JP2017177857A - Control method and control apparatus for automatic driving vehicle power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method and a control apparatus for an automatic driving vehicle power supply, the method and apparatus that prevent the capacity of an additional battery from increasing while securing the continuation of automatic driving functionality.SOLUTION: A first load circuit 1, using a lead battery 11 as power supply, interconnects a starter motor 12 necessary for continuing a normal drive mode by a driver and a load actuator 13. A second load circuit 2, using a lithium ion battery 21 as power supply, interconnects automatic drive function loads 22, 23, 24 that are required to continue an automatic drive mode and require a voltage to be maintained. A circuit disconnect-connect mechanism 3 connects or disconnects between the first and second load circuits 1, 2. In controlling this automatic driving vehicle power supply, the circuit disconnect-connect mechanism 3 is shut off in a case where power output from the lithium ion battery 21 toward the first load circuit 1-side is determined on the basis of a load condition detected on the second load circuit 2-side while the circuit disconnect-connect mechanism 3 is connected.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control method and a control device for an automatic driving vehicle power source having a circuit interrupting mechanism between a first load circuit using a main battery as a power source and a second load circuit using an additional battery as a power source.

  In recent years, driver assistance technology in automobiles has been constantly improving. In other words, it not only issues a warning to the driver by detecting the driving position and driving state, but also uses an electric actuator such as a motor to operate the steering and brakes to actively support the driver's operation. Has led to. In the future, more advanced driver support functions that do not require driver operations are expected to be adopted.

  Since such a driver support function uses an electric actuator such as a motor, higher reliability is required for a power supply system that is a power source. As a technique for improving the reliability of the power supply system for vehicles, an additional battery other than the main battery mounted is provided, and separated from a circuit in which a load such as a starter that consumes a large current and fluctuates voltage exists. As a result, a power supply configuration that can stabilize the voltage of a load connected to the additional battery side and improve the reliability of the power supply system is disclosed (for example, see Patent Document 1).

JP 2009-23469 A

  However, in the prior art, for example, the two batteries are connected under conditions that cause a change in current and voltage of the load connected to the main battery connected side, such as engine restart due to idling stop. The interrupting device is shut off.

  Therefore, for example, when the electric steering or the electric brake is connected to the circuit on the additional battery side, the two batteries are connected when the electric steering or the electric brake is operated. For this reason, when the additional battery supplies power to the load on the main battery side, the voltage is excessively lowered, and driver support functions such as electric steering and electric brake do not function sufficiently. As a result, it is difficult to continue the automatic driving function. In addition, there is a problem that if an attempt is made to maintain the voltage while supplying power to the load on the main battery side, the additional battery is increased in capacity and becomes large.

  The present invention has been made paying attention to the above problems, and provides a control method and a control device for an automatic driving vehicle power source that prevents the additional battery from increasing in capacity while ensuring the continuation of the automatic driving function. For the purpose.

In order to achieve the above object, the present invention has a circuit interrupting mechanism between a first load circuit that uses a main battery as a power source and a second load circuit that uses an additional battery as a power source.
In this control method for an automatic driving vehicle power source, when it is determined that power is taken out from the additional battery to the first load circuit side based on a load state detected on the second load circuit side during connection of the circuit interrupting mechanism, Shut off the intermittent mechanism.

  As a result, it is possible to prevent the additional battery from increasing in capacity while ensuring the continuation of the automatic operation function.

It is a power supply system figure which shows the power supply system to which the control method and control apparatus of the automatic driving vehicle power supply of Example 1 were applied. 6 is a flowchart showing a flow of connection / disconnection control processing of the circuit interruption mechanism executed in the control unit of the first embodiment. It is a figure which shows the definition of the threshold value of the battery voltage used by the connection / disconnection control process of the circuit interruption mechanism of FIG. It is a flowchart which shows the flow of the connection / disconnection control process of the circuit interruption mechanism performed in the control unit of Example 2. FIG. It is a figure which shows the definition of the threshold value of a battery capacity used by the connection / disconnection control process of the circuit interruption mechanism of FIG.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for realizing a control method and a control device for an autonomous driving vehicle power supply according to the present invention will be described below based on Embodiments 1 and 2 shown in the drawings.

First, the configuration will be described.
When the automatic driving mode is selected during traveling, the control method and the control device for the automatic driving vehicle power supply in the first embodiment are applied to an engine-equipped vehicle having an automatic driving function that does not require a steering operation, an accelerator operation, or a brake operation by the driver. It is applied. Hereinafter, the control method of the autonomous driving vehicle power source and the configuration of the control device according to the first embodiment will be described by dividing them into “a power system configuration” and “a circuit interruption mechanism connection / disconnection control processing configuration”.

[Power system configuration]
FIG. 1 shows a power supply system to which a control method and a control apparatus for an autonomous driving vehicle power supply according to a first embodiment are applied. Hereinafter, the configuration of the power supply system will be described with reference to FIG.

  As shown in FIG. 1, the power supply system for an autonomous driving vehicle power supply includes a first load circuit 1, a second load circuit 2, a circuit interrupting mechanism 3, and a control unit 4.

  The first load circuit 1 is a load circuit that uses a lead battery 11 (main battery) as a power source and connects a first load necessary for the continuation of the normal operation mode by the driver to a downstream circuit of the lead battery 11. The first load includes a starter motor 12 and a load actuator 13.

  The lead battery 11 is a secondary battery as a main battery conventionally mounted on an engine vehicle or the like. The lead battery 11 is charged by an alternator 14 as a generator included in the first load circuit 1 so that the battery capacity does not decrease. The alternator 14 generates electric power by rotational driving by an engine (not shown) and charges the lead battery 11 so as to maintain the charging capacity.

  The starter motor 12 is an engine start motor that starts the engine at the time of start and restarts the engine at the time of idling stop.

  The load actuator 13 is an auxiliary machine that operates using the lead battery 11 as a power source, such as an electric motor or a headlight that drives a compressor of an air conditioner.

  The second load circuit 2 uses a lithium ion battery 21 (additional battery) as a power source, and supplies a second load downstream of the lithium ion battery 21 that is necessary for continuation of the automatic operation mode and that requires voltage maintenance. A load circuit connected to the circuit. The second load (hereinafter referred to as “automatic operation function load”) includes an EPS actuator 22, an ABS actuator 23, and an ADAS actuator 24.

  The lithium ion battery 21 is a secondary battery as an additional battery added as a new power source for exhibiting an automatic driving function with respect to the power source by the lead battery 11, and is a power source for a traveling motor mounted on the electric vehicle. The battery is frequently used. The lithium ion battery 21 is provided with a discharge circuit and a charging circuit. The charging circuit includes a DC / DC converter, the circuit interrupting mechanism 3 is in a connected state, and when the voltage on the first load circuit 1 side is high, the generated power from the alternator 14 (generator) is generated according to the charging request. Charged.

  The lithium ion battery 21 has a characteristic that the internal resistance is smaller than that of the lead battery 11 as the main battery. For this reason, for example, even when the EPS actuator 22 operates and consumes a large current, the voltage can be maintained high. In the power supply system of the first embodiment, when the circuit interrupting mechanism 3 is interrupted during traveling in the automatic operation mode in which the automatic operation function load is activated, the interrupted state is maintained until the return condition is satisfied, and the lithium ion battery 21 is not recharged. For this reason, the capacity | capacitance of the lithium ion battery 21 is set to a suitable capacity | capacitance so that the driving | running | working continuation time by automatic operation mode may become more than request | requirement time at least, for example.

  The EPS actuator 22 is an automatic driving function load by an EPS motor that generates an electric assist force. The EPS actuator 22 is used in an electric power steering system that assists the power necessary for the steering wheel operation electrically to lighten the steering force. Here, “EPS” is an abbreviation for Electric Power Steering.

  The ABS actuator 23 is an automatic operation function load by a pump motor or an electromagnetic valve that drives a hydraulic pump. The ABS actuator 23 has an electric hydraulic pump, and is used in a brake hydraulic pressure control system that independently controls each wheel cylinder hydraulic pressure based on hydraulic oil from a master cylinder or a hydraulic pump. Here, “ABS” is an abbreviation for “Antilock Brake System”.

  The ADAS actuator 24 is an automatic driving function load by various driving operation support actuators for supporting a steering operation, a brake operation, and an accelerator operation performed by the driver during normal driving. The ADAS actuator 24 is used in an advanced driving system in which the surrounding situation of the vehicle is detected by a camera, a radar, or the like, and automatic brake control, auto cruise control, lane keep control, or the like is performed based on the detection information. Here, “ADAS” is an abbreviation for “Advanced Driver Assistance System”.

  The circuit interrupting mechanism 3 is provided at a position where the first load circuit 1 and the second load circuit 2 are connected, and connects or disconnects the first load circuit 1 and the second load circuit 2. When the circuit interrupting mechanism 3 is cut off, the voltage fluctuation of the first load circuit 1 does not affect the second load circuit 2, and power is taken out from the lithium ion battery 21 of the second load circuit 2 to the first load circuit 1 side. Stopped. The circuit interrupting mechanism 3 of the first embodiment is a mechanism using a relay switch that is connected / disconnected by electromagnetic force.

  The control unit 4 performs connection control and disconnection control of the circuit interrupting mechanism 3. This control unit 4 is input from a current sensor 41, an automatic operation mode switch 42, a first voltage sensor 43, a second voltage sensor 44, a battery voltage sensor 45, a brake switch 46, a torque sensor 47, and other sensors / switches 48. Get information. And according to the result of the judgment process based on these input information, a control command is output to the circuit interruption mechanism 3, the indicator 49, and the buzzer 50.

  The current sensor 41 is provided in the middle of the circuit connecting the lithium ion battery 21 and the circuit interrupting mechanism 3 and detects the direction in which the current flows. The automatic operation mode switch 42 is an automatic operation mode start switch. The first voltage sensor 43 detects the circuit voltage of the first load circuit 1. The second voltage sensor 44 detects the circuit voltage of the second load circuit 2. The battery voltage sensor 45 detects the battery voltage of the lithium ion battery 21. The brake switch 46 detects a brake operation by the driver. The torque sensor 47 detects the steering torque applied to the steering shaft by the steering operation by the driver.

[Connection / disconnection control processing configuration of circuit interruption mechanism]
FIG. 2 shows a flow of connection / disconnection control processing of the circuit interrupt mechanism 3 executed in the control unit 4 of the first embodiment. Hereinafter, each step of FIG. 2 showing the connection / disconnection control processing configuration of the circuit interruption mechanism 3 will be described. This control process is started when the ignition is on when the circuit interrupting mechanism 3 is in the connected state.

In step S1, following the start, or after determining that the automatic operation function load is not activated in step S4, or following connection of the circuit interrupting mechanism 3 in step S8, the additional battery side (= the second load circuit 2 side) ) Is detected, and the process proceeds to step S2.
Here, the “load state” means a battery discharge in which power stored in the lithium ion battery 21 in the second load circuit 2 is taken out to the first load circuit 1 side via the circuit interrupting mechanism 3 in the connected state. Information that can be judged.

In step S2, following the detection of the load state on the additional battery side in step S1, it is determined whether or not a decrease in the second load circuit voltage on the additional battery side (= second load circuit 2 side) has occurred. If YES (the second load circuit voltage has dropped), the process proceeds to step S5. If NO (second load circuit voltage has not dropped), the process proceeds to step S3.
Here, the “second load circuit voltage” is acquired from the second voltage sensor 44 by sensor information.

In step S3, whether or not current has flowed from the additional battery side (second load circuit 2) to the main battery side (first load circuit 1) following the determination that the second load circuit voltage does not decrease in step S2. Judging. If YES (current flow is present), the process proceeds to step S5. If NO (current flow is absent), the process proceeds to step S4.
Here, “the current flows from the second load circuit 2 to the first load circuit 1” is acquired from the sensor information from the current sensor 41.

In step S4, it is determined whether or not the automatic operation function load (EPS actuator 22, ABS actuator 23, ADAS actuator 24) is operating or is scheduled to operate following the determination that no current flows in step S3. To do. If YES (automatic operation function load operation), the process proceeds to step S5. If NO (automatic operation function load non-operation), the process returns to step S1.
Here, “automatic operation function load in operation” means from the start (including the operation schedule) of the automatic operation function load to the end of the operation of the automatic operation function load. The operation start of the automatic driving function load may be determined by, for example, an ON signal from the automatic driving mode switch 42, or may be determined by outputting a control command for operating the load with respect to the automatic driving function load. Also good. The scheduled operation start of the automatic driving function load may be determined to be the scheduled operation start of the automatic driving function load when, for example, the vehicle is predicted to enter an expressway based on road information from the navigation system. . In addition, if the road conditions around the vehicle are detected using a camera, radar, etc., and it is detected that the traveling road of the vehicle is suitable for automatic driving, it is determined that the scheduled operation of the automatic driving function load has started. You may do it.

In step S5, following the determination of YES in step S2, or step S3, or step S4, or following the determination of first load circuit voltage <A in step S7, the circuit interrupting mechanism 3 that is in the connected state is shut off, Proceed to step S6.
That is, when at least one of the circuit voltage drop condition in step S2, the current direction condition in step S3, and the second load operation condition in step S4 is satisfied, the circuit interrupting mechanism 3 is interrupted in step S5. .

In step S6, following the interruption of the circuit interrupting mechanism 3 in step S5, it is determined whether or not the battery voltage of the lithium ion battery 21 is equal to or lower than the voltage B. If YES (battery voltage ≦ voltage B), the process proceeds to step S9. If NO (battery voltage> voltage B), the process proceeds to step S7.
Here, “battery voltage” is obtained from sensor information from the battery voltage sensor 45. “Voltage B” is determined based on the method of determining the voltage threshold shown in FIG. FIG. 3 shows the characteristic that the lithium ion battery 21 decreases with a constant gradient from the fully charged state, and how to determine “voltage A”, “voltage B”, and “voltage C” is as follows. is there.
Voltage A: A circuit voltage on the generator side (first load circuit 1 side) necessary for charging the lithium ion battery 21.
Voltage B: The battery voltage of the lithium ion battery 21 that reaches the voltage C when the automatic operation function load is activated within an assumed time.
Voltage C: The lower limit battery voltage of the lithium ion battery 21 at which the automatic operation function load can maintain the performance.

In step S7, following the determination that battery voltage> voltage B in step S6, it is determined whether the first load circuit voltage on the generator side is equal to or higher than voltage A. If YES (first load circuit voltage ≧ voltage A), the process proceeds to step S8. If NO (first load circuit voltage <voltage A), the process returns to step S5.
Here, the “first load circuit voltage” is acquired from the sensor information from the first voltage sensor 43. “Voltage A” depends on how to determine the voltage threshold shown in FIG.

  In step S8, following the determination that the first load circuit voltage ≧ the voltage A in step S7 or the determination that there is a transition to the normal operation mode in step S10, the circuit interruption mechanism 3 that is in the cut-off state is Connect and return to step S1.

In step S9, following the determination that battery voltage ≦ voltage B in step S6 or the determination that the predetermined time has not elapsed in step S11, a warning is issued to the driver and Prompt the mode transition and proceed to step S10.
Here, the “warning to the driver” is performed by appealing to the sight and hearing by, for example, displaying a warning on the display 49 and a warning sound from the buzzer 50.

In step S10, following the warning to the driver in step S9, it is determined whether or not the automatic operation mode has shifted to the normal operation mode. If YES (there is a transition to the normal operation mode), the process proceeds to step S8, and if NO (there is no transition to the normal operation mode), the process proceeds to step S11.
Here, the “transition to the normal operation mode” uses the operation intervention by the driver as a condition for releasing the automatic operation mode. For example, when the brake operation by the driver is detected by the brake switch 46, the operation mode is changed to the normal operation mode. It is determined that there is a transition. Further, when the steering operation by the driver is detected by the torque sensor 47, it is determined that there is a transition to the normal operation mode.

In step S11, following the determination that there is no transition to the normal operation mode in step S10, it is determined whether or not a predetermined time has elapsed since the warning was issued. If YES (predetermined time has elapsed), the process proceeds to step S12. If NO (predetermined time has not elapsed), the process returns to step S9.
Here, for example, when the driver who has received the warning shifts to the normal operation mode, the predetermined time is set by recognizing the warning content and adding a margin time to the time required to start the driving operation.

In step S12, following the determination that the predetermined time has elapsed in step S11, automatic brake control for stopping the vehicle is executed, and the process proceeds to the end.
The automatic brake control here is different from the automatic brake control by rapid deceleration that avoids contact with an obstacle, and stops the vehicle as a strong warning, and is therefore automatic brake control by gentle deceleration. Further, the position at which the vehicle is stopped by executing the automatic brake control may be such that a vehicle retracted position existing at a position closest to the traveling direction of the host vehicle is searched, and the searched vehicle retracted position is set as the target stop position.

Next, the operation will be described.
The operation of the first embodiment will be described by dividing it into “connection / disconnection control processing operation of the circuit interruption mechanism” and “characteristic operation of connection / disconnection control of the circuit interruption mechanism”.

[Connection / disconnection control processing action of circuit interruption mechanism]
Hereinafter, the connection / disconnection control processing operation of the circuit interruption mechanism 3 will be described based on the flowchart of FIG.

  While traveling in the normal operation mode with the circuit interrupting mechanism 3 in the connected state, the circuit voltage drop condition in step S2, the current direction condition in step S3, and the second load operating condition in step S4 are not satisfied. is there. At this time, in the flowchart of FIG. 2, the flow of going from step S 1 → step S 2 → step S 3 → step S 4 → step S 5 is repeated, and the connection state of the circuit interrupting mechanism 3 is maintained.

  If the circuit voltage of the second load circuit 2 decreases during traveling in the normal operation mode with the circuit interrupting mechanism 3 connected, the process proceeds from step S1 to step S2 to step S5 in the flowchart of FIG. In step S5, the circuit interruption mechanism 3 is interrupted at the timing when the circuit voltage of the second load circuit 2 decreases.

  When a current flows from the second load circuit 2 to the first load circuit 1 during traveling in the normal operation mode with the circuit interrupting mechanism 3 connected, in the flowchart of FIG. 2, step S1, step S2, step S3, step S5 are performed. Proceed to In step S5, the circuit interrupting mechanism 3 is interrupted at the timing when the current flow is determined.

  While the circuit interrupting mechanism 3 is traveling in the connected state, for example, when switching from the normal operation mode to the automatic operation mode, it is determined that the automatic operation function load is activated, or switching to the automatic operation mode is predicted. It is determined that the automatic driving function load is scheduled to start. At this time, in the flowchart of FIG. 2, the process proceeds from step S1, step S2, step S3, step S4, and step S5. In step S5, the circuit interrupting mechanism 3 is cut off from the timing when the automatic driving function load starts (including the scheduled start of operation).

  When the circuit interrupting mechanism 3 is interrupted in step S5, the process proceeds from step S5 to step S6. In step S6, it is determined whether or not the battery voltage of the lithium ion battery 21 is equal to or lower than the voltage B. When the battery voltage of the lithium ion battery 21 exceeds the voltage B, the process proceeds to step S7. In step S7, it is determined whether or not the first load circuit voltage on the generator side is equal to or higher than the voltage A.

  While it is determined in step S7 that the first load circuit voltage is less than the voltage A, the flow of steps S5, S6, and S7 is repeated, and the interruption state of the circuit interrupting mechanism 3 is maintained. The On the other hand, when it is determined in step S7 that the first load circuit voltage is equal to or higher than the voltage A, the process proceeds to step S8, and in step S8, the circuit interrupting mechanism 3 that is in the cut-off state is connected. And it returns to step S1 and the interruption | blocking conditions (step S2-step S4) of the circuit interruption mechanism 3 are judged again.

  If it is determined in step S6 that the battery capacity of the lithium ion battery 21 is reduced and the battery voltage is equal to or lower than the voltage B, the process proceeds to step S9. In step S9, a warning is issued to the driver, prompting the driver to shift to the normal operation mode. In the next step S10, it is determined whether or not the automatic operation mode has been shifted to the normal operation mode. In the next step S11, it is determined whether or not a predetermined time has elapsed since the warning was issued. If it does not shift to normal operation mode after progressing to step S9 which issues a warning to a driver | operator, until the predetermined time passes, the flow which progresses to step S9-> step S10-> step S11 is repeated in the flowchart of FIG. It is.

  And if it transfers to normal operation mode before predetermined time passes, it will progress to step S8 from step S10, and the circuit interruption mechanism 3 which is a interruption | blocking state will be connected in step S8. And it returns to step S1 and the interruption | blocking conditions (step S2-step S4) of the circuit interruption mechanism 3 are judged again. On the other hand, if it does not shift to the normal operation mode before the predetermined time elapses, the process proceeds from step S11 to step S12. In step S12, automatic brake control for stopping the vehicle is executed, and the control is terminated.

  Thus, during traveling in the normal operation mode with the circuit interrupting mechanism 3 in the connected state, the circuit voltage drop condition in step S2, the current direction condition in step S3, and the second load operating condition in step S4 Of these, at least one condition is satisfied. At this time, the process proceeds to step S5 in FIG. 2, and the circuit interrupting mechanism 3 is shut off.

  There are a first return condition and a second return condition as return conditions from the interrupted state to the connected state of the circuit interrupt mechanism 3. The first return condition is that the battery voltage of the lithium ion battery 21 exceeds the voltage B (NO in step S6), and the first load circuit voltage is equal to or higher than the voltage A (YES in step S7). The second return condition is that the battery voltage of the lithium ion battery 21 is equal to or lower than the voltage B (YES in step S6), but is a transition confirmation to the normal operation mode (YES in step S10). The first return condition is a condition given by adapting to recharge of the lithium ion battery 21. The second return condition is a condition given by the transition to the normal operation mode in which the automatic operation function load does not operate even when the battery voltage of the lithium ion battery 21 is lowered.

  Further, when the battery voltage of the lithium ion battery 21 is lowered, when the automatic operation function load is not activated and the normal operation mode is not shifted, the driver can experience that the automatic operation mode cannot be continued any more. To make it happen, the vehicle is stopped.

[Characteristics of connection / disconnection control of circuit interruption mechanism]
In the first embodiment, it is determined that power is taken out from the lithium ion battery 21 to the first load circuit 1 side based on the load state detected on the second load circuit 2 side while the circuit interruption mechanism 3 is connected. Then, the circuit interrupting mechanism 3 is shut off.

  That is, when the automatic driving vehicle power source has a circuit interrupting mechanism between the first load circuit that uses the main battery as a power source and the second load circuit that uses the additional battery as a power source, High voltage is required to maintain the performance of electric brakes. Focusing on this point, the condition determination whether or not to interrupt the circuit interrupting mechanism 3 is made not on the first load circuit 1 side but on the second load circuit 2 side, and priority is given to maintaining the automatic operation function. did.

  That is, when it is determined that power is taken out from the lithium ion battery 21 to the first load circuit 1 side, the circuit interrupting mechanism 3 is interrupted. When the circuit interrupting mechanism 3 is interrupted, the influence of voltage change and voltage fluctuation on the first load circuit 1 side is interrupted, and the voltage of the lithium ion battery 21 is maintained. For this reason, the continuation of the automatic driving function using the electric steering, the electric brake or the like is ensured.

  When the circuit interrupting mechanism 3 is interrupted, power is not taken out from the lithium ion battery 21 to the first load circuit 1 side. For this reason, when setting the battery capacity of the lithium ion battery 21, it is not necessary to consider the amount of power supplied to the first load circuit 1, and the capacity of the lithium ion battery 21 is increased (= enlarged). Is prevented.

  In the first embodiment, when the circuit voltage of the second load circuit 2 decreases while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted at the timing when the circuit voltage decreases.

  For example, if the circuit voltage drop of the second load circuit 2 occurs due to deterioration or discharge of the lithium ion battery 21 while the circuit interrupting mechanism 3 is connected, if the connection of the circuit interrupting mechanism 3 is maintained, the second load circuit The circuit voltage of 2 further decreases. If the state in which the circuit voltage is lowered is left unattended, the voltage drops below the circuit voltage of the second load circuit 2 that maintains the performance of the electric steering, the electric brake, etc., and the automatic driving function is not exhibited. On the other hand, the lithium ion battery 21 is the last security battery for the automatic operation function load.

  On the other hand, if the circuit interrupting mechanism 3 is cut off at the timing when the circuit voltage of the second load circuit 2 is reduced, the power is brought from the lithium ion battery 21 to the first load circuit 1 side at the time of the interruption. The power supply is possible only for the automatic operation function load. For this reason, when the circuit voltage of the second load circuit 2 decreases while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is shut off and the circuit voltage is maintained thereafter, so that the automatic operation function is reliably exhibited. .

  In the first embodiment, when a current flows from the second load circuit 2 toward the first load circuit 1 while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted at the timing when the current flows.

  For example, when a current flows from the second load circuit 2 toward the first load circuit 1 due to discharge from the lithium ion battery 21 during connection of the circuit interrupting mechanism 3, if the connection of the circuit interrupting mechanism 3 is maintained, the second The circuit voltage of the load circuit 2 further decreases. If the state in which a current flows to the first load circuit 1 is left unattended, the voltage is lower than the circuit voltage of the second load circuit 2 that maintains the performance of the electric steering, the electric brake, etc., and the automatic driving function is not exhibited.

  On the other hand, if the circuit interrupting mechanism 3 is shut off at the timing when the current flows from the second load circuit 2 toward the first load circuit 1, the lithium ion battery 21 is switched from the lithium ion battery 21 toward the first load circuit 1 when the current is cut off. There is no need to carry out power, and it is possible to supply power only to the automatic operation function load. For this reason, if a current flows from the second load circuit 2 to the first load circuit 1 while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted and the subsequent power take-off is eliminated. Function is demonstrated.

  In the first embodiment, when the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is disconnected when an automatic driving function load that exhibits the automatic driving function is in operation.

  For example, when the automatic operation function load is operated while the circuit interrupting mechanism 3 is in the connected state, the influence on the first load circuit 1 side is directly received on the second load circuit 2 side. When the influence on the first load circuit 1 side is received on the second load circuit 2 side, the power voltage is taken out from the second load circuit 2 and the circuit voltage decreases or fluctuates, so the automatic operation function is continued. Difficult to do. The “influence on the first load circuit 1 side” means voltage fluctuation due to, for example, voltage change due to engine restart, abnormality of the alternator 14, operation of a large current load or load failure.

  On the other hand, if the circuit interrupting mechanism 3 is cut off during the operation of the automatic operation function load, the influence on the first load circuit 1 side is also cut off at the time of being cut off, and the circuit voltage of the second load circuit 2 is stabilized, It only changes depending on the operation of the automatic driving function load. For this reason, when the automatic operation function load is in operation while the circuit interrupting mechanism 3 is connected, the automatic operation function is stabilized by interrupting the circuit interrupting mechanism 3 and disconnecting the influence from the first load circuit 1 side. Will continue.

  Furthermore, if the lithium ion battery 21 is recharged while the circuit interrupting mechanism 3 is kept connected during operation of the automatic operation function load, chattering that repeatedly connects and disconnects the circuit interrupting mechanism 3 may occur in a short cycle. On the other hand, chattering during the operation of the automatic driving function load is prevented by continuing the interruption of the circuit interrupting mechanism 3 during the operation of the automatic driving function load. Here, “chattering” refers to a phenomenon that causes minute and very fast mechanical vibration when a movable contact or the like is brought into contact.

  In the first embodiment, when the circuit interrupting mechanism 3 is interrupted and the battery voltage of the lithium ion battery 21 becomes equal to or lower than the voltage B, a warning for prompting the driver to shift to the normal operation mode is issued. When the transition to the normal operation mode is confirmed before the predetermined time elapses after the warning is issued, the circuit interruption mechanism 3 is connected.

  That is, if the automatic operation mode is continued while the circuit interrupting mechanism 3 is cut off, the lithium ion battery 21 is not recharged during the operation of the automatic operation function load, so the battery voltage of the lithium ion battery 21 is in the middle of the automatic operation mode. May fall below the voltage B. When the battery voltage becomes equal to or lower than the voltage B, the recharging of the lithium ion battery 21 can be ensured by shifting to the normal operation mode and connecting the circuit interruption mechanism 3.

  Therefore, when the battery voltage of the lithium ion battery 21 becomes equal to or lower than the voltage B due to the continuation of the automatic operation mode with the circuit interruption mechanism 3 cut off, the automatic operation mode is ensured by ensuring the recharge of the lithium ion battery 21. Return to is possible.

  In the first embodiment, after the warning is issued, if the shift to the normal operation mode is not confirmed until the predetermined time elapses, the automatic brake control for automatically stopping the vehicle is performed after the predetermined time elapses.

  For example, if the automatic operation mode is maintained even when the battery voltage of the lithium ion battery 21 is lower than the voltage B, the lithium ion battery 21 is lower than the lower limit voltage at which the automatic operation function can be maintained, and the automatic operation function is lowered. Transition to automatic driving.

  On the other hand, when the predetermined time when the lithium ion battery 21 approaches the lower limit voltage at which the automatic operation function can be maintained has elapsed, the vehicle is forcibly stopped. For this reason, when the shift to the normal operation mode is not confirmed before the predetermined time elapses after the warning is issued, the shift to the automatic driving traveling with the reduced automatic driving function is prevented.

Next, the effect will be described.
In the control method and control device for the autonomous driving vehicle power source in the first embodiment, the effects listed below can be obtained.

(1) The first load circuit 1 uses a main battery (lead battery 11) as a power source, and connects a first load (starter motor 12, load actuator 13) necessary for the continuation of the normal operation mode by the driver.
The second load circuit 2 uses an additional battery (lithium ion battery 21) as a power source and connects a second load (automatic operation function load) that is necessary for the continuation of the automatic operation mode and that needs to maintain the voltage. .
A circuit interrupting mechanism 3 for connecting or disconnecting the first load circuit 1 and the second load circuit 2 is provided, and the circuit interrupting mechanism 3 is intermittently controlled.
In this automatic driving vehicle power supply control method, an additional battery (lithium ion battery 21) is connected to the first load circuit 1 side based on a load state detected on the second load circuit 2 side while the circuit interrupting mechanism 3 is connected. When it is determined that power is to be taken out, the circuit interrupting mechanism 3 is shut off (FIG. 2).
For this reason, it is possible to provide a control method for an automatically operated vehicle power source that prevents the additional battery (lithium ion battery 21) from increasing its capacity while ensuring the continuity of the automatic operation function.

(2) When the circuit voltage of the second load circuit 2 decreases while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted at the timing when the circuit voltage decreases (S2 → S5 in FIG. 2).
For this reason, in addition to the effect of (1), when the circuit voltage of the second load circuit 2 decreases while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted and the circuit voltage is maintained thereafter, thereby ensuring The automatic driving function can be demonstrated.

(3) When a current flows from the second load circuit 2 toward the first load circuit 1 while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted at the timing when the current flows (S3 → S5 in FIG. 2). ).
For this reason, in addition to the effect of (1), if a current flows from the second load circuit 2 toward the first load circuit 1 while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted and power thereafter The automatic driving function can be demonstrated by removing the carry-out.

(4) While the circuit interrupting mechanism 3 is connected, if the second load (automatic operation function load) that exhibits the automatic operation function is operating, the circuit interrupting mechanism 3 is interrupted (S4 → S5 in FIG. 2).
For this reason, in addition to the effect of (1), if the automatic operation function load is in operation while the circuit interrupting mechanism 3 is connected, the circuit interrupting mechanism 3 is interrupted and the influence from the first load circuit 1 side is interrupted. Thus, the automatic driving function can be continued stably. In addition, chattering that occurs when recharging is permitted during the operation of the automatic driving function load can be prevented by continuing the interruption of the circuit interrupting mechanism 3 during the operation of the automatic driving function load.

(5) When the circuit interrupting mechanism 3 is shut off and the battery voltage of the additional battery (lithium ion battery 21) becomes equal to or lower than a predetermined value (voltage B), a warning that prompts the driver to shift to the normal operation mode is issued. (S6 → S9 in FIG. 2).
When the transition to the normal operation mode is confirmed before the predetermined time elapses after issuing the warning, the circuit interrupting mechanism 3 is connected (S10 → S8 in FIG. 2).
For this reason, in addition to the effects of (1) to (4), when the battery voltage of the additional battery (lithium ion battery 21) becomes equal to or lower than the voltage B with the circuit interrupting mechanism 3 shut off, the automatic operation mode is entered. A return can be made possible.

(6) If the shift to the normal operation mode is not confirmed before the predetermined time elapses after the warning is issued, automatic brake control is executed to automatically stop the vehicle after the predetermined time elapses (S9 in FIG. 2). → S10 → S11 → S12).
For this reason, in addition to the effect of (5), when the transition to the normal operation mode is not confirmed before the predetermined time elapses after the warning is issued, the transition to the automatic driving traveling with the reduced automatic driving function is prevented. be able to.

(7) The first load circuit 1 uses the main battery (lead battery 11) as a power source and connects the first load (starter motor 12, load actuator 13) necessary for the continuation of the normal operation mode by the driver.
The second load circuit 2 uses an additional battery (lithium ion battery 21) as a power source and connects a second load (automatic operation function load) that is necessary for the continuation of the automatic operation mode and that needs to maintain the voltage. .
The circuit interrupting mechanism 3 connects or disconnects the first load circuit 1 and the second load circuit 2.
The control unit 4 performs intermittent control of the circuit intermittent mechanism 3.
In this automatic driving vehicle power supply control device, the control unit 4 controls the first load from the additional battery (lithium ion battery 21) based on the load state detected on the second load circuit 2 side while the circuit interrupting mechanism 3 is connected. When it is determined that power is to be taken out to the circuit 1, the control process for shutting off the circuit interrupting mechanism 3 is executed (FIG. 2).
Therefore, it is possible to provide a control device for an automatic driving vehicle power source that prevents the additional battery (lithium ion battery 21) from increasing in capacity while ensuring the continuation of the automatic driving function.

  The second embodiment is an example in which, after the circuit breaking mechanism is cut off, the determination of the return condition to the connection is made by the battery capacity instead of the battery voltage of the first embodiment.

  First, the configuration will be described. The control method of the automatic driving vehicle power source and the “power system configuration” in the control device in the second embodiment are the same as those in the first embodiment, and the illustration and description are omitted.

[Connection / disconnection control processing configuration of circuit interruption mechanism]
FIG. 4 shows a flow of connection / disconnection control processing of the circuit interrupt mechanism 3 executed in the control unit 4 of the second embodiment. Hereinafter, each step of FIG. 4 showing the connection / disconnection control processing configuration of the circuit interruption mechanism 3 will be described. Each of step S21 to step S25 corresponds to each step of step S1 to step S5 in FIG. 2, and each of step S27 to step S32 corresponds to each step of step S7 to step S12 in FIG. Therefore, description of these steps is omitted.

In step S26, following the interruption of the circuit interruption mechanism 3 in step S25, it is determined whether or not the battery capacity of the lithium ion battery 21 is equal to or less than the capacity B ′. If YES (battery capacity ≦ capacity B ′), the process proceeds to step S29. If NO (battery capacity> capacity B ′), the process proceeds to step S27.
Here, “battery capacity” is obtained by using the voltage / capacity conversion map shown in the middle of FIG. 5 for the battery voltage obtained from the sensor information from the battery voltage sensor 45. As shown in FIG. 5, “capacitance B ′” is a capacity corresponding to “voltage B” determined based on the method of determining the voltage threshold shown in FIG. That is, it is the battery capacity of the lithium ion battery 21 that reaches the capacity C ′ when the automatic driving function load is activated within an assumed time.

  Next, the operation of the second embodiment will be described. In the second embodiment, when the circuit interrupting mechanism 3 is interrupted and the battery capacity of the lithium ion battery 21 becomes equal to or less than the capacity B ′, a warning for prompting the driver to shift to the normal operation mode is issued. When the transition to the normal operation mode is confirmed before the predetermined time elapses after the warning is issued, the circuit interruption mechanism 3 is connected.

That is, if the automatic operation mode is continued while the circuit interrupting mechanism 3 is cut off, the lithium ion battery 21 is not recharged during the operation of the automatic operation function load, so the battery capacity of the lithium ion battery 21 during the automatic operation mode. May become less than the capacity B ′. When the battery capacity becomes equal to or less than the capacity B ′, the lithium ion battery 21 can be recharged by shifting to the normal operation mode and connecting the circuit interruption mechanism 3.
Since other operations are the same as those of the first embodiment, description thereof is omitted.

  In the control method and the control device for the automatic driving vehicle power source in the second embodiment, the effects (1) to (7) in the first embodiment can be obtained.

  As mentioned above, although the control method and control apparatus of the automatic driving vehicle power supply of this invention were demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Claim Modifications and additions of the design are permitted without departing from the spirit of the invention according to each claim in the scope of the above.

  In Example 1 and Example 2, the example which uses the lead battery 11 as a main battery was shown. However, the main battery may be an example using a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

  In Example 1 and Example 2, the example which uses the lithium ion battery 21 as an additional battery was shown. However, as the additional battery, a plurality of batteries may be used, an example in which a capacitor and a DC / DC converter are combined, or an example in which a nickel metal hydride battery is used may be used.

  In Example 1 and Example 2, the example using the alternator 11 as the generator of the first load circuit 1 was shown. However, a generator or a motor generator may be used as the generator of the first load circuit.

  In the first embodiment and the second embodiment, an example in which an EPS actuator, an ABS actuator, and an ADAS actuator are used as the automatic operation function load that is the second load has been described. However, the automatic driving function load as the second load may be changed according to the vehicle specification or the automatic driving function specification.

  In Example 1 and Example 2, the example using the mechanism by a relay switch as the circuit interruption mechanism 3 was shown. However, the circuit interrupting mechanism may be a mechanism having a circuit configuration that uses a semiconductor such as a diode or FET and behaves like a relay switch.

  Example 1 and Example 2 show an example in which the circuit interrupting mechanism 3 is interrupted when any one of the three conditions is established during connection of the circuit interrupting mechanism 3 as the interrupting control of the circuit interrupting mechanism 3. It was. However, as the interruption control of the circuit interruption mechanism, it is determined that power is taken out from the additional battery to the first load circuit side based on the load state detected on the second load circuit side while the circuit interruption mechanism is connected. Other conditions may be added. In addition, for reasons such as detection of the presence or absence of a failure, control for switching to a shut-off state may be added even if the connection state is possible.

  In the first embodiment and the second embodiment, the example in which the control method and the control device for the automatic driving vehicle power supply according to the present invention are applied to the engine-equipped vehicle on which the engine is mounted is shown. However, the control method and the control device for the autonomous driving vehicle power supply according to the present invention can be applied not only to an engine vehicle and a hybrid vehicle equipped with an engine but also to an electric vehicle and a fuel cell vehicle.

  In the first and second embodiments, when the automatic driving mode is selected while the automatic driving vehicle power supply control method and control device of the present invention is running, the driver does not need steering operation, accelerator operation, or brake operation. An example of applying to an autonomous driving vehicle having a driving function was shown. However, the control method and the control device for the automatic driving vehicle power supply according to the present invention include a semi-automatic driving vehicle having an automatic driving function that allows an operation intervention by the driver for a part of the driver operations during driving, The present invention can also be applied to a vehicle called a driving assistance vehicle. In short, the present invention can be applied to a vehicle having an automatic driving vehicle power source having a circuit interrupting mechanism between a first load circuit using a main battery as a power source and a second load circuit using an additional battery as a power source.

1 First load circuit 11 Lead battery (main battery)
12 Starter motor (first load)
13 Load actuator (first load)
14 Alternator (generator)
2 Second load circuit 21 Lithium ion battery (additional battery)
22 EPS actuator (second load, automatic operation function load)
23 ABS actuator (second load, automatic operation function load)
24 ADAS actuator (second load, automatic operation function load)
3 Circuit interrupting mechanism 4 Control unit 41 Current sensor 42 Automatic operation mode switch 43 First voltage sensor 44 Second voltage sensor 45 Battery voltage sensor 46 Brake switch 47 Torque sensor 48 Other sensors / switches 49 Indicator 50 Buzzer

Claims (7)

The main battery is the power source, and the first load circuit that connects the first load necessary for the driver to continue the normal operation mode and the additional battery are the power sources. A second load circuit for connecting a required second load;
A circuit interrupting mechanism for connecting or disconnecting the first load circuit and the second load circuit;
In a method of controlling an autonomous driving vehicle power supply having
When it is determined that power is taken out from the additional battery to the first load circuit side based on a load state detected on the second load circuit side during connection of the circuit interruption mechanism, the circuit interruption mechanism A method for controlling an autonomous driving vehicle power supply characterized by shutting off the power. In the control method of the automatic driving vehicle power supply according to claim 1,
When the circuit voltage of the second load circuit decreases during connection of the circuit interrupting mechanism, the circuit interrupting mechanism is interrupted at a timing when the circuit voltage decreases. In the control method of the automatic driving vehicle power supply according to claim 1,
When a current flows from the second load circuit toward the first load circuit during connection of the circuit interrupting mechanism, the circuit interrupting mechanism is interrupted at a timing when the current flows. Control method. In the control method of the automatic driving vehicle power supply according to claim 1,
An automatic driving vehicle power supply control method characterized in that the circuit interrupting mechanism is interrupted when the second load that exhibits an automatic driving function is in operation while the circuit interrupting mechanism is connected. In the control method of the automatic driving vehicle power supply according to any one of claims 1 to 4,
When the circuit interrupting mechanism is interrupted and the battery voltage or the battery capacity of the additional battery is equal to or less than a predetermined value, a warning that prompts the driver to shift to the normal operation mode is issued,
After the warning is issued, when the transition to the normal operation mode is confirmed before a predetermined time elapses, the circuit intermittent mechanism is connected. In the control method of the automatic driving vehicle power supply according to claim 5,
After the warning is issued, if the transition to the normal operation mode is not confirmed until the predetermined time elapses, automatic braking control is executed to automatically stop the vehicle after the predetermined time elapses. Vehicle power control method. The main battery is the power source, and the first load circuit that connects the first load necessary for the driver to continue the normal operation mode and the additional battery are the power sources. A second load circuit for connecting a required second load;
A circuit interrupting mechanism for connecting or disconnecting the first load circuit and the second load circuit;
A control unit for performing intermittent control of the circuit intermittent mechanism;
In a control device for an autonomous driving vehicle power supply having
When it is determined that the control unit is carrying out power from the additional battery to the first load circuit side based on a load state detected on the second load circuit side while the circuit interrupting mechanism is connected. A control process for shutting off the circuit interrupting mechanism is executed.