JP5098796B2 - Vibration control device and vehicle - Google Patents

Description

  The present invention relates to a vibration damping device that suppresses generated vibrations and a vehicle including the vibration damping device.

  2. Description of the Related Art Conventionally, there has been known a vibration damping device that cancels vehicle vibrations by generating vibration damping force by a vibration means and actively vibrating vehicle vibrations caused by fluctuations in the output torque of a vehicle engine. More specifically, such a vibration damping device includes a linear actuator that is a vibration means provided in an engine that is a vibration generation source, a means that detects the rotational speed of the engine that is a vibration generation source, Proposed is provided with vibration detection means for detecting vibration at a position to be shaken, and an adaptive control algorithm for outputting a vibration command to the linear actuator based on the detected engine speed and vibration at the position to be dampened (For example, refer to Patent Document 1). In this vibration damping device, it is possible to output a vibration command having an optimum amplitude and phase corresponding to the vibration currently detected at the position to be damped by the adaptive control algorithm. The vibration generated from the engine that is the source of vibration due to the vibration control force generated by the vibration means, and transmitted to the position to be controlled such as the seat portion can be reduced.

  In addition, the vehicle at the predetermined point in the vehicle interior based on the vibration generator, the characteristic map storing the vibration transmission characteristics from the place where the vibrator is installed to the predetermined point in the vehicle interior, and the detection signal and the vibration transmission characteristic by the acceleration sensor. There is known an apparatus that includes a digital filter that predicts vibration and reduces vibration by applying vibration using a shaker so as to reduce the predicted vibration (see, for example, Patent Document 2).

  On the other hand, a linear actuator in which a movable element is supported by an elastic support portion (plate spring) so that the movable element can reciprocate with respect to a stator is known as a vibrating means that performs reciprocating movement (for example, Patent Documents). 3). In this linear actuator, since the mover does not wear, the accuracy of shaft support does not deteriorate even after being used for a long time. Further, since sliding resistance does not act on the mover, power loss due to sliding resistance is small. Furthermore, since the bulky coil and the elastic support portion can be disposed close to each other, the linear actuator can be miniaturized.

The linear actuator described in Patent Document 3 can cancel the vibration generated by the target device to be controlled by the reaction force during driving. That is, the actuator can reduce the vibration of the vibration suppression target device by applying a current command so that the reaction force generated by the actuator has an opposite phase with respect to the vibration acceleration of the vibration suppression target device. In general, in order to increase the reaction force of the actuator, an auxiliary mass (weight) is given to the mover. By attaching a vibration damping device using such a linear actuator to the vehicle body, it is possible to cancel the force applied to the vehicle body from the engine of the vehicle, so that the vibration of the vehicle body can be reduced.
Japanese Patent Laid-Open No. 10-492204 Japanese Patent Application Laid-Open No. 08-226489 JP 2004-343964 A

  Incidentally, in the vibration damping device disclosed in Patent Document 1, a linear actuator that is a vibration means is mounted in the vicinity of an engine that is a vibration generation source of the vehicle body. For example, the linear actuator described in Patent Document 3 is a vibration means. Even if it is going to be retrofitted to the vehicle body, it may not be installed in the vicinity of the engine or the position to be damped due to the installation space. In such a case, it is necessary to move the mounting position of the vibration means away from the engine and the position where vibration is to be suppressed. However, the vibration source (engine), vibration means (linear actuator), and position where the vibration is to be suppressed (seat part) Therefore, there is a problem that optimal vibration control force cannot be obtained. That is, the transmission characteristic from the vibration source to the position to be damped is different from the transmission characteristic from the position where the oscillating means is provided to the position to be damped, so the damping force to be generated by the oscillating means The amplitude and phase cannot be uniquely determined from the engine speed. Each transfer characteristic is determined by the rigidity of the vehicle body, the response to the command of the vibration means, the filter characteristic of the acceleration sensor, and the like.

  In order to solve such a problem, the vibration damping device of Patent Document 2 predicts the generated vibration based on the vibration transmission characteristics, and determines the phase and amplitude of the vibration damping force to be generated by the vibration excitation means. Therefore, vibration suppression control can be performed in consideration of vibration transfer characteristics.

  However, when the phase obtained based on the vibration transfer characteristics changes significantly, the phase difference increases before and after the change, and even if vibration suppression control is performed in consideration of the vibration transfer characteristics obtained in advance. There is a problem that the control becomes unstable and diverges.

  The present invention has been made in view of such circumstances, and when the vibration is controlled by adjusting the phase based on the vibration transmission characteristics of the control target device to generate the damping force, the phase greatly changes. It is an object of the present invention to provide a vibration damping device and a vehicle that can stably perform control.

  The present invention provides vibration detection means for detecting vibration at a position to be damped transmitted from a vibration generation source and outputting the vibration signal as a vibration signal, and provided at a position different from the position to be damped, for damping the vibration. Based on the vibration signal output from the vibration detection means for generating the vibration suppression force for canceling the vibration at the power position, an excitation command for the vibration suppression force to be generated by the vibration means is output. And a phase of the vibration command output by the vibration command generation means based on a vibration signal output from the vibration detection means and a transmission characteristic from the vibration means to the vibration detection means. And a phase gradient limit value representing the amount of change in phase that can be changed every control cycle is set in advance, and is output every predetermined control cycle. Memorize phase command When the phase difference between the previous phase command and the current phase command is larger than the phase gradient limit value, each control is performed so that the phase difference for each control period changes below the phase gradient limit value over a plurality of control cycles. And a phase change gradient limiting means for limiting the phase command for each period and outputting it to the excitation command generating means.

  In this configuration, the vibration detecting means detects the vibration at the position to be damped transmitted from the vibration generating source, and outputs it to the value setting unit as a vibration signal. The value setting unit determines the phase of the vibration command based on the vibration signal and the transfer characteristic from the vibration means to the vibration detection means, and outputs it as a phase command. Then, the vibration command generation means generates and outputs a vibration command based on the phase command output from the value setting unit, and generates a damping force by the vibration means. The phase change gradient limiting means stores a phase command output every predetermined control cycle, and compares whether or not the phase difference between the previous phase command and the current phase command is greater than a preset phase gradient limit value. doing. The phase change gradient limiting means limits the phase change for each control period so that it is less than or equal to the phase gradient limit value when the difference between the previous phase command and the current phase command is greater than the phase gradient limit value. To do. In other words, the phase command is sequentially changed so that the phase command is changed below the phase gradient limit value for each control cycle so that the phase command is output by the value setting unit in a plurality of control cycles. Output. For this reason, even if the phase changes significantly, the excitation command can be output from the excitation command generation means by changing the phase by the amount of change below the phase gradient limit value. For this reason, the vibration control means can generate a vibration suppression force in consideration of the transfer characteristics from the vibration control means to the vibration detection means while suppressing the phase change below the phase gradient limit value. The vibration at the position to be performed can be stably controlled.

In addition, the vehicle of the present invention includes a vibration damping device.
According to the present invention, it is possible to stably suppress the vibration at the position to be controlled, which is transmitted from the vibration generating source by the vibration control device, and to provide a comfortable ride for the occupant.

  According to the present invention, by providing the phase change gradient limiting means, the phase changes greatly when the vibration is controlled by generating the damping force by adjusting the phase based on the vibration transfer characteristic of the controlled device. However, stable control can be performed.

  Hereinafter, a vibration damping device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 1 denotes an engine (vibration generation source) mounted on the vehicle in order to generate a driving force for driving the vehicle such as an automobile, and is a generation source of vibration generated in the vehicle. Reference numeral 10 includes an auxiliary mass 11 having a predetermined mass, and a linear actuator that generates a damping force for suppressing vibration generated in the vehicle by a reaction force obtained by vibrating the auxiliary mass 11 (hereinafter referred to as a linear actuator). , Referred to as “actuator” (vibration means). Reference numeral 2 denotes a vehicle body frame of the vehicle. The engine 1 is mounted by the engine mount 1m, and the actuator 10 is mounted at a predetermined position. Here, it is assumed that the actuator 10 suppresses and controls vibration in the vertical direction (gravity direction) generated in the vehicle body frame 2.

  Reference numeral 3 denotes a control unit that performs control to generate vibration damping force in the actuator 10 and suppress vibration generated in the vehicle. Reference numeral 4 denotes an amplifier that supplies a current for driving the actuator 10 to the actuator 10 based on a command value output from the control unit 3. Reference numeral 5 denotes an acceleration sensor (vibration detecting means) mounted in the vicinity of a passenger seat 6 in the vehicle. The control unit 3 obtains an excitation command for driving the actuator 10 based on the engine pulse signal (ignition timing signal) output from the engine 1 and the acceleration sensor output signal output from the acceleration sensor 5. Output to the amplifier 4. Based on this vibration command, the amplifier 4 obtains a current value to be supplied to the actuator 10 and supplies it to the actuator 10, whereby the auxiliary mass reciprocates (in the example shown in FIG. ) And the reaction force can be used to reduce the vibration generated in the vicinity of the seat, which is the position to be damped.

  Here, the detailed configuration of the actuator 10 shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a diagram showing a detailed configuration of the actuator 10 shown in FIG. In this figure, reference numeral 12 denotes a stator having a permanent magnet, which is fixed to the vehicle body frame 2. Reference numeral 13 denotes a mover that reciprocates in the same direction as the vibration direction to be suppressed (up and down movement on the paper surface of FIG. 2). Here, the body frame 2 is fixed to the body frame 2 so that the vibration direction to be suppressed coincides with the reciprocating direction (thrust direction) of the mover 13. Reference numeral 14 denotes a leaf spring that supports the movable element 13 and the auxiliary mass 11 so as to be movable in the thrust direction, and is fixed to the stator 12. Reference numeral 15 denotes a shaft that joins the mover 13 and the auxiliary mass 11, and is supported by a leaf spring 14. The actuator 10 and the auxiliary mass 11 constitute a dynamic vibration absorber.

  Next, the operation of the actuator 10 shown in FIG. 2 will be described. When an alternating current (sine wave current, rectangular wave current) is passed through a coil (not shown) constituting the actuator 10, the magnetic flux is changed from the S pole to the N pole in the permanent magnet when a current in a predetermined direction flows through the coil. As a result, a magnetic flux loop is formed. As a result, the mover 13 moves in a direction (upward) against gravity. On the other hand, when a current in a direction opposite to the predetermined direction is applied to the coil, the mover 13 moves in the direction of gravity (downward). The mover 13 repeats the above operation by alternately changing the direction of the current flow to the coil by the alternating current, and reciprocates in the axial direction of the shaft 15 with respect to the stator 12. As a result, the auxiliary mass 11 joined to the shaft 15 vibrates in the vertical direction. A dynamic vibration absorber composed of the actuator 10 and the auxiliary mass 11 is generated in the vehicle body frame 2 by controlling the acceleration of the auxiliary mass 11 and adjusting the damping force based on the current control signal output from the amplifier 4. The vibration can be reduced by canceling the vibration.

  Next, the vibration transmission characteristics of the vehicle body frame 2 shown in FIG. 1 will be described with reference to FIG. Here, it is assumed that the vibration source of the vehicle body frame 2 is only the engine 1 and that vibrations generated in the vicinity of the passenger seat (driver's seat) 6 among vibrations generated in the vehicle body frame 2 are described. . The engine pulse for driving the engine 1 is a pulse that rises at the timing of ignition, and is output as a 40 Hz pulse signal if the rotational speed of the engine 1 of four cylinders is 1200 rpm (FIG. 4 ( a)). In response to the engine pulse, each cylinder of the engine 1 is ignited, and vibrations synchronized with the ignition timing are generated from the engine 1 (see FIG. 4B). Vibration waves generated in the engine 1 reach the seat 6 through the body frame 2. The vibration transmission characteristic of the vehicle body frame 2 at this time is G ′. The vibration generated in the engine 1 changes in phase (for example, delayed by θ ′) and changes in amplitude due to the vibration transfer characteristic G ′ of the body frame 2 and appears as vibration of the seat 6. By detecting this vibration wave with the acceleration sensor 5, it is possible to detect vibration generated in the seat 6 (see FIG. 4C). If vibration in the opposite phase of the vibration wave signal obtained by the acceleration sensor 5 (vibration wave indicated by a broken line in FIG. 4) is generated at the position of the seat 6, the vibration generated in the seat 6 can be canceled out. The vibration of the seat 6 can be suppressed.

  However, it may not be possible to provide a vibration source that generates a damping force for suppressing vibration in the vicinity of the seat 6 due to restrictions on the layout of the vehicle. For this reason, the actuator 10 shown in FIG. 1 may have to be provided at a position different from the position where vibration should be suppressed (position where the acceleration sensor 5 is provided). Therefore, the damping force generated by vibrating the auxiliary mass 11 is transmitted through the body frame 2 and reaches the seat 6. At this time, the phase and amplitude of the vibration wave generated in the actuator 10 change due to the transfer characteristic G of the body frame 2. Therefore, the vibration wave to be generated by the actuator 10 takes into account the phase change and amplitude change based on the vibration transfer characteristic G from the mounting position of the actuator 10 to the mounting position of the acceleration sensor 5 (position of the seat 6) (for example, It is necessary to generate a signal having a phase opposite to that of the output signal of the acceleration sensor 5 (see FIG. 4D). Therefore, if the damping force is generated in consideration of the phase change and the amplitude change based on the vibration transfer characteristic G from the mounting position of the actuator 10 to the mounting position of the acceleration sensor 5 (the position of the seat 6), the expected control is achieved. A vibration effect can be obtained. However, the vibration transfer characteristic G also changes depending on the frequency of the transmitted vibration and the like, and the change amount of the phase and amplitude changes accordingly. At this time, especially when the amount of change in phase is large, the discontinuity of the damping force transmitted before and after that becomes remarkable, which causes the control to become unstable and diverge, making it impossible to control the vibration. There is a case. Further, the vibration transfer characteristic G also changes due to aging, temperature change, and the like. The present invention generates a damping force in consideration of changes in phase and amplitude based on vibration transmission characteristics, and stabilizes control even when the phase changes greatly.

  Next, referring to FIG. 3, the control unit 3 shown in FIG. 1 takes into account the phase change and amplitude change based on the vibration transfer characteristic G from the mounting position of the actuator 10 to the mounting position of the acceleration sensor 5. An operation for generating a vibration wave signal (vibration command) for generating a force will be described. When generating the vibration wave signal, the control unit 3 generates a signal in which the phase of the vibration wave to be generated is corrected according to the change in the vibration transfer characteristic. FIG. 3 is a control block diagram showing a detailed configuration of the control unit 3 shown in FIG. The control unit 3 inputs an output signal of the acceleration sensor 5 and an engine pulse signal of the engine 1 and outputs an excitation command to the amplifier 4.

  First, the control unit 3 considers the phase change and the amplitude change based on the vibration transfer characteristic G from the mounting position of the actuator 10 to the mounting position of the acceleration sensor 5, and generates a vibration wave signal ( The basic operation for generating the vibration command will be described.

  The BPF (band pass filter) 50 outputs Asin (ωt + φ) as a vibration signal among the output signals of the acceleration sensor 5. Here, Asin (ωt + φ) is a component of the frequency f of the engine pulse signal detected by the frequency detector 31 (ω = 2πf). The vibration signal output from the BPF 50 is a signal obtained by detecting the vibration occurring at the present time. That is, since this vibration signal is a detection signal of vibration generated by using the engine 1 as a vibration source, a signal obtained by inverting the phase of this signal is generated, and the vibration transfer characteristic G of the signal obtained by inverting this phase is generated. By giving an inverse characteristic (1 / G) and outputting it to the amplifier 4, vibration suppression control of vibration generated using the engine 1 as a vibration source is performed.

  Next, the signal (Asin (ωt + φ)) output from the BPF 50 is multiplied by a convergence gain of 2μ. The multipliers 33 and 34 multiply the multiplication results by the reference sine wave sin (ωt) and the reference cosine wave cos (ωt) output from the sine wave transmitter 32, respectively, and output the result to the integrators 35 and 36. . The integrators 35 and 36 integrate the outputs from the multipliers 33 and 34 and output signals having both an amplitude correction component and a phase difference component, respectively. That is, the integrator 35 outputs −A ′ cos φ ′ and the integrator 36 outputs −A ′ sin φ ′ to the multipliers 39, 40, 46 and 47. In FIG. 3 and the following description, the components detected by the acceleration sensor 5 are expressed as “A” and “φ”, and the components generated in the control unit 3 are “A ′” and “φ ′”. Is written.

The sine wave oscillator 32 generates a reference angle ωt from a frequency f of the engine pulse signal detected by the frequency detection unit 31 by a built-in electrical angle generation unit (not shown), and from the reference angle ωt, the reference wave sin (ωt) and reference wave cos (ωt) are output.
The value setting unit 37 includes an amplitude table and a phase table for the frequency f of the engine pulse signal. In these two tables, the result of the pre-measurement of the vibration transfer characteristics from the vibration means to the vibration detection means, that is, the transfer function G from the generated force of the actuator to the acceleration detected by the acceleration sensor before aging and temperature change. Is recorded with the amplitude component | 1 / G (jω) | and the phase component ｊ1 / G (jω), which are the opposite characteristics. The value setting unit 37 receives the frequency f of the engine pulse signal detected by the frequency detection unit 31, and the phase component ∠1 / G (jω) and the amplitude component | 1 / G (jω) related to the frequency f. ) | Is read from each of the two tables. Then, the value setting unit 37 outputs the phase component as P to the change amount suppression unit 42 and outputs the amplitude component as (1 / G) to the sine wave oscillator 38.

  In the change amount suppression unit 42, the value of the phase component P input every m sampling periods is held inside. Then, the phase difference between the value of the phase component P input last time from the value setting unit 37 and the phase component P input this time is calculated, and whether or not the phase difference is larger than a preset changeable upper limit value. Make a comparison. If the phase difference is larger than the changeable upper limit value, the phase difference with the previously input phase component P is corrected so as to be equal to or less than the changeable upper limit value, and is output to the change gradient suppressing unit 45 (FIG. 6).

The change gradient suppression unit 45 retains the value of P + Δp output every m sampling periods so that the change gradient from Δp (f, nm) to Δp (f, n) becomes gentle. , The change amount is output for each change gradient limit value s. That is, for example, as shown in FIG. 7, the phase correction amount is changed from Δp (f, n−1) to the change gradient limit value s = {Δp (f, n) −Δp (f, n−1) for each sampling period. } / 4, and Δp (f, n) after 4 sampling periods. As described above, since the change gradient of P + Δp output every m sampling periods is suppressed, the control can be stably performed without divergence.
Here, the change gradient limit value s refers to a control value having a value smaller than the fixed angle h, and is set to 1/20 (0.05) of the fixed angle h, for example.

  The sine wave oscillator 38 receives the frequency f, the amplitude component (1 / G) of the inverse characteristic of the vibration transfer characteristic G, and the output of the change gradient suppression unit 45. Based on these input values, the sine wave oscillator 38 multiplies the inverse characteristic (∠1 / G (jω) and | 1 / G (jω) |) of the vibration transfer characteristic G by multiplying the reference sine wave (1 / G) sin (ωt + P + Δp) and reference cosine wave (1 / G) cos (ωt + P + Δp) are output. Here, Δp is a phase correction amount for correcting the phase component P of the inverse characteristic of the vibration transfer characteristic G, and details will be described later.

The adder 41 outputs (−A′cosφ ′) × (1 / G) sin (ωt + P + Δp) from the multiplier 39 and the output (−A′sinφ ′) × (1 / G) cos (ωt + P + Δp) from the multiplier 40. And-(A ′ / G) sin (ωt + φ ′ + P + Δp) is output from the addition theorem. That is, the vibration exciter 41 has an amplitude component (as an amplitude component approximate to the amplitude A ′ and an inverse characteristic of the vibration transfer characteristic) with respect to Asin (ωt + φ) which is a component of the frequency f of the engine pulse signal in the acceleration sensor output signal. 1 / G), a signal obtained by correcting the phase difference φ ′ approximated with respect to the phase, the amplitude characteristic P of the inverse characteristic of the vibration transfer characteristic, and the phase correction amount Δp is output. Reference numeral (-1) is for phase inversion by 180 ° with respect to the acceleration sensor output signal.
The output − (A ′ / G) sin (ωt + φ ′ + P + Δp) of the adder 41 is an excitation command output to the bandpass filter 51.

The BPF 51 is a filter that passes frequencies near the frequency f. Note that f is the frequency of the engine pulse signal output from the frequency detector 31.
When the frequency to be damped changes, a plurality of frequency components exist in the damping force in the transient state. Therefore, for example, when there is a resonance frequency to be damped in the vicinity of the changed frequency, the vibration damping force has a frequency component that matches the resonance frequency and has a phase that is different from the vibration phase that can reduce the resonance vibration. In some cases, the resonance frequency is vibrated and the control becomes unstable.
By removing the damping force other than the frequency to be damped by the BPF 51, it is possible to enhance the damping effect and prevent the control from becoming unstable.

  When this vibration command is output to the amplifier 4 via the bandpass filter 51, the auxiliary mass 11 vibrates and generates a damping force, thereby suppressing the vibration generated by the engine 1 detected by the acceleration sensor 5. Will be. At this time, the vibration damping force generated when the actuator 10 vibrates the auxiliary mass is a vibration damping considering the phase change and amplitude change based on the vibration transfer characteristic G from the mounting position of the actuator 10 to the mounting position of the acceleration sensor 5. Since it is force, even if the position where the vibration is detected (the position of the seat 6) is different from the position where the damping force is generated, the generated vibration can be efficiently suppressed. In addition, as described above, the phase change based on the vibration transfer characteristics changes depending on the vibration frequency. generate. Furthermore, as described above, the change gradient is suppressed so that the change gradient of the value of P + Δp output every control cycle becomes a predetermined change gradient. For this reason, it is possible to stably perform the vibration suppression without causing the control by generating the vibration control force from the vibration means due to the sudden phase change to diverge. In the present embodiment, both the change amount suppression unit 42 and the change gradient suppression unit 45 are provided. However, by providing at least one, it is possible to cope with a sudden phase change.

  Next, when generating a vibration wave signal, the phase correction unit 43, the change gradient suppression unit 45, and the table correction unit 49 correct the phase of the excitation command according to the change in vibration transfer characteristics due to secular change or the like. An operation of correcting by the amount Δp will be described.

The table correction unit 49 outputs (−A′sinφ ′) × cos (ωt) + (− A′cosφ ′) × sin (ωt) = − A′sin (ωt + φ ′) of the adder 48 and the engine pulse signal. Frequency f and Asin (ωt + φ) which is a component of frequency f of the acceleration sensor output signal. Then, the phase difference Δφ between the two input signals (−A′sin (ωt + φ ′) and Asin (ωt + φ)) is detected.
Here, Δφ is a difference between the component φ detected by the acceleration sensor 5 and the component φ ′ generated in the control unit 3 and is a numerical value of a change in vibration transfer characteristics due to secular change or the like. That is, as the vibration transfer characteristic in the actual vehicle body differs from the vibration transfer characteristic stored in the value setting unit 37 due to secular change or the like, Δφ becomes farther from zero.
In the present invention, the phase of the vibration command is corrected by the phase correction amount Δp so that Δφ becomes zero. Hereinafter, the phase correction amount Δp will be described.

  First, when there is no secular change or the like and there is no change in the vibration transfer characteristic G, Asin (ωt + φ) and (−A′sin (ωt + φ ′)) are in opposite phases as shown in FIG. That is, Asin (ωt + φ) and (−A′sin (ωt + φ ′)) coincide with each other at the time of the zero cross point at which the sign changes from negative to positive, for example. At this time, the vibration transmitted from the engine 1 to the position to be damped and the damping force generated by the actuator 10 cancel each other, and the vibration at the position to be damped is suppressed without performing phase correction. . Therefore, the table correction unit 49 determines that there is no need for phase correction.

  Next, the case where the vibration transfer characteristic G changes due to secular change or the like will be described. At this time, (−A′sin (ωt + φ ′)) is a phase advance of Δφ as shown in FIG. 10 (0 ≦ Δφ ≦ π) or a phase delay of Δφ as shown in FIG. 11 with respect to Asin (ωt + φ). (−π ≦ Δφ ≦ 0). The table correction unit 49 corrects the phase of the vibration command using the phase correction amount Δp when Δφ ≠ 0.

Here, a method of calculating the phase correction amount Δp will be described. The phase correction amount Δp is a function of the vibration frequency f of the engine pulse signal and is defined by the following equation.
Δp (f, n) = Δp (f, nm) (φ = 0)
Δp (f, n) = Δp (f, nm) −h (0 ≦ Δφ ≦ π)
Δp (f, n) = Δp (f, nm) + h (−π ≦ Δφ ≦ 0)
Note that n and m are integers of n ≧ m, and h is a preset fixed angle described above. That is, the phase correction amount Δp (f, n) in a certain sampling period is obtained by adding or subtracting 0 or h to Δp (f, mn) before the m sampling period.

  Then, the table correction unit 49 updates the correction value table 44 based on the obtained Δp value and the frequency f output from the frequency detection unit 31. FIG. 5 shows a table structure of the correction value table 44 shown in FIG. As shown in FIG. 5, the correction value table 44 is a table in which the phase correction amount (Δp) is associated and stored for each frequency. The initial value of the table stores, for example, “0” for all frequencies. The correction value table 44 is composed of a nonvolatile memory, and the stored contents are retained even when the power is turned off.

When the phase correction amount is updated, the table correction unit 49 reads out the phase correction amount related to the frequency to be updated, and sets a predetermined correction value for making Δφ close to 0 with respect to the phase correction amount. to add. For example, in the example illustrated in FIG. 5, when the frequency f is 40 Hz, the phase correction amount Δp is defined as “−1 °” in the previous state (Δp (40 Hz, n−1) = − 1 °). . At this time, if a “phase delay” is detected, as shown in the following equation, for example, a predetermined value (for a phase correction amount Δp (40 Hz, n−1) before one sampling period) ( For example, 1 °) is added.
Δp (40 Hz, n) = Δp (40 Hz, n−1) + 1 ° = 0 °
Here, the value to be added is set to a predetermined small value. In order to accurately determine the amount of phase shift, the amount of calculation increases, and if a large correction is performed once, the control may become unstable. The reason is that there is. Since the change in characteristics due to secular change does not change in a short time, the value to be corrected at a time is set to a small value, and the correction is made gradually while keeping the control operation stable. By this operation, the correction value table 44 always stores a phase correction value when the vibration transfer characteristic G is changed due to the characteristic change due to the secular change or the like.

  Next, the phase correction unit 43 reads the phase correction amount (Δp) related to the frequency output from the frequency detection unit 31 from the correction value table 44, and uses the read phase correction value as the change amount suppression described above. This is added to the signal output from the unit 42. The signal (P + Δp) to which the phase correction value has been added is output to the sine wave oscillator 38 via the change gradient suppressing unit 45 described above.

  By outputting this P + Δp to the sine wave oscillator 38, a vibration command to the actuator 10 is generated by the basic operation described above. That is, the generated vibration wave signal (vibration command) is a signal that has been phase-corrected by the phase correction unit 43 in accordance with changes in vibration transfer characteristics due to secular change or the like.

The table correction unit 49 of the present embodiment not only updates the phase correction amount of the vibration frequency f to be corrected for the phase correction amount stored in the correction value table 44, but at least either immediately before or immediately after that. The phase correction amount of one of the vibration frequencies is updated so as to decrease stepwise. This method of updating the phase correction amount is hereinafter referred to as front / rear phase correction.
For example, as shown in FIG. 8 and the following equation, when a preset value h = 1 is added to a phase correction amount Δp = 0 ° at f = 40 Hz to obtain Δp = 1 °, Δp at a frequency in the vicinity thereof Also for h, a value of 1/2 or 1/4 of h = 1 is added.
Δp (39.8 Hz, n) = Δp (39.8 Hz, n−1) + 0.25 °
Δp (39.9 Hz, n) = Δp (39.9 Hz, n−1) + 0.5 °
Δp (40.0 Hz, n) = Δp (40.0 Hz, n−1) + 1 °
Δp (40.1 Hz, n) = Δp (40.1 Hz, n−1) + 0.5 °
Δp (40.2 Hz, n) = Δp (40.2 Hz, n−1) + 0.25 °

That is, in the front and rear phase correction, the phase correction amount Δp of the frequency immediately before and after the phase correction amount Δp (f, n) to be updated is centered on the phase correction amount Δp (f, n) so as to be symmetric with respect to Δp (f, n). As for (f−k, n) and Δp (f + k, n), a value obtained by multiplying a preset h by a constant is added. Note that k is an integer or a positive decimal number.
By doing so, it is possible to prevent only the phase correction amount at one frequency from becoming large and to continuously change the phase correction amount for each frequency, so that phase correction is stably performed. It becomes possible.
The front-rear phase correction does not have to be symmetrical about the frequency f to be updated. For example, as shown in FIG. 12, Δp (f−k, n) is constant as the distance from the center frequency f increases. The value (for example, 0.25) may be decreased, and Δp (f + k, n) may be decreased exponentially as the distance from the center frequency f increases. In addition, Δp (f−k, n) and Δp (f + k, n) are updated so as to be symmetric with respect to the center frequency f in the preset frequency band, and so as to be asymmetric in the front and back directions in other frequency bands. You may update to By changing the amount to be updated with respect to the frequency in this way, for example, the change in the phase correction amount near the resonance point of the vehicle body frame 2 or near the noisy frequency band can be smoothed. Can be performed stably.

  If Δφ which is the difference between the component φ detected by the acceleration sensor 5 and the component φ ′ generated in the control unit 3 is smaller than a predetermined threshold value, the phase correction amount is not updated, or The phase correction may not be performed. In other words, by providing a dead zone for phase correction, even if a minute frequency change occurs transiently at the vibration source or the position to be controlled, the control unit will not follow the change and control will not be possible. Stabilization can be prevented. Note that whether or not the control tends to become unstable is also affected by whether or not the vibration of the vibration source is in the vicinity of the resonance frequency to be controlled, so the above-described threshold value may be set for each frequency. It may be a constant value regardless of the frequency.

  Further, the phase correction unit 43 may update the phase correction amount or correct the phase when the frequency f of the vibration source is continuously detected within a preset range for a preset number of times. good. For example, when 10 samples of the frequency of f ± 1 Hz are detected, the phase correction amount is updated or the phase correction is performed, so that a minute frequency change is transiently reduced at the vibration source or the position to be controlled. Even if it occurs, it is possible to prevent the control from becoming unstable due to the controller following the change excessively. Note that whether or not the control is likely to become unstable is also affected by whether or not the vibration of the vibration source is in the vicinity of the resonance frequency to be controlled, so the above setting range or number of times is set for each frequency. Alternatively, it may be a constant value regardless of the frequency.

  Further, the phase correction unit 43 updates the phase correction amount or corrects the phase when the amplitude of the excitation command is continuously output to the amplifier 4 within a preset range for a preset number of times. May be. For example, when the amplitude fluctuation of the vibration command is within a range of ± 2% and 10 samples are output, the phase correction amount is updated or the phase correction is performed, so that the vibration source or the position to be controlled is controlled. Even when a minute change in frequency occurs transiently, it is possible to prevent the control from becoming unstable due to the controller following the change excessively. Note that whether or not the control is likely to become unstable is also affected by whether or not the vibration of the vibration source is in the vicinity of the resonance frequency to be controlled, so the above setting range or number of times is set for each frequency. Alternatively, it may be a constant value regardless of the frequency.

  Further, when the acceleration amplitude detected by the acceleration sensor 5 is larger than a preset threshold value, the phase correction amount may be updated or the phase correction may be performed. For example, if the position to be damped is a vehicle seat, the acceleration amplitude of vibration that a seated person feels large is set as a threshold value, and if it is above the threshold value, the occupant is surely damped. While providing a comfortable ride comfort, the calculation load can be reduced and the calculation error can be prevented due to the quantization error because the phase correction amount is not updated or the phase correction is not performed when the value is below the threshold value. Note that, for example, since vibrations that are easily felt by humans vary depending on the frequency, the above-described threshold value may be set for each frequency, or may be a constant value regardless of the frequency.

  The correction value table 44 is not necessarily a non-volatile memory, and may be another rewritable recording medium. Further, for example, the phase correction amount for each vibration frequency may be stored in a recording medium at every predetermined timing such as when the vehicle is stopped or the engine is stopped, and may be read at the time of restart and used for vibration control. That is, by using the phase correction amount updated before restarting, vibration suppression control can be performed without a sense of incongruity even immediately after restarting. When restarting, the previously recorded phase correction amount may be multiplied by a predetermined value such as 0.5 to be used for vibration suppression control.

  As described above, since the phase of the excitation command is corrected based on Δφ which is the difference between the component φ detected by the acceleration sensor 5 and the component φ ′ generated in the control unit 3, the secular change and the temperature change Even when the vibration transfer characteristic G of the body frame 2 changes due to the above or the like, a high vibration damping effect equivalent to that before the change can be obtained. In other words, even if it is necessary to correct the vibration transfer characteristic G set in the vibration damping device in advance due to secular change, the vibration damping device can autonomously correct the change in G, which makes it complicated for the user. It is possible to keep the vibration control effect before aging, etc. without making any corrective work.

  In the above description, the phase P set by the value setting unit 37 is corrected by the phase correcting unit 43 after passing through the change amount suppressing unit 42. However, the present invention is not limited to this, but by the phase correcting unit 43. After the correction, the change amount suppressing unit 42 may compare whether or not the changeable upper limit value is larger than the changeable upper limit value. In this case, the change amount suppression unit 42 not only changes the phase P set by the value setting unit 37 but also changes in phase due to secular change, temperature change, etc. of the transfer characteristic G considered by the phase correction unit 43. Judgment can also be made. In addition, the change gradient suppression unit 45 receives the phase P + Δp corrected by the phase correction unit 43 and the change gradient is limited. However, the change gradient suppression unit 45 is not limited to this, and the change gradient suppression unit 45 changes the gradient. It is also possible to correct the phase after limiting.

  Further, while obtaining the amplitude component 1 / G and the phase component P from the inverse characteristic table based on the frequency f of the engine pulse signal, the output of the adder 48 -A'sin (ωt + φ ') and the frequency of the acceleration sensor output signal The phase correction amount Δp is obtained so that the phase difference Δφ with respect to Asin (ωt + φ) which is the component of f becomes 0, and the phase of the vibration command is corrected by P and Δp. Therefore, for example, the calculation process can be simplified and the calculation time can be shortened as compared with the case where the inverse characteristic itself is calculated from the engine pulse signal and the acceleration sensor output signal. That is, not only can the control with good responsiveness be realized, but also the circuit necessary for the calculation can be configured at low cost, so that it is possible to provide the user with a vibration control device that is inexpensive and has high vibration control performance.

  In addition, since the damping force is generated taking into account the reverse characteristic of the vibration transmission characteristic from the vibration means to the vibration detection means, the actuator 10 as the vibration means can be placed at an arbitrary position on the body frame 2. Can be installed later. For this reason, for example, even when retrofitted to a used vehicle that has undergone aging, vibration control can be performed without requiring any complicated adjustment work. It is also possible to install it from the beginning on a new vehicle that does not change over time.

In the above description, the case of suppressing and controlling the vibration in the vertical direction (gravity direction) generated in the body frame 2 has been described. However, the direction of vibration to be controlled is not limited to the vertical direction, and vibration detection is performed. The detection position and direction of the means and the vibration position and direction of the vibration means can be changed as appropriate. For example, if the detection means is installed on the vehicle handle, the vibration transmitted from the handle to the driver's hand can be reduced without being affected by aging.
Further, the linear actuator 10 shown in FIG. 2 is used to generate a damping force. However, the driving source can generate a reaction force that can suppress vibration by vibrating the auxiliary mass 11. For example, any means for vibrating the auxiliary mass 11 may be used.

  The vibration damping device according to the present invention can be applied to a vibration suppressing application in a case where a position where vibration is to be suppressed and a position where a damping force is generated are different. In the above description, the vibration suppression target is described as being a vehicle body frame. However, the vibration suppression target device according to the vibration suppression device of the present invention does not necessarily have to be a vehicle body frame. It may be a car body, a robot arm, or the like.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a schematic diagram which shows the structure of the actuator 10 shown in FIG. It is a block diagram which shows the structure of the control part 3 shown in FIG. It is explanatory drawing which shows the vibration transmission characteristics G and G 'of the vehicle body frame 2 shown in FIG. It is explanatory drawing which shows the table structure of the correction value table 44 shown in FIG. It is explanatory drawing which shows operation | movement of the variation suppression part 42 shown in FIG. It is explanatory drawing which shows operation | movement of the change gradient suppression part 45 shown in FIG. It is explanatory drawing which shows operation | movement of the table correction | amendment part 49 shown in FIG. It is explanatory drawing which shows the phase shift state of the produced | generated signal and the detected signal. It is explanatory drawing which shows the phase shift state of the produced | generated signal and the detected signal. It is explanatory drawing which shows the phase shift state of the produced | generated signal and the detected signal. It is explanatory drawing which shows the modification of the phase correction | amendment of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Body frame, 3 ... Control part (Excitation command generation means, Phase correction means), 4 ... Amplifier, 5 ... Acceleration sensor (vibration detection means), 6 ... Seat, 10 ... Actuator (linear actuator, excitation means), 11 ... Auxiliary mass, 31 ... Frequency detector, 32, 38 ... Sine wave oscillator, 37 ... Value Setting unit 42 ... Change amount suppressing unit 43 ... Phase correcting unit 44 ... Correction value table 45 ... Change gradient suppressing unit 49 ... Table correcting unit 50, 51 ...・ BPF (band pass filter)

Claims (2)

Vibration detection means for detecting vibration at a position to be damped transmitted from the vibration source and outputting it as a vibration signal;
An excitation means that is provided at a position different from the position to be damped, and generates a damping force for canceling vibration at the position to be damped;
Based on the vibration signal output from the vibration detection means, an excitation command generation means for outputting an excitation command of a damping force to be generated by the excitation means;
Based on the vibration signal output from the vibration detection means and the transfer characteristics from the vibration means to the vibration detection means, the phase of the vibration command output by the vibration command generation means is determined and output as a phase command. A value setting section;
A phase gradient limit value representing the amount of change in phase that can change every control cycle is set in advance, the phase command output every predetermined control cycle is stored, and the previous phase command and the current phase command are stored. If the phase difference from the phase command is larger than the phase gradient limit value, the phase command is limited for each control cycle so that the phase difference for each control cycle is less than the phase gradient limit value and changes over multiple control cycles. And a phase change gradient limiting means for outputting to the vibration command generating means.   A vehicle comprising the vibration damping device according to claim 1.

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