JP2023124420A - Antenna arrangement determination system, antenna arrangement determination method, and program - Google Patents

Abstract

To provide an antenna arrangement determination system, an antenna arrangement determination method, and a program with which it is possible to determine the arrangement of antennas on the basis of the analysis result of noise distribution in a three-dimensional space.SOLUTION: An antenna arrangement determination system 1 for mobile entities includes: a design information input unit 101 for inputting circuit information regarding the characteristic of a digital circuit, structure information regarding the structure of the digital circuit, antenna information regarding the antenna characteristic, circuit module arrangement information regarding the arrangement of the digital circuit, and antenna position information regarding antenna arrangement, as design information; a noise distribution estimation unit 103 that calculates a noise strength distribution on the basis of the circuit information, structure information and circuit module arrangement information; an antenna sensitivity estimation unit 105 that calculates an antenna sensitivity distribution on the basis of the antenna information and antenna position information; and an optimization unit 107 that evaluates the overlapping of the noise strength distribution and antenna sensitivity distribution, and changes the design information when the overlapping evaluation result does not satisfy a prescribed criterion.SELECTED DRAWING: Figure 1

Description

The present invention relates to an antenna placement determination system, an antenna placement determination method, and a program, and more particularly to product design technology for determining antenna placement based on analysis results of noise distribution in a three-dimensional space.

2. Description of the Related Art In an electronic product having a communication function, if electromagnetic noise enters a communication module, the communication performance is significantly degraded. Therefore, when designing such a product, it is necessary to reduce noise and place antennas and the like at locations that are less susceptible to noise. In particular, mobile objects such as drones, robots, and vehicles are subject to weight reduction requirements, mechanical and aerodynamic constraints, and the like, and therefore, the positions where antennas can be placed are likely to be restricted.

For example, Japanese Unexamined Patent Application Publication Nos. 2002-100003 and 2003-100000 disclose conventional techniques related to the analysis and visualization of electromagnetic noise. Patent Literature 1 describes a method for visualizing electromagnetic noise propagating on a circuit board or on a transmission line such as a cable connected to a device. Patent Literature 2 describes a method of performing EMC (Electro Magnetic Compatibility: electromagnetic field) analysis using a model equivalent circuit in the design stage of an electrical product.

For example, Japanese Unexamined Patent Application Publication No. 2002-100002 and Japanese Unexamined Patent Application Publication No. 2002-200043 are known as prior art related to the design of moving bodies. Patent Document 3 describes that in an unmanned mobile object such as a drone, by providing a shielding plate between the main body and a retrofitted antenna, the influence of noise emitted by the main body on the antenna can be suppressed. Patent Literature 4 describes that, in an autonomously traveling vacuum cleaner, by devising the arrangement position of the communication module, it is possible to suppress the influence of noise generated during main body operation on the communication module.

JP 2014-222215 A Japanese Unexamined Patent Application Publication No. 2010-198201 JP 2021-061473 A JP 2019-111161 A

However, the technique described in Patent Document 1 is a technique that can be applied when making small improvements to existing products, and cannot be applied when making major improvements or creating new designs. The technique described in Patent Document 2 requires a step of actually measuring noise, which is costly. Neither of Patent Literatures 1 and 2 determine the appropriate placement position of the antenna in the product.

In this respect, Patent Literatures 3 and 4 propose appropriate placement positions of antennas in mobile bodies. However, Patent Documents 3 and 4 only disclose one of the results of optimizing the antenna arrangement for a specific moving object. In other words, it does not disclose a general-purpose optimization technique for antenna placement that can be applied to various moving bodies.

The present invention has been made to solve such problems, and provides an antenna placement determination system capable of determining antenna placement based on the analysis results of noise distribution in a three-dimensional space. It aims at providing a method and a program.

According to one embodiment, a system for determining antenna placement in a moving object includes circuit information on characteristics of a digital circuit, structural information on the structure of the digital circuit, antenna information on characteristics of the antenna, and placement of the digital circuit. a design information input unit for inputting circuit module layout information regarding the layout of the antenna and antenna position information regarding the layout of the antenna as design information; a distribution estimating unit, an antenna sensitivity estimating unit that calculates an antenna sensitivity distribution based on the antenna information and the antenna position information, and an overlap between the noise intensity distribution and the antenna sensitivity distribution that is evaluated so that the evaluation result of the overlap is and an optimization unit that modifies the design information if a predetermined criterion is not met.
According to one embodiment, when the evaluation result of the overlap does not satisfy a predetermined criterion, the optimization unit changes the antenna position information and causes the antenna sensitivity estimation unit to recalculate the antenna sensitivity distribution. , again evaluate the overlap.
According to one embodiment, if the evaluation result of the overlap does not satisfy a predetermined criterion, the optimization unit changes the circuit module placement information, and causes the noise distribution estimation unit to recalculate the noise intensity distribution. and evaluate the overlap again.
According to one embodiment, the optimization unit uses the noise channel power at the antenna output terminal when noise is applied as the evaluation result of the overlap, and sets the allowable noise channel power defined by the communication module to the antenna output terminal when noise is applied. The predetermined criterion is that the noise channel power at .
According to one embodiment, the system further includes an aerodynamic characteristic calculation unit that calculates lift and drag generated in the moving body based on the design information, and when the evaluation results of the lift and drag do not satisfy a predetermined criterion. , to change the design information.
According to one embodiment, it further includes a center-of-gravity characteristic calculation unit that calculates the center-of-gravity balance of the moving body based on the design information, and if the evaluation result of the center-of-gravity balance does not satisfy a predetermined criterion, the design information to change
According to one embodiment, the design information is changed when the evaluation result of the radio wave reception sensitivity does not satisfy a predetermined standard, further comprising a reception sensitivity test section that calculates the radio wave reception sensitivity based on the design information. do.
According to one embodiment, a method for determining an antenna arrangement in a mobile object by a computer includes circuit information concerning characteristics of a digital circuit, structural information concerning a structure of the digital circuit, antenna information concerning characteristics of an antenna, and arrangement of the digital circuit. a design information input step of inputting circuit module layout information relating to noise and antenna position information regarding said antenna layout as design information; and calculating a noise intensity distribution based on said circuit information, said structural information and said circuit module layout information. a distribution estimation step; an antenna sensitivity estimation step of calculating an antenna sensitivity distribution based on the antenna information and the antenna position information; and evaluating overlap between the noise intensity distribution and the antenna sensitivity distribution, and evaluating the overlap evaluation result. and an optimization step of modifying the design information if predetermined criteria are not met.
According to one embodiment, in the optimization step, the noise channel power at the antenna output terminal when noise is applied is set as the evaluation result of the overlap, and the allowable noise channel power defined by the communication module is set to the antenna output terminal when noise is applied. The predetermined criterion is that the noise channel power at .
According to one embodiment, a program causes a computer to perform the above method.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an antenna placement determination system, an antenna placement determination method, and a program capable of determining antenna placement based on analysis results of noise distribution in a three-dimensional space.

2 is a block diagram illustrating the hardware configuration of the antenna placement determination system 1; FIG. 2 is a diagram showing an example of a hardware configuration of a mobile object 2; FIG. 2 is a block diagram illustrating the functional configuration of the antenna placement determination system 1; FIG. FIG. 5 is a diagram showing an example of estimation processing of noise intensity distribution and antenna sensitivity distribution; It is a figure which shows an example of estimation processing of noise intensity distribution. It is a figure which shows an example of the estimation process of antenna sensitivity distribution. FIG. 10 is a diagram showing an example of evaluation processing of overlap between noise intensity distribution and antenna sensitivity distribution; 4 is a flowchart showing an operation example of the antenna placement determination system 1; 4 is a flowchart showing an operation example of the antenna placement determination system 1; 2 is a block diagram illustrating the functional configuration of the antenna placement determination system 1; FIG. 4 is a flowchart showing an operation example of the antenna placement determination system 1; 2 is a block diagram illustrating the functional configuration of the antenna placement determination system 1; FIG. 4 is a flowchart showing an operation example of the antenna placement determination system 1;

<Embodiment 1>
FIG. 1 is a block diagram illustrating the hardware configuration of an antenna placement determination system 1 according to Embodiment 1 of the present invention.

The antenna placement determination system 1 is a computer system that supports the design of mobile objects, and typically has a processor 11 , a memory 13 , an input section 15 and an output section 17 .

The processor 11 logically implements a processing unit, which will be described later, by reading programs and data stored in the memory 13 and executing predetermined processing.

The input unit 15 is a device for inputting data and instructions necessary for processing, and typically receives information from a character input device such as a keyboard, a pointing device such as a mouse, an external storage device, or a communication line. Communication devices and the like are included.

The output unit 17 is a device for outputting processing results, various notifications, and the like, and typically includes a display device such as a display, an external storage device, a communication device for transmitting information to a communication line, and the like.

FIG. 2 is a diagram showing an example of the hardware configuration of the mobile object 2 to be designed by the antenna placement determination system 1. As shown in FIG. In this example, the moving body 2 is assumed to be a drone. The moving body 2 has a communication/sensor section 21 , a control section 23 , a drive section 25 and a power supply section 27 .

The communication/sensor unit 21 typically includes a position sensor 211 , a video data transmission communication module 213 , an operation communication module 215 , a 6-axis sensor 217 and an image sensor 219 .
The position sensor 211 calculates and outputs the position information of the moving body 2 using, for example, GNSS (Global Navigation Satellite System).
The video data transmission communication module 213 transmits the image data acquired by the image sensor 219 to an external device by wired or wireless communication.
The operation communication module 215 receives an operation signal transmitted by wire or wireless communication from an external controller (propo) and notifies the controller 231 of it.
The 6-axis sensor 217 typically detects changes in acceleration in 6-axis directions, and calculates and outputs the tilt and movement speed of the moving body 2 .
The image sensor 219 captures and outputs an image of the outside of the moving body 2 .

Control unit 23 includes a controller 231 .
The controller 231 is typically a microcomputer, and controls the communication/sensor section 21, drive section 25, and power supply section 27 according to a program. For example, the controller 231 generates a PWM (Pulse Width Modulation) control signal according to the operation signal notified from the operation communication module 215 and inputs it to the ESC 251 .

The drive unit 25 typically includes an ESC (Electric Speed Controller) 251 , a motor 253 and a propeller 255 .
The ESC 251 controls the rotation speed of the motor 253 according to the PWM control signal input from the controller 231 .
Motor 253 rotates at a predetermined speed under the control of ESC 251 to drive propeller 255 .
The propeller 255 is driven by the motor 253 to rotate and float and move the moving body 2 .

The power supply section 27 typically includes a battery 271 and a DCDC converter 273 .
Battery 271 is a DC power supply.
The DCDC converter 273 converts the output from the battery 271 into a predetermined voltage and supplies it to the communication/sensor section 21 , the control section 23 and the drive section 25 .

From the viewpoint of EMC (Electromagnetic Compatibility), the controller 231 and the DCDC converter 273 among the above components can be the main sources of noise. Also, the path from the controller 231 and the DCDC converter 273 to the motor 253 can be a noise transmission path. If this noise enters the communication/sensor section 21, it may adversely affect its function. For example, in the video data transmission communication module 213 and the operation communication module 215, the communication range may be reduced and the communication speed (throughput) may be lowered. In addition, the position sensor 211 may deteriorate the measurement accuracy. Therefore, when designing the moving body 2, it is important to suppress noise input to the communication/sensor section 21 in particular.

FIG. 3 is a block diagram illustrating the functional configuration of the antenna placement determination system 1. As shown in FIG. The antenna placement determination system 1 has a design information input section 101, a noise distribution estimation section 103, an antenna sensitivity estimation section 105, and an optimization section 107 as logical processing sections for realizing its functions.

The design information input unit 101 receives input of design information of the moving body 2 . The design information typically includes circuit information, structural information, antenna information, circuit module placement information, and antenna position information. By using these design information, it becomes possible to estimate the noise distribution and antenna sensitivity in the moving object 2 .

For example, the noise distribution can be calculated from the noise current distribution and noise voltage distribution in the communication band. Here, noise current is the current that flows through the wiring that connects the circuits, and noise voltage is the potential difference between each part generated by the operation of the circuit. Once this is known, it is possible to calculate the electromagnetic noise in the analysis space by dividing it into minute sections and treating each section as an excitation source. Here, the noise current flows through conductors such as semiconductors and metals, and the noise voltage is generated on the surfaces of the conductors. Therefore, specifically, only the printed wiring board and wiring need be considered in the calculation. That is, the noise current and the noise voltage can be calculated from the circuit information and the structural information, which is the positional information. The reason why the structural information is necessary here is to provide the positional information of the excitation source. In practice, the mutual inductance and mutual capacitance between the conductors of the circuit board and the wiring appear as parasitic components on the circuit, but it goes without saying that incorporating this into the circuit information can improve the calculation accuracy of the noise distribution. Nor.

The circuit information is data defining basic information about digital circuits that constitute the communication/sensor unit 21 , the control unit 23 , the drive unit 25 , and the power supply unit 27 . For example, the circuit information includes information such as the clock frequency, current, and voltage of the digital circuit. The circuit information includes information that defines voltages and currents, such as the characteristic impedance of substrate wiring, the impedance of wiring cables, the driving point impedance of semiconductor circuits, and the input impedance. The noise in the communication band is a harmonic component of this clock, and even if the clock is about 10 MHz, it appears as noise in the communication band of the GHz band. Furthermore, a DC voltage conversion circuit (DCDC converter) is often used in a power supply section from the viewpoint of voltage conversion efficiency, but inside the circuit it is converted once into a rectangular wave AC, and this AC becomes a noise source. Recent advances in power devices have increased the switching speed, and this harmonic easily affects the communication bandwidth.

Structural information is data defining basic information about the structure of a digital circuit. For example, the structural information includes information such as the size of the circuit module on which the circuit is to be mounted, the mounting position, the mounting direction, the length and route (path) of the wiring, and the wiring configuration whether the cable is a discrete wire or a coaxial wire.

The antenna information is data defining information about the characteristics of the antenna included in the communication/sensor unit 21 . For example, the antenna information includes information such as input impedance, antenna pattern, and radiation sensitivity in the target radio band.

Note that the communication/sensor unit 21 can include a plurality of antennas for different purposes. Normally, the frequency is different for each application (eg, GNSS, WiFi, etc.), but this is not the only option, and antennas for multiple applications may use the same frequency. If multiple antennas exist, antenna information also exists for each antenna.

The circuit module placement information is data that defines where on the moving object 2 the modules that make up the digital circuit are to be mounted.

The antenna position information is data defining at which position on the moving object 2 the antenna included in the communication/sensor unit 21 is mounted. For example, the antenna position information includes information such as the position of the antenna module and the position of the noise filter. When there are multiple antennas, antenna position information also exists for each antenna.

The noise distribution estimator 103 calculates the noise intensity distribution (electromagnetic field distribution) at a predetermined frequency generated by the digital circuit based on the input design information. The frequency here is the same as the frequency of the antenna described later. When there are multiple antennas and the antennas use different frequencies, the noise distribution estimator 103 calculates the noise intensity distribution for each frequency used by the multiple antennas. Noise generated by circuit operation can be calculated by dividing it into current and voltage in circuit analysis. Methods for estimating how much noise intensity is distributed in the analysis space using noise currents and noise voltages as noise excitation sources in minute sections based on circuit analysis and structural information include, for example, the finite element method, boundary element method, and FDTD (Finite-difference time). -domain) method, moment method, and the like. Since these estimation methods are publicly known, detailed description thereof will be omitted.

FIG. 5A shows an example of the result of estimating the noise intensity distribution. FIG. 5A is a diagram showing the estimation result of the noise intensity distribution on the plane (see FIG. 4) set at the height Z position. The dashed closed curve connects the points where the noise intensity is equal, and shows the points where the noise intensity is X1 (dBm), X2 (dBm), and X3 (dBm) in order from the inside (X1>X2>X3). .

Note that the noise distribution estimation unit 103 actually estimates the noise intensity distribution in the three-dimensional space. For example, as shown in FIG. 4, a thin plate-like space with a thickness d is set at the position of the height Z, this three-dimensional space is divided into a number of computational grids (not shown), and the noise intensity distribution in each computational grid is are calculated respectively. FIG. 5A can be understood as a projection of the noise intensity distribution in this thin plate-like space onto a plane. The noise distribution estimator 103 calculates the heights Z+d, Z+2d, . . . Similarly, a thin plate-shaped space having a thickness of d is set at the position of , and the noise intensity distribution is calculated. By repeating this as appropriate, the noise intensity distribution in the space surrounding the moving body 2 can be examined thoroughly.

The antenna sensitivity estimator 105 calculates the antenna sensitivity distribution at the frequencies used by the antenna based on the input design information. Since the method for estimating the antenna sensitivity distribution is publicly known, detailed description thereof will be omitted. When there are multiple antennas and the antennas use different frequencies, the antenna sensitivity estimation unit 105 calculates the antenna sensitivity distribution for each of the frequencies used by the multiple antennas.

FIG. 5B shows an example of the estimation result of the antenna sensitivity distribution. FIG. 5B is a diagram showing estimation results of the antenna sensitivity distribution on the plane of height Z (see FIG. 4). The dashed closed curve connects the points where the antenna sensitivity is equal, and shows the points where the antenna sensitivity is Y1 (dBm), Y2 (dBm), and Y3 (dBm) in order from the inside (Y1>Y2>Y3). .

Note that the antenna sensitivity estimation unit 105 actually estimates the antenna sensitivity distribution in a three-dimensional space. For example, as shown in FIG. 4, a thin plate-like space with a thickness d is set at a position of height Z, this three-dimensional space is divided into a number of computational grids (not shown), and the antenna sensitivity distribution in each computational grid is are calculated respectively. FIG. 5B can be understood as a projection of the antenna sensitivity distribution in this thin plate-like space onto a plane. Antenna sensitivity estimating section 105 detects heights Z+d, Z+2d, . . . Similarly, a thin plate-like space having a thickness of d is set at the position of , and the antenna sensitivity distribution is calculated. By repeating this as appropriate, the antenna sensitivity distribution in the space surrounding the moving body 2 can be examined thoroughly.

The optimization unit 107 evaluates the overlap (scalar product) of the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105 as an evaluation index D. FIG. 5C shows how the estimation results of the noise intensity distribution and the antenna sensitivity distribution in a certain space are superimposed. Here, for example, when a computational grid having a noise intensity of a certain level or more (for example, X3 or more) and a computational grid having an antenna sensitivity of a certain level or more (for example, Y3 or more) overlap, the number of overlapping regions is calculated. and this can be used as the evaluation index D. Although the above is a relatively simple example, the present invention is not limited to this. For example, weighting may be performed such that the evaluation index D increases as the noise strength and antenna sensitivity strength of the superimposed computational grid increase.

The above is an example in which the noise distribution is treated as a scalar and the evaluation index D is calculated. Since the propagation of electromagnetic waves can be expressed as a flow of energy, a vector quantity (referred to as a Poynting vector) may be used as the evaluation index D. For example, the evaluation index D may be the product of a Poynting vector whose excitation source is the antenna and a Poynting vector whose excitation source is the body of the moving body 2 . In this case, not only overlap of scalar quantities as shown in FIG. 5C but also overlap of directions can be taken into consideration, so that the accuracy of design can be further improved. Therefore, the overlap of distributions, which is the evaluation index D, may be a scalar quantity or a vector quantity.

Alternatively, the evaluation index D and the threshold may be set as follows. When the power of noise power in the communication band used by the antenna (hereinafter referred to as output noise channel power) estimated at the antenna output end of the communication module 215 increases, the communication performance is significantly affected. For example, the block error rate, which is an index of wireless communication performance, deteriorates rapidly when the output noise channel power exceeds a predetermined amount, and reaches an unacceptable limit. Therefore, the evaluation index D is set to the output noise channel power, and the threshold is set to an arbitrary value below the "predetermined amount" (hereinafter referred to as the allowable noise channel power). That is, the output noise channel power when noise is applied should be less than the allowable noise channel power unique to the communication module 215 . This makes it possible to verify whether the deterioration of communication performance due to noise is within the permissible limit.
The output noise channel power can also be converted into noise power in the communication band used by the antenna (hereinafter referred to as input noise channel power) estimated at the antenna input terminal. Each antenna has a different antenna factor (efficiency), and multiplying the input noise channel power by the antenna factor gives the output noise power. That is, even if the same noise channel power is input to the antenna input terminal, the noise channel power output from the antenna differs according to the antenna factor. Therefore, if the antenna factor is known, the input noise channel power may be used as the evaluation index D. Also, the input noise channel power can be converted into the electromagnetic noise strength (hereinafter referred to as reception noise strength) input to the antenna. Therefore, the reception noise strength can be adopted as the evaluation index D.
Therefore, as the evaluation index D, the output noise channel power when noise is applied may be used in addition to the scalar quantity and vector quantity overlap (spatial integration) of the noise and the antenna pattern.

When the evaluation index D is equal to or less than the predetermined threshold, the optimization unit 107 determines that the influence of noise on the antenna is equal to or less than the allowable value. In this case, optimization section 107 outputs the current antenna position information as a result of optimization processing.

On the other hand, when the evaluation index D exceeds the predetermined threshold, the optimization unit 107 determines that the influence of noise on the antenna is unacceptable. In this case, the optimization unit 107 rearranges the antennas by changing the antenna position information (for example, at least one of the position of the antenna module and the position of the noise filter). Then, again, the noise distribution estimator 103 estimates the noise intensity distribution, and the antenna sensitivity estimator 105 estimates the antenna sensitivity distribution. After that, the optimization unit 107 evaluates again the overlap between the noise intensity distribution and the antenna sensitivity distribution. A series of these processes are repeatedly executed until the evaluation index D becomes equal to or less than a predetermined threshold.

The optimization unit 107 can employ known techniques such as the steepest descent method and genetic algorithm when rearranging the antennas, that is, when changing the antenna position information.

Note that in the above-described embodiment, the optimization unit 107 ends the processing when the evaluation index D is equal to or less than a predetermined threshold. However, the present invention is not limited to this. Antenna position information may be output as a result of the optimization process.

As described above, in Embodiment 1, the optimization unit 107 evaluates the overlap between the noise intensity distribution and the antenna sensitivity distribution, and adjusts the parameters of the antenna position information so that this evaluation index is equal to or less than a predetermined threshold value or minimized. do. Note that when there are multiple antennas and these antennas use different frequencies, the optimization unit 107 performs optimization processing for each of the frequencies used by the multiple antennas.

FIG. 6 is a flow chart showing an operation example of the antenna placement determination system 1 according to the first embodiment. Note that when there are a plurality of antennas and these antennas use different frequencies, the following series of processes are executed for each of the frequencies used by the plurality of antennas.

S<b>101 : Input of Design Information The design information input unit 101 receives input of design information of the moving body 2 .

S102: Estimation of Noise Intensity Distribution The noise distribution estimation unit 103 calculates the noise intensity distribution (electromagnetic field distribution) generated by the digital circuit at a predetermined frequency based on the design information input in S101.

S103: Estimation of Antenna Sensitivity Distribution The antenna sensitivity estimation unit 105 calculates the antenna sensitivity distribution at the frequencies used by the antenna based on the input design information.

S104: Evaluate overlap between noise intensity distribution and antenna sensitivity distribution The optimization unit 107 evaluates overlap between the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105. Calculate index D.

S105: Is the evaluation index below the allowable value?
If the evaluation index D is equal to or less than the allowable value, the optimization unit 107 outputs the current design information as the result of the optimization process, and terminates the process. Otherwise, the process proceeds to S106.

S106: Change of antenna position information The optimization unit 107 rearranges the antennas by changing the antenna position information. Transition to S102.

According to Embodiment 1, the antenna placement determination system 1 evaluates the overlap between the noise intensity distribution and the antenna sensitivity distribution based on given design information, and the evaluation index satisfies or minimizes a predetermined criterion. output the correct antenna position. As a result, when designing the moving body 2, the optimal antenna arrangement can be determined with high precision and ease.

<Embodiment 2>
In Embodiment 1, the optimization unit 107 outputs the antenna position such that the evaluation index D satisfies or minimizes the predetermined criterion. That is, the position of the antenna was moved in order to suppress the influence of noise on the communication/sensor unit 21 .

In contrast, in the second embodiment, the optimization unit 107 suppresses the influence of noise on the communication/sensor unit 21 by moving the position of the circuit module. It should be noted that the circuit module layout information in the present embodiment includes the positions of the modules that are noise sources (typically, the controller 231, the DCDC converter 273, the path from the controller 231 and the DCDC converter 273 to the motor 253, etc.), The position of noise countermeasure components may also be included.

The hardware configuration and functional configuration of the antenna placement determination system 1 according to the second embodiment are the same as those of the first embodiment. Processing specific to the second embodiment will be described below, focusing on the operation of the optimization unit 107 .

The optimization unit 107 evaluates overlap between the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105 . For example, when a grid having a noise intensity of X3 or more and a grid having an antenna sensitivity of Y3 or more overlap, the number of overlapping regions is calculated and used as an evaluation index.

When the evaluation index D is equal to or less than the predetermined threshold, the optimization unit 107 determines that the influence of noise on the antenna is equal to or less than the allowable value. In this case, the optimization unit 107 outputs the current circuit module placement information as a result of optimization processing.

On the other hand, when the evaluation index D exceeds the predetermined threshold, the optimization unit 107 determines that the influence of noise on the antenna is unacceptable. In this case, the optimization unit 107 rearranges the circuit modules by changing the circuit module placement information (for example, at least one of the position of the module that is the noise source and the noise countermeasure component). Then, again, the noise distribution estimator 103 estimates the noise intensity distribution, and the antenna sensitivity estimator 105 estimates the antenna sensitivity distribution. After that, the optimization unit 107 evaluates again the overlap between the noise intensity distribution and the antenna sensitivity distribution. A series of these processes are repeatedly executed until the evaluation index D becomes equal to or less than a predetermined threshold.

The optimization unit 107 can employ a known method such as the steepest descent method, genetic algorithm, or the like when rearranging the circuit modules.

Note that in the above-described embodiment, the optimization unit 107 ends the processing when the evaluation index D is equal to or less than a predetermined threshold. However, the present invention is not limited to this. may be output as a result of optimization processing.

As described above, in Embodiment 2, the optimization unit 107 evaluates the overlap between the noise intensity distribution and the antenna sensitivity distribution, and adjusts the parameters of the circuit module placement information so that this evaluation index is equal to or less than a predetermined threshold value or is minimized. adjust. Note that when there are multiple antennas and these antennas use different frequencies, the optimization unit 107 performs optimization processing for each of the frequencies used by the multiple antennas.

FIG. 7 is a flow chart showing an operation example of the antenna placement determination system 1 according to the second embodiment. Note that when there are a plurality of antennas and these antennas use different frequencies, the following series of processes are executed for each of the frequencies used by the plurality of antennas.

S<b>201 : Input of Design Information The design information input unit 101 receives input of design information of the moving body 2 .

S202: Estimation of Noise Intensity Distribution The noise distribution estimation unit 103 calculates the noise intensity distribution (electromagnetic field distribution) generated by the digital circuit at a predetermined frequency based on the design information input in S201.

S203: Estimation of Antenna Sensitivity Distribution The antenna sensitivity estimation unit 105 calculates the antenna sensitivity distribution at the frequency used by the antenna based on the input design information.

S204: Evaluate overlap between noise intensity distribution and antenna sensitivity distribution The optimization unit 107 evaluates overlap between the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105. Calculate index D.

S205: Is the evaluation index below the allowable value?
If the evaluation index D is equal to or less than the allowable value, the optimization unit 107 outputs the current design information as the result of the optimization process, and terminates the process. Otherwise, the process proceeds to S206.

S206: Change of Circuit Module Placement Information The optimization unit 107 rearranges the circuit modules by changing the circuit module placement information. Transition to S202.

According to Embodiment 2, the antenna placement determination system 1 evaluates the overlap between the noise intensity distribution and the antenna sensitivity distribution based on given design information, and the evaluation index satisfies or minimizes a predetermined criterion. outputs a circuit module layout. As a result, when designing the moving body 2, it is possible to determine the optimum circuit module layout with high precision and ease.

<Embodiment 3>
In the first or second embodiment, the placement of the antenna or circuit module is optimized from the viewpoint of communication sensitivity characteristics. By the way, especially when the moving object 2 is a flying object such as a drone, it is desirable to satisfy predetermined criteria in terms of aerodynamic characteristics and center-of-gravity characteristics when determining the placement of the antenna or circuit module. Therefore, in the third embodiment, in addition to communication sensitivity characteristic calculation, aerodynamic characteristic (lift-to-drag ratio) calculation and center-of-gravity calculation are performed to determine the placement of antennas or circuit modules.

FIG. 8 is a block diagram illustrating the functional configuration of the antenna placement determination system 1 according to the third embodiment. Antenna placement determination system 1 has design information input section 101 , noise distribution estimation section 103 , antenna sensitivity estimation section 105 , optimization section 107 , aerodynamic characteristic calculation section 109 , and centroid characteristic calculation section 111 .

The operations of the design information input section 101, the noise distribution estimation section 103, and the antenna sensitivity estimation section 105 are the same as those in Embodiments 1 and 2, so the description thereof is omitted.

The aerodynamic characteristic calculation unit 109 calculates lift and drag generated in the body of the moving body 2 based on the input design information. Lift and drag can be affected, among other things, by the relationship between the direction of travel of the vehicle and the position and orientation of the antenna. Since the method of calculating the lift force and the drag force is well known, detailed description thereof will be omitted. The aerodynamic characteristic calculation unit 109 outputs an evaluation index E as a calculation result of lift and drag.

The center-of-gravity characteristic calculator 111 calculates the center-of-gravity balance of the airframe based on the input design information. Center-of-gravity balance can be particularly affected by the position and orientation of antennas installed on the fuselage. Since the calculation method of the center-of-gravity balance is publicly known (see, for example, Japanese Patent Application Publication No. 2018-507814), detailed description will be omitted. The center-of-gravity characteristic calculation unit 111 outputs an evaluation index F as a calculation result of the center-of-gravity balance.

The optimization unit 107 calculates the evaluation index D of the overlap between the noise intensity distribution and the antenna sensitivity distribution by the method shown in the first and second embodiments.

In addition, the optimization unit 107 determines whether or not the lift and drag evaluation index E, the center-of-gravity balance evaluation index F, and the overlap evaluation index D of the noise intensity distribution and the antenna sensitivity distribution satisfy predetermined criteria. are judged in order. If all evaluation indices satisfy the criteria, the optimization unit 107 outputs the current design information as the optimization result. On the other hand, if at least one of the evaluation indices does not satisfy the criteria, the optimization unit 107 changes the antenna arrangement or the circuit module arrangement, and calculates all the evaluation indices again. The modification of the antenna layout and the modification of the circuit module layout have been described in the first and second embodiments, so the description is omitted. The optimization unit 107 repeatedly executes a series of these processes until all evaluation indices satisfy the criteria.

In the above-described embodiment, the optimization unit 107 serially determines whether or not each evaluation index satisfies a predetermined standard, and when all the evaluation indexes are equal to or less than a predetermined threshold, Finished processing. However, the present invention is not limited to this. good. Since the solution of the optimization problem of the multi-objective function is well known (see, for example, Nozomu Ogiso, Utilization of the Optimal Design Method for Morphing Wings, Journal of the Japan Aerospace Society, Vol. 64, No. 6, pp. 180-185, June 2016 See) Detailed description is omitted.

FIG. 9 is a flow chart showing an operation example of the antenna placement determination system 1 according to the third embodiment. Note that when there are a plurality of antennas and these antennas use different frequencies, the following series of processes are executed for each of the frequencies used by the plurality of antennas.

S<b>301 : Input of Design Information The design information input unit 101 receives input of design information of the moving body 2 .

S302: Estimation of Noise Intensity Distribution The noise distribution estimation unit 103 calculates the noise intensity distribution (electromagnetic field distribution) generated by the digital circuit at a predetermined frequency based on the design information input in S301.

S303: Estimation of Antenna Sensitivity Distribution The antenna sensitivity estimation unit 105 calculates the antenna sensitivity distribution at the frequency used by the antenna based on the input design information.

S304: Aerodynamic Characteristic Calculation The aerodynamic characteristic calculation unit 109 calculates an evaluation index E of lift force and drag force generated in the body of the moving object 2 based on the input design information.

S305: Is the evaluation index below the allowable value?
If the evaluation index E is equal to or less than the allowable value, the process transitions to S306. Otherwise, the process proceeds to S310.

S306: Calculation of center-of-gravity characteristics The center-of-gravity characteristics calculation unit 111 calculates an evaluation index F of the center-of-gravity balance of the airframe based on the input design information.

S307: Is the evaluation index below the allowable value?
If the evaluation index F is equal to or less than the allowable value, the process transitions to S308. Otherwise, the process proceeds to S310.

S308: Evaluate overlap between noise intensity distribution and antenna sensitivity distribution The optimization unit 107 evaluates overlap between the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105. Calculate index D.

S309: Is the evaluation index below the allowable value?
If the evaluation index D is equal to or less than the allowable value, the optimization unit 107 outputs the current design information as the result of the optimization process, and terminates the process. Otherwise, the process proceeds to S310.

S310: Change of Antenna Position Information or Circuit Module Layout Information The optimization unit 107 rearranges antennas or circuit modules by changing antenna position information or circuit module layout information. Transition to S302.

According to Embodiment 3, the antenna placement determination system 1 performs aerodynamic characteristic (lift-drag ratio) calculation and center-of-gravity calculation in addition to communication sensitivity characteristic calculation to determine the placement of antennas or circuit modules. As a result, when designing the moving body 2, the optimum antenna arrangement or circuit module arrangement can be determined with high accuracy and ease.

<Embodiment 4>
In Embodiment 4, after the antenna arrangement and circuit module arrangement are determined by any of the methods of Embodiments 1 to 3, it is confirmed that radio waves (plane waves) from communication stations, satellites, etc. can be reliably received. .

FIG. 10 is a block diagram illustrating the functional configuration of the antenna placement determination system 1 according to the fourth embodiment. Antenna placement determination system 1 has design information input section 101 , noise distribution estimation section 103 , antenna sensitivity estimation section 105 , optimization section 107 and reception sensitivity test section 113 . The aerodynamic property calculator 109 and the center-of-gravity property calculator 111 may be provided.

The operations of the design information input unit 101, the noise distribution estimation unit 103, the antenna sensitivity estimation unit 105, the aerodynamic characteristics calculation unit 109, and the center-of-gravity characteristics calculation unit 111 are the same as those in Embodiment 1, 2 or 3, so descriptions thereof are omitted. do.

The reception sensitivity test section 113 simulates a plane wave that simulates radio waves from a communication station, a satellite, or the like, and calculates the radio reception sensitivity based on the input design information. Since the method of calculating the reception sensitivity is known, the description thereof is omitted. The reception sensitivity test section 113 outputs an evaluation index G as the reception sensitivity calculation result.

In addition, the optimization unit 107 calculates the lift and drag evaluation index E (if the aerodynamic characteristics calculation unit 109 exists), the center-of-gravity balance evaluation index F (if the center-of-gravity characteristics calculation unit 111 exists), and the noise intensity distribution. It is determined in order whether or not the evaluation index D of the overlap between the antenna sensitivity distribution and the evaluation index D of the reception sensitivity and the evaluation index G of the reception sensitivity satisfy predetermined criteria. If all evaluation indices satisfy the criteria, the optimization unit 107 outputs the current design information as the optimization result. On the other hand, if at least one of the evaluation indices does not satisfy the criteria, the optimization unit 107 changes the antenna arrangement or the circuit module arrangement, and calculates all the evaluation indices again. The modification of the antenna layout and the modification of the circuit module layout have been described in the first and second embodiments, so the description is omitted. The optimization unit 107 repeatedly executes a series of these processes until all evaluation indices satisfy the criteria.

In the above-described embodiment, the optimization unit 107 serially determines whether or not each evaluation index satisfies a predetermined standard, and when all the evaluation indexes are equal to or less than a predetermined threshold, Finished processing. However, the present invention is not limited to this. may

FIG. 11 is a flow chart showing an operation example of the antenna placement determination system 1 according to the fourth embodiment. Note that when there are a plurality of antennas and these antennas use different frequencies, the following series of processes are executed for each of the frequencies used by the plurality of antennas.

S<b>401 : Input of Design Information The design information input unit 101 receives input of design information of the moving body 2 .

S402: Estimation of Noise Intensity Distribution The noise distribution estimation unit 103 calculates the noise intensity distribution (electromagnetic field distribution) generated by the digital circuit at a predetermined frequency based on the design information input in S401.

S403: Estimation of Antenna Sensitivity Distribution The antenna sensitivity estimation unit 105 calculates the antenna sensitivity distribution at the frequencies used by the antenna based on the input design information.

S404: Aerodynamic Characteristic Calculation The aerodynamic characteristic calculation unit 109 calculates an evaluation index E of lift force and drag force generated in the body of the moving body 2 based on the input design information.

S405: Is the evaluation index below the allowable value?
If the evaluation index E is equal to or less than the allowable value, the process transitions to S406. Otherwise, the process proceeds to S41.

S406: Calculation of center-of-gravity characteristics The center-of-gravity characteristics calculation unit 111 calculates an evaluation index F of the center-of-gravity balance of the airframe based on the input design information.

S407: Is the evaluation index below the allowable value?
If the evaluation index F is equal to or less than the allowable value, the process transitions to S408. Otherwise, the process proceeds to S412.

S408: Evaluate overlap between noise intensity distribution and antenna sensitivity distribution The optimization unit 107 evaluates overlap between the noise intensity distribution estimated by the noise distribution estimation unit 103 and the antenna sensitivity distribution estimated by the antenna sensitivity estimation unit 105. Calculate index D.

S409: Is the evaluation index below the allowable value?
If the evaluation index D is equal to or less than the allowable value, the process transitions to S410. Otherwise, the process proceeds to S412.

S410: Reception Sensitivity Calculation The reception sensitivity test section 113 simulates a plane wave that simulates radio waves from a communication station, a satellite, etc., and outputs an evaluation index G of radio reception sensitivity based on the input design information. .

S411: Is the evaluation index below the allowable value?
If the evaluation index G is equal to or less than the allowable value, the optimization unit 107 outputs the current design information as the result of the optimization process, and terminates the process. Otherwise, the process proceeds to S412.

S412: Change of Antenna Position Information or Circuit Module Layout Information The optimization unit 107 rearranges antennas or circuit modules by changing antenna position information or circuit module layout information. Transition to S402.

According to Embodiment 4, the antenna placement determination system 1 performs reception sensitivity tests in addition to communication sensitivity characteristic calculations to determine placement of antennas or circuit modules. As a result, when designing the moving body 2, the optimum antenna arrangement or circuit module arrangement can be determined with high accuracy and ease.

<Other embodiments>
It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention. For example, in the above-described embodiments, a drone is mainly assumed as the mobile object 2, but the present invention is not limited to this, and any object that can move by itself, such as a vehicle, ship, or robot, can be moved. Contained in body 2.

Further, in Embodiments 3 and 4, the aerodynamic characteristics, the center of gravity characteristics, the overlap between the noise intensity distribution and the antenna sensitivity distribution, and the reception sensitivity were evaluated in order, but this evaluation order may be arbitrarily changed.

Further, in the above-described embodiments, the present invention has been described mainly as a hardware configuration, but the present invention is not limited to this. It is also possible to realize by In this case, the computer program can be stored and provided to the computer using various types of non-transitory computer readable medium. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (eg, flexible discs, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R/W, semiconductor memory (eg, mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory)). The program may also be supplied to the computer on various types of transitory computer readable medium. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can deliver the program to the computer via wired channels, such as wires and optical fibers, or wireless channels.

1 antenna placement determination system 11 processor 13 memory 15 input unit 17 output unit 101 design information input unit 103 noise distribution estimation unit 105 antenna sensitivity estimation unit 107 optimization unit 109 aerodynamic characteristic calculation unit 111 center of gravity characteristic calculation unit 113 reception sensitivity test unit 21 Communication/sensor unit 211 Position sensor 213 Video data transmission communication module 215 Operation communication module 217 6-axis sensor 219 Image sensor 23 Control unit 231 Controller 25 Driving unit 251 ESC
253 Motor 255 Propeller 27 Power supply

Claims (10)

A system for determining antenna placement in a mobile object,
Circuit information about characteristics of the digital circuit, structural information about the structure of the digital circuit, antenna information about the characteristics of the antenna, circuit module layout information about the layout of the digital circuit, and antenna position information about the layout of the antenna are input as design information. a design information input unit;
a noise distribution estimation unit that calculates a noise intensity distribution based on the circuit information, the structure information, and the circuit module placement information;
an antenna sensitivity estimation unit that calculates an antenna sensitivity distribution based on the antenna information and the antenna position information;
an optimization unit that evaluates overlap between the noise intensity distribution and the antenna sensitivity distribution, and changes the design information if the evaluation result of the overlap does not satisfy a predetermined criterion. When the evaluation result of the overlap does not satisfy a predetermined criterion, the optimization unit changes the antenna position information, causes the antenna sensitivity estimation unit to recalculate the antenna sensitivity distribution, and evaluates the overlap again. The antenna placement determination system according to claim 1. When the evaluation result of the overlap does not satisfy a predetermined criterion, the optimization unit changes the circuit module placement information, causes the noise distribution estimation unit to recalculate the noise intensity distribution, and evaluates the overlap again. The antenna placement determination system of claim 1. The optimization unit uses the noise channel power at the antenna output end when noise is applied as the evaluation result of the overlap, and determines that the noise channel power at the antenna output end when noise is applied is lower than the allowable noise channel power defined by the communication module. 4. The antenna placement determination system according to any one of claims 1 to 3, wherein said predetermined reference is used. further comprising an aerodynamic characteristic calculation unit that calculates lift and drag generated in the moving object based on the design information;
5. The antenna placement determination system according to any one of claims 1 to 4, wherein the design information is changed when evaluation results of the lift force and the drag force do not satisfy predetermined criteria. further comprising a center-of-gravity characteristic calculation unit that calculates the center-of-gravity balance of the moving object based on the design information;
4. The antenna placement determination system according to any one of claims 1 to 3, wherein the design information is changed when the evaluation result of the center-of-gravity balance does not satisfy a predetermined criterion. further comprising a reception sensitivity testing unit that calculates radio reception sensitivity based on the design information;
7. The antenna placement determination system according to any one of claims 1 to 6, wherein the design information is changed when the evaluation result of the radio reception sensitivity does not satisfy a predetermined criterion. A method for a computer to determine antenna placement in a mobile object, comprising:
Circuit information about characteristics of the digital circuit, structural information about the structure of the digital circuit, antenna information about the characteristics of the antenna, circuit module layout information about the layout of the digital circuit, and antenna position information about the layout of the antenna are input as design information. a design information input step;
a noise distribution estimation step of calculating a noise intensity distribution based on the circuit information, the structure information, and the circuit module placement information;
An antenna sensitivity estimation step of calculating an antenna sensitivity distribution based on the antenna information and the antenna position information;
an optimization step of evaluating overlap between the noise intensity distribution and the antenna sensitivity distribution, and changing the design information if the evaluation result of the overlap does not satisfy a predetermined criterion. In the optimization step, the noise channel power at the antenna output end when noise is applied is used as the evaluation result of the overlap, and it is determined that the noise channel power at the antenna output end when noise is applied is lower than the allowable noise channel power defined by the communication module. 9. The antenna placement determination method according to claim 8, wherein said predetermined reference is used. A program for causing a computer to execute the method according to claim 8 or 9.

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