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

Abstract

To provide a radar system and the like capable of estimating a phase offset component while shortening transmission processing time.SOLUTION: A processor of a radar system is configured to cause a transmission signal encoded by a code group to be transmitted from respective transmission antennas within overlapping transmission periods in a compensation transmission cycle. The code group includes a plurality of codes that encode a speed phase by being assigned to each cluster of chirp signals having a shared speed phase among a plurality of chirp signals in a single transmission antenna, the plurality of codes differing between speed phases shared between the transmission antennas. The processor is configured to acquire, in a compensation reception cycle, a phase offset component correlated with phase components of each peak in respective speed spectra for each decoded signal component decoded for each received signal component corresponding to the cluster. The processor is configured to output sensing data correlated with a received signal from which the phase offset component has been removed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to radar control technology. [Background technology]

[0002] 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 periodic phase offset components that occur for each phase given by DDM modulation. In estimating the phase offset components, transmission signals are transmitted in sequence from each transmission antenna. When a transmission signal transmitted from one transmission antenna is received, a Doppler spectrum is acquired by FFT processing. The phase offset components are estimated from the peaks of spurious components contained in the Doppler spectrum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2023 / 0129203 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if transmission signals are transmitted sequentially from each transmitting antenna to estimate the phase offset component, as in Patent Document 1, the transmission processing takes time equal to the number of transmitting antennas. Here, if transmission signals are transmitted from each transmitting antenna in overlapping periods to shorten the transmission processing time, it is conceivable to multiplex the transmission signals using Code Division Multiplex (CDM) modulation. However, CDM modulation makes the phase offset component non-periodic. This may cause the peaks of spurious components in the Doppler spectrum to spread, making it difficult to estimate the phase offset component.

[0005] An object of the present disclosure is to provide a radar system capable of estimating a phase offset component while shortening the transmission processing time. Another object of the present disclosure is to provide a radar control device capable of estimating a phase offset component while shortening the transmission processing time. Yet another object of the present disclosure is to provide a radar control method capable of estimating a phase offset component while shortening the transmission processing time. Yet another object of the present disclosure is to provide a radar control program capable of estimating a phase offset component while shortening the transmission processing time. [Means for solving the problem]

[0006] The technical means of the present disclosure for solving the problems will be described below. Note that the claims and the reference characters in parentheses in this section 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.

[0007] A first aspect of the present disclosure is a radar system having a plurality of transmit antennas (TX), at least one receive antenna (RX), and a processor (7b), The processor transmitting, from each transmitting antenna for each measurement transmission cycle, a transmission signal including a plurality of chirp signals whose frequencies change over time, and in which the rotation amount of the velocity phase, which is the phase rotated for each chirp signal by a specific rotation amount, differs between the transmitting antennas; outputting sensing data correlating with received signals obtained by receiving signals from a plurality of transmitting antennas at a receiving antenna in a measurement receiving cycle corresponding to the measurement transmitting cycle; configured to run To transmit a transmission signal is In a compensation transmission cycle before the measurement transmission cycle, a transmission signal is transmitted from each transmitting antenna during an overlapping transmission period, the transmission signal being coded with a code group including different codes for the common velocity phases among a plurality of chirp signals transmitted from a single transmitting antenna, the codes being assigned to each cluster of chirp signals having a common velocity phase, and coding the velocity phases; Outputting sensing data is In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code is defined; Obtaining, for each transmitting antenna, a phase offset component for each velocity phase in the transmitted signal that correlates with a phase component of each peak in each velocity spectrum defined for each decoded signal component corresponding to the cluster; In a measurement reception cycle after the compensation reception cycle, outputting sensing data correlated with the reception signal from which the phase offset component has been removed; Includes:

[0008] A second aspect of the present disclosure is a radar control device having a processor (7b) for controlling a radar system (1) having a plurality of transmitting antennas (TX) and at least one receiving antenna (RX), The processor transmitting, from each transmitting antenna for each measurement transmission cycle, a transmission signal including a plurality of chirp signals whose frequencies change over time, and in which the rotation amount of the velocity phase, which is the phase rotated for each chirp signal by a specific rotation amount, differs between the transmitting antennas; outputting sensing data correlating with received signals obtained by receiving signals from a plurality of transmitting antennas at a receiving antenna in a measurement receiving cycle corresponding to the measurement transmitting cycle; configured to run To transmit a transmission signal is In a compensation transmission cycle before the measurement transmission cycle, a transmission signal is transmitted from each transmitting antenna during an overlapping transmission period, the transmission signal being coded with a code group including different codes for the common velocity phases among a plurality of chirp signals transmitted from a single transmitting antenna, the codes being assigned to each cluster of chirp signals having a common velocity phase, and coding the velocity phases; Outputting sensing data is In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code is defined; Obtaining, for each transmitting antenna, a phase offset component for each velocity phase in the transmitted signal that correlates with a phase component of each peak in each velocity spectrum defined for each decoded signal component corresponding to the cluster; In a measurement reception cycle after the compensation reception cycle, outputting sensing data correlated with the reception signal from which the phase offset component has been removed; Includes:

[0009] A third aspect of the present disclosure provides 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), the method comprising: transmitting, from each transmitting antenna for each measurement transmission cycle, a transmission signal including a plurality of chirp signals whose frequencies change over time, and in which the rotation amount of the velocity phase, which is the phase rotated for each chirp signal by a specific rotation amount, differs between the transmitting antennas; outputting sensing data correlating with received signals obtained by receiving signals from a plurality of transmitting antennas at a receiving antenna in a measurement receiving cycle corresponding to the measurement transmitting cycle; Including, To transmit a transmission signal is In a compensation transmission cycle before the measurement transmission cycle, a transmission signal is transmitted from each transmitting antenna during an overlapping transmission period, the transmission signal being coded with a code group including different codes for the common velocity phases among a plurality of chirp signals transmitted from a single transmitting antenna, the codes being assigned to each cluster of chirp signals having a common velocity phase, and coding the velocity phases; Outputting sensing data is In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code is defined; Obtaining, for each transmitting antenna, a phase offset component for each velocity phase in the transmitted signal that correlates with a phase component of each peak in each velocity spectrum defined for each decoded signal component corresponding to the cluster; In a measurement reception cycle after the compensation reception cycle, outputting sensing data correlated with the reception signal from which the phase offset component has been removed; Includes:

[0010] A fourth aspect of the present disclosure provides 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 program comprising: The command is, transmitting, from each transmitting antenna for each measurement transmission cycle, a transmission signal including a plurality of chirp signals whose frequencies change over time, and in which the rotation amount of the velocity phase, which is the phase rotated for each chirp signal by a specific rotation amount, differs between the transmitting antennas; outputting sensing data correlating with received signals obtained by receiving signals from a plurality of transmitting antennas at a receiving antenna in a measurement receiving cycle corresponding to the measurement transmitting cycle; Including, To transmit a transmission signal is In a compensation transmission cycle before the measurement transmission cycle, a transmission signal is transmitted from each transmitting antenna during an overlapping transmission period, the transmission signal being coded with a code group including different codes for the common velocity phases among a plurality of chirp signals transmitted from a single transmitting antenna, the codes being assigned to each cluster of chirp signals having a common velocity phase, and coding the velocity phases; To output sensing data, In a compensated reception cycle corresponding to the compensated transmission cycle, a decoded signal component decoded with respect to a corresponding code is defined for each received signal component corresponding to each cluster in the received signal; Acquiring, for each transmitting antenna, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each decoded signal component corresponding to the cluster; In a measurement reception cycle after the compensation reception cycle, outputting sensing data correlated with the reception signal from which the phase offset component has been removed; Includes:

[0011] According to these first to fourth aspects, the transmission signal transmitted from a single transmitting antenna in a compensation transmission cycle is coded for each cluster of chirp signals having a common velocity phase. Therefore, in a compensation reception cycle, a decoded signal component decoded with respect to the corresponding code can be defined for each received signal component corresponding to each cluster in the received signal. Therefore, the phase offset component for each velocity phase in the transmission signal can be obtained as a parameter correlated with the phase component of each peak in each velocity spectrum defined for each decoded signal component corresponding to the cluster. Therefore, by transmitting transmission signals in overlapping transmission periods, it is possible to estimate the phase offset component while shortening the transmission processing time. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a radar system. [Figure 2]3A and 3B are schematic diagrams for explaining phases assigned to transmission signals at each transmitting antenna. [Figure 3] 10 is a table showing an example of a phase assigned to a transmission signal. [Figure 4] FIG. 2 is a diagram illustrating an example of a transmission cycle and a reception cycle. [Figure 5] FIG. 10 is a diagram for explaining a phase offset component. [Figure 6] FIG. 2 is a block diagram showing the functional configuration of a control unit in the radar system. [Figure 7] 10 is a flowchart showing a radar control flow. [Figure 8] 10 is a flowchart showing details of a process for estimating a phase offset component. [Figure 9] FIG. 10 is a diagram illustrating a decoding process. [Figure 10] 10 is a table showing an example of a phase assigned to a transmission signal in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] (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 a moving object such as a vehicle. The radar device 1 transmits a transmission signal to the outside world and receives the transmission signal reflected by a target as a reception signal. The radar device 1 acquires and outputs sensing data related to the target that reflected the transmission signal by analyzing the reception signal. The radar device 1 is a so-called MIMO (Multiple-Input-Multiple-Output) radar that transmits transmission signals from multiple transmission antennas TX to artificially increase the number of reception antennas RX beyond the actual number. The radar device 1 is an example of a "radar system."

[0015] 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 (registered trademark). The in-vehicle ECU executes various processes for automatic driving of the vehicle and advanced driving assistance based on the acquired sensing data of each target.

[0016] 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.

[0017] 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 transmission signals and reception processing of reception signals. 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.

[0018] 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 its 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 compensation transmission cycle Tt_c and measurement transmission cycle Tt_m as transmission cycles. The number of chirp signals is, for example, an even number. The number of chirp signals is constant throughout all transmission cycles, regardless of the compensation transmission cycle Tt_c and the measurement transmission cycle Tt_m. 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.

[0019] 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.

[0020] The transmitting circuit 5 and the receiving circuit 6 are each mainly composed of a semiconductor integrated circuit device such as an MMIC (Monolithic Microwave Integrated Circuit). The transmitting circuit 5 is connected to a transmitting antenna TX and outputs a transmission signal to the transmitting antenna TX. The transmitting circuit 5 includes the same number of phase shifters 51 and amplifiers 52 as the number of connected transmitting antennas TX.

[0021] The phase shifter 51 imparts a specific phase change to the input transmission signal. More specifically, the phase shifter 51 imparts at least a phase change that rotates a plurality of chirp signals arranged in time by a substantially constant amount of rotation for each chirp period Tc. As a result, the plurality of transmission signals transmitted from the plurality of transmission antennas TX are subjected to so-called Doppler division multiplexing (DDM) modulation. 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 i (i is a natural number from 1 to m) may be added to the end of the symbol "TX" to distinguish them.

[0022] For example, as shown in FIG. 2, suppose that a rotation amount ω1 is imparted to multiple chirp signals transmitted from a specific transmitting antenna TX1 among multiple transmitting antennas TX. In this case, the phase of the kth chirp signal is rotated by the chirp number multiplied by the rotation amount ω1 relative to the phase before input to the phase shifter 51. As a result, the phases of multiple chirp signals aligned in time that have passed through the phase shifter 51 change linearly for each chirp period Tc. This linear change in phase imparts a pseudo Doppler velocity corresponding to the rotation amount to the chirp signals. This phase change can also be referred to as a Doppler shift. Each phase shifter 51 imparts a rotation amount in both the compensation transmission cycle Tt_c and the measurement transmission cycle Tt_m.

[0023] In FIG. 2, the chirp number k ranges from "1" to "N", which is the maximum number of chirp signals in one transmission cycle. c However, the chirp number k can be set from "0" to "N c It may be set from any number to any number, such as "-1".

[0024] Each of the multiple phase shifters 51 imparts a different rotation amount. That is, in FIG. 2, a rotation amount ω2 different from the rotation amount ω1 is imparted to the multiple chirp signals transmitted from a transmitting antenna TX2 different from the transmitting antenna TX1. Similarly, for the transmitting antenna TXm, a rotation amount ω2 different from the rotation amounts ω1, ω2, etc. is imparted to the multiple chirp signals transmitted.m Each phase shifter 51 may impart the same amount of rotation to the chirp signal for each transmission cycle. Alternatively, each phase shifter 51 may impart a different amount of rotation for each transmission cycle in response to a control command from the control unit 7.

[0025] In the following, the initial phase rotated by the rotation amount for each chirp signal may be referred to as the DDM phase. For example, assume that the rotation amount is π / 2 and the DDM phase of the first chirp signal is 0. In this case, as shown in Figure 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. The DDM phase then completes one cycle with the fifth chirp signal. In other words, when the rotation amount is π / 2, the DDM phase rotation period Tr is four chirp signals, and the number of DDM phases Nph is four. The DDM phase is an example of a "velocity phase."

[0026] Furthermore, in the compensation transmission cycle Tt_c before the measurement transmission cycle Tt_m, the phase shifter 51 encodes the transmission signal with a code set that differs for each transmitting antenna TX in addition to DDM modulation, so that the transmission signal is in a state in which so-called code division multiplexing modulation has been performed.

[0027] Here, a code set is a combination of additional phases added to a series of chirp signals within a transmission cycle. In the following, each phase constituting a code set may be referred to as a CDM phase.

[0028] The code set includes multiple codes. Each code constituting the code set is assigned to a phase cluster, which is a cluster of chirp signals with a common DDM phase over a DDM phase rotation period Tr. In the example shown in Figure 3, among the 256 chirp signals, a code is assigned to each of the phase clusters with a DDM phase of 0, π / 2, π, and 3π / 2. That is, for a transmission signal with a DDM phase number Nph of 4, a code is assigned to each of the four phase clusters.

[0029] Each code is composed of a sequence of CDM phases that imparts zero-rotation phase shifts and half-rotation phase shifts in a substantially random manner. When the CDM phase sequence is random, the CDM phase sequence is aperiodic. Furthermore, when the CDM phase sequence is random, the spectrum of the CDM phase sequence is distributed in a substantially flat manner when it is Fourier transformed.

[0030] The code is common between, for example, phase clusters. The code is, for example, a pseudo-random CDM phase sequence of "0" and "π." In the example shown in FIG. 3, a code consisting of a CDM phase sequence of [0, 0, π, ...] is assigned as a common code to each of the phase clusters with a DDM phase of 0, the phase cluster with a π / 2 phase, the phase cluster with a π phase, and the phase cluster with a 3π / 2 phase. The code may be, for example, an M-sequence code or an APAS code. Alternatively, the code may be a Gold code or a ZCZ code. Alternatively, the code may be a code of any type to which any CDM phase has been added so that the number of "0"s and "π"s is the same. The CDM phase is an example of an "additional phase."

[0031] Due to the above coding, the multiple chirp signals that pass through the phase shifter 51 in the compensated transmission cycle Tt_c are assigned a coded phase that is the sum of the DDM phase and the CDM phase. For example, in the example shown in FIG. 3, assume that the CDM phase for chirp numbers 1 to 4 and 5 to 8 is 0, and the CDM phase for chirp numbers 9 to 12 is π. In this case, the coded phases for chirp numbers 1 to 4 and 5 to 8 are the same as the DDM phases. The coded phases for chirp numbers 9 to 12 are π, 3π / 2, 0, and π / 2, in ascending order of chirp number. In practice, the phase shifter 51 assigns coded phases, which are pre-designed combinations of DDM and CDM phases, to each input chirp signal.

[0032] Each phase shifter 51 may assign the same code group to the chirp signal for each transmission cycle, or may assign a different code group for each transmission cycle in response to a control command from the control unit 7. The amplifiers 52 amplify the transmission signals output from the phase shifters 51 and output the amplified signals to the corresponding transmitting antennas TX.

[0033] 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. A single transmitting antenna TX includes at least one antenna element. For example, the transmitting antenna TX is a patch antenna having multiple flat antenna elements. The antenna elements are arranged on the opposite side of a dielectric substrate having a ground plane on one side thereof, facing the ground plane. The multiple antenna elements are connected, for example, in series, by a feeder line that supplies an electrical signal. Each transmission signal transmitted from each of the multiple transmitting antennas TX is given a different rotation amount for each transmitting antenna TX by the corresponding phase shifter 51. Furthermore, each transmission signal transmitted from each of the multiple transmitting antennas TX in the compensation transmission cycle Tt_c is encoded by the corresponding phase shifter 51 using a different code set for each transmitting antenna TX.

[0034] 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 compensation transmission cycle Tt_c and measurement transmission cycle Tt_m. The transmission cycles Tt_c and Tt_m are 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 the transmission signals from each transmitting antenna TX overlap. Note that the transmission cycles Tt_c and Tt_m of one transmitting antenna TX may be shifted from the transmission cycles Tt_c and Tt_m of another transmitting antenna TX, as long as the transmission signal at least partially overlaps in time with the transmission signal of another transmitting antenna TX.

[0035] The receiving antenna RX receives, as a received signal, a radio wave signal that includes a transmitted signal reflected by a target in the external world. Each of the multiple receiving antennas RX receives a signal that is a mixture of received signals corresponding to the transmitted signals from the multiple transmitting antennas TX. Hereinafter, this mixed signal received by each receiving antenna RX will be referred to as a mixed received signal.

[0036] 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.

[0037] The receiving circuit 6 is connected to the receiving antenna RX and acquires a received signal received by the receiving antenna RX. The receiving circuit 6 acquires a received signal as a reflected signal of a transmitted signal reflected by a target for each compensation receiving cycle Tr_c and measurement receiving cycle Tr_m as receiving cycles. The compensation receiving cycle Tr_c corresponds to the compensation transmitting cycle Tt_c. The measurement receiving cycle Tr_m corresponds to the measurement transmitting cycle Tt_m. As shown in FIG. 4, each receiving cycle is synchronized with the corresponding transmitting cycle. Furthermore, the receiving cycles are synchronized between receiving channels. The receiving circuit 6 has the same number of amplifiers 61, signal mixing units 62, and AD converters 63 as the number of connected receiving antennas RX.

[0038] The amplifier 61 amplifies the received signal received by the receiving antenna RX and outputs it 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 that represents 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 IF signal.

[0039] 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.

[0040] In the above-described transceiver unit 2, the transmission signals transmitted from each transmitting antenna TX contain a phase offset component as an error due to the imparted phase change. The phase offset component is caused by hardware in the transmission circuit 5, such as the phase shifter 51. The phase offset component is an error whose magnitude corresponds to the overall value of the imparted phase. That is, in the measurement transmission cycle Tt_m, only the DDM phase is imparted to the chirp signal, so each chirp signal contains a phase offset component corresponding to the DDM phase. Furthermore, in the compensation transmission cycle Tt_c, a phase offset component corresponding to the coded phase, which is the sum of the DDM phase and the CDM phase, is contained.

[0041] For example, in the measurement transmission cycle Tt_m, when the rotation amount is π / 2 as shown in Figure 3, each chirp signal with a DDM phase of 0, π / 2, π, or 3π / 2 contains a different phase offset component. The phase offset components corresponding to each DDM phase of 0, π / 2, π, or 3π / 2 are denoted as δ0, δ1, δ2, δ3, δ4, δ5, δ6, δ7, δ8, δ9, δ10, δ11, δ12, δ13, δ14, δ15, δ16, δ17, δ18, δ19, δ20, δ21, δ22, δ23, δ24, δ25, δ26, δ27, δ28, δ29, δ30, δ31, δ32, δ33 90 ,δ 180 ,δ 270In this case, as shown in Fig. 5, a phase offset component occurs periodically as a spurious component with the same period as the rotation period Tr.

[0042] The time waveform of such a periodic phase offset component can be assumed to be composed of a linear sum of sine waves. Therefore, if a phase offset component is included in a transmission signal, multiple periodic peaks (spurious peaks) will appear in the Doppler spectrum of the corresponding beat signal. Such a phase offset component changes depending on temperature, aging degradation of the transmission circuit 5, etc. Therefore, when compensating for the phase offset component, it may be necessary to periodically estimate and update the actually occurring phase offset component.

[0043] The control unit 7 processes the acquired beat signal. The control unit 7 estimates and compensates for the phase offset component described above. The control unit 7 is connected to the transceiver unit 2 via at least one of, for example, a LAN (Local Area Network) line, a wire harness, an internal bus, and a wireless communication line. The configuration of the control unit 7 will be described later.

[0044] 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 made 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 signals to be transmitted and received by the antennas TX and RX. The case body 82, together with the radome 81, defines an accommodation space that accommodates the components of the radar device 1 described above.

[0045] 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 supervising ECU that comprehensively controls multiple radar devices 1 mounted on a moving object. The dedicated computer constituting the control unit 7 may be a sensor supervising ECU that comprehensively controls multiple sensors including the radar device 1 and other sensors such as LiDAR (Light Detection and Ranging / Laser Imaging Detection and Ranging).

[0046] The dedicated computer constituting the control unit 7 has at least one memory 7a and one processor 7b. 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, that non-temporarily stores computer-readable programs and data. Here, "storage" may refer to accumulation in which data is retained even when the radar device 1 is turned on or 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 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).

[0047] 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. 6. The control unit 7 is an example of a "radar control device."

[0048] 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 Figures 7 and 8. 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.

[0049] First, in S10 of Fig. 7, a process for estimating a phase offset component is executed. More specifically, in S101 of Fig. 8, the transmission processing block 71 outputs an instruction to start transmission processing to the transceiver unit 2, thereby causing the transmission signal to be transmitted from the multiple transmission antennas TX. As described above, the phase shifter 51 imparts a different rotation amount and code group to the transmission signal for each transmission antenna TX.

[0050] The transmission processing block 71 may transmit a command to start the transmission process, causing the transceiver unit 2 to transmit a transmission signal with a preset rotation amount and code group. Alternatively, the transmission processing block 71 may change the rotation amount and code for each compensation transmission cycle Tt_c.

[0051] Next, in S102, the reception processing block 72 acquires, from each reception circuit 6, beat signals defined from the reception signals acquired for each reception antenna RX. Then, in S103, the reception processing block 72 acquires a distance spectrum using the beat signals defined from the reception signals received at a single reception antenna RX. The reception processing block 72 may acquire a beat signal corresponding to a specific, predefined single reception antenna RX. Alternatively, the reception processing block 72 may change the single reception antenna RX corresponding to the acquired beat signal for each compensation reception cycle Tr_c.

[0052] Specifically, the reception processing block 72 performs a Fast Fourier Transform (FFT) on the beat signal. As a result, the reception processing block 72 acquires a distance spectrum, which is a spectrum that exhibits peaks at frequency positions corresponding to the distance to the target, for each chirp signal. The distance spectrum data includes signal strength information for each distance bin according to the distance resolution. Each distance spectrum for each chirp signal is an example of a "signal component correlated to the received signal."

[0053] Next, in S104, the reception processing block 72 sets i = 1 and j = 1 to perform iterative processing. Then, in S105, the reception processing block 72 executes decoding processing on the distance spectrum in accordance with the code group assigned to the transmission signal from the transmission antenna TXi, as shown in Figs.

[0054] In the decoding process, the receiver processing block 72 performs decoding processing according to the corresponding code for each distance spectrum cluster corresponding to each phase cluster in the transmitted signal. For example, in the example shown in FIG. 3, the multiple distance spectra in the time series can be classified into four distance spectrum clusters corresponding to the four phase clusters with DDM phases of 0, π / 2, π, and 3π / 2. For each distance spectrum cluster, the receiver processing block 72 decodes the corresponding phase cluster using the code. The receiver processing block 72 defines a decoded spectrum obtained by decoding the distance spectrum by performing an arithmetic process to cancel out the phase shift imparted by the code. Each distance spectrum cluster is an example of a "received signal component" corresponding to each phase cluster in the received signal. The decoded spectrum is an example of a "decoded signal component."

[0055] In the next step S106, the reception processing block 72 acquires a Doppler spectrum using the group of distance spectra that have been subjected to the decoded processing. To describe the acquisition of the Doppler spectrum in more detail, the reception processing block 72 performs a second FFT process on one of the distance spectrum clusters. In the second FFT process, the reception processing block 72 performs FFT processing on the waveform in which the phases at the distance bins obtained in the first FFT process are aligned. As a result of the second FFT process, the reception processing block 72 acquires, for each distance bin, a frequency spectrum (Doppler spectrum) that shows a peak at a position corresponding to the Doppler velocity (relative velocity) of the target. The Doppler spectrum acquired in this step is a Doppler spectrum defined only from a specific distance spectrum cluster. As a result, the reception processing block 72 acquires a two-dimensional spectrum of the distance R and the Doppler velocity V. The Doppler spectrum is also called a velocity spectrum, and the two-dimensional spectrum is also called an RV map.

[0056] In the following S107, the reception processing block 72 acquires the phase component (peak phase) of the target peak in the Doppler spectrum. Next, in S108, the reception processing block 72 counts up j to j + 1. Then, in S109, the reception processing block 72 determines whether j exceeds the DDM phase number Nph. If it is determined that j does not exceed the DDM phase number Nph, acquisition of peak phases for all distance spectrum clusters has not been completed, and the flow returns to S105. On the other hand, if it is determined that j exceeds the DDM phase number Nph, acquisition of peak phases for all distance spectrum clusters has been completed, and the flow proceeds to S110.

[0057] In S110, the reception processing block 72 estimates a phase offset component included in the transmission signal of the transmitting antenna TXi. Specifically, the reception processing block 72 acquires a relative phase offset component between the DDM phases according to the peak phase of each Doppler spectrum acquired for each DDM phase, i.e., for each distance spectrum cluster.

[0058] For example, when the rotation amount of DDM modulation is π / 2, the peak phase in the Doppler spectrum corresponding to the phase cluster with a DDM phase of 0 is 0 + δ0. Similarly, the peak phases in the Doppler spectrum corresponding to the phase clusters with DDM phases of π / 2, π, and 3π / 2 are π / 2 + δ in that order. 90 ,π+δ 180 ,3π / 2+δ 270 Therefore, the receiver processing block 72 estimates the relative phase offset component of each DDM phase from the difference between the peak phases. For example, the receiver processing block 72 estimates the relative phase offset component of another DDM phase with respect to the reference DDM phase from the difference between the reference peak phase and another peak phase. The reference peak phase may be, for example, a peak phase corresponding to a phase cluster with a DDM phase of 0.

[0059] Then, in S111, the reception processing block 72 stores the estimated phase offset components of the transmitting antenna TXi in a storage medium such as the memory 7a. Subsequently, in S112, the reception processing block 72 counts up i to i+1. Then, in S113, the reception processing block 72 determines whether the value of i after counting up exceeds the number m of the transmitting antennas TX. If it is determined that i does not exceed the number m, that is, that phase offset component estimation for all the transmitting antennas TX is incomplete, the flow returns to S105. On the other hand, if it is determined that i exceeds the number m, that is, that phase offset component estimation for all the transmitting antennas TX is complete, the flow ends and returns to S20 in FIG. 7. The above series of processes are executed in the compensated transmission cycle Tt_c and the compensated reception cycle Tr_c.

[0060] Returning to FIG. 7, in S20, the transmission processing block 71 transmits a transmission signal in the measurement transmission cycle Tt_m. Next, in S30, the reception processing block 72 acquires, from the reception circuit 6, a beat signal that correlates with the reception signal received in the measurement reception cycle Tr_m. Next, in S40, the reception processing block 72 acquires a Doppler spectrum. The Doppler spectrum acquired in this step is a Doppler spectrum defined from the total distance spectrum in time series. Therefore, the peaks in this Doppler spectrum are given a pseudo Doppler velocity that corresponds to the amount of rotation due to DDM modulation.

[0061] Next, in S50, the reception processing block 72 performs compensation processing for the phase offset component based on the phase offset component acquired in the previous compensation reception cycle Tr_c. For example, the reception processing block 72 may generate a spurious spectrum from the stored phase offset component and subtract it from the Doppler spectrum to compensate for the phase offset component.

[0062] 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 peaks at positions 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 called MIMO angle measurement processing.

[0063] 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, acquired by the MIMO angle measurement process.

[0064] The control unit 7 repeatedly executes the above series of processes during the activation of the radar device 1. As a result, the control unit 7 of the first embodiment transmits a transmission signal in the compensation transmission cycle Tt_c every time before the measurement transmission cycle Tt_m.

[0065] According to the first embodiment described above, the transmit signal transmitted from a single transmit antenna TX in the compensated transmit cycle Tt_c is coded for each cluster of chirp signals with a common DDM phase. Therefore, in the compensated receive cycle Tr_c, a decoded signal component decoded with respect to the corresponding code can be defined for each received signal component corresponding to each cluster in the received signal. Therefore, the phase offset component for each velocity phase in the transmit signal can be obtained as a parameter correlated with the phase component of each peak in each Doppler spectrum defined for each decoded signal component corresponding to the cluster. Therefore, by transmitting the transmit signals in overlapping transmission periods, it is possible to estimate the phase offset component while shortening the transmission processing time.

[0066] Furthermore, according to the first embodiment, a transmission signal is transmitted that is coded using a code group including codes defined by a sequence of CDM phases that impart a zero-rotation phase shift and CDM phases that impart a half-rotation phase shift, which makes it possible to code the transmission signal using codes that are easier to decode.

[0067] Furthermore, according to the first embodiment, the transmit signal is encoded using a code set including codes in which the number of chirp signals to which a zero-rotation phase shift is applied is equal to the number of chirp signals to which a half-rotation phase shift is applied, which makes it possible to encode the transmit signal using codes more suitable for CDM modulation.

[0068] In addition, according to the first embodiment, a transmission signal is transmitted that is coded using a code group that includes a common code for each phase cluster, which makes it relatively easy to design the code.

[0069] Second Embodiment As shown in FIG. 10, the second embodiment is a modification of the first embodiment. In the second embodiment, the codes constituting the code group differ between phase clusters. In the example shown in FIG. 10, a phase cluster with a DDM phase of 0 is assigned a code consisting of the sequence [0, 0, π, ...]. A phase cluster with a DDM phase of π / 2 is assigned a code consisting of the sequence [0, π, π, ...]. Furthermore, a phase cluster with a DDM phase of π is assigned a code consisting of the sequence [0, π, 0, ...]. In addition, a phase cluster with a DDM phase of 3π / 2 is assigned a code consisting of the sequence [π, 0, π, ...].

[0070] According to the second embodiment, a transmission signal is transmitted that is coded using a code set that includes a different code for each phase cluster, thereby improving the randomness of the sequence of CDM phases in the entire series of chirp signals.

[0071] (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.

[0072] In a modified example, the control unit 7 may set the compensation transmission cycle Tt_c next to the previous compensation transmission cycle Tt_c after one of the multiple measurement transmission cycles Tt_m following the previous compensation transmission cycle Tt_c. In other words, the control unit 7 does not necessarily need to estimate the phase offset component before each measurement transmission cycle Tt_m. The control unit 7 may periodically estimate and update the phase offset component by setting the compensation transmission cycle Tt_c for each of a predetermined number of measurement transmission cycles Tt_m. Alternatively, the control unit 7 may perform phase offset component estimation when a specific condition related to the state of the radar device 1 or the vehicle on which the radar device 1 is mounted is met.

[0073] In a modified example, the reception processing block 72 in S105 may perform decoding processing for each distance spectrum group corresponding to each reception antenna RX. The reception processing block 72 may perform processing from S106 to S110 for each distance spectrum group to calculate a phase offset component for each reception antenna RX, and integrate the processing results.

[0074] In a modified example, the transmission processing block 71 may transmit a transmission signal that has been subjected to CDM modulation in addition to DDM modulation, also in the measurement transmission cycle Tt_m.

[0075] 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 a vehicle equipped with the radar device 1. In this case, the "radar system" includes the radar device 1 and the processor of the on-board ECU.

[0076] In a modified example, the radar device 1 may include only one receiving antenna RX. In this case, the receiving processing block 72 outputs sensing data correlated with the received signal received by the single receiving antenna RX.

[0077] 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 ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), an SOC (System on a Chip), a PGA (Programmable Gate Array), and a CPLD (Complex Programmable Logic Device). Such a digital circuit may also have a memory 7a that stores a program.

[0078] In a modified example, the mobile body to which the radar device 1 is applied may be, for example, an autonomous robot that can transport luggage or collect information by autonomous traveling or remote traveling. Examples of the autonomous robot include an autonomous vehicle.

[0079] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0080] (Technical thought 1) A radar system having a plurality of transmitting antennas (TX), at least one receiving antenna (RX), and a processor (7b), The processor: transmitting, from each of the transmitting antennas, a transmission signal including a plurality of chirp signals whose frequencies change over time, the transmission signal having a velocity phase that is a phase rotated for each of the chirp signals by a specific rotation amount, the rotation amount of which varies between the transmitting antennas; outputting sensing data correlating the transmission signals from the plurality of transmission antennas with reception signals received by the reception antennas in a measurement reception cycle corresponding to the measurement transmission cycle; configured to run The transmitting of the transmission signal includes: In a compensation transmission cycle before the measurement transmission cycle, the transmission signals are transmitted from each of the transmitting antennas during overlapping transmission periods, the transmission signals being coded with a code group including a plurality of codes assigned to each cluster of the chirp signals having a common velocity phase among the plurality of chirp signals transmitted from a single transmitting antenna, the codes being different for the velocity phases common among the transmitting antennas; The outputting of the sensing data includes: In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code; Obtaining, for each of the transmitting antennas, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each of the decoded signal components corresponding to the cluster; outputting the sensing data correlated with the received signal from which the phase offset component has been removed in a measurement receive cycle after the compensation receive cycle; A radar system including:

[0081] (Technical thought 2) The outputting of the sensing data includes: A radar system according to technical idea 1, which includes acquiring the relative phase offset component between the velocity phases, which is correlated to the relative relationship of each of the phase components.

[0082] (Technical Thought 3) The transmitting of the transmission signal includes: A radar system according to Technical Idea 1 or Technical Idea 2, which includes transmitting the transmission signal encoded with the code group including the code defined by a sequence of an additional phase that adds a phase shift of no rotation and an additional phase that adds the phase shift of a half rotation.

[0083] (Technical Thought 4) The transmitting of the transmission signal includes: A radar system according to any one of Technical Ideas 1 to 3, which includes transmitting the transmission signal encoded with the code group including the code in which the number of chirp signals to which a phase shift of no rotation is imparted is the same as the number of chirp signals to which a phase shift of half rotation is imparted.

[0084] (Technical Thought 5) The transmitting of the transmission signal includes: A radar system according to any one of technical ideas 1 to 4, which includes transmitting the transmission signal encoded by the code group including the code common to each cluster.

[0085] (Technical Thought 6) The transmitting of the transmission signal includes: A radar system according to any one of technical ideas 1 to 4, which includes transmitting the transmission signal encoded by the code group including the code that differs for each cluster.

[0086] The above technical ideas 1 to 6 may be implemented in the form of a radar control device, a radar control method, and a radar control program. [Explanation of symbols]

[0087] 1: radar device (radar system), 7: control unit (radar control device), 7a: memory (storage medium), 7b: processor, TX: transmitting antenna, RX: receiving antenna

Claims

1. A radar system having a plurality of transmit antennas (TX), at least one receive antenna (RX), and a processor (7b), The processor: transmitting, from each of the transmitting antennas, a transmission signal including a plurality of chirp signals whose frequencies change over time, the transmission signal having a velocity phase that is a phase rotated for each of the chirp signals by a specific rotation amount, the rotation amount of which varies between the transmitting antennas; outputting sensing data correlating the transmission signals from the plurality of transmission antennas with reception signals received by the reception antennas in a measurement reception cycle corresponding to the measurement transmission cycle; configured to run The transmitting of the transmission signal includes: In a compensation transmission cycle before the measurement transmission cycle, the transmission signals are transmitted from each of the transmitting antennas during overlapping transmission periods, the transmission signals being coded with a code group including a plurality of codes assigned to each cluster of the chirp signals having a common velocity phase among the plurality of chirp signals transmitted from a single transmitting antenna, the codes being different for the velocity phases common among the transmitting antennas; The outputting of the sensing data includes: In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code; Obtaining, for each of the transmitting antennas, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each of the decoded signal components corresponding to the cluster; outputting the sensing data correlated with the received signal from which the phase offset component has been removed in a measurement receive cycle after the compensation receive cycle; A radar system including:

2. The outputting of the sensing data includes: The radar system of claim 1 , further comprising: obtaining the relative phase offset components between the velocity phases that correlate to the relative relationship of each of the phase components.

3. The transmitting of the transmission signal includes:

2. The radar system according to claim 1, further comprising transmitting the transmission signal encoded with the code group including the code defined by a sequence of an additional phase that adds a phase shift of no rotation and the additional phase that adds the phase shift of a half rotation.

4. The transmitting of the transmission signal includes:

2. The radar system according to claim 1, further comprising transmitting the transmission signal encoded with the code group including the code in which the number of chirp signals to which a phase shift of no rotation is imparted is equal to the number of chirp signals to which a phase shift of a half rotation is imparted.

5. The transmitting of the transmission signal includes: The radar system according to claim 1 , further comprising transmitting the transmission signal coded by the code group including the code common to each cluster.

6. The transmitting of the transmission signal includes: The radar system according to claim 1 , further comprising transmitting the transmission signal coded by the code group including the code that differs for each cluster.

7. A radar control device for controlling a radar system (1) having a plurality of transmitting antennas (TX) and at least one receiving antenna (RX), the radar control device comprising: The processor: transmitting, from each of the transmitting antennas, a transmission signal including a plurality of chirp signals whose frequencies change over time, the transmission signal having a velocity phase that is a phase rotated for each of the chirp signals by a specific rotation amount, the rotation amount of which varies between the transmitting antennas; outputting sensing data correlating the transmission signals from the plurality of transmission antennas with reception signals received by the reception antennas in a measurement reception cycle corresponding to the measurement transmission cycle; configured to run The transmitting of the transmission signal includes: In a compensation transmission cycle before the measurement transmission cycle, the transmission signals are transmitted from each of the transmitting antennas during overlapping transmission periods, the transmission signals being coded with a code group including a plurality of codes assigned to each cluster of the chirp signals having a common velocity phase among the plurality of chirp signals transmitted from a single transmitting antenna, the codes being different for the velocity phases common among the transmitting antennas; The outputting of the sensing data includes: In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code; Obtaining, for each of the transmitting antennas, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each of the decoded signal components corresponding to the cluster; outputting the sensing data correlated with the received signal from which the phase offset component has been removed in a measurement receive cycle after the compensation receive cycle; A radar control device comprising:

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, a transmission signal including a plurality of chirp signals whose frequencies change over time, the transmission signal having a velocity phase that is a phase rotated for each of the chirp signals by a specific rotation amount, the rotation amount of which varies between the transmitting antennas; outputting sensing data correlating the transmission signals from the plurality of transmission antennas with reception signals received by the reception antennas in a measurement reception cycle corresponding to the measurement transmission cycle; Including, The transmitting of the transmission signal includes: In a compensation transmission cycle before the measurement transmission cycle, the transmission signals are transmitted from each of the transmitting antennas during overlapping transmission periods, the transmission signals being coded with a code group including a plurality of codes assigned to each cluster of the chirp signals having a common velocity phase among the plurality of chirp signals transmitted from a single transmitting antenna, the codes being different for the velocity phases common among the transmitting antennas; The outputting of the sensing data includes: In a compensated reception cycle corresponding to the compensated transmission cycle, for each received signal component corresponding to each cluster in the received signal, a decoded signal component decoded with respect to the corresponding code; Obtaining, for each of the transmitting antennas, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each of the decoded signal components corresponding to the cluster; outputting the sensing data correlated with the received signal from which the phase offset component has been removed in a measurement receive cycle after the compensation receive cycle; A radar control method comprising:

9. A radar control program stored in a storage medium (7a) and including instructions to be 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), The instruction: transmitting, from each of the transmitting antennas, a transmission signal including a plurality of chirp signals whose frequencies change over time, the transmission signal having a velocity phase that is a phase rotated for each of the chirp signals by a specific rotation amount, the rotation amount of which varies between the transmitting antennas; outputting sensing data correlating the transmission signals from the plurality of transmission antennas with reception signals received by the reception antennas in a measurement reception cycle corresponding to the measurement transmission cycle; Including, The transmitting of the transmission signal includes: In a compensation transmission cycle before the measurement transmission cycle, the transmission signals are transmitted from each of the transmitting antennas during overlapping transmission periods, the transmission signals being coded with a code group including a plurality of codes assigned to each cluster of the chirp signals having a common velocity phase among the plurality of chirp signals transmitted from a single transmitting antenna, the codes being different for the velocity phases common among the transmitting antennas; The outputting of the sensing data includes: In a compensated reception cycle corresponding to the compensated transmission cycle, a decoded signal component decoded with respect to the corresponding code is defined for each received signal component corresponding to each cluster in the received signal; Acquiring, for each of the transmitting antennas, a phase offset component for each velocity phase in the transmission signal that correlates with a phase component of each peak in each velocity spectrum defined for each of the decoded signal components corresponding to the cluster; In a measurement reception cycle after the compensation reception cycle, outputting the sensing data correlated with the reception signal from which the phase offset component has been removed; A radar control program including:

Images