JP4329433B2 - Fail judgment device for shift-by-wire automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fail determination device for a shift-by-wire automatic transmission that includes range command means for commanding a range position selected by a driver's switching operation and sets a range environment requested by the driver based on the command. It is.
[0002]
[Prior art]
Some shift-by-wire automatic transmissions use two electric actuators. Usually, one electric actuator (hereinafter referred to as a “main actuator”) has P (parking) and R (selected by the driver). By instructing the operation according to the range position such as reverse), N (neutral), D (drive), L (low), etc., and displacing the range position transmission member according to the operation of this main actuator, the driver can There is one that sets the selected range environment and uses the other electric actuator as a backup when the main actuator fails (hereinafter referred to as “backup actuator”) (see, for example, Patent Document 1).
[0003]
In addition, the range command means (hereinafter referred to as “shift device”) that commands the range position selected by the driver's switching operation is variable such as a potentiometer (variable resistor) that commands the driver's operation position as a continuous value. There is an apparatus using a resistor (see, for example, Patent Document 2). In actuality, a shift device is configured by multiply arranging a plurality of potentiometers in series.
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 6-40513
[Patent Document 2]
JP-A-7-310823
[0005]
[Problems to be solved by the invention]
However, in the shift device having the above configuration, the range signal output areas are specified for the purpose of preventing the occurrence of command hunting in the vicinity of the boundary line between adjacent range signal output areas. Since there may be an out-of-range signal output area that does not command the range position of the shift device, if the driver does not command a specific range signal for more than a certain period after starting the switching operation, the shift device will fail It is necessary to avoid a fail state in which the position where the driver performs the switching operation remains in the out-of-range signal output region by determining and warning.
[0006]
However, such determination of the fail state may induce erroneous determination of the fail state if the determination time is set short, for example, when the driver accidentally operates the shift device in the out-of-range signal output region or when driving When the driver performs a very slow switching operation, a warning is issued to the driver due to an erroneous fail determination, and the driver feels uncomfortable. On the other hand, if the judgment time is set to be long, the time from when the range position is commanded until the actuator can actually be started increases.For example, when the driver is performing the switching operation quickly, The driver feels uncomfortable due to the operation delay with respect to the position command.
[0007]
The problem to be solved by the present invention has been made in view of these facts, and in determining the fail state in setting the range environment required by the driver based on the selection command by the switching operation of the driver. Shift-by-wire that ensures comfortable operability by reducing the sense of incongruity felt by the driver due to inconsistency between the switching operation of the driver and the timing of fail judgment by appropriately setting the time required according to the switching operation of the driver It is an object of the present invention to provide a fail determination device for an automatic transmission.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 A plurality of range signal output areas that continuously output signals instructing the range position according to the driving mode desired by the driver, and outside the range that does not command a specific range position that exists between the range signal output areas A signal output area, In a shift-by-wire automatic transmission that has range command means for commanding the range position selected by the switching operation of the driver and sets the range environment requested by the driver based on this command, the range command means commands the range position. When the non-stop time continues for a predetermined determination time or more, a fail determination unit that determines that the range command unit is in a fail state, and a range position switching speed at a predetermined set interval after the driver starts switching the range position. A failure determination device comprising: a range position switching speed detection means for detecting; and a determination time setting means for setting a determination time based on the switching speed.
[0009]
The invention according to claim 2 is characterized in that, in claim 1, the determination time setting means sets the determination time longer as the switching speed is lower.
[0010]
According to a third aspect of the present invention, in the first or second aspect, the determination time setting means holds the determination time at the previous determination time when the switching speed falls below the lower limit value of the speed range. It is a feature.
[0011]
The invention according to claim 4 is provided with warning means for warning the driver when the switching speed is lower than the lower limit value of the speed range according to any one of claims 1 to 3. It is a feature.
[0012]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the fail determining means determines that the range command means is in a fail state when the switching speed exceeds an upper limit value of the speed range. It is characterized by being.
[0013]
【The invention's effect】
In the invention according to claim 1, when the time during which the shift command means does not perform the range position continues for a predetermined determination time or more, the shift command means is determined to be in a failed state. Is set based on the switching speed detected at predetermined intervals after the start of switching. For this reason, the time required to determine the fail state can be appropriately set according to the driver's switching operation.
[0014]
Therefore, according to the first aspect of the present invention, since the fail state can be determined at an appropriate timing according to the driver's switching operation, the driver feels uncomfortable due to the discord between the driver's switching operation and the fail determination timing. Can be reduced to ensure comfortable operability.
[0015]
In the invention according to claim 2, since the determination time is set longer as the switching speed is lower, it is possible to set a failure occurrence time suitable for a different operation time for each driver, thereby reducing the driver's uncomfortable feeling. It becomes possible.
[0016]
By the way, when the switching speed is extremely low, there is a high possibility that the range operation means is in a fail state. Therefore, in the invention according to claim 3, when the switching speed falls below the lower limit value of the speed range, the determination time is held at the previous determination time. According to this configuration, while ensuring comfortable operability, when there is a high possibility that the range command means is in a fail state, it is possible to quickly execute a fail determination.
[0017]
If the switching speed is extremely slow, the range operation means is likely to be in a failed state, but it is also a fact that the driver needs to consider when the range position is fixed at the wrong position. . In view of this, the invention according to claim 4 is additionally provided with warning means for warning the driver when the switching speed falls below the lower limit value of the speed range. According to such a configuration, when a fail state is caused by the switching operation of the driver, the driver is made to recognize it and prompt the switching of the normal range position, thereby preventing the fail processing from being performed carelessly. Can do.
[0018]
Even when the switching speed is extremely high, there is a high possibility that the range operation means is in a fail state. This state is an electrical failure of the shift range operation means and is not caused by the operation of the driver. Therefore, in the invention according to claim 5, when the switching speed exceeds the upper limit value of the speed range, it is determined that the range command means is in a fail state without actually determining the failure. According to this configuration, while ensuring comfortable operability, it is possible to execute a rapid fail process for a fail state that causes a sudden change in behavior to the vehicle.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram showing a fail determination device for a shift-by-wire automatic transmission according to an embodiment of the present invention. FIGS. 2 (a) and 2 (b) are two steps each of which is an electric actuator. It is the schematic diagram and the perspective view which illustrate the principal part of the drive system which sets the range environment in an automatic transmission using a motor.
[0020]
In FIG. 1, reference numeral 1 denotes a shift-by-wire automatic transmission. The automatic transmission 1 uses a step motor 2 as a main motor that operates in accordance with a range position selected by a normal driver, and a step motor 3. The step motor 2 is used as a backup motor when a failure occurs, and the range environment corresponding to the desired range position is set by the switching operation of the shift device 10 by the operation of the main motor 2 or the backup motor 3.
[0021]
Worm gears G2 and G3 are attached to the main motor 2 and the backup motor 3, respectively, and are drivingly coupled to the planetary gear mechanism 4 via the worm gears G2 and G3. The planetary gear mechanism 4 receives the sun gear S and the ring gear R as inputs, and outputs a carrier C that supports a plurality of pinions P that mesh with the sun gear S and the ring gear R, respectively. Specifically, as shown in FIG. 2 (a), the worm gear G2 of the main motor 2 is meshed with the ring gear R, while the worm gear G3 of the backup motor 3 is meshed with the input gear So provided integrally with the sun gear S. A manual shaft 5 as a position transmission member is integrally coupled with the carrier C.
[0022]
That is, each of the main motor 2 and the backup motor 3 is connected to the manual shaft 5 via the planetary gear mechanism 4 so that the operations of the main motor 2 and the backup motor 3 are input independently of each other. The manual shaft 5 can be displaced according to one, and the direction in which the manual shaft 5 is displaced (rotated) is determined by the difference between the rotational speeds of the main motor 2 and the backup motor 3 input to the planetary gear mechanism 4. .
[0023]
In FIG. 2B, reference numeral 6 denotes a so-called detent mechanism that sets a range environment in the automatic transmission 1 according to the position where the manual shaft 5 is rotated. The detent mechanism 6 integrally fixes a fan-shaped lever 61 to the manual shaft 5 and moves the spool 62a of the existing range switching valve 62 in the axial direction by the lever 61, while the engaging portion 61a of the lever 61 is a cantilever spring. By engaging with a roller 63 a provided at the tip of 63, the spool 62 a is positioned according to the rotation of the manual shaft 5.
[0024]
That is, the manual shaft 5 has a P (parking) range position selected by the shift device 10 with the range switching valve 62 arranged in the automatic transmission 1 depending on the position displaced according to the rotational speed of the main motor 2 or the backup motor 3. , R (reverse) range position, N (neutral) range position, and D (drive) range position. Accordingly, the range switching valve 62 selects a hydraulic circuit corresponding to the P to D range positions, and sets the inside of the automatic transmission 1 to a range environment corresponding to the P to D range positions.
[0025]
In the present embodiment, the rotation of the step motors 2 and 3 is controlled by the controller 100. Therefore, as shown in FIG. 1, the controller 100 receives an angle signal Θ from an angle sensor 21 that detects the angle θ of the manual shaft 5 and a dial position signal Sd that indicates a switching operation at the shift device 10. The
[0026]
As shown in FIG. 3, the shift device 10 includes a circular select dial 12 in the switch body 11. The select dial 12 is rotatably supported with respect to the switch main body 11, and selects the P, R, N, and D range positions according to the driving mode desired by the driver. As shown in FIG. 3, three movable elements 12a that rotate together with the movable element 12a are provided.
[0027]
The shift device 10 includes three shift switches 13 as shown in FIG. As shown in FIG. 4, each of the shift switches 13 is a circular resistance element that is fixed in the switch body 11 and has resistance values that continuously vary along the rotation direction of the movable element 12a. The areas corresponding to the P range position, R range position, N range position, and D range position are provided with fan-shaped range position resistance portions 13p, 13r, 13n, and 13d as shown in FIG.
[0028]
That is, the shift switch 13 is a so-called potentiometer, and when the movable element 12a is in contact with any one of the range position resistance portions 13p, 13r, 13n, 13d, the range position resistance portions 13p, 13r, 13n, 13d. The dial position signal Sd for instructing the P range position, R range position, N range position, and D range position is continuously output in accordance with the resistance value, respectively, and the mover 12a receives the range position resistance units 13p, 13r, 13n, When contact is made at a place other than 13d, a dial position signal Sd indicating that the position is outside the P range position, R range position, N range position, or D range position is continuously output.
[0029]
The three shift switches 13 are integrally coupled in series so that the range position resistor portions 13p, 13r, 13n, and 13d are aligned to form one switch system (hereinafter collectively referred to as “triple system switch 13”). . Therefore, for example, even if one shift switch 13 fails, the normal dial position signal Sd can be output from the other shift switch 13 to the controller 100. Thereby, the rotation of the step motors 2 and 3 is controlled according to the P range position, R range position, N range position, and D range position selected by the switching operation by the select dial 12.
[0030]
However, in the shift device 10 having the above-described configuration, the movable element 12a is disposed between the range position resistance units 13p, 13r, 13n, and 13d as illustrated in FIG. , 13n, and 13d, that is, there is an out-of-range signal output region (region shown by hatching in FIG. 5) in which a specific range position is not commanded, and a multiplex shift switch as in this embodiment is provided. When used, if there is an assembly error in the arrangement of the range position resistor units 13p, 13r, 13n, 13d between the three shift switches 13, the same range position should be commanded by all of the three shift switches 13. Regardless of the area, all the shift switches 13 have an out-of-range signal output area with an unknown range position.
[0031]
For this reason, when the state where the shift device 10 does not output a specific range signal continues for a certain period or more after the driver starts the switching operation, it is determined as a fail state, and the position where the driver performs the switching operation. However, it is necessary to avoid the fail state in the out-of-range signal output region, but the appropriate timing for determining the fail state in the out-of-range signal output region is greatly affected by the switching speed of the range position accompanying the driver's switching operation. Involved.
[0032]
Therefore, in the present embodiment, in the controller 100, when the time during which the shift device 10 does not command the range position continues for a predetermined determination time T or longer, the shift device 10 is determined to be in the fail state, while the range position by the shift device 10 is determined. The failure determination is executed according to the determination routine shown in the flowchart of FIG.
[0033]
The determination routine of FIG. 6 is triggered by the input of the dial position signal Sd from the triple switch 13, and first, at step 1, an extension determination timing for determining whether or not the determination time T needs to be extended. The management timer is operated, and the dial position signal Sd is a signal indicating one of the P range position, R range position, N range position, and D range position, or a signal indicating that the range position is unknown. It is determined whether.
[0034]
If the dial position signal Sd is a signal for instructing one of the range positions in step 1, in step 9, the operation corresponding to the range position is instructed to the step motor 2, whereby the automatic transmission 1 The process of setting the range environment requested by the driver is executed.
[0035]
On the other hand, if the dial position signal Sd is a signal indicating the out of range position in step 1, the select dial 12 is out of the range position. 2 In step 2, the timer value TR of the extension determination timing management timer is updated to TR = TR (OLD) +1 by adding “1” to the previous timer value TR (OLD). However, since the timer value TR at the start of determination is initialized to TR = 0, the previous timer value TR (OLD) is processed as TR (OLD) = 0.
[0036]
In step 3, it is determined whether or not the timer value TR has reached the set value TR (0). If the timer value TR has not reached the set value TR (0), in step 1, the P range position, R Unless it is determined that the position is the range position, the N range position, or the D range position, the timer value TR is added until the timer value TR reaches the set value TR (0), and the timer value TR reaches the set value TR (0). Then, it is determined that the set interval Δt has elapsed since it is determined that the position is out of the range position, and the process proceeds to step 4. The set value TR (0) is appropriately determined according to the average shift switching time determined by the mode of the shift operation means.
[0037]
In step 4, the switching speed V when the set interval Δt is reached is calculated. Specifically, the switching speed V is the rate of change A of the dial position signal Sd for each set value TR (0) interval. Therefore, the value obtained by dividing the current dial position signal Sd by the set value TR (0) is the signal change rate A for the first time, and thereafter, the change in the dial position signal Sd from the previous determination timing is the set value TR. The value divided by (0) is the signal change rate A.
[0038]
In step 5, it is determined whether or not the driver erroneously operates the shift device 10 in the out-of-range signal output region or the driver is performing a very slow switching operation. Specifically, it is determined whether the signal change rate A is smaller than a preset lower limit value Amin. The lower limit value Amin is appropriately determined according to the maximum value of the shift switching time determined by the form of the shift operation means.
[0039]
If it is determined in step 5 that the signal change rate A is smaller than the preset lower limit value Amin, the driver erroneously operates the shift device 10 to the out-of-range signal output region, or the driver is very slow. Assuming that the switching operation is being carried out, the routine proceeds to step 10, where the lighting is instructed to the warning light 7 disposed in the vehicle, the driver is warned, and the driver is prompted to operate the shift device, while the judgment time T is held at the previous determination time value T (OLD) (initial value T10 for the first time), and the time when the shift device 10 does not command the range position after the driver starts switching the range position is a predetermined determination. When it continues for time T or more, the shift device 10 is determined to be in a failed state.
[0040]
On the other hand, if it is determined in step 5 that the signal change rate A is greater than or equal to the preset lower limit value Amin, the driver erroneously operates the shift device 10 to the out-of-range signal output region, However, it is further assumed that no very slow switching operation has been performed, and the process proceeds to step 6. In Step 6, it is determined whether or not the signal change rate A that cannot be a normal dial operation due to the failure of the shift device 10 is obtained. Specifically, it is determined whether the signal change rate A is larger than a preset upper limit value Amax. The upper limit value Amax is appropriately determined according to the fastest shift operation time that is restricted by the form of the shift operation means.
[0041]
When it is determined in step 6 that the signal change rate A is larger than the upper limit value Amax, it is assumed that the signal change rate A that cannot be a normal dial operation due to the failure of the shift device 10 is actually obtained. Without the fail determination, it is determined that the shift device 10 is in a fail state, and in step 11, a command is issued to execute a fail process.
[0042]
In this fail processing, for example, when the system of the shift-by-wire automatic transmission 1 is stopped, or when one shift switch 13 fails, the dial position signal Sb output by the remaining two shift switches 13 is used. There are processes that are adopted as command values.
[0043]
As shown in FIG. 4, the shift device 10 includes an optical distance sensor 14 in the switch body 11, and outputs a distance L from the distance sensor 14 to the mover 12 a to the controller 100. Therefore, in step 11, if the movable element 12a is not in contact with any of the range position resistance portions 13p, 13r, 13n, 13d, that is, if the range position is unknown (see FIG. 5), another failure is detected. As a process, based on the previous range position and the distance L detected by the distance sensor 14, the driver moves the select dial 12 from the previous range position (for example, the R range position) (P → R or R → N). The range position adjacent to the previous range position (R range position) (N range position for P → R and P range position for R → N) was selected by the driver in the direction of the operation. The range environment may be set by regarding the range position.
[0044]
On the other hand, if it is determined in step 6 that the signal change rate A is less than or equal to the upper limit value Amax, the shift device 10 is broken or the driver erroneously operates the shift device 10 to the out-of-range signal output region. Or the signal change rate A obtained by the driver performing a very slow switching operation, but the normal signal change rate A obtained by the driver's switching operation, the process proceeds to step 7.
[0045]
Therefore, according to Steps 5 and 6, as shown in FIG.
(I) 0 <A <Amin: The driver erroneously fixes the shift device 10
(II) Amin ≦ A ≦ Amax: The driver operates the shift device 10 normally.
(III) Amax <A <∞: Signal change due to failure of shift device 10
It can be classified into three areas.
[0046]
In step 7, since the signal change rate A is within the range (III) of Amin ≦ A ≦ Amax, the driver assumes that the range position switching speed V is the switching speed when the shift device 10 is normally operated. If the time during which the shift device 10 does not command the range position continues for a predetermined determination time T or longer after the start of the range position switching, the shift device 10 is determined to be in a failed state.
[0047]
The determination time T is an initial value of a time T10 obtained by adding a margin δ to the ideal time To when the driver performs a switching operation at a constant speed according to the upper limit value Amax of the range (II) of the signal change rate A that is not determined to fail. Each time the signal change rate A is calculated at the set interval Δt after the driver starts switching the range position, the signal change rate A is set.
[0048]
Specifically, the signal change rate A obtained in step 4 is multiplied by a coefficient α to obtain an extension time ΔT (= A × α), and this extension time ΔT is added to the previous determination time T (OLD). The determined value T (OLD) + ΔT is set as the determination time T. However, the coefficient α may be a constant value that does not depend on the signal change rate A or a variable that changes in accordance with the signal change rate A.
[0049]
After correcting the determination time T, the process proceeds to step 8 in consideration of the possibility of correcting the determination time T after the set interval Δt. After the timer value TR is reset to TR = 0 in this step 8, the step Return to 1.
[0050]
FIG. 8 is a time chart showing an operation when the determination time T is corrected by using the determination routine of FIG. 6 in a certain switching operation. In FIG. 8, the solid line L1 is an actual operation curve illustrating the signal change rate due to the switching operation actually performed by the driver, and the alternate long and short dash line L2 is the range (II) of the signal change rate A where the fail determination is not made. It is an ideal operation curve which shows the signal change rate A when a driver | operator performs at the constant speed by the upper limit Amax.
[0051]
In FIG. 8, when the driver starts switching the range position at time t = 0, the signal change rate A varies as indicated by the solid line L1. For this reason, the controller 100 first starts measuring the set interval Δt at time t = 0 (steps 1 to 3). Then, at time t = t1 when the set interval Δt is reached, signal change rate A = A1 is calculated in order to perform extension determination (step 4). Since the signal change rate A1 at time t = t1 is within the range (II) of Amin ≦ A ≦ Amax as shown by the solid line L1, it is determined that the driver is operating the shift device 10 normally (step 5, 6). At the same time, the signal change rate A1 is multiplied by a coefficient α to obtain an extension time ΔT (= T11 = A1 × α), and this extension time T11 is added to the initial value T10 to obtain a new determination time T (T1 = After setting as T10 + T11), initialization for calculating the signal change rate A is executed at every set interval Δt (step 8).
[0052]
That is, the determination of the fail state between time t = 0 and time t = t1 uses determination time T = T10, and the shift device 10 is in the range after the driver starts the switching operation at time t = 0. When the time during which the position is not commanded continues for the determination time T10 or more, the shift device 10 is determined to be in the fail state, and after time t = t1, the fail state is determined using the determination time T = T1.
[0053]
Then, the set interval Δt is measured again (steps 1 to 3). Even at the time t = t2 when the set interval Δt has elapsed, a new signal change rate A2 is calculated (step 4), and this signal change rate A2 is within the range (II). ) (Steps 5 and 6), the signal change rate A2 is multiplied by a coefficient α to obtain an extension time ΔT (= T12 = A1 × α), and this extension time T12 is added to the previous determination time T1. Then, after setting as a new determination time T (T2 = T1 + T12) (step 7), initialization for calculating the signal change rate A is executed again at every set interval Δt (step 8).
[0054]
That is, determination time T = T1 is used for determination of a fail state between time t = t1 and time t = t2, and the shift device 10 starts the range after the driver starts the switching operation at time t = 0. When the time when the position is not commanded continues for the determination time T1 or more, the shift device 10 is determined to be in the fail state, and after time t = t2, the fail state is determined using the determination time T = T2.
[0055]
Similarly, in the state where the signal change rate A is within the range (II), extension determination is performed at each set interval Δt at time t = t3, t4, t5, and from time t = t3 to time t = t4. In the meantime, the fail state is determined by a new determination time T (T3 = T2 + T13) obtained by adding the extension time ΔT (= T13 = A3 × α) to the previous determination time T2, and from time t = t4 to time t = t5. In the meantime, the failure state is determined at a new determination time T (T4 = T3 + T14) obtained by adding the extension time ΔT (= T14 = A4 × α) to the previous determination time T2, and from time t = t5 to time t = t6 In the meantime, the fail state is determined at a new determination time T (T5 = T4 + T15) obtained by adding the extension time ΔT (= T15 = A5 × α) to the previous determination time T2.
[0056]
Therefore, in the present embodiment, the signal change rate A is detected as the range position switching speed at each set interval Δt after the driver starts switching the range position, and the signal change rate A is within the range (II). In some cases, when the time during which the shift device 10 is not in the range position continues for the determination time T or longer, the shift device 10 is determined to be in a failed state. The determination time T at this time is the signal change rate detected at each set interval Δt. Set based on A. For this reason, the time required to determine the fail state can be appropriately set according to the driver's switching operation.
[0057]
Therefore, according to the present embodiment, the fail state can be determined at an appropriate timing according to the driver's switching operation, so that the driver feels uncomfortable due to the discord between the driver's switching operation and the fail determination timing. Comfortable operability can be ensured.
[0058]
Particularly in this embodiment, it is preferable to set the determination time T longer as the signal change rate A is smaller with the coefficient α as a variable, that is, as the switching speed is lower, the determination time is set longer. According to such a configuration, it is possible to set a failure occurrence time suitable for a different operation time for each driver, and it is possible to reduce the uncomfortable feeling felt by the driver.
[0059]
By the way, when the switching speed V is extremely low, there is a high possibility that the shift device 10 is in a fail state. Therefore, in this embodiment, when the signal change rate A, which is the switching speed, falls below the lower limit value Amin of the range (II) in step 10, the determination time T is held at the previous determination time T (OLD). Yes.
[0060]
Specifically, referring to FIG. 8, when the extension determination at time t = t2 and the signal change rate A2 falls below the lower limit value Amin of the range (II), the determination time T1 (= T10 + T11) in the previous extension determination. ). According to this configuration, while ensuring comfortable operability, when there is a high possibility that the shift device 10 is in a fail state, a fail determination can be performed quickly.
[0061]
Further, when the switching speed V is extremely slow, the shift device 10 is likely to be in a failed state, but it is also a fact that the driver needs to consider the case where the range position is fixed at an incorrect position. is there. Therefore, in the present embodiment, as shown in FIG. 1, a warning lamp 7 is provided to warn the driver when the signal change rate A is lower than the lower limit value Amin. According to such a configuration, when a fail state is caused by the switching operation of the driver, the driver is made to recognize it and prompt the switching of the normal range position, thereby preventing the fail processing from being performed carelessly. Can do.
[0062]
Even when the switching speed V is extremely fast, there is a high possibility that the shift device 10 is in a fail state. This state is an electrical failure of the shift range operation means and is not caused by the operation of the driver. Therefore, in the present embodiment, when the signal change rate A exceeds the upper limit value Amax of the range (II), it is determined that the shift device 10 is in the fail state without actually performing the fail determination as in step 11. . According to this configuration, while ensuring comfortable operability, it is possible to execute a rapid fail process for a fail state that causes a sudden change in behavior to the vehicle.
[0063]
The above description is only a preferred embodiment of the present invention, and various modifications can be made by those skilled in the art within the scope of the claims. For example, the mechanism for drivingly coupling the motors 2 and 3 and the manual shaft 5 is not limited to the planetary gear mechanism.
[0064]
Further, the parameter for obtaining the switching speed V is not limited to the resistance value, and a current or a voltage may be used. The electric control actuator is not limited to a motor, and may be a direct acting type such as a telescopic rod. For this reason, the range position transmission member is not limited to the rotary shaft, and may be any member that can transmit the operation of the electric actuator to the range environment setting means, such as a member that moves along the axial direction thereof.
[0065]
In addition, the range environment setting means is not limited to the range switching valve 62 that changes the range environment by switching the hydraulic circuit as long as the range environment can be set according to the operation of the electric actuator. The environment may be changed. The shift device 10 is not limited to the dial type as long as it can continuously detect the range position switching operation, and may be a shift lever type.
[0066]
Further, the automatic transmission 1 is not limited to the stepped type, and for example, there is no need to change the pulley groove width by driving a belt between input and output pulleys so that power can be transmitted and driving either of the input and output pulleys. It may be a V-belt type continuously variable transmission mechanism that performs step shifting. Similarly, the automatic transmission 1 arranges a power roller rotatably supported by a trunnion between input and output disks so that power can be transmitted, and supplies a control pressure based on the hydraulic pressure from a mechanical oil pump to the trunnion. A toroidal-type continuously variable transmission mechanism that performs a stepless transmission by tilting the power roller along the slope of the input / output disk may be used.
[Brief description of the drawings]
FIG. 1 is a system diagram showing a failure diagnosis apparatus for a shift-by-wire automatic transmission according to an embodiment of the present invention.
FIGS. 2A and 2B are a schematic view and a perspective view, respectively, illustrating a main part of a drive system that sets a range environment in an automatic transmission using two step motors.
FIGS. 3A and 3B are an enlarged front view and an enlarged side view of a shift device, respectively.
FIGS. 4A and 4B are an enlarged front view and an enlarged side view for explaining the internal structure of the shift device, respectively.
FIGS. 5A and 5B are an enlarged front view and an enlarged side view for explaining the internal structure when the shift device is in a no-signal state, respectively.
FIG. 6 is a flowchart executed by a controller as an embodiment of the present invention.
FIG. 7 is a diagram illustrating a determination region based on a signal change rate A;
FIG. 8 is a time chart showing an operation when the determination time T is corrected by using the determination routine of FIG. 6 in the switching operation.
[Explanation of symbols]
1 Shift-by-wire automatic transmission
2, 3 step motor
4 Planetary gear mechanism
5 Manual shaft
6 Range environment setting means
7 Warning means
10 Range selector
100 controller

Claims (5)

A plurality of range signal output areas that continuously output signals instructing the range position according to the driving mode desired by the driver, and outside the range that does not command a specific range position that exists between the range signal output areas In a shift-by-wire automatic transmission that has a signal output area , includes range command means for commanding a range position selected by a driver's switching operation, and sets a range environment requested by the driver based on this command.
A fail determination means for determining that the range command means is in a fail state when the time during which the range command means does not command the range position continues for a predetermined determination time;
Range position switching speed detecting means for detecting the switching speed of the range position at a predetermined set interval after the driver starts switching the range position;
And a determination time setting means for setting a determination time based on the switching speed. A fail determination device for a shift-by-wire automatic transmission. 2. The fail determination device for a shift-by-wire automatic transmission according to claim 1, wherein the determination time setting means sets the determination time longer as the switching speed is lower. 3. The shift-by-wire automatic according to claim 1, wherein the determination time setting means holds the determination time at the previous determination time when the switching speed falls below a lower limit value of the speed range. Transmission failure determination device. The shift-by-wire automatic according to any one of claims 1 to 3, further comprising warning means for giving a warning to the driver when the switching speed falls below a lower limit value of the speed range. Transmission failure determination device. The shift according to any one of claims 1 to 4, wherein the fail determining means determines that the range command means is in a fail state when a switching speed exceeds an upper limit value of the speed range. Fail determination device for by-wire automatic transmission.

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