control device

Abstract

To provide a control device capable of, as one example, inspecting abnormality of a switch regardless of a state of one of two power supplies.SOLUTION: As one sample, a control device according to an embodiment includes: a first device; a first power supply capable of feeding electric power to the first device through a first electric path; a second power supply capable of feeding electric power to the first device through a second electric path; a first switch provided in the second electric path; a third electric path connected to the second electric path between the second power supply and the first switch and capable of conducting between the first power supply and the first switch; and a first voltage monitor configured to measure a voltage between the first device and the first switch in the second electric path.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a control device.

Background Art

[0002] Conventionally, a control device capable of selectively supplying power to a target device from two power sources has been known. For example, when power supply from the main power source is lost, the control device can supply power to the device from the backup power source (Patent Document 1).

[0003] In the control device, various switches are provided in the electrical paths between the two power sources and the device. The control device can inspect for the occurrence of abnormalities such as an open failure or a short circuit failure in a desired switch by controlling the opening and closing of the various switches and measuring the voltage in the electrical path(s).

Prior Art Documents

Patent Documents

[0008] [Figure 1] Figure 1 is a circuit block diagram showing a brake control device according to the first embodiment. [Figure 2] Figure 2 is a flowchart showing an example of the abnormality inspection operation in the first embodiment. [Figure 3] Figure 3 is a circuit block diagram showing a brake control device according to the second embodiment. [Modes for carrying out the invention]

[0009] (First embodiment) The first embodiment will be described below with reference to Figures 1 and 2. Note that in this specification, the components of the embodiment and their descriptions may be described using multiple expressions. The components and their descriptions are examples and are not limited by the expressions used herein. Components may also be identified by names different from those used herein. Furthermore, components may also be described using expressions different from those used herein.

[0010] Figure 1 is a circuit block diagram showing a brake control device 10 according to the first embodiment. The brake control device 10 is mounted on a vehicle 1, such as an automobile, and controls the braking force of the brakes of the vehicle 1. The brake control device 10 is an example of a control device. Note that the control device is not limited to the brake control device 10, and may be an automatic driving or automatic braking control device in the vehicle 1, or a control device in another device.

[0011] The brake control device 10 includes an electronic control unit (ECU) 11, a motor 12, a solenoid 13, a main power supply 21, a sub power supply 22, multiple electrical paths 31, 32, 33, 34, 35, 36, 37, multiple diodes 41, 42, 43, 44, multiple switches 51, 52, 53, 54, 55, 56, multiple voltage monitors 61, 62, 63, 64, 65, 66, 67, and multiple electrical resistors 71, 72, 73.

[0012] The ECU 11 may also be called the control unit. The motor 12 is an example of the first device. The solenoid 13 is an example of the second device. The main power supply 21 is an example of the first power supply. The sub power supply 22 is an example of the second power supply. However, the sub power supply 22 may be an example of the first power supply and the main power supply 21 may be an example of the second power supply.

[0013] Electrical path 31 is an example of the first electrical path. Electrical path 32 is an example of the second electrical path. Electrical path 33 is an example of the fourth electrical path. Electrical path 34 is an example of the fifth electrical path. Electrical path 37 is an example of the third electrical path. Switches 51 and 52 are examples of the third switches. Switch 53 is an example of the first switch. Voltage monitor 61 is an example of the first voltage monitor. Voltage monitors 63 and 64 are examples of the second voltage monitors.

[0014] The ECU 11 controls the entire brake control device 10. For example, the ECU 11 controls the supply of power to the motor 12 and solenoid 13. The motor 12 and solenoid 13 may also be referred to as loads.

[0015] The ECU11 includes an IC11a and a microcontroller (microcontroller) 11b. The IC11a is an electronic circuit that transforms the input voltage to a predetermined voltage corresponding to the operating voltage of the microcontroller 11b and outputs it to the microcontroller 11b. The microcontroller 11b controls a plurality of switches 51, 52, 53, 54, 55, and 56.

[0016] The motor 12 drives, for example, the pump of the brake control device 10 and adjusts the pressure in the fluid passage of the brake control device 10. The solenoid 13 drives the solenoid valve and opens and closes the fluid passage of the brake control device 10. The brake control device 10 may have other loads.

[0017] The main power supply 21 is the primary power source that supplies power to the ECU 11, motor 12, and solenoid 13. The main power supply 21 is, for example, the battery of vehicle 1. However, the main power supply 21 is not limited to this example.

[0018] The sub-power supply 22 is an auxiliary power supply that supplies power to the ECU 11, the motor 12, and the solenoid 13 when the supply of power from the main power supply 21 is lost or reduced. The sub-power supply 22 is, for example, an electric double layer capacitor and has a plurality of capacitors. The energy density of the sub-power supply 22 is smaller than that of the main power supply 21. Note that the sub-power supply 22 is not limited to this example.

[0019] The main power supply 21 and the sub-power supply 22 may also serve as the power supplies for devices different from the brake control device 10 in the vehicle 1. Further, as another example of the first power supply and the second power supply, the brake control device 10 may have a power supply circuit that converts the power of the main power supply 21 and the sub-power supply 22 and supplies it to the load.

[0020] The electrical paths 31, 32, 33, 34, 35, 36, 37 have conductors such as wiring, for example, and may further have various electrical components. The electrical paths 31, 32, 33, 34, 35, 36, 37 can electrically connect at least two elements.

[0021] The electrical path 31 is an electrical path that can conduct between the main power supply 21 and the motor 12. That is, the main power supply 21 can supply power to the motor 12 through the electrical path 31. The electrical path 32 is an electrical path that can conduct between the sub-power supply 22 and the motor 12. That is, the sub-power supply 22 can supply power to the motor 12 through the electrical path 32.

[0022] The electrical path 32 is connected (merged) to the electrical path 31 at the connection part P1. Between the connection part P1 and the motor 12, the electrical path 31 and the electrical path 32 form a common electrical path. For this reason, the electrical path 31 can conduct between the main power supply 21 and the motor 12 through the common part of the electrical paths 31 and 32. Also, the electrical path 32 can conduct between the sub-power supply 22 and the motor 12 through the common part of the electrical paths 31 and 32. Note that the electrical paths 31 and 32 are not limited to this example.

[0023] The electrical path 33 is an electrical path that can conduct electricity between the main power supply 21 and the solenoid 13. That is, the main power supply 21 can supply power to the solenoid 13 through the electrical path 33. The current flowing through the electrical path 33 is smaller than the current flowing through the electrical path 31. Note that the currents flowing through the electrical paths 31 and 33 are not limited to this example.

[0024] The electrical path 34 is an electrical path that can conduct electricity between the sub-power supply 22 and the solenoid 13. That is, the sub-power supply 22 can supply power to the solenoid 13 through the electrical path 34. The electrical path 34 is connected to the electrical path 32 at connection point P2. Between connection point P2 and the sub-power supply 22, the electrical path 32 and the electrical path 34 form a common electrical path.

[0025] Electrical path 34 is connected to (merges with) electrical path 33 at connection point P3. Between connection point P3 and solenoid 13, electrical path 33 and electrical path 34 form a common electrical path. Therefore, electrical path 33 can conduct electricity between the main power supply 21 and the solenoid 13 via the common part of electrical paths 33 and 34. Also, electrical path 34 can conduct electricity between the sub-power supply 22 and the solenoid 13 via the common part of electrical paths 33 and 34. Note that electrical paths 33 and 34 are not limited to this example.

[0026] The electrical path 35 is an electrical path that can conduct electricity between the main power supply 21 and IC 11a. That is, the main power supply 21 can supply power to IC 11a through the electrical path 35. The electrical path 35 is connected to the electrical path 33 at connection point P4. Between connection point P4 and the main power supply 21, the electrical path 33 and the electrical path 35 form a common electrical path.

[0027] The electrical path 36 is an electrical path that can conduct electricity between the sub-power supply 22 and IC 11a. That is, the sub-power supply 22 can supply power to IC 11a through the electrical path 36. The electrical path 36 is connected to electrical paths 32 and 34 at connection point P2. Between connection point P2 and the sub-power supply 22, electrical paths 32, 34, and 36 form a common electrical path.

[0028] Electrical path 36 is connected to (merges with) electrical path 35 at connection point P5. Between connection point P5 and IC 11a, electrical paths 35 and 36 form a common electrical path. Therefore, electrical path 35 can conduct electricity between the main power supply 21 and IC 11a via the common portion of electrical paths 35 and 36. Also, electrical path 36 can conduct electricity between the sub-power supply 22 and IC 11a via the common portion of electrical paths 35 and 36. Note that electrical paths 35 and 36 are not limited to this example.

[0029] One end of electrical path 37 is connected to the common electrical path of electrical paths 32, 34, and 36 between connection point P2 and sub-power supply 22. The other end of electrical path 37 is connected to connection point P3. Therefore, electrical path 37 can conduct electricity between electrical path 32 and electrical path 33. Note that electrical path 37 is not limited to this example.

[0030] Diode 41 is provided in the electrical path 33 between connection point P3 and connection point P4. The cathode of diode 41 is electrically connected to solenoid 13. The anode of diode 41 is electrically connected to main power supply 21.

[0031] Diode 42 is provided in the electrical path 34 between connection point P2 and connection point P3. The cathode of diode 42 is electrically connected to solenoid 13. The anode of diode 42 is electrically connected to sub-power supply 22.

[0032] Diode 43 is provided in the electrical path 35 between connection point P4 and connection point P5. The cathode of diode 43 is electrically connected to IC 11a. The anode of diode 43 is electrically connected to the main power supply 21.

[0033] Diode 44 is provided in the electrical path 36 between connection point P2 and connection point P5. The cathode of diode 44 is electrically connected to IC 11a. The anode of diode 44 is electrically connected to sub-power supply 22.

[0034] Switches 51, 52, 53, 54, 55, and 56 are various components capable of switching the conduction state (conductivity / disconnection) in an electrical path by opening and closing the electrical path. For example, switches 51, 52, 53, and 54 are semiconductor elements such as MOSFETs. Switches 55 and 56 are relays, for example. Note that switches 51, 52, 53, 54, 55, and 56 are not limited to these examples.

[0035] Switch 51 is provided in the electrical path 31 between the connection part P1 and the main power supply 21. Switch 51 has a body diode 51a. The cathode of the body diode 51a is electrically connected to the main power supply 21.

[0036] Switch 52 is provided in the electrical path 31 between connection part P1 and switch 51. Switch 52 has a body diode 52a. The cathode of the body diode 52a is electrically connected to the motor 12.

[0037] Switch 53 is provided in the electrical path 32 between connection part P1 and connection part P2. Switch 53 has a body diode 53a. The cathode of the body diode 53a is electrically connected to the sub-power supply 22.

[0038] Switch 54 is provided in the electrical path 32 between connection part P1 and switch 53. Switch 54 has a body diode 54a. The cathode of the body diode 54a is electrically connected to the motor 12.

[0039] Switch 55 is provided in the electrical path 33 between the connector P4 and the diode 41. Switch 56 is provided in the electrical path 35 between the connector P4 and the diode 43. Switches 55 and 56 are provided, for example, for fail-safe purposes.

[0040] Voltage monitors 61, 62, 63, 64, 65, 66, and 67 are devices (voltage sensors) that measure voltage. Voltage monitors 61, 62, 63, 64, 65, 66, and 67 transmit the measured voltage values ​​to the ECU 11.

[0041] The voltage monitor 61 is connected to a common electrical path between the connection point P1 and the motor 12, specifically between the electrical paths 31 and 32. Therefore, the voltage monitor 61 can measure the voltage between the motor 12 and the switch 53 in the electrical path 32.

[0042] Voltage monitor 62 is connected to electrical path 31 between the main power supply 21 and switch 51. Voltage monitor 63 is connected to a common electrical path of electrical paths 32, 34, and 36 between connection point P2 and sub-power supply 22.

[0043] Voltage monitor 64 is connected to the common electrical path of electrical paths 33 and 34 between connection point P3 and solenoid 13. Voltage monitor 65 is connected to electrical path 33 between diode 41 and switch 55. Voltage monitor 66 is connected to connection point P4. Voltage monitor 67 is connected to electrical path 35 between diode 43 and switch 56.

[0044] Electrical resistor 71 is provided in electrical path 37. Electrical resistor 72 is provided between the common electrical path of electrical paths 32, 34, and 36 and the voltage monitor 63. Electrical resistor 73 is provided between the voltage monitor 63 and ground. Electrical resistors 72 and 73 are used for voltage measurement by the voltage monitor 63.

[0045] One end of electrical path 37 is connected to electrical path 32 between the sub-power supply 22 and the switch 53. The other end of electrical path 37 is connected to electrical paths 33 and 34 between the solenoid 13 and the cathodes of diodes 41 and 42. This allows electrical path 37 to conduct electricity between the main power supply 21 and the switch 53.

[0046] The voltage monitor 63 can substantially measure the voltage in the electrical path 37 between the connection P2 and the electrical resistor 71. Similarly, the voltage monitor 64 can substantially measure the voltage in the electrical path 37 between the connection P3 and the electrical resistor 71. In other words, the voltage monitors 63 and 64 can measure the voltage between the main power supply 21 and the switch 53 in the electrical path 37.

[0047] The electrical path 31 is connected to the electrical path 32 at the connection point P1 between the motor 12 and the switch 53. The switches 51 and 52 provided on the electrical path 31 can interrupt the conductivity between the main power supply 21 and the switches 53 and 54.

[0048] In the brake control device 10 described above, the ECU 11 basically sets switches 51, 52, 55, and 56 to the ON (conductive) state and switches 53 and 54 to the OFF (disconnected) state. As a result, the main power supply 21 supplies power to the ECU 11, motor 12, and solenoid 13.

[0049] The sub-power supply 22 is shut off by setting a switch located inside it to the off position. The main power supply 21 supplies power to the sub-power supply 22 through an interface different from the electrical paths 31, 32, 33, 34, 35, 36, and 37. As a result, charge is stored in the capacitor of the sub-power supply 22.

[0050] The sub-power supply 22 acquires the status of the main power supply 21. If the power supply from the main power supply 21 is lost or reduced, the sub-power supply 22 sets a switch located inside the sub-power supply 22 to the ON state. As a result, the sub-power supply 22 supplies power to the ECU 11, motor 12, and solenoid 13. Furthermore, the ECU 11 sets switches 53 and 54 to the ON state.

[0051] The switching time of the switch located inside the sub-power supply 22 is set to be shorter than the time from when the power supply from the main power supply 21 to the ECU 11 is cut off until the ECU 11 is reset. This allows the ECU 11 to continue control without stopping its operation.

[0052] The sub-power supply 22 may output power when the main power supply 21 is outputting power, for example, for self-diagnosis to check for abnormalities in the sub-power supply 22. However, the voltage output by the main power supply 21 is greater than the voltage output by the sub-power supply 22. Therefore, the power from the main power supply 21 is supplied to the ECU 11, motor 12, and solenoid 13, and the sub-power supply 22 does not substantially supply power to the ECU 11, motor 12, and solenoid 13.

[0053] The electrical path 33 connected to the main power supply 21 and the electrical paths 32, 34, and 36 connected to the sub-power supply 22 are electrically connected to each other by the electrical path 37. However, the electrical resistance 71 prevents power from the main power supply 21 from flowing from the electrical path 33 through the electrical paths 32, 34, and 36 to the sub-power supply 22, ECU 11, motor 12, and solenoid 13 by causing a voltage drop.

[0054] Furthermore, the voltages in the electrical paths 32, 34, 36, and 37 between the sub-power supply 22 and the electrical resistor 71 are the voltages output from the sub-power supply 22. Therefore, the ECU 11 can determine, for example, whether the sub-power supply 22 is outputting normally based on the measurement value of the voltage monitor 63.

[0055] Figure 2 is a flowchart illustrating an example of the abnormality inspection operation in the first embodiment. For example, if an open fault (off-locked) occurs in switch 53, the sub-power supply 22 cannot supply power to the motor 12. On the other hand, if a short-circuit fault (on-locked) occurs in switch 53, the charge stored in the capacitor of the sub-power supply 22 will be consumed. Therefore, the ECU 11 inspects for the occurrence of abnormalities such as open faults or short-circuit faults in switch 53.

[0056] Below, with reference to Figure 2, an example of the abnormal inspection operation of switch 53 in this embodiment will be described. Note that the abnormal inspection operation of switch 53 is not limited to the method described below.

[0057] The ECU11 checks for abnormalities in switch 53, for example, immediately after the ignition is turned on and during initial checks after the ignition is turned off. The ECU11 may also check for abnormalities in switch 53 at other times.

[0058] First, ECU11 sets the state of switches 51, 52, 54, 55, and 56, excluding switch 53 which is the target of inspection (S11). Specifically, ECU11 sets switches 54, 55, and 56 to the ON state and switches 51 and 52 to the OFF state.

[0059] Next, the ECU 11 sets the switch 53, which is the object of inspection, to the ON state (S12). As a result, the main power supply 21 supplies power to the motor 12 through the electrical path 33, diode 41, electrical path 37, electrical resistor 71, electrical path 32, and switches 53 and 54.

[0060] Next, the ECU 11 obtains the measured values ​​from the voltage monitors 63, 64, 65, and 66 located upstream of the switch 53 (S13). Then, the ECU 11 determines whether the measured values ​​from the voltage monitors 63, 64, 65, and 66 exceed a predetermined first threshold (S14).

[0061] For example, if diode 41 or switch 55 has an open circuit fault, at least one measurement from voltage monitors 63, 64, 65, and 66 will fall below the first threshold (S14: No). In other words, at least one of voltage monitors 63, 64, 65, and 66 will show low (low voltage). Therefore, the ECU 11 determines that an abnormality has occurred and notifies the driver of the abnormality by, for example, illuminating a lamp (S15), and terminates the abnormality inspection operation of switch 53.

[0062] In S14, if the measured values ​​of voltage monitors 63, 64, 65, and 66 exceed the first threshold (S14: Yes), and voltage monitors 63, 64, 65, and 66 indicate high (high voltage), the ECU 11 obtains the measured value of voltage monitor 61 located downstream of switch 53 (S16). Next, the ECU 11 determines whether the measured value of voltage monitor 61 exceeds a predetermined second threshold (S17).

[0063] For example, if switch 53 is open-circuited, the measurement value of the voltage monitor 61 will fall below the second threshold (S17: No). In other words, the voltage monitor 61 will show a low value. Therefore, the ECU 11 will notify of the abnormality (S15) and terminate the abnormality check operation for switch 53.

[0064] In S17, if the measurement value of the voltage monitor 61 exceeds the second threshold (S17: Yes) and the voltage monitor 61 indicates high, the ECU 11 sets the switch 53 to be inspected to the off state (S18). Next, the ECU 11 acquires the measurement value of the voltage monitor 61 (S19). Next, the ECU 11 determines whether the measurement value of the voltage monitor 61 is below a predetermined third threshold (S20).

[0065] For example, if switch 53 is short-circuited, the measurement value of the voltage monitor 61 will exceed the third threshold (S20: No). In other words, the voltage monitor 61 will show a high. Therefore, the ECU 11 will notify of the abnormality (S15) and terminate the abnormality check operation for switch 53.

[0066] In S20, if the voltage monitor 61's measurement falls below the third threshold (S20: Yes) and the voltage monitor 61 shows a low reading, it means that neither an open-circuit nor a short-circuit fault has occurred in switch 53. Therefore, ECU 11 determines that there is no abnormality in switch 53 and terminates the abnormality inspection operation for switch 53. ECU 11 may output the inspection results for switch 53 to another device.

[0067] The ECU 11 can check for abnormalities in other switches 51, 52, 54, 55, and 56 through various other operations. For example, the ECU 11 can set switch 52 to the ON state, set switches 53, 54, 55, and 56 to the OFF state, and then switch the state of switch 51. Based on the measurement value from the voltage monitor 61, the ECU 11 can check for abnormalities in switch 51.

[0068] Furthermore, the ECU 11 sets switches 51, 52, and 53 to the ON state, sets switches 55 and 56 to the OFF state, and then switches the state of switch 54. Based on the measurement values ​​from the voltage monitor 63, the ECU 11 can check for abnormalities in switch 54.

[0069] In the brake control device 10 according to the first embodiment described above, the main power supply 21 can supply power to the motor 12 through the electrical path 31. The sub-power supply 22 can supply power to the motor 12 through the electrical path 32. The switch 53 is provided in the electrical path 32. The electrical path 37 is connected to the electrical path 32 between the sub-power supply 22 and the switch 53, and is conductive between the main power supply 21 and the switch 53. The voltage monitor 61 measures the voltage between the motor 12 and the switch 53 in the electrical path 32. The brake control device 10 switches the switch 53 to an ON state and an OFF state when the main power supply 21 is outputting power and the output of the sub-power supply 22 is stopped. The brake control device 10 can detect that the switch 53 is short-circuited if the voltage measurement by the voltage monitor 61 is higher than a third threshold when the switch 53 is in the OFF state. Furthermore, the brake control device 10 can detect an open-circuit fault in switch 53 if the voltage measurement by the voltage monitor 61 is lower than a second threshold when switch 53 is in the ON state. As described above, the brake control device 10 can inspect for abnormalities in switch 53 located in the electrical path 32 without outputting power from the sub-power supply 22. Therefore, the brake control device 10 can inspect for abnormalities in switch 53 regardless of the operation and output status of the sub-power supply 22.

[0070] For example, the sub-power supply 22 may have its output shut off due to various factors. Also, the capacitor of the sub-power supply 22 may not have enough charge stored for the abnormality test operation of the switch 53. Even in such cases, the brake control device 10 can still check for abnormalities in the switch 53 using the main power supply 21. Furthermore, the abnormality test operation of the switch 53 does not consume the charge stored in the capacitor of the sub-power supply 22. Therefore, if the power supply from the main power supply 21 is lost or reduced, the sub-power supply 22 can more reliably supply power to the ECU 11, motor 12, and solenoid 13.

[0071] An electrical resistor 71 is provided in the electrical path 37. By providing the electrical resistor 71 in the electrical path 37, it is possible to suppress the supply of high-voltage electricity from the main power supply 21 to the electrical path 32. Therefore, the electrical resistor 71 can suppress the high-voltage electricity supplied from the main power supply 21 from affecting the inspection of the state of the sub-power supply 22, and can also suppress the flow of overcurrent into the sub-power supply 22.

[0072] Electrical path 33 allows conduction between the main power supply 21 and the solenoid 13. Electrical path 34 allows conduction between the sub-power supply 22 and the solenoid 13. Electrical path 37 allows conduction between electrical path 32 and electrical path 33. As a result, the main power supply 21 can serve as both a terminal for supplying power to the solenoid 13 through electrical path 33 and a terminal for supplying electricity to the switch 53 through electrical path 37. Therefore, the number of terminals in the main power supply 21 can be reduced.

[0073] Voltage monitors 63 and 64 measure the voltage between the main power supply 21 and the switch 53 in the electrical path 37. This allows the brake control device 10 to inspect for abnormalities in the components and wiring in the electrical path between the main power supply 21 and the switch 53, including the electrical path 37. Therefore, the brake control device 10 can more accurately inspect for abnormalities in the switch 53.

[0074] Switches 51 and 52 are provided in the electrical path 31. The electrical path 31 is connected to the electrical path 32 between the motor 12 and switch 53. By turning off switches 51 and 52, the brake control device 10 can suppress the influence of electricity supplied from the main power supply 21 to the electrical path 32 through the electrical path 31 on the measurement values ​​of the voltage monitor 61.

[0075] In the abnormality inspection operation described above, the target switch 53 is set to the ON state in S12 and to the OFF state in S18. However, the order of setting the switch 53 may be reversed. For example, the switch 53 may be set to the OFF state in S12 and to the ON state in S18. In that case, for example, in the step equivalent to S17, the ECU 11 determines whether the measurement value of the voltage monitor 61 is below a predetermined second threshold. For example, if the switch 53 has a short circuit fault, the measurement value of the voltage monitor 61 will be above the second threshold. In other words, the voltage monitor 61 will show high. Therefore, the ECU 11 notifies of the abnormality in the step equivalent to S15 and terminates the abnormality inspection operation for the switch 53. On the other hand, in the step equivalent to S17, if the measurement value of the voltage monitor 61 is below the second threshold and the voltage monitor 61 shows low, the ECU 11 sets the target switch 53 to the ON state in the step equivalent to S18. Then, in the step equivalent to S20, after the ECU 11 obtains the measurement value from the voltage monitor 61 in S19, the ECU 11 determines whether the measurement value from the voltage monitor 61 exceeds a predetermined third threshold. For example, if the switch 53 has an open circuit fault, the measurement value from the voltage monitor 61 will be below the third threshold. In other words, the voltage monitor 61 will show a low value. Therefore, the ECU 11 notifies of the abnormality in the step equivalent to S15 and terminates the abnormality inspection operation for the switch 53. On the other hand, in the step equivalent to S20, if the measurement value from the voltage monitor 61 exceeds the third threshold and the voltage monitor 61 shows a high value, it means that the switch 53 has neither a short circuit fault nor an open circuit fault. Therefore, the ECU 11 determines that there is no abnormality in the switch 53 and terminates the abnormality inspection operation for the switch 53.

[0076] (Second embodiment) A second embodiment will be described below with reference to Figure 3. In the following description of the embodiments, components having the same function as those already described will be denoted by the same reference numerals as those previously described, and their description may be omitted. Furthermore, multiple components denoted by the same reference numerals do not necessarily share all functions and properties, and may have different functions and properties depending on the embodiment.

[0077] Figure 3 is a circuit block diagram showing a brake control device 10 according to a second embodiment. In the second embodiment, the brake control device 10 has a switch 57 instead of an electrical resistor 71. Switch 57 is an example of a second switch. Switch 57 may be various switches, such as a semiconductor element like a MOSFET or a relay.

[0078] In the second embodiment, the ECU 11 essentially sets the switch 57 to the off state. This prevents the switch 57 from supplying power from the main power supply 21 to the sub-power supply 22, ECU 11, motor 12, and solenoid 13 via electrical paths 32, 34, and 36 from the electrical path 33.

[0079] On the other hand, the ECU 11 sets switch 57 to the ON state during the abnormality inspection operation of switch 53. For example, in S11 of Figure 2, the ECU 11 sets switch 57 to the ON state. As a result, switch 57 conducts electricity between the main power supply 21 and switch 53.

[0080] In the brake control device 10 of the second embodiment described above, a switch 57 is provided in the electrical path 37. By setting the switch 57 to the off state, it is possible to suppress the high-voltage electricity supplied from the main power supply 21 from affecting the inspection of the state of the sub-power supply 22, and to suppress the inflow of overcurrent into the sub-power supply 22.

[0081] As an example, the control device according to at least one embodiment described above includes: a first device; a first power supply capable of supplying power to the first device through a first electrical path; a second power supply capable of supplying power to the first device through a second electrical path; a first switch provided in the second electrical path; a third electrical path connected to the second electrical path between the second power supply and the first switch, enabling conductivity between the first power supply and the first switch; and a first voltage monitor configured to measure the voltage between the first device and the first switch in the second electrical path. Thus, as an example, when the first power supply is outputting power and the output of the second power supply is stopped, the control device can switch the first switch between an ON state and an OFF state in order to check for abnormalities in the first switch. When the first switch is in the OFF state, if the voltage measurement result by the first voltage monitor is higher than a predetermined threshold, the control device can detect that the first switch is short-circuited (stuck in the ON state). Furthermore, the control device can detect that the first switch is open-circuited (stuck in the off position) if the voltage measurement result from the first voltage monitor is lower than a predetermined threshold when the first switch is in the ON position. As described above, the control device can inspect for abnormalities in the first switch installed in the second electrical path without outputting power from the second power supply. Therefore, the control device can inspect for abnormalities in the first switch regardless of the operation and output status of the second power supply.

[0082] The control device described above further includes, as an example, an electrical resistor or a second switch provided in the third electrical path. For example, by providing an electrical resistor in the third electrical path, it is possible to suppress the supply of high-voltage electricity from the first power source to the second electrical path. Thus, the electrical resistor can suppress the influence of high-voltage electricity supplied from the first power source on the inspection of the state of the second power source, and can also suppress the inflow of overcurrent into the second power source. By setting the second switch to the off state, it is possible to suppress the influence of high-voltage electricity supplied from the first power source on the inspection of the state of the second power source, and can also suppress the inflow of overcurrent into the second power source.

[0083] As an example, the control device further comprises a second device, a fourth electrical path that allows conduction between the first power supply and the second device, and a fifth electrical path that allows conduction between the second power supply and the second device, wherein the third electrical path allows conduction between the second electrical path and the fourth electrical path. Therefore, as an example, the first power supply can serve as both a terminal for supplying power to the second device through the fourth electrical path and a terminal for supplying electricity to the first switch through the third electrical path. Consequently, the number of terminals in the first power supply can be reduced.

[0084] The control device further includes, as an example, a second voltage monitor configured to measure the voltage between the first power supply and the first switch in the third electrical path. Thus, as an example, the control device can inspect for abnormalities in components and wiring provided in the electrical path between the first power supply and the first switch, including the third electrical path. Consequently, the control device can more accurately inspect for abnormalities in the first switch.

[0085] The control device, as an example, further comprises a third switch provided in the first electrical path, wherein the first electrical path is connected to the second electrical path between the first device and the first switch. Therefore, as an example, the control device can suppress the influence of electricity supplied from the first power source to the second electrical path through the first electrical path on the measurement value of the first voltage monitor by turning off the third switch.

[0086] In the above explanation, suppression is defined, for example, as preventing the occurrence of an event, effect, or influence, or reducing the degree of an event, effect, or influence.

[0087] Although embodiments of the present invention have been illustrated above, these embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and changes can be made without departing from the spirit of the invention. Furthermore, the configurations and shapes of each embodiment and modification can be partially replaced. [Explanation of Symbols]

[0088] 10...Brake control device (control device), 12...Motor (first device), 13...Solenoid (second device), 21...Main power supply (first power supply), 22...Sub power supply (second power supply), 31...Electrical path (first electrical path), 32...Electrical path (second electrical path), 33...Electrical path (fourth electrical path), 34...Electrical path (fifth electrical path), 37...Electrical path (third electrical path), 51, 52...Switch (third switch), 53...Switch (first switch), 57...Switch (second switch), 61...Voltage monitor (first voltage monitor), 63, 64...Voltage monitor (second voltage monitor), 71...Electrical resistance.

Claims

1. The first device and A first power supply capable of supplying power to the first device through a first electrical path, A second power supply capable of supplying power to the first device through a second electrical path, The first switch provided in the second electrical path, A third electrical path is connected to the second electrical path between the second power supply and the first switch, and is capable of conducting electricity between the first power supply and the first switch. A first voltage monitor configured to measure the voltage between the first device and the first switch in the second electrical path, A control unit that checks for abnormalities in the first switch based on the voltage measurement of the first voltage monitor, obtained by switching the on / off state of the first switch without outputting power from the second power supply, A control device equipped with the following.

2. An electrical resistor or a second switch provided in the third electrical path, The control device according to claim 1, further comprising:

3. The second device, A fourth electrical path that allows electrical conduction between the first power supply and the second device, A fifth electrical path that allows electrical conduction between the second power supply and the second device, Furthermore, it is equipped with, The third electrical path is capable of conducting electricity between the second electrical path and the fourth electrical path. A control device according to claim 1 or claim 2.

4. A second voltage monitor configured to measure the voltage between the first power supply and the first switch in the third electrical path, A control device further comprising any one of claims 1 to 3.

5. A third switch provided in the first electrical path, Furthermore, it is equipped with, The first electrical path is connected to the second electrical path between the first device and the first switch. A control device according to any one of claims 1 to 4.

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