JP2003166641A - Range selection device of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select a range when a sensor has trouble in a range selection device for selecting the range by feed-back controlling an actuator based on the result of detection by the sensor for continuously detecting the position of a range selection value. <P>SOLUTION: When a potentiometer for continuously detecting the position of the range selection value has trouble (S5), the operation condition is shifted to the fail-safe state when driving of the actuator is stopped (S6), a warning on the abnormality of the sensor is given, and a command to operate an emergency switch is given (S7). When a driver operates the emergency switch (S8), the fail-safe state is cancelled (S9), a virtual detection pattern of the potentiometer is set based on a signal of an inhibitor switch for detecting the range position (S10), and the actuator is controlled based on the virtual detection pattern (S11). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a range switching device for an automatic transmission in which a range switching valve is driven by an actuator, and more specifically, a countermeasure when a position sensor for continuously detecting the position of the range switching valve fails. Regarding technology.

[0002]

2. Description of the Related Art Conventionally, in automatic transmissions for vehicles,
A range switching device is known in which a range switching valve (manual valve) is driven to a plurality of range positions by an actuator such as a motor (Japanese Patent Laid-Open No. 5-0872).
33). In the range switching device, a position sensor such as a potentiometer for continuously detecting the position of the range switching valve is provided, and based on the deviation between the detection result of the position sensor and the target position corresponding to the target range,
The actuator was sometimes feedback-controlled.

[0003]

As described above, in the case of the structure in which the actuator is feedback-controlled from the detection result of the position sensor, if the position sensor fails and the actual valve position cannot be detected, the range is detected. Since the position of the switching valve is unknown, the valve has been switched to the fail-safe state in which the valve drive by the actuator is stopped.

However, for example, if shifting to the fail safe in the state of being shifted to the P range, it is fixed to the P range even if the motor and the motor drive circuit are normal, so that traveling is completely impossible. There was a problem. The present invention has been made in view of the above problems, and generally pays attention to the fact that a switch (inhibitor switch) for detecting a range position is provided together with a position sensor, and even if the position sensor fails, An object of the present invention is to provide a range switching device for an automatic transmission that can exhibit a limited range switching function.

[0005]

Therefore, in the invention according to claim 1, the range switching valve is driven to a plurality of range positions by an actuator, and the position of the range switching valve is continuously detected. In a range switching device for an automatic transmission that includes a sensor and feedback-controls the actuator based on a detection result of the position sensor, a range position switch for detecting a range position in the automatic transmission when the position sensor fails. The actuator is controlled based on a signal.

According to the above construction, the position sensor normally detects the position of the range switching valve continuously, and the actuator is feedback-controlled based on the result.
If the position sensor fails, it will not be possible to know the actual valve position from the position sensor, so instead use the discrete position information of the range position switch to indicate in which range the range switching valve is located, Control the actuator.

Note that the position sensor failure includes not only the failure of the sensor itself but also the disconnection of the output line of the sensor signal. In the invention according to claim 2, when the position sensor fails, a time-series control pattern of the actuator is set from the current range position detected by the range position switch and the target range position, The actuator is configured to perform feed forward control according to the set control pattern.

According to the above construction, when the position sensor fails, the current range position is detected by the range position switch, the actuator control pattern is set in advance from the detected current position and target position, and the set control pattern is set. Feed forward control the actuator according to. In the invention according to claim 3, when the position sensor fails, the position when the position of the range switching valve changes from the current range position detected by the range position switch toward the target range position. A virtual detection pattern of the sensor is set, and the actuator is controlled based on the virtual detection pattern.

According to the above structure, the position change pattern of the range switching valve when moving from the current range position determined based on the range position switch to the target range position is virtually preset, and the position change is performed according to this pattern. The actuator is controlled as if it is operating. In the invention according to claim 4, the pattern is set as a characteristic that the range is switched in a longer time than when the position sensor is normal.

According to the above construction, when the position sensor is out of order and the actuator is controlled using the control pattern or the virtual detection pattern, the range switching is performed for a longer time than when the position sensor is normal. As described above, the control pattern or the virtual detection pattern is set. According to a fifth aspect of the present invention, when a failure of the position sensor occurs, a warning of the occurrence of the failure is given, and a transition to a fail-safe state in which the driving of the actuator is stopped is performed, while the fail-safe state is arbitrarily canceled. The operating unit is provided, and the actuator is controlled based on the signal of the range position switch on condition that the operation of the operating unit instructs cancellation of the fail-safe state.

According to the above configuration, when the position sensor fails, the drive control of the actuator based on the detection result of the position sensor is stopped, and the fail safe state is entered. Warning the driver that When the driver operates the operation unit based on the warning, the actuator is controlled based on the signal from the range position switch.

[0012]

According to the invention described in claim 1, when the position sensor fails, the actuator is controlled from the current range position determined based on the range position switch, so that the range switching valve is moved to the target range position. Therefore, even if the position sensor fails, it is possible to prevent the vehicle from being unable to travel.

According to the second aspect of the present invention, by setting the pattern for controlling the actuator from the current range position toward the target range position, the range switching valve can be operated without using the position sensor. There is an effect that it can be driven to the target position. According to the third aspect of the present invention, since the position change of the range switching valve on the way from the current range position to the target range position is virtually set, the actuator is controlled in the same manner as when the position sensor is normal. As a result, the range position can be switched.

According to the fourth aspect of the present invention, the range switching is performed over a longer period of time.
This has the effect of avoiding the occurrence of overshoot when the intermediate position cannot be detected. According to the fifth aspect of the present invention, the driver intentionally permits the control based on the range position switch while avoiding erroneous control of the range position due to a position sensor failure. The effect is that it can be shifted to a possible range.

[0015]

BEST MODE FOR CARRYING OUT 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 this FIG.
A motor 2 as an actuator of a range switching device is attached to the vehicle automatic transmission 1.

A deceleration mechanism 3 is provided on the output shaft of the motor 2, and the manual shaft 4 is rotationally driven via the deceleration mechanism 3. A detent mechanism 5 for positioning the manual shaft 4 at angles corresponding to a plurality of ranges is attached to the manual shaft 4. As shown in FIG. 2, the detent mechanism 5 includes a detent lever 5A and a detent lever 5A that are fixed to the manual shaft 4 and rotate integrally.
A detent spring 5B that supports a roller that engages with a concave portion formed corresponding to each range and that biases the roller toward the cutout is formed on the peripheral edge of the.

With the above structure, the manual shaft 4 is moved to the P range, R range (reverse range), N range.
Position at an angle corresponding to range, D range (drive range), 2 range, or 1 range. The rotary movement of the manual shaft 4 is performed by the detent lever 5
By engaging A with the manual valve 6 (range switching valve), the movement of the manual valve 6 is converted into an axial movement, and the manual valve 6 is displaced in the valve body 7 in the axial direction, so that opening / closing of the hydraulic port is switched. 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.
The parking pole 10 supported so as to be swingable is driven to swing by the sliding contact with the cam 9, and at the P range position, the claw 10a of the parking pole 10 meshes with the recess 11a of the parking gear 11 to cause the parking gear 11 to move.
Is fixed.

Further, the manual shaft 4 is provided with a potentiometer 21 as a position sensor for continuously detecting the angle of the manual shaft 4, while
Detect which of each range is switched,
An inhibitor switch 22 is provided as a range position switch. Further, a range select switch 23 is provided which detects which range of P, R, N, D, 2, 1 is selected by the range select lever operated by the driver.

The signals from the potentiometer 21, the inhibitor switch 22 and the range select switch 23 are sent to the A / T control unit (A / TC / U) 2
4 is input. Then, the A / T control unit 24 drives the motor 2 to rotationally drive the manual shaft 4 to a position corresponding to the range selected by the driver by the arithmetic processing based on the signal from the switch sensor. Control.

Specifically, the range select switch 23
The feedback control of the drive signal of the motor 2 is performed by proportional / integral / derivative control according to the deviation between the target angle of the manual shaft 4 required from the above and the actual angle detected by the potentiometer 21. In this embodiment,
The average applied voltage is controlled by the ON time ratio when the power supply to the motor 2 is turned ON / OFF at a high frequency, and the drive signal is calculated as a duty ratio (%) indicating the ON time ratio. .

The feedback control is not limited to the proportional / integral / derivative control, but a sliding mode control may be used for feedback.
In addition, the A / T control unit 24 has a structure shown in FIG.
The fail-safe processing function shown in the flowchart of FIG. In the flowchart of FIG. 3, first, in step S1, it is diagnosed whether or not a failure has occurred in a drive system such as a motor or a motor energization circuit.

In step S2, it is determined whether or not it is diagnosed that a failure has occurred in the drive system as a result of the diagnosis in step S1. If there is a failure in the drive system such as the motor,
In step S3, the power supply to the motor 2 is shut off as a fail-safe process. Further, in the next step S4, the warning device 29 warns the driver that a failure has occurred in the drive system including the motor 2.

The warning device 29 is a console of the vehicle.
It is configured by a warning lamp provided on a panel or the like, a monitor device, and / or a speaker that generates a buzzer, a synthetic voice, or the like. On the other hand, if it is determined in step S2 that there is no failure in the drive system such as the motor 2, the process proceeds to step S5, and it is determined whether or not the potentiometer 21 is in failure.

The failure of the potentiometer 21 includes not only the failure of the potentiometer 21 itself (sticking failure etc.) but also the disconnection / short circuit of the signal line of the potentiometer 21. Then, the disconnection / short circuit of the signal line can be judged from the output voltage value of the potentiometer 21,
Further, the failure of the potentiometer 21 itself can be judged from the change of the detected angle (output voltage value) in the driving state of the motor 2.

When it is determined in step S5 that the potentiometer 21 is normal, this routine is ended as it is. On the other hand, in step S5, the potentiometer 2
If it is determined that No. 1 is out of order, the process proceeds to step S6, and the power supply to the motor 2 is stopped as a fail-safe process.

In the next step S7, the driver is warned of the occurrence of the sensor abnormality in the same manner as in step S3, and at the same time, the driver is pressed by the emergency switch 30 (operation section) provided on the console panel or the like. A warning for prompting is also issued using the warning device 29. Step S8
Then, it is determined whether or not the emergency switch 30 is pressed by the driver. When the driver presses the emergency switch 30, the process proceeds to step S9.

In step S9, the fail-safe processing in step S6 is canceled to permit the energization of the motor 2. In the next step S10, when the manual valve 6 is driven from the current range position determined from ON / OFF of the inhibitor switch 22 toward the requested range position determined based on the range select switch 23, The virtual pattern of the position change of the manual valve 6 is set as the virtual pattern of the output (detection angle) of the potentiometer 21.

The virtual pattern is derived from the detected angle of the potentiometer 21 which should correspond to the current range position judged from the ON / OFF state of the inhibitor switch 22,
The detection angle (target angle) of the potentiometer 21 that should correspond to the requested range position is set as a response in a first-order lag system with a predetermined time constant (see FIG. 4).

When the motor 2 is controlled according to the deviation (virtual deviation) between the virtual pattern and the target angle, the virtual pattern requires a longer time for range switching than when the potentiometer 21 is normal. It is set as such a characteristic. In step S11, instead of the detected angle of the potentiometer 21, a deviation (virtual deviation) between the angle in the virtual pattern and the target angle is calculated, and the motor 2 is controlled by proportional / integral / derivative control based on the virtual deviation.
The drive signal of is controlled by feedback.

When it is judged from the signal from the inhibitor switch 22 that the requested range position is judged based on the range select switch 23, the motor 2
Stop driving. As described above, if the configuration is such that the virtual detection pattern of the potentiometer 21 is set when the potentiometer 21 fails, the motor 2 is driven and the range is switched by the same processing as when the potentiometer 21 is normal. Therefore, it is possible to prevent the potentiometer 21 from being fixed to a specific range due to a failure of the potentiometer 21, and it is possible to secure a minimum traveling property.

The control of the motor 2 is not limited to the total feedback control based on the control deviation. For example, the motor 2 is driven by a control signal having a constant duty ratio until a predetermined intermediate opening degree is reached, and thereafter, The configuration may be such that the feedback control is performed based on the detected angle of the potentiometer 21, and in this case, when the potentiometer 21 fails, it is determined whether or not the angle in the virtual pattern has reached a predetermined intermediate opening, and the predetermined opening is determined. After the intermediate opening is reached, the control of the motor 2 based on the virtual deviation may be started.

The flowchart of FIG. 5 shows a second embodiment of the fail-safe processing. In the flowchart of FIG. 5, each step other than step S10A and step S11A performs the same process as that of the flowchart of FIG.
Only 0A and step S11A will be described. Step S1
At 0A, the inhibitor switch 22 is turned on / off.
The motor 2 when driving the manual valve 6 from the current range position determined from the above to the required range position determined based on the range select switch 23.
Set the time-series control pattern of.

The control pattern represents the duty ratio of the drive signal of the motor 2 for each elapsed time from the start of control, and is preset for each type of range switching, and the motor 2 is controlled according to the control pattern. The control is adapted so that the range can be gradually switched in a longer time than in the case where the feedback control based on the detection result of the potentiometer 21 is performed.

At step S11A, at step S1
The motor 2 is feed-forward controlled according to the control pattern set by 0A, and when it is judged from the signal of the inhibitor switch 22 that the required range is reached, the drive of the motor 2 is immediately stopped even in the middle of the control pattern. To do so. As described above, when the potentiometer 21 fails, the motor 2 is driven according to a predetermined control pattern.
If the configuration is controlled, it is possible to prevent the potentiometer 21 from being fixed to a specific range due to a failure of the potentiometer 21 even if the response of the range switching is lowered, and it is possible to secure a minimum traveling property.

[Brief description of 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 manual shaft.

FIG. 3 is a flowchart showing a first embodiment of failsafe processing.

FIG. 4 is a diagram showing a virtual pattern of changes in the angular position of a manual valve.

FIG. 5 is a flowchart showing a second embodiment of failsafe processing.

[Explanation of symbols]

1 ... Automatic transmission 2 ... Motor (actuator) 3 ... Reduction mechanism 4 ... Manual shaft 5 ... Detent mechanism 6 ... Manual valve (range switching valve) 21 ... Potentiometer 22 ... Inhibitor switch 23 ... Range select switch 24 ... A / T control unit 29 ... Warning device 30 ... Emergency switch

Claims (5)

[Claims] 1. A structure in which a range switching valve is driven to a plurality of range positions by an actuator, and a position sensor for continuously detecting the position of the range switching valve is provided, and the position sensor detects the position based on the detection result of the position sensor. In a range switching device for an automatic transmission that feedback-controls an actuator, when the position sensor fails, the actuator is controlled based on a signal from a range position switch that detects a range position in the automatic transmission. Range changer for automatic transmission. 2. When the position sensor fails, a time-series control pattern of the actuator is set from the current range position detected by the range position switch and a target range position, and the set pattern is set. The range switching device for an automatic transmission according to claim 1, wherein the actuator is feed-forward controlled according to a control pattern. 3. A virtual position sensor when the position of the range change valve changes from a current range position detected by the range position switch toward a target range position when the position sensor fails. 2. The range switching device for an automatic transmission according to claim 1, wherein a detection pattern is set and the actuator is controlled based on the virtual detection pattern. 4. The range switching device for an automatic transmission according to claim 2, wherein the pattern is set as a characteristic that the range is switched in a longer time than when the position sensor is normal. . 5. An operation unit for, when a failure of the position sensor occurs, warning the occurrence of the failure and shifting to a fail-safe state in which driving of the actuator is stopped, while canceling the fail-safe state arbitrarily. 5. The actuator is controlled based on a signal from the range position switch on condition that cancellation of the fail-safe state is instructed by operation of the operation unit. 2. A range switching device for an automatic transmission according to any one of the above.