Method for acquiring speed of target object, method for acquiring Doppler fuzzy number and sensor

Abstract

The invention relates to a method for acquiring the speed of a target object, a method for acquiring a Doppler fuzzy number, a sensor, computer equipment and a storage medium, and relates to the technical field of sensors. According to the method, two chirp signals are transmitted at a time through a first transmitting channel, namely, one chirp signal is added in front of or behind a signal transmitted by one transmitting channel in a traditional FMCW sensor, and the phase difference of the two chirp signals at the target peak position in an echo signal is obtained, so that a Doppler fuzzy number (namely q) is obtained; and the Doppler fuzzy number can be used for solving velocity ambiguity so as to determine the velocity of the target object.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 202011139094.2, invention name “Method, sensor, computer device and storage medium for obtaining target object speed”, and application date October 22, 2020. Technical Field

[0002] The present application relates to the field of sensor technology, and in particular to a method for obtaining target object velocity, a method for obtaining Doppler fuzzy number, and a sensor. Background Art

[0003] Frequency Modulation Continuous Wave (FMCW) is a common speed measurement technology and is widely used in various sensor speed measurement scenarios. The process of speed measurement based on FMCW is usually: using the transmitting antenna to send a frequency modulated continuous wave, and obtaining the echo signal reflected by the target object, and then performing signal processing on the mixed signal obtained by mixing the transmitting signal and the echo signal to determine the speed of the target object based on the Doppler frequency shift.

[0004] However, in practical applications, the velocity of the target object obtained based on the Doppler frequency shift is not accurate enough, especially when the Doppler frequency shift f d When the value exceeds (-F / 2, F / 2), the accuracy of the target obtained by the traditional sensor is not high, which affects the effect of target detection. Where F represents the repetition frequency of the chirp signal in the transmission signal. Summary of the invention

[0005] Based on this, it is necessary to address the problem of low accuracy in measuring the speed of a target object, and provide a method for obtaining the speed of a target object, a method for obtaining a Doppler fuzzy number, a sensor, a computer device, and a storage medium.

[0006] In a first aspect, a method for acquiring a speed of a target object can be applied to a sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner, wherein the sensor has a first transmitting channel and at least one second transmitting channel, wherein the first transmitting channel can transmit two chirp signals at a time, and each of the second transmitting channels transmits one chirp signal at a time, and the method may include:

[0007] Obtain the target peak position in the echo signal;

[0008] Acquire a phase difference between the two chirp signals (i.e., the two chirp signals transmitted by the first transmitting channel at one time) at the target peak position;

[0009] Determining a Doppler ambiguity number based on the phase difference; and

[0010] A velocity of the target object is determined based on the Doppler ambiguity number.

[0011] The above method for obtaining the speed of the target object improves the accuracy of the sensor's speed measurement by introducing the Doppler ambiguity number, that is, using the first transmitting channel to transmit two chirp signals at a time, which is equivalent to adding a chirp signal before or after the signal transmitted by a transmitting channel in a traditional FMCW sensor, and obtaining the phase difference of the two chirp signals at the target peak position in the echo signal to obtain the Doppler ambiguity number (i.e., q), and the Doppler ambiguity number can be used to resolve the speed ambiguity, thereby determining the speed of the target object.

[0012] Optionally, there is a first preset time delay between two chirp signals transmitted by the first transmission channel each time; and determining the Doppler ambiguity number according to the phase difference includes:

[0013] Determine the Doppler ambiguity number according to the phase difference and the first preset time delay;

[0014] Wherein, the value of the first preset delay is greater than zero.

[0015] In this embodiment, by setting a first preset time delay between two chirps transmitted at the same time, the accuracy of the obtained Doppler ambiguity number is improved, thereby further improving the accuracy of the sensor's speed measurement.

[0016] Optionally, the two chirp signals include a first chirp signal and a second chirp signal transmitted in sequence; and determining a Doppler ambiguity number according to the phase difference includes:

[0017] Acquire a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position;

[0018] acquiring a phase difference between the first chirp signal and the second chirp signal at the target peak position according to a phase value of the first chirp signal and a phase value of the second chirp signal; and

[0019] The Doppler ambiguity number is determined according to the phase difference.

[0020] In this embodiment, the accuracy of the obtained Doppler ambiguity number is improved by utilizing all phase differences, thereby further improving the accuracy of the sensor speed measurement.

[0021] Optionally, acquiring a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position includes:

[0022] Acquire a time domain subsequence of the first chirp signal and a time domain subsequence of the second chirp signal;

[0023] Two-dimensional fast Fourier transform processing is performed on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal respectively to obtain a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position.

[0024] In this embodiment, two time domain subsequences of chirps emitted at the same time are obtained by sampling, and processed by two-dimensional fast Fourier transform, which can be combined with the traditional signal processing process to obtain the phase value corresponding to the chirp signal at the target peak position, which can effectively reduce the difficulty of designing and implementing data signal processing.

[0025] Optionally, there is a first preset time delay between two chirp signals transmitted by the first transmission channel each time; and acquiring the phase difference at the target peak position according to the phase value of the first chirp signal and the phase value of the second chirp signal includes:

[0026] Obtaining the ambiguous Doppler frequency; and

[0027] The phase difference is acquired according to the phase value of the first chirp signal, the phase value of the second chirp signal, the first preset time delay, the ambiguous Doppler frequency, and the chirp period in the frequency modulated continuous wave signal.

[0028] In this embodiment, since the first preset time delay and chirp period can be directly obtained, and the ambiguous Doppler frequency can be easily obtained in combination with some embodiments of the present application or traditional technologies, the difficulty of designing and implementing subsequent data signal processing such as phase difference and velocity ambiguity resolution can be further reduced.

[0029] Optionally, the first chirp signal and the second chirp signal are the same.

[0030] In this embodiment, since the two chirp signals have the same parameters such as shape, starting frequency of the sweep and period, the difficulty of generating the chirp signal can be effectively reduced. At the same time, if only one chirp signal is added compared to the traditional sensing system to form the two chirp signals emitted by the first transmitting channel each time, it can be achieved based on a traditional signal generating device, thereby reducing the difficulty and cost of system implementation.

[0031] Optionally, determining a Doppler ambiguity number according to the phase difference includes:

[0032] The Doppler ambiguity number is obtained according to the fractional part of the phase difference.

[0033] In this embodiment, the Doppler ambiguity number can be quickly obtained by using the traditional round function, so as to further reduce the difficulty of system implementation.

[0034] Optionally, there is a first preset time delay between two chirp signals transmitted by the first transmission channel each time; and obtaining the Doppler ambiguity number according to the decimal part of the phase difference includes:

[0035] Obtain the value of the decimal part of the phase difference divided by 360 degrees;

[0036] The Doppler ambiguity number is obtained based on the first preset time delay, the chirp period in the frequency modulated continuous wave signal, the transmission period of the sensor, and the value of the fractional part.

[0037] In this embodiment, the Doppler ambiguity number is obtained by dividing the first preset time delay, the chirp period, and the decimal part of the phase difference by 360 degrees. The difficulty of implementing the technical solution of the present application can be further reduced by using some data that can be easily obtained by the embodiments of the present application.

[0038] Optionally, the first transmitting channel transmits two chirp signals in each transmitting cycle, and each of the second transmitting channels transmits one chirp signal in each transmitting cycle.

[0039] In this embodiment, the first transmission channel transmits two chirp signals in each transmission cycle, and each second transmission channel transmits one chirp signal in each transmission cycle, thereby achieving the purpose of adding a chirp signal before or after the signal transmitted by the first transmission channel in each transmission cycle, and based on this, the phase difference of the two chirp signals at the target peak position in the echo signal is obtained to obtain the Doppler ambiguity number (i.e., q), thereby improving the accuracy of the detected target object's velocity.

[0040] Optionally, the first transmitting channel transmits two chirp signals in a first transmitting period and transmits one chirp signal in a second transmitting period, and each of the second transmitting channels transmits one chirp signal each time.

[0041] In this embodiment, during the entire signal transmission process, the first transmission channel only adds a chirp signal before or after the signal transmitted in the first transmission cycle, which reduces the difficulty of controlling the transmission signal and further reduces the difficulty of implementing the technical solution of the present application.

[0042] Optionally, the sensor is a MIMO (multiple input multiple output) sensor (such as millimeter wave radar, and other frequency radio sensors, etc.). Under the premise of no conflict, the solution in the embodiment of the present application can also be applied to various MIMO communication systems.

[0043] Optionally, the first transmitting channel may further transmit at least three chirp signals at a time, and each of the second transmitting channels may transmit one chirp signal at a time; and obtaining the phase difference between the two chirp signals at the target peak position includes:

[0044] The phase difference between two adjacent chirp signals among the at least three chirp signals at the target peak position is obtained.

[0045] In this embodiment, it can be realized based on a traditional signal generating device, thereby reducing the difficulty and cost of system implementation.

[0046] In a second aspect, a method for obtaining a Doppler ambiguity number can be applied to a sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner, wherein the sensor has a first transmission channel and at least one second transmission channel, wherein the first transmission channel transmits two chirp signals in each cycle of at least part of the transmission cycle, wherein a second time delay exists between the two chirp signals, and each of the second transmission channels transmits a chirp signal in each transmission cycle, wherein the method comprises:

[0047] Obtain the target peak position in the echo signal;

[0048] Acquiring a phase difference between the two chirp signals at the target peak position; and

[0049] determining a Doppler ambiguity number according to the phase difference and the second time delay;

[0050] The value of the second delay is greater than or equal to zero.

[0051] In this embodiment, the Doppler ambiguity number is accurately obtained by utilizing the phase difference of two chirp signals transmitted by the same transmission channel in the same transmission cycle and the time delay between the two chirp signals, so that the Doppler ambiguity number can be subsequently used to reduce or even eliminate the influence of the excessive absolute value of the Doppler frequency shift (such as greater than half the frequency of the chirp signal) on the resolution of velocity ambiguity, and the accuracy of other data signal processing based on the Doppler modulus can also be improved.

[0052] Optionally, the two chirp signals include a first chirp signal and a second chirp signal transmitted in sequence; and obtaining a phase difference between the two chirp signals at the target peak position includes:

[0053] Acquire a time domain subsequence of the first chirp signal and a time domain subsequence of the second chirp signal;

[0054] performing two-dimensional fast Fourier transform processing on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal respectively, so as to obtain a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position; and

[0055] Based on the phase value of the first chirp signal and the phase value of the second chirp signal, a phase difference between the first chirp signal and the second chirp signal at the target peak position is acquired.

[0056] In this embodiment, two time domain subsequences of chirps emitted at the same time are obtained by sampling, and processed by two-dimensional fast Fourier transform, which can be combined with the traditional signal processing process to obtain the phase value corresponding to the chirp signal at the target peak position, which can effectively reduce the difficulty of designing and implementing data signal processing.

[0057] Optionally, determining a Doppler ambiguity number according to the phase difference and the second time delay comprises:

[0058] Get the fuzzy Doppler frequency;

[0059] Obtaining a chirp period of the frequency modulated continuous wave signal;

[0060] Acquiring the emission period of the sensor; and

[0061] The Doppler ambiguity number is acquired based on the phase difference, the ambiguous Doppler frequency, the chirp period, the second time delay, and the transmission period.

[0062] In this embodiment, the chirp period, the transmission period, and the second delay can all be directly obtained, while the Doppler frequency and the phase difference can be easily obtained by combining some embodiments of the present application or traditional technologies, thereby further reducing the difficulty of designing and implementing data signal processing such as resolving velocity ambiguity.

[0063] Optionally, the acquiring the Doppler ambiguity number based on the phase difference, the ambiguous Doppler frequency, the chirp period, the second time delay and the transmission period further includes:

[0064] Acquire a phase difference between two chirp signals at a target peak position based on the phase difference, the ambiguous Doppler frequency, the chirp period and the second time delay;

[0065] Obtaining a decimal part of a first value, where the first value is equal to the phase difference divided by 360 degrees;

[0066] Obtaining a fractional part of a second value, where the second value is equal to the sum of the chirp period and the second delay multiplied by the Doppler ambiguity number divided by the transmission period; and

[0067] The Doppler ambiguity number is obtained according to that the decimal part of the first value is equal to the decimal part of the second value.

[0068] In this embodiment, by obtaining the Doppler fuzzy number when the decimal part of the first value is equal to the decimal part of the second value, the accuracy of the obtained Doppler fuzzy number is improved, thereby further improving the accuracy of the sensor speed measurement.

[0069] In a third aspect, a sensor may include:

[0070] A first transmission channel, used for transmitting two chirp signals in at least part of a transmission period;

[0071] A second transmission channel is used to transmit a chirp signal in each transmission cycle;

[0072] A receiving channel, used for receiving an echo signal; and

[0073] The signal processing module is used to obtain the target peak position in the echo signal, obtain the phase difference between the two chirp signals at the target peak position, and determine the Doppler ambiguity number according to the phase difference.

[0074] Optionally, the signal processing module may also be used to implement a method for obtaining a target object speed as described in any one of the embodiments of the present application, and / or

[0075] Implement the method for obtaining the Doppler ambiguity number as described in any one of the embodiments of the present application.

[0076] Optionally, the sensor is a millimeter wave radar chip.

[0077] Optionally, the millimeter wave radar chip is an AiP (Antennas in Package) chip.

[0078] It should be noted that in various embodiments of the present application, at least two chirp signals (such as 2, 3, 4 or 5 chirp signals, and the number of chirp signals can be set based on actual needs) can be transmitted based on the same transmission channel in the same transmission cycle (or the same transmission), and the Doppler ambiguity number can be obtained by obtaining the phase difference of any adjacent chirp signals in the at least two chirp signals on the target peak. Among them, the Doppler ambiguity number can be obtained based on the phase difference of two adjacent chirp signals on the target peak, or by obtaining the phase difference of at least two adjacent chirp signals on the target peak, and obtaining a more accurate phase difference by averaging the obtained phase difference, and obtaining the above-mentioned Doppler ambiguity number based on the more accurate phase difference to further improve the accuracy of resolving velocity ambiguity.

[0079] In a fourth aspect, a computer device may include a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the method described in any one of the embodiments of the present application are implemented, and / or when the processor executes the computer program, the steps of the method for obtaining the Doppler ambiguity number described in any one of the embodiments of the present application are implemented.

[0080] In a fifth aspect, a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in any one of the embodiments of the present application, and / or the processor, when executing the computer program, implements the steps of the method for obtaining the Doppler ambiguity number described in any one of the embodiments of the present application.

[0081] The above-mentioned method for obtaining the target object speed, method for obtaining the Doppler ambiguity number, sensor, computer equipment and storage medium can improve the accuracy of resolving speed ambiguity by introducing the Doppler ambiguity number, and can be based on the traditional FMCW sensor, by transmitting two chirp signals each time the chirp signal is transmitted in the transmission channel, and obtaining the phase difference on the target peak based on the time domain subsequence of the two chirp signals, and then obtaining the accurate Doppler ambiguity number based on the phase difference to correct the Doppler frequency shift, so as to further improve the accuracy of resolving speed ambiguity, and at the same time, it can also effectively improve the accuracy of other data signal processing results based on the Doppler modulus. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 A schematic diagram of an application environment of an embodiment of the present application;

[0083] Figure 2 is an internal structure diagram of a computer device in one embodiment;

[0084] Figure 3 is a waveform diagram of two chirp signals transmitted by a first transmitting channel in one embodiment;

[0085] Figure 4 is a waveform diagram of a chirp signal transmitted by a second transmitting channel in one embodiment;

[0086] Figure 5 is a waveform diagram of a transmitted signal in one embodiment;

[0087] Figure 6 A schematic diagram of a flow chart of a method for obtaining a target object speed in one embodiment;

[0088] Figure 7 A schematic diagram of obtaining a target peak position in one embodiment;

[0089] Figure 8is a waveform diagram of a transmitted signal in another embodiment;

[0090] Fig. 9 A schematic diagram of a flow chart of a method for obtaining a target object speed in one embodiment;

[0091] Fig.10 A schematic flow chart of a method for obtaining Doppler ambiguity numbers in one embodiment;

[0092] Fig.11 A module diagram of a sensor in one embodiment. DETAILED DESCRIPTION

[0093] The method, device, equipment and storage medium for obtaining the speed of a target object provided by the present application are intended to solve the problem of inaccurate speed of a target object determined by conventional methods. The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems will be described in detail below through embodiments and in conjunction with the accompanying drawings. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0094] The method for obtaining the speed of a target object provided in this embodiment can be applied to Figure 1 In the application environment shown. The transmission signal sent by the transmitting antenna of the radar 100 is reflected by the target 200, so that the receiving antenna on the radar 100 can receive the echo signal reflected by the target 200, and then determine the speed of the target 200 according to the echo signal. When the radar 100 is a multi-transmit and multi-receive antenna, the distance between each transmitting antenna can be the same or different, and the embodiment of the present application does not limit this. The distance between each receiving antenna can be the same or different, and the embodiment of the present application does not limit this.

[0095] In the traditional method, the Doppler frequency shift is obtained by fast Fourier transforming the mixed signal. The range of the obtained Doppler frequency shift is closely related to the repetition frequency of the chirp signal of the transmitted signal, which is affected by the sampling frequency. Where F represents the repetition frequency of the chirp of the transmitted signal, f d represents the Doppler frequency shift determined by fast Fourier transform of the mixed signal. That is to say, when the speed of the target exceeds the range of (-F / 2, F / 2), spectrum aliasing will occur. However, the existing technology cannot accurately distinguish the Doppler frequency shift f. d The number of folds between the pulse repetition frequency F, that is, the Doppler frequency shift f cannot be accurately obtained d The Doppler ambiguity between the pulse repetition frequencies F results in low accuracy of the target obtained by the sensor, which in turn affects the effect of target detection.

[0096] In order to solve the above technical problems, the embodiment of the present application improves the accuracy of velocity ambiguity resolution by introducing Doppler ambiguity numbers, and can be based on the traditional FMCW sensor, by transmitting two chirp signals each time a chirp signal is transmitted in the transmission channel, and obtaining the phase difference on the target peak based on the time domain subsequences of the two chirp signals, and then obtaining an accurate Doppler ambiguity number based on the phase difference to correct the Doppler frequency shift, so as to further improve the accuracy of velocity ambiguity resolution, and at the same time, it can also effectively improve the accuracy of other data signal processing results based on the Doppler modulus.

[0097] Below, the implementation environment involved in the method for obtaining the target object velocity and the method for obtaining the Doppler fuzzy number provided in the embodiments of the present application will be briefly described.

[0098] like Figure 2 As shown, in one embodiment of the present application, a computer device is provided, and its internal structure diagram can be as shown in FIG. Figure 2 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for obtaining a target object speed or a method for obtaining a Doppler ambiguity number is implemented.

[0099] Those skilled in the art will understand that Figure 2 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0100] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0101] First, the sensor used in the embodiment of the present application and the transmission signal emitted by the sensor are introduced as follows:

[0102] The method for obtaining the speed of a target object provided in an embodiment of the present application is applied to a sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner. Optionally, the sensor is a MIMO sensor.

[0103] The sensor has a first transmitting channel and at least one second transmitting channel, the first transmitting channel can transmit two chirp signals at a time, and each second transmitting channel transmits one chirp signal at a time, wherein Figure 3 As shown, Figure 3 FIG. 4 is a schematic diagram showing two chirp signals transmitted by the first transmission channel. Figure 4 As shown, Figure 4 FIG. 2 is a schematic diagram of a chirp signal transmitted by the second transmission channel, wherein the chirp signal (chirp) is a high-frequency continuous wave whose frequency changes with time, and can generally be sawtooth or triangular.

[0104] The emission period of the sensor refers to the duration of the emission signal in one period. The emission period T D It is composed of the chirp periods of multiple chirp signals, where the chirp period refers to the duration of each chirp signal. The chirp period is denoted by T r Indicates. Figure 5 As shown, Figure 5 The waveform diagram of the emission signal of a sensor is shown as an example. Figure 5 It can be seen that the sensor is a four-transmitter antenna, including a first transmission channel and three second transmission channels. Optionally, in the embodiment of the present application, the first transmission channel can transmit two chirp signals in each transmission cycle, and each second transmission channel transmits one chirp signal in each transmission cycle. In this case, one transmission cycle can be expressed as: T D =5T r For example, a traditional frame includes 256 chirp signals, which require 64 transmission cycles to complete. In the embodiment of the present application, in each transmission cycle, the first transmission channel changes from transmitting one chirp signal to transmitting two chirp signals. In this technical solution, based on Figure 5 The four antennas shown can transmit up to 320 chirp signals, that is, 64 chirp signals are added in transmitting one frame signal.

[0105] Optionally, in the case where there is a first preset time delay between the first chirp signal and the second chirp signal, one transmission period can be expressed as T D =5T r +a.

[0106] In another embodiment of the present application, the first transmission channel transmits two chirp signals in the first transmission period, and transmits one chirp signal in the second transmission period, and each second transmission channel transmits one chirp signal each time. For example, a conventional frame signal includes 256 chirp signals. Figure 5 It can be seen from the waveform of the sensor's transmission signal that the sensor has four antennas, which means that in the traditional technology, 64 transmission cycles are required to complete. In the embodiment of the present application, at least one of the 64 transmission cycles is a first transmission cycle, and the remaining transmission cycles are second transmission cycles. In the first transmission cycle, the sensor can transmit 5 chirp signals, and in the second transmission cycle, the sensor can transmit 4 chirp signals, that is, 1-64 chirp signals can be added to a frame of the transmitted signal. Then, based on the above content, as Figure 6 As shown, the method for obtaining the speed of a target object provided in an embodiment of the present application may include the following steps:

[0107] Step 601: The computer device obtains the target peak position in the echo signal.

[0108] In the embodiment of the present application, after the transmission signal is sent out by the transmitting antenna of the radar, the signal reflected by the target object is received by the receiving antenna of the radar, that is, the above-mentioned echo signal.

[0109] The transmission signal and the echo signal are mixed to obtain a mixed signal. In the embodiment of the present application, the computer device can perform a two-dimensional fast Fourier transform on the mixed signal to obtain the target peak position (k peak ,P peak ). Among them, Figure 7 As shown, Figure 7 A schematic diagram of a target peak position is shown, wherein the process of performing a two-dimensional fast Fourier transform on a mixed signal is: sampling the mixed signal, storing the sampled data on a chirp as rows of a matrix, for example, there are M chirps, and correspondingly, there are M rows of the matrix, and the number of sampling points of each chirp is N, indicating that there are N columns of the matrix, so that an M×N sampled data matrix can be obtained.

[0110] For each row of the data matrix, an N-point FFT can be performed, i.e., a distance-dimensional Fourier transform, and then a longitudinal Doppler FFT can be performed across chirps on each column of the data matrix, i.e., a speed-dimensional Fourier transform. The combined operation of the distance FFT (row by row) and the Doppler FFT (column by column) can be regarded as a two-dimensional FFT of the sampling data corresponding to each frame. The two-dimensional FFT can simultaneously distinguish the distance and speed of the target. Therefore, the target peak position of the two-dimensional FFT corresponds to the distance information and speed information of the target in front of the radar.

[0111] Step 602: The computer device obtains the phase difference between two chirp signals at the target peak position.

[0112] In an embodiment of the present application, the two chirp signals are a first chirp signal and a second chirp signal transmitted in sequence, wherein the first chirp signal or the second chirp signal may be a newly added signal unit, or a signal unit in the original FMCW signal, and the order of the first chirp signal and the second chirp signal may be arranged arbitrarily. The embodiment of the present application is described by taking the first chirp signal being transmitted first and the second chirp signal being transmitted later as an example. Optionally, the first chirp signal and the second chirp signal are the same.

[0113] In one embodiment of the present application, the process of a computer device obtaining the phase difference between two chirp signals at a target peak position includes the following: the computer device can obtain the phase values ​​of the two chirp signals at the target peak position respectively, and calculate the difference between the phase values ​​of the two chirp signals, thereby obtaining the phase difference between the two chirp signals at the target peak position.

[0114] The process of obtaining the phase values ​​of the two chirp signals at the target peak positions by the computer device includes the following:

[0115] A time domain subsequence of the first chirp signal and a time domain subsequence of the second chirp signal are obtained. The time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal are respectively subjected to two-dimensional fast Fourier transform processing to obtain a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position.

[0116] The time domain subsequence of the first chirp signal can be expressed as:

[0117]

[0118] Where n represents the sampling number of the chirp signal, l represents the number of the chirp signal, and f B Represents the frequency component corresponding to the target object, T s represents the sampling interval for sampling the chirp signal, f rd represents the Doppler frequency, T D Indicates the duration of a transmission signal cycle, T r represents the duration of a chirp signal, and R represents the distance between the target and the radar.

[0119] The time domain subsequence of the second chirp signal can be expressed as:

[0120]

[0121] in, f Drepresents the corrected frontal Doppler frequency, f c represents the starting frequency of the chirp signal, v represents the speed of the target object, and c represents the speed of light.

[0122] According to equations 1 and 2, there is a phase difference f between the first chirp signal and the second chirp signal. D ·T r .

[0123] After performing a two-dimensional Fourier transform on the first chirp signal and the second chirp signal corresponding to equations 1 and 2, the phase values ​​of the first chirp signal and the second chirp signal can be obtained.

[0124] The expressions of equations 1 and 2 can be used to obtain the expression of the phase value of the first chirp signal:

[0125]

[0126] The expression of the phase value of the second chirp signal is:

[0127]

[0128] In the embodiment of the present application, the phase difference between the first chirp signal and the second chirp signal can be obtained by subtracting the phase value of the second chirp signal from the phase value of the first chirp signal, wherein the phase difference between the two can be expressed as:

[0129]

[0130] In the embodiment of the present application, the phase value of the first chirp signal can be obtained according to the above formula 3, the phase value of the second chirp signal can be obtained according to the above formula 4, and the phase difference between the phase value of the first chirp signal and the phase value of the second chirp signal can be obtained according to the above formula 5.

[0131] Step 603: The computer device determines the Doppler ambiguity number according to the phase difference.

[0132] In an optional implementation, the computer device may obtain the Doppler ambiguity number according to the decimal part of the phase difference, wherein the decimal part of the phase difference may be a value of the decimal part of the phase difference divided by 360 degrees, and the decimal part of the phase difference may be expressed as:

[0133] Formula 7 is constructed based on the chirp period in the FMCW signal, the transmission period of the sensor and the value of the fractional part:

[0134]

[0135] Among them, the sensor's transmission period T D , chirp period T rare all known numbers, so it can be seen that by Make a decision, and then the Doppler fuzzy number q can be obtained based on Formula 7.

[0136] In step 604, the computer device determines the speed of the target object based on the Doppler ambiguity number.

[0137] The Doppler frequency can be corrected based on the Doppler fuzzy number q obtained above to obtain a corrected Doppler frequency, and then the speed of the target object is calculated based on the corrected Doppler frequency.

[0138] The embodiment of the present application transmits two chirp signals each time a chirp signal is transmitted in a transmission channel, and obtains a phase difference on a target peak based on a time domain subsequence of the two chirp signals, and then obtains a precise Doppler ambiguity number based on the phase difference to correct the Doppler frequency, thereby improving the accuracy of resolving velocity ambiguity and thus improving the accuracy of the detected velocity of the target object.

[0139] It should be noted that, in the case of only one receiving antenna, after the echo signals reflected by each target object are processed in step 601, the target peak position corresponding to the echo signal of each target object can be obtained, and the target peak position corresponding to the echo signals of different targets is different. For each target object, the phase difference between the first chirp signal and the second chirp signal and the target peak position corresponding to the echo signal of the target object is calculated, and then the Doppler ambiguity number is determined according to the phase difference, and the speed of the target object is calculated by the Doppler ambiguity number.

[0140] In practical applications, there may be multiple receiving antennas. For ease of description, a target object is used as an example. The echo signal reflected by the target object can be received by multiple receiving antennas respectively. Then, by performing a two-dimensional fast Fourier transform on the echo signal received by each receiving antenna, the target peak position corresponding to each receiving antenna can be obtained. Then, the computer device can calculate the phase difference between the first chirp signal and the second chirp signal at each target peak position respectively, and then determine the Doppler ambiguity number based on all phase differences.

[0141] The process of determining the Doppler ambiguity number according to all phase differences may refer to: averaging all phase differences to obtain an average phase difference, and determining the Doppler ambiguity number based on the average phase difference. The process of determining the Doppler ambiguity number according to the average phase difference may refer to the content disclosed in step 603.

[0142] In another embodiment of the present application, there is a first preset time delay a between two chirp signals transmitted by the first transmission channel each time, and the waveform diagram of the transmission signal can be as follows: Figure 8 As shown, the value of the first preset delay a is greater than zero. Based on this situation, Fig. 9As shown, the embodiment of the present application provides another method for obtaining the speed of a target object, the method comprising the following steps:

[0143] Step 901: A computer device obtains a target peak position in an echo signal.

[0144] Please refer to the contents disclosed in step 601.

[0145] Step 902: The computer device obtains the phase difference between two chirp signals at the target peak position.

[0146] In the embodiment of the present application, the two chirp signals transmitted by the first transmission channel each time include a first chirp signal and a second chirp signal transmitted in sequence, and optionally, the first chirp signal and the second chirp signal are the same. Since there is a first preset time delay a between the first chirp signal and the second chirp signal, the time domain expression of the second chirp signal can be expressed as Formula 8:

[0147]

[0148] Combined with the time domain subsequence of the first chirp signal shown in equation 1 It can be seen that there is a phase difference f between the time domain subsequences of the first chirp signal and the second chirp signal D ·(a+T r ).

[0149] In the embodiment of the present application, after performing a two-dimensional Fourier transform on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal, it is assumed that the target peak position is (k peak ,P peak ), then the expression of the phase value of the first chirp signal is:

[0150]

[0151] The expression of the phase value of the second chirp signal is:

[0152]

[0153] On this basis, the phase difference between the first chirp signal and the second chirp signal can be expressed as:

[0154]

[0155] Optionally, in another embodiment, the process of obtaining the phase difference between the two chirp signals at the target peak position by the computer device may include the following: the computer device may obtain the first preset time delay a and the chirp period T in the frequency modulated continuous wave signal. r , based on the first preset time delay a and the chirp period T rGet the fuzzy Doppler frequency, where the fuzzy Doppler frequency is expressed as: f rd (a+T r ).

[0156] Then, the computer device can obtain the phase value of the first chirp signal Phase value of the second chirp signal The phase difference between the first chirp signal and the second chirp signal at the target peak position is determined according to the phase value of the first chirp signal, the phase value of the second chirp signal, and the fuzzy Doppler frequency. The calculation process of the phase difference can be shown as formula 12:

[0157]

[0158] Step 903: The computer device determines a Doppler ambiguity number according to the phase difference and the first preset time delay.

[0159] In the embodiment of the present application, the computer device may obtain the fractional part of the phase difference, wherein the fractional part of the phase difference may be the value of the fractional part of the phase difference divided by 360 degrees, and the fractional part of the phase difference may be expressed as:

[0160] The computer device may construct Formula 14 according to the first preset time delay, the chirp period in the frequency modulated continuous wave signal, the transmission period of the sensor and the value of the fractional part:

[0161]

[0162] Due to the first preset delay a, the sensor's transmission period T D , chirp period T r are all known numbers, so it can be seen that by Make a decision, and then the Doppler fuzzy number q can be obtained based on formula (14).

[0163] In step 904 , the computer device determines the speed of the target object based on the Doppler ambiguity number.

[0164] The Doppler frequency can be corrected based on the Doppler fuzzy number q obtained above to obtain a corrected Doppler frequency, and then the speed of the target object is calculated based on the corrected Doppler frequency.

[0165] In the embodiment of the present application, by setting a first preset time delay between two chirps transmitted at the same time, the accuracy of the obtained Doppler ambiguity number is improved, thereby further improving the accuracy of the sensor's speed measurement.

[0166] The embodiment of the present application provides a method for obtaining a Doppler ambiguity number. The method is applied to a sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner. The sensor has a first transmission channel and at least one second transmission channel. The first transmission channel transmits two chirp signals in each cycle of at least part of the transmission cycle. There is a second time delay between the two chirp signals. The value of the second time delay is greater than or equal to zero. Each second transmission channel transmits a chirp signal in each transmission cycle. Fig.10 As shown, the method comprises the following steps:

[0167] Step 1001: A computer device obtains a target peak position in an echo signal.

[0168] Step 1002: The computer device obtains the phase difference between two chirp signals at the target peak position.

[0169] In an optional implementation, the two chirp signals include a first chirp signal and a second chirp signal transmitted in sequence, wherein the process of obtaining the phase difference between the two chirp signals at the target peak position includes:

[0170] Step A1: Acquire a time domain subsequence of a first chirp signal and a time domain subsequence of a second chirp signal.

[0171] The time domain subsequence of the first chirp signal is:

[0172] The time domain subsequence of the second chirp signal is:

[0173]

[0174] Step A2: Perform two-dimensional fast Fourier transform processing on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal respectively to obtain the phase value of the first chirp signal and the phase value of the second chirp signal at each target peak position.

[0175] The expression of the phase value of the first chirp signal is:

[0176]

[0177] The expression of the phase value of the second chirp signal is:

[0178]

[0179] Step A3: acquiring a phase difference between the first chirp signal and the second chirp signal at a target peak position based on the phase value of the first chirp signal and the phase value of the second chirp signal.

[0180] The computer device can obtain the second time delay a and the chirp period T in the frequency modulated continuous wave signal.r , based on the second time delay a and the chirp period T r Get the fuzzy Doppler frequency, where the fuzzy Doppler frequency is expressed as: f rd (a+T r ).

[0181] Then, the computer device can calculate the phase value of the first chirp signal according to the phase value of the first chirp signal. Phase value of the second chirp signal And the fuzzy Doppler frequency determines the phase difference between the first chirp signal and the second chirp signal at the target peak position. The phase difference is:

[0182]

[0183] Step 1003: The computer device determines the Doppler ambiguity number according to the phase difference and the second time delay.

[0184] In an embodiment of the present application, the computer device may obtain the fuzzy Doppler frequency, the chirp period of the frequency modulated continuous wave signal, and the transmission period of the sensor, and determine the Doppler fuzzy number according to the phase difference, the fuzzy Doppler frequency, the chirp period, the second time delay, and the transmission period. The process may include the following steps:

[0185] Step B1, acquiring the phase difference between two chirp signals at the target peak position based on the phase difference, the fuzzy Doppler frequency, the chirp period and the second time delay;

[0186] Among them, the phase difference between the two chirp signals at the target peak position can be expressed as

[0187] Step B2, obtaining the decimal part of the first value.

[0188] The first value is equal to the phase difference divided by 360 degrees, which can be expressed as

[0189] The fractional part of the first value can be expressed as:

[0190] Step B3, obtaining the decimal part of the second value.

[0191] The second value is equal to the sum of the chirp period and the second delay multiplied by the Doppler ambiguity number divided by the transmission period, which can be expressed as:

[0192] The fractional part of the second value can be expressed as:

[0193] Step B4: acquiring the Doppler ambiguity number according to the fact that the decimal part of the first value is equal to the decimal part of the second value.

[0194] make Due to the second delay a, the sensor's transmission period T D , chirp period T r are all known numbers, so we can know that by By making a decision, the Doppler fuzzy number q can be obtained.

[0195] In the embodiment of the present application, the accuracy of the sensor speed measurement is improved by introducing the Doppler fuzzy number, that is, using the first transmission channel to transmit two chirp signals at a time, which is equivalent to adding a chirp signal before or after the signal transmitted by a transmission channel in a traditional FMCW sensor, and obtaining the phase difference of the two chirp signals at the target peak position in the echo signal to obtain the Doppler fuzzy number (i.e., q). In addition, by setting a first preset time delay between the two chirps transmitted at the same time, the accuracy of the obtained Doppler fuzzy number is improved, thereby further improving the accuracy of the sensor speed measurement.

[0196] It should be understood that although Figure 6-Figure 10 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 6-Figure 10 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0197] In one embodiment of the present application, Fig.11 As shown, a sensor is provided, the sensor comprising:

[0198] The first transmitting channel 1101 is used to transmit two chirp signals in at least part of the transmitting cycle.

[0199] The second transmitting channel 1102 is used to transmit a chirp signal in each transmitting cycle.

[0200] The receiving channel 1103 is used to receive the echo signal.

[0201] The signal processing module 1104 is used to obtain the target peak position in the echo signal, obtain the phase difference between the two chirp signals at the target peak position, and determine the Doppler ambiguity number according to the phase difference.

[0202] In one embodiment, the signal processing module 1104 may also be used to implement the method for obtaining the target object velocity provided in the above embodiment, and / or implement the method for obtaining the Doppler ambiguity number provided in the above embodiment.

[0203] In one embodiment, the sensor is a millimeter wave radar chip.

[0204] In one embodiment, the millimeter wave radar chip is an AiP (Antennas in Package) chip.

[0205] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for obtaining the target object velocity in the above embodiment are implemented, or the steps of the method for obtaining the Doppler ambiguity number in the above embodiment are implemented.

[0206] The implementation principle and technical effects of the computer device provided in this embodiment are similar to those of the above method embodiments, and will not be repeated here.

[0207] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for obtaining the target object velocity in the above embodiment are implemented, or the steps of the method for obtaining the Doppler ambiguity number in the above embodiment are implemented.

[0208] In an optional embodiment, for sensor devices such as FMCW MIMO radars, when transmitting signals, in a frame signal or a transmitting antenna transmission cycle, a transmitting antenna in the MIMO antenna can be controlled to transmit two chirp signals at a time, which is equivalent to adding a "new" chirp signal before or after the "original" chirp signal traditionally transmitted by the transmitting antenna, and a preset time delay can be added between the "original" chirp signal and the "new" chirp signal to achieve the purpose of modifying the transmission waveform. Subsequently, according to the phase difference between the "original" chirp signal and the "new" chirp signal at the target peak position in the echo signal obtained based on the modified transmission waveform, combined with the calculation method described in other embodiments, the Doppler ambiguity number can be determined to resolve the velocity ambiguity, thereby obtaining a more accurate target object velocity.

[0209] The computer-readable storage medium provided in this embodiment has similar implementation principles and technical effects to those of the above method embodiments, and will not be described in detail here.

[0210] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0211] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0212] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for obtaining the speed of a target object, characterized in that: Applicable to a MIMO sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner, the sensor having a first transmitting channel and at least one second transmitting channel, each of the second transmitting channels transmitting a chirp signal at a time; The first transmission channel transmits at least two chirp signals at a time in at least part of the transmission cycle, so as to add at least one chirp signal before or after the signal transmitted by the transmission channel, and the method comprises: Obtain the target peak position in the echo signal; For the same target peak, the phase difference between adjacent chirp signals in the at least two chirp signals transmitted by the first transmitting channel at one time is calculated at the position of the target peak, and a more accurate phase difference is obtained based on all the calculated phase differences; Determining a Doppler ambiguity number according to the relatively accurate phase difference; and A velocity of the target object is determined based on the Doppler ambiguity number.

2. The method according to claim 1, characterized in that There is a first preset time delay between two adjacent chirp signals of at least two chirp signals transmitted by the first transmission channel each time; and determining the Doppler ambiguity number according to the phase difference includes: Determine the Doppler ambiguity number according to the phase difference and the first preset time delay; Wherein, the value of the first preset delay is greater than zero.

3. The method according to claim 1 or 2, characterized in that: The at least two chirp signals include a first chirp signal and a second chirp signal transmitted in sequence; and determining a Doppler ambiguity number according to the phase difference includes: Acquire a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position; acquiring a phase difference between the first chirp signal and the second chirp signal at the target peak position according to a phase value of the first chirp signal and a phase value of the second chirp signal; and The Doppler ambiguity number is determined according to the phase difference.

4. The method according to claim 3, characterized in that The acquiring, at the target peak position, a phase value of the first chirp signal and a phase value of the second chirp signal comprises: Acquire a time domain subsequence of the first chirp signal and a time domain subsequence of the second chirp signal; Two-dimensional fast Fourier transform processing is performed on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal respectively to obtain a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position.

5. The method according to claim 3, characterized in that: There is a first preset time delay between the two chirp signals transmitted by the first transmission channel each time; and obtaining the phase difference at the target peak position according to the phase value of the first chirp signal and the phase value of the second chirp signal includes: Obtaining the ambiguous Doppler frequency; and The phase difference is acquired according to the phase value of the first chirp signal, the phase value of the second chirp signal, the first preset time delay, the ambiguous Doppler frequency, and the chirp period in the frequency modulated continuous wave signal.

6. The method according to claim 3, characterized in that The first chirp signal and the second chirp signal are identical.

7. The method according to claim 1, characterized in that Determining the Doppler ambiguity number according to the phase difference comprises: The Doppler ambiguity number is obtained according to the fractional part of the phase difference.

8. The method according to claim 7, characterized in that There is a first preset time delay between two chirp signals transmitted by the first transmission channel each time; and obtaining the Doppler ambiguity number according to the decimal part of the phase difference includes: Obtain the value of the decimal part of the phase difference divided by 360 degrees; The Doppler ambiguity number is obtained based on the first preset time delay, the chirp period in the frequency modulated continuous wave signal, the transmission period of the sensor, and the value of the fractional part.

9. The method according to claim 1, characterized in that: The first transmission channel transmits two chirp signals in each transmission cycle, and each of the second transmission channels transmits one chirp signal in each transmission cycle.

10. The method according to claim 1, characterized in that The first transmitting channel transmits two chirp signals in a first transmitting period and transmits one chirp signal in a second transmitting period, and each of the second transmitting channels transmits one chirp signal each time.

11. The method according to claim 1, characterized in that: The first transmitting channel may also transmit at least three chirp signals at a time, and each of the second transmitting channels may transmit one chirp signal at a time; and obtaining the phase difference between the two chirp signals at the target peak position includes: The phase difference between two adjacent chirp signals of the at least three chirp signals at the target peak position is obtained.

12. A method for obtaining a Doppler fuzzy number, characterized in that: The invention is applied to a MIMO sensor that transmits a frequency modulated continuous wave signal in a time division multiplexing manner, wherein the sensor has a first transmitting channel and at least one second transmitting channel, wherein the first transmitting channel transmits at least two chirp signals at a time in at least part of a transmitting period, so as to add at least one chirp signal before or after a signal transmitted by the transmitting channel, wherein adjacent chirp signals in the at least two chirp signals have a second time delay, and each of the second transmitting channels transmits a chirp signal in each transmitting period, and the method comprises: Obtain the target peak position in the echo signal; Acquire a phase difference between the two chirp signals transmitted once by the first transmitting channel at the target peak position; and determining a Doppler ambiguity number according to the phase difference and the second time delay; The value of the second delay is greater than or equal to zero.

13. The method according to claim 12, characterized in that The two chirp signals include a first chirp signal and a second chirp signal transmitted in sequence; and obtaining a phase difference between the two chirp signals at the target peak position includes: Acquire a time domain subsequence of the first chirp signal and a time domain subsequence of the second chirp signal; performing two-dimensional fast Fourier transform processing on the time domain subsequence of the first chirp signal and the time domain subsequence of the second chirp signal respectively, so as to obtain a phase value of the first chirp signal and a phase value of the second chirp signal at the target peak position; and Based on the phase value of the first chirp signal and the phase value of the second chirp signal, a phase difference between the first chirp signal and the second chirp signal at the target peak position is acquired.

14. The method according to claim 12, characterized in that The determining of the Doppler ambiguity number according to the phase difference and the second time delay comprises: Get the fuzzy Doppler frequency; Obtaining a chirp period of the frequency modulated continuous wave signal; Acquiring the emission period of the sensor; and The Doppler ambiguity number is acquired based on the phase difference, the ambiguous Doppler frequency, the chirp period, the second time delay, and the transmission period.

15. The method according to claim 14, characterized in that The acquiring the Doppler ambiguity number based on the phase difference, the ambiguous Doppler frequency, the chirp period, the second time delay and the transmission period further includes: Acquire a phase difference between two chirp signals at a target peak position based on the phase difference, the ambiguous Doppler frequency, the chirp period and the second time delay; Obtaining a decimal part of a first value, where the first value is equal to the phase difference divided by 360 degrees; Obtaining a fractional part of a second value, where the second value is equal to the sum of the chirp period and the second delay multiplied by the Doppler ambiguity number divided by the transmission period; and The Doppler ambiguity number is obtained according to that the decimal part of the first value is equal to the decimal part of the second value.

16. A sensor, characterized in that: include: A first transmission channel, used to transmit at least two chirp signals at a time in at least part of the transmission cycle, so as to add at least one chirp signal before or after the signal transmitted by the transmission channel; A second transmission channel is used to transmit a chirp signal in each transmission cycle; A receiving channel, used for receiving an echo signal; as well as The signal processing module is used to obtain the target peak position in the echo signal, obtain the phase difference between the two chirp signals transmitted once by the first transmission channel at the target peak position, and determine the Doppler ambiguity number according to the phase difference.

17. The sensor according to claim 16, characterized in that The signal processing module can also be used to implement the method for obtaining the speed of a target object as described in any one of claims 1 to 11, and / or Implement the method for obtaining Doppler ambiguity number as described in any one of claims 12 to 15.

18. The sensor according to claim 16 or 17, characterized in that The sensor is a millimeter wave radar chip.

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