JP4397352B2 - Vehicle control system - Google Patents

Description

  The present invention relates to a vehicle control system that determines whether there is an abnormality in a shift-by-wire system and selects vehicle travel control.

  In recent years, a shift-by-wire system that detects an instruction shift range selected by a vehicle occupant and drives a shift range switching valve that switches a shift range of an automatic transmission according to the detected instruction shift range by an actuator such as an electric motor has been used. (See, for example, Patent Document 1). When such a shift-by-wire system is used, if there is an abnormality in the shift-by-wire system, it is desirable to perform fail-safe.

In Patent Document 1, whether the shift range indicated by the two signals of the contact signal accompanying the operation of the range selector switch and the range position signal that detects the switching position of the shift range switching valve driven by the electric motor match. And fail safe is implemented.
However, in Patent Document 1, since only two signals of the contact signal and the range position signal are collated, it cannot be determined which of the two signals is abnormal. Therefore, fail safe according to the abnormal device cannot be implemented.

Japanese Patent No. 29766885

  The present invention has been made to solve the above problem, and can determine which of the electric motor, the rotation angle detection device, and the shift range detection device is abnormal, and the vehicle according to the abnormal device An object of the present invention is to provide a vehicle control system capable of selecting travel control.

  In a shift-by-wire system, an electric motor that drives a shift range switching valve that switches a shift range of an automatic transmission, an angle detection device that detects a rotation angle of the electric motor, and a shift range detection that detects a shift range position of the automatic transmission There is a very low possibility that two or more of the devices will fail and become abnormal at the same time. That is, at the time of abnormality determination, at least two devices are often normal.

  Therefore, in the first aspect of the present invention, the rotation instruction that the motor control device instructs the electric motor according to the instruction shift range selected by the vehicle occupant, the angle detection signal that the angle detection device detects, and the shift range detection device By collating the shift range detection signal to be detected, for example, if the shift ranges indicated by the rotation instruction, the angle detection signal, and the shift range detection signal match, the three devices are normal, and the rotation instruction and the angle detection are detected. When only one of the shift ranges indicated by the signal and the shift range detection signal indicates a shift range different from the other, it can be determined that the device indicating the different shift range is abnormal. By specifying the abnormal device in this way, it is possible to select vehicle travel control according to the abnormal device.

In the invention according to claim 2 , there is a case where an abnormality occurs in one of the electric motor, the angle detection device, and the shift range detection device, and then an abnormality occurs in one of the two remaining devices. By comparing the shift ranges indicated by the remaining two devices, it can be determined that one of the remaining devices is abnormal and the two devices are abnormal. Therefore, it is possible to select the vehicle travel control when abnormality occurs in two of the electric motor, the angle detection device, and the shift range detection device.

  According to the second aspect of the present invention, when at least one of the electric motor, the angle detection device, and the shift range detection device is abnormal, the output torque of the automatic transmission is reduced or the output torque is not generated. By selecting the vehicle travel control, the travel speed of the vehicle can be reduced and fail safe can be implemented. For example, the state of the automatic transmission may be set to a non-transmission state where the power generated by the engine is not transmitted (hereinafter, the “non-transmission state where the power generated by the engine is not transmitted” is simply expressed as a non-transmission state), or the output of the engine Vehicle traveling control that reduces the output torque of the automatic transmission or does not generate the output torque by reducing or stopping the torque may be selected.

  In particular, among the electric motor, the angle detection device, and the shift range detection device, if the electric motor is abnormal and does not operate normally, the shift range switching valve cannot be driven according to the instruction shift range selected by the vehicle occupant. . In such a state, the instruction shift range and the actual shift range of the automatic transmission selected by the electric motor driving the shift range switching valve (hereinafter referred to as “the electric motor driving the shift range switching valve is selected. In some cases, the actual shift range of the automatic transmission is expressed as an actual shift range). For example, although the vehicle occupant has selected the D range, the R range may be selected by the automatic transmission, and the traveling direction of the vehicle may be opposite to the direction of the vehicle occupant.

Therefore, as in the invention described in claim 4, when the electric motor is abnormal and the angle detection device and the shift range detection device are normal, the vehicle reduces the output torque of the automatic transmission or does not generate the output torque. By selecting the travel control, the travel speed of the vehicle can be reduced and fail safe can be implemented even when the instruction shift range and the actual shift range do not match.
According to a third aspect of the present invention, when at least one of the electric motor, the angle detection device, and the shift range detection device is abnormal, the automatic transmission is set to a non-transmission state, thereby Can be prohibited or the vehicle traveling speed can be reduced. In addition, since the engine is operating even under vehicle driving control conditions in which the state of the automatic transmission is set to the non-transmission state, functions such as power steering using the driving force of the engine and brake assist are continuously used. it can.

  Further, as described above, if the electric motor is abnormal and does not operate normally among the electric motor, the angle detection device, and the shift range detection device, the instruction shift range and the actual shift range may not match. Therefore, when the electric motor is abnormal and the angle detection device and the shift range detection device are normal as in the fifth aspect of the invention, the instruction shift range and Even if the actual shift range is different, it is possible to implement a fail safe that prohibits the start of the vehicle or decelerates the vehicle traveling speed. Further, since the engine is operating even under the above circumstances, functions such as power steering and brake assist using the driving force of the engine can be continuously used.

  By the way, if the electric motor operates normally according to the instruction of the motor control device, the instruction shift range and the actual shift range should be matched by controlling the rotation angle of the electric motor according to the instruction shift range. Is possible. For example, when the three devices of the electric motor, the angle detection device, and the shift range detection device are normal, the motor control device controls the rotation angle of the electric motor and the angle detection signal detected by the angle detection device. The angle detection device can be created by creating a correspondence table while controlling the electric motor, or by creating a correspondence table between the control signal for controlling the rotation angle of the electric motor by the motor control device and the rotation angle of the electric motor. The so-called motor open control for controlling the rotation angle of the electric motor can be implemented without referring to the angle detection signal.

Moreover, the electric motor may be controlled while referring to the shift range detection signal detected by the shift range detection device so that the instruction shift range and the actual shift range coincide with each other.
Therefore, as in the sixth aspect of the invention, when the angle detection device is abnormal and the electric motor and the shift range detection device are normal, the motor control device responds to the indicated shift range without referring to the angle detection signal. By rotating the electric motor at the rotation angle, it is possible to select the vehicle travel control in which the instruction shift range and the actual shift range match.

  By the way, as in the sixth aspect of the invention, even when the angle detection device is abnormal, control is performed to rotate the electric motor to the rotation angle corresponding to the instruction shift range without referring to the angle detection signal, and the instruction shift range. When the vehicle travel control in which the actual shift range matches the actual shift range is continued, an abnormality may occur in the electric motor or the shift range detection device. In such a case, according to the seventh aspect of the invention, it is possible to determine whether the shift range detection signal is switched by the rotation control of the electric motor, and to select the vehicle traveling control according to the determination result to implement the fail safe.

  Even if the shift range detection device is abnormal, if the electric motor and the angle detection device are normal, the rotation angle of the electric motor can be accurately controlled while referring to the angle detection signal of the angle detection device. Therefore, in the invention according to claim 8, when the shift range detection device is abnormal and the electric motor and the angle detection device are normal, the motor control device is rotated according to the designated shift range while referring to the angle detection signal. By rotating the electric motor at an angle, it is possible to select the vehicle travel control in which the instruction shift range and the actual shift range match.

  Note that each function of the plurality of apparatuses provided in the present invention is realized by a hardware resource whose function is specified by the configuration itself, a hardware resource whose function is specified by a program, or a combination thereof. In addition, hardware resources that are physically independent of each other may realize each function of a plurality of devices, a common hardware resource may realize a plurality of functions, or a plurality of hardware resources May implement each function.

Hereinafter, a vehicle control system according to an embodiment of the present invention will be described. In the following description, the electronic control device is abbreviated as ECU.
A vehicle system using a shift-by-wire system 10 according to an embodiment of the present invention is shown in FIG. In the present embodiment, the shift-by-wire system 10 constitutes the vehicle control system described in the claims. The shift-by-wire system 10 is a system that controls the traveling of a two-wheel drive or four-wheel drive vehicle, and includes an actuator 20 and an ECU 80 for shift-by-wire (SBW). The ECU 80 also serves as the motor control device and the travel control selection device described in the claims.

  The ECU 80 for the SBW, the ECU 86 for the engine (E / G) 2 and the ECU 88 for the automatic transmission (A / T) 6 are all electric circuits mainly composed of a microcomputer, CPU, RAM, ROM , EEPROM and the like. In the ROM and EEPROM, control programs executed by the ECUs 80, 86, and 88 are stored. The ECUs 80, 86, and 88 operate by being supplied with electric power from a battery 90 that is a main power source of the vehicle. The ECUs 80, 86, and 88 are electrically or optically interconnected via the in-vehicle LAN line 92, and can transmit and receive signals to and from each other.

  The SBW ECU 80 detects an instruction shift range selected by a vehicle occupant by operating a shift lever 84 as a shift range switching device, and operates the actuator 20 in accordance with the instruction shift range to operate the manual valve 60 (FIG. 2) is controlled. When the manual valve 60 as a shift range switching valve reciprocates according to the command shift range, the hydraulic pressure applied to the oil passage in the automatic transmission control device 12 is switched, and the shift range of the automatic transmission 6 is switched. The device for selecting the shift range by the vehicle occupant may be a button-type shift switch instead of the shift lever 84, or a voice recognition device in which the vehicle occupant instructs the shift range by voice. The shift range position of the shift lever 84 is detected by a contact switch or the like whose contact position changes in conjunction with the shift lever 84.

The E / G ECU 86 detects the operating state of the engine 2 based on detection signals from the rotational speed sensor 3, the intake air amount sensor 4, and the like, and controls an injection amount of an injector (not shown), an opening degree of a throttle device, and the like.
The A / T ECU 88 controls the electromagnetic valve 14 and the like of the automatic transmission control device 12 to increase or decrease the drive hydraulic pressure applied to the friction engagement elements such as the clutch and brake of the automatic transmission 6. Switching between engagement and release. When the engagement and disengagement of the friction engagement elements of the automatic transmission 6 are switched, the gear stage of the automatic transmission 6 is switched. The ECU 88 includes a hydraulic sensor 16 that detects a drive hydraulic pressure applied to the friction engagement element of the automatic transmission 6 from the automatic transmission control device 12, a vehicle speed sensor 18 that detects a vehicle speed from the rotation speed of the output shaft of the automatic transmission 6, and the like. Further, each solenoid valve 14 is controlled based on the detection signal of the indicated shift range selected by the shift lever 84, and the shift stage is switched by switching the engagement / release state of the friction engagement element of the automatic transmission 6. is doing. The detection position of the instruction shift range may be notified from the ECU 80 to the ECU 88, or may be detected directly by the ECU 88. Although the hydraulic sensor 16 is installed in the automatic transmission control device 12 in FIG. 1, it may be installed on the automatic transmission 6 side.

(Shift-by-wire system)
A shift-by-wire system 10 is shown in FIG. The ECU 80 detects the instruction shift range position of the shift lever 84 selected by the vehicle occupant with a contact switch or the like, and instructs the electric motor 22 of the actuator 20 to rotate according to the detected instruction shift range. The electric motor 22 is controlled so as to rotate the rotation angle amount. The control rod 50 is coupled to the output shaft 38 (see FIG. 3) of the electric motor 22, and the driving force of the electric motor 22 is transmitted via a speed reducer 30 described later. A detent plate 52 is fixed to the control rod 50 so as to rotate integrally. When the detent plate 52 rotates in the directions of arrows A and B in FIG. 2, the reciprocating position of the manual valve 60 is determined.

First, the actuator 20, detent plate 52, and shift range detector 58 (see FIG. 5) of the shift-by-wire system 10 will be described in detail.
(Actuator 20)
As shown in FIG. 3, the actuator 20 includes an electric motor 22, a speed reducer 30, an encoder 40, and the like.

  The electric motor 22 of the present embodiment is a brushless SR motor (switched reluctance motor) that does not use a permanent magnet. The electric motor 22 includes a rotor core 24 installed at the center, a stator core 26 surrounding the outer periphery of the rotor core 24, a coil 28 wound around the stator core 26, and the like. The rotor core 24 is provided with a plurality of rotor teeth 25 in the rotation direction that protrude toward the stator core 26 on the outer peripheral side. The stator core 26 is provided with a plurality of stator core teeth 27 that protrude toward the inner circumferential rotor core 24 in the rotational direction. The coil 28 is wound around each stator core tooth 27. As shown in FIG. 4, the coils 28 corresponding to the U phase, the V phase, and the W phase are star-connected. Although only three coils 28 are illustrated in FIG. 4, U-phase, V-phase, and W-phase coils 28 are actually wound around 12 stator core teeth 27 sequentially in the rotation direction. Energization of the coil 28 is controlled by the ECU 80 turning on and off the transistor 82. When the ECU 80 sequentially switches energization to the U-phase, V-phase, and W-phase coils 28, the magnetization state of each magnetic pole on the rotor core 24 side of the stator core teeth 27 is sequentially switched. Thereby, the rotor teeth 25 facing the stator core teeth 27 are attracted to the stator core teeth 27 in one rotational direction, and the rotor core 24 rotates. The rotation direction of the rotor core 24 is determined by the energization order of the U-phase, V-phase, and W-phase coils 28. When energization is switched in the order of U-phase, V-phase, and W-phase, When energization is switched in the order of the phase and the U phase, it is reversed.

  The reduction gear 30 is a reduction gear using an inscribed planetary gear mechanism. The rotation shaft of the sun gear 32 of the speed reducer 30 is eccentric with respect to the rotation shaft of the rotor core 24. A ring gear 34 in which the sun gear 32 is in mesh with the sun gear 32 is installed on the outer periphery of the sun gear 32. The disc 36 is attached to the end face side opposite to the rotor core 24 with respect to the sun gear 32. A plurality of through holes 37 formed in the disc 36 in the rotational direction are loosely fitted into the projections 33 of the sun gear 32 projecting toward the disc 36 side. When the rotor core 24 rotates, the sun gear 32 in mesh with the ring gear 34 revolves while rotating. Then, due to the loose fitting between the projection 33 of the sun gear 32 and the through hole 37 of the disk 36, only the rotation component of the sun gear 32 revolving while rotating is transmitted from the disk 36 to the output shaft 38. A control rod 50 is coupled to the output shaft 38. With such a configuration of the speed reducer 30, the rotation of the sun gear 32 that rotates at a reduced speed while being eccentric with respect to the rotor core 24 is transmitted from the output shaft 38 to the control rod 50 and the detent plate 52.

  The encoder 40 as an angle detection device includes a plurality of magnets 42 attached in the rotational direction of the rotor core 24, a Hall IC 44 for magnetic detection installed on the circuit board facing the magnet 42 in the housing of the actuator 20, and the like. Become. In this embodiment, the encoder 40 is an incremental digital encoder that adds and subtracts the number of pulses according to the rotation angle amount of the rotor core 24 and outputs the result. The ECU 80 controls the rotation of the electric motor 22 until the target count number is reached while referring to the count number that is the rotation angle amount of the rotor core 24 output from the encoder 40, thereby detenting the rotation position corresponding to the indicated shift range. The plate 52 is rotated. The ECU 80 determines that the detent plate 52 has reached the rotation position corresponding to the designated shift range when the electric motor 22 rotates within a range of a predetermined count number including the target count number, and ends the rotation control of the electric motor 22. To do.

  FIG. 6 shows the relationship between the count number that is the angle detection signal of the encoder 40 of the actuator 20 and the shift range detection signal of the shift range detection device 58 described later. The count number output from the encoder 40 increases as the shift range is switched from the P range to the D range, and decreases as the shift range is switched from the P range to the D range.

(Detent plate 52)
As shown in FIG. 2, the detent plate 52 is a plate-like member having a substantially fan shape, and a plurality of concave portions 53 are formed on the arc-shaped outer peripheral portion thereof. The detent spring 62 is a leaf spring and is fixed to the automatic transmission control device 12 in a cantilever manner. A roller 63 that engages with the recess 53 of the detent plate 52 is attached to the tip of the detent spring 62, and the roller 63 engages with any of the recesses 53 of the detent plate 52 by the elastic force of the detent spring 62. The detent plate 52 is provided with a pin 54 fitted to the manual valve 60. When the detent plate 52 rotates together with the control rod 50, the manual valve 60 fitted to the pin 54 reciprocates according to the rotational position of the detent plate 52. The concave portion 53 and the roller 63 are arranged corresponding to the set positions of the respective shift ranges in the manual valve 60, and when the roller 63 is completely engaged with any one of the concave portions 53, the shift range corresponding to the concave portion 53 is set. The manual valve 60 is set at the position. When the electric motor 22 of the actuator 20 rotates and the manual valve 60 moves to a shift range position corresponding to the indicated shift range selected by the shift lever 84, the shift stage of the automatic transmission 6 is moved back and forth by the manual valve 60. It is controlled by the automatic transmission control device 12 so as to be a gear position corresponding to the actual shift range specified by the position.

(Shift range detector 58)
As shown in FIG. 5, a plurality of shift range terminals T1, T2, T3, T4, T5 and two ground terminals are provided on one end surface in the thickness direction of the detent plate 52 along the rotation direction of the detent plate 52. T6 is installed. The shift range detection device 58 is configured by a configuration in which the terminals T1, T2, T3, T4, T5, and T6 rotate together with the detent plate 52 and sequentially contact the two contact terminals 56.

  The shift range terminals T1, T2, T3, and T4 are formed so as not to be electrically connected to each other on the same arc, and viewed from the control rod 50 that is the rotating shaft, the P range, R range, N range, and D range Are disposed on the same radius as the recesses 53p, 53r, 53n, and 53d corresponding to. The shift range terminal T5 is installed on the same radius as the terminal T1 on the control rod 50 side than the shift range terminals T1, T2, T3, and T4. The two ground terminals T6 are respectively arranged between the shift range terminals T1, T2, T3, T4 and the shift range terminal T5, and closer to the control rod 50 than the shift range terminal T5, and between the recess 53p and the recess 53d. It is continuously formed in an arc shape. The shift range detection device 58 is configured by the shift range terminals T1, T2, T3, T4, T5, the ground terminal T6, and the contact terminal 56.

  The two contact terminals 56 extend in the radial direction and are attached to the support member 57. Since the support member 57 is attached to a fixing member (not shown), the contact terminal 56 does not rotate with the detent plate 52. The contact terminal 56 electrically connects the shift range terminals T1, T2, T3, T4 and one ground terminal T6, and the shift range terminal T5 and the other ground terminal T6. When the detent plate 52 is rotated in both directions of arrows A and B in FIG. 5 by the rotation of the electric motor 22, the contact terminal 56 is shifted to the shift range terminals T1, T2, T3, T4, T5 and the ground terminal T6 depending on the rotation position of the detent plate 52. As shown in FIG. From this conductive state, the rotational position of the detent plate 52, that is, the reciprocating position of the manual valve 60 can be known, so that the actual shift range selected by the automatic transmission 6 can be detected.

(Parking lock mechanism)
As shown in FIG. 2, the parking lock mechanism is configured to stop the rotation of the output shaft of the automatic transmission 6 by engaging the claw 73 of the parking lock pole 72 with the recess formed in the outer peripheral portion of the parking gear 70. It is configured. One end of the park rod 74 is fixed to the detent plate 52, and a tapered cone-shaped cam 76 is fitted to the other end. The cam 76 is fitted to the park rod 74 while being pressed to the other end side by the spring 78, and can reciprocate along the park rod 74. As the detent plate 52 rotates, the park rod 74 reciprocates, whereby the cam 76 moves the parking lock pawl 72 up and down, and the pawl 73 of the parking lock pawl 72 engages or disengages from the parking gear 70. . When the pawl 73 of the parking lock pole 72 is engaged with the parking gear 70, the rotation of the output shaft of the automatic transmission 6 is mechanically prohibited.

  Next, abnormality determination of the shift-by-wire system and vehicle travel control selection based on the abnormality determination result will be described. In the present embodiment, the shift-by-wire system 10 performs the function indicated by each step of the flowchart described below. On the other hand, the functions may be shared by the shift-by-wire system 10, the automatic transmission control device 12, and the ECUs 86 and 88.

(Abnormal judgment of shift-by-wire system)
The abnormality determination of the shift-by-wire system will be described with reference to FIG. The routine shown in FIG. 7 is periodically executed. FIG. 8 is a table showing the abnormality determination shown in FIG.
In step 200, the ECU 80 detects whether the vehicle occupant has switched the shift lever 84. If there is no instruction to switch the shift range, the routine is terminated. When there is an instruction to switch the shift range, the ECU 80 switches the transistor 82 to sequentially switch energization to the coils 28 corresponding to the U phase, V phase, and W phase of the electric motor 22 to rotate the electric motor 22. Then, the electric motor 22 rotates, and the electric motor 22 is rotated to the rotation angle corresponding to the instruction shift range while referring to whether the count number of the encoder 40 falls within a predetermined count number corresponding to the instruction shift range. Rotation control is performed.

  In step 202, the ECU 80 determines whether the count number of the encoder 40 increases or decreases in the rotation direction corresponding to the instruction shift range in accordance with the rotation of the electric motor 22. The ECU 80 proceeds to step 204 when the count number of the encoder 40 changes, and proceeds to step 210 when the count number of the encoder 40 does not change.

  In step 204, the ECU 80 determines whether the shift range detection signal detected by the shift range detection device 58 changes to a signal on the rotational direction side toward the instruction shift range. When the shift range detection signal changes in step 204, the ECU 80 controls the rotation of the electric motor 22 in accordance with the designated shift range. As a result, the count number of the encoder 40 and the shift range detection signal of the shift range detection device 58 are normal. In step 206, it is determined that the shift-by-wire system 10 is normal. In this normal state, the ECU 80 sequentially creates a shift range correspondence table by associating the count number of the encoder 40 with the shift range detection signal detected by the shift range detection device 58.

If the shift range detection signal does not change in step 204, the ECU 80 determines in step 208 that the shift range detection device 58 is abnormal.
When the count number of the encoder 40 does not change normally in step 202, the ECU 80 determines in step 210 whether the shift range detection signal changes.

If the count value of the encoder 40 does not change normally but the shift range detection signal changes normally, the ECU 80 determines in step 212 that the encoder 40 is abnormal.
When the count number of the encoder 40 and the shift range detection signal do not change normally, the ECU 80 determines in step 214 that the electric motor 22 is abnormal.

  If any of the electric motor 22, the encoder 40, and the shift range detection device 58 is abnormal, the ECU 80 turns on a warning lamp 94 as a warning device in step 216 and notifies the vehicle occupant of the occurrence of the abnormality. Instead of the warning lamp 94, the vehicle occupant may be notified of the occurrence of an abnormality by display display or audio output by a navigation system (not shown) or the like. The ECU 80 sets an abnormality flag that indicates which of the electric motor 22, the encoder 40, or the shift range detection device 58 is abnormal in steps 208, 212, and 214.

(Vehicle travel control selection)
FIG. 9 shows a vehicle travel control selection routine corresponding to the abnormal device of the shift-by-wire system 10. The abnormality determination in steps 220, 224, and 228 is performed based on the abnormality flag set in the routine shown in FIG.
If there is an abnormality in the shift range detection device 58 (step 220), the ECU 80 ignores the shift range detection signal detected by the shift range detection device 58 in step 222 and creates it when the shift range detection device 58 is normal. A vehicle that controls the rotation of the electric motor 22 so that the rotation angle amount is equal to the count number of the encoder 40 corresponding to the indicated shift range based on the shift range correspondence table in which the shift range detection signal and the count number of the encoder 40 are associated with each other. Select travel control.

  When the shift range detection device 58 is normal and the encoder 40 is abnormal (step 224), the ECU 80 ignores the count number of the encoder 40 in step 226 and sets the electric motor 22 to the U phase, V phase, and W phase. The motor open control is performed in which the rotation angle of the electric motor 22 is estimated from the number of times of switching the energization to the corresponding coil 28 and the electric motor 22 is rotated to the rotation angle corresponding to the instruction shift range to switch the shift range of the automatic transmission 6. Select as travel control.

When the shift range detection device 58 and the encoder 40 are normal and the electric motor 22 is abnormal (step 228), the ECU 80 stops the rotation control of the electric motor 22 in step 230. Then, the electromagnetic valve 14 of the automatic transmission control device 12 is controlled to release all the frictional engagement elements of the automatic transmission 6 so that the state of the automatic transmission 6 is not transmitted regardless of the reciprocating position of the manual valve 60. The A / T ECU 88 is notified to execute the forced neutral control. By performing forced neutral control and setting the torque transmitted to the output shaft of the automatic transmission 6 to zero, it is possible to implement a fail safe such as deceleration of the vehicle traveling speed or prohibition of transmission.
If the electric motor 22, the encoder 40, and the shift range detection device 58 are normal, the ECU 80 selects vehicle travel control that controls the rotation angle of the electric motor 22 while referring to the count number of the encoder 40.

(Abnormality judgment during motor open control)
10 and 11 show the abnormality determination routine when the motor open control is selected in the vehicle travel control selection routine of FIG.
If the motor open control is not selected (step 240), the ECU 80 ends this routine.
When the motor open control is selected, the ECU 80 detects whether the vehicle occupant has switched the shift lever 84 based on the detection signal from the contact switch, and ends this routine if there is no shift range switching instruction. . When there is an instruction to switch the shift range, the ECU 80 switches the transistor 82 and sequentially switches energization to the coils 28 corresponding to the U-phase, V-phase, and W-phase of the electric motor 22, thereby increasing the count number of the encoder 40. Rotation control for rotating the electric motor 22 to a rotation angle corresponding to the instruction shift range is performed while referring to whether the predetermined count number corresponding to the instruction shift range falls (step 242).

In step 244, the ECU 80 determines whether the shift range detection signal of the shift range detection device 58 changes in the rotation direction corresponding to the designated shift range in accordance with the rotation control for the electric motor 22. When the shift range detection signal changes normally, the ECU 80 selects to continue the motor open control in the next step 246.
The ECU 80 determines that either the electric motor 22 or the shift range detection device 58 is abnormal when the shift range detection signal does not change normally despite the rotation control of the electric motor 22, and in step 248. Then, the rotation control of the electric motor 22 is stopped. Then, the electromagnetic valve 14 of the automatic transmission control device 12 is controlled to release all the frictional engagement elements of the automatic transmission 6 so that the state of the automatic transmission 6 is not transmitted regardless of the reciprocating position of the manual valve 60. The A / T ECU 88 is notified to execute the forced neutral control.

(Motor open control)
FIG. 11 shows an example of a motor open control routine executed in step 246 of FIG. FIG. 11 is a motor open control routine when the designated shift range is switched from the P range to the R range. In the present embodiment, when the shift range is switched from the P range side to the D range side, the coil 28 is energized in the order of the U phase, the V phase, and the W phase. When the shift range is switched from the D range side to the P range side, the coil 28 is energized in the order of W phase, V phase, and U phase.

  In step 250, the ECU 80 energizes the coil 28 in the order of the U phase, the V phase, and the W phase. If the number of times the coil 28 is switched in the order of the U phase, V phase, and W phase is within the number corresponding to the indicated shift range (step 252), the ECU 80 determines that the shift range detection signal of the shift range detection device 58 is in step 254. It is determined whether the state has changed to the state corresponding to the R range. If the shift range detection signal has not changed to a state corresponding to the R range, ECU 80 returns the process to step 250.

When the shift range detection signal changes to a state corresponding to the R range, the ECU 80 rotates the electric motor 22 to a rotation angle corresponding to the designated shift range, and the shift range of the automatic transmission 6 corresponds to the designated shift range. It is determined that the range has been switched to the range, and energization to the electric motor 22 is stopped.
When the number of times the coil 28 is switched in the order of the U phase, the V phase, and the W phase exceeds the number corresponding to the indicated shift range (step 252), either of the electric motor 22 or the shift range detection device 58 is abnormal. In step 258, the rotation control of the electric motor 22 is stopped. Then, the electromagnetic valve 14 of the automatic transmission control device 12 is controlled to release all the frictional engagement elements of the automatic transmission 6 so that the state of the automatic transmission 6 is not transmitted regardless of the reciprocating position of the manual valve 60. The A / T ECU 88 is notified to execute the forced neutral control.

  As described above, in the present embodiment, when the electric motor 22 is rotationally controlled according to the instruction shift range, the electric motor is determined by determining whether the encoder 40 and the shift range detection device 58 are operating normally. 22, which of the encoder 40 and the shift range detection device 58 is abnormal is determined. And the optimal vehicle travel control is selected according to an abnormal device, and the fail safe is implemented.

(Other embodiments)
In the above embodiment, the SR motor is used as the electric motor, and the encoder 40 is used as the angle detection device that detects the rotation angle of the electric motor. However, the DC motor is used as the electric motor, and the magnetoresistive element or the angle detection device is used as the angle detection device. You may use the rotation angle sensor which detects a rotation angle based on the output level which changes according to a rotation angle using a Hall element etc.

In the above embodiment, the vehicle travel control is selected according to the abnormal device among the electric motor 22, the encoder 40, and the shift range detection device 58. However, if any of these three devices becomes abnormal, the automatic shift is performed. The same vehicle traveling control such as reducing the output torque of the machine 6 may be selected.
Further, instead of the vehicle travel control for reducing the output torque of the automatic transmission 6 by forced neutral that changes the state of the automatic transmission 6 to the non-transmission state, the opening degree of the throttle device is reduced or the injection amount of the injector is reduced. Thus, the output of the engine 2 may be reduced, and the output torque of the automatic transmission 6 may be reduced. Further, the engine 2 may be stopped.

In the above embodiment, the rotational position of the detent plate 52 is detected by the shift range detector 58, but a shift range detector that detects the reciprocating position of the manual valve 60 may be used.
Further, although the shift range detection device 58 detects the rotational position of the detent plate 52, a shift range detection device that detects the reciprocating position of the manual valve 60 may be used.

  In the above embodiment, the SBW ECU 80 constitutes the abnormality determination device and the travel control selection device. However, the functions of the abnormality determination device and the travel control selection device may be realized by separate devices, or the abnormality determination device and A part of the function of the travel control selection device may be realized not only by the ECU 80 but also by the E / G ECU 86 or the A / T ECU 88, for example.

The block diagram of the vehicle system by this embodiment. The block diagram of the shift-by-wire system by this embodiment. Sectional drawing of the actuator of this embodiment. The circuit diagram which shows simply the energization control circuit to the electric motor by this embodiment. The schematic diagram of the detent plate and shift range detection apparatus by this embodiment. Explanatory drawing which shows a response | compatibility with the shift range detection signal by a shift range detection apparatus, and the count number of an encoder. A routine for determining an abnormal device in a shift-by-wire system. A table for determining an abnormal device of a shift-by-wire system. A vehicle travel control selection routine for selecting vehicle travel control according to an abnormal device. Abnormality judgment routine during motor open control. Motor open control routine.

Explanation of symbols

2: Engine, 10: Shift-by-wire system (vehicle control system), 12: Automatic transmission control device, 20: Actuator, 22: Electric motor, 30: Reducer, 40: Encoder (angle detection device), 58: Shift range Detection device, 60: manual valve (shift range switching valve), 80: ECU for SBW (motor control device, travel control selection device), 86: ECU for A / T, 88: ECU for E / G, 94: warning light (Warning device)

Claims (8)

An electric motor that drives a shift range switching valve that switches the shift range of the automatic transmission;
An angle detection device for detecting a rotation angle of the electric motor;
A shift range detection device for detecting a shift range position of the automatic transmission;
A motor control device that rotates the electric motor to a rotation angle corresponding to an instruction shift range that is a shift range selected by a vehicle occupant while referring to an angle detection signal detected by the angle detection device;
The electric motor and the electric motor by comparing the rotation instruction that the motor control apparatus instructs to the electric motor according to the instruction shift range, the angle detection signal, and the shift range detection signal that the shift range detection apparatus detects determining whether there is abnormality in any one of the devices of the shift range detection equipment and the angle detection device, the running control selection unit for selecting a vehicle traveling control according to the determination result,
A vehicle control system comprising:   The travel control selection device reduces an output torque of the automatic transmission or outputs an output torque when at least one of the electric motor, the angle detection device, and the shift range detection device is abnormal. The vehicle control system according to claim 1, wherein the vehicle travel control that is not generated is selected.   The travel control selection device does not transmit the power generated by the engine to the state of the automatic transmission when at least one of the electric motor, the angle detection device, and the shift range detection device is abnormal. The vehicle control system according to claim 2, wherein the vehicle travel control to be in a non-transmission state is selected.   When the electric motor is abnormal and the angle detection device and the shift range detection device are normal, the travel control selection device reduces the output torque of the automatic transmission or does not generate the output torque. The vehicle control system according to claim 2, wherein control is selected.   When the electric motor is abnormal and the angle detection device and the shift range detection device are normal, the travel control selection device changes the state of the automatic transmission to a non-transmission state that does not transmit the power generated by the engine. The vehicle control system according to claim 4, wherein the vehicle travel control to be performed is selected.   In the travel control selection device, when the angle detection device is abnormal and the electric motor and the shift range detection device are normal, the motor control device does not refer to the angle detection signal and enters the designated shift range. The vehicle control system according to claim 1, wherein the vehicle travel control for rotating the electric motor at a corresponding rotation angle is selected.   Whether the shift range detection signal is switched when the motor control device performs control to rotate the electric motor to a rotation angle corresponding to the instruction shift range without referring to the angle detection signal. The vehicle control system according to claim 6, wherein the vehicle travel control is selected according to the determination result.   When the shift range detection device is abnormal and the electric motor and the angle detection device are normal, the travel control selection device sets the shift range detected by the motor control device while referring to the angle detection signal. The vehicle control system according to claim 1, wherein the vehicle travel control for rotating the electric motor at a corresponding rotation angle is selected.

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