Target distance simulation device and method

Abstract

The purpose of this disclosure is to provide a target distance simulation device that can set the amount of change in attenuation, delay, Doppler amount, etc., at set intervals corresponding to the radar update cycle. [Solution] The target distance simulation device 2 is a target distance simulation device that simulates the target distance for a frequency modulation radar device 1 that measures the target distance between a target object and the device itself, and comprises a transmission wave input unit 21 to which the transmission wave of the frequency modulation radar device 1 is input, and a target distance processing unit 20 (frequency shift unit 22, delay processing unit 23, attenuation processing unit 24) that adds a predetermined amount of change corresponding to the target distance to the transmission wave according to the update cycle of the frequency modulation radar device 1.

Description

Technical Field

[0001] The present disclosure relates to a target distance simulation device that simulates a target distance for a radar device that measures a target distance between a target and the own device.

Background Art

[0002] Conventionally, a target distance simulation device that generates a high-frequency signal simulating a received radio wave in a real environment for a transmitted radio wave emitted by a radar device for performance confirmation of a frequency-modulated radar device such as a radio altimeter is known.

[0003] For example, Patent Document 1 discloses a target distance simulation device in which a target distance control unit reads stored data from a target storage device and sets each part of the device.

[0004] Here, in order to accurately reproduce the distance change of an aircraft equipped with a radar device, it is necessary to set the attenuation amount, delay amount, Doppler amount, etc. at a cycle equal to or faster than the update cycle of the radar. In other words, when setting each change amount at a slow cycle for a scenario where the aircraft moves fast, an accurate simulation cannot be performed. On the other hand, when setting each change amount at a fast cycle for a scenario where the aircraft moves slowly, unnecessary settings are continued. That is, when not considering the update cycle of the radar when setting each change amount, the target distances of radars with different update cycles cannot be simulated with the same device.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, the present disclosure aims to provide a target distance simulation device and method that can set the amount of change in attenuation, delay, Doppler amount, etc., at set intervals corresponding to the radar update cycle.

[0007] To achieve the above objective, the target distance simulation device and method of this disclosure employ a method of adding a predetermined amount of change corresponding to the target distance to the transmitted wave in accordance with the update cycle of the radar device.

[0008] Specifically, the target distance simulation device of this disclosure is A target distance simulation device for a radar device that measures the target distance between a target object and its own device, The radar device includes a transmission wave input section into which the transmission wave is input, A target distance processing unit that adds a predetermined amount of change corresponding to the target distance to the transmitted wave in accordance with the update cycle of the radar device, It is equipped with.

[0009] In the above configuration, The update cycle corresponds to the speed of the aircraft on which the radar device is installed. The system may further include a target distance control unit that sets the target distance processing unit at a predetermined set interval based on speed information calculated from the update cycle.

[0010] Furthermore, the target distance control unit may set the target distance processing unit at a predetermined set period based on a clock from a clock generation unit that generates a clock at a predetermined timing.

[0011] Furthermore, the target distance control unit, The system includes a buffer in which setting data for the target distance processing unit is stored, The setting data may be stored in the buffer at a faster rate than the predetermined setting cycle.

[0012] Furthermore, the target distance control unit, The setting data may be read from the buffer at a speed of the predetermined setting period.

[0013] Furthermore, the target distance control unit, The radar device may receive the setting data from the information processing unit that generates the setting data based on user input at a communication speed corresponding to the update cycle of the radar device.

[0014] Furthermore, the target distance control unit, If the buffer usage capacity exceeds a predetermined first threshold, a setting stop command signal is sent to the information processing unit to stop the transmission of the setting data. If the buffer usage capacity falls below a predetermined second threshold, a setting restart command signal is sent to the information processing unit to restart the transmission of the setting data. The first threshold and the second threshold may be determined according to the update cycle.

[0015] Furthermore, the clock generation unit may be a crystal oscillator.

[0016] Furthermore, the target distance processing unit includes a frequency shifting unit that adds a frequency shift to the transmitted wave, a delay processing unit that adds a delay amount to the transmitted wave, and an attenuation processing unit that adds an attenuation amount to the transmitted wave. The target distance control unit may include a frequency shift setting unit for setting the frequency shift unit, a delay setting unit for setting the delay processing unit, and an attenuation setting unit for setting the attenuation processing unit.

[0017] Furthermore, the target distance simulation method described herein is A target distance simulation method performed by a target distance simulation device that simulates the target distance for a radar device that measures the target distance between a target object and its own device, The radar device receives the transmitted wave, A predetermined amount of change is added to the transmitted wave according to the target distance, in accordance with the update cycle of the radar device. Target distance simulation method.

[0018] Furthermore, the above disclosures can be combined as much as possible. [Effect of the Invention]

[0019] According to the present disclosure, the amounts of change such as the attenuation amount, the delay amount, the Doppler amount, etc. can be set at set intervals according to the update cycle of the radar. [Brief Description of the Drawings]

[0020] [Figure 1] It is a diagram for explaining the simulation of received radio waves. [Figure 2] It is a block diagram for explaining the configuration of a target distance simulation system according to an embodiment of the present disclosure. [Figure 3] It is a flowchart for explaining the outline of the processing of the target distance simulation device. [Figure 4] It is a flowchart for explaining the initial setting process. [Figure 5] It is a diagram for explaining the data exchange in the initial setting process. [Figure 6] It is a flowchart for explaining the continuous setting process. [Figure 7] It is a diagram for explaining the data exchange in the continuous setting process. [Figure 8] It is a diagram for explaining the threshold value of the buffer. [Figure 9] It is a diagram for explaining the sequence of the setting process for the target distance control unit. [Figure 10] It is a diagram for explaining the sequence of the setting data storage process in the buffer and the setting process for each setting unit. [Figure 11] It is a block diagram for explaining the outline of the related target distance simulation system. [Figure 12] It is a diagram for explaining the effect of the present disclosure while comparing with related technologies. [Figure 13] It is a block diagram for explaining the configuration of a target distance simulation system according to the second embodiment of the present disclosure. [Figure 14] It is a flowchart for explaining the processing of the target distance simulation device according to the second embodiment of the present disclosure. [Figure 15]This is a block diagram illustrating the configuration of a target distance simulation system according to a third embodiment of the present disclosure. [Figure 16] This diagram illustrates an example of a database. [Modes for carrying out the invention]

[0021] Embodiments of this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the embodiments shown below. These examples are illustrative, and this disclosure can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. In this specification and in the drawings, components with the same reference numerals refer to the same components.

[0022] [System Configuration] The configuration of the target distance simulation system according to the embodiment of this disclosure will be described with reference to Figures 1 and 2. As shown in Figure 1, the target distance simulation system comprises a frequency modulation radar device 1 and a target distance simulation device 2.

[0023] Figure 1(A) illustrates measurements in a real environment using the frequency modulation radar device 1. The radio waves transmitted from the frequency modulation radar device 1 are reflected by the Earth's surface, the sea surface, etc. The frequency modulation radar receives the reflected radio waves as received radio waves. The received radio waves are subject to attenuation, delay, Doppler, etc., due to spatial propagation, etc.

[0024] Figure 1(B) illustrates the simulation of received radio waves in a real environment using the target distance simulation device 2. In this embodiment, the target distance simulation device 2 is used to reproduce (simulate) received radio waves in a real environment in order to perform performance tests and operational verification at ground facilities, etc., without actually transmitting radio waves from the frequency modulation radar device 1. Specifically, the frequency modulation radar device 1 sends a high-frequency signal to the target distance simulation device 2. The target distance simulation device 2 adds attenuation, delay, Doppler amount, etc., according to distance, etc., to the high-frequency signal from the frequency modulation radar device 1 to reproduce the real environment.

[0025] As shown in Figure 2, the frequency modulation radar device 1 mainly comprises a transmit wave output unit 11, a transmit wave generation unit 12, a transmit / receive correlation unit 13, and a receive wave input unit 14.

[0026] The transmitting wave output unit 11 is configured to send a high-frequency signal (transmitting signal) to the target distance simulation device 2. The receiving wave input unit 14 is configured to receive the high-frequency signal (receiving signal) transmitted from the target distance simulation device 2. The transmitting / receiving correlation unit 13 calculates the correlation between the transmitting wave and the receiving wave in the device 1 and calculates the beat frequency between the transmitting wave and the receiving wave in the device 1. The transmitting wave generation unit 12 controls the modulation period of the frequency of the transmitting wave in the device 1 and generates the transmitting wave in the device 1. Here, the method of controlling the modulation period of the frequency of the transmitting wave by the transmitting wave generation unit 12 is arbitrary. For example, servo control similar to that described in Patent Document 1 may be performed.

[0027] The target distance simulation device 2 mainly comprises a target distance processing unit 20, a transmit wave input unit 21, a frequency shift unit 22, a delay processing unit 23, an attenuation processing unit 24, a receive wave output unit 25, a target distance control unit 26, a clock generation unit 27, and an information processing unit 29. The target distance processing unit 20 comprises a frequency shift unit 22, a delay processing unit 23, and an attenuation processing unit 24. However, the target distance processing unit 20 may be configured to include at least one of the frequency shift unit 22, the delay processing unit 23, and the attenuation processing unit 24.

[0028] Specifically, the target distance simulation device 2 is: A target distance simulation device for frequency-modulated radar device 1 that measures the target distance between a target object and its own device, The frequency modulation radar device 1 has a transmission wave input section 21 to which the transmission wave is input, A target distance processing unit 20 (frequency shifting unit 22, delay processing unit 23, and / or attenuation processing unit 24) adds a predetermined amount of change to the transmitted wave according to the target distance, A target distance control unit 26 sets a target distance processing unit at a predetermined set period based on a clock from a clock generation unit 27 that generates a clock at a predetermined timing, It is equipped with.

[0029] The transmission wave input unit 21 receives a high-frequency signal from the frequency modulation radar device 1. The transmission wave input unit 21 outputs the high-frequency signal to the frequency shift unit 22.

[0030] The frequency shifting unit 22 comprises a mixer 221, a filter 222, and a signal generation unit 223, and is configured to add an arbitrary amount of Doppler (frequency shift) to the high-frequency signal. The mixer 221 performs frequency conversion by multiplying the high-frequency signal from the transmit wave input unit 21 with the frequency of the signal oscillated by the signal generation unit 223. The filter 222 is configured to allow signals of a desired frequency to pass through. For example, the filter 222 may be a band-pass filter (BPF) or a low-pass filter (LPF).

[0031] The signal generation unit 223 can be any configuration that generates a signal of a desired frequency. In this embodiment, a Direct Digital Synthesizer (DDS) capable of handling high-speed frequency changes is used as the signal generation unit 223. In this embodiment, the amplitude of the DDS is configured to be adjustable. The signal generation unit 223 may also be a Direct Memory Access (DAC).

[0032] The delay processing unit 23 is configured to add an arbitrary amount of delay to the high-frequency signal by selecting a delay line. The attenuation processing unit 24 is a variable ATT (Attenuator), and is configured to add an arbitrary amount of attenuation to the high-frequency signal depending on the setting value of the ATT.

[0033] The receiving wave output unit 25 outputs a high-frequency signal as a received signal, which simulates the target distance (assumed altitude) by adding Doppler, delay, and attenuation. This received signal is input to the receiving wave input unit 14 of the frequency modulation radar device 1.

[0034] The target distance control unit 26 is, for example, an FPGA (Field Programmable Gate Array) and mainly comprises a target distance setting unit 31, a target distance setting data processing unit 32, a frequency generation unit 33, and a serial communication implementation unit 34. The target distance setting unit 31 comprises a frequency shift setting unit 311, a delay setting unit 312, an attenuation setting unit 313, and a setting processing unit 314. The target distance setting data processing unit 32 comprises a buffer storage data processing unit 321, a buffer usage capacity confirmation unit 322, and a buffer 323. An information processing unit (PC) 28 is provided outside the target distance control unit 26. Although Figure 2 shows an example in which the information processing unit 28 is provided inside the target distance simulation device 2, the information processing unit 28 may be provided outside the target distance simulation device 2.

[0035] In this embodiment, the target distance control unit 26 precisely sets the setting timing of the Doppler amount of the frequency shift unit 22, the delay amount of the delay processing unit 23, and the attenuation amount of the attenuation processing unit 24 according to the desired setting period. In other words, in this embodiment, the target distance control unit 26 is configured to set the frequency shift unit 22, the delay processing unit 23, and the attenuation processing unit 24 at equal intervals with respect to time.

[0036] Specifically, the target distance setting unit 31 includes a frequency shift setting unit 311 corresponding to the frequency shift unit 22, a delay setting unit 312 corresponding to the delay processing unit 23, and an attenuation setting unit 313 corresponding to the attenuation processing unit 24. In the following description, the frequency shift setting unit 311, the delay setting unit 312, and the attenuation setting unit 313 may be collectively referred to as "each setting unit." Also, the frequency shift unit 22, the delay processing unit 23, and the attenuation processing unit 24 may be collectively referred to as "each block."

[0037] Furthermore, the target distance setting unit 31 includes a setting processing unit 314 common to all setting units. The setting processing unit 314 reads setting data, including information on frequency shift amount, delay amount, and attenuation amount, from the buffer 323 at a speed (period) greater than or equal to the setting period of each setting unit. However, the speed at which the setting processing unit 314 reads the setting data from the buffer 323 is less than the speed at which the setting data is stored in the buffer 323. Specifically, the setting processing unit 314 may read the setting data from the buffer 323 at the same speed as the setting period of each setting unit. In the following explanation, we will assume that the setting processing unit 314 reads the setting data from the buffer 323 at the same speed as the setting period of each setting unit. The generation of setting data will be described later. Specifically, the setting processing unit 314 operates using the setting timing frequency generated by the frequency generation unit 33 based on the reference clock of the clock generation unit 27 of the target distance control unit 26. The setting processing unit 314 distributes and outputs the setting data to each setting unit. Each setting unit sets the frequency shift unit 22, delay processing unit 23, and attenuation processing unit 24 at equal intervals (at a constant period) based on the setting data from the setting processing unit 314. While each setting unit is processing, each block continues to process, and the received signal is always output from the receiving wave output unit 25.

[0038] In this embodiment, a temperature-compensated crystal oscillator (TCXO) is used as the clock generation unit 27, but other crystal oscillators such as a simple packaged crystal oscillator (SPXO), an oven-controlled crystal oscillator (OCXO), or a voltage-controlled crystal oscillator (VCXO) may also be used. In this embodiment, a phase-locked loop (PLL) is used as the frequency generation unit 33. In this embodiment, an example is shown in which the clock generation unit 27 is provided inside the target distance simulation device 2, but the clock generation unit 27 may be provided outside the target distance simulation device 2.

[0039] In this embodiment, the settings of each setting unit are not affected by FPGA settings or serial communication accuracy. Then, the target distance setting unit 31 adjusts the setting intervals for each block (frequency shift unit 22, delay processing unit 23, and attenuation processing unit 24) based on the movement speed (assumed speed) included in the scenario data (altitude information on the time axis) input by the user to the information processing unit 28.

[0040] The setting interval (corresponding to the assumed speed) may be fixed within the same operation. In this case, it may be changed when the device is not operating, or a fixed setting interval may be used for the device. Also, a fixed value may be set for low-speed movement. Note that the setting interval only needs to correspond to the assumed speed, and it may be faster than the update cycle. For example, the setting interval may be determined by the cycle of a high-speed PLL.

[0041] Alternatively, the target distance setting unit 31 may temporarily store the setting data for each block read from the buffer 323 and set each block according to a setting interval corresponding to the update cycle (assumed speed) of the frequency modulation radar device 1.

[0042] The target distance setting data processing unit 32 is configured to store the setting data acquired from the information processing unit 28 in the buffer 323 using the buffer storage data processing unit 321. Specifically, the buffer storage data processing unit 321 acquires the setting data via serial communication by the serial communication implementation unit 34. In this way, the buffer 323 stores the setting data for each setting unit.

[0043] The buffer usage capacity confirmation unit 322 checks the amount of data (setting data) accumulating in the buffer 323. Based on this, the buffer usage capacity confirmation unit 322 sends a setting stop / restart command signal to the information processing unit 28 via serial communication by the serial communication implementation unit 34, according to the amount of data accumulating in the buffer 323. Here, the "setting stop command signal" is a signal to stop the transmission of setting data from the information processing unit 28 to the target distance control unit 26. The "setting restart command signal" is a signal to restart the transmission of setting data from the information processing unit 28 to the target distance control unit 26.

[0044] The information processing unit 28 includes a target distance setting data generation unit 282 and a serial communication implementation unit 281.

[0045] The target distance setting data generation unit 282 is configured to allow the user to input scenario data (altitude information on the time axis) at any time. For example, it may be configured to allow the user to input scenario data using any input device (such as a keyboard) provided in the information processing unit. In this embodiment, the scenario for simulating the target distance can be changed immediately at any time the user desires. The scenario data may also include the type of radar.

[0046] The target distance setting data generation unit 282 generates setting data including frequency shift amount, delay amount, and attenuation amount information from the scenario data input by the user. However, the scope of this disclosure is not limited to cases where the scenario data is input at any time the user chooses. Setting data may also be generated based on scenario data stored in the storage unit of the information processing unit 28.

[0047] The serial communication unit 281 serially transmits the setting data generated by the target distance setting data generation unit 282 to the target distance control unit 26. Specifically, it serially transmits the data using RS (Recommended Standard) 422 or the like at a faster frequency than the setting interval (setting period) of the target distance control unit 26. The serial communication unit 281 also stops and restarts transmission based on a command signal (setting stop / restart command signal) from the target distance control unit 26.

[0048] [effect] The effects of the target distance simulation system according to the embodiment of this disclosure will be explained with reference to Figures 11 and 12. Figure 11 shows the relevant target distance simulation system. Figure 12(A) shows the setting interval of the set value by the target distance simulation system according to this embodiment. Figure 12(B) shows the setting interval of the set value by the relevant target distance simulation system.

[0049] In Figure 11, the reference numerals for the configuration corresponding to the configuration of this embodiment are indicated by adding "A" to the reference numerals for the configuration of this embodiment. In particular, the related target distance simulation system employs a PLL as the signal generation unit 223A within the frequency shift unit 22A. Furthermore, in the related target distance simulation system, each setting unit sets the frequency shift unit 22A, the delay processing unit 23A, and the attenuation processing unit 24 according to the application clock of the information processing unit 28A. In other words, in the related target distance simulation system, each time the target distance control unit 26A receives setting data from the information processing unit 28A, it performs the setting of the frequency shift unit 22A, the delay processing unit 23A, and the attenuation processing unit 24A.

[0050] In the related target distance simulation system, the frequency setting time is not considered in the signal generation unit 223A. Specifically, when a PLL circuit is provided in the frequency shift unit to change the frequency, the lock time may differ depending on the set frequency, and if the frequency is changed finely depending on the scenario, it may not be possible to set the frequency at an accurate interval.

[0051] This is also true when using measuring instruments such as RF (Radio Frequency) signal generators as the signal generation unit 223A, as it may not be possible to accurately set the desired frequency. This is because the frequency may shift due to settings of the PLL inside the SG (Signal Generator), switching of filters inside the SG, etc.

[0052] In contrast, in this embodiment, as described above, the above-mentioned problems are addressed by employing a DDS capable of handling high-speed frequency changes as the signal generation unit 223. This reduces the number of components and adjustment costs compared to the case of a PLL.

[0053] However, even if the signal generation unit is a DDS or DAC capable of handling high-speed frequency changes, setting the frequency shift unit, delay unit, and attenuation unit at the same time as receiving commands from the information processing unit will cause discrepancies in the setting intervals, making accurate simulation impossible. This is thought to be due to the instability of the serial communication between the information processing unit 28A and the target distance control unit 26A. In other words, it is due to the inaccuracy of the PC application's clock. However, the relevant target distance simulation system does not have a mechanism to control the setting timing.

[0054] Here, in order to accurately reproduce the distance change of an aircraft equipped with a radar device, it is necessary to accurately set the attenuation amount, delay amount, and Doppler amount according to the desired set period. However, in the relevant target distance simulation system, the timing of setting the attenuation amount, delay amount, and Doppler amount was not taken into consideration, and the accuracy of the settings was not guaranteed. Specifically, as shown in Figure 12(B), if the setting interval is incorrect (not equal), it is not possible to accurately reproduce the change in target distance (velocity).

[0055] Furthermore, regarding the setting update cycle, if the setting update is not performed faster than the update cycle (expected speed) of the frequency modulation radar device 1, the inspection cannot be performed correctly. Also, since the frequency modulation radar device 1 acquires and outputs data at a fixed interval, the setting update must be performed at a faster or similar interval.

[0056] Therefore, in this embodiment, accurate equal-interval settings are achieved by using a clock generation unit (crystal oscillator) 27, which is more accurate than the application clock of the information processing unit 28, to control the timing of the target distance control unit 26 using the setting data stored in the buffer 323. Specifically, the buffer 323 stores the setting data at a faster period than the setting interval for each setting unit, and the setting processing unit 314 reads the setting data from the buffer 323 at the same period as the setting interval for each setting unit.

[0057] [Overview of the target distance simulation device's processing] Referring to Figure 3, we will now explain the general process performed by the target distance simulation device 2.

[0058] In step S11, scenario data is input to the information processing unit 28. For example, a user can input scenario data at any time using any input device.

[0059] In step S12, the target distance setting data generation unit 282 of the information processing unit 28 generates setting data including information on frequency shift amount, delay amount, and attenuation amount from the scenario data input by the user. Subsequently, the information processing unit 28 performs the initial setting process and continuous setting process, which will be described later, in cooperation with the target distance control unit 26.

[0060] In step S15, the target distance control unit 26 sets the frequency to be used for setting. Specifically, the target distance control unit 26 sets the frequency generation unit 33.

[0061] In step S16, the target distance control unit 26 checks whether a frequency has been output. Specifically, the target distance control unit 26 checks whether the lock signal of the PLL inside the frequency generation unit 33 has been output. If it is confirmed that a frequency has been output (step S16: Yes), the target distance control unit 26 performs the initial setting process and continuous setting process, which will be described later, in cooperation with the information processing unit 28. On the other hand, if it is not confirmed that a frequency has been output (step S16: No), the target distance control unit 26 issues an error notification.

[0062] In this embodiment, the initial setup process and the continuous setup process are separated, thereby reducing the amount of communication required for the continuous setup process.

[0063] [Initial setup process] The initial setup process will be explained with reference to Figures 4 and 5. Figure 4 is a flowchart of the initial setup process. Figure 5 is a diagram illustrating the data exchange during the initial setup process. The following explanation will primarily be based on the flowchart in Figure 4, with reference to Figure 5 as needed.

[0064] In the initial setup process, it is confirmed whether communication is possible between the target distance control unit 26 and the information processing unit 28, and the time-independent elements are set in each block in advance. Examples of time-independent elements include the amplitude of the DDS in the frequency shift unit 22 and the time-independent setting values ​​of the ATT in the attenuation processing unit.

[0065] In step S21, the information processing unit 28 transmits initial setting data to the target distance control unit 26 in a single transmission. Specifically, the serial communication implementation unit 281 of the information processing unit 28 transmits setting data to the target distance control unit 26 in a single transmission, including information such as the amplitude of the DDS in the frequency shift unit 22 and the time-unchanging settings of the ATT in the attenuation processing unit. In Figure 5, the transmission of initial setting data from the information processing unit 28 to the target distance control unit 26 is indicated by the arrow labeled "(1) Initial setting data".

[0066] In step S22, when the serial communication execution unit 34 of the target distance control unit 26 receives setting data from the serial communication execution unit 281, it transmits the received setting data to the loopback information processing unit 28. In Figure 5, the transmission of the loopback signal from the serial communication execution unit 34 to the serial communication execution unit 281 is indicated by the arrow labeled "(2) Data loopback".

[0067] Furthermore, in step S22, the target distance control unit 26 processes the received setting data and performs initial settings on the frequency shift unit 22 and the attenuation processing unit 24. In Figure 5, the processing flow of the initial setting data is indicated by the arrow labeled "(3) Initial Settings".

[0068] In step S23, the information processing unit 28 determines whether the loopback signal was received successfully. If the loopback signal is received successfully (step S23: Yes), the process proceeds to the continuous setting process. On the other hand, if the information processing unit 28 does not receive the loopback signal within the specified time, or if the content of the loopback signal differs from the content of the transmitted signal (step S23: No), it issues an error notification. Here, if the loopback signal is not received within the specified time, this includes cases where the signal itself is not received, or where a signal of a different format than expected is received.

[0069] [Continuous setting process] The continuous setting process will be explained with reference to Figures 6 through 8. Figure 6 is a flowchart of the continuous setting process. Figure 7 is a diagram illustrating the data exchange in the continuous setting process. Figure 8 is a diagram illustrating the buffer threshold. The following explanation will primarily be based on the flowchart in Figure 6, with reference to Figures 7 and 8 as appropriate.

[0070] In the continuous setting process, time-varying elements are set continuously. Examples of time-varying elements include the frequency of the DDS in the frequency shift section 22, the selection of the delay line in the delay processing section 23 corresponding to the delay amount, and the setting value of the ATT in the attenuation processing section 24 corresponding to the spatial attenuation amount.

[0071] In step S31, the information processing unit 28 continuously transmits setting data to the target distance control unit 26. Specifically, the information processing unit 28 continuously transmits data at a faster frequency than the equally spaced setting cycles of the setting processing unit 314 and each setting unit. In Figure 7, the arrow labeled "(1) Continuously transmit setting data" shows how the information processing unit 28 continuously transmits setting data at a faster frequency than the setting cycles of each setting unit.

[0072] In step S32, the buffer storage data processing unit 321 of the target distance setting data processing unit 32 stores the setting data in the buffer 323 for each frame. This process is performed based on the buffer clock supplied from the frequency generation unit 33. This process is also performed each time the information processing unit 28 receives setting data for each frame. In other words, this process is performed in parallel with the process in step S31. In Figure 7, the arrow labeled "(2) Store setting data in buffer" shows how the buffer storage data processing unit 321 stores the setting data in the buffer 323.

[0073] In step S33, the setting processing unit 314 of the target distance control unit 26 reads setting data from the buffer 323 as long as data exists in the buffer 323. This process is performed based on the setting timing clock supplied from the frequency generation unit 33. In Figure 7, the arrow labeled "(3) Read setting data at the same period as the setting period of each setting unit" shows how the setting processing unit 314 reads setting data from the buffer 323.

[0074] Furthermore, in step S33, each setting unit (frequency shift setting unit 311, delay setting unit 312, attenuation setting unit 313) executes setting processing for each block (frequency shift unit 22, delay processing unit 23, attenuation processing unit 24) based on the setting data read from the buffer 323 by the setting processing unit 314. In particular, in this embodiment, each setting unit sets each block at equal intervals. This processing is executed based on the setting timing clock supplied from the frequency generation unit 33. In Figure 7, the arrow labeled "(4) Setting at equal intervals" shows how each setting unit sets each block at equal intervals.

[0075] As explained above, the setting interval (setting period) for each setting unit is determined by the assumed speed of the aircraft on which the frequency modulation radar device 1 is installed. Furthermore, the process in step S33 is executed in parallel with other processes in the continuous setting process.

[0076] In the continuous setting process, buffer 323 performs processing according to the buffer's usage capacity to suppress overflow. Specifically, as shown in Figure 8, an upper threshold A and a lower threshold B are set for buffer 323. Then, each threshold is compared with the usage capacity and predetermined processing is performed.

[0077] Specifically, (i) when the amount of data stored in buffer 323 exceeds threshold A (or is greater than or equal to threshold A), the target distance control unit 26 sends a setting stop command signal to the information processing unit 28 to stop the transmission of setting data, and (ii) after the transmission of setting data has stopped, when the amount of data in buffer 323 falls below threshold B (or is less than or equal to threshold B), the target distance control unit 26 sends a setting restart command signal to the information processing unit 28 to restart the transmission of setting data.

[0078] Here, the maximum storage capacity of buffer 323 is, for example, approximately 32 bits × 256 words. This maximum storage capacity is determined based on the assumed maximum speed of the onboard radar.

[0079] Furthermore, threshold A is, for example, about 200 words. Threshold A is set as a value that, if exceeded, may cause an overflow. Threshold A is determined based on the assumed maximum speed of the onboard radar. Threshold A may also be set with a margin from the maximum storage capacity of the buffer memory. Threshold A is an example of the "first threshold" in this disclosure.

[0080] Furthermore, threshold A is, for example, about 50 words. Threshold B is set as a value below which setting at equally spaced timings may become impossible. Threshold B is determined based on the assumed maximum speed of the onboard radar. Threshold B may be set with a margin above the lower limit of the buffer memory. Threshold B is an example of the "second threshold" in this disclosure.

[0081] Return to Figure 6. In step S34, the buffer usage capacity confirmation unit 322 of the target distance setting data processing unit 32 checks the usage capacity of buffer 323. In Figure 7, the arrow labeled "(5) Usage capacity confirmation" shows how the buffer usage capacity confirmation unit 322 checks the usage capacity of buffer 323.

[0082] Furthermore, in step S34, the buffer usage capacity confirmation unit 322 compares the usage capacity of buffer 323 with the upper threshold A. If the usage capacity of buffer 323 exceeds threshold A (step S34: Yes), the buffer usage capacity confirmation unit 322 sends a continuous setting stop command signal to the information processing unit 28 via the serial communication implementation unit 34. This process is executed based on the buffer clock generated by the frequency generation unit 33. Also, while this process is being executed, the setting process for each block by each setting unit continues. In Figure 7, the arrow labeled "(6) Command signal" shows how the command signal is sent according to the threshold.

[0083] In step S35, the information processing unit 28, upon receiving the continuous setting stop command signal, stops transmitting the setting data.

[0084] In step S34, if the used capacity of buffer 323 does not exceed threshold A (step S34: No), in step S36, the buffer used capacity confirmation unit 322 compares the used capacity of buffer 323 with the lower threshold B. If the used capacity of buffer 323 is below threshold B (step S36: No), the buffer used capacity confirmation unit 322 sends a continuous setting restart command signal to the information processing unit 28 via the serial communication implementation unit 34. This process is executed based on the buffer clock generated by the frequency generation unit 33. Furthermore, while this process is being executed, the setting process for each block by each setting unit continues.

[0085] In step S37, the information processing unit 28, having received the continuous setting start command signal, resumes transmitting the setting data.

[0086] In step S36, if the used capacity of buffer 323 is not below threshold B, the buffer used capacity confirmation unit 322 waits for a certain period of time in step S38 and repeats the processing in steps S34 and S36.

[0087] Furthermore, if the target distance control unit 26 does not receive setting data for a certain period of time, it may temporarily terminate the operation of storing the setting data in the buffer 323. Also, if the buffer 323 becomes empty, each setting unit may temporarily terminate the operation of setting each block.

[0088] In step S39, the information processing unit 28 determines whether all of the setting data related to the scenario entered by the user has been transmitted. If the information processing unit 28 determines that all of the setting data related to the scenario has been transmitted, the continuous setting process ends. On the other hand, if the information processing unit 28 determines that all of the setting data related to the scenario has not been transmitted, the process from S31 onwards is repeated.

[0089] As described above, the information processing unit 28 temporarily stops the transmission of setting data after receiving the continuous setting stop command signal. Subsequently, the information processing unit 28 resumes the transmission of setting data upon receiving the continuous setting restart command signal.

[0090] The scope of this disclosure is not limited to comparing the buffer's used capacity with a threshold, but may also be configured to compare the buffer's remaining capacity with a threshold.

[0091] [Processing Sequence] Referring to Figures 9 and 10, the sequence of various processes during the continuous setting process will be explained in relation to the flowchart described above.

[0092] Figure 9 shows the sequence of setting data transmission processing to the target distance control unit 26 in relation to the processing of the information processing unit 28. In step S41, the serial communication implementer 281 of the information processing unit 28 starts transmitting setting data. Thereafter, the information processing unit 28 continues to perform the setting data transmission processing until it receives a continuous setting stop command signal from the target distance control unit 26. If the information processing unit 28 receives a continuous setting stop command signal (step S35), it stops the setting data transmission processing in step S42. Thereafter, the information processing unit 28 stops the setting data transmission processing until it receives a continuous setting restart command signal from the target distance control unit 26.

[0093] When the information processing unit 28 receives a continuous setting restart command signal (step S37), it restarts the setting data transmission process in step S43. Thereafter, the information processing unit 28 continues the setting data transmission process. In step S44, when the transmission of all setting data is complete, the information processing unit 28 terminates the setting data transmission process.

[0094] In addition, the system may receive another command signal to stop continuous setting while the setting data transmission process is ongoing. In this case, the information processing unit 28 will stop the setting data transmission process again, and upon receiving a command signal to resume continuous setting, will resume the setting data transmission process. Thereafter, the information processing unit 28 will repeat the same process.

[0095] Figure 10 shows the sequence of processes related to the processing of the target distance control unit 26, including the process of storing setting data in the buffer 323 and the setting process of each setting unit.

[0096] In step S51, when the buffer storage data processing unit 321 of the target distance setting data processing unit 32 receives setting data from the information processing unit 28, it starts the process of storing the setting data in the buffer 323. This process continues until the transmission of setting data from the information processing unit 28 stops.

[0097] When a continuous setting stop command signal is sent to the information processing unit 28, the transmission of setting data from the information processing unit 28 stops. In this case, in step S52, the buffer storage data processing unit 321 stops the process of storing setting data in the buffer 323 after a certain period of time has elapsed since it stopped receiving setting data.

[0098] When a command signal to restart continuous setting is sent to the information processing unit 28, the transmission of setting data from the information processing unit 28 resumes. In this case, in step S53, the buffer storage data processing unit 321 resumes the process of storing setting data in the buffer 323. This process continues until the transmission of setting data from the information processing unit 28 stops.

[0099] When the information processing unit has finished transmitting the configuration data, the information processing unit 28 stops transmitting configuration data. In this case, in step S54, the buffer storage data processing unit 321 stops storing configuration data in the buffer 323 after a certain period of time has elapsed since it stopped receiving configuration data.

[0100] In step S61, each setting unit starts the setting process for each block. This process continues until all the data stored in buffer 323 is gone. If all the data stored in the buffer is gone, in step S62, each setting unit terminates the setting process.

[0101] [Second Embodiment] A target distance simulation system according to a second embodiment of this disclosure will be described with reference to Figures 13 and 14.

[0102] Here, the setting interval (setting period (frequency)) by each setting unit of the target distance simulation device 2 must satisfy the following relationship. Frequency Modulation Radar Device 1 ≤ Target Distance Simulation Device 2 Setting Interval < Data Storage Period of Buffer 323, Serial Clock

[0103] In other words, to accurately reproduce the distance changes of an aircraft equipped with a frequency-modulated radar system, it is necessary to set the attenuation, delay, Doppler, etc., at a frequency equal to or faster than the update cycle of the frequency-modulated radar system. To put it another way, if the settings for each change are made at a slow frequency for a scenario in which the aircraft is moving quickly, accurate simulation cannot be performed. On the other hand, if the settings for each change are made at a fast frequency for a scenario in which the aircraft is moving slowly, unnecessary settings will continue to be made. In other words, if the update cycle of the frequency-modulated radar system is not considered when setting each change, it is not possible to simulate the target distance of frequency-modulated radar systems with different update cycles using the same target distance simulation device.

[0104] Therefore, in this embodiment, during the initial communication between the information processing unit and the target distance control unit, data is transmitted at a predetermined communication speed, while the setting period of each setting unit, the communication speed between the information processing unit and the target distance control unit, and the buffer threshold are updated based on the update period (maximum assumed speed) of the radar being measured. The upper limit of the setting period corresponds to the radar update period.

[0105] Specifically, as shown in Figure 13, the target distance control unit 26 according to the second embodiment further comprises a reset unit 35 and a setting period / frequency setting unit 36. The information processing unit 28 according to the second embodiment comprises a target distance setting data generation unit 282, a setting data frame generation unit 283, a setting data calculation unit 284, and a setting frequency calculation unit 285.

[0106] The target distance simulation device 2 in this embodiment is A target distance simulation device for frequency-modulated radar device 1 that measures the target distance between a target object and its own device, The frequency modulation radar device 1 has a transmission wave input section 21 to which the transmission wave is input, A target distance processing unit 20 (frequency shift unit 22, delay processing unit 23, attenuation processing unit 24) adds a predetermined amount of change to the transmitted wave according to the target distance in accordance with the update cycle of the frequency modulation radar device 1, It is equipped with.

[0107] The target distance setting data generation unit 282 of the information processing unit 28 is configured to accept input of the update cycle of the frequency modulation radar device 1 in addition to the scenario. Here, the update cycle corresponds to the speed of the aircraft on which the frequency modulation radar device 1 is mounted. Specifically, as in the embodiment described above, it is configured so that the user can input data at any timing. However, this data may be stored in advance in the storage unit of the information processing unit 28.

[0108] The setting data calculation unit 284 calculates the frequency shift amount (Doppler amount), delay amount, and attenuation amount from the input scenario.

[0109] The setting frequency calculation unit 285 calculates the maximum speed of the scenario from the input update cycle. The setting frequency calculation unit 285 also determines the setting cycle of each setting unit in the target distance setting unit 31 and the serial communication speed between the information processing unit 28 and the target distance control unit 26 based on the calculated maximum speed of the scenario. In other words, the target distance control unit 26 sets the target distance processing unit at a predetermined setting interval based on the speed information calculated from the update cycle. The target distance control unit 26 also receives setting data from the frequency modulation radar device 1 via the information processing unit 28 at a communication speed corresponding to the update cycle. Furthermore, the setting frequency calculation unit 285 calculates the threshold values ​​(thresholds A and B) for the buffer 323 from the calculated maximum speed of the scenario. In other words, the threshold values ​​are determined according to the update cycle. In this case, the setting frequency calculation unit 285 may calculate the threshold values ​​for the buffer 323 according to the calculated serial communication speed.

[0110] The setting data frame generation unit 283 generates frequency setting data that includes setting period, communication speed, and buffer threshold information (setting period information, communication speed information, and threshold information) calculated by the setting frequency calculation unit 285. The setting data frame generation unit 283 also generates setting data from the frequency shift amount, delay amount, and attenuation amount calculated by the setting data calculation unit 284. The setting data and frequency setting data are transmitted to the target distance control unit 26 by the serial communication implementation unit 281.

[0111] Upon receiving the frequency setting data, the serial communication implementation unit 34 of the target distance control unit 26 transmits the setting period information and threshold information, which are among the pieces of information included in the frequency setting data, to the setting period / frequency setting unit 36. The serial communication implementation unit 34 also changes the serial communication speed based on the communication speed information.

[0112] The setting period / frequency setting unit 36, having received frequency setting data (setting period information, threshold information) from the serial communication implementation unit 34, transmits the setting period information to the frequency generation unit 33. The frequency generation unit 33 sets the frequency for setting the timing based on the setting period information. The setting period / frequency setting unit 36 ​​also transmits the threshold information to the buffer usage capacity confirmation unit 322. The buffer usage capacity confirmation unit 322 sets the threshold of the buffer 323 based on the threshold information. When the setting based on the threshold information and setting period information is completed, the setting period / frequency setting unit 36 ​​sends a notification to the reset unit 35 indicating that the setting is complete.

[0113] Upon receiving notification from the setting period / frequency setting unit 36, the reset unit 35 transmits a reset signal to the information processing unit 28 indicating that the setting based on the frequency setting data has been completed.

[0114] Upon receiving a reset signal from the reset unit 35, the serial communication implementation unit 281 of the information processing unit 28 starts communication with the serial communication implementation unit 34 of the target distance control unit 26 at a new communication speed based on the communication speed information.

[0115] Referring to the flowchart in Figure 14, the processes performed by the target distance simulation device 2 according to the second embodiment will be described.

[0116] In step S70, the user inputs the scenario, along with the update cycle of the frequency modulation radar device 1, to the target distance setting data generation unit 282 of the information processing unit 28.

[0117] In step S71, the set frequency calculation unit 285 calculates the maximum speed of the scenario from the input update cycle. The set frequency calculation unit 285 also calculates the set cycle, communication speed, and buffer threshold. The set data frame generation unit 283 generates set frequency data including set cycle information, communication speed information, and threshold information. The serial communication execution unit 281 transmits the set frequency data to the target distance control unit 26.

[0118] In step S72, the period / frequency setting unit 36 ​​transmits the set frequency information to the frequency generation unit 33. The period / frequency setting unit 36 ​​also transmits threshold information to the buffer usage capacity confirmation unit 322.

[0119] In step S73, the reset unit 35 transmits a reset signal to the information processing unit 28. In step S74, the serial communication implementation unit 281 changes the serial communication speed based on the communication speed information. Note that steps S73 and S74 can be performed in any order, and step S73 may be performed after step S74.

[0120] In step S75, the serial communication implementation unit 281 of the information processing unit 18 determines whether the reset signal is normal or not. If the reset signal is normal (step S75: Yes), the serial communication implementation unit 281 changes the serial communication speed. On the other hand, if the reset signal is abnormal (step S75: No), the serial communication implementation unit 281 issues an abnormality notification. Here, an abnormality in the reset signal means that the reset signal is not received within a specified time. Cases where the reset signal is not received within a specified time include not receiving the signal at all, receiving a signal of a different format than expected, and receiving a signal that is not a reset signal.

[0121] In step S77, the information processing unit 28 generates setting data including information on frequency shift amount, delay amount, and attenuation amount, similar to the first embodiment. Subsequently, the information processing unit 28 performs initial setting processing and continuous setting processing in cooperation with the target distance control unit 26.

[0122] In step S78, the target distance control unit 26 sets the frequency for the set timing based on the set period information. Specifically, the target distance control unit 26 sets the frequency generation unit 33.

[0123] In step S79, the target distance control unit 26 checks whether a frequency has been output. Specifically, the target distance control unit 26 checks whether the lock signal of the PLL inside the frequency generation unit 33 has been output. If it is confirmed that a frequency has been output (step S16: Yes), the target distance control unit 26 performs the initial setting process and the continuous setting process in cooperation with the information processing unit 28. On the other hand, if it is not confirmed that a frequency has been output (step S16: No), the target distance control unit 26 issues an error notification.

[0124] According to this embodiment, by considering the update cycle of the frequency modulation radar device 1, the setting cycle of the target distance simulation device 2 can be matched to the assumed speed of the scenario, thereby avoiding unnecessary settings and achieving highly accurate simulation. Furthermore, simulations corresponding to multiple frequency modulation radar devices with different update cycles can be realized with a single target distance simulation device.

[0125] Furthermore, since the clock speed can be reduced, it leads to a reduction in computational load and power consumption. This is particularly effective in scenarios where the aircraft equipped with frequency modulation radar is moving at low speeds.

[0126] [Third Embodiment] A target distance simulation system according to a third embodiment of this disclosure will be described with reference to Figures 15 and 16. Here, the attenuation characteristics, frequency characteristics, and delay characteristics differ depending on the type of reflective surface, such as the Earth's surface or the sea surface. Therefore, in the target distance simulation system according to the third embodiment, the setting data for the target distance processing unit 20 is corrected based on the characteristic data of the reflective surface.

[0127] The target distance simulation device 2 in this embodiment is A target distance simulation device for frequency-modulated radar device 1 that measures the target distance between a target object and its own device, The frequency modulation radar device 1 has a transmission wave input section 21 to which the transmission wave is input, A target distance processing unit 20 (frequency shift unit 22, delay processing unit 23, attenuation processing unit 24) adds a predetermined amount of change, corrected for the characteristics of the reflecting surface, to the transmitted wave according to the target distance, It is equipped with.

[0128] As shown in Figure 15, the target distance setting data generation unit 282 of the information processing unit 28 includes a reflective surface database 286. The reflective surface database 286 stores a database that has been pre-created from characteristic data of reflective surfaces. Specifically, the reflective surface database 286 stores correction coefficients measured according to the type of reflective surface with respect to a predetermined standard. As a predetermined standard, for example, data measured by a general radar reflector can be used as a reference.

[0129] Figure 16 shows an example of a database. Figure 16 shows the correction coefficients for attenuation, frequency shift, and delay for sea surface (water surface), forest, urban area, pasture / farmland, and desert. The correction coefficient for attenuation is the correction coefficient for the setting data of the attenuation processing unit 24, the correction coefficient for frequency shift is the correction coefficient for the frequency shift unit 22, and the correction coefficient for delay is the correction coefficient for the delay processing unit 23.

[0130] In this embodiment, corrections are made to the setting data of the frequency shift unit 22, the delay processing unit 23, and the attenuation processing unit 24, but the scope of this disclosure is not limited thereto. For example, since the effect of the attenuation amount is the greatest, only the correction of the setting data of the attenuation processing unit 23 may be performed. However, if the effects of the frequency shift amount and the delay amount are also known, a more accurate simulation can be performed.

[0131] In this embodiment, as shown in Figure 15, when a scenario is input, in addition to altitude information with respect to time changes, information on the reflective surface is input. The setting data calculation unit 284 of the target distance setting data generation unit 282 of the information processing unit 28 retrieves a correction coefficient for the reflective surface corresponding to the information input from the reflective surface database 286. Based on the correction coefficient, the setting data calculation unit 284 performs corrections on the frequency shift amount, delay amount, and attenuation amount.

[0132] The setting data frame generation unit 283 generates corrected setting data from the corrected frequency shift amount, corrected delay amount, and corrected attenuation amount calculated by the setting data calculation unit 284. The setting data is transmitted to the target distance control unit 26 by the serial communication implementation unit 281. The scope of this disclosure is not limited to correcting the frequency shift amount, delay amount, and attenuation amount in the setting data calculation unit 284, but the setting data frame generation unit 283 may also perform the correction when generating the setting data.

[0133] Each setting unit of the target distance control unit 26 sets the target distance processing unit 20 (frequency shift unit 22, delay processing unit 23, and attenuation processing unit 24) based on the corrected setting data.

[0134] According to this embodiment, damping characteristics and the like can be simulated more accurately, allowing for simulations that are closer to the actual environment. [Other examples] This disclosure can be applied to the inspection of radars other than radars for altitude measurement, such as frequency-modulated radar device 1.

[0135] Furthermore, this disclosure provides three circuit configurations that are subject to setting: a frequency shift unit 22, a delay processing unit 23, and an attenuation processing unit 24. However, the scope of this disclosure is not limited to these, and for example, the frequency shift unit 22 is not necessarily an essential configuration. In addition, a separate processing unit may be provided for setting physical quantities other than the Doppler amount, delay amount, and attenuation amount.

[0136] Furthermore, although the above describes an example of controlling the target distance control unit using an information processing unit, the scope of this disclosure is not limited to this. The technology of this disclosure can also be applied to controlling the target distance control unit via a network. For example, by applying the technology of this disclosure as a countermeasure for a network with unstable communication conditions, it is possible to achieve highly accurate simulation without being affected by the instability of the communication. [Industrial applicability]

[0137] The target simulation device described herein is applicable for conducting ground tests such as attitude control tests of aircraft or projectile platforms. For example, it can be mounted on an aircraft or projectile to measure altitude, etc. [Explanation of Symbols]

[0138] 1: Frequency Modulation Radar Equipment 2: Target distance simulator 11: Transmitter Wave Output Section 12: Transmitter wave generation unit 13: Transmit / Receive Correlation Section 14: Receiver input section 21: Transmitter input section 22: Frequency shift section 221: Mixer 222: Filter 223: Signal generation unit 23: Delay Processing Unit 24: Attenuation Processing Unit 25: Receiver output section 26: Target Distance Control Unit 27: Clock generation unit 28: Information Processing Section 281: Serial Communication Implementation Unit 282: Target distance setting data generation unit 283: Configuration Data Frame Generation Unit 284: Setting Data Calculation Unit 285: Setting frequency calculation unit 286: Reflective Surface Database 31: Target distance setting unit 311: Frequency shift setting section 312: Delay setting section 313: Damping setting section 314: Configuration Processing Unit 32: Target distance setting data processing unit 321: Buffer storage data processing unit 322: Buffer usage capacity confirmation section 323: Buffer 34: Serial Communication Implementation Unit 35: Reset 36: Setting period / frequency setting section

Claims

1. A target distance simulation device for a radar device that measures the target distance between a target object and its own device, The radar device includes a transmission wave input section into which the transmission wave is input, A target distance processing unit that adds a predetermined amount of change corresponding to the target distance to the transmitted wave in accordance with the update cycle of the radar device, Equipped with, Target distance simulator.

2. The update cycle corresponds to the speed of the aircraft on which the radar device is installed. The system further includes a target distance control unit that sets the target distance processing unit at a predetermined set interval based on speed information calculated from the update cycle. The target distance simulation device according to claim 1.

3. The target distance control unit sets the target distance processing unit at a predetermined set period based on a clock from a clock generation unit that generates a clock at a predetermined timing. The target distance simulation device according to claim 2.

4. The target distance control unit, The system includes a buffer in which setting data for the target distance processing unit is stored, The setting data is stored in the buffer faster than the predetermined setting cycle. The target distance simulation device according to claim 3.

5. The target distance control unit, The setting data is read from the buffer at the speed of the predetermined setting period. The target distance simulation device according to claim 4.

6. The target distance control unit, The information processing unit generates the setting data based on user input, and the radar device receives the setting data at a communication speed corresponding to the update cycle. The target distance simulation device according to claim 5.

7. The target distance control unit, If the buffer usage capacity exceeds a predetermined first threshold, a setting stop command signal is sent to the information processing unit to stop the transmission of the setting data. If the buffer usage capacity falls below a predetermined second threshold, a setting restart command signal is sent to the information processing unit to restart the transmission of the setting data. The first threshold and the second threshold are determined according to the update cycle. The target distance simulation device according to claim 6.

8. The clock generation unit is a crystal oscillator. The target distance simulation device according to claim 3.

9. The target distance processing unit comprises a frequency shifting unit that adds a frequency shift to the transmitted wave, a delay processing unit that adds a delay amount to the transmitted wave, and an attenuation processing unit that adds an attenuation amount to the transmitted wave. The target distance control unit comprises a frequency shift setting unit for setting the frequency shift unit, a delay setting unit for setting the delay processing unit, and an attenuation setting unit for setting the attenuation processing unit. A target distance simulation device according to any one of claims 2 to 7.

10. A target distance simulation method performed by a target distance simulation device that simulates the target distance for a radar device that measures the target distance between a target object and its own device, The radar device receives the transmitted wave, A predetermined amount of change is added to the transmitted wave according to the target distance, in accordance with the update cycle of the radar device. Target distance simulation method.

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