Radar system, target detection method and unmanned device

Abstract

The embodiment of the invention provides a radar system, a target detection method and unmanned equipment, and relates to the technical field of radars. A signal processing module of the radar system alternately works in a first mode and a second mode, a radio frequency module is controlled to gate a transmitting antenna in a first mode in the first mode, and the radar system performs target detection based on a 4D imaging technology; in the second mode, the radio frequency module is controlled to gate the transmitting antenna in a second mode, and the radar system carries out target detection based on the phased array technology; the radio frequency module processes the echo signal received by the receiving antenna; and the signal processing module obtains target detection data according to a processing result of the echo signal. As the radar system can alternately work in the first mode and the second mode, target detection is carried out based on the 4D imaging technology in the first mode, and accurate measurement of a close-range target is realized; and in the second mode, target detection is carried out based on a phased array technology, and remote target detection is realized, so that various working scene requirements are met.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a radar system, a target detection method and unmanned equipment. Background Art

[0002] Millimeter-wave radar is a radar technology that uses electromagnetic waves with a wavelength of millimeter level to detect targets. It has a wide range of applications in the fields of automobile obstacle avoidance and imaging, drone obstacle avoidance and measurement, etc.

[0003] Existing millimeter-wave radars usually use phased array technology or 4D imaging technology for target detection. Millimeter-wave radars using 4D imaging technology can achieve accurate measurement of close-range targets, but cannot detect long-range targets; millimeter-wave radars using phased array technology can detect long-range targets, but the measurement accuracy is not high. Therefore, existing millimeter-wave radars have certain limitations in actual use and are difficult to meet the needs of a variety of work scenarios. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a radar system, a target detection method and an unmanned device, which can realize long-range target detection and close-range target precise measurement, thereby meeting the needs of various work scenarios.

[0005] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0006] In a first aspect, the present invention provides a radar system, the radar system comprising a signal processing module, a radio frequency module and an antenna array, the signal processing module is electrically connected to the radio frequency module, the radio frequency module is electrically connected to the antenna array; the antenna array comprises a multi-channel transmitting antenna and a multi-channel receiving antenna;

[0007] The radio frequency module is used to generate a radio frequency signal under the control of the signal processing module;

[0008] The signal processing module works alternately in a first mode and a second mode. In the first mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology; in the second mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology;

[0009] The radio frequency module is also used to receive the echo signal through the receiving antenna and process the echo signal;

[0010] The signal processing module is used to obtain target detection data according to the processing result of the echo signal.

[0011] In an optional implementation manner, the first manner is to control the RF module to alternately select one transmitting antenna, and transmit the RF signal through the selected transmitting antenna.

[0012] In an optional implementation, the second method is to control the RF module to select all transmitting antennas, and adjust the amplitude and phase of the RF signal to be transmitted by each transmitting antenna to change the direction and shape of the synthetic beam of the multiple transmitting antennas.

[0013] In an optional implementation, two ends of the multiple transmitting antennas are aligned and arranged in a direction perpendicular to the vertical direction, and two ends of the multiple receiving antennas are respectively arranged on two straight lines that form a preset angle with the vertical direction.

[0014] In an optional implementation, the radio frequency module is used to output a difference frequency signal according to the echo signal and the corresponding radio frequency signal; and the signal processing module is used to obtain target detection data according to the difference frequency signal.

[0015] In an optional embodiment, the radio frequency module includes a signal generator, a plurality of phased array chips and a mixer; the signal generator is electrically connected to the signal processing module, the plurality of phased array chips and the mixer; the plurality of phased array chips are electrically connected to the plurality of transmitting antennas in a one-to-one correspondence; the mixer is electrically connected to the signal processing module and the plurality of receiving antennas; the signal processing module is electrically connected to the plurality of phased array chips;

[0016] The signal generator is used to generate the radio frequency signal under the control of the signal processing module;

[0017] The signal processing module is used to control the plurality of phased array chips to be turned on alternately in the first mode, so as to alternately select one transmitting antenna to transmit the radio frequency signal; in the second mode, control the plurality of phased array chips to be turned on simultaneously, and adjust the amplitude and phase of the radio frequency signal passing through each phased array chip;

[0018] The mixer is used to mix the echo signal with the corresponding radio frequency signal to obtain the difference frequency signal.

[0019] In an optional implementation, the radio frequency module further includes a low noise amplifier and an operational amplifier, the operational amplifier is electrically connected between the signal processing module and the mixer, and the low noise amplifier is electrically connected between the mixer and the multiple receiving antennas;

[0020] The low noise amplifier is used to amplify the received echo signal and output the amplified echo signal to the mixer;

[0021] The mixer is used to mix the amplified echo signal with the corresponding radio frequency signal to obtain the difference frequency signal;

[0022] The operational amplifier is used to amplify the difference frequency signal and then output it to the signal processing module.

[0023] In an optional embodiment, the signal generator includes a phase-locked loop circuit, a crystal oscillator and a voltage-controlled oscillator, the phase-locked loop circuit is electrically connected to the crystal oscillator, the voltage-controlled oscillator and the signal processing module, and the voltage-controlled oscillator is also electrically connected to the mixer and the plurality of phased array chips;

[0024] The crystal oscillator is used to provide a reference clock for the phase-locked loop circuit;

[0025] The phase-locked loop circuit is used to output a control voltage under the control of the signal processing module;

[0026] The voltage controlled oscillator is used to output a radio frequency signal according to the control voltage.

[0027] In an optional embodiment, the signal processing module includes an analog-to-digital converter, a time-frequency analysis module and a controller, the analog-to-digital converter is electrically connected to the radio frequency module and the time-frequency analysis module, and the controller is electrically connected to the time-frequency analysis module and the radio frequency module;

[0028] The analog-to-digital converter is used to sample the processing result of the echo signal to obtain sampling data;

[0029] The time-frequency analysis module is used to perform time-frequency analysis on the sampled data to obtain corresponding frequency domain data;

[0030] The controller is used to obtain target detection data according to the frequency domain data.

[0031] In an optional embodiment, the time-frequency analysis module includes a preprocessing module and a fast Fourier transform module, the preprocessing module is electrically connected to the fast Fourier transform module and the analog-to-digital converter; the fast Fourier transform module is also electrically connected to the controller;

[0032] The preprocessing module is used to preprocess the sampled data;

[0033] The fast Fourier transform module is used to perform fast Fourier transform on the preprocessed sampled data to obtain corresponding frequency domain data.

[0034] In an optional embodiment, the signal processing module further includes a data storage module and a constant false alarm detection module, the data storage module is electrically connected between the analog-to-digital converter and the time-frequency analysis module, and the constant false alarm detection module is electrically connected between the time-frequency analysis module and the controller;

[0035] The data storage module is used to store the sampled data;

[0036] The constant false alarm detection module is used to detect frequency domain data of a valid target from the frequency domain data.

[0037] In an optional implementation, the signal processing module operates alternately in the first mode and the second mode according to a preset cycle.

[0038] In a second aspect, the present invention provides a target detection method, which is applied to a radar system, wherein the radar system includes a signal processing module, a radio frequency module and an antenna array, wherein the signal processing module is electrically connected to the radio frequency module, and the radio frequency module is electrically connected to the antenna array; the antenna array includes multiple transmitting antennas and multiple receiving antennas; the method includes:

[0039] The radio frequency module generates a radio frequency signal under the control of the signal processing module;

[0040] The signal processing module works alternately in a first mode and a second mode. In the first mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology; in the second mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology;

[0041] The radio frequency module receives the echo signal through the receiving antenna and processes the echo signal;

[0042] The signal processing module obtains target detection data according to the processing result of the echo signal.

[0043] In a third aspect, the present invention provides an unmanned device, comprising a main control module and the radar system described in any one of the aforementioned embodiments, wherein the main control module is communicatively connected with the signal processing module.

[0044] The radar system, target detection method and unmanned equipment provided by the embodiment of the present invention include a signal processing module, a radio frequency module and an antenna array, the signal processing module is electrically connected to the radio frequency module, and the radio frequency module is electrically connected to the antenna array; the antenna array includes a multi-channel transmitting antenna and a multi-channel receiving antenna; the radio frequency module generates a radio frequency signal under the control of the signal processing module; the signal processing module works alternately in a first mode and a second mode, in the first mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology; in the second mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology; the radio frequency module receives the echo signal through the receiving antenna and processes the echo signal; the signal processing module obtains the target detection data according to the processing result of the echo signal. Since the radar system can work alternately in the first mode and the second mode, in the first mode, the target detection is performed based on the 4D imaging technology, and the accurate measurement of close-range targets can be achieved; in the second mode, the target detection is performed based on the phased array technology, and the long-range target detection can be achieved, thereby meeting the needs of various working scenarios.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 A structural block diagram of a radar system provided by an embodiment of the present invention is shown;

[0048] Figure 2 A schematic diagram of the layout of an antenna array is shown;

[0049] Figure 3 Another structural block diagram of a radar system provided by an embodiment of the present invention is shown;

[0050] Figure 4 Another structural block diagram of a radar system provided by an embodiment of the present invention is shown;

[0051] Figure 5 Another structural block diagram of a radar system provided by an embodiment of the present invention is shown;

[0052] Figure 6Another structural block diagram of a radar system provided by an embodiment of the present invention is shown;

[0053] Figure 7 A schematic diagram of a process flow of a target detection method provided by an embodiment of the present invention is shown;

[0054] Figure 8 A structural block diagram of an unmanned device provided by an embodiment of the present invention is shown.

[0055] Icons: 100- radar system; 110- signal processing module; 120- radio frequency module; 130- antenna array; 131- transmitting antenna; 132- receiving antenna; 121- signal generator; 1211- phase-locked loop circuit; 1212- crystal oscillator; 1213- voltage-controlled oscillator; 122- phased array chip; 123- mixer; 124- low noise amplifier; 125- operational amplifier; 111- analog-to-digital converter; 112- time-frequency analysis module; 113- controller; 1121- preprocessing module; 1122- fast Fourier transform module; 114- data storage module; 115- constant false alarm detection module; 200- unmanned equipment; 210- main control module. DETAILED DESCRIPTION

[0056] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0058] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0059] In the prior art, since 4D imaging technology has the problem of short detection distance, and phased array technology has the problem of low measurement accuracy, for some more stringent or complex and changeable application scenarios, no matter which millimeter wave radar is used, there are deficiencies and it is difficult to meet the needs of the work scene. Based on this, an embodiment of the present invention provides a radar system, a target detection method and an unmanned device. The radar system can realize both long-distance target detection and close-range target precise measurement by integrating 4D imaging and phased array technology, thereby meeting the needs of a variety of work scenarios.

[0060] The following describes various embodiments of the present invention in detail.

[0061] Please refer to Figure 1 The radar system 100 provided in an embodiment of the present invention includes a signal processing module 110, a radio frequency module 120 and an antenna array 130. The signal processing module 110 is electrically connected to the radio frequency module 120, and the radio frequency module 120 is electrically connected to the antenna array 130; the antenna array 130 includes a multi-channel transmitting antenna 131 and a multi-channel receiving antenna 132.

[0062] The RF module 120 is used to generate a RF signal under the control of the signal processing module 110 .

[0063] In this embodiment, the signal processing module 110 of the radar system 100 can control the RF module 120 to generate a RF signal (millimeter wave radar signal), and the RF signal will be radiated through the transmitting antenna 131 in one path, and the echo signal will be mixed with the RF signal in another path after receiving the echo signal. The RF signal can be a frequency modulated continuous wave or other types of signals, which are not limited in this embodiment.

[0064] The signal processing module 110 works alternately in a first mode and a second mode. In the first mode, the signal processing module 110 controls the RF module 120 to select the transmitting antenna 131 in a first manner, and the radar system 100 performs target detection based on the 4D imaging technology; in the second mode, the signal processing module 110 controls the RF module 120 to select the transmitting antenna 131 in a second manner, and the radar system 100 performs target detection based on the phased array technology.

[0065] The radio frequency module 120 is further used to receive the echo signal through the receiving antenna 132 and process the echo signal; the signal processing module 110 is used to obtain target detection data according to the processing result of the echo signal.

[0066] In this embodiment, since the signal processing module 110 can alternately work in the first mode and the second mode, when working in the first mode, the radar system 100 will perform target detection based on 4D imaging technology; when working in the second mode, the radar system 100 will perform target detection based on phased array technology. Therefore, the radar system 100 is a system that integrates 4D imaging technology and phased array technology, and can achieve high-precision target detection and tracking. By cooperating with 4D radar and phased array radar, more comprehensive and accurate target information can be provided, and it has strong anti-interference ability, which is suitable for various fields, including smart devices, smart transportation, etc.

[0067] It should be noted that in actual applications, due to the excellent target tracking and long-distance measurement performance of phased array technology, when the two technologies are used alternately, the measurement data of phased array radar is preferentially adopted for long-distance target tracking and angle measurement; and the excellent angle measurement accuracy capability of 4D imaging technology is mainly used for close-range target detection, so for close-range targets, the measurement data of 4D radar is preferentially adopted. Through the integration of 4D imaging technology and phased array technology, the deficiencies of each other are effectively supplemented. The phased array mode (second mode) can make up for the problem of short detection distance of 4D radar, and the 4D radar mode (first mode) can make up for the problem of fuzzy angle measurement of phased array radar. Combining the advantages of the two can achieve long-distance target detection and close-range accurate angle measurement, so that radar system 100 can meet the needs of more diverse work scenarios.

[0068] It can be seen that in the radar system provided by the embodiment of the present invention, the RF module generates a RF signal under the control of the signal processing module; the signal processing module works alternately in the first mode and the second mode. In the first mode, the signal processing module controls the RF module to select the transmitting antenna in the first mode, and the radar system detects targets based on the 4D imaging technology; in the second mode, the signal processing module controls the RF module to select the transmitting antenna in the second mode, and the radar system detects targets based on the phased array technology; the RF module receives the echo signal through the receiving antenna and processes the echo signal; the signal processing module obtains the target detection data according to the processing result of the echo signal. Since the radar system can work alternately in the first mode and the second mode, in the first mode, target detection is performed based on the 4D imaging technology, which can achieve accurate measurement of close-range targets; in the second mode, target detection is performed based on the phased array technology, which can achieve long-range target detection, thereby meeting the needs of various work scenarios.

[0069] In one implementation, the signal processing module 110 may operate alternately in the first mode and the second mode according to a preset period.

[0070] The preset period can be set according to actual conditions, for example, according to the working time in each mode. The signal processing module 110 periodically works in the first mode and the second mode alternately, so the first mode and the second mode are time-division multiplexed at a microscopic level. However, due to the application of electronic computer technology, the working time of the two modes is extremely short, and the work can be completed in less than 1 millisecond (ms). Therefore, at a macroscopic level, the two modes can be approximately working at the same time.

[0071] In one embodiment, the first method mentioned above can be to control the RF module 120 to alternately select one transmitting antenna 131 and transmit the RF signal through the selected transmitting antenna 131; the second method mentioned above can be to control the RF module 120 to select all transmitting antennas 131, and adjust the amplitude and phase of the RF signal to be transmitted by each transmitting antenna 131 to change the direction and shape of the synthetic beam of multiple transmitting antennas 131.

[0072] That is to say, the signal processing module 110 periodically alternates between the first mode and the second mode. In the first mode, the RF module 120 is controlled to alternately select one transmitting antenna 131 and transmit the RF signal through the selected transmitting antenna 131; in the second mode, the RF module 120 is controlled to select all transmitting antennas 131 and adjust the amplitude and phase of the RF signal to be transmitted by each transmitting antenna 131 to change the direction and shape of the synthetic beam of the multiple transmitting antennas 131.

[0073] In this embodiment, since the signal processing module 110 controls the RF module 120 to alternately select one transmitting antenna 131 in the first mode, the multiple transmitting antennas 131 transmit RF signals alternately; in the second mode, the RF module 120 is controlled to select all transmitting antennas 131, and the multiple antennas will form an aggregated antenna, and by adjusting the amplitude and phase of the RF signal to be transmitted by each transmitting antenna 131, the direction and shape of the synthetic beam of the multiple transmitting antennas 131 can be changed, so that the long-distance target can be effectively detected. After the signal radiated by the transmitting antenna 131 encounters the target, the target will reflect a part of the signal back to the radar system 100, and the echo signal reflected back by the target will be received by the multiple receiving antennas 132.

[0074] It can be seen that in the radar system provided by the embodiment of the present invention, the signal processing module works alternately in the first mode and the second mode. In the first mode, the RF module is controlled to alternately select one transmitting antenna and transmit the RF signal through the selected transmitting antenna; in the second mode, the RF module is controlled to select all transmitting antennas and adjust the amplitude and phase of the RF signal to be transmitted by each transmitting antenna to change the direction and shape of the composite beam of multiple transmitting antennas; the RF module receives the echo signal through the receiving antenna and processes the echo signal, and the signal processing module obtains the target detection data according to the processing result of the echo signal. Since the radar system can work alternately in the first mode and the second mode, in the first mode, the RF signal is alternately transmitted by multiple transmitting antennas, so that the accurate measurement of close-range targets can be achieved; in the second mode, the beams of multiple transmitting antennas are aggregated and transmitted, so that the detection of long-range targets can be achieved, thereby meeting the needs of various working scenarios.

[0075] In this embodiment, in order to realize both phased array imaging and 4D imaging in the radar system 100, it is necessary to improve the design and layout of the antenna array 130. In one implementation, the two ends of the multi-channel transmitting antenna 131 are aligned and the arrangement direction is perpendicular to the vertical direction, and the two ends of the multi-channel receiving antenna 132 are respectively arranged on two straight lines at a preset angle to the vertical direction.

[0076] Among them, the multiple transmitting antennas 131 arranged in the horizontal direction can transmit millimeter wave signals independently or in an aggregated manner; the multiple receiving antennas 132 arranged at a preset angle to the vertical direction can receive millimeter wave signals simultaneously or individually.

[0077] In this embodiment, in the multi-channel transmitting antennas 131 arranged in the horizontal direction, the interval between two adjacent transmitting antennas 131 may be half of the working wavelength (λ / 2), and in the multi-channel receiving antennas 132 arranged at a preset angle to the vertical direction, the preset angle may be 45°, and the interval between two adjacent receiving antennas 132 along the direction of 45° to the vertical direction is half the root of a wavelength.

[0078] In practical applications, considering that the detection distance in the 4D radar mode is relatively short, in order to increase the receiving distance, the length of one of the multiple receiving antennas 132 can be increased to increase the gain of the antenna, thereby increasing the measuring distance. Therefore, the two ends of one of the multiple receiving antennas 132 can be aligned with the two ends of the transmitting antenna 131, and are consistent with the arrangement direction of the multiple transmitting antennas 131, such as Figure 2 shown.

[0079] It can be seen that compared with the traditional 4D radar, in the layout of the antenna array 130, the antennas arranged in the direction of 45° to the vertical direction transmit signals, and the antennas arranged in the horizontal direction receive signals. In the embodiment of the present invention, in the 4D radar mode, the antennas arranged in the horizontal direction alternately transmit radio frequency signals, and the tilted antennas receive echo signals; in the phased array mode, the beams of multiple antennas arranged in the horizontal direction are aggregated and transmitted, and the tracking of distant targets is achieved by adjusting the direction and shape of the synthetic beam.

[0080] In one embodiment, the radio frequency module 120 may be used to output a difference frequency signal according to the echo signal and the corresponding radio frequency signal. The signal processing module 110 may be used to obtain target detection data according to the difference frequency signal.

[0081] In this embodiment, after the RF module 120 receives the echo signal, the frequency of the echo signal has changed compared to the RF signal previously transmitted. After mixing processing by the RF module 120, the obtained signal is a difference frequency signal, and the difference frequency signal carries relevant information of the target.

[0082] Since the difference frequency signal carries relevant information of the target, by processing the difference frequency signal, information such as the target distance, speed, azimuth, etc. can be obtained. In the first mode, since the multi-channel transmitting antenna 131 transmits the radio frequency signal alternately, the signal processing module 110 can obtain the distance between the target and the radar system 100, the azimuth of the target relative to the radar system 100, the pitch angle of the target, and the speed of the target after obtaining and processing the difference frequency signal; while in the second mode, the multi-channel transmitting antenna 131 transmits the radio frequency signal at the same time, and the direction and shape of the synthetic beam of the multi-channel transmitting antenna 131 can be changed, so the signal processing module 110 can obtain the distance between the target and the radar system 100, the azimuth of the target relative to the radar system 100, and the speed of the target after obtaining and processing the difference frequency signal.

[0083] In one embodiment, see Figure 3 The RF module 120 includes a signal generator 121, multiple phased array chips 122 and a mixer 123; the signal generator 121 is electrically connected to the signal processing module 110, multiple phased array chips 122 and the mixer 123; the multiple phased array chips 122 are electrically connected to the multiple transmitting antennas 131 in a one-to-one correspondence; the mixer 123 is electrically connected to the signal processing module 110 and the multiple receiving antennas 132; the signal processing module 110 is electrically connected to the multiple phased array chips 122.

[0084] The signal generator 121 is used to generate a radio frequency signal under the control of the signal processing module 110 .

[0085] Among them, the signal generator 121 includes a phase-locked loop circuit 1211, a crystal oscillator 1212 and a voltage-controlled oscillator 1213. The phase-locked loop circuit 1211 is electrically connected to the crystal oscillator 1212, the voltage-controlled oscillator 1213 and the signal processing module 110. The voltage-controlled oscillator 1213 is also electrically connected to the mixer 123 and multiple phased array chips 122.

[0086] The crystal oscillator 1212 is used to provide a reference clock for the phase-locked loop circuit 1211; the phase-locked loop circuit 1211 is used to output a control voltage under the control of the signal processing module 110; and the voltage-controlled oscillator 1213 is used to output a radio frequency signal according to the control voltage.

[0087] In this embodiment, the crystal oscillator 1212 may be an active temperature compensated crystal oscillator 1212 (OSC), the signal processing module 110 controls the phase-locked loop circuit 1211 to output a control voltage, and the voltage-controlled oscillator 1213 adjusts the signal output frequency according to the control voltage, thereby generating a radio frequency signal.

[0088] The signal processing module 110 is used to control the multiple phased array chips 122 to turn on alternately in the first mode, thereby alternately selecting one transmitting antenna 131 to transmit the RF signal; in the second mode, control the multiple phased array chips 122 to turn on at the same time, and adjust the amplitude and phase of the RF signal passing through each phased array chip 122.

[0089] In this embodiment, each transmitting antenna 131 is connected to a phased array chip 122. In the first mode, the multiple transmitting antennas 131 transmit RF signals alternately, so the signal processing module 110 needs to control the phased array chips 122 to turn on alternately; in the second mode, the multiple transmitting antennas 131 transmit RF signals simultaneously, and the signal processing module 110 needs to turn on all the phased array chips 122 and adjust the amplitude and phase of the RF signal passing through the phased array chip 122 at the same time, so as to change the radiation direction and shape of the synthetic beam.

[0090] The mixer 123 is used to mix the echo signal with the corresponding radio frequency signal to obtain a difference frequency signal.

[0091] In this embodiment, a mixer 123 is provided to mix the received echo signal with the RF signal generated by the signal generator 121, thereby obtaining a difference frequency signal. In practical applications, it is considered that the echo signal received by the receiving antenna 132 may be relatively weak and inconvenient for subsequent circuit processing. Based on this, after the echo signal enters the RF module 120 in the embodiment of the present invention, it needs to be amplified. Please refer to Figure 4 In one embodiment, the RF module 120 further includes a low noise amplifier 124 and an operational amplifier 125, the operational amplifier 125 is electrically connected between the signal processing module 110 and the mixer 123, and the low noise amplifier 124 is electrically connected between the mixer 123 and the multi-channel receiving antenna 132.

[0092] The low noise amplifier 124 is used to amplify the received echo signal and output the amplified echo signal to the mixer 123; the mixer 123 is used to mix the amplified echo signal with the corresponding RF signal to obtain a difference frequency signal; the operational amplifier 125 is used to amplify the difference frequency signal and output it to the signal processing module 110.

[0093] In this embodiment, the echo signal received by the receiving antenna 132 will first enter the low noise amplifier 124 for amplification, which can reduce noise interference while amplifying the echo signal; the amplified echo signal enters the mixer 123 to be mixed with the generated RF signal, and the generated difference frequency signal is amplified again by the operational amplifier 125 and then output to the signal processing module 110.

[0094] In one embodiment, see Figure 5The signal processing module 110 includes an analog-to-digital converter 111, a time-frequency analysis module 112 and a controller 113. The analog-to-digital converter 111 is electrically connected to the RF module 120 and the time-frequency analysis module 112. The controller 113 is electrically connected to the time-frequency analysis module 112 and the RF module 120.

[0095] The controller 113 may be specifically electrically connected to the phase-locked loop circuit 1211 in the RF module 120 ; and the analog-to-digital converter 111 may be specifically electrically connected to the operational amplifier 125 in the RF module 120 .

[0096] The analog-to-digital converter 111 is used to sample the processing result of the echo signal to obtain sampled data. Specifically, the analog-to-digital converter 111 can sample the difference frequency signal output by the radio frequency module 120 to obtain sampled data. The time-frequency analysis module 112 is used to perform time-frequency analysis on the sampled data to obtain corresponding frequency domain data; the controller 113 is used to obtain target detection data based on the frequency domain data.

[0097] In one embodiment, the time-frequency analysis module 112 includes a preprocessing module 1121 and a fast Fourier transform module 1122. The preprocessing module 1121 is electrically connected to the fast Fourier transform module 1122 and the analog-to-digital converter 111; the fast Fourier transform module 1122 is also electrically connected to the controller 113. The preprocessing module 1121 is used to preprocess the sampled data; the fast Fourier transform module 1122 is used to perform a fast Fourier transform on the preprocessed sampled data to obtain corresponding frequency domain data.

[0098] In this embodiment, the difference frequency signal amplified by the operational amplifier 125 is sampled by the analog-to-digital converter 111, and then the preprocessing module 1121 preprocesses the sampled data, such as sorting the data or adding a window function, etc. The preprocessed sampled data enters the fast Fourier transform module 1122 for fast Fourier transform operation to obtain the corresponding frequency domain data. Finally, the controller 113 performs a simple physical calculation conversion based on the frequency domain data to obtain data such as distance, angle, and speed.

[0099] In practical applications, in order to facilitate data storage and avoid detecting false targets, please refer to Figure 6 In this embodiment, the signal processing module 110 may further include a data storage module 114 and a constant false alarm detection module 115. The data storage module 114 is electrically connected between the analog-to-digital converter 111 and the time-frequency analysis module 112, and the constant false alarm detection module 115 is electrically connected between the time-frequency analysis module 112 and the controller 113.

[0100] The data storage module 114 is used to store the sampled data; the constant false alarm detection module 115 is used to detect the frequency domain data of the valid target from the frequency domain data.

[0101] In this embodiment, the data storage module 114 may include a RAM (Random Access Memory). The data sampled by the analog-to-digital converter 111 will first be stored in the RAM, and then the preprocessing module 1121 will perform data preprocessing. After the fast Fourier transform module 1122 performs a fast Fourier transform operation on the preprocessed sampled data, the constant false alarm detection module 115 detects the frequency domain data to obtain the frequency domain data of the effective target, ensuring that the detected target is a real target.

[0102] Next, the working process of the radar system 100 provided by the embodiment of the present invention in two modes is described. In the first mode, the transmitting antenna 131 transmits the radio frequency signals TX1′~TXn′ alternately, and the receiving antenna 132 simultaneously receives the echo signals TX1″~TXn″ reflected by the target, and all the received TXn″ and TXn′ are frequency-differencing-mixed by the mixer 123 to obtain the difference frequency signal fn, fn=TXn″-TXn′, unit Hertz (Hz).

[0103] According to the radar angle measurement principle, Wherein θ represents the target angle, Ω represents the phase difference received by adjacent receiving antennas 132, λ represents the operating wavelength = 1 / f (f represents the operating frequency), d represents the spacing between adjacent receiving antennas 132, π is pi, and arcsin() is the inverse sine function.

[0104] After performing time-frequency analysis on the difference frequency signal and obtaining the spectrum (frequency domain data), the target distance and target speed can be calculated based on the frequency components in the spectrum. The phase difference Ω between the difference frequency signals can be obtained based on the phase in the spectrum. According to the angle measurement principle formula Thus, the horizontal azimuth angle θ of the target is obtained 水平 When calculating the azimuth angle, the difference frequency signal corresponding to the echo signal received by a designated receiving antenna 132 (such as RX1) is used. Since there are multiple phase differences, the horizontal azimuth angles calculated based on each phase difference can be averaged to obtain the final horizontal azimuth angle θ of the target. 水平 .

[0105] When calculating the pitch angle, the difference frequency signals corresponding to the echo signals received by all receiving antennas 132 are used. That is, after obtaining the phase difference Ω between the difference frequency signals corresponding to the echo signals received by RX1 to RXn, the angle measurement principle formula is also used. Thus, the vertical pitch angle θ of the target is obtained 垂直 Similarly, since there are multiple phase differences, the vertical pitch angles calculated based on each phase difference can be averaged to obtain the final vertical pitch angle θ of the target. 垂直 .

[0106] In the second mode, driven by the phased array chip 122, the transmitting antenna 131 is centered on the transmitting antenna 131 (TXn / 2) labeled n / 2, and the interval between two adjacent transmitting antennas 131 is half a wavelength (λ / 2). At this time, TX1~TXn form an aggregated antenna TXmax. Since TXmax is the energy aggregated from multiple transmitting antennas 131, the energy of TXmax is the energy of a single antenna. times, the antenna phase center is the position of TXn / 2. TXmax has times the energy, so TXmax is very suitable for detecting distant targets. In addition, by adjusting the phase and amplitude of the transmitted signal, it is easy to track the target or beam scan a certain area. It should be noted that in the second mode, the calculation of distance and speed parameters based on the difference frequency signal is similar to that in the first mode, but the pitch angle is not calculated in the second mode, and the horizontal azimuth angle is not calculated by phase difference, but the signal strength of the echo signal is converted from the frequency domain data, and then the horizontal azimuth angle of the target is determined based on the signal strength.

[0107] Optionally, see Figure 7 Based on the same inventive concept, the embodiment of the present invention also provides a target detection method. It should be noted that the target detection method of the present invention is not based on Figure 7 It should be understood that in other embodiments, the order of some steps in the target detection method of the present invention can be interchanged according to actual needs, or some steps can be omitted or deleted. The target detection method can be applied to the above-mentioned radar system 100. Figure 7 The specific process shown is described in detail.

[0108] Step S701: The radio frequency module generates a radio frequency signal under the control of the signal processing module.

[0109] In step S702, the signal processing module operates alternately in a first mode and a second mode. In the first mode, the signal processing module controls the RF module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology. In the second mode, the signal processing module controls the RF module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology.

[0110] Step S703: The radio frequency module receives the echo signal through the receiving antenna and processes the echo signal.

[0111] Step S704: The signal processing module obtains target detection data according to the processing result of the echo signal.

[0112] It should be noted that the basic principle and technical effects of the target detection method provided in this embodiment are the same as those of the above embodiments. For the sake of brief description, for parts not mentioned in this embodiment, reference may be made to the corresponding contents in the above embodiments.

[0113] Optionally, see Figure 8 The embodiment of the present invention further provides an unmanned device 200, which includes a main control module 210 and the above-mentioned radar system 100, and the main control module 210 is communicatively connected with the signal processing module 110.

[0114] In this embodiment, the main control module 210 can communicate with the controller 113 in the signal processing module 110 via the CANFD bus. After calculating the distance, angle, speed and other data of the target, the radar system 100 sends the data to the main control module 210 via the CANFD bus.

[0115] In this embodiment, the unmanned device 200 can be a drone, an unmanned vehicle, or other smart transportation or intelligent equipment, which is not limited in this embodiment.

[0116] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0117] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0118] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0119] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radar system, characterized in that: The radar system comprises a signal processing module, a radio frequency module and an antenna array, wherein the signal processing module is electrically connected to the radio frequency module, and the radio frequency module is electrically connected to the antenna array; the antenna array comprises a multi-channel transmitting antenna and a multi-channel receiving antenna; The radio frequency module is used to generate a radio frequency signal under the control of the signal processing module; The signal processing module works alternately in a first mode and a second mode. In the first mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology; In the second mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology; The radio frequency module is also used to receive the echo signal through the receiving antenna and process the echo signal; The signal processing module is used to obtain target detection data according to the processing result of the echo signal.

2. The radar system according to claim 1, characterized in that The first method is to control the radio frequency module to alternately select one transmitting antenna, and transmit the radio frequency signal through the selected transmitting antenna.

3. The radar system according to claim 1, characterized in that The second method is to control the RF module to select all transmitting antennas, and adjust the amplitude and phase of the RF signal to be transmitted by each transmitting antenna, so as to change the direction and shape of the synthetic beam of the multiple transmitting antennas.

4. The radar system according to claim 1, characterized in that Two ends of the multiple transmitting antennas are aligned and arranged in a direction perpendicular to the vertical direction, and two ends of the multiple receiving antennas are respectively arranged on two straight lines that are at a preset angle to the vertical direction.

5. The radar system according to claim 1, characterized in that The radio frequency module is used to output a difference frequency signal according to the echo signal and the corresponding radio frequency signal; and the signal processing module is used to obtain target detection data according to the difference frequency signal.

6. The radar system according to claim 5, characterized in that The radio frequency module includes a signal generator, a plurality of phased array chips and a mixer; the signal generator is electrically connected to the signal processing module, the plurality of phased array chips and the mixer; the plurality of phased array chips are electrically connected to the plurality of transmitting antennas in a one-to-one correspondence; the mixer is electrically connected to the signal processing module and the plurality of receiving antennas; the signal processing module is electrically connected to the plurality of phased array chips; The signal generator is used to generate the radio frequency signal under the control of the signal processing module; The signal processing module is used to control the plurality of phased array chips to be turned on alternately in the first mode, so as to alternately select one transmitting antenna to transmit the radio frequency signal; In the second mode, the plurality of phased array chips are controlled to be turned on simultaneously, and the amplitude and phase of the radio frequency signal passing through each phased array chip are adjusted; The mixer is used to mix the echo signal with the corresponding radio frequency signal to obtain the difference frequency signal.

7. The radar system according to claim 6, characterized in that The radio frequency module further includes a low noise amplifier and an operational amplifier, wherein the operational amplifier is electrically connected between the signal processing module and the mixer, and the low noise amplifier is electrically connected between the mixer and the multiple receiving antennas; The low noise amplifier is used to amplify the received echo signal and output the amplified echo signal to the mixer; The mixer is used to mix the amplified echo signal with the corresponding radio frequency signal to obtain the difference frequency signal; The operational amplifier is used to amplify the difference frequency signal and then output it to the signal processing module.

8. The radar system according to claim 6, characterized in that The signal generator comprises a phase-locked loop circuit, a crystal oscillator and a voltage-controlled oscillator, the phase-locked loop circuit is electrically connected to the crystal oscillator, the voltage-controlled oscillator and the signal processing module, and the voltage-controlled oscillator is also electrically connected to the mixer and the plurality of phased array chips; The crystal oscillator is used to provide a reference clock for the phase-locked loop circuit; The phase-locked loop circuit is used to output a control voltage under the control of the signal processing module; The voltage controlled oscillator is used to output a radio frequency signal according to the control voltage.

9. The radar system according to claim 1, characterized in that The signal processing module includes an analog-to-digital converter, a time-frequency analysis module and a controller, the analog-to-digital converter is electrically connected to the radio frequency module and the time-frequency analysis module, and the controller is electrically connected to the time-frequency analysis module and the radio frequency module; The analog-to-digital converter is used to sample the processing result of the echo signal to obtain sampling data; The time-frequency analysis module is used to perform time-frequency analysis on the sampled data to obtain corresponding frequency domain data; The controller is used to obtain target detection data according to the frequency domain data.

10. The radar system according to claim 9, characterized in that The time-frequency analysis module includes a preprocessing module and a fast Fourier transform module, wherein the preprocessing module is electrically connected to the fast Fourier transform module and the analog-to-digital converter; the fast Fourier transform module is also electrically connected to the controller; The preprocessing module is used to preprocess the sampled data; The fast Fourier transform module is used to perform fast Fourier transform on the preprocessed sampled data to obtain corresponding frequency domain data.

11. The radar system according to claim 9 or 10, characterized in that The signal processing module also includes a data storage module and a constant false alarm detection module, wherein the data storage module is electrically connected between the analog-to-digital converter and the time-frequency analysis module, and the constant false alarm detection module is electrically connected between the time-frequency analysis module and the controller; The data storage module is used to store the sampled data; The constant false alarm detection module is used to detect frequency domain data of a valid target from the frequency domain data.

12. The radar system according to claim 1, characterized in that The signal processing module operates alternately in the first mode and the second mode according to a preset period.

13. A target detection method, characterized in that: Applied to a radar system, the radar system comprises a signal processing module, a radio frequency module and an antenna array, the signal processing module is electrically connected to the radio frequency module, and the radio frequency module is electrically connected to the antenna array; The antenna array includes multiple transmitting antennas and multiple receiving antennas; the method includes: The radio frequency module generates a radio frequency signal under the control of the signal processing module; The signal processing module works alternately in a first mode and a second mode. In the first mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a first manner, and the radar system performs target detection based on 4D imaging technology; in the second mode, the signal processing module controls the radio frequency module to select the transmitting antenna in a second manner, and the radar system performs target detection based on phased array technology; The radio frequency module receives the echo signal through the receiving antenna and processes the echo signal; The signal processing module obtains target detection data according to the processing result of the echo signal.

14. An unmanned device, characterized in that: A radar system comprising a main control module and any one of claims 1 to 12, wherein the main control module is communicatively connected with the signal processing module.

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