Radar system, self-calibration method and vehicle

Abstract

The application provides a radar system, a self-calibration method and a vehicle, and relates to the technical field of radars.The radar system comprises: a plurality of radar chips connected in cascade, each radar chip comprising at least one receiving channel; a calibration transmitting module arranged in at least one of the plurality of radar chips, used for generating a calibration signal in a calibration mode of the radar system; a coupling network connected between the internal calibration transmitting module and each receiving channel of the plurality of radar chips, used for distributing the calibration signal to each receiving channel; and a signal processing module used for determining compensation data of each receiving channel according to amplitude differences and / or phase differences between received signals of the receiving channels in the calibration mode, the compensation data being used for compensating signals received by each receiving channel in a working mode of the radar system.Thus, the consistency of radio frequency amplitude and phase can be improved, and the detection performance and stability of the radar system can be improved.

Description

Technical Field

[0001] This application relates to the field of radar technology, and more particularly to a radar system, a self-calibration method, and a vehicle. Background Technology

[0002] With the development of intelligent sensing technology, millimeter-wave radar systems are widely used in vehicle-mounted environmental perception systems due to their advantages such as strong all-weather operation and high ranging and speed measurement accuracy. To improve the angular resolution and spatial perception capabilities of radar systems, existing millimeter-wave radar products are gradually adopting array structures with multiple transmit and receive channels, and expanding the equivalent antenna aperture through virtual array technology. Due to the limitations of the number of transmit and receive channels per radar chip, existing technologies typically use cascaded multiple radar chips to construct large-scale antenna arrays. However, while the multi-chip cascaded structure improves system performance, it also introduces more complex radio frequency consistency problems. Due to unavoidable local oscillator phase deviations, radio frequency link gain errors, device process discreteness, and amplitude and phase drift caused by temperature changes between different chips and different radio frequency channels, errors between different channels are superimposed during virtual array synthesis, easily leading to array amplitude and phase inconsistencies. This results in decreased angular measurement accuracy, sidelobe rise, and false targets, seriously affecting the detection performance and stability of the radar system. Summary of the Invention

[0003] In view of this, this application provides a radar system, a self-calibration method, and a vehicle, which aim to improve radio frequency amplitude and phase consistency and enhance the detection performance and stability of the radar system.

[0004] According to a first aspect of the embodiments of this application, a radar system is provided, comprising: Multiple cascaded radar chips, each including at least one receiving channel.

[0005] A calibration transmission module, disposed within at least one of the plurality of radar chips, is used to generate a calibration signal in the calibration mode of the radar system.

[0006] A coupling network, connected between the internal calibration transmission module and each receiving channel of the plurality of radar chips, is used to distribute the calibration signal to each receiving channel.

[0007] The signal processing module is used to determine compensation data for each receiving channel based on the amplitude difference and / or phase difference between the received signals of the receiving channels in the calibration mode. The compensation data is used to compensate the signals received by each receiving channel in the operating mode of the radar system.

[0008] In some possible implementations, the plurality of radar chips includes a main radar chip and at least one slave radar chip. The calibration transmission module is disposed inside the main radar chip, which has a calibration signal transmission channel, and the internal calibration transmission module outputs the calibration signal through the calibration signal transmission channel.

[0009] In some possible implementations, the coupling network includes: A power distribution unit is used to distribute the calibration signal into multiple channels.

[0010] A signal input element is connected between the calibration signal transmission channel and the power distribution unit, and is used to transmit the calibration signal to the power distribution unit.

[0011] Multiple signal distribution elements are connected between multiple output terminals of the power distribution unit and each receiving channel, for transmitting the signals distributed by the power distribution unit to each receiving channel respectively.

[0012] In some possible implementations, both the signal access element and the signal distribution element are couplers. Alternatively, both the signal access element and the signal distribution element are radio frequency (RF) switches. The RF switches are configured to: in the calibration mode, connect each receiving channel to the calibration signal transmitting channel respectively; and in the operating mode, connect each receiving channel to its corresponding antenna respectively.

[0013] In some possible implementations, the radar system is configured to trigger the calibration mode under preset conditions and switch from the calibration mode to the operating mode after a preset duration; or, the operating mode has a preset idle time slot during which the system switches to the calibration mode.

[0014] In some possible implementations, the preset triggering conditions include at least one of the following: system power-on signal; system running time reaching a preset threshold; temperature change exceeding a set range; receiving an external calibration trigger command.

[0015] In some possible implementations, the signal processing module is further configured to, in the calibration mode, send a calibration command to the calibration transmission module to control the calibration transmission module to generate the calibration signal. The radar system also includes an amplitude-phase compensation module, configured to, in the operating mode, perform compensation processing on the operating signals received by each receiving channel based on the compensation data.

[0016] In some possible implementations, the radar system is a vehicle-mounted millimeter-wave radar system, installed on a vehicle. The signal processing module is communicatively connected to the vehicle's central control platform via an onboard communication bus.

[0017] According to a second aspect of the embodiments of this application, a radar system radio frequency self-calibration method is also provided, comprising: In response to the radar system operating in calibration mode, a calibration transmission module located inside at least one of the cascaded radar chips is controlled to generate a calibration signal.

[0018] Based on the coupling network, the calibration signal is distributed to each receiving channel of the plurality of radar chips, wherein each radar chip includes at least one receiving channel.

[0019] Compensation data for each receiving channel is determined based on the amplitude and / or phase differences between the received signals in the calibration mode.

[0020] In response to the radar system's operating mode being the working mode, compensation processing is performed on the working signals received by each receiving channel based on the compensation data.

[0021] In some possible implementations, the method further includes: controlling the radar system to switch from the calibration mode to the operating mode in response to the continuous duration of the calibration mode reaching a preset duration; or, the operating mode having a preset idle time slot, controlling the radar system to switch to the calibration mode within the preset idle time slot.

[0022] According to a third aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the method described in the above embodiments.

[0023] According to a fourth aspect of the embodiments of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the above embodiments.

[0024] According to a fifth aspect of the embodiments of this application, a vehicle is also provided, including a central control platform and a radar system as described in any of the above embodiments, wherein a signal processing module in the radar system is communicatively connected to the central control platform via an on-board communication bus.

[0025] According to a sixth aspect of the embodiments of this application, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the method described in the above embodiments.

[0026] The technical solutions provided by the embodiments of this application may include the following beneficial effects: In this embodiment, at least one internal calibration transmission module of multiple radar chips generates calibration signals in the calibration mode of the radar system. A coupling network connecting the internal calibration transmission module and each receiving channel of the multiple radar chips distributes the calibration signals to each receiving channel. A signal processing module determines compensation data for each receiving channel based on the amplitude and / or phase differences between the received signals in the calibration mode. The compensation data is used to compensate the signals received by each receiving channel in the operating mode of the radar system. Based on this, a highly versatile internal RF self-calibration architecture that does not rely on external calibration can be constructed in a multi-chip cascaded radar system. By setting a calibration transmission module and a coupling network inside the RF front-end system, the calibration signal is injected into each receiving channel in a coupling manner, without relying on external calibration equipment or air interface reflection targets, and is unaffected by environmental scenes, multipath effects, and changes in target distribution. By performing amplitude and phase compensation on the received signals of each receiving channel in the radar system during operation, amplitude and phase deviations caused by differences in device process technology, inconsistencies in RF links, and temperature changes in multi-chip cascaded structures can be effectively reduced. This reduces virtual array synthesis errors and helps avoid the problem of difficulty in ensuring RF channel consistency under multi-chip cascaded conditions, thereby improving the angle measurement accuracy and stability of the radar system. The aforementioned internal RF self-calibration architecture can stably execute under different usage scenarios and complex operating conditions. It can achieve unified acquisition and compensation of amplitude and / or phase errors of each receiving channel in a multi-chip cascaded structure, and is not limited by the specific number of radar chips or cascaded method. It is applicable to multi-chip cascaded radar systems of different scales, enhancing the versatility and scalability of the aforementioned internal self-calibration architecture. This is beneficial for improving the engineering usability and deployment flexibility of multi-chip cascaded radar systems and avoids the problem of repetitive design for specific chip numbers or specific array structures.

[0027] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the architecture of a radar system provided in an embodiment of this application; Figure 2 This is a schematic diagram of a coupled network structure provided in an embodiment of this application; Figure 3 This is a schematic diagram of another coupled network structure provided in an embodiment of this application; Figure 4 This is a schematic diagram of a radar system with a three-chip cascaded architecture provided in an embodiment of this application; Figure 5AThis is a schematic diagram illustrating the operation of a calibration mode provided in an embodiment of this application; Figure 5B This is a schematic diagram illustrating the operation of one working mode provided in an embodiment of this application; Figure 5C This is a schematic diagram of a process for switching operating modes provided in an embodiment of this application; Figure 6A This is a timing diagram of a pre-calibration mode provided in an embodiment of this application; Figure 6B This is a timing diagram of a real-time calibration mode provided in an embodiment of this application; Figure 7 This is a schematic diagram of another radar system provided in an embodiment of this application; Figure 8 This is a flowchart of a radar system radio frequency self-calibration method provided in an embodiment of this application; Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0029] In radar systems, to improve angular resolution and spatial awareness, a multi-transmit, multi-receive array structure is typically employed, and the equivalent antenna aperture is expanded using virtual array technology. However, in multi-chip cascaded radar systems, the array amplitude and phase inconsistency often exists, severely impacting the radar system's detection performance and stability.

[0030] In related technologies, external calibration equipment or reflective targets in the actual environment are typically used to acquire echo signals via air interface for offline or online calibration. This involves transmitting the signal through the radar transmitting antenna, which is then reflected back to the radar receiving antenna by external calibration equipment or reflective targets in the environment to obtain the echo signal. However, this type of calibration method is highly dependent on the test environment and target distribution, and is easily affected by multipath propagation, obstruction, and environmental changes. It is difficult to achieve a stable and repeatable calibration process in complex or dynamic scenarios, and it is also not conducive to rapid calibration and maintenance of the system during actual operation.

[0031] In some technologies, angle measurement results are compensated through signal processing or algorithms. However, this method usually cannot directly eliminate the amplitude and phase errors caused by the cascading of multiple chips within the RF front end. Its compensation effect depends on model assumptions and algorithm accuracy, making it difficult to adapt to complex operating conditions such as changes in the number of chips, differences in array structure, and temperature drift. It is also difficult to balance system versatility and engineering feasibility.

[0032] In view of this, this application proposes a highly versatile internal radio frequency self-calibration architecture for radar systems, which eliminates amplitude and phase errors caused by multi-chip cascading and improves system amplitude and phase consistency without relying on external calibration. Figure 1 As shown, Figure 1 This is a schematic diagram of the architecture of a radar system provided in an embodiment of this application.

[0033] This radar system comprises multiple cascaded radar chips, forming a radar chipset 10. Each radar chip includes at least one receive channel (RX). The cascaded radar chips include one master radar chip and the rest are slave radar chips. In this multi-chip cascaded radar system, by synchronously controlling and cascading the signals of multiple radar chips, higher angular resolution and longer detection range can be achieved, thus improving the overall system performance.

[0034] Figure 1 The Sino-Israeli radar system is illustrated using three radar chips as an example, with only one receiving channel shown for each chip. The three radar chips are, in order, radar chip 11 (first radar chip 11), radar chip 12 (second radar chip 12), and radar chip 13 (third radar chip 13), where radar chip 11 is the master radar chip, and radar chips 12 and 13 are slave radar chips. It is understood that multiple radar chips can be cascaded in a predetermined order, with the selection of the master radar chip determined based on the actual configuration. The number of radar chips and the number of receiving channels in each radar chip can be determined according to the actual application scenario, preferably including multiple receiving channels, but this is not limited here.

[0035] like Figure 1 As shown, the radar system also includes a calibration transmission module 20, a coupling network 30, and a signal processing module 40.

[0036] The calibration transmission module 20 is disposed within at least one of the plurality of radar chips and is used to generate a calibration signal in the calibration mode of the radar system. For example, the calibration transmission module 20 may be disposed within the main radar chip, or it may be disposed within a slave radar chip. Figure 1 The following example illustrates the calibration transmission module 20, which is located inside the main radar chip. The calibration signal has preset frequency, amplitude, and phase characteristics, and its signal form can be a continuous wave signal, a linear frequency modulated signal, or other calibration waveforms isomorphic to the radar's operational transmission signal.

[0037] The coupling network 30 is connected between the internal calibration transmission module 20 and each receiving channel of the plurality of radar chips, and is used to distribute the calibration signal to each receiving channel.

[0038] For example, the coupling network 30 is disposed inside the radio frequency front end of the radar system, and is used to simultaneously inject the calibration signal generated by the calibration transmission module 20 inside the radar chipset 10 into each receiving channel of the radar system in a coupling manner (or, in other words, non-radiative).

[0039] This non-radiative injection method avoids environmental reflections and multipath interference introduced by the calibration signal being radiated from the antenna into the external environment of the radar system, and is especially suitable for the high-precision amplitude and phase calibration requirements in a three-chip cascaded structure.

[0040] Due to the limitations of hardware design, the timing of echo signal reception by multiple receiving channels of a radar chip varies. In this application, the coupling network 30 is located inside the RF front-end of the radar system. This reduces signal transmission paths and time, thus mitigating latency deviation. Furthermore, by rationally designing the signal transmission paths corresponding to different receiving channels within the coupling network 30, multiple receiving channels can simultaneously receive the calibration signal, thereby reducing residual deviations caused by trace delays and further improving the accuracy of the radar system's signal reception.

[0041] The signal processing module 40 is used to determine compensation data for each receiving channel based on the amplitude difference and / or phase difference between the received signals of the receiving channels in the calibration mode. The compensation data is used to compensate the signals received by each receiving channel in the operating mode of the radar system.

[0042] In other words, calibration mode and operating mode are two parallel operating modes of the radar system. In calibration mode, the calibration transmission module 20 generates a calibration signal, and the coupling network 30 couples this calibration signal into each receiving channel of the radar system. Each radar chip is connected to the signal processing module 40, and the received signal from each receiving channel is transmitted to the signal processing module 40 through the circuit structure (such as an analog-to-digital converter) within the radar chip.

[0043] Based on the received signal of each receiving channel and the preset calibration signal, the signal processing module 40 can determine the amplitude difference and / or phase difference between different radar chips and between different receiving channels, which can characterize both the amplitude and phase consistency characteristics at the chip level and the amplitude and phase consistency characteristics at the receiving channel level.

[0044] The signal processing module 40 acquires and processes the received signals from each receiving channel. Based on the target of amplitude and phase consistency, it can determine the compensation data for each receiving channel. Furthermore, in operating mode, the radar system can compensate for the actual operating signals received by each receiving channel based on this compensation data.

[0045] For example, if the received signal of a certain receiving channel in calibration mode exceeds the calibration signal, the excess value can be used as the absolute value of the compensation data. In operating mode, this compensation data is subtracted from the actual operating signal received by that receiving channel before being used in subsequent radar imaging calculations and processing. Alternatively, in calibration mode, the received signal of one of the multiple receiving channels can be used as the reference signal. If the received signals of the other receiving channels exceed this reference signal, the excess value can be used as the absolute value of the compensation data. The same logic applies to the case where the received signal is less than the calibration signal or less than the aforementioned reference signal, which will not be elaborated here.

[0046] Based on the aforementioned calibration transmission module 20, coupling network 30, and signal processing module 40, a highly versatile internal radio frequency self-calibration architecture that does not rely on external calibration can be constructed in a multi-chip cascaded radar system. By setting the calibration transmission module 20 and coupling network 30 within the radio frequency front-end system, calibration signals are injected into each receiving channel in a coupled manner, without relying on external calibration equipment or air interface reflection targets, and unaffected by environmental scenes, multipath effects, and changes in target distribution.

[0047] By performing amplitude and phase compensation on the working signals received by each receiving channel of the radar system in the working mode, the amplitude and phase deviation caused by differences in device process, inconsistency of radio frequency links and temperature changes in the multi-chip cascade structure can be effectively reduced, the virtual array synthesis error can be reduced, and the problem of difficulty in ensuring the consistency of radio frequency channels under multi-chip cascade conditions can be avoided, thereby improving the angle measurement accuracy and stability of the radar system.

[0048] The aforementioned internal self-calibration architecture for radio frequency can operate stably under different usage scenarios and complex operating conditions. It can achieve unified acquisition and compensation of amplitude and / or phase errors of each receiving channel in a multi-chip cascaded structure. Furthermore, it does not limit the specific number of radar chips or the cascade method, and can be applied to multi-chip cascaded radar systems of different scales. This enhances the versatility and scalability of the aforementioned internal self-calibration architecture, which is conducive to improving the engineering availability and deployment flexibility of multi-chip cascaded radar systems and avoids the problem of repetitive design for a specific number of chips or a specific array structure.

[0049] Combination Figure 1 As shown, in a radar system with three cascaded radar chips, each chip has multiple transmit channels and multiple receive channels. The three chips work together to form a virtual array structure with multiple transmit and multiple receive channels. Compared to a four-chip cascade structure, the three-chip cascade structure has certain advantages in terms of system cost, power consumption, and hardware complexity. However, its virtual array structure has reduced symmetry and is more sensitive to amplitude and phase consistency across chips and across receive channels.

[0050] Based on the technical solution of this application, the amplitude and phase consistency of the three-chip cascaded radar system can be improved, meeting its high-precision requirements for amplitude and phase consistency across chips and across receiving channels, and ensuring better system performance.

[0051] Combination Figure 1 As shown, in some possible implementations, the calibration transmission module is located inside the main radar chip, and the main radar chip also has a calibration signal transmission channel, through which the internal calibration transmission module outputs the calibration signal.

[0052] Understandably, each radar chip has at least one transmit channel and at least one receive channel, which are used to multiply the angular resolution of the radar system based on virtual aperture technology in the operating mode.

[0053] In some possible implementations, the internal calibration transmission module is set up independently of the original transmission channel of the radar chip, and its output is directly connected to the coupling network. The calibration signal does not pass through the power amplifier of the original transmission channel of the radar chip. In this implementation, the main radar chip may have a dedicated calibration signal output port, and the internal calibration transmission module outputs the calibration signal to the coupling network through the dedicated calibration signal output port.

[0054] In other possible implementations, the calibration signal transmission channel can reuse the original transmission channel within the radar chip. The internal calibration transmission module includes components such as a baseband signal generator corresponding to the transmission channel. The generated calibration signal with preset frequency, amplitude, and phase is output to the coupling network via the transmission channel, which helps to reduce the complexity and cost of the radar system and helps to ensure the universality and scalability of the aforementioned internal self-calibration architecture.

[0055] Figure 2 This is a schematic diagram of a coupling network provided in an embodiment of this application. In some possible implementations, the coupling network includes a power distribution unit 311, a signal access element 321, and multiple signal distribution elements, which are also known as a signal distribution element group 331.

[0056] The number of signal distribution elements in signal distribution element group 331 should be greater than or equal to the number of receiving channels. Figure 2 The radar system illustrated in the diagram includes n receiving channels, denoted as RX1, RX2...RXn, and the number of signal distribution elements is equal to the number of receiving channels.

[0057] The power distribution unit 311 is used to distribute the calibration signal into multiple channels. A signal input element 321 is connected between the calibration signal transmission channel TX and the power distribution unit 311, and is used to transmit the calibration signal to the power distribution unit 311. Multiple signal distribution elements are connected between multiple output terminals of the power distribution unit 311 and each receiving channel, and are used to transmit the signals distributed by the power distribution unit 311 to each receiving channel respectively.

[0058] For example, signal access element 321 is used to access calibration signals, power distribution unit 311 is used to distribute calibration signals, and signal distribution element group 331 is used to output the distributed calibration signals to the corresponding receiving channels.

[0059] In some possible implementations, the power distribution unit 311 includes a power divider, combined with Figure 2 As shown, taking a power divider with a 1:2 specification as an example, the power distribution unit 311 includes multiple cascaded power divider stages, and the final number of branches of the power divider is not less than the total number of receiving channels n of the radar system. For example, if the radar system includes m1 radar chips, and each radar chip has m2 receiving channels, then n = m1 × m2.

[0060] The power divider in the power distribution unit 311 can be an equal-division power divider or an unequal-division power divider. The signal processing module 40 can normalize the received signal of the receiving channel according to the actual value of the calibration signal after distribution, so as to determine the amplitude and phase difference based on the same reference.

[0061] It is understandable that the power divider can also be of other specifications such as 1:3 or 1:4, and this is not limited here. In the power distribution unit 311, the number of power dividers is related to their specifications, ensuring that the final number of splits is greater than or equal to the total number of receiving channels of the radar system.

[0062] In some possible implementations, combined Figure 2 As shown, the routing design of the signal transmission path from the output port of the calibration signal transmission channel TX to the input port of any receiving channel RX can be combined with the transmission delay of the components in different transmission paths to perform signal synchronization design, so that the signal transmission time on each transmission path is equal, thereby enabling each receiving channel to receive the signal allocated by the coupling network 30 at the same time.

[0063] For example, if the number of power dividers in the transmission path corresponding to a certain receiving channel is small and the signal delay caused by the devices is small, or if the physical distance between the receiving channel and the calibration signal output channel is short and the signal transmission delay is small, the trace length on the transmission path can be increased, for example by increasing the physical length of the transmission line through serpentine routing, so that the total path transmission delay of this channel is equal to that of other channels.

[0064] In some possible implementations, such as Figure 2 As shown, both the signal access element 321 and the signal distribution element are couplers.

[0065] That is, the direct port (Dir) of each coupler is connected to the calibration signal transmission channel TX of the radar chip or the corresponding receiving channel RX, so as to ensure signal transmission between each receiving channel and the antenna when the radar system is in operation. The coupled ports (Cop) of each coupler are interconnected, for example, through the power distribution unit 311, thereby forming a calibration signal network channel for transmitting calibration signals. That is, in this calibration signal network channel, the power distributor performs multi-level distribution on the calibration signal connected to the signal access element 321, and provides it to each receiving channel respectively.

[0066] Based on the working principle of the coupler, the coupling network 30 can couple the calibration signal into the receiving channel while maintaining the normal connection structure of the radar system's radio frequency front end. This does not damage the original working system and can achieve non-radiative injection.

[0067] Or, such as Figure 3 As shown, Figure 3 This is a schematic diagram of another coupling network structure provided in an embodiment of this application. The signal distribution elements in the signal access element 322 and the signal distribution element group 332 are all radio frequency switches. The radio frequency switches are configured to: in the calibration mode, connect each receiving channel to the calibration signal transmitting channel; and in the operating mode, connect each receiving channel to its corresponding antenna.

[0068] For example, the RF switch is a single-pole double-throw switch. Its common terminal is connected to the calibration signal transmission channel TX of the radar chip or to each corresponding receiving channel RX. The first of its two output terminals is connected to the antenna, and the second output terminal is connected to the power distribution unit 312. In calibration mode, the switch connects the common terminal to the second output terminal, thereby connecting each receiving channel to the calibration signal transmission channel, achieving non-radiative injection of the calibration signal. In operating mode, the switch connects the common terminal to the first output terminal, thereby connecting each receiving channel to its corresponding antenna, and simultaneously disconnecting the connection between each receiving channel and the power distribution unit 312 in the coupling network.

[0069] Compared to Figure 2 The embodiment shown utilizes the switching of an RF switch to achieve different circuit operating states in the working mode and calibration mode, thus decoupling the circuit structures in the two modes. Specifically, it decouples the signal receiving channel based on the antenna array in the working mode from the calibration signal network channel in the calibration mode, achieving isolation between the power distribution unit 31 and the antenna array. This helps avoid the coupler allocating a portion of the antenna-received working signal to the coupling port in the working mode, which would increase the loss of useful signals. It also helps avoid echo signals generated at the coupling port that would affect signal reception, reducing insertion loss from the coupling network while improving the isolation of the coupling network from the normal communication link.

[0070] It is understood that the single-pole double-throw switch is only an example for illustration, and other radio frequency switches that can achieve switching functions are within the scope of this application.

[0071] Figure 4 This is a schematic diagram of a radar system with a three-chip cascaded architecture provided in an embodiment of this application. Figure 4 The example shown uses two transmit channels and two receive channels per radar chip. It can be understood that when a radar chip includes a larger number of transmit or receive channels, the system composition can be referenced. Figure 4 To expand upon.

[0072] In some possible implementations, the signal processing module 40 is further configured to send a calibration command to the calibration transmission module 20 in the calibration mode to control the calibration transmission module to generate the calibration signal. That is, the signal processing module 40 controls the generation of the calibration signal and acquires the corresponding radar received data, thereby realizing closed-loop operation of the calibration mode.

[0073] Combination Figure 4The radar chip includes a frequency synthesizer (SYNTH) to generate a stable, tunable local oscillator signal. Combined with the components of the calibration transmission module 20, the signal is frequency-converted by a mixer (MIX) to finally generate a calibration signal with preset frequency, amplitude, and phase. This signal is then output to the coupling network 30 through one of the transmission channels.

[0074] Taking the example that both the signal access element and the signal distribution element in the coupling network 30 are couplers, the correction signal output from the transmitting channel is input to the power distribution unit through the coupler, and after distribution, it is injected into each receiving channel through the coupler.

[0075] If the radar chip's receiving channel receives the allocated calibration signal, the signal is down-frequency processed by the mixer (MIX) within the radar chip to generate an intermediate frequency (IF) signal. The IF signal is then further amplified and subjected to anti-aliasing filtering, before being converted into radar calibration receive data via an analog-to-digital converter (ADC).

[0076] The radar calibration data received by each receiving channel is fed back to the signal processing module 40, which then processes the data to determine the compensation data for each receiving channel.

[0077] The process described above can be similarly applied by replacing the coupler with an RF switch, and will not be elaborated further here.

[0078] Figure 5A This is a schematic diagram illustrating the operation of a calibration mode provided in an embodiment of this application. Figure 5B This is a schematic diagram illustrating one operating mode provided in an embodiment of this application. Figure 5C This is a schematic diagram of a running mode switching process provided in an embodiment of this application.

[0079] like Figures 5A-5B As shown, the signal processing module 40 is located inside the host computer of the radar system. This host computer is the controller of the radar system and is used to control the operating mode of the radar system and realize the switching between calibration mode and working mode.

[0080] like Figure 5A and Figure 5C As shown, in calibration mode, the host computer controls the calibration transmission module 20 on the main radar chip in the radar chipset 10 to generate a calibration signal. This calibration signal enters the coupling network through the calibration signal transmission channel. The coupling network distributes the calibration signal and then couples it into each receiving channel of the radar chipset with a preset coupling coefficient. The coupling coefficient here can be determined according to the allocation result of the power distribution unit for each receiving channel.

[0081] Each receiving channel receives the allocated calibration signal, and the radar chip decodes the received signal to generate radar calibration received data, which is then transmitted to the signal processing module 40. The signal processing module 40 analyzes and compares the received data from each receiving channel, calculates the amplitude error and / or phase error between each receiving channel, and thus obtains the compensation data required for RF calibration, completing this round of calibration.

[0082] Understandably, in calibration mode, the above calibration process can be repeated multiple times. For example, after each calibration is completed, in response to the system operating mode being calibration mode, a calibration command is issued again to control the calibration transmission module 20 to generate a calibration signal again and repeat the above process. The signal processing module 40 can determine the compensation parameters based on multiple calibration tasks.

[0083] After that, as Figure 5B and Figure 5C As shown, after the radar system switches to the working mode, the calibration transmission module stops generating calibration signals, the host computer issues working instructions, and the radar chipset receives and transmits radar signals and performs target detection tasks according to the normal radar workflow. That is, the host computer issues control parameters corresponding to the working mode, the radar chipset 10 receives and transmits radar signals through antenna 70, and converts the received radar signals into imaging data and feeds it back to the host computer for imaging data processing.

[0084] For the radar calibration received data acquired by each receiving channel in the working mode, the host computer can perform compensation processing on the radar received data according to the compensation parameters determined in the calibration mode, and then perform imaging data processing. This can improve the amplitude and phase consistency of each receiving channel in the multi-chip cascaded radar system and improve the target angle estimation accuracy.

[0085] In some possible implementations, the radar system is configured to trigger the calibration mode under preset conditions and switch from the calibration mode to the operating mode after a preset duration.

[0086] In other words, the system can perform calibration within a specific time period through a preset program, such as starting the calibration mode at a set time, and then continuing to execute the working mode after the calibration is completed.

[0087] For example, the preset trigger conditions include at least one of the following: system power-on signal; system running time reaching a preset threshold; temperature change exceeding a set range; receiving an external calibration trigger command.

[0088] For example, when the system is powered on, it adaptively starts the calibration mode and, after a preset time, adaptively switches to the working mode to ensure the normal operation of the radar system.

[0089] Alternatively, to avoid the amplitude and phase consistency of the radar system drifting over time due to factors such as temperature changes, power fluctuations, and component aging, an adaptive calibration mode is initiated when the system operating time reaches a preset threshold or the temperature change exceeds a set range. This update the compensation data and compensates the radar received data in the operating mode based on the updated compensation data.

[0090] Alternatively, upon receiving an external calibration trigger command, the calibration mode can be initiated in response to the user-triggered calibration command.

[0091] The adaptive switching mechanism between calibration mode and operating mode is beneficial for maintaining the amplitude and phase consistency of radar system radio frequency signals in practical application scenarios.

[0092] In some possible implementations, the operating mode has a preset idle time slot during which the calibration mode is switched.

[0093] In other words, real-time calibration can be achieved during the normal operation of the radar system based on time-division multiplexing, which is beneficial for coping with changes in the working environment that occur in real time during operation and improving the real-time accuracy and reliability of the system.

[0094] For example, Figure 6A This is a timing diagram of a pre-calibration mode provided in an embodiment of this application. Figure 6B This is a timing diagram of a real-time calibration mode provided in an embodiment of this application.

[0095] To facilitate differentiation, time is divided into multiple consecutive time slots.

[0096] In pre-calibration mode, calibration mode is initiated based on preset trigger conditions. The runtime of calibration mode can be a preset value, which includes multiple time slots (e.g., ...). Figure 6A As shown in the three time slots, a calibration task (cal) is performed in each time slot. After the preset duration is reached, the system switches to the working mode, and in each subsequent time slot, the normal target detection task is performed, and the radar system transmits and receives working signals normally.

[0097] In real-time calibration mode, the calibration process can be reused at a fixed position on the radar signal frame. For example... Figure 6B As shown, within a time slot, the operating mode has a preset idle time slot, during which the control radar system operates in calibration mode. For example, combined with Figure 4 As shown, time-division multiplexing of calibration signals and radar signals is achieved through the switching of radio frequency switches in the high-speed shear coupling network, thereby realizing real-time calibration.

[0098] Figure 7This is a schematic diagram of another radar system provided in an embodiment of this application. This example illustrates a radar system comprising m cascaded radar chips.

[0099] like Figure 7 As shown, the radar system also includes an amplitude and phase compensation module 50, used to perform compensation processing on the working signals received by each receiving channel according to the compensation data in the operating mode. For example, the host computer 60 includes the aforementioned signal processing module 40 and amplitude and phase compensation module 50, and the compensation data calculated and determined by the signal processing module 40 can be transmitted to the amplitude and phase compensation module 50.

[0100] In the calibration mode, the signal processing module 40 sends a calibration command to the calibration transmission module 20 to control the calibration transmission module 20 to generate the calibration signal, and then couples the calibration signal into each receiving channel via the coupling network 30. The signal received by each receiving channel is fed back to the signal processing module 40 to determine the compensation data.

[0101] In operating mode, the amplitude and phase compensation module 50 first compensates the radar received data (i.e., the data after decoding the working signal received by each receiving channel) acquired in real time based on the compensation data, and then performs subsequent imaging data processing. The compensation data here can be an amplitude compensation coefficient or a phase compensation coefficient. After compensation, the angle measurement error caused by array asymmetry, device deviation, and temperature drift in the multi-chip cascaded structure can be reduced.

[0102] In some possible implementations, the radar system is a vehicle-mounted millimeter-wave radar system, installed on a vehicle. The signal processing module is communicatively connected to the vehicle's central control platform via an onboard communication bus.

[0103] Vehicle-mounted millimeter-wave radar systems can transmit and receive millimeter-wave electromagnetic waves in the 30GHz-300GHz frequency band, with the 77GHz band being preferred in some scenarios. By analyzing the time, frequency, and phase difference of the echo signals, the distance, speed, and angle of targets around the vehicle (such as vehicles, pedestrians, and road obstacles) can be accurately detected. Millimeter waves have strong penetrating power, effectively penetrating rain, fog, and dust, and are unaffected by adverse weather and lighting conditions. Vehicles equipped with vehicle-mounted millimeter-wave radar systems have a significant advantage in all-weather operation, which is beneficial to improving the user's driving experience.

[0104] Vehicle-mounted millimeter-wave radar systems can be widely used in driver assistance scenarios such as adaptive cruise control, blind spot monitoring, lane change assist, and rear cross-traffic alert. The radar data acquired by the signal processing module can be transmitted to the vehicle's central control platform via the vehicle's communication bus. The central control platform can also combine data from other sensors (such as cameras) to perform multi-sensor fusion and risk assessment, providing users with better perception and decision-making capabilities.

[0105] Figure 8 This is a flowchart of a radar system radio frequency self-calibration method provided in an embodiment of this application. The method includes the following steps S801 to S804: Step S801: In response to the radar system operating mode being calibration mode, control the calibration transmission module located inside at least one of the cascaded radar chips to generate a calibration signal.

[0106] Step S802: Based on the coupling network, the calibration signal is distributed to each receiving channel of the plurality of radar chips, wherein each radar chip includes at least one receiving channel.

[0107] Step S803: Determine the compensation data for each receiving channel based on the amplitude difference and / or phase difference between the received signals of the receiving channels in the calibration mode.

[0108] Step S804: In response to the radar system's operating mode being the working mode, perform compensation processing on the working signals received by each receiving channel according to the compensation data.

[0109] In some possible implementations, the method further includes: controlling the radar system to switch from the calibration mode to the operating mode in response to the continuous duration of the calibration mode reaching a preset duration; or, the operating mode having a preset idle time slot, controlling the radar system to switch to the calibration mode within the preset idle time slot.

[0110] In other words, this application constructs a highly versatile internal radio frequency self-calibration architecture in a multi-chip cascaded radar system that does not rely on external calibration. By setting up a calibration transmission module and coupling network inside the radio frequency front-end system, the calibration signal is injected into each receiving channel in a coupling manner, without relying on external calibration equipment or air interface reflection targets, and is unaffected by environmental scenes, multipath effects, and changes in target distribution.

[0111] By performing amplitude and phase compensation on the working signals received by each receiving channel of the radar system in the working mode, the amplitude and phase deviation caused by differences in device process, inconsistency of radio frequency links and temperature changes in the multi-chip cascade structure can be effectively reduced, the virtual array synthesis error can be reduced, and the problem of difficulty in ensuring the consistency of radio frequency channels under multi-chip cascade conditions can be avoided, thereby improving the angle measurement accuracy and stability of the radar system.

[0112] The aforementioned internal self-calibration architecture for radio frequency can operate stably under different usage scenarios and complex operating conditions. It can achieve unified acquisition and compensation of amplitude and / or phase errors of each receiving channel in a multi-chip cascaded structure. Furthermore, it does not limit the specific number of radar chips or the cascade method, and can be applied to multi-chip cascaded radar systems of different scales. This enhances the versatility and scalability of the aforementioned internal self-calibration architecture, which is conducive to improving the engineering availability and deployment flexibility of multi-chip cascaded radar systems and avoids the problem of repetitive design for a specific number of chips or a specific array structure.

[0113] The system can be calibrated within a specific time period through a preset program to avoid the amplitude and phase consistency of the radar system drifting over time due to conditions such as temperature changes, power fluctuations, and device aging. It can also achieve real-time calibration during operation through time-division multiplexing, thereby improving the real-time accuracy and reliability of the system.

[0114] In an exemplary embodiment, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in any of the above embodiments.

[0115] For the device embodiments and computer program product embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. Furthermore, the device embodiments described above are illustrative; the modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, i.e., they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0116] This application can be implemented by executing several computer program code flows using an electronic device. The electronic device loads the computer program into non-volatile memory and uses the processor of the electronic device to read these computer program instructions into memory for execution.

[0117] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The following is in conjunction with... Figure 9 The electronic devices described in some embodiments of this application will be explained.

[0118] Reference Figure 9 Electronic devices 900 can be mobile phones, computers, digital broadcasting terminals, messaging devices, game consoles, tablets, medical devices, fitness equipment, personal digital assistants, etc.

[0119] Device 900 may include one or more of the following components: processing component 901, memory 902, power supply component 903, multimedia component 904, audio component 905, input / output (I / O) interface 906, sensor component 907, and communication component 908.

[0120] Processing component 901 typically controls the overall operation of device 900, such as operations associated with display, telephone calls, data communication, camera operation, and recording. Processing component 901 may include one or more processors 909 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 901 may include one or more modules to facilitate interaction between processing component 901 and other components. For example, processing component 901 may include a multimedia module to facilitate interaction between multimedia component 904 and processing component 901.

[0121] Memory 902 is configured to store various types of data to support the operation of device 900. Examples of this data include instructions for any application or method operating on device 900, contact data, phonebook data, messages, pictures, videos, etc. Memory 902 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0122] Power supply component 903 provides power to various components of device 900. Power supply component 903 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to device 900.

[0123] Multimedia component 904 includes a screen that provides an output interface between the device 900 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, swipe, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 904 includes a front-facing camera and / or a rear-facing camera. When the device 900 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or the rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0124] Audio component 905 is configured to output and / or input audio signals. For example, audio component 905 includes a microphone (MIC) configured to receive external audio signals when device 900 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 902 or transmitted via communication component 908. In some embodiments, audio component 905 also includes a speaker for outputting audio signals.

[0125] Input / output (I / O) interface 906 provides an interface between processing component 901 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0126] Sensor assembly 907 includes one or more sensors for providing status assessments of various aspects of device 900. For example, sensor assembly 907 can detect the on / off state of device 900, the relative positioning of components such as the display and keypad of device 900, changes in the position of device 900 or a component of device 900, the presence or absence of user contact with device 900, the orientation or acceleration / deceleration of device 900, and temperature changes of device 900. Sensor assembly 907 may also include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 907 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 907 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0127] Communication component 908 is configured to facilitate wired or wireless communication between device 900 and other devices. Device 900 can access wireless networks based on communication standards, such as WiFi, 2G or 3G, 4G or 5G, or combinations thereof. In one exemplary embodiment, communication component 908 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 908 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0128] In an exemplary embodiment, device 900 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components.

[0129] In an exemplary embodiment, this application also provides a vehicle. Figure 10 This is a schematic diagram of a vehicle structure provided in an embodiment of this application. The vehicle includes a central control platform and a radar system 1001 as described in any of the above embodiments. The signal processing module 40 of the radar system is communicatively connected to the central control platform 1002 via an onboard communication bus. For example, the central control platform 1002 may include the aforementioned electronic device 900. In application scenarios such as assisted driving, based on the radio frequency self-calibration mechanism of the radar system, it can provide users with better perception and decision-making capabilities.

[0130] In an exemplary embodiment, this application also provides a non-transitory computer-readable storage medium including instructions, such as a memory 902 including instructions that can be executed by a processor 909 of a device 900. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, or optical data storage device, etc.

Claims

1. A radar system, characterized in that, include: Multiple cascaded radar chips, each radar chip including at least one receiving channel; A calibration transmission module, disposed within at least one of the plurality of radar chips, is used to generate a calibration signal in the calibration mode of the radar system. A coupling network, connected between the internal calibration transmission module and each receiving channel of the plurality of radar chips, is used to distribute the calibration signal to each receiving channel; The signal processing module is used to determine compensation data for each receiving channel based on the amplitude difference and / or phase difference between the received signals of the receiving channels in the calibration mode. The compensation data is used to compensate the signals received by each receiving channel in the operating mode of the radar system.

2. The radar system according to claim 1, characterized in that, The plurality of radar chips includes a main radar chip and at least one slave radar chip; The calibration transmission module is located inside the main radar chip, which has a calibration signal transmission channel. The internal calibration transmission module outputs the calibration signal through the calibration signal transmission channel.

3. The radar system according to claim 2, characterized in that, The coupling network includes: A power distribution unit is used to distribute the calibration signal into multiple channels; A signal input element is connected between the calibration signal transmission channel and the power distribution unit, and is used to transmit the calibration signal to the power distribution unit; Multiple signal distribution elements are connected between multiple output terminals of the power distribution unit and each receiving channel, for transmitting the signals distributed by the power distribution unit to each receiving channel respectively.

4. The radar system according to claim 3, characterized in that, Both the signal access element and the signal distribution element are couplers; or Both the signal access element and the signal distribution element are radio frequency switches; The radio frequency switch is configured to: in the calibration mode, connect each receiving channel to the calibration signal transmitting channel respectively; and in the operating mode, connect each receiving channel to the corresponding antenna respectively.

5. The radar system according to claim 1, characterized in that, The radar system is configured to trigger the calibration mode under preset conditions, and switch from the calibration mode to the operating mode after a preset duration; or... The working mode has a preset idle time slot, during which the calibration mode is switched.

6. The radar system according to claim 5, characterized in that, The preset triggering conditions include at least one of the following: System power-on signal; The system runtime has reached a preset threshold; Temperature change exceeds the set range; Received external calibration trigger command.

7. The radar system according to claim 1, characterized in that, The signal processing module is further configured to, in the calibration mode, send a calibration command to the calibration transmission module to control the calibration transmission module to generate the calibration signal; The radar system also includes an amplitude and phase compensation module, which is used to perform compensation processing on the working signals received by each receiving channel according to the compensation data in the working mode.

8. The radar system according to claim 1, characterized in that, The radar system is a vehicle-mounted millimeter-wave radar system, installed on the vehicle; The signal processing module is connected to the vehicle's central control platform via an onboard communication bus.

9. A method for radio frequency self-calibration of a radar system, characterized in that, include: In response to the radar system operating mode being calibration mode, a calibration transmission module located inside at least one of the cascaded radar chips is controlled to generate a calibration signal. Based on the coupling network, the calibration signal is distributed to each receiving channel of the plurality of radar chips, wherein each radar chip includes at least one receiving channel. Based on the amplitude and / or phase differences between the received signals of the receiving channels in the calibration mode, compensation data for each receiving channel is determined. In response to the radar system's operating mode being the working mode, compensation processing is performed on the working signals received by each receiving channel based on the compensation data.

10. The method according to claim 9, characterized in that, The method further includes: In response to the calibration mode lasting for a preset duration, the radar system is controlled to switch from the calibration mode to the operating mode; or, The operating mode has a preset idle time slot, and the radar system is controlled to switch to the calibration mode within the preset idle time slot.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 9-10.

12. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method as described in any one of claims 9-10.

13. A vehicle, characterized in that, include: Central control platform; The radar system as described in any one of claims 1-8, wherein the signal processing module in the radar system is communicatively connected to the central control platform via an onboard communication bus.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 9-10.

Images