JP2005098428A - Select assist device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a select assist device for an automatic transmission having select lever operating force property on demand by reducing the size of a select lever to produce a higher degree of freedom in layout while allowing range selection with mechanical connection between the select lever and a range position selector. <P>SOLUTION: A deviation amount is defined as an abnormality determination value (Xo), which is smaller than the amount of a detection position deviation between a potentiometer 51 and a potentiometer 25 due to the lost motion of control cables 8, 18 connecting a control lever 20 of the automatic transmission 19 to the select lever 2. A failure diagnosis block 55 determines abnormality when detecting the abnormality determination value (Xo). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention belongs to a technical field of a selection assist device for an automatic transmission that assists a driver's select lever operating force in a vehicle equipped with the automatic transmission.

  Conventionally, a select lever of an automatic transmission is mechanically connected to a manual valve of the automatic transmission via an operating force transmission means such as a rod or a cable. The operating force of the driver input to the select lever is transmitted to the manual valve via the operating force transmission means, and the range position is switched according to the operation amount (see, for example, Patent Document 1).

On the other hand, what uses what is called shift-by-wire technique in which the select lever and the manual valve are electrically connected is known. In this prior art, an actuator that operates a manual valve is provided, and the range position is switched by driving the actuator by changing the rotation operation of the select lever into an electric signal (see, for example, Patent Document 2).
JP-A-9-323559 JP 2003-97694 A

  When the select lever is operated, a mechanical operating reaction force such as friction of the operating force transmission means, resistance of detent, etc. is generated, and thus a large operating force is required. Therefore, in order to reduce the necessary operating force of the driver, it is necessary to set the length of the select lever to a length that can obtain a sufficient lever force.

  Therefore, the former of the above prior arts has a problem that the shape becomes large due to the length of the select lever, so that there are many restrictions on the installation place and the degree of freedom in layout in the vehicle interior is low.

  On the other hand, in the latter, the selection lever can be designed shorter by adopting the actuator, and the degree of freedom in layout becomes higher than that in the former. However, since the select lever and the manual valve are not mechanically connected, the range cannot be switched during a failure.

  The present invention has been made paying attention to the above problems, and its object is to enable range switching by mechanically connecting the select lever and the range position switching device, while also allowing freedom in layout by downsizing the select lever. It is an object of the present invention to provide a selection assist device for an automatic transmission that can achieve a widening range of the automatic transmission and obtain a select lever operating force characteristic according to demand.

  In order to achieve the above object, in the automatic transmission select assist device according to claim 1 of the present invention, a lever operation position detecting means for detecting an operation position of a select lever connected to a range position switching device of the automatic transmission. And an assist actuator for outputting an assist force for assisting a driver's operation force between the select lever and the range position switching device, and an assist operation position detecting means for detecting an operation position assisted by the assist actuator. An assist force control means for outputting a control command for changing the assist force to the assist actuator based on the two operation positions, wherein the assist actuator is a select assist device for the automatic transmission. Before by the lost motion of the connecting member to be connected A failure diagnosis means for determining an abnormality by detecting a deviation amount smaller than a deviation amount of a detection position between the lever operation position detection means and the assist position detection means and detecting the abnormality determination value; .

  According to a second aspect of the present invention, in the select assist device for an automatic transmission according to the first aspect, the connecting member that connects the assist actuator and the select lever uses a wire, and the failure diagnosis means includes When it is determined that there is an abnormality, a signal for stopping the assist control is output.

  According to the first aspect of the present invention, it is possible to switch the range while maintaining the mechanical connection between the select lever and the range position switching device and assisting the lever operating force of the driver with the assist actuator. The layout flexibility can be expanded by making it easier.

  Further, the assist actuator is driven by a failure of the lever operation position detection means or the assist operation position detection means, and it is possible to prevent malfunction of the assist control in which the assist actuator precedes the operation of the select lever.

  In the invention according to claim 2, by stopping the assist control at the time of detecting an abnormality, the operation becomes heavy, but the operation can be manually performed, further malfunction is prevented, and the safety side that enables the operation is enabled. Allow processing.

  Hereinafter, an embodiment for realizing a select assist device for an automatic transmission according to the present invention will be described based on examples.

(Example)
First, the configuration will be described.
FIG. 1 is a side view showing a configuration of an automatic transmission apparatus according to an embodiment, and FIG.

  The automatic transmission apparatus according to the embodiment mainly includes a select mechanism unit 1, a control cable 8, an assist actuator 9, a control cable 18, an automatic transmission 19, and a control unit (assist force control means) 22. Yes.

The selection mechanism unit 1 has a selection lever 2 that is operated by a driver, and is provided, for example, in a center cluster 3 beside the driver's seat. At the upper end of the select lever 2, a select knob 4 is attached for the driver to hold during the select operation. The select lever 2 is rotated about the fulcrum shaft 5 and is set to 100 mm, which is 250 mm shorter than a conventional general select lever.
The fulcrum shaft 5 is provided with a potentiometer 51 (corresponding to a lever operation position detection means) that detects the operation position of the select lever 2 by an angle and sends the signal to the control unit 22.

  A push-pull control cable 8 is connected to the lower end of the select lever 2 via a select lever joint 7. The control cable 8 is rotatably connected to the input lever 10 of the assist actuator 9 via the input lever joint 11. That is, the rotational movement of the select lever 2 is converted into a linear movement, and the operating force generated by the operation of the select lever 2 is transmitted to the input lever 10.

  The input lever 10 is connected to an output lever 13 via an output shaft 12 that is rotatably provided. The output shaft 12 is provided with a worm gear 14 that meshes with a motor output shaft 16 of an electric motor 15 having a speed reduction mechanism.

  A push-pull control cable 18 is connected to the output lever 13 via an output lever joint 17. The control cable 18 is connected to a control arm 20 (corresponding to a range position switching device) of the automatic transmission 19. That is, the rotational movement of the output lever 13 is converted into a linear movement by the control cable 18, and the combined force of the driver's operating force and the driving force of the electric motor 15 is transmitted to the control arm 20 of the automatic transmission 19.

  A contact 24 for position detection is attached and fixed to the worm gear 14. The contact 24 rotates integrally with the worm gear 14 and makes electrical contact with a carbon resistor printed on a substrate (not shown), whereby the displacement angle of the output shaft 12 (assisting an assist force for the operation of the select lever 2) ( A voltage signal corresponding to the stroke angle is output to the control unit 22. The contactor 24 and the carbon resistance constitute a potentiometer (assist operation position detecting means) 25.

  The potentiometer 25 and the potentiometer 51 detect the stroke angle of the select lever 2 at any time with the angle when the select lever 2 is stopped at the P range position as the base point angle.

  The control unit 22 (corresponding to assist force control means) sets a target assist current value based on the detected stroke angle of the select lever 2 and the stroke angle of the assist actuator 9, and outputs the output of the electric motor 15 to PWM. Control.

FIG. 3 shows a control block diagram of the control unit 22.
In the selection mechanism unit 1, the change in the stroke of the selection lever 2 that has been subjected to the range switching operation is input to a potentiometer 51 provided on the fulcrum shaft 5. The potentiometer 51 detects a stroke angle corresponding to the operation amount of the select lever 2 and outputs it to the control unit 22 as a stroke angle signal.

  In addition, when the operating force is transmitted through the control cable 8 and the output shaft 12 is rotationally displaced, the stroke change of the select lever 2 that has been subjected to the range switching operation is also detected by the potentiometer 25 of the assist actuator 9. The stroke angle signal is output to the control unit 22.

  The operation speed / operation direction determination block 33 determines the current stroke angle of the select lever 2 based on the stroke angle signal from the potentiometers 25 and 51. Further, a differential value is calculated for the stroke angle to determine the operation speed and the operation direction, and the determination result is output to the FF compensation table 43 and the alignment error compensation block 52.

  The alignment error compensation block 52 corrects the outputs of the potentiometers 25 and 51 in a state where the range position is fixed, and outputs the correction value to the adder 54.

  The adder 54 calculates the deviation between the stroke angle signal from the potentiometer 25 and the stroke angle signal from the potentiometer 51, adds the difference so as to take into account the error, and outputs the result to the target speed generation block 34.

  In the target speed generation block 34, the target speed of the select lever 2 corresponding to the magnitude of the deviation of the stroke angle signal is determined and output to the adder 35.

  The differentiator 53 calculates the differential value of the stroke angle signal from the potentiometer 25 of the assist actuator 9 and outputs the calculation result to the adder 35.

  The adder 35 calculates the deviation between the actual operation speed from the differentiator 53 and the target speed from the target speed generation block 34, and outputs the calculation result to the FB control unit 36.

  The FB control unit 36 includes a multiplier 37, an adder 38, a multiplier 39, and an integrator 40. The multiplier 37 outputs a value obtained by multiplying the deviation between the actual operation speed and the target speed by a proportional gain to the adder 38 as a drive current value of the electric motor 15 (proportional output). The multiplier 39 outputs a value obtained by multiplying the deviation between the actual operation speed and the target speed by the integral gain to the integrator 40 as a drive current value of the electric motor 15. The integrator 40 integrates the output of the multiplier 39 and outputs it to the adder 38 (integration output). The adder 38 outputs a feedback assist current value that is the sum of the proportional output and the integral output to the adder 41.

  The FF compensation table block 43 outputs a preset value corresponding to the two stroke angle signals, the operation speed and the operation direction, that is, a feedforward assist current value to the adder 41.

  The adder 41 outputs the output sum (feedback assist current value + feedforward assist current value) of the FB control unit 36 and the FF control unit 42, that is, the target assist current value to the motor drive control block 45.

  A motor drive control block (corresponding to an assist force control unit) 45 drives the electric motor 15 based on the target assist current value.

  In the failure diagnosis block 55 (failure diagnosis means), it is determined from the detection signals from the potentiometer 51 and the potentiometer 25 whether or not there is an abnormality based on the amount of deviation between the two detection operation positions. To output an assist control stop signal.

Next, the detent structure of the automatic transmission 19 will be described.
FIG. 4 is a perspective view showing a detent structure of the automatic transmission 19.
The control arm 20 is provided with a rotation shaft 26, and a detent plate 27 is supported on the rotation shaft 26. At the upper end of the detent plate 27, a valley portion 27b corresponding to five ranges (P, R, N, D, and L) is formed between the cam peaks 27a. Then, the detent pin 29 formed at the tip of the spring plate 28 is engaged with the valley portion 27b and the selected range position is maintained, thereby preventing an unintended range select due to vehicle vibration or the like. Yes.

  That is, the rotating shaft 26 is rotated by the operating force of the select lever 2, and the detent plate 27 is moved relative to the detent pin 29 in accordance with the rotation. At this time, the detent pin 29 gets over the cam crest 27 a and engages with the valley portion 27 b corresponding to the adjacent range, and the engaged state is held by the elastic force of the spring plate 28. This elastic force becomes a main load force when the select lever 2 is operated.

  Note that one end of the parking pole 30 is rotatably connected to the detent plate 27. When the select lever 2 is moved to the P range, the parking pole 30 prevents rotation of the parking gear 32 via the cam-like plate 31 and locks driving wheels (not shown). Thereby, when the vehicle is parked on the slope road in the P range, a vehicle load is applied so as to lock the driving wheel according to the slope, and acts as a force for biting the parking pole 30.

Next, the operation will be described.
[Select lever assist control processing]
FIG. 5 is a flowchart showing a flow of assist control processing of the select lever 2 executed by the control unit 22.

  In step S1, the stroke angle of the select lever 2 portion is read from the stroke angle signal of the potentiometer 51, and the process proceeds to step S2.

  In step S2, the stroke angle of the assist actuator 9 is read from the stroke angle signal of the potentiometer 25, and the process proceeds to step S3.

  In step S3, the deviation between the stroke angle of potentiometer 51 and the stroke angle of potentiometer 25 is calculated, and the process proceeds to step S4.

  In step S4, the target speed of the select lever 2 is calculated from the deviation of the stroke angle, and the process proceeds to step S5.

  In step S5, the drive current value of the electric motor 15 is calculated from the target speed, and the process proceeds to step S6.

  In step S6, the drive current value of the electric motor 15 is calculated with reference to the table data of the FF compensation table. The optimum FF compensation table is selected from a plurality of preset tables according to the stroke angle and the operation speed.

  In step S7, the target assist current value is output from the sum of the set FF assist current value and FB assist current value, and this control is terminated.

  In step S8, failure diagnosis is performed, and when it is determined that there is an abnormality, the assist control is stopped.

[Operation reaction force characteristics of automatic transmission]
FIG. 6 is a diagram showing the output values of the stroke angle signals of the potentiometers 25 and 51, the shape of the detent plate 27, and the motor drive current in the P → R range direction.

Among these, in order for the detent pin 29 to get over the cam crest 27a of the detent plate 27 with respect to the shape of the detent plate 27 shown in FIG. 6 (b), the motor is driven as shown in FIG. 6 (c). A current is required.
That is, when the select lever 2 is operated in the P → R range direction, first, since the detent pin 29 exceeds the steep slope of the cam crest 27a of the detent plate 27, a large force is required. Since the gradient becomes gentler as it approaches the apex of the cam peak 27a, the necessary force becomes smaller. Therefore, the assist current value required for the select lever 2 draws a mountain-shaped curve as shown in FIG. 6C between the detent plate 27 and the top of the cam crest 27a.

After the detent pin 29 gets over the cam peak 27a, the detent pin 29 falls into the groove of the next cam peak 27a to generate a pull-in force (inertial force), which also converges at the position of the R range. In this embodiment, no assist is performed in this region (assist region).
In the operation of the select lever 2 from the P range to the R range, the select lever 2 is loaded with the frictional forces of the control cables 8 and 18 and the inertia of the electric motor 15.

[FF control assist current value map]
FIG. 6C shows an assist current value map in the P → R range direction in the FF control. In this assist current value map, according to the stroke angle of the select lever 2, a drive current value that is approximately ½ of the drive current value corresponding to the detent operation reaction force shown in FIG. Is set to

[FF control + FB control]
In the embodiment, the assist force is set to a deviation between the feedforward assist current value set so as to be about a half of the current value corresponding to the detent operation reaction force, and the actual operation speed and the target operation speed. By using the two components of the feedback assist current value set based on this, it is possible to achieve both responsiveness and disturbance suppression at a high level in the assist control of a select lever with a steep and large torque deviation, and good operating characteristics. realizable.

[Assist control]
When the select lever 2 is operated, the value of the potentiometer 51 changes. In response to the change in the value, the electric motor 15 is driven to assist the operation of the select lever 2, and the value of the potentiometer 25 of the assist actuator 9 is changed. Set to the normal range position.
As a result, the movement of the select lever 2 and the movement of the assist actuator 25 move in synchronism, and the wire cable 8 between them is the same as idle, but the movement of the select lever 2 and the movement of the assist actuator 25 are in sync. The operation can be performed.

[Detection displacement due to lost motion]
Here, the detection shift due to the lost motion will be described.
In this embodiment, the control arm 20 of the automatic transmission 19 and the select lever 2 are connected by the control cables 8 and 18.
Since the control cables 8 and 18 function as a connecting member in a state where the control cables 8 and 18 are extended or contracted appropriately from the free state, the control cables 8 and 18 have lost motion.
Therefore, when there is no assist control, the output value of the potentiometer 25 moves after the displacement due to the lost motion occurs as shown in FIG. 8 (a) with respect to the stroke amount of the select lever 2 detected by the potentiometer 51. However, when moving backward from the range position, it shows the characteristic of moving after a shift due to lost motion occurs.
If the control is normal, the lost motion amount first increases when the range position starts to be switched. This is because when the select lever 2 is operated, the control cables 8 and 18 are appropriately extended. Thereafter, the operation of the control arm of the automatic transmission 19 is synchronized with the operation of the select lever 2 with good followability. Since the assist actuator 9 is used for assisting, the control cables 8 and 18 are very close to the free state.

Also, when returning from the range position thus switched to the original range position, the amount of lost motion increases at the start of switching and then decreases to a state that is very close to the free state.
Even when the control is normally performed as described above, a predetermined lost motion amount is detected by the potentiometers 51 and 25 as shown in FIG.

[About sensor failures]
In the select assist device of the automatic transmission 19 according to the present embodiment, if an abnormality occurs in the potentiometers 51 and 25, a malfunction may occur in which the assist force becomes larger than a predetermined value.
At this time, if a tensile force exceeding the amount of lost motion shown in FIG. 8 is applied to the control cables 8 and 18, the control cables 8 and 18 and the parts and devices connected to the control cables 8 and 18 are excessive. It becomes a load and is not preferable.
On the other hand, in this embodiment, a failure diagnosis block 55 is provided.

[Failure diagnosis processing]
FIG. 7 is a flowchart showing a flow of failure diagnosis processing in step S8 (see FIG. 5) executed by the control unit.

  In step S101, the absolute value (| Xa−Xb |) of the difference is calculated from the output value (Xa) of the potentiometer 51 and the output value (Xb) of the potentiometer 25, and the output values of the two potentiometers 51 and 25 are calculated. It is determined whether the deviation does not exceed the abnormality determination value (Xo). If it does not exceed, the process proceeds to step S102, and if it exceeds, the process proceeds to step S103.

  In step S102, normal assist control is performed, and this process is terminated.

  In step S103, it is determined whether the time that the output deviation (| Xa−Xb |) exceeds Xo has not reached the predetermined time. If the predetermined time has not been reached, the process proceeds to step S102, and the predetermined time is exceeded. If this time is reached, the process proceeds to step S104.

  In step S104, since the system is abnormal, a signal instructing to perform an abnormality alarm is output, and a control stop signal for stopping the assist control is output to the motor drive control block 45, and this process ends.

[Failure diagnosis and processing]
<1> When normal (lost motion by normal control)
In this embodiment, as shown in FIGS. 8 and 9, it is detected in step S <b> 101 that a deviation that exceeds the abnormality determination value set smaller than the maximum amount of lost motion has occurred at the detection positions of the potentiometers 51 and 25. Detect by processing. At this time, the detection is performed without distinguishing between the lost motion in the normal control and the detection shift due to the abnormality.
Next, in the case of a normal lost motion, the movement amount or time in a state where the abnormality determination value is exceeded as shown in FIG. 9A decreases with a predetermined movement amount or time. In the case of normal lost motion, it is determined in step S103, and normal assist processing is performed.

<2> In the case of abnormality If any abnormality occurs in the potentiometer 51 or the potentiometer 25, the deviation of the output value exceeds the abnormality judgment value, and the state exceeds the movement amount or time of the normal lost motion, step In step S103, it is determined that there is an abnormality, and in step S104, an assist control stop signal is output to the motor drive control block 45 to stop the assist control.
In this state, the operation becomes heavy, but the operation is manually performed so that the process on the safe side is performed so as not to cause further malfunction.
If the abnormality is determined in this way, the abnormality can be detected without providing a separate sensor.
In the process of step S103, the determination may be made based on the movement amount exceeding the abnormality determination value, the determination may be made based on the time exceeding the abnormality determination value, or both the movement amount and the time. You may make it judge by.

Next, the effect will be described.
In the automatic transmission select assist device of the present embodiment, the following effects can be obtained.

(1) The select lever 2 has a projection amount of about 150 mm less than the conventional select lever, and the select lever 2 and the control arm 20 are connected via control cables 8 and 18. The degree of freedom of the interior layout of the vehicle is greater than that of the product, and the select lever 2 can be set at an arbitrary position in the vehicle interior such as an instrument panel.
Further, since the select lever 2 and the control arm 20 are mechanically connected by the control cables 8 and 18, the driver can manually switch the range position even when the assist actuator 9 or the control unit 22 fails.

Further, a deviation amount that is smaller than the deviation amount of the detection position of the potentiometer 51 and the potentiometer 25 due to the lost motion of the control cable 8 that connects the control lever 20 and the select lever 2 of the automatic transmission 19 is defined as an abnormality determination value (Xo). Since the failure diagnosis block 55 for determining abnormality by detecting the abnormality determination value (Xo) is provided, the electric motor 15 of the assist actuator 9 is driven by the failure of the potentiometer 51 or the potentiometer 25, and the assist actuator 9 is operated by the operation of the select lever 2. An erroneous operation of the assist control preceded by the electric motor 15 can be prevented.
Further, it is possible to detect an abnormality while suppressing cost without providing another sensor.

  (2) Since the control cable 8 for connecting the assist actuator 9 and the select lever 2 uses a wire, and the failure diagnosis block 45 outputs a signal to stop the assist control when it is determined to be abnormal, At this time, the assist control is stopped, so that the operation becomes heavy, but the operation can be manually performed, and further malfunction can be prevented, and the processing to the safe side that enables the operation can be performed.

  Further, in this embodiment, since the failure diagnosis block 55 detects an abnormality so as to distinguish between a detection position deviation due to a normal lost motion and a detection position deviation due to an abnormality, an abnormality is accurately determined in a control system having a lost motion. it can.

(Other embodiments)
As described above, the embodiments of the present invention have been described based on the examples. However, the specific configuration of the present invention is not limited to the examples, and there are design changes and the like without departing from the scope of the invention. However, it is included in the present invention.
In the present embodiment, the configuration is shown in which the select lever 2 and the control arm 20 of the automatic transmission 19 are connected by the control cables 8, 18. It is good also as a structure using a rod or linkage. In that case, the play of the rod or linkage becomes the lost motion.
The shape and size of the select lever 2 are arbitrary, and may be a switch shape that can be operated with a fingertip.
Since the control cable of the present embodiment is composed of one wire, it has a lost motion on the expansion side and the contraction side, but when using a pair of two wires, whichever In the direction of, the lost motion is also present on the extension side. Such a control cable may be configured.

  The distribution ratio between the FF assist current value and the FB assist current value with respect to the target assist current value can be freely set according to the target operation characteristics.

It is a side view which shows the structure of the automatic transmission of an Example. It is a principal part perspective view which shows the detailed structure of an assist actuator. It is a control block diagram of a control unit. It is a perspective view which shows the structure of the detent of an automatic transmission. It is a flowchart which shows the flow of the assist control process of the select lever performed with a control unit. It is explanatory drawing which shows the output value of the stroke angle signal of the potentiometers 25 and 51 in a P-> R range direction, the shape of a detent plate, and a motor drive current. It is a flowchart which shows a flow to the failure diagnosis and process performed with a control unit. It is explanatory drawing which shows the relationship of the output value of two potentiometers. It is explanatory drawing which shows the relationship between the difference of the output value of two potentiometers, and time or movement amount.

Explanation of symbols

1 select mechanism 2 select lever 3 center cluster 4 select knob 5 fulcrum shaft 7 select lever joint 8 control cable 9 assist actuator 10 input lever 11 input lever joint 12 output shaft 13 output lever 14 worm gear 15 electric motor 16 motor output shaft 17 output Lever joint 18 Control cable 19 Automatic transmission 20 Control arm 22 Control unit 23 Wire harness 24 Contactor 25 Potentiometer 26 Rotating shaft 27 Detent plate 27a Cam mountain 27b Valley 28 Spring plate 29 Detent pin 30 Parking pole 31 Cam-shaped plate 32 Parking Gear 33 Operation speed / operation direction discrimination block 34 Target speed generation block 35 Adder 36 FB control Unit 37 multiplier 38 adder 39 multiplier 40 integrator 41 adder 42 FF control unit 43 FF compensation table block 45 motor drive control block 51 potentiometer 52 alignment error compensation block 53 differentiator 54 adder 55 fault diagnosis block

Claims (2)

Lever operating position detecting means for detecting the operating position of the select lever connected to the range position switching device of the automatic transmission;
An assist actuator that outputs an assist force for assisting a driver's operation force between the select lever and the range position switching device;
Assist operation position detecting means for detecting an operation position assisted by the assist actuator;
Assist force control means for outputting a control command for changing the assist force to the assist actuator based on the two detected operation positions;
A selection assist device for an automatic transmission having
A deviation amount smaller than the deviation amount of the detection position between the lever operation position detecting means and the assist position detecting means due to the lost motion of the connecting member that connects the assist actuator and the select lever is set as an abnormality determination value, and the abnormality determination value Failure diagnosis means for judging abnormality by detection,
A selection assist device for an automatic transmission. In the automatic transmission select assist device according to claim 1,
The connecting member that connects the assist actuator and the select lever uses a wire,
When the failure diagnosis means determines that there is an abnormality, it outputs a signal for stopping the assist control.
A select assist device for an automatic transmission.

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