Radar system, radar control device, radar control method, and radar control program

Abstract

A processor of this radar system is configured to execute transmission of a transmission signal, of each transmission antenna, in which an allocation pattern of phase rotation amount allocated to the transmission signal is changed for each transmission cycle. The processor is configured to execute, for each of a plurality of reception cycles, definition of a signal component assumed to be included in each peak of the Doppler spectrum from among a target component and each phase offset component in correlation with the corresponding allocation pattern. The processor is configured to execute output of sensing data correlated with the reception signal from which the phase offset component estimated from the relationship between each peak in the plurality of reception cycles and the signal component has been removed.

Description

Radar system, radar control device, radar control method, and radar control program CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-131074 filed in Japan on August 7, 2024, and the contents of the original application are incorporated by reference in their entirety.

[0002] The present disclosure relates to radar control technology.

[0003] Patent Document 1 discloses a MIMO (Multiple-Input Multiple-Output) radar system that transmits Doppler Division Multiplexing (DDM) modulated transmission signals from multiple transmission antennas. The radar system estimates and compensates for periodic phase offset, which is an error that occurs for each phase given by DDM modulation. In estimating the phase offset component, a transmission signal is transmitted sequentially from each transmission antenna. When a transmission signal transmitted from one transmission antenna is received, a Doppler spectrum is obtained by FFT processing. The phase offset is estimated from the peak of a spurious component contained in the Doppler spectrum.

[0004] US Patent Application Publication No. 2023 / 0129203

[0005] However, if transmission signals are transmitted in order from each transmitting antenna to estimate the phase offset, as in Patent Document 1, the transmission processing takes time equal to the number of transmitting antennas.If the transmission periods are overlapped to shorten the transmission processing time, a received signal in which each transmitted signal is mixed will be obtained, making it difficult to estimate and compensate for the phase offset.

[0006] An object of the present disclosure is to provide a radar system that can both shorten the transmission processing time and compensate for the phase offset. Another object of the present disclosure is to provide a radar control device that can both shorten the transmission processing time and compensate for the phase offset. Yet another object of the present disclosure is to provide a radar control method that can both shorten the transmission processing time and compensate for the phase offset. Yet another object of the present disclosure is to provide a radar control program that can both shorten the transmission processing time and compensate for the phase offset.

[0007] The technical means of the present disclosure for solving the problems will be described below. Note that the reference numerals in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described later in detail, and do not limit the technical scope of the present disclosure.

[0008] A first aspect of the present disclosure is a radar system having a plurality of transmitting antennas, at least one receiving antenna, and a processor, wherein the processor is configured to: transmit, from each transmitting antenna, a transmission signal for each transmission cycle, the transmission signal including a plurality of chirp signals whose frequencies vary over time, and the phase rotation amount for each chirp signal being rotated by a specific phase rotation amount differs between the transmitting antennas; acquire, for each reception cycle corresponding to the transmission cycle, signal data correlating with a received signal obtained by reflecting the transmission signals from the plurality of transmitting antennas on a target and receiving the same at a single receiving antenna; and output sensing data correlating with the signal data, wherein transmitting the transmission signal includes transmitting transmission signals in which an allocation pattern of each phase rotation amount assigned to each transmission signal for each transmitting antenna is changed for each transmission cycle, and outputting sensing data correlating with the signal data, for each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, from among target components corresponding to targets from which the transmission signals from each transmitting antenna have been reflected and phase offset components corresponding to each phase rotation amount, in correlation with the corresponding allocation pattern, for each of a plurality of reception cycles; and outputting sensing data correlated with the signal data from which the phase offset component estimated from the relationship between each peak and the signal component in a plurality of reception cycles has been removed.

[0009] A second aspect of the present disclosure is a radar control device having a processor and controlling a radar system equipped with a plurality of transmitting antennas and at least one receiving antenna, wherein the processor is configured to perform the following: transmit, from each transmitting antenna, transmission signals each including a plurality of chirp signals whose frequencies vary over time, and each of which is assigned a phase rotation amount that varies for each chirp signal by a specific phase rotation amount, for each transmitting antenna, for each receiving cycle; acquire, for each receiving cycle corresponding to the transmitting cycle, signal data correlating with received signals obtained by receiving the transmission signals from the plurality of transmitting antennas after they have been reflected by a target; and output sensing data correlating with the signal data; wherein transmitting the transmission signals includes transmitting transmission signals in which an allocation pattern of each phase rotation amount assigned to each of the transmission signals for each transmitting antenna is changed for each transmitting cycle; and outputting sensing data correlating with the signal data, for each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, from among target components corresponding to targets from which the transmission signals from each transmitting antenna have been reflected and phase offset components corresponding to each phase rotation amount, in correlation with the corresponding allocation pattern, for each of a plurality of receiving cycles; and outputting sensing data correlated with the signal data from which the phase offset component estimated from the relationship between each peak and the signal component in a plurality of reception cycles has been removed.

[0010] A third aspect of the present disclosure is a radar control method executed by a processor to control a radar system having a plurality of transmitting antennas and at least one receiving antenna, the method comprising: transmitting, from each transmitting antenna, transmit signals in each transmission cycle, each transmit signal including a plurality of chirp signals whose frequencies vary over time, the transmit signals being assigned a specific phase rotation amount such that the phase rotation amount for each chirp signal differs between the transmitting antennas; acquiring, for each reception cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by reflecting the transmit signals from the plurality of transmitting antennas on a target and receiving the same at a single receiving antenna; and outputting sensing data correlating with the signal data, wherein transmitting the transmit signals includes transmitting transmit signals in which an allocation pattern of each phase rotation amount assigned to each transmit signal for each transmitting antenna is changed for each transmission cycle; and outputting the sensing data includes defining, for each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, signal components expected to be included in each peak from among target components corresponding to targets from which the transmit signals from each transmitting antenna have been reflected and phase offset components corresponding to each phase rotation amount, in correlation with the corresponding allocation pattern, for each of a plurality of reception cycles; and outputting sensing data correlated with the signal data from which the phase offset component estimated from the relationship between each peak and the signal component in a plurality of reception cycles has been removed.

[0011] A fourth aspect of the present disclosure is a radar control program stored in a storage medium and including instructions to be executed by a processor that controls a radar system having a plurality of transmitting antennas and at least one receiving antenna, the instructions including: transmitting, from each transmitting antenna, transmission signals each including a plurality of chirp signals whose frequencies vary over time, and each chirp signal being rotated by a specific phase rotation amount such that the phase rotation amount varies between the transmitting antennas; acquiring, for each receiving cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by receiving, at a single receiving antenna, the transmission signals from the plurality of transmitting antennas after being reflected by a target; and outputting sensing data correlating with the signal data, wherein transmitting the transmission signals includes transmitting transmission signals in which an allocation pattern of each phase rotation amount assigned to each transmission signal for each transmitting antenna is changed for each transmission cycle; and outputting the sensing data includes: For a plurality of peaks in a Doppler spectrum corresponding to signal data, the signal components assumed to be included in each peak are defined for each of a plurality of reception cycles from among target components corresponding to targets from which transmitted signals from each transmitting antenna are reflected and each phase offset component corresponding to each phase rotation amount, in correlation with the corresponding allocation pattern; and outputting sensing data correlated with signal data from which the phase offset component estimated from the relationship between each peak and signal component in the plurality of reception cycles has been removed.

[0012] According to these first to fourth aspects, the allocation pattern of the phase rotation amount for the transmit signal for each transmit antenna differs for each transmit cycle. Therefore, if the signal components expected to be included in the peak are defined for each of multiple receive cycles, correlating with the corresponding allocation pattern from among the target component and each phase offset component corresponding to each phase rotation amount, a different phase offset component will be included for each receive cycle for the peak corresponding to each transmit signal. Therefore, the phase offset component can be estimated from the relationship between each peak and the signal component in multiple receive cycles, and sensing data correlated with the receive signal from which the phase offset component has been removed can be output. Therefore, the phase offset component can be estimated and removed from the receive signal mixed with the transmit signals from each transmit antenna. As a result, it is possible to achieve both a reduction in transmission processing time and compensation for phase offset.

[0013] FIG. 1 is a schematic diagram showing the overall configuration of a radar system. FIG. 1 is a schematic diagram for explaining phases imparted to transmission signals in each transmitting antenna. FIG. 2 is a table showing an example of phases imparted to transmission signals. FIG. 3 is a diagram showing an example of a transmission cycle and a reception cycle. FIG. 4 is a diagram for explaining a phase offset. FIG. 5 is a diagram for explaining spurious components caused by a phase offset. FIG. 6 is a diagram for explaining an example of a change in an allocation pattern. FIG. 7 is a diagram for explaining an example of a Doppler spectrum and a defined simultaneous equation. FIG. 8 is a diagram for explaining a matrix representation of the simultaneous equations. FIG. 9 is a block diagram showing the functional configuration of a control unit in a radar system. FIG. 10 is a flowchart showing a radar control flow. FIG. 11 is a diagram for explaining an example of a change in an allocation pattern in a second embodiment. FIG. 12 is a diagram for explaining an example of a Doppler spectrum and a defined simultaneous equation in the second embodiment. FIG. 13 is a diagram for explaining a matrix representation of the simultaneous equations in the second embodiment. FIG. 14 is a flowchart showing a radar control flow in the second embodiment. FIG. 15 is a flowchart showing a radar control flow in a third embodiment.

[0014] Hereinafter, multiple embodiments of the present disclosure will be described with reference to the drawings. Note that corresponding components in each embodiment are designated by the same reference numerals, and redundant description may be omitted. Furthermore, when only a portion of the configuration is described in each embodiment, the configuration of another previously described embodiment may be applied to the remaining portions of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0015] First Embodiment A first embodiment of the present disclosure will be described with reference to FIGS. 1 to 9. The radar device 1 shown in FIG. 1 is mounted on, for example, a vehicle 10, which is a moving body. The radar device 1 transmits a transmission signal to the outside world and receives the transmission signal reflected by a target as a received signal. The radar device 1 acquires and outputs sensing data related to the target that reflected the transmission signal by analyzing the received signal. The radar device 1 is a so-called MIMO (Multiple-Input-Multiple-Output) radar that transmits transmission signals from multiple transmission antennas TX, thereby artificially increasing the number of receiving antennas RX beyond the actual number. The radar device 1 is an example of a "radar system."

[0016] The sensing data output from the radar device 1 is input to an in-vehicle ECU (Electronic Control Unit) via an in-vehicle network such as a Control Area Network (CAN) (registered trademark) or Ethernet. The in-vehicle ECU executes various processes for autonomous driving and advanced driving assistance of the vehicle 10 based on the acquired sensing data of each target.

[0017] The processes based on the sensing data include, for example, collision avoidance processing, warning processing, etc. The collision avoidance processing is a process of controlling the vehicle to avoid collision with the target by controlling the brake system, steering system, etc. based on the sensing data of each target. The warning processing is a process of warning the driver of the possibility of collision with the target based on the sensing data of each target.

[0018] 1, the radar device 1 of this embodiment includes a transceiver unit 2, a control unit 7, and a storage unit 8. The transceiver unit 2 is a processing unit that performs transmission processing of a transmission signal and reception processing of a reception signal. The transceiver unit 2 includes a clock oscillator 3, a signal generator 4, multiple transmission circuits 5, multiple transmission antennas TX, multiple reception antennas RX, and multiple reception circuits 6.

[0019] The clock oscillator 3 generates a periodic clock signal. The clock oscillator 3 transmits the clock signal to the signal generator 4 and each receiving circuit 6. As shown in FIG. 2 , the signal generator 4 generates a chirp signal modulated so that the frequency varies over time, for each chirp period Tc corresponding to the clock signal. The signal generator 4 generates a specified number of chirp signals for each transmission cycle Tt. The number of chirp signals is, for example, an even number. For example, the number of chirp signals is constant for all transmission cycles Tt, regardless of the transmission cycle Tt. The generated multiple chirp signals are distributed and output to each channel of the transmitting circuit 5 and the receiving circuit 6. Note that in FIG. 2 and other figures, the chirp signals are shown as so-called up-chirp signals, whose frequency increases over time. However, the chirp signals may also be so-called down-chirp signals, whose frequency decreases over time.

[0020] In the following, the multiple chirp signals output from the signal generator 4 to the transmitter circuit 5 and transmitted from the transmitter antenna TX may be referred to as transmission signals. Furthermore, the multiple chirp signals output to the receiver circuit 6 in response to the transmission signals may be referred to as local signals.

[0021] The transmitter circuit 5 and receiver circuit 6 are each mainly composed of a semiconductor integrated circuit device such as an MMIC (Monolithic Microwave Integrated Circuit). The transmitter circuit 5 is connected to a transmitter antenna TX and outputs a transmit signal to the transmitter antenna TX. The transmitter circuit 5 includes the same number of phase shifters 51 and amplifiers 52 as the number of connected transmitter antennas TX.

[0022] The phase shifter 51 imparts a specific phase change to the input transmission signal. More specifically, the phase shifter 51 imparts a phase change to a plurality of chirp signals arranged in time, rotating the signals by a substantially constant amount for each chirp period Tc. In the following description, it is assumed that the radar device 1 is provided with a total of m transmission antennas TX. In order to distinguish between the individual transmission antennas TX, an index n (n is a natural number from 1 to m) may be added to the end of the symbol "TX" to distinguish them from one another.

[0023] For example, as shown in FIG. 2, a plurality of chirp signals transmitted from a specific transmitting antenna TX1 among a plurality of transmitting antennas TX have a phase rotation amount ω １ In this case, the i-th chirp signal has a phase rotation amount ω １ The phase is rotated by a factor of 1 / Tc times the chirp number. As a result, the phase of the multiple chirp signals that are aligned in time and that have passed through the phase shifter 51 changes linearly for each chirp period Tc. This linear change in phase imparts a pseudo Doppler velocity to the chirp signal according to the amount of phase rotation. This phase change can also be called a Doppler shift.

[0024] In FIG. 2, the chirp number i ranges from "1" to "N", which is the maximum number of chirp signals in one transmission cycle Tt. ｃ However, the chirp number i ranges from "0" to "N ｃ It may be set from any number to any number, such as "-1".

[0025] Each of the phase shifters 51 applies a different rotation amount. That is, in FIG. 2, the phase rotation amount ω １ A phase rotation amount ω different from ２ Similarly, for the transmitting antenna TXm, a phase rotation amount ω is assigned to the multiple chirp signals to be transmitted. １ , ω ２ The phase rotation amount ω is different from ｍ are assigned. As a result, the multiple transmit signals transmitted from the multiple transmit antennas TX are subjected to so-called Doppler division multiplexing (DDM) modulation. Hereinafter, the initial phase rotated by the rotation amount in each chirp signal may be referred to as the DDM phase. The DDM phase is an example of a "velocity phase."

[0026] For example, assume that the amount of rotation is π / 2 and the DDM phase of the first chirp signal is 0. In this case, as shown in FIG. 3, the DDM phase of the second chirp signal is π / 2, the DDM phase of the third chirp signal is π, and the DDM phase of the fourth chirp signal is 3π / 2. Then, the DDM phase completes one cycle with the fifth chirp signal. In other words, when the amount of rotation is π / 2, the rotation period Td of the DDM phase is four chirp signals, and the number of DDM phases N is 3π / 2. ｋ There are four.

[0027] The manner in which each phase shifter 51 allocates a phase rotation amount to each transmission signal will be described in detail later.

[0028] The amplifiers 52 amplify the transmission signals output from the phase shifters 51 and output the amplified signals to the corresponding transmission antennas TX.

[0029] The transmitting antenna TX converts the transmission signal supplied from the transmitting circuit 5 from an electrical signal to a radio wave signal and transmits it to the outside world. A single transmitting antenna TX is configured to include at least one antenna element. For example, the transmitting antenna TX is a patch antenna equipped with multiple flat antenna elements. The antenna elements are arranged on the opposite side of a dielectric substrate having a ground plane on one side, facing the ground plane. The multiple antenna elements are connected, for example, in series, by a feeder line that supplies the electrical signal. Each transmission signal transmitted from the multiple transmitting antennas TX is given a different phase rotation by the corresponding phase shifter 51.

[0030] As a result, as shown in Figure 2, each transmitting antenna TX transmits a specified number of chirp signal groups as transmission signals for each transmission cycle Tt. The transmission cycle Tt is synchronized between the transmitting antennas TX. That is, the transmission of each transmission signal from each transmitting antenna TX starts substantially simultaneously. As a result, the transmission periods of each transmission signal from each transmitting antenna TX overlap from the start to the end of transmission. Note that the start times of transmission from each transmitting antenna TX may be offset as long as the transmission periods of the transmission signals overlap at least partially in time.

[0031] The receiving antenna RX receives, as a received signal, a radio wave signal including a transmitted signal reflected by a target in the external world. Each of the multiple receiving antennas RX receives a signal in a state in which the received signals corresponding to the transmitted signals from the multiple transmitting antennas TX are mixed together. Hereinafter, this mixed signal received by each receiving antenna RX will be referred to as a mixed received signal.

[0032] The receiving antenna RX converts the received signal as a radio wave signal into an electrical signal and outputs it to the corresponding receiving circuit 6. The receiving antenna RX is, for example, a patch antenna, similar to the transmitting antenna TX, in which at least one antenna element is connected in series by a feeder line. Note that the transmitting antenna TX and the receiving antenna RX may also be monopole antennas, inverted-F antennas, loop antennas, or the like. Note that, hereinafter, multiple received signals received by multiple receiving antennas RX may be collectively referred to as a received signal group.

[0033] The receiving circuit 6 is connected to the receiving antenna RX and acquires the received signal received by the receiving antenna RX. The receiving circuit 6 acquires the received signal as a reflected signal of the transmitted signal reflected by the target for each receiving cycle Tr corresponding to the transmitting cycle Tt. As shown in FIG. 4, each receiving cycle Tr is synchronized with the corresponding transmitting cycle. Furthermore, the receiving cycles Tr are synchronized between receiving channels. The receiving circuit 6 includes amplifiers 61, signal mixers 62, and AD converters 63, the number of which is the same as the number of connected receiving antennas RX.

[0034] The amplifier 61 amplifies the received signal received by the receiving antenna RX and outputs the amplified signal to the signal mixer 62. The signal mixer 62 generates a beat signal by mixing the local signal from the signal generator 4 with the received signal. The generated beat signal becomes an interference signal representing the frequency difference between the received signal and the local signal. The beat signal generated by the signal mixer 62 may be filtered by a low-pass filter (not shown) to remove high-frequency components that deviate from the frequency difference between the received signal and the local signal. The beat signal is also called an intermediate frequency (IF) signal.

[0035] The AD converter 63 converts the beat signal, which is an analog signal, into a digital signal. The AD converter 63 acquires the clock signal output from the clock oscillator 3, samples the beat signal at time intervals corresponding to the cycle of the clock signal, and digitizes it. The AD converter 63 sequentially outputs the digitized beat signal to the control unit 7.

[0036] In the above-described transceiver unit 2, the transmission signals transmitted from each transmitting antenna TX may include a phase offset, which is a phase error corresponding to the amount of phase rotation imparted, for each chirp signal. The phase offset is caused by hardware in the transmission circuit 5, such as the phase shifter 51. The phase offset is an error whose magnitude corresponds to the initial phase imparted by the phase shifter 51.

[0037] As shown in Figure 5, the DDM phase imparted to the transmitted signal by phase rotation is a periodic function. Therefore, the phase offset corresponding to that DDM phase is also a periodic function. The time waveform of such a periodic function can be assumed to be composed of a linear sum of sine waves. Therefore, in the Doppler spectrum of a beat signal containing this periodic phase offset, a peak corresponding to the phase offset appears at a unique position that depends on the amount of phase rotation.

[0038] For example, if the target is a stationary object, the Doppler spectrum of the beat signal is a convolution of the spectrum of the periodic function of the set DDM phase and the spectrum of the periodic function of the phase offset that actually occurs. As a result, the Doppler spectrum of the beat signal contains a mixture of peaks originating from the target that appear at the velocity bin position according to the DDM phase and peaks originating from the phase offset that appear at the velocity bin position according to the phase offset. In the following, the peaks originating from the target may be referred to as target components, and peaks originating from the phase offset may be referred to as spurious components. The number of DDM phases N ｋ , chirp number N ｃ , the spurious components are ｃ / N ｋ And N ｋ The spurious component is an example of a "phase offset component."

[0039] As a specific example, when the amount of phase rotation is π / 2, as shown in FIGS. 3 and 5, the phase offset δ corresponding to each of the DDM phases 0, π / 2, π, and 3π / 2 is ０ , δ ９０ , δ １８０ , δ ２７０is included in each chirp signal in the transmission signal. The Doppler spectrum of the beat signal for this transmission signal is expressed as N ｃ The spectrum of the peak corresponding to the phase rotation amount π / 2 appears at the position of N ｃ The Doppler spectrum is convoluted with the spectrum of peaks corresponding to the 0th to 3rd order phase offsets that appear at intervals of 1 / 4. As a result, the Doppler spectrum contains three spurious components. Note that the 0th order component in the phase offset spectrum is essentially a DC component.

[0040] The magnitude of the phase offset changes depending on the temperature and aging of the transmission circuit 5. Therefore, when compensating for the phase offset, it may be necessary to periodically estimate and update the magnitude of the spurious components that actually occur.

[0041] Therefore, the radar device 1 of this embodiment specifies the allocation of the amount of phase rotation to each transmission signal by each phase shifter 51 over multiple transmission cycles Tt in a manner that enables estimation of the phase offset component. Details of the allocation manner will be described below.

[0042] Each phase shifter 51 imparts phase rotation so that an allocation pattern of the amount of phase rotation assigned to each transmission signal for each transmitting antenna TX is changed for each transmission cycle Tt. That is, each phase shifter 51 imparts phase rotation so that the amount of phase rotation assigned to each transmission signal for each transmitting antenna TX is switched between the transmitting antennas TX for each transmission cycle Tt. The allocation pattern can also be expressed as a correspondence between each transmitting antenna TX and the amount of phase rotation assigned to the transmission signal transmitted from that transmitting antenna TX.

[0043] The above allocation mode will be described using an example in which a total of three transmitting antennas, TX1, TX2, and TX3, are provided in the radar device 1. It is assumed that a phase rotation amount of 0, π / 2, or π is assigned to each transmission signal of each of the transmitting antennas TX1, TX2, and TX3.

[0044] Here, we consider a Doppler spectrum generated from a beat signal corresponding to a received signal that is a mixture of these transmitted signals. The Doppler spectrum is expected to have multiple peaks that are a mixture of signal components due to target components related to the targets from which each transmitted signal was reflected and spurious components corresponding to the amount of phase rotation of each transmitted signal.

[0045] For example, in response to a transmit signal with a phase rotation of 0, a peak representing a target component appears in the Doppler spectrum at a position corresponding to the relative velocity of the target. Since no phase rotation is applied, no spurious components appear in this Doppler spectrum. Furthermore, in response to a transmit signal with a phase rotation of π / 2, a peak representing a target component appears in the Doppler spectrum at a position obtained by adding the relative velocity of the target and the pseudo velocity imparted by the phase rotation of π / 2. Furthermore, as described above, three peaks representing spurious components corresponding to this phase rotation of π / 2 appear at positions different from the target components.

[0046] In addition, for a transmitted signal with a phase rotation of π, a peak appears in the Doppler spectrum as a target component at a position where the relative velocity of the target is added to the pseudo velocity imparted by the phase rotation of π. Furthermore, a peak appears as a spurious component corresponding to this phase rotation of π at a position different from the target component.

[0047] The Doppler spectrum actually obtained is generated from a mixed received signal obtained by mixing these transmitted signals, and therefore, it can be assumed that the peaks at each position in the Doppler spectrum contain at least one of the target component and the spurious component due to each transmitted signal.

[0048] That is, an equation can be defined for each peak, with the intensity of the peak in the acquired Doppler spectrum as a known quantity and at least one of the target component and spurious component assumed to be contained in the peak as an unknown quantity. Therefore, if simultaneous equations that can solve all the unknowns can be defined, the spurious components contained in each transmission signal can be obtained as the solution of the simultaneous equations. Each phase shifter 51 changes its allocation pattern so that the spurious components can be obtained as the solution of the simultaneous equations.

[0049] The allocation mode that can obtain the spurious components as a solution to the simultaneous equations is an allocation mode that satisfies both the rank condition and the target component condition.

[0050] The rank condition is that the coefficient matrix A that equates the unknown matrix x, which defines the target components and spurious components assumed to be contained in each peak as unknowns, to the peak group matrix b, which defines a peak group, which is a plurality of assumed peaks, is full rank.

[0051] The target component condition is that a peak equivalent to the target component exists in the Doppler spectrum for each allocation pattern in the allocation cycle. A peak equivalent to the target component is a peak consisting of a single target component originating from a transmission signal from a single transmitting antenna TX. In other words, a peak equivalent to the target component is a peak that does not include spurious components originating from transmission signals from other transmitting antennas TX.

[0052] An example of how to change the allocation pattern that satisfies the above rank conditions and target component conditions will be described with reference to Figures 7 to 9. Each phase shifter 51 corresponding to each transmitting antenna TX1, TX2, and TX3 applies phase rotation so that the allocation pattern of the three phase rotation amounts is changed every transmission cycle Tt. In the following, the phase rotation amount ω １ , the phase rotation amount ω of the transmission signal of the transmitting antenna TX2 ２ , the phase rotation amount ω of the transmission signal of the transmitting antenna TX3 ３ The allocation pattern when is assigned is defined as [ω１ , ω ２ , ω ３ ] may be used for explanation.

[0053] Here, the four consecutive transmission cycles Tt are a first transmission cycle Tt_1, a second transmission cycle Tt_2, a third transmission cycle Tt_3, and a fourth transmission cycle Tt_4. For example, in the first transmission cycle Tt_1, each phase shifter 51 imparts a phase rotation to each transmission signal so that the assignment pattern becomes [0, π, π / 2] as shown in FIG. 7 . In the subsequent second transmission cycle Tt_2, each phase shifter 51 imparts a phase rotation to each transmission signal so that the assignment pattern becomes [π / 2, 0, π], which is different from that of the first transmission cycle Tt_1. Furthermore, in the third transmission cycle Tt_3, each phase shifter 51 imparts a phase rotation to each transmission signal so that the assignment pattern becomes [π, π / 2, 0], which is different from that of the two immediately preceding transmission cycles Tt_1 and Tt_2. Each phase shifter 51 imparts a phase rotation so that these three assignment patterns are repeated. In other words, phase rotation is imparted so that the assignment patterns do not overlap in the three consecutive transmission cycles Tt. Therefore, the allocation pattern of the fourth transmission cycle Tt_4 is the same as that of the first transmission cycle Tt_1.

[0054] As a result, in the Doppler spectrum corresponding to each transmission cycle Tt, N ｃ Four peaks appear at bin intervals of 1 / 4. Here, the bin position kN of the Doppler spectrum corresponding to the transmission cycle Tt_f is ｃ The intensity of the peak appearing at / 4 is b ｋ＿ｆ Let's say.

[0055] Each peak contains at least one of a target component and a spurious component corresponding to the transmission signal from each transmitting antenna TX. Here, the intensity of the target component corresponding to the transmission signal from the transmitting antenna TXn is denoted by s ｎ Also, the spurious component corresponding to the transmission signal from the transmitting antenna TXn is set to bin position kN. ｃ The intensity of the spurious component appearing at / 4 is x ｋ＿ｎ The intensity of each peak in the Doppler spectrum is b ｋ＿ｆ are the intensities sｎ , x ｋ＿ｎ Therefore, the intensity b ｋ＿ｆ is a known quantity, and the intensity s ｎ , x ｋ＿ｎ As unknowns, the simultaneous equations shown in FIG. 8 can be defined.

[0056] Here, when the simultaneous equations are expressed as a matrix using a coefficient matrix A, an unknown matrix x, and a peak group matrix b, the simultaneous equations can be defined as Ax = b. The coefficient matrix A shown in FIG. 9 is full rank and satisfies the rank condition. Here, the coefficient matrix A being full rank means that both the rows and columns are full rank. In FIG. 9, the numbers in the dashed line boxes are the components of the coefficient matrix A. However, if the dashed line box is blank, the component is "0". In addition, to make it easier to understand the correspondence between the components of the coefficient matrix A and the unknowns, the unknown matrix x, which is a column vector, is written horizontally. In FIG. 9, the components of the peak group matrix B, which is a column vector, are listed in order from the first row, b ０＿１ , b １＿１ , b ２＿１ , b ３＿１ , b ０＿２ , b １＿２ , b ２＿２ , b ３＿２ , b ０＿３ , b １＿３ , b ２＿３ , b ３＿３ is.

[0057] 8, in each allocation pattern in each transmission cycle Tt, there is a peak equivalent to the target component. Specifically, in the Doppler spectrum of the first reception cycle Tr_1 corresponding to the first transmission cycle Tt_1, ｃThe peak appearing at position 0 / 4 contains only the target component corresponding to the transmission signal from the transmitting antenna TX3. In this Doppler spectrum, spurious components corresponding to the transmission signals from the other transmitting antennas TX1 and TX2 are not included. In addition, in the Doppler spectrum of the second receiving cycle Tr_2 corresponding to the second transmitting cycle Tt_2, the peak appearing at position 0 contains only the target component corresponding to the transmission signal from the transmitting antenna TX2. Furthermore, in the Doppler spectrum of the third receiving cycle Tr_3 corresponding to the third transmitting cycle Tt_3, the peak appearing at position 0 contains only the target component corresponding to the transmission signal from the transmitting antenna TX2. ｃ The peak appearing at position / 4 contains only the target component corresponding to the transmission signal from the transmitting antenna TX2. In other words, this modification of the allocation pattern satisfies the target component condition.

[0058] When both the rank condition and the target component condition are satisfied, the simultaneous equations described above have a unique solution. In other words, solving the simultaneous equations makes it possible to estimate the spurious components. The control unit 7 estimates and removes the spurious components by executing a process equivalent to calculating the simultaneous equations described above.

[0059] The control unit 7 is connected to the transceiver unit 2 via at least one of a LAN (Local Area Network) line, a wire harness, an internal bus, a wireless communication line, etc. The configuration of the control unit 7 will be described later.

[0060] The accommodation unit 8 is a housing that accommodates the transceiver unit 2 and the control unit 7. The accommodation unit 8 includes a radome 81 and a case body 82. The radome 81 is mainly formed of a transparent material that allows millimeter-wave band radio waves to pass through. The radome 81 is attached to the case body 82 so as to cover the antennas TX and RX. The radome 81 protects the antennas TX and RX while allowing radio waves to pass through, enabling the antennas TX and RX to transmit and receive signals. The case body 82, together with the radome 81, defines an accommodation space that accommodates the components of the radar device 1 described above.

[0061] The control unit 7 includes at least one dedicated computer. The dedicated computer constituting the control unit 7 may be a radar ECU (Electronic Control Unit) specialized for controlling a specific radar device 1. The dedicated computer constituting the control unit 7 may be a radar management ECU that controls multiple radar devices 1 mounted on a moving object in an integrated manner. The dedicated computer constituting the control unit 7 may be a sensor management ECU that controls multiple sensors including the radar device 1 and other sensors such as LiDAR (Light Detection and Ranging / Laser Imaging Detection and Ranging).

[0062] The dedicated computer constituting the control unit 7 has at least one memory 7a and one processor 7b. The memory 7a is a storage medium that non-temporarily stores computer-readable programs, data, and the like. The memory 7a is at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium. Here, "storage" may refer to accumulation in which data is retained even when the radar device 1 is turned off, or may refer to temporary storage in which data is erased when the radar device 1 is turned off. The processor 7b includes at least one type of core selected from the group consisting of a central processing unit (CPU), a graphics processing unit (GPU), a reduced instruction set computer (RISC)-CPU, a data flow processor (DFP), and a graph streaming processor (GSP).

[0063] In the control unit 7, the processor 7b executes a plurality of instructions included in a radar control program stored in the memory 7a in order to control the radar device 1. In this way, the control unit 7 constructs a plurality of functional blocks for controlling the radar device 1. The functional blocks constructed in the control unit 7 include a transmission processing block 71 and a reception processing block 72, as shown in Fig. 10. The control unit 7 is an example of a "radar control device."

[0064] The radar control method in which the control unit 7 controls the radar device 1 through cooperation of these blocks 71 and 72 is executed in accordance with the radar control flow shown in Fig. 11. This radar control flow is executed repeatedly while the radar device 1 is running. Note that each "S" in this radar control flow represents a plurality of steps executed by a plurality of commands included in the radar control program.

[0065] First, in S10 of FIG. 7 , the transmission processing block 71 outputs a transmission processing start instruction to the transceiver unit 2, thereby causing transmission signals to be transmitted from the multiple transmission antennas TX. As described above, each transmission signal is assigned a different phase rotation amount between the transmission antennas TX by the phase shifter 51. Furthermore, the assignment pattern of the phase rotation amounts assigned to each transmission signal is an assignment pattern corresponding to the current transmission cycle Tt, according to the assignment mode described above. Next, in S20, the reception processing block 72 acquires, from each reception circuit 6, beat signals defined from each reception signal acquired for each reception antenna RX. The beat signals are an example of "signal data correlated to the reception signals."

[0066] Then, in S30, the reception processing block 72 acquires a Doppler spectrum using a beat signal defined from a reception signal received by a single reception antenna RX. The reception processing block 72 may acquire a Doppler spectrum from a beat signal corresponding to a specific reception antenna RX that has been predefined. Alternatively, the reception processing block 72 may change the reception antenna RX from which the Doppler spectrum is acquired for each reception cycle Tr.

[0067] To acquire the Doppler spectrum, the receiver processing block 72 performs two Fast Fourier Transform (FFT) processes on the beat signal. Specifically, the receiver processing block 72 performs a first FFT process on each signal portion of the beat signal that corresponds to a chirp signal. As a result, the receiver processing block 72 acquires, for each chirp signal, a distance spectrum that shows a peak at a frequency corresponding to the distance to the target. The distance spectrum data includes signal strength information for each distance bin that corresponds to the distance resolution. The first FFT is also referred to as a distance FFT.

[0068] The receiver processing block 72 then performs a second FFT on the waveform in which the phases of each range bin in the range spectrum are arranged in the time direction. The second FFT is also called a velocity FFT or a Doppler FFT. As a result of the second FFT, the receiver processing block 72 obtains a Doppler spectrum for each range bin. The Doppler spectrum is a frequency spectrum that exhibits a peak at a position corresponding to the combined velocity of the pseudo velocity assigned to the transmitted signal by DDM modulation and the Doppler velocity (relative velocity) of the target. As a result, the receiver processing block 72 obtains a two-dimensional spectrum of the range R and the Doppler velocity V. The Doppler spectrum is also called a velocity spectrum. The two-dimensional spectrum is also called an RV map.

[0069] In the following S50, the reception processing block 72 executes a phase offset estimation process. Specifically, the reception processing block 72 defines, for each reception cycle Tr, signal components that are expected to be included in each peak for each Doppler spectrum for the required number of cycles. The reception processing block 72 defines signal components from among the target component and each phase offset component in correlation with the allocation pattern corresponding to the reception cycle Tr. Here, the required number of cycles is the number of cycles set as the number of transmission cycles Tt required for phase offset estimation. In the example shown in FIG. 7, the required number of cycles is "3."

[0070] For example, if the current reception cycle Tr is the third reception cycle Tr_3, the reception processing block 72 defines the signal components from the Doppler spectra of the first reception cycle Tr_1, the second reception cycle Tr_2, and the third reception cycle Tr_3. Also, if the current reception cycle Tr is the fourth reception cycle Tr_4, the reception processing block 72 defines the signal components from the Doppler spectra of the second reception cycle Tr_2, the third reception cycle Tr_3, and the fourth reception cycle Tr_4.

[0071] As a result, the reception processing block 72 defines a peak group matrix b of the Doppler spectrum, a coefficient matrix A, and an unknown matrix x. The reception processing block 72 then estimates the spurious components by obtaining a solution to a simultaneous equation that corresponds to the equivalent relationship between the peak group matrix b and the product of the coefficient matrix A multiplied by the unknown matrix x.

[0072] Next, in S60, the reception processing block 72 performs a phase offset compensation process. For example, the reception processing block 72 may compensate for the phase offset by removing the currently estimated spurious component from the Doppler spectrum. Alternatively, if there is a previously estimated spurious component, the reception processing block 72 may perform the compensation process using the average value of the previously estimated spurious component and the current spurious component.

[0073] If the Doppler spectrum for the required number of cycles has not been acquired, for example, immediately after the radar device 1 is started, the reception processing block 72 acquires the phase offset by reading an estimated value of the phase offset stored in advance in the memory 7a or the like in S50. Then, the reception processing block 72 executes compensation processing based on the estimated value in S60. The estimated value of the phase offset is stored, for example, in the form of a table corresponding to the internal temperature of the radar device 1. Alternatively, if the Doppler spectrum for the required number of cycles has not been acquired, the reception processing block 72 may skip the processing in S50 and S60.

[0074] Next, in S60, the reception processing block 72 performs angle measurement processing on the Doppler spectrum corresponding to each transmitting antenna TX. That is, the reception processing block 72 performs a third FFT process on a waveform obtained by arranging the phases of each peak in an integrated spectrum obtained by integrating multiple Doppler spectra. As a result, the reception processing block 72 obtains an angle spectrum showing a peak at a position corresponding to the relative angle from the target. Note that the FFT process in S60 is performed using a group of beat signals corresponding to a group of received signals obtained by receiving signals from multiple transmitting antennas TX at each of multiple receiving antennas RX. For this reason, this FFT process is also referred to as MIMO angle measurement processing.

[0075] Furthermore, in S70, the reception processing block 72 outputs sensing data. The reception processing block 72 outputs information about the target, such as the distance to the target, the relative speed, and the relative angle, as sensing data. The distance information, relative speed information, and relative angle information are information that correlates the transmission signals from the multiple transmission antennas TX with the reception signals received by each of the multiple reception antennas RX, obtained by the MIMO angle measurement process.

[0076] The control unit 7 repeatedly executes the above series of processes during the startup of the radar device 1. In this way, the control unit 7 of the first embodiment executes the phase offset estimation process every time.

[0077] According to the first embodiment described above, the allocation pattern of the phase rotation amount for the transmit signal for each transmit antenna TX differs for each transmission cycle Tt. Therefore, the signal components expected to be included in the peak can be defined for each of multiple reception cycles Tr in correlation with the corresponding allocation pattern from among the target component and each phase offset component corresponding to each phase rotation amount. In this case, a different phase offset component is included for each reception cycle Tr for the peak corresponding to each transmit signal. Therefore, the phase offset component can be estimated from the relationship between each peak and the signal component in multiple reception cycles Tr. Therefore, sensing data correlated with the receive signal from which the phase offset component has been removed can be output. Therefore, the phase offset component can be estimated and removed from the receive signal in which the transmit signals from each transmit antenna TX are mixed by simultaneous transmission. As a result, it is possible to achieve both a reduction in transmission processing time and suppression of the phase offset component.

[0078] Furthermore, according to the first embodiment, the transmission signal is transmitted so that the coefficient matrix A has full rank. Then, the spurious components are estimated according to the equivalent relationship between the peak group matrix b and the product of the coefficient matrix A multiplied by the unknown matrix x. Therefore, the transmission signal is transmitted so that the simultaneous equations can be uniquely solved, making it possible to reliably estimate the spurious components.

[0079] Furthermore, according to the first embodiment, sensing data correlated with the received signal from which the spurious components estimated each time are removed is output for each reception cycle Tr. Therefore, the current spurious components can be removed from the current sensing data. Therefore, even if the phase offset and spurious components change over time, it is possible to reliably respond.

[0080] Second Embodiment As shown in FIGS. 12 to 15, the second embodiment is a modification of the first embodiment.

[0081] In the second embodiment, each of the multiple phase shifters 51 changes its allocation pattern for each transmission cycle Tt so that the coefficient matrix A has less than full rank. For example, as shown in FIG. 12 , each phase shifter 51 allocates [0, π, π / 2] in the first transmission cycle Tt_1 and [π / 2, 0, π] in the second transmission cycle Tt_2.

[0082] Furthermore, among the multiple phase shifters 51, the phase shifter 51 corresponding to a specific transmitting antenna TX generates a transmission complementary signal by assigning a phase rotation amount that complements the coefficient matrix A to full rank in a transmission complementary cycle Ttc outside the transmission cycle Tt. In this embodiment, the phase shifter 51 corresponding to the transmitting antenna TX2 transmits a transmission signal to which a phase rotation amount of π / 2 has been assigned in the transmission complementary cycle Ttc following the second transmission cycle Tt_2. In the transmission complementary cycle Ttc, a transmission complementary signal is transmitted only from the single transmitting antenna TX2, and transmission from the other transmitting antennas TX1 and TX3 is prohibited.

[0083] As described above, the transceiver unit 2 repeatedly transmits transmission signals using two allocation patterns, and then transmits a transmission complementary signal. Therefore, the allocation patterns of the second transmission cycle Tt_2 and the third transmission cycle Tt_3 after the transmission complementary cycle Ttc in FIG. 12 are the same as those of the first transmission cycle Tt_1.

[0084] As shown in FIG. 15 , the radar control flow in the second embodiment proceeds to S40 after S30. In S40, the reception processing block 72 determines whether the set number of cycles has elapsed. Here, the set number of cycles is the number of allocation patterns in the transmission cycle Tt. In the example shown in FIG. 12 , the set number of cycles is "2." If it is determined that the set number of cycles has not elapsed, the flow proceeds to S50.

[0085] On the other hand, if it is determined that the set number of cycles has elapsed, the flow proceeds to S41. In S41, the transmission processing block 71 transmits a transmission complementary signal with a full-rank coefficient matrix A in a transmission complementary cycle Ttc outside the transmission cycle Tt. Specifically, the transmission processing block 71 transmits a transmission signal to which a phase rotation amount of π / 2 has been applied from only the single transmitting antenna TX2.

[0086] Next, in S42, the reception processing block 72 acquires a beat signal based on a reception complementary signal corresponding to the transmission complementary signal in a reception complementary cycle Trc corresponding to the transmission complementary cycle Ttc. The beat signal based on a reception complementary signal is an example of "complementary signal data." Next, in S43, the reception processing block 72 acquires a Doppler spectrum from the beat signal. Then, in S50, the reception processing block 72 estimates spurious components from each peak of the Doppler spectrum acquired in the reception cycle Tr and the Doppler spectrum acquired in the reception complementary cycle Trc.

[0087] For example, if the current cycle is the reception complementary cycle Trc, the reception processing block 72 defines the signal components from the Doppler spectra of the first reception cycle Tr_1, the second reception cycle Tr_2, and the reception complementary cycle Trc. From these three cycles, the simultaneous equations shown in FIG. 13 can be defined. Also, if the current cycle is the third reception cycle Tr_3, the reception processing block 72 defines the signal components from the Doppler spectra of the second reception cycle Tr_2, the reception complementary cycle Trc, and the third reception cycle Tr_3. From these three cycles, the simultaneous equations shown in FIG. 13 ｋ＿１ A b ｋ＿４ can be defined as a system of equations with

[0088] That is, the reception processing block 72 estimates the spurious components by solving simultaneous equations according to the equivalent relationship between the peak group matrix b in each Doppler spectrum of the reception cycle Tr and the reception complementary cycle Trc and the product of the coefficient matrix A and the unknown matrix x. Since the complementary coefficient matrix A shown in FIG. 14 is full rank, the simultaneous equations have a unique solution.

[0089] According to the second embodiment described above, a transmission signal is transmitted in a transmission cycle Tt such that the coefficient matrix A has less than full rank, and a transmission complementary signal with a full rank coefficient matrix is ​​transmitted in a transmission complementary cycle Ttc outside the transmission cycle Tt. Furthermore, spurious components estimated in accordance with the equivalence relationship between the peak group matrix b and the product of the coefficient matrix A, complemented so that the coefficient matrix A has full rank in the reception complementary signal, multiplied by the unknown matrix x are removed. Therefore, even if the spurious components cannot be estimated using only the transmission cycle Tt, they can be estimated using the transmission complementary cycle Ttc.

[0090] Third Embodiment As shown in FIG. 16, the third embodiment is a modification of the first embodiment.

[0091] The radar control flow of the third embodiment proceeds to S35 after S30. In S35, the reception processing block 72 determines whether an estimation execution condition for executing phase offset estimation is met. For example, the estimation execution condition is that the vehicle 10 on which the radar device 1 is mounted and the target are stationary. The reception processing block 72 may acquire vehicle speed information from an MCU or the like via an in-vehicle network, and determine that the vehicle 10 is stationary when the vehicle speed is zero. Furthermore, when a peak appears at a speed bin position corresponding only to the pseudo speed obtained by DDM modulation in the Doppler spectrum when the vehicle 10 is stationary, the reception processing block 72 may determine that the target corresponding to the peak is stationary.

[0092] If it is determined in S35 that the estimation execution condition is met, the flow proceeds to S40. On the other hand, if it is determined that the estimation execution condition is not met, the flow proceeds to S60.

[0093] As a result, during a period in which the estimation execution condition is not met, the reception processing block 72 in S60 executes compensation processing based on the previously estimated spurious components. Then, during a period in which the estimation execution condition is met, the reception processing block 72 in S60 executes compensation processing based on the currently estimated spurious components. In other words, when the estimation execution condition is met, the reception processing block 72 re-estimates the spurious components. The period in which the estimation execution condition is met is an example of a "specific period."

[0094] According to the third embodiment described above, sensing data correlated with a received signal from which past spurious components have been removed in the current reception cycle Tr is output, and the spurious components are re-estimated in a specific reception cycle Tr. Therefore, the spurious components are not estimated every time, and the processing load is reduced.

[0095] Furthermore, according to the third embodiment, the specific reception cycle Tr is a reception cycle Tr during which the moving object and the target are stationary. This prevents changes in the peak velocity bin position due to changes in the relative velocity between the moving object and the target. This allows for more robust and highly accurate spurious component estimation processing.

[0096] (Other Embodiments) Although multiple embodiments have been described above, the present disclosure should not be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0097] In a modified example, the reception processing block 72 may update the phase offset correction value stored in advance in the memory 7 a or the like using the estimated spurious component in the compensation process. For example, the reception processing block 72 acquires the internal temperature of the radar device 1 using a temperature sensor or the like, and updates the correction value corresponding to the temperature to a correction value correlated with the estimated spurious component.

[0098] In a modified example, at least a part of the processing executed in blocks 71 and 72 may be executed by a processor external to the radar device 1. For example, at least a part of the processing may be executed by a processor of an on-board ECU mounted on the vehicle 10 in which the radar device 1 is installed. In this case, the "radar system" includes the radar device 1 and the processor of the on-board ECU.

[0099] In a modified example, the radar device 1 may include only one receiving antenna RX. In this case, the reception processing block 72 outputs sensing data correlated with the reception signal received by the single receiving antenna RX.

[0100] In a modified example, the dedicated computer constituting the control unit 7 may have at least one of a digital circuit and an analog circuit as the processor 7b. Here, the digital circuit is at least one of an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system on a chip (SOC), a programmable gate array (PGA), and a complex programmable logic device (CPLD). Such a digital circuit may also have a memory 7a storing a program.

[0101] In a modified example, the mobile body equipped with the radar device 1 may be, for example, an autonomous robot that can transport luggage or collect information by autonomous driving or remote driving. Examples of the autonomous robot include an autonomous vehicle.

Claims

1. A radar system having a plurality of transmitting antennas (TX), at least one receiving antenna (RX), and a processor (7b), wherein the processor is configured to: transmit, from each of the transmitting antennas, transmission signals each including a plurality of chirp signals whose frequencies vary over time, the transmission signals being assigned a specific phase rotation amount for each of the chirp signals such that the phase rotation amount varies between the transmitting antennas; acquire, for each reception cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by receiving the transmission signals from the plurality of transmitting antennas after they have been reflected by a target at a single receiving antenna; and output sensing data correlating with the signal data; wherein transmitting the transmission signals includes transmitting the transmission signals in which an allocation pattern of the phase rotation amounts assigned to each of the transmission signals for each of the transmitting antennas is changed for each transmission cycle; and outputting the sensing data. a radar system including: defining, for each of a plurality of reception cycles, a signal component assumed to be included in each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, from among target components corresponding to the targets from which the transmission signals from each of the transmission antennas are reflected and phase offset components corresponding to each of the phase rotation amounts, in correlation with the corresponding allocation pattern; and outputting the sensing data correlated with the signal data from which the phase offset components estimated from the relationship between each of the peaks and the signal components in the plurality of reception cycles have been removed.

2. The radar system according to claim 1, wherein transmitting the transmission signals includes transmitting the transmission signals in which the allocation pattern is changed for each transmission cycle so that a coefficient matrix that equates an unknown matrix defined with the target component and each of the phase offset components as unknowns to a peak group matrix that defines the multiple peaks to be expected has full rank, and so that the peak equivalent to the target component is present for each transmission signal from each of the transmitting antennas, and wherein outputting the sensing data includes outputting the sensing data that correlates with the signal data from which the phase offset component estimated in accordance with the equivalent relationship between the peak group matrix defined in accordance with the acquired signal data and the product of the coefficient matrix multiplied by the unknown matrix is ​​removed.

3. Transmitting the transmission signals includes transmitting the transmission signals with the allocation pattern changed for each transmission cycle so that a coefficient matrix that equates an unknown matrix defined with the target component and each of the phase offset components as unknowns to a peak group matrix that defines the plurality of expected peaks has less than full rank, transmitting transmission complementary signals with the coefficient matrix having full rank in a transmission complementary cycle outside the transmission cycle, and transmitting the transmission signals with the allocation pattern changed for each transmission cycle and transmission complementary cycle so that the peak equivalent to the target component exists in each of the transmission signals from each of the transmission antennas; acquiring the signal data includes acquiring complementary signal data that correlates the transmission complementary signals with a reception complementary signal received by a single reception antenna for each reception complementary cycle that corresponds to the transmission complementary cycle; and outputting the sensing data includes 2. The radar system according to claim 1, further comprising: outputting the sensing data correlated with the signal data from which the phase offset component estimated in accordance with an equivalent relationship between the peak group matrix defined in accordance with the acquired signal data and the complementary signal data, and a product obtained by multiplying the coefficient matrix complemented to have a full rank using the complementary signal data by the unknown matrix.

4. A radar system according to any one of claims 1 to 3, wherein outputting the sensing data includes outputting the sensing data correlated with the signal data from which the phase offset component estimated for each reception cycle has been removed.

5. A radar system according to any one of claims 1 to 3, wherein outputting the sensing data includes: outputting the sensing data in which the phase offset component estimated in a past receiving cycle is correlated with the signal data from which the phase offset component has been removed in the current receiving cycle; and re-estimating the phase offset component in a specific receiving cycle.

6. A radar system according to claim 5, which is mounted on a moving body (10), and wherein the specific reception cycle is the reception cycle during a period when the moving body and the target are stationary.

7. A radar control device having a processor (7b) for controlling a radar system (1) equipped with a plurality of transmitting antennas (TX) and at least one receiving antenna (RX), wherein the processor is configured to execute the following: transmit, from each of the transmitting antennas, a transmission signal, which includes a plurality of chirp signals whose frequencies change over time, and in which the phase rotation amount for each chirp signal is assigned so that the phase rotation amount varies between the transmitting antennas; acquire, for each receiving cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by reflecting the transmission signals from the plurality of transmitting antennas off a target and receiving them at a single receiving antenna; and output sensing data correlating with the signal data; wherein transmitting the transmission signals includes transmitting the transmission signals in which an allocation pattern of the phase rotation amounts assigned to each of the transmission signals for each transmitting antenna is changed for each transmission cycle; and outputting the sensing data a radar control device that defines, for each of a plurality of reception cycles, a signal component that is assumed to be included in each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, from among target components corresponding to the targets from which the transmission signals from each of the transmission antennas are reflected and phase offset components corresponding to each of the phase rotation amounts, in correlation with the corresponding allocation pattern; and outputs the sensing data that correlates with the signal data from which the phase offset components estimated from the relationship between each of the peaks and the signal components in the plurality of reception cycles have been removed.

8. A radar control method executed by a processor (7b) for controlling a radar system (1) having a plurality of transmitting antennas (TX) and at least one receiving antenna (RX), comprising: transmitting, from each of the transmitting antennas, transmission signals each including a plurality of chirp signals whose frequencies vary over time, and in which the phases rotated for each of the chirp signals by a specific phase rotation amount are assigned such that the phase rotation amount differs between the transmitting antennas; acquiring, for each reception cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by receiving the transmission signals from the plurality of transmitting antennas after they are reflected by a target at a single receiving antenna; and outputting sensing data correlating with the signal data, wherein transmitting the transmission signals comprises transmitting the transmission signals in which an allocation pattern of the phase rotation amounts assigned to each of the transmission signals for each transmitting antenna is changed for each transmission cycle; and outputting the sensing data comprises a radar control method including: defining, for each of a plurality of reception cycles, a signal component assumed to be included in each of a plurality of peaks in a Doppler spectrum corresponding to the signal data, from among target components corresponding to the targets from which the transmission signals from each of the transmission antennas are reflected and phase offset components corresponding to each of the phase rotation amounts, in correlation with the corresponding allocation pattern; and outputting the sensing data correlated with the signal data from which the phase offset components estimated from the relationship between each of the peaks and the signal components in the plurality of reception cycles have been removed.

9. A radar control program stored in a storage medium (7a) and including instructions to be executed by a processor (7b) that controls a radar system (1) having a plurality of transmitting antennas (TX) and at least one receiving antenna (RX), the instructions including: transmitting, from each of the transmitting antennas, transmission signals each including a plurality of chirp signals whose frequencies change over time, the phases of which are rotated for each of the chirp signals by a specific phase rotation amount being assigned so that the phase rotation amount differs between the transmitting antennas; acquiring, for each reception cycle corresponding to the transmission cycle, signal data correlating with received signals obtained by reflecting the transmission signals from the plurality of transmitting antennas off a target and receiving them at a single receiving antenna; and outputting sensing data correlating with the signal data, wherein transmitting the transmission signals includes transmitting the transmission signals in which an allocation pattern of the phase rotation amounts assigned to each of the transmission signals for each of the transmitting antennas is changed for each transmission cycle; and outputting the sensing data includes: for each of a plurality of reception cycles, a signal component estimated to be included in each of a plurality of peaks in a Doppler spectrum corresponding to the signal data is defined from among target components corresponding to the target from which the transmission signal from each of the transmission antennas is reflected and each phase offset component corresponding to each of the phase rotation amounts, in correlation with the corresponding allocation pattern; and outputting the sensing data correlated with the signal data from which the phase offset component estimated from the relationship between each of the peaks and the signal component in the plurality of reception cycles has been removed.

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