Reusability determination device and reusability determination method

Abstract

A reusability determination device (20) acquires usage history data regarding the usage history of a component in a vehicle. The usage history data includes data regarding at least one stress factor to which the component was subjected while in use in the vehicle. The reusability determination device (20) then calculates the remaining life of the component on the basis of the acquired usage history data. Thus, the remaining life of the component can be obtained with high accuracy on the basis of the actual usage record of the component. Furthermore, it is possible to appropriately determine whether or not the component can be reused on the basis of the calculated remaining life.

Description

Reusability determination device and method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-188968 filed in Japan on November 3, 2023, and the contents of the original application are incorporated by reference in their entirety.

[0002] The present disclosure relates to a reuse possibility determination device and a reuse possibility determination method for determining whether a part used in a vehicle can be reused.

[0003] For example, Patent Document 1 discloses a method for predicting the power cycle life of a power semiconductor in a power conversion device when the power conversion device is used in an application where the device is started and stopped frequently. Specifically, in response to the number of repetitions per unit time set on an operation panel, the power cycle life in years is calculated from the temperature detected by a temperature detection circuit of the power semiconductor in the operating state and the power cycle life curve of the power semiconductor.

[0004] Japanese Patent Application Laid-Open No. 2008-271703

[0005] As described above, in Patent Document 1, the number of repetitions per unit time is set via an operation panel. The power cycle lifespan is calculated when the power conversion device is operated at the set number of repetitions per unit time. In other words, Patent Document 1 does not calculate the lifespan based on the actual operation history (usage history) of the power conversion device. Therefore, for example, when a power conversion device has been used for a certain period of time, it is difficult to accurately calculate the remaining lifespan based on the actual usage history of the power conversion device.

[0006] The present disclosure has been made in consideration of the above-mentioned points, and aims to provide a reuse eligibility determination device and a reuse eligibility determination method that are capable of calculating the remaining lifespan of a part with high accuracy based on the usage history of the part, and determining whether the part can be reused based on that remaining lifespan.

[0007] In order to achieve the above object, the reuse feasibility determination device according to the present disclosure is a reuse feasibility determination device that determines whether a part that has been used in a vehicle can be reused, and is configured to include: an acquisition unit that acquires usage history data regarding the usage history of the part in the vehicle; the usage history data including data regarding at least one stress factor that the part was subjected to while being used in the vehicle; a calculation unit that calculates the remaining lifespan of the part based on the usage history data acquired by the acquisition unit; and a determination unit that determines whether the part can be reused based on the remaining lifespan of the part calculated by the calculation unit.

[0008] Furthermore, a reuse feasibility determination method according to the present disclosure is a reuse feasibility determination method executed by at least one processor for determining whether a part that has been used in a vehicle can be reused, and is configured to include the steps of: acquiring usage history data regarding the usage history of the part in the vehicle; the usage history data including data regarding at least one stress factor to which the part was subjected while being used in the vehicle; calculating the remaining lifespan of the part based on the acquired usage history data; and determining whether the part can be reused based on the calculated remaining lifespan of the part.

[0009] According to the reuse feasibility determination device and reuse feasibility determination method disclosed herein, usage history data relating to the usage history of a part in a vehicle is acquired. The usage history data includes data relating to at least one stress factor to which the part was subjected while in use in the vehicle. The remaining lifespan of the part is then calculated based on the acquired usage history data. This makes it possible to determine the remaining lifespan of the part with high accuracy based on the actual usage history of the part. Therefore, it is possible to appropriately determine whether the part can be reused based on the calculated remaining lifespan.

[0010] The reference numbers in parentheses in the claims merely indicate an example of the correspondence with specific configurations in the embodiments described below, in order to facilitate understanding of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0011] Furthermore, the technical features of the present disclosure other than those described above will become apparent from the following description of the embodiments and the accompanying drawings.

[0012] 1 is a configuration diagram showing an example of a system configuration including a reuse determination device according to an embodiment. FIG. 2 is a flowchart showing an example of processing executed by the reuse determination device to determine whether a part can be reused. FIGS. 1A to 1D are explanatory diagrams for explaining an example of calculating the remaining lifespan of a part when determining whether the part can be reused for a vehicle application and a second application other than the vehicle application. FIG. 1A is a diagram showing an example of the availability (on-time ratio) and maximum temperature of a part, including a capacitor, switching element, solder, etc., assumed at the time of design. FIG. 1B is a diagram showing an example of the availability and maximum temperature of the part when the part is actually used in a vehicle. FIG. 1C is a diagram showing an example of the availability and maximum temperature of the part when the part is reused for a second application other than the vehicle application. FIG. 2 is a graph showing an example of the relationship between the operating temperature and the estimated lifespan of a part, including a capacitor, switching element, and / or solder, etc. 1A is a diagram showing an example of a change in stress acting on a part assumed when the part is designed for use in a vehicle; 1B is a diagram showing an example of a change in stress as determined from usage history data during use in a vehicle; and 1C is a diagram showing an example of a change in stress as determined from usage history data during use in a vehicle; and 1D is a graph showing an example of a change in stress as determined from usage history data during use in a vehicle; and 1E is a graph showing an example of a change in stress as determined from usage history data during use in a vehicle; and 1F is a graph showing an example of a change in temperature as determined from usage history data during use in a vehicle; and 1F is a graph showing an example of a change in temperature as determined from usage history data during use in a vehicle; and 1F is a graph showing an example of a change in vibration intensity ... 10 is a flowchart illustrating an example of a process executed by the reuse possibility determination device according to the second embodiment to determine whether a part can be reused.10 is a flowchart showing an example of a process executed by a reuse possibility determination device according to a modified example to determine whether a part can be reused.

[0013] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Note that identical or similar configurations may be omitted from the description by assigning the same reference numerals across multiple drawings. When only a portion of a configuration is described in each embodiment, the configuration of another previously described embodiment may be applied to the remaining portion of the configuration. Furthermore, configurations of multiple embodiments may be partially combined together, even if not explicitly stated, as long as there is no particular problem with the combination.

[0014] First Embodiment FIG. 1 is a configuration diagram showing an example of a system configuration including a reuse possibility determination device 20 according to this embodiment. In this embodiment, as shown in FIG. 1 , the reuse possibility determination device 20 is provided outside the vehicle 10. Then, for example, when the vehicle 10 is disposed of or inspected, the reuse possibility determination device 20 acquires usage history data related to the usage history of at least one part from equipment including various sensors mounted on the vehicle 10. The equipment may be included in the parts to be subjected to the reuse possibility determination. Based on the acquired usage history data, the reuse possibility determination device 20 calculates the remaining lifespan of the part when it is reused in another vehicle or when it is reused for an application other than a vehicle. Then, the reuse possibility determination device 20 determines whether the part can be reused based on the calculated remaining lifespan of the part.

[0015] The part to be determined for reuse may be, for example, a motor generator in a hybrid vehicle, a fuel cell vehicle, an electric vehicle, or the like, which functions as a drive source for running the vehicle 10 and also functions as a generator for converting kinetic energy into electrical energy and recovering it when braking the vehicle 10. Alternatively, the part to be determined for reuse may be a storage battery that supplies power to the motor generator, stores power generated by the motor generator, and / or is rechargeable by an external charging facility. Furthermore, the part to be determined for reuse may be a power control unit for driving the motor generator.

[0016] It is expected that hybrid vehicles, fuel cell vehicles, and electric vehicles will increase in the future, and from the perspective of resource conservation, if the above-mentioned parts are reusable, it is desirable to reuse them, for example, in other vehicles in which the corresponding parts have broken down, or to reuse them in applications such as solar power generation, wind power generation, and hydroelectric power generation for DC to AC power conversion, storage of generated power, and / or as a generator. Note that the uses of reused parts are not limited to these, and they can also be used, for example, in machine tools or solid oxide fuel cells (SOFCs). Furthermore, parts that are the subject of reuse eligibility determination may be parts other than those mentioned above.

[0017] The component usage history data includes data on at least one stress factor that the component subject to reuse determination experienced while in use in the vehicle 10. The stress factor data includes, for example, at least one of the following: the magnitude and frequency of temperature changes of the component (hereinafter referred to as thermal stress); the magnitude and duration of current flow when the component is used while an electric current is applied (hereinafter referred to as current-flow time stress); the magnitude and frequency of vibrations acting on the component (hereinafter referred to as vibration stress); and the magnitude and frequency of stress fluctuations acting on the component (hereinafter referred to as stress stress). These factors can, for example, cause deterioration of electrical connections such as solder or connectors in the component, deterioration of electrical components such as capacitors and switching elements, or a decrease in the mechanical strength of each component, thereby affecting the component's lifespan. However, the stress factor data is not limited to these. For example, the magnitude and duration of voltage applied to the component (hereinafter referred to as voltage stress) may be used in addition to or instead of the current-flow time stress. Furthermore, if the component is a storage battery, the number of full charges or quick charges, which can cause deterioration of the battery's performance, may also be used as stress factor data. Alternatively, if the parts are to be reused in machine tools that are used in poor environments where dust, oil mist, etc. are present, the change in the amount of current leakage (the difference between the input current and the output current) may be used as a stress factor to check the degree of resistance to foreign matter.

[0018] The above-mentioned usage history data can be acquired from devices, including sensors, mounted on the vehicle 10. The sensor-including devices periodically detect data related to stress factors throughout the life of the components in the vehicle 10 and store the data in a storage device such as a memory. For example, the sensors can include a temperature sensor that detects the temperature of the components, a current sensor that detects the current flowing through the components, a voltage sensor that detects the voltage applied to the components, and a vehicle speed sensor and acceleration sensor that detect data indicating the magnitude of vibration acting on the components. Thermal stress can be calculated from changes in the temperature of the components detected by the temperature sensor. Current flow time stress can be calculated from the magnitude and duration of current flowing through the components, detected by the current sensor. Voltage stress can be calculated from the magnitude and duration of voltage application, detected by the voltage sensor. Vibration stress can be calculated based on the speed of the vehicle 10 and the acceleration acting on the components, detected by the speed sensor and acceleration sensor. This is because the magnitude of vibration acting on the components correlates with the speed of the vehicle 10 and / or the acceleration acting on the components.

[0019] However, the temperature change of the component may be detected directly by a temperature sensor, or the temperature change of the component may be estimated from the pattern of current flow to the component. Furthermore, for mechanical components such as a motor generator, the stress can be estimated from the change in the magnitude of the acceleration of the vehicle 10 detected by an acceleration sensor, and for electrical components such as a power control unit, the stress can be estimated from the difference in the linear expansion coefficient of the materials constituting the electrical component based on the temperature change (e.g., the difference between the maximum and minimum temperatures) detected by a temperature sensor.

[0020] 1, the reuse possibility determination device 20 includes a computer including, for example, a processor 21, a memory 22, an I / O unit 23, and a display unit 24. The memory 22 includes, for example, RAM and ROM. RAM is an abbreviation for Random Access Memory. ROM is an abbreviation for Read Only Memory.

[0021] The processor 21 executes a predetermined process (control) by executing a program stored in the ROM while using the RAM as a temporary storage area. The processor 21 constructs multiple functional units by executing multiple instructions included in the program. There may be one processor 21 or multiple processors 21. The storage medium for the program is not limited to ROM. Various storage media, such as an HDD or SSD, can be used. HDD is an abbreviation for Hard-disk Drive. SSD is an abbreviation for Solid State Drive.

[0022] The processor 21 may be, for example, a CPU, an MPU, a GPU, or a DFP. CPU is an abbreviation for Central Processing Unit. MPU is an abbreviation for Micro-Processing Unit. GPU is an abbreviation for Graphics Processing Unit. DFP is an abbreviation for Data Flow Processor. The processor 21 may be realized by combining multiple types of arithmetic processing devices, such as a CPU, an MPU, and a GPU. Alternatively, the processor 21 may be realized as an SoC. SoC is an abbreviation for System on Chip. Furthermore, the processor 21 may be realized using an ASIC or FPGA. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array. Alternatively, the processor 21 may be configured by appropriately combining functional units constructed by executing a program with hardware circuits.

[0023] The I / O unit 23 inputs and outputs data to and from devices external to the reuse possibility determination device 20, such as devices including sensors mounted on the vehicle 10. Furthermore, the I / O unit 23 also includes an operation panel that can instruct the operation details of the reuse possibility determination device 20. The display unit 24 displays the results of the reuse possibility determination, the intended use and remaining life if it is determined that the item is reuseable, etc. Note that if there is only one type of reuse use, the display of the intended use may be omitted.

[0024] Next, an example of processing executed by the reuse possibility determination device 20 to determine whether a part can be reused will be described with reference to the flowchart in Fig. 2. The flowchart in Fig. 2 shows processing performed by the reuse possibility determination device 20 to determine whether a part can be reused for multiple applications (application 1 and application 2).

[0025] First, in step S100, the reuse possibility determination device 20 acquires usage history data of the part that is the subject of reuse possibility determination from equipment including a sensor mounted on the vehicle 10. As described above, the reuse possibility determination device 20 can acquire usage history data when the vehicle 10 is inspected or scrapped. In the following step S110, the reuse possibility determination device 20 determines whether or not an instruction from, for example, an operation panel indicates scrapping of the vehicle 10. If scrapping is indicated, the reuse possibility determination device 20 proceeds to step S120. If scrapping is not indicated and the instruction is simply to acquire usage history data, the reuse possibility determination device 20 returns to step S100.

[0026] Note that, when the reuse possibility determination device 20 acquires usage history data at a timing other than when the vehicle 10 is scrapped, the reuse possibility determination device 20 may store the acquired usage history data in association with the identifier of the vehicle 10, and may delete the usage history data in the vehicle 10. This eliminates the need for a large-capacity memory to store the usage history data in the vehicle 10. Alternatively, the reuse possibility determination device 20 may be configured to periodically acquire the usage history data from the vehicle 10 via, for example, V2X communication. Alternatively, the reuse possibility determination device 20 may be configured to acquire the usage history data all at once when the vehicle 10 is scrapped.

[0027] In step S120, the reuse possibility determination device 20 calculates the remaining lifespan of the part when the reuse purpose is a first purpose (application 1) based on the acquired usage history data. The first purpose (application 1) can be, for example, a vehicle purpose. Below, an example of calculating the remaining lifespan of a part when the first purpose is a vehicle purpose and it is determined whether the part can be reused in another vehicle will be described with reference to the drawings.

[0028] As shown in Figure 3(a), conventionally, the lifespan of the vehicle 10 has been roughly determined based on the mileage of the vehicle 10 and the number of years of use of the vehicle 10. For example, in the example shown in Figure 3(a), the design lifespan is set to X0 km in terms of the mileage of the vehicle 10, and the design lifespan is set to Y0 years in terms of the period of use of the vehicle 10. Then, the remaining lifespan LTveh of the vehicle 10 is determined to be the shorter of the remaining lifespan calculated from the difference between the actual mileage (X km) and the design lifespan of the mileage X0 (km), and the remaining lifespan calculated from the difference between the actual period of use (Y years) and the design lifespan of the lifespan Y0 (years).

[0029] However, vehicle 10 is used in a variety of ways, and even if the period of use and mileage are the same, the above-mentioned stress factors (heat stress, power-on time stress, vibration stress, stress stress, etc.) that the parts installed in vehicle 10 are subjected to usually vary greatly from vehicle 10 to vehicle 10.

[0030] Therefore, the reuse possibility determination device 20 of this embodiment calculates the remaining lifespan of a part based on usage history data including data on at least one stress factor to which the part was subjected while being used in the vehicle 10. This makes it possible to calculate the remaining lifespan of a part with high accuracy based on the results of the stress factors to which the part was actually subjected when used in the vehicle. Therefore, the reuse possibility determination device 20 can appropriately determine whether the part can be reused based on the calculated remaining lifespan.

[0031] FIG. 3(b) shows an example of calculating the remaining life of a part based on multiple stress factors when reusing the part for vehicle use. In the example shown in FIG. 3(b), the multiple stress factors include thermal stress, current flow time stress, vibration stress, and stress. Below, for each stress factor, specific examples of a calculation method for calculating the usage history of the part based on usage history data, and a calculation method for calculating the remaining life of the part based on usage history data, are explained. Note that the remaining life of a part may be calculated based on one of the multiple stress factors described above.

[0032] First, we will explain how to calculate the usage history regarding the current flow time stress and how to calculate the remaining life of a component. Figure 4(a) shows the component availability (on-time ratio) Rd and maximum temperature Tdmax assumed at the time of designing components including capacitors, switching elements, solder, etc.

[0033] As shown in FIG. 5 , components such as capacitors, switching elements, and / or solder have a lifespan in terms of usage time, i.e., current flow time. If a component is used for a period corresponding to its lifespan, it is highly likely that the component will no longer be able to perform as expected. As shown in FIG. 5 , capacitors, switching elements, and / or solder have a characteristic in which the higher the operating temperature, the shorter their estimated lifespan, and the lower the operating temperature, the longer their estimated lifespan. Thus, the component's current flow time lifespan is related to the current flow time and the operating temperature. Therefore, the component's current flow time lifespan can be calculated based on the component's operating rate (on-time ratio) Rd and maximum temperature Tdmax assumed at the time of design. For example, the current flow time lifespan LT2 shown in FIG. 3( b ) represents the component's current flow time lifespan when the component is operated at the operating rate Rd assumed at the time of design, and the component's temperature is at the maximum temperature Tdmax during the on-time of the operating rate Rd.

[0034] 4B shows an example of the actual component availability rate Rr and maximum temperature Trmax as determined from the acquired usage history data. In this example, the vehicle 10 was used under a relatively low load, so the actual component availability rate Rr is lower than the availability rate Rd assumed at the time of design. Furthermore, the actual component maximum temperature Trmax is also lower than the maximum temperature Tdmax assumed at the time of design.

[0035] In this case, the used usage record T2 of the part life (current-flow time life LT2) related to current-flow time stress in actual use in a vehicle can be calculated by the following equation 1. In the above formula 1, the usage history T2 is calculated by multiplying the actual usage period T of the vehicle by the ratio of the actual availability rate Rr to the design availability rate Rd. However, the usage history T2 may be calculated taking into account not only the availability rate but also the maximum temperature. For example, as described above, if the actual maximum temperature Trmax is smaller than the design maximum temperature Tdmax, the usage history T2 may be calculated so that the usage history T2 is shorter. Then, the remaining life related to the current-flow time stress can be calculated by subtracting the calculated usage history T2 from the life period Y0 related to the vehicle usage period.

[0036] Alternatively, the remaining life related to the current-flow time stress may be calculated based on the current-flow time life LT2 estimated from the component availability rate (on-time ratio) Rd and the maximum temperature Tdmax assumed at the time of design, rather than based on the life period Y0 years related to the period of use of the vehicle. Specifically, the remaining life related to the current-flow time stress may be calculated by subtracting the actual usage history T2 from the current-flow time life LT2 shown in FIG.

[0037] Furthermore, the current-flow life LT2a may be calculated for use under similar conditions in consideration of the availability rate Rr and maximum temperature Trmax when the current-flow life LT2 is actually used in a vehicle. Figure 3(c) shows an example of the calculated current-flow life LT2a. In this case, the remaining life related to current-flow stress is calculated by subtracting the actual usage history T2 from the calculated current-flow life LT2a. The current-flow life LT2a can be calculated, for example, using the following equation 2. Using Equation 2, the current-carrying life LT2a is calculated to be twice the length of the current-carrying life LT2 at the time of design, for example, if the maximum temperature Trmax during actual use is 10 degrees lower than the maximum temperature Tdmax at the time of design.

[0038] The above description of the remaining life related to the current flow time stress relates to a method for calculating the remaining life of a part when the reuse application of the part is the first application, which is a vehicle application. However, parts are not limited to vehicle applications, and as mentioned above, they can also be reused for applications such as solar power generation, wind power generation, hydroelectric power generation, machine tools, and SOFCs. Below, we will explain a method for calculating the remaining life related to the current flow time stress when a part is reused for a second application (application 2) other than a vehicle application.

[0039] 4C shows an example of the component availability Rs and maximum temperature Tsmax expected when the component is reused for a second use. In this example, when the component is reused for a second use, the component availability Rs is lower than the component availability Rd expected at the time of design for the vehicle use and the actual component availability Rr. The component maximum temperature Tsmax is also lower than the component maximum temperature Tdmax expected at the time of design for the vehicle use and the maximum temperature Trmax during actual use.

[0040] Therefore, when the part is reused for the second use, the current-flow life LT2b will be longer than the current-flow life LT2 determined from the operating conditions at the time of design for the vehicle use and the current-flow life LT2a determined from the actual usage experience in the vehicle. The current-flow life LT2b can be calculated, for example, using the following equation 3. According to Equation 3, the current-flow time life LT2b is calculated so that the remaining life (LT2a-T2) excluding the life already achieved by usage record T2 is extended if the maximum temperature Tsmax when the part is reused for a second use is lower than the maximum temperature Trmax in actual use in a vehicle. Note that the current-flow time life LT2b can also be calculated using the maximum temperature Tdmax assumed at the time of design, the current-flow time life LT2, etc.

[0041] Next, a method for calculating the usage history regarding stress and a method for calculating the remaining lifespan of a part will be described. FIG. 6( a) shows an example of the change in stress (Δσ) acting on a part when the part is used in a vehicle. FIG. 6( b) shows an example of the change in stress (Δσ) determined from the acquired usage history data. Furthermore, FIG. 6( c) shows an example of the change in stress (Δσ) when the part is reused for a second use. As described above, the change in stress (Δσ) can be estimated from the change in the magnitude of acceleration detected by an acceleration sensor that detects the magnitude of the force acting on the part. Alternatively, it can be estimated from the change in temperature (e.g., the difference between the maximum and minimum temperatures) detected by a temperature sensor.

[0042] For example, as shown in Fig. 7, for each material that constitutes a part, the number of cycles to failure is determined according to the magnitude of the change in stress (Δσ). In the example shown in Fig. 7, it is shown that material A may reach failure with a smaller number of cycles of change in stress (Δσ) than material B. It is also shown that material B will not reach failure with a change in stress (Δσ) smaller than a predetermined magnitude.

[0043] For the part of a component that is most vulnerable to stress changes (Δσ), the stress life LT4 shown in Figure 3(b) is determined at the time of component design based on the amplitude Δσd, which indicates the magnitude of the expected stress change (Δσ), and its period td (Δσd).

[0044] 6(b) shows an example of the amplitude Δσs of stress changes acting on a part and its period ts (Δσs) as determined from the acquired usage history data. In this example, the vehicle 10 was used in a favorable environment with relatively little vibration or temperature change, so the amplitude Δσr, which indicates the magnitude of the actual stress changes (Δσ), is generally smaller than the amplitude Δσd assumed at the time of design. Furthermore, the period tr (Δσr) of the actual stress changes (Δσ) is also longer than the period td (Δσd) assumed at the time of design.

[0045] In this case, the part life (stress life LT4) related to stress in actual use in a vehicle, the actual usage record T4 after use, can be calculated by the following Equation 4.

[0046] In the above equation 4, the damage rate of the part per amplitude Δσd can be calculated by multiplying the number of cycles to destruction Nc(Δσd) that lead to destruction due to the amplitude Δσd of the stress change at the time of design by the period td(Δσd) of that amplitude Δσd, and using the product as the denominator. The damage rate can then be calculated by integrating it over the usage period T. In equation 4, the usage history T4 is calculated by multiplying the usage period T by the ratio of the integrated damage rate resulting from actual use in the vehicle to the integrated damage rate according to the conditions at the time of design. The remaining life related to the current-flow time stress can then be calculated by subtracting the calculated usage history T4 from the life period Y0 related to the vehicle usage period.

[0047] Alternatively, the remaining life related to stress may be calculated not based on the life period Y0 years related to the period of use of the vehicle, but based on the stress life LT4 determined from the amplitude Δσd indicating the magnitude of the change in stress (Δσ) and its period td (Δσd) assumed at the time of design. Specifically, the remaining life related to stress may be calculated by subtracting the actual usage history T4 from the stress life LT4 shown in Figure 3(b).

[0048] Furthermore, for the stress life LT4, a stress life LT4a for use under similar conditions may be calculated in consideration of the amplitude Δσr and period tr (Δσr) of the stress change (Δσ) when actually used in a vehicle. FIG. 3(c) shows an example of the calculated stress life LT4a. The remaining life related to stress may then be calculated by subtracting the actual usage history T4 from the calculated stress life LT4a. The stress life LT4a can be calculated, for example, using the following equation 5.

[0049] Furthermore, when a part is reused for a second use (application 2) other than a vehicle use, the method for calculating the remaining life regarding the stress life LT4b is as follows.

[0050] 6(c) shows an example of the amplitude Δσs of the stress change acting on the part and its period ts (Δσs) that are assumed when the part is reused for a second use. In this example, when the part is reused for a second use, the amplitude Δσs of the stress change is smaller than the amplitude Δσd assumed at the time of design for vehicle use and the amplitude Δσr during actual use. The period ts (Δσs) is shorter than the period td (Δσd) assumed at the time of design for vehicle use, but is approximately equal to the period tr (Δσt) during actual use.

[0051] Therefore, the stress life LT4b of the part when reused for the second use will be longer than the stress life LT4 determined from the operating conditions at the time of design for the vehicle use and the stress life LT4a determined from the actual usage experience in the vehicle. The stress life LT4b can be calculated, for example, using the following equation 6. According to Equation 6, the stress life LT4b is calculated so that the remaining life (LT4a-T4), excluding the life already achieved by usage record T4, is extended if the cumulative damage rate when the part is reused for a second use is lower than the cumulative damage rate when the part is actually used in a vehicle. As a result, the stress life LT4b is calculated to be longer than the stress life LT4a. Note that the stress life LT4b can also be calculated using the damage rate assumed at the time of design.

[0052] Next, a method for calculating usage history related to thermal stress and a method for calculating the remaining lifespan of a part will be described. FIG. 8( a) shows an example of a temperature change Δθd of a part assumed when the part is designed for use in a vehicle. FIG. 8( b) shows an example of a temperature change Δθr determined from acquired usage history data. Furthermore, FIG. 8( c) shows an example of a temperature change Δθs assumed when the part is reused for a second use. As described above, the temperature change Δθ of the part may be determined from the value detected by a temperature sensor that detects the temperature of the part, or may be estimated from the current flow pattern to the part.

[0053] Here, when thermal stress due to a temperature change Δθ is applied to a component, the thermal strain amplitude Δε occurring in each part of the component is proportional to the temperature change Δθ (Δε = k1 × Δθ). Furthermore, the amplitude Δσ of stress σ occurring in each part of the component is proportional to the thermal strain amplitude Δε occurring in each part. Therefore, the stress amplitude Δσ is determined in proportion to the thermal stress due to the temperature change Δθ. Therefore, using the same concept as for stress stress, it is possible to calculate the component life (thermal life LT1 in Figure 3(b)) related to thermal stress, including the used usage record T1, the remaining life if reused for vehicle use (Y0-T1, LT1-T1, or LT1a-T1), and the remaining life if reused for a second purpose other than vehicle use (LT1b-T1). Therefore, further explanation is omitted.

[0054] Next, a method for calculating the usage history regarding vibration stress and a method for calculating the remaining life of a part will be described. FIG. 9( a) shows an example of a change in vibration intensity Gd of a part assumed when the part is designed for use in a vehicle. FIG. 9( b) shows an example of a change in vibration intensity Gr determined from acquired usage history data. Furthermore, FIG. 9( c) shows an example of a change in vibration intensity Gs assumed when the part is reused for a second use. As described above, the vibration intensity G of a part can be calculated based on the speed of the vehicle 10 and the acceleration acting on the part, which are detected by a speed sensor and an acceleration sensor.

[0055] Here, when a vibration intensity G is applied to a component, the force F applied to each part of the component is proportional to the vibration intensity G (F = K2 x G). Furthermore, the stress σ applied to each part of the component is proportional to the force F applied to each part of the component. Therefore, the stress amplitude Δσ is determined in proportion to the vibration intensity G. Therefore, using the same concept as for stress stress, it is possible to calculate the component life (vibration life LT3 in FIG. 3B) related to vibration stress, including the actual usage T3 after use, the remaining life if reused for vehicle use (Y0-T3, LT3-T3, or LT3a-T3), and the remaining life if reused for a second purpose other than vehicle use (LT3b-T3). Therefore, further explanation is omitted.

[0056] As described above, for each of the multiple stress factors, the usage history T1-T4 of the part's lifespan is calculated, which is the amount of time the part has already been used. Furthermore, the remaining lifespan for vehicle use is calculated based on these usage history T1-T4. The remaining lifespan of the part if reused for vehicle use is then calculated. For example, as shown in FIG. 3B, the remaining lifespan of the part can be calculated as the shortest difference between the usage history T1-T4 for each stress factor and the vehicle's lifespan Y0. In this case, the remaining lifespan of the part is calculated based on the usage history T1-T4 that indicates the longest portion of the lifespan among the usage history T1-T4 of each stress factor. Alternatively, the remaining lifespan of the part can be calculated as the shortest difference between the usage history T1-T4 for each stress factor and the design lifespan LT1-LT4 for each stress factor. Furthermore, as shown in Figure 3(c), the remaining life of a part can be calculated as the shortest difference between the actual usage results T1 to T4 for each stress factor and the lifespans LT1a to LT4a calculated according to the conditions when the part is actually used in a vehicle.

[0057] Returning to the flowchart of Figure 2, the explanation will continue. In step S130, the reuse possibility determination device 20 determines whether the part can be reused for vehicle use based on whether the remaining life calculated in step S120 is greater than a predetermined first threshold. If the remaining life is equal to or less than the first threshold, it is determined that the part cannot be reused, and the process proceeds to step S140. On the other hand, if the remaining life is greater than the first threshold, it is determined that the part can be reused, and the process proceeds to step S160.

[0058] In step S140, the reuse possibility determination device 20 calculates the remaining lifespan of the part if the part is reused for the second use (application 2) based on the acquired usage history data. For example, the remaining lifespan of the part may be calculated as the difference between the longest usage history (T2) and the shortest lifespan (LT1b) based on the usage history data T1 to T4 for each stress factor and the lives LT1b to LT4b calculated according to the conditions when the part was used for the second use, as shown in FIG. 3(d). Alternatively, the remaining lifespan of the part may be calculated as the shortest difference between the usage history data T1 to T4 for each stress factor and the lives LT1b to LT4b calculated according to the conditions when the part was used for the second use.

[0059] In addition, if the stress factors to which a part is subjected when reused for a second purpose are limited to some of the multiple stress factors to which the part is subjected while used in a vehicle, the remaining life of the part can be calculated based on the part life and the lifespan for each of the stress factors within the limit, excluding the stress factors outside the limit, as shown in FIG. 3(d). For example, as described above, when parts are reused for purposes such as solar power generation, wind power generation, and hydroelectric power generation, the parts are often used in a fixed position. In such cases, since the part is not affected by vibration stress after reuse, the remaining life of the part can be calculated excluding vibration stress, as shown in FIG. 3(d). Furthermore, for example, if the part is used in an environment with little temperature change after reuse, the remaining life of the part can be calculated excluding thermal stress. Other stress factors can also be excluded from the calculation of the remaining life of the part depending on the usage environment after reuse.

[0060] In step S150, the reuse possibility determination device 20 determines whether the part can be reused for the second purpose based on whether the remaining life calculated in step S140 is greater than a predetermined second threshold. If the remaining life is greater than the second threshold, it is determined that the part can be reused, and the process proceeds to step S170. On the other hand, if the remaining life is equal to or less than the second threshold, it is determined that the part cannot be reused, and the process proceeds to step S180. Note that the second threshold may be the same as or different from the first threshold.

[0061] In step S160, the reuse possibility determination device 20 determines that the part is a reuse item intended for vehicle use (application 1). In step S170, the part is determined to be a reuse item intended for a second use (application 2). In step S180, the part is determined to be eligible for material recycling because the reusable period of the part is equal to or less than the first or second threshold. Then, in step S190, the determination results from steps S160 to S180 are displayed on the display unit 24. If the part is reusable, only the reuse destination may be displayed, or both the reuse destination and the remaining lifespan may be displayed.

[0062] As described above, according to this embodiment, the reuse possibility determination device 20 calculates the remaining lifespan of a part based on usage history data including data on at least one stress factor that the part was subjected to while being used in a vehicle. Therefore, the remaining lifespan of a part can be determined with high accuracy based on the actual usage record (history) of the part. As a result, the reuse possibility determination device 20 can appropriately determine whether the part can be reused based on the calculated remaining lifespan.

[0063] Second Embodiment Next, a reuse possibility determination device 20 according to a second embodiment of the present disclosure will be described. Note that the reuse possibility determination device 20 according to this embodiment has the same configuration as the reuse possibility determination device 20 according to the first embodiment, and therefore a description of the configuration will be omitted.

[0064] The reuse possibility determination device 20 of the first embodiment first determines whether the product can be reused for a first use (for example, for a vehicle), and if it is determined that the product cannot be reused for the first use, it determines whether the product can be reused for a second use.

[0065] In contrast, the reuse possibility determination device 20 according to this embodiment is configured to calculate the remaining lifespan of each part for multiple uses for which the part may be reused, and to decide to reuse the part for the use with the longest remaining lifespan.

[0066] Fig. 10 is a flowchart showing an example of processing executed by the reuse possibility determination device 20 according to this embodiment. In the flowchart shown in Fig. 10, the remaining lifespan of a part when reused for a first use (application 1) is calculated in step S120, as in the first embodiment. In this embodiment, following step S120, the reuse possibility determination device 20 calculates the remaining lifespan of a part when reused for a second use (application 2) in step S140.

[0067] In step S152, it is determined whether at least one of the remaining lifespans of the parts calculated in step S120 and step S140 is equal to or greater than a predetermined threshold. At this time, the reuse possibility determination device 20 may compare the remaining lifespan when the part is reused for a first purpose with a first threshold, and the remaining lifespan when the part is reused for a second purpose with a second threshold. If at least one of the remaining lifespans is equal to or greater than the predetermined threshold, the reuse possibility determination device 20 proceeds to step S154. On the other hand, if both remaining lifespans are less than the threshold, the reuse possibility determination device 20 proceeds to step S180.

[0068] In step S154, the reuse possibility determination device 20 determines whether the remaining lifespan of the part when reused for the first purpose is equal to or greater than the remaining lifespan of the part when reused for the second purpose. If the remaining lifespan of the part when reused for the first purpose is equal to or greater than the remaining lifespan of the part when reused for the second purpose, the reuse possibility determination device 20 proceeds to step S160. On the other hand, if the remaining lifespan of the part when reused for the first purpose is less than the remaining lifespan of the part when reused for the second purpose, the reuse possibility determination device 20 proceeds to step S170. The processes of steps S160 to S190 are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0069] The above describes preferred embodiments of the present disclosure, but the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms within the scope of the gist of the present disclosure.

[0070] For example, in each of the above-described embodiments, the reuse possibility determination device 20 determines whether a part can be reused for a plurality of uses. However, the reuse possibility determination device 20 may determine whether a part can be reused for only one type of use. Fig. 11 is a flowchart showing an example of processing by the reuse possibility determination device 20 to determine whether a part can be reused for only one type of use. The processing content of each step in Fig. 11 is the same as the processing content of the corresponding step number in the flowchart in Fig. 2, and therefore description thereof will be omitted.

[0071] In each of the above-described embodiments, the reuse possibility determination device 20 calculates the remaining lifespan of a part based on a plurality of stress factors. However, the reuse possibility determination device 20 may select one stress factor that has a particularly large effect on the lifespan of the part, and calculate the remaining lifespan of the part based on the selected one stress factor.

[0072] Furthermore, the vehicle 10 or the part to be determined as to whether it is reusable (for example, a power control unit) may have the functions of the above-described reuse possibility determination device 20. In this case, for example, the remaining lifespan of the relevant part may be displayed at any timing when an instruction to display the remaining lifespan is given. Furthermore, the vehicle 10 or the part to be determined as to whether it is reusable may cooperate to calculate the remaining lifespan of the part.

[0073] In each of the above-described embodiments, a preferred use for reusing a part is selected, and the selected use and / or remaining lifespan is displayed on the display unit 24. However, instead of selecting any one use, the reuse possibility determination device 20 may be configured to display multiple uses and the remaining lifespan for each of the multiple uses on the display unit 24.

[0074] Finally, this specification discloses the following technical ideas and their combinations. The combinations of the following technical ideas apply not only to the reuse possibility determination device but also to the reuse possibility determination method.

[0075] (Technical Idea 1) A reuse possibility determination device that determines whether a part that was used in a vehicle (10) can be reused, comprising: an acquisition unit (S100) that acquires usage history data relating to the usage history of the part in the vehicle; the usage history data including data relating to at least one stress factor that the part was subjected to while being used in the vehicle; a calculation unit (S120, S140) that calculates the remaining lifespan of the part based on the usage history data acquired by the acquisition unit; and a determination unit (S130, S150, S152, S154) that determines whether the part can be reused based on the remaining lifespan of the part calculated by the calculation unit.

[0076] (Technical Idea 2) The reuse possibility determination device described in Technical Idea 1, wherein the usage history data includes a plurality of the stress factors, and for each of the plurality of stress factors, a part life is determined taking into account the usage conditions when used in the vehicle, and the calculation unit determines the life usage portion of the part life for each of the plurality of stress factors based on the usage history data, and calculates the remaining life of the part based on the part life and life usage portion for each stress factor.

[0077] (Technical Idea 3) When the part is reused for an application other than the vehicle, the calculation unit calculates the remaining lifespan of the part for the application other than the vehicle as the remaining lifespan based on the usage history data, taking into account the usage history data and the planned usage state of the part in the application for which the part is to be reused, and the determination unit determines whether the part can be reused for the application for which the part is to be reused based on the remaining lifespan of the part calculated by the calculation unit, in this reuse possibility determination device according to Technical Idea 1.

[0078] (Technical Idea 4) The reuse possibility determination device according to Technical Idea 3, wherein the usage history data includes a plurality of the stress factors, and for each stress factor, a part life is determined taking into account the usage conditions when the part is used for a purpose for which it will be reused, and the calculation unit calculates, for each stress factor based on the usage history data, the part life usage of the part when used for a purpose for which it will be reused due to use in the vehicle, and calculates the remaining part life when the part is used for a purpose for which it will be reused based on the part life and part life usage for each stress factor.

[0079] (Technical Idea 5) In the case where the stress factors to which the part is subjected when used for reuse are limited to some of the multiple stress factors to which the part is subjected while being used in the vehicle, the calculation unit calculates the portion of the part's lifespan that will be achieved when the part is used for reuse due to use in the vehicle for some of the stress factors to which the part is subjected when used for reuse, and calculates the remaining lifespan of the part when used for reuse based on the part lifespan and portion of the lifespan for each of the some of the stress factors. This is a reuse feasibility determination device as described in Technical Idea 4.

[0080] (Technical Idea 6) When there are multiple types of uses for which the part can be reused, the calculation unit calculates the remaining lifespan of the part when used for a corresponding use for each of the multiple types of uses, and the judgment unit judges whether the part can be reused for the use for which the longer remaining lifespan is calculated. This is a reuse feasibility determination device described in any one of Technical Ideas 3 to 5.

[0081] (Technical Idea 7) A reuse eligibility determination device according to any one of Technical Ideas 1 to 6, wherein the data on the stress factors included in the usage history data includes at least one of the range and frequency of temperature changes of the part, the magnitude and duration of current flow when the part is used with current flowing through it, the magnitude and frequency of vibrations acting on the part, and the magnitude and frequency of stress fluctuations acting on the part.

[0082] (Technical Concept 8) The reuse possibility determination device according to any one of Technical Concepts 1 to 7, wherein the acquisition unit acquires the usage history data from the part or a device mounted on the vehicle.

[0083] (Technical Concept 9) The reuse possibility determination device according to any one of Technical Concepts 1 to 8, wherein the component is one of a motor generator, a storage battery, and a power control unit for driving the motor generator.

[0084] (Technical Concept 10) The reuse possibility determination device according to Technical Concept 9, wherein the component and / or the external device has functions as the acquisition unit, the calculation unit, and the determination unit.

[0085] (Technical Idea 11) A reuse possibility determination device described in any one of Technical Ideas 1 to 10, wherein the calculation of the remaining lifespan of the part by the calculation unit is performed at any time while the part is being used in the vehicle and / or when the part is recovered from the vehicle.

[0086] (Technical Concept 12) The reuse possibility determination device according to any one of Technical Concepts 1 to 11, wherein the vehicle is any one of a hybrid vehicle, a fuel cell vehicle, and an electric vehicle.

Claims

1. A reuse feasibility determination device that determines whether a part used in a vehicle (10) can be reused, comprising: an acquisition unit (S100) that acquires usage history data relating to the usage history of the part in the vehicle; the usage history data including data on at least one stress factor to which the part was subjected while it was used in the vehicle; a calculation unit (S120, S140) that calculates a remaining lifespan of the part based on the usage history data acquired by the acquisition unit; and a determination unit (S130, S150, S152, S154) that determines whether the part can be reused based on the remaining lifespan of the part calculated by the calculation unit.

2. The reuse feasibility determination device as described in claim 1, wherein the usage history data includes a plurality of the stress factors, and a part life is determined for each of the plurality of stress factors taking into account the usage conditions when used in the vehicle, and the calculation unit determines the part life usage portion of the part life for each of the plurality of stress factors based on the usage history data, and calculates the remaining part life based on the part life and the part life usage portion for each stress factor.

3. The reuse feasibility determination device as described in claim 1, wherein when the part is reused for an application other than the vehicle, the calculation unit calculates the remaining life of the part for the application other than the vehicle as the remaining life based on the usage history data, taking into account the usage history data and the planned usage state of the part in the application for which the part is to be reused, and the determination unit determines whether the part can be reused for the application for which the part is to be reused based on the remaining life of the part calculated by the calculation unit.

4. The reuse feasibility determination device as described in claim 3, wherein the usage history data includes a plurality of the stress factors, and for each of the stress factors, a part life is determined taking into account the usage conditions when the part is used for the purpose of reusing, and the calculation unit determines, based on the usage history data, for each of the stress factors, the part life usage portion of the part life when used for the purpose of reusing the part due to use in the vehicle, and calculates the remaining part life when used for the purpose of reusing the part based on the part life and part life usage portion for each of the stress factors.

5. A reuse feasibility determination device as described in claim 4, wherein, in the case where the stress factors to which the part is subjected when used for the purpose of reuse are limited to some of the multiple stress factors to which the part is subjected while being used in the vehicle, the calculation unit determines the portion of the part's lifespan that would be achieved by use in the vehicle when the part is used for the purpose of reuse for the some of the stress factors to which the part is subjected when used for the purpose of reuse, and calculates the remaining lifespan of the part when used for the purpose of reuse based on the part lifespan and the portion of the lifespan for each of the some of the stress factors.

6. A reuse feasibility determination device as described in any one of claims 3 to 5, wherein when there are multiple types of uses for which the part can be reused, the calculation unit calculates the remaining lifespan of the part when used for a corresponding use for each of the multiple types of uses, and the determination unit determines whether the part can be reused for the use for which a longer remaining lifespan is calculated.

7. A reuse eligibility determination device as claimed in any one of claims 1 to 5, wherein the data on the stress factors included in the usage history data includes at least one of the range and frequency of temperature changes of the part, the magnitude and duration of current flow when the part is used while current is passed through it, the magnitude and frequency of vibration acting on the part, and the magnitude and frequency of stress fluctuation acting on the part.

8. A reuse feasibility determination device as claimed in any one of claims 1 to 5, wherein the acquisition unit acquires the usage history data from equipment installed in the part or the vehicle.

9. A reuse possibility determination device according to any one of claims 1 to 5, wherein the part is one of a motor generator, a storage battery, and a power control unit for driving the motor generator.

10. The reuse possibility determination device according to claim 9, wherein the part and / or the external device has the functions of the acquisition unit, the calculation unit, and the determination unit.

11. A reuse feasibility determination device as described in any one of claims 1 to 5, wherein the calculation of the remaining life of the part by the calculation unit is performed at any time while the part is in use in the vehicle and / or when the part is recovered from the vehicle.

12. The reuse possibility determination device according to any one of claims 1 to 5, wherein the vehicle is one of a hybrid vehicle, a fuel cell vehicle, and an electric vehicle.

13. A method for determining whether a part used in a vehicle (10) can be reused, executed by at least one processor, comprising: acquiring usage history data relating to the usage history of the part in the vehicle (S100); the usage history data including data on at least one stress factor to which the part was subjected while being used in the vehicle; calculating a remaining lifespan of the part based on the acquired usage history data (S120, S140); and determining whether the part can be reused based on the calculated remaining lifespan of the part (S130, S150, S152, S154).

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