Methods and systems for preventing vehicle roll

Methods and systems are provided for preventing vehicle roll. In one embodiment, a method includes: determining a first switch state; determining a second switch state; evaluating the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred; and selectively generating at least one of a control signal to control an electronic park brake and a notification message based on the determination.

TECHNICAL FIELD

The present disclosure generally relates to vehicles, and more particularly relates to methods and systems for controlling the vehicle to prevent vehicle movement.

BACKGROUND

Vehicles equipped with an automatic transmission often include a shift control lever mounted on a console, the dashboard, or the steering column of the vehicle. A vehicle operator may manually move the shift control lever between shift lever positions. The shift lever positions indicate particular transmission ranges (park, reverse, neutral, drive 1, drive 2, drive 3, etc.). Movement of the shift lever into a particular shift lever position causes the transmission to be operated in a particular gear or set of gears.

For example, the shift control lever includes mechanical linkages that couple to the automatic transmission. The mechanical linkages cause the automatic transmission to operate in the particular gear or set of gears. For example, when the shift control lever is moved to the park position, a mechanical linkage activates a parking pawl device or other device of the transmission. The parking pawl device locks the movement of the transmission output shaft thereby preventing movement of the vehicle wheels.

In some cases, conditions can occur in one or more of the mechanical linkages that prevent proper operation. The conditions can cause unexpected movement of the vehicle. For example, when the shift control lever is in the park position and when a condition exists in the mechanical linkage between the shift control lever and the transmission, the vehicle may roll forward or backward (referred to hereinafter as vehicle roll).

Accordingly, it is desirable to provide methods and systems for preventing vehicle roll. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.

SUMMARY

Methods and systems are provided for preventing vehicle roll. In one embodiment, a method includes: determining a first switch state; determining a second switch state; evaluating the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred; and selectively generating at least one of a control signal to control an electronic park brake and a notification message based on the determination.

In another embodiment, a system includes at least two switch devices; and a control module. The control module receives switch data from the at least two switch devices, determines a first switch state based on the switch data from the first switch device, determines a second switch state based on the data from the second switch device, evaluates the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred, and selectively generates at least one of a control signal to control an electronic park brake and a notification message based on the determination.

In another embodiment, a vehicle is provided. The vehicle includes an automatic transmission having a transmission mode switch, a range selection device having a park switch, an electronic park brake system having an electronic park brake, and a control module. The control module receives switch data from the transmission mode switch and the park switch, determines a first switch state based on the switch data from the transmission mode switch, determines a second switch state based on the data from the park switch, evaluates the first switch state and the second switch state to determine whether a condition of a mechanical linkage between the range selection device and the transmission has occurred, and selectively generates at least one of a control signal to control an electronic park brake and a notification message based on the determination.

DETAILED DESCRIPTION

With reference toFIG. 1, a vehicle100is shown that includes a vehicle roll prevention system102in accordance with various embodiments. Although the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood thatFIG. 1is merely illustrative and may not be drawn to scale.

As depicted inFIG. 1, the vehicle100generally includes a chassis104, a body106, front wheels108, rear wheels110, a propulsion system112, an electronic park brake system113, and at least one control module114. The body106is arranged on the chassis104and substantially encloses the other components of the vehicle100. The body106and the chassis104may jointly form a frame. The wheels108-110are each rotationally coupled to the chassis104near a respective corner of the body106. As can be appreciated, the vehicle100may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD) or all-wheel drive (AWD).

The propulsion system112generally includes an engine/motor116and a transmission118. The engine/motor116may be any number of different types of propulsion devices, such as, for example, a gasoline or diesel fueled combustion engine, a “flex fuel vehicle” (FFV) engine (i.e., using a mixture of gasoline and ethanol), a gaseous compound (e.g., hydrogen or natural gas) fueled engine, a combustion/electric motor hybrid engine, and an electric motor. The transmission118may be any number of different types of automatic transmissions that automatically change the gear ratios as the vehicle100is moving. In various embodiments, the transmission118includes a transmission mode switch120. The transmission mode switch120generates mode signals. The mode signals indicate a bit encoding corresponding to states of circuits of the transmission mode switch120. The control module114receives the mode signals and interprets the mode signals as a transmission mode switch state. The control module114controls engine operation and transmission shift patterns based on the interpreted transmission mode switch state.

The vehicle100further includes a range selection device122that is movable by a vehicle operator to a number of defined positions. Each position corresponds to a desired operating range of the transmission118. In various embodiments, the desired positions include a park position, a reverse position, a neutral position, and one or more forward drive positions. In various embodiments, the range selection device122includes a park switch124that communicates park switch data to the control module114. The control module114determines whether the range selection device122is in the park position based on the park switch state data.

In some instances, mechanical linkages126couple the range selection device122directly to the transmission118and cause the automatic transmission118to operate in the intended range. For example, a mechanical linkage126associated with the park position of the range selection device122causes the transmission118to operate in a park range.

In some instances, a condition may occur in the mechanical linkage126causing the transmission118to not operate in the intended range. For example, one or more cables and/or solid linkages of the mechanical linkage126can become detached from the interfaces at the transmission118and/or the range selection device122. In another example, one or more cable core wires can fracture from corrosion and/or cyclic operation. As can be appreciated, other conditions may occur in the mechanical linkage126, in various embodiments, causing the transmission to not operate in the intended range, as the disclosure is not limited to the present examples.

The control module114identifies the condition of the mechanical linkage126between the range selection device122and the transmission118and generates messages indicating the condition and/or controls the electronic park brake system113such that a vehicle roll does not occur. In general, the control module114monitors the state of the park switch124of the range selection device122and the switch state of the transmission mode switch120and identifies a condition in the mechanical linkage126based on a comparison of the two switch states. When the park switch state indicates a park position and the transmission mode switch state indicates a non-park position (e.g., neutral, reverse, drive 1, drive 2, drive 3, etc.), a condition is identified and a message is generated and/or the electronic park brake system113(if present on the vehicle100) is controlled such that an electronic park brake is applied. Applying the electronic park brake prevents vehicle roll.

Referring now toFIG. 2and with continued reference toFIG. 1, a dataflow diagram illustrates the control module114ofFIG. 1in accordance with various embodiments. As can be appreciated, various embodiments of the control module114, according to the present disclosure, may include any number of sub-modules. For example, the sub-modules shown inFIG. 2may be combined and/or further partitioned to similarly prevent a vehicle roll condition. As discussed above, inputs to the control module114may be received from sensors or switches, received from other control modules (not shown) within the vehicle100, and/or determined by sub-modules (not shown) within the control module114. In various embodiments, the control module114includes a park switch state determination module130, a transmission mode switch state determination module132, and an electronic park brake control module134.

The park switch state determination module130receives as input data136from the park switch124. The data136is evaluated to determine a park switch state138. In various embodiments, the park switch state determination module130determines the park switch state138to be at least one of PARK, meaning the range selection device122is in the park position, and OTHER meaning the range selection device122is in a position other than the park position.

The transmission mode switch state determination module132receives as input data140from the transmission mode switch120. The data140is evaluated to determine a transmission mode switch state142. In various embodiments, the transmission mode switch state determination module132determines the transmission mode switch state142to be at least one of PARK meaning the range selection device122is in the park position, REVERSE meaning the range selection device122is in a reverse position, NEUTRAL meaning the range selection device122is in a neutral position, DRIVE 1 meaning the range selection device122is in a drive position, and any other values indicating a position of the range selection device122.

The electronic park brake control module134receives as input the park switch state138and the transmission mode switch state142. The electronic park brake control module134evaluates the park switch state138and the transmission mode switch state142to determine whether a condition has occurred in the mechanical linkage126between the range selection device122and the transmission118. For example, the electronic park brake control module134compares the park switch state138to the transmission mode switch state142. When the park switch state138indicates OTHER, the electronic park brake control module134determines that a condition cannot be determined and no control signals and/or message are generated.

When the park switch state138indicates PARK and the transmission mode switch state142indicates a state other than PARK, the electronic park brake control module134determines a condition and generates a control signal146to the electronic park brake system113and/or a message144that is communicated on a communication bus (not shown) to the electronic park brake system133indicating to activate the electronic park brake.

With reference now toFIG. 3, a flowchart is shown of a method200for preventing vehicle roll, in accordance with exemplary embodiments. The method200can be utilized in connection with the vehicle100ofFIG. 1and can be performed by control module ofFIG. 2, in accordance with exemplary embodiments. As can be appreciated in light of the disclosure, the order of operation within the method is not limited to the sequential execution as illustrated inFIG. 3, but may be performed in one or more varying orders as applicable and in accordance with the present disclosure. As can further be appreciated, the method ofFIG. 3may be scheduled to run at predetermined time intervals during operation of the vehicle100and/or may be scheduled to run based on predetermined events.

As depicted inFIG. 3, the method may begin at205. The park switch data136is received and the park switch state138is determined210. The transmission mode switch data140is received and the transmission mode switch state142is determined at220.

The park switch state138and the transmission mode switch state142are evaluated at230-250. For example, if the park switch state138and the transmission mode switch state142do not indicate PARK at230, the method continues at205. If, however, at least one of the park switch state138and the transmission mode switch state142indicates PARK at230, the method continues at240.

At240, if the park switch state138does not indicate PARK at240, the method continues at205. If, however, the park switch state138does indicate PARK at240, and the transmission mode switch state142indicates PARK at250, the method continues at205. If however, the park switch state138does indicate PARK, and the transmission mode switch does not indicate PARK at250, it is determined that a condition in the mechanical linkage exists at260. One or more control signals146and/or messages144are generated to indicate a condition exists and/or to control the electronic park brake system133at270. Thereafter, the method may end at280.

As can be appreciated, the disclosed methods and systems may vary from those depicted in the Figures and described herein. For example, as mentioned above, the vehicle100ofFIG. 1, and the control module114ofFIGS. 1 and 2, and/or portions and/or components thereof may vary, and/or may be disposed in whole or in part in any one or more of a number of different vehicle units, devices, and/or systems, in certain embodiments. In addition, it will be appreciated that certain steps of the method200may vary from those depicted inFIG. 3and/or described above in connection therewith. It will similarly be appreciated that certain steps of the method200may occur simultaneously or in a different order than that depicted inFIG. 3and/or described above in connection therewith.