In-vehicle control device

Abstract

To more appropriately finish battery-less travel.SOLUTION: An on-vehicle control device is mounted on an automobile, together with an engine, an electric motor which is connected to a crank shaft of the engine and can generate power, a high voltage battery connected to the electric motor by a high voltage-based power line, a low voltage battery, a DC / DC converter which is connected to a low voltage-based power line connected to the high voltage power line and the low voltage battery, and a relay mounted on the high voltage battery side by the DC / DC converter of the high voltage-based power line. When finishing battery-less travel of turning off the relay, separating the high voltage battery and traveling, the on-vehicle control device stops driving of the electric motor and then stops driving of the DC / DC converter.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an on-board control device, and more particularly to an on-board control device mounted on an automobile having an electric motor capable of generating electricity connected to an engine crankshaft, a high-voltage battery connected to the electric motor, a low-voltage battery, and a DC / DC converter connected to a high-voltage power line and a low-voltage power line. [Background technology]

[0002] A conventional vehicle control device of this type is mounted on an automobile together with a planetary gear having three rotating elements connected to three axes: an engine, a first motor, and a drive shaft; a second motor connected to the drive shaft; and a high-voltage battery that exchanges power with the first and second motors (see, for example, Patent Document 1). In the event of an abnormality in the high-voltage battery, this vehicle control device turns off the system main relay to disconnect the high-voltage battery and performs batteryless running, in which all of the power generated by the first motor is consumed by the second motor. When terminating batteryless running, the vehicle control device determines whether the back electromotive force of the second motor is greater than the DC voltage, and while it is determined that the back electromotive force of the second motor is greater than the DC voltage, performs PWM control of the inverter so that the DC voltage is within a voltage range that allows PWM control to be continued. When the vehicle control device determines that the back electromotive force of the second motor is smaller than the DC voltage, it controls the inverter to reduce the DC voltage, and stops the inverter when the DC voltage reaches a predetermined stop voltage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-200582 Summary of the Invention [Problem to be solved by the invention]

[0004] Some on-board control devices have been proposed that are installed in automobiles together with the engine, automatic transmission, and other components, such as a generator-capable electric motor connected to the engine crankshaft and a high-voltage battery that supplies power to the electric motor. These automobiles often also include a low-voltage battery that supplies power to auxiliary equipment, and a DC / DC converter connected to a high-voltage power line connected to the high-voltage battery and a low-voltage power line connected to the low-voltage battery. Because these automobiles have different hardware configurations from the automobiles described in the background art, they cannot perform the same control when terminating batteryless running, and if batteryless running is not terminated appropriately, a load dump may occur.

[0005] The primary purpose of the vehicle control device disclosed herein is to more appropriately terminate battery-less driving in a vehicle equipped with a generating electric motor connected to the engine crankshaft and a high-voltage battery that exchanges electric power with the electric motor. [Means for solving the problem]

[0006] The in-vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The in-vehicle control device of the present disclosure includes: The engine and an electric motor capable of generating electricity connected to a crankshaft of the engine; a high-voltage battery connected to the electric motor by a high-voltage power line; A low voltage battery; a DC / DC converter connected to the high-voltage power line and a low-voltage power line connected to the low-voltage battery; a relay attached to the high-voltage power line on the high-voltage battery side of the DC / DC converter; An in-vehicle control device mounted on an automobile comprising: When the relay is turned off to terminate battery-less traveling, in which the vehicle travels while disconnecting the high-voltage battery, the driving of the electric motor is stopped and then the driving of the DC / DC converter is stopped. It is characterized by:

[0008] The on-board control device of the present disclosure is mounted on a vehicle together with an engine, an electric motor capable of generating electricity connected to the engine crankshaft, a high-voltage battery connected to the electric motor via a high-voltage power line, a low-voltage battery, a DC / DC converter connected to the high-voltage power line and a low-voltage power line connected to the low-voltage battery, and a relay attached to the high-voltage power line closer to the high-voltage battery than the DC / DC converter. When terminating batteryless running, in which the relay is turned off to run the vehicle while disconnecting the high-voltage battery, the on-board control device of the present disclosure stops driving the electric motor and then stops driving the DC / DC converter. This prevents load dump and enables batteryless running to be properly terminated.

[0009] In the on-board control device of the present disclosure, if the vehicle is equipped with a capacitor attached to the high-voltage power line closer to the DC / DC converter than the relay, when terminating the batteryless running, the drive of the electric motor may be stopped, the charge of the capacitor may be discharged, and then the drive of the DC / DC converter may be stopped. If a capacitor is attached to the high-voltage power line, the charge of the capacitor may be discharged and then the drive of the DC / DC converter may be stopped, thereby more appropriately discharging the capacitor and terminating the batteryless running. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing an outline of the configuration of an automobile 20 equipped with an in-vehicle control device according to an embodiment of the present disclosure. [Figure 2] 4 is a flowchart showing an example of a running end process executed by the main ECU 70 of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, an embodiment of the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of an automobile 20 equipped with an on-board control device according to an embodiment of the present disclosure. As shown in the figure, the automobile 20 of the embodiment includes an engine 22, a starter 25, a motor 30, an inverter 32, an automatic transmission 40, a high-voltage battery 50, a low-voltage battery 60, a DC / DC converter 66, and a main electronic control unit (hereinafter referred to as "main ECU") 70. In the embodiment, the main electronic control unit 70 corresponds to the on-board control device.

[0012] The engine 22 is configured as a multi-cylinder (four-cylinder, six-cylinder, etc.) internal combustion engine that uses gasoline, diesel, etc., supplied as fuel from a fuel tank via a fuel supply system. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24.

[0013] Although not shown, the engine ECU 24 is configured as a microcomputer centered around a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input port, an output port, and a communication port. The engine ECU 24 receives signals from various sensors required for controlling the operation of the engine 22, such as a crank angle θcr from a crank position sensor 23a that detects the rotational position of a crankshaft 23 of the engine 22, via the input port. The engine ECU 24 outputs various control signals for controlling the operation of the engine 22 via the output port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 23a.

[0014] The starter motor 25 is connected to a crankshaft 23 serving as an output shaft of the engine 22. The starter motor 25 receives power from a low-voltage battery 60 to crank the engine 22. The crankshaft 23 of the engine 22 is also connected to the input side of a damper 28 serving as a torsion element. A pulley 23b is attached to the crankshaft 23 of the engine 22.

[0015] The motor 30 is configured as, for example, a synchronous generator motor. A pulley 30b is attached to the rotating shaft of the motor 30. The pulley 30b is rotationally driven by power transmitted by a belt 31 that is wound around a pulley 23b attached to the crankshaft 23 of the engine 22. The motor 30 is driven by an inverter 32. The inverter 32 is connected to a high-voltage power line 61. The motor 30 is rotationally driven by the main ECU 70 controlling the switching of multiple switching elements of the inverter 32.

[0016] The automatic transmission 40 includes a torque converter 43, an automatic transmission 45 with, for example, six speeds, and a hydraulic circuit (not shown). The torque converter 43 is configured as a typical fluid-type transmission device. The torque converter 43 amplifies the torque of the input shaft 41 connected to the rotating shaft of the motor 30 and transmits it to an intermediate rotating shaft 44, which is the input shaft of the automatic transmission 45, or transmits the torque directly without amplifying it. The automatic transmission 45 is connected to the intermediate rotating shaft 44 and to an output shaft 42, which is connected to a drive shaft 46. The automatic transmission 45 has multiple planetary gears and multiple hydraulically driven friction engagement elements (clutches, brakes). The drive shaft 46 is connected to drive wheels 49a, 49b via an axle 48 and a rear differential gear 47. The automatic transmission 45 transmits power between the intermediate rotary shaft 44 and the output shaft 42, for example, by forming forward speeds from 1st to 6th speeds and reverse speeds by engaging and disengaging a plurality of friction engagement elements.

[0017] The high-voltage battery 50 is configured as, for example, a lithium-ion battery or a nickel-metal hydride battery. The high-voltage battery 50 is connected to a high-voltage power line 51 that is connected to the inverter 32. A relay 52 is attached to the high-voltage power line 51 for disconnecting the high-voltage battery 50. The low-voltage battery 60 is configured as, for example, a lead battery having a lower rated voltage than the high-voltage battery 50. The low-voltage battery 60 is connected to the low-voltage power line 51 that is connected to the starter motor 25 and auxiliary equipment 68. A DC / DC converter 66 is connected to the high-voltage power line 51 and the low-voltage power line 61. The DC / DC converter 66 is controlled by the main ECU 70 to step down the power from the high-voltage power line 51 and supply it to the low-voltage power line 61, or to step up the power from the low-voltage power line 61 and supply it to the high-voltage power line 51. A smoothing capacitor 54 is attached to the high-voltage power line 51, and a smoothing capacitor 64 is attached to the low-voltage power line 61.

[0018] Although not shown, the main ECU 70 is configured as a microcomputer centered around a CPU, and in addition to the CPU, it is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, an input port, an output port, and a communication port.

[0019] The main ECU 70 receives, via an input port, the rotational position φm of the rotor of the motor 30 from a rotational position sensor (not shown) that detects the rotational position of the rotor of the motor 30, the rotational speed Np of the drive shaft 46 from a rotational speed sensor 46a attached to the drive shaft 46, etc. The main ECU 70 also receives, via the input port, the battery voltage Vb from a voltage sensor 50a attached to the output terminal of the high-voltage battery 50, the charge / discharge current Ib from a current sensor 50b, the battery temperature Tb from a temperature sensor 60c attached to the high-voltage battery 50, the high-voltage system voltage VH from a voltage sensor 54a attached to the high-voltage system power line 51, and the low-voltage system voltage VL from a voltage sensor 64a attached to the low-voltage system power line 61. The main ECU 70 also receives, via the input port, an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88.

[0020] The main ECU 70 outputs, via its output ports, a control signal to the starter motor 25, a control signal to the inverter 32, a drive control signal to the relay 52, a control signal to the automatic transmission 40, a control signal to the DC / DC converter 66, a drive control signal to the auxiliary equipment 68, and the like.

[0021] The main ECU 70 is connected via a communication port to the engine ECU 24. The main ECU 70 calculates the state of charge (SOC) of the high-voltage battery 60 based on the voltage VH of the high-voltage battery 60, the current Ib flowing through the high-voltage battery 60, and the like.

[0022] While the automobile 20 is traveling, the main ECU 70 sets a drive shaft torque demand Td* required of the drive shaft 46 based on the accelerator pedal position Acc and the vehicle speed V, and also sets a motor torque demand Tm* to be output from the motor 30. The main ECU 70 calculates an effective torque Teg* as the sum of the torque obtained by converting the drive shaft torque Td* to the crankshaft 23 and the torque obtained by converting the motor torque Tm* to the crankshaft 23, and transmits the effective torque Teg* to the engine ECU 24. The engine ECU 24 controls the intake air amount, fuel injection, and ignition so that the received effective torque Teg* is output from the engine 22. The main ECU 70 controls the switching elements of the inverter 32 so that the motor torque demand Tm* is output from the motor 30. The main ECU 70 controls the automatic transmission 40 to shift to a gear position determined by a gear shift map in which gear positions are divided according to the vehicle speed V and the drive shaft torque demand Td*.

[0023] Next, a description will be given of the operation of the automobile 20 of this embodiment, particularly the operation when terminating batteryless running by disconnecting the high-voltage battery 50. FIG.

[0024] When the traveling end process is executed, the main ECU 70 first waits until a command to shut off the inverter 32 is output (step S100). When the command to shut off the inverter 32 is output, the main ECU 70 determines whether or not the vehicle is in batteryless traveling mode (step S110). In batteryless traveling, if an abnormality occurs in the high-voltage battery 50, the relay 52 is turned off and the vehicle travels with the high-voltage battery 50 disconnected. In this case, the main ECU 70 performs batteryless control by controlling the inverter 32 so that the motor 30 functions as a generator and controlling the DC / DC converter 66 so that the power on the high-voltage power line 51 (power generated by the motor 30) is reduced in voltage and supplied to the low-voltage power line 61.

[0025] When the main ECU 70 determines in step S110 that the vehicle is not in battery-less running mode, it stops driving the DC / DC converter 66 (step S120), then stops driving the inverter 32 to stop driving the motor 30 (step S130), and then discharges the capacitor 34 (step S140), terminating this process. The capacitor 34 can be discharged by switching the inverter 32 to supply electricity to the motor 30 and consuming the electricity as heat, for example.

[0026] When the main ECU 70 determines in step S110 that the vehicle is in battery-less running, it first stops driving the inverter 32 and stops driving the motor 30 (step S150), then discharges the capacitor 34 (step S160), and then stops driving the DC / DC converter 66 (step S170), terminating the process. This is to prevent load dump from occurring by stopping driving the inverter and stopping driving the motor 30 while the DC / DC converter 66 is being driven.

[0027] In the main ECU 70 (on-board control device) mounted on the automobile 20 of the embodiment described above, when battery-less traveling in which the relay 52 is turned off and the high-voltage battery 50 is disconnected is terminated, the main ECU 70 stops driving the inverter while the DC / DC converter 66 is still being driven, thereby stopping driving the motor 30, and then stops driving the DC / DC converter 66. This makes it possible to prevent load dump from occurring.

[0028] In the automobile 20 of the embodiment, the engine 22 and the motor 30 are connected by two pulleys 23b, 30b and a belt 31 wound around both pulleys 23b, 30b. However, the engine 22 and the motor 30 may be connected by a chain mechanism, via a gear mechanism, or directly.

[0029] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problems" section will be explained below. In the embodiment, the engine 22 corresponds to the "engine," the motor 30 corresponds to the "electric motor," the high-voltage battery 50 corresponds to the "high-voltage battery," the low-voltage battery 60 corresponds to the "low-voltage battery," the DC / DC converter 66 corresponds to the "DC / DC converter," the relay 52 corresponds to the "relay," and the main electronic control unit (main ECU) 70 corresponds to the "on-vehicle control device."

[0030] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section is not intended to limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are merely examples for specifically explaining the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0031] The above describes forms (embodiments) for implementing the present disclosure, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be implemented in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0032] The present disclosure is applicable to the manufacturing industry of in-vehicle control devices, etc. [Explanation of symbols]

[0033] 20 automobile, 22 engine, 23 crankshaft, 23a crank position sensor, 23b pulley, 24 engine ECU, 25 starter motor, 28 damper, 30 motor, 30b pulley, 31 belt, 32 inverter, 40 automatic transmission, 41 input shaft, 42 output shaft, 43 torque converter, 44 intermediate rotating shaft, 45 automatic transmission, 46 drive shaft, 46a rotation speed sensor, 47 rear differential gear, 48 axle, 49a, 49b drive wheel, 50 high-voltage battery, 50a voltage sensor, 50b current sensor, 50c temperature sensor, 51 high-voltage power line, 52 relay, 54 capacitor, 54a voltage sensor, 60 low-voltage battery, 61 low-voltage power line, 64 capacitor, 64a voltage sensor, 66 DC / DC converter, 68 auxiliary equipment, 70 main electronic control unit (main ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor.

Claims

1. The engine and an electric motor capable of generating electricity connected to a crankshaft of the engine; a high-voltage battery connected to the electric motor by a high-voltage power line; A low voltage battery; a DC / DC converter connected to the high-voltage power line and a low-voltage power line connected to the low-voltage battery; a relay attached to the high-voltage power line on the high-voltage battery side of the DC / DC converter; An in-vehicle control device mounted on an automobile comprising: When the relay is turned off to terminate batteryless traveling in which the vehicle is traveling while disconnecting the high-voltage battery, the driving of the electric motor is stopped and then the driving of the DC / DC converter is stopped.

1. An in-vehicle control device comprising:

2. 2. The vehicle-mounted control device according to claim 1, the vehicle includes a capacitor attached to the high-voltage power line on the DC / DC converter side of the relay, When the battery-less traveling is terminated, the driving of the electric motor is stopped, the charge of the capacitor is discharged, and then the driving of the DC / DC converter is stopped. In-vehicle control device.

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