阅读说明：本技术 用于机动车辆动力系的制动变速器换挡互锁系统和控制逻辑 (Brake transmission shift interlock system and control logic for a motor vehicle powertrain ) 是由 M.A.范坎普 于 2020-03-27 设计创作，主要内容包括：提出了用于车辆动力系的制动变速器换挡互锁(BTSI)系统、用于制造/操作此类BTSI系统的方法、以及配备有BTSI系统的车辆。用于机动车辆的BTSI系统包含换挡器螺线管,该换挡器螺线管具有：螺线管主体,其安装到车身；以及螺线管衔铁,其可移动地附接到螺线管主体以在锁定位置和解锁位置之间来回转换。换挡器螺线管可经由制动控制模块选择性地操作以在锁定位置和解锁位置之间移动螺线管衔铁,由此分别阻挡和不阻挡换挡器从驻车位置的移动。位置开关安装到车身而与换挡器螺线管相邻,并且检测车辆变速器处于驻车模式。位置开关选择性地与换挡器螺线管机械地接合,使得螺线管衔铁在移动到锁定位置时将位置开关推动到闭合。(A Brake Transmission Shift Interlock (BTSI) system for a vehicle powertrain, a method for manufacturing/operating such a BTSI system, and a vehicle equipped with a BTSI system are presented. A BTSI system for a motor vehicle includes a shifter solenoid having: a solenoid body mounted to a vehicle body; and a solenoid armature movably attached to the solenoid body to transition back and forth between a locked position and an unlocked position. The shifter solenoid is selectively operable via the brake control module to move the solenoid armature between a locked position and an unlocked position, thereby blocking and unblocking movement of the shifter from the park position, respectively. A position switch is mounted to the vehicle body adjacent the shifter solenoid and detects that the vehicle transmission is in a park mode. The position switch is selectively mechanically engaged with the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position.)

1. A Brake Transmission Shift Interlock (BTSI) system for a motor vehicle having: a vehicle body; a transmission mounted to the vehicle body; a shifter movable between a park position and a gear position to shift the transmission between different operating modes; and an electronic control module communicatively connected with the shifter, the BTSI system comprising:

a shifter solenoid, the shifter solenoid including: a solenoid body configured to be mounted to the vehicle body; and a solenoid armature movably attached to the solenoid body to transition between a locked position and an unlocked position, the shifter solenoid selectively operable via the electronic control module to move the solenoid armature between the locked position and the unlocked position, thereby blocking and unblocking, respectively, movement of the shifter from the park position; and

a position switch configured to be mounted to the vehicle body adjacent the shifter solenoid and to detect that the transmission is in a park mode, the position switch being selectively mechanically engageable with the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position.

2. The BTSI system of claim 1, further comprising a resistor ladder electrically connected to the position switch.

3. The BTSI system of claim 2, further comprising a first resistor electrically connected to and interposed between the resistor ladder circuit and the position switch.

4. A BTSI system according to claim 3, wherein the resistor ladder, the first resistor and the position switch are configured to be electrically connected in series with the electronic control module.

5. The BTSI system of claim 3, wherein the resistor ladder circuit comprises a plurality of ladder resistors electrically connected in parallel with each other, and wherein each of the ladder resistors is electrically connected in series with the position switch and the first resistor.

6. The BTSI system of claim 5, wherein the plurality of resistor ladders comprises a first resistor ladder, a second resistor ladder, and a third resistor ladder, the resistor ladder further comprising a first ladder switch electrically connected in series with the second resistor ladder and a second ladder switch electrically connected in series with the third resistor ladder.

7. A BTSI system according to claim 6, wherein:

transmitting, by the BTSI system, a first lock signal to the electronic control module in response to the position switch being closed and the first and second keyswitches being open;

transmitting, by the BTSI system, a second lock signal to the electronic control module in response to the position switch and the first ladder switch being closed and the second ladder switch being open; and

transmitting, by the BTSI system, a third lock signal to the electronic control module in response to the position switch and the second ladder switch closing and the first ladder switch opening.

8. A BTSI system according to claim 6, wherein the motor vehicle further comprises an electronic input device configured to receive an upshift request and a downshift request from a driver, wherein receipt of the upshift request by the electronic input device causes the first trapezoidal switch to close, and wherein receipt of the downshift request by the electronic input device causes the second trapezoidal switch to close.

9. A BTSI system according to claim 1, wherein the position switch comprises a micro-switch, a reed-type switch and/or a hall effect switch.

10. A BTSI system according to claim 1, wherein the position switch is characterized by a lack of selective mechanical engagement with the shifter.

Technical Field

The present disclosure relates generally to motor vehicle powertrains. More specifically, aspects of the present disclosure relate to a shifter interlock system for controlling shifting of an automatic vehicle transmission between different operating modes.

Background

Currently produced motor vehicles, such as modern automobiles, are initially equipped with a powertrain that operates to propel the vehicle and power the onboard electronics of the vehicle. In automotive applications, for example, a vehicle powertrain is generally represented by a prime mover that delivers drive power to the final drive system (e.g., differential, axle, road wheels, etc.) of the vehicle through an automatically or manually shifted transmission. Historically, automobiles were powered by reciprocating piston Internal Combustion Engine (ICE) assemblies due to their ready availability and relatively inexpensive cost, light weight and overall efficiency. As some non-limiting examples, such engines include two-stroke and four-stroke Compression Ignition (CI) diesel engines, four-stroke Spark Ignition (SI) gasoline engines, six-stroke architectures, and rotary engines. Hybrid and electric vehicles, on the other hand, utilize alternative power sources, such as electric traction motors, to propel the vehicle, and thus minimize or eliminate reliance on fossil fuel-based engines to obtain traction power.

Vehicle transmissions may use differential gearing to achieve variable torque and multiple speed ratios between an input shaft and an output shaft of the transmission. One form of differential transmission is an epicyclic "planetary gear" arrangement. Planetary transmissions offer the advantages of compactness and different torque and speed ratios among the members of the planetary transmission subset. Hydraulically-actuated torque-establishing devices, such as clutches and brakes (the term "clutch" is often used to refer to both clutches and brakes), are selectively engageable to activate the gear elements described above to establish desired forward and reverse speed ratios between the input and output shafts of the transmission. Shifts from one speed ratio to another are typically performed in response to engine throttle and vehicle speed, and typically involve releasing one or more "off-going" clutches associated with the current or achieved speed ratio and applying one or more "on-coming" clutches associated with the desired or commanded speed ratio.

Most automatic power transmissions have multiple operating modes; for example, an automobile that meets U.S. government standards has at least a park (P) mode, a reverse (R) mode, a neutral (N) mode, and a plurality of driving modes, including a full-range driving (D) mode and a low (L) range mode. A gear selector mechanism, such as a shift lever or shift knob, colloquially referred to as a "shifter" or "PRNDL" ("park-reverse-neutral-drive-low"; pronounced "printle") is controlled by the vehicle operator for selective movement between these various transmission operating modes. Modern automobiles are equipped with a Brake Transmission Shift Interlock (BTSI) feature that inhibits movement of the shift lever from the park position unless the ignition switch is on and the brake pedal is depressed by the vehicle operator. As a result, a vehicle equipped with an automatic transmission is prevented from powering the drive wheels in either the reverse or forward direction without first releasing the steering wheel to drive normally by releasing the "park-lock" feature and immobilizing the vehicle by the driver placing his or her foot on the brake pedal.

Disclosure of Invention

Disclosed herein are Brake Transmission Shift Interlock (BTSI) systems and accompanying control logic for motor vehicle powertrains, methods for manufacturing and operating such BTSI systems, and motor vehicles equipped with BTSI sensors that utilize a resistor ladder to detect a current BTSI state (locked or unlocked). By way of example, a BTSI system architecture is presented that integrates a BTSI position switch sensor with a BTSI shifter solenoid, both of which are electrically connected to a "tap up/tap down" resistor ladder circuit. The resistor ladder circuit includes three resistors electrically connected in parallel with each other, and has control switches on at least two of the three ladder resistors. All three resistor ladders are electrically connected in series with a fourth resistor which serves as a current limiting device. The BTSI position switch is electrically connected in series with the resistor ladder via a fourth resistor. Additionally, the BTSI shifter solenoid directly mechanically engages the BTSI position switch such that moving the solenoid to the locked position will physically close the position switch. When moved to the unlocked position, the BTSI shifter solenoid mechanically disengages the BTSI position switch so that the switches are simultaneously open.

The attendant benefits of at least some of the disclosed concepts include a BTSI system architecture that uses a multi-function resistor ladder in combination with a combination of BTSI solenoids and position switches to detect shifter conditions, thereby eliminating the need for electromechanical switches and other specialized hardware for system condition monitoring. In doing so, the associated material, manufacturing, warranty, and design costs associated with such specialized hardware are minimized or otherwise eliminated. Removing the electromechanical BTSI state switch and its supporting circuitry also helps to eliminate any induced noise associated with operating the switch. Other attendant benefits may include the ability to address severe ten (10) failure modes and impact analysis (FMEA) system failures, such as a vehicle parking lock mechanism of a BTSI system that fails in an unlocked position.

Aspects of the present disclosure are directed to a BTSI system and accompanying control logic for preventing an automatic vehicle transmission from shifting out of a park position without first depressing a brake pedal. In an example, a representative BTSI system is presented that includes a shifter solenoid fabricated with a protective solenoid body that is rigidly mounted to the vehicle body, e.g., adjacent to the shifter, that moves between a park position and various shift positions to shift the vehicle's power transmission between different transmission operating modes. A solenoid armature is movably attached to the solenoid body to transition back and forth between a locked position and an unlocked position. A resident or remote electronic controller, such as a dedicated system control module, controls the shifter solenoid to selectively move the solenoid armature to the locked (or unlocked) position, thereby blocking (or unblocking) movement of the shifter from the park position. An electrical position switch mounted to the shifter body adjacent the shifter solenoid is operable to detect that the transmission is in the park mode. In particular, the position switch selectively mechanically engages the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position. Conversely, movement of the solenoid armature to the unlocked position allows the position switch to open, for example, under the force of a return spring.

Other aspects of the present disclosure are directed to a motor vehicle having a BTSI system that utilizes a resistor ladder circuit and a combination of a position switch and a shifter solenoid for detecting a current state of the BTSI system. As used herein, the term "motor vehicle" may encompass any relevant vehicle platform, such as passenger vehicles (internal combustion engines (ICEs), hybrid, electric only, fuel cell, partially or fully autonomous, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles (ATVs), snowmobiles, motorcycles, boats, aircraft, and the like. In an example, a motor vehicle is presented that is equipped with a prime mover (e.g., an engine and/or motor) mounted to the vehicle body and operable to drive one or more of the road wheels of the vehicle, thereby propelling the motor vehicle. A multi-speed automatic transmission mounted to the vehicle body and operatively connected to the prime mover is operable to selectively modify torque transmitted from the prime mover to the road wheel(s). A shifter mechanism is mounted within the passenger compartment and is movable between a park position, a neutral position, and a plurality of shift positions (e.g., reverse, drive, and low positions) to shift the transmission between different transmission operating modes. In at least some embodiments, the shifter mechanism can include a P-R-N-D shift knob that operates in conjunction with a terrain selective low range rotary dial. As a further option, the transmission may be an electro-hydraulic automatic-manual transmission controlled by an electronic input device, such as an upshift/downshift trigger integrated into the gear shifter and/or an upshift/downshift paddle integrated into the driver's steering wheel. A resident or remote electronic control module is communicatively connected with the shifter, the vehicle braking system, and the vehicle starter system.

Continuing with the above example, the motor vehicle also includes a BTSI system having a shifter solenoid and a position switch. Shifter solenoids are manufactured with: a solenoid body mounted to a vehicle body; and a solenoid armature movably attached to the solenoid body to transition back and forth between a locked position and an unlocked position. The shifter solenoid is selectively operable, e.g., via an electronic control module, to move the solenoid armature between a locked position and an unlocked position, thereby blocking or unblocking, respectively, movement of the shifter from the park position. A position switch mounted to the vehicle body adjacent the shifter solenoid detects whether the transmission is in the park mode. The position switch may be electrically connected in series to the resistor ladder. The position switch is selectively mechanically engageable with the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position, e.g., under the biasing force of a spring. Movement of the solenoid armature to the unlocked position, for example via a selectively energizable solenoid coil, allows the position switch to open.

Additional aspects of the present disclosure are directed to control algorithms and computer readable media storing instructions executable by a processor for making and using a BTSI system. In an example, a method for governing operation of a BTSI system is presented. The foregoing representative methods comprise, in any order and in any combination with any of the above and following options and features: transmitting an actuation command signal via a resident or remote electronic control module to a shifter solenoid, the shifter solenoid comprising: a solenoid body mounted to a vehicle body; and a solenoid armature attached to the solenoid body for movement between a locked position and an unlocked position, the actuation command signal causing the solenoid armature to move from the locked position to the unlocked position thereby unblocking movement of the shifter from the park position; and interrupting transmission of an actuation command signal to the shifter solenoid via the electronic control module to cause the solenoid armature to move from the unlocked position to the locked position, thereby blocking movement of the shifter from the park position. With this architecture, moving the solenoid armature to the unlocked position mechanically disengages the shifter solenoid from a BTSI position switch mounted adjacent to the shifter solenoid such that the position switch is open and the electronic control module detects that the transmission is not in the park mode. Moving the solenoid armature to the locked position mechanically engages the shifter solenoid with the position switch such that the solenoid armature pushes the position switch closed and the electronic control module detects that the transmission is in the park mode.

The invention provides the following technical scheme:

1. a Brake Transmission Shift Interlock (BTSI) system for a motor vehicle having: a vehicle body; a transmission mounted to the vehicle body; a shifter movable between a park position and a gear position to shift the transmission between different operating modes; and an electronic control module communicatively connected with the shifter, the BTSI system comprising:

a shifter solenoid, the shifter solenoid including: a solenoid body configured to be mounted to the vehicle body; and a solenoid armature movably attached to the solenoid body to transition between a locked position and an unlocked position, the shifter solenoid selectively operable via the electronic control module to move the solenoid armature between the locked position and the unlocked position, thereby blocking and unblocking, respectively, movement of the shifter from the park position; and

a position switch configured to be mounted to the vehicle body adjacent the shifter solenoid and to detect that the transmission is in a park mode, the position switch being selectively mechanically engageable with the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position.

2. The BTSI system of scheme 1, further comprising a resistor ladder electrically connected to the position switch.

3. The BTSI system of claim 2, further comprising a first resistor electrically connected to and interposed between the resistor ladder circuit and the position switch.

4. The BTSI system of claim 3, wherein the resistor ladder, the first resistor, and the position switch are configured to be electrically connected in series with the electronic control module.

5. The BTSI system of claim 3, wherein the resistor ladder circuit comprises a plurality of ladder resistors electrically connected in parallel with each other, and wherein each of the ladder resistors is electrically connected in series with the position switch and the first resistor.

6. The BTSI system of scheme 5, wherein the plurality of resistor ladders includes a first resistor ladder, a second resistor ladder, and a third resistor ladder, the resistor ladder further including a first ladder switch electrically connected in series with the second resistor ladder and a second ladder switch electrically connected in series with the third resistor ladder.

7. The BTSI system of scheme 6, wherein:

transmitting, by the BTSI system, a first lock signal to the electronic control module in response to the position switch being closed and the first and second keyswitches being open;

transmitting, by the BTSI system, a second lock signal to the electronic control module in response to the position switch and the first ladder switch being closed and the second ladder switch being open; and

transmitting, by the BTSI system, a third lock signal to the electronic control module in response to the position switch and the second ladder switch closing and the first ladder switch opening.

8. The BTSI system of claim 6, wherein the motor vehicle further comprises an electronic input device configured to receive an upshift request and a downshift request from a driver, wherein receipt of the upshift request by the electronic input device causes the first trapezoidal switch to close, and wherein receipt of the downshift request by the electronic input device causes the second trapezoidal switch to close.

9. A BTSI system according to scheme 1, wherein the position switch comprises a micro-switch, a reed-type switch and/or a hall effect switch.

10. The BTSI system of option 1, wherein the position switch is characterized by a lack of selective mechanical engagement with the shifter.

11. The BTSI system of scheme 1, wherein the shifter solenoid further comprises:

an electrically conductive coil surrounding at least a portion of the solenoid armature and configured to move the solenoid armature to the unlocked position when energized; and

a biasing member biasing the solenoid armature to the locked position thereby mechanically closing the position switch and blocking movement of the shifter from the park position to either of the gear positions.

12. The BTSI system of claim 11, wherein the shifter solenoid further includes a dampener attached to the solenoid armature and configured to abut a shift lever pawl when the solenoid armature is in the locked position and thereby prevent shift lever pawl from moving out of engagement with a parking stop in a shifter door.

13. A motor vehicle, comprising:

a vehicle body;

a plurality of road wheels attached to the body;

a prime mover attached to the body and configured to drive at least one of the road wheels, thereby propelling the motor vehicle;

a multi-speed power transmission attached to the body and operable to selectively modify torque transfer from the prime mover to the at least one of the road wheels;

a shifter movable between a park position and a plurality of shift positions to shift the transmission between different transmission operating modes;

an electronic control module communicatively connected with the shifter; and

a Brake Transmission Shift Interlock (BTSI) system, comprising:

a shifter solenoid having: a solenoid body mounted to the vehicle body; and a solenoid armature movably attached to the solenoid body to transition between a locked position and an unlocked position, the shifter solenoid selectively operable via the electronic control module to move the solenoid armature between the locked position and the unlocked position, thereby blocking and unblocking, respectively, movement of the shifter from the park position; and

a position switch mounted to the vehicle body adjacent the shifter solenoid and configured to detect that the transmission is in a park mode, the position switch selectively mechanically engageable with the shifter solenoid such that the solenoid armature urges the position switch closed when moved to the locked position.

14. A method of controlling operation of a Brake Transmission Shift Interlock (BTSI) system for a motor vehicle having: a vehicle body; a transmission mounted to the vehicle body; a shifter mounted to the vehicle body and movable between a park position and a gear position to shift the transmission between different operating modes; and an electronic control module communicatively coupled with the shifter, the method comprising:

transmitting, via the electronic control module, an actuation command signal to a shifter solenoid, the shifter solenoid including: a solenoid body mounted to the vehicle body; and a solenoid armature attached to the solenoid body for movement between a locked position and an unlocked position, the actuation command signal causing the solenoid armature to move from the locked position to the unlocked position, thereby unblocking movement of the shifter from the park position,

wherein moving the solenoid armature to the unlocked position mechanically disengages the shifter solenoid from a position switch mounted to the vehicle body adjacent the shifter solenoid such that the position switch is open and the electronic control module detects that the transmission is not in a park mode; and

discontinuing transmission of the actuation command signal to the shifter solenoid via the electronic control module to cause the solenoid armature to move from the unlocked position to the locked position, thereby blocking movement of the shifter from the park position,

wherein moving the solenoid armature to the locked position mechanically engages the shifter solenoid with the position switch such that the solenoid armature pushes the position switch closed and the electronic control module detects that the transmission is in a park mode.

15. The method of scheme 14, wherein the BTSI system further comprises a resistor ladder electrically connected to the position switch.

16. The method of scheme 15, wherein the BTSI system further comprises a first resistor electrically connected to and interposed between the resistor ladder and the position switch.

17. The method of claim 16, wherein the resistor ladder, the first resistor, and the position switch are configured to be electrically connected in series with the electronic control module.

18. The method of claim 16, wherein the resistor ladder circuit comprises a plurality of ladder resistors electrically connected in parallel with each other, and wherein each of the ladder resistors is electrically connected in series with the position switch and the first resistor.

19. The method of claim 18, wherein the plurality of resistor ladders includes a first resistor ladder, a second resistor ladder, and a third resistor ladder, the resistor ladder further including a first ladder switch electrically connected in series with the second resistor ladder and a second ladder switch electrically connected in series with the third resistor ladder.

20. The method of scheme 19, further comprising:

receiving, via an electronic input device, an upshift request from a driver of the motor vehicle that caused the first keyswitch to close; and

receiving a downshift request from the driver of the motor vehicle via the electronic input device that causes the second keyswitch to close.

The above summary is not intended to represent each embodiment or every aspect of the present disclosure. Rather, the foregoing summary merely provides an illustration of some of the novel concepts and features set forth herein. The above features and advantages, and other features and attendant advantages of the present disclosure will be readily apparent from the following detailed description of the illustrated examples and representative modes for carrying out the present disclosure when taken in connection with the accompanying drawings and appended claims. Moreover, the present disclosure expressly encompasses any and all combinations and subcombinations of the elements and features presented above and below.

Drawings

Fig. 1 is a perspective illustration of a representative motor vehicle in which an inset view of the passenger compartment of the vehicle shows the driver's seat with a representative shifter, according to aspects of the present disclosure.

Fig. 2 is a schematic diagram of select electronics of the representative shifter of fig. 1, which is a representative Brake Transmission Shift Interlock (BTSI) system, according to aspects of the present disclosure.

Fig. 3 is a flow diagram illustrating a representative BTSI control algorithm for detecting a current BTSI state, which may correspond to memory-stored instructions executed by an onboard and/or remote control logic circuit, a programmable electronic control unit, or other computer-based device or network of devices, in accordance with aspects of the disclosed concept.

The present disclosure is subject to various modifications and alternative forms, and some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the above-enumerated drawings. Rather, the disclosure is to cover all modifications, equivalents, combinations, sub-combinations, permutations, groups, and alternatives falling within the scope of the disclosure as covered by the appended claims.

Detailed Description

The present disclosure is susceptible of embodiments in many different forms. Representative embodiments of the present disclosure are shown in the drawings and will be described herein in detail with the understanding that these embodiments are provided as illustrations of the principles of the disclosure and are not intended to limit the broad aspects of the disclosure. To the extent that elements and limitations are described in, for example, abstract, introductory, summary and detailed description, but not explicitly recited in the claims, they are not individually or collectively incorporated by implication, inference or otherwise into the claims.

For the purposes of this detailed description, unless explicitly disclaimed: singular encompasses plural and vice versa; the words "and" or "shall both be conjunctive and non-conjunctive; the words "any" and "all" shall both mean "any and all"; and the words "comprising", "containing", "including", "having", and the like shall each mean "including but not limited to". Further, for example, approximating words such as "about," "almost," "substantially," "approximately," "generally," and the like may be used herein in the sense of "… …, approaching … …, or approaching … …," or "within 0% to 5% of … …," or "within acceptable manufacturing tolerances," or any logical combination thereof. Finally, directional adjectives and adverbs, such as front, rear, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, forward, rear, left, right, etc., may be relative to the motor vehicle, such as a forward driving direction of the motor vehicle when the vehicle is operatively oriented on a normal driving surface.

Referring now to the drawings, in which like reference numerals refer to like features throughout the several views, there is shown in fig. 1 a representative automobile, indicated generally at 10 and depicted as a two-seat, two-door passenger vehicle for purposes of discussion. A hood assembly 18 is mounted to the body 12 of the vehicle 10, for example, in front of the vehicle passenger compartment 14 and behind the front bumper assembly 16, and extends across and covers an upper extent of the engine compartment 20. The illustrated automobile 10, also referred to herein as a "motor vehicle" or simply a "vehicle," is merely an exemplary application with which various aspects and features of the present disclosure may be practiced. Likewise, implementing the present concepts as a particular shift handle arrangement as presented in the drawings should also be understood as an exemplary application of the novel concepts disclosed herein. Thus, it will be understood that aspects and features of the present disclosure may be integrated into other shifter architectures and implemented for any logically related type of motor vehicle. Furthermore, only the shifter interlock system and selected components of the motor vehicle are shown and will be described in additional detail below. However, the vehicle and system architectures discussed herein may include numerous additional and alternative features, such as for implementing the various methods and functions of the present disclosure, as well as other available peripheral components.

Presented in the inset view of fig. 1 is a perspective view of the interior of the vehicle passenger compartment 14 showing: a driver seat assembly 22 facing a steering wheel 24 of a vehicle steering system; and an instrument panel 26 that displays instrumentation, vehicle dynamics data, and controls for vehicle operation. A vehicle powertrain, represented in FIG. 1 by transmission 28 and prime mover 32, is designed to launch and propel vehicle 10 to operate vehicle 10 in a reverse gear and all forward gear ranges between low and high travel speeds and to power any combination of on-board electronics. The transmission 28 may be embodied as an electro-hydraulic automatic-manual transmission assembly having a series of intermeshing gear elements (not visible) that are selectively engaged by operation of discrete controller automatic-type clutch elements. The prime mover 32 transmits power, preferably by torque, to the input side of the transmission 28 via an output shaft or similar suitable output member. The prime mover 32 may be embodied as a re-startable reciprocating piston Internal Combustion Engine (ICE) assembly drivingly connected to the final drive system (e.g., road wheels 15) through the multi-speed power transmission 28. The ICE assemblies may operate alone or in conjunction with one or more electric Motor Generator Units (MGUs), or may be replaced by one or more electric Motor Generator Units (MGUs). Although not explicitly depicted in fig. 1, it should be appreciated that the final drive system of the vehicle may take on any useful configuration, including a Front Wheel Drive (FWD) topology, a Rear Wheel Drive (RWD) topology, a four wheel drive (4 WD) topology, an All Wheel Drive (AWD) topology, and the like.

The slowing and stopping of the vehicle 10 is at least partially controlled by a vehicle braking system 30 that is activated and deactivated by a vehicle operator (not shown) depressing and releasing a brake pedal 34 with his/her foot, respectively. The brake pedal 34 is movable between a release position and any one of a plurality of apply positions in which the brake pedal 34 is pressed against a linear or rotary transducer 36 operable to determine the position of the brake pedal 34 and the corresponding braking force to be applied to the road wheels 15. The transducer 36 may take the form of any of a variety of suitable electronic and electromechanical sensing device configurations that are actuated by engagement of the pedal 34. Brake pedal position signalS _BP Via the transducer 36 to an Electronic Control Unit (ECU) 38 as part of the parking lock and shifter interlock control of the shifter assembly 40. In fig. 1, the dashed arrows interconnecting the various electronic and electromechanical components symbolize an electronic signal or other communication exchange by which data and/or control commands are transmitted from one component to another component in a wired or wireless manner.

With continued reference to fig. 1, the shifter assembly 40 includes a manually controlled shift handle 42 that is movable in forward and rearward directions in a park (P) positionP _P The reverse (R) positionP _R Neutral (N) positionP _N Driving position (D)P _D And low gear (L) positionP _L To move in between. The shift handle 42 is supported on the upper end of a shaft 44 that extends into a shifter housing 46. Actuation of the shifter button 48 protruding from the upper extent of the shift handle 42 allows the shaft 44 to move relative to the shifter housing 46 between the aforementioned shifter positions. Brake Transmission Shift Interlock (BTSI) System 60 (schematically illustrated in FIG. 2)And discussed in great detail below) prevents the shift handle 42 from moving from the park (P) positionP _P Out unless and until the brake pedal 34 is depressed. Alternatively, shift lever 42 may also be blocked from the park (P) positionP _P Out until prime mover 32 is started, e.g., from the OFF position to the ON position via vehicle ignition switch 50, as signaled by an electric park lockS _PL As confirmed. After the prime mover 32 is cranked and the brake pedal 34 is pushed to the apply position, the shifter button 48 may be depressed and the shift handle 42 moved to the reverse (R) positionP _R Neutral (N) positionP _N Driving position (D)P _D Low gear (L) positionP _L In (1). Electric shifter position signal corresponding to a selected position of shift handle 42S _SP Is sent to the ECU 38; a Powertrain Control Module (PCM) (fig. 2) embedded within the vehicle ECU 38, which in turn sends electrical command signalsS _TM For shifting the transmission 28 into the appropriate transmission operating mode.

Fig. 2 diagrammatically illustrates select components of the representative shifter assembly 40 of fig. 1 having a representative BTSI system 60 that inhibits the shift handle 42 from the park (P) position unless the vehicle ignition switch 50 is in the on state and the brake pedal 34 is depressed by the vehicle operatorP _P And (4) moving. When the vehicle 10 is stopped and the prime mover 32 is turned off, a vehicle key (not shown) may be inserted into the key cylinder 52 of the ignition switch 50. Once fully inserted, the vehicle key is then rotated (e.g., counterclockwise in fig. 1) to the ON position. In doing so, the electrical ignition starter switch 54 is closed to electrically connect the 12V start-light-ignition (SLI) battery 56 to the starter solenoid and starter motor (not shown), thereby causing the starter system of the vehicle to start the prime mover 32. With the park lock feature, the vehicle key is prevented from being removed from the ignition switch 50 until the vehicle 10 is stopped and the vehicle key is rotated (e.g., clockwise in FIG. 1) to the OFF position. When the vehicle 10 is stopped and the shift lever 42 is moved to the park (P) positionP _P At this time, an electrical signal is sent to the vehicle ignition switch 50 by a Brake Control Module (BCM) embedded in the ECU 38 to energize the key release solenoid 58 so that the vehicle key can be removed from the key cylinder 52. It should be appreciated that the disclosed features are similarly applicable to vehicle platforms equipped with an ignition button or other keyless ignition system operable for turning the prime mover 32 on and off. More importantly, the BTSI system 60 of fig. 2 does not require a park lock function to implement many of the disclosed aspects and features.

The BTSI system 60 of fig. 2 generally consists of two main components: an electromechanical BTSI sensor assembly 62 and an "upshift/downshift" resistor ladder 64. The BTSI sensor assembly 62 includes a BTSI shifter solenoid 66 that selectively mechanically engages a BTSI position switch 68. As shown, the BTSI position switch 68 is mounted in close proximity to the BTSI shifter solenoid 66, for example, within the shifter housing 46 inside the vehicle passenger compartment 14. The position switch 68 detects whether the BTSI system 60 is in the locked state or the unlocked state and at the same time detects whether the transmission 28 is in the parking mode or the shift mode. By way of non-limiting example, the BTSI position switch 68 may be a normally open (N/O) electrical switching device that is selectively closed by direct physical contact with the BTSI shifter solenoid 66. Closing of the BTSI position switch 68 will transmit an electrical signal to the ECU 38 indicating that the BTSI system 60 is locked and the transmission 28 is in park. Conversely, as explained below, releasing the BTSI position switch 68 by operation of the BTSI shifter solenoid 66 will transmit an electrical signal to the ECU 38 indicating that the BTSI system 60 is unlocked and the transmission 28 is in gear or neutral. Unlike many conventional BTSI systems, the position switch 68 does not physically engage either the shifter door pawl 43 or the shift handle 42/shaft 44. It is contemplated that BTSI position switch 68 takes the form of any suitable electrical switch design, including a microswitch, a reed switch, a hall effect switch, or the like.

With continued reference to fig. 2, the BTSI shifter solenoid 66 is provided with a solenoid body 70 mounted to the vehicle body 12, for example, within the shifter housing 46 interposed between the park stop on the shifter door 41 and the shift door pawl 43 (fig. 1). A metallic solenoid armature 72 is slidably attached to the solenoid body 70 to translate back and forth in a reciprocating manner along a linear path between a locked position and an unlocked position. The BTSI shifter solenoid 66 is an electromagnetic device that is selectively operable via an electrical actuation signal from the BCM of the vehicle ECU 38. The actuation signal energizes a conductive helical coil 74 that encircles at least a portion of the solenoid armature 72. In doing so, a magnetic field is generated that causes the solenoid armature 72 to translate between the locked and unlocked positions. It is contemplated that the BTSI shifter solenoid 66 takes any suitable solenoid design, including normally open and normally closed configurations. Notably, in the architecture of fig. 2, there is no direct electrical connection between the BTSI shifter solenoid 66 and the BTSI position switch 68.

For a normally closed (N/C) solenoid configuration, a biasing member, such as the leaf spring 76 of FIG. 2, urges the solenoid armature 72 outward from the solenoid body 70 to a fully extended and "locked" position. In this locked position, solenoid armature 72 physically presses against and closes BTSI position switch 68 and concomitantly blocks shift lever 42 from the park (P) positionP _P And (4) removing. According to the illustrated example, the dampener 78 is attached to the distal end of the solenoid armature 72 outside of the solenoid body 70. When the solenoid armature 72 is biased to the locked position, the inhibitor 78 abuts the shift door pawl 43 and thereby prevents the shift door pawl 43 from moving out of engagement with the park stop on the shifter door 41. For at least some applications, the solenoid armature 72 may simultaneously actuate the parking brake system and/or lock the transmission output shaft, thereby locking the automobile 10 in park. After the prime mover 32 is turned on and the brake pedal 34 is depressed, the BTSI shifter solenoid 66 is energized via the ECU 38 to retract the solenoid armature 72 from its normal (unpowered) position; this will physically disengage the armature 72 from the BTSI position switch 68 and concomitantly unblock the shift handle 42. As described above, the BTSI position switch 68 automatically opens upon physical disengagement from the solenoid armature 72.

The BTSI system 60 of fig. 2 is also equipped with a resistor ladder 64 electrically connected to the BTSI sensor assembly 62. By way of example, and not limitation, a series connected (first) resistorR ₁ Is electrically connected to the resistor ladder 64 and the BTSI sensor assembly 62 and is disposed between the resistor ladder 64 and the BTSI sensor assembly 62. For at least some implementations, resistors in seriesR ₁ Acting as a current limiting device. As shown, a resistor ladder 64, a BTSI position switch 68, and a series resistorR ₁ Are electrically connected in series with each other and with the ECU 38. Similar to the BTSI position switch 68, in the architecture of fig. 2, there is no direct electrical connection between the resistor ladder 64 and the BTSI shifter solenoid 66.

As the name implies, the resistor ladder circuit 64 of FIG. 2 is representative of a circuit having a plurality of resistors electrically connected in parallel with one another in a ladder arrangement. Although it is contemplated that the resistor ladder 64 may include a wide variety of combinations of resistors and switches, as well as other circuit devices, the resistor ladder 64 is shown in fig. 2 as having: three "ladder" resistors, i.e. the first ladder resistor respectivelyR _L1 A second resistor ladderR _L2 And a third resistor ladderR _L3 (ii) a And two "ladder" switches, namely, a first ladder switch 80 and a second ladder switch 82, respectively. These ladder resistorsR _L1 、R _L2 、R _L3 With a BTSI position switch 68 and a resistor in seriesR ₁ The two are electrically connected in series. In addition, the first ladder switch 80 and the second ladder resistorR _L2 Electrically connected in series, and a second ladder switch 82 and a third ladder resistorR _L3 Are electrically connected in series. The operation of the two keyswitches 80, 82 may be controlled in whole or in part by electronic input devices such as an upshift trigger/paddle 84 and a downshift trigger/paddle 86, respectively, which may be integrated into the shift handle 42 and/or the driver's steering wheel 24. Gear-up touchThe launcher/paddle 84 receives an upshift request from the driver of the vehicle 10; receipt of an upshift request causes the first keyswitch 80 to close. Likewise, a downshift trigger/paddle 86 receives a downshift request from the vehicle driver; receipt of a downshift request causes the second keyswitch 82 to close.

To determine the current operating state of the BTSI system 60 and the current operating mode of the transmission 28, the ECU 38 monitors one or more electrical characteristics of the BTSI sensor assembly 62 and the resistor ladder 64. For example, in response to BTSI position switch 68 being closed and both ladder switches 80, 82 being open, a resistor will be received by BTSI system 60R _L1 AndR ₁ active (first) lock-in signal for a managed first current/voltageS _L1 To the ECU 38. In response to BTSI position switch 68 and first ladder switch 80 closing and second ladder switch 82 opening, a resistor will be received by BTSI system 60R _L1 、R _L2 AndR ₁ active (second) lock signal for the second current/voltage being commandedS _L2 To the ECU 38. Finally, in response to position switch 68 and second ladder switch 82 being closed and first ladder switch 80 being open, resistor will be received by BTSI system 60R _L1 、R _L3 AndR ₁ active (third) lock signal for the third current/voltage being managedS _L3 To the ECU 38. In general, the first and second ladder switches 80 and 82 may not be closed at the same time.

Referring now to the flowchart of fig. 3, an improved method or control strategy for governing the operation of a shifter interlock system, such as the BTSI system 60 of fig. 2, of a motor vehicle, such as the automobile 10 of fig. 1, in accordance with aspects of the present disclosure is generally described at 100. Some or all of the operations illustrated in fig. 3 and described in further detail below may represent an algorithm corresponding to processor-executable instructions that may be stored in, for example, a main or secondary memory or a remote memory and executed, for example, by a resident or remote controller, processing unit, control logic circuit or other module, device, and/or network of devices to perform any or all of the functions described above or below associated with the disclosed concepts. It is to be appreciated that the order of execution of the illustrated operational blocks can be changed, additional blocks can be added, and some of the described blocks can be modified, combined, or eliminated.

The method 100 begins at an end block 101 of fig. 3 with processor-executable instructions for a programmable controller or control module or similarly suitable processor to invoke an initialization procedure for the BTSI state determination protocol. The routine may be executed in real time, continuously, systematically, sporadically, and/or at regular intervals during active vehicle operation. To implement this protocol, the vehicle control system, or any combination of one or more subsystems, is operable to receive, process, and synthesize pertinent information and inputs, and execute control logic and algorithms to adjust various powertrain, starter, and brake system components to achieve desired control goals. At input/output block 103, method 100 includes receiving one or more electrical signals indicating that a prime mover of the vehicle (e.g., prime mover 32 of fig. 1) is on and one or more electrical signals indicating that a brake pedal is depressed by an operator of the vehicle.

In response to the electrical signal(s) received at the input/output block 103, the process block 105 provides processor-executable instructions to an electronic control module, such as the BCM and/or PCM of the ECU 38, to transmit one or more actuation command signals to a shifter solenoid, such as the BTSI shifter solenoid 66. The actuation command signal causes a solenoid armature of the shifter solenoid to move from a locked position to an unlocked position, e.g., as described above with respect to fig. 2, thereby unblocking movement of the shifter (such as shift handle 42 of fig. 1). At decision block 107, the method 100 determines whether the BTSI system is in an unlocked state. As indicated above in the discussion of fig. 2, for example, moving the solenoid armature 72 of the BTSI shifter solenoid 66 to the unlocked position mechanically decouples the shifter solenoid 66 from the BTSI position switch 68. This in turn allows the BTSI position switch 68 to open. ECU 38 is controlled, for example, byAt least resistor of figure 2R ₁ AndR _L1 the resulting change in circuit voltage/current caused by the electrical disconnection of (a) to detect the disconnection of the BTSI position switch 68. If the ECU 38 does not detect that the BTSI system 60 is in the unlocked state (block 107 — no), the method 100 proceeds to process block 109 and outputs a fault mode signal indicative of a fault detected in the BTSI system.

If a fault is not detected (block 107 = yes), the method 100 continues to the input/output block 111 and receives one or more electrical signals indicating that a brake pedal of the vehicle (e.g., the brake pedal 34 of fig. 1) is being depressed and that the shifter has moved back to the park position. In response to the electrical signal(s) received at the input/output block 111, the process block 113 provides processor-executable instructions for an electronic control module, such as a BCM and/or PCM of the ECU 38, to interrupt transmission of the actuation command signal to the shifter solenoid. This will cause the solenoid armature to return to its locked position, thereby blocking movement of the shifter from the park position. At decision block 115, the method 100 determines whether the BTSI system is now in a locked state. As indicated above in the discussion of fig. 2, for example, moving the solenoid armature to the locked position mechanically engages the shifter solenoid with the position switch. In this manner, the solenoid armature urges the position switch closed and locks the transmission in park mode. If the ECU 38 does not detect that the BTSI system 60 is in a locked state (block 115 — no), the method 100 proceeds to process block 109 and outputs a fault mode signal indicative of a fault detected in the BTSI system. Otherwise, the method 100 continues to the end block 117 and temporarily terminates or returns to the end block 101 and continues in a continuous loop.

In some embodiments, aspects of the disclosure may be implemented by a computer-executable program of instructions (such as program modules), generally referred to as software applications or application programs, executed by any of the controllers or controller variations described herein. In non-limiting examples, software may include routines, programs, objects, components, and data structures that perform particular tasks or implement particular data types. The software may form an interface to allow the computer to react according to the input source. The software may also cooperate with other code segments to initiate various tasks in response to data received in conjunction with the source of the received data. The software may be stored on any of a variety of memory media such as CD-ROM, magnetic disk, bubble memory, and semiconductor memory (e.g., various types of RAM or ROM).

Moreover, aspects of the present disclosure may be practiced with a variety of computer system and computer network configurations, including multiprocessor systems, microprocessor-based or consumer programmable electronics, minicomputers, mainframe computers, and the like. In addition, aspects of the disclosure may be practiced in distributed computing environments where tasks are performed by resident and remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. Accordingly, aspects of the present disclosure may be implemented in various hardware, software, or combinations thereof, in a computer system or other processing system.

Any of the methods described herein may include machine-readable instructions for execution by: (a) a processor, (b) a controller, and/or (c) any other suitable processing device. Any algorithm, software, control logic, protocol, or method disclosed herein can be implemented as software stored on a tangible medium, such as: such as flash memory, CD-ROM, floppy disks, hard drives, Digital Versatile Disks (DVDs), or other memory devices. A complete algorithm, control logic, protocol or method, and/or portions thereof, may alternatively be executed by a device other than a controller and/or embodied in firmware or dedicated hardware in a manner that is available (e.g., as implemented by an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Logic Device (FPLD), discrete logic, etc.). Further, although a particular algorithm is described with reference to the flowcharts depicted herein, many other methods may alternatively be used to implement the example machine readable instructions.

Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, variations and alterations apparent from the foregoing description are within the scope of the present disclosure as defined by the appended claims. Moreover, the present concepts expressly encompass any and all combinations and subcombinations of the foregoing elements and features.