JP2005003085A - 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 an increased degree of freedom of layout with a smaller size of select lever and select lever operating force property as requested while securing reliability by mechanically connecting the select lever to a range position changing device. <P>SOLUTION: A failure determining block 50 is provided for determining a failure when an operation position detected by a potentiometer 25 is not displaced at fixed time intervals in the state that the displacement of input operating force is detected by a torque sensor 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
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.
[0002]
[Prior art]
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).
[0003]
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).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-323559
[0005]
[Patent Document 2]
JP 2003-97694 A
[0006]
[Problems to be solved by the invention]
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.
[0007]
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.
[0008]
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. Therefore, there are problems in terms of reliability and safety.
[0009]
The present invention has been made paying attention to the above problems, and its object is to secure the reliability by mechanical connection of the select lever and the range position switching device, and to reduce the degree of freedom of 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.
[0010]
[Means for Solving the Problems]
In order to achieve the above-described object, in the automatic transmission select assist device according to claim 1 of the present invention, the input operation force for detecting the input operation force to the select lever connected to the range position switching device of the automatic transmission. Based on a detection means, an operation position detection means for detecting the operation position of the select lever, an assist actuator for outputting an assist force for assisting the operation force of the driver to the select lever, and the detected input operation force and operation position An assist force control means for outputting a control command for changing the assist force to the assist actuator, wherein the input operation force detection means detects a displacement of the input operation force. In this state, the operation position detected by the operation position detection means is not displaced at a constant time interval. Characterized by providing an abnormality judgment means for judging an abnormality when.
[0011]
According to a second aspect of the invention, in the select assist device for an automatic transmission according to the first aspect, when the abnormality determining means determines that there is an abnormality, a control stop command for stopping the control of the assist actuator by the assist control means. Is output.
[0012]
【The invention's effect】
According to the first aspect of the present invention, while maintaining the mechanical connection between the select lever and the range position switching device, the lever operating force of the driver is assisted by the assist actuator, thereby ensuring reliability and reducing the size of the select lever. The expansion of the layout freedom by can be achieved together.
[0013]
Further, when the input operation force is displaced, the position of the select lever should be displaced corresponding to the input operation force. In the case of no displacement, the abnormality determining means determines that there is an abnormality. As a result, it is possible to prevent an assist control that cannot actually occur from being performed, and to operate with a natural feeling.
[0014]
According to the second aspect of the invention, the assist control is stopped when it is determined that there is an abnormality, so that malfunction can be prevented.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment for realizing a select assist device for an automatic transmission according to the present invention will be described based on examples.
[0016]
(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. 2 is a perspective view of a main part showing a detailed structure of an assist actuator.
[0017]
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.
[0018]
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.
[0019]
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.
[0020]
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.
[0021]
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 the control arm 20 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.
[0022]
The output shaft 12 is provided with a torque sensor (input operation force detection means) 21 that detects distortion (twist) generated between the input lever 10 and the worm gear 14. The operation force signal detected by the torque sensor 21 is amplified by an amplification amplifier (not shown) and transmitted to the control unit 22 via the wire harness 23. Based on the detection signal of the torque sensor 21, the operation force in the select lever operation can be estimated.
[0023]
A contact 24 for position detection is attached and fixed to the worm gear 14. The contactor 24 rotates integrally with the worm gear 14 and makes electrical contact with a carbon resistor printed on a substrate (not shown), thereby outputting a voltage signal corresponding to the stroke angle of the select lever 2 to the control unit 22. . The contactor 24 and the carbon resistance constitute a potentiometer (operation position detecting means) 25.
[0024]
The potentiometer 25 detects 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.
[0025]
The control unit 22 sets a target assist force based on the detected stroke angle of the select lever 2 and the operation force of the driver, and performs PWM control on the output duty ratio of the electric motor 15.
[0026]
FIG. 3 shows a control block diagram of the control unit 22.
The change in the stroke of the select lever 2 that has been subjected to the range switching operation in the select mechanism unit 1 is input to the potentiometer 25 of the assist actuator 9 via the control cable 8. The potentiometer 25 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.
[0027]
Further, the operating force of the select lever 2 is input to the torque sensor 21 of the assist actuator 9 via the control cable 8. The torque sensor 21 detects the operation force of the select lever 2 and outputs it to the control unit 22 as an operation force signal.
[0028]
The position / operation start / direction discriminating block 33 determines the current stroke angle of the select lever 2 based on the stroke angle signal. Further, the operation start, the operation direction, the operation speed, and the operation acceleration of the select lever 2 are determined from the stroke angle signal, the differential value of the stroke angle signal, and the operation force signal, and the determination results are obtained from the FF compensation table 43 and the target table block 34. Output to the motor drive control block 45.
[0029]
The timer 51 always measures time and outputs a time signal to the abnormality determination block 50.
[0030]
The abnormality determination block 50 determines that there is an abnormality when there is a displacement of the operation reaction force obtained from the torque sensor 21 and the displacement of the select lever 2 obtained from the potentiometer 25 via the position / operation start / direction determination block 33 does not occur for a predetermined time. The assist control stop signal is output to the motor drive control block 45.
[0031]
In the target table block 34, the target operation reaction force corresponding to the stroke angle of the select lever 2 is calculated from the stroke angle signal and the operation direction of the select lever 2 obtained by the position / operation start / direction determination block 33. It is output to the adder 35.
[0032]
Here, since the target operation reaction force varies depending on the stroke angle of the select lever 2, the target operation reaction force for each stroke angle is stored in a table in the target table block 34.
[0033]
The adder 35 calculates the deviation between the operation force signal and the target operation reaction force, and outputs the calculation result to the FB control unit 36.
[0034]
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 operation force signal and the target operation reaction force by a proportional gain to the adder 38 (proportional output). The multiplier 39 outputs a value obtained by multiplying the deviation between the operation force signal and the target operation reaction force by an integral gain to the integrator 40. 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 force that is the sum of the proportional output and the integral output to the adder 41.
[0035]
The FF control unit 42 includes an FF compensation table block 43 and a multiplier 44. The FF compensation table block 43 outputs preset values corresponding to the stroke angle signal, the operation speed, and the operation acceleration to the multiplier 44. The multiplier 44 outputs a value obtained by multiplying the FF assist force by the FF gain, that is, a feed forward assist force to the adder 41.
[0036]
The adder 41 outputs the output sum (feedback assist force + feed forward assist force) of the FB control unit 36 and the FF control unit 42, that is, the target assist force, to the motor drive control block 45.
[0037]
A motor drive control block (corresponding to an assist force control unit) 45 drives the electric motor 15 based on the target assist force.
[0038]
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.
[0039]
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.
[0040]
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.
[0041]
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.
[0042]
In step S1, the operation force is read from the operation force signal of the torque sensor 21, and the process proceeds to step S2.
[0043]
In step S2, the stroke angle is read from the stroke angle signal of the potentiometer 25, and the process proceeds to step S3.
[0044]
In step S3, the operation direction of the select lever 2 is calculated from the stroke angle of the select lever 2 and the increase / decrease difference between the stroke angles read in the previous control cycle, and the process proceeds to step S4.
[0045]
In step S4, the operation speed of the select lever 2 is calculated from the stroke angle of the select lever 2 and the change rate of the stroke angle read in the previous control cycle, and the operation acceleration of the select lever 2 is calculated from the differential value of the operation speed. Then, the process proceeds to step S5.
[0046]
In step S5, an FF compensation table reading process is performed, and the process proceeds to step S6. The optimum FF compensation table is selected from a plurality of preset tables according to the stroke angle, the operation speed, and the operation acceleration.
[0047]
In step S6, target table reading processing is performed, and the process proceeds to step S7.
[0048]
In step S7, the FF assist force is set from the read FF compensation table, and the process proceeds to step S8.
[0049]
In step S8, the FB assist force is set from the read target table, and the process proceeds to step S9.
[0050]
In step S9, the target assist force is set from the sum of the set FF assist force and FB assist force, and the process proceeds to step S10.
[0051]
In step S10, the output duty ratio of the electric motor 15 is controlled so as to achieve the target assist force.
[0052]
In step S11, it is determined whether or not there is an abnormality from the displacement of the operation reaction force and the displacement of the position of the select lever 2. If an abnormality is detected, an abnormality process is performed and this control is terminated.
[0053]
[Operation reaction force characteristics of automatic transmission]
FIG. 6 is a characteristic diagram showing an operation reaction force generated in the select lever 2 in the P → R range direction, more precisely, the select knob 4 held by the driver. This operation reaction force characteristic is an axis detected as an operation reaction force on the output shaft 12 of the assist actuator 9 when the driver operates the select lever 2 in the P → R range direction without driving the electric motor 15. The torque is converted as an operation reaction force Fm [N] generated in the select knob 4 and compared with the stroke angle acquired by the potentiometer 25.
[0054]
This operation reaction force is a combination of the load force generated by the detent of the automatic transmission 19 described above and the frictional force of the control cables 8 and 18 and the inertia of the electric motor 15. That is, in order to perform range switching in the absence of the assist force by the electric motor 15, a manual operation force greater than the operation reaction force Fm is required.
[0055]
As shown in FIG. 6, the operation reaction force Fm generated when the select lever 2 is operated in the P → R range direction is initially opposite to the operation direction of the select lever 2 (D → N range) between the ranges. Direction), changes direction after the peak, occurs in the same direction as the operation direction (P → R range direction), and converges to zero near the range switching position (stop position). This characteristic is caused by the load force generated when the detent pin 29 gets over the cam crest 27 a of the detent plate 27. That is, until the detent pin 29 gets over the cam mountain 27a, a resistance force is generated by the urging force of the spring plate 28, and after the detent pin 29 gets over the cam mountain 27a, the detent pin 29 moves to the next cam mountain 27a. This is because a pulling force (inertial force) is generated by falling into the groove.
[0056]
[Target operation reaction force characteristics]
FIG. 7 is a characteristic diagram showing the target operation reaction force of the select lever 2 in the P → R range direction. This target operation reaction force characteristic is obtained by presetting a target operation reaction force Ft [N] that provides a good operation characteristic with a sense of moderation for the driver according to the stroke angle of the select lever 2.
[0057]
[Target assist force map]
FIG. 8 is a target assist force map in the P → R range direction. In this target assist force map, the target assist force Fa [N] is set so that the select knob 4 can obtain the target operation reaction force Ft according to the stroke angle of the select lever 2.
[0058]
The target assist force Fa is obtained by subtracting the target operation reaction force Ft from the operation reaction force Fm, and the supply current to the electric motor 15 is controlled using the target assist force Fa as the target assist force (output duty ratio of supply voltage) The target operation reaction force characteristic shown in FIG. 7 is obtained by performing PWM control.
[0059]
[FF control + FB control]
[0060]
In the embodiment, the target assist force Fa is based on the deviation between the feedforward assist force Fff [N] set so as to be smaller than the expected target assist force Fa and the actual operation force and the target operation reaction force Ft. The feedback assist force FFb [N] that is set in the above two components makes it possible to achieve both a high level of response and disturbance suppression in the assist control of the select lever with a steep and large torque deviation. The characteristics can be realized.
[0061]
[Positometer position output]
Here, the detection abnormality of the position of the select lever 2 by the potentiometer 25 will be described. In the present embodiment, assist control is performed on the detection position of the select lever 2 by the potentiometer 25 so that the preset reaction force of the target table block 34 is obtained. If the position of the select lever 2 is not output from the potentiometer 25 for some reason, it becomes a problem at which position it is stopped for control purposes.
When there is no output from the potentiometer 25, when it is determined that the required operation reaction force is stopped at a position where it is determined that it is necessary, assist control is performed, which may cause a malfunction. Become.
For this reason, in this embodiment, an abnormality determination block 50 is provided.
[0062]
[Abnormal judgment judgment / processing]
FIG. 9 is a flowchart showing the abnormality determination determination / processing in step S11 of FIG.
[0063]
In step S101, it is detected from the operation force signal from the torque sensor 21 that the input operation force to the select lever 2 is displaced.
[0064]
In step S102, the displacement of the position of the select lever 2 during a fixed time interval Δt from the time information from the timer 51 and the position information of the select lever 2 obtained from the stroke angle signal from the position / operation start / direction determination block 33. If there is position displacement, the process proceeds to step S103. If there is no position displacement, the process proceeds to step S104.
[0065]
In step S103, the normal process is performed without performing the abnormal process when it is determined to be normal.
[0066]
In step S104, it is determined that the system is abnormal, and an assist control stop signal is output to the motor drive control unit 45 to stop the assist control.
[0067]
[Abnormality detection of potentiometer]
(1) Normal processing
When the potentiometer 25 is normal, if the torque sensor 21 detects the displacement of the operation reaction force in the process of step S101, it indicates that the select lever 2 has been operated. This should be accompanied by displacement of the select lever 2. Therefore, the displacement from the potentiometer 25 is detected in step S102 at a constant short time interval Δt. Therefore, the process proceeds to step S103, where it is determined to be normal, and normal assist processing is performed.
[0068]
(2) Abnormal processing
If the potentiometer 25 stops outputting the stroke angle signal due to some abnormality, the stroke angle signal will not be output even if the select lever 2 is operated and the operating force signal detected by the torque sensor 21 is displaced. . In this case, when the torque sensor 21 detects the displacement of the operation reaction force in the process of step S101, the displacement from the potentiometer 25 is not detected in step S102 at a constant short time interval Δt. Therefore, it is determined that there is an abnormality, and an assist control stop signal is output to the motor drive control block 45 by the process of step S104. Thereby, the motor drive control block 45 stops the control, and malfunction is prevented. Therefore, there is no possibility of giving a great sense of resistance or excessive assist due to abnormal assist due to misidentification of the position.
[0069]
Next, the effect will be described.
In the automatic transmission select assist device of the present embodiment, the following effects can be obtained.
[0070]
(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 the 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.
In addition, an abnormality determination block 50 is provided for determining an abnormality when the operation position detected by the potentiometer 25 is not displaced at a constant time interval while the displacement of the input operation force is detected by the torque sensor 21. Actually, it is possible to prevent an assist control that cannot occur and to operate with a natural feeling.
[0071]
(2) If the abnormality determination block 50 determines that there is an abnormality, a control stop command for stopping the control of the electric motor 15 by the motor drive control block 45 is output. The operation can be prevented.
[0072]
(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.
For example, in the embodiment, the torque sensor 21 is used as the input operation force detection means for detecting the input operation force of the select lever 2, but the input operation force is determined from the supply current value to the electric motor 15, the rotation speed of the electric motor 15, and the like. It is good also as a structure which estimates.
In the embodiment, the configuration in which the select lever 2 and the control arm 20 of the automatic transmission 19 are connected by the control cables 8 and 18 is shown. However, the operation force transmitting means for transmitting the operation force of the select lever 2 to the control arm 20 is arbitrary. There may be a configuration using a rod or a linkage.
The shape and size of the select lever 2 are arbitrary, and may be a switch shape that can be operated with a fingertip. In addition, the target operation reaction force characteristic is also changed to a characteristic that provides good operation characteristics according to the shape of the select lever 2.
[0073]
The distribution ratio of the FF assist force Fff and the FB assist force Ffb to the target assist force Fa can be freely set according to the target operation characteristics.
In the embodiment, the main controller performs assist control by FF + FB control, but may perform assist control by other control.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of an automatic transmission according to an embodiment.
FIG. 2 is a main part perspective view showing a detailed structure of an assist actuator.
FIG. 3 is a control block diagram of a control unit.
FIG. 4 is a perspective view showing a detent structure of the automatic transmission.
FIG. 5 is a flowchart showing a flow of select lever assist control processing executed by the control unit;
FIG. 6 is a characteristic diagram showing an operation reaction force generated in the select lever in the P → R range direction.
FIG. 7 is a characteristic diagram showing a target operation reaction force of the select lever in the P → R range direction.
FIG. 8 is a target assist force map in a P → R range direction.
FIG. 9 is a flowchart showing a flow of abnormality determination / processing executed by the control unit.
[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
21 Torque sensor
22 Control unit
23 Wire harness
24 Contact
25 Potentiometer
26 Rotating shaft
27 Detent plate
27a Cam Mountain
27b Tanibe
28 Spring plate
29 Detent pin
30 Parking pole
31 Cam plate
32 Parking gear
33 Direction discrimination block
34 Target table block
35 Adder
36 FB control unit
37 multiplier
38 Adder
39 Multiplier
40 integrator
41 Adder
42 FF controller
43 FF compensation table block
44 multiplier
45 Motor drive control block
50 Abnormality judgment block
51 timer
221 Main controller

Claims (2)

An input operation force detecting means for detecting an input operation force to the select lever connected to the range position switching device of the automatic transmission;
An operation position detecting means for detecting an operation position of the select lever;
An assist actuator that outputs an assist force to assist the operating force of the driver to the select lever;
An assist force control means for outputting a control command for changing the assist force to the assist actuator based on the detected input operation force and operation position;
A selection assist device for an automatic transmission having
Provided is an abnormality determination means for determining that an abnormality occurs when the operation position detected by the operation position detection means is not displaced at a predetermined time interval in a state where the displacement of the input operation force is detected by the input operation force detection means. A select assist device for an automatic transmission. In the automatic transmission select assist device according to claim 1,
A selection assist device for an automatic transmission that outputs a control stop command for stopping control of an assist actuator by the assist control means when the abnormality determination means determines that an abnormality has occurred.

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