Shift control method of electronic shift lever

A shift control method of an electronic shift lever may include detecting a collision of a vehicle when the vehicle is in an ignition-on state, detecting a shift range of the electronic shift lever, and preventing shifting by interrupting delivery of a signal for changing the shift range to a transmission, when the signal for changing the shift range is detected within a predetermined time after the detection of the collision.

CROSS-REFERENCE(S) TO RELATED APPLICATION

The present application claims priority to Korean Patent Application Number 10-2015-0055662 filed Apr. 21, 2015, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to a shift control method of an electronic shift lever. More particularly, the present invention relates to a shift control method of an electronic shift lever, which prevents a further secondary collision by impeding shifting or by shifting into a parking range, when a signal for changing a shift range is generated by the movement of the electronic shift lever during a collision.

Description of Related Art

Generally, a vehicle in which an automatic transmission is mounted controls oil pressure within a shift range set according to the vehicle speed, whereby a transmission gear automatically operates to shift into a target shift range.

To perform the shifting process, the automatic transmission sets up a gear ratio using a hydraulic circuit, a planetary gear, and friction elements; and a transmission control unit (TCU) serves to control such components.

Unlike an existing mechanical shift lever, a shift-by-wire (hereinafter, referred to SBW) automatic transmission is an electronic gear shift system without a mechanical coupler between the transmission and a shift lever, such as a cable. When a lever sensor value, which is obtained by operating the electronic shift lever, is delivered to a TCU, a solenoid or an electric motor is operated by an electronic signal instructed by the TCU. Then, by the operation of the solenoid or the electric motor, oil pressure is applied to or shut off from a hydraulic circuit for each shift position, whereby the transmission may electronically perform the shift control.

Therefore, an automatic transmission based on SBW delivers a driver's intention of shifting, in a form of an electric signal, to a TCU through the simple operation of an electronic shift lever or a button. Accordingly, shifting into a driving range (D), a reverse range (R), a neutral range (N), a parking range (P), and the like is easily performed. Also, the size of the shift lever can be reduced, thus securing more space between a driver's seat and a passenger's seat.

An electronic shift lever is simple to operate but when an external force is applied, it tends to be operated against a driver's intention. Especially, by an external force from a collision, the shift lever moves regardless of the driver's intention, thus causing a signal that changes a shift range. This may lead to a secondary collision.

In other words, when a collision occurs while the shift range is in D, R, or N position, an electronic shift lever moves by inertia and may generate a signal that changes the shift range from D to R position, from R to D position, or from N to R position. In this case, because a TCU operates a transmission based on the signal of the shift lever, there may be a secondary collision with the car ahead or the car behind.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a shift control method of an electronic shift lever, which prevents a secondary collision by impeding shifting or by shifting to a parking (P) range, when a signal for changing a shift range occurs during a collision.

According to various aspects of the present invention, a shift control method of an electronic shift lever may include detecting a collision of a vehicle when the vehicle is in an ignition-on state, detecting a shift range of the electronic shift lever, and preventing shifting by interrupting delivery of a signal for changing the shift range to a transmission, when the signal for changing the shift range is detected within a predetermined time after the detection of the collision.

The shift control method may further include, when the predetermined time has passed after the preventing shifting and a subsequent collision has not been detected, when the ignition is turned off and then turned on, enabling the shifting by releasing the interruption of the delivery of the signal to the transmission.

The shift control method may further include, when the predetermined time has passed after preventing the shifting and a subsequent collision has not been detected, when a signal for changing to a new shift range is generated, enabling the shifting by releasing the interruption of the delivery of the signal to the transmission.

The collision of the vehicle may be detected by a collision sensor or an airbag sensor.

The collision of the vehicle may occur inside the vehicle or outside the vehicle.

The shift range of the electronic shift lever may be detected by a lever sensor.

The shifting of the transmission may be controlled by a Transmission Control Unit (TCU), and the TCU may be controlled by an Electronic Control Unit (ECU).

When a signal for changing the shift range is not generated within the predetermined time after a collision of the vehicle occurs, the transmission may maintain an immediately pre-collision shift range.

According to various aspects of the present invention, a shift control method of an electronic shift lever may include detecting, by a collision sensor or an airbag sensor, a collision of a vehicle when the vehicle is in an ignition-on state, detecting, by a lever sensor, a shift range of the electronic shift lever immediately before the collision, detecting, by the lever sensor, a shift range of the electronic shift lever immediately after the collision, and interrupting, by control of a Transmission Control Unit (TCU), a shifting process so that a signal for changing the shift range, which is generated immediately after the collision, is not delivered to a transmission, when the shift range immediately before the collision and the shift range immediately after the collision are different within a predetermined time after the detection of the collision.

In a state in which the predetermined time has passed after the interruption of the signal for changing the shift range not to be delivered to the transmission by the control of the TCU and in which a subsequent collision has not occurred, when an ignition is turned off and then turned on, a signal for changing the shift range may be delivered to the transmission by the control of the TCU.

In a state in which a predetermined time has passed after the interruption of the signal for changing the shift range not to be delivered to the transmission by the control of the TCU and in which a subsequent collision has not occurred, when a signal for changing the shift range is generated again, the signal for changing the shift range may be delivered to the transmission by control of the TCU.

When a collision of the vehicle occurs and when the immediately pre-collision shift range is the same as the shift range immediately after the collision, the transmission may maintain the immediately pre-collision shift range by control of the TCU.

According to various aspects of the present invention, a shift control method of an electronic shift lever may include detecting, by a collision sensor or an airbag sensor, a collision of a vehicle when the vehicle is in an ignition-on state, detecting, by a lever sensor, a shift range of the electronic shift lever immediately before the collision, detecting, by the lever sensor, a shift range of the electronic shift lever immediately after the collision, and shifting, by control of a TCU, a transmission into a parking range, when the shift range immediately before the collision and the shift range immediately after the collision are different within a predetermined time after the detection of the collision.

According to the present invention, when a signal for changing a shift range of an electronic shift lever is generated during a collision, a transmission is not shifted for a predetermined time or is forcibly shifted into a parking (P) range, thus a further secondary collision may be prevented.

DETAILED DESCRIPTION

As illustrated inFIG. 1toFIG. 3, in the case of a shift-by-wire (SBW) automatic transmission, a wire4for delivering an electric signal connects between an electronic shift lever1and a Transmission Control Unit (TCU), and connects between the TCU and a transmission. A lever sensor5detects a shift range of the electronic shift lever1.

Various embodiments according to the present invention include a collision detection step in which a collision of a vehicle6is detected when the vehicle is in an ignition-on state, a range detection step in which a shift range of an electronic shift lever1is detected, and a shifting prevention step in which, when a collision occurs and a signal for changing the shift range is detected within a predetermined time (T1) after the collision, shifting is prevented by interrupting the delivery of the signal to the transmission3.

The collision may occur inside or outside the vehicle6, and is detected by a collision sensor7or an airbag sensor8, which is installed in the vehicle.

Therefore, when the vehicle is in an ignition-on state, both a collision signal, which is detected by the collision sensor7or the airbag sensor8, and a shift range signal of the electronic shift lever1, which is detected by the lever sensor5, are delivered to an Electronic Control Unit (ECU)9.

The Electronic Control Unit (ECU)9determines whether a signal for changing the shift range is generated within the predetermined time (T1) after the collision, and controls the TCU2when determining that the signal is generated. Accordingly, the TCU2prevents the delivery of the signal for changing the shift range to the transmission3, whereby the transmission3may not be shifted.

The ECU9can be referred to a lever-ECU of the electronic shift lever1.

On the other hand, various embodiments according to the present invention further include a shifting permission step in which under the condition that the predetermined time (T1) has passed after the shifting prevention step and that a subsequent collision is not detected, when the ignition is turned off and then turned on or when a signal for changing to a new shift range is generated, shifting is enabled by releasing the interruption of the signal to the transmission.

In other words, in a case in which the predetermined time (T1) has passed since the TCU2has interrupted the delivery of the signal for changing the shift range, and in which another collision has not occurred, if an ignition of the vehicle is turned off and then turned on, a logic that has interrupted the delivery of the signal to the transmission is initialized. Since then, if a driver operates the electronic shift lever1, a signal for changing the shift range is delivered to the transmission3and the shifting process is smoothly performed.

Also, in various embodiments according to the present invention, the transmission3maintains the immediately pre-collision shift range if a signal for changing the shift range has not been generated within the predetermined time (T1) after the collision of the vehicle6occurred.

Various embodiments of the present invention include a step in which a collision of a vehicle6is detected by a collision sensor7or an airbag sensor8, when the vehicle is in an ignition-on state, a step in which a shift range of an electronic shift lever1is detected by a lever sensor5immediately before the collision, a step in which a shift range of the electronic shift lever1is detected immediately after the collision, and a step in which a transmission3is shifted into a parking (P) range by the control of a TCU2if the immediately pre-collision shift range is different from the shift range immediately after the collision within a predetermined time (T1) after the collision.

In other words, when a signal for changing the shift range is generated within the predetermined time (T1) after the collision, the TCU2, which is controlled by an ECU9, compels the transmission3to shift into a parking (P) range, so that a secondary collision with the vehicle ahead or the vehicle behind is prevented.

Hereinafter, the operation of various embodiments of the present invention is described referring toFIG. 2.

When a collision occurs in an ignition-on state of a vehicle, a collision signal detected by a collision sensor7or an airbag sensor8is delivered to an ECU9, and the ECU9determines the collision of the vehicle at step S1.

Also, a shift range signal of an electronic shift lever1, which is detected by a lever sensor5, is delivered to the ECU9.

When determining that the collision has occurred, the ECU9determines whether a signal for changing the shift range is generated within a predetermined time (T1) after the collision at step S2. When determining that the signal is generated, the ECU9controls a TCU2and the TCU2interrupts the delivery of the signal to a transmission3at step S3. Accordingly, the transmission3may not be shifted.

In other words, when a collision occurs while a shift range of the electronic shift lever1is in D, R, or N position, the electronic shift lever1moves by inertia and is prone to generate a signal for changing the shift range from D to R, R to D, or N to R position. In this case, because the TCU2operates the transmission3based on the signal of the shift lever1, a secondary collision with a vehicle ahead or a vehicle behind may occur.

Therefore, in the present invention, when a signal for changing a shift range is generated within a predetermined time (T1) after a collision, the delivery of the signal to a transmission3is interrupted by a TCU2and the transmission3is not shifted, whereby a further secondary collision can be prevented.

On the other hand, when it is determined that a signal for changing the shift range is not generated within the predetermined time (T1) after the collision, the transmission3maintains the immediately pre-collision shift range by the control of the TCU2at step S4.

Also, in a case in which the predetermined time (T1) has passed since the signal for changing the shift range was interrupted not to be delivered to the transmission3by the control of the TCU2and in which a subsequent collision has not occurred, the ECU9determines whether a driver turns off and then turns on an ignition of a vehicle at step S5. When the ignition is turned off and then turned on, a logic, which has been controlled to interrupt the delivery of the shift range change signal to the transmission3, is initialized. Therefore, since then, if the driver operates the electronic shift lever1, a signal for changing the shift range is delivered to the transmission3and the shifting process is normally performed at step S6.

In this case, when it is determined that the driver has not turned off and then turned on the ignition, the process returns to the step before S3.

Also, in a case in which the predetermined time (T1) has passed since the signal for changing the shift range was interrupted not to be delivered to the transmission3by the control of the TCU2and in which a subsequent collision has not occurred, the ECU9determines whether a signal for changing the shift range is generated again at step S7. If it is determined that the signal for changing the shift range is generated again, a signal, which is generated when the driver operates the electronic shift lever1after the determination, is delivered to the transmission3and the shifting process is normally performed at step S6.

Here, when it is determined that that the signal for changing the shift range is not generated again, the process returns to the step before S3.

Under the condition of a normal shift process, the above steps are repeatedly performed before the ignition of the vehicle is turned off.

Subsequently, the operation of various embodiments of the present invention are briefly described referring toFIG. 3.

When a collision occurs in an ignition-on state of a vehicle, a collision signal detected by a collision sensor7or an airbag sensor8is delivered to an ECU9, and the ECU9determines the collision of the vehicle at step S11.

Also, a shift range signal of an electronic shift lever1, which is detected by a lever sensor5, is delivered to the ECU9.

When determining that the collision has occurred, the ECU9determines whether an immediately pre-collision shift range is different from a shift range immediately after the collision, within a predetermined time (T1) after the collision, namely, whether a signal for changing the shift range is generated at step S12. When it is determined that the two shift ranges are different, namely, that the signal for changing the shift range is generated, the transmission3is shifted to a parking (P) range by the control of the TCU2at step S13.

In other words, in the present invention, if, within a predetermined time (T1) after the collision, an immediately pre-collision shift range is different from the shift range immediately after the collision, the transmission3is forcibly shifted to a parking (P) range by the control of the TCU2, whereby a further secondary collision can be prevented.

On the other hand, within the predetermined time (T1) after the collision, if it is determined that the immediately pre-collision shift range is the same as the shift range immediately after the collision, namely, that the signal for changing the shift range is not generated, the transmission3maintains the immediately pre-collision shift range by the control of the TCU2at step S14.

As described above, various embodiments of the present invention compel a transmission3not to shift for a predetermined time or to shift to a parking (P) range, whereby a further secondary collision may be prevented and passenger safety may be improved.