JP2018061304A - Backup device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backup device that can perform a backup operation using a second power supply unit even in the case of a stoppage of power supply from a first power supply unit and can effectively reduce the power consumption of the second power supply unit during the backup operation.SOLUTION: A backup device 1 comprises: a discharge unit 4 that performs a discharge operation in which an electric power is supplied to a shift-by-wire ECU 120 (a power supply target) and the like based on the power supply from a second power supply unit 7 and also performs a stop operation so as to stop the discharge operation; and a control unit 10 to control the discharge unit 4. The control unit 10 having a function as a discharge control unit makes the discharge unit 4 perform a discharge operation to supply an electric power to the shift-by-wire ECU 120 (a power supply target) and the like by discharging the electric power of the second power supply unit 7 when it is determined that an abnormal power supply from a first power supply unit 91 is detected by an abnormality detection unit and that a speed of the vehicle is determined as a threshold level or less by a determination unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a backup device for a vehicle.

  In recent years, like vehicles disclosed in Patent Document 1, vehicles equipped with an electronic control system such as a shift-by-wire control system or an electric parking brake system are increasing. In this type of vehicle, if the main power supply fails and power supply is interrupted, there is a concern that the electronic control system cannot be operated. Therefore, it is required to perform a backup operation by some method. In particular, the need for such backup operations is increasing as the importance of electronic control systems increases.

Japanese Patent No. 4171495

  In a power supply system installed in a vehicle, power is supplied to a backup target (for example, a shift-by-wire control system or an electric parking brake system) by discharging a power storage unit that functions as a backup power supply when the main power supply fails. Can continue.

  However, if power is immediately supplied to any load from the backup power supply when the main power supply fails, power consumption immediately after the main power supply failure will increase. That is, since the amount of energy required for the backup power supply increases, there is a problem that the size and cost of the backup power supply must be increased.

  The present invention has been made based on the above-described circumstances. Even when the power supply from the first power supply unit is interrupted, the backup can be performed by the power supply from the second power supply unit. It is an object of the present invention to realize a backup device that can effectively reduce power consumption of a power supply unit.

The present invention
A backup device for a vehicle power supply system, comprising: a first power supply unit mounted on a vehicle; and a second power supply unit serving as a power supply source when power supply from at least the first power supply unit is interrupted. ,
A discharge unit that performs a discharge operation for supplying power to a predetermined power supply target based on power supply from the second power supply unit and a stop operation for stopping the discharge operation;
An abnormality detection unit for detecting an abnormality in which power supply from the first power supply unit is reduced or interrupted;
A determination unit that determines whether the speed of the vehicle is equal to or lower than a threshold based on an output from a sensor that generates a signal reflecting the speed of the vehicle;
When the abnormality detection unit detects an abnormality in power supply from the first power supply unit and the determination unit determines that the speed of the vehicle is equal to or lower than the threshold value, the second power supply unit is discharged. A discharge control unit for causing the discharge unit to perform a discharge operation for supplying power to the power supply target;
Have

  The backup device discharges the second power supply unit when the abnormality detection unit detects an abnormality in power supply from the first power supply unit and the determination unit determines that the vehicle speed is equal to or lower than a threshold value. The discharging unit performs a discharging operation for supplying power to the power supply target. That is, even if an abnormality occurs in which the power supply from the first power supply unit is reduced or cut off, the power from the second power supply unit is supplied to a predetermined power supply target until the vehicle speed falls below the threshold value. Therefore, it is possible to perform backup for a predetermined power supply target while effectively suppressing the power consumption of the second power supply unit. If the power supply target to be backed up is something that should be operated when the vehicle speed is less than or equal to the threshold value, or if it can be operated when the vehicle speed is less than or equal to the threshold value, the abnormality of the first power supply unit Even if a power drop state or a cut-off state occurs between when the vehicle speed becomes equal to or lower than the threshold after the occurrence of the problem, a problem hardly occurs.

1 is a block diagram schematically illustrating a vehicle electronic control system including a vehicle backup device according to a first embodiment. 3 is a flowchart illustrating the flow of control performed by the vehicle backup device according to the first embodiment. The output voltage of the first power supply unit, the backup voltage supplied to the vehicle speed sensor, and the shift when the first power supply unit switches from the normal state to the failure state in the vehicle power supply system including the vehicle backup device of the first embodiment It is a timing chart which illustrates the relation of the backup voltage supplied to a by-wire ECU.

  Here, a desirable example of the present invention will be shown. However, the present invention is not limited to the following examples.

  The discharge control unit detects an abnormality in power supply from the first power supply unit by the abnormality detection unit, and a condition in which a predetermined operation is performed on the operation unit provided in the vehicle or an abnormality in the first power supply unit occurs. When the necessary condition including at least one of the conditions after a certain period of time has been satisfied, the second power supply unit is discharged on condition that the determination unit determines that the vehicle speed is equal to or lower than the threshold value. You may function so that the discharge part may perform the discharge operation which supplies electric power to electric power supply object.

  In the backup device, when an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit, a predetermined operation has been performed on the operation unit, or an abnormality has occurred in the first power supply unit. When a predetermined time has elapsed, a discharge operation for supplying power to a predetermined power supply target can be performed by the discharge unit, and the predetermined power supply target performs a predetermined operation on the operation unit. Alternatively, the configuration is advantageous when the target is to be operated when a certain time has elapsed since the occurrence of the abnormality of the first power supply unit. Even when an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit, a necessary condition (a condition in which a predetermined operation is performed on the operation unit or an abnormality in the first power supply unit occurs) If at least one of the conditions after a certain period of time has not been satisfied), it is possible to stop the discharge and reduce power consumption. This is more advantageous in reducing the amount of energy.

  The discharge control unit performs a first discharge operation of discharging the second power supply unit and supplying power to the sensor when the abnormality detection unit detects an abnormality in power supply from the first power supply unit and a necessary condition is satisfied. When the determination unit determines that the speed of the vehicle is equal to or lower than the threshold value based on the output from the sensor that is supplied to the discharge unit and is supplied with power by the first discharge operation, the second power supply unit is discharged to generate power. You may function so that the discharge part may perform the 2nd discharge operation which supplies electric power to supply object.

  In the backup device, when an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit and a necessary condition is satisfied, the second power supply unit is discharged and power is supplied to the sensor. Thus, even if the power supply from the first power supply unit becomes abnormal, the second power supply unit can be discharged to supply power to the sensor when the necessary condition is satisfied, and the sensor can be operated properly. Therefore, even if an abnormality occurs in the power supply from the first power supply unit, it is possible to determine whether or not the vehicle speed is equal to or less than the threshold based on the power from the second power supply unit. In addition, since the power supply to the sensor is after the necessary condition is satisfied, the power consumption can be suppressed until then. Further, after the power is supplied to the sensor, when it is determined that the vehicle speed is equal to or lower than the threshold value based on the output from the sensor that operates by receiving the power supply, the second power supply unit is discharged to The second discharge operation for supplying power to the supply target can be performed by the discharge unit. Thus, in order to perform power supply step by step so as to supply power to a predetermined power supply target on condition that the speed of the vehicle is determined to be equal to or less than the threshold value after power is supplied to the sensor. Thus, more efficient power supply becomes possible and power consumption can be more effectively suppressed.

  The backup device may include a first conductive path serving as a discharge path from the discharge unit to the sensor and a second conductive path serving as a discharge path from the discharge unit to the power supply target. The discharge unit may include a switching unit that switches the second conductive path between an energized state in which a discharge current from the second power supply unit flows and a cut-off state in which the discharge current from the second power supply unit does not flow. When the abnormality detection unit detects an abnormality in the power supply from the first power supply unit and the necessary condition is satisfied, the discharge control unit discharges the second power supply unit while keeping the switching unit in a cut-off state, A first discharge operation for supplying electric power to the sensor via the discharge unit, and based on an output from the sensor supplied with electric power by the first discharge operation, the speed of the vehicle is equal to or less than a threshold by the determination unit. If it is determined, the second power supply unit is discharged while the switching unit is energized, and the discharge unit functions to perform a second discharge operation for supplying power to the power supply target via the second conductive path. May be.

  The backup device performs a second operation when performing a discharge operation (first discharge operation) for supplying power from the second power supply unit to the sensor via the first conductive path when power supply from the first power supply unit is abnormal. The discharge current can be reliably stopped from flowing to the power supply target via the conductive path. That is, when the second power supply unit is discharged, power can be reliably supplied to the sensor, but power can be reliably prevented from being supplied to a predetermined power supply target. Thereafter, when the determination unit determines that the speed of the vehicle is equal to or less than the threshold value, the discharge current can be reliably supplied to the power supply target through the second conductive path in the energized state.

  The backup device may have a transmission path serving as a path for transmitting a signal from the sensor to the determination unit in a state where power supply from the first power supply unit is interrupted.

  The backup device can transmit a signal from the sensor to the determination unit via the transmission path without using a control device that requires power supply from the first power supply unit.

  The power supply target may be a shift-by-wire control system that switches the shift range by the driving force of the actuator. The discharge control unit causes the second power supply unit to discharge and shift when the abnormality detection unit detects an abnormality in power supply from the first power supply unit and the determination unit determines that the vehicle speed is equal to or less than a threshold value. The discharging unit may perform a discharging operation for supplying power to the by-wire control system, and may function to instruct the shift-by-wire control system to switch to the parking position.

  When the abnormality detection unit detects an abnormality in power supply from the first power supply unit, the backup device switches to the parking position with respect to the shift-by-wire control system on condition that the vehicle speed is equal to or less than a threshold value. Can be instructed. Accordingly, it is possible to prevent an instruction to switch to the parking position when the vehicle speed is a relatively high speed exceeding the threshold.

<Example 1>
A vehicle electronic control system 100 shown in FIG. 1 includes a vehicle power supply system 110 (hereinafter also referred to as power supply system 110) including a vehicle backup device 1 (hereinafter also referred to as backup device 1), and the power supply. The system includes various objects (shift-by-wire control system 120, electronic control brake system 130, body ECU 140, vehicle speed sensor 132, and the like) that are to be supplied with electric power from the system 110.

  The shift-by-wire control system 120 is provided, for example, in a vehicle such as a passenger car that uses an engine such as a gasoline engine as a driving power source, and performs range switching of an automatic transmission such as a CVT or a step AT. The shift-by-wire control system 120 corresponds to an example of a power supply target, and operates so as to switch the shift range of an automatic transmission (not shown) by the driving force of the actuator 126. The shift-by-wire control system 120 includes a shift-by-wire ECU 122, a range switch 124, an actuator 126, a range switching device 128, and the like.

  The shift-by-wire ECU 122 includes an information processing device such as a CPU, a storage device such as a RAM and a ROM, an input / output interface, a bus connecting these components, and the like. A range switch 124 including a parking switch 124A is connected to the shift-by-wire ECU 122. In FIG. 1, the switches other than the parking switch 124A for instructing the shift to the parking range are omitted from the range switch 124.

  The range switching device 128 switches the forward (D) range, reverse (R) range, neutral (N) range, and parking (P) range of the automatic transmission by the actuator 126. The range switching device 128 includes a hydraulic control mechanism that engages and releases the forward clutch and the reverse clutch, a parking lock mechanism that mechanically locks the output shaft, and the like. In the D range, the forward clutch is engaged and the reverse clutch is released. In the R range, the forward clutch is released and the reverse clutch is engaged. In the N range, both the forward clutch and the reverse clutch are released. In the P range, both the forward clutch and the reverse clutch are released, and the parking lock mechanism is activated.

  The actuator 126 is an electric actuator such as a motor or a solenoid, and has a function of driving the range switching device 128 to perform a range switching operation. The actuator 126 includes a shift position sensor (not shown) that detects which range (shift position) the range switching device 128 is in based on the position of the internal driving member, and the like. The shift position information is transmitted to the shift-by-wire ECU 122.

  In the shift-by-wire control system 120 configured as described above, a range switch 124 is provided in an operation unit such as a shift lever through which a driver inputs a range switching operation (selection operation), and the range switch 124 is selected by the operation unit. A range request signal corresponding to the range is transmitted to the shift-by-wire ECU 122. The shift-by-wire ECU 122 drives the actuator 126 in response to the range request signal from the range switch 124 and operates the range switching device 128 so that the requested range is obtained.

  An ECB (Electronically Controlled Brake System) 130 is configured as a known electronically controlled brake system. The ECB 130 includes an ECB motor that generates a braking force transmitted to driving wheels of the vehicle, and an ECB electronic control device (ECB ECU) that controls the ECB motor. The ECB ECU outputs an operation command signal for operating the ECB motor, and the ECB motor operates according to the operation command signal. The ECB ECU outputs a drive signal for driving the ECB motor when it is determined that the ECB motor needs to be activated based on sensor signals from the vehicle speed sensor 132, acceleration sensor, yaw rate sensor, rudder angle sensor, and the like. The ECB motor operates in accordance with the drive signal, and the braking force can be adjusted by this operation. As a result, the behavior of the vehicle can be stabilized.

  The vehicle speed sensor 132 is configured as a known vehicle speed sensor, and when the first power supply unit 91 is in a normal state, an operating voltage based on power supply from the first power supply unit 91 is supplied through a path (not shown). It works by. On the other hand, during the first discharging operation performed when the first power supply unit 91 fails, the vehicle speed sensor 132 operates by being supplied with an operating voltage via the first conductive path 31, and the vehicle speed sensor 132 is mounted. A signal indicating the vehicle speed is output to the signal line 34.

  The body ECU 140 is a device that controls body-type equipment mounted on the vehicle, and includes a control unit such as a CPU or MPU, and a storage unit such as a ROM, a RAM, and a nonvolatile memory. The storage unit stores a control program executed by the control unit, and the control unit controls the operation of the body-type device by executing the control program stored in the storage unit. The body ECU 140 is connected to a courtesy switch 144 that is turned on when the door is opened.

  The ECB ECU and the body ECU 140 in the shift-by-wire ECB 122 and ECB 130 are communicably connected via a CAN communication line 152 (hereinafter also referred to as a communication line 152). These ECUs and other ECUs (not shown) perform data transmission / reception via the communication line 152 using, for example, a CAN (Controller Area Network) protocol. The gateway 150 is connected to the communication line 152 and functions as a relay device.

  The power supply system 110 is a power supply unit mounted on a vehicle and the first power supply unit 91 serving as a main power supply for supplying power to the various objects described above, and power supply from at least the first power supply unit 91 is interrupted. And a backup device 1 having a function of discharging the second power supply unit 7 when power supply from at least the first power supply unit 91 is interrupted. And is configured as a system for supplying power using the first power supply unit 91 or the second power supply unit 7 as a power supply source. In the following, a configuration in which the second power supply unit 7 is included as a part of the backup device 1 will be described as a representative example. However, the second power supply unit 7 may be provided outside the backup device 1.

  In the power supply system 110, when the power supply from the first power supply unit 91 is normal, the output voltage of the first power supply unit 91 is applied to the wiring unit 102 serving as a power line, and the first power supply unit 91 supplies the wiring unit. Electric power is supplied to various electrical components via 102. In this configuration, “when the power supply from the first power supply unit 91 is normal and not lowered” is when the output voltage of the first power supply unit 91 exceeds a predetermined value, specifically, the control unit 10. This is when the voltage of the wiring unit 102 detected by the (detecting unit) exceeds a predetermined value. Conversely, “when the power supply from the first power supply unit 91 is reduced or interrupted” is when the output voltage of the first power supply unit 91 is equal to or lower than a predetermined value. Specifically, the control unit This is when the voltage of the wiring part 102 detected by 10 (detection part) is below a predetermined value. In this configuration, the control unit 10 corresponds to an example of an abnormality detection unit, and has a function of detecting an abnormality in which the power supply from the first power supply unit 91 is reduced or cut off.

  The 1st power supply part 91 is comprised as well-known vehicle-mounted batteries, such as a lead battery, for example. The first power supply unit 91 has a high-potential side terminal electrically connected to the wiring unit 102 and applies a predetermined output voltage (hereinafter also referred to as + B voltage) to the wiring unit 102.

  The 2nd power supply part 7 is comprised by well-known electrical storage means, such as an electric double layer capacitor (EDLC), for example. The second power supply unit 7 is electrically connected to the charging circuit 3 and the discharging circuit 5, charged by the charging circuit 3, and discharged by the discharging circuit 5.

  The backup device 1 includes a charging circuit 3, a discharging unit 4 including a discharging circuit 5, the above-described second power supply unit 7, and a control unit 10. The backup device 1 is also provided with switches 41 and 42, conductive paths 31 and 32, signal lines 34, 36, and 38.

  The charging circuit 3 is configured as a known charging circuit such as a step-up DCDC converter, for example, and is configured to be controlled by the control unit 10. The control unit 10 performs charging control so as to give the charging circuit 3 a charging instruction signal for instructing charging of the second power source unit 7 or a charging stop signal for instructing to stop charging of the second power source unit 7. For example, the control unit 10 causes the charging circuit 3 to perform a charging operation at the start of predetermined charging (for example, immediately after the ignition switch is turned on), and the output voltage (charging voltage) of the second power supply unit 7 is predetermined. A charging instruction signal is given to the charging circuit 3 until the target voltage is reached. When the charging instruction signal is given from the control unit 10, the charging circuit 3 performs a voltage conversion operation for increasing or decreasing the power supply voltage input via the wiring unit 102, and the converted voltage is supplied to the second power supply. Applied to part 7. When the charging stop signal is given to the charging circuit 3 from the control unit 10, the charging circuit 3 does not perform the charging operation, and at this time, the wiring unit 102 and the second power supply unit 7 are brought into a non-conduction state.

  The discharge unit 4 includes a discharge circuit 5 and a plurality of switches 41 and 42, and supplies power to the shift-by-wire control system 120 (power supply target) and the like based on power supply from the second power supply unit 7. A discharge operation and a stop operation for stopping the discharge operation can be performed. The discharge unit 4 has a function of switching between discharge and stop of discharge of the second power supply unit 7 and also has a function of switching a discharge path (path through which discharge current flows) from the second power supply unit 7.

  The discharge circuit 5 is configured as a known discharge circuit such as a DCDC converter, and is configured to be controlled by the control unit 10. The discharge circuit 5 is given a discharge instruction signal for instructing the discharge of the second power supply unit 7 or a discharge stop signal for instructing the discharge stop of the second power supply unit 7 by the control unit 10. When the discharge instruction signal is given from the control unit 10, the discharge circuit 5 outputs a target voltage set toward the output-side conductive path 30 based on the output voltage of the second power supply unit 7 ( Specifically, a discharge operation in which a target voltage indicated by the control unit 10 is applied to the conductive path 30 is performed. When the discharge stop signal is given from the control unit 10, the discharge circuit 5 stops such a discharge operation and makes the conductive path 30 and the second power supply unit 7 non-conductive.

  Between the discharge circuit 5 and the vehicle speed sensor 132, a first conductive path 31 serving as a discharge path from the discharge unit 4 to the vehicle speed sensor 132 is provided. The first conductive path 31 is a path for supplying a discharge current to the vehicle speed sensor 132 during the discharge operation of the discharge circuit 5. Further, a second conductive path 32 serving as a discharge path from the discharge unit 4 to the shift-by-wire control system 120 (power supply target) is provided between the discharge circuit 5 and the shift-by-wire control system 120.

  The on / off operation of the switches 41 and 42 is controlled by the control unit 10. The switch 41 is configured by a semiconductor switch such as a MOSFET, for example, and is turned on when an on signal is given by the control unit 10, and conducts between the discharge circuit 5 and the vehicle speed sensor 132. The switch 41 is turned off when an off signal is given by the control unit 10, and makes the discharge circuit 5 and the vehicle speed sensor 132 non-conductive. The switch 42 is configured by, for example, a semiconductor switch such as a MOSFET, and is turned on when an on signal is given by the control unit 10 to conduct between the discharge circuit 5 and the shift-by-wire ECU 122. The switch 42 is turned off when an off signal is given by the control unit 10, and makes the discharge circuit 5 and the shift-by-wire ECU 122 non-conductive. The switch 42 corresponds to an example of a switching unit, and has a function of switching the second conductive path 32 between an energized state in which a discharge current from the second power supply unit 7 flows and a cut-off state in which the discharge current from the second power supply unit 7 does not flow. Have

  Between the vehicle speed sensor 132 and the control unit 10, a first signal line 34 (hereinafter also referred to as a signal line 34) serving as a signal line that transmits a signal without using the CAN communication line 152 is provided. The first signal line 34 corresponds to an example of a transmission path, and transmits a signal from the vehicle speed sensor 132 (sensor) to the control unit 10 corresponding to a determination unit in a state where power supply from the first power supply unit 91 is interrupted. It becomes a route to do. A second signal line 36 (hereinafter also referred to as a signal line 36) is provided between the conductive path 129 connected to the parking switch 124A and the control unit 10, and the conductive path 149 connected to the courtesy switch 144 A third signal line 38 (hereinafter also referred to as a signal line 38) is provided between the control units 10.

  The control unit 10 is configured as a microcomputer, for example, and includes a CPU, a memory such as a ROM or a RAM, an AD converter, and the like. The control unit 10 is configured to be able to receive power supply from the second power supply unit 7 without going through the discharge circuit 5. That is, even when the power supply from the first power supply unit 91 is interrupted, it is possible to operate with the power from the second power supply unit 7.

  A value indicating the voltage of the wiring unit 102 (that is, the output voltage value of the first power supply unit 91) is input to the control unit 10 by a voltage detection unit (not shown), and the control unit 10 continuously increases the voltage of the wiring unit 102. It can be monitored. The configuration in which the control unit 10 detects the output voltage of the first power supply unit 91 may be a configuration in which the wiring unit 102 and the control unit 10 are connected by a conductive path and the voltage is directly input to the control unit 10. Alternatively, a voltage obtained by dividing the voltage of the wiring unit 102 by a voltage dividing circuit or the like may be input to the control unit 10.

  FIG. 1 conceptually shows functions of the control unit 10, and the control unit 10 operates as at least a function as a detection unit that detects a signal, an abnormality detection unit, a determination unit, and a discharge control unit. For each function. Specifically, the AD converter and the CPU function as a detection unit, an abnormality detection unit, and a determination unit. The CPU functions as a discharge control unit.

Next, backup processing performed by the control unit 10 will be described.
The control unit 10 repeatedly executes the backup control shown in FIG. 2 until the ignition switch is turned off after the ignition switch is turned on.

  When the backup control shown in FIG. 2 is executed, first, in step S1, it is determined whether or not a failure of the first power supply unit 91 has occurred. Specifically, the control unit 10 can detect the voltage of the wiring unit 102. When the control unit 10 determines that the voltage of the wiring unit 102 exceeds a predetermined value (threshold voltage), the step is performed. No in S1, and the control in FIG. 2 is terminated. When the control of FIG. 2 is finished, the control unit 10 monitors the output of the first power supply unit 91 by repeating the control of FIG. 2 so that the control of FIG. 2 is started again at short time intervals.

  When it is determined in step S1 that the voltage of the wiring unit 102 is equal to or lower than the predetermined value (Yes in step S1), the control unit 10 starts timer counting in step S2. That is, the timer is counted starting from step S2, and the time from step S2 is measured. Then, after step S2, the control unit 10 performs the determination of step S3, and whether or not the timer count is equal to or greater than a specified value (that is, whether or not the elapsed time from step S2 has reached a predetermined time). Judging.

  When determining in step S3 that the count of the timer has exceeded the specified value, the control unit 10 determines that the elapsed time from step S2 has reached a predetermined time (Yes in step S3). Step S5 is performed.

  On the other hand, when the control unit 10 determines in step S3 that the timer count is not equal to or greater than the specified value (that is, the elapsed time from step S2 has not reached the predetermined time, step S3). In step S4, it is determined whether or not a predetermined operation by the user (hereinafter also referred to as a user operation) has been performed.

  In this configuration, the predetermined operation by the user is either an operation of the parking switch 124A instructing a shift to the parking range or an operation of turning on the courtesy switch 144. In the example of FIG. 1, a predetermined voltage is applied to the conductive path 129 connected to one end of the parking switch 124 </ b> A from the shift-by-wire ECU 122 and the control unit 10 (part that functions as a detection unit). When the parking switch 124A is not turned on (operation for instructing the parking range), the voltage of the conductive path 129 becomes a high level equal to or higher than a predetermined voltage threshold, and the parking switch 124A is turned on (instructing the parking range). When the operation is performed, the low level is lower than a predetermined voltage threshold. When the signal line 36 connected to the conductive path 129 is at a low level, the control unit 10 determines that the parking switch 124A is on, and when the signal line 36 is at a high level, the parking switch 124A is off. It is determined that Similarly, a predetermined voltage is applied to the conductive path 149 connected to one end of the courtesy switch 144 from the body ECU 140 and the control unit 10 (part that functions as a detection unit). When the courtesy switch 144 is not turned on (opening the vehicle door), the voltage of the conductive path 149 becomes a high level that is equal to or higher than a predetermined voltage threshold, and the courtesy switch 144 is turned on (opening the vehicle door). When the opening operation is performed, the low level is lower than a predetermined voltage threshold. When the signal line 38 connected to the conductive path 149 is at a low level, the control unit 10 determines that the courtesy switch 144 is in an on state. When the signal line 38 is at a high level, the courtesy switch 144 is in an off state. It is determined that

  The control unit 10 determines whether either the parking switch 124A or the courtesy switch 144 is turned on in step S4 of FIG. Specifically, it is determined whether either the second signal line 36 or the third signal line 38 has been switched to the low level indicating the ON state, and either the second signal line 36 or the third signal line 38 is determined. Is switched to the low level, it is determined that there is a user operation, and the process proceeds to Yes in step S4. If it is determined in step S4 that a user operation has been performed (Yes in step S4), the process of step S5 is performed.

  On the other hand, if the second signal line 36 and the third signal line 38 are continuously maintained at the high level, it is determined that there is no user operation, and the process proceeds to No in step S4. If it is determined in step S4 that there is no user operation (No in step S4), the processes in and after step S3 are performed again.

  Thus, when the power failure occurs, the control unit 10 is in a standby state until the timer count reaches a specified value or until a predetermined operation is performed by the user, and when the timer count reaches a specified value, Alternatively, when a predetermined operation is performed by the user, the process of step S5 is executed.

  When it becomes Yes at Step S3 or when it becomes Yes at Step S4, the control unit 10 starts power supply to the vehicle speed sensor 132 at Step S5, and outputs a vehicle speed signal from the vehicle speed sensor 132 after the power supply is started. get. That is, in order to restore the state in which the output of the vehicle speed sensor 132 cannot be detected due to the interruption of the power supply from the first power supply unit 91, the power from the second power supply unit 7 is supplied to the vehicle speed sensor 132, Above, the vehicle speed signal output from the vehicle speed sensor 132 is acquired. Specifically, while the operation of discharging the second power supply unit 7 by the discharge circuit 5 is performed, the switching state in which the switch 42 is turned off and the switch 41 is turned on is maintained. By such control, the electric power from the second power supply unit 7 is supplied only to the vehicle speed sensor 132.

  In this configuration, the ECB ECU in the shift-by-wire ECB 122, the ECB 130, the body ECU 140, the gateway 150, and the like perform CAN communication using the power supplied from the first power supply unit 91 when the power supply from the first power supply unit 91 is normal. Can be done. Thus, in a state where CAN communication is possible, vehicle speed information generated by the vehicle speed sensor 132 can also be transmitted by CAN communication. However, if the power supply from the first power supply unit 91 is interrupted due to a ground fault of the wiring unit 102, CAN communication cannot be performed. For this reason, unless CAN communication returns, vehicle speed information generated by the vehicle speed sensor 132 cannot be transmitted by CAN communication. Therefore, in the configuration of FIG. 1, a dedicated signal line 34 is provided, and a vehicle speed signal (vehicle speed information) output from the vehicle speed sensor 132 can be input to the control unit 10 via the signal line 34 without passing through the CAN communication line 152. I am doing so.

  After acquiring the vehicle speed signal from the vehicle speed sensor 132 while supplying power to the vehicle speed sensor 132 in step S5, the control unit 10 performs the process of step S6 and determines the vehicle speed specified by the vehicle speed signal acquired in step S5 (that is, It is determined whether the speed of the vehicle on which the system 100 is mounted is equal to or less than a threshold value. When it is determined in step S6 that the vehicle speed exceeds the threshold value (in the case of No in step S6), the control unit 10 performs the processing after step S3.

  When it is determined in step S6 that the vehicle speed is equal to or less than the threshold value (Yes in step S6), the control unit 10 performs a backup operation on the shift-by-wire control system 120 including the shift-by-wire ECU 122. Specifically, while the operation of discharging the second power supply unit 7 by the discharge circuit 5 is performed, the switching state is maintained in which the switch 41 is turned off and the switch 42 is turned on. Through such control, the power from the second power supply unit 7 is supplied to the shift-by-wire control system 120. Further, the control unit 10 instructs the shift-by-wire ECU 122 to shift to the parking range in such a power supply state. The shift-by-wire control system 120 can operate because it is supplied with power by the discharging operation from the second power supply unit 7, and the shift-by-wire ECU 122 receives an instruction from the control unit 10 (instruction to shift to the parking range). Accordingly, the actuator 126 is operated to switch the range switching device 128 to the P range (a state in which the forward clutch and the reverse clutch are both released and the parking lock mechanism is activated).

  FIG. 3 shows an output voltage (shown as a BAT voltage in FIG. 3) and a vehicle speed sensor 132 when the first power supply unit 91 is switched from a normal state to a failed state in the vehicle power supply system 110. 2 illustrates the relationship between the backup voltage supplied to the shift-by-wire ECU 122 and the backup voltage supplied to the shift-by-wire ECU 122.

  When the voltage of the wiring unit 102 indicating the output voltage (BAT voltage) of the first power supply unit 91 decreases to around 0 V as shown by the timing of “power failure” in FIG. It is determined that the power supply from the first power supply unit 91 is abnormal. After that, a predetermined necessary condition (a condition in which a predetermined operation is performed on the operation unit provided in the vehicle or a condition in which a predetermined time has elapsed since the abnormality of the first power supply unit 91 occurs) is determined in steps S3 and S4. In the case where the above-described user operation is performed as in the case of “user operation” in FIG. 3, “Yes” is determined in step S 4, and in step S 5. The second power supply unit 7 is discharged while the switch 42 (switching unit) is cut off, and the discharge unit 4 is caused to perform a first discharge operation for supplying power to the sensor via the first conductive path 31. Thereby, as shown in FIG. 3, the backup voltage for the vehicle speed sensor 132 is applied immediately after the user operation. If it is determined in step S6 that the vehicle speed is equal to or lower than the threshold value based on the output from the vehicle speed sensor 134 (sensor) that is supplied with power by the first discharge operation executed in step S5, step S7 is executed. 2, the second power supply unit 7 is discharged while the switch 42 (switching unit) is energized, and the second discharge operation for supplying power to the shift-by-wire control system 120 (power supply target) via the second conductive path 32 is performed. Let the discharge part 4 perform. Thereby, a backup voltage is applied to the shift-by-wire ECU 122 as shown in FIG.

Here, the effect of this structure is illustrated.
The backup device 1 discharges the second power supply unit 7 when the abnormality detection unit detects an abnormality in power supply from the first power supply unit 91 and the determination unit determines that the vehicle speed is equal to or less than a threshold value. Then, the discharging unit 4 is caused to perform a discharging operation for supplying power to the shift-by-wire control system 120 (a predetermined power supply target). That is, even if an abnormality occurs in which the power supply from the first power supply unit 91 is reduced or cut off, the power from the second power supply unit 7 is supplied to the shift-by-wire control system 120 until the vehicle speed is equal to or lower than the threshold value. Therefore, it is possible to perform backup for a predetermined power supply target while effectively suppressing power consumption of the second power supply unit 7. And, like the parking range of the shift-by-wire control system 120, the power supply target to be backed up should be operated when the vehicle speed is less than or equal to the threshold, or operated when the vehicle speed is less than or equal to the threshold. If it is good, the problem is unlikely to occur even if a power drop state or a cut-off state occurs between the time when the abnormality of the first power supply unit 91 occurs and the time when the vehicle speed falls below the threshold value.

  In this configuration, the control unit 10 detects a power supply abnormality from the first power supply unit 91 by the abnormality detection unit, and performs a predetermined operation on the operation units (parking switch 124A, courtesy switch 144) provided in the vehicle. When the necessary condition including at least one of the conditions for which a certain time has elapsed since the occurrence of the abnormality or the abnormality of the first power supply unit 91 is satisfied, the determination unit determines that the vehicle speed is equal to or less than the threshold value The discharge unit 4 is caused to perform a discharging operation for discharging the second power supply unit 7 and supplying power to the shift-by-wire control system 120 (predetermined power supply target).

  When the abnormality detection unit detects an abnormality in power supply from the first power supply unit 91, the backup device 1 has performed a predetermined operation on the operation unit or an abnormality has occurred in the first power supply unit. The discharge unit 4 can be caused to perform a discharge operation for supplying power to the shift-by-wire control system 120 on the condition that a certain time has passed since the start of the operation. In such a system, as in the shift-by-wire control system 120, when a predetermined operation is performed on the operation unit, or a certain time has elapsed since the abnormality of the first power supply unit 91 has occurred. It is advantageous when it is an object to be operated. Even if an abnormality in power supply from the first power supply unit 91 is detected by the abnormality detection unit, a necessary condition (a condition in which a predetermined operation is performed on the operation unit or an abnormality in the first power supply unit occurs) If at least one of the conditions after a certain period of time has not been satisfied), the discharge can be stopped and the power consumption can be suppressed. It becomes more advantageous in suppressing the amount of energy required.

  The backup device 1 discharges the second power supply unit 7 to supply power to the vehicle speed sensor 132 (sensor) when the abnormality detection unit detects an abnormality in power supply from the first power supply unit 91 and a necessary condition is satisfied. Supply. Thus, even if the power supply from the first power supply unit 91 becomes abnormal, the second power supply unit 7 is discharged to supply power to the vehicle speed sensor 132 when the necessary condition is satisfied, and the vehicle speed sensor 132 operates properly. Can be made. Therefore, even if an abnormality occurs in the power supply from the first power supply unit 91, it is possible to determine whether or not the vehicle speed is equal to or less than the threshold based on the power from the second power supply unit 7. In addition, since the power supply to the vehicle speed sensor 132 is performed after the necessary conditions are satisfied, the power consumption is suppressed until then. Furthermore, after power is supplied to the vehicle speed sensor 132, when it is determined that the vehicle speed is equal to or lower than the threshold value based on the output from the vehicle speed sensor 132 that operates by receiving power supply, the second power supply unit 7. It is possible to cause the discharge unit 4 to perform a second discharge operation for discharging the power and supplying power to the shift-by-wire control system 120 (a predetermined power supply target). In this manner, after supplying power to the vehicle speed sensor 132, the power is supplied stepwise so that power is supplied to the shift-by-wire control system 120 on the condition that the speed of the vehicle is determined to be equal to or less than the threshold value. As a result, more efficient power supply is possible, and power consumption can be more effectively suppressed.

  The backup device 1 performs a discharge operation (first discharge operation) in which power is supplied from the second power supply unit 7 to the vehicle speed sensor 132 via the first conductive path 31 when power supply from the first power supply unit 91 is abnormal. Since the switch 42 is turned off, the discharge current can be reliably stopped from flowing to the shift-by-wire control system 120 via the second conductive path 32 at this time. That is, when the second power supply unit 7 is discharged, power can be reliably supplied to the vehicle speed sensor 132, but power can be reliably prevented from being supplied to the shift-by-wire control system 120. Thereafter, when the determination unit determines that the vehicle speed is equal to or less than the threshold value, the switch 42 is switched to the ON state, and the shift-by-wire control system 120 is reliably connected via the energized second conductive path 32. A discharge current can be passed through

  Since the backup device 1 includes the signal line 34 (transmission path) serving as a path for transmitting a signal from the vehicle speed sensor 132 to the determination unit in a state where power supply from the first power supply unit 91 is interrupted, the first power supply unit The signal from the vehicle speed sensor 132 can be transmitted to the determination unit via the signal line 34 without using a control device that requires power supply from 91.

  The power supply target for supplying power from the backup device 1 includes a shift-by-wire control system 120 that switches the shift range of the automatic transmission by the driving force of the actuator 126. The control unit 10 discharges the second power supply unit 7 when the abnormality detection unit detects an abnormality in power supply from the first power supply unit 91 and the determination unit determines that the vehicle speed is equal to or less than the threshold value. The discharge unit 4 performs a discharging operation for supplying power to the shift-by-wire control system 120, and functions to instruct the shift-by-wire control system 120 to switch to the parking position. As described above, when the abnormality detection unit detects an abnormality in the power supply from the first power supply unit 91, the backup device 1 can control the shift-by-wire control system 120 on the condition that the vehicle speed is equal to or less than the threshold value. Can be instructed to switch to the parking position. Accordingly, it is possible to prevent an instruction to switch to the parking position when the vehicle speed is a relatively high speed exceeding the threshold.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  In the above-described embodiment, the lead battery is used for the first power supply unit 91. However, the present invention is not limited to this configuration. In any of the above-described embodiments or the modified embodiments, the lead battery may be used instead of the lead battery. Other known power supply means may be used for the first power supply unit 91 in combination. The number of power supply means configuring the first power supply unit 91 is not limited to one, and may be configured by a plurality of power supply means.

  In the above-described embodiment, an electric double layer capacitor (EDLC) is used for the second power supply unit 7. However, the present invention is not limited to this configuration, and the second embodiment is not limited to the second embodiment. Other power storage means such as a lithium ion battery, a lithium ion capacitor, or a nickel metal hydride battery may be used for the power supply unit 7. Moreover, the number of the electrical storage means which comprises the 2nd power supply part 7 is not limited to one, You may be comprised by the several electrical storage means.

  In the above-described embodiment, the switches 41 and 42 configured as MOSFETs are exemplified as the switching unit. However, in any example in which the above-described embodiment or the above-described embodiment is changed, the present invention is not limited to this configuration, A semiconductor switching element or the like may be used, or a mechanical relay may be used.

  In the above-described embodiment, the vehicle speed sensor is illustrated as an example of a sensor that outputs a signal reflecting the vehicle speed. However, in any of the above-described embodiments or the modified embodiments, a wheel speed sensor, an acceleration sensor, or the like is used. There may be.

  In the embodiment described above, the shift-by-wire control system 120 performs the operation of switching to the parking range in accordance with the instruction of the control unit 10 in step S7 shown in FIG. 2, but any example in which the above embodiment or the above embodiment is changed. However, the shift-by-wire control system 120 may be configured to switch to the parking range without receiving such an instruction. That is, the shift-by-wire ECU 122 automatically starts power supply from the second power supply unit 7 to the shift-by-wire ECU 122 after the power supply from the first power supply unit 91 has failed, and if the vehicle speed is equal to or lower than the threshold value. You may be comprised so that it may switch to a parking range.

  In the above-described embodiment, the shift-by-wire control system 120 is exemplified as the predetermined power supply target. However, in any example in which the above-described embodiment or the above-described embodiment is changed, the present invention is not limited to this example, and the vehicle speed is low. Or what is necessary is just the object which can be requested | required to operate | move in the stopped state. For example, EPB (Electronic Parking Brake) may be a power supply target.

DESCRIPTION OF SYMBOLS 1 ... Backup device for vehicles 4 ... Discharge part 7 ... 2nd power supply part 10 ... Control part (Abnormality detection part, determination part, discharge control part)
31 ... 1st conductive path 32 ... 2nd conductive path 34 ... Signal line (transmission path)
42 ... Switch (switching part)
91 ... 1st power supply part 110 ... Power supply system for vehicles 120 ... Shift-by-wire control system (electric power supply object)
126 ... Actuator

Claims (6)

A backup device for a vehicle power supply system, comprising: a first power supply unit mounted on a vehicle; and a second power supply unit serving as a power supply source when power supply from at least the first power supply unit is interrupted. ,
A discharge unit that performs a discharge operation for supplying power to a predetermined power supply target based on power supply from the second power supply unit and a stop operation for stopping the discharge operation;
An abnormality detection unit for detecting an abnormality in which power supply from the first power supply unit is reduced or interrupted;
A determination unit that determines whether the speed of the vehicle is equal to or lower than a threshold based on an output from a sensor that generates a signal reflecting the speed of the vehicle;
When the abnormality detection unit detects an abnormality in power supply from the first power supply unit and the determination unit determines that the speed of the vehicle is equal to or lower than the threshold value, the second power supply unit is discharged. A discharge control unit for causing the discharge unit to perform a discharge operation for supplying power to the power supply target;
A backup device for a vehicle having   In the discharge control unit, a condition in which an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit and a predetermined operation is performed on an operation unit provided in the vehicle or the first power supply unit If a necessary condition including at least one of the conditions after a certain time has elapsed since the occurrence of the abnormality is satisfied, the determination unit determines that the speed of the vehicle is equal to or less than the threshold, The backup device for a vehicle according to claim 1, wherein the discharging unit performs a discharging operation of discharging the second power supply unit to supply power to the power supply target. The discharge controller is
When an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit and the necessary condition is satisfied, a first discharge operation is performed to discharge the second power supply unit and supply power to the sensor. Let the discharge part do,
When the determination unit determines that the speed of the vehicle is equal to or lower than the threshold based on the output from the sensor supplied with power by the first discharge operation, the second power supply unit is discharged to The vehicle backup device according to claim 2, wherein the discharge unit performs a second discharge operation for supplying power to a power supply target. A first conductive path serving as a discharge path from the discharge unit to the sensor;
A second conductive path serving as a discharge path from the discharge unit to the power supply target;
Have
The discharge unit includes a switching unit that switches the second conductive path between an energized state in which a discharge current from the second power supply unit flows and a cut-off state in which the discharge current from the second power supply unit does not flow,
The discharge controller is
When an abnormality in power supply from the first power supply unit is detected by the abnormality detection unit and the necessary condition is satisfied, the second power supply unit is discharged while the switching unit is in the cutoff state, and the first conductive Causing the discharge unit to perform the first discharge operation for supplying electric power to the sensor via a path,
When the determination unit determines that the speed of the vehicle is equal to or lower than the threshold value based on an output from the sensor supplied with power by the first discharging operation, the switching unit is set in the energized state The backup device for a vehicle according to claim 3, wherein the second power supply unit is discharged and the discharge unit performs a second discharge operation for supplying power to the power supply target through the second conductive path.   5. The vehicle according to claim 1, further comprising: a transmission path serving as a path for transmitting a signal from the sensor to the determination unit in a state where power supply from the first power supply unit is interrupted. Backup device. The power supply target is a shift-by-wire control system that switches a shift range by the driving force of an actuator,
The discharge control unit is configured to detect the second when the abnormality detection unit detects an abnormality in power supply from the first power supply unit and the determination unit determines that the speed of the vehicle is equal to or less than the threshold value. 6. A discharge operation for discharging a power supply unit to supply power to the shift-by-wire control system is performed by the discharge unit, and the shift-by-wire control system is instructed to switch to a parking position. The backup apparatus for vehicles as described in any one of these.

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