JP4072029B2 - Automatic transmission range switching device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a range switching device that switches a range of an automatic transmission by an actuator that is electrically driven and controlled, and more particularly to a technique for learning a control target position of each range.
[0002]
[Prior art]
Conventionally, a predetermined play amount is provided in a power transmission path between an actuator that is electrically driven and controlled and a range switching shaft that is positioned at an angle corresponding to each range by a detent mechanism. 2. Description of the Related Art A range switching device for an automatic transmission that is switched to a plurality of ranges by rotation is known (see, for example, Patent Document 1).
[0003]
Further, a configuration is known in which a control target position of each range is learned in order to compensate for a shift in the detection position of the range switching valve (range switching shaft). When the change of the position detection value becomes minute within the range recognized as the range position, the position detection value at that time is used as the learning value at the specific range position.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 07-280083 [Patent Document 2]
Japanese Patent Laid-Open No. 07-081448
[Problems to be solved by the invention]
However, as described above, the configuration for determining a minute change in the position detection value is greatly affected by noise and voltage fluctuation, and there is a high possibility that the target position of each range is erroneously learned.
The present invention has been made in view of the above problems, and is an automatic transmission range that can learn the target position of each range without being greatly affected by noise superposition or voltage fluctuation. An object is to provide a switching device.
[0006]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 provides a predetermined play amount in the power transmission path between the actuator that is electrically driven and controlled and the range switching shaft that is positioned at an angle corresponding to each range by the detent mechanism. And detecting the angle of the range switching shaft in an automatic transmission range switching device that controls the actuator so that the actual angle of the range switching shaft matches a target angle corresponding to a required range. calculating the angular acceleration based on, when the angle of the range change shaft is within a predetermined reference angle range for each range, the angular acceleration based on the angle indicating the peak value, the target in the range The angle is obtained and stored .
[0009]
The above configuration captures the pulling action of the detent mechanism as a change in angular acceleration , obtains an angle at which the angular acceleration shows a peak value, and learns a target angle in the range based on the peak generation timing.
Therefore, the so-called valley position (position positioned by the detent mechanism) of the detent mechanism can be accurately learned without being affected by a minute change in the detected angle value.
[0010]
In the invention of claim 2 , a predetermined play amount is provided in the power transmission path between the actuator that is electrically driven and controlled and the range switching shaft that is positioned at an angle corresponding to each range by the detent mechanism, In an automatic transmission range switching device that controls the actuator so that an actual angle of the range switching shaft matches a target angle corresponding to a required range, the angle of the range switching shaft is detected and based on the angle The angular velocity and the angular acceleration are calculated, and when the angle of the range switching shaft is within a reference angle range set in advance for each range, the product of the angular velocity and the angular acceleration is based on an angle indicating a peak value, The target angle in the range is obtained and stored .
[0011]
The above configuration captures the pulling action of the detent mechanism as a change in the integrated value of the angular velocity and the angular acceleration, obtains the angle at which the product of the angular velocity and the angular acceleration shows a peak value, and uses the peak generation timing as a reference. Learn the target angle in the range.
Therefore, the so-called valley position (position positioned by the detent mechanism) of the detent mechanism can be accurately learned without being affected by a minute change in the detected angle value.
[0012]
Incidentally, in the invention of claim 1 or 2, wherein the angle of the angular velocity or the like exhibits a peak value, even deviate from Itani position at the detent mechanism (true target angle), the shift amount, the characteristics of the detent mechanism or the like Therefore, the target angle can be learned from the peak generation timing.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a system configuration diagram of a range switching device for an automatic transmission according to an embodiment.
In FIG. 1, a motor 2 (actuator) for driving a range switching valve 6 described later is attached to an automatic transmission 1 mounted on a vehicle.
[0014]
A reduction gear mechanism 3 is provided on the output shaft of the motor 2, and the range switching shaft 4 is driven to rotate via the reduction gear mechanism 3.
A predetermined play amount is provided in the rotational direction at the connecting portion between the final stage of the reduction gear mechanism 3 and the range switching shaft 4.
A detent mechanism 5 for positioning the range switching shaft 4 at an angle corresponding to each of a plurality of ranges is attached to the range switching shaft 4.
[0015]
As shown in FIG. 2, the detent mechanism 5 includes a detent lever 5A that is fixed to the range switching shaft 4 and rotates integrally therewith, and a roller that engages a recess formed on the periphery of the detent lever 5A corresponding to each range. And a detent spring 5B that presses and urges the roller toward the concave portion.
Then, the detent mechanism 5 is configured so that the range switching shaft 4 is converted into the P range (parking range), R range (reverse range), N range (neutral range), D range (drive range), 2 ranges, 1 range. Position at an angle corresponding to any of the above.
[0016]
The rotational movement of the range switching shaft 4 is converted into the axial movement of the range switching valve 6 by the engagement of the detent lever 5A and the range switching valve 6, and the range switching valve 6 is displaced in the axial direction within the valve body 7. By doing so, the opening and closing of the hydraulic port is switched, and the line pressure is delivered according to each shift range.
A cam 9 is attached to the other end of the rod 8 whose one end is attached to the detent lever 5A, and a parking pole 10 supported so as to be swingable is driven to swing by sliding contact with the cam 9, so that the P range position is reached. , The pawl 10a of the parking pole 10 meshes with the recess 11a of the parking gear 11, and the parking gear 11 is fixed.
[0017]
The range switching shaft 4 is provided with a potentiometer 21 that continuously detects the angle of the range switching shaft 4, while an inhibitor switch 22 that detects which of the ranges the automatic transmission 1 is switched to. Is provided.
Further, a range select switch 23 that is operated by the driver is provided.
[0018]
Signals from the potentiometer 21, the inhibitor switch 22 and the range select switch 23 are input to an A / T control unit (A / TC / U) 24.
Then, the A / T control unit 24 sets a target angle of the range switching shaft 4 corresponding to the range select switch 23, and the actual angle detected by the potentiometer 21 matches the target angle. The drive signal of the motor 2 (duty drive signal for turning on / off the power supply at a high frequency) is feedback-controlled.
[0019]
By the electric drive control of the motor 2 by the A / T control unit 24, the range switching shaft 4 rotates, whereby the range of the automatic transmission 1 is switched to the range required by the driver.
Further, the A / T control unit 24 has a function of learning a target angle for each of the ranges in order to compensate for a deviation of a detection angle by the potentiometer 21, and a reference example of such learning control is shown in FIG. It demonstrates according to a flowchart.
[0020]
In the flowchart of FIG. 3, in step S11, the angle of the range switching shaft 4 detected by the potentiometer 21 is read.
In step S12, it is determined whether or not the angle read in step S11 is included in any of the reference angle ranges (learning angle ranges) of the ranges including the reference target angle set in advance for each range.
[0021]
When it is within the reference angle range, the process proceeds to step S13, and the angular velocity is calculated by differentiating the angle of the range switching shaft 4 detected by the potentiometer 21.
In the next step S14, digital low-pass filter processing (LPF) is performed on the angular velocity calculated in step S13.
[0022]
In step S15, the detection angle by the potentiometer 21 when the angular velocity after the low-pass filter processing shows a peak value is obtained.
For example, as shown in FIG. 6 (A), if the detected angle of the potentiometer 21 decreases and changes in the P → D switching direction, the angular velocity at this time is negative as shown in FIG. 6 (B). Since it is calculated as a value, in the P → D switching direction, a negative peak value of the angular velocity is obtained in step S15, and the detected angle by the potentiometer 21 when the peak value is indicated is referred to.
[0023]
On the other hand, since the detection angle of the potentiometer 21 increases and changes in the D → P switching direction, a positive peak value is obtained in step S15, and the detection angle by the potentiometer 21 when the peak value is indicated is referred to.
When the pull-in operation of the detent mechanism 5 having play is started at the time of range switching, the absolute value of the angular velocity suddenly increases to show a peak value. By performing the filtering process, an angular position delayed from the actual peak position is detected.
[0024]
However, since the deviation angle between the angle at which the angular velocity after the low pass filter processing (LPF) shows the peak value and the valley position (true target angle) of the detent mechanism 5 is constant, the angular velocity after the LPF has the peak value. It is possible to estimate the valley position of the detent mechanism 5 from the angle shown.
Therefore, in step S16, a target angle in the range is obtained based on the angle at which the angular velocity after LPF shows the peak value and the correction angle stored in advance, and this is obtained as the ROM (nonvolatile) of the A / T control unit 24. Update memory).
[0025]
If the target angle corresponding to the target range has already been learned when performing the range switching control, the A / T control unit 24 performs feedback control of the motor 2 based on the target angle of the learning result, and if it has not been learned. For example, the motor 2 is feedback-controlled according to a reference target angle stored in advance.
According to the above configuration, the angle at which the angular velocity subjected to the low-pass filter processing obtains an angle indicating the peak value, and the target angle is learned from the angle indicating the peak value, so that it is not affected by a minute change in the detected angle value, The target angle of each range can be learned with high accuracy.
[0026]
The flowchart of FIG. 4 shows a first embodiment of target angle learning control according to the present invention .
The first embodiment shown in the flowchart of FIG. 4 is different in that the angular velocity of the reference example shown in the flowchart of FIG. 3 is replaced with an angular acceleration.
In the flowchart of FIG. 4, when the angle of the range switching shaft 4 is detected in step S21 and it is determined in step S22 that it is within the reference angle range, the process proceeds to step S23.
[0027]
In step S23, the angular velocity is calculated by differentiating the angle detected in step S21. Further, in the next step S24, the angular velocity is differentiated to calculate angular acceleration.
In step S25, the digital low-pass filter process is performed on the angular acceleration calculated in step S24.
[0028]
In step S26, an angle at which the angular acceleration after the low-pass filter processing shows a peak value is obtained (see FIG. 6C).
In the present embodiment in which the detection angle of the potentiometer 21 decreases in the P → D switching direction, as shown in FIG. 6C, a negative peak value of angular acceleration is obtained in the P → D switching direction. Conversely, in the D → P switching direction, a positive peak value of angular acceleration is obtained.
[0029]
The timing at which the angular acceleration exhibits a peak value is detected as an angular position that is delayed from the actual peak position by performing low-pass filter processing on the angular acceleration.
However, since the angle of deviation between the angle at which the angular acceleration after the low pass filter process (LPF) shows the peak value and the valley position (true target angle) of the detent mechanism 5 is constant, the angular acceleration after the LPF is at a peak. It is possible to estimate the valley position of the detent mechanism 5 from the angle indicating the value.
[0030]
Therefore, in step S27, the target angle in the range is obtained based on the angle at which the angular acceleration after LPF shows the peak value and the correction angle stored in advance, and this is obtained as the ROM ( Update storage in a non-volatile memory.
According to the above configuration, the angle at which the angular acceleration subjected to the low-pass filter processing obtains the angle at which the peak value is obtained, and the target angle is learned from the angle at which the peak value is shown. The target angle of each range can be learned with high accuracy.
[0031]
The flowchart of FIG. 5 shows a second embodiment of target angle learning control according to the present invention .
The second embodiment shown in the flowchart of FIG. 5 differs from the reference example shown in the flowchart of FIG. 3 in that an integrated value of angular velocity and angular acceleration is used instead of the angular velocity.
In the flowchart of FIG. 5, when the angle of the range switching shaft 4 is detected in step S31 and it is determined in step S32 that the angle is within the reference angle range, the process proceeds to step S33.
[0032]
In step S33, the angular velocity is calculated by differentiating the angle detected in step S21.
The angular velocity calculated in step S33 is subjected to digital low-pass filter processing in step S34, and is used for calculating angular acceleration in step S35.
[0033]
In step S36, the digital low-pass filter process is performed on the angular acceleration calculated based on the angular velocity before the digital low-pass filter process is performed.
Then, the angular velocity that has been subjected to the digital low-pass filter process (LPF) and the angular acceleration that has also been subjected to the digital low-pass filter process are integrated in step S37.
[0034]
In step S38, an angle at which the integrated value (= post-LPF angular velocity × LPF angular acceleration) shows a peak value is obtained (see FIG. 6D).
In the present embodiment, a negative peak value appears relatively clearly in the integrated value from the relationship of the phase shift between the LPF rear angular velocity and the LPF rear angular acceleration. Therefore, the integrated value does not depend on the range switching direction. The negative peak value is obtained (see FIG. 6D). However, it may be configured to obtain a positive peak value of the integrated value.
[0035]
The timing at which the integrated value indicates the peak value is detected as an angular position delayed from the actual peak position by performing low-pass filter processing on the angular velocity and the angular acceleration, respectively.
However, since the deviation angle between the angle at which the integrated value indicates the peak value and the valley position (true target angle) of the detent mechanism 5 is constant, the valley of the detent mechanism 5 from the angle at which the integrated value indicates the peak value. It is possible to estimate the position.
[0036]
Therefore, in step S27, a target angle in the range is obtained based on the angle at which the integrated value indicates the peak value and the correction angle stored in advance, and this is obtained as a ROM (nonvolatile) of the A / T control unit 24. Memory).
According to the above configuration, the integrated value of the angular velocity and angular acceleration subjected to low-pass filter processing is used to obtain the angle at which the peak value is obtained, and the target angle is learned from the angle representing the peak value. It is possible to learn the target angle of each range with high accuracy without being influenced by.
[0037]
In the first and second embodiments, the target angle is individually learned for each range switching direction, and the target angle is set according to the range switching direction and the target range, so that the feedback control of the motor 2 is performed. Anyway.
Further, technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.
(A) In the automatic transmission range switching device according to claim 1 or 2 ,
A range switching device for an automatic transmission, wherein the target angle is individually learned for each range switching direction.
[0038]
According to the above configuration, for example, as the target angle of the neutral range N, the target range when switching from the parking range P or reverse range R to the neutral range N and the target range when switching from the drive range D to the neutral range N are individually set. Even if the target range after switching is the same neutral range N, the target angle is set depending on which range is switched from.
[0039]
Accordingly, it is possible to learn a target angle that is optimal for convergence to the valley position of the detent mechanism, which varies depending on the range switching direction, and high convergence stability can be obtained.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing a range switching device of an automatic transmission.
FIG. 2 is a perspective view showing a drive mechanism of a range switching shaft.
FIG. 3 is a flowchart showing a reference example of target angle learning control;
FIG. 4 is a flowchart showing a first embodiment of target angle learning control;
FIG. 5 is a flowchart showing a second embodiment of target angle learning control;
FIG. 6 is a timing chart showing changes in angle, angular velocity, angular acceleration, angular velocity × angular acceleration when the P → D range is switched.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Automatic transmission, 2 ... Motor (actuator), 3 ... Deceleration mechanism, 4 ... Range switching shaft, 5 ... Detent mechanism, 6 ... Range switching valve, 21 ... Potentiometer, 22 ... Inhibitor switch, 23 ... Range selection switch, 24 ... A / T control unit

Claims (2)

A predetermined play amount is provided in the power transmission path between the actuator that is electrically driven and controlled and the range switching shaft that is positioned at an angle corresponding to each range by the detent mechanism.
In the automatic transmission range switching device for controlling the actuator so that the actual angle of the range switching shaft matches the target angle corresponding to the required range ,
Detecting the angle of the range switching shaft and calculating the angular acceleration based on the angle ;
When the angle of the range switching shaft is within a reference angle range preset for each range, the target angle in the range is obtained and stored based on an angle at which the angular acceleration shows a peak value. Automatic transmission range switching device. A predetermined play amount is provided in the power transmission path between the actuator that is electrically driven and controlled and the range switching shaft that is positioned at an angle corresponding to each range by the detent mechanism.
In the automatic transmission range switching device for controlling the actuator so that the actual angle of the range switching shaft matches the target angle corresponding to the required range ,
Detecting an angle of the range switching shaft, and calculating an angular velocity and an angular acceleration based on the angle ;
When the angle of the range switching shaft is within a reference angle range set in advance for each range, the target angle in the range is obtained based on the angle at which the product of the angular velocity and the angular acceleration shows a peak value. An automatic transmission range switching device characterized by memorizing .

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