digital signal output by the ambient light acquisition module 6; determining a target threshold of the comparator 2 according to the ambient light digital signal; in case the current threshold value is not identical to the target threshold value, the threshold value of the comparator 2 is adjusted from the current threshold value to the target threshold value by the comparator threshold adjustment module 3.
Specifically, the tunable power module 5 provides bias for the optoelectronic device 4, utilizing a device in which the optoelectronic device 4 is purely linear in a bias range generally less than its operating voltage, with very low ambient light uncertainty, hereinafter referred to as ambient light harvesting voltage. By changing the operating voltage of the optoelectronic device 4 to be within this range before lasing, the ambient light signal becomes a direct current component, so that the ambient light information does not need to be collected multiple times, and the target ambient light can be predicted only once. If the main body of the ambient light collecting module 6 is an ADC, the sampling frequency of the ADC is only consistent with the laser emission frequency, that is, the sampling frequency of the ADC is less than or equal to 5Mhz, thereby greatly reducing the cost and the power consumption. In practice, the adjustable power supply module 5 is a voltage conversion device, and the voltage conversion device at least includes one of a digital-to-analog converter (Digital Analog Converter, DAC), a potentiometer, and an operational amplifier. The ambient light acquisition module 6 is an analog-to-digital converter; the comparator threshold adjustment module 3 is a DAC or potentiometer.
Fig. 5 is an output schematic diagram of an adjustable power supply module according to an embodiment of the present invention. The main control signal sent by the controller 1 enters the voltage conversion device and then is biased to be output to the photoelectric device 4. It should be noted that, the main control signal sent by the controller 1 may be adapted according to the type of the voltage conversion device, and when the main control signal is a DAC or a potentiometer, the main control signal is in accordance with the communication protocol of the device; when the main control is an operational amplifier, the main control only outputs pulse signals to be amplified and shaped through the operational amplifier, and then outputs voltage. Fig. 6 is a block diagram of an apparatus for adjusting a threshold of a specific comparator according to an embodiment of the present invention. As shown in fig. 6, the comparator threshold adjustment module 3 is a DAC 8, the adjustable power supply module 5 is an operational amplifier 9, and the ambient light collection module 6 is an ADC 7. Fig. 7 is a schematic diagram of a result of ambient light collection using an 8bit wide ADC according to an embodiment of the present invention. The result of ambient light collection using an 8bit wide ADC for different targets at a 240Khz sampling frequency is shown in fig. 7, where it can be seen that the stronger the ambient light, the greater the ADC 7 output, and beyond that range, the slower the ADC 7 output changes even though the ambient light intensity increases. As shown in fig. 7, the ambient light is between 0.7Klux and 0.925Klux, the larger the output of the ADC 7 is, and the larger the output variation of the ADC 7 is as the ambient light increases; after ambient light is greater than 0.925Klux, the output of ADC 7 varies slowly, fluctuating between 123bit and 124 bit.
The complete workflow diagram of the comparator threshold adjustment system provided by the embodiment of the invention is as follows:
1. before ranging starts, the controller 1 sends an instruction to the adjustable power supply module 5 to gradually increase the output voltage from a very small voltage;
2. when the voltage reaches the ambient light collection voltage of the photoelectric device 4, the controller 1 notifies the ambient light collection module 6 to collect the ambient light;
3. the voltage supplied by the adjustable power supply module 5 continues to rise until the rated operating voltage of the optoelectronic device 4;
4. at the same time, the controller 1 obtains the ambient light signal and then issues a command to change the threshold of the comparator 2 to the comparator threshold adjustment module 3.
5. In order to avoid a blind area formed by stray light of the laser light, the laser light is emitted before the bias voltage of the photoelectric device 4 is smaller than the avalanche voltage of the photoelectric device 4.
The workflow of the comparator threshold adjustment system provided in this embodiment is the same as the above-described comparator threshold adjustment method, and the method for implementing the adjustment of the comparator threshold is described in detail in the above-described comparator threshold adjustment method, so the detailed workflow of the comparator threshold adjustment system is not described here again.
In fig. 4, the comparator 2 has a non-inverting input connected to the output of the optoelectronic device 4, an inverting input connected to the comparator threshold adjustment module 3, and an output connected to the controller 1. After the threshold value of the comparator is adjusted by the threshold value adjusting system of the comparator, the laser emission is controlled, at the moment, the photoelectric device 4 responds to the laser and outputs an analog electric signal to the non-inverting input end of the comparator 2, then the analog electric signal is compared with the adjusted threshold value of the inverting input end of the comparator 2, namely the target threshold value, when the analog electric signal exceeds the target threshold value, the comparator 2 outputs a pulse signal to the controller 1, and the controller 1 carries out timing according to the pulse signal, so that the distance measurement of the target is realized.
The comparator threshold adjustment system provided in this embodiment has the technical features corresponding to the above-described comparator threshold adjustment method, and has the same advantageous effects as the above-mentioned comparator threshold adjustment method.
The above describes a comparator threshold adjustment system, and the present embodiment also provides a laser radar including the above-described comparator threshold adjustment system, and has the same advantageous effects as the above-mentioned comparator threshold adjustment system.
In the above embodiments, the detailed description is given for the method of adjusting the threshold value of the comparator, and the invention also provides a corresponding embodiment of the device for adjusting the threshold value of the comparator. It should be noted that the present invention describes an embodiment of the device portion from two angles, one based on the angle of the functional module and the other based on the angle of the hardware.
Fig. 8 is a block diagram of a comparator threshold adjusting device according to an embodiment of the present invention. The embodiment is based on the angle of the functional module, and comprises:
a receiving module 10 for receiving an ambient light signal reflected by a target in a case where the photoelectric device having an avalanche effect operates in a non-avalanche region;
a determining module 11, configured to determine a target threshold of the comparator according to the ambient light signal;
an obtaining module 12, configured to obtain a current threshold of the comparator;
and the adjusting module 13 is used for adjusting the threshold value of the comparator from the current threshold value to the target threshold value in the case that the current threshold value is different from the target threshold value.
Since the embodiments of the apparatus portion and the embodiments of the method portion correspond to each other, the embodiments of the apparatus portion are referred to the description of the embodiments of the method portion, and are not repeated herein.
In the comparator threshold adjustment device provided in this embodiment, in the case that the photoelectric device having the avalanche effect operates in the non-avalanche region, the ambient light signal reflected by the target is received by the receiving module; determining a target threshold of the comparator according to the ambient light signal by using a determining module; acquiring a current threshold value of the comparator through an acquisition module; and in the case that the current threshold value is different from the target threshold value, adjusting the threshold value of the comparator from the current threshold value to the target threshold value through an adjusting module. Compared with the prior art that the output of the linear photoelectric device is collected for a period of time, noise is collected through multiple times of collection, then the noise and the ambient light are fitted to determine the ambient light reflected by the target, and the threshold value of the comparator is determined; in addition, the method is not influenced by noise when the ambient light reflected by the target is collected, so that the collected ambient light reflected by the target is more accurate, and the target threshold value to which the comparator is to be adjusted can be accurately determined according to the ambient light reflected by the target.
Fig. 9 is a block diagram of a comparator threshold adjusting device according to another embodiment of the present invention. The present embodiment is based on a hardware angle, and as shown in fig. 9, the comparator threshold adjusting device includes:
a memory 20 for storing a computer program;
a processor 21 for implementing the steps of the comparator threshold adjustment method as mentioned in the above embodiments when executing a computer program.
Processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 may be implemented in hardware in at least one of a digital signal processor (Digital Signal Processor, DSP), a Field programmable gate array (Field-Programmable Gate Array, FPGA), a programmable logic array (Programmable Logic Array, PLA). The processor 21 may also comprise a main processor, which is a processor for processing data in an awake state, also called central processor (Central Processing Unit, CPU), and a coprocessor; a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 21 may be integrated with a graphics processor (Graphics Processing Unit, GPU) for taking care of rendering and drawing of content that the display screen is required to display. In some embodiments, the processor 21 may also include an artificial intelligence (Artificial Intelligence, AI) processor for processing computing operations related to machine learning.
Memory 20 may include one or more computer-readable storage media, which may be non-transitory. Memory 20 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used for storing a computer program 201, which, when loaded and executed by the processor 21, is capable of implementing the relevant steps of the comparator threshold adjustment method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may further include an operating system 202, data 203, and the like, where the storage manner may be transient storage or permanent storage. The operating system 202 may include Windows, unix, linux, among others. The data 203 may include, but is not limited to, the data referred to above in relation to the comparator threshold adjustment method, and the like.
In some embodiments, the comparator threshold adjusting device may further include a display 22, an input-output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.
Those skilled in the art will appreciate that the configuration shown in fig. 9 is not limiting of the comparator threshold adjustment means and may include more or fewer components than shown.
The comparator threshold value adjusting device provided by the embodiment of the invention comprises a memory and a processor, wherein the processor can realize the following method when executing a program stored in the memory: the threshold value adjusting method of the comparator has the same effect.
The invention also provides a corresponding embodiment of the computer readable storage medium. The computer-readable storage medium has stored thereon a computer program which, when executed by a processor, performs the steps as described in the method embodiments above.
It will be appreciated that the methods of the above embodiments, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored on a computer readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium for performing all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The computer readable storage medium provided by the invention comprises the comparator threshold value adjusting method, and the effects are the same as the above.
The method, the system, the laser radar, the device and the medium for adjusting the threshold value of the comparator are provided in the invention. In the description, each embodiment is described in a progressive manner, and each embodiment is mainly described by the differences from other embodiments, so that the same similar parts among the embodiments are mutually referred. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.
It should also be noted that in this specification, 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.
Claims (11)
1. A method of comparator threshold adjustment, comprising:
receiving an ambient light signal reflected by a target in the case of an optoelectronic device having an avalanche effect operating in a non-avalanche region;
determining a target threshold of the comparator from the ambient light signal;
acquiring a current threshold of the comparator;
and in the case that the current threshold value is different from the target threshold value, adjusting the threshold value of the comparator from the current threshold value to the target threshold value.
2. The comparator threshold adjustment method of claim 1, further comprising, prior to said receiving the ambient light signal reflected by the target:
controlling the bias voltage of the optoelectronic device to increase from a preset value until the optoelectronic device operates in the non-avalanche region, and entering the step of receiving the ambient light signal reflected by the target.
3. The comparator threshold adjustment method according to claim 2, characterized by further comprising, after the adjustment of the threshold of the comparator from the current threshold to the target threshold:
acquiring the current bias voltage of the photoelectric device;
controlling laser emission in the event that the current bias voltage is less than the avalanche voltage of the optoelectronic device.
4. The comparator threshold adjustment method according to claim 2, characterized by further comprising, after the adjustment of the threshold of the comparator from the current threshold to the target threshold:
acquiring the current bias voltage of the photoelectric device;
reducing the current bias voltage to the preset value, and controlling the bias voltage of the photoelectric device to increase from the preset value;
during the increase of the bias voltage of the optoelectronic device, laser emission is controlled.
5. A comparator threshold adjustment system comprising: the device is characterized by further comprising a controller (1), a comparator (2) and a comparator threshold adjusting module (3), and further comprising: the photoelectric device (4) with the avalanche effect, the adjustable power supply module (5) and the ambient light acquisition module (6);
the adjustable power supply module (5) is connected with the photoelectric device (4);
the controller (1) is connected with the adjustable power supply module (5) and is used for adjusting bias voltage provided by the adjustable power supply module (5) for the photoelectric device (4) so that the photoelectric device (4) can receive an ambient light signal reflected by a target and convert the ambient light signal into an ambient light analog electric signal under the condition that the photoelectric device (4) works in a non-avalanche region under the action of the bias voltage;
the ambient light acquisition module (6) is connected with the photoelectric device (4) and is used for converting the ambient light analog electric signal into an ambient light digital signal;
the controller (1) is respectively connected with the ambient light acquisition module (6), the comparator threshold value adjusting module (3) and the comparator (2) and is used for acquiring the current threshold value of the comparator (2) and receiving an ambient light digital signal output by the ambient light acquisition module (6); determining a target threshold of the comparator (2) from the ambient light digital signal; -adjusting, by the comparator threshold adjustment module (3), the threshold value of the comparator (2) from the current threshold value to the target threshold value, in case the current threshold value is not the same as the target threshold value.
6. The comparator threshold adjustment system of claim 5, wherein the non-avalanche region is a linear region.
7. The comparator threshold adjustment system according to claim 5, characterized in that the adjustable power supply module (5) is a voltage conversion device, wherein the voltage conversion device comprises at least one of a digital-to-analog converter, a potentiometer, an operational amplifier (9);
the ambient light acquisition module (6) is an analog-to-digital converter;
the comparator threshold adjusting module (3) is a digital-to-analog converter or a potentiometer.
8. A lidar comprising the comparator threshold adjustment system of any of claims 5 to 7.
9. A comparator threshold adjustment device, comprising:
a receiving module for receiving an ambient light signal reflected by a target in a case where the photoelectric device having an avalanche effect operates in a non-avalanche region;
a determining module, configured to determine a target threshold of the comparator according to the ambient light signal;
an acquisition module for acquiring a current threshold of the comparator;
and the adjusting module is used for adjusting the threshold value of the comparator from the current threshold value to the target threshold value under the condition that the current threshold value is different from the target threshold value.
10. A comparator threshold adjustment device, comprising:
a memory for storing a computer program;
processor for implementing the steps of the comparator threshold adjustment method according to any one of claims 1 to 4 when executing said computer program.
11. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the steps of the comparator threshold adjustment method of any of claims 1 to 4.
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