JP2016124444A - Power supply control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable communication between apparatuses even if an abnormality occurs in a power supply system of a vehicle.SOLUTION: Power supply control devices (100, 200) comprise first batteries (12) which are electrically connected in parallel with each other, second batteries (14), first communication means (13), second communication means (15), and power generation means (11). The first communication means and the second communication means are mounted to a vehicle in which the means are constituted so as to be communicable to each other by a pulse modulation system. The power supply control devices comprise voltage adjustment means (11, 16) which can adjust at least either of a first voltage applied to the first communication means and a second voltage applied to the second communication means, and control means (13, 15) which control the voltage adjustment means so that a voltage difference becomes smaller than a prescribed value on a condition that the voltage difference between the first voltage and the second voltage is larger than the prescribed value when there occur open failures in the second batteries.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technical field of a power supply control device that controls a power supply mounted on a vehicle.

  This type of device includes, for example, a plurality of ECUs (Electronic Control Units) each having an auxiliary battery, and a vehicle-mounted battery that supplies power to the plurality of ECUs. In such a case, a device has been proposed in which a plurality of ECUs receive power supply from their respective auxiliary batteries and maintain communication with other ECUs (see Patent Document 1).

  Alternatively, by providing a booster circuit in the ECU and inputting the voltage boosted by the booster circuit to the power supply circuit of the ECU when the input voltage of the ECU is lower than the operation guarantee voltage for the ECU An apparatus that guarantees the operation of the ECU has been proposed (see Patent Document 2).

JP 2002-261780 A JP 2013-220705 A

  In the technique described in Patent Document 1, when a certain time elapses after the power source is switched to the auxiliary battery, a voltage difference is generated between a voltage applied to one ECU and a voltage applied to another ECU. There is a technical problem that there is a possibility that appropriate communication may not be possible between the ECU and another ECU. With the technique described in Patent Document 2, it is difficult to solve this problem.

  The present invention has been made in view of the above problems, for example, and it is an object to provide a power supply control device that enables appropriate communication between in-vehicle devices even when an abnormality occurs in a power supply system. And

  In order to solve the above problems, a power supply control device according to the present invention includes a first battery, a second battery, a first communication unit, a second communication unit, and a power generation unit that are electrically connected in parallel to each other, The first communication means and the second communication means are a power supply control device in a vehicle configured to be able to communicate with each other by a pulse modulation method, and the first voltage and the first voltage that are applied to the first communication means A voltage adjusting means capable of adjusting at least one of a second voltage that is a voltage applied to the second communication means; the second battery; the second communication means; the first battery; the first communication means; When the electrical connection with the power generation means is interrupted and power is supplied to the second communication means only from the second battery, a voltage difference that is a difference between the first voltage and the second voltage is Greater than the specified value The conditions, as the voltage difference is less than the predetermined value, and a control means for controlling said voltage regulating means.

  A vehicle equipped with the power supply control device of the present invention includes a first battery, a second battery, a first communication unit, a second communication unit, and a power generation unit that are electrically connected in parallel to each other. . Here, the first communication unit and the second communication unit are configured to be able to communicate with each other by a pulse modulation method. Note that the vehicle may include three or more batteries.

  The voltage adjusting means is configured to be able to adjust at least one of a first voltage that is a voltage applied to the first communication means and a second voltage that is a voltage applied to the second communication means.

  For example, the control means comprising a memory, a processor, etc., is electrically disconnected from the second battery and the second communication means, and the first battery, the first communication means and the power generation means, When power is supplied only to the second battery from the second battery, the voltage difference is the predetermined value on condition that a voltage difference that is a difference between the first voltage and the second voltage is larger than a predetermined value. The voltage adjusting means is controlled so as to be less than.

  “When the electrical connection between the second battery and the second communication means and the first battery, the first communication means and the power generation means is interrupted”, the first communication means includes, for example, other than the second battery. Electric power is supplied from the first battery, power generation means, or the like.

  When the electrical connection between the second battery and the first battery and the power generation means is interrupted, the voltage of the second battery gradually decreases, and the second voltage applied to the second communication means and the first communication There is a difference between the first voltage applied to the means. However, in order to communicate using the pulse modulation method, the difference between the first voltage and the second voltage must be within an allowable range.

  Therefore, in the present invention, as described above, on the condition that the voltage difference, which is the difference between the first voltage and the second voltage, is larger than the predetermined value, the control means causes the voltage difference to be less than the predetermined value. The voltage adjusting means is controlled.

  Here, the “predetermined value” is a value that determines whether or not the voltage adjusting means is controlled so that the voltage difference between the first voltage and the second voltage is small, and is previously set as a fixed value or some physical quantity. Alternatively, it is set as a variable value according to the parameter. Such a “predetermined value” is obtained experimentally, empirically, or by simulation, for example, to obtain the relationship between the voltage difference between the first voltage and the second voltage and the communication quality, and based on the obtained relationship, What is necessary is just to set as a value smaller than the voltage difference corresponded to the boundary value of permissible communication quality.

  Therefore, even if the electrical connection between the second battery and the second communication means and the first battery, the first communication means and the power generation means is interrupted due to disconnection or disconnection of the terminal, for example, Communication can be appropriately performed between the communication unit and the second communication unit by a pulse modulation method.

  In one aspect of the power supply control device of the present invention, the voltage adjusting unit is configured integrally with the power generation unit, and the second battery and the second communication unit, the first battery, and the first communication unit. And when the electric connection with the power generation means is cut off and power is supplied only from the second battery to the second communication means, the control means is provided that the voltage difference is larger than a predetermined value. In addition, the voltage adjusting means is controlled so as to adjust the first voltage so that the voltage difference is less than the predetermined value.

  According to this aspect, when the electrical connection between the second battery and the second communication unit and the first battery, the first communication unit and the power generation unit is interrupted, the first voltage is relatively easily increased. The voltage difference between the second voltage and the second voltage can be less than a predetermined value, which is very advantageous in practice.

  The “voltage adjusting means configured integrally with the power generating means” corresponds to a generator having a voltage adjusting function, for example.

  Alternatively, in another aspect of the power supply control device of the present invention, the voltage adjusting means is a step-up / step-down element, the second battery and the second communication means, the first battery, the first communication means, When the electrical connection with the power generation means is cut off and power is supplied to the second communication means only from the second battery, the control means is conditioned on the condition that the voltage difference is greater than a predetermined value. The voltage adjusting means is controlled to adjust the second voltage so that the voltage difference is less than the predetermined value.

  According to this aspect, when the electrical connection between the second battery and the second communication unit and the first battery, the first communication unit and the power generation unit is interrupted, the first voltage is relatively easily increased. The voltage difference between the second voltage and the second voltage can be less than a predetermined value, which is very advantageous in practice.

  For example, a DCDC converter or the like can be applied to the “boost / buck element”.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a schematic structure figure showing the outline of the power supply control device concerning a 1st embodiment. It is a flowchart which shows the power supply control process which concerns on 1st Embodiment. It is a conceptual diagram which shows an example of the concept of the power supply control which concerns on 1st Embodiment. It is a conceptual diagram which shows the other example of the concept of the power supply control which concerns on 1st Embodiment. It is a schematic block diagram which shows the outline | summary of the power supply control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the power supply control process which concerns on 2nd Embodiment. It is a conceptual diagram which shows an example of the concept of the power supply control which concerns on 2nd Embodiment. It is a conceptual diagram which shows the other example of the concept of the power supply control which concerns on 2nd Embodiment.

  An embodiment according to a power supply control device of the present invention will be described with reference to the drawings.

<First Embodiment>
A first embodiment of the power supply control device of the present invention will be described with reference to FIGS.

(Constitution)
The configuration of the power supply control apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram illustrating an overview of the power supply control device according to the first embodiment.

  In FIG. 1, the vehicle on which the power supply control device 100 is mounted includes an alternator 11, a lead battery 12, a first ECU 13, a second battery 14, and a second ECU 15. The alternator 11, the lead battery 12, the first ECU 13, the second battery 14, and the second ECU 15 are electrically connected to each other in parallel. The vehicle is not limited to the lead battery 12 and the second battery 14, and may include three or more batteries.

  The switch SW is configured to be able to switch between energization and interruption between the alternator 11, the lead battery 12 and the first ECU 13, and the second battery 14. Note that the description of the control processing of the switch SW is omitted because it is not relevant to the present embodiment.

  The first ECU 13 is an ECU that controls an auxiliary machine (not shown) such as a shift-by-wire. The vehicle is not limited to the first ECU 13 and the second ECU 15, and may include three or more ECUs.

  The second battery 14 is a battery having an OCV characteristic similar to the OCV (Open Circuit Voltage) characteristic of the lead battery 12 such as a lithium ion battery or a nickel metal hydride battery.

  Here, in particular, the second ECU 15 is built in the second battery 14. That is, the second ECU 15 is an ECU dedicated to the second battery 14. Further, the second ECU 15 and the first ECU 13 are configured to be able to communicate with each other by a pulse modulation (PWM) system via a signal line.

  The first ECU 13 and the second ECU 15 transmit a state (for example, an applied voltage) to each other via a signal line. For example, when an abnormality occurs in the lead battery 12 and its function is lost, the second ECU 15 detects the abnormality of the lead battery 12 and, for example, power is supplied from the second battery 14 to the first ECU 13 or the like. Perform a predetermined power backup.

  The “alternator 11”, “lead battery 12”, “first ECU 13”, and “second ECU 15” according to the embodiment are respectively referred to as “power generation means”, “first battery”, “first communication means” according to the present invention. "And" second communication means ".

  The power supply control device 100 includes an alternator 11, a first ECU 13, a second ECU 15, and voltage sensors 21 and 22. Here, the “alternator 11” according to the present embodiment is an example of the “voltage adjusting unit” according to the present invention. The “first ECU 13” and the “second ECU 15” according to the present embodiment are examples of the “control unit” according to the present invention. That is, in this embodiment, some of the functions of the first ECU 13 and the second ECU 15 for various electronic controls of the vehicle are used as part of the function of the power supply control device 100.

(Power control processing)
Next, power control processing performed by the power control device 100 configured as described above will be described with reference to FIGS.

  For example, the ground line of the second battery 14 is disconnected (for example, the portion surrounded by the dotted circle C1 in FIG. 1 is disconnected), and the second battery 14 is electrically connected to the alternator 11, the lead battery 12, and the first ECU 13. Is disconnected, or the positive line of the second battery 14 is disconnected (for example, the portion surrounded by the dotted circle C2 in FIG. 1 is disconnected) and the switch SW is in the open state, or 2 When the terminal of the battery 14 is disconnected, electric power is supplied to the second ECU 15 only from the second battery 14, so that there is a voltage difference between the applied voltage of the first ECU 13 and the applied voltage of the second ECU 15 over time. As a result, communication between the first ECU 13 and the second ECU 15 becomes impossible. Then, for example, control of the switch SW, diagnosis, etc. cannot be performed.

  Therefore, when the second ECU 15 detects disconnection of the ground line or the positive electrode line of the second battery 14 or disconnection of the terminal (hereinafter referred to as “open failure” as appropriate), the output from the voltage sensor 22 to the first ECU 13. A signal indicating the voltage of the second battery 14 based on (that is, the applied voltage V2 of the second ECU 15) is transmitted via the signal line.

  The first ECU 13 compares the applied voltage V1 of the first ECU 13 based on the output from the voltage sensor 21 with the applied voltage V2 of the second ECU 15, and on the condition that the voltage difference is greater than a predetermined value V0, the voltage difference is the predetermined voltage. The generated voltage of the alternator 11 is controlled so as to be less than the value V0.

  Here, the “predetermined value V0” is, for example, several volts, and the relationship between the communication voltage and the voltage difference between the applied voltage V1 and the applied voltage V2 is obtained, for example, experimentally or empirically or by simulation. On the basis of the relationship, a value smaller than a voltage difference corresponding to an allowable communication quality boundary value is set.

  Therefore, since the voltage difference between the applied voltage V1 and the applied voltage V2 can be kept relatively small, it is possible to appropriately communicate between the first ECU 13 and the second ECU 15 even after the open failure of the second battery 14.

  The power supply control process according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 2, the second ECU 15 determines whether or not an open failure has occurred in the second battery 14 (step S101). When it is determined that an open failure has not occurred (step S101: No), the second ECU 15 once ends the process, and performs the process of step S101 again after a predetermined time has elapsed.

  On the other hand, when it is determined that an open failure has occurred (step S101: Yes), the second ECU 15 transmits a signal indicating the applied voltage V2 to the first ECU 13 via the signal line. The first ECU 13 determines whether or not the voltage difference obtained by subtracting the applied voltage V1 from the applied voltage V2 is greater than a predetermined value V0 (step S102).

  When it is determined that the voltage difference is less than the predetermined value V0 (step S102: No), the first ECU 13 once ends the process, and performs the process of step S102 again after a predetermined time has elapsed. On the other hand, when it is determined that the voltage difference is greater than the predetermined value V0 (step S102: Yes), the first ECU 13 determines whether or not the applied voltage V2 is within the control range of the power generation voltage of the alternator 11 (step). S103).

  Here, “the control range of the power generation voltage of the alternator 11” typically means a control range of a voltage that can be tolerated by the power supply system of the vehicle. For example, a voltage that can be indicated by a circuit including the alternator 11 It may be a control range.

  When it is determined that the applied voltage V2 is not within the control range of the power generation voltage of the alternator 11 (step S103: No), the first ECU 13 once ends the process, and performs the process of step S102 again after a predetermined time has elapsed. .

  On the other hand, when it is determined that the applied voltage V2 is within the control range of the generated voltage of the alternator 11 (step S103: Yes), the first ECU 13 changes the generated voltage of the alternator 11 to the applied voltage V2 (step S104). . Thereafter, the first ECU 13 performs the process of step S102.

  Here, the effect of the process of step S104 will be described with reference to FIGS.

  The variation of the applied voltages V1 and V2 when the open failure is the disconnection of the ground line of the second battery 14 will be described with reference to FIG.

  Before an open failure occurs in the second battery 14, as shown in FIG. 3A, the positive potential (+ B) and ground potential (GND) of the applied voltage V1, the positive potential (+ B) of the applied voltage V2, and It matches the ground potential (GND).

  When the ground line of the second battery 14 is disconnected, the potential on the positive electrode side of the second battery 14 is the same as that of the first ECU 13 and the like, and therefore when the voltage of the second battery 14 decreases, it is shown in FIG. Thus, the ground potential of the applied voltage V1 and the ground potential of the applied voltage V2 do not match.

  Therefore, when the power generation voltage of the alternator 11 is changed by the first ECU 13, the applied voltage V1 is lowered, and as shown in FIG. 3C, the difference between the ground potential of the applied voltage V1 and the ground potential of the applied voltage V2. Is reduced.

  On the other hand, fluctuations in the applied voltages V1 and V2 when the open failure is the disconnection of the positive electrode line of the second battery 14 and the switch SW is in the open state will be described with reference to FIG.

  Before an open failure occurs in the second battery 14, as shown in FIG. 4A, the positive potential (+ B) and ground potential (GND) of the applied voltage V1, the positive potential (+ B) of the applied voltage V2, and It matches the ground potential (GND).

  When the positive electrode line of the second battery 14 is disconnected, the potential on the ground side of the second battery 14 is the same as that of the first ECU 13 and the like. Therefore, when the voltage of the second battery 14 decreases, the voltage shown in FIG. As described above, the positive potential of the applied voltage V1 and the positive potential of the applied voltage V2 are inconsistent.

  Therefore, when the power generation voltage of the alternator 11 is changed by the first ECU 13, the applied voltage V1 is lowered, and as shown in FIG. 4C, the difference between the positive potential of the applied voltage V1 and the positive potential of the applied voltage V2. Is reduced.

  The “applied voltage V1” and “applied voltage V2” according to the present embodiment are examples of the “first voltage” and the “second voltage” according to the present invention, respectively.

  In the present embodiment, “first ECU 13” and “second ECU 15” are given as an example of “first communication means” and “second communication means”, but are not limited to “first ECU 13” and “second ECU 15”. For example, a sensor having a communication function may be used.

Second Embodiment
A second embodiment according to the power supply control apparatus of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the configuration of the power supply control device is partially different. Therefore, the description overlapping with that of the first embodiment is omitted, and the same place on the drawing is omitted. The second embodiment will be described with reference to FIGS. 5 to 8 only for parts that are basically different from the first embodiment.

  In FIG. 5, the power supply control device 200 according to this embodiment includes an alternator 11, a first ECU 13, a second ECU 15, a DCDC converter 16, and voltage sensors 21 and 22. Here, the DCDC converter 16 is built in the second battery 14. The “DCDC converter 16” according to the present embodiment is another example of the “voltage adjusting unit” according to the present invention, and is an example of the “boost / step-down element” according to the present invention.

  Particularly in the present embodiment, when an open failure occurs in the second battery 14, the generated voltage of the alternator 11 so that the voltage difference between the applied voltage V1 of the first ECU 13 and the applied voltage V2 of the second ECU 15 is less than a predetermined value V0. Alternatively, the adjustment voltage of the DCDC converter 16 is changed.

  The power supply control process according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 5, when it is determined in step S103 that the applied voltage V2 is not within the control range of the power generation voltage of the alternator 11 (step S103: No), the first ECU 13 notifies the second ECU 15 to that effect. And a signal indicating the applied voltage V1 are transmitted through the signal line. The second ECU 15 determines whether or not the applied voltage V1 is within the control range of the adjustment voltage of the DCDC converter 16 (step S201).

  When it is determined that the applied voltage V1 is not within the control range of the adjustment voltage of the DCDC converter 16 (step S201: No), the second ECU 15 once ends the process. On the other hand, when it is determined that the applied voltage V1 is within the control range of the adjustment voltage of the DCDC converter 16 (Step S201: Yes), the second ECU 15 changes the adjustment voltage of the DCDC converter 16 to the application voltage V1 (Step S201). S202).

  Here, the effect of the process of step S202 will be described with reference to FIGS.

  Variations in the applied voltages V1 and V2 when the open failure is the disconnection of the ground line of the second battery 14 will be described with reference to FIG.

  Before an open failure occurs in the second battery 14, as shown in FIG. 7A, the positive potential (+ B) and ground potential (GND) of the applied voltage V1, and the positive potential (+ B) of the applied voltage V2 and It matches the ground potential (GND).

  When the ground line of the second battery 14 is disconnected, the potential on the positive electrode side of the second battery 14 is the same as that of the first ECU 13 and the like, and therefore when the voltage of the second battery 14 decreases, it is shown in FIG. Thus, the ground potential of the applied voltage V1 and the ground potential of the applied voltage V2 do not match.

  Accordingly, the adjustment voltage of the DCDC converter 16 is changed by the second ECU 15 to boost the applied voltage V2, and as shown in FIG. 7C, the ground potential of the applied voltage V1 and the ground potential of the applied voltage V2 are increased. The difference is reduced.

  On the other hand, fluctuations in the applied voltages V1 and V2 when the open failure is the disconnection of the positive electrode line of the second battery 14 and the switch SW is in the open state will be described with reference to FIG.

  Before an open failure occurs in the second battery 14, as shown in FIG. 8A, the positive potential (+ B) and ground potential (GND) of the applied voltage V1, the positive potential (+ B) of the applied voltage V2, and It matches the ground potential (GND).

  When the positive line of the second battery 14 is disconnected, the ground-side potential of the second battery 14 is the same as that of the first ECU 13 and the like, and therefore, when the voltage of the second battery 14 decreases, FIG. As described above, the positive potential of the applied voltage V1 and the positive potential of the applied voltage V2 are inconsistent.

  Therefore, the adjustment voltage of the DCDC converter 16 is changed by the second ECU 15 to boost the applied voltage V2, and as shown in FIG. 8C, the positive potential of the applied voltage V1 and the positive potential of the applied voltage V2 are increased. The difference is reduced.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Alternator, 12 ... Lead battery, 13 ... 1ECU, 14 ... 2nd battery, 15 ... 2ECU, 16 ... DCDC converter, 21, 22 ... Voltage sensor, 100, 200 ... Power supply control apparatus

Claims (3)

A first battery, a second battery, a first communication means, a second communication means, and a power generation means, which are electrically connected in parallel with each other, wherein the first communication means and the second communication means are in accordance with a pulse modulation method; A power supply control device in a vehicle configured to be able to communicate with each other,
Voltage adjusting means capable of adjusting at least one of a first voltage which is a voltage applied to the first communication means and a second voltage which is a voltage applied to the second communication means;
The electrical connection between the second battery and the second communication means and the first battery, the first communication means and the power generation means is cut off, and power is supplied to the second communication means from only the second battery. Is supplied, the voltage adjusting means is set so that the voltage difference is less than the predetermined value on condition that a voltage difference that is a difference between the first voltage and the second voltage is larger than a predetermined value. Control means for controlling;
A power supply control device comprising: The voltage adjustment means is configured integrally with the power generation means,
The electrical connection between the second battery and the second communication means and the first battery, the first communication means and the power generation means is cut off, and power is supplied to the second communication means from only the second battery. Is supplied, the control means adjusts the first voltage so that the voltage difference is less than the predetermined value on the condition that the voltage difference is larger than a predetermined value. It controls. The power supply control apparatus of Claim 1 characterized by the above-mentioned. The voltage adjusting means is a step-up / step-down element,
The electrical connection between the second battery and the second communication means and the first battery, the first communication means and the power generation means is cut off, and power is supplied to the second communication means from only the second battery. Is supplied, the control means adjusts the second voltage so that the voltage difference is less than the predetermined value on the condition that the voltage difference is larger than a predetermined value. It controls. The power supply control apparatus of Claim 1 characterized by the above-mentioned.

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