Simulation apparatus and simulation method

Abstract

This program performs highly accurate simulations of detecting surrounding objects using object detection sensors. [Solution] The simulation device of the embodiment comprises: a first vibration analysis unit that calculates the displacement of the vibration surface using a vibration analysis algorithm based on the three-dimensional shapes and characteristic values ​​of the object detection sensor and surrounding objects, and the voltage value applied to the piezoelectric element; an acoustic analysis unit that calculates the sound pressure of the surrounding air and the pressure acting on the vibration surface due to the reflected waves of the transmitted waves generated by the displacement of the vibration surface calculated by the first vibration analysis unit, the three-dimensional shapes and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor using an acoustic analysis algorithm; and a second vibration analysis unit that calculates the voltage excited by the piezoelectric element using a vibration analysis algorithm based on the pressure acting on the vibration surface calculated by the acoustic analysis unit, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and surrounding objects.

Description

Technical Field

[0001] This embodiment relates to a simulation device and a simulation method.

Background Art

[0002] Conventionally, an object (obstacle) detection sensor may be provided in a vehicle (such as an automobile). The object detection sensor detects objects (for example, other vehicles, pedestrians, buildings, etc.) around the vehicle.

[0003] Also, in a conventional simulation device equipped with an obstacle detection sensor, before actually mounting an obstacle detection sensor on a vehicle, there is a device that determines whether the arrangement state of the obstacle detection sensor is good or not. According to this, it is possible to determine whether or not the sensor detection area and the wheel stopper interfere with each other based on the sensor data representing the position and detection area of the sonar, which is the obstacle detection sensor, and the simulated object data representing the shape and dimensions of the wheel stopper mock-up.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The objects detected by an object detection sensor actually installed in a vehicle are not limited to other vehicles that are originally intended to be detected, but may also include the vehicle's own parts (for example, bumpers, etc.) that are not originally intended to be detected. However, in the above-described conventional technology, it was possible to determine whether or not the sensor detection area and the wheel stopper interfere with each other in the simulation, but it was not possible to determine whether or not the vehicle's own parts would be detected.

[0006] Furthermore, even if we were to consider using simulation to determine whether or not the sensor detection area interferes with the vehicle's components, it would be difficult to obtain highly accurate results because the characteristic values ​​of the vehicle's components (for example, material properties) would not be taken into account.

[0007] Therefore, one of the objectives of this embodiment is to provide a simulation device and a simulation method that can perform highly accurate simulations regarding the detection of surrounding objects by an object detection sensor. [Means for solving the problem]

[0008] The simulation device of this embodiment is a simulation device that performs a simulation of a received signal of a reflected wave generated when a transmitted wave generated by an object detection sensor, on which a piezoelectric element is provided on a vibrating surface, is reflected by surrounding objects, and comprises: a first vibration analysis unit that calculates the displacement of the vibrating surface using a predetermined vibration analysis algorithm with respect to the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element; an acoustic analysis unit that calculates the sound pressure of the surrounding air and the pressure applied to the vibrating surface by the reflected wave of the transmitted wave generated by the displacement of the vibrating surface using a predetermined acoustic analysis algorithm with respect to the displacement of the vibrating surface calculated by the first vibration analysis unit, the three-dimensional shapes and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor; and a second vibration analysis unit that calculates the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm with respect to the pressure applied to the vibrating surface calculated by the acoustic analysis unit, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects.

[0009] Furthermore, the simulation method of this embodiment is a simulation method using a simulation device that performs a simulation of a received signal of a reflected wave generated when a transmitted wave generated by an object detection sensor, on which a piezoelectric element is provided on the vibration surface, is reflected by surrounding objects, and includes: a first vibration analysis step in which a first vibration analysis unit calculates the displacement of the vibration surface using a predetermined vibration analysis algorithm, using the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element; an acoustic analysis step in which an acoustic analysis unit calculates the sound pressure of the surrounding air and the pressure applied to the vibration surface by the reflected wave of the transmitted wave generated by the displacement of the vibration surface calculated in the first vibration analysis step, the three-dimensional shapes and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor, using a predetermined acoustic analysis algorithm; and a second vibration analysis step in which a second vibration analysis unit calculates the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm, using the pressure applied to the vibration surface calculated in the acoustic analysis step, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects. [Effects of the Invention]

[0010] According to the simulation device and simulation method of this embodiment, it is possible to perform highly accurate simulations regarding the detection of surrounding objects by an object detection sensor. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a functional configuration diagram of the simulation device according to the embodiment. [Figure 2] Figure 2 shows an example of how an object detection sensor is installed on a bumper in an embodiment. [Figure 3] Figure 3 is an explanatory diagram of the analysis model in the embodiment. [Figure 4] Figure 4 shows the structure of an object detection sensor in an embodiment. [Figure 5] Figure 5 is a graph showing an example of the applied voltage to the piezoelectric element in the embodiment. [Figure 6] Figure 6 shows the pressure distribution on the vibration surface of the object detection sensor in the embodiment. [Figure 7] Figure 7 is a graph showing a first example of the received signal from the object detection sensor in the embodiment. [Figure 8] Figure 8 is a graph showing a second example of the received signal from the object detection sensor in the embodiment. [Figure 9] Figure 9 is a flowchart showing the processing performed by the simulation device of the embodiment. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the simulation apparatus and simulation method of the present invention will be described with reference to the drawings.

[0013] Figure 1 is a functional configuration diagram of the simulation device 1 of the embodiment. The simulation device 1 is a computer device that performs a simulation of the received signal of a reflected wave generated when a transmitted wave generated by an object detection sensor 7 (Figures 2 to 4), which has a piezoelectric element attached to its vibration surface, is reflected by surrounding objects. The simulation device 1 has the following functional configuration: a processing unit 2, a storage unit 3, an input unit 4, a display unit 5, and a communication unit 6.

[0014] The memory unit 3 is implemented by, for example, RAM (Random Access Memory), ROM (Read Only Memory), SSD (Solid State Drive), HDD (Hard Disk Drive), etc., and stores various types of information. The memory unit 3 stores, for example, the operation program of the processing unit 2, various data, and various calculation results.

[0015] The processing unit 2 is implemented by, for example, a CPU (Central Processing Unit) and executes various information processes. The processing unit 2 includes, for example, an acquisition unit 21, a first vibration analysis unit 22, an acoustic analysis unit 23, a second vibration analysis unit 24, and a control unit 25 as functional components.

[0016] The acquisition unit 21 acquires various information. The acquisition unit 21 acquires, for example, information used for the processes of the first vibration analysis unit 22, the acoustic analysis unit 23, the second vibration analysis unit 24, and the control unit 25 from the storage unit 3.

[0017] Here, FIG. 2 is a diagram showing an installation example of the object detection sensor 7 with respect to the bumper B (an example of a surrounding object) in the embodiment. Two object detection sensors 7 are installed with respect to the bumper B of the vehicle. Note that the number of object detection sensors 7 is not limited to two, and may be three or more.

[0018] Further, FIG. 3 is an explanatory diagram of the analysis model in the embodiment. FIG. 3(a) is a diagram extracted from a part of FIG. 2. FIG. 3(b) is a Z-Z cross-sectional view of FIG. 3(a). In the analysis model, an object such as the bumper B around the object detection sensor 7 is assumed to totally reflect the transmission wave by the object detection sensor 7. Further, the air A in the calculation target area is divided on the three-dimensional coordinate space, and the calculation is executed for each divided unit.

[0019] Further, FIG. 4 is a diagram showing the structure of the object detection sensor 7 in the embodiment. As shown in the cross-sectional view of FIG. 4(a), the object detection sensor 7 is fixed to the bumper B by a cylindrical retainer R.

[0020] Further, as shown in FIG. 4(b), the object detection sensor 7 includes a piezoelectric element 71, an aluminum case 72, an outer rubber 73, an inner rubber 74, a housing 75, a foamed silicon 76, and the like.

[0021] The first vibration analysis unit 22 uses the three-dimensional shapes and characteristic values ​​of the object detection sensor 7 and surrounding objects (such as bumper B), as well as the voltage value applied to the piezoelectric element 71, to calculate the displacement of the vibration surface using a predetermined vibration analysis algorithm (for example, FEM (Finite Element Method)).

[0022] Here, Figure 5 is a graph showing an example of the applied voltage to the piezoelectric element 71 in the embodiment. The horizontal axis represents time, and the vertical axis represents voltage.

[0023] Furthermore, the following are set in the memory unit 3 as characteristic values ​​of the object detection sensor 7. • Material properties of the aluminum case 72, outer rubber 73, inner rubber 74, and housing 75, including Young's modulus [Pa] and density [kg / m³]. 3 ], Poisson's ratio, damping coefficient • Acoustic material properties of foamed silicon 76: sound velocity [m / s], density [kg / m³] 3 ], damping coefficient These models may also be linear models, for example, to reduce computation time.

[0024] Furthermore, the piezoelectric element 71 is divided two-dimensionally or three-dimensionally by dividing the surface that transmits and receives sound waves into a mesh (finite element) shape, and the elastic matrix, piezoelectric matrix, and dielectric matrix are set as characteristic values ​​for the divided regions in the memory unit 3.

[0025] The acoustic analysis unit 23 uses the displacement of the vibrating surface calculated by the first vibration analysis unit 22, the three-dimensional shape and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor 7 to calculate the sound pressure of the surrounding air and the pressure acting on the vibrating surface due to the reflected waves of the transmitted waves generated by the displacement of the vibrating surface, using a predetermined acoustic analysis algorithm (for example, DGM (Discontinuous Galerkin Method)).

[0026] Here, the material properties related to the acoustics of air A are defined as sound velocity [m / s] and density [kg / m³]. 3 The damping coefficient is set in the memory unit 3.

[0027] In addition, other values ​​such as admittance [m / s / Pa] and standard impedance [Pa·s / m] as material properties related to the reflection of bumper B may also be set in the memory unit 3.

[0028] The second vibration analysis unit 24 uses the pressure applied to the vibration surface calculated by the acoustic analysis unit 23, as well as the three-dimensional shapes and characteristic values ​​of the object detection sensor 7 and the surrounding objects, to calculate the voltage excited by the piezoelectric element 71 (hereinafter also referred to as the received signal or amplitude) using a predetermined vibration analysis algorithm (for example, FEM).

[0029] Here, Figure 6 shows the pressure distribution on the vibration surface of the object detection sensor 7 in the embodiment. On the vibration surface, the pressure level is represented by the intensity of the black color.

[0030] The control unit 25 performs various controls. For example, the control unit 25 displays various information on the display unit 5.

[0031] The input unit 4 is a means for the user to input information, and can be implemented, for example, by a keyboard or mouse.

[0032] The display unit 5 is a means of displaying information and is implemented, for example, by an LCD (Liquid Crystal Display).

[0033] The communication unit 6 is a communication interface for communicating with an external device (not shown).

[0034] Next, an example of a received signal from the object detection sensor 7 will be described with reference to Figures 7 and 8. Note that in the explanation of Figure 8, explanations of matters similar to those in Figure 7 will be omitted as appropriate.

[0035] Figure 7 is a graph showing a first example of the received signal from the object detection sensor 7 in the embodiment. In Figures 7(a) and 7(b), the horizontal axis represents time and the vertical axis represents amplitude. Figure 7(a) shows the simulation result, and Figure 7(b) shows the measured result.

[0036] Figure 7 shows an example where the transmitted and received waves of the object detection sensor 7 are not significantly affected by the bumper B. In this case, as shown in Figure 7(a), the simulation results show that the received signal RS1 increases monotonically in response to the transmission wave, then decreases monotonically, with no peaks during the decrease. The code TH1 is the detection threshold.

[0037] Similar to Figure 7(a), the measured results shown in Figure 7(b) also show that the received signal RS2 monotonically increases and then monotonically decreases in response to the transmission wave, with no peaks during the decrease. The code TH2 is the detection threshold.

[0038] Furthermore, the received signal RS1 in Figure 7(a) and the received signal RS2 in Figure 7(b) have similar shapes, indicating that a highly accurate simulation was performed.

[0039] Next, Figure 8 is a graph showing a second example of the received signal of the object detection sensor 7 in the embodiment. In Figure 8, Figure 8(a) is the simulation result, and Figure 8(b) is the measured result. Figure 8 is an example where the transmitted and received waves of the object detection sensor 7 are affected to a certain extent by the bumper B. In this case, as shown in Figure 8(a), in the simulation result, the received signal RS3 increases monotonically in response to the emission of the transmitted wave, and then decreases, but there is a peak during the decrease.

[0040] Furthermore, similar to Figure 8(a), the measured results shown in Figure 8(b) also show that the received signal RS4 increases monotonically in response to the transmission wave, then decreases, but there is a peak during the decrease.

[0041] Furthermore, the received signal RS3 in Figure 8(a) and the received signal RS4 in Figure 8(b) have similar shapes, indicating that a highly accurate simulation was performed.

[0042] Next, the processing performed by the simulation device 1 will be described with reference to Figure 9. Figure 9 is a flowchart showing the processing performed by the simulation device 1 in this embodiment.

[0043] In step S1, the first vibration analysis unit 22 uses the three-dimensional shapes and characteristic values ​​of the object detection sensor 7 and the surrounding objects (such as the bumper B), as well as the voltage value applied to the piezoelectric element 71, to calculate the displacement of the vibration surface using a predetermined vibration analysis algorithm.

[0044] Next, in step S2, the acoustic analysis unit 23 uses the displacement of the vibrating surface calculated in step S1, the three-dimensional shape and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor 7 to calculate the sound pressure of the surrounding air and the pressure acting on the vibrating surface due to the reflected waves of the transmitted waves generated by the displacement of the vibrating surface, using a predetermined acoustic analysis algorithm.

[0045] Next, in step S3, the second vibration analysis unit 24 uses the pressure applied to the vibration surface calculated in step S2, as well as the three-dimensional shapes and characteristic values ​​of the object detection sensor 7 and the surrounding objects, to calculate the voltage excited to the piezoelectric element 71 using a predetermined vibration analysis algorithm.

[0046] Next, in step S4, the control unit 25 outputs the calculation result from step S3 (for example, by storing it in the memory unit 3 or displaying it on the display unit 5).

[0047] In this way, according to the simulation device 1 of this embodiment, by using the three-dimensional shapes and characteristic values ​​of the object detection sensor 7 and bumper B, it is possible to perform a highly accurate simulation of the detection of surrounding objects by the object detection sensor 7.

[0048] Furthermore, Figures 7 and 8 show that the simulation results and the actual measurement results show the same trend. Therefore, based on the simulation results, it is possible to predict in advance (before actually installing the object detection sensor 7 in the vehicle) signs of false detection by the object detection sensor 7, allowing for the implementation of effective and efficient countermeasures.

[0049] (modified version) Next, we will explain a modified example. In this modified example, we assume that moisture (raindrops, snow, water droplets, etc.) adheres to the object detection sensor 7. Even in this case, by incorporating the three-dimensional shape and characteristic values ​​of the moisture into the analysis model, it is possible to obtain the received signal when moisture adheres to the object detection sensor 7 through simulation.

[0050] At this time, the second vibration analysis unit 24 further uses the three-dimensional shape and characteristic values ​​of the moisture adhering to the object detection sensor 7 to calculate the voltage excited in the piezoelectric element 71 using a predetermined vibration analysis algorithm.

[0051] Thus, according to the modified simulation device 1, even when moisture is present on the object detection sensor 7, the simulation can obtain a received signal that reflects that effect.

[0052] The program executed by the simulation device 1 of this embodiment can be provided as an installable or executable file recorded on a computer-readable recording medium such as a CD (Compact Disc)-ROM (Read Only Memory), flexible disk (FD), CD-R (Recordable), or DVD (Digital Versatile Disk). Alternatively, the program may be provided or distributed via a network such as the Internet.

[0053] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0054] For example, the surrounding objects set in the simulation are not limited to the vehicle's bumper B, but may also include other vehicle parts such as lights (lighting devices) or license plates.

[0055] Furthermore, in the above-described embodiment, for the sake of brevity, the transmitting piezoelectric element and the receiving piezoelectric element of the object detection sensor 7 were made the same, but the invention is not limited to this, and they may be separate.

[0056] Furthermore, the analysis model may include the three-dimensional shape and characteristic values ​​of the road surface.

[0057] Furthermore, the vibration analysis algorithm is not limited to FEM; other algorithms may also be used. Furthermore, the acoustic analysis algorithm is not limited to DGM; other algorithms may also be used.

[0058] Furthermore, other types of characteristic values ​​besides those described above may be used for the characteristic values ​​of the object detection sensor 7 and surrounding objects.

[0059] [Summary of this embodiment] This embodiment comprises at least the following configurations.

[0060] A simulation device for performing a simulation of a received signal of a reflected wave generated when a transmitted wave generated by an object detection sensor, on which a piezoelectric element is provided on a vibrating surface, is reflected by surrounding objects, comprising: a first vibration analysis unit that calculates the displacement of the vibrating surface using a predetermined vibration analysis algorithm with respect to the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element; an acoustic analysis unit that calculates the sound pressure of the surrounding air and the pressure applied to the vibrating surface by the reflected wave of the transmitted wave generated by the displacement of the vibrating surface using a predetermined acoustic analysis algorithm with respect to the displacement of the vibrating surface calculated by the first vibration analysis unit, the three-dimensional shapes and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor; and a second vibration analysis unit that calculates the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm with respect to the pressure applied to the vibrating surface calculated by the acoustic analysis unit, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects.

[0061] With this configuration, by using the three-dimensional shape and characteristic values ​​of objects around the object detection sensor and bumper, it is possible to perform highly accurate simulations of the detection of surrounding objects by the object detection sensor.

[0062] Furthermore, the object detection sensor is installed on the vehicle's bumper, and the surrounding objects include the bumper.

[0063] This configuration allows for highly accurate simulations of object detection sensors installed on the vehicle's bumper.

[0064] Furthermore, the second vibration analysis unit uses the three-dimensional shape and characteristic values ​​of the moisture adhering to the object detection sensor to calculate the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm.

[0065] With this configuration, it is possible to perform highly accurate simulations even for objects detected by sensors that come into contact with moisture.

[0066] Furthermore, the simulation method of this embodiment is a simulation method using a simulation device that performs a simulation of a received signal of a reflected wave generated when a transmitted wave generated by an object detection sensor, on which a piezoelectric element is provided on the vibration surface, is reflected by surrounding objects, and includes: a first vibration analysis step in which a first vibration analysis unit calculates the displacement of the vibration surface using a predetermined vibration analysis algorithm, using the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element; an acoustic analysis step in which an acoustic analysis unit calculates the sound pressure of the surrounding air and the pressure applied to the vibration surface by the reflected wave of the transmitted wave generated by the displacement of the vibration surface calculated in the first vibration analysis step, the three-dimensional shapes and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor, using a predetermined acoustic analysis algorithm; and a second vibration analysis step in which a second vibration analysis unit calculates the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm, using the pressure applied to the vibration surface calculated in the acoustic analysis step, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects.

[0067] With this configuration, by using the three-dimensional shape and characteristic values ​​of objects around the object detection sensor and bumper, it is possible to perform highly accurate simulations of the detection of surrounding objects by the object detection sensor.

[0068] Furthermore, the effects of the dependent claims and embodiments are additional effects separate from the effects of the independent claims. [Explanation of Symbols]

[0069] 1...Simulation device, 2...Processing unit, 3...Storage unit, 4...Input unit, 5...Display unit, 6...Communication unit, 21...Acquisition unit, 22...First vibration analysis unit, 23...Acoustic analysis unit, 24...Second vibration analysis unit, 25...Control unit

Claims

1. A simulation device that performs a simulation of the received signal of a reflected wave generated when a transmitted wave, which is attached to a vibrating surface of an object detection sensor, is reflected by surrounding objects, A first vibration analysis unit calculates the displacement of the vibration surface using a predetermined vibration analysis algorithm, based on the three-dimensional shape and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element. An acoustic analysis unit calculates the sound pressure of the surrounding air and the pressure acting on the vibrating surface by the reflected waves of the transmitted waves generated by the displacement of the vibrating surface using a predetermined acoustic analysis algorithm, using the displacement of the vibrating surface calculated by the first vibration analysis unit, the three-dimensional shape and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor. A simulation apparatus comprising: a second vibration analysis unit that calculates the voltage excited by the piezoelectric element using a predetermined vibration analysis algorithm, using the pressure applied to the vibrating surface calculated by the acoustic analysis unit, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, respectively.

2. The object detection sensor is installed on the vehicle's bumper. The simulation apparatus according to claim 1, wherein the surrounding objects include the bumper.

3. The simulation apparatus according to claim 1, wherein the second vibration analysis unit further uses the three-dimensional shape and characteristic values ​​of the moisture adhering to the object detection sensor to calculate the voltage excited by the piezoelectric element using the predetermined vibration analysis algorithm.

4. A simulation method using a simulation device that performs a simulation of a received signal of a reflected wave generated when a transmitted wave, which is attached to a vibrating surface of an object detection sensor, is reflected by surrounding objects, wherein the transmitted wave is a reflected wave. The first vibration analysis unit performs a first vibration analysis step in which it calculates the displacement of the vibration surface using a predetermined vibration analysis algorithm, based on the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, and the voltage value applied to the piezoelectric element. The acoustic analysis unit performs an acoustic analysis step in which it uses the displacement of the vibrating surface calculated in the first vibration analysis step, the three-dimensional shape and characteristic values ​​of the surrounding objects, and the characteristic values ​​of the air around the object detection sensor to calculate the sound pressure of the surrounding air and the pressure acting on the vibrating surface due to the reflected waves of the transmitted waves generated by the displacement of the vibrating surface, using a predetermined acoustic analysis algorithm. A simulation method comprising: a second vibration analysis step in which a second vibration analysis unit calculates the voltage excited by the piezoelectric element using a predetermined vibration analysis algorithm, using the pressure applied to the vibration surface calculated by the acoustic analysis step, and the three-dimensional shapes and characteristic values ​​of the object detection sensor and the surrounding objects, respectively.

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