Control device

Abstract

To provide a technique which can determine whether foreign matter is infiltrated into a connector.SOLUTION: A control device is connected from an external side of a driving system through a connector to a temperature sensor installed on the driving system of a vehicle. The control device executes the treatments of: periodically acquiring a detection temperature by the temperature sensor; calculating a first temperature difference that is an absolute difference between the detection temperature and a previous detection temperature acquired at the previous period every time when acquiring the detection temperature; and determining, when a temperature sudden change condition that the first temperature difference is a first specified temperature or more is repeatedly satisfied for a specified number of times within a first specified time period, foreign matter is infiltrated into the connector.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a control device. [Background technology]

[0002] Patent Document 1 discloses a control device that detects an abnormality in a vehicle wire harness. This control device detects an abnormality in the wire harness based on a temperature detected by a thermistor wound around the wire harness. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-139223 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle, a foreign object such as water may enter the connector of a temperature sensor. In this case, the terminals in the connector are shorted by the foreign object, causing the temperature detected by the temperature sensor to indicate an abnormal value. Therefore, by monitoring the temperature detected by the temperature sensor, the intrusion of a foreign object into the connector can be detected. However, when the amount of foreign object (typically water) that has entered the connector is small, the foreign object moves within the connector in response to the acceleration or deceleration of the vehicle, causing the terminals in the connector to be shorted by the foreign object, or the short circuit is cleared. In this case, the temperature detected by the temperature sensor will intermittently indicate an abnormal value, making it difficult to distinguish whether the abnormal value is due to the intrusion of a foreign object into the connector or a simple fluctuation due to noise.

[0005] This specification provides a technique that can determine whether a foreign object has entered a connector. [Means for solving the problem]

[0006] In a first aspect disclosed in the present specification, a control device is disclosed that is connected to a temperature sensor disposed in a drive device of a vehicle via a connector from outside the drive device. The control device executes an acquisition process for periodically acquiring a temperature detected by the temperature sensor, a first calculation process for calculating a first temperature difference, which is an absolute difference between the detected temperature and a previous detected temperature acquired one cycle before, each time the detected temperature is acquired, and a first determination process for determining that a foreign object has entered the connector when a sudden temperature change condition, that the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly satisfied a predetermined number of times at intervals within a first predetermined time.

[0007] As described above, when a foreign object enters the connector, the terminals in the connector are short-circuited by the foreign object. In this case, the temperature detected by the temperature sensor indicates an abnormal value, and the sudden temperature change condition is established in which the first temperature difference is equal to or greater than the first predetermined temperature. At this time, if the amount of foreign object that has entered the connector is small, the terminals in the connector are intermittently short-circuited, and the sudden temperature change condition is also established intermittently. The sudden temperature change condition may be established accidentally due to the influence of noise, but if it is caused by a small amount of foreign object that has entered the connector, the sudden temperature change condition is repeatedly established at relatively short intervals. Therefore, by determining that a foreign object has entered the connector when the sudden temperature change condition is repeatedly established up to a predetermined number of times at intervals within the first predetermined time, the intrusion of the foreign object into the connector can be accurately determined even if the amount of the foreign object that has entered the connector is small.

[0008] In a second aspect, in the first aspect described above, when the sudden temperature change condition is satisfied, a second calculation process may be executed to store the previously detected temperature and calculate a second temperature difference, which is the absolute difference between the detected temperature detected thereafter and the previously detected temperature that has been stored, and a second determination process may be executed to determine that an abnormality has occurred in the temperature sensor when the second temperature difference is determined to be equal to or greater than a second predetermined temperature for a second predetermined time period that is shorter than the first predetermined time period.

[0009] When the second temperature difference is determined to be equal to or greater than the second predetermined temperature continuously for the second predetermined time, there is a possibility that an abnormality other than the abnormality caused by the intrusion of a foreign object into the connector (e.g., a break in the wiring portion of the temperature sensor) has occurred. According to the above configuration, the control device can determine that a foreign object has intruded into the connector, and can also determine that the above-mentioned different abnormality has occurred.

[0010] In a third aspect, in the first or second aspect above, the first judgment process may include a process of counting the number of times that the sudden temperature change condition is repeatedly satisfied at intervals within a first predetermined time, a process of determining that a foreign object has entered the connector when the counted number reaches the predetermined number, and a process of clearing the counted number when the sudden temperature change condition is not satisfied for the first predetermined time before the counted number reaches the predetermined number.

[0011] According to the above configuration, when the sudden temperature change determination is not established for the first predetermined time, the control device clears the counted number of times. With this configuration, it is possible to more accurately determine that a foreign object has entered the connector, compared to a configuration in which the counted number of times is not cleared.

[0012] In a fourth aspect, in any one of the first to third aspects, the temperature sensor may be a sensor for detecting a temperature of lubricating liquid in the drive device.

[0013] In a fifth aspect, in any one of the first to fourth aspects, the drive device may have an electric motor that drives wheels of the vehicle.

[0014] In a sixth aspect, in any one of the first to fifth aspects above, the control device may further execute a third determination process of determining that a first type of foreign object has entered the connector when the sudden temperature change condition is met and the first temperature difference is equal to or greater than a second predetermined temperature, and a fourth determination process of determining that a second type of foreign object has entered the connector when the sudden temperature change condition is met and the first temperature difference is less than the second predetermined temperature.

[0015] The amount of change in the detected temperature varies depending on the type of foreign object that has entered the connector. With the above configuration, the control device can appropriately determine the type of foreign object that has entered the connector based on the first temperature difference.

[0016] In a seventh aspect, in the sixth aspect, the first type of foreign matter may be water, and the second type of foreign matter may be metal.

[0017] Foreign objects that are likely to enter the connector are water and metal, so the control device can identify whether the foreign object that has entered the connector is water or metal. [Brief description of the drawings]

[0018] [Figure 1] The configuration of vehicle 2 is shown. [Diagram 2] 2 shows a flowchart of an abnormality determination process executed by a control device 14 of a vehicle 2. [Diagram 3] 1 shows a flowchart of a foreign object determination process executed by a control device 14 of a vehicle 2. [Figure 4] 13 shows a time chart in the case where a small amount of water has entered the connector 34 of the temperature sensor 28. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (Example) As shown in Fig. 1, the vehicle 2 includes a drive unit 10, a battery 12, a control unit 14, a left front wheel 16L, a right front wheel 16R, a left rear wheel 18L, and a right rear wheel 18R. The battery 12 has multiple built-in secondary battery cells and is configured to be rechargeable by an external power source (not shown). As an example, the secondary battery cells are lithium ion cells.

[0020] The drive device 10 includes an electric motor 20 and a gear unit 22. The electric motor 20 is a device that drives the left front wheel 16L and the right front wheel 16R of the vehicle 2 by using power supplied from the battery 12. The electric motor 20 is connected to the left front wheel 16L and the right front wheel 16R via the gear unit 22. The gear unit 22 includes a planetary gear mechanism 24 and a differential mechanism 26. The planetary gear mechanism 24 amplifies the output torque of the electric motor 20. The differential mechanism 26 distributes the power transmitted from the planetary gear mechanism 24 to the left front wheel 16L and the right front wheel 16R.

[0021] Lubricating liquid for lubricating and cooling the electric motor 20 and the gear unit 22 is stored inside the drive device 10. A temperature sensor 28 for detecting the temperature of the lubricating liquid is attached to the drive device 10. The temperature sensor 28 has a detection unit 30, a wiring unit 32, and a connector 34. The detection unit 30 is connected to one end of the wiring unit 32, and the connector 34 is connected to the other end. The connector 34 is electrically connected to a connector of the control device 14.

[0022] The control device 14 is a controller having a memory 14A. The control device 14 controls the operation of the electric motor 20 and the like according to a program (not shown) stored in the memory 14A. The temperature sensor 28 is electrically connected to the control device 14. The control device 14 is configured to periodically (for example, at a period of several tens of milliseconds) acquire the temperature detected by the temperature sensor 28. The memory 14A stores a first abnormality flag and a second abnormality flag. The first abnormality flag indicates either "OFF" indicating that no abnormality caused by the intrusion of water into the connector 34 has occurred, or "ON" indicating that an abnormality has occurred in the temperature sensor 28 due to the intrusion of water into the connector 34 being determined. The second abnormality flag indicates either "OFF" indicating that no abnormality caused by the intrusion of metal into the connector 34 has occurred, or "ON" indicating that an abnormality has occurred in the temperature sensor 28 due to the intrusion of metal into the connector 34 being determined.

[0023] (Abnormality determination process; Figure 2) The abnormality determination process executed by the control device 14 of the vehicle 2 will be described with reference to Fig. 2. The abnormality determination process is a process for determining whether or not various abnormalities have occurred, based on the temperature detected by the temperature sensor 28. The control device 14 starts the process of Fig. 2 when an ignition switch (not shown) of the vehicle 2 is turned on.

[0024] In S10, the control device 14 calculates a first temperature difference using the detected temperature periodically acquired from the temperature sensor 28. The first temperature difference is an absolute difference between the acquired detected temperature and the detected temperature acquired one cycle before (hereinafter, referred to as the "previously detected temperature"). The previously detected temperature is stored in the memory 14A.

[0025] In S12, the control device 14 monitors whether a sudden temperature change condition, that is, the first temperature difference is equal to or greater than a first predetermined temperature, is satisfied. The first predetermined temperature is set as a threshold value for detecting an abnormality in the temperature detected by the temperature sensor 28. As an example, the first predetermined temperature is 10° C. If the first temperature difference is equal to or greater than the first predetermined temperature, the control device 14 determines YES in S12 and proceeds to S14.

[0026] In S14, the controller 14 stores the previously detected temperature in the memory 14A as a specific previously detected temperature.

[0027] In S20, the control device 14 calculates a second temperature difference using the periodically acquired detected temperature and a specific previously detected temperature stored in the memory 14A. The second temperature difference is an absolute difference between the acquired detected temperature and the specific previously detected temperature.

[0028] In S22, the control device 14 monitors whether the second temperature difference becomes equal to or less than a second predetermined temperature. The second predetermined temperature is set as a threshold value for detecting that the temperature sensor 28 is normal. As an example, the second predetermined temperature is 5° C. If the second temperature difference becomes equal to or less than the second predetermined temperature, the control device 14 determines YES in S22 and proceeds to S30.

[0029] Simultaneously with the monitoring in S22, the control device 14 monitors in S24 whether the first elapsed time is equal to or greater than the first judgment time. The first elapsed time is the time elapsed since the judgment in S12 was YES. When the first elapsed time is equal to or greater than the first judgment time, the control device 14 judges YES in S24 and proceeds to S26.

[0030] In S26, the control device 14 determines that an abnormality has been detected in the temperature sensor 28. In this case, the abnormality is an abnormality in which the wiring portion 32 of the temperature sensor 28 is disconnected, an abnormality in which a large amount of water has infiltrated into the connector 34, or the like. When it is determined that an abnormality has been detected in the temperature sensor 28, the control device 14 notifies the user that an abnormality has occurred in the temperature sensor 28. As an example, the control device 14 turns on a warning lamp (not shown) on the instrument panel. This allows the user to know that an abnormality has occurred in the temperature sensor 28. When S26 ends, the control device 14 ends the processing of FIG. 2.

[0031] Furthermore, in S30, the controller 14 calculates a first temperature difference.

[0032] In S32, the controller 14 monitors whether a sudden temperature change condition (i.e., the first temperature difference is equal to or greater than a first predetermined temperature) is satisfied. If the sudden temperature change condition is satisfied, the controller 14 determines YES in S32 and proceeds to S34.

[0033] In S34, the control device 14 counts up the number of times N that the condition has been met that is stored in the memory 14A. The number of times N that the condition has been met indicates the number of times that the sudden temperature change condition has been met within an interval of a second judgment time, which will be described later.

[0034] In S36, the control device 14 judges whether the number of occurrences N in the memory 14A has reached a predetermined number (for example, 10 times). If the number of occurrences N has reached the predetermined number (YES in S36), the control device 14 proceeds to S38. On the other hand, if the number of occurrences N has not reached the predetermined number (NO in S36), the control device 14 returns to S30.

[0035] In S38, the control device 14 determines that an abnormality has been detected in the temperature sensor 28. The abnormality detected in this case is, for example, an abnormality in which a small amount of water has entered the connector 34. When it is determined that an abnormality has been detected in the temperature sensor 28, the control device 14 notifies the user that an abnormality has occurred in the temperature sensor 28. As an example, the control device 14 turns on a warning lamp on the instrument panel. This allows the user to know that an abnormality has occurred in the temperature sensor 28. When S38 ends, the control device 14 ends the processing of FIG. 2.

[0036] Simultaneously with the monitoring in S32, the control device 14 monitors in S40 whether the second elapsed time is equal to or greater than the second judgment time. The second elapsed time is the time that elapses without the sudden temperature change condition being satisfied. As an example, the second judgment time is 20 seconds, which is longer than the first judgment time. When the second elapsed time is equal to or greater than the second judgment time, the control device 14 judges YES in S40 and proceeds to S42.

[0037] In S42, the control device 14 determines that the temperature sensor 28 is normal, and clears the number of occurrences N. When S42 ends, the control device 14 returns to S10.

[0038] (Foreign object detection process; Fig. 3) The foreign object determination process executed by the control device 14 of the vehicle 2 will be described with reference to Fig. 3. The foreign object determination process is a process for identifying the type of foreign object that has entered the connector 34. The control device 14 starts the process of Fig. 3 when the ignition switch of the vehicle 2 is turned on.

[0039] S50 and S52 are similar to S10 and S12 in FIG. 2, respectively.

[0040] In S54, the control device 14 judges whether the first temperature difference is equal to or greater than a third predetermined temperature. The third predetermined temperature is a threshold for determining whether the foreign matter that has entered the connector 34 is water or metal. Specifically, the control device 14 converts the first temperature difference into a change in voltage, and uses the converted change in voltage to identify a change in resistance value (hereinafter, referred to as "resistance change amount"). Then, the control device 14 judges whether the resistance change amount is equal to or greater than a predetermined change amount. If the resistance change amount is equal to or greater than the predetermined change amount, the control device 14 judges that the first temperature difference is equal to or greater than the third predetermined temperature (YES in S54), and proceeds to S60. On the other hand, if the resistance change amount is less than the predetermined change amount, the control device 14 judges that the first temperature difference is less than the third predetermined temperature (NO in S54), and proceeds to S70.

[0041] In S60, the control device 14 judges whether or not it has been determined in the abnormality judgment process of Fig. 2 that an abnormality has been determined in the temperature sensor 28. If it has been determined that an abnormality has been determined in the temperature sensor 28 (YES in S60), the control device 14 proceeds to S62. On the other hand, if it has been determined that the temperature sensor 28 is normal (NO in S60), the control device 14 ends the process of Fig. 3.

[0042] In S62, the control device 14 determines that the foreign matter that has entered the connector 34 is water.

[0043] In S64, the control device 14 changes the first abnormality flag from "OFF" to "ON". In response to the first abnormality flag being changed to "ON", the control device 14 lowers the upper limit of the output value of the electric motor 20 to the first upper limit value. When S64 ends, the control device 14 ends the processing of FIG. 3.

[0044] The S70 is similar to the S60.

[0045] Furthermore, in S72, the control device 14 determines that the foreign object that has entered the connector 34 is metal.

[0046] In S74, the control device 14 changes the second abnormality flag from "OFF" to "ON". In response to the second abnormality flag being changed to "ON", the control device 14 lowers the upper limit of the output value of the electric motor 20 to a second upper limit value that is smaller than the first upper limit value. That is, the control device 14 switches the upper limit of the output value of the electric motor 20 depending on the type of foreign matter that has entered the connector 34. When S64 ends, the control device 14 ends the processing of FIG. 3.

[0047] (Specific case; Figure 4) 4, a specific case in which it is determined that an abnormality has been detected in temperature sensor 28 due to a small amount of water entering connector 34 of temperature sensor 28 will be described. The vertical axis of the time chart in FIG. 4 represents the detected temperature.

[0048] The detected temperature between times T0 and T1 is substantially constant at temperature TE1. Therefore, between times T0 and T1, the vehicle 2 determines that the first temperature difference is less than the first predetermined temperature (NO in S12 in FIG. 2, NO in S52 in FIG. 3).

[0049] At time T2, water entering the connector 34 of the temperature sensor 28 causes a short circuit in the terminals in the connector 34. As a result, the temperature detected by the temperature sensor 28 suddenly changes from temperature TE1 to temperature TE2. That is, the detected temperature indicates an abnormal value. The absolute difference between temperatures TE2 and TE1 is greater than the first predetermined temperature. For this reason, the vehicle 2 determines that the first temperature difference is equal to or greater than the first predetermined temperature (YES in S12), and stores temperature TE1 in memory 14A as a specific previously detected temperature (S14).

[0050] Furthermore, at time T2, the vehicle 2 determines that the first temperature difference is equal to or greater than the first predetermined temperature (YES in S52 in FIG. 3), and uses the first temperature difference to identify the amount of change in resistance value (hereinafter, referred to as "resistance change amount"). In this case, water has entered the connector 34, so the amount of change in resistance value is greater than the predetermined amount of change. For this reason, the vehicle 2 determines YES in S54 in FIG. 3.

[0051] As in this case, when a small amount of water has entered connector 34, the terminals in connector 34 are shorted by the water and the short circuit is eliminated depending on the acceleration or deceleration of vehicle 2. As the short circuit of the terminals in connector 34 is eliminated, the detected temperature becomes temperature TE3 that is lower than temperature TE2 by the second predetermined temperature at time T3, which is before the first determination time has elapsed since time T2. In this case, vehicle 2 determines that the second temperature difference is equal to or lower than the second predetermined temperature (YES in S22 of FIG. 2). Thereafter, the detected temperature returns to temperature TE1.

[0052] Next, at time T4, which is before the second determination time has elapsed after the second temperature difference becomes equal to or less than the second predetermined temperature, the terminals in the connector 34 are short-circuited by water. As a result, the detected temperature suddenly changes from temperature TE1 to temperature TE2. In this case, the vehicle 2 determines that the first temperature difference is equal to or greater than the first predetermined temperature (YES in S32), counts up the number of occurrences N to "1" (S34), and determines that the number of occurrences N has not reached the predetermined number (NO in S36). Thereafter, the detected temperature returns to temperature TE1.

[0053] Next, at time T5, which is before the second determination time has elapsed since the first temperature difference became equal to or greater than the first predetermined temperature, the terminals in the connector 34 are short-circuited by water. As a result, the detected temperature suddenly changes from temperature TE1 to temperature TE2. In this case, the vehicle 2 determines that the first temperature difference is equal to or greater than the first predetermined temperature (YES in S32), counts up the number of occurrences N to "2" (S34), and determines that the number of occurrences N has not reached the predetermined number (NO in S36). Thereafter, the terminals in the connector 34 are short-circuited by water, and the short circuit is eliminated. As a result, the sudden temperature change condition is intermittently satisfied. Then, as the sudden temperature change condition is satisfied, the number of occurrences N is counted up (S34).

[0054] At time T6 after the number of occurrences N is counted up to "9", the terminals in the connector 34 are short-circuited by water. As a result, the detected temperature suddenly changes from temperature TE1 to temperature TE2. In this case, the vehicle 2 determines that the first temperature difference is equal to or higher than the first predetermined temperature (YES in S32), counts up the number of occurrences N to "10" (S34), and determines that the number of occurrences N has reached the predetermined number (YES in S36). In this case, the vehicle 2 determines that an abnormality has been determined in the temperature sensor 28 (S38), and turns on a warning lamp on the instrument panel. This allows the user to know that an abnormality has occurred in the temperature sensor 28. In this way, even if the amount of water that has entered the connector 34 is small, the intrusion of water into the connector 34 of the temperature sensor 28 is detected.

[0055] 2, the vehicle 2 determines that an abnormality has been detected in the temperature sensor 28 (YES in S60 in FIG. 3), determines that the foreign object that has entered the connector 34 is water (S62), and changes the first abnormality flag from "OFF" to "ON." As a result, the vehicle 2 lowers the upper limit of the output value of the electric motor 20 to the first upper limit value.

[0056] As described above, the control device 14 executes the following processes: periodically acquiring the temperature detected by the temperature sensor 28; each time the detected temperature is acquired, calculating a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature acquired one cycle prior (S10, S30 in FIG. 2); and determining that water (an example of a "foreign object") has entered the connector 34 when the sudden temperature change condition, in which the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly met a predetermined number of times within an interval within a second judgment time (an example of a "first predetermined time") (YES in S36).

[0057] When water infiltrates into the connector 34, the terminals in the connector 34 are short-circuited by the water. In this case, the temperature detected by the temperature sensor 28 indicates an abnormal value, and thus a sudden temperature change condition is established in which the first temperature difference is equal to or greater than the first predetermined temperature (YES in S32 in FIG. 2). At this time, if the amount of water that has infiltrated into the connector 34 is small, the terminals in the connector 34 are intermittently short-circuited in response to acceleration / deceleration of the vehicle 2, etc. As a result, the sudden temperature change condition is also established intermittently. The sudden temperature change condition may be established accidentally due to the influence of noise, but if it is caused by a small amount of water that has infiltrated into the connector 34, the sudden temperature change condition is repeatedly established at relatively short intervals. Therefore, when the sudden temperature change condition is repeatedly established a predetermined number of times within the second determination time (YES in S36), it is determined that water has infiltrated into the connector 34 (S38), and thus the infiltration of water into the connector 34 can be accurately determined even if the amount of water that has infiltrated into the connector 34 is small.

[0058] In addition, when the sudden temperature change condition is met, the control device 14 stores the previously detected temperature (S14), and further executes a second calculation process (S20) to calculate a second temperature difference, which is the absolute difference between the detected temperature detected thereafter and the previously detected temperature that has been stored, and a second determination process (S26) to determine that an abnormality has occurred in the temperature sensor 28 when the determination that the second temperature difference is equal to or greater than the second predetermined temperature continues for a first determination time (an example of a "second predetermined time") that is shorter than the first predetermined time (YES in S24).

[0059] When the determination that the second temperature difference is equal to or greater than the second predetermined temperature continues for the first determination time, there is a possibility that an abnormality other than the abnormality of water infiltrating into the connector 34 (e.g., a break in the wiring portion 32 of the temperature sensor 28, adhesion of a foreign object to the detection portion 30, etc.) has occurred. According to the above configuration, the control device 14 can determine that water has infiltrated into the connector 34, and can also determine that the above-mentioned different abnormality has occurred.

[0060] The control device 14 also executes a process (S34) of counting the number of times N that the sudden temperature change condition is repeatedly satisfied at intervals within the second judgment time, a process (S38) of determining that water has entered the connector 34 when the number of times N that the condition is satisfied reaches a predetermined number (YES in S36), and a process (S42) of clearing the number of times N that the condition is satisfied if the sudden temperature change judgment is not satisfied for the second judgment time before the number of times N that the condition is satisfied reaches the predetermined number (YES in S40).

[0061] According to the above configuration, when the sudden temperature change determination is not satisfied for the second determination time, the control device 14 clears the number of times the determination is satisfied N. According to such a configuration, it is possible to more accurately determine that water has entered the connector 34, compared to a configuration in which the number of times the determination is satisfied N is not cleared.

[0062] In addition, if the sudden temperature change condition is met and the first temperature difference is equal to or greater than the third predetermined temperature (YES in S32 of FIG. 2, YES in S54 of FIG. 3, YES in S60), the control device 14 determines that water (an example of a "first type of foreign matter") has entered the connector 34 (S62), and if the sudden temperature change condition is met and the first temperature difference is less than the third predetermined temperature (YES in S32 of FIG. 2, NO in S54 of FIG. 3, YES in S70), the control device 14 determines that metal (an example of a "second type of foreign matter") has entered the connector 34 (S72).

[0063] The amount of change in the detected temperature differs depending on the type of foreign matter that has entered the connector 34. According to the above configuration, the control device 14 can appropriately determine the type of foreign matter that has entered the connector 34 based on the first temperature difference. In particular, in this embodiment, the control device 14 can identify whether the foreign matter that has entered the connector 34 is water or metal.

[0064] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above embodiments are listed below.

[0065] (First Modification) S10 to S26 in FIG. 2 can be omitted.

[0066] (Second Modification) S42 in Fig. 2 may be omitted. In this modification, the number of times N that the condition is met may be stored in a volatile memory. In this modification, when the power supply of the vehicle 2 is turned off, the number of times N that the condition is met is automatically cleared.

[0067] (Third Modification) The "temperature sensor" is not limited to a sensor for detecting the temperature of the lubricating fluid, and may be a sensor for detecting the temperatures of a high-voltage cable and a low-voltage cable of an electric vehicle.

[0068] (Fourth Modification) The "vehicle" is not limited to an electric vehicle, but may be an engine vehicle, a hybrid vehicle, a fuel cell vehicle, a hydrogen engine vehicle, or the like.

[0069] (Fifth Modification) The process in FIG. 3 can be omitted.

[0070] (Sixth Modification) The third predetermined temperature may be, for example, a threshold value for determining whether the foreign matter that has entered the connector 34 is resin or water.

[0071] (Seventh Modification) When the first abnormality flag is "ON", the control device 14 may not change the upper limit of the output value of the electric motor 20, and may change the upper limit of the output value of the electric motor 20 only when the second abnormality flag is "ON". In other words, the control device 14 may switch the content of the process (control mode, etc.) applied when the first abnormality flag is "ON" and when the second abnormality flag is "ON".

[0072] The technical elements described in this specification or drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0073] 2: vehicle, 10: drive unit, 12: battery, 14: control unit, 14A: memory, 16L: left front wheel, 16R: right front wheel, 18L: left rear wheel, 18R: right rear wheel, 20: electric motor, 22: gear unit, 24: planetary gear mechanism, 26: differential mechanism, 28: temperature sensor, 30: detection unit, 32: wiring unit, 34: connector

Claims

1. A control device that is connected to a temperature sensor disposed in a drive device of a vehicle from outside the drive device via a connector, an acquisition process for periodically acquiring a temperature detected by the temperature sensor; a first calculation process for calculating a first temperature difference, which is an absolute difference between the detected temperature and a previously detected temperature obtained one cycle before the detected temperature, every time the detected temperature is obtained; a first determination process for determining that a foreign object has entered the connector when a temperature sudden change condition, that is, the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly satisfied a predetermined number of times within a first predetermined time interval; A control device that executes the above.

2. a second calculation process for storing the previously detected temperature when the sudden temperature change condition is satisfied, and calculating a second temperature difference which is an absolute difference between the detected temperature detected thereafter and the previously detected temperature that has been stored; 2. The control device according to claim 1, further comprising: a second determination process for determining that an abnormality has occurred in the temperature sensor when the determination that the second temperature difference is equal to or greater than a second predetermined temperature continues for a second predetermined time that is shorter than the first predetermined time.

3. The first determination process includes: Counting the number of times the sudden temperature change condition is repeatedly satisfied within a first predetermined time interval; a process of determining that a foreign object has entered the connector when the counted number reaches the predetermined number; and clearing the counted number of times when the temperature sudden change condition is not satisfied for the first predetermined time before the counted number of times reaches the predetermined number of times. The control device according to claim 2.

4. The control device according to claim 1 , wherein the temperature sensor is a sensor for detecting a temperature of a lubricating liquid in the drive device.

5. The control device according to claim 1 , wherein the drive device has an electric motor that drives wheels of the vehicle.

6. a third determination process for determining that a first type of foreign matter has entered the connector when the sudden temperature change condition is satisfied and the first temperature difference is equal to or greater than a third predetermined temperature; The control device according to claim 1, further comprising a fourth determination process for determining that a second type of foreign object has entered the connector when the sudden temperature change condition is met and the first temperature difference is less than the third predetermined temperature.

7. the first type of foreign matter is water, The control device according to claim 6 , wherein the second type of foreign matter is metal.

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