JP2009118646A - Electromagnetic actuator short-circuit detection device - Google Patents

Abstract

An electromagnetic actuator short-circuit detection device capable of appropriately detecting a short-circuit of an electromagnetic actuator is provided.
An electromagnetic actuator short-circuit detection device obtains a first resistance value of an electromagnetic actuator based on a voltage value and a current value output from a drive circuit of the electromagnetic actuator, and acquires a temperature of the electromagnetic actuator. Based on the temperature, a second resistance value of the electromagnetic actuator is obtained. Then, when the obtained second resistance value is larger than a value obtained by adding a predetermined value to the first resistance value, it is determined that the electromagnetic actuator is short-circuited. Thereby, it is possible to detect a short circuit of the electromagnetic actuator with high accuracy.
[Selection] Figure 3

Description

  The present invention relates to a technical field for detecting a short circuit of an electromagnetic actuator that operates an electromagnetic clutch or the like.

  Conventionally, an electronically controllable clutch or the like is known. For example, Patent Document 1 describes a technique for detecting the temperature of such a clutch. Specifically, in Patent Document 1, the input energy applied to the clutch is calculated, and the clutch temperature is estimated based on this input energy. Patent Document 2 describes a technique for calculating the temperature of a solenoid from a solenoid resistance value calculated based on a solenoid voltage and a preset energization amount of the solenoid in a solenoid driving device for driving an electromagnetic clutch. Has been.

JP 2002-168270 A Japanese Utility Model Publication 5-77631

  However, Patent Documents 1 and 2 described above do not describe a method for appropriately detecting a short circuit of an electromagnetic actuator that drives an electromagnetic clutch or the like.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a short-circuit detection device for an electromagnetic actuator that can appropriately detect a short-circuit of the electromagnetic actuator.

  In one aspect of the present invention, a short-circuit detection device for an electromagnetic actuator includes a first resistance value for determining a first resistance value of the electromagnetic actuator based on a voltage value and a current value output from a drive circuit of the electromagnetic actuator. A calculating means; a second resistance value acquiring means for acquiring a temperature of the electromagnetic actuator; and obtaining a second resistance value of the electromagnetic actuator based on the temperature; and the second resistance value is the first resistance. Short-circuit detecting means for determining that the electromagnetic actuator is short-circuited when the value is larger than a value obtained by adding a predetermined value to the value.

  The electromagnetic actuator short-circuit detection device is preferably used for detecting a short-circuit of an electromagnetic actuator that operates an electromagnetic clutch or the like. Specifically, the first resistance value calculating unit obtains the first resistance value of the electromagnetic actuator based on the voltage value and the current value output from the drive circuit of the electromagnetic actuator to the electromagnetic actuator. The second resistance value acquisition means acquires the temperature of the electromagnetic actuator, and obtains the second resistance value of the electromagnetic actuator based on the temperature. For example, the second resistance value acquisition unit acquires the second resistance value with reference to a map in which the second resistance value is associated with the temperature of the electromagnetic actuator. Then, the short-circuit detection means determines that the electromagnetic actuator is short-circuited when the second resistance value is larger than a value obtained by adding a predetermined value to the first resistance value. According to the above-described electromagnetic actuator short-circuit detection device, it is possible to accurately detect a short-circuit of the electromagnetic actuator.

  In one aspect of the electromagnetic actuator short-circuit detection device, the second resistance value calculating means acquires the temperature of the electromagnetic actuator from an oil temperature sensor. Thereby, the short circuit of the electromagnetic actuator can be detected easily and without increasing the cost.

  In another aspect of the electromagnetic actuator short-circuit detection device, the short-circuit detection means detects the short-circuit of the electromagnetic actuator after a predetermined time has elapsed from the start of operation. Preferably, the predetermined time corresponds to a time required from when the operation is started until the temperature detected by the oil temperature sensor substantially matches the temperature of the electromagnetic actuator. Thereby, it is possible to appropriately prevent the detection of the short circuit from occurring when there is a difference between the temperature detected by the oil temperature sensor and the temperature of the electromagnetic actuator. Therefore, occurrence of erroneous detection can be prevented.

  According to another aspect of the electromagnetic actuator short-circuit detection device, the short-circuit detection unit includes a current feedback stop unit that stops current feedback in the drive circuit when the short-circuit detection unit detects short-circuit of the electromagnetic actuator. Thereby, it becomes possible to prevent the detection accuracy from deteriorating due to the execution of current feedback at the time of short circuit detection.

  Preferably, the electromagnetic actuator short-circuit detection device includes a cutting unit that performs control to cut the voltage and current in the drive circuit when the short-circuit detection unit determines that the electromagnetic actuator is short-circuited. . Thereby, generation | occurrence | production of the malfunction resulting from the short circuit of an electromagnetic actuator can be prevented appropriately.

  The short-circuit detection device for an electromagnetic actuator in the present invention obtains the first resistance value of the electromagnetic actuator based on the voltage value and the current value output from the drive circuit of the electromagnetic actuator, and acquires the temperature of the electromagnetic actuator, A second resistance value of the electromagnetic actuator is obtained based on the temperature. Then, when the obtained second resistance value is larger than a value obtained by adding a predetermined value to the first resistance value, it is determined that the electromagnetic actuator is short-circuited. Thereby, it is possible to detect a short circuit of the electromagnetic actuator with high accuracy.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
First, a first embodiment of the present invention will be described.

  FIG. 1 is a diagram showing a schematic configuration of a system according to the first embodiment of the present invention. This system mainly includes a drive circuit 101, an electromagnetic actuator 102, a voltage sensor 103, a current sensor 104, a temperature sensor 105, and a controller 110. This system is mounted on a vehicle or the like.

  The drive circuit 101 is a circuit for driving the electromagnetic actuator 102, and supplies a current to the electromagnetic actuator 102 via the wiring 106. The electromagnetic actuator 102 is driven by a current supplied from the drive circuit 101 and is used to operate a component not shown. For example, the electromagnetic actuator 102 operates a clutch or the like.

  The voltage sensor 103 detects the voltage value V <b> 1 output from the drive circuit 101 to the electromagnetic actuator 102. The current sensor 104 detects a current value I1 output from the drive circuit 101 to the electromagnetic actuator 102. The voltage sensor 103 supplies a detection signal S3 corresponding to the detected voltage value V1 to the controller 110, and the current sensor 104 supplies a detection signal S4 corresponding to the detected current value I1 to the controller 110. A temperature sensor 105 is provided in the vicinity of the electromagnetic actuator 102. The temperature sensor 105 detects the temperature T1 of the electromagnetic actuator 102 and supplies a detection signal S5 corresponding to the detected temperature T1 to the controller 110.

  The controller 110 includes a CPU, a ROM, a RAM, an A / D converter, and the like (not shown), and corresponds to an ECU (Electronic Control Unit) in the vehicle. The controller 110 obtains detection signals from the various sensors described above and supplies the control signal S1 to the drive circuit 101 based on the detection signals, thereby controlling the drive circuit 101. Specifically, the controller 110 performs a process of detecting a short circuit of the electromagnetic actuator 102 based on detection signals from various sensors, and controls the drive circuit 101 according to the processing result. Thus, the controller 110 corresponds to the electromagnetic actuator short-circuit detection device in the present invention. Specifically, the controller 110 operates as a first resistance value calculation unit, a second resistance value acquisition unit, a short circuit detection unit, and a cut unit.

  Here, a method of detecting a short circuit in the electromagnetic actuator 102 performed by the controller 110 will be described. First, the controller 110 calculates the resistance value Rk1 of the electromagnetic actuator 102 from the voltage value V1 and the current value I1 acquired from the voltage sensor 103 and the current sensor 104. Specifically, the controller 110 calculates the resistance value Rk1 by calculating “Rk1 = V1 / I1”. This resistance value Rk1 corresponds to a first resistance value. Next, the controller 110 obtains the resistance value Rt1 of the electromagnetic actuator 102 based on the temperature T1 of the electromagnetic actuator 102 acquired from the temperature sensor 105. Specifically, the controller 110 refers to a map in which the resistance value Rt1 is associated with the temperature T1 of the electromagnetic actuator 102, and acquires the resistance value Rt1 corresponding to the acquired temperature T1. This resistance value Rt1 corresponds to a second resistance value.

  FIG. 2 shows an example of a map in which the resistance value Rt1 is associated with the temperature T1 of the electromagnetic actuator 102. In FIG. 2, the horizontal axis indicates the temperature T1, and the vertical axis indicates the resistance value Rt1. From this, it can be seen that the resistance value Rt1 decreases as the temperature T1 of the electromagnetic actuator 102 increases. Such a map can be obtained by measuring in advance.

  Next, the controller 110 determines whether or not the electromagnetic actuator 102 is short-circuited by comparing the resistance value Rk1 obtained as described above and the resistance value Rt1. Specifically, when the resistance value Rt1 greatly exceeds the resistance value Rk1, specifically, when the resistance value Rt1 is larger than the value obtained by adding the predetermined value α to the resistance value Rk1, the controller 110 Is judged to be short-circuited. The predetermined value α is a value set in consideration of, for example, a sensor error, and a value larger than 0 is used.

  The reason why a short circuit can be detected as described above is as follows. It can be said that the resistance value Rt1 obtained from the temperature T1 of the electromagnetic actuator 102 is basically a value that does not change between when the electromagnetic actuator 102 is short-circuited and when it is not short-circuited. That is, it can be said that the resistance value Rt1 is a value that is hardly affected by the short circuit of the electromagnetic actuator 102. On the other hand, the resistance value Rk1 obtained from the voltage value V1 and current value I1 output from the drive circuit 101 tends to change between when the electromagnetic actuator 102 is short-circuited and when it is not short-circuited. That is, it can be said that the resistance value Rk1 is a value affected by a short circuit of the electromagnetic actuator 102. For example, when the electromagnetic actuator 102 is short-circuited, the current value I1 is a relatively large value and the resistance value Rk1 is a small value. From the above, it can be said that a short circuit of the electromagnetic actuator 102 can be appropriately determined by comparing the resistance value Rk1 and the resistance value Rt1. Note that the controller 110 performs control to cut the voltage and current of the drive circuit 101 when determining that the electromagnetic actuator 102 is short-circuited. This is to prevent problems that may occur due to heat generation of the electric wires and cables.

  Next, a short circuit detection process according to the first embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a short circuit detection process according to the first embodiment. This process is repeatedly executed by the controller 110.

  First, in step S101, the controller 110 calculates the resistance value Rk1 of the electromagnetic actuator 102 from the voltage value V1 and the current value I1 acquired from the voltage sensor 103 and the current sensor 104. Then, the process proceeds to step S102. In step S <b> 102, the controller 110 obtains the resistance value Rt <b> 1 of the electromagnetic actuator 102 based on the temperature T <b> 1 of the electromagnetic actuator 102 acquired from the temperature sensor 105. Specifically, the controller 110 refers to a map (for example, a map as shown in FIG. 2) in which the resistance value Rt1 is associated with the temperature T1 of the electromagnetic actuator 102, and corresponds to the acquired temperature T1. The resistance value Rt1 is acquired. Then, the process proceeds to step S103.

  In step S103, the controller 110 compares the resistance value Rk1 obtained in step S101 with the resistance value Rt1 obtained in step S102. By doing so, it is determined whether or not the electromagnetic actuator 102 is short-circuited. Specifically, the controller 110 determines whether or not the resistance value Rt1 is larger than a value obtained by adding a predetermined value α to the resistance value Rk1.

  When the resistance value Rt1 is larger than the value obtained by adding the predetermined value α to the resistance value Rk1 (step S103; Yes), the process proceeds to step S104. In this case, the controller 110 determines that the electromagnetic actuator 102 is short-circuited, and performs control to cut the voltage and current of the drive circuit 101 (step S104). Then, the process exits the flow. On the other hand, when the resistance value Rt1 is equal to or less than the value obtained by adding the predetermined value α to the resistance value Rk1 (step S103; No), the process proceeds to step S105. In this case, the controller 110 determines that the electromagnetic actuator 102 is not short-circuited, and performs normal control on the drive circuit 101 (step S105). That is, the control for cutting the voltage and current is not performed. Then, the process exits the flow.

  According to the short circuit detection process according to the first embodiment described above, it is possible to detect a short circuit of the electromagnetic actuator 102 with high accuracy. In addition, it is possible to appropriately prevent the occurrence of problems due to the short circuit of the electromagnetic actuator 102.

  Here, an application example of the system shown in FIG. 1 will be described with reference to FIG. FIG. 4 shows a schematic configuration of a hybrid vehicle to which the system according to the first embodiment is applied.

  The example of FIG. 4 is a hybrid vehicle called a mechanical distribution type two-motor type, which mainly includes an engine (internal combustion engine) 1, a first motor generator MG1, a second motor generator MG2, a power distribution mechanism 20, Is provided. An engine 1 corresponding to a power source and a first motor generator MG1 corresponding to a rotation speed control mechanism are connected to a power distribution mechanism 20. The output shaft 3 of the power distribution mechanism 20 is connected to a second motor generator MG2 that is a sub power source for assisting drive torque or braking force. Second motor generator MG2 and output shaft 3 are connected via MG2 transmission 6. Furthermore, the output shaft 3 is connected to the drive wheels via a final reduction gear (not shown). The first motor generator MG1 and the second motor generator MG2 are electrically connected via a battery, an inverter, or an appropriate controller (not shown) or directly, and are generated in the first motor generator MG1. The second motor generator MG2 is driven by the generated electric power.

  The engine 1 is a heat engine that generates power by burning fuel, and examples thereof include a gasoline engine and a diesel engine. The first motor generator MG1 generates power mainly by receiving torque from the engine 1 and rotating, and a reaction force of torque accompanying power generation acts. By controlling the rotational speed of first motor generator MG1, the rotational speed of engine 1 changes continuously. The second motor generator MG2 is a device that assists the driving torque or the braking force. When assisting the drive torque, the second motor generator MG2 receives power supply and functions as an electric motor. On the other hand, when assisting the braking force, the second motor generator MG2 functions as a generator that is rotated by the torque transmitted from the drive wheels 9 to generate electric power.

  The power distribution mechanism 20 is a mechanism that distributes the output torque of the engine 1 to the first motor generator MG1 and the output shaft 3, and is configured to generate a differential action. Specifically, the engine 1 is connected to the first rotating element among the four rotating elements that are provided with a plurality of sets of differential mechanisms and have a differential action, and the first motor generator MG1 is connected to the second rotating element. Are connected, and the output shaft 3 is connected to the third rotating element. The fourth rotating element can be fixed by the brake unit 7. The brake unit 7 is configured by a dog clutch, for example, and is operated by an electromagnetic actuator 102a described later. In a state where the brake unit 7 does not fix the fourth rotating element, the rotational speed of the engine 1 is continuously changed by continuously changing the rotational speed of the first motor generator MG1, and the continuously variable transmission mode Is realized. On the other hand, in a state where the brake unit 7 is fixing the fourth rotating element, the transmission gear ratio determined by the power distribution mechanism 20 is fixed to the overdrive state (that is, the engine rotational speed is smaller than the output rotational speed). Thus, the fixed gear ratio mode is realized.

  More specifically, the power distribution mechanism 20 is configured by combining two planetary gear mechanisms. The first planetary gear mechanism includes a ring gear 21, a carrier 22, and a sun gear 23. The second planetary gear mechanism is a double pinion type and includes a ring gear 25, a carrier 26, and a sun gear 27. The output shaft 2 of the engine 1 is connected to the carrier 22 of the first planetary gear mechanism, and the carrier 22 is connected to the ring gear 25 of the second planetary gear mechanism. These constitute the first rotating element. The rotor 11 of the first motor generator MG1 is connected to the sun gear 23 of the first planetary gear mechanism, and these constitute a second rotating element. The ring gear 21 of the first planetary gear mechanism and the carrier 26 of the second planetary gear mechanism are connected to each other and to the output shaft 3. These constitute the third rotating element. Further, the sun gear 27 of the second planetary gear mechanism is connected to the rotation shaft 29 and constitutes a fourth rotation element together with the rotation shaft 29. The rotating shaft 29 can be fixed by the brake unit 7.

  The system according to the first embodiment described above is applied to the electromagnetic actuator 102a. That is, a short circuit is detected for the electromagnetic actuator 102a. Specifically, the drive circuit 101a, electromagnetic actuator 102a, voltage sensor 103a, current sensor 104a, and temperature sensor 105a are the same as the drive circuit 101, electromagnetic actuator 102, voltage sensor 103, current sensor 104, and temperature sensor 105 shown in FIG. Correspond to each. Then, the ECU 4 performs the same process as the controller 110 described above. That is, the ECU 4 performs a process of detecting a short circuit of the electromagnetic actuator 102a based on the detection signals from the voltage sensor 103a, the current sensor 104a, and the temperature sensor 105a (for example, the process shown in the flowchart of FIG. 3). In addition to such processing, the ECU 4 executes various controls for the engine 1, the first motor generator MG1, and the second motor generator MG2.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The second embodiment is the same as the first embodiment in that a process of detecting a short circuit of the electromagnetic actuator 102 is performed based on detection signals from various sensors. Specifically, also in the second embodiment, the resistance value of the electromagnetic actuator 102 obtained from the voltage value and current value output from the drive circuit 101 is compared with the resistance value of the electromagnetic actuator 102 obtained from the temperature of the electromagnetic actuator 102. Thus, a short circuit of the electromagnetic actuator 102 is detected.

  However, in the second embodiment, the first embodiment is that the resistance value Rt2 of the electromagnetic actuator 102 is obtained based on the temperature (oil temperature) T2 detected by the oil temperature sensor instead of the temperature T1 detected by the temperature sensor 105. Different from form. That is, the resistance value Rt2 of the electromagnetic actuator 102 is obtained using the oil temperature T2 as the temperature of the electromagnetic actuator 102. In the second embodiment, detection of a short circuit of the electromagnetic actuator 102 is executed after a predetermined time has elapsed from the start of operation. That is, detection of a short circuit of the electromagnetic actuator 102 is not performed until a predetermined time has elapsed from the start of operation (for example, at the start). This predetermined time corresponds to the time required from the start of operation until the oil temperature T2 detected by the oil temperature sensor substantially matches the temperature of the electromagnetic actuator 102. By using the oil temperature T2 detected by the oil temperature sensor in this way, it is not necessary to measure the inductance or the like in the electromagnetic part, so it is simple and can detect a short circuit of the electromagnetic actuator 102 without increasing the cost. Is possible.

  Furthermore, in the second embodiment, when the voltage supplied to the drive circuit 101 is duty-controlled, the voltage supplied to the drive circuit 101 (hereinafter referred to as “drive circuit supply voltage Vs”) and the duty ratio. Based on the above, the voltage value V2 output from the drive circuit 101 is obtained, and the resistance value Rk2 of the electromagnetic actuator 102 is calculated from the voltage value V2. In addition, in the second embodiment, when current feedback is executed in the drive circuit 101 when detecting the short circuit of the electromagnetic actuator 102, the current feedback is stopped. That is, detection of a short circuit of the electromagnetic actuator 102 is performed in a state where the current feedback is temporarily stopped. Thereby, it becomes possible to prevent the detection accuracy from deteriorating due to the execution of current feedback at the time of short circuit detection.

  FIG. 5 is a diagram showing a schematic configuration of a system according to the second embodiment of the present invention. This system mainly includes a drive circuit 101, an electromagnetic actuator 102, a current sensor 104, a voltage sensor 107, an oil temperature sensor 108, and a controller 120. This system is also installed in vehicles. The system according to the second embodiment is different from the system according to the first embodiment in that it includes a voltage sensor 107, an oil temperature sensor 108, and a controller 120 instead of the voltage sensor 103, the temperature sensor 105, and the controller 110. . In addition, the component which attached | subjected the code | symbol same as the component shown in FIG. 1 shall have the same meaning, and the description is abbreviate | omitted.

  The voltage sensor 107 detects the drive circuit supply voltage Vs supplied to the drive circuit 101, and supplies a detection signal S7 corresponding to the detected drive circuit supply voltage Vs to the controller 120. The oil temperature sensor 108 detects an oil temperature T2 such as lubricating oil in which the electromagnetic actuator 102 is immersed. For example, the oil temperature sensor 108 is provided in the transaxle and detects the temperature of the lubricating oil used in the transaxle. The oil temperature sensor 108 supplies a detection signal S8 corresponding to the detected oil temperature T2 to the controller 120.

  The controller 120 includes a CPU, a ROM, a RAM, an A / D converter, and the like (not shown), and corresponds to an ECU in the vehicle. The controller 120 acquires the detection signals from the various sensors described above and supplies the control signal S2 to the drive circuit 101 based on the detection signals, thereby controlling the drive circuit 101. Specifically, the controller 120 performs processing for detecting a short circuit of the electromagnetic actuator 102 based on detection signals from various sensors, and controls the drive circuit 101 according to the processing result. Thus, the controller 120 corresponds to the electromagnetic actuator short-circuit detection device in the present invention. Specifically, the controller 120 operates as a first resistance value calculation unit, a second resistance value acquisition unit, a short circuit detection unit, a cut unit, and a current feedback stop unit.

  Specifically, the controller 120 performs short circuit detection for the electromagnetic actuator 102 in the following procedure. The controller 120 detects a short circuit of the electromagnetic actuator 102 after a predetermined time has elapsed from the start of operation. That is, detection of a short circuit of the electromagnetic actuator 102 is not executed until a predetermined time has elapsed from the start of operation. The predetermined time corresponds to the time required from the start of operation until the oil temperature T2 detected by the oil temperature sensor 108 substantially matches the temperature of the electromagnetic actuator 102. That is, the controller 120 does not detect a short circuit during a period in which there is a difference between the oil temperature T2 and the temperature of the electromagnetic actuator 102.

  When a predetermined time has elapsed from the start of operation, the controller 120 drives based on the drive circuit supply voltage Vs acquired from the voltage sensor 107 and the duty ratio (%) in the voltage supplied to the drive circuit 101. A voltage value V2 output from the circuit 101 is calculated. Specifically, the controller 120 calculates the voltage value V2 by calculating “V2 = Vs × (Duty rate) / 100”. Then, the controller 120 calculates the resistance value Rk2 of the electromagnetic actuator 102 from the calculated voltage value V2 and the current value I2 acquired from the current sensor 104. Specifically, the controller 120 calculates the resistance value Rk2 by calculating “Rk2 = V2 / I2”. The resistance value Rk2 corresponds to the first resistance value.

  Next, the controller 120 determines the resistance value Rt2 of the electromagnetic actuator 102 based on the oil temperature T2 acquired from the oil temperature sensor 108. Specifically, the controller 120 refers to a map in which the resistance value Rt2 is associated with the oil temperature T2, and acquires the resistance value Rt2 corresponding to the acquired oil temperature T2. This resistance value Rt2 corresponds to a second resistance value.

  FIG. 6 shows an example of a map that is referred to when the resistance value Rt2 of the electromagnetic actuator 102 is obtained. Here, the case where the oil temperature of the lubricating oil in the transaxle (hereinafter referred to as “transaxle oil temperature”) is used as the oil temperature T2 described above. FIG. 6 shows the transaxle oil temperature T2 on the horizontal axis and the resistance value Rt2 on the vertical axis. From this, it can be seen that the resistance value Rt2 decreases as the transaxle oil temperature T2 increases. Such a map can be obtained by measuring in advance.

  Next, the controller 120 determines whether or not the electromagnetic actuator 102 is short-circuited by comparing the resistance value Rk2 and the resistance value Rt2 obtained as described above. Specifically, the controller 120 determines that the electromagnetic actuator 102 when the resistance value Rt2 is significantly higher than the resistance value Rk2, specifically, when the resistance value Rt2 is larger than a value obtained by adding the predetermined value β to the resistance value Rk2. Is judged to be short-circuited.

  The controller 120 performs control to cut the voltage and current of the drive circuit 101 when it is determined that the electromagnetic actuator 102 is short-circuited. In addition, the controller 120 performs control to stop the current feedback when the drive circuit 101 is executing current feedback when detecting the short circuit of the electromagnetic actuator 102.

  Next, a short circuit detection process according to the second embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing a short circuit detection process according to the second embodiment. This process is repeatedly executed by the controller 120.

  First, in step S201, the controller 120 determines whether or not a predetermined time has elapsed from the start of operation. Here, the controller 120 determines whether or not the oil temperature T2 detected by the oil temperature sensor 108 and the temperature of the electromagnetic actuator 102 substantially match. If the predetermined time has elapsed (step S201; Yes), the process proceeds to step S202. In this case, it is considered that the oil temperature T2 and the temperature of the electromagnetic actuator 102 are approximately the same. On the other hand, when the predetermined time has not elapsed (step S201; No), the process proceeds to step S204. In this case, it is considered that there is a difference between the oil temperature T2 and the temperature of the electromagnetic actuator 102. Therefore, the controller 120 does not execute short circuit detection for the electromagnetic actuator 102.

  In step S <b> 202, the controller 120 determines whether it is time to detect a short circuit of the electromagnetic actuator 102. When it is the short circuit detection timing of the electromagnetic actuator 102 (step S202; Yes), the process proceeds to step S203. In this case, the controller 120 stops the current feedback of the drive circuit 101 in order to ensure the detection accuracy with respect to the short circuit of the electromagnetic actuator 102 (step S203). Then, the process proceeds to step S205. On the other hand, when it is not the short circuit detection timing of the electromagnetic actuator 102 (step S202; No), the process proceeds to step S204. In this case, since the short circuit detection for the electromagnetic actuator 102 is not executed, the controller 120 executes current feedback of the drive circuit 101 (step S204). That is, the current feedback of the drive circuit 101 is not stopped. Then, the process proceeds to step S209.

  In step S205, the controller 120 calculates the resistance value Rk2 of the electromagnetic actuator 102. Specifically, the controller 120 is based on the drive circuit supply voltage Vs acquired from the voltage sensor 107, the duty ratio in the voltage supplied to the drive circuit 101, and the current value I2 acquired from the current sensor 104. Then, the resistance value Rk2 of the electromagnetic actuator 102 is calculated. Then, the process proceeds to step S206. In step S206, the controller 120 obtains the resistance value Rt2 of the electromagnetic actuator 102 based on the oil temperature T2 acquired from the oil temperature sensor 108. Specifically, the controller 120 refers to a map (for example, a map as shown in FIG. 6) in which the resistance value Rt2 is associated with the oil temperature T2, and the resistance value corresponding to the acquired oil temperature T2. Get Rt2. Then, the process proceeds to step S207.

  In step S207, the controller 120 compares the resistance value Rk2 obtained in step S205 with the resistance value Rt2 obtained in step S206. By doing so, it is determined whether or not the electromagnetic actuator 102 is short-circuited. Specifically, the controller 120 determines whether or not the resistance value Rt2 is larger than a value obtained by adding the predetermined value β to the resistance value Rk2.

  When the resistance value Rt2 is larger than the value obtained by adding the predetermined value β to the resistance value Rk2 (step S207; Yes), the process proceeds to step S208. In this case, the controller 120 determines that the electromagnetic actuator 102 is short-circuited, and performs control to cut the voltage and current of the drive circuit 101 (step S208). Then, the process exits the flow. On the other hand, when the resistance value Rt2 is equal to or less than the value obtained by adding the predetermined value β to the resistance value Rk2 (step S207; No), the process proceeds to step S209. In this case, the controller 120 determines that the electromagnetic actuator 102 is not short-circuited, and performs normal control on the drive circuit 101 (step S209). That is, the control for cutting the voltage and current is not performed. Then, the process exits the flow.

  The short circuit detection process according to the second embodiment described above can also detect the short circuit of the electromagnetic actuator 102 with high accuracy. In the second embodiment, since the oil temperature T2 detected by the oil temperature sensor 108 is used as the temperature of the electromagnetic actuator 102, a short circuit of the electromagnetic actuator 102 is detected easily and without increasing the cost. be able to.

  The system according to the second embodiment described above can be similarly applied to a hybrid vehicle as shown in FIG.

1 shows a schematic configuration of a system according to a first embodiment. An example of the map with which resistance value was matched with the temperature of the electromagnetic actuator is shown. It is a flowchart which shows the short circuit detection process which concerns on 1st Embodiment. 1 shows a schematic configuration of a hybrid vehicle to which a system according to a first embodiment is applied. 2 shows a schematic configuration of a system according to a second embodiment. An example of the map with which resistance value was matched with the transaxle oil temperature is shown. It is a flowchart which shows the short circuit detection process which concerns on 2nd Embodiment.

Explanation of symbols

1 Engine 3 Output shaft 4 ECU
7 Brake unit 20 Power distribution mechanism 101 Drive circuit 102 Electromagnetic actuator 103, 107 Voltage sensor 104 Current sensor 105 Temperature sensor 108 Oil temperature sensor 110, 120 Controller

Claims (6)

First resistance value calculating means for obtaining a first resistance value of the electromagnetic actuator based on a voltage value and a current value output from a drive circuit of the electromagnetic actuator;
Second resistance value acquisition means for acquiring a temperature of the electromagnetic actuator and obtaining a second resistance value of the electromagnetic actuator based on the temperature;
Short-circuit detecting means for determining that the electromagnetic actuator is short-circuited when the second resistance value is larger than a value obtained by adding a predetermined value to the first resistance value. Actuator short-circuit detection device.   The short-circuit detection device for an electromagnetic actuator according to claim 1, wherein the second resistance value calculating means acquires the temperature of the electromagnetic actuator from an oil temperature sensor.   The short-circuit detection device for an electromagnetic actuator according to claim 2, wherein the short-circuit detection unit detects a short-circuit of the electromagnetic actuator after a predetermined time has elapsed since the start of operation.   The electromagnetic actuator short-circuit detection device according to claim 3, wherein the predetermined time corresponds to a time required for the temperature detected by the oil temperature sensor to substantially coincide with the temperature of the electromagnetic actuator after the operation is started. .   5. The electromagnetic actuator according to claim 1, further comprising a current feedback stop unit that stops current feedback in the drive circuit when detection of a short circuit of the electromagnetic actuator is performed by the short circuit detection unit. Short-circuit detection device.   6. The cutting device according to claim 1, further comprising a cutting unit that performs control to cut a voltage and a current in the drive circuit when the short-circuit detection unit determines that the electromagnetic actuator is short-circuited. Electromagnetic actuator short-circuit detection device.

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