JP2019170020A - Movement amount control device for moving member - Google Patents

Abstract

To appropriately control the movement amount of a moving member when the ration state of an electric motor is difficult to accurately get to know because of generation of electric noise.SOLUTION: The movement amount control device controls the movement amount of a window plate that moves by being driven by a brush-provided electric motor. A ripple frequency detection unit 328 performs frequency analysis of the detected waveform of an electric current flowing through the electric motor so as to detect a peak frequency, and detects the peak frequency as a ripple frequency which is the frequency of a ripple generated in the electric current. A movement control unit 336 detects the rotation state of the electric motor on the basis of the ripple frequency, and controls the movement amount of the window plate. When there are a plurality of the peak frequencies. The ripple frequency detection unit 328 selects a peak frequency to be detected as the ripple frequency, on the basis of the moving direction of the window plate at the detection time of the detected waveform.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a moving amount control device for a moving member that moves by driving of an electric motor.

Conventionally, as a method of grasping the rotation state of the electric motor, a method of detecting the amount of rotation by counting the period of a current waveform (ripple waveform) generated from brush noise is known.
For example, in Patent Document 1 below, a brush is provided; a motor control unit that controls power supplied to the motor; a current detection unit that detects a current flowing through the motor; Speed detection means for detecting the rotation frequency of the motor by detecting the ripple frequency emitted from the portion, and the motor control means controls the rotation speed detected by the speed detection means so as to become the target rotation speed. There is disclosed a brush motor speed control device configured to perform highly accurate control without being affected by temperature and motor variations without using an external detection means such as the above.
Patent Document 2 listed below discloses a method for detecting rotation information of an electric motor for the purpose of reducing the influence of noise and accurately detecting rotation information of the electric motor. More specifically, frequency analysis is performed on the time-series waveform data of the current flowing through the electric motor, and the frequency having the maximum value in the low band of the obtained frequency spectrum is set as the basic frequency candidate Fb, and among the basic frequency candidates Fb The ripple frequency candidate Frb is calculated by multiplying the frequency Fbm having the maximum amplitude by a coefficient set in advance based on the number of commutators of the electric motor and the change characteristics of the current flowing through the electric motor. In the frequency spectrum, the frequencies having the maximum values on both sides of the ripple frequency candidate Frb are added as ripple frequency candidates Frr and Frl. When the maximum amplitude of these ripple frequency candidates Frb, Frr, Frl is equal to or greater than a predetermined threshold, the ripple frequency candidate Frl having the maximum amplitude is estimated as the ripple frequency. Based on this ripple frequency, rotation information of the electric motor is detected.

Japanese Patent Application Laid-Open No. 2004-080921 JP 2013-212028 A

In a vehicle power window, a power slide door, and the like, the position of a moving member (window plate, door plate, etc.) is recognized based on the rotation state of the electric motor, and pinch prevention control or the like is performed.
However, when the periodic noise generated from the vehicle is mixed in the motor power source, there is a problem that the ripple waveform may not be accurately captured.
The present invention has been made in view of such circumstances, and an object of the present invention is to determine the state of the moving member when it is difficult to accurately grasp the rotation state of the electric motor due to electrical noise. It is to control appropriately.

In order to achieve the above-mentioned object, a moving amount control device for a moving member according to the invention of claim 1 is a moving amount control device for a moving member that moves by driving of an electric motor provided with a brush. A current detection unit that detects a flowing current; a ripple frequency detection unit that detects a peak frequency by performing frequency analysis on a detection waveform of the current; and detects the peak frequency as a ripple frequency that is a frequency of a ripple generated in the current; A movement control unit that detects a rotation state of the electric motor based on the ripple frequency and controls a movement amount of the moving member, and when the ripple frequency detection unit has a plurality of the peak frequencies, Based on the moving direction of the moving member at the time of detection of the detection waveform, the peak frequency to be detected as the ripple frequency is selected. And wherein the door.
According to a second aspect of the present invention, there is provided a movement amount control device for a moving member, wherein the moving member is an opening / closing member that opens and closes an opening, and the ripple frequency detection unit detects when the detection waveform is closed The peak frequency on the lowest frequency side is set as the ripple frequency, and when the detection waveform is detected when the opening / closing member is opened, the peak frequency on the highest frequency side is set as the ripple frequency. It is characterized by that.
According to a third aspect of the present invention, the moving member moving amount control device is characterized in that the opening is a window opening of a vehicle, and the opening and closing member is a window plate that opens and closes the window opening.

According to the invention of claim 1, when a plurality of peak frequencies are detected due to electrical noise or the like, the peak frequency detected as the ripple frequency based on the moving direction of the moving member at the time of detecting the detected waveform is Since the selection is made, it is advantageous in appropriately controlling the state of the moving member even when the position of the moving member cannot be accurately grasped.
According to the invention of claim 2, when the detection waveform is detected when the switching member is closed, the peak frequency on the lowest frequency side is set as the ripple frequency, and the detection waveform is detected when the switching member is opened. In this case, the peak frequency on the highest frequency side is set as the ripple frequency, so that it is possible to avoid erroneously detecting that the opening / closing member is in the dead zone when a predetermined control dead zone is set on the closing position side of the opening / closing member. Thus, it is advantageous for reliably performing the predetermined control.
According to the invention of claim 3, since the window plate for opening and closing the window opening of the vehicle is used as the opening and closing member, it is advantageous for reliably operating the pinching prevention function in the vehicle power window system.

It is a figure showing composition of power window system 10 concerning an embodiment. 3 is a block diagram showing a detailed configuration of a window plate position detection unit 320. FIG. It is a graph which shows various waveforms. It is explanatory drawing which shows a ripple frequency detection method typically. It is explanatory drawing which shows typically the dead zone in a pinching prevention function. It is explanatory drawing which shows typically the time of obstruction | occlusion of the window board 16 (at the time of upward movement). It is explanatory drawing which shows typically the time of opening of the window board 16 (at the time of a downward movement).

Exemplary embodiments of a moving member moving amount control apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings.
In the present embodiment, a description will be given of window position control in a vehicle power window system, that is, a case where a moving member that is a moving object of an electric motor is a window plate that opens and closes a vehicle window opening (opening).

FIG. 1 is a diagram illustrating a configuration of a power window system 10 according to an embodiment.
The power window system 10 is a mechanism for moving the position of the window plate 16 for opening and closing the window opening 14 provided in the door member 12 of the vehicle by the electric motor 40.
As shown in FIG. 1, a door sash 18 is provided inside the door member 12, and a window plate 16 is supported on the door sash 18 so as to be movable up and down (openable and closable). A window regulator 20 is disposed inside the door panel of the door member 12, and the window plate 16 is driven up and down (opening and closing) by the window regulator 20.

More specifically, the window regulator 20 is provided with an electric motor 40, and by driving the electric motor 40, the window plate 16 is driven up and down (open / close drive) via the drive gear 22, the lift arm 24, and the driven arm 26. .
The amount of movement (opening amount) of the window plate 16 is determined by the vehicle occupant operating the operation switch 32 in the passenger compartment. The operation switch 32 is connected to the movement amount control device 30 of the window plate 16, and when the operation switch 32 is operated, the movement amount control device 30 outputs a drive control signal to the electric motor 40. The electric motor 40 is driven based on the drive control signal and the window regulator 20 is operated, whereby the window plate 16 moves to a desired position.

  The electric motor 40 is a DC (direct current) motor including a brush and a commutator. The electric motor 40 is connected to the battery 28 and is driven by a current supplied from the battery 28. A current flowing through the electric motor 40 (hereinafter referred to as “motor current”) is detected by the current detector 34, and the detected value is output to the movement amount control device 30.

The movement amount control device 30 includes a window plate position detection unit 320 and a pinching prevention function unit 340.
The window plate position detection unit 320 detects the rotation state (the number of rotations, etc.) of the electric motor 40 and detects the position of the window plate 16 based on this. Details of the window plate position detector 320 will be described with reference to FIG.
The pinching prevention function unit 340 executes pinching prevention control in order to prevent the object from being caught between the window plate 16 and the window frame. In the pinching prevention control, the rotation speed of the electric motor 40 when the window plate 16 is closed is detected, and when the rotation speed becomes a predetermined value or less, it is determined that pinching has occurred and the rotation of the electric motor 40 is reversed. Thus, the window plate 16 is moved in the opening direction.

Here, the decrease in the rotation speed of the electric motor 40 occurs not only when the pinching occurs but also when the window plate 16 reaches the upper end position and the lower end position (movement limit position) of the window frame. Even in such a case, if the moving direction is reversed, the position of the window plate 16 cannot be maintained appropriately.
Therefore, the pinching prevention function unit 340 makes the dead zone within a predetermined distance from the upper end position of the window frame as shown in FIG. 5 and reduces the rotation speed of the electric motor 40 when the upper end position of the window plate 16 is located in the dead zone. Even if it is detected, the pinch prevention function is not activated.

FIG. 5 schematically shows the window plate 16 and the window opening 14.
As described above, the window plate 16 can be moved up and down by the operation of the window regulator 20. The window opening 14 has an opening upper end position F1 and an opening lower end position F2. The upper end position T0 of the window plate 16 is movable between the opening upper end position F1 and the opening lower end position F2.
Here, when the window plate 16 moves upward (when the window is closed), if an object is sandwiched between the upper end position T0 of the window plate 16 and the upper end position F1 of the opening, the movement of the window plate 16 (electric motor) 40). When such a decrease in the rotational speed of the electric motor 40 occurs, the pinching prevention function unit 340 reverses the movement of the electric motor 40 and changes the movement direction of the window plate 16 downward (window opening direction). .

A dead zone D is set in a range of a distance d downward from the opening upper end position F1. This is because if the reversal control is performed when the window plate 16 reaches the opening upper end position F1, the window cannot be completely closed.
Therefore, the pinching prevention function unit 340 does not perform reversal control when the upper end position T0 of the window plate 16 is located in the dead zone D, and the reversal region E where the upper end position T0 of the window plate 16 is a region other than the dead zone D. When it is positioned at, reversal control is performed.
As described above, in order to properly function the pinching prevention function, it is necessary to grasp the position of the window plate 16 by the movement amount control device 30.

Next, details of the window plate position detector 320 will be described with reference to FIG.
The window plate position detection unit 320 includes a tendency correction unit 322, a frequency analysis unit 326, a ripple frequency detection unit 328, a filter design unit 330, a filtering processing unit 332, a pulse processing unit 334, and a movement control unit 336.

  The trend correction unit 322 corrects the trend of the time series waveform data of the motor current detected by the current detection unit 34. More specifically, the trend correction unit 322 calculates approximate data by approximating the time series waveform data of the motor current as shown in FIG. 3A with a quadratic function by the least square method. Then, each value of the approximate data is subtracted from each value of the time series waveform data of the motor current to correct the tendency of the time series waveform data of the motor current. Note that the waveform in FIG. 3A includes a noise component.

  The frequency analysis unit 326 performs frequency analysis on the time-series waveform data (current detection waveform) of the motor current after the trend correction by FFT (Fast Fourier Transform). Thereby, the time-series waveform data of the motor current as shown in FIG. 3A is converted into a frequency spectrum (waveform data in frequency units) as shown in FIG. 3B, for example.

The ripple frequency detection unit 328 detects the peak frequency from the analysis result of the frequency analysis unit 326, and detects the peak frequency as a ripple frequency that is a frequency of a ripple generated in the current.
FIG. 4 is an explanatory diagram schematically showing a ripple frequency detection method.
FIG. 4A shows time series waveform data of an ideal motor current free from noise, etc., the left figure shows a waveform when the rotation of the electric motor 40 is relatively slow, and the right figure shows a case where the rotation of the electric motor 40 is relatively fast. The waveform is shown.
In the motor current, a ripple waveform due to brush noise appears as the electric motor 40 rotates. Since the ripple waveform is a periodic waveform, a prominent peak is obtained when frequency analysis is performed. That is, when the rotation of the electric motor 40 is slow as shown in the left figure of FIG. 4A, a peak appears on the low frequency side as shown in the left figure of FIG. 4B, and the rotation of the electric motor 40 is fast as shown in the right figure of FIG. In FIG. 4B right, a peak appears on the high frequency side.
As described above, the ripple frequency can be detected by detecting the peak frequency of the motor current subjected to the frequency analysis.

On the other hand, as shown in FIG. 3A, noise generated from the vehicle is mixed in the actual motor current waveform. When such a waveform is frequency-converted, a plurality of peak frequencies may appear as shown in FIG. 3B. For example, in FIG. 3B, two peak frequencies P1 and P2 are detected.
Thus, when there are a plurality of peak frequencies in the waveform after frequency analysis, the ripple frequency detection unit 328 detects the ripple frequency based on the moving direction of the window plate 16 (moving member) when detecting the detected waveform of the motor current. Select the peak frequency to be used.
More specifically, the ripple frequency detector 328 uses the lowest peak frequency as the ripple frequency when the motor current (detected waveform) is detected when the window plate 16 is closed, and the motor current (detected waveform). When the window plate 16 is opened, the peak frequency on the highest frequency side is set as the ripple frequency.
This is to ensure that the pinching prevention function functions even if the selected peak frequency is wrong.

For example, when two peak frequencies appear as shown in FIG. 3B, one peak frequency is a true ripple frequency and the other peak frequency is a peak due to noise. When one of the two peak frequencies is adopted as the ripple frequency, the actual amount of rotation of the electric motor, that is, the position of the window plate 16 can be correctly calculated if the true ripple frequency can be selected, but the peak due to noise is adopted. In this case, the position of the window plate 16 cannot be calculated correctly.
For example, when the true ripple frequency is P1 and the peak P2 on the high frequency side is set as the ripple frequency, the movement amount of the window plate 16 is calculated to be larger than the actual amount. When the true ripple frequency is P2, and the peak P1 on the low frequency side is set as the ripple frequency, the movement amount of the window plate 16 is calculated to be smaller than the actual amount.

FIG. 6 is an explanatory diagram schematically showing when the window plate 16 is closed (upward movement). FIG. 6A shows a case where a peak value on the higher frequency side than the actual ripple frequency is adopted as the ripple frequency. The case where the peak value on the lower frequency side than the actual ripple frequency is adopted as the ripple frequency is shown.
In FIG. 6A, the solid line indicates the position of the actual window plate 16, and the dotted line indicates the position of the erroneously detected window plate 16 when the peak value on the higher frequency side than the actual ripple frequency is adopted as the ripple frequency. is there. As described above, when the peak on the higher frequency side than the actual is the ripple frequency, the amount of movement of the window plate 16 is calculated to be larger than the actual. Therefore, the upper end position T1 of the erroneously detected window plate 16 is higher than the actual upper end position T0 of the window plate 16.
In this case, although the actual upper end position T0 is in the inversion area E, it may be determined that the erroneously detected upper end position T1 is in the dead zone D, and the pinching prevention function may not work.

In FIG. 6B, the solid line indicates the position of the actual window plate 16, and the dotted line indicates the erroneously detected window plate 16 when a peak value on the lower frequency side than the actual ripple frequency is adopted as the ripple frequency. Is the position. As described above, when the peak on the lower frequency side than the actual is the ripple frequency, the amount of movement of the window plate 16 is calculated to be smaller than the actual. Therefore, the upper end position T2 of the window plate 16 erroneously detected is lower than the upper end position T0 of the actual window plate 16.
In this case, even when the actual upper end position T0 is in the dead zone D, it is determined that the erroneously detected upper end position T2 is in the inversion area E, and the pinching prevention function is activated. As a result, although the window plate 16 is inverted at the opening upper end position F1 of the window frame and the window may not be completely closed, it is possible to prevent the object from being caught.
Therefore, the ripple frequency detector 328 ripples the peak frequency on the lowest frequency side when the motor current (detected waveform) is detected when the window plate 16 is closed, when there are a plurality of peak frequencies in the waveform after frequency analysis. The frequency.

FIG. 7 is an explanatory view schematically showing when the window plate 16 is opened (during downward movement). FIG. 7A shows a case where a peak value on the higher frequency side than the actual ripple frequency is adopted as the ripple frequency. The case where the peak value on the lower frequency side than the actual ripple frequency is adopted as the ripple frequency is shown.
In FIG. 7A, the solid line indicates the position of the actual window plate 16, and the dotted line indicates the position of the erroneously detected window plate 16 when the peak value on the higher frequency side than the actual ripple frequency is adopted as the ripple frequency. is there. As described above, when the peak on the higher frequency side than the actual is the ripple frequency, the amount of movement of the window plate 16 is calculated to be larger than the actual. Thus, the erroneously detected upper end position T3 of the window plate 16 is lower than the actual upper end position T0 of the window plate 16.
In this case, even when the actual upper end position T0 is in the dead zone D, it is determined that the erroneously detected upper end position T3 is in the reversal area E. For example, when the moving direction of the window plate 16 is reversed, The trapping prevention function is activated when an object is present.

In FIG. 7B, the solid line indicates the position of the actual window plate 16, and the dotted line indicates the erroneously detected window plate 16 when the peak value on the lower frequency side than the actual ripple frequency is adopted as the ripple frequency. Is the position. As described above, when the peak on the lower frequency side than the actual is the ripple frequency, the amount of movement of the window plate 16 is calculated to be smaller than the actual. Thus, the erroneously detected upper end position T4 of the window plate 16 is higher than the actual upper end position T0 of the window plate 16.
In this case, it is determined that the erroneously detected upper end position T1 is in the dead zone D even though the actual upper end position T0 is in the reversal zone E. For example, when the moving direction of the window plate 16 is reversed, the window opening 14 The pinch prevention function may not work when there is an object inside.
For this reason, the ripple frequency detector 328 selects the lowest peak frequency when the motor current (detected waveform) is detected when the window plate 16 is closed when there are a plurality of peak frequencies in the waveform after frequency analysis. Ripple frequency.
Thus, the ripple frequency detection unit 328 sets the peak frequency on the highest frequency side as the ripple frequency when the motor current (detection waveform) is detected when the window plate 16 is opened.

Returning to the description of FIG. 2, the filter design unit 330 sets the low frequency side and high frequency side edge frequencies based on the ripple frequency detected by the ripple frequency detection unit 328. More specifically, values obtained by increasing / decreasing the ripple frequency by a predetermined ratio C% are set as edge frequencies on the high frequency side and the low frequency side, respectively.
Then, bandpass filter coefficients are calculated based on the low frequency side and high frequency side edge frequencies. More specifically, a general FIR (finite impulse response) filter based on the window function method is designed to calculate each filter coefficient.

The filtering processing unit 332 filters the time-series waveform data of the motor current using the filter designed by the filter design unit 330 and extracts the time-series waveform data of the ripple current. As a result, it is possible to extract time series waveform data only of ripple current as shown in FIG. 3C from time series waveform data of motor current including noise as shown in FIG. 3A.
The pulse processing unit 334 binarizes the time-series waveform data of the ripple current as shown in FIG. 3C to generate a rectangular wave ripple pulse signal as shown in FIG. 3D.

The movement control unit 336 detects the rotation state of the electric motor 40 based on the ripple frequency (more specifically, the ripple pulse signal generated by the pulse processing unit 334), and controls the movement amount of the window plate 16.
The movement control unit 336 detects rotation information such as the rotation speed and rotation angle of the electric motor 40 and calculates the current position of the window plate 16 (for example, the upper end position T0 of the window plate 16). Then, the amount of movement of the window plate 16 is controlled by controlling the amount of rotation of the electric motor 40 based on the current position of the window plate 16.
Note that the rotation speed of the electric motor 40 is calculated based on, for example, the number of commutators of the electric motor 40 and the number of pulses per unit time, or the reciprocal of the width of one pulse. Further, the rotation angle of the electric motor 40 is calculated based on, for example, the number of pulses from the base point.

The waveform calculation method shown in this embodiment mode is an example, and various modifications can be applied. For example, in the present embodiment, an example in which the frequency analysis unit 326 performs frequency analysis on the time series waveform data of the motor current by FFT has been described, but frequency analysis is performed by another algorithm such as DFT (Discrete Fourier Transform). May be.
Further, in the present embodiment, an FIR filter based on the window function method is designed based on the ripple frequency, a band pass filter coefficient is calculated, and time series data of ripple pulse current is calculated from time series data of motor current by FIR filter calculation. However, the time series data of the ripple pulse current may be extracted from the time series data of the motor current by a signal processing method based on other ripple frequencies.

As described above, according to the movement amount control device 30 according to the embodiment, when a plurality of peak frequencies after frequency analysis are detected due to electrical noise or the like, a window at the time of detection of a detected waveform is detected. Since the peak frequency to be detected as the ripple frequency is selected based on the moving direction of the plate 16, it is advantageous in appropriately controlling the state of the window plate 16 even when the position of the window plate 16 cannot be accurately grasped.
Further, according to the movement amount control device 30, when the detection waveform is detected when the window plate 16 is closed, the peak frequency on the lowest frequency side is set as the ripple frequency, and the detection waveform is detected when the detection waveform is detected. Since the peak frequency on the highest frequency side is set as the ripple frequency when it is open, it is erroneously assumed that the window plate 16 is in the dead zone when the dead zone of the pinching prevention function is set on the closed position side of the window plate 16. This is advantageous in avoiding detection and reliably implementing the pinching prevention function.

In the present embodiment, the case where the dead zone of the pinching prevention function is set on the closing position side (opening upper end position F1 side) of the window plate 16 has been described. For example, the opening position side (opening lower end) of the window plate 16 is described. It is also conceivable that a dead zone for predetermined control is set on the position F2 side).
In this case, when the detection waveform is detected when the opening / closing member is closed, the ripple frequency detection unit sets the peak frequency on the highest frequency side as the ripple frequency, and the detection waveform is detected when the opening / closing member is open. In this case, the peak frequency on the lowest frequency side may be set as the ripple frequency.

  In the present embodiment, the example in which the electric motor 40 is applied to the power window system has been shown. However, various devices that require rotation information of the electric motor including other brushes, for example, a power slide door system of a vehicle. The present invention can also be applied to the above.

DESCRIPTION OF SYMBOLS 10 Power window system 12 Door member 14 Window opening 16 Window board 18 Door sash 20 Window regulator 28 Battery 30 Movement control apparatus 34 Current detection part 40 Electric motor 320 Window board position detection part 322 Trend correction part 326 Frequency analysis part 328 Ripple frequency Detection unit 330 Filter design unit 332 Filtering processing unit 334 Pulse processing unit 336 Movement control unit 340 Anti-pinch function unit

Claims (3)

A moving amount control device for a moving member that moves by driving an electric motor provided with a brush,
A current detector for detecting a current flowing through the electric motor;
A ripple frequency detection unit that detects a peak frequency by performing frequency analysis on the detection waveform of the current, and detects the peak frequency as a ripple frequency that is a frequency of a ripple generated in the current;
A movement control unit that detects a rotation state of the electric motor based on the ripple frequency and controls a movement amount of the moving member;
The ripple frequency detection unit selects the peak frequency to be detected as the ripple frequency based on the moving direction of the moving member at the time of detection of the detection waveform when there are a plurality of the peak frequencies.
A moving amount control device for a moving member. The moving member is an opening and closing member for opening and closing the opening;
The ripple frequency detection unit sets the peak frequency on the lowest frequency side as the ripple frequency when the detection waveform is detected when the switching member is closed, and the detection waveform is detected when the detection waveform is detected. If it is open, the peak frequency on the highest frequency side is the ripple frequency,
The moving amount control device for a moving member according to claim 1. The opening is a window opening of a vehicle;
The opening and closing member is a window plate that opens and closes the window opening.
The moving amount control device for a moving member according to claim 2.

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