CN114839161A

CN114839161A - Dirt detection method and device, vehicle and storage medium

Info

Publication number: CN114839161A
Application number: CN202210345362.9A
Authority: CN
Inventors: 张明达; 冯铁
Original assignee: Guangzhou Xiaopeng Autopilot Technology Co Ltd
Current assignee: Guangzhou Xiaopeng Autopilot Technology Co Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2022-08-02

Abstract

The embodiment of the application provides a pollution detection method, a device, a vehicle and a storage medium, wherein the method is applied to the vehicle, the vehicle is provided with at least one laser radar, and the method comprises the following steps: acquiring a first echo signal of the laser radar in a target detection period; determining whether the target detection period is an abnormal detection period or not based on the signal intensity of the first echo signal; and determining that a contamination event occurs under the condition that the number of the continuous abnormal detection periods is greater than or equal to the preset number, wherein the contamination event refers to the event that the surface of the light-transmitting cover plate of the laser radar, which is far away from the laser emission device, is contaminated. The embodiment of the application provides a dirty detection measure to laser radar, whether there is dirty on the surface that can in time detect out laser radar, and then proposes corresponding treatment, for example reminds the user to clean, can guarantee that laser radar works under higher working property, improves driving safety.

Description

Dirt detection method and device, vehicle and storage medium

Technical Field

The present disclosure relates to the field of laser radar technologies, and more particularly, to a contamination detection method and apparatus, a vehicle, and a storage medium.

Background

The laser radar is a radar system that detects a characteristic amount such as a position and a velocity of a target by emitting a laser beam. In the automotive field, lidar is typically provided on both sides of the vehicle head to detect obstacles in front of the vehicle.

Laser radar includes laser emitter, laser receiver and printing opacity apron, and this printing opacity apron sets up on laser emitter's transmission route, and under the condition that the dirt (such as winged insect, ice and snow, mud) appeared in the printing opacity apron, laser radar's range can descend. In order to ensure the normal work of the laser radar, whether dirt exists on a light-transmitting cover plate of the laser radar needs to be detected in time, and a user is reminded of clearing the dirt in time under the condition that the dirt exists.

The related art does not provide a technical scheme for detecting whether contamination exists on a light-transmitting cover plate of a laser radar.

Disclosure of Invention

The embodiment of the application provides a dirt detection method and device, a vehicle and a storage medium.

In a first aspect, an embodiment of the present application provides a contamination detection method, which is applied to a processor of a vehicle, where the vehicle is provided with at least one lidar, the lidar includes a laser emission device and a transparent cover plate disposed on an emission side of the laser emission device, and the method includes: acquiring a first echo signal of the laser radar in a target detection period, wherein the first echo signal is an echo signal of a laser beam emitted by a laser emitting device reflected by a light-transmitting cover plate; determining whether the target detection period is an abnormal detection period or not based on the signal intensity of the first echo signal; and determining that a contamination event occurs under the condition that the number of the continuous abnormal detection periods is greater than or equal to the preset number, wherein the contamination event refers to the event that the surface of the light-transmitting cover plate of the laser radar, which is far away from the laser emission device, is contaminated.

In a second aspect, the present application provides a dirty detection device, and the device is applied to the vehicle, and the vehicle is equipped with at least one lidar, and lidar includes laser emission device and sets up the printing opacity apron in laser emission device's transmission side, and the device includes: the signal acquisition module is used for acquiring a first echo signal of the laser radar in a target detection period; the period detection module is used for determining whether the target detection period is an abnormal detection period or not based on the signal intensity of the first echo signal; and the event detection module is used for determining that a contamination event occurs under the condition that the number of the continuous abnormal detection periods is greater than or equal to the preset number, wherein the contamination event refers to the event that the surface of the light-transmitting cover plate of the laser radar departs from the laser emission device and is contaminated.

In a third aspect, embodiments of the present application provide a vehicle comprising a processor, a memory and at least one lidar, the memory storing computer program instructions, the computer program instructions being invoked by the processor to perform the method of soil detection according to the first aspect.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a program code is stored, and the program code is called by a processor to execute the contamination detection method according to the first aspect.

In a fifth aspect, the present application provides a computer program product, which when executed, can implement the contamination detection method according to the first aspect.

The embodiment of the application provides a dirt detection method, which determines whether a target detection period is not an abnormal detection period based on the signal intensity of a first echo signal in the target detection period, and then determines whether a dirt event occurs according to the number of continuous abnormal detection periods, wherein the reflectivity of a laser beam under the condition that dirt exists on a light-transmitting cover plate is greater than the reflectivity of the laser beam under the condition that dirt does not exist on the light-transmitting cover plate, so that the signal intensity of the first echo signal, which is reflected by the light-transmitting cover plate when the dirt exists on the light-transmitting cover plate, of the laser beam is generally greater than the signal intensity of the first echo signal, which is reflected by the light-transmitting cover plate when the dirt does not exist on the light-transmitting cover plate, therefore, the dirt event can be detected in time through the detection steps so as to take corresponding treatment measures in the following step, the working performance of the laser radar is always kept at a higher level, and the driving safety is further ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of an operation of a lidar according to an embodiment of the present disclosure.

FIG. 2 is a schematic illustration of an implementation environment provided by an embodiment of the present application.

Fig. 3 is a flowchart of a contamination detection method according to an embodiment of the present application.

Fig. 4 is a schematic interface diagram of a reminder message according to an embodiment of the present application.

Fig. 5 is a flow chart of a contamination detection method according to another embodiment of the present application.

Fig. 6 is a flow chart of a contamination detection method according to another embodiment of the present application.

Fig. 7 is a flow chart of a contamination detection method according to another embodiment of the present application.

Fig. 8 is a block diagram of a contamination detection apparatus according to an embodiment of the present application.

Fig. 9 is a block diagram of a vehicle according to an embodiment of the present application.

Fig. 10 is a block diagram of a computer-readable storage medium according to an embodiment of the present application.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The operating principle of the lidar will be described first.

The laser radar 10 comprises a laser emitting device 11, a laser receiving device 12, a light-transmitting cover plate 13 and a micro-processing unit 14. The light-transmitting cover 13 is disposed opposite to the laser emitting device 11 and is located on the optical path of the laser beam emitted by the laser emitting device 11, that is, the laser beam emitted by the laser emitting device 11 needs to pass through the light-transmitting cover 13. The micro-processing unit 14 is electrically connected with the laser emitting device 11 and the laser receiving device 12 respectively.

Step 10, the laser emitting device 11 emits a laser beam.

And step 11, generating a first echo signal under the condition that the laser beam hits the light-transmitting cover plate 13.

Step 12, the laser receiving device 12 receives the first echo signal T0.

In step 13, the laser receiving device 12 sends the parameter of the first echo signal T0 to the microprocessor unit 14.

The parameters of the first-time echo signal T0 include signal strength, reception time stamp, and the like.

In step 14, the laser beam generates a secondary echo signal T1 when striking an obstacle.

In step 15, the laser receiver 12 receives the secondary echo signal T1.

In step 16, the laser receiver 12 sends the parameters of the secondary echo signal T1 to the microprocessor unit 14.

The parameters of the secondary echo signal T0 include signal strength, reception time stamp, and the like.

In step 17, the microprocessor unit 14 determines parameters such as the distance between the obstacle and the vehicle, the shape, and the like based on the parameters of the secondary echo signal T1.

For example, the micro-processing unit 14 obtains the emitting time stamp T1 of the laser beam, the receiving time stamp T2 of the secondary echo signal T1, and the distance d between the vehicle and the obstacle is (T2-T1) × v/2, where v is the speed of light.

Referring to fig. 2, a schematic diagram of an implementation environment provided by an embodiment of the application is shown. Referring to fig. 2, a schematic diagram of an implementation environment provided by an embodiment of the application is shown. The environment of implementation is a vehicle 200. The vehicle 200 may be an automobile, an airplane, or the like, and the embodiment of the present application is not limited thereto.

The vehicle 200 is provided with at least one lidar 210, a processor. A communication link is established between lidar 210 and the processor. The lidar 200 is used for detecting whether an obstacle exists in front of the vehicle 200 and relevant parameters of the obstacle, and the working principle is as follows: the laser radar emits a plurality of laser beams at the same time, and if an obstacle appears in front of the vehicle 200 (within the detection range of the laser radar 210), the laser beams are reflected after passing through the obstacle, and the laser radar 210 receives the reflected laser beams and determines parameters such as the distance, the direction, the height, the speed, the posture, the shape, and the like of the obstacle based on the received laser beams and the emitted laser beams. In the embodiment of the present application, the vehicle 200 is provided with two laser radars 210, which are respectively located at two sides of the vehicle head position.

The lidar 210 includes a laser emitting device, a laser receiving device, and a light-transmitting cover plate disposed opposite to the laser emitting device. When the light-transmitting cover plate of laser radar 210 is dirty, such as winged insect, ice and snow, sludge and the like, the range of laser radar 210 can be reduced, that is, the working performance of laser radar 210 can be reduced, so that detection measures need to be provided for the dirt on laser radar 210, a user can timely find and process the dirt on laser radar 210, and the working performance of laser radar 210 is ensured.

Because the reflectivity of the transparent cover plate for the laser beam is greater than the reflectivity of the transparent cover plate for the laser beam when the transparent cover plate is not dirty, the signal intensity of the first echo signal of the laser beam reflected by the transparent cover plate when the transparent cover plate is dirty is generally greater than the signal intensity of the first echo signal of the laser beam reflected by the transparent cover plate when the transparent cover plate is not dirty, the embodiment of the application provides a detection measure for a dirty event, the detection period is judged to be an abnormal detection period by the signal intensity of the first echo signal of the laser radar in one detection period, the dirty event is determined to occur under the condition that a plurality of continuous abnormal detection periods exist, so that the vehicle 200 can detect the dirty event in time, and corresponding treatment measures are taken subsequently, the working performance of the laser radar 210 is always kept at a high level, and the driving safety is further ensured.

In some embodiments, the Vehicle 200 further includes a display device for displaying the reminder information, which may be an In-Vehicle Infotainment (IVI). The display device may be disposed on a peripheral side of a dashboard of the vehicle 200 so that the user can view the reminder information through the display device while controlling the vehicle 200 to travel. In other possible implementations, the vehicle 200 further includes a voice interaction device for playing the reminder information in voice form. The voice interaction device may be a speaker.

According to the technical solution provided in the embodiment of the present application, the main body for executing each step may be a processor in the vehicle 200, or may be the laser radar 210, which is not limited in the embodiment of the present application. In the embodiment of the present application, only the execution subject of each step is described as an example of the vehicle 200.

Fig. 3 is a flowchart of a contamination detection method according to an embodiment of the present application. The method comprises the following steps:

step 301, acquiring a first echo signal of the laser radar in a target detection period.

The target detection period may be any detection period. Illustratively, the target detection period is the one closest to the current time.

The first echo signal is an echo signal reflected by a laser beam emitted by a laser radar after the laser beam strikes the light-transmitting cover plate. In some embodiments, after receiving an echo signal, the laser radar determines whether a receiving timestamp for receiving the echo signal is within a preset time range, if so, the echo signal is a first echo signal, and if not, the echo signal is not the first echo signal.

The preset time range is a time range with a laser emission time stamp of a target detection period as a starting point and a time length as a preset length. The preset length is set according to experiments or experience, for example, if the duration of the target detection period is 10 seconds, the preset length may be any value within 1 to 6, and exemplarily, the preset length is 5 seconds. In one example, in a test environment, a laser radar emits a laser beam at a certain time, after the emission time, an echo signal of the laser beam received by the laser radar for the first time is a first echo signal of the laser beam, the laser radar records a receiving time of the first echo signal when receiving the first echo signal of each laser beam, and then sets a time interval between the receiving time of the last received first echo signal and the emission time to be a preset length.

In some embodiments, the laser radar acquires a first echo signal after being powered on, and starts a subsequent contamination detection process. In other embodiments, the laser radar acquires a first echo signal when it is monitored that a range down event occurs, and starts a subsequent contamination detection process. The range down event is an event that the ratio of the actual range to the calibrated range of the laser radar is less than a third preset percentage. In still other embodiments, the laser radar acquires a first echo signal and starts a subsequent contamination detection process when it detects that no occlusion event occurs. The shielding event refers to an event that the surface of the light-transmitting cover plate, which is far away from the laser emitting device, is covered with a target object. In still other embodiments, the laser radar detects whether a blocking event occurs or not when monitoring that a range down event occurs, acquires a first echo signal when detecting that no blocking event occurs, and starts a subsequent contamination detection process.

The flow of detection of a range down event and an occlusion event will be explained in the following embodiments. The starting event of the contamination detection process is set in the above mode, so that unnecessary contamination detection process executed by the laser radar can be avoided, and processing resources are saved.

Step 302, determining whether the target detection period is an abnormal detection period based on the signal intensity of the first echo signal.

The target detection period refers to a detection period in which the ratio of the number of abnormal first-time echo signals to the total number of laser beams is greater than a first preset percentage. The abnormal first echo signal is the first echo signal of which the ratio between the actual intensity and the calibrated intensity is greater than a preset value.

Based on the above principle, the embodiment of the application can judge whether the detection period is an abnormal detection period through the signal intensity of the first echo signal in the target detection period, determine that a dirty event occurs under the condition that a plurality of continuous abnormal detection periods exist, enable a vehicle to detect the dirty event in time, so that corresponding treatment measures can be taken subsequently, and enable the working performance of the laser radar to be kept at a higher level all the time, thereby ensuring the driving safety.

In some embodiments, step 302 may include the following sub-steps:

step 302a, determining whether the first echo signal is an abnormal first echo signal based on the signal strength of the first echo signal.

Optionally, the laser radar acquires a first ratio between the signal intensity of the first echo signal and the calibration intensity; and determining that the first echo signal is an abnormal first echo signal under the condition that the first ratio is larger than a preset value.

Wherein the calibration strength is obtained by testing. Under the test environment, the light-transmitting cover plate of the laser radar is not dirty, the laser radar emits laser beams at a certain moment, after the emission moment, the echo signals of the laser beams received by the laser radar for the first time are the first echo signals of the laser beams, the laser radar records the signal intensity of each first echo signal, and then the calibration intensity under the non-dirty condition is determined based on the signal intensity of each first echo signal. In one example, the lidar determines an average of the signal strengths of the respective first-time echo signals as a nominal strength.

The preset value is set experimentally or empirically. For another example, in a test environment, dirt exists on a light-transmitting cover plate of the laser radar, the laser radar emits a laser beam at a certain moment, after the emission moment, an echo signal of the laser beam received by the laser radar for the first time is a first echo signal of the laser beam, the laser radar records the signal intensity of each first echo signal, and then the calibration intensity under the dirt condition is determined based on the signal intensity of each first echo signal. In one example, the lidar determines a minimum value of the signal strength of each first-time echo signal as a nominal strength under dirty conditions. And then, determining the ratio of the calibration strength under the dirty condition to the calibration strength under the non-dirty condition as a preset value. For example, the preset value may be any value between 1.5 and 5. Illustratively, the preset value is 2.

Illustratively, the signal intensity of the first echo signal received by the laser radar is 500, the calibrated intensity is 200, the preset value is 2, the ratio between the signal intensity of the first echo signal and the calibrated intensity is 2.5, and if the ratio is greater than the preset value, the first echo signal is an abnormal first echo signal.

And step 302b, determining whether the target detection period is an abnormal detection period or not based on the number of the abnormal first echo signals.

Optionally, the laser radar acquires a second ratio between the number of the abnormal first echo signals and the total number of laser beams in the target detection period; and determining the target detection period as an abnormal detection period under the condition that the second ratio is greater than or equal to the first preset percentage.

The first predetermined percentage is set experimentally or empirically. For example, the first predetermined percentage may be any value between 50% and 90%. Illustratively, the first preset percentage is 60%. Illustratively, if the number of abnormal first-time echo signals of the laser radar in the target detection period is 72, and the total number of laser beams in the target detection period is 100, the second ratio is 72% and is greater than the first preset percentage, so that the target detection period is an abnormal detection period.

Step 303, determining that a contamination event occurs when the number of consecutive abnormality detection periods is greater than or equal to a preset number.

The preset number is set according to experiments or experience, for example, the preset number may be any value between 4 and 10, and exemplarily, the preset number is 6. The dirty event refers to the event that the surface of the light-transmitting cover plate of the laser radar, which is far away from the laser transmitting device, is dirty.

In some embodiments, after the occurrence of the contamination event is detected, the laser radar sends a notification message to the processor, and the processor sends a reminding message according to the notification message to remind a user of timely removing the contamination on the surface of the light-transmitting cover plate of the laser radar, which is away from the laser emitting device, so that the influence on the range of the laser radar is reduced. The reminding information can be voice information, and the processor controls the loudspeaker to perform voice broadcast. The reminding information can also be character information, and the processor controls the display device to display. Referring to fig. 4, a schematic interface diagram of a reminder message provided in an embodiment of the present application is shown. The display device in the vehicle displays a reminder message 41 "radar dirty, please wipe".

To sum up, the method for detecting contamination provided in the embodiment of the present application determines whether the target detection period is not an abnormal detection period based on the signal intensity of the first echo signal in the target detection period, and then determines whether a contamination event occurs according to the number of consecutive abnormal detection periods, because the reflectivity of the laser beam when the contamination exists on the transparent cover plate is greater than the reflectivity of the laser beam when the contamination does not exist on the transparent cover plate, the signal intensity of the first echo signal reflected by the transparent cover plate when the contamination exists on the transparent cover plate is generally greater than the signal intensity of the first echo signal reflected by the transparent cover plate when the contamination does not exist on the transparent cover plate, so that the contamination event can be detected in time through the above detection steps, so as to take corresponding processing measures in the following, the working performance of the laser radar is always kept at a higher level, and the driving safety is further ensured.

Fig. 5 is a flowchart illustrating detection of an anomaly detection period according to another embodiment of the present application. The detection process of the abnormal detection period comprises the following steps:

step 501, setting the initial values of the first counter and the second counter to be 0.

The first counter is used to count the number of dirty points, and is set to 0, that is, t0_ dirty _ num is 0. The second counter is used for counting the number of traversed points, and is set to be 0, that is, total _ point _ num is set to be 0.

Step 502, receiving an echo signal.

The laser receiving device receives the echo signal.

Step 503, detecting whether the echo signal is a first echo signal.

Since the transparent cover plate is closer to the laser transmitter than to the obstacle, the time of receiving the first echo signal T0 by the laser receiver should be shorter than the time of receiving the second echo signal T5.

The micro-processing unit detects whether the echo signal is a primary echo signal or not based on a difference value between a receiving event stamp of the echo signal and a transmitting time stamp of the laser beam, if the difference value is smaller than a first preset difference value, the echo signal is indicated as the primary echo signal, and if the difference value is larger than the first preset difference value and smaller than a second preset difference value, the echo signal is indicated as a secondary echo signal.

If yes, go to step 504. If not, no processing is carried out.

Step 504, increment the value of the second counter by 5.

And 505, detecting whether the ratio of the actual intensity to the calibrated intensity of the echo signal is greater than a preset value.

The preset value is used for judging whether the first echo signal T0 is an abnormal first echo signal. If the ratio of the actual intensity to the calibrated intensity of the primary echo signal T0 is greater than the preset value, it is determined that the primary echo signal T0 is an abnormal primary echo signal.

If yes, go to step 502.

Step 506, the value of the first counter is incremented by 1.

Step 507, detecting whether the value of the second counter is greater than the total number of the laser beams.

If yes, go to step 508, otherwise, resume execution from step 505.

Step 508, calculating the dirty/dirty ratio based on the value of the first counter.

The micro-processing unit determines a ratio between the value of the first counter and the total number of laser beams as a dirty-spot rate. For example, if the first counter has a value of 56 and the total number of laser beams is 100, the contamination point rate is 56%.

Step 509, it is checked whether the dirty/dirty ratio is greater than a first predetermined percentage.

If yes, go to step 510, otherwise go to step 511.

Step 510, determining the target detection period as an abnormal detection period.

In step 511, the target detection period is determined as a normal detection period.

Fig. 6 is a flow chart of a contamination detection method according to another embodiment of the present application. The method comprises the following steps:

step 601, detecting whether the laser radar generates a shielding event or not under the condition that the laser radar is monitored to generate a range reduction event.

The range down event is an event that the ratio of the actual range to the calibrated range of the laser radar is less than a third preset percentage. The calibration range is obtained through testing. In one example, in the test environment, an obstacle (such as a black vehicle or a pedestrian with black clothes) is disposed in front of the vehicle, and the distance between the obstacle and the vehicle is gradually increased until the detection rate of the laser radar on the obstacle reaches the preset detection rate threshold, and then the distance between the obstacle and the vehicle is set as the calibration range. The third predetermined percentage is set according to experiments or experience, and may be any value between 50% and 90%, for example, the third predetermined percentage is 70%.

Optionally, when the laser radar detects a certain obstacle, if the detection rate is smaller than a preset detection rate threshold, determining the distance between the obstacle and the vehicle as the actual measurement range of the laser radar. The detection rate is a ratio between the number of secondary echo signals reflected by the obstacle and the total number of laser beams. The predetermined detection rate threshold is set experimentally or empirically, and is illustratively 50%.

The shielding event refers to an event that the surface of the light-transmitting cover plate, which is far away from the laser emitting device, is covered with a target object. The target object refers to an object having a reflectivity greater than a preset reflectivity, such as a plastic bag, paper, and the like. Because the reflectivity of the target object is very large, the laser beam cannot penetrate through the target object and project to the obstacle, and the range of the laser radar is almost zero at the moment. The process for detecting whether the occlusion event occurs comprises the following steps:

step 601a, acquiring the number of secondary echo signals received in a target detection period.

The secondary echo signal is an echo signal obtained by reflecting a laser beam emitted by the laser emitting device through an obstacle. In some embodiments, after receiving an echo signal, the laser radar determines whether a receiving timestamp for receiving the echo signal is within a preset time range, and if not, the echo signal is a secondary echo signal.

Step 601b, obtaining a third ratio between the difference between the total number of the laser beams in the target detection period and the number of the secondary echo signals and the total number of the laser beams in the target detection period.

Under the condition that the surface of the light-transmitting cover plate, which is far away from the laser emitting device, covers the target object, the laser beams cannot penetrate through the target object to be projected onto the obstacle, and at the moment, the laser radar cannot receive secondary echo signals reflected by the obstacle, so that whether the laser radar is shielded by a large area can be determined based on the number of the laser beams which do not receive the secondary echo signals. The third ratio may be referred to as a shading ratio. For example, if the total number of laser beams in the target detection period is 100 and the number of received secondary echo signals is 30, the third ratio is (100-30)/100, which is 70%.

Step 601c, determining that the occlusion event occurs under the condition that the third ratio is greater than or equal to the second preset percentage.

The second predetermined percentage is set experimentally or empirically and may be any value between 50% and 90%. Illustratively, the second preset percentage is 65%.

Step 602, under the condition that the laser radar does not generate a shielding event, acquiring a first echo signal of the laser radar in a target detection period.

The first echo signal is an echo signal reflected by a laser beam emitted by the laser emitting device through the light-transmitting cover plate.

Step 603, determining whether the target detection period is an abnormal detection period based on the signal intensity of the first echo signal.

In step 604, it is determined that a contamination event occurs when the number of consecutive abnormality detection periods is greater than or equal to a preset number.

A soiling event is an event in which the surface of the light-transmitting cover plate facing away from the laser emitting device is soiled.

In summary, according to the technical scheme provided by the embodiment of the application, when the occurrence of the range-down event is monitored and the blocking event is not detected, the subsequent contamination detection process is executed, so that the unnecessary contamination detection process can be avoided, and the processing resource can be saved.

It should be noted that the lidar may also have a reduced range due to other factors, such as a heavy rain weather, a nearby portion (e.g., within 50 cm) of the lidar being blocked by an obstacle, a light-transmitting cover of the lidar being cracked or dented by a crushed stone impact, a water mist on a side of the light-transmitting cover of the lidar facing the laser transmitter, and so on. Since the above factors are factors that cannot be eliminated by a human, there is no need to remind the user. Therefore, the dirt detection method provided by the embodiment of the application also needs to eliminate the range reduction caused by other factors based on the working parameters of the vehicle or the functional components included in the vehicle. The embodiment of the application also provides a dirt detection method, which comprises the following steps:

and 701, acquiring a first echo signal of the laser radar in a target detection period.

Step 702, determining whether the target detection period is an abnormal detection period based on the signal intensity of the first echo signal.

And 703, acquiring the working parameters of the vehicle under the condition that the number of the continuous abnormal detection periods is greater than or equal to the preset number.

The operating parameters include at least one of: the vehicle speed parameter, the vehicle temperature parameter and the vehicle windscreen wiper operating position.

The speed parameter of the vehicle is used to indicate the travel speed of the vehicle.

The temperature parameters of the vehicle include a first temperature parameter and a second temperature parameter. The first temperature parameter represents the ambient temperature of the vehicle, and can be measured by a temperature sensor arranged on the surface of the vehicle or acquired from a cloud end by a processor of the vehicle. The second temperature parameter characterizes an internal temperature of the lidar. Optionally, a temperature sensor is arranged in the closed space on one side, facing the laser emitting device, of the light-transmitting cover plate of the laser radar, and the second temperature parameter is measured through the temperature sensor.

The working gear of the windscreen wiper of the vehicle represents the movement speed of the windscreen wiper. The vehicle also includes a wiper blade that also establishes a communication connection, such as an I2C connection, with the processor. The wiper blade is an important accessory mounted on the windshield of the vehicle 300 for sweeping rain, snow and dust which obstruct the view of the windshield. In general, the wiper is provided with different gears, and the higher the gear is, the faster the moving speed of the wiper is, and the faster the obstacle is cleaned, so the higher the gear of the wiper is when the rain is strong. In the embodiment of the application, the windscreen wiper sends the gear information of the windscreen wiper to the processor. In some embodiments, the windscreen wiper reports its own working gear to the processor every preset time. In other embodiments, the processor sends a query instruction to the wiper when the contamination detection result meets a preset condition, and the wiper reports its own working gear to the processor based on the query instruction.

In step 704, a driving scenario of the vehicle is determined based on the operating parameters of the vehicle.

When the operating parameters of the vehicle include the operating range of the wiper blade, step 704 is implemented as: and under the condition that the working gear of the windscreen wiper is a preset gear, determining that the driving scene of the vehicle is a rainstorm scene. And under the condition that the working gear of the windscreen wiper is not a preset gear, determining that the driving scene of the vehicle is not a rainstorm scene.

The working gear represents the speed parameter of the windscreen wiper. The preset gear has a higher speed parameter than the non-preset gear. In some examples, the operating positions of the wiper blade include low, medium, and high. The speed parameter corresponding to the high gear is the highest, and the speed parameter corresponding to the low gear is the lowest. The preset gear is high, namely when the working gear of the windscreen wiper is high, the driving scene of the vehicle is determined to be a rainstorm scene. In other examples, the operating range of the wiper blade is represented by numbers, such as 1 st gear, 2 nd gear, 3 rd gear, 4 th gear and the like, wherein the speed parameter corresponding to the 1 st gear is the highest, and the speed parameter corresponding to the 2 nd gear is the lowest. The preset gear is a 1 gear and a 2 gear, namely when the working gear of the windscreen wiper is the 1 gear or the 2 gear, the driving scene of the vehicle is determined to be a rainstorm scene.

In the case where the operating parameters of the vehicle include temperature parameters, step 704 is implemented as: under the condition that the temperature difference between the first temperature parameter and the second temperature parameter is larger than a preset difference, heating materials covered on the surface of the laser radar are controlled to heat; after the heating time is longer than or equal to the preset time, acquiring a dirt detection result again; determining that the driving scene of the vehicle is an internal fogging scene under the condition that the obtained dirt detection result does not meet the preset condition; and under the condition that the obtained dirt detection result meets the preset condition, determining that the driving scene of the vehicle is not an internal fogging scene.

The vehicle further comprises a heating circuit and a heating control circuit. The processor is in communication connection with the heating control circuit and the temperature sensor. The heating control circuit is electrically connected with the heating circuit. The heating control circuit is used for controlling the conduction of the heating circuit. Heating circuit is including setting up the material that generates heat on laser radar's printing opacity apron, for example the coating film that generates heat, and this material that generates heat has electrically conductive and high electrically conductive characteristic, and after heating circuit switched on, the material that generates heat was with the water smoke on evaporation laser radar's the printing opacity apron.

The preset time period may be set according to experiments or experience. For example, the preset time period may be any value between 2 and 15, and illustratively, the preset time period is 3 minutes, that is, the heating circuit is controlled to be in the on state for 3 minutes. The process of retrieving the contamination detection result may refer to the embodiment in fig. 3, which is not described herein again. The preset condition means that the detection period of the laser radar after being heated is not an abnormal detection period. Because under the scene of internal fogging, if the heating material generates heat, then can evaporate the water smoke on the laser radar, when carrying out dirty detection this moment again, unusual first echo signal significantly reduces, consequently can judge whether the scene of traveling of vehicle is the scene of internal fogging according to the dirty detection result after the heating, if the dirty detection result after the heating represents the quantity reduction of the unusual first echo signal that the laser radar received, does not have unusual detection cycle, then explains that the scene is the scene of internal fogging.

When the operating parameters of the vehicle include a speed parameter of the vehicle, step 704 is implemented as: determining that the driving scene of the vehicle is a low-speed driving scene under the condition that the speed parameter of the vehicle is less than the preset speed; and under the condition that the running speed of the vehicle is greater than the preset speed, determining that the running scene of the vehicle is a high-speed running scene. The preset speed can be set according to actual requirements, and the preset speed is not limited in the embodiment of the application. For example, the preset speed may be any value between 5 and 25, and is illustratively 20 km/h.

Step 705, in case that the working scene of the vehicle is not a preset scene, determining that the dirty event occurs.

The preset scene includes at least one of: a rainstorm scene, a low speed driving scene, and an internal fogging scene. In the embodiment of the application, before determining whether a dirty event occurs, the driving scene of the vehicle is determined to eliminate the range reduction of the laser radar caused by other factors (such as rain sheltering, water mist generated on one side of the light-transmitting cover plate of the laser radar facing the laser emitting device, and obstacles generated at the short distance of the laser radar), so that whether the dirty event occurs can be accurately determined.

It should be noted that the processor may sequentially detect whether the driving scene of the vehicle is a low-speed driving scene, a rainstorm scene, and an internal fogging scene, and determine that a contamination event occurs in a case where the driving scene of the vehicle is not any of the three scenes. In addition, the detection order of detecting whether the scene is any of the three scenes is not limited in the embodiments of the present application. In addition, it should be noted that the processor does not need to perform the subsequent determination step after determining that the driving scene of the vehicle is any one of the preset scenes. For example, in the case where it is determined that the driving scene of the vehicle is a low-speed driving scene, it is not necessary to continuously determine whether it is a heavy rain scene or an internal fogging scene.

To sum up, the method for detecting fouling provided by the embodiment of the application determines the driving scene of the vehicle before determining whether the fouling happens so as to eliminate the range reduction of the laser radar caused by other factors (such as rain sheltering, water mist generated on one side of the light-transmitting cover plate of the laser radar facing the laser emitting device, and obstacles generated at the short distance of the laser radar), and then can accurately judge whether the fouling happens.

Referring to fig. 8, a block diagram of a contamination detection apparatus 800 according to an embodiment of the present disclosure is shown. The device is applied to vehicles, and vehicles is equipped with at least one lidar, and lidar includes laser emission device and sets up the printing opacity apron in laser emission device's transmission side. The apparatus 800 comprises: a signal acquisition module 810, a period detection module 820, and an event detection module 830. The signal acquiring module 810 is configured to acquire a first echo signal of the laser radar in a target detection period, where the first echo signal is an echo signal of a laser beam emitted by the laser emitting device reflected by the light-transmitting cover plate. And a period detection module 820, configured to determine whether the target detection period is an abnormal detection period based on the signal strength of the first echo signal. And the event detection module 830 is configured to determine that a contamination event occurs when the number of the consecutive abnormal detection periods is greater than or equal to a preset number, where the contamination event is an event that a surface of the light-transmitting cover plate of the laser radar facing away from the laser emitting device is contaminated.

To sum up, the contamination detection apparatus provided in the embodiment of the present application determines whether the target detection period is not an abnormal detection period based on the signal intensity of the first echo signal in the target detection period, and then determines whether a contamination event occurs according to the number of consecutive abnormal detection periods, because the reflectivity of the laser beam in the case that the contamination exists on the transparent cover plate is greater than the reflectivity of the laser beam in the case that the contamination does not exist on the transparent cover plate, the signal intensity of the first echo signal reflected by the transparent cover plate when the contamination exists on the transparent cover plate is generally greater than the signal intensity of the first echo signal reflected by the transparent cover plate when the contamination does not exist on the transparent cover plate, so that the contamination event can be detected in time through the above detection steps, so as to take corresponding processing measures in the following steps, the working performance of the laser radar is always kept at a higher level, and the driving safety is further ensured.

In some embodiments, the period detection module 820 is configured to determine whether the first-time echo signal is an abnormal first-time echo signal based on the signal strength of the first-time echo signal; and determining whether the target detection period is an abnormal detection period or not based on the number of the abnormal first echo signals.

In some embodiments, the period detection module 820 is configured to obtain a first ratio between the signal strength of the first-time echo signal and the calibration strength; and determining that the first echo signal is an abnormal first echo signal under the condition that the first ratio is larger than a preset value.

In some embodiments, the period detection module 820 is configured to obtain a second ratio between the number of the abnormal first echo signals and the total number of laser beams in the target detection period; and determining the target detection period as an abnormal detection period under the condition that the second ratio is greater than or equal to the preset percentage.

In some embodiments, the apparatus further comprises a first detection module (not shown in fig. 8). The first detection module is used for detecting whether the laser radar generates a shielding event, wherein the shielding event refers to an event that a target object covers the surface, deviating from the laser emitting device, of the light-transmitting cover plate. The signal obtaining module 810 is further configured to, in a case that the laser radar does not generate a blocking event, perform a step of obtaining a first echo signal of the laser radar in a target detection period.

In some embodiments, the first detection module is configured to acquire the number of secondary echo signals received in a target detection period, where the secondary echo signals are echo signals reflected by an obstacle from a laser beam emitted by the laser emission device; acquiring a difference value between the total number of the laser beams and the number of the secondary echo signals in a target detection period, and acquiring a third ratio value between the total number of the laser beams in the target detection period and the total number of the laser beams in the target detection period; and determining that the occlusion event occurs under the condition that the third ratio is greater than or equal to a second preset percentage.

In some embodiments, the signal obtaining module 810 is further configured to, in a case that it is monitored that the laser radar has a range down event, perform the step of obtaining a first echo signal of the laser radar in a target detection period, where the range down event is an event that a ratio between an actual range and a calibrated range of the laser radar is smaller than a third preset percentage.

As shown in fig. 9, the present example further provides a vehicle 900, where the vehicle 900 includes a processor 910, a memory 920, and a laser radar 930. Wherein memory 920 stores computer program instructions.

Processor 910 may include one or more processing cores. The processor 910 interfaces with various components throughout the battery management system using various interfaces and lines to perform various functions of the battery management system and to process data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 920 and invoking data stored in the memory 920. Alternatively, the processor 910 may be implemented in hardware using at least one of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), and Programmable Logic Array (PLA). The processor 910 may integrate one or more of a Central Processing Unit (CPU) 910, a Graphics Processing Unit (GPU) 910, a modem, and the like. Wherein, the CPU mainly processes an operating system, a user interface, an application program and the like; the GPU is used for rendering and drawing display content; the modem is used to handle wireless communications. It is understood that the modem may not be integrated into the processor 910, but may be implemented by a communication chip.

The Memory 920 may include a Random Access Memory (RAM) or a Read-Only Memory (Read-Only Memory) 920. The memory 920 may be used to store instructions, programs, code sets, or instruction sets. The memory 920 may include a stored program area and a stored data area, wherein the stored program area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a touch function, a sound playing function, an image playing function, etc.), instructions for implementing various method examples described below, and the like. The stored data area may also store data created during use of the vehicle (such as a phonebook, audiovisual data, chat log data) and the like.

Referring to fig. 10, a computer-readable storage medium 1000 is further provided according to an embodiment of the present application, where the computer-readable storage medium 1000 stores computer program instructions 1010, and the computer program instructions 1010 can be called by a processor to execute the method described in the foregoing embodiment.

The computer-readable storage medium 1000 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read only memory), an EPROM, a hard disk, or a ROM. Alternatively, the computer-readable storage medium 1000 includes a non-volatile computer-readable storage medium. The computer readable storage medium 1000 has storage space for computer program instructions 1010 to perform any of the method steps of the method described above. The computer program instructions 1010 may be read from or written to one or more computer program products. The computer program instructions 1010 may be compressed in a suitable form.

Although the present application has been described with reference to preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application, and all changes, substitutions and alterations that fall within the spirit and scope of the application are to be understood as being covered by the following claims.

Claims

1. A soiling detection method, characterized in that it is applied to a vehicle provided with at least one lidar comprising a laser emitting device and a light-transmitting cover plate arranged on the emitting side of the laser emitting device, the method comprising:

acquiring a first echo signal of the laser radar in a target detection period, wherein the first echo signal is an echo signal of a laser beam emitted by the laser emitting device reflected by the light-transmitting cover plate;

determining whether the target detection period is an abnormal detection period based on the signal intensity of the first echo signal;

And determining that a contamination event occurs when the number of the continuous abnormity detection periods is greater than or equal to a preset number, wherein the contamination event refers to an event that the surface of the light-transmitting cover plate, which faces away from the laser emission device, is contaminated.

2. The method of claim 1, wherein determining whether a target detection period is an abnormal detection period based on the signal strength of the first echo signal comprises:

determining whether the first echo signal is an abnormal first echo signal based on the signal intensity of the first echo signal;

and determining whether the target detection period is the abnormal detection period or not based on the number of the abnormal first echo signals.

3. The method of claim 2, wherein determining whether the first-time echo signal is an abnormal first-time echo signal based on the signal strength of the first-time echo signal comprises:

acquiring a first ratio between the signal intensity and the calibration intensity of the first echo signal;

and determining the first echo signal as the abnormal first echo signal when the first ratio is larger than a preset value.

4. The method of claim 2, wherein determining whether the target detection period is the anomaly detection period based on the number of anomalous first-time echo signals comprises:

Acquiring a second ratio between the number of the abnormal first echo signals and the total number of the laser beams in the target detection period;

and determining the target detection period as the abnormal detection period when the second ratio is greater than or equal to a first preset percentage.

5. The method of any one of claims 1 to 4, wherein the acquiring the first echo signal of the lidar in the target detection period further comprises:

detecting whether the laser radar generates a shielding event, wherein the shielding event is an event that a target object covers the surface of the light-transmitting cover plate, which is far away from the laser emitting device;

and under the condition that the laser radar does not generate the shielding event, executing the step of acquiring a first echo signal of the laser radar in a target detection period.

6. The method of claim 5, wherein the detecting whether the lidar has an occlusion event comprises:

acquiring the number of secondary echo signals received in the target detection period, wherein the secondary echo signals are echo signals reflected by a barrier by laser beams emitted by the laser emitting device;

Acquiring a third ratio between the difference between the total number of the laser beams in the target detection period and the number of the secondary echo signals and the total number of the laser beams in the target detection period;

and determining that the occlusion event occurs when the third ratio is greater than or equal to a second preset percentage.

7. The method of any one of claims 1 to 4, wherein the acquiring the first echo signal of the lidar in the target detection period further comprises:

and under the condition that the laser radar is monitored to have a range down event, executing the step of acquiring a first echo signal of the laser radar in a target detection period, wherein the range down event is an event that the ratio of the actual range to the calibrated range of the laser radar is smaller than a third preset percentage.

8. A soiling detection device, characterized in that the device is applied to a vehicle provided with at least one lidar comprising a laser emitting device and a light-transmitting cover plate arranged on the emitting side of the laser emitting device, the device comprising:

the signal acquisition module is used for acquiring a first echo signal of the laser radar in a target detection period, wherein the first echo signal is an echo signal of a laser beam emitted by the laser emission device reflected by the light-transmitting cover plate;

The period detection module is used for determining whether the target detection period is an abnormal detection period or not based on the signal intensity of the first echo signal;

and the event detection module is used for determining that a contamination event occurs under the condition that the number of the continuous abnormal detection periods is greater than or equal to the preset number, wherein the contamination event refers to the event that the surface of the light-transmitting cover plate of the laser radar, which is far away from the laser emission device, is contaminated.

9. A vehicle comprising a processor, a memory and at least one lidar, the memory storing computer program instructions which are invoked by the processor to perform the soil detection method of any of claims 1-7.

10. A computer-readable storage medium, characterized in that a program code is stored in the computer-readable storage medium, which program code is invoked by a processor to perform the contamination detection method according to any one of claims 1 to 7.