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 Art

[0002] [[ID=1l]] Patent Document 1 discloses a control device for detecting an abnormality in a vehicle wire harness. This control device detects an abnormality in the wire harness based on the detected temperature by a thermistor wound around the wire harness.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle, foreign matter such as water may enter the connector of a temperature sensor. In this case, the terminals in the connector are short-circuited by the foreign matter, and the detected temperature by the temperature sensor shows an abnormal value. Therefore, by monitoring the detected temperature by the temperature sensor, it is possible to detect the entry of foreign matter into the connector. However, when the foreign matter (typically water) that has entered the connector is small, the foreign matter moves within the connector according to the acceleration and deceleration of the vehicle, causing the terminals in the connector to be short-circuited by the foreign matter or the short circuit to be eliminated. In this case, the detected temperature by the temperature sensor intermittently shows an abnormal value, and it is difficult to distinguish whether it is due to the entry of foreign matter into the connector or simply due to fluctuations caused by noise.

[0005] This specification provides a technology capable of determining that foreign matter has entered the connector.

Means for Solving the Problems

[0006] In a first aspect disclosed herein, a control device is disclosed which is connected to a temperature sensor located in the drive unit of a vehicle via a connector from outside the drive unit. The control device performs an acquisition process to periodically acquire the temperature detected by the temperature sensor; a first calculation process to calculate a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature acquired one cycle earlier, each time the detected temperature is acquired; and a first determination process to determine that a foreign object has entered the connector when the temperature change condition, in which the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly met up to a predetermined number of times at intervals within a first predetermined time.

[0007] As mentioned above, if foreign matter enters the connector, the terminals inside the connector will short-circuit due to the foreign matter. In this case, the temperature detected by the temperature sensor will show an abnormal value, and the condition of rapid temperature change, where the first temperature difference is greater than or equal to the first predetermined temperature, will be met. If only a small amount of foreign matter enters the connector, the terminals inside the connector will short-circuit intermittently, and the condition of rapid temperature change will also be met intermittently. The condition of rapid temperature change may be met accidentally due to the influence of noise, but if it is caused by a small amount of foreign matter that has entered the connector, the condition of rapid temperature change will be met repeatedly at relatively short intervals. Therefore, by determining that foreign matter has entered the connector when the condition of rapid temperature change is met repeatedly up to a predetermined number of times at intervals within the first predetermined time, it is possible to accurately determine the presence of foreign matter even if only a small amount has entered the connector.

[0008] In the second embodiment, in the first embodiment, when the condition for a sudden temperature change is met, a second calculation process may be performed in which the previously detected temperature is stored and a second temperature difference is calculated, which is the absolute difference between the detected temperature detected thereafter and the stored previously detected temperature; and a second determination process may be performed in which, when the determination that the second temperature difference is equal to or greater than a second predetermined temperature is made for a second predetermined time that is shorter than the first predetermined time, an abnormality is determined to have occurred in the temperature sensor.

[0009] If the determination that the second temperature difference is equal to or greater than the second predetermined temperature continues for a second predetermined time, there is a possibility that an abnormality other than the abnormality of foreign matter entering the connector (for example, a break in the wiring of the temperature sensor) has occurred. With the above configuration, the control device can determine that foreign matter has entered the connector and can also determine that the above-mentioned different abnormality has occurred.

[0010] In a third embodiment, in the first or second embodiment, the first determination process may include: counting the number of times the rapid temperature change condition is repeatedly met at intervals within a first predetermined time; determining that a foreign object has entered the connector when the counted number reaches the predetermined number; and clearing the counted number if the rapid temperature change condition is not met over the first predetermined time before the counted number reaches the predetermined number.

[0011] According to the above configuration, the control device clears the count if the temperature change detection is not successful within a first predetermined time. With this configuration, it is possible to more accurately determine if a foreign object has entered the connector compared to a configuration that does not clear the count.

[0012] In a fourth embodiment, in any one of the first to third embodiments described above, the temperature sensor may be a sensor for detecting the temperature of the lubricating fluid in the drive unit.

[0013] In the fifth embodiment, in any one of the first to fourth embodiments described above, the drive system may have an electric motor that drives the wheels of the vehicle.

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

[0015] The amount of temperature variation detected differs depending on the type of foreign object that enters 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 the seventh embodiment, in the sixth embodiment, the first type of foreign matter may be water, and the second type of foreign matter may be metal.

[0017] The foreign objects most likely to enter the connector are water and metal. Therefore, the control device can determine whether the foreign object that has entered the connector is water or metal. [Brief explanation of the drawing]

[0018] [Figure 1] The configuration of vehicle 2 is shown. [Figure 2] This shows a flowchart of the abnormality detection process performed by the control device 14 of vehicle 2. [Figure 3] This shows a flowchart of the foreign object detection process performed by the control device 14 of vehicle 2. [Figure 4] This shows a time chart for when a small amount of water enters the connector 34 of the temperature sensor 28. [Modes for carrying out the invention]

[0019] (Examples) As shown in FIG. 1, the vehicle 2 includes a drive device 10, a battery 12, a control device 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 incorporates a plurality of 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 the supplied power 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 has 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] In the drive device 10, a lubricant for lubricating and cooling the electric motor 20 and the gear unit 22 is stored. A temperature sensor 28 for detecting the temperature of the lubricant 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 the connector of the control device 14.

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

[0023] (Abnormality determination process; FIG. 2) Referring to FIG. 2, the abnormality determination process executed by the control device 14 of the vehicle 2 will be described. The abnormality determination process is a process for determining whether various abnormalities have occurred based on the detected temperature by the temperature sensor 28. The control device 14 starts the process of FIG. 2 when the 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 the absolute difference between the acquired detected temperature and the detected temperature acquired one cycle before (hereinafter referred to as "previous detected temperature"). The previous detected temperature is stored in the memory 14A.

[0025] In S12, the control device 14 monitors whether the temperature change condition, where the first temperature difference is equal to or greater than the first predetermined temperature, is met. The first predetermined temperature is set as a threshold for detecting an abnormality in the temperature detected by the temperature sensor 28. For 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 control device 14 stores the previously detected temperature as a specific previously detected temperature in the memory 14A.

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

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

[0029] Furthermore, simultaneously with monitoring in S22, the control device 14 monitors in S24 to ensure that the first elapsed time is equal to or greater than the first determination time. The first elapsed time is the time elapsed since the determination of YES in S12. If the first elapsed time is equal to or greater than the first determination time, the control device 14 determines YES in S24 and proceeds to S26.

[0030] In S26, the control device 14 determines that there is an abnormality in the temperature sensor 28. This abnormality could be a broken wire in the wiring section 32 of the temperature sensor 28, or a large amount of water entering the connector 34. Upon determining that there is an abnormality in the temperature sensor 28, the control device 14 notifies the user that an abnormality has occurred in the temperature sensor 28. For example, the control device 14 illuminates a warning lamp (not shown) on the instrument panel. This allows the user to know that there is an abnormality in the temperature sensor 28. When S26 ends, the control device 14 terminates the process shown in Figure 2.

[0031] Furthermore, in S30, the control device 14 calculates the first temperature difference.

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

[0033] In S34, the control device 14 increments the number of occurrences N stored in memory 14A. The number of occurrences N indicates the number of times the rapid temperature change condition was met within the interval of the second judgment time, which will be described later.

[0034] In S36, the control device 14 determines whether the number of occurrences N in 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 such as a small amount of water entering the connector 34. Upon determining 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. For example, the control device 14 illuminates 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 terminates the process shown in Figure 2.

[0036] Furthermore, simultaneously with monitoring in S32, the control device 14 monitors in S40 to ensure that the second elapsed time is equal to or greater than the second judgment time. The second elapsed time is the time that has elapsed without the condition of a sudden temperature change being met. For example, the second judgment time is 20 seconds, which is longer than the first judgment time. If the second elapsed time is equal to or greater than the second judgment time, the control device 14 determines YES in S40 and proceeds to S42.

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

[0038] (Foreign object detection process; Figure 3) Referring to Figure 3, the foreign object detection process performed by the control device 14 of vehicle 2 will be described. The foreign object detection process is a process to identify the type of foreign object that has entered the connector 34. The control device 14 starts the process shown in Figure 3 when the ignition switch of vehicle 2 is turned on.

[0039] S50 and S52 are the same as S10 and S12 in Figure 2, respectively.

[0040] In S54, the control device 14 determines whether the first temperature difference is equal to or greater than the third predetermined temperature. The third predetermined temperature is a threshold value used to determine 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 determine the change in resistance (hereinafter referred to as "change in resistance"). The control device 14 then determines whether the change in resistance is equal to or greater than a predetermined change. If the change in resistance is equal to or greater than a predetermined change, the control device 14 determines 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 change in resistance is less than a predetermined change, the control device 14 determines 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 determines whether or not an abnormality has been detected in the temperature sensor 28 during the abnormality detection process shown in Figure 2. If the control device 14 determines that an abnormality has been detected in the temperature sensor 28 (YES in S60), it proceeds to S62. On the other hand, if the control device 14 determines that the temperature sensor 28 is normal (NO in S60), it terminates the process shown in Figure 3.

[0042] In S62, the control device 14 determines that the foreign substance 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 change of the first abnormality flag to "ON", the control device 14 reduces 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 terminates the process shown in Figure 3.

[0044] The S70 is the same as 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 change of the second abnormality flag to "ON", the control device 14 lowers the upper limit of the output value of the electric motor 20 to a second upper limit that is smaller than the first upper limit. In other words, the control device 14 switches the upper limit of the output value of the electric motor 20 according to the type of foreign object that has entered the connector 34. When S64 is completed, the control device 14 terminates the process shown in Figure 3.

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

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

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

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

[0051] In this case, if a small amount of water enters the connector 34, the terminals inside the connector 34 may short-circuit due to the water or be resolved depending on the acceleration and deceleration of the vehicle 2. As the short-circuit of the terminals inside the connector 34 is resolved, at time T3, which is before the first judgment time has elapsed from time T2, the detected temperature becomes temperature TE3, which is lower than temperature TE2 by a second predetermined temperature. In this case, the vehicle 2 determines that the second temperature difference is less than or equal to the second predetermined temperature (YES in S22 of Figure 2). After that, the detected temperature returns to temperature TE1.

[0052] Next, at time T4, before the second determination time has elapsed after the second temperature difference falls below the second predetermined temperature, the terminals in connector 34 are short-circuited by water. As a result, the detected temperature abruptly changes from temperature TE1 to temperature TE2. In this case, vehicle 2 determines that the first temperature difference is above 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). After that, the detected temperature returns to temperature TE1.

[0053] Next, at time T5, before the second judgment 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 changes abruptly from temperature TE1 to temperature TE2. In this case, vehicle 2 determines that the first temperature difference is equal to or greater than the first predetermined temperature (YES in S32), increments 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). Subsequently, the terminals in the connector 34 are short-circuited by water, and the short circuit is resolved. This causes the abrupt temperature change condition to be met intermittently. Then, the number of occurrences N is incremented in accordance with the meeting of the abrupt temperature change condition (S34).

[0054] At time T6, after the number of occurrences N has been counted up to "9", the terminals in the connector 34 are short-circuited by water. As a result, the detected temperature changes abruptly from temperature TE1 to temperature TE2. In this case, vehicle 2 determines that the first temperature difference is greater than or equal to 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, vehicle 2 determines that there is an abnormality in the temperature sensor 28 (S38) and illuminates the warning lamp on the instrument panel. This allows the user to know that there is an abnormality in the temperature sensor 28. In this way, even if only a small amount of water enters the connector 34, the ingress of water into the connector 34 of the temperature sensor 28 can be detected.

[0055] Furthermore, at time T6, vehicle 2 determines that an abnormality has been detected in the temperature sensor 28 during the abnormality detection process in Figure 2 (YES at S60 in Figure 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, vehicle 2 reduces 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 performs the following processes: periodically acquire the temperature detected by the temperature sensor 28; calculate a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature acquired one cycle earlier, each time a detected temperature is acquired (S10, S30 in Figure 2); and determine that water (an example of "foreign matter") has entered the connector 34 when the 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 at intervals within a second determination time (an example of the "first predetermined time") (YES in S36) (S38).

[0057] When water enters the connector 34, the terminals inside the connector 34 are short-circuited by the water. In this case, the temperature detected by the temperature sensor 28 shows an abnormal value, and the condition for a sudden temperature change, where the first temperature difference is greater than or equal to the first predetermined temperature, is met (YES in S32 of Figure 2). At this time, if only a small amount of water enters the connector 34, the terminals inside the connector 34 will short-circuit intermittently in response to the acceleration and deceleration of the vehicle 2. As a result, the condition for a sudden temperature change will also be met intermittently. The condition for a sudden temperature change may be met accidentally due to the influence of noise, but if it is caused by a small amount of water entering the connector 34, the condition for a sudden temperature change will be met repeatedly at relatively short intervals. Therefore, by determining that water has entered the connector 34 (S38) when the condition for a sudden temperature change is met repeatedly up to a predetermined number of times within the interval of the second judgment time (YES in S36), it is possible to accurately determine the intrusion of water into the connector 34 even if only a small amount has entered.

[0058] Furthermore, when a rapid temperature change condition is met, the control device 14 stores the previously detected temperature (S14) and performs a second calculation process (S20) to calculate a second temperature difference, which is the absolute difference between the subsequently detected temperature and the previously stored previously detected temperature. It also performs 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 a second predetermined temperature continues for a first determination time shorter than the first predetermined time (an example of the "second predetermined time") (YES in S24).

[0059] If the determination that the second temperature difference is equal to or greater than the second predetermined temperature continues for the duration of the first determination time, it is possible that an abnormality other than the abnormality of water entering the connector 34 has occurred (for example, a break in the wiring portion 32 of the temperature sensor 28, or the adhesion of foreign matter to the detection unit 30). With the above configuration, the control device 14 can determine that water has entered the connector 34, and can also determine that the above-mentioned different abnormalities have occurred.

[0060] Furthermore, the control device 14 performs the following processes: counting the number of times (S34) the sudden temperature change condition is repeatedly met at intervals within the second judgment time; determining that water has entered the connector 34 when the number of times N is met reaches a predetermined number (YES in S36) (S38); and clearing the number of times N is met (S42) if the sudden temperature change determination is not met over the second judgment time before the number of times N is met reaches a predetermined number (YES in S40).

[0061] With the above configuration, the control device 14 clears the number of successful occurrences N if the temperature change detection does not occur within the second detection time. With this configuration, it is possible to more accurately determine whether water has entered the connector 34 compared to a configuration in which the number of successful occurrences N is not cleared.

[0062] Furthermore, the control device 14 determines that water (an example of a "Type 1 foreign object") has entered the connector 34 when the rapid temperature change condition is met and the first temperature difference is equal to or greater than the third predetermined temperature (YES in S32 in Figure 2, NO in S54 in Figure 3, and YES in S60) (S62), and determines that metal (an example of a "Type 2 foreign object") has entered the connector 34 when the rapid temperature change condition is met and the first temperature difference is less than the third predetermined temperature (YES in S32 in Figure 2, NO in S54 in Figure 3, and YES in S70) (S72).

[0063] The amount of temperature fluctuation varies depending on the type of foreign matter that enters the connector 34. With 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] The specific examples of the technology disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. Modifications of the above embodiments are listed below.

[0065] (First modified example) Steps S10 to S26 in Figure 2 can be omitted.

[0066] (Second Modification) Step S42 in Figure 2 can be omitted. In this modification, the number of occurrences N is preferably stored in volatile memory. In this modification, when the power to vehicle 2 is turned off, the number of occurrences N is automatically cleared.

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

[0068] (Fourth modified example) The term "vehicle" is not limited to electric vehicles, but may also refer to engine vehicles, hybrid vehicles, fuel cell vehicles, hydrogen engine vehicles, etc.

[0069] (Fifth modified example) The process shown in Figure 3 can be omitted.

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

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

[0072] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [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 connected to a temperature sensor located in the vehicle's drive unit via a connector from outside the drive unit, An acquisition process that periodically acquires the temperature detected by the temperature sensor, Each time the detected temperature is obtained, a first calculation process is performed to calculate a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature obtained one cycle earlier. A first determination process determines that a foreign object has entered the connector when the temperature change condition, in which the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly met up to a predetermined number of times at intervals within a first predetermined time; Execute, The control device is When the aforementioned rapid temperature change condition is met, a second calculation process is performed to store the previously detected temperature and to calculate a second temperature difference, which is the absolute difference between the subsequently detected temperature and the previously stored previously detected temperature. A second determination process is further executed in which, when the determination that the second temperature difference is equal to or greater than the second predetermined temperature occurs continuously for a second predetermined time that is shorter than the first predetermined time, it is determined that an abnormality has occurred in the temperature sensor. Control device.

2. The first determination process is, A process for counting the number of times the aforementioned rapid temperature change condition is repeatedly met at intervals within a first predetermined time period, When the number of counted times reaches the predetermined number, a process is performed to determine that a foreign object has entered the connector. If the temperature change condition does not occur for a first predetermined time before the counted number reaches the predetermined number, the process includes clearing the counted number. The control device according to claim 1.

3. A control device connected to a temperature sensor located in the vehicle's drive unit via a connector from outside the drive unit, An acquisition process that periodically acquires the temperature detected by the temperature sensor, Each time the detected temperature is obtained, a first calculation process is performed to calculate a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature obtained one cycle earlier. A first determination process determines that a foreign object has entered the connector when the temperature change condition, in which the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly met up to a predetermined number of times at intervals within a first predetermined time; Execute, The temperature sensor is a sensor for detecting the temperature of the lubricating fluid in the drive unit. Control device.

4. A control device connected to a temperature sensor located in the vehicle's drive unit via a connector from outside the drive unit, An acquisition process that periodically acquires the temperature detected by the temperature sensor, Each time the detected temperature is obtained, a first calculation process is performed to calculate a first temperature difference, which is the absolute difference between the detected temperature and the previously detected temperature obtained one cycle earlier. A first determination process determines that a foreign object has entered the connector when the temperature change condition, in which the first temperature difference is equal to or greater than a first predetermined temperature, is repeatedly met up to a predetermined number of times at intervals within a first predetermined time; Execute, The control device is A third determination process determines that a first type of foreign object has entered the connector when the above-mentioned rapid temperature change condition is met and the first temperature difference is equal to or greater than a third predetermined temperature, If the above-mentioned rapid temperature change condition is met and the first temperature difference is less than the third predetermined temperature, a fourth determination process is further performed to determine that a second type of foreign object has entered the connector. Control device.

5. The aforementioned first type of foreign substance is water, The control device according to claim 4, wherein the second type of foreign matter is metal.

6. The control device according to any one of claims 1 to 5, wherein the drive device has an electric motor for driving the wheels of the vehicle.

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