Detection method and device, terminal equipment and storage medium

Abstract

A detection method and device, a terminal device and a storage medium are used for reducing the influence of an interference signal on a detection signal and can be applied to the fields of automatic driving, intelligent driving or surveying and mapping and the like. The method includes transmitting a first detection signal in a first frequency range, receiving a first echo signal, and then transmitting a second detection signal in a second frequency range, the second frequency range having an offset in a first direction relative to the first frequency range, the first direction is determined according to the distribution characteristics of the interference frequency points in the first echo signal in the first frequency range. The frequency range of the next detection is determined by using the distribution characteristics of the interference frequency points in the frequency range of the last detection, and the frequency hopping operation can be carried out directionally, thereby facilitating jumping to the frequency band with small interference influence as soon as possible, further effectively reducing the influence of the interference signal on the detection signal, and improving the detection accuracy. Meanwhile, the situation that the severity of interference is aggravated due to frequency hopping in a wrong direction can be avoided, and the time cost for jumping out of an interference frequency band is saved.

Description

Technical Field

[0001] The present application relates to the field of detection technology, and in particular to a detection method, apparatus, terminal device and storage medium. Background Art

[0002] With the development and progress of sensor technology, intelligent detection sensors for vehicles have become a research hotspot in the field of vehicle assisted driving. Intelligent vehicles (smart vehicles for short) can bring everyone a more convenient and safe driving experience. For example, smart vehicles can be equipped with radar sensors to obtain environmental information around the vehicle at all times of the day and night, especially long-distance environmental information, to achieve assisted driving or even advanced autonomous driving.

[0003] Among many radar sensors, millimeter-wave radar sensors have been widely used in the automotive field due to their advantages such as low cost, large bandwidth, high resolution and strong penetration. However, with the large-scale popularization of millimeter-wave radar sensors, the penetration rate of automotive radars has been greatly improved, and the limited frequency range will lead to mutual interference between automotive radars. For example, the opponent's radar signal mixes into its own radar receiver, causing its own radar signal to be interfered, which in turn causes target missed alarms, false alarms and shortened detection distances. If the interference of the opponent's radar signal cannot be effectively suppressed, it will seriously endanger the driving safety of the vehicle.

[0004] In summary, how to reduce the impact of interference signals on detection signals is a technical problem that needs to be urgently solved in the current automotive field. Summary of the invention

[0005] The present application provides a detection method, device, terminal equipment and storage medium to improve the anti-interference ability of the detection device.

[0006] In a first aspect, the present application provides a detection method, comprising: sending a first detection signal within a first frequency range, and receiving a first echo signal, and then sending a second detection signal within a second frequency range; wherein the first echo signal is an echo signal of the first detection signal, the second frequency range is offset in a first direction relative to the first frequency range, and the first direction is determined based on the distribution characteristics of interference frequency points in the first echo signal within the first frequency range.

[0007] In the above scheme, the frequency range for next detection is determined by utilizing the distribution characteristics of the interference frequency points within the frequency range of the last detection, and frequency hopping operations can be performed directionally, which helps to jump to the frequency band with less interference as soon as possible, thereby effectively reducing the impact of the interference signal on the radar detection signal. At the same time, it can also avoid frequency hopping in the wrong direction and aggravating the severity of the interference, saving the time cost of jumping out of the interference frequency band.

[0008] In a possible implementation, the first detection signal and the second detection signal may be linear frequency modulation signals. The linear frequency modulation signal has high range resolution and anti-interference performance, and the echo signal has a large Doppler frequency shift, which helps to simplify the signal processing system.

[0009] In one possible implementation, the first echo signal may include a signal (called a useful signal) formed by the first detection signal being reflected and / or scattered by the target, and may also include an interference signal. The interference signal may include, for example, detection signals emitted by other radars, echo signals corresponding to detection signals emitted by other radars, and useless signals formed by the detection signal of this radar being reflected or scattered inside the radar.

[0010] In a further possible implementation, the interference frequency point can be understood as the central frequency point of the frequency where the interference signal and the first detection signal overlap. The interference frequency point can also have an intermediate frequency widening, which depends on the intermediate frequency bandwidth of the interference signal and the first detection signal. By utilizing the characteristic that the amplitude of the interference signal is much larger than the amplitude of the useful signal, the interference frequency point can usually be detected from the echo signal.

[0011] In one possible implementation, before sending the second detection signal within the second frequency range, it is also possible to first determine the echo signals that are interfered with in the multi-frame echo signals detected using the first frequency range, and then count the number of consecutively interfered echo signals. When the number is greater than or equal to a first preset number, the second detection signal can be sent within the second frequency range. Conversely, when the number is less than the first preset number, the second detection signal can continue to be sent within the first frequency range.

[0012] In the above implementation, by analyzing the continuous interference of multi-frame echo signals, it is possible to comprehensively determine whether frequency hopping is needed based on the duration and severity of the interference, and then start frequency hopping only when interference actually exists. Frequency hopping may not be started when there is no interference or the interference is very small or the duration of the interference is very short. In this way, it is possible to accurately avoid interference while avoiding the time consumption of the system due to incorrect scheduling of the frequency hopping scheme and saving unnecessary resource loss.

[0013] In a further possible implementation, before determining that at least a first preset number of continuous echo signals in multiple frames of echo signals are interfered with, whether any frame of echo signal is interfered with can be determined in the following manner: based on the amplitude of each sampling point in the echo signal, determine the target sampling points in the echo signal whose amplitude is greater than the first amplitude; when the number of target sampling points is greater than or equal to a second preset number, determine that the echo signal is interfered with.

[0014] In the above implementation, by utilizing the feature that the amplitude of the interference signal is greater than the amplitude of the effective signal, the sampling points in the echo signal whose amplitude is greater than the first amplitude (also called the interference suppression threshold) are determined as potential interference points, and then the number of potential interference points contained in the echo signal is combined to determine whether the echo signal is interfered with. The two factors of whether the echo signal is interfered with and the degree of interference can be comprehensively considered, and the echo signal that is more seriously affected by interference can be regarded as the echo signal that is truly interfered with, which helps to improve the accuracy of interference detection.

[0015] In a further possible implementation, the first frame echo signal can use the initial interference suppression threshold as the threshold for judging whether the sampling point is a potential interference point, and any subsequent frame echo signal other than the first frame can use the interference suppression threshold inverted from the interference detection result of the previous frame echo signal as the threshold for judging whether the sampling point is a potential interference point. In this way, using the interference detection result of the previous frame echo signal to update the interference suppression threshold of the next frame echo signal can not only make the interference suppression threshold change with the change of the interference signal, thereby improving the accuracy of interference detection of the next frame echo signal, but also can obtain the interference suppression threshold of the frame echo signal in advance before performing interference detection of any frame echo signal, and then can immediately start interference detection of the frame echo signal when receiving the digital signal of the frame echo signal, which helps to reduce system time consumption.

[0016] In a possible implementation manner, the first direction may be determined according to the following determination manner 1 or determination manner 2:

[0017] Determination method 1: within the first frequency range, if the number of interference frequency points included in the low frequency band part is greater than the number of interference frequency points included in the high frequency band part, then the first direction is determined to be a direction of increasing frequency; if the number of interference frequency points included in the low frequency band part is less than or equal to the number of interference frequency points included in the high frequency band part, then the first direction is determined to be a direction of decreasing frequency; wherein the low frequency band part is a part of the first frequency range that is lower than the center frequency point of the first frequency range, and the high frequency band part is a part of the first frequency range that is higher than the center frequency point of the first frequency range.

[0018] Determination method two: determine the central interference frequency point located at the center position among all interference frequency points of the first echo signal. If the central interference frequency point is less than the central frequency point of the first frequency range, determine that the first direction is the direction of increasing frequency. If the central interference frequency point is greater than or equal to the central frequency point of the first frequency range, determine that the first direction is the direction of decreasing frequency.

[0019] The above-mentioned determination method 1 uses the number of interference frequencies distributed on both sides of the center frequency as a basis for judgment, and the above-mentioned determination method 2 uses the relative position of the center interference frequency and the center frequency of the first frequency range as a basis for judgment. Both determination methods can determine the frequency band to which the interference frequency is more inclined, and then shift the frequency range in the opposite direction of the frequency band, so that the interference frequency moves away from the center frequency relative to the shifted frequency range, so as to quickly avoid the interference frequency and jump to a position with less interference as soon as possible.

[0020] In one possible implementation, the second frequency range has an offset of one or more preset frequency band values ​​in a first direction relative to the first frequency range. The preset frequency band value may be a preset value pre-configured in the detection device, and may be flexibly adjusted according to user needs or usage scenarios. In order to achieve comprehensive coverage of frequency hopping, the preset frequency band value may be configured to be smaller. In this case, although jumping one or more preset frequency band values ​​at a time may not be able to directly avoid the interference frequency point, it can also move the interference frequency point in a direction away from the center frequency point of the first frequency range, which helps to reduce the impact of the interference frequency point on the detection signal.

[0021] In a possible implementation, the second frequency range has a relative frequency in the first direction to the first frequency range. With this implementation, half the bandwidth is jumped at a time, which can make the second frequency range directly avoid the interference frequency point with a high probability, thus helping to speed up the speed of jumping out of the interference frequency band.

[0022] In a possible implementation, after sending the second detection signal within the second frequency range, a second echo signal may be received, where the second echo signal is an echo signal of the second detection signal. Then, second noise floor information corresponding to the second echo signal is determined, and a second noise floor difference between the second noise floor information and the ambient noise floor information is determined. Then, the second noise floor difference, the preset noise floor difference, and the first noise floor difference are compared. The first noise floor difference is the noise floor difference between the first noise floor information corresponding to the first echo signal and the ambient noise floor information. The ambient noise floor information is the noise floor information measured in an interference-free environment:

[0023] In case 1, when the second noise floor difference is greater than the preset noise floor difference and less than or equal to the first noise floor difference, it means that the noise floor after frequency hopping is optimized, but still does not reach an acceptable noise range. In this case, frequency hopping can continue to be performed in the first direction, such as sending a third detection signal within a third frequency range, and the third frequency range has an offset in the first direction relative to the second frequency range, so as to continue to optimize the interference noise;

[0024] In the second scenario, when the second noise floor difference is less than or equal to the preset noise floor difference, it means that the noise floor after the frequency hopping has reached an acceptable noise range. In this case, the third detection signal can continue to be sent within the second frequency range. In this way, by accurately detecting the scenario where the frequency hopping is not required again, meaningless frequency hopping can be avoided, thus avoiding resource waste.

[0025] In the third scenario, when the second noise floor difference is greater than the preset noise floor difference and greater than the first noise floor difference, it means that the noise floor is not optimized but degraded after frequency hopping, and the first direction is wrong. In this case, frequency hopping can be performed in the opposite direction, such as sending the third detection signal within the fourth frequency range. The fourth frequency range has an offset in the second direction relative to the second frequency range, and the second direction is opposite to the first direction.

[0026] In a further possible implementation of the above situation one, before sending the third detection signal within the third frequency range, the first edge frequency of the second frequency range in the first direction and the second edge frequency of the detectable frequency range of the detection device in the first direction may be compared. If the first edge frequency is less than the second edge frequency, it means that the frequency point has not yet been jumped to the most edge, and the frequency hopping in the first direction can continue. In this case, the third detection signal can be sent within the third frequency range. On the contrary, if the first edge frequency is equal to the second edge frequency, it means that the frequency point has not yet been jumped to the most edge, and the frequency hopping in the first direction can no longer be done. In this case, the third detection signal can be sent within the fifth frequency range, and the edge frequency of the fifth frequency range in the second direction is the edge frequency of the detectable frequency range in the second direction, and the second direction is opposite to the first direction.

[0027] In the above implementation, by jumping to the edge frequency point in the opposite direction once when it is impossible to continue frequency hopping, it is possible to avoid jumping back to the frequency range with more serious background noise in the middle position, thereby accelerating the probability of jumping out of the interference frequency point.

[0028] In a possible implementation, after sending the second detection signal in the second frequency range, a second echo signal may be received, and the credibility of the current frequency hopping may be determined according to the background noise distribution characteristics and interference distribution characteristics of the second echo signal, wherein the second echo signal is an echo signal of the second detection signal.

[0029] In the above design, the credibility of this frequency hopping is evaluated by combining the background noise distribution index and the interference distribution index, so that the credibility can at least take into account the two factors of background noise distribution characteristics and interference distribution characteristics after frequency hopping. The evaluation reference factors are relatively comprehensive, which helps to improve the accuracy of credibility evaluation.

[0030] In a second aspect, the present application provides a detection device, which is used to implement the above-mentioned first aspect or any one of the methods in the first aspect, and is used to implement the steps in the above method respectively. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0031] In a possible implementation, the detection device may be an independent detection device, or a module used in a detection device, such as a chip or a chip system or a circuit. The beneficial effects can be found in the description of the first aspect above, which will not be repeated here. The detection device may include: an interface circuit and at least one processor. The processor may be configured to support the detection device to execute the above first aspect or any one of the methods in the first aspect, and the interface circuit is used to support communication between the detection device and other detection devices and other devices. Among them, the interface circuit can be an independent receiver, an independent transmitter, an input and output port with integrated transceiver functions, etc. Optionally, the detection device may also include a memory, which may be coupled to a processor, and which stores necessary program instructions and data for the detection device.

[0032] In a third aspect, the present application provides a detection device, which is used to implement the above-mentioned first aspect or any one of the methods in the first aspect, and includes corresponding functional modules, which are respectively used to implement the steps in the above method. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0033] In a possible implementation, the detection device may include a processor and a transceiver, and the processor and the transceiver may execute the above-mentioned first aspect or any one of the methods in the first aspect. For details, please refer to the detailed description in the method example, which will not be repeated here.

[0034] In a fourth aspect, the present application provides a detection device, which may be, for example, a millimeter wave radar. The detection device includes a transmitting module, a receiving module, and a control module, wherein the transmitting module is used to perform operations related to transmission in the first aspect or any one of the designs of the first aspect, the receiving module is used to perform operations related to reception in the first aspect or any one of the designs of the first aspect, and the control module is used to perform operations related to control in the first aspect or any one of the designs of the first aspect, such as determination operations.

[0035] In a possible implementation, the transmitting module may be a transmitting antenna, and the receiving module may be a receiving antenna.

[0036] In a possible implementation, the control module may be a microcontroller unit (MCU).

[0037] In a possible implementation, the detection device may further include a monolithic microwave integrated circuit (MMIC) for performing interference detection and interference suppression on the echo signal.

[0038] In a fifth aspect, the present application provides a terminal device, which includes any detection device in the second to fourth aspects above.

[0039] In a sixth aspect, the present application provides a chip, which includes at least one processor and an interface circuit. Further, optionally, the chip may also include a memory, and the processor is used to execute computer programs or instructions stored in the memory, so that the chip executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0040] In the seventh aspect, the present application provides a computer-readable storage medium, in which a computer program or instructions are stored. When the computer program or instructions are executed by a detection device, the detection device executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0041] In an eighth aspect, the present application provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a detection device, the detection device executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0042] The beneficial effects of any design in the second to eighth aspects mentioned above can refer to the beneficial effects that can be achieved by the corresponding design in the first aspect mentioned above, and this application will not repeat them one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1a An exemplary frequency modulation diagram of a chirp signal is shown;

[0044] Figure 1b An illustrative frequency modulation diagram of a single tone signal is shown;

[0045] Figure 1c An FM graph of a non-single tone signal having the same FM slope sign is exemplarily shown;

[0046] Figure 1d An FM graph of a non-single tone signal with an opposite sign of FM slope is shown by way of example;

[0047] Figure 1e An amplitude diagram of a chirp signal is exemplarily shown;

[0048] Figure 1fA schematic diagram showing an exemplary noise floor curve;

[0049] Figure 1g An echo signal diagram in which interference frequency points are distributed in a core area is exemplarily shown;

[0050] Figure 1h An echo signal diagram in which interference frequency points are distributed in a non-core area is exemplarily shown;

[0051] Figure 2 A schematic diagram showing a possible application scenario of the present application is exemplified;

[0052] Figure 3 A possible schematic diagram of the structure of a detection device provided by the present application is exemplified;

[0053] Figure 4 A schematic diagram showing an exemplary process of a detection method provided by the present application;

[0054] Figure 5a A schematic diagram exemplarily illustrates an interference detection method provided by the present application;

[0055] Figure 5b An amplitude diagram of a chirp signal in the distance dimension provided by the present application is exemplarily shown;

[0056] Figure 5c A schematic diagram showing an interference zeroing curve provided by the present application is exemplified;

[0057] Figure 5d An amplitude diagram of another chirp signal provided by the present application in the distance dimension is exemplarily shown;

[0058] Figure 6a A schematic diagram exemplarily showing another interference nulling curve provided by the present application;

[0059] Figure 6b A digital signal diagram provided by the present application is exemplarily shown;

[0060] Figure 6c An exemplary diagram showing a frequency range comparison diagram before and after frequency hopping provided by the present application is shown;

[0061] Figure 7a A schematic diagram exemplarily showing another interference zeroing curve provided by the present application;

[0062] Figure 7b Another digital signal diagram provided by the present application is exemplarily shown;

[0063] Figure 7c Another frequency range comparison diagram before and after frequency hopping provided by the present application is exemplarily shown;

[0064] Figure 8 An illustrative example shows a frequency modulation diagram corresponding to a detection signal with different frequency hopping amplitudes provided by the present application;

[0065] Fig. 9 A schematic diagram showing an example of a comparison of interference noise floor curves before and after frequency hopping provided by the present application;

[0066] Fig.10 A schematic diagram showing an exemplary flow chart of a frequency hopping method provided by the present application;

[0067] Fig.11 A schematic diagram showing an example of another comparison of interference noise floor curves before and after frequency hopping provided by the present application;

[0068] Fig.12 A flowchart of a method for determining frequency hopping reliability provided by the present application is exemplified;

[0069] Fig.13 A possible structural schematic diagram of a detection device provided by the present application is exemplified;

[0070] Fig.14 A possible structural schematic diagram of another detection device provided in the present application is shown as an example. DETAILED DESCRIPTION

[0071] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0072] Below, some terms in this application are explained. It should be noted that these explanations are for the convenience of understanding by those skilled in the art and do not constitute a limitation on the scope of protection claimed in this application.

[0073] 1. Chirp signal

[0074] Chirp signal refers to a signal in which the carrier frequency increases linearly during the pulse duration, also known as linear frequency modulation signal. Figure 1a Chirp signal is a commonly used detection signal in millimeter wave radar. When the pulse changes to the audio ground, it will emit a sound that sounds like the chirping of birds, so it is called the "chirp" signal.

[0075] 2. Center frequency, high frequency band and low frequency band

[0076] The center frequency, also known as the center frequency of the detection signal, refers to the center of gravity of the frequency component in the detection signal. In simple terms, it can be understood as the frequency point at the center of the frequency band (referred to as the transmission frequency band) in which the radar emits electromagnetic waves. Taking the center frequency as the dividing line, the part of the transmission frequency band that is lower than the center frequency is called the low frequency band, and the part of the transmission frequency band that is higher than the center frequency is called the high frequency band. For example, assuming that the transmission frequency band is [30GHz, 300GHz], the center frequency is 165GHz, the low frequency band is [30GHz, 165GHz), and the high frequency band is (165GHz, 300GHz].

[0077] 3. Radar Jamming

[0078] Radar interference can be divided into single-tone interference and non-single-tone interference based on whether the interference frequency changes. The interference frequency can be understood as the central frequency of the frequency where the interference signal overlaps with the detection signal reflected by the target, and has a certain width, which is related to the intermediate frequency bandwidth of the interference signal and the detection signal. The interference frequencies of single-tone interference and non-single-tone interference are explained below.

[0079] Single-tone interference is a type of interference with a fixed frequency, also known as single-frequency interference. The frequency modulation slope of the interference signal is zero. Figure 1b Single-tone interference appears as a horizontal line segment on the time-frequency diagram (i.e., the interference frequency point, represented by the black line segment in the figure). The length of the line segment is related to the duration of the interference, and the width of the line segment (i.e., the spread) is related to the maximum detection distance of the radar.

[0080] In contrast to single-tone interference, non-single-tone interference is interference with multiple interference frequencies, also known as non-single-frequency interference. The FM slope of the interference signal is not zero. According to the relationship between the FM slope and the FM slope of the radar signal (such as the Chirp signal), it can be divided into two types: Type 1: The FM slope of the interference signal has the same sign as the FM slope of the radar signal. For example, the FM slope of the radar signal and the FM slope of the interference signal are both positive. Please refer to Figure 1c ; Type 2: The FM slope of the interference signal is different from the FM slope of the radar signal. For example, the FM slope of the radar signal is positive, but the FM slope of the interference signal is negative. Please refer to Figure 1d Please also refer to Figure 1c and Figure 1d , non-single-tone interference is shown as a line segment with a slope on the time-frequency diagram (i.e., the interference frequency, represented by the black line segment in the figure). The width of the line segment is related to the maximum detection distance of the radar, and the length of the line segment is related to the duration of the interference and the interference frequency. Since the interference signal and the radar signal overlap in both time and frequency, the interference signal and the radar signal will be aliased within the common transmission interval.

[0081] For single-tone interference, since the interference is distributed at the same frequency point, it will be accumulated in azimuth when performing the fast Fourier transform (FFT) (also called 1D-FFT) in the distance dimension to form a sinc envelope function. The 3dB width of the sinc envelope function is inversely proportional to the interference time, that is, the longer the interference time, the narrower the 3dB width of the sinc envelope function, which causes the radar to have a false alarm phenomenon of the target and reduces the credibility of the radar detection result. For non-single-tone interference, since the interference is distributed at different frequencies, the 3dB width of the sinc envelope function formed between radar signals at the same frequency is very narrow, and the 3dB width of the sinc envelope function formed after the subsequent FFT in the velocity dimension (also called 2D-FFT) is very wide. Therefore, after the two-dimensional FFT processing, the interference energy will cause the noise floor information of the range-velocity (RV) spectrum to rise, which is easy to drown out the peak of weak targets (i.e. targets with relatively low radar cross-section (RCS), such as pedestrians or cyclists), thereby causing the radar to miss targets and reduce the radar's detection performance.

[0082] 4. Interference Signals and Useful Signals

[0083] Interference signals are signals with a higher amplitude (also called magnitude). In other words, the amplitude of the interference signal is much larger than the amplitude of the desired signal. For example, see Figure 1e , shows an amplitude diagram of a chirp signal. The amplitude of the chirp signal is particularly large in the time period of 1.3ms to 1.5ms. Therefore, 1.3ms to 1.5ms can be considered as an interference period. Please refer to Figure 1a and Figure 1e Since the frequency of the chirp signal is linearly related to time, the time period of 1.3ms to 1.5ms can be converted into the corresponding frequency band according to the linear relationship. This frequency band is the frequency band affected by the interference signal.

[0084] 5. Environmental noise floor information and interference noise floor information

[0085] Noise floor information can be understood as the noise signal in the radar echo signal other than the useful signal. Noise floor information can be divided into environmental noise floor information and interference noise floor information. Environmental noise floor information refers to the noise floor information obtained by the radar in a clean and interference-free environment, which is usually related to the radar's hardware. Interference noise floor information refers to the noise floor information obtained by the radar in an environment with interference, which is related to the interference environment and the radar's hardware. Due to the superposition of the influence of the interference environment, the amplitude (i.e., signal strength) of the interference noise floor information is higher than that of the environmental noise floor information. For example, please refer to Figure 1f , a schematic diagram of a background noise curve provided by the present application is shown, wherein the illustrated curve L0 corresponds to the environment background noise curve, and the illustrated curve L1 corresponds to the interference background noise curve. The amplitude of the interference background noise curve is basically stable at 40dB, while the amplitude of the environment background noise curve is stable at 30dB. Therefore, the amplitude of the interference background noise information is about 10dB higher than that of the environment background noise information. The 10dB can be considered as the noise caused by the interference signal in the interference environment to the frequency range used for the current detection.

[0086] VI. Correlation between interference distribution area and interference severity

[0087] The interference distribution area refers to the distribution area of ​​the interference frequency point in the radar transmission frequency band, which can include the core area and the non-core area. The core area can be understood as a section of the radar transmission frequency band including the central frequency point and its nearby frequency points, and the non-core area can be understood as the area of ​​the radar transmission frequency band except the core area. For example, Figure 1g An echo signal diagram showing the distribution of interference frequency points in the core area is shown. Figure 1h An echo signal diagram of interference frequency points distributed in non-core areas is shown, where: Figure 1g Middle (A) and Figure 1h (A) shows the signal amplitude diagram of the echo signal. Figure 1g Middle (B) and Figure 1h (B) shows the distance distribution diagram of the target background noise. Figure 1g The center position of the interference signal (approximately at sampling point 280) is about 220 sampling points away from the center sampling point 500 (corresponding to the center frequency point). 11 Relative to the ambient noise information L 10 The amplitude is raised by about 10dB. The interference signal has a greater impact on the interference noise floor information, causing the target to be basically submerged under the interference noise floor information, and the interference effect is relatively serious. Figure 1f The center position of the interference signal (approximately at sampling point 830) is about 330 sampling points away from the center sampling point 500 (corresponding to the center frequency point). 11 Relative to the ambient noise information L10 The amplitude is raised by about 2dB. The interference signal has a relatively small impact on the interference background noise information, and the interference impact is relatively light. Figure 1g and Figure 1h It can be seen that when the interference signal is distributed in the non-core area, the interference signal is far away from the central frequency point, the interference signal has a smaller lifting effect on the interference background noise information, and the interference effect is smaller. Conversely, when the interference signal is distributed in the core area, the interference signal is close to the central frequency point, the interference signal has a larger lifting effect on the interference background noise information, and the interference effect is also greater.

[0088] The foregoing text introduces some of the terms involved in this application. The following text introduces possible application scenarios of this application.

[0089] In a possible implementation, the detection method may be applied to a detection device, which may be installed on a vehicle. The detection device may be, for example, a millimeter wave radar. Figure 2 , which exemplarily shows a possible application scenario of the present application. In this application scenario, the detection device is installed at the front bumper of the vehicle as an example, but it should be understood that the detection device can also be installed in any direction or multiple directions of the six directions of the front, rear, left, right, top and bottom of the vehicle, such as around the headlights, around the rearview mirrors, near the doors, at the rear bumper, behind the windshield or on the roof, so as to capture the vehicle's surrounding environment information. When the detection device is installed behind the windshield, it has a lower requirement for no risk of gravel collision, and will not affect the appearance of the vehicle. In addition, the front windshield itself has the functions of window heating, demisting and wiper cleaning.

[0090] Taking millimeter wave radar as an example, the working principle of the detection device is as follows: the detection device emits millimeter waves (such as millimeter waves with a carrier frequency of 77GHz) to the detection area. If there is a target in the detection area, the target can reflect the received millimeter waves back to the detection device (the reflected millimeter waves can be called echo signals). The detection device determines the associated information of the target after processing the echo signals. For example, the detection device can obtain the physical environment information around the vehicle body in real time or periodically, such as the relative distance (Range), relative speed (Velocity), relative angle (such as horizontal angle (Azimuth Angle)) and pitch angle (Elevation) between the vehicle and other objects, and then track and identify the target according to the detected physical environment information, and then combine the vehicle body dynamic information for data fusion. After making a reasonable decision, the driver is informed or warned in various ways such as sound, light and touch, or the car is actively intervened in time, so as to ensure the safety and comfort of the driving process and reduce the probability of accidents. At present, vehicles can use millimeter-wave radar to realize functions of advanced driving assistant systems (ADAS), such as adaptive cruise control, forward collision warning, blind spot detection, parking aid, lane change assistant, etc., and thus realize assisted driving or automatic driving of the vehicle.

[0091] It should be understood that the above application scenarios are only examples, and the detection device provided in this application can also be applied to other possible scenarios, not limited to the scenarios exemplified above. For example, the detection device can also be installed in the car for dynamic detection of living targets in the car. Alternatively, the detection device can also be installed on a roadside traffic radar for violation detection of vehicles passing on surrounding roads, or for monitoring the congestion level of the current traffic environment and evacuating in time, or for communicating with vehicles to achieve intelligent vehicle-road collaborative communication, etc. Alternatively, the detection device can also be installed on an aircraft, such as a drone, a passenger plane, a forest protection aircraft or an aerial survey aircraft, to monitor obstacles in the flight environment and avoid them in time to reduce accidents. For another example, the detection device can also be installed on a ship as a ship-borne detection device to assist the ship in safe driving. For another example, the detection device can also be applied to a terminal device, or be set in a component of a terminal device, and the terminal device can be, for example, a smart home device (for example, for privacy detection), a smart manufacturing device (for example, for monitoring the operation status), a robot, or a smart transportation device, and the smart transportation device can be, for example, an automated guided vehicle (AGV) or an unmanned transport vehicle, etc. They are not listed here one by one.

[0092] It should be noted that the application scenarios described in this application are intended to more clearly illustrate the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. The above application scenarios can be applied to unmanned driving, automatic driving, assisted driving, intelligent driving, connected cars, security monitoring, biomedicine or mapping (such as three-dimensional mapping) and other fields.

[0093] As described in the background technology, there is an interference problem in the existing millimeter wave radar, and it is necessary to suppress the interference signal in the echo signal. At present, the opportunity for interference suppression of the radar is mainly after receiving the echo signal, by performing interference detection on the echo signal, determining the interference signal in the echo signal, and then filtering the interference signal from the echo signal to obtain a relatively pure useful signal. However, this method actually belongs to interference detection of the current frame echo signal, and it is impossible to avoid the interference frequency from the source. In view of this, frequency hopping (frequency-hopping spread spectrum, FHSS) is proposed in some interference suppression schemes. Frequency hopping means that when the radar encounters co-frequency interference or severe interference, in order to avoid continuous interference with the same frequency, it can choose to jump out of the frequency or out of band and jump to a new frequency to avoid the interference frequency in advance. Frequency hopping is a common solution in interference avoidance and suppression technology, but most existing frequency hopping solutions choose random hopping. For example, several frequency points are set in advance. When it is determined that the interference is serious, one of the frequency points is randomly selected for frequency hopping. After the frequency hopping is completed, the background noise information after jumping to the new frequency point is used to determine whether to continue the frequency hopping. Obviously, this frequency hopping solution belongs to post-verification and has great ambiguity, which brings a great time cost for the subsequent jump out of the interference frequency point. Therefore, how to quickly jump to the interference-free frequency band is a key research direction in the field of radar interference avoidance.

[0094] In view of this, the present application provides a detection method, which determines the frequency hopping direction by referring to the distribution characteristics of the interference frequency point in the frequency range of the previous detection, which helps to avoid the interference frequency point in the frequency range after jumping in the frequency hopping direction, so as to jump to the interference-free frequency band as soon as possible. By avoiding frequency hopping in the wrong direction, the time cost of frequency hopping is saved and the efficiency of interference avoidance is improved.

[0095] The following first introduces the system architecture to which the detection method proposed in this application can be applied.

[0096] Figure 3 A possible schematic diagram of the structure of a detection device provided in this application. Figure 3As shown, the detection device 300 may include a transmitter 3101, a receiver 3102, a monolithic microwave integrated circuit (MMIC) 320 and a microcontroller unit (MCU) 330. The MMIC 320 may include a signal generator 321, and a mixer 322, a low-pass filter 323, an analog-to-digital converter (ADC) 324 and a digital signal processor (DSP) 325 coupled in sequence. The signal generator 321 is coupled to the MCU 330 and the transmitter 3101 respectively, the MCU 330 is also coupled to the DSP 325, the transmitter 3101 is also coupled to the mixer 322, and the mixer 322 is also coupled to the receiver 3102.

[0097] It should be noted here that the various components included in the architecture are only an exemplary description. The detection device 300 may include more or fewer components than shown in the figure. The components shown or not shown may be combined or divided in any way, and any component may be replaced by other components with equivalent functions. For example, in one example, the MMIC 320 may also include one or more of a low noise amplifier (LNA), a power amplifier (PA), an up-converter, a detector, and a voltage-controlled oscillator. For example, in another example, the signal generator 321 may also be replaced by components such as a modulator, a phase shifter, and a switch, the MCU 330 may also be replaced by other components with control functions, and the DSP 325 may also be replaced by other components with signal processing capabilities, etc. This application does not make specific limitations on this.

[0098] Below Figure 3 The structure and function of each component shown are introduced in detail.

[0099] Exemplarily, the transmitter 3101 may be a transmitting antenna, and the receiver 3102 may be a receiving antenna. The MMIC 320 may also have a transmitting channel and a receiving channel, the transmitting antenna is connected to the transmitting channel, and the receiving antenna is connected to the receiving channel. The transmitting antenna and the receiving antenna may be located on a printed circuit board (PCB), and the transmitting channel and the receiving channel may be located in a chip, i.e., AOB (antenna on PCB); or, the transmitting antenna and the receiving antenna may be located in a chip package, and the transmitting channel and the receiving channel may be located in a chip, i.e., AIP (antenna in package). The combination form is not specifically limited in the embodiments of the present application.

[0100] Exemplarily, the MCU 330 can control the operation of the MMIC 320. For example, the MCU 330 can control the signal generator 321 to generate a detection signal (such as a millimeter wave), and then send the detection signal through the transmitter 3101. Optionally, the detection signal can be composed of one or more burst packets, each burst packet is used to perform a frame of detection, including multiple chirp signals. While sending the detection signal, the transmitter 3101 can also synchronously send the detection signal to the mixer 322 in the MMIC 320. After the detection signal is sent, it is reflected and / or scattered by one or more targets to form an echo signal, and the echo signal is received by the receiver 3102 and then transmitted to the mixer 322. The mixer 322 can perform mixing processing on the detection signal and the echo signal, such as subtracting the frequency of the echo signal from the frequency of the detection signal, and subtracting the phase of the echo signal from the phase of the detection signal to obtain an intermediate frequency signal, which is then input into the low-pass filter 323 for de-skewing processing (which can be considered as filtering out the high-frequency components and retaining only the medium and low-frequency components) to obtain a pure intermediate frequency signal (such as Figure 1e The pure intermediate frequency signal is then converted into a digital signal after discrete sampling by ADC 324 and then sent to DSP 325. DSP 325 first performs 1D-FFT processing on the digital signal from ADC 324 to obtain the distribution characteristics of the echo signal in the distance dimension (as shown in FIG. Figure 1g (B) or (B) in 1h), and then perform 2D-FFT processing on the distribution characteristics to obtain the distribution characteristics of the echo signal in the velocity dimension (not involved in this application and will not be described in detail), and then transmit these two distribution characteristics to the MCU 330.

[0101] Further, optionally, the MCU 330 can determine the associated information of the target based on the relevant information of the echo signal from the MMIC 320. For example, the MCU 330 can determine the relative distance of the target based on the distribution characteristics of the echo signal in the distance dimension, and determine the relative speed of the target based on the distribution characteristics of the echo signal in the speed dimension. Optionally, relative angles, such as the aforementioned horizontal angle and pitch angle, can also be determined. In some scenarios, the MCU 330 can also be connected to an external controller, such as a vehicle-mounted controller, and by sending the associated information of the target to the vehicle-mounted controller, it is convenient for the vehicle-mounted controller to perform trajectory planning to achieve assisted driving or automatic driving, etc.

[0102] Understandable, combined Figure 1e Due to the presence of the interference signal, there will be some protruding abnormal peaks in the intermediate frequency signal received by ADC 324, and the positions of these abnormal peaks correspond to the positions of the interference frequency points. Whether it is single-tone interference or non-single-tone interference, the position of the abnormal peak corresponding to the interference frequency point can be detected from the intermediate frequency signal received by ADC 324 according to the characteristic that the amplitude of the interference signal is greater than the amplitude of the effective signal. The detection method provided in the present application is to determine the frequency hopping direction of the next detection by analyzing and processing the positions of the abnormal peaks appearing in the historical detection, so as to quickly and accurately avoid the interference frequency point.

[0103] based on Figure 3 The system architecture shown below is combined with the attached Figure 4 To Attachment Fig.12 , the detection method proposed in this application is specifically explained.

[0104] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0105] like Figure 4 As shown, it is a flow chart of a detection method provided by the present application. The detection method can be applied to a detection device, such as Figure 3 The detection device 300 shown. Figure 4 As shown, the method comprises the following steps:

[0106] Step 401: The detection device sends a first detection signal within a first frequency range.

[0107] Optionally, the first detection signal may be a chirp signal. The chirp signal has high distance resolution and anti-interference performance, and the echo signal has a large Doppler frequency shift, which helps to simplify the signal processing system.

[0108] Further, optionally, the detection device may send multiple chirp signals within the first frequency range. For example, for any frame detection, the detection device may send multiple chirp signals within the same frequency range. Taking the first frame detection as an example, refer to Figure 3 Assuming that the detection device completes one frame of detection every 66 ms, when detecting the first frame, the MCU 330 can control the signal generator 321 to periodically generate and send 100 identical chirp signals within the first 20 ms (it can be understood that the frequency starting point, frequency modulation slope and duration of the 100 chirp signals are the same, and the 100 chirp signals overlap on the time-frequency diagram), and the next 46 ms is reserved for other components in the MMIC 320, such as the mixer 322, the low-pass filter 323, the ADC 324 and the DSP 325, to convert and sample the echo signals corresponding to the 100 chirp signals, and to be reserved for the MCU 330 for target recognition of the first frame echo signal.

[0109] Step 402: The detection device receives a first echo signal, where the first echo signal is an echo signal of the first detection signal.

[0110] Optionally, the first echo signal may include a signal (called a useful signal) formed by the first detection signal being reflected and / or scattered by the target, and may also include an interference signal, such as a detection signal emitted by other radars, an echo signal corresponding to a detection signal emitted by other radars, and an interference signal formed when the detection signal of this radar is reflected or scattered inside the radar and transmitted to the receiver 3102.

[0111] Optionally, the detection device can perform target recognition based on the received first echo signal. For example, the echo signal is received within the aforementioned last 46ms, and the received echo signal is processed to obtain the associated information of the target existing in the current scene, such as the relative speed, relative distance and relative angle of the target, or a three-dimensional point cloud can be constructed.

[0112] Further, optionally, after receiving the first echo signal, the detection device may also perform interference detection and interference suppression on the first echo signal before performing target identification on the first echo signal. Exemplarily, it is also possible to determine whether the echo signal of the current frame is interfered with based on the result of the interference detection. Among them, the echo signal that is interfered with can be considered as an echo signal with a relatively serious interference degree, and the interference degree can be determined according to the number of interference points (or the proportion of the frequency band where the interference point is located in the wave transmission frequency band, etc.). For example, taking the number of interference points as an example, the detection device may first detect the echo signal corresponding to a certain frame, determine the interference points contained in the echo signal, and when the number of interference points is greater than or equal to the second preset number, determine that the frame echo signal is an interfered echo signal. Among them, the second preset number is used to characterize the critical number of interference points contained in the interfered echo signal and the uninterrupted echo signal, which can be set according to the user's experience, or obtained according to experimental tests, or can also support user customization to adapt to different application scenarios.

[0113] To facilitate understanding, a specific example is given below to illustrate.

[0114] See also Figure 5a , assuming that Figure 5a In the scenario shown in (A), the MCU 330 controls the signal generator 321 to send out 100 chirp signals to perform the first frame detection, and the corresponding echo signal is mixed with the chirp signal by the mixer 322, filtered out the high-frequency component by the low-pass filter 323, and converted into a digital signal by the ADC 324. Figure 5a The digital signal diagram shown in (C). Figure 5a The horizontal axis of (C) is used to represent the number of chirp signals, and the vertical axis is used to represent the sampling points. The sampling points can be considered as sampling the chirp signal period. Each sampling point can correspond to a unique time point, a unique distance, and a unique frequency point. In addition to the horizontal and vertical axes, Figure 5a (C) also includes the amplitude of any chirp signal at each sampling point. The amplitude is represented by the depth of gray. The shallower the depth of gray, the greater the probability that the sampling point is an interference point.

[0115] First, please refer to Figure 3 and Figure 5a The process of performing interference detection and interference suppression on the first frame echo signal may specifically include the following steps 1 to 3:

[0116] Step 1: ADC 324 extracts the corresponding relationship between the sampling point and the amplitude of each chirp signal from the digital signal corresponding to the 100 chirp signals. Figure 5a A cut is made at each chirp number on the horizontal axis shown in (C) in a direction parallel to the vertical axis, and then the vertical axis of the cut straight line is transformed into the horizontal axis (i.e., the horizontal axis is used to represent the sampling points), and the gray depth of each sampling point on the cut straight line is converted into the corresponding amplitude and used as the vertical axis (i.e., the vertical axis is used to represent the amplitude), thereby constructing the amplitude diagram corresponding to each of the 100 chirp signals. Figure 5a (B) shows the amplitude diagram corresponding to a chirp signal, which can be considered as Figure 5a The 50th chirp signal in (C) is obtained by cutting along the straight line L shown in the figure and then transforming it.

[0117] In some scenarios, the horizontal axis of the amplitude graph can also be transformed, such as into a distance dimension or a frequency dimension. For example, see Figure 5b , shows another amplitude diagram corresponding to a chirp signal, which uses the distance dimension as the horizontal axis. The amplitude diagram can be understood as the distribution characteristics of the target in the distance dimension obtained after the DSP 325 performs 1D-FFT. The distribution characteristics usually also include an interference background noise curve, which is mainly used to provide the MCU 330 with subsequent interference suppression effect analysis. See the subsequent Appendix Fig.10 .

[0118] Step 2: For any chirp signal, ADC 324 obtains the initial interference suppression threshold (i.e., the first amplitude), and determines the sampling points whose amplitude exceeds the initial interference suppression threshold from the amplitude diagram of the chirp signal, and uses these sampling points as target sampling points. The initial interference suppression threshold can be understood as the default interference suppression threshold, which is used to characterize the critical amplitude between the default interference point and the non-interference point. When the amplitude of the sampling point is greater than the initial interference suppression threshold, the sampling point is likely to be an interference point. For example, Figure 5a The sampling points corresponding to the peak values ​​and nearby positions on the amplitude diagram shown in (B) can be considered as the target sampling points. Figure 5a The digital signal shown in (C) refers to those sampling points with lighter gray depth.

[0119] Step 3: ADC 324 sets the amplitude of the target sampling points in the amplitude map of each chirp signal to zero according to the target sampling points determined from the amplitude map of each chirp signal. Optionally, the amplitudes of other sampling points except the target sampling points can also be set to 1. Here, setting to zero can be understood as configuring the amplitude to the maximum value, and setting to 1 can be understood as configuring the amplitude to the minimum value. Figure 5aThe amplitude of each peak value and the sampling points near the position shown in (B) becomes 0, which is equivalent to removing each peak point and the points near the position in the amplitude diagram. Figure 5a The gray depth at the target sampling point shown in (C) is updated to the lightest, and the gray depth at locations other than the target sampling point is updated to the darkest, and the following is obtained: Figure 5a The digital signal after the interference is reset to zero is shown in (D).

[0120] Furthermore, Figure 5a The digital signal diagram shown in (D) can be understood as a digital signal diagram after interference suppression. ADC 324 can send the digital signal diagram after interference suppression to DSP 325, so that DSP 325 can perform 1D-FFT on the digital signal after interference suppression to obtain a relatively accurate distribution feature of the first frame echo signal in the distance dimension, and perform 2D-FFT on the digital signal after interference suppression to obtain a relatively accurate distribution feature of the first frame echo signal in the speed dimension, so as to improve the accuracy of target recognition.

[0121] Further, optionally, after performing interference detection on the first frame echo signal, the initial interference suppression threshold can be updated according to the interference detection result of the first frame echo signal, and then the updated interference suppression threshold is used to perform interference detection on the second frame echo signal, and then the interference suppression threshold is continued to be updated according to the interference detection result of the second frame echo signal, and then the updated interference suppression threshold is used to perform interference detection on the third frame echo signal, and so on. In other words, the first frame echo signal uses the initial interference suppression threshold as the threshold for determining whether the sampling point is a potential interference point, and any subsequent frame echo signal other than the first frame uses the interference suppression threshold inverted from the interference detection result of the previous frame echo signal as the threshold for determining whether the sampling point is a potential interference point. In this way, the interference suppression threshold of the next frame echo signal is updated using the interference detection result of the previous frame echo signal. This not only allows the interference suppression threshold to change with changes in the interference signal and improve the accuracy of interference detection for the next frame echo signal, but also allows the interference suppression threshold of the frame echo signal to be acquired in advance before performing interference detection on any frame echo signal. As a result, interference detection on the frame echo signal can be started immediately when the digital signal of the frame echo signal is received, thereby helping to reduce system time consumption.

[0122] Further, optionally, the method for updating the interference suppression threshold can be designed by a person skilled in the art based on experience. For example, in one possible updating method, when the interference detection result of the echo signal of the previous frame indicates that the number of zero points is greater than a certain value (such as 100), it means that the amplitudes corresponding to the various sampling points in the current scene are relatively large, and the current scene may belong to a high-frequency scene. In this case, in order to avoid misjudging normal sampling points as interference points, the interference suppression threshold can be increased. Conversely, when the interference detection result of the echo signal of the previous frame indicates that the number of zero points is less than a certain value (such as 20), it means that the amplitudes corresponding to the various sampling points in the current scene are relatively small, and the current scene may belong to a low-frequency scene. In this case, in order to avoid misjudging normal sampling points as interference points, the interference suppression threshold can be reduced.

[0123] It should be noted that the specific update amount of the interference suppression threshold, such as how much to increase or decrease at a time, can be designed by those skilled in the art based on experience, and this application does not make any specific limitation on this.

[0124] The above steps 1 to 3 introduce how to perform interference detection and interference suppression on the echo signal. The following will explain how to determine whether the echo signal is interfered.

[0125] Still taking the first frame echo signal as an example, please continue to refer to Figure 3 and Figure 5a The process of determining whether the first frame echo signal is interfered may specifically include the following steps 4 to 6:

[0126] Step 4, ADC 324 converts the amplitude diagram after zeroing and setting to 1 corresponding to each chirp signal to obtain the 0-1 matrix after interference suppression corresponding to each chirp signal, and superimposes the 0-1 matrices after interference suppression corresponding to 100 chirp signals in the chirp dimension to obtain the interference zeroing curve corresponding to the first frame echo signal.

[0127] Here, the interference suppressed 0-1 matrix corresponding to a chirp signal can be understood as a matrix containing the number of zero points corresponding to the chirp signal at each sampling point, and the interference zeroing curve after superposition of the 0-1 matrices corresponding to 100 chirp signals can be understood as a curve containing the total number of zero points corresponding to the 100 chirp signals at each sampling point. For example, see Figure 5c , is a schematic diagram of an interference zeroing curve provided in the present application, the interference zeroing curve includes multiple sampling points and the number of zeroing points corresponding to each of the multiple sampling points. The zeroing point corresponding to any sampling point can be understood as the total number of zeroing points contained in 100 chirp signals at the sampling point.

[0128] Step 5: ADC 324 determines relevant information of interference points in the first frame echo signal, such as the number and position of interference points, by analyzing the number and position of zeroing points corresponding to each sampling point on the interference zeroing curve corresponding to the first frame echo signal.

[0129] It can be understood that on the interference zeroing curve, if a sampling point corresponds to a larger number of zeroing points, it means that most of the 100 chirp signals are interfered at the sampling point, and the probability that the sampling point corresponds to an interference point is greater. Conversely, if a sampling point corresponds to a smaller number of zeroing points, it means that the 100 chirp signals are basically not or rarely interfered at the sampling point, and the probability that the sampling point corresponds to an interference point is smaller.

[0130] Based on this, in one example, the peak on the interference zeroing curve corresponding to the first frame echo signal and the sampling points corresponding to the nearby positions can be confirmed as interference points contained in the first frame echo signal. For example, a threshold can be set, and the number of zeroing points of each sampling point on the interference zeroing curve is compared with the threshold. If it is less than the threshold, it is determined that the sampling point is not an interference point. If it is greater than the threshold, it is determined that the sampling point is an interference point. Among them, the frequency point corresponding to the sampling point determined as an interference point can be considered as an interference frequency point, which has a relatively large impact on the transmission frequency band. When the wave is transmitted next time, the frequency point needs to be avoided in advance by frequency hopping. Using this example, by statistically analyzing the total number of zeroing points corresponding to a frame echo signal, the interference peak conditions in all echo signals of a frame echo signal can be comprehensively considered to accurately determine whether each sampling point is an interference point, thereby improving the accuracy of interference judgment.

[0131] In step six, ADC 324 compares the number of interference points contained in the first frame echo signal with a second preset number based on relevant information of the interference points in the first frame echo signal. If the number of interference points is greater than or equal to the second preset number, it means that the interference level of the first frame echo signal is relatively serious. Therefore, the first frame echo signal can be determined as a frame of interfered echo signal. If the number of interference points is less than the second preset number, it means that the interference level of the first frame echo signal is relatively light. Therefore, the first frame echo signal can be determined as a frame of undisturbed echo signal.

[0132] It should be noted that using the number of interference points as an indicator to measure whether an echo signal is an interfered echo signal is only one possible implementation method, and other indicators of interference points can also be used in actual detection devices. For example, in another example, the proportion of the frequency band where the interference point is located in the transmitting frequency band can be used as an indicator to measure whether the echo signal is an interfered echo signal. When the proportion of the frequency band where the interference point is located in the transmitting frequency band is greater than a certain proportion, the interference point covers most of the frequency points in the transmitting frequency band, and the interference level is relatively serious. The first frame of the echo signal can be considered to be a frame of interfered echo signal. Otherwise, the first frame of the echo signal can be considered to be a frame of undisturbed echo signal. For example, in yet another example, the number of sampling points on the echo signal affected by the interference signal can be used as an indicator to measure whether the echo signal is an interfered echo signal. For example, for Figure 5d The amplitude diagram of a chirp signal in the distance dimension shown can first determine a distance area corresponding to the peak value and the nearby position, and then calculate the product of the time period corresponding to this distance area and the sampling frequency to obtain the number of points N of influence of the interference signal on the effective signal, and then superimpose the number of influence points N corresponding to each chirp signal to obtain the total number of points affected by the interference signal for a frame of echo signal. When the total number of points is greater than the preset number of points, it can be determined that the frame of echo signal is interfered. And so on. It can be understood that any indicator that can reflect the severity of interference can be used as an indicator to measure whether the echo signal is interfered, and this application does not make specific restrictions on this.

[0133] In addition, the above content is based on the example of ADC 324 performing interference detection, interference suppression and determining whether the echo signal is interfered with, but in the actual detection device, these operations can also be performed by other devices. For example, in another example, ADC 324 can also send the digital signal to DSP 325, and DSP 325 can perform the above interference detection, interference suppression and operations to determine whether the echo signal is interfered with. For example, in another example, ADC 324 can also send the digital signal to MCU330, and MCU 330 can perform the above interference detection, interference suppression and operations to determine whether the echo signal is interfered with. Or, in another example, at least two of ADC 324, DSP 325 and MCU 330 can also be combined to perform the above operations, such as ADC 324 performing interference detection, DSP 325 performing interference suppression, MCU 330 determining whether the echo signal is interfered with, etc., and this application does not make specific limitations on this.

[0134] Step 403: The detection device sends a second detection signal within a second frequency range, the second frequency range is offset in a first direction relative to the first frequency range, and the first direction is determined based on the distribution characteristics of the interference frequency points in the first echo signal within the first frequency range.

[0135] Optionally, the second detection signal may be a chirp signal.

[0136] Further, optionally, the second detection signal can be understood as one or more signals used to perform the next frame detection. For example, taking a signal as an example, refer to Figure 3 Assuming that the detection device completes one frame detection every 66ms, the MCU330 can start timing after the control signal generator 322 sends the first chirp signal used to detect the previous frame. After the timing reaches 66ms, the control signal generator 322 generates and sends the first chirp signal used to detect the next frame. The frequency range of the chirp signal and the frequency range of the chirp signal used to perform the previous frame detection (i.e., the first frequency range) can be the same or different, and there is no specific limitation.

[0137] Exemplarily, whether the frequency range of the next frame detection is the same as the frequency range of the previous frame detection can be determined specifically according to the interference of the previous frame echo signal (or the previous multiple frames echo signal). For example, when the interference of the previous frame echo signal (or the previous multiple frames echo signal) is serious, the MCU 330 determines to perform frequency hopping. At this time, the MCU 330 can control the signal generator 321 to adjust the frequency range of the previous frame detection as the frequency range (i.e., the second frequency range) of the next frame detection, so that the frequency range of the next frame detection is different from the frequency range of the previous frame detection, and the probability of the frequency range avoiding or staying away from the interference frequency point is increased. On the contrary, if the interference of the previous frame detection (or the previous multiple frames detection) is relatively not serious and belongs to the interference acceptable to the current scene, the MCU 330 determines that frequency hopping is not required. At this time, the MCU 330 can control the signal generator 321 to still use the frequency range of the previous frame detection to perform the next frame detection to save unnecessary operations.

[0138] Further, illustratively, the MCU 330 can combine the interference conditions detected by the previous multiple frames to comprehensively determine whether to hop the frequency. For example, for any frame echo signal detected using the first frequency range, the MCU 330 can obtain information from the ADC 324 on whether the frame echo signal is interfered with, and the information can be determined by the ADC 324 in the manner of steps 4 to 6 in the above step 402; then, the MCU 330 can count the number of echo signals that are continuously interfered with among these echo signals, and then compare the number with the first preset number:

[0139] If the number of echo signals that are continuously interfered with is greater than or equal to the first preset number, it means that most of the echo signals detected in the first frequency range are continuously interfered with by the same interference signal, which means that there is a long-term overlap between the first frequency range and the interference frequency of the interference signal, and the interference effect is relatively large. In this case, the MCU 330 can determine the distribution position of the interference frequency in the first frequency range based on the interference analysis results of these continuously interfered echo signals, and then determine the frequency hopping direction (i.e., the first direction) to avoid the interference frequency or reduce the influence of the interference frequency with reference to these distribution positions, and then control the signal generator 321 to shift the first frequency range along the first direction to obtain the second frequency range, and send the second detection signal in the second frequency range;

[0140] On the contrary, if the number of echo signals that are continuously interfered with is less than the first preset number, it means that the echo signals detected in the first frequency range are not interfered with or only a small part of them are interfered with, which further indicates that the first frequency range is likely to have no overlap with the interference frequency point of the interference signal, or although there is overlap, it ends in a very short time and does not cause serious interference. In this case, the first frequency range can be considered to be a frequency range that is more suitable for detection in the current scenario, and no frequency hopping is required. Therefore, MCU 330 can control the signal generator 321 to continue using the first frequency range to send the second detection signal.

[0141] In the above implementation, by analyzing the continuous interference of multi-frame echo signals, it is possible to comprehensively determine whether frequency hopping is needed based on the duration and severity of the interference, and then start frequency hopping only when interference actually exists. In the scenario where there is no interference or the interference is very small or the interference duration is very short, frequency hopping may not be started. In this way, while accurately avoiding interference, it is possible to avoid incorrect scheduling of frequency hopping schemes, affect system time consumption, and save unnecessary resource loss.

[0142] Optionally, when it is determined that frequency hopping is to be performed, the frequency hopping direction can be determined according to the distribution characteristics of the interference frequency points within the first frequency range. The interference frequency point may refer to the interference frequency point in one frame of the echo signal (such as the most recent frame of the echo signal) in the echo signal that has been previously determined to be continuously interfered with, or may be the sum set of all the interference frequency points in the echo signal that has been previously determined to be continuously interfered with, or may be the sum set of at least two but not all interference frequency points in the echo signal that has been previously determined to be continuously interfered with, without specific limitation.

[0143] In a possible implementation, the distribution characteristics of the interference frequency point in the first frequency range may include the distribution position characteristics of the interference frequency point in the first frequency range. According to the distribution position characteristics, the MCU 330 can determine the frequency hopping direction according to the principle of directional deviation of the interference frequency point away from the center frequency point of the frequency range, so that the interference frequency point in the core area of ​​the first frequency range is located in the non-core area of ​​the second frequency range, or the interference frequency point in the non-core area of ​​the first frequency range close to the center frequency point is located in the non-core area of ​​the second frequency range away from the center frequency point. According to the content of the term explanation part, the more the interference frequency point deviates from the center frequency point, the smaller the interference frequency point raises the background noise information, the lighter the interference degree, and the better the effect of interference avoidance. It can be seen that by using the distribution position characteristics of the interference frequency point in the frequency range of the previous detection to guide the direction of frequency hopping, the frequency hopping operation can be performed in a directional manner, which helps to jump to the frequency band with less interference as soon as possible, thereby effectively reducing the influence of the interference signal on the radar detection signal, while also avoiding frequency hopping in the wrong direction and aggravating the severity of interference, saving the time cost of frequency hopping to the interference-free frequency band.

[0144] Based on the above principles, a variety of methods may be used to determine the frequency hopping direction. Two possible determination methods are exemplarily given below.

[0145] Determine method one

[0146] In determination method 1, MCU 330 can determine the first number of interference frequencies contained in the low frequency band part of the first frequency range and the second number of interference frequencies contained in the high frequency band part according to the distribution position characteristics of the interference frequencies in the first frequency range, and then compare the first number and the second number. If the first number is greater than the second number, it means that the interference frequencies are mostly distributed in the low frequency band part of the first frequency range. In order to make the interference frequencies away from the center frequency, it is necessary to perform frequency hopping to the high frequency band part. In this case, MCU 330 can use the direction of increasing frequency as the frequency hopping direction, that is, the second frequency range is offset to the high frequency direction relative to the first frequency range, and the starting frequency point of the second frequency range is greater than the starting frequency point of the first frequency range. On the contrary, if the first number is less than the second number, it means that the interference frequency points are mostly distributed in the high frequency band of the first frequency range. In order to make the interference frequency points away from the center frequency points, it is necessary to perform frequency hopping to the low frequency band part. In this case, MCU330 can use the direction of frequency reduction as the frequency hopping direction, that is, the second frequency range is offset to the low frequency direction relative to the first frequency range, and the starting frequency point of the second frequency range is smaller than the starting frequency point of the first frequency range. Furthermore, if the first number is equal to the second number, it means that the interference frequency points are distributed in the center position of the first frequency range. In this case, frequency hopping in any direction is acceptable. Therefore, MCU 330 can select a direction as the frequency hopping direction randomly or according to a preset rule, such as selecting the direction of frequency reduction.

[0147] For example, see Figure 6a The interference zeroing curve shown in the figure assumes that the sampling points within the elliptical area of ​​the figure are determined as interference frequencies, or, see Figure 6b In the digital signal diagram shown in FIG. 1 , the sampling points in the shallow gray rectangular area are determined as interference frequency points. Then: the sampling point range corresponding to the first frequency range is [0, 500]. Therefore, the sampling point of the center frequency point corresponding to the first frequency range is 250, and the sampling points corresponding to the interference frequency points are basically distributed in the range of 350 to 450. Obviously, this range is larger than the sampling point 250 corresponding to the center frequency point, indicating that most of the interference frequency points are distributed in the high frequency band, and the low frequency band is less affected by the interference signal. In this case, MCU 330 can perform frequency hopping to the low frequency direction by controlling signal generator 321. For example, please refer to Figure 6c , assuming that the signal generator 321 is originally Figure 6c The first detection signal S1 is sent within the first frequency range [35GHz, 45GHz] shown in (A), and then after frequency hopping to the low frequency direction, Figure 6cA second detection signal S2 is emitted within the second frequency range [33 GHz, 43 GHz] shown in (B). The first frequency range [35 GHz, 45 GHz] and the second frequency range [33 GHz, 43 GHz] can be understood as line segments of different time periods intercepted on the same oblique line. For example, the first frequency range [35 GHz, 45 GHz] corresponds to a line segment within the time period of 10s to 50s on an oblique line, and the second frequency range [33 GHz, 43 GHz] corresponds to a line segment within the time period of 2s to 42s on the oblique line.

[0148] By adopting the above-mentioned determination method 1, according to the number of interference frequencies distributed on both sides of the center frequency, it can be determined whether the interference frequency is more inclined to the low frequency band or the high frequency band, and then the frequency range can be shifted in the opposite direction of the frequency band to which the interference frequency tends, so that the interference frequency moves away from the center frequency relative to the offset frequency range, so as to quickly avoid the interference frequency and jump to a position with less interference as soon as possible. Among them, the number of interference frequencies has been calculated in the aforementioned interference detection process and belongs to existing information. In other words, the scheme can directly use the existing information to confirm the frequency hopping direction, which helps to improve the speed of determining the frequency hopping direction.

[0149] Determination method 2

[0150] In the second determination method, the MCU 330 can determine the central interference frequency located at the center of all interference frequencies according to the distribution position characteristics of the interference frequencies in the first frequency range, and then compare the central interference frequency with the central frequency of the first frequency range. If the central interference frequency is smaller than the central frequency of the first frequency range, it means that the interference frequency band is closer to the low frequency band of the first frequency range. In order to make the interference frequency band away from the central frequency of the first frequency range, it is necessary to perform frequency hopping to the high frequency band. In this case, the MCU 330 can use the direction of increasing frequency as the frequency hopping direction, that is, the second frequency range is offset to the high frequency direction relative to the first frequency range, and the starting frequency of the second frequency range is larger than the starting frequency of the first frequency range. On the contrary, if the central interference frequency is greater than the central frequency of the first frequency range, it means that the interference frequency band is closer to the high frequency band of the first frequency range. In order to make the interference frequency band away from the central frequency, it is necessary to perform frequency hopping to the low frequency band. In this case, MCU 330 can use the direction of frequency reduction as the frequency hopping direction, that is, the second frequency range is offset to the low frequency direction relative to the first frequency range, and the starting frequency of the second frequency range is smaller than the starting frequency of the first frequency range. Furthermore, if the central interference frequency is equal to the central frequency of the first frequency range, it means that the central interference frequency is located at the center of the first frequency range. In this case, frequency hopping in any direction is acceptable. Therefore, MCU 330 can select a direction as the frequency hopping direction randomly or according to a preset rule, such as selecting the direction of frequency reduction.

[0151] For example, see Figure 7a The interference zeroing curve shown in the figure assumes that the sampling points within the elliptical area of ​​the figure are determined as interference frequencies, or, see Figure 7b In the digital signal diagram shown in the figure, the sampling points in the shallow gray rectangular area are determined as interference frequency points. Then: the sampling point range corresponding to the first frequency range is [0, 1000]. Therefore, the sampling point corresponding to the center frequency of the first frequency range is 500, and the sampling points corresponding to the interference frequency points are basically distributed in the range of 250 to 300. The sampling point corresponding to the center frequency of the interference frequency point is 275. Obviously, the sampling point 275 corresponding to the center frequency of the interference frequency point is smaller than the sampling point 500 corresponding to the center frequency of the first frequency range, indicating that most of the interference frequency points are distributed in the low frequency band, and the high frequency band is less affected by the interference signal. In this case, the MCU 330 can hop to the high frequency direction by controlling the signal generator 321. For example, please refer to Figure 7c , assuming that the signal generator 321 is originally Figure 7c In the first frequency range [35GHz, 45GHz] shown in (A), a first detection signal S1 is sent, and after frequency hopping to the high frequency direction, the first detection signal S1 can be Figure 7c A second detection signal S2 is emitted within the second frequency range [38GHz, 48GHz] shown in (B). The first frequency range [35GHz, 45GHz] and the second frequency range [38GHz, 48GHz] can be understood as line segments of different time periods intercepted on the same oblique line. For example, the first frequency range [35GHz, 45GHz] corresponds to a line segment within the time period of 10s to 50s on an oblique line, and the second frequency range [38GHz, 48GHz] corresponds to a line segment within the time period of 22s to 62s on the oblique line.

[0152] By adopting the above-mentioned determination method 2, according to the relative position of the central interference frequency point and the central frequency point of the first frequency range, it can be determined whether the interference frequency point is more inclined to the low frequency band or the high frequency band, and then the frequency range can be shifted in the opposite direction of the frequency band to which the interference frequency point is inclined, so that the interference frequency point moves in the direction away from the central frequency point relative to the offset frequency range, so as to quickly avoid the interference frequency point and jump to a position with small interference effect as soon as possible. Among them, the central frequency point of the interference frequency point can be calculated based on the various interference frequency points calculated in the aforementioned interference detection process, which is information that can be obtained by simple calculation based on existing information, and the calculation process is relatively simple, so it also helps to improve the speed of determining the frequency hopping direction.

[0153] Further, optionally, after determining the frequency hopping direction, the MCU 320 may control the signal generator 321 to hop one or more preset frequency band values ​​in the frequency hopping direction at a time. In other words, the second frequency range may have an offset of one or more preset frequency band values ​​relative to the first frequency range in the first direction. The preset frequency band value may be a preset value configured in the MCU 320, and its value may be flexibly adjusted according to user needs or actual scenarios. Taking frequency hopping in the direction of increasing frequency as an example, please refer to Figure 8 , showing the frequency modulation diagram corresponding to the detection signal with different frequency hopping amplitudes. The figure takes the preset frequency band value of 1GHz as an example, where Figure 8 (A) shows the frequency modulation diagram of the first detection signal S1. Figure 8 (B) shows a frequency modulation diagram of the second detection signal S21 which jumps by a preset frequency band value at a time. Figure 8 (C) shows the frequency modulation diagram of the second detection signal S22 that jumps 5 preset frequency band values ​​at a time. It can be seen that the starting frequency of the second detection signal S21 is 1GHz higher than the starting frequency of the first detection signal S1, and the starting frequency of the second detection signal S21 is 5GHz higher than the starting frequency of the first detection signal S1. The second detection signal S21 and the second detection signal S22 have the same wave duration as the first detection signal S1.

[0154] Further, optionally, in order to jump out of the frequency band where the interference frequency point is located at one time, the MCU 320 can also control the signal generator 321 to jump half the bandwidth of the first frequency range in the frequency hopping direction at one time. In other words, the second frequency range can have a half bandwidth offset in the first direction relative to the first frequency range. For example, assuming that the bandwidth of the first frequency range is 200GHz, please refer to Figure 8 In (D), the frequency modulation diagram of the second detection signal S23 with a half bandwidth jump is shown. Figure 8 Compared with the first detection signal S1 shown in (A), the starting frequency of the second detection signal S23 is half the bandwidth higher than the starting frequency of the first detection signal S1, that is, 100GHz, and the second detection signal S23 has the same wave duration as the first detection signal S1. In this way, by jumping half the bandwidth at a time, it is highly likely that the second frequency range can directly avoid the interference frequency point, which helps to further speed up the speed of jumping out of the interference frequency band.

[0155] In the above scheme, jumping half the bandwidth at a time can directly jump out of the interference frequency band with a high probability, and jumping one or more frequency points at a time, although it may not be possible to directly avoid the interference frequency point, it can also move the interference frequency point in the direction away from the center frequency point of the first frequency range. Combined with the introduction of the core area and non-core area in the term explanation section, it can be seen that the farther the interference frequency point is from the center frequency point, the less the interference frequency point raises the real background noise information, so that the weak target is submerged in the real background noise information less, and the interference effect is smaller.

[0156] For example, taking non-single tone interference as an example, please refer to Fig. 9 , shows a comparison diagram of the interference noise floor curve before and after frequency hopping, wherein curve L1 is the interference noise floor curve corresponding to the detection using the first frequency range before frequency hopping, and curve L2 is the interference noise floor curve corresponding to the detection using the second frequency range after frequency hopping. It can be seen that due to the presence of interference signals, the amplitude of the interference noise floor information is generally high, resulting in the amplitude of the interference noise floor information before frequency hopping being basically greater than 35dB, which is much higher than the noise floor information in an interference-free environment. If interference suppression is not performed, the noise floor will greatly reduce the performance of target detection, affect the detection accuracy of weak targets, and cause target missed detection. After frequency hopping in the aforementioned manner, the amplitude of the interference noise floor information after frequency hopping is stabilized at 20dB, which is about 15dB better than the interference noise floor information before frequency hopping. It can be seen that the frequency hopping direction is correct and can better avoid the interference frequency point, thereby enabling the interference after frequency hopping to be better detected and suppressed, greatly enhancing the performance of target detection and effectively avoiding target missed detection.

[0157] It should be noted that the distribution characteristics of the interference frequency points within the first frequency range may also include other characteristics, not limited to the above-mentioned distribution position characteristics. Similarly, the frequency hopping amplitude may also include other amplitudes, not limited to the above-mentioned one or more preset frequency band values ​​or half the system bandwidth. For example, in other examples, the distribution characteristics of the interference frequency points within the first frequency range may also include the density of the distribution. After the MCU330 determines the area where the interference frequency points are densely distributed, it chooses to perform frequency hopping in the direction where the distribution is not dense. Or, in another example, the first frequency range may also be divided into 3 or more sections, each section corresponding to a frequency hopping value, for example, the section farther away from the center frequency point of the first frequency range corresponds to a smaller frequency hopping value, and the section closer to the center frequency point of the first frequency range corresponds to a larger frequency hopping value. According to the section where the center interference frequency point is located, the frequency hopping value corresponding to the section is jumped in the direction away from the center frequency point of the first frequency range, so that the interference frequency points distributed in any section can directly jump out of the interference frequency band once or a few times, further reducing the number of frequency hopping. It can be understood that there are many possible implementation methods, which are not listed here one by one.

[0158] The above content introduces how to perform frequency hopping according to the distribution position of the interference frequency points within the historical detection frequency. Usually, one frequency hopping may not be able to completely avoid the interference frequency points. Therefore, in some scenarios, it is also possible to determine whether to hop again based on the interference changes before and after the frequency hopping. Optionally, the interference changes before and after the frequency hopping can be measured by any one or more indicators that can reflect the degree of interference impact, such as the change of the interference background noise before and after the frequency hopping, the change of the number of interference points before and after the frequency hopping, and the change of the distribution frequency band of the interference points before and after the frequency hopping. Exemplarily, the following takes the change of the interference background noise before and after the frequency hopping as an example to introduce in detail how to refer to this indicator to perform frequency hopping again. The implementation of other indicators can be referred to and executed, and this application will not repeat the introduction.

[0159] See also Fig.10 , showing a flow chart of a frequency hopping method provided by the present application, the method comprising the following steps:

[0160] Step 1001: The detection device sends a second detection signal within a second frequency range and receives a second echo signal, where the second echo signal is an echo signal of the second detection signal.

[0161] Here, the second frequency range is a frequency range after frequency hopping of the first frequency range. The frequency hopping process can refer to the relevant contents in the above steps 401 to 403, which will not be repeated here.

[0162] Optionally, the second echo signal includes a signal in which the second detection signal is reflected and / or scattered by the target, and may also include an interference signal, such as a detection signal emitted by other radars, an echo signal corresponding to a detection signal emitted by other radars, and an interference signal formed when the detection signal of this radar is reflected or scattered inside the radar and transmitted to the receiver.

[0163] Step 1002: The detection device determines second interference background noise information corresponding to the second echo signal, and determines a second background noise difference between the second interference background noise information and the environment background noise information.

[0164] Optionally, see Figure 3 The second echo signal is mixed with the second detection signal by the mixer 322, high-frequency components are filtered out by the low-pass filter 323, and analog-to-digital conversion is performed by the ADC 324, and then converted into a digital signal. The digital signal is sent to the DSP 325, and then the distribution characteristics of the second echo signal in the distance dimension are obtained after 1D-FFT processing by the DSP 325. Among them, the distribution characteristics of the echo signal in the distance dimension include not only the amplitude of the target in the distance dimension, but also the interference background noise curve, such as Figure 5b shown.

[0165] Further, optionally, the second noise floor difference can be understood as the difference between the nearly stable noise floor amplitude in the second interference noise floor information and the nearly stable noise floor amplitude in the ambient noise floor information. Fig.11 , showing a schematic diagram of the comparison of interference noise floor curves before and after frequency hopping provided by the present application. The illustrated curve L2 represents the second interference noise floor curve corresponding to the second echo signal, which is used to characterize the noise impact of an environment with interference on a radar using a second frequency range for detection, and the illustrated curve L0 represents the environmental noise floor curve, which is used to characterize the noise impact of an environment without interference on the radar. The amplitude that approaches stability on the second interference noise floor curve L2 is 33dB, while the amplitude that approaches stability on the environmental noise floor curve L0 is 30dB. Therefore, the second noise floor difference can be considered to be the difference between 33dB and 30dB, that is, 3dB.

[0166] Step 1003: The detection device compares the second noise floor difference, the preset noise floor difference and the first noise floor difference:

[0167] When the second background noise difference is less than or equal to the preset background noise difference, executing step 1004;

[0168] When the second noise floor difference is greater than the preset noise floor difference but less than or equal to the first noise floor difference, executing step 1005;

[0169] When the second noise floor difference is greater than the preset noise floor difference and greater than the first noise floor difference, step 1006 is executed.

[0170] Optionally, the preset noise floor difference can be considered as an acceptable noise floor difference for the radar in the current application scenario, and can generally be configured as a noise floor difference that has a relatively small impact on radar echo detection. It can be configured by technical personnel in this field based on experience, or it can be configured according to actual scenario requirements, or it can be configured by user instructions, etc., without specific limitation.

[0171] Further, optionally, the first noise floor difference can be understood as the noise floor difference between the first interference noise floor information and the environment noise floor information corresponding to the first echo signal. The first interference noise floor information can be obtained by performing 1D-FFT processing on the digital signal from ADC 324 by DSP 325 during the previous frame detection, and is used to characterize the noise impact of the environment with interference on the radar using the first frequency range for detection. For example, refer to Fig.11 Assuming that curve L1 represents the first interference noise floor curve corresponding to the first echo signal, the amplitude that approaches stability on the first interference noise floor curve L1 is 40dB, and the amplitude that approaches stability on the environmental noise floor curve L0 is 30dB. Therefore, the first noise floor difference can be considered to be the difference between 40dB and 30dB, that is, 10dB.

[0172] Step 1004: The detection device sends a third detection signal within the second frequency range.

[0173] Optionally, the third detection signal may be one or more signals used to perform next frame detection, or may be one or more signals located after the second detection signal used to perform current frame detection, without specific limitation.

[0174] It is understandable that when the second noise floor difference is less than the preset noise floor difference, it means that although there is interference in the current environment, the noise impact of the interference on the detection signal emitted in the second frequency range can be ignored, and it is acceptable noise in the current scenario. In this case, MCU 330 can control the signal generator 321 to continue to use the second frequency range to perform subsequent detections, such as sending a third detection signal within the second frequency range. In this way, by setting a start threshold for re-frequency hopping, scenarios that do not require re-frequency hopping can be accurately detected, thereby avoiding meaningless frequency hopping and wasting resources.

[0175] Step 1005: The detection device sends a third detection signal within a third frequency range, where the third frequency range is offset in a first direction relative to the second frequency range.

[0176] It can be understood that when the second noise floor difference is less than the first noise floor difference but greater than the preset noise floor difference, it means that the interference noise corresponding to the second frequency range after frequency hopping is optimized compared to the interference noise corresponding to the first frequency range before frequency hopping, but still does not reach the noise range acceptable to the radar. Therefore, it can be considered that the first direction of hopping from the first frequency range to the second frequency range is correct, but the previous frequency hopping may not have avoided the interference frequency well. In this case, MCU 330 can determine to continue frequency hopping in the first direction to continue to optimize the interference noise, and repeat the above process until the noise range acceptable to the radar is reached.

[0177] Further, optionally, after determining to continue frequency hopping in the first direction, the MCU 330 may also first determine a first edge frequency of the second frequency range in the first direction, and determine a second edge frequency of the detectable frequency range of the detection device in the first direction, and compare the first edge frequency with the second edge frequency:

[0178] If the first edge frequency is less than the second edge frequency, it means that the second frequency range has not touched the edge of the detectable frequency range, and has not yet jumped to the most edge frequency point. It can continue to hop in the first direction. In this case, the MCU 330 can control the signal generator 321 to perform frequency hopping in the first direction. For example, the control signal generator 321 continues to shift the second frequency range along the first direction to obtain the third frequency range, and then sends a third detection signal in the third frequency range. Among them, the third frequency range can have an offset of a preset frequency band value relative to the second frequency range, and can also have an offset of multiple preset frequency band values, and can also have an offset of half the bandwidth, etc., which is not specifically limited;

[0179] On the contrary, if the first edge frequency is equal to the second edge frequency, it means that the second frequency range has touched the edge of the detectable frequency range, and has currently jumped to the most edge frequency point, and can no longer continue to hop in the first direction. In this case, the MCU 330 can control the signal generator 321 to perform frequency hopping in the opposite direction (i.e., the second direction) of the first direction. For example, the control signal generator 321 shifts the second frequency range along the second direction to obtain the fifth frequency range, and then sends the third detection signal in the fifth frequency range. Among them, the fifth frequency range can have one or more frequency offsets relative to the second frequency range. For example, in order to avoid jumping back to the first frequency range with more serious bottom noise, more frequency points can be offset at one time, such as offsetting to the edge of the second direction, so that the edge frequency of the fifth frequency range in the second direction is the edge frequency of the detectable frequency range in the second direction, so as to facilitate re-detection from the most edge position in the opposite direction.

[0180] Step 1006: The detection device sends a third detection signal within a fourth frequency range, the fourth frequency range is offset in a second direction relative to the second frequency range, and the second direction is opposite to the first direction.

[0181] It can be understood that when the second noise floor difference is greater than the first noise floor difference, it means that the interference noise corresponding to the second frequency range after frequency hopping has become worse than the interference noise corresponding to the first frequency range before frequency hopping. This frequency hopping not only does not optimize the noise floor but also degrades the noise floor. Therefore, it can be considered that the first direction of jumping from the first frequency range to the second frequency range is wrong, and the frequency hopping should be performed in the opposite direction of the first direction (i.e., the second direction). In this case, the MCU 330 can control the signal generator 321 to shift the second frequency range along the second direction to obtain a fourth frequency range, and then send a third detection signal in the fourth frequency range. Among them, the fourth frequency range can have an offset of a preset frequency band value relative to the second frequency range, and can also have an offset of multiple preset frequency band values, and can also have an offset of half the bandwidth, etc., which is not specifically limited. In this way, by hopping in the opposite direction after determining that the noise floor has deteriorated, the scene of the wrong frequency hopping direction can be accurately monitored, and corrections can be made in time to ensure that the frequency hopping is always in the correct direction, saving the time cost of jumping to the interference-free frequency band.

[0182] In order to facilitate understanding of the various frequency hopping schemes given in the above steps 1004 to 1006, a specific example is given below for illustration. In this example, assuming that the detectable frequency range of the detection device is [30 GHz, 300 GHz], and the first direction is the direction of increasing frequency, then:

[0183] Scenario 1 (corresponding to the above step 1004), assuming that the detection device has previously hopped from the first frequency range [230 GHz, 280 GHz] to the second frequency range [240 GHz, 290 GHz], and the noise floor after the frequency hopping reaches the ideal noise floor, the MCU 330 may determine not to hop the frequency, for example, the signal generator 321 may be controlled to continue to send the third detection signal in the second frequency range [240 GHz, 290 GHz].

[0184] Scenario 2 (corresponding to the branch that does not jump to the edge frequency point in the above step 1005), assuming that the detection device has previously hopped from the first frequency range [230GHz, 280GHz] to the second frequency range [240GHz, 290GHz], and the noise floor has improved after the frequency hopping but has not yet reached the ideal noise floor, then the MCU 330 can determine to continue hopping in the direction of increasing the frequency. In addition, since the maximum frequency point 290GHz of the second frequency range [240GHz, 290GHz] is less than the maximum detectable frequency point 300GHz of the detectable frequency range [30GHz, 300GHz], it means that the maximum frequency point has not yet been jumped. Therefore, the MCU 330 can control the signal generator 321 to perform frequency hopping in the high frequency direction, for example, control the signal generator 321 to send a third detection signal in the third frequency range [250GHz, 300GHz];

[0185] Scenario three (corresponding to the branch that has jumped to the edge frequency in the above step 1005), assuming that the detection device has previously jumped from the first frequency range [230GHz, 280GHz] to the second frequency range [250GHz, 300GHz], and the noise floor has improved after the frequency hopping but has not yet reached the ideal noise floor, then the MCU 330 can determine to continue to hop in the direction of increasing the frequency. However, since the maximum frequency point of 300GHz in the second frequency range [250GHz, 300GHz] is exactly equal to the maximum detectable frequency point of 300GHz in the detectable frequency range [30GHz, 300GHz], it means that the maximum frequency point has been jumped and it is no longer possible to continue to jump to the high frequency. Therefore, the MCU 330 can determine to hop in the opposite direction, for example, it can jump to the lowest detectable frequency point of 30GHz at one time. In other words, the control signal generator 321 sends the third detection signal in the fifth frequency range [30GHz, 80GHz];

[0186] Scenario four (corresponding to the above step 1006), assuming that the detection device has previously hopped from the first frequency range [230GHz, 280GHz] to the second frequency range [250GHz, 300GHz], and after the frequency hopping, not only the ideal noise floor is not achieved, but the noise floor is worse than before the frequency hopping, then the MCU 330 can determine to hop in the opposite direction, for example, the control signal generator 321 sends a third detection signal in the fourth frequency range [240GHz, 290GHz].

[0187] use Fig.10 The scheme shown, by analyzing the background noise information before and after the frequency hopping, can further decide whether to continue the frequency hopping according to the change of the background noise information, and when it is determined to continue the frequency hopping, locate the direction of the next frequency hopping, so that the detection device can gradually jump to the frequency range that meets the ideal background noise through multiple frequency hopping, and then accurately avoid the interference frequency points in the current environment, effectively increase the proportion of effective signals contained in the echo signal, reduce the difficulty of subsequent interference suppression, and improve the accuracy of detection.

[0188] The foregoing content mainly introduces how to avoid interference frequencies by one or more frequency hopping. Optionally, in order to determine the reliability of the frequency hopping scheme so as to optimize the frequency hopping scheme when the reliability is poor, the present application may also provide a method for determining the credibility of frequency hopping. The method may be executed by a detection device, or may be executed by other devices after obtaining relevant information from the detection device, and the specific implementation is not limited. The following takes the detection device executing the method as an example to describe the specific implementation of the method in detail.

[0189] See also Fig.12 , is a flow chart of a method for determining frequency hopping credibility provided by the present application, the method comprising the following steps:

[0190] Step 1201: The detection device determines the value of the current frequency hopping under a preset evaluation index according to the echo signal after the frequency hopping.

[0191] Optionally, the preset evaluation index may be any one or more indexes that can reflect the interference avoidance performance or the interference suppression performance, such as: a background noise distribution index and an interference distribution index, etc. The following describes these two indexes and the corresponding value methods in detail.

[0192] Noise distribution index

[0193] The noise floor distribution index is used to characterize the impact of this frequency hopping on the noise floor distribution characteristics, such as the impact on the lifting of the interference noise floor information in the echo signal. When the lifting of the interference noise floor information after the frequency hopping is smaller, the value of this frequency hopping under the noise floor distribution index can be higher; when the lifting of the interference noise floor information after the frequency hopping is larger, the value of this frequency hopping under the noise floor distribution index can be lower.

[0194] In a possible value-taking method, a correspondence between a noise floor difference range and a value can be preconfigured, and the correspondence includes multiple noise floor difference ranges, each noise floor difference range corresponds to a value, and when the noise floor difference range is larger, it means that the interference has a more serious impact on the noise floor and the credibility is worse, so the value can be set smaller. Then, based on the correspondence between the noise floor difference range and the value, taking frequency hopping from the first frequency range to the second frequency range as an example, after the detection device sends a second detection signal within the second frequency range and receives a second echo signal, the MCU 330 can obtain the second interference noise floor information corresponding to the second echo signal in the manner of the aforementioned step 1002, and calculate the second noise floor difference between the second interference noise floor information and the ambient noise floor information, and then determine the noise floor difference range to which the second noise floor difference belongs from the correspondence between the noise floor difference range and the value, and then the value corresponding to the noise floor difference range can be used as the value of this frequency hopping under the noise floor distribution index.

[0195] For example, assume that the ambient noise floor information is stable at 100 dB, and the corresponding relationship between the noise floor difference range and the value is configured as shown in Table 1 below:

[0196] Table 1

[0197] Noise floor difference range (dB) Value [0，10) 100 [10，20) 70 [20，30) 40 [30，+∞) 0

[0198] Then: when the second interference noise floor information is stable at 113dB, the second noise floor difference is 13dB, which is within the noise floor difference range of [10, 20), therefore, MCU 330 can use the value 70 corresponding to the noise floor difference range as the value of this frequency hopping under the noise floor distribution index; when the second interference noise floor information is stable at 105dB, the second noise floor difference is 5dB, which is within the noise floor difference range of [0, 10), therefore, MCU 330 can use the value 100 corresponding to the noise floor difference range as the value of this frequency hopping under the noise floor distribution index. And so on, which will not be listed one by one here.

[0199] In the above-mentioned value-taking method, the value of this frequency hopping under the background noise distribution index is determined by referring to the background noise difference after this frequency hopping, so that the value can be used to represent the lifting effect of this frequency hopping on the background noise information, and then can be used as a parameter to measure the credibility of the frequency hopping. In addition, the above-mentioned value-taking method pre-configures the corresponding relationship between the background noise difference range and the value, so the value can be obtained by querying the corresponding relationship. The value-taking method is relatively simple, which helps to improve the credibility evaluation speed.

[0200] Interference distribution index

[0201] The interference distribution index is used to characterize the impact of this frequency hopping on the interference distribution characteristics, such as the degree to which the echo signal after the frequency hopping is affected by the interference frequency. The smaller the degree to which the echo signal after the frequency hopping is affected by the interference frequency, the larger the value of this frequency hopping under the interference distribution index can be; and the greater the degree to which the echo signal after the frequency hopping is affected by the interference frequency, the smaller the value of this frequency hopping under the interference distribution index can be.

[0202] In a possible value-taking method, considering that the influence of interference frequencies on echo signals can be determined by the number of interference frequencies and the distribution positions of the frequencies, the corresponding relationship between the number range and the value and the corresponding relationship between the frequency range and the weight can be preconfigured. In the corresponding relationship between the number range and the value, the larger the number range, the more interference frequencies there are, and the greater the influence on the echo signal, so the corresponding value can be configured smaller. In the corresponding relationship between the frequency range and the weight, the farther the frequency range is from the center frequency of the radar, the smaller the increase in the background noise information, that is, the smaller the influence on the echo signal, so the corresponding weight can be configured larger. Then, based on these two corresponding relationships, still taking frequency hopping from the first frequency range to the second frequency range as an example, after the detection device sends the second detection signal in the second frequency range and receives the second echo signal, the MCU 330 can obtain the interference zeroing curve contained in the second echo signal from the ADC 324 (refer to the aforementioned step 402), and can determine the number of zeroing points corresponding to each interference frequency point from the interference zeroing curve, and then determine the number range to which the number of zeroing points of each interference frequency point belongs from the corresponding relationship between the number range and the value, and determine the frequency range to which each interference frequency point belongs from the corresponding relationship between the frequency range and the weight, and then calculate the product of the score corresponding to the number range to which each interference frequency point belongs and the weight corresponding to the frequency range to which the interference frequency point belongs, and use it as the value corresponding to each interference frequency point, and then superimpose the values ​​corresponding to each interference frequency point to obtain the value of this frequency hopping under the interference distribution index, for example, use the average value or weighted average value of the values ​​corresponding to each interference frequency point as the value of this frequency hopping under the interference distribution index.

[0203] For example, taking the average value of the values ​​corresponding to each interference frequency point as the value of this frequency hopping under the interference distribution index, assuming that the central frequency point of the radar is 77GHz, the corresponding relationship between the number range and the value is configured as shown in the following Table 2.1, and the corresponding relationship between the frequency point range and the weight is configured as shown in the following Table 2.2:

[0204] Table 2.1

[0205] Quantity range Value [0，10) 100 [10，20) 90 …… …… [90，100) 10 [100，+∞) 0

[0206] Table 3

[0207] Frequency range(GHz) Weight [30，50) 0.5 [50，72) 0.1 [72，82] 0 (82，104] 0.5 (104，300] 1

[0208] but:

[0209] When the second echo signal contains 15 interference frequencies, 10 of which are distributed in the frequency range of [30, 50) and 5 of which are distributed in the frequency range of [50, 72], the value corresponding to the number range [10, 20) to which the 10 interference frequencies belong is 90, and the weight corresponding to the frequency range [30, 50) is 0.5, the value corresponding to the number range [0, 10) to which the 5 interference frequencies belong is 100, and the weight corresponding to the frequency range [50, 72] is 0.1. Therefore, the MCU 330 can determine the value of this frequency hopping under the interference distribution index as follows: That is 52.5;

[0210] When the second echo signal contains 94 interference frequencies, 90 of which are distributed in the frequency range of (82, 104] and 4 of which are distributed in the frequency range of (104, 300], the value corresponding to the number range [90, 100] to which the 90 interference frequencies belong is 10, and the weight corresponding to the frequency range (82, 104) is 0.5, the value corresponding to the number range [0, 10) to which the 4 interference frequencies belong is 100, and the weight corresponding to the frequency range (104, 300) is 1. Therefore, the MCU 330 can determine the value of this frequency hopping under the interference distribution index as follows: That is 52.5.

[0211] In the above-mentioned value-taking method, the value of this frequency hopping under the interference distribution index is determined by comprehensively referring to the number of interference frequencies after this frequency hopping and the distance of the interference frequencies relative to the center frequency, so that the value can be used to accurately characterize the degree of influence of the interference frequencies on this frequency hopping, and can be used as a parameter to measure the credibility of the frequency hopping. In addition, the above-mentioned value-taking method pre-configures the corresponding relationship between the data range and the value and the corresponding relationship between the frequency range and the weight. Therefore, by querying these two corresponding relationships and performing simple addition and product, the value of the interference distribution index can be obtained. The calculation method is relatively simple, which helps to improve the evaluation speed of credibility.

[0212] It should be noted that the above content is only an illustrative introduction to a possible way of taking values ​​of the background noise distribution index and the interference distribution index. Other ways of taking values ​​may also be used in actual detection devices. Any way of taking values ​​that can reflect that the greater the background noise impact, the smaller the value or the greater the interference impact, the smaller the value may be accepted, and this application does not make any specific limitations on this.

[0213] Step 1202: The detection device determines the credibility of the current frequency hopping according to the value of the current frequency hopping under the preset evaluation index.

[0214] Optionally, the detection device can calculate the credibility of the current frequency hopping based on the values ​​of the current frequency hopping under various preset evaluation indicators, for example, the average value or weighted average value of the current frequency hopping under various preset evaluation indicators can be used as the credibility of the current frequency hopping. Taking the average value as an example, assuming that the MCU 330 calculates the value of the current frequency hopping under the background noise distribution indicator as 70 and the value under the interference distribution indicator as 52.5 in the manner of the above step 1201, the MCU 330 can determine the credibility of the current frequency hopping as: That is 61.25. The closer the credibility is to 100, the higher the credibility is, and the closer it is to 0, the lower the credibility is.

[0215] In the above implementation, the credibility of this frequency hopping is evaluated by combining the background noise distribution index and the interference distribution index, so that the credibility can at least take into account the two factors of background noise distribution characteristics and interference distribution characteristics after frequency hopping. The evaluation reference factors are relatively comprehensive, which helps to improve the accuracy of credibility evaluation.

[0216] It is understandable that in addition to the background noise distribution index and the interference distribution index, there may be other evaluation indexes. For example, in some scenarios, an interference suppression threshold index may be configured. This index is used to characterize the influence of the interference suppression threshold updated according to the interference distribution characteristics of the previous frame (see the aforementioned step 402 for details) on the interference detection of the next frame detection. When the updated interference suppression threshold makes the interference detection result of the next frame detection more accurate, the value of this index may be larger. When the updated interference suppression threshold makes the interference detection result of the next frame detection less accurate, the value of this index may be smaller. For the relevant content of this index, please refer to the existing explanation, and this application will not be introduced in detail.

[0217] Based on the above detection method, the present application also provides a detection device. Fig.13 , which is a possible structural diagram of the detection device provided in the present application. The detection device 1300 can be used to implement the functions of the detection device in the above method embodiment, and thus can also achieve the beneficial effects possessed by the above method embodiment.

[0218] like Fig.13 As shown, the detection device 1300 includes a processor 1301 and a transceiver 1302. The detection device 1300 is used to implement the above Figure 4 , Fig.10 or Fig.12 Optionally, the detection device 1300 may further include a memory 1303, which may be coupled to the processor 1301 to store necessary program instructions and data for the detection device 1300.

[0219] When the detection device 1300 is used to implement Figure 4 The function of the detection device of the method embodiment shown is: the processor 1301 is used to send a first detection signal within a first frequency range through the transceiver 1302, and receive a first echo signal, and then send a second detection signal within a second frequency range; wherein the first echo signal includes a signal of the first detection signal reflected by the target, and the second frequency range is offset in a first direction relative to the first frequency range, and the first direction is determined based on the distribution characteristics of the interference frequency points in the first echo signal within the first frequency range.

[0220] For a more detailed description of the processor 1301 and the transceiver 1302, please refer to Figure 4 The relevant descriptions in the method embodiment shown are directly obtained and will not be repeated here.

[0221] It should be understood that the processor 1301 in the embodiment of the present application can be implemented by a processor or a processor-related circuit module, and the transceiver 1302 can be implemented by an interface circuit or an interface circuit-related circuit module.

[0222] Based on the above detection method, the present application also provides a detection device. The detection device may be, for example, a millimeter wave radar. Fig.14 , which is a possible structural schematic diagram of the detection device provided in the present application. The detection device 1400 includes a transmitting module 1401, a receiving module 1402 and a control module 1403. Among them, the transmitting module 1401 is used to send a first detection signal within a first frequency range; the receiving module 1402 is used to receive a first echo signal, and the first echo signal is an echo signal of the first detection signal; the control module 1403 is used to determine the first direction according to the distribution characteristics of the interference frequency point in the first echo signal within the first frequency range; the transmitting module 1401 is also used to send a second detection signal within a second frequency range, and the second frequency range has an offset in the first direction relative to the first frequency range. Optionally, the detection device 1400 may also include a processing module 1404, and the processing module 1404 is used to perform interference detection on the first echo signal, determine the interference frequency point in the first echo signal, and can also perform interference suppression on the first echo signal according to the interference frequency point.

[0223] The transmitting module 1401 can be understood as the aforementioned transmitter, such as the transmitter 3101. The receiving module 1402 can be understood as the aforementioned receiver, such as the receiver 3102. The control module 1403 can be understood as the aforementioned MCU 330. The processing module 1404 can be understood as the aforementioned MMCI 320. The functions of the transmitting module 1401, the receiving module 1402, the control module 1403 and the processing module 1404 can refer to the aforementioned description of the transmitter, the receiver, the MCU and the MMIC, which will not be repeated here.

[0224] Based on the aforementioned detection device, the present application also provides a terminal device. The terminal device may include any detection device in the aforementioned content, such as detection device 1300 or detection device 1400. Further, optionally, the terminal device may also include a memory, and the memory is used to store programs or instructions. Of course, the terminal device may also include other devices, such as a wireless control device, etc.

[0225] Exemplarily, the terminal device can be, for example, a vehicle (such as an unmanned vehicle, a smart vehicle, an electric vehicle, or a digital car), a robot, a surveying and mapping equipment, a drone, a smart home device (such as a television, a sweeping robot, a smart desk lamp, an audio system, a smart lighting system, an electrical appliance control system, home background music, a home theater system, an intercom system, or video surveillance, etc.), smart manufacturing equipment (such as industrial equipment), smart transportation equipment (such as AGV, an unmanned transport vehicle, or a truck, etc.), or a smart terminal (a mobile phone, a computer, a tablet computer, a PDA, a desktop computer, headphones, audio, wearable devices, vehicle-mounted devices, virtual reality devices, augmented reality devices, etc.), etc.

[0226] Based on the above detection method, the present application also provides a chip, which includes at least one processor and an interface circuit. Further, optionally, the chip may also include a memory, and the processor is used to execute a computer program or instruction stored in the memory, so that the chip executes the above Figure 4 , Fig.10 or Fig.12 The method described in any embodiment.

[0227] Based on the above detection method, the present application also provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by the detection device, the detection device executes the above Figure 4 , Fig.10 or Fig.12 The method described in any one of the embodiments.

[0228] Based on the above detection method, the present application also provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a detection device, the detection device executes the above Figure 4 , Fig.10 or Fig.12 The method described in any one of the embodiments.

[0229] In the present application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple. In the text description of the present application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship. In the formula of the present application, the character " / " indicates that the associated objects before and after are in a "divided" relationship. In addition, in the present application, the word "exemplarily" is used to indicate examples, illustrations or explanations. Any embodiment or design described as an "example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Alternatively, it can be understood that the use of the word "example" is intended to present concepts in a specific way and does not constitute a limitation on this application.

[0230] It is to be understood that the various digital numbers involved in the present application are only for the convenience of description and are not intended to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic. The terms "first", "second" and similar expressions are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, including a series of steps or units. Methods, systems, products or equipment are not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

Claims

1. A detection method, characterized in that: include: Sending a first detection signal within a first frequency range; receiving a first echo signal, where the first echo signal is an echo signal of the first detection signal; A second detection signal is sent within a second frequency range, wherein the second frequency range is offset in a first direction relative to the first frequency range, and the first direction is determined based on distribution characteristics of interference frequency points in the first echo signal within the first frequency range.

2. The method according to claim 1, characterized in that The interference frequency point is a central frequency point of the frequency at which the interference signal overlaps with the first detection signal.

3. The method according to claim 1 or 2, characterized in that Before sending the second detection signal within the second frequency range, the method further includes: It is determined that at least a first preset number of continuous echo signals in a plurality of frames of echo signals are interfered, and the plurality of frames of echo signals are echo signals detected using the first frequency range.

4. The method according to any one of claims 1 to 3, characterized in that The first direction is determined according to distribution characteristics of interference frequency points in the first echo signal within the first frequency range, including: In the first frequency range, if the number of interference frequency points included in the low frequency band part is greater than the number of interference frequency points included in the high frequency band part, the first direction is a direction of increasing frequency; if the number of interference frequency points included in the low frequency band part is less than or equal to the number of interference frequency points included in the high frequency band part, the first direction is a direction of decreasing frequency; The low frequency band part is a part of the first frequency range that is lower than the center frequency point of the first frequency range, and the high frequency band part is a part of the first frequency range that is higher than the center frequency point of the first frequency range.

5. The method according to any one of claims 1 to 3, characterized in that The first direction is determined according to distribution characteristics of interference frequency points in the first echo signal within the first frequency range, including: If the central interference frequency is less than the central frequency of the first frequency range, the first direction is a direction of increasing frequency; if the central interference frequency is greater than or equal to the central frequency of the first frequency range, the first direction is a direction of decreasing frequency; The central interference frequency point is an interference frequency point located at the center position among all interference frequency points of the first echo signal.

6. The method according to any one of claims 1 to 5, characterized in that The second frequency range has an offset of one or more preset frequency band values ​​relative to the first frequency range in the first direction.

7. The method according to any one of claims 1 to 6, characterized in that The second frequency range has a 2 in the first direction relative to the first frequency range. B , and B is the bandwidth of the first frequency range.

8. The method according to any one of claims 1 to 7, characterized in that After sending the second detection signal within the second frequency range, the method further includes: receiving a second echo signal, where the second echo signal is an echo signal of the second detection signal; Determine second background noise information corresponding to the second echo signal, and determine a second background noise difference between the second background noise information and the environment background noise information, and when the second background noise difference is greater than a preset background noise difference and less than or equal to the first background noise difference, send a third detection signal within a third frequency range, and the third frequency range has an offset in the first direction relative to the second frequency range; The first noise floor difference is the noise floor difference between the first noise floor information corresponding to the first echo signal and the environmental noise floor information, and the environmental noise floor information is the noise floor information measured in an interference-free environment.

9. The method according to claim 8, characterized in that The method further comprises: If the second background noise difference is greater than the preset background noise difference and greater than the first background noise difference, the third detection signal is sent within a fourth frequency range, and the fourth frequency range is offset in a second direction relative to the second frequency range, and the second direction is opposite to the first direction.

10. The method according to claim 8 or 9, characterized in that Before sending the third detection signal within the third frequency range, the method further includes: It is determined that the edge frequency of the second frequency range in the first direction is smaller than the edge frequency of the detectable frequency range of the detection device in the first direction.

11. The method according to claim 10, characterized in that The method further comprises: If it is determined that the edge frequency of the second frequency range in the first direction is equal to the edge frequency of the detectable frequency range in the first direction, the third detection signal is sent within the fifth frequency range, the edge frequency of the fifth frequency range in the second direction is the edge frequency of the detectable frequency range in the second direction, and the second direction is opposite to the first direction.

12. A detection device, characterized in that: Including control module, transmitting module and receiving module; The transmitting module is used to send a first detection signal within a first frequency range; The receiving module is used to receive a first echo signal, where the first echo signal is an echo signal of the first detection signal; The control module is used to determine a first direction according to a distribution characteristic of interference frequency points in the first echo signal within the first frequency range, and determine a second frequency range according to the first frequency range and the first direction, wherein the second frequency range is offset in the first direction relative to the first frequency range; The transmitting module is also used to send a second detection signal within the second frequency range.

13. The detection device according to claim 12, characterized in that The interference frequency point is a central frequency point of the frequency at which the interference signal overlaps with the first detection signal.

14. The detection device according to claim 12 or 13, characterized in that: Before determining the first direction according to the distribution characteristics of the interference frequency points in the first echo signal within the first frequency range, the control module is further configured to: It is determined that at least a first preset number of continuous interference signals exist in a plurality of frames of echo signals, wherein the plurality of frames of echo signals are echo signals detected using the first frequency range.

15. The detection device according to any one of claims 12 to 14, characterized in that The control module is specifically used for: In the first frequency range, if the number of interference frequency points included in the low frequency band part is greater than the number of interference frequency points included in the high frequency band part, the first direction is determined to be a direction in which the frequency increases; if the number of interference frequency points included in the low frequency band part is less than or equal to the number of interference frequency points included in the high frequency band part, the first direction is determined to be a direction in which the frequency decreases; The low frequency band part is a part of the first frequency range that is lower than the center frequency point of the first frequency range, and the high frequency band part is a part of the first frequency range that is higher than the center frequency point of the first frequency range.

16. The detection device according to any one of claims 12 to 14, characterized in that The control module is specifically used for: If the central interference frequency is less than the central frequency of the first frequency range, the first direction is determined to be a direction of increasing frequency; if the central interference frequency is greater than or equal to the central frequency of the first frequency range, the first direction is determined to be a direction of decreasing frequency; The central interference frequency point is an interference frequency point located at the center position among all interference frequency points of the first echo signal.

17. The detection device according to any one of claims 12 to 16, characterized in that The second frequency range has an offset of one or more Ts relative to the first frequency range in the first direction, where T is a preset frequency band value.

18. The detection device according to any one of claims 12 to 17, characterized in that The second frequency range has a 2 in the first direction relative to the first frequency range. B , and B is the bandwidth of the first frequency range.

19. The detection device according to any one of claims 12 to 18, characterized in that After the transmitting module sends the second detection signal within the second frequency range: The receiving module is further used to: receive a second echo signal, where the second echo signal is an echo signal of the second detection signal; The control module is further used to: determine second background noise information corresponding to the second echo signal, and determine a second background noise difference between the second background noise information and the environmental background noise information; when the second background noise difference is greater than a preset background noise difference and less than or equal to the first background noise difference, determine a third frequency range according to the second frequency range and the first direction, and the third frequency range is offset in the first direction relative to the second frequency range; wherein the first background noise difference is the background noise difference between the first background noise information corresponding to the first echo signal and the environmental background noise information, and the environmental background noise information is the background noise information measured in an interference-free environment; The transmitting module is further used to send a third detection signal within the third frequency range.

20. The detection device according to claim 19, characterized in that The control module is further configured to: if the second noise floor difference is greater than the preset noise floor difference and greater than the first noise floor difference, determine a fourth frequency range according to the second frequency range and the second direction, wherein the fourth frequency range is offset in the second direction relative to the second frequency range, and the second direction is opposite to the first direction; The transmitting module is further used to send the third detection signal within the fourth frequency range.

21. The detection device according to claim 19 or 20, characterized in that Before the transmitting module sends the third detection signal within the third frequency range, the control module is further used to: It is determined that the edge frequency of the second frequency range in the first direction is smaller than the edge frequency of the detectable frequency range of the detection device in the first direction.

22. The detection device according to claim 21, characterized in that The control module is further configured to: if it is determined that the edge frequency of the second frequency range in the first direction is equal to the edge frequency of the detectable frequency range in the first direction, determine a fifth frequency range according to the detectable frequency range and the second direction, wherein the edge frequency of the fifth frequency range in the second direction is the edge frequency of the detectable frequency range in the second direction, and the second direction is opposite to the first direction; The transmitting module is further used to send the third detection signal within the fifth frequency range.

23. A terminal device, characterized in that: Comprising a detection device as claimed in any one of claims 12 to 22.

24. A computer-readable storage medium, characterized in that: A computer program or instruction is stored, and when the computer program or instruction is executed by the detection device, the detection device executes the method according to any one of claims 1 to 11.

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