JP5880377B2 - Torque fluctuation suppression device - Google Patents

Description

  The present invention relates to a torque fluctuation suppressing device that suppresses torque fluctuation.

  A torque for moving the vehicle is transmitted to the drive shaft through the transmission from the engine, but at the same time, torque fluctuation is also transmitted (see FIG. 9). This torque fluctuation is transmitted as vibration to the inside of the vehicle through the tires and suspension, and causes in-vehicle sound and vibration. In order to reduce the torque fluctuation of the drive shaft, if the automatic transmission (AT) or continuously variable transmission (CVT) is used for the transmission, the rigidity value of the lockup damper should be Making it smaller is done.

JP 2004-150508 A Japanese Patent No. 4062666 Japanese Patent No. 3867869

  The rigidity value of the lockup damper described above is not a value that can be determined only by the request for in-vehicle sound and vibration, and does not lead to a sufficient reduction in in-vehicle sound and vibration. In the case of AT and CVT, the so-called half-clutch operation called slip direct connection is also used to reduce vehicle interior noise and vibration. There are problems, and fuel consumption deteriorates, so it cannot be used frequently.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a torque fluctuation suppressing device capable of suppressing torque fluctuation and reducing vehicle interior sound and vibration.

A torque fluctuation suppressing device according to a first aspect of the present invention for solving the above problems is as follows.
An electromagnetic induction means comprising a magnet and a coil, wherein one of the magnet or the coil is attached to the outer periphery of a vehicle axle, and the other of the magnet or the coil is arranged around the one of the magnet or the coil;
Torque fluctuation detection means for detecting torque fluctuation of the axle based on a current value and a voltage value generated by electromagnetic induction by the electromagnetic induction means as the axle rotates.
And a current control means for calculating a suppression current value for suppressing the torque fluctuation based on the detected torque fluctuation and outputting the suppression current value to the coil.

A torque fluctuation suppressing device according to a second invention that solves the above-described problem,
In the torque fluctuation suppressing device according to the first aspect,
The torque fluctuation detection means has a rotation angle differential value calculation means for calculating a rotation angle differential value that is a differential value of the rotation angle of the axle based on the current value and the voltage value,
The current control means calculates the suppression current value based on the rotation angle differential value.

A torque fluctuation suppressing device according to a third aspect of the present invention for solving the above problem is as follows.
In the torque fluctuation suppressing device according to the second invention,
The rotational angle differential value calculating means includes direct current component removing means for subtracting a direct current component value from the rotational angle differential value, and removing the direct current component value from the differential value of the rotational angle of the axle to obtain the rotational angle differential value. Is calculated.

A torque fluctuation suppressing device according to a fourth aspect of the present invention for solving the above problem is as follows.
In the torque fluctuation suppressing device according to the third aspect,
The current control means outputs the suppression current value to the coil when the absolute value of the rotation angle differential value is equal to or greater than a predetermined rotation angle differential value.

A torque fluctuation suppressing device according to a fifth aspect of the present invention for solving the above problem is as follows.
In the torque fluctuation suppressing device according to the third or fourth invention,
The current control means calculates and outputs a negative constant current value when the rotation angle differential value is positive, and a positive constant current value as the suppression current value when the rotation angle differential value is negative. It is characterized by that.

A torque fluctuation suppressing device according to a sixth aspect of the present invention for solving the above problem is
In the torque fluctuation suppressing device according to the third or fourth invention,
The current control means suppresses a negative current value proportional to the value when the rotation angle differential value is positive, and a positive current value proportional to the value when the rotation angle differential value is negative. It is calculated and output as a current value.

A torque fluctuation suppressing device according to a seventh invention for solving the above-described problem is
In the torque fluctuation suppressing device according to any one of the first to sixth inventions,
The current control unit outputs the suppression current value to the coil when the absolute value of the voltage value is equal to or less than a predetermined voltage value.

  According to the first invention, it is possible to suppress in-vehicle noise and vibration by suppressing torque fluctuation of the axle. In addition, the electromagnetic induction means consisting of a magnet and a coil detects the torque fluctuation of the axle and suppresses the torque fluctuation, so there is no need to provide a separate detection device for detecting the torque fluctuation and the number of parts can be reduced. It becomes.

  According to the second invention, since the rotation angle differential value is a value corresponding to the torque fluctuation, the torque fluctuation can be accurately detected.

  According to the third aspect, since the direct current component value is subtracted from the rotation angle differential value, it is possible to calculate the suppression current value corresponding to the torque fluctuation.

  According to the fourth invention, it is possible to suppress the torque fluctuation when a torque fluctuation (rotational differential value) of a predetermined value or more is detected.

  According to the fifth and sixth inventions, the torque fluctuation can be suppressed because the suppression current value having the opposite sign to the rotational differential value is output to the coil.

  According to the seventh aspect, the suppression control can be performed within the operable range of the torque fluctuation suppressing device.

It is the schematic which shows an example of embodiment of the torque fluctuation suppression apparatus which concerns on this invention. It is a figure explaining the torque fluctuation suppression apparatus shown in FIG. 1, and is a schematic block diagram explaining especially the structure of a shaft damper. It is a figure explaining the basic view of torque fluctuation reduction in the shaft damper shown in FIG. FIG. 3 is a diagram for explaining a current supplied for torque fluctuation reduction in the shaft damper shown in FIG. 2. FIG. 3 is a diagram showing an analog electronic circuit as an example of a circuit for obtaining a rotation angle differential value in the shaft damper shown in FIG. 2. It is a figure explaining the torque fluctuation suppression apparatus shown in FIG. 1, and is a block diagram explaining especially the structure of a control apparatus. It is a figure explaining an example of the electric current supplied from the control apparatus shown in FIG. It is a figure explaining another example of the electric current supplied from the control apparatus shown in FIG. It is a figure explaining the torque fluctuation of a drive shaft.

  Hereinafter, with reference to FIGS. 1-7, embodiment of the torque fluctuation suppression apparatus which concerns on this invention is described.

Example 1
FIG. 1 is a schematic diagram illustrating a torque fluctuation suppressing device according to the present embodiment, and FIG. 2 is a schematic configuration diagram illustrating a configuration of a shaft damper, in particular, in the torque fluctuation suppressing device. 3 is a diagram for explaining the basic concept of torque fluctuation reduction in the shaft damper shown in FIG. 2, and FIG. 4 is a diagram for explaining current supplied for torque fluctuation reduction. FIG. 5 is a diagram illustrating an analog electronic circuit as an example of a circuit for obtaining a rotation angle differential value. FIG. 6 is a block diagram for explaining the configuration of the control device, in particular, in the torque fluctuation suppressing device shown in FIG. FIG. 7 is a diagram for explaining an example of the current supplied from the control device shown in FIG. 5, and FIG. 8 is a diagram for explaining another example of the current.

  In a vehicle such as an automobile, the drive torque output from the engine 11 (internal combustion engine) is transmitted to the drive shaft 12 (axle) to drive the drive wheels 13. At this time, torque fluctuation is transmitted to the drive shaft 12 together with the drive torque. Therefore, in the torque fluctuation suppressing device of this embodiment, as shown in FIG. 1, in order to reduce (reduce) this torque fluctuation, an intelligent drive shaft damper (hereinafter referred to as a shaft damper) 20 is provided on the drive shaft 12. A control device 30 for controlling the shaft damper 20 is provided.

  The position of the drive shaft 12 to which the shaft damper 20 is attached may be disposed either before or after the transmission (transmission) or the final reduction gear. Further, the axle to be attached is not limited to the drive shaft 12 but may be a drive shaft such as a propeller shaft. Further, the shaft damper 20 may be attached to the axle portion inside the tire wheel serving as the driving wheel 13, and when an in-wheel motor is provided, the driving voltage is supplied to the in-wheel motor. The in-wheel motor itself may be used as the shaft damper 20 in a situation where it is not applied to the shaft damper 20.

  In the torque fluctuation suppressing device of the present embodiment, the shaft damper 20 (electromagnetic induction means) includes a magnet 21 and a coil 22. A plurality of magnets 21 are attached to the outer peripheral surface of the drive shaft 12, and the coils 22 are arranged around the magnet 21. Several are arranged. For example, the coil 22 is fixed to the vehicle body side by attaching it to the inner peripheral side of the container 23 and attaching the outer peripheral side of the container 23 to a bracket (support member) of a transmission or a propeller shaft. In FIG. 2, four magnets 21 and four coils 22 are illustrated as an example, but the number thereof may be increased or decreased as appropriate. The arrangement positions of the magnet 21 and the coil 22 may be reversed. The magnet 21 may be a permanent magnet, but may be an electromagnet.

  When the shaft damper 20 is attached to the drive shaft 12, the magnet 21 also rotates as the drive shaft 12 rotates. Then, electromagnetic induction occurs between the magnet 21 and the coil 22 due to this rotation, and current and voltage are generated in the coil 22 due to this electromagnetic induction. The torque fluctuation can be calculated based on the generated current and voltage, and further, the current supplied to the coil 22 to suppress the torque fluctuation can be calculated based on the calculated torque fluctuation. Then, by supplying the calculated current to the coil 22 and applying torque from the coil 22 to the magnet 21, that is, to the drive shaft 12, it is possible to reduce torque fluctuation in the drive shaft 12. The basic concept of such torque fluctuation reduction will be described with reference to FIG.

As shown in FIG. 3, a circuit including the shaft damper 20 is considered, and an electrical equation in the circuit is created. The inductance value of the shaft damper 20 is L, the resistance value is R, the current value generated from the shaft damper 20 is i, the voltage value is V, the rotation angle of the drive shaft 12 is θ, and the proportionality constant (counterelectromotive force constant) is K. _If it is set to _e , it can represent with the electrical equation of following formula (1).

The equation of motion in the shaft damper 20 can be expressed by the equation of motion of the following equation (2), where I _d is the inertial mass of the drive shaft 12 and K _m is the proportionality constant (torque constant).

  Here, what is desired is the rotation angle differential value [dθ / dt] of the rotation angle θ, which is a value corresponding to torque fluctuation. Since the inductance value L and the resistance value R of the shaft damper 20 are known in advance, if the current value i and the voltage value V generated from the shaft damper 20 are measured, the rotation angle differential value is obtained as can be seen from the above equation (1). [Dθ / dt] can be obtained. Then, using the obtained rotation angle differential value [dθ / dt], and applying a current value that is opposite to the rotation angle differential value [dθ / dt] to the shaft damper 20, torque fluctuation of the drive shaft 12 Can be reduced. The current value supplied for torque fluctuation reduction will be further described with reference to FIG.

As shown in FIG. 4, a configuration in which a current generator 41 is added to a circuit including the shaft damper 20 is considered, and an electrical equation in the circuit is created in the same manner as in FIG. Here, if the current value flowing through the current generator 41 is i _c , it can be represented by the following electrical equation (3).

Similarly to FIG. 3, the equation of motion of the shaft damper 20 can also be expressed by the equation of equation (4) below. The current value _ic is defined by a function f shown in the following formula (5).

Although the current value i flows due to the torque fluctuation of the drive shaft 12, by supplying the current value _ic using the current generator 41, the torque necessary for reducing the torque fluctuation can be seen from the above equation (4). It is possible to reduce torque fluctuations.

At this time, the current value _ic is obtained using the above equation (5) based on the rotation angle differential value [dθ / dt], but the function f on the right side can be freely set. For example, in FIG. 7 to be described later, the function is a function that returns a constant value whose sign is opposite to the sign of the rotation angle differential value [dθ / dt]. In FIG. The sign of dt] is a function that returns a proportional value with the opposite sign. Further, in the function f, the rotation angle differential value [dθ / dt] is integrated to obtain the rotation angle θ, and an LQR (Linear Quadratic Regulation) control law or HQ is calculated from the rotation angle θ and the rotation angle differential value [dθ / dt]. The current value _ic may be obtained using an ∞ control law or the like.

  The rotation angle θ obtained by integrating the rotation angle differential value [dθ / dt] and the rotation angle differential value [dθ / dt] obtained by using the above formula (3) is further obtained by a low-pass filter, a Kalman filter, and an H∞ filter. The error is removed (filtered) using a filter using short-time Fourier transform or wavelet transform, and the filtered rotation angle differential value [dθ / dt] and rotation angle θ are used in the function f. Good.

The rotation angle differential value [dθ / dt] is obtained using the above equation (3). In the above formula (3), the current value i in the above formula (1) is the current value [i + _ic ], but as described in FIG. 3, the inductance value L and the resistance value R of the shaft damper 20 are Since the current value [i + i _c ] and the voltage value V flowing in the circuit shown in FIG. 4 can be measured in advance, the rotation angle differential value [dθ / dt] can be obtained from the above equation (3). .

As an example, an analog electronic circuit for obtaining a rotation angle differential value [dθ / dt] will be described with reference to FIG. For example, in the circuit shown in FIG. 4, it is possible to create a negative inductance 42 (inductance value [-L]) and negative resistance 43 (resistance value [-R]) using an operational amplifier. As shown in FIG. 5, a negative inductance 42, a negative resistance 43 and a resistor 44 by an operational amplifier are used in the circuit. In such a circuit, if the current value flowing through the circuit is i, the voltage drop in the negative inductance 42 is [−L (di / dt)], and the voltage drop in the negative resistance 43 is [−Ri]. [K _e (dθ / dt)], that is, the rotation angle differential value [dθ / dt] can be obtained by measuring the voltage between terminals of the device 44 (resistance value is r) with a voltmeter.

An example of the control device 30 configured based on the contents described with reference to FIGS. This control device 30 is based on the torque fluctuation detecting means for calculating the rotational angle differential value [dθ / dt] corresponding to the torque fluctuation and the current value i _c (suppression) based on the calculated rotational angle differential value [dθ / dt]. A current control unit 35 serving as a current control unit that calculates and controls the output, and the torque fluctuation detection unit includes a voltage / current measurement unit 31, a rotation angle differential value acquisition unit 33, and a second DC component removal unit. Part 34 is provided. The control device 30 can be implemented as an analog electronic circuit, a digital electronic circuit, or software in a computer or ECU (Electronics Control Unit).

  In the control device 30, the voltage / current measurement unit 31 measures the voltage value V and the current value i generated by electromagnetic induction caused by the rotation of the drive shaft 12 by the shaft damper 20, and supplies the voltage to the rotation angle differential value acquisition unit 33. The value V and the current value i are output to the current control unit 35 as a voltage value V.

  Further, in the rotation angle differential value acquisition unit 33 included in the rotation angle differential value calculation unit 32 (rotation angle differential value calculation means), based on the voltage value V and the current value i measured by the voltage / current measurement unit 31, Using the above formula (1) or the above formula (3), the first rotation angle differential value [dθ / dt] corresponding to the torque fluctuation is calculated and acquired, and similarly included in the rotation angle differential value calculation unit 32. The first rotation angle differential value [dθ / dt] is output to the second DC component removal unit 34. For example, when the rotation angle differential value acquisition unit 33 is realized by an analog electronic circuit, it can be realized by the circuit shown in FIG. Since the first rotation angle differential value [dθ / dt] acquired here is a value corresponding to the torque fluctuation, the torque fluctuation can be accurately detected.

  The second DC component removing unit 34 (direct current component removing unit) subtracts the DC (direct current) component value from the first rotational angle differential value [dθ / dt] acquired by the rotational angle differential value acquisition unit 33. The second rotation angle differential value [dθ / dt] from which the DC component value has been removed is output to the current control unit 35. The DC component value is a value corresponding to the DC component.

In the rotation angle differential value acquisition unit 33 described above, the first item [L (di / dt)] or [L (d (i + i _c ) / dt) is obtained from the right side of the above formula (1) or the above formula (3). ] And [Ri] or [R (i + _ic )] of the second item are subtracted, and the DC component value is removed by this subtraction. That is, the rotation angle differential value acquisition unit 33 described above performs substantially the same as the second DC component removal unit 34, and the DC component value is removed by this subtraction. This is a first DC component removal unit 33a (DC component removal means) in the acquisition unit 33. Further, the second DC component removal unit 34 reliably removes the DC component value from the first rotation angle differential value [dθ / dt] by removing the DC component value. On the other hand, since the first DC component removal unit 33a included in the rotation angle differential value acquisition unit 33 substantially removes the DC component value, the second DC component removal unit 34 is not used. The first rotation angle differential value [dθ / dt] acquired by the rotation angle differential value acquisition unit 33 may be directly output to the current control unit 35.

In the current control unit 35, the absolute value of the voltage value V output from the voltage / current measurement unit 31 is equal to or less than a predetermined voltage value threshold defined in advance, and the calculated first or second rotation angle is calculated. When the absolute value of the differential value [dθ / dt] is equal to or greater than a predetermined rotation angle differential value threshold value defined in advance, the rotation angle differential is calculated based on the calculated first or second rotation angle differential value [dθ / dt]. A current value _ic whose polarity is opposite to that of the value [dθ / dt] is applied to the coil 22 of the shaft damper 20. In particular, when the second rotation angle differential value [dθ / dt] from which the DC component value is removed by the second DC component removal unit 34 is used, the current value _ic corresponding to the torque fluctuation can be calculated. .

On the other hand, if the absolute value of the voltage value V output from the voltage / current measuring unit 31 exceeds the predetermined voltage value threshold, the control device 30 may be broken. The current value _ic is not output from the current control unit 35. If the absolute value of the first or second rotational angle differential value [dθ / dt] is smaller than the predetermined rotational angle differential value threshold, it is determined that the torque fluctuation is sufficiently reduced, and nothing is done. The current value _ic is not output from the current control unit 35. Thereby, suppression control can be performed within the operable range of the torque fluctuation suppressing device, and torque fluctuation can be suppressed when a torque fluctuation of a predetermined value or more is detected.

The current value _ic supplied from the control device 30 (current control unit 35) will be described by exemplifying time-changing currents as shown in FIGS.

In FIG. 7, it is assumed that the torque fluctuation of the drive shaft 12 is oscillating with a sine wave, and the time change of the current value _ic for suppressing the vibration is shown. Specifically, with respect to the rotation angle θ of the drive shaft 12, a constant current value whose sign is opposite to the sign of the rotation angle differential value [dθ / dt], that is, the rotation angle differential value [dθ / dt]. Torque fluctuation is suppressed by supplying a negative constant current value to the coil 22 of the shaft damper 20 when the sign is positive and a positive constant current value when the sign is negative.

In this case, the function f for obtaining the current value _ic can be defined as the following formula (6). In the following equation (6), K ₁ is a proportionality constant, “sign” is a sign function, which is “+1” when a given variable is positive, “0” when zero, and negative It is a function that returns “−1”. As a variable of the sign function “sign”, the first rotation angle differential value [dθ / dt] acquired by the rotation angle differential value acquisition unit 33 or the DC component value is removed by the second DC component removal unit 34. The second rotation angle differential value [dθ / dt] is used.

In FIG. 8, it is assumed that the torque fluctuation of the drive shaft 12 is oscillating with a sine wave, and the time change of the current value _ic for suppressing the vibration is shown. Specifically, the sign of the rotation angle differential value [dθ / dt] is opposite to the sign of the rotation angle θ of the drive shaft 12, and the magnitude of the rotation angle differential value [dθ / dt] ( Current value proportional to the absolute value), that is, if the sign of the rotational angle differential value [dθ / dt] is positive, it is a negative value proportional to the magnitude (absolute value) of the rotational angle differential value [dθ / dt]. When the sign of the current value is negative, a positive current value proportional to the magnitude (absolute value) of the rotational angle differential value [dθ / dt] is supplied to the coil 22 of the shaft damper 20. Torque fluctuation is suppressed.

In this case, the function f for obtaining the current value _ic can be defined as the following equation (7). In the following formula (7), K ₂ is a proportionality constant. As the rotation angle differential value [dθ / dt], the first rotation angle differential value [dθ / dt] acquired by the rotation angle differential value acquisition unit 33 or the DC component value by the second DC component removal unit 34 is used. The removed second rotation angle differential value [dθ / dt] is used.

  Such a control law is generally called DVFB (Direct Velocity Feed Back) control. Not only this DVFB control but also other control laws such as LQR control law, H∞ control law, etc. Applicable.

Thus, in the present embodiment, the current value _ic having the opposite sign to the rotational angle differential value [dθ / dt] representing the torque fluctuation is applied to the coil 22 of the shaft damper 20 so as to cancel the torque fluctuation. The magnetic field generated by the coil 22 is applied to the drive shaft 12 having the magnet 21, and as a result, the torque fluctuation of the drive shaft 12 is reduced. As a result, vibration transmitted to the interior of the vehicle through the tires and suspension can be reduced, and vehicle interior sound and vibration can be reduced.

  Further, in this embodiment, the shaft damper 20 is configured to detect torque fluctuation and suppress torque fluctuation, and there is no need to separately provide a detection device for detecting torque fluctuation. The number of parts can be reduced as compared with the conventional technique in which the suppression device to be suppressed is individually required.

  The present invention can be applied to all vehicles, and is particularly suitable for vehicles using an automatic transmission or a continuously variable transmission as a transmission.

DESCRIPTION OF SYMBOLS 11 Engine 12 Drive shaft 13 Drive wheel 20 Shaft damper 21 Magnet 22 Coil 23 Container 30 Control apparatus 31 Voltage / current measurement part 32 Rotation angle differential value calculation part 33 Rotation angle differential value acquisition part 33a 1st DC component removal part 34 1st DC component removal unit 2 35 Current control unit

Claims (7)

An electromagnetic induction means comprising a magnet and a coil, wherein one of the magnet or the coil is attached to the outer periphery of a vehicle axle, and the other of the magnet or the coil is arranged around the one of the magnet or the coil;
Torque fluctuation detection means for detecting torque fluctuation of the axle based on a current value and a voltage value generated by electromagnetic induction by the electromagnetic induction means as the axle rotates.
A torque fluctuation suppression device comprising: current control means for calculating a suppression current value for suppressing the torque fluctuation based on the detected torque fluctuation and outputting the suppression current value to the coil. The torque fluctuation suppressing device according to claim 1,
The torque fluctuation detection means has a rotation angle differential value calculation means for calculating a rotation angle differential value that is a differential value of the rotation angle of the axle based on the current value and the voltage value,
The torque control device according to claim 1, wherein the current control means calculates the suppression current value based on the rotation angle differential value. The torque fluctuation suppressing device according to claim 2,
The rotational angle differential value calculating means includes direct current component removing means for subtracting a direct current component value from the rotational angle differential value, and removing the direct current component value from the differential value of the rotational angle of the axle to obtain the rotational angle differential value. The torque fluctuation suppressing device characterized by calculating. The torque fluctuation suppressing device according to claim 3,
The current control means outputs the suppression current value to the coil when the absolute value of the rotation angle differential value is greater than or equal to a predetermined rotation angle differential value. In the torque fluctuation suppressing device according to claim 3 or 4,
The current control means calculates and outputs a negative constant current value when the rotation angle differential value is positive, and a positive constant current value as the suppression current value when the rotation angle differential value is negative. Torque fluctuation suppressing device characterized by the above. In the torque fluctuation suppressing device according to claim 3 or 4,
The current control means suppresses a negative current value proportional to the value when the rotation angle differential value is positive, and a positive current value proportional to the value when the rotation angle differential value is negative. A torque fluctuation suppressing device that calculates and outputs a current value. In the torque fluctuation suppression device according to any one of claims 1 to 6,
The said current control means outputs the said suppression current value to the said coil, when the absolute value of the said voltage value is below a predetermined voltage value, The torque fluctuation suppression apparatus characterized by the above-mentioned.

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