Vehicle shift position determination device

Abstract

To provide a vehicular shift position determination device which can inhibit fail-safe processing from being executed by mistake despite a situation where shift position sensors are actually normal.SOLUTION: When an abnormality occurs in one of shift position sensors 40a, 40b, 40c, a CPU 22 determines detection results of the other two shift position sensors as a shift position used for controlling on condition that the detection results of the other two shift position sensors match with each other. The CPU 22 sets the shift position used for the controlling to an N position if the duration time during which the detection results of the other two sensors do not match with each other is longer than or equivalent to a specified time. The CPU 22 makes the specified time longer in a case where the N position is included in the unmatched detection results, compared to a case where the N position is not included in the detection results.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle shift position determining device. [Background technology]

[0002] For example, the following Patent Document 1 describes a shift lever that returns to a neutral position when the user releases the shift lever after operating the shift lever. An N position exists between the neutral position and both the D position and the R position. Therefore, when the user moves the shift lever from the neutral position to the D position or the R position, the shift lever goes through the N position. Then, when the user releases the shift lever, the shift lever returns to the neutral position.

[0003] The document also describes that the vehicle is equipped with multiple sensors that detect the position of the shift lever, and that if an abnormality occurs in any of the sensors, a fail-safe process is executed to switch to the N position (paragraph "0004"). The document also describes that if an abnormality occurs in which the signal output from the sensor is stuck, the abnormality is only discovered when the shift lever is operated. This means that if such an abnormality occurs, the sensor detection results will not match when the shift lever is operated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-38002 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, due to individual differences and deterioration over time among the multiple sensors, differences in the responsiveness of the sensors may occur. Therefore, when the shift lever is operated, there is a risk of a temporary inconsistency in the detection results of the multiple sensors. In particular, when the shift lever is shifted to either the D position or the R position in the above configuration, there may be an inconsistency in the detection results, which may include both the N position and the D position, or both the N position and the R position. In that case, if the shift lever is switched to the N position, the vehicle may not be able to run even though the sensors are normal. [Means for solving the problem]

[0006] Means for solving the above problems and their effects will be described below. The vehicle shift position determination device is applied to a vehicle equipped with a transmission, the vehicle comprising a shift operation member and two or more shift position sensors, the shift operation member being displaceable to each of a plurality of positions and passing through a neutral position when displaced to one or more driving positions, the two or more shift position sensors each detecting displacement of the shift operation member, and executing a match determination process and a determination process, the match determination process being a process for determining whether or not the detection results of the two or more shift position sensors match, the determination process being a process for determining, if the match is determined by the match determination process, the shift position related to the detection result as the shift position to be used for control, and including a fail-safe process, the fail-safe process being a process for determining the neutral position as the shift position to be used for control if a state in which the match determination process determines that there is no match continues for a specified time or more, the specified time being longer when the detection results include a result in which the neutral position is detected than when there is no such result.

[0007] In the above configuration, when the state in which the detection results are determined to be inconsistent continues for a specified time or more, the neutral position is determined as the shift position to be used for control. This makes it possible to execute a fail-safe process when an abnormality occurs in the shift position sensor. In the above configuration, the shift lever is operated to one or more of the driving positions via the N position. Therefore, when the shift lever is operated to the driving position, if there is a difference in the response delay of each of the detection results of two or more shift position sensors, a mismatch occurs in the detection results. However, if the shift position sensor is normal, the mismatch is quickly resolved. Therefore, in the above configuration, the specified time is made longer when the detection results are inconsistent and the detection results include the N position than when they do not. This makes it possible to suppress the erroneous execution of the fail-safe process even when the shift position sensor is actually normal. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of a drive system and a control device for a vehicle according to an embodiment; [Diagram 2] 4 is a flowchart showing a procedure of a process executed by the control device according to the embodiment. [Diagram 3] 4 is a time chart illustrating the operation of the embodiment; [Figure 4] 4 is a time chart illustrating the operation of the embodiment; [Diagram 5] 4 is a time chart illustrating the operation of the embodiment; [Figure 6] 4 is a time chart illustrating the operation of the embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings. A vehicle VC shown in Fig. 1 includes a prime mover 10 as a thrust generating device for the vehicle VC. The prime mover 10 includes an internal combustion engine or an internal combustion engine and a rotating electric machine. An output shaft of the prime mover 10 is mechanically connected to an input shaft 12a of a transmission 12. An output shaft 12b of the transmission 12 is mechanically connected to driving wheels 14.

[0010] The control device 20 controls the gear ratio, which is a control amount of the transmission 12 as a control target. The control device 20 includes a CPU 22, a ROM 24, a peripheral circuit 26, and a communication line 28. The CPU 22, the ROM 24, and the peripheral circuit 26 are capable of communicating with each other via the communication line 28. The peripheral circuit 26 includes a circuit that generates a clock signal that regulates the internal operation, a power supply circuit, a reset circuit, and the like. The control device 20 controls the gear ratio by the CPU 22 executing a program stored in the ROM 24.

[0011] The control device 20 controls the gear ratio based on the shift position designated by the operation of the shift lever 30. The shift lever 30 is a shift operation unit for indicating the drive position (D position), neutral position (N position), reverse position (R position), and brake position (B position). In FIG. 1, the D position, N position, R position, and B position are written as "D", "N", "R", and "B", respectively. Here, the D position is a position for forward driving. The N position is a position for cutting off the power transmission between the prime mover 10 and the driving wheels 14. The R position is a position for reverse driving. The B position is a position for generating engine braking.

[0012] The parking position (P position) is selected by a user operating the P switch 42. In detail, when the P switch 42 is operated, the control device 20 acquires an output signal Dp corresponding to the operation and sets the shift position to be used for control to the P position.

[0013] The shift lever 30 has a mechanism that automatically returns to the H position indicated by "H" in the figure. For example, when the user selects the D position, the shift lever 30, which is in the H position, is operated to the D position via the N position. Then, when the user releases the shift lever 30, the shift lever 30 naturally returns to the H position. Therefore, the control device 20 monitors the displacement of the shift lever 30 based on the output signals Da, Db, and Dc of the shift position sensors 40a to 40c.

[0014] When the shift position sensors 40a-40c are normal, the control device 20 determines the shift position specified by the user by operating the shift lever 30 based on their detection results. When an abnormality occurs in any one of the shift position sensors 40a-40c, the control device 20 operates the display 44 to notify the user of the abnormality. Then, the control device 20 determines the shift position based on the detection results of the remaining two sensors.

[0015] Fig. 2 shows the procedure of the process when an abnormality occurs in any one of the shift position sensors 40a to 40c. The process shown in Fig. 2 is realized by the CPU 22 repeatedly executing a program stored in the ROM 24, for example, at a predetermined interval. In the following, the step number of each process is represented by a number preceded by "S."

[0016] In the series of processes shown in FIG. 2, the CPU 22 first determines whether or not an abnormality occurs in any one of the shift position sensors 40a to 40c (S10). If the CPU 22 determines that an abnormality occurs (S10: YES), it determines whether or not the detection results of the shift position by the remaining two sensors are different (S12). That is, if the abnormality of the shift position sensor 40c is confirmed, for example, the CPU 22 determines whether or not the output signals Da, Db of the shift position sensors 40a, 40b are different. Then, if the CPU 22 determines that the pair of detection results match (S12: NO), it determines whether or not the detection result is other than the N position (S14). If the CPU 22 determines that the detection result is other than the N position (S14: YES), it assigns the matching detection result to the shift position as a variable used in controlling the transmission 12 (S16). That is, the CPU 22 regards the shift position instructed by the operation of the shift lever 30 as the detection result of the two sensors, and adopts the detection result as the actual shift position.

[0017] On the other hand, when the CPU 22 determines that the position is the N position (14: NO), it determines whether or not the duration of the state in which the detection results of the two sensors match at the N position has reached a first threshold value T1 (S18). This process is a process for determining whether or not a condition for switching the shift position used for control to the N position is satisfied. That is, when the shift lever 30 is operated to the D position or the R position, it goes through the N position. Therefore, if the detection results of the two sensors match and the shift is immediately switched to the N position, there is a risk that the switching will be against the user's will. Therefore, the condition for switching to the N position is that the duration of the state in which the detection results of the two sensors match is equal to or longer than the first threshold value T1. When the CPU 22 determines that the first threshold value T1 or longer has elapsed (S18: YES), it proceeds to the process of S16.

[0018] On the other hand, if the CPU 22 determines that the shift position detection results from the remaining two sensors are different (S12: YES), it determines whether the shift position used for control is the P position (S20). If the CPU 22 determines that the shift position is the P position (S20: NO), it maintains the P position (S22). In other words, if the detection results from the two sensors do not match, the CPU 22 determines that it is unclear in which direction the shift lever 30 has been operated from the H position, and maintains the P position.

[0019] On the other hand, when the CPU 22 determines that the shift position used for control is not the P position (S20: YES), it determines whether or not one of the detection results of the two sensors is the N position (S24). When the CPU 22 determines that neither of the detection results of the two sensors is the N position (S24: NO), it determines whether or not the duration of the state in which the detection results of the two sensors are different has reached a second threshold value T2 (S26). When the CPU 22 determines that the second threshold value T2 has been reached (S26: YES), it assigns the N position to the shift position as a variable used for controlling the transmission 12 (S28). This process is intended to avoid control being performed using the position opposite to the user's intention, either forward or reverse.

[0020] On the other hand, when the CPU 22 determines that either of the detection results of the two sensors is the N position (S24: YES), the CPU 22 proceeds to processing of S30. In the processing of S30, the CPU 22 determines whether or not the duration of the state in which the detection results of the two sensors are different and either of the detection results is the N position has reached a third threshold value T3. The third threshold value T3 is set to a value larger than the second threshold value T2. Then, when the CPU 22 determines that the third threshold value T3 has been reached (S30: YES), the CPU 22 proceeds to processing of S28.

[0021] It should be noted that the CPU 22 temporarily ends the series of processes shown in FIG. 2 when it completes the processes of S16, S22, and S28, or when a negative determination is made in the processes of S10, S18, S26, and S30.

[0022] Here, the operation and effects of this embodiment will be described. 3 to 6 show examples of the process shown in FIG. 2 when it has been determined that an abnormality has occurred in the shift position sensor 40c.

[0023] Fig. 3 shows the process when the shift lever 30 is operated to the D position when the shift position is in the R position. Fig. 3 also shows the process shown in Fig. 2 when the shift position sensors 40a, 40b are normal.

[0024] As shown in FIG. 3, when the operation of the shift lever 30 is started at time t1, the output signal Da of the shift position sensor 40a switches from the value when the H position is detected to the value when the N position is detected. However, the output signal Db of the shift position sensor 40b switches from the value when the H position is detected to the value when the N position is detected at time t2, which is later than time t1. This is due to a response delay caused by an individual difference or aging of the shift position sensor 40b. Here, the period from time t1 to t2, during which a mismatch occurs between the detection results of the shift position sensors 40a and 40b due to the response delay, is shorter than the third threshold value T3. Therefore, the CPU 22 does not change the shift position used for control from the R position.

[0025] After that, at time t3, the shift lever 30 is switched from the N position to the D position. In response to this, the output signal Da of the shift position sensor 40a is switched to a value indicating the D position. However, the output signal Db of the shift position sensor 40b is switched to a value when the D position is detected at time t4, which is later than time t3. Here, the period from time t3 to t4, during which the detection results of the shift position sensors 40a and 40b do not match due to a response delay, is shorter than the third threshold value T3. Therefore, the CPU 22 does not change the shift position used for control from the R position. Incidentally, the interval from time t2 to time t3 is the time interval during which the shift lever 30 passes through the N position when it is operated from the H position to the D position, and is therefore shorter than the first threshold value T1, and the shift lever is not switched to the N position.

[0026] Then, at time t4, the output signals Da, Db of the shift position sensors 40a, 40b match each other in values ​​indicating the D position, so that the CPU 22 switches the shift position to the D position.

[0027] In this way, during the transition through the N position, the setting of the third threshold T3 prevents the erroneous determination that an abnormality has occurred in either of the remaining shift position sensors 40a, 40b. Therefore, it is possible to prevent the shift position from being switched to the N position despite the intention to switch to the D position.

[0028] Fig. 4 shows the process when the shift lever 30 is operated to the D position when the shift position is in the R position. Fig. 4 also shows an example in which an abnormality occurs in which the output signal Db of the shift position sensor 40b is fixed to a signal indicating the R position during the operation of the shift lever 30. In Fig. 4, the operation before time t3 is the same as in Fig. 3.

[0029] When the output signal Db of the shift position sensor 40b switches to a value indicating the R position at time t3, the CPU 22 determines that the detection results of the shift position sensors 40a, 40b do not match. Then, at time t4 when the duration of the mismatch state reaches the second threshold value T2, the CPU 22 switches the shift position to the N position.

[0030] In this case, since the two detection results do not include the N position, the detection results will not match, allowing for rapid switching to the N position. Fig. 5 shows the process when the shift lever 30 is operated to the D position when the shift position is the R position. Fig. 5 also shows an example in which an abnormality occurs in which the output signal Db of the shift position sensor 40b is fixed to a signal indicating the N position during the operation of the shift lever 30. In Fig. 5, the operation before time t3 is the same as in Fig. 3.

[0031] When the output signal Da of the shift position sensor 40a switches to a value indicating the D position at time t3, the CPU 22 determines that the detection results of the shift position sensors 40a, 40b do not match. Then, at time t4 when the duration of the mismatch state reaches a third threshold value T3, the CPU 22 switches the shift position to the N position.

[0032] In this way, even if the two detection results do not match and one of them is in the N position, if that state continues for the third threshold value T3 or more, it is possible to switch to the N position.

[0033] Fig. 6 shows the process when the shift lever 30 is operated to the D position when the shift position is in the P position. Fig. 6 also shows an example in which an abnormality occurs in which the output signal Db of the shift position sensor 40b is fixed to a signal indicating the R position during the operation of the shift lever 30.

[0034] 6, when the operation of the shift lever 30 is started at time t1, the output signal Da of the shift position sensor 40a switches from the value when the H position is detected to the value when the N position is detected. However, the output signal Db of the shift position sensor 40b switches from the value when the H position is detected to the value when the N position is detected at time t2, which is later than time t1. Therefore, the CPU 22 determines that the detection results of the shift position sensors 40a, 40b do not match during the period from time t1 to t2. However, since the current shift position is the P position, the CPU 22 maintains the current shift position.

[0035] After that, at time t3, the shift lever 30 reaches the D position. As a result, the output signal Da of the shift position sensor 40a switches to a value indicating the D position, but because an abnormality has occurred in the shift position sensor 40b, its output signal Db has a value indicating the R position. Therefore, the CPU 22 determines that the detection results of the shift position sensors 40a, 40b do not match after time t3. However, because the current shift position is the P position, the CPU 22 maintains the current shift position.

[0036] In this way, when a mismatch occurs between the detection results of the shift position sensors 40a, 40b while the current position is the P position, the P position is maintained, thereby preventing the P position from being erroneously released.

[0037] <Correspondence> The correspondence between the matters in the above embodiment and the matters described in the "Means for solving the problem" section is as follows: The vehicle shift position determination device corresponds to the control device 20. The shift operation member corresponds to the shift lever 30. The one or more driving positions correspond to the D position and the R position. The "two or more shift position sensors" correspond to the shift position sensors 40a, 40b in Figs. 3 to 6. The match determination process corresponds to the process of S12. The determination process corresponds to the processes of S14 to S30. The fail-safe process corresponds to the processes of S20 to S30. The specified time when there is no result of detecting the neutral position corresponds to the second threshold value T2. The specified time when there is a result of detecting the neutral position corresponds to the third threshold value T3.

[0038] <Other embodiments> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0039] The driving positions that can be changed from the H position via the N position are not limited to the D position and the R position. For example, it may be either one of the two positions, the D position and the R position. It may also be the B position. For example, it may be three positions, the D position, the R position, and the B position. It may also be either the D position and the B position, or the R position and the B position. However, the driving positions that can be changed via the N position are not limited to the D position, the R position, and the B position.

[0040] The shift lever 30 is not limited to a type that returns to the H position as a neutral position when released. For example, even if the shift lever 30 remains in the D position, R position, etc., when it is displaced from the D position or the R position to the other, if it passes through the N position, the setting of the third threshold T3 is effective.

[0041] It is not essential to immediately execute the process of S16 when the process of S14 is determined to be positive. For example, the process of S16 may be executed when the duration of the state determined to be positive is equal to or longer than a predetermined value. In this case, the predetermined value is set to a value smaller than the first threshold value.

[0042] In the above embodiment, the magnitude relationship between the second threshold value T2 and the first threshold value T1 is not particularly limited. However, for example, the second threshold value T2 may be set to a value smaller than the first threshold value T1. It is not essential that prime mover 10 include an internal combustion engine. [Explanation of symbols]

[0043] 10. Prime mover 12...Gearbox 12a…Input shaft 12b…Output shaft 14…Drive wheel 20...Control device 30…Shift lever 40a, 40b, 40c...Shift position sensor

Claims

[Claim 1] Applies to vehicles equipped with a transmission, The vehicle includes a shift operation member and two or more shift position sensors. the shift operation member is displaceable to each of a plurality of positions and passes through a neutral position when displacing to one or more driving positions; The two or more shift position sensors each detect a displacement of the shift operation member, Execute a match determination process and a decision process; the match determination process is a process for determining whether or not the detection results of the two or more shift position sensors match each other, The determination process is a process for determining, when it is determined by the match determination process that there is a match, a shift position related to the detection result as a shift position to be used for control, and includes a fail-safe process; the fail-safe process is a process for determining a neutral position as a shift position to be used for control when a state in which the coincidence determination process determines that the two signals do not match continues for a specified time or longer; The specified time is set to be longer when the detection results include a result of detecting a neutral position than when the specified time does not include a result of detecting a neutral position.

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