CN112534302A

CN112534302A - Radar and gain control method

Info

Publication number: CN112534302A
Application number: CN201980052105.2A
Authority: CN
Inventors: 李强
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2021-03-19
Anticipated expiration: 2039-02-15
Also published as: CN112534302B; WO2020164121A1

Abstract

A radar (300) and a gain control method relate to an automatic driving technology in the field of artificial intelligence, and the radar (300) comprises: the device comprises a transmitting module (310), a receiving module (320), a gain control module (330) and a gain adjusting module (340). The transmitting module (310) is used for transmitting a first signal for detecting a target object; the receiving module (320) is used for receiving a second signal reflected by the first signal after encountering the target object and outputting the second signal to the gain adjusting module (340); the gain control module (330) is configured to determine a gain at a first time according to the first propagation time and a corresponding relationship between the signal gain and the propagation time, and output the determined gain to the gain adjustment module (340), where the first propagation time is a time from a time when the transmission module (310) transmits the first signal to the first time, and the first time is a time when the gain adjustment module (340) receives the second signal; the gain adjusting module (340) is used for adjusting the strength of the second signal according to the gain of the first time.

Description

Radar and gain control method

Technical Field

The application relates to the field of automatic driving, in particular to a radar and a gain control method.

Background

Artificial Intelligence (AI) is a theory, method, technique and application system that uses a digital computer or a machine controlled by a digital computer to simulate, extend and expand human intelligence, perceive the environment, acquire knowledge and use the knowledge to obtain the best results. In other words, artificial intelligence is a branch of computer science that attempts to understand the essence of intelligence and produce a new intelligent machine that can react in a manner similar to human intelligence. Artificial intelligence is the research of the design principle and the realization method of various intelligent machines, so that the machines have the functions of perception, reasoning and decision making. Research in the field of artificial intelligence includes robotics, natural language processing, computer vision, decision and reasoning, human-computer interaction, recommendation and search, AI basic theory, and the like.

Automatic driving is a mainstream application in the field of artificial intelligence, and the automatic driving technology depends on the cooperative cooperation of computer vision, radar (radar), a monitoring device, a global positioning system and the like, so that the automatic driving of a motor vehicle can be realized without the active operation of human beings. Autonomous vehicles use various computing systems to assist in transporting passengers from one location to another. Some autonomous vehicles may require some initial input or continuous input from an operator, such as a pilot, driver, or passenger. Autonomous vehicles permit an operator to switch from a manual mode of operation to an autonomous mode or an intermediate mode. Because the automatic driving technology does not need human to drive the motor vehicle, the driving error of human can be effectively avoided theoretically, the occurrence of traffic accidents is reduced, and the transportation efficiency of the road can be improved. Therefore, the automatic driving technique is increasingly emphasized.

The radar can realize the functions of obstacle measurement, collision prediction, adaptive cruise control and the like in a vehicle-mounted environment, effectively reduces the driving difficulty and the accident rate, and is widely applied to the field of automobiles. The laser radar can perform ranging scanning on target objects in the surrounding environment to generate 3D point cloud, provides real-time data input for the automatic driving auxiliary system, has the characteristics of high space-time resolution, high sensitivity, strong anti-interference capability and the like, and is increasingly widely applied to the driving auxiliary system.

At present, a laser radar measures a distance between the laser radar and a target object through a flight time of an echo signal reflected by the target object, and therefore, a power of the echo signal reflected by the target object has a large influence on a measurement accuracy of the laser radar. In order to ensure the ranging accuracy of the laser radar, a signal processing circuit in the laser radar needs to work in a linear interval so as to avoid ranging errors caused by saturation or weak echo signals. Generally, the industry adjusts the gain of a Variable Gain Amplifier (VGA) according to a detection result by detecting the intensity of an echo signal, so that the amplitude of a signal to be processed by a signal processing circuit in a laser radar is kept within a certain range, and thus the signal processing circuit in the laser radar works in a linear range. However, if it is to be ensured that the gain adjustment of the VGA is completed when the echo signal reaches the laser radar, a long time delay is required for the echo signal, and the long time delay is difficult to implement in practical application.

Disclosure of Invention

The application provides a radar and a gain control method, which are used for realizing real-time adjustment of signal gain reflected by a target object received by the radar and improving the detection precision of the radar.

In a first aspect, the present application provides a radar including a transmitting module, a gain adjustment module, a gain control module, and a receiving module, wherein the gain control module is connected to the transmitting module and the gain adjustment module, respectively, and the gain adjustment module is further connected to the receiving module. The transmitting module is used for transmitting a first signal, and the first signal is used for detecting a target object; the receiving module is used for receiving a second signal and outputting the second signal to the gain adjusting module; wherein the second signal is a signal reflected by the first signal after encountering the target object; the gain control module is used for determining the gain at a first moment according to the first propagation time length and the corresponding relation between the signal gain and the propagation time length, and outputting the determined gain to the gain adjustment module; wherein the first propagation duration is a duration from a time when the transmission module transmits the first signal to the first time, and the first time is a time when the gain adjustment module receives the second signal; the gain adjusting module is configured to adjust the strength of the second signal according to the gain at the first time.

Through the above scheme, the gain control module in the radar can determine the gain of the time when the gain adjustment module receives the second signal according to the first propagation time from the time when the transmission module transmits the first signal to the time when the gain adjustment module receives the second signal and the corresponding relationship between the signal gain and the propagation time, so that the gain adjustment module can adjust the intensity of the second signal according to the gain of the time when the second signal is received, wherein the second signal is a signal reflected after the first signal meets a target object, that is, the gain control module can determine the gain of the time when the second signal is received in real time through the first propagation time and the corresponding relationship between the signal gain and the propagation time, and adjust the intensity of the second signal in real time through the gain adjustment module, compared with the prior art, the method is simple in implementation mode and good in real-time performance.

In one possible implementation, the gain control module includes a timing module and a gain determination module. The timing module is configured to determine the first propagation duration according to a time at which the first signal is transmitted and the first time; the gain determining module is configured to determine a gain at the first time according to the first propagation duration and the corresponding relationship, and transmit the determined gain to the gain adjusting module.

Further, the gain control module further comprises a reflectivity determination module. Wherein the transmitting module is further configured to: transmitting a third signal for detecting the target object; the receiving module is further configured to: receiving a fourth signal, and transmitting the fourth signal to the gain adjustment module, where the fourth signal is a signal of the third signal reflected by the target object; the timing module is further configured to: determining a second propagation time length according to the time of transmitting the third signal and a second time, wherein the second propagation time length is the time of receiving the fourth signal by the gain adjustment module; the reflectivity determining module is used for determining the reflectivity of the target object according to the adjusted second signal; the gain determination module is further to: determining the gain at the second moment according to the reflectivity of the target object, the second propagation time length and the corresponding relation, and transmitting the determined gain to the gain adjusting module; the gain adjustment module is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.

In the process of detecting the target object by the radar, the reflectivity of the target object has a large influence on the strength of the signal reflected by the target object, so that the gain control module determines the gain at the second moment according to the reflectivity of the target object, the first propagation time and the corresponding relationship between the signal gain and the propagation time, so that the accuracy of the determined gain can be improved, and the detection precision of the radar can be further improved.

In a possible implementation, the radar further includes a waveform detection module, which is respectively connected to the reflectivity determination module and the gain adjustment module. The waveform detection module is configured to detect an amplitude of the adjusted second signal; the reflectivity determination module is specifically configured to: and determining the reflectivity of the target object according to the adjusted amplitude of the second signal.

The waveform detection module may be a peak detection circuit.

In a possible implementation, the gain control module further comprises a weather estimation module. The weather estimation module is configured to determine weather information according to the adjusted second signal, where the weather information is used to characterize a current weather condition; the gain determination module is further to: and determining the gain at the second moment according to the reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length, and transmitting the determined gain to the gain adjusting module.

In a possible implementation manner, the gain determining module specifically determines the gain at the second time by any one of the following methods:

A. correcting the reflectivity of the target object according to the weather information; and determining the gain at the second moment according to the corrected reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length.

B. Determining a reference gain according to the reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.

Since the weather condition of the signal propagation path reflected by the target object also affects the intensity of the signal reflected by the target object and the determined reflectivity of the target object, the gain determining module corrects the reflectivity of the target object according to the weather information, and further corrects the determined gain at the second moment, or directly corrects the determined gain without considering weather factors according to the weather information, and adjusts the intensity of the fourth signal according to the corrected gain, so that the detection accuracy of the radar can be further improved.

In a possible embodiment, the radar further includes a waveform detection module, which is respectively connected to the reflectivity determination module, the weather estimation module, and the gain adjustment module. The waveform detection module is configured to detect an amplitude of the adjusted second signal and a waveform characteristic of the adjusted second signal; the reflectivity determination module is specifically configured to: determining the reflectivity of the target object according to the adjusted amplitude of the second signal; the weather estimation module is specifically configured to: and determining the weather information according to the adjusted waveform characteristics of the second signal.

In a possible implementation, the gain control module further comprises a weather estimation module. Wherein the transmitting module is further configured to: transmitting a third signal for detecting the target object; the receiving module is further configured to: receiving a fourth signal, and transmitting the fourth signal to the gain adjustment module, where the fourth signal is a signal of the third signal reflected by the target object; the timing module is further configured to: determining a second propagation time length according to the time of transmitting the third signal and a second time, wherein the second propagation time length is the time of receiving the fourth signal by the gain adjustment module; the weather estimation module is used for determining weather information according to the adjusted second signal, wherein the weather information is used for representing the current weather condition; the gain determination module is further to: determining the gain at the second moment according to the weather information, the second propagation time length and the corresponding relation, and transmitting the determined gain to the gain adjusting module; the gain adjustment module is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.

Because the weather condition on the signal propagation path reflected by the target object also affects the strength of the signal reflected by the target object, for example, in fog days, the signal reflected by the target object is scattered by particles suspended in the air, so that the strength of the signal reflected by the target object when the signal propagates to the radar is affected, and the detection precision of the radar is affected, therefore, the gain determination module determines the gain at the second moment according to the determined weather information, the second propagation time length and the corresponding relationship between the signal gain and the propagation time length, and considers the influence of weather factors on the gain of the fourth signal, so that the accuracy of the determined gain at the current moment can be improved, and the detection precision of the radar can be further improved.

In a possible implementation, the gain determining module specifically determines the gain at the second time instant by: determining a reference gain according to the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.

Since the weather condition on the signal propagation path reflected by the target object also affects the strength of the signal reflected by the target object, the gain determining module corrects the gain determined when the weather factor is not considered according to the determined weather information, and adjusts the strength of the fourth signal according to the corrected gain, so that the accuracy of the determined gain at the second moment can be improved, and the detection precision of the radar can be further improved.

In a possible embodiment, the gain adjustment module is a variable gain amplifier VGA, or a multi-stage amplifier.

In a second aspect, the present application provides a gain control method for radar. The method comprises the following steps: transmitting a first signal for detecting a target object; determining a gain at a first moment according to a first propagation time and a corresponding relation between a signal gain and the propagation time, wherein the first propagation time is a time from the moment of transmitting the first signal to the first moment, the first moment is the moment of receiving a second signal, and the second signal is a signal reflected by the first signal after encountering the target object; and when the second signal is received, adjusting the strength of the second signal according to the gain at the first moment.

By the method, the radar can determine the gain of the first moment when the second signal is received according to the first propagation time length from the moment when the first signal is transmitted to the moment when the second signal is received and the corresponding relation between the signal gain and the propagation time length, and adjust the strength of the second signal according to the determined gain when the second signal is received, wherein the second signal is the signal reflected by the first signal after encountering a target object, namely, the radar can determine the gain of the first moment in real time according to the first propagation time length and the corresponding relation between the signal gain and the propagation time length, and adjust the strength of the second signal in real time when the second signal is received.

In a possible implementation manner, after the radar adjusts the second signal according to the gain at the first time, the radar may further determine the reflectivity of the target object according to the adjusted second signal; and transmitting a third signal for detecting the target object; determining the gain at a second moment according to the reflectivity of the target object, the second propagation time length and the corresponding relation, and adjusting the intensity of the fourth signal according to the gain at the second moment; the second propagation time is a time when a fourth signal is received, the second time is a time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object.

In the process of detecting the target object by the radar, the influence of the reflectivity of the target object on the strength of the signal reflected by the target object is large, the strength of the signal reflected by the target object with the large reflectivity is large, and the strength of the signal reflected by the target object with the small reflectivity is small, so that the accuracy of the determined gain can be improved by determining the gain at the second moment by the radar according to the reflectivity of the target object, the determined second propagation time and the corresponding relation between the signal gain and the propagation time, and the detection precision of the radar can be further improved.

Further, the radar may specifically determine the reflectivity of the target object by: and the radar detects the amplitude of the adjusted second signal and determines the reflectivity of the target object according to the amplitude of the adjusted second signal. Specifically, the radar may estimate an amplitude of the received second signal (that is, an amplitude of the second signal after loss in a propagation path) according to the first propagation time and a corresponding relationship between the propagation time of the second signal and the amplitude of the second signal, and then determine the reflectivity of the target object according to the gain at the first time, the estimated amplitude of the second signal, and the detected amplitude of the second signal.

In a possible implementation manner, after the radar adjusts the second signal according to the gain at the first time, weather information may be determined according to the adjusted second signal, where the weather information is used to characterize a current weather condition; and determining the gain at the second moment according to the reflectivity of the target object, the weather information, the second propagation time and the corresponding relation between the signal gain and the propagation time.

Since the weather condition of the signal propagation path reflected by the target object may also affect the strength of the signal reflected by the target object, and further may affect the accuracy of the determined reflectivity of the target object, the radar determines the gain at the second time according to the reflectivity of the target object, the weather information, the second propagation time and the corresponding relationship between the signal gain and the propagation time, and thus the accuracy of the determined gain can be improved, and the detection accuracy of the radar can be further improved.

In one possible embodiment, the radar may determine the gain of the current time by, but not limited to, any one of the following two ways:

the method I is used for correcting the reflectivity of the target object according to the weather information; and determining the gain at the second moment according to the corrected reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length.

Mode II, determining a reference gain according to the reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.

Since the weather condition of the signal propagation path reflected by the target object may also affect the intensity of the signal reflected by the target object, and further may affect the accuracy of the determined reflectivity of the target object, the radar corrects the reflectivity of the target object according to the determined weather information, and further corrects the determined gain at the second time, or directly corrects the determined gain when the weather factor is not considered according to the determined weather information, and the intensity of the fourth signal is adjusted by the corrected gain, so that the detection accuracy of the radar can be further improved.

In a possible implementation manner, after the radar adjusts the second signal according to the gain at the first time, weather information may be determined according to the adjusted second signal, where the weather information represents a current weather condition; transmitting a third signal for detecting the target object; determining the gain at a second moment according to the weather information, the second propagation time and the corresponding relation, and adjusting the strength of the fourth signal according to the gain at the second moment; the second propagation time is a time when a fourth signal is received, the second time is a time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object.

In one possible embodiment, the radar may determine the gain at the second time by, but not limited to: determining a reference gain according to the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.

Because the weather condition on the signal propagation path reflected by the target object also affects the intensity of the signal reflected by the target object, for example, in fog days, the signal reflected by the target object is scattered by particles suspended in the air, so that the intensity of the signal reflected by the target object when the signal propagates to the radar is affected, and the detection accuracy of the radar is affected, therefore, the radar corrects the gain determined when the weather factor is not considered according to the determined weather information, and the detection accuracy of the radar can be further improved by adjusting the intensity of the fourth signal through the corrected gain.

Further, the radar may specifically determine the weather information by: the radar detects the waveform characteristics of the adjusted second signal, wherein the waveform characteristics of the second signal comprise the waveform shape, the steepness of a falling edge and the like of the second signal; and determining the current weather condition according to the adjusted waveform characteristics of the second signal. For example, when the falling edge of the second signal is relatively gentle and the tail is relatively long, the weather is a foggy day or a sand-dust day, in which there are significant scattering particles in the air.

In a third aspect, the present application further provides a computer storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are called by the computer, the computer is enabled to execute the method provided by any one of the possible implementation manners in the second aspect.

In a fourth aspect, the present application also provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the method provided by any one of the possible embodiments of the second aspect.

In a fifth aspect, the present application further provides a chip, where the chip is connected to a memory or includes the memory, and is configured to read and execute a software program stored in the memory, so as to implement the method provided in any one of the possible implementation manners in the second aspect.

Drawings

FIG. 1a is a schematic structural diagram of a laser radar augmented control device in the prior art;

FIG. 1b is a second schematic structural diagram of a laser radar gain control apparatus in the prior art;

FIG. 2 is a schematic structural diagram of a vehicle according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a radar according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a gain control module in a radar according to an embodiment of the present disclosure;

fig. 5 is a second schematic structural diagram of a gain control module in a radar according to an embodiment of the present disclosure;

fig. 6 is a second schematic structural diagram of a radar according to an embodiment of the present invention;

fig. 7 is a third schematic structural diagram of a gain control module in a radar according to an embodiment of the present disclosure;

fig. 8a is a schematic structural diagram of a gain adjustment module in a radar according to an embodiment of the present disclosure;

fig. 8b is a second schematic structural diagram of a gain adjustment module in a radar according to an embodiment of the present application;

fig. 9 is a third schematic structural diagram of a gain adjustment module in a radar according to an embodiment of the present disclosure;

fig. 10 is a third schematic structural diagram of a radar according to an embodiment of the present invention;

FIG. 11 is a fourth schematic structural diagram of a radar according to an embodiment of the present invention;

fig. 12 is a flowchart illustrating a gain control method according to an embodiment of the present application.

Detailed Description

The laser radar generally measures the distance between the laser radar and the target object by using the flight time of the echo signal reflected by the target object, and therefore, the power of the echo signal reflected by the target object has a large influence on the measurement accuracy of the laser radar. However, in order to meet the requirements of the automatic driving assistance system, the lidar generally needs to cover a detection range of several meters to hundreds of meters, and meanwhile, the reflectivity of the target object detected by the lidar varies greatly, so that the power fluctuation range of the echo signal reflected by the target object is large. In order to ensure the ranging accuracy of the laser radar, a signal processing circuit in the laser radar needs to work in a linear interval so as to avoid ranging errors caused by saturation or weak echo signals.

At present, the following two kinds of modes are mainly adopted in the industry, guarantee that the signal processing circuit work among the laser radar is in linear interval, and then guarantee laser radar's range finding precision:

first, the gain control device 111 shown in fig. 1a is used to adjust the amplitude of the signal to be processed by the signal processing circuit in the laser radar. The gain control device 110 includes a delay module 111, a gain set circuit 112, and a variable gain amplifier VGA 113. When the gain adjusting circuit 112 determines that the amplitude of the echo signal (i.e., the input signal) reflected by the target object is smaller, the gain of the VGA113 is increased, and when the gain adjusting circuit 112 determines that the amplitude of the input signal is larger, the gain of the VGA113 is decreased, so as to ensure that the signal output to a constant fraction timing (CFD) circuit by the gain control device 110 is maintained in a certain linear interval, thereby reducing the drift error of the CFD circuit. In order to ensure that the gain adjustment of the VGA113 is completed before the echo signal reflected by the target object arrives, the signal input into the VGA needs to be delayed by the delay module 111, so as to implement the real-time adjustment of the gain of the echo signal received by the laser radar.

However, in practical applications, in order to implement real-time adjustment of the gain of the echo signal received by the laser radar, the delay module 111 generally needs to delay for more than 20ns, which is difficult to implement. If the coaxial cable is adopted to realize the time delay of more than 20ns, the length of the coaxial cable is too long, and the volume and the convenience of the whole control device 110 are directly influenced. In addition, there is no chip that can achieve this long time delay.

In the second mode, the gain control device 120 shown in fig. 1b is used to adjust the amplitude of the signal to be processed by the signal processing circuit in the laser radar. The gain control device 120 includes a VGA121, a gain control module 122 and a peak detection module 123. The echo signal (i.e., the input signal) reflected by the target object directly enters the VGA121, and the VGA121 initially amplifies the echo signal reflected by the target object according to a preset initial gain. After the VGA121 preliminarily amplifies the echo signal reflected by the target object, the peak detection module 123 detects the amplitude of the signal output by the VGA121, and the gain control module 122 adjusts the gain setting of the VGA121 according to the detection result of the peak detection module 123, so that the VGA121 adjusts the echo signal reflected by the target object according to the adjusted gain in the next period of the echo signal reflected by the target object.

The method has a relatively simple structure and is easy to implement, but can only be applied to the next period of the echo signal reflected by the target object, and the echo signal reflected by the target object is adjusted according to the adjusted gain, so that the real-time performance is poor.

In order to solve the above problems in the prior art, the present application provides a radar and a gain control method, so as to implement real-time adjustment of signal gain reflected by a target object received by the radar, and improve detection accuracy of the radar. In the embodiment of the application, the gain control mode of the radar is mainly improved, and the radar can be a radar with large influence on target detection precision by the amplitude of received signals such as laser radar. However, it should be understood that the radar provided in the embodiments of the present application is a complete radar, and has a structure of a known radar, and only components related to gain control in the radar are described herein, and details of other components are not described herein.

In addition, it is to be understood that the terms first, second, etc. in the description of the present application are used for distinguishing between the descriptions and not necessarily for describing a sequential or chronological order.

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

Fig. 2 is a functional block diagram of a vehicle 200 with an automatic driving function according to an embodiment of the present application. In one embodiment, the vehicle 200 is configured in a fully or partially autonomous driving mode. For example, the vehicle 200 may control itself while in the autonomous driving mode, and may determine a current state of the vehicle and its surroundings by human operation, determine a possible behavior of at least one other vehicle in the surroundings, and determine a confidence level corresponding to a likelihood that the other vehicle performs the possible behavior, controlling the vehicle 200 based on the determined information. When the vehicle 200 is in the autonomous driving mode, the vehicle 200 may be placed into operation without human interaction.

The vehicle 200 may include various subsystems such as a travel system 202, a sensing system 204, a control system 206, one or more peripherals 208, as well as a power source 210, a computer system 212, and a user interface 216. Alternatively, vehicle 200 may include more or fewer subsystems, and each subsystem may include multiple elements. In addition, each of the sub-systems and elements of the vehicle 200 may be interconnected by wire or wirelessly.

The travel system 202 may include components that provide powered motion to the vehicle 200. In one embodiment, the travel system 202 may include an engine 218, an energy source 219, a transmission 220, and wheels/tires 221. The engine 218 may be an internal combustion engine, an electric motor, an air compression engine, or other type of engine combination, such as a hybrid engine of a gasoline engine and an electric motor, or a hybrid engine of an internal combustion engine and an air compression engine. The engine 218 converts the energy source 219 into mechanical energy.

Examples of energy sources 219 include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, solar panels, batteries, and other sources of electrical power. The energy source 219 may also provide energy to other systems of the vehicle 100.

The transmission 220 may transmit mechanical power from the engine 218 to the wheels 221. The transmission 220 may include a gearbox, a differential, and a drive shaft. In one embodiment, the transmission 220 may also include other devices, such as a clutch. Wherein the drive shaft may comprise one or more shafts that may be coupled to one or more wheels 221.

The sensing system 204 may include a number of sensors that sense information about the environment surrounding the vehicle 200. For example, the sensing system 204 may include a positioning system 222 (which may be a Global Positioning System (GPS) system, a Beidou system, or other positioning system), an Inertial Measurement Unit (IMU) 224, a radar 226, a laser range finder 228, and a camera 230. The sensing system 204 may also include sensors of internal systems of the monitored vehicle 200 (e.g., an in-vehicle air quality monitor, a fuel gauge, an oil temperature gauge, etc.). Sensor data from one or more of these sensors may be used to detect the object and its corresponding characteristics (position, shape, orientation, velocity, etc.). Such detection and identification is a critical function of the safe operation of the autonomous vehicle 100.

The positioning system 222 may be used to estimate the geographic location of the vehicle 200. The IMU 224 is used to sense position and orientation changes of the vehicle 200 based on inertial acceleration. In one embodiment, the IMU 224 may be a combination of an accelerometer and a gyroscope.

The radar 226 may utilize radio signals to sense objects within the surrounding environment of the vehicle 200. In some embodiments, in addition to sensing objects, radar 226 may also be used to sense the speed and/or heading of an object.

The laser rangefinder 228 may utilize laser light to sense objects in the environment in which the vehicle 100 is located. In some embodiments, laser rangefinder 228 may include one or more laser sources, laser scanners, and one or more detectors, among other system components.

The camera 230 may be used to capture multiple images of the surrounding environment of the vehicle 200. The camera 230 may be a still camera or a video camera.

The control system 206 is for controlling the operation of the vehicle 200 and its components. The control system 206 may include various elements including a steering system 232, a throttle 234, a braking unit 236, a sensor fusion algorithm 238, a computer vision system 240, a route control system 242, and an obstacle avoidance system 244.

The steering system 232 is operable to adjust the heading of the vehicle 200. For example, in one embodiment, a steering wheel system.

The throttle 234 is used to control the operating speed of the engine 218 and thus the speed of the vehicle 200.

The brake unit 236 is used to control the vehicle 200 to decelerate. The brake unit 236 may use friction to slow the wheel 221. In other embodiments, the brake unit 236 may convert the kinetic energy of the wheel 221 into an electrical current. The brake unit 236 may take other forms to slow the rotational speed of the wheel 221 to control the speed of the vehicle 200.

The computer vision system 240 may be operable to process and analyze images captured by the camera 230 in order to identify objects and/or features in the environment surrounding the vehicle 200. The objects and/or features may include traffic signals, road boundaries, and obstacles. The computer vision system 240 may use object recognition algorithms, motion from motion (SFM) algorithms, video tracking, and other computer vision techniques. In some embodiments, the computer vision system 240 may be used to map an environment, track objects, estimate the speed of objects, and so forth.

The route control system 242 is used to determine a travel route of the vehicle 200. In some embodiments, the route control system 142 may combine data from the sensors 238, the GPS 222, and one or more predetermined maps to determine a travel route for the vehicle 200.

The obstacle avoidance system 244 is used to identify, assess, and avoid or otherwise negotiate potential obstacles in the environment of the vehicle 200.

Of course, in one example, the control system 206 may additionally or alternatively include components other than those shown and described. Or may reduce some of the components shown above.

The vehicle 200 interacts with external sensors, other vehicles, other computer systems, or users through peripherals 208. Peripheral devices 208 may include a wireless communication system 246, an in-vehicle computer 248, a microphone 250, and/or a speaker 252.

In some embodiments, the peripheral device 208 provides a means for a user of the vehicle 200 to interact with the user interface 216. For example, the onboard computer 248 may provide information to a user of the vehicle 200. The user interface 216 may also operate the in-vehicle computer 248 to receive user input. The in-vehicle computer 248 can be operated through a touch screen. In other cases, the peripheral device 208 may provide a means for the vehicle 200 to communicate with other devices located within the vehicle. For example, the microphone 250 may receive audio (e.g., voice commands or other audio input) from a user of the vehicle 200. Similarly, the speaker 252 may output audio to a user of the vehicle 200.

The wireless communication system 246 may communicate wirelessly with one or more devices, either directly or via a communication network. For example, the wireless communication system 246 may use 3G cellular communication such as Code Division Multiple Access (CDMA), EVD0, global system for mobile communications (GSM)/General Packet Radio Service (GPRS), or 4G cellular communication such as Long Term Evolution (LTE), or 5G cellular communication. The wireless communication system 246 may communicate with a Wireless Local Area Network (WLAN) using WiFi. In some embodiments, the wireless communication system 246 may communicate directly with the device using an infrared link, bluetooth, or ZigBee. Other wireless protocols, such as various vehicular communication systems, for example, the wireless communication system 246 may include one or more Dedicated Short Range Communications (DSRC) devices that may include public and/or private data communications between vehicles and/or roadside stations.

The power supply 210 may provide power to various components of the vehicle 200. In one embodiment, power source 210 may be a rechargeable lithium ion or lead acid battery. One or more battery packs of such batteries may be configured as a power source to provide power to various components of the vehicle 200. In some embodiments, the power source 210 and the energy source 219 may be implemented together, such as in some all-electric vehicles.

Some or all of the functions of the vehicle 200 are controlled by the computer system 212. The computer system 212 may include at least one processor 213, the processor 213 executing instructions 215 stored in a non-transitory computer readable medium, such as the memory 214. The computer system 212 may also be a plurality of computing devices that control individual components or subsystems of the vehicle 200 in a distributed manner.

The processor 213 may be any conventional processor, such as a commercially available Central Processing Unit (CPU). Alternatively, the processor may be a dedicated device such as an Application Specific Integrated Circuit (ASIC) or other hardware-based processor. Although fig. 2 functionally illustrates a processor, memory, and other elements of the computer 210 in the same block, those skilled in the art will appreciate that the processor, computer, or memory may actually comprise multiple processors, computers, or memories that may or may not be stored within the same physical housing. For example, the memory may be a hard drive or other storage medium located in a different enclosure than the computer 210. Thus, references to a processor or computer are to be understood as including references to a collection of processors or computers or memories which may or may not operate in parallel. Rather than using a single processor to perform the steps described herein, some components, such as the steering component and the retarding component, may each have their own processor that performs only computations related to the component-specific functions.

In various aspects described herein, the processor may be located remotely from the vehicle and in wireless communication with the vehicle. In other aspects, some of the processes described herein are executed on a processor disposed within the vehicle and others are executed by a remote processor, including taking the steps necessary to perform a single maneuver.

In some embodiments, the memory 214 may contain instructions 215 (e.g., program logic), which instructions 215 may be executed by the processor 213 to perform various functions of the vehicle 200, including those described above. The memory 214 may also contain additional instructions, including instructions to send data to, receive data from, interact with, and/or control one or more of the travel system 202, the sensing system 204, the control system 206, and the peripheral devices 208.

In addition to instructions 215, memory 214 may also store data such as road maps, route information, the location, direction, speed of the vehicle, and other such vehicle data, among other information. Such information may be used by the vehicle 200 and the computer system 212 during operation of the vehicle 200 in autonomous, semi-autonomous, and/or manual modes.

A user interface 216 for providing information to or receiving information from a user of the vehicle 200. Optionally, the user interface 216 may include one or more input/output devices within the collection of peripheral devices 208, such as a wireless communication system 246, a car-to-car computer 248, a microphone 250, and a speaker 252.

The computer system 212 may control the functions of the vehicle 200 based on inputs received from various subsystems (e.g., the travel system 202, the sensing system 204, and the control system 206) and from the user interface 216. For example, the computer system 212 may utilize input from the control system 206 to control the steering unit 232 to avoid obstacles detected by the sensing system 204 and the obstacle avoidance system 244. In some embodiments, the computer system 212 is operable to provide control over many aspects of the vehicle 200 and its subsystems.

Alternatively, one or more of these components described above may be mounted or associated separately from the vehicle 200. For example, the memory 214 may exist partially or completely separate from the vehicle 200. The above components may be communicatively coupled together in a wired and/or wireless manner.

Optionally, the above components are only an example, in an actual application, components in the above modules may be added or deleted according to an actual need, and fig. 2 should not be construed as limiting the embodiment of the present application.

An autonomous automobile traveling on a roadway, such as vehicle 200 above, may identify objects within its surrounding environment to determine an adjustment to the current speed. The object may be another vehicle, a traffic control device, or another type of object. In some examples, each identified object may be considered independently, and based on the respective characteristics of the object, such as its current speed, acceleration, separation from the vehicle, etc., may be used to determine the speed at which the autonomous vehicle is to be adjusted.

Optionally, the autonomous automobile vehicle 200 or a computing device associated with the autonomous vehicle 200 (e.g., computer system 212, computer vision system 240, memory 214 of fig. 2) may predict behavior of the identified objects based on characteristics of the identified objects and the state of the surrounding environment (e.g., traffic, rain, ice on the road, etc.). Optionally, each identified object depends on the behavior of each other, so it is also possible to predict the behavior of a single identified object taking all identified objects together into account. The vehicle 200 is able to adjust its speed based on the predicted behaviour of said identified object. In other words, the autonomous vehicle is able to determine what steady state the vehicle will need to adjust to (e.g., accelerate, decelerate, or stop) based on the predicted behavior of the object. In this process, other factors may also be considered to determine the speed of the vehicle 200, such as the lateral position of the vehicle 200 in the road on which it is traveling, the curvature of the road, the proximity of static and dynamic objects, and so forth.

In addition to providing instructions to adjust the speed of the autonomous vehicle, the computing device may also provide instructions to modify the steering angle of the vehicle 200 to cause the autonomous vehicle to follow a given trajectory and/or maintain a safe lateral and longitudinal distance from objects in the vicinity of the autonomous vehicle (e.g., cars in adjacent lanes on the road).

The vehicle 200 may be a car, a truck, a motorcycle, a bus, a boat, an airplane, a helicopter, a lawn mower, an amusement car, a playground vehicle, construction equipment, a trolley, a golf cart, a train, a trolley, etc., and the embodiment of the present invention is not particularly limited.

As shown in fig. 3, the present application provides a radar 300, which radar 300 may be used in a vehicle 200 as shown in fig. 2. Specifically, the radar 300 includes: the wireless communication device comprises a transmitting module 310, a receiving module 320, a gain control module 330 and a gain adjusting module 340, wherein the gain control module 330 is respectively connected with the transmitting module 310 and the gain adjusting module 340, and the gain adjusting module 340 is further connected with the receiving module 320. Wherein the content of the first and second substances,

the transmitting module 310 is configured to transmit a first signal, where the first signal is used to detect a target object.

The receiving module 320 is configured to receive a second signal and output the second signal to the gain adjusting module 340; the second signal is a signal reflected by the first signal after encountering the target object, that is, the second signal is an echo signal.

The gain control module 330 is configured to determine a gain at a first time according to the first propagation duration and the corresponding relationship between the signal gain and the propagation duration, and transmit the determined gain to the gain adjustment module 340; the first propagation duration is a duration from a time when the transmitting module 310 transmits the first signal to the first time, and the first time is a time when the gain adjusting module 340 receives the second signal.

The gain adjustment module 340 is configured to adjust the strength of the second signal according to the gain at the first time. Specifically, the gain adjustment module 340 may adjust the second signal amplitude or power according to the gain at the current time. The initial value of the gain may be pre-configured in the gain adjustment module 340 as the gain in the initial state (i.e., when the radar 300 is just started).

When implemented in hardware, in the embodiment of the present application, the transmitting module 310 and the receiving module 320 may be a transceiver circuit, etc., the gain control module 330 may be a processor or a controller, and the gain adjusting module 340 may be a gain-adjustable power amplifier circuit.

In a specific implementation, the gain control module 330 may determine, at each time within the first propagation duration, the gain at each time according to the propagation duration corresponding to each time and the corresponding relationship between the signal gain and the propagation duration, so that when the gain adjustment module 340 receives the second signal, the strength of the second signal may be adjusted according to the gain at the current time, so as to implement real-time adjustment of the radar gain.

Specifically, as shown in fig. 4, the gain control module 330 may include a timing module 331 and a gain determination module 332. The timing module 331 is configured to determine the first propagation duration according to a time when the first signal is transmitted and the first time; the gain determining module 332 is configured to determine the gain at the first time according to the first propagation time and the corresponding relationship between the signal gain and the propagation time, and transmit the determined gain to the gain adjusting module 340. In a specific implementation, the timing module 331 may be implemented by a timer, and the gain determination module 332 may be implemented by a processor, for example, a micro processor unit (MCU) or a Central Processing Unit (CPU).

Further, the weather condition of the signal propagation path reflected by the target object may also affect the strength of the second signal, for example, in a fog day, the signal reflected by the target object may be scattered by particles suspended in the air, and then the strength of the signal reflected by the target object when the signal propagates to the radar 300 may be affected, and further the detection accuracy of the radar 300 may be affected, and therefore, in order to further improve the detection accuracy of the radar 300, the gain control module 330 may further include a weather estimation module 333 in addition to the timing module 331 and the gain determination module 332, as shown in fig. 5.

At this time, the transmitting module 310 is further configured to: transmitting a third signal for detecting the target object; the receiving module 320 is further configured to: receiving a fourth signal and transmitting the fourth signal to the gain adjustment module; wherein the fourth signal is a signal of the third signal after being reflected by the target object; the timing module 331 is further configured to: determining a second propagation duration according to the time of transmitting the third signal and a second time; wherein the second propagation duration is a time when the fourth signal is received by the gain adjustment module 340; the weather estimation module 333 is configured to determine weather information according to the adjusted second signal, where the weather information is used to characterize a current weather condition; the gain determination module 332 is further configured to: determining the gain at the second moment according to the weather information, the second propagation duration and the corresponding relationship, and transmitting the determined gain to the gain adjustment module 340; the gain adjustment module 340 is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.

Wherein the gain determination module 332 may determine the gain at the second time by, but not limited to: determining a reference gain according to the determined propagation duration and the corresponding relationship between the gain of the second signal and the propagation duration; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the current moment.

The gain determining module 332 corrects the determined reference gain according to the determined weather information, and determines the corrected reference gain as the gain at the second time, that is, the gain determining module 332 may determine the gain at the current time (the second time) by using the reflectivity of the target object determined by the signal (the second signal) received at the previous time, so that the accuracy of the determined gain at the current time can be improved, and the detection accuracy of the radar 300 can be further improved.

It should be noted that, the timing of transmitting the third signal by the transmitting module 310 is not limited in this application, and the timing of transmitting the third signal by the reflectivity determining module 334 may be applicable to this application, where the timing can satisfy the condition that the reflectivity of the target object can be determined by the reflectivity determining module 334 when the gain adjusting module 340 receives the fourth signal. For example, the transmitting module 310 transmits the third signal after the receiving module 320 or the gain adjusting module 340 receives the second signal.

Further, as shown in fig. 6, the radar 300 further includes a waveform detection module 350, which is respectively connected to the gain control module 330 and the gain adjustment module 340. The waveform detection module 350 is configured to detect a waveform characteristic of the adjusted second signal, where the waveform characteristic of the second signal includes a waveform shape of the second signal, a steepness of a falling edge, and the like; when determining the weather information according to the adjusted second signal, the weather estimation module 333 is specifically configured to: and determining the weather information according to the adjusted waveform characteristics of the second signal. For example, when the falling edge of the second signal is relatively gentle and the tail is relatively long, the weather is a foggy day or a sand-dust day, in which there are significant scattering particles in the air.

In addition, in the process of detecting the target object by the radar, the reflectivity of the target object has a large influence on the intensity of the signal reflected by the target object, the intensity of the signal reflected by the target object with a large reflectivity is large, and the intensity of the signal reflected by the target object with a small reflectivity is small, so as to further improve the detection accuracy of the radar 300, as shown in fig. 7, the gain control module 330 may further include a reflectivity determination module 334 in addition to the timing module 331 and the gain determination module 332.

At this time, the transmitting module 310 is further configured to: transmitting a third signal for detecting the target object; the receiving module 320 is further configured to: receiving a fourth signal and transmitting the fourth signal to the gain adjustment module; wherein the fourth signal is a signal of the third signal after being reflected by the target object; the timing module 331 is further configured to: determining a second propagation duration according to the time of transmitting the third signal and a second time; wherein the second propagation duration is a time when the gain adjustment module receives the fourth signal; the reflectivity determining module 334 is configured to determine the reflectivity of the target object according to the adjusted second signal; the gain determination module 332 is further configured to: determining the gain at the second moment according to the reflectivity of the target object, the second propagation duration and the corresponding relationship, and transmitting the determined gain to the gain adjustment module 340; the gain adjustment module 340 is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.

It should be noted that, the timing for transmitting the third signal by the transmitting module 310 is not limited in this application, and the transmitting timing for determining the reflectivity of the target object and the weather information by the reflectivity determining module 334 may be applicable to this application whenever the condition that the fourth signal is received by the gain adjusting module 340 is satisfied. For example, the transmitting module 310 transmits the third signal after the receiving module 320 or the gain adjusting module 340 receives the second signal.

Further, the waveform detection module 350 may be further configured to: detecting the amplitude of the adjusted second signal; the reflectivity determination module 334 is specifically configured to: and determining the reflectivity of the target object according to the adjusted amplitude of the second signal. The waveform detection module 350 may be implemented by a peak detection circuit.

Specifically, the reflectivity determining module 334 may estimate the amplitude of the second signal received by the receiving module 320 (i.e., the amplitude of the second signal after the second signal is lost on the propagation path) according to the first propagation time and the corresponding relationship between the propagation time and the amplitude of the second signal, and then determine the reflectivity of the target object according to the gain at the first time, the estimated amplitude of the second signal, and the amplitude of the second signal detected by the waveform detecting module 350.

Further, since the weather condition of the second signal propagation path reflected by the target object may also affect the strength of the second signal, and further may also affect the accuracy of the determined reflectivity of the target object, in order to further improve the detection accuracy of the radar 300, the gain control module 330 further includes a weather estimation module 333 in addition to the timing module 331, the gain determination module 332 and the reflectivity determination module 334, where the weather estimation module 333 is configured to determine weather information according to the adjusted second signal, and the weather information is used to characterize the current weather condition; the gain determination module 332 is further configured to: and determining the gain at the second moment according to the reflectivity of the target object, the weather information, the second propagation time and the corresponding relation between the signal gain and the propagation time.

At this time, the waveform detection module 350 is respectively connected to the reflectivity determination module 334, the weather estimation module 333, the gain determination module and the gain adjustment module, and the waveform detection module 350 is further configured to detect a waveform characteristic of the adjusted second signal in addition to the amplitude of the adjusted second signal, so that the gain control module 330 determines the weather information according to the waveform characteristic of the adjusted second signal, where the waveform characteristic of the second signal includes a waveform shape of the second signal, a steepness of a falling edge, and the like.

The gain determining module 332 may determine the gain at the second time by, but not limited to, any of the following two ways:

the method A is characterized in that the reflectivity of the target object is corrected according to the weather information; and determining the gain at the second moment according to the corrected reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length.

The gain determining module 332 corrects the reflectivity of the target object according to the current weather condition, and then determines the gain at the second time according to the second propagation duration and the corrected reflectivity of the target object, so that the accuracy of the determined gain can be improved, and the purpose of improving the detection accuracy of the radar 300 can be achieved.

Determining a reference gain according to the reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the current moment.

The gain determination module 332 corrects the determined reference gain according to the current weather condition, so that the accuracy of the determined gain can be improved, and the purpose of improving the detection precision of the radar 300 can be achieved.

In a specific implementation, the gain adjustment module 340 may be implemented by a variable gain amplifier VGA, where the VGA may be an analog control VGA, that is, the gain control module 330 controls the analog control VGA by a first control signal, and the first control signal is an analog signal for controlling the gain of the analog control VGA, as shown in fig. 8 a; the VGA may also be a digital control VGA, that is, the gain control module 330 controls the digital control VGA through a second control signal, where the second control signal is a digital signal for controlling the gain of the digital control VGA, as shown in fig. 8 b.

Alternatively, the gain adjustment module 340 may be implemented by a multi-stage amplifier, as shown in fig. 9. The gain control module 330 may control the gain of each amplifier in the multiple stages of amplifiers through a control signal, so that the gain of the multiple stages of amplifiers is the gain of the current time determined by the gain control module 330, for example, the control signal may control the gain of each amplifier in the multiple stages of amplifiers simultaneously in a coding manner; the gain control module 330 may control the gain of each of the plurality of amplifiers by a plurality of control signals, respectively.

It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation. The functional modules in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit. For example, the weather estimation module 333 may be integrated with the waveform detection module 350 into a physical unit, and the physical unit may detect the waveform characteristics of the adjusted second signal, determine the current weather condition according to the waveform characteristics of the adjusted second signal, and output the determined weather condition to the gain determination module 332; the reflectivity determination module 334 may be integrated with the waveform detection module 350 into a physical unit, which may detect the adjusted amplitude of the second signal, determine the reflectivity of the target object according to the adjusted amplitude of the second signal, and output the determined reflectivity to the gain determination module 332; alternatively, the weather estimation module 333 and the reflectivity determination module 334 are integrated with the waveform detection module 350 in a physical unit, which can detect the waveform characteristics of the adjusted second signal, determine the current weather condition according to the waveform characteristics of the adjusted second signal, detect the amplitude of the adjusted second signal, determine the reflectivity of the target object according to the amplitude of the adjusted second signal, and output the determined weather condition and reflectivity to the gain determination module 332.

In practical applications, the radar 300 may include a plurality of receiving modules 320 and a plurality of gain adjustment modules 340, wherein the plurality of receiving modules 320 and the plurality of gain adjustment modules 340 are in one-to-one correspondence, and the plurality of receiving modules 320 and the plurality of gain adjustment modules 340 are configured to simultaneously transmit a plurality of (e.g., 2, 8, 16, 32, or 64, etc.) signals and process a plurality of reflected echo signals to improve the detection range and the detection accuracy of the radar 300. That is, the radar 300 includes at least one transmitting module 310, at least one receiving module 320, at least one gain control module 330, and at least one gain adjustment module 340, wherein each gain control module 330 controls one or more gain adjustment modules 340, and the at least one receiving module 320 and the at least one gain adjustment module 340 are in one-to-one correspondence. When one gain control module 330 controls a plurality of gain adjustment modules 340, the gain control module 330 needs to determine gains of the plurality of gain adjustment modules 340 at the current time in parallel.

Further, the radar 300 may also include one or more waveform detection modules 350. When the radar 300 includes one waveform detection module 350, the waveform detection module 350 needs to detect the second signal fed back by each of the plurality of receiving modules 310 through the corresponding gain adjustment module 340 in parallel.

For example, as shown in fig. 10, the radar 300 includes a transmitting module 310, a plurality of receiving modules 320, a gain control module 330, a plurality of gain adjustment modules 340, and an environment monitoring module 350; as another example, as shown in fig. 11, the radar 300 includes a transmitting module 310, a plurality of receiving modules 320, a plurality of gain control modules 330, and a plurality of gain adjustment modules 340, wherein one gain control module 330 controls one gain adjustment module group (as shown by the dashed line box in fig. 11), and each gain adjustment module group includes one or more gain adjustment modules 340.

With the above solution, the gain control module 330 in the radar 300 can determine the gain at the time when the gain adjustment module 340 receives the second signal according to the first propagation time from the time when the transmission module 310 transmits the first signal to the time when the gain adjustment module 340 receives the second signal and the corresponding relationship between the signal gain and the propagation time, and transmit the determined gain to the gain adjustment module 340, so that the gain adjustment module 340 can adjust the strength of the second signal according to the gain at the time when the gain adjustment module 340 receives the second signal, where the second signal is a signal reflected after the first signal encounters a target object, that is, the gain control module 330 can determine the gain at the time when the second signal is received in real time according to the first propagation time and the corresponding relationship between the signal gain and the propagation time, and the strength of the second signal is adjusted in real time through the gain adjustment module 340, compared with the prior art, the implementation manner is simple, and the real-time performance is better.

The application also provides a gain control method which is applied to the radar so as to improve the real-time performance of signal gain adjustment in the radar detection process. As shown in fig. 12, the gain control method specifically includes the following steps:

s1201: a first signal for detecting a target object is transmitted.

S1202: and determining the gain at the first moment according to the first propagation time length and the corresponding relation between the signal gain and the propagation time length.

The first propagation duration is a duration from a time when the first signal is transmitted to the first time, the first time is a time when a second signal is received, and the second signal is a signal reflected by the first signal after encountering the target object.

S1203: and when the second signal is received, adjusting the strength of the second signal according to the gain at the first moment.

In a specific implementation, the radar may determine, at each time within the first propagation duration, the gain at each time according to the propagation duration corresponding to each time and the corresponding relationship between the signal gain and the propagation duration, so that when the radar receives the second signal, the radar may adjust the intensity of the second signal according to the gain at the current time, thereby implementing real-time adjustment of the radar gain.

Further, after the radar adjusts the second signal, weather information may be determined according to the adjusted second signal, where the weather information is used to represent a current weather condition. At this time, the radar also transmits a third signal for detecting the target object, determines a gain at a second moment according to the weather information, a second propagation time and the corresponding relationship between the signal gain and the propagation time, and adjusts the intensity of the fourth signal according to the gain at the second moment; the second propagation time is a time when a fourth signal is received, the second time is a time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object.

Wherein the radar may determine the gain at the second time instance by, but not limited to: determining a reference gain according to the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.

Because the weather condition on the second signal propagation path reflected by the target object may also affect the intensity of the signal reflected by the target object, for example, in fog days, the fourth signal may be scattered by particles suspended in the air, and then the intensity of the fourth signal when the fourth signal propagates to the radar is affected, and then the detection accuracy of the radar is affected, therefore, the radar corrects the gain determined when the weather factor is not considered according to the weather condition at the current time, and adjusts the intensity of the fourth signal through the corrected gain, that is, determines the gain at the current time (the second time) by using the weather information determined by the signal (the second signal) received at the previous time, and can further improve the detection accuracy of the radar.

Further, after the radar adjusts the second signal, the reflectivity of the target object may be determined according to the adjusted second signal. At this time, the radar also transmits a third signal for detecting the target object, determines a gain at a second moment according to the reflectivity of the target object, a second propagation time and the corresponding relationship between the signal gain and the propagation time, and adjusts the intensity of the fourth signal according to the gain at the second moment; the second propagation time is a time when a fourth signal is received, the second time is a time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object.

In the process of detecting the target object by the radar, the influence of the reflectivity of the target object on the strength of the signal reflected by the target object is large, the strength of the signal reflected by the target object with the large reflectivity is large, and the strength of the signal reflected by the target object with the small reflectivity is small, so that the accuracy of the determined gain can be improved by determining the gain at the second moment by the radar according to the reflectivity of the target object, the second propagation time and the corresponding relation between the signal gain and the propagation time, and the detection precision of the radar can be further improved.

Wherein the radar is specifically operable to determine the reflectivity of the target object by: and the radar detects the amplitude of the adjusted second signal and determines the reflectivity of the target object according to the amplitude of the adjusted second signal. Specifically, the radar may estimate an amplitude of the received second signal (that is, an amplitude of the second signal after loss on the propagation path) according to the propagation duration and the corresponding relationship between the propagation duration of the second signal and the amplitude of the second signal, and then determine the reflectivity of the target object according to the gain at the first time, the estimated amplitude of the second signal, and the detected amplitude of the second signal.

Further, after the radar adjusts the intensity of the second signal, the weather information may be determined according to the adjusted second signal; and determining the gain at the second moment according to the reflectivity of the target object, the weather information, the second propagation time and the corresponding relation between the signal gain and the propagation time, and adjusting the strength of the fourth signal according to the gain at the second moment.

Wherein the radar may determine the gain at the second time by, but not limited to, any of the following two ways:

Mode II, determining a reference gain according to the reflectivity of the target object, the second propagation time length and the corresponding relation between the signal gain and the propagation time length; and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the current moment.

Since the weather condition of the signal propagation path reflected by the target object may also affect the intensity of the signal reflected by the target object and the determined reflectivity of the target object, the radar corrects the reflectivity of the target object according to the determined weather information, and further corrects the gain at the second time, or directly corrects the gain determined when the weather factor is not considered according to the weather information, and adjusts the intensity of the fourth signal through the corrected gain, that is, determines the gain at the current time (the second time) by using the weather information determined by the signal (the second signal) received at the previous time and the reflectivity of the target object, so as to further improve the detection accuracy of the radar.

By the method, the radar can determine the gain at a first moment according to a first propagation time length and the corresponding relation between the signal gain and the propagation time length, and adjust the intensity of a second signal according to the determined gain when the first signal is received and meets the second signal reflected by a target object, wherein the first propagation time length is the time length from the moment of transmitting the first signal to the first moment, and the first moment is the moment of receiving the second signal, that is, the radar can determine the gain at the moment of receiving the signal reflected by the target object in real time and adjust the intensity of the signal reflected by the target object in real time according to the first propagation time length and the corresponding relation between the signal gain and the propagation time length.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Claims

A radar, comprising: the device comprises a transmitting module, a gain adjusting module, a gain control module and a receiving module; the gain control module is respectively connected with the transmitting module and the gain adjusting module, and the gain adjusting module is also connected with the receiving module;

the transmitting module is used for transmitting a first signal, and the first signal is used for detecting a target object;

the receiving module is used for receiving a second signal and outputting the second signal to the gain adjusting module; the second signal is a signal obtained by reflecting the first signal by the target object;

the gain control module is used for determining the gain at a first moment according to the first propagation time length and the corresponding relation between the signal gain and the propagation time length, and outputting the determined gain to the gain adjustment module; wherein the first propagation duration is a duration from a time when the transmission module transmits the first signal to the first time, and the first time is a time when the gain adjustment module receives the second signal;

the gain adjusting module is configured to adjust the strength of the second signal according to the gain at the first time.
The radar of claim 1, wherein the gain control module includes a timing module and a gain determination module;

the timing module is configured to determine the first propagation duration according to the time at which the first signal is transmitted and the first time;

the gain determining module is configured to determine a gain at the first time according to the first propagation duration and the corresponding relationship, and transmit the determined gain to the gain adjusting module.
The radar of claim 2, wherein the gain control module further comprises: a reflectivity determination module, wherein:

the transmitting module is further configured to: transmitting a third signal for detecting the target object;

the receiving module is further configured to: receiving a fourth signal and transmitting the fourth signal to the gain adjustment module; wherein the fourth signal is a signal of the third signal after being reflected by the target object;

the timing module is further configured to: determining a second propagation duration according to the time of transmitting the third signal and a second time; wherein the second propagation duration is a time when the gain adjustment module receives the fourth signal;

the reflectivity determining module is used for determining the reflectivity of the target object according to the adjusted second signal;

the gain determination module is further to: determining the gain at the second moment according to the reflectivity of the target object, the second propagation time length and the corresponding relation, and transmitting the determined gain to the gain adjusting module;

the gain adjustment module is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.
The radar of claim 3, further comprising a waveform detection module respectively coupled to the reflectivity determination module and the gain adjustment module, wherein:

the waveform detection module is used for detecting the amplitude of the adjusted second signal;

the reflectivity determination module is specifically configured to: and determining the reflectivity of the target object according to the adjusted amplitude of the second signal.
The radar of claim 4 wherein said waveform detection module is a peak detection circuit.
The radar of claim 3, wherein the gain control module further comprises a weather estimation module;

the weather estimation module is used for determining weather information according to the adjusted second signal, wherein the weather information is used for representing the current weather condition;

the gain determination module is further to: and determining the gain at the second moment according to the reflectivity of the target object, the second propagation time length and the corresponding relation, and transmitting the determined gain to the gain adjusting module.
The radar of claim 6, wherein the gain determination module is specifically configured to:

correcting the reflectivity of the target object according to the weather information;

and determining the gain at the second moment according to the corrected reflectivity of the target object, the second propagation time and the corresponding relation.
The radar of claim 6, wherein the gain determination module is specifically configured to:

determining a reference gain according to the reflectivity of the target object, the second propagation time length and the corresponding relation;

and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.
The radar of any one of claims 6-8, further comprising a waveform detection module respectively coupled to the reflectivity determination module, the weather estimation module, and the gain adjustment module;

the waveform detection module is used for detecting the amplitude of the adjusted second signal and the waveform characteristic of the adjusted second signal;

the reflectivity determination module is specifically configured to: determining the reflectivity of the target object according to the adjusted amplitude of the second signal;

the weather estimation module is specifically configured to: and determining the weather information according to the adjusted waveform characteristics of the second signal.
The radar of claim 2, wherein the gain control module further comprises a weather estimation module, wherein:

the transmitting module is further configured to: transmitting a third signal for detecting the target object;

the receiving module is further configured to: receiving a fourth signal and transmitting the fourth signal to the gain adjustment module; wherein the fourth signal is a signal of the third signal after being reflected by the target object;

the timing module is further configured to: determining a second propagation duration according to the time of transmitting the third signal and a second time; wherein the second propagation duration is a time when the gain adjustment module receives the fourth signal;

the weather estimation module is used for determining weather information according to the adjusted second signal, wherein the weather information is used for representing the current weather condition;

the gain determination module is further to: determining the gain at the second moment according to the weather information, the second propagation time length and the corresponding relation, and transmitting the determined gain to the gain adjusting module;

the gain adjustment module is further configured to: and adjusting the strength of the fourth signal according to the gain at the second moment.
The radar of claim 10, wherein the gain determination module is specifically configured to:

determining a reference gain according to the second propagation duration and the corresponding relation;

and correcting the reference gain according to the current weather condition, and determining the corrected reference gain as the gain of the second moment.
The radar of claim 10 or 11, further comprising a waveform detection module connected to the weather estimation module and the gain adjustment module, respectively;

the waveform detection module is used for detecting the waveform characteristics of the adjusted second signal;

the weather estimation module is specifically configured to: and determining the weather information according to the adjusted waveform characteristics of the second signal.
The radar of any one of claims 1-12 wherein the gain adjustment module is a variable gain amplifier VGA, or a multi-stage amplifier.
A gain control method is applied to radar, and comprises the following steps:

transmitting a first signal for detecting a target object;

determining a gain at a first moment according to a first propagation time and a corresponding relation between a signal gain and the propagation time, wherein the first propagation time is a time from the moment of transmitting the first signal to the first moment, the first moment is the moment of receiving a second signal, and the second signal is a signal obtained by reflecting the first signal by the target object;

and when the second signal is received, adjusting the strength of the second signal according to the gain at the first moment.
The method of claim 14, wherein after adjusting the strength of the second signal based on the gain at the first time, further comprising: determining the reflectivity of the target object according to the adjusted second signal;

transmitting a third signal for detecting the target object;

determining the gain at a second moment according to the reflectivity of the target object, the second propagation time and the corresponding relation; the second propagation time is the time when a fourth signal is received, the second time is the time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object;

and adjusting the strength of the fourth signal according to the gain at the second moment.
The method of claim 15, wherein after adjusting the strength of the second signal based on the gain at the first time, further comprising: determining weather information according to the adjusted second signal, wherein the weather information is used for representing the current weather condition;

and determining the gain of the second moment according to the reflectivity of the target object, the current weather condition, the second propagation time and the corresponding relation.
The method of claim 16, wherein determining the gain at the second time based on the reflectivity of the target object, the weather information, the second propagation duration, and the correspondence comprises:

correcting the reflectivity of the target object according to the weather information;

and determining the gain at the second moment according to the corrected reflectivity of the target object, the second propagation time and the corresponding relation.
The method of claim 16, wherein determining the gain at the second time based on the reflectivity of the target object, the weather information, the second propagation duration, and the correspondence comprises:

determining a reference gain according to the second propagation duration and the corresponding relation;

and correcting the reference gain according to the reflectivity of the target object and the weather information, and determining the corrected reference gain as the gain of the second moment.
The method of any of claims 15-18, wherein determining the reflectivity of the target object based on the adjusted second signal comprises:

detecting the amplitude of the adjusted second signal;

and determining the reflectivity of the target object according to the adjusted amplitude of the second signal.
The method of claim 14, wherein after adjusting the strength of the second signal based on the gain at the first time, further comprising: determining weather information according to the adjusted second signal, wherein the weather information is used for representing the current weather condition;

transmitting a third signal for detecting the target object;

determining the gain at a second moment according to the weather information, the second propagation time and the corresponding relation; the second propagation time is the time when a fourth signal is received, the second time is the time when the fourth signal is received, and the fourth signal is a signal obtained by reflecting the third signal by the target object;

and adjusting the strength of the fourth signal according to the gain at the second moment.
The method of claim 20, wherein determining the gain at the second time based on the weather information, a second propagation duration, and the correspondence comprises:

determining a reference gain according to the second propagation duration and the corresponding relation;

and correcting the reference gain according to the weather information, and determining the corrected reference gain as the gain of the second moment.
The method of any one of claims 16-18, 20 or 21, wherein determining weather information from the adjusted second signal, the weather information characterizing current weather conditions, comprises:

detecting the waveform characteristics of the adjusted second signal;

and determining the weather information according to the adjusted waveform characteristics of the second signal.