JP2014151695A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle including an engine and motor as a driving source, and avoid unnecessary restriction to be imposed on restart of an engine succeeding initiation of evacuation travel (battery-less travel).SOLUTION: A hybrid vehicle includes: a battery; an engine that is started through cranking to be performed using power of the battery; a first motor generator capable of generating electricity using the power of the engine; a second motor generator capable of being driven with the power fed from at least one of the battery and first motor generator; a monitoring unit that monitors the state of the battery; and an ECU. If an abnormality occurs in the battery, the ECU calculates a permissible number of times of cranking Nc on the basis of the storage capacity (SOC) of the battery observed immediately prior to the occurrence of the abnormality (S12), permits cranking (restart) of the engine according to whether the number of times of cranking performed after the occurrence of the abnormality has reached the permissible number of times Nc (S13), and decides whether or not to make a transition to battery-less travel (S14).

Description

  The present invention relates to a vehicle (so-called hybrid vehicle) including an engine and a motor as drive sources.

  In Japanese Unexamined Patent Publication No. 2010-111291 (Patent Document 1), in a hybrid vehicle including an engine and a motor as a drive source, when the motor is driven by battery power after the engine malfunctions, It is disclosed that the number of engine restarts after the start of evacuation travel is limited to a predetermined allowable number.

JP 2010-1111291 A Japanese Patent Laid-Open No. 11-173179

  As described above, in the hybrid vehicle disclosed in Patent Document 1, the number of engine restarts after the start of evacuation travel is limited to a predetermined permissible number. It is a value determined from the lower limit of use (fixed value) or the like, and is not a value according to the actual battery storage amount (variation value). Therefore, when the actual amount of electricity stored in the battery is larger than the lower limit value of use, the restart of the engine is unduly limited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to avoid unduly limiting restarting of the engine after the start of retreat travel.

  The vehicle according to the present invention can be driven by electric power from a battery, an engine that is started by cranking using electric power of the battery, a generator that can generate electric power using the power of the engine, and at least one of the battery and the generator. A motor, a monitoring device that monitors the state of the battery, and a control device that controls the engine, the motor, and the generator are provided. When an abnormality occurs in at least one of the battery and the monitoring device, the control device calculates the allowable number of cranking according to the storage amount of the battery before the abnormality occurs, and the number of cranking after the occurrence of the abnormality reaches the allowable number. If it is not, start the engine by cranking and use the power generated by the generator to drive the motor without using the battery power. Do not run without battery without allowing ranking.

  According to the present invention, it is possible to avoid unduly restricting restart of the engine after the start of retreat travel (battery-less travel).

1 is an overall block diagram of a vehicle. It is a flowchart (the 1) which shows an example of the process sequence of ECU. It is a figure for demonstrating operation | movement of ECU. It is a flowchart (the 2) which shows an example of the process sequence of ECU.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is an overall block diagram of a vehicle 1 according to the present embodiment. The vehicle 1 includes an engine 100, a first motor generator (hereinafter referred to as “first MG”) 200, a power split mechanism 300, a second motor generator (hereinafter referred to as “second MG”) 400, an output shaft 560, a power A control unit (hereinafter referred to as “PCU”) 600, a battery 700, a system main relay (hereinafter referred to as “SMR”) 710, a monitoring unit 720, and a control device (hereinafter referred to as “ECU”) 1000 are provided.

  The engine 100 is an internal combustion engine that outputs power by burning fuel. The power of engine 100 is input to power split device 300.

  Power split device 300 splits the power input from engine 100 into power to output shaft 560 and power to first MG 200.

  Power split device 300 rotates sun gear (S) 310, ring gear (R) 320, pinion gear (P) 340 meshed with sun gear (S) 310 and ring gear (R) 320, and pinion gear (P) 340. It is a planetary gear mechanism having a carrier (C) 330 that is held to revolve freely.

  Carrier (C) 330 is connected to the crankshaft of engine 100. Sun gear (S) 310 is coupled to the rotor of first MG 200. Ring gear (R) 320 is connected to output shaft 560.

  The first MG 200 and the second MG 400 are AC rotating electrical machines, and function as both an electric motor (motor) and a generator (generator). First MG 200 is mainly controlled to function as a generator that generates electric power using the power of engine 100 transmitted through power split device 300. In the present embodiment, first MG 200 also functions as a motor for cranking engine 100. That is, when cranking engine 100, first MG 200 is driven by the electric power of battery 700, and cranking torque is applied to engine 100 from first MG 200. When the rotational speed of engine 100 increases to a predetermined speed due to cranking torque from first MG 200, fuel control of engine 100 is started and engine 100 is started.

  The rotor of second MG 400 is connected to output shaft 560. Output shaft 560 is rotated by at least one of the power of engine 100 and the power of second MG 400 transmitted through power split device 300. The rotational force of the output shaft 560 is transmitted to the left and right drive wheels 82 via the speed reducer 81. Thereby, the vehicle 1 travels.

  By configuring power split mechanism 300 as described above, the rotational speed of sun gear (S) 310 (= the rotational speed of first MG 200), the rotational speed of carrier (C) 330 (= the rotational speed of engine 100), the ring gear (R) The rotational speed of 320 (= the rotational speed of the second MG 400, that is, the vehicle speed) is a straight line on the alignment chart of the power split mechanism 300 (if any two rotational speeds are determined, the remaining rotational speed is also Determined relationship).

  PCU 600 converts high-voltage DC power supplied from battery 700 into AC power and outputs the AC power to first MG 200 and / or second MG 400. Thereby, first MG 200 and / or second MG 400 is driven. PCU 600 converts AC power generated by first MG 200 and / or second MG 400 into DC power and outputs the DC power to battery 700. Thereby, the battery 700 is charged.

  Battery 700 stores high-voltage (for example, about 200 V) DC power for driving first MG 200 and / or second MG 400. The battery 700 typically includes nickel metal hydride and lithium ions. Note that a large-capacity capacitor may be used instead of the battery 700.

  SMR 710 is a relay for switching connection and disconnection between battery 700 and PCU 600. SMR 710 includes two relays respectively provided on two power lines connecting battery 700 and PCU 600. When SMR 710 is off (at least one of the two relays is off), battery 700 is disconnected from PCU 600. When SMR 710 is on (both the two relays are on), battery 700 is connected to PCU 600. SMR 710 is controlled in accordance with a control signal from ECU 1000.

  The monitoring unit 720 monitors the state of the battery 700 (for example, the current, voltage, temperature, etc. of the battery 700). The monitoring unit 720 is configured to be able to communicate with the ECU 1000 via a CAN (Controller Area Network). The monitoring unit 720 outputs the monitoring result of the battery 700 to the ECU 1000 by CAN communication.

  The ECU 1000 is connected to an accelerator position sensor 31, an ignition (hereinafter referred to as “IG”) switch 32, and the like.

  The accelerator position sensor 31 detects the actual accelerator opening A (actual operation amount of the accelerator pedal by the user) and outputs the detection result to the ECU 1000.

  The IG switch 32 is a switch for the user to perform an operation for switching between a vehicle travelable state (hereinafter also referred to as “Ready-ON state”) and a vehicle travel impossible state (hereinafter also referred to as “Ready-OFF state”). It is. The IG switch 32 outputs a signal IG corresponding to the user operation to the ECU 1000.

  ECU 1000 includes a CPU (Central Processing Unit) and an internal memory (not shown), executes predetermined arithmetic processing based on information stored in the memory and information from each sensor, and each device based on the result of the arithmetic processing To control. For example, ECU 1000 calculates the amount of power stored in battery 700 (hereinafter referred to as “SOC”) based on information from monitoring unit 720.

  When the user presses the IG switch 32 in the Ready-OFF state, an IG relay (not shown) is turned on (closed), and the vehicle control system including the ECU 1000 is activated. When the activated ECU 1000 switches the SMR 710 from the off state to the on state, the battery 700 is connected to the PCU 600 and enters the Ready-ON state.

  Next, battery-less traveling will be described. ECU 1000 determines whether or not battery 700 has an abnormality (for example, whether it is an overvoltage) based on information received from monitoring unit 720 by CAN communication. When an abnormality occurs in battery 700, ECU 1000 causes vehicle 1 to retreat while SMR 710 is turned off and battery 700 is disconnected from PCU 600. This retreat travel is “battery-less travel”.

  Since the electric power of battery 700 cannot be used during battery-less traveling, second MG 400 is driven by the electric power generated by first MG 200 using the power of engine 100. Therefore, when shifting to battery-less running, ECU 1000 drives first MG 200 using the power of battery 700 before cranking SMR 710 to crank engine 100, and engine 100 is started by cranking. After that, the SMR 710 is turned off to shift to battery-less running.

  Thus, when shifting to battery-less travel, it is necessary to crank engine 100 using the electric power of battery 700. Therefore, conventionally, the allowable number of cranking is determined in advance based on the lower limit value (fixed value) of use of the SOC, and when the number of cranking after the occurrence of the abnormality reaches the allowable number, the engine 100 is restarted ( Transition to battery-less driving). However, in such conventional control, the allowable number of cranking becomes a fixed value regardless of the actual SOC. Therefore, when the actual SOC is larger than the lower limit value of use, there is a problem that restart of engine 100 is unreasonably restricted and the number of times of batteryless traveling is reduced.

  In view of such a problem, when an abnormality occurs in battery 700, ECU 1000 according to the present embodiment allows cranking based on the SOC (variable value) immediately before the occurrence of the abnormality, not the lower limit value (fixed value) of use of SOC. The number of times Nc is calculated, and it is determined whether or not the restart of the engine 100 (shift to battery-less travel) is permitted depending on whether or not the actual number of cranking after the occurrence of an abnormality has reached the allowable number of times Nc. This is the most characteristic point of the present invention.

  FIG. 2 is a flowchart illustrating an example of a processing procedure of the ECU 1000. This flowchart is repeatedly executed at a predetermined cycle in the Ready-ON state.

  In S10, ECU 1000 determines whether or not battery 700 is abnormal based on information from monitoring unit 720.

  If battery 700 is abnormal (YES in S10), ECU 1000 determines in S11 whether or not the allowable cranking count Nc stored at the end of the previous trip exists in the internal memory. Note that “trip” is a unit representing a travel period of the vehicle, and usually means a period from when the vehicle control system is started to when it is next stopped.

  If cranking allowable number Nc does not exist in the internal memory (NO in S11), ECU 1000 moves the process to S12, and is calculated based on information acquired from monitoring unit 720 immediately before the abnormality of battery 700 is detected. The cranking allowable number Nc is calculated according to the SOC. As described above, in the present embodiment, the cranking allowable number Nc is calculated based on the SOC (variable value) before the occurrence of an abnormality rather than the SOC use lower limit value (fixed value). Note that the cranking allowable number Nc may be calculated based on the voltage of the battery 700 acquired from the monitoring unit 720 immediately before the occurrence of the abnormality. Thereafter, the ECU 1000 moves the process to S13.

  On the other hand, when cranking allowable number Nc already exists in the internal memory (YES in S11), ECU 1000 moves the process to S13 without performing the process of S12.

  In S13, ECU 1000 determines whether or not cranking allowable number Nc is larger than zero. The allowable cranking count Nc is decremented by 1 every time cranking is executed in the process of S15 described later. Therefore, the cranking allowable number Nc being larger than 0 means that the actual cranking number after occurrence of an abnormality has not reached the cranking allowable number Nc.

  If allowable cranking number Nc is greater than 0 (YES in S13), that is, if the actual number of cranking after occurrence of abnormality does not reach allowable cranking number Nc, ECU 1000 shifts the process to S14.

  In S14, ECU 1000 determines whether or not a transition to battery-less travel is possible. For example, ECU 1000 determines that transition to battery-less travel is possible when the SOC is higher than a threshold value (for example, a lower limit value for use).

  If it is possible to shift to battery-less travel (YES in S14), ECU 1000 shifts the process to S15, executes cranking, and shifts to battery-less travel. At this time, the ECU 1000 subtracts the cranking allowable number Nc by 1 (Nc = Nc−1). In S16, ECU 1000 stores the cranking allowable number Nc in the internal memory at the end of the current trip.

  On the other hand, if cranking allowable number Nc is 0 (NO in S13), or if it is not possible to shift to batteryless running (NO in S14), ECU 1000 moves the process to S17, and batteryless running. In this case, the Ready-OFF state is set. As a result, the vehicle 1 cannot travel.

  If it is determined that battery 700 is not abnormal (YES in S10), ECU 1000 moves the process to S18 and clears (erases) the allowable cranking count Nc stored in the internal memory.

FIG. 3 is a diagram for explaining the operation of ECU 1000.
When the user performs an IG on operation (operation of pressing the IG switch 32 in the Ready-OFF state) at time t1, ECU 1000 is activated, and activated ECU 1000 turns on (closes) SMR 710. As a result, the Ready-ON state is established and the first trip is started. When the user performs an IG off operation (operation to press IG switch 32 in the Ready-ON state) at time t2, ECU 1000 turns off (opens) SMR 710. As a result, the Ready-OFF state is entered and the first trip is terminated. In the first trip, no abnormality of the engine 100 is detected. Therefore, engine 100 is operated as necessary.

  When the user performs the IG on operation at time t3, the second trip is started. When abnormality of battery 700 is detected at time t4, ECU 1000 calculates cranking allowable number Nc according to the SOC immediately before the occurrence of abnormality (immediately before time tt4). FIG. 3 shows an example in which the cranking allowable number Nc corresponding to the SOC immediately before the occurrence of the abnormality is calculated as “20”.

  Conventionally, even when the actual SOC is larger than the lower limit value of use, the allowable number of cranking is fixed to a value determined based on the lower limit value of use of SOC (“15” in the example shown in FIG. 3). It had been. Therefore, there has been a problem that cranking (engine restart) is unduly limited. On the other hand, in the present embodiment, since the allowable number of crankings Nc is a variable value corresponding to the actual SOC, the conventional problem is solved.

  Since the allowable cranking count Nc (= “20”) calculated at time t4 is greater than 0, the ECU 1000 executes the cranking and shifts to battery-less travel (retreat travel). At this time, the ECU 1000 subtracts the cranking allowable number Nc by 1 to obtain “19 (= 20−1)”. When the second trip is terminated at time t5, the cranking allowable number Nc (= “19”) at the end of the second trip is stored in the internal memory.

  When the third trip is started at time t6, the abnormality of the battery 700 continues, and the abnormality of the battery 700 is detected from the start of the third trip. The internal memory of ECU 1000 stores the cranking allowable number Nc (= “19”) at the end of the second trip, and this cranking allowable number Nc is larger than zero. Therefore, at time t7 immediately after time t6, ECU 1000 performs cranking and performs battery-less travel (retreat travel). At this time, the ECU 1000 subtracts 1 from the allowable cranking count Nc to obtain “18 (= 19−1)”.

  As described above, when an abnormality occurs in battery 700, ECU 1000 according to the present embodiment calculates cranking allowable number Nc based on the SOC (variable value) immediately before the occurrence of abnormality, and the number of cranking after the occurrence of abnormality. Determines whether or not to shift to battery-less travel by allowing cranking (restarting) of engine 100 according to whether or not the allowable number Nc has been reached. Therefore, it is possible to avoid that the cranking (restarting) of engine 100 is unduly limited and the number of battery-less travels is reduced.

<Modification>
In the process of “S10” in FIG. 2 described above, the presence / absence of an abnormality in the battery 700 is determined. It may be determined whether or not a CAN communication abnormality with the unit 720 has occurred.

  FIG. 4 is a flowchart illustrating an example of a processing procedure of ECU 1000 according to a modification of the present embodiment. The flowchart in FIG. 4 is obtained by changing S10 in FIG. 2 to S20. The other steps S11 to S18 are the same as those in FIG. 2 described above, and since they have already been described, detailed description thereof will not be repeated here.

  For example, when a CAN communication abnormality occurs between the ECU 1000 and the monitoring unit 720, the ECU 1000 cannot grasp the state of the battery 700, so it is desirable to retreat with battery-less travel.

  Therefore, ECU 1000 determines in S20 whether or not CAN communication abnormality with monitoring unit 720 has occurred. ECU 1000 moves the process to S11 if a CAN communication abnormality has occurred (YES in S20), and moves the process to S18 if no CAN communication abnormality has occurred (NO in S20). Thereby, even when a CAN communication abnormality (abnormality of the monitoring unit 720) occurs, it is possible to prevent the cranking (restarting) of the engine 100 from being unduly restricted.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 31 Accelerator position sensor, 32 IG switch, 81 Reducer, 82 Drive wheel, 100 Engine, 200 1st MG, 300 Power split mechanism, 400 2nd MG, 560 Output shaft, 600 PCU, 700 Battery, 720 Monitoring unit, 1000 ECU.

Claims (1)

Battery,
An engine that is started by cranking using the power of the battery;
A generator capable of generating electric power using the power of the engine;
A motor that can be driven by electric power from at least one of the battery and the generator;
A monitoring device for monitoring the state of the battery;
A control device for controlling the engine, the motor and the generator;
The control device calculates an allowable number of cranking according to a storage amount of the battery before the occurrence of an abnormality when at least one abnormality of the battery and the monitoring device occurs, and the number of times of cranking after the occurrence of the abnormality When the engine has not reached the allowable number of times, the engine is started by cranking and the motor is driven by the power generated by the generator without using the power of the battery. A vehicle in which the batteryless running is not performed without allowing the cranking when the number of rankings reaches the allowable number.

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