JP2004208473A - Vibration suppression controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the vibrations of a carbody resulting from the torque fluctuations of the engine. <P>SOLUTION: A hybrid vehicle comprises an engine 40 as a driving power source, and a motor generator 20. The motor generator 20 is meshed with the three-speed gear 43 of the transmission 40. A control unit 100 measures torque fluctuations of the engine using a torque sensor 104 when a clutch is disconnected or shifted to the neutral position. The control unit 100 determines the torque for canceling the vibration of the vehicle based on the measured torque fluctuation and generates a canceling torque in the motor generator through an inverter 120. With such an arrangement, the motor generator 20 can suppress the vibrations of the vehicle by receiving a reaction force from a tire 52. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for suppressing vibration of a vehicle body caused by fluctuation in engine torque.
[0002]
[Prior art]
Conventionally, a technique described in Patent Document 1 has been disclosed as a technique for reducing torque fluctuation of an engine. In this technique, a motor generator meshed with a flywheel via a gear is controlled to directly cancel a torque fluctuation occurring on a crankshaft.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H11-22504
[Problems to be solved by the invention]
However, according to the conventional technique, the vibration can be reduced only when the engine and the motor generator are always connected. That is, for example, in a configuration in which the motor generator is coupled to a predetermined gear in the transmission instead of the engine, when the clutch is disengaged or the transmission is neutral, the torque fluctuation of the engine is directly canceled by the driving force of the motor generator. I couldn't do that.
[0005]
The present invention has been made in view of such a problem, and has as its object to suppress vibration of a vehicle body caused by torque fluctuation of an engine even when a motor generator and a crankshaft of an engine are not directly coupled. .
[0006]
[Means for Solving the Problems and Their Functions and Effects]
In order to solve at least a part of the above problems, the present invention is configured as follows. That is, a vehicle that travels by outputting power from a drive shaft, and is provided between the engine and the engine and the drive shaft, and is capable of switching a connection state between the engine and the drive shaft to disconnection and connection. A transmission mechanism, an electric motor coupled to the power transmission mechanism in a state capable of transmitting power to the drive shaft even during the disconnection, and suppressing vibration of the vehicle based on a torque variation generated in the engine in the disconnected state. And a vibration suppression control unit that controls the motor so as to output a predetermined canceling torque set in advance in relation to the torque fluctuation.
[0007]
According to the present invention, when the engine and the drive shaft are disconnected from each other, vibration of the vehicle due to torque fluctuations of the engine is suppressed by generating a canceling torque in the electric motor coupled to the power transmission mechanism. The electric motor cannot cancel the engine torque fluctuation, but can transmit power to the drive shaft even when the engine and the drive shaft are disconnected. Can be suppressed. With such a configuration, even when the crankshaft of the engine and the electric motor are not directly coupled, it is possible to suppress the vibration of the vehicle body due to the torque fluctuation of the engine.
[0008]
When the power transmission mechanism includes at least one of a transmission and a clutch, the disconnected state refers to a neutral state of the transmission or a disconnected state of the clutch. Of course, the transmission may be of any type, such as a manual transmission, an automatic transmission, or a CVT.
[0009]
It is preferable that the vibration suppression control unit controls the electric motor such that an integral value of the canceling torque per unit time becomes substantially zero. This can prevent the vehicle from suddenly starting to move. Further, the maximum value of the canceling torque that can be generated may be set in advance regardless of the result of the integration. This is because the generation of a large offset torque may cause the vehicle to move.
[0010]
Further, in the vehicle, the power transmission mechanism includes a stepped transmission, and the electric motor is connected to a gear in the transmission that is coupled to the drive shaft even when the coupled state is disconnected. Preferably, power is transmitted to the drive shaft. Such a gear is, for example, a third to fifth gear in the case of a manual transmission as shown in FIG. These gears have a higher gear ratio than first- or second-speed starting gears, so they can quickly obtain tire reaction force. Also, compared to starting gears designed for strength, This is because noise during driving is low.
[0011]
In the above-described vehicle, if the electric motor is a motor generator, it becomes possible to regenerate the moving energy and store the power in the battery when the vehicle is decelerated. Therefore, the vehicle of the present invention can be configured as a hybrid vehicle, which is preferable.
[0012]
It is preferable that the vehicle is driven by a front engine front drive system or a rear engine rear drive system. This is because such a drive system does not have a propeller shaft or the like and the physical distance between the electric motor and the drive shaft is short, so that it is easy to obtain the reaction force of the tire.
[0013]
In the present invention, the various aspects described above can be applied by appropriately combining or omitting some of them. Further, the present invention may be configured as a control method for suppressing vibration of the vehicle, in addition to the configuration as the vehicle described above. In any of the configurations, the above-described embodiments can be appropriately applied.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in the following order.
A. Overall configuration of the vehicle:
B. Vibration suppression processing:
C. Modification:
[0015]
FIG. 1 is an explanatory diagram illustrating a schematic configuration of a hybrid vehicle as an embodiment. This hybrid vehicle has an engine 10 and a motor generator 20 as a driving force source. The engine 10 may be a gasoline engine or a diesel engine. Motor generator 20 is coupled to transmission 40, and its rotating shaft meshes with third speed gear 43 via a predetermined gear.
[0016]
The power supply of the motor generator 20 is a battery 110. The DC current supplied from battery 110 is converted into three-layer AC by inverter 120 and supplied to motor generator 20. Inverter 120 also has a function of rotating motor generator 20 in the reverse direction by switching the switching control. Motor generator 20 also functions as a generator, and can also charge battery 110 with this power. The power source is not limited to the battery 110, and various chargeable and dischargeable storage means such as a capacitor can be used.
[0017]
The torque output from engine 10 is output from crankshaft 31. Crankshaft 31 is coupled to input shaft 32 of transmission 40 via flywheel 30 and clutch 34. The transmission 40 of the present embodiment is a well-known mechanism that mechanically shifts forward five steps and reverse one step. The transmission 40 is not limited to the illustrated configuration, and various configurations can be applied. The clutch 34 may be mechanically engaged and disengaged according to a driver's operation of a clutch pedal, or may be automatically engaged based on an instruction from the control unit 100 in response to a driver's operation of a shift lever. Alternatively, cutting may be performed.
[0018]
As shown in the figure, the transmission 40 according to the present embodiment has a configuration including gears 41 to 45 for first to fifth speeds and a reverse gear 46. The 1st and 2nd speed gears 41 and 42 and the reverse gear 46 are always connected to the input shaft 32, but are disconnected from the intermediate transmission shaft 33 and thus the drive shaft 51 when the 3rd to 5th speed is selected or in the neutral state. The third to fifth gears 43 to 45 are always connected to the intermediate transmission shaft 33 and thus to the drive shaft 51, but are disconnected from the input shaft 32 during first speed, second speed, reverse running, and neutral. In this mechanism, each shift can be realized by moving the dog clutches 47 to 49 shown in the figure in the left-right direction in the figure. The output from the transmission 40 is transmitted to the drive shaft 51 and the tire 52 via the differential gear 50.
[0019]
The operation of each part of the hybrid vehicle is controlled by the control unit 100. The control unit 100 is a microcomputer including a CPU, a RAM, and a ROM therein, and controls each unit according to control software.
[0020]
In order to realize this control, various signals are input and output to and from the control unit 100. The input signals include, for example, the output of the torque sensor 104 and the output of the vehicle speed sensor 101, the signal of the shift position of the shift lever 102, the signal of the operation state of the clutch pedal 103, the output from the accelerator opening sensor, and the like. . The output signal includes a control signal for driving the motor to the inverter 120 and a signal for adjusting the fuel injection amount to the engine.
[0021]
The torque sensor 104 detects a torque fluctuation occurring on the crankshaft 31 of the engine. Although there are various types of torque sensors, in this embodiment, a sensor that detects a change in torque by detecting a change in the amount of magnetostriction generated in a magnetic plate provided on the flywheel 30 in a disk shape is used. . As such a torque sensor, for example, the one disclosed in Japanese Patent Application Laid-Open No. H11-295164 can be applied. Of course, various other sensors can be used. For example, the torque fluctuation may be obtained from the fluctuation of the rotational acceleration of the crankshaft.
[0022]
B. Vibration suppression processing:
FIG. 2 is a flowchart of a vibration suppression process that is always executed by the control unit 100 when the ignition of the vehicle is turned on.
[0023]
First, the control unit 100 determines from the vehicle speed sensor 101 whether the vehicle is not moving and whether the shift lever is in the neutral state or the clutch pedal is in the disengaged state (step S10). When these conditions are not satisfied (step S10: No), all the subsequent processes are skipped.
[0024]
When the above condition is satisfied (Step S10: Yes), the control unit 100 measures the torque fluctuation of the engine 40 using the output from the torque sensor 104 (Step S20). FIG. 3 is a graph showing an output from the torque sensor 104. The control unit 100 obtains a canceling torque for suppressing the vibration of the vehicle based on the measured value of the torque fluctuation (step S30). This can be determined from a predetermined function or map that has a correlation with the torque fluctuation of the engine. FIG. 4 is a graph showing a temporal change of the canceling torque.
[0025]
Next, the control unit 100 calculates the integral value of the canceling torque per unit time. The hatched portion in FIG. 4 indicates the integrated value of the canceling torque per unit time Tu. As a result of the calculation, if the integrated value is substantially zero (Step S40: Yes), an instruction is given to the inverter 120 to cause the motor generator 20 to generate a canceling torque (Step S50).
[0026]
In step S40, if the integrated value is not substantially zero (step S40: No), there is a possibility that the vehicle will move back and forth, so the offset torque obtained in step S30 is adjusted to be zero (step S40). Step S60). The portion surrounded by A in FIG. 4 represents the result of such adjustment. The dotted line is the graph before adjustment, and the solid line is the graph after adjustment. It is desirable that the maximum value of the absolute value of the canceling torque be regulated in advance. This is because the vehicle may move by generating a large canceling torque. The portion surrounded by B in FIG. 4 represents the adjustment result of the offset torque due to this regulation. The dotted line is the graph before adjustment, and the solid line is the graph after adjustment. Of course, the adjustment using the integral value and the adjustment using the maximum value may be performed simultaneously.
[0027]
In order to make the processing simpler, if the integrated value is not substantially zero at the time of the determination in step S40, neither step S50 nor step S60 may be executed, and a canceling torque may not be generated.
[0028]
By the above processing, motor generator 20 obtains the reaction force of tire 52 via third speed gear 43, intermediate transmission shaft 33, differential gear 50, and drive shaft 51, so that the vehicle Vibration can be suppressed.
[0029]
C. Modification:
FIG. 5 is an explanatory diagram showing a modification of the attachment position of motor generator 20. In the above embodiment, the third speed gear 43 is engaged with the motor generator 20. However, as shown in FIG. 5 (a), it may be engaged with the fourth speed gear 44, or as shown in FIG. 5 (b), it may be engaged with the fifth speed gear 45. Further, it may mesh with the final gear or the differential gear 50.
[0030]
The embodiments of the present invention have been described above. However, it is needless to say that the present invention is not limited to the above-described embodiments, and can adopt various configurations without departing from the gist of the present invention. For example, the above-described control processing may be realized by hardware. Further, in the embodiments, the case where the manual transmission is used has been described, but the present invention can use various transmissions such as an automatic transmission and a CVT.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of a hybrid vehicle.
FIG. 2 is a flowchart of a vibration suppression process.
FIG. 3 is a graph showing an output from a torque sensor.
FIG. 4 is a graph showing a temporal change of a canceling torque.
FIG. 5 is an explanatory view showing a modified example of a mounting position of a motor generator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Engine 20 ... Motor generator 30 ... Flywheel 31 ... Crankshaft 32 ... Input shaft 33 ... Intermediate transmission shaft 34 ... Clutch 40 ... Transmission 41-45 ... 1st-5th gear 46 ... Reverse gear 47-49 ... Dog clutch 50 ... Differential gear 51 ... Drive shaft 52 ... Tire 100 ... Control unit 101 ... Vehicle speed sensor 102 ... Shift lever 103 ... Clutch pedal 104 ... Torque sensor 110 ... Battery 120 ... Inverter

Claims (6)

A vehicle that travels by outputting power from a drive shaft,
Engine and
A power transmission mechanism that is provided between the engine and the drive shaft and that can switch a connection state of the engine and the drive shaft to disconnection and connection;
An electric motor coupled to the power transmission mechanism in a state where power can be transmitted to the drive shaft even at the time of cutting.
In the disconnection state, a vibration suppression control unit that controls the electric motor to output a predetermined canceling torque set in advance in relation to the torque fluctuation based on the torque fluctuation generated in the engine so as to suppress vibration of the vehicle. When,
Vehicle equipped with. The vehicle according to claim 1,
The vehicle, wherein the vibration suppression control unit controls the electric motor such that an integral value of the canceling torque per unit time becomes substantially zero. The vehicle according to claim 1,
The power transmission mechanism includes at least one of a transmission and a clutch,
The vehicle in which the disconnected state refers to a neutral state of the transmission or a disconnected state of the clutch. The vehicle according to claim 1,
The power transmission mechanism includes a stepped transmission,
The vehicle, wherein the electric motor transmits power to the drive shaft via a gear in the transmission coupled to the drive shaft even when the coupling state is a disconnection. The vehicle according to claim 1, wherein the electric motor is a motor generator. A control method for suppressing vehicle vibration,
The vehicle is
Engine and
A power transmission mechanism that is provided between the engine and the drive shaft and that can switch a connection state of the engine and the drive shaft to disconnection and connection;
An electric motor coupled to the power calculator mechanism in a state where power can be transmitted to the drive shaft even at the time of cutting.
Detecting the cutting state;
Detecting a torque fluctuation occurring in the engine;
Controlling the electric motor to output a predetermined canceling torque set in advance in relation to the torque fluctuation so as to suppress vibration of the vehicle;
Control method including:

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