Vehicle control device

Abstract

To provide a vehicle control device which can suppress errors in torque for damping vibrations.SOLUTION: A vehicle control device comprises a first electric motor and a second electric motor, and performs vibration control for controlling vibrations in such a manner that the first electric motor and the second electric motor output torque. The vehicle control device comprises: an acquisition part for acquiring first torque; and a setting part which acquires second torque by performing high-pass filter processing for the first torque, and sets the second torque as torque for controlling vibrations.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] BACKGROUND ART Vehicles equipped with an internal combustion engine and two electric motors are known (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Patent No. 2012 / 029170 Summary of the Invention [Problem to be solved by the invention]

[0004] Electric motors generate torque to suppress vehicle vibrations. Cooperative vibration suppression control is sometimes performed to suppress vibrations using two electric motors. Errors in torque due to factors such as road resistance can make vibration suppression difficult. Therefore, the objective of this invention is to provide a vehicle control device that can suppress errors in torque for vibration suppression. [Means for solving the problem]

[0005] The above object can be achieved by a vehicle control device that includes an internal combustion engine, a first electric motor, and a second electric motor, and that performs vibration suppression control by controlling vibrations by having the first electric motor and the second electric motor output torque, the vehicle control device including: an acquisition unit that acquires a first torque; and a setting unit that acquires a second torque by performing high-pass filter processing on the first torque, and sets the second torque as a torque for the vibration suppression control.

[0006] The setting unit may remove low-frequency components from the first torque by the high-pass filtering process, and set high-frequency components from the first torque as the second torque.

[0007] The setting unit may set components of 5 Hz or higher to the second torque by the high-pass filtering process. [Effects of the Invention]

[0008] A vehicle control device can be provided that can suppress errors in torque for vibration suppression. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a vehicle according to this embodiment. [Figure 2] FIG. 2 is a flowchart illustrating the processing executed by the ECU. [Figure 3] FIG. 3 is a diagram illustrating an example of a time chart. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a schematic diagram of a vehicle 1 according to this embodiment. The vehicle 1 is a hybrid vehicle and includes an ECU (Electronic Control Unit) 50, an engine 10 (internal combustion engine), a first motor generator (hereinafter referred to as "first MG (Motor Generator)") 14 (first electric motor), a second motor generator (hereinafter referred to as "second MG") 15 (second electric motor), a PCU (Power Control Unit) 17, a battery 18, a torsional damper 19, a power split mechanism 20, a reduction mechanism 22, a differential gear 24, and drive wheels 26. The engine 10 may be a gasoline engine or a diesel engine. The engine 10, the first MG 14, and the second MG 15 are power sources for driving the vehicle 1.

[0011] The first MG 14 and the second MG 15 function as an electric motor and a generator. When drive power is supplied to the first MG 14 and the second MG 15, they output torque, and when torque is applied to them, they generate regenerative power. The first MG 14 and the second MG 15 are, for example, AC rotating electric machines. The AC rotating electric machine is, for example, a permanent magnet synchronous motor having a rotor with a permanent magnet embedded therein.

[0012] The first MG 14 and the second MG 15 are electrically connected to the battery 18 via the PCU 17. The PCU 17 charges the battery 18 using regenerative power generated in the first MG 14 or the second MG 15, and drives the first MG 14 or the second MG 15 using the power charged in the battery 18. The PCU 17 includes a first inverter that exchanges power with the first MG 14, a second inverter that exchanges power with the second MG 15, and a converter. The converter boosts the power of the battery 18 and supplies it to the first and second inverters, and reduces the power supplied from the first and second inverters and supplies it to the battery 18. The first inverter converts DC power from the converter into AC power and supplies it to the first MG 14, and converts AC power from the first MG 14 into DC power and supplies it to the converter. The second inverter converts DC power from the converter into AC power and supplies it to second MG 15, and converts AC power from second MG 15 into DC power and supplies it to the converter.

[0013] The battery 18 is made up of a plurality of stacked cells, which may be secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries.

[0014] The power split mechanism 20 is, for example, a planetary gear mechanism including a sun gear, a planetary carrier, a pinion gear, and a ring gear. The crankshaft 27 of the engine 10 is connected to the power split mechanism 20 via a torsional damper 19. The power split mechanism 20 mechanically connects the crankshaft 27 of the engine 10, the rotating shaft of the first MG 14, and the output shaft of the power split mechanism 20.

[0015] The reduction mechanism 22 is a multi-stage automatic transmission that changes the gear ratio. Under the control of the ECU 50, the reduction mechanism 22 changes the gear ratio and switches between multiple power transmission states. The multiple power transmission states include an N (neutral) range, a D (drive) range, an R (reverse) range, and a P (parking) range. A continuously variable transmission (CVT) that continuously changes the gear ratio may be used instead of the reduction mechanism 22.

[0016] The output shaft of the power split mechanism 20 is connected to a reduction mechanism 22. The rotating shaft of the second MG 15 is also connected to the reduction mechanism 22. The reduction mechanism 22 is connected to a differential gear 24. A drive shaft 25 is connected to the differential gear 24. A drive wheel 26 is attached to the tip of the drive shaft 25.

[0017] The engine 10, the first MG 14, and the second MG 15 function as drive sources that generate drive forces. The drive forces of the engine 10, the first MG 14, and the second MG 15 are transmitted to drive wheels 26 via a reduction gear mechanism 22 and a differential gear 24.

[0018] The ECU 50 is a control device of the vehicle 1, and includes an arithmetic unit such as a CPU (Central Processing Unit), and storage devices such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The ECU 50 performs various controls by executing programs stored in the ROM and the storage device. The ECU 50 acquires the engine speed detected by the engine speed sensor 29. The ECU 50 controls the engine 10, the first MG 14, the second MG 15, the PCU 17, and the battery 18.

[0019] When engine 10 rotates, the torque generated by engine 10 is transmitted to torsional damper 19, power split mechanism 20, reduction gear mechanism 22, drive shaft 25, etc. The transmission of torque may cause vibration in vehicle 1. ECU 50 performs cooperative vibration suppression control, which is vibration suppression control using both the torque of first MG 14 and the torque of second MG 15. Vibration is suppressed by cooperative vibration suppression control.

[0020] In cooperative vibration suppression control, the ECU 50 acquires, for example, the vibration mode (torsion speed, torsion amount) of the drive suspension system (power plant, torsional damper 19, drive shaft 25, etc.) and feeds back the vibration mode to adjust the torque of the first MG 14 and the torque of the second MG 15. The ECU 50 functions as an acquisition unit that acquires the torque of the first MG 14 and as a setting unit that sets the torque for vibration suppression control.

[0021] Forcing forces are generated on the vehicle 1 due to road resistance, road gradient, braking force from the brakes (not shown) of the vehicle 1, and the like. The forcing forces result in errors in the torque of the vibration damping control. The errors may reduce the effectiveness of the vibration damping control and increase vibrations. In this embodiment, the ECU 50 removes the errors and sets the torque to an appropriate value.

[0022] 2 is a flowchart illustrating the processing executed by the ECU 50. The ECU 50 acquires a state quantity (step S10). The state quantity is a parameter used to calculate torque, and may be, for example, a vibration mode (torsion speed, torsion amount, etc.) of the drive suspension system (engine 10, MG, torsional damper 19, drive shaft 25, etc.), or another quantity.

[0023] The ECU 50 acquires the first torque T1 based on the state quantity (step S12). The ECU 50 performs high-pass filtering on the first torque to remove low-frequency components from the first torque and leave high-frequency components. The high-frequency components are set as the second torque T2 (steps S14 and S16). The second torque T2 becomes the torque for cooperative vibration suppression control. This completes the processing of FIG. 2.

[0024] FIG. 3 is a diagram illustrating an example of torque. The horizontal axis represents time. The vertical axis represents torque. The dashed line represents the first torque T1. The solid line represents the second torque T2. The second torque T2 can be obtained by performing high-pass filtering on the first torque T1.

[0025] According to this embodiment, the ECU 50 acquires the first torque T1 and performs high-pass filtering on the first torque T1 to acquire the second torque T2. This makes it possible to reduce errors in the torque for vibration suppression. By outputting the second torque in cooperative vibration suppression control, vibration is suppressed.

[0026] The high-pass filter process removes low-frequency components from the first torque T1, and the high-frequency components are set to the second torque T2. Errors in the torque caused by factors such as road resistance tend to occur as low-frequency components, such as 1 Hz. Removing the low-frequency components through the high-pass filter process can suppress the errors. The second torque T2 obtained through the high-pass filter process can suppress vibrations.

[0027] The resonant frequency of the drive suspension system is, for example, about 10 Hz. There is a risk that the vibration of the engine 10 will resonate at the resonant frequency, resulting in increased vibration. Components of the torque around 10 Hz have a greater vibration-reducing effect than other frequency components. Low-frequency components of the first torque, for example, about 1 Hz to 2 Hz, are removed by high-pass filtering. Components of the first torque, for example, 5 Hz or higher, remain. Therefore, the second torque T2 includes components of the first torque T1 that are about 10 Hz. Vibrations can be effectively suppressed by outputting the second torque T2 in cooperative vibration suppression control. The frequencies removed and left by high-pass filtering may be changed. Vibrations can be suppressed by leaving frequency components that increase vibration through high-pass filtering.

[0028] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as set forth in the claims. [Explanation of symbols]

[0029] 1 vehicle 10 Engine 14 First motor generator 15 Second motor generator 17 PCU 18 Battery 19 Torsional Damper 20 Power split mechanism 22 Reduction mechanism 24 Differential gear 25 drive shaft 26 Drive wheels 27 crankshaft 29 Rotational speed sensor 50 ECU

Claims

1. A vehicle control device that controls a vehicle including an internal combustion engine, a first electric motor, and a second electric motor, wherein the control device performs vibration damping control to control vibration by causing the first electric motor and the second electric motor to output torque; a drive suspension system of the vehicle including a drive shaft, the internal combustion engine, the first electric motor, and the second electric motor; the internal combustion engine, the first electric motor, and the second electric motor are connected to a drive shaft; the control device includes an acquisition unit that acquires a first torque based on a vibration mode of the drive suspension system when torque of the internal combustion engine is transmitted to the drive shaft; a setting unit that acquires a second torque by performing high-pass filtering on the first torque and sets the second torque as a torque for the vibration suppression control, the setting unit performs the high-pass filtering process on the first torque to remove low-frequency components from the first torque, and sets, as the second torque, a high-frequency component from the first torque that is not removed by the high-pass filtering process; the high-frequency components include components of a resonance frequency of the drive suspension system, A vehicle control device in which the sum of the torque output by the first electric motor and the torque output by the second electric motor during the vibration damping control is the second torque.

2. The vehicle control device according to claim 1 , wherein the setting unit sets components of 5 Hz or higher to the second torque by the high-pass filtering.

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