Control device for vehicle

Abstract

To more appropriately determine overcharge of a battery.SOLUTION: A vehicle includes a first voltage sensor for detecting a voltage of a first power line, a second voltage sensor for detecting a voltage of a second power line, a third voltage sensor for detecting a voltage between terminals of a battery, and a determination device for determining overcharge of the battery on the basis of the voltage between terminals detected by the third voltage sensor, wherein when having detected that abnormality occurs in at least one of the second voltage sensor and the determination device, the determination device determines the overcharge of the battery on the basis of the voltage of the first power line detected by the first voltage sensor.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control device for a vehicle. [Background technology]

[0002] Conventionally, a control device for this type of vehicle has been proposed for use in a vehicle that includes a motor connected to the output shaft of the engine, an inverter that drives the motor, a battery that is connected to a first power line that is the power line of the inverter and exchanges power with the motor, and a DCDC converter that is connected to the first power line via a second power line and converts the voltage from the battery (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-231769 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned vehicle control device, it is recognized that determining whether the battery is overcharged is an important issue from the viewpoint of battery protection. As a method for determining whether the battery is overcharged, it is possible to detect the terminal voltage of the battery by a voltage sensor and determine whether the battery is overcharged based on the terminal voltage detected by a determination device. However, if an abnormality occurs in the voltage sensor or the determination device, it becomes impossible to properly determine whether the battery is overcharged.

[0005] The main object of the vehicle control device disclosed herein is to more appropriately determine whether the battery is overcharged. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object. The vehicle control device of the present disclosure is used in a vehicle including a motor connected to an output shaft of an engine, an inverter for driving the motor, a battery connected to a first power line that is a power line of the inverter and exchanging electric power with the motor, and a DC-DC converter connected to the first power line via a second power line and converting a voltage from the battery, and controls the DC-DC converter, the vehicle including a first voltage sensor for detecting a voltage of the first power line, a second voltage sensor for detecting a voltage of the second power line, a third voltage sensor for detecting a voltage between terminals of the battery, and a determination device for determining whether the battery is overcharged based on the voltage between terminals detected by the third voltage sensor, and when an abnormality is detected in at least one of the second voltage sensor and the determination device, the vehicle determines whether the battery is overcharged based on the voltage of the first power line detected by the first voltage sensor. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing an outline of the configuration of an automobile 20 equipped with a vehicle control device. [Diagram 2] FIG. 2 is an explanatory diagram for explaining mounting positions of an engine 22, a motor 30, etc. [Diagram 3] 5 is a flowchart showing an example of an abnormality determination process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Next, an embodiment of the present disclosure will be described. Fig. 1 is a schematic diagram showing the configuration of an automobile 20 equipped with a vehicle control device according to an embodiment of the present disclosure. Fig. 2 is an explanatory diagram for explaining the mounting positions of an engine 22, a motor 30, and the like. As shown in the figure, the automobile 20 of the embodiment includes an engine 22, a starter (starter motor) 25, the motor 30, an inverter 32, an automatic transmission 40, a high-voltage battery 50, a monitoring IC 52, a low-voltage battery 60, a DCDC converter 66, a DCDC converter electronic control unit (hereinafter referred to as "DCDCECU") 67, and a main electronic control unit (hereinafter referred to as "main ECU") 70.

[0009] The engine 22 is configured as a multi-cylinder (4-cylinder, 6-cylinder, etc.) internal combustion engine that uses gasoline, diesel, or the like as fuel supplied 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. Although not shown, the engine ECU 24 is configured as a microcomputer centered on 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 inputs 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 an input port. The engine ECU 24 outputs various control signals for controlling the operation of the engine 22 via an 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.

[0010] The starter 25 is connected to a crankshaft 23 serving as an output shaft of the engine 22. The starter 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.

[0011] The motor 30 is configured as, for example, a synchronous generator motor. A pulley 30b is attached to a 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 (first power line) 51. The motor 30 is rotationally driven by a main ECU 70 controlling the switching of multiple switching elements of the inverter 32.

[0012] 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 general 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 connected to a drive shaft 46. The automatic transmission 45 has a plurality of planetary gears and a plurality of 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 rotating shaft 44 and the output shaft 42, for example, by forming forward gears from 1st to 6th gears and reverse gears by engaging and disengaging a plurality of friction engagement elements.

[0013] 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 (first power line) 51 connected to the inverter 32 via a high-voltage power line (second power line) 55. A relay 52 for disconnecting the high-voltage battery 50 is attached to the high-voltage power line 51. The high-voltage battery 50 is managed by a monitoring IC 52.

[0014] The monitoring IC 52 is configured as a semiconductor integrated circuit, and receives as input a voltage Vb from a voltage sensor (third voltage sensor) 50a that detects the inter-terminal voltage of the high-voltage battery 50, a current Ib from a current sensor 50b that detects the charge / discharge current of the high-voltage battery 50, and a battery temperature Tb from a temperature sensor 50c that detects the temperature of the high-voltage battery 50. The monitoring IC 52 outputs the voltage Vb, current Ib, and battery temperature Tb of the high-voltage battery 50 to a sub-microcomputer 67b of the DCDCECU 67.

[0015] The low-voltage battery 60 is configured as, for example, a lead battery having a rated voltage lower than that of the high-voltage battery 50. The low-voltage battery 60 is connected to a low-voltage power line 61 which is connected to the starter 25 and the auxiliary equipment 68.

[0016] The DCDC converter 66 is connected to a high-voltage power line 55 connected to the high-voltage power line 51 and the high-voltage battery 50, and to a low-voltage power line 61. The DCDC converter 66 is controlled by a main microcomputer (hereinafter referred to as the "main microcomputer") 67a of the DCDCECU 67 to step down the power of the high-voltage power line 55 and supply it to the low-voltage power line 61, or step up the power of the low-voltage power line 61 and supply it to the high-voltage power line 55. A smoothing capacitor 54 is attached to the high-voltage power line 55, and a smoothing capacitor 64 is attached to the low-voltage power line 61.

[0017] The DCDCECU 67 includes a main microcomputer 67a having a CPU, a ROM, a RAM, a flash memory, an input port, an output port, and a communication port, and a sub-microcomputer (determination device, hereinafter referred to as a "sub-microcomputer") 67b having a CPU, a ROM, a RAM, a flash memory, an input port, an output port, and a communication port. The main microcomputer 67a receives a voltage Vinv from a voltage sensor (first voltage sensor) 51a that detects the voltage of the high-voltage power line 51 and a voltage VH from a voltage sensor (second voltage sensor) 54a that detects the voltage of the capacitor 54 (the voltage of the high-voltage power line 55). The main microcomputer 67a outputs a control signal to the DCDC converter 66 and a control signal to the relay 52. ​​The main microcomputer 67a is connected to the sub-microcomputer 67b and the main ECU 70 via the communication port. The sub-microcomputer 67b is connected to the monitoring IC 52 via the communication port. The sub-microcomputer 67b calculates the charge ratio SOC of the high-voltage battery 50 based on the voltage VH, current Ib, battery temperature Tb, and the like of the high-voltage battery 50 input from the monitoring IC 52. The sub-microcomputer 67b judges whether the high-voltage battery 50 is overcharged based on the voltage Vb of the high-voltage battery 50. In this judgment, when the voltage Vb of the high-voltage battery 50 is equal to or lower than the judgment threshold Vbmax, it is judged that the high-voltage battery 50 is not overcharged. When the voltage Vb of the high-voltage battery 50 exceeds the judgment threshold Vbmax, it is judged that the high-voltage battery 50 is overcharged. The judgment threshold Vbmax is a threshold for judging whether the high-voltage battery 50 is overcharged or not, and is set to a voltage higher than the rated voltage.

[0018] The main ECU 70 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input port, an output port, and a communication port. The main ECU 70 inputs, via the 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, the low-voltage system voltage VL from a voltage sensor 64a attached to the low-voltage system power line 61, an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the depression amount of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the depression amount of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88. The main ECU 70 outputs, via an output port, a control signal to the starter 25, a control signal to the inverter 32, a control signal to the automatic transmission 40, a drive control signal to the auxiliary devices 68, etc. The main ECU 70 is connected to the engine ECU 24 via a communication port.

[0019] While the automobile 20 is traveling, the main ECU 70 sets the drive shaft torque demand Td* required for the drive shaft 46 based on the accelerator opening Acc and the vehicle speed V, and also sets the motor torque demand Tm* to be output from the motor 30. The main ECU 70 calculates the 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 executes intake air amount control, fuel injection control, and ignition control so that the received effective torque Teg* is output from the engine 22. The main ECU 70 controls the switching of 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 so that the gear shift stage is determined by a gear shift map in which the gear shift stages are divided according to the vehicle speed V and the drive shaft torque demand Td*.

[0020] In this embodiment, as shown in Fig. 2, the engine 22 and a motor assembly 130 are mounted in an engine compartment at the front of the vehicle body. The motor assembly 130 includes a motor 30, an inverter 32, a voltage sensor 51a, and, although not shown, a current sensor 51b and a temperature sensor 51c. A DCDC assembly 160 and a battery pack 150 are mounted on a floor surface below a seat on which an occupant sits in the vehicle interior. The DCDC assembly 160 includes a DCDC converter 66, a voltage sensor 54a, and a DCDC ECU 67. The battery pack 150 includes a high-voltage battery 50, a voltage sensor 50a, a current sensor 50b, a temperature sensor 50c, and a monitoring IC 52.

[0021] Next, a description will be given of the operation of the automobile 20 equipped with the vehicle control device of the embodiment. Fig. 3 is a flowchart showing an example of an abnormality determination process executed by the main microcomputer 67a of the DCDCECU 67. This routine is executed by the CPU of the main microcomputer 67a.

[0022] When this routine is executed, the CPU of the main microcomputer 67a judges whether or not an abnormality has occurred in the DCDC assembly 160 (S100). Here, when an abnormality has occurred in at least one of the voltage sensor 54a and the sub-microcomputer 67b of the DCDC ECU 67, it is judged that an abnormality has occurred in the DCDC assembly 160. An example of an abnormality in the sub-microcomputer 67b is an abnormality in a circuit such as an AD conversion circuit in the sub-microcomputer 67b. An example of an abnormality in the voltage sensor 54a is an abnormality in which the detection value from the voltage sensor 54a is interrupted.

[0023] When no abnormality occurs in the DCDC assembly 160 in S100, the voltage VH from the voltage sensor 54a is input (S110), and it is determined whether or not the voltage VH exceeds the judgment threshold Vbmax (S120). When the voltage VH is equal to or less than the judgment threshold Vbmax, it is determined that the battery is not overcharged (S130), and this routine is terminated. When the voltage VH exceeds the judgment threshold Vbmax, it is determined that the battery is overcharged (S160), and this routine is terminated. When no abnormality occurs in the DCDC assembly 160, it is determined whether or not the high-voltage battery 50 is overcharged based on the voltage VH from the voltage sensor 54a. As described above, whether or not the high-voltage battery 50 is overcharged is also determined by the sub-microcomputer 67b based on the voltage Vb detected by the voltage sensor 50a. In this way, since the main microcomputer 67a and the sub-microcomputer 67b determine whether or not the high-voltage battery 50 is overcharged, it is possible to more reliably determine whether or not the high-voltage battery 50 is overcharged.

[0024] When an abnormality occurs in the DCDC assembly 160 in S100, the voltage Vinv of the high voltage system power line 51 from the voltage sensor 51a is input (S110), and it is determined whether or not the voltage Vinv exceeds the judgment threshold Vbmax (S150). When the voltage Vinv is equal to or less than the judgment threshold Vbmax, it is determined that there is no overcharging (S130), and this routine is terminated. When the voltage Vinv exceeds the judgment threshold Vbmax, it is determined that there is overcharging (S160), and this routine is terminated. In the embodiment, the DCDC assembly 160 and the battery pack 150 are mounted on the floor surface of the vehicle interior. Therefore, when the automobile 20 is submerged in water, the sub-microcomputer 67b and the voltage sensor 54a in the DCDC assembly 160 may be submerged at the same time, causing an abnormality. In this case, since the voltage sensor 51a is mounted in the engine compartment, it is considered that no abnormality occurs. In the embodiment, when an abnormality occurs in the DCDC assembly 160, it is determined whether or not the high-voltage battery 50 is overcharged based on the voltage VH from the voltage sensor 51a mounted in the engine compartment, so that it is possible to more accurately determine whether the high-voltage battery 50 is overcharged.

[0025] According to the vehicle control device of the present embodiment described above, when an abnormality is detected in at least one of the voltage sensor 54a and the sub-microcomputer 67b, overcharging of the high-voltage battery 50 is determined based on the voltage VH of the high-voltage power line 51 detected by the voltage sensor 50a, so that overcharging of the high-voltage battery 50 can be determined more accurately.

[0026] In the above-described embodiment, the DCDC assembly 160 and the battery pack 150 are mounted on the floor of the vehicle interior, and the engine 22 and the motor assembly 130 are mounted in the engine compartment, but these may be mounted in any position as long as they are mounted on the automobile 20.

[0027] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0028] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Explanation of symbols]

[0029] 20 Automotive, 51a Voltage Sensor, 67a Main Battery.

Claims

[Claim 1] A vehicle control device for controlling a DC-DC converter, the vehicle control device being used in a vehicle including a motor connected to an output shaft of an engine, an inverter for driving the motor, a battery connected to a first power line which is a power line of the inverter and exchanging electric power with the motor, and a DC-DC converter connected to the first power line and the battery via a second power line and converting a voltage from the battery, the vehicle control device comprising: the vehicle includes a first voltage sensor that detects a voltage of the first power line, a second voltage sensor that detects a voltage of the second power line, a third voltage sensor that detects a voltage between terminals of the battery, and a determination device that determines whether the battery is overcharged based on the terminal voltage detected by the third voltage sensor, When it is detected that an abnormality has occurred in at least one of the second voltage sensor and the determination device, it is determined whether the battery is overcharged based on the voltage of the first power line detected by the first voltage sensor. Vehicle control device.

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