Distortion measurement method for moving objects, program and device

Abstract

To provide a strain measurement method for moving bodies, a strain measurement program for moving bodies and a strain measurement device for moving bodies with which it is possible to reduce manufacturing-hours and costs.SOLUTION: This strain measurement method for moving bodies comprises: a strain data acquisition step S4 for acquiring time-series strain data regarding the strain of a moving body; a movement state data acquisition step S4 for acquiring time-series movement state data regarding the movement state of the moving body that is synchronized with the strain data; frequency determination steps S5, S6 for determining the prescribed frequency that is used in under-mentioned removal steps, on the basis of the movement state data acquired in the movement state data acquisition step; and removal steps S7, S8 for removing frequency components lower than or equal to a prescribed frequency from the strain data acquired in the strain data acquisition step.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for measuring distortion of a moving body, a program for measuring distortion of a moving body, and an apparatus for measuring distortion of a moving body. [Background technology]

[0002] In recent years, optical fiber sensing technology has been researched and developed to measure distributed strain and temperature using optical fiber as a sensor for monitoring buildings, bridges, and other structures, dams, tunnels, and other structures, as well as moving objects, such as vehicles, aircraft, and ships. Known methods for measuring strain and temperature using optical fiber include, for example, a method using Brillouin scattering, a method using Rayleigh scattering, and a method using fiber Bragg grating (FBG). In these methods, the optical fiber is used as a medium for detecting at least one of the strain and temperature in the environment in which the optical fiber is placed. Because the influence of thermal expansion of the optical fiber affects the accuracy of strain measurement in such optical fiber sensors, it is necessary to eliminate the influence of heat when measuring strain. A technique for eliminating the influence of heat is disclosed, for example, in Patent Document 1.

[0003] The strain distribution measurement system disclosed in Patent Document 1 uses an optical fiber core as a sensor and measures the strain distribution of an optical fiber cable using Brillouin scattered light in the optical fiber core.The system measures the temperature distribution of the optical fiber core, and when deriving the strain distribution of the optical fiber cable from the Brillouin scattered light distribution measurement result, the temperature distribution measurement result is used to derive the strain distribution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3365286 (Japanese Unexamined Patent Publication No. 11-173943) Summary of the Invention [Problem to be solved by the invention]

[0005] However, the strain distribution measurement system disclosed in Patent Document 1 requires an optical fiber for temperature measurement in addition to an optical fiber for strain measurement in order to eliminate the influence of heat on strain measurement, which increases the labor required to lay the optical fiber for temperature measurement and the cost of the optical fiber for temperature measurement.

[0006] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a method for measuring distortion for a moving body, a program for measuring distortion for a moving body, and an apparatus for measuring distortion for a moving body that can reduce labor and costs. [Means for solving the problem]

[0007] After extensive investigation, the inventors have found that the above object can be achieved by the present invention described below. That is, a strain measurement method for a moving body according to one aspect of the present invention comprises: a strain data acquisition step of acquiring time-series strain data related to the strain of the moving body; a moving state data acquisition step of acquiring time-series moving state data related to the moving state of the moving body synchronized with the strain data; a frequency determination step of determining a predetermined frequency to be used in a removing step described below based on the moving state data acquired in the moving state data acquisition step; and a removal step of removing frequency components below the predetermined frequency from the strain data acquired in the strain data acquisition step. Preferably, in the above-described strain measurement method for a moving body, the moving body comprises a heat source. The moving body is a vehicle, and the moving state data is time-series running state data related to the running state of the vehicle.

[0008] The temperature of a moving object is affected by, for example, the outside air temperature (environmental temperature) and the heat source of the motor, and this temperature changes relatively slowly due to convection, heat conduction, etc., and appears on the low-frequency side. Therefore, it is thought that components affected by temperature can be removed from the strain data by removing low-frequency components below a predetermined frequency from time-series strain data. After extensive research, the inventors discovered that, because changes in the temperature of a moving object are not directly related to changes in the moving state of the moving object, the predetermined frequency can be determined based on moving state data. The above-mentioned moving object strain measurement method determines a predetermined frequency (cutoff frequency) based on moving state data and removes frequency components below the predetermined frequency from the strain data, eliminating the need for temperature measurement and thereby reducing labor and costs.

[0009] In another aspect, in the above-described method for measuring distortion for a moving body, the distortion data and the moving state data are data detected while the moving body is moving.

[0010] For example, if the movement path and movement state of a moving object are known in advance and the temperature can be predicted based on these, it is thought that the influence of temperature can be removed from the strain data based on this predicted temperature. The above-mentioned strain measurement method for a moving object detects strain data and movement state data while the moving object is moving, so it is possible to remove the influence of temperature from the strain data even for moving objects whose temperature cannot be predicted.

[0011] In another aspect, in the above-described strain measurement method for a moving body, the strain data is data detected by using an optical fiber laid in the moving body.

[0012] Such a strain measurement method for a moving body uses optical fibers laid on the moving body, and therefore can measure strain distribution.

[0013] In another aspect, in the above-mentioned strain measurement method for a moving body, the moving state data is data related to the operation of the moving body by a passenger riding in the moving body. Preferably, in the above-mentioned strain measurement method for a moving body, the data related to the operation includes data (steering angle data) from a steering angle detection unit that detects (measures) a steering angle, data (accelerator depression amount data) from an accelerator depression amount detection unit that detects (measures) an accelerator pedal depression amount, and data (brake depression amount data) from a brake depression amount detection unit that detects (measures) an accelerator pedal depression amount.

[0014] This provides a method for measuring distortion of a moving body using moving state data relating to the operation of the moving body by a passenger riding on the moving body.

[0015] In another aspect, in the above-mentioned strain measurement method for a moving body, the movement state data is data related to the movement of the moving body. Preferably, in the above-mentioned strain measurement method for a moving body, the movement of the moving body includes acceleration, deceleration, and turning. Preferably, in the above-mentioned strain measurement method for a moving body, the data related to the movement includes data (acceleration data) from an acceleration detection unit that detects (measures) acceleration caused by the movement of the moving body, data (yaw rate data) from a yaw rate detection unit that detects (measures) yaw rate caused by the movement of the moving body, and data (brake fluid pressure data) from a brake fluid pressure detection unit that detects (measures) brake fluid pressure.

[0016] This provides a method for measuring distortion for a moving body using movement state data relating to the movement of the moving body.

[0017] In another aspect, in the above-mentioned strain measurement method for a moving body, the moving state data is data acquired from a detector that detects the moving state via a CAN (Controller Area Network). Preferably, in the above-mentioned strain measurement method for a moving body, the CAN is a network that uses a communication protocol standardized in the ISO11898 series.

[0018] Such a method for measuring distortion for a moving body uses a CAN, so that moving state data can be acquired from the detection unit with low noise.

[0019] Another aspect of the present invention provides a distortion measurement program for a moving body that causes a computer to execute a distortion data acquisition process for acquiring time-series distortion data relating to the distortion of the moving body, a moving state data acquisition process for acquiring time-series moving state data relating to the moving state of the moving body synchronized with the distortion data, a frequency determination process for determining a predetermined frequency to be used in a removal process based on the moving state data acquired in the moving state data acquisition process, and a removal process for removing frequency components below a predetermined frequency from the distortion data acquired in the distortion data acquisition process.

[0020] Another aspect of the present invention provides a strain measuring device for a moving body, comprising: a strain data acquisition unit that acquires time-series strain data relating to the strain of the moving body; a moving state data acquisition unit that acquires time-series moving state data relating to the moving state of the moving body synchronized with the strain data; a frequency determination unit that determines a predetermined frequency to be used in a removal unit based on the running state data acquired by the moving state data acquisition unit; and a removal unit that removes frequency components below a predetermined frequency from the strain data acquired by the strain data acquisition unit.

[0021] Such a strain measurement program for a moving body and a strain measurement device for a moving body determine a predetermined frequency (cutoff frequency) based on the moving state data and remove frequency components below the predetermined frequency from the strain data, thereby eliminating the need for temperature measurement and reducing labor and costs. [Effects of the Invention]

[0022] The moving body distortion measurement method, moving body distortion measurement program, and moving body distortion measurement device according to the present invention can reduce the number of steps and costs. [Brief explanation of the drawings]

[0023] [Figure 1]1 is a schematic diagram showing the configuration of a vehicle equipped with a strain measuring device for a moving body according to an embodiment; [Figure 2] FIG. 2 is a schematic diagram illustrating a first installation state of an optical fiber as an example. [Figure 3] FIG. 10 is a schematic diagram illustrating a second installation state of the optical fiber as another example. [Figure 4] FIG. 10 is a diagram showing steering angle data as an example. [Figure 5] FIG. 10 is a diagram showing distortion data as an example. [Figure 6] 4 is a flowchart showing the operation of the mobile body distortion measuring device and the vehicle with respect to distortion measurement. [Figure 7] FIG. 10 is a diagram showing data relating to the movement of a moving object, as an example. [Figure 8] 10A and 10B are diagrams for explaining a modified embodiment of the strain measuring device for a moving body. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In addition, components with the same reference numerals in each drawing indicate the same components, and their description will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual component, a reference numeral with a subscript is used.

[0025] The mobile body distortion measuring device in the embodiment is a device for measuring distortion of a mobile body. The mobile body is a device that can change its position, such as an aircraft, a ship, or a vehicle. Examples of the vehicle include passenger cars, buses, trucks, special vehicles, and railcars. This mobile body distortion measuring device includes a distortion data acquisition unit that acquires time-series distortion data related to the distortion of the mobile body, a moving state data acquisition unit that acquires time-series moving state data related to the moving state of the mobile body synchronized with the distortion data, a frequency determination unit that determines a predetermined frequency to be used in a removing unit based on the driving state data acquired by the moving state data acquisition unit, and a removing unit that removes frequency components below a predetermined frequency from the distortion data acquired by the distortion data acquisition unit. Below, such a mobile body distortion measuring device and a mobile body distortion measurement method and program implemented therein will be described in more detail, taking as an example a case where they are applied to a vehicle.

[0026] FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with a mobile body strain measuring device according to an embodiment. FIG. 2 is a schematic diagram illustrating a first optical fiber installation state as an example. FIG. 3 is a schematic diagram illustrating a second optical fiber installation state as another example. FIG. 3A is a diagram of the vehicle viewed from above, and FIG. 3B is a diagram of the vehicle viewed from below. FIG. 4 is a diagram showing steering angle data as an example. In FIG. 4, the steering angle data is shown in frequency space. The horizontal axis of FIG. 4 is logarithmic frequency (Hz), and the vertical axis is signal amplitude (Signal Amplitude). FIG. 5 is a diagram showing strain data as an example. FIG. 5A shows the data in time space, and FIG. 5B shows the data in frequency space. The horizontal axis of FIG. 5A is elapsed time (Time) (sec), and the vertical axis is strain (μstrain). The horizontal axis of FIG. 5B is frequency [Hz] on a logarithmic scale, and the vertical axis is power spectrum [dB] on a logarithmic scale.

[0027] In the following description, terms indicating directions such as "front," "rear," "right," "left," "up," and "down" refer to the respective directions of the vehicle when the direction of travel of the vehicle when traveling forward is defined as "front."

[0028] As shown in FIG. 1, a vehicle VC equipped with a moving body strain measuring device according to an embodiment includes a motor 18 at its front as an example of a prime mover for driving a pair of left and right front wheels 11. The motor 18 also functions as a generator during regeneration. Each front wheel 11 is suspended from a body (not shown) of the vehicle VC via a respective suspension 13. Note that FIG. 1 does not show the rear portion of the vehicle, including the pair of left and right rear wheels. The motor 18 is connected to a battery (secondary battery) 31 that charges and discharges power via an AC-DC inverter 21 that converts AC to DC, and each front wheel 11 and the motor 18 are connected via a clutch 19 and a transmission 20. When the vehicle is driven, the motor 18 is driven by power supplied from the battery 31 via the inverter 21, and power is transmitted from the motor 18 to each front wheel 11. During regeneration, rotational force is transmitted from each of the front wheels 11 to the motor 18, and the electric power generated by the motor 18 is charged into the battery 31 via the inverter 21. The inverter 21 is connected to and controlled by a so-called ECU (Electrical Control Unit) 32. Note that instead of the motor 18, an internal combustion engine or a hybrid engine thereof may be used as the prime mover.

[0029] The vehicle VC is equipped with a brake control unit 14 that supplies brake fluid pressure to the wheel cylinders and brake calipers of each of the brake devices 12, 12 provided on each of the front wheels 11, 11. The brake control unit 14 is equipped with a brake fluid pressure pump 15 that generates the brake fluid pressure required to generate braking force in each of the brake devices 12, 12. The brake fluid pressure pump 15 is connected to a battery 31, is powered by the battery 31, and generates brake fluid pressure. Valve units 16, 16 are arranged in each fluid pressure supply line that supplies brake fluid pressure from the brake control unit 14 to each of the brake devices 12, 12, and brake fluid pressure detectors 17, 17 are arranged downstream of each valve unit 16. The valve unit 16 is a device that adjusts the pressure of the brake fluid pressure supplied from the brake control unit 14 to the brake devices 12, and is configured with a valve such as a solenoid valve whose valve opening can be adjusted, for example. The brake fluid pressure detection unit 17 is a device that detects (measures) brake fluid pressure, and is configured to include, for example, a brake pressure sensor, etc. The brake control unit 14 controls the rotation speed of the brake fluid pressure pump 15 and the valve opening degree of each valve unit 16, 16 based on a braking force command value from the ECU 32 and each data (brake fluid pressure data) detected by each brake fluid pressure detection unit 17, 17, thereby controlling the braking force of each brake device 12, 12.

[0030] Regarding driving operations, the vehicle VC is equipped with a steering device 22 including a steering angle detection unit 25, an accelerator depression amount detection unit 26, a brake depression amount detection unit 27, a vehicle speed detection unit 28, an acceleration detection unit 29, and a yaw rate detection unit 30. These detection units 25 to 30 are connected to an ECU 32 via, for example, a CAN (Controller Area Network). The CAN is a network that uses a communication protocol standardized in the ISO11898 series. The brake fluid pressure detection unit 17 described above is also connected to the ECU 32 via the CAN, and outputs its output (brake fluid pressure data) to the ECU 32 via the CAN.

[0031] The steering device 22 is a mechanism for steering steered wheels such as the front wheels 11. The steering device 22 includes, for example, a steering wheel 23, a steering shaft 24 connected to the steering wheel 23, a steering angle detection unit 25 that detects (measures) the steering angle generated in the steering shaft 24 by operating the steering wheel 23, and a steering angle drive mechanism (not shown) that applies a steering angle to the steered wheels in accordance with the steering angle detected by the steering angle detection unit 25. The steering angle detection unit 25 includes, for example, a steering angle sensor that detects the steering angle by electromagnetic induction, and outputs its output (steering angle data) to the ECU 32 via the CAN.

[0032] Accelerator depression amount detection unit 26 is a device that detects (measures) the depression amount of the accelerator pedal (accelerator pedal stroke amount). Accelerator depression amount detection unit 26 is attached to an accelerator pedal (not shown) that inputs an instruction for the magnitude of power from motor 18, and is configured to include a pedal stroke sensor or the like that detects the pedal depression amount by detecting the pedal movement angle of the accelerator pedal using, for example, a potentiometer or a Hall element. Accelerator depression amount detection unit 26 outputs its output (accelerator depression amount data) to ECU 32 via the CAN.

[0033] The brake depression amount detection unit 27 is a device that detects (measures) the depression amount of the brake pedal (brake pedal stroke amount). The brake depression amount detection unit 27 is attached to a brake pedal (not shown) for inputting an instruction for the magnitude of the braking force to be applied by the brake devices 12, 12, and is configured to include, for example, a pedal stroke sensor that detects the depression amount of the brake pedal by detecting the pedal movable angle of the brake pedal. The brake depression amount detection unit 27 outputs its output (brake depression amount data) to the ECU 32 via the CAN.

[0034] The vehicle speed detection unit 28 is a device that detects (measures) the speed (vehicle speed) of the vehicle VC. The vehicle speed detection unit 28 is configured to include, for example, a rotary encoder or the like, and is a wheel speed sensor or the like that measures the wheel speed (wheel rotation speed) from the amount of rotational displacement of the wheel (axle) per unit time. The vehicle speed detection unit 28 outputs its output (vehicle speed data) to the ECU 32 via the CAN.

[0035] The acceleration detection unit 29 is a device that detects (measures) the acceleration of the vehicle VC. The acceleration detection unit 29 is configured to include, for example, a capacitance type or piezoelectric type acceleration sensor. The acceleration detection unit 29 outputs its output (acceleration data) to the ECU 32 via the CAN. The acceleration detection unit 29 may calculate the acceleration from the vehicle speed detected by the vehicle speed detection unit 28.

[0036] The yaw rate detection unit 30 is a device that detects (measures) the yaw rate generated by the movement of a moving object, in the example shown in FIG. 1, the traveling vehicle VC. The yaw rate is the speed at which the rotational motion (yawing) of the vehicle VC changes around its vertical axis. The yaw rate detection unit 30 is configured to include, for example, a capacitive yaw rate sensor that detects angular velocity. The yaw rate detection unit 30 outputs its output (yaw rate data) to the ECU 32 via the CAN.

[0037] The acceleration detection unit 29 and the yaw rate detection unit 30 may be configured to include a MEMS sensor integrated on one chip.

[0038] The ECU 32 is configured with a microcomputer including, for example, a CPU (Central Processing Unit), memory, an I / O (Input / Output) circuit (I / O port), and its peripheral circuits. The memory includes, for example, a ROM (Read Only Memory), which is a nonvolatile memory element, an EEPROM (Electrically Erasable Programmable Read Only Memory), which is a rewritable nonvolatile memory element, and a RAM (Random Access Memory), which serves as a working memory for the CPU and stores data generated during the execution of a predetermined program. The ECU 32 stores (records) each piece of data from the detectors 17, 17, 26 to 30, and controls the brake control unit 14, motor 18, clutch 19, transmission 20, etc. based on this data in order to drive the vehicle VC in accordance with the driving operation of the occupant.

[0039] The vehicle VC comprises an optical fiber 1, a distortion measurement unit 2, a data processing unit 3, and a CAN data collection unit 4 for measuring distortion of a moving object, in the example shown in FIG.

[0040] The optical fiber 1 is laid on a moving object, in the example shown in Fig. 1, a vehicle VC, and is used as a medium for detecting strain in the environment in which the optical fiber 1 is placed. The optical fiber 1 is laid at an appropriate location on the vehicle VC where it is desired to measure strain. The optical fiber 1 is adhered and fixed to the vehicle VC, for example, with an adhesive, so that it distorts in accordance with the strain of the vehicle VC at least at the measurement location.

[0041] The strain measurement unit 2 is connected to the optical fiber 1 and is a device that measures (detects) strain using the optical fiber 1. The strain measurement unit 2 includes a laser light source LD that emits laser light incident on the optical fiber 1, and a measuring instrument DM that receives Rayleigh scattered light generated by the laser light from the laser light source LD and detects strain based on the received Rayleigh scattered light. The strain measurement unit 2 may be a device that measures strain using Brillouin scattering or a device that measures strain using a fiber Bragg grating (FBG). However, in this embodiment, a device that measures strain using Rayleigh scattering is used because it can measure distributed strain with relatively high spatial differentiation on the order of millimeters. Rayleigh scattering exhibits a unique light intensity pattern for each individual optical fiber. Therefore, strain can be determined based on the deviation of the measured Rayleigh scattered light intensity pattern (measurement pattern) from a reference Rayleigh scattered light intensity pattern (e.g., a reference pattern, a Rayleigh scattered light intensity pattern for an optical fiber in an unstrained state). Known devices can be used for the strain measurement unit 2; for example, the ODiSI6100 series manufactured by LUNA Corporation is used.

[0042] Two cases will be used as examples to explain the various strain measurement locations of a vehicle VC where distribution measurement is performed using such optical fibers 1 (1a, 1b) and strain measurement unit 2. Note that the strain measurement locations are not limited to these examples, and as mentioned above, they are installed at appropriate locations where strain measurement is desired. Figures 2 and 3 mainly show components necessary for explaining the installation of the optical fibers 1 (1a, 1b), and omit, for example, the motor, wheels, seats, etc.

[0043] In the first case, for example, as shown in FIG. 2, the connection position between the optical fiber 1a and the strain measurement unit 2 is the rear end of the side sill SSL on the other side (left side in the forward direction). The optical fiber 1a is connected to a laser light source LD and a measuring instrument DM via an optical branching coupler (optical coupler) in the strain measurement unit 2. The optical fiber 1a is laid from the rear end LD of the side sill SSL along the side sill SSL on the other side, folded back (making a U-turn) at the front end of the side sill SSL, laid along the side sill SSL, rear pillar (C-pillar) RPL, roof side rail LSL, front pillar (A-pillar) FPL and apron reinforcement (shotgun) ELL, folded back (making a U-turn) at the front end of the apron reinforcement ELL, and laid along the apron reinforcement ELL and the front The optical fiber 1a is laid along the front pillar FPR, the front roof header FLH, the front roof header FLH, the rear pillar EPR, and the side sill SSR, and the front pillar FPR and the rear pillar EPR are laid along the front roof header FLH, the rear roof header FLH, the rear roof header FLH, and the rear roof header FLH. The optical fiber 1a is laid along the front pillar FPR and the front roof header FLH, the rear roof header FLH, the rear roof header FLH, and the rear roof header FLH. The optical fiber 1a extends from the strain measurement unit 2 along the front pillar FPR and the front roof header FLH. The optical fiber 1a is folded back at the front end of the apron reinforcement ELR, the front pillar FPR, the roof side rail LSR, the rear pillar EPR, and the side sill SSR. Thus, one optical fiber 1a extends from the strain measurement unit 2. Laser light emitted from the laser light source LD propagates through the optical fiber 1a via the optical branching coupler, is reflected by the front end of the side sill SSR on the one side, propagates through the optical fiber 1a, and is received by the measuring device DM via the optical branching coupler. Rayleigh scattered light resulting from the laser light is also received by the measuring device DM. The optical fiber 1a is laid in the vehicle VC so as to be substantially symmetrical with respect to a center line extending in the longitudinal direction of the vehicle VC. The optical fiber 1a is laid in each of these parts by being bonded with an adhesive, for example, and functions as a sensor to detect strain in each of these parts.In the apron reinforcements ELR and ELL, the optical fiber 1a is laid in double by folding back at its front end, as described above. In this first case example, one of the optical fibers 1a (shown by the solid line in the figure) is used for strain measurement, and the other optical fiber 1a (shown by the dashed line in the figure) is used for temperature measurement. However, since temperature is not necessary to remove components affected by temperature from strain data, it does not need to be used for temperature measurement. Furthermore, Rayleigh scattering occurring in the optical fiber 1a (shown by the dashed line in the figure) at the connection points (routing parts) of each part is excluded from strain measurement.

[0044] In the first case, the optical fiber 1a is laid in the apron reinforcements ELR and ELL, so that distortion caused by a heat source such as a motor in a vehicle VC equipped with the heat source can be analyzed.

[0045] In the second case, for example, as shown in FIG. 3, the connection position between the optical fiber 1b and the strain measuring unit 2 is the front end of the rear frame RFL on the other side (left side in the forward direction). On the other side, the optical fiber 1b is laid along the rear frame (C-frame) RFL, folded back at the rear end of the rear frame RFL, laid along each of the rear frame RFL and floor frame (B-frame) FFL, folded back at the front end of the floor frame FFL, laid along each of the floor frame FFL and rear pillar RPL, laid along the rear roof header RLH from the other side to one side (the right side in the forward direction), laid along each of the rear pillar RPR and floor frame FFR, folded back at the front end of the floor frame FFR, laid along each of the floor frame FFR and rear frame RFR, folded back at the rear end of the rear frame RFR, and laid along the rear frame RFR. In this way, one optical fiber 1b is extended from the strain measurement unit 2. The laser light emitted from the laser light source LD propagates through the optical fiber 1b via the optical branching / coupler, is reflected at the front end of the rear frame RER on one side, propagates through the optical fiber 1b, and is received by the measuring instrument DM via the optical branching / coupler. At this time, Rayleigh scattered light resulting from the laser light is also received by the measuring instrument DM. In the rear frames RFR and RFL, the optical fiber 1b is laid in double by folding back at its rear end as described above. In the floor frames FFR and FFL, the optical fiber 1b is also laid in double by folding back at its front end as described above. One of the optical fibers 1a (shown by the solid line in the figure) is used for strain measurement, and the other optical fiber 1a (shown by the dashed-dotted line in the figure) is used for temperature measurement. However, as in the first case, temperature is not necessary to remove temperature-affected components from strain data, so it need not be used for temperature measurement.

[0046] The CAN data collection unit 4 is connected to the ECU 32 via the input / output terminals of the ECU 32, and is a device that reads the data of the detectors 17, 17, 26 to 30 stored in the ECU 32 and outputs the data to the data processing unit 3.

[0047] The data processing unit 3 is connected to the distortion measurement unit 2, the CAN data collection unit 4, and the ECU 32, respectively, and is a device that executes predetermined data processing to remove components affected by temperature from time-series distortion data relating to the distortion of a moving object, in the example shown in Fig. 1, a vehicle VC, and is configured, for example, as with the ECU 32, with a microcomputer that is configured with a CPU, memory, I / O circuits and their peripheral circuits, etc. The memory includes, for example, ROM, EEPROM, RAM, etc.

[0048] The memory stores various predetermined programs and various predetermined data. The various predetermined programs include, for example, a control processing program. The control processing program includes, for example, a data acquisition processing program that acquires time-series strain data related to the distortion of a moving body (e.g., the distortion of the vehicle VC in the example shown in FIG. 1 ) and acquires time-series movement state data synchronized with the strain data related to the movement state of the moving body (e.g., the running state of the vehicle VC in the example shown in FIG. 1 ), a frequency determination program that determines a predetermined frequency to be used in a removal program described below based on the movement state data acquired by the data acquisition processing program, and a removal program that removes frequency components below the predetermined frequency determined by the frequency determination program from the distortion data acquired by the data acquisition processing program. The various predetermined data include data necessary for executing these programs, such as sampling intervals (e.g., on the order of milliseconds) in the time-series distortion data and the time-series movement state data. The change in the moving state is caused, for example, by the operation of the vehicle VC by the occupant riding in the vehicle VC, such as steering, so the moving state data is, for example, data relating to the operation of the vehicle VC by the occupant riding in the vehicle VC, and the data relating to the operation is, for example, data (steering angle data) of the steering angle detection unit 25 that detects (measures) the steering angle in this embodiment.

[0049] The data processing unit 3 executes the control processing program to functionally include a data acquisition processing unit 301, a frequency determination unit 302, and a removal unit 303.

[0050] The data acquisition processing unit 301 acquires time-series strain data relating to the strain of a moving body, i.e., the strain of the vehicle VC in the example shown in FIG. 1, and acquires time-series movement state data synchronized with the strain data, relating to the movement state of the moving body, i.e., the driving state of the vehicle VC in the example shown in FIG. 1. More specifically, the data acquisition processing unit 301 causes the strain measurement unit 2 to detect strain at the sampling interval, and causes the ECU 32 to sample steering angle data from the steering angle detection unit 25 at the sampling interval so as to be synchronized with the strain data. More specifically, the sampling interval of the strain measurement unit 2 and the sampling interval of the ECU 32 are set to be the same, and the data acquisition processing unit 301 causes the strain measurement unit 2 to start detecting strain data and the ECU 32 to start sampling steering angle data so that the detection start timing of the strain measurement unit 2 and the sampling start timing of the ECU 32 are the same. This makes it possible to acquire time-series strain data and time-series steering angle data (an example of time-series movement state data) that are synchronized with each other. The data acquisition processing unit 301 acquires this time-series distortion data from the distortion measuring unit 2 , and acquires the time-series steering angle data from the ECU 32 via the CAN data collection unit 4 .

[0051] The frequency determination unit 302 determines a predetermined frequency to be used by the removal unit 303 based on the moving state data acquired by the data acquisition processing unit 301, which in this embodiment is steering angle data. More specifically, to determine the predetermined frequency, the frequency determination unit 302 first converts time-series steering angle data, which is an example of time-series moving state data, from time space to frequency space data by Fourier transform (e.g., fast Fourier transform). An example is shown in FIG. 4. Then, the frequency determination unit 302 compares the steering angle data in the frequency space with a predetermined threshold (first determination threshold) Th1, and determines, as the predetermined frequency f1, a frequency f1 at which the steering angle data in the frequency space is equal to or greater than the first determination threshold Th1, starting from the low frequency side. The first determination threshold Th1 is a threshold for determining whether or not there is a change in the moving state (a change in the driving state in the case of the vehicle VC). In this example, it is a threshold for determining whether or not the occupant has started steering. For example, it is appropriately set in advance from a plurality of samples.

[0052] The removal unit 303 removes frequency components equal to or lower than the predetermined frequency f1 determined by the frequency determination unit 302 from the strain data acquired by the data acquisition processing unit 301. More specifically, the removal unit 303 forms a high-pass filter whose cutoff frequency f1 is the predetermined frequency f1 determined by the frequency determination unit 302, and filters the strain data acquired by the data acquisition processing unit 301 using this high-pass filter. As a result, frequency components equal to or lower than the predetermined frequency f1 determined by the frequency determination unit 302 are removed from the strain data acquired by the data acquisition processing unit 301. An example of this is shown in FIG. 5. The strain data shown in FIG. 5 is measurement data from one predetermined location on the vehicle VC. Since the strain measurement is a distributed measurement using the optical fiber 1, in reality, each strain data as shown in FIG. 5 is obtained at each of multiple measurement locations. As shown in FIG. 5A, the time-series strain data α1 detected by the strain measurement unit 2 shows acceleration and deceleration due to steering by the occupant, and its value generally gradually increases over time (the baseline (e.g., moving average, etc.) of the time-series strain data α1 rises to the right). When this time-series strain data α1 is filtered with a high-pass filter, processed time-series strain data β1 is obtained. In this processed time-series strain data β1, its value generally does not gradually increase over time (the baseline (e.g., moving average, etc.) of the time-series strain data α1 becomes approximately horizontal), and components affected by temperature have been removed from the time-series strain data α1. When the time-series strain data α1 and β1 shown in FIG. 5A are represented as power spectra, they become the strain data α2 and β2 shown in FIG. 5B. Compared to the strain data α2, power below the cutoff frequency f1 has been removed from the strain data β2, and components affected by temperature have been removed.

[0053] 1, the data processing unit 3 constitutes an example of a moving body distortion measuring device. The data acquisition processing unit 301 corresponds to an example of a distortion data acquisition unit that acquires time-series distortion data related to the distortion of the moving body, and also corresponds to an example of a moving state data acquisition unit that acquires time-series moving state data related to the moving state of the moving body synchronized with the distortion data.

[0054] In the above description, the data processing unit 3 is configured as a separate unit from the ECU 32, but it may be incorporated into the ECU 32 and configured integrally therewith.

[0055] Next, the operation of this embodiment will be described below: Fig. 6 is a flowchart showing the operation of the moving body distortion measuring device and the vehicle in relation to distortion measurement.

[0056] In a vehicle VC equipped with such a mobile body distortion measuring device, when the vehicle VC starts operating, for example by operating an ignition key or ignition button, the necessary initialization of each unit is performed, and the mobile body distortion measuring device starts operating. By executing the control processing program, the data processing unit 3 is functionally configured with a data acquisition processing unit 301, a frequency determination unit 302, and a removal unit 303.

[0057] 6, when the vehicle VC starts to travel, detection (measurement) of the distortion data and steering angle data is started (S1). More specifically, the data processing unit 3 causes the data acquisition processing unit 301 to cause the distortion measurement unit 2 to start detecting the distortion data and the ECU 32 to start sampling the steering angle data.

[0058] As a result, the distortion measurement unit 2 acquires and stores distortion data at a predetermined sampling interval, thereby accumulating (recording) time-series distortion data during driving. In synchronization with this, the ECU 32 acquires and stores steering angle data at the predetermined sampling interval, thereby accumulating (recording) time-series steering angle data during driving (S2).

[0059] When the vehicle VC has finished traveling (S3), the data processing unit 3 acquires (collects) time-series distortion data from the distortion measurement unit 2 using the data acquisition processing unit 301, and acquires (collects) time-series steering angle data from the ECU 32 via the CAN data collection unit 4 (S4, distortion data acquisition process, steering angle data acquisition process (an example of a moving state data acquisition process)). The start and end of traveling of the vehicle VC can be determined based on, for example, the operation status (on or off) of the ignition key (or ignition button) and the presence or absence of vehicle speed detected by the vehicle speed detection unit 28.

[0060] Next, the data processing unit 3 uses the frequency determination section 302 to perform a Fourier transform on the steering angle data acquired in step S4, converting it from time space to frequency space (S5, the first half of the frequency determination step).

[0061] Next, the data processing unit 3 determines the cutoff frequency f1 to be used in the removal unit 303 by comparing the steering angle data in the frequency space with the first determination threshold Th1 using the frequency determination unit 302 (S6, latter half of the frequency determination step).

[0062] Next, the data processing unit 3 causes the elimination section 303 to form (create) a high-pass filter having the cutoff frequency f1 determined by the frequency determination section 302 in step S6 (S7, first half of the elimination step).

[0063] Next, the data processing unit 3 uses the elimination unit 303 to filter the time-series strain data acquired in step S4 using the high-pass filter formed in step S7 (S8, the latter half of the elimination step), thereby obtaining time-series strain data from which components affected by temperature have been removed.

[0064] Then, the data processing unit 3 outputs the processed time-series strain data and ends this process (S9). For example, the data processing unit 3 outputs the processed time-series strain data to the ECU 32. Alternatively, for example, the data processing unit 3 outputs the processed time-series strain data to an external device via the I / O circuit.

[0065] The temperature of a moving body (e.g., a vehicle VC in the above example) is affected by factors such as the ambient temperature and the heat source of the engine. This temperature changes relatively slowly due to factors such as convection and heat conduction, and appears on the low-frequency side. Therefore, it is believed that temperature-affected components can be removed from time-series strain data by removing low-frequency components below a predetermined frequency from the strain data. After extensive research, the inventors discovered that, because temperature changes in a moving body are not directly related to changes in the moving state of the moving body, the predetermined frequency can be determined based on the moving state data. The moving body strain measuring device provided in the vehicle VC, as well as the moving body strain measuring method and moving body strain measuring program implemented therein, determine a predetermined frequency (cutoff frequency) f1 based on moving state data—e.g., steering angle data in the above example—and remove frequency components below the predetermined frequency f1 from the strain data, thereby eliminating the need for temperature measurement and reducing labor and costs.

[0066] For example, if the travel path and travel state of a moving body are known in advance and the temperature can be predicted based on these, it is thought that the influence of temperature can be removed from the strain data based on this predicted temperature. The above-mentioned strain measurement device for a moving body, strain measurement method for a moving body, and strain measurement program for a moving body detect strain data and travel state data while the vehicle VC is traveling, so the influence of temperature can be removed from the strain data even for vehicles VC whose temperature cannot be predicted.

[0067] The above-described strain measuring device for a moving body, strain measuring method for a moving body, and strain measuring program for a moving body use the optical fiber 1 laid in the vehicle VC, and therefore can measure strain distribution.

[0068] The above-mentioned strain measuring device for a moving body, strain measuring method for a moving body, and strain measuring program for a moving body use a CAN, so that steering angle data, an example of moving state data, can be acquired with low noise from a detection unit, which in the above-mentioned example is an example of the steering angle detection unit 25.

[0069] According to this embodiment, it is possible to provide a method for measuring distortion for a moving body using moving state data relating to the operation of the moving body by a passenger riding on the moving body.

[0070] In the above-described embodiment, the moving state data is data related to the operation of the moving body by a passenger riding on the moving body, and the data related to the operation is, for example, steering angle data. However, the present invention is not limited to this. For example, the data related to the operation may be, for example, data (accelerator depression amount data) from the accelerator depression amount detection unit 26. Since the driving state changes depending on the depression amount of the accelerator pedal, accelerator depression amount data can be used. Alternatively, for example, the data related to the operation may be, for example, data (brake depression amount data) from the brake depression amount detection unit 27. Since the driving state changes depending on the depression amount of the brake pedal, brake depression amount data can be used. Alternatively, for example, the data related to the operation may be multiple of steering angle data, accelerator depression amount data, and brake depression amount data. In this case, the predetermined frequency (cutoff frequency) is calculated for each of the multiple data, and the average, maximum, minimum, etc. of these multiple cutoff frequencies are used as the cutoff frequencies of the removal unit 303.

[0071] In the above embodiment, the moving state data is data relating to the operation of the moving body by a passenger riding on the moving body, but since the operation of the moving body causes a change in the movement of the moving body, the moving state data may be data relating to the movement of the moving body. Preferably, the movement of the moving body includes acceleration, deceleration, and turning.

[0072] 7A and 7B are diagrams showing examples of data relating to the movement of a moving object, where Fig. 7A shows an example of acceleration data, and Fig. 7B shows an example of yaw rate data.

[0073] The data relating to the movement may be, for example, data (acceleration data) from the acceleration detection unit 29. Since acceleration changes depending on the operation of the accelerator pedal or the brake pedal, acceleration data can be used. An example of this is shown in frequency space in FIG. 7A. As in the case of the steering angle data, the frequency determination unit 302 performs a Fourier transform on the time-series acceleration data, and as shown in FIG. 7A, compares the acceleration data in frequency space with a predetermined threshold (second determination threshold) Th2, and determines a frequency f2 at which the acceleration data in frequency space, starting from the low frequency side, becomes equal to or greater than the second determination threshold Th2 as the predetermined frequency (cutoff frequency of the high-pass filter formed in the removal unit 303). The second determination threshold Th2 is set in advance as appropriate from, for example, a plurality of samples.

[0074] Alternatively, for example, the data related to the operation may be data (yaw rate data) from the yaw rate detection unit 30. Because the yaw rate changes due to steering, yaw rate data can be used. An example of this is shown in frequency space in FIG. 7B. As in the case of steering angle data, the frequency determination unit 302 performs a Fourier transform on the time-series yaw rate data, and as shown in FIG. 7B, compares the yaw rate data in frequency space with a predetermined threshold (third decision threshold) Th3. The frequency determination unit 302 determines a frequency f3 at which the yaw rate data in frequency space, starting from the low frequency side, becomes equal to or greater than the third decision threshold Th3 as the predetermined frequency (cutoff frequency of the high-pass filter formed in the removal unit 303). The third decision threshold Th3 is set in advance as appropriate from, for example, a plurality of samples.

[0075] Alternatively, for example, the data related to the operation may be data (brake fluid pressure data) from the brake fluid pressure detection unit 17. The brake fluid pressure data changes depending on the operation of the brake pedal, so the brake fluid pressure data can be used. Note that, because the amount of brake depression can be estimated from the brake fluid pressure, the brake fluid pressure data can also be seen as data related to the operation of the vehicle by the occupant riding in the vehicle.

[0076] Alternatively, for example, the data relating to the operation may be a plurality of data selected from the group consisting of acceleration data, yaw rate data, and brake fluid pressure data. In this case, the predetermined frequency (cutoff frequency) is calculated for each of the plurality of data, and the average, maximum, minimum, or the like of the plurality of cutoff frequencies is used as the cutoff frequency of the elimination unit 303.

[0077] Alternatively, for example, the moving state data may be a plurality of data selected from steering angle data, accelerator depression amount data, brake depression amount data, acceleration data, yaw rate data, and brake hydraulic pressure data. In this case, the predetermined frequency (cutoff frequency) is calculated for each of the plurality of data, and the average value, maximum value, minimum value, etc. of the plurality of cutoff frequencies are used as the cutoff frequencies of the elimination unit 303.

[0078] In the above-described embodiment, the frequency determination steps S5 and S6 and the removal steps S7 and S8 are performed using the strain data and the movement state data stored (recorded) in the strain measurement unit 2 and the ECU 32, respectively, after the vehicle VC has finished traveling. However, these frequency determination steps and removal steps may be performed substantially in real time while the moving body is moving, such as while the vehicle VC is traveling in the above-described example. In this case, for example, the frequency determination step and the removal step are performed at each sampling using time-series strain data and time-series movement state data from the present time to a predetermined time in the past. Alternatively, for example, the frequency determination step and the removal step are performed at the end of each predetermined period (e.g., 5 minutes, 10 minutes, 30 minutes, 60 minutes, etc.) using the time-series strain data and time-series movement state data for that period.

[0079] Furthermore, in the above-described embodiment, the moving body distortion measuring device is provided in a vehicle VC, which is an example of a moving body, but it may also be configured as a standalone device.

[0080] Fig. 8 is a diagram for explaining a modified form of the strain measuring device for a moving body. For example, as shown in Fig. 8, the modified strain measuring device for a moving body D comprises a computer that includes a control processing unit 101, an input unit 102 such as a keyboard or a mouse for inputting predetermined commands and predetermined data, a display unit 103 such as a liquid crystal display device for displaying the commands and the data, an interface unit (IF unit) 104 for inputting and outputting data to and from external devices, and a storage unit 105 such as a ROM, EEPROM, or RAM for storing the various predetermined programs and the various predetermined data.

[0081] The control processing unit 101 is connected to each unit 102-105, controls each unit 102-105 of the mobile body distortion measuring device D according to the function of each unit, and is a circuit for obtaining time-series strain data from which components affected by temperature have been removed, and is configured with, for example, a CPU and its peripheral circuits. By executing a control program for controlling each unit 102-105 of the mobile body distortion measuring device D, the frequency determination program, and the removal program, which are included in the various predetermined programs, the control processing unit 101 functionally comprises a control unit 111 for controlling each unit 102-105 of the mobile body distortion measuring device D, a frequency determination unit 112 similar to the above-mentioned frequency determination unit 302, and a removal unit 113 similar to the above-mentioned removal unit 303.

[0082] The IF unit 104 is, for example, an interface circuit for RS-232C, which is a serial communication method, an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit using the USB standard, etc. The IF unit 104 may also be, for example, a communication interface circuit that transmits and receives communication signals to and from an external device, such as a data communication card or a communication interface circuit conforming to the IEEE802.11 standard or the like.

[0083] Time-series distortion data and time-series moving state data, in the above example, time-series steering angle data, are acquired while the moving body is moving, in the above example, while the vehicle VC is traveling, and are stored (recorded) in the distortion measuring unit 2 and the ECU 32, respectively. The time-series distortion data and time-series steering angle data are read from the distortion measuring unit 2 and the ECU 32, respectively, and stored or recorded in a storage medium or recording medium. The storage medium is, for example, a USB (Universal Serial Bus) memory, an SD card (registered trademark), or the like. The recording medium is, for example, a CD-R (Compact Disc Recordable), a DVD-R (Digital Versatile Disc Recordable), or the like.

[0084] Time-series strain data and time-series steering angle data acquired while traveling and stored, for example, in a storage medium are read from the storage medium via IF unit 104 into mobile body strain measuring device D and acquired. Cutoff frequency f1 is determined by frequency determination unit 112 based on the time-series steering angle data, and the time-series strain data is filtered by a high-pass filter of cutoff frequency f1 formed in removal unit 113 to obtain strain data from which components affected by temperature have been removed.

[0085] In this modified form, the IF unit 104 corresponds to another example of a distortion data acquisition unit that acquires time-series distortion data related to the distortion of a moving body, and also corresponds to another example of a moving state data acquisition unit that acquires time-series moving state data related to the moving state of the moving body synchronized with the distortion data.

[0086] In order to express the present invention, the present invention has been properly and sufficiently described above through the embodiments with reference to the drawings, but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that causes departure from the scope of the claims described in the claims, such changes or improvements are interpreted as being included in the scope of the claims. [Explanation of symbols]

[0087] VC vehicle D. Distortion measurement device for moving objects 1, 1a, 1b optical fiber 2 Distortion measurement unit 3 Data Processing Unit 301 Data acquisition processing unit 302, 112 Frequency determination unit 303, 113 removal part 101 control processing section 104 Interface section (IF section) 105 Storage section

Claims

1. a distortion data acquisition step of acquiring time-series distortion data relating to distortion of the moving body; a movement state data acquisition step of acquiring time-series movement state data relating to the movement state of the moving object, the time-series movement state data being synchronized with the distortion data; a frequency determination step of determining a predetermined frequency to be used in a removal step, which will be described later, based on the movement state data acquired in the movement state data acquisition step so as to remove components affected by temperature; a removal step of removing frequency components equal to or lower than a predetermined frequency from the strain data acquired in the strain data acquisition step. Distortion measurement method for moving objects.

2. the distortion data and the movement state data are data detected while the moving object is moving, 2. The method for measuring distortion for a moving body according to claim 1.

3. the strain data is data detected by using an optical fiber laid on the moving body; 3. The method for measuring distortion for a moving body according to claim 1 or 2.

4. The moving state data is data related to the operation of the moving body by a passenger riding on the moving body.

4. A method for measuring distortion for a moving body according to claim 1.

5. The movement state data is data regarding the movement of the moving object.

4. A method for measuring distortion for a moving body according to claim 1.

6. The movement state data is data acquired from a detection unit that detects the movement state via a CAN (Controller Area Network).

6. A method for measuring distortion for a moving body according to claim 1.

7. On the computer, a distortion data acquisition step of acquiring time-series distortion data relating to distortion of the moving body; a movement state data acquisition step of acquiring time-series movement state data relating to the movement state of the moving object, the time-series movement state data being synchronized with the distortion data; a frequency determination step of determining a predetermined frequency to be used in a removal step, which will be described later, based on the movement state data acquired in the movement state data acquisition step so as to remove components affected by temperature; a removal step of removing frequency components equal to or lower than a predetermined frequency from the distortion data acquired in the distortion data acquisition step; Distortion measurement program for mobile devices.

8. a distortion data acquisition unit that acquires time-series distortion data relating to distortion of the moving object; a movement state data acquisition unit that acquires time-series movement state data related to the movement state of the moving object, the time-series movement state data being synchronized with the distortion data; a frequency determination unit that determines a predetermined frequency to be used in a removal unit that will be described later, based on the traveling state data acquired by the traveling state data acquisition unit, so as to remove components affected by temperature; a removal unit that removes frequency components equal to or lower than a predetermined frequency from the distortion data acquired by the distortion data acquisition unit, Distortion measurement device for moving objects.

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