Circulating air purging method for rotary clutches

Abstract

Vehicles, related systems, and methods are provided for recirculating air purging of disengaged clutches. One method involves obtaining multiple weighting factors associated with respective clutches among a plurality of clutches in a vehicle transmission; obtaining an exhaust time associated with each respective clutch; determining a corresponding priority metric associated with each respective clutch based at least in part on the exhaust time associated with the respective clutch and the corresponding weighting factors associated with the respective clutch; determining a highest priority clutch among the plurality of clutches based at least in part on the corresponding priority metric associated with the respective clutches among the plurality of clutches; and operating one or more valves according to a pulse command to pulsate the highest priority clutch with a command pressure for a command time period.

Description

Technical Field

[0001] This technical field generally relates to transmission control systems for vehicles, and more specifically to transmission control systems and methods for purging air from the clutches of a transmission. Background Technology

[0002] In an automatic transmission, control valves supply hydraulic pressure to the clutch and belt to engage each gear. A pump draws fluid from a reservoir at the bottom of the transmission and supplies it to the hydraulic system. Once the clutch is no longer needed, the fluid is drained back into the reservoir. When the transmission is in park, neutral, or the engine is off, the pressurized fluid can be completely drained from the clutch and collected in the reservoir.

[0003] During this period, the rotational clutch experience in the clutch-to-clutch transmission leads to a problem of air venting into the clutch. Despite the vent hole, air remains trapped in the clutch. The trapped air causes the first gear shift after it is fully vented into a burst. Therefore, it is desirable to remove air from the clutch of the transmission to improve passenger comfort. Other desirable features and characteristics will become apparent from the following detailed description and appended claims, taking into account the accompanying drawings and the foregoing technical and background information. Summary of the Invention

[0004] A method for operating a vehicle's transmission is provided. The method involves a control module associated with the vehicle's transmission obtaining multiple weighting factors, each corresponding weighting factor being associated with a corresponding clutch among multiple clutches of the vehicle's transmission; obtaining an exhaust time associated with each corresponding clutch among the multiple clutches; determining a corresponding priority metric associated with the corresponding clutch based at least in part on the exhaust time associated with the corresponding clutch and the corresponding weighting factor associated with the corresponding clutch; determining a highest priority clutch among the multiple clutches based at least in part on the corresponding priority metric associated with the corresponding clutch among the multiple clutches; and operating one or more valves according to a pulse command to pulsate the highest priority clutch with commanded pressure for a commanded time period.

[0005] In one example, the method involves resetting a timer for the exhaust time associated with the highest priority clutch after operating one or more valves to pulsate the highest priority clutch. In another example, after resetting the timer for the exhaust time associated with the highest priority clutch, a control module determines a newer highest priority clutch among a plurality of clutches based at least in part on a corresponding priority metric associated with the respective clutch among the plurality of clutches, wherein the newer highest priority clutch is different from the highest priority clutch, and operates the one or more valves according to a second pulse command to pulsate the newer highest priority clutch with a second command pressure for a second command time period after pulsating the highest priority clutch.

[0006] In another example, the method involves identifying multiple disengaged clutches of a vehicle's transmission based on a current gear ratio indicated by a range selection device, wherein the clutches are implemented as multiple rotary clutches of the transmission when the current gear ratio corresponds to parking or neutral. In another example, the method involves a control module operating one or more valves to pulsate the brake clutch according to a start pulse command before pulsating the highest priority clutch. According to another example, the method involves obtaining a current temperature measurement from a temperature sensor associated with the transmission, wherein obtaining multiple weighting factors involves identifying multiple weighting factors corresponding to the current temperature measurement. In yet another example, the method involves operating one or more valves according to a pulse command to pulsate the highest priority clutch by actuating the piston associated with the highest priority clutch from an exhaust state to an intermediate actuation state without engaging the highest priority clutch.

[0007] An apparatus for a vehicle is provided, the vehicle including a transmission having a plurality of clutches, one or more valves operable to control the operation of the plurality of clutches, a data storage element holding computer-readable instructions, and a processing means for executing the computer-readable instructions. The computer-readable instructions control the processing means to perform operations including obtaining a plurality of weighting factors, each of the plurality of weighting factors being associated with a corresponding clutch among the plurality of clutches; obtaining, for each corresponding clutch, an exhaust time associated with that corresponding clutch; determining, for each corresponding clutch, a corresponding priority metric associated with that corresponding clutch based at least in part on the exhaust time associated with that corresponding clutch and the corresponding weighting factor associated with that corresponding clutch; determining a highest priority clutch among the plurality of clutches based at least in part on the corresponding priority metric associated with that corresponding clutch among the plurality of clutches; and operating the one or more valves according to a pulse command to pulsate the highest priority clutch for a commanded time period with a commanded pressure.

[0008] In one example, the vehicle includes a temperature sensor to obtain a current temperature measurement associated with the transmission, wherein a weighting factor is influenced by the current temperature measurement. In another example, the computer-readable instructions control the processing device to perform operations including: after resetting a timer for an exhaust time associated with the highest priority clutch among the plurality of clutches, determining a newer highest priority clutch among the plurality of clutches based at least in part on the corresponding priority metric associated with the corresponding clutch among the plurality of clutches, wherein the newer highest priority clutch is different from the previous highest priority clutch; and after pulsating the highest priority clutch, operating the one or more valves according to a second pulse command to pulsate the newer highest priority clutch with a second command pressure for a second command time period. In another example, the computer-readable instructions control the processing device to perform operations including identifying a plurality of disengaged clutches of the vehicle's transmission based on a current gear ratio indicated by a gear selection device, wherein the plurality of clutches include a plurality of rotating clutches of the transmission when the current gear ratio corresponds to parking or neutral. In another example, the computer-readable instructions control the processing device to perform operations including operating the one or more valves according to a start pulse command to pulsate the brake clutch before pulsating the highest priority clutch.

[0009] A vehicle system is provided, the vehicle system including a transmission, the transmission including a plurality of clutches, a pressure source, one or more valves coupled between the pressure source and the plurality of clutches to control pressure applied to the plurality of clutches, and a control module coupled to the one or more valves, the control module determining a corresponding priority metric associated with each of the plurality of clutches based at least in part on a depletion time associated with the corresponding clutch and a corresponding weighting factor associated with the corresponding clutch, identifying a highest priority clutch among the plurality of clutches based at least in part on the corresponding priority metric associated with the corresponding clutch, and operating the one or more valves according to a pulse command to pulsate the highest priority clutch with a command pressure for a command time period.

[0010] In one example, the vehicle system includes a temperature sensor to obtain a current temperature measurement associated with the transmission, wherein a control module is coupled to the temperature sensor to identify a corresponding weighting factor in a manner influenced by the current temperature measurement. In another example, the control module is configured to, after resetting a timer for the exhaust time associated with the highest priority clutch, dynamically determine a newer highest priority clutch among the plurality of clutches based at least in part on a corresponding priority metric associated with a respective clutch among the plurality of clutches, and operate one or more valves according to a second pulse command to pulsate the newer highest priority clutch with a second command pressure for a second command time period after pulsating the highest priority clutch, wherein the newer highest priority clutch is different from the highest priority clutch. In another example, the vehicle system includes a gear selection device to provide a signal indicating the current gear ratio of the transmission, wherein a control module is coupled to the gear selection device to identify a plurality of disengaged clutches of the transmission based on the current gear ratio, wherein, in some examples, the clutches are implemented as a plurality of rotary clutches of the transmission. In another example, the control module is configured to operate one or more valves according to a start pulse command to pulsate the brake clutch before pulsating the highest priority clutch among the plurality of rotary clutches. Attached Figure Description

[0011] Exemplary embodiments will be described below in conjunction with the accompanying drawings, wherein the same reference numerals denote the same elements, and wherein:

[0012] Figure 1 A block diagram depicts a system suitable for use with a vehicle according to one or more embodiments described herein;

[0013] Figure 2 Depicting suitable implementations of one or more according to the description herein, for use by Figure 1 The flowchart of the transmission starting process implemented by the system;

[0014] Figure 3 This document describes one or more implementations suitable for use by [the entity / organization]. Figure 1 The flowchart of the circulating air purging process implemented by the system; and

[0015] Figure 4 It describes one or more implementations based on the description in this article. Figure 2 In the context of the transmission starting process Figure 3 A timing diagram of an example implementation of the circulating air purging process. Detailed Implementation

[0016] The detailed description below is merely exemplary in nature and is not intended to limit application or use. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing introduction, summary of the invention, or the following detailed description. As used herein, the term module refers to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (shared, dedicated, or grouped) and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the described functionality.

[0017] Figure 1 An exemplary system 100 suitable for use with a vehicle 10 to provide recirculated air scavenging is depicted. The vehicle includes an engine 12 that drives a transmission 14 via a torque converter 16. Air is drawn into the engine 12 through a throttle valve 18. The air is mixed with fuel and burned in the cylinders of the engine 12 to generate drive torque. The torque converter 16 supplies engine torque to the transmission via an input shaft 20. The transmission 14 in the exemplary embodiment is a multi-speed automatic clutch-to-clutch transmission based on engine torque driving an output shaft 22.

[0018] Output shaft 22 drives the transmission 24 of vehicle 10. Gear selection device 26 allows the operator to set transmission 14 to a desired operating range, including but not limited to parking, reverse, neutral, and one or more forward drive positions. The speed and torque relationship between engine 12 and transmission 24 is controlled by hydraulically operated clutches 51, 52, 53, 54, and 55 of transmission 14. Pressurized fluid is supplied to the clutches from a regulated hydraulic pressure source 28. Clutches 51, 52, 53, 54, and 55 are connected to the hydraulic pressure source via control valve 30, which regulates the clutch pressure by supplying or discharging fluid to or from clutches 51, 52, 53, 54, and 55.

[0019] In one or more exemplary embodiments, the five clutches 51, 52, 53, 54, 55 of the transmission 14 are selectively engaged to provide neutral, one or more reverse gear ratios, and one or more forward gear ratios. Although the subject matter may be described herein in the context of an automatic transmission 14 comprising eight forward gear ratios (e.g., an 8-speed transmission), it should be understood that the circulating air purging method and system for the rotary clutches described herein can be implemented in automatic transmissions with more or fewer gear ratios. Different combinations or subsets of clutches 51, 52, 53, 54, 55 correspond to or otherwise establish different gear ratios associated with the transmission 14. For example, a first forward gear ratio can be established by engaging the first clutch 51, the second clutch 52, and the third clutch 53; a second forward gear ratio can be established by disengaging the third clutch 53 and engaging the fourth clutch 54 substantially simultaneously; a third forward gear ratio can be established by disengaging the first clutch 51 and engaging the third clutch 53 substantially simultaneously; a fourth forward gear ratio can be established by disengaging the third clutch 53 and engaging the fifth clutch 55 substantially simultaneously; a fifth forward gear ratio can be established by disengaging the fourth clutch 54 and engaging the third clutch 53 substantially simultaneously; a sixth forward gear ratio can be established by disengaging the second clutch 52 and engaging the fourth clutch 54 substantially simultaneously; a seventh forward gear ratio can be established by disengaging the fourth clutch 54 and engaging the first clutch 51 substantially simultaneously; and an eighth forward gear ratio can be established by disengaging the fourth clutch 54 and engaging the third clutch 53 substantially simultaneously. In one embodiment, a reverse gear ratio is established by engaging the first clutch 51, the second clutch 52, and the fifth clutch 55, and the transmission 14 is in neutral when only the first clutch 51 and the second clutch 52 are engaged.

[0020] Still referencing Figure 1 Speed ​​sensor 32 senses the rotational speed of engine 12 and generates an engine speed signal. Temperature sensor 36 senses the temperature of the transmission fluid and generates a transmission temperature signal. Gear selection device 26 generates a gear signal.

[0021] In one or more exemplary embodiments, control module 40 generally represents another combination of processing system, computing device, computing system or processing logic, circuitry, hardware and / or other components, configured to receive the aforementioned signals and control the operation of control valve 30 to pulse-engage and disengage the clutch of transmission 14 and support the relevant processes, tasks, operations and / or functions described herein. In this regard, control module 40 can be implemented using any suitable processing system and / or device, such as, for example, one or more processors, central processing units (CPUs), controllers, microprocessors, microcontrollers, processing cores and / or other hardware computing resources configured to support the operation of control module 40 described herein. Control module 40 may also include or otherwise access data storage elements (or memory) capable of storing programming instructions that, when read and executed, enable control module 40 to support the processes described herein. Depending on the implementation, memory may be implemented as random access memory (RAM), read-only memory (ROM), flash memory, magnetic or optical mass storage devices, or any other suitable non-transitory short-term or long-term data storage devices or other computer-readable media, and / or any suitable combination thereof.

[0022] Figure 2 Exemplary embodiments of a transmission starting process 200 suitable for implementation by a vehicle system (such as system 100 associated with vehicle 10) according to one or more embodiments described herein are depicted. For illustrative purposes, the following description may be referenced in conjunction with the above. Figure 1 The components mentioned. Although parts of the transmission starting process 200 can be performed by different components of the vehicle system, for illustrative purposes, the subject matter can be described herein primarily in the context that the transmission starting process 200 is primarily performed by the control module 40.

[0023] In an exemplary embodiment, the transmission starting process 200 is automatically initiated or otherwise autonomously executed in response to the control module 40 detecting or otherwise recognizing a wake-up event before the user operates the vehicle 10. For example, the control module 40 may automatically initiate the transmission starting process 200 in response to detecting an electronic key card associated with the vehicle 10 near the vehicle 10 or in response to receiving one or more signals from the electronic key card associated with the vehicle 10 indicating a potential desire to operate the vehicle 10. In this regard, the transmission starting process 200 is executed to clear or otherwise purge air from clutches 51, 52, 53, 54, 55, and to move or otherwise preheat the pistons associated with clutches 51, 52, 53, 54, 55 (e.g., lubricate pistons, seals, etc.) before a shift event, in order to improve passenger comfort associated with the initial shift (e.g., to / from one or more of the aforementioned forward gear ratios) after the engine 12 is engaged (e.g., by reducing the likelihood of accidental shift events, momentary neutral, etc.).

[0024] At point 202, the transmission starting process 200 is initiated or otherwise started by pulsating the first brake clutch associated with the transmission to engage the first brake clutch. In an exemplary embodiment, control module 40 provides a command, signal, or other instruction to activate pressure source 28, and then the command, signal, or other instruction operates a corresponding control valve 30 associated with the first brake clutch 52 (which may alternatively be referred to herein as clutch C2) to provide a pressure pulse to the corresponding piston associated with clutch C2 52, thereby actuating the piston from the fully disengaged state of clutch C2 52 through the piston's range of motion until reaching an intermediate state where clutch C2 52 is not engaged. In this respect, control module 40 operates control valve 30 to provide a commanded amount of pressure to piston C2 for a commanded duration, wherein the combination of the commanded amount of pressure and the commanded duration is configured to actuate piston C2 without engaging clutch C2 52 with the gears of transmission 14. In one or more embodiments, the control module 40 operates the C2 control valve 30 to grade the command amount of pressure by initially providing a higher pressure amount to the C2 piston before the pressure applied to the C2 piston is reduced to a lower pressure amount configured to maintain the current actuation state of the C2 clutch 52 for the remainder of the transmission start-up process 200.

[0025] Similarly, at 204, the transmission starting process 200 pulses the second brake clutch associated with the transmission to engage the second brake clutch. Similar to the first brake clutch 52, the control module 40 provides commands, signals, or other instructions to operate the corresponding control valve 30 associated with the second brake clutch 51 (which may alternatively be referred to herein as clutch C1) to provide pressure pulses to the corresponding piston associated with clutch C1 51, thereby actuating the piston from the fully disengaged state of clutch C1 51 through its range of motion until reaching the intermediate state where clutch C1 51 is not engaged. In this respect, the control module 40 operates the C1 control valve 30 to achieve a commanded amount of pressure on the C1 piston for the commanded duration, wherein the combination of the commanded amount of pressure and the commanded duration is configured to actuate the C1 piston without engaging the gears of the transmission 14 with clutch C1 51. Similar to clutch 52 C2, in one or more embodiments, control module 40 grades the pressure of command quantity by initially operating control valve 30 C1 to provide a higher pressure quantity to piston C1 before operating control valve 30 C1 to reduce the pressure quantity applied to piston C1 to a lower pressure quantity, the lower pressure quantity being configured to maintain the current actuation state of clutch 51 C1 for the remainder of the transmission starting process 200.

[0026] After engaging the brake clutch, the transmission starting process 200 receives or otherwise obtains measurement data indicating the current temperature of the transmission at 206, identifies, determines, or otherwise obtains a weighting factor associated with the corresponding rotary clutch among the rotary clutches of the transmission corresponding to the current temperature at 208, and then, at 210, alternately pulsates the rotary clutches in a cyclic manner, at least in part based on the corresponding weighting factor. In this respect, as follows... Figure 3 In the context of the circulating air purging process 300, described in more detail, the control module 40 uses a temperature-related weighting factor to dynamically determine and assign different priorities to the rotary clutches 53, 54, 55 of the transmission 14, and then alternately pulsates the different corresponding rotary clutches 53, 54, 55 in a cyclic manner according to their respective priorities.

[0027] In an exemplary embodiment, the transmission starting process 200 continuously pulses the rotating clutches cyclically according to their associated temperature-related weighting factor, while maintaining the brake clutches in an actuated state until an engine start event is detected at 212. In response to engine start, the transmission starting process 200 disengages the brake clutches from their actuated state at 214. In this regard, in response to receiving a signal or other indication that the engine 12 has started, the control module 40 operates control valves C1 and C2 to remove pressure from clutches C1 and C2, allowing clutches C1 and C2 to return to a fully disengaged state when pistons C1 and C2 become exhausted. By maintaining clutches C1 and C2 in an actuated state until engine start, air is purged from pistons C1 and C2 prior to the initial shift event, during which at least one of brake clutches C1 and C2 is engaged (e.g., in first gear).

[0028] Figure 3 An exemplary embodiment of a recirculating air purging process 300 is described, which is adapted to be implemented to purge air from a disengaged clutch of a transmission. For illustrative purposes, the following description may be referenced in conjunction with the above. Figure 1 The components mentioned. While portions of the recirculating air purging process 300 may be performed by different components of the vehicle system, for illustrative purposes, this subject matter may be described primarily in the context that the recirculating air purging process 300 is primarily performed by the control module 40. In one or more exemplary embodiments, the recirculating air purging process 300 is performed in conjunction with the transmission starting process 200 (e.g., at 210). That is, in other implementations, the recirculating air purging process 300 may be implemented independently of the transmission starting process 200. For example, in some embodiments, whenever the transmission 14 is in park or neutral and the engine 12 is started, the recirculating air purging process 300 is performed after the start-up event to continuously purge air from the disengaged clutches before future shift events. Furthermore, in some embodiments, the recirculating air purging process 300 may be implemented at the engagement of a particular gear ratio or otherwise implemented at the transmission 14 to purge air from the remaining subgroups of disengaged clutches that have never been involved in the current gear ratio.

[0029] The recirculating air purging process 300 is initialized or otherwise started by identifying a subset of disengaged clutches available for purging at 302. In this respect, when engaged... Figure 2During the transmission start-up process 200, the control module 40 identifies the rotary clutches 53, 54, and 55 as a subset of clutches available for cyclic air purging. That is, in an embodiment where the cyclic air purging process 300 is performed when the engine 12 is engaged, the control module 40 can identify a subset of currently disengaged clutches of the transmission 14 based on the current gear ratio indicated by the gear selection device 26, for example, by identifying a subset of clutches unrelated to or otherwise involved in generating the current gear ratio, and excluding clutches engaged to generate the current gear ratio.

[0030] After identifying a subset of clutches available for purging, the recirculating air purging process 300 at 304 calculates or otherwise determines a corresponding priority metric associated with each potential clutch based at least in part on a weighting factor associated with the respective clutch, and then at 306 selects or otherwise identifies the highest priority clutch from the subset of available clutches based on the priority metric associated with the clutch. In an exemplary embodiment, for each available clutch, the control module 40 calculates or otherwise determines a current value of the priority metric associated with that respective clutch, which is a function of the identified weighting factor associated with that respective clutch and the depletion time associated with that respective clutch, for example, by multiplying the respective depletion time by the respective weighting factor to calculate a corresponding priority score to be assigned to the respective clutch. The depletion time (or purging time) represents the amount of time elapsed since the respective clutch returned to a de-energized and fully disengaged state after it has recently been engaged, pulsated, or otherwise actuated from a fully disengaged state. Therefore, based on the differences in the times of most recent excitation or actuation of the clutches and the differences or variations in the depletion rates among the clutches (e.g., some clutches return to de-excitation and fully disengaged states faster or slower than others), each clutch can have a different depletion time associated with it. The weighting factor represents the relative priority of the corresponding clutch, reflecting the degree or amount to which the actuation of the corresponding clutch during a shift event is associated with the occurrence of erroneous shift events, momentary neutral, etc. In this respect, the transmission 14 can be calibrated prior to deployment in the vehicle 10, wherein the behavior of different clutches is analyzed at different operating temperatures (or operating temperature ranges), and based on the behavior of each corresponding clutch relative to other clutches at the corresponding operating temperature (or temperature range), a corresponding weighting factor is assigned to each corresponding clutch for those different operating temperatures (or operating temperature ranges). Thus, in addition to the potential or possibility that available clutches have different depletion times associated with other available clutches, available clutches can also have different corresponding weighting factors (which can also vary based on temperature), such that each clutch can be assigned a different priority score calculated for that corresponding clutch. Furthermore, as time passes, the corresponding exhaust time associated with the corresponding clutch will also change relative to time, causing the priority score associated with the available clutch to change dynamically relative to time as the exhaust time changes.

[0031] After calculating or otherwise determining the current priority score of each available clutch, control module 40 selects or otherwise identifies the clutch with the highest priority score (e.g., the highest product of its associated weighting factor and exhaust time) as the highest priority clutch to be purged during the current iteration of recirculating air purging process 300. After identifying the highest priority clutch at 306, recirculating air purging process 300 pulsates the selected clutch at 308. In this regard, in a manner similar to that described above, control module 40 commands, signals, or otherwise operates the corresponding control valve 30 associated with the selected clutch to provide a pressure pulse to the corresponding piston associated with the highest priority clutch, thereby actuating the piston from a fully disengaged state through a range of piston movement for a command duration using the commanded pressure. The combination of the commanded pressure and the command duration is configured to actuate the piston of the selected clutch without engaging the gears of transmission 14. After pulsating the highest priority clutch at 308, recirculating air purging process 300 resets or otherwise reinitializes the exhaust timer or similar feature associated with the corresponding clutch at 310. For example, in one or more embodiments, the control module 40 implements a timer or similar feature for each clutch that tracks the amount of time elapsed since the corresponding clutch was fully disengaged. In this regard, after pulsating the selected clutch, the control module 40 resets the timer to zero and then restarts it once the piston associated with the selected clutch has exhausted and the clutch has returned to its fully disengaged state. That is, in other embodiments, the control module 40 may store or otherwise maintain a timestamp associated with the most recent pulsation or disengagement of the corresponding clutch, and then calculate or otherwise determine the current exhaust time associated with that corresponding clutch based on the difference between the current time and the corresponding timestamp associated with that clutch.

[0032] Still referencing Figure 3The cyclic air purging process 300, defined by 302, 304, 306, 308, and 310, is continuously repeated while the cyclic air purging process 300 is active or otherwise enabled to alternately pulsate different clutches among the available clutches in a cyclic manner according to corresponding weighting factors and exhaust times. In this respect, the order and sequence of the clutches will vary according to the weighting factors and exhaust times. For example, a clutch assigned a higher priority weighting factor may pulsate more frequently than a clutch assigned a lower priority weighting factor, but the clutches assigned a lower priority weighting factor will still pulsate periodically during the cyclic air purging process 300 because their respective exhaust times accumulate to offset or otherwise negate the difference in weighting factors due to the exhaust times associated with those clutches that are continuously reset after each pulsation. In this way, the cyclic air purging process 300 ensures that all available clutches will be pulsated, while prioritizing pulsating the more likely problematic clutches at a higher frequency to better purge air and lubricate these clutches, thereby reducing the likelihood of mis-shifting events, momentary neutral shifts, and / or similar events.

[0033] Figure 4This is a timing diagram depicting the pulse sequence applied to different clutches 51, 52, 53, 54, 55 of the transmission 14 in an example embodiment of a transmission start-up process 200, which is combined with a recirculating air purging process 300 to alternately pulsate the rotary clutches 53, 54, 55 at 210. As described above, in response to a wake-up event, the control module 40 operates the C2 control valve 30 to actuate the C2 brake clutch by applying an initial pulse phase 402 with relatively high pressure for a temporary duration, followed by a second pulse phase 404 with relatively high pressure for the remaining duration, until the start-up event. In this respect, the amount or magnitude of the command pressure associated with the initial pulse phase 402 is calibrated or otherwise configured to correspond to the duration (or width) of the initial pulse phase 402, so as to actuate the C2 piston from the fully disengaged and disengaged state of the C2 clutch 52 at least partially through the piston's range of motion until reaching an intermediate actuated state where the C2 clutch 52 is not engaged. After a calibration duration associated with the initial pulse phase 402 (which may be stored or otherwise maintained in a data memory associated with the control module 40), the control module 40 operates the C2 control valve 30 to reduce the pressure applied to the C2 piston to a lower pressure associated with the subsequent pulse phase 404, in order to maintain the current partially actuated state of the C2 clutch 52 for the remainder of the transmission starting process 200, so that the C2 clutch 52 does not disengage before the start-up event. After pulsating the C2 brake clutch 52, the control module 40 operates the C1 control valve 30 in a similar manner to provide an initial pulse phase 406 with a relatively high pressure for a temporary duration, thereby actuating the C1 piston from the fully disengaged state of the C1 clutch 51 through the piston's range of motion before reducing the command pressure, until reaching an intermediate actuated state to provide a second pulse phase 408 associated with a lower pressure, which is configured to maintain the partially actuated state of the C1 clutch 51 without engaging it until the start-up event.

[0034] After engaging the starting and braking clutches 51 and 52, the control module 40 obtains the current temperature measurement value from the temperature sensor 36, and then, using the corresponding weighting factors associated with the rotary clutches 53, 54, and 55, alternately pulses the rotary clutches 53, 54, and 55 one at a time in a cyclical manner, according to the dynamic change of the weighting factors over time. In this respect, Figure 4A scenario is depicted in which, when the recirculating air purging process 300 is initialized at 210, the current value of the priority metric associated with clutch C4 54 (e.g., the product of the C4 weighting factor of the current temperature and the current depletion timer value of clutch C4 54) is greater than the corresponding values ​​of the priority metrics associated with the other rotating clutches 53, 55. Therefore, control module 40 identifies or otherwise selects clutch C4 54 as the current highest priority clutch (e.g., at 306) and then operates C4 control valve 30 to provide a pulse 410 with an associated command pressure for a duration of command (e.g., at 308). The combination of command pressure and command duration is cooperatively configured to at least partially actuate the C4 piston from the fully depleted and disengaged states of clutch C4 54 through the range of motion of the C4 piston until an intermediate actuated state is reached without engaging clutch C4 54. For example, the control module 40 can open the C4 control valve 30 by an amount corresponding to the command pressure of the pulse 410 during the command duration, and then close the C4 control valve 30 after the command duration, so as to depressurize the C4 piston and allow the C4 piston to begin to deplete from the partially actuated state to the fully disengaged state of the C4 clutch 54.

[0035] After pulsating clutch C4 54, control module 40 waits for the exhaustion period to allow clutch C4 54 to begin exhausting before dynamically determining and pulsating the next highest priority clutch. For example, after pulsating clutch C4 54 and resetting the C4 exhaustion timer, while clutch C4 54 is still exhausting, control module 40 determines updated priority values ​​for the currently exhausting rotary clutches 53 and 55 to identify which clutch is now the highest priority clutch to pulsate. In this respect, Figure 4 A scenario is depicted where the current value of the priority metric associated with clutch C3 53 (e.g., the product of the C3 weighting factor for the current temperature and the current depletion timer value of clutch C3 53) is greater than the corresponding value of the priority metric associated with clutch C5 55. Therefore, control module 40 identifies or otherwise selects clutch C3 53 as the updated and currently highest priority clutch (e.g., at 306), and then operates C3 control valve 30 to provide a pulse 412 with an associated command pressure and command duration (e.g., at 308), which are cooperatively configured to at least partially actuate the C3 piston from the fully depleted and disengaged state of clutch C3 53 through the range of motion of the C3 piston until an intermediate actuated state is reached without engaging clutch C3 53.

[0036] In a similar manner to that described above in the context of pulsating clutch C4 54, after pulsating clutch C3 53, control module 40 waits for an exhaustion period to allow clutch C3 53 to begin exhaustion before dynamically determining and pulsating the updated highest priority clutch. For example, after pulsating clutch C3 53 and resetting the C3 exhaustion timer, while clutch C3 53 is still exhausting, control module 40 determines updated priority values ​​for the other rotating clutches 54, 55 to identify which clutch is now the highest priority clutch to pulsate. In this respect, Figure 4 The scenario described depicts a scenario where the current value of the priority metric associated with clutch C5 55 (e.g., the product of the C5 weighting factor at the current temperature and the current exhaustion timer value of clutch C5 55) is greater than the corresponding value of the priority metric associated with clutch C4 54. In this respect, since clutch C4 54 has already pulsed more recently, the exhaustion time associated with the C4 exhaustion timer will be less than the exhaustion time associated with clutch C5 55. That is, in some cases, if the weighting factor associated with clutch C4 54 is significantly higher than the weighting factor associated with clutch C5 55, clutch C4 54 can alternatively be identified as the highest priority clutch and pulsed a second time before the first pulse of clutch C5 55. Alternatively, if clutch C4 54 has not yet reached full exhaustion, the C4 exhaustion timer can remain at zero, and the priority metrics of both clutch C4 54 and clutch C3 53 can be equal to zero, such that clutch C5 55 is identified as the highest priority clutch available for pulsation.

[0037] In a similar manner to that described above in the context of clutches C3 and C4, control module 40 operates control valve 30 of C5 to provide a pulse 414 with a command pressure and command duration, which is configured to at least partially actuate piston C5 from the fully disengaged and fully exhausted state of clutch C5 55 through the range of motion of piston C5 without engaging clutch C5 55. After pulsating clutch C5 55 and resetting the C5 exhaust timer, Figure 4A scenario is depicted in which the control module 40 identifies the C4 clutch 54 as the updated highest priority exhaust clutch during the next iteration of the recirculating air purging process 300, and operates the C4 control valve 30 in a similar manner to provide another pulse 416 with a commanded pressure and commanded duration. In this respect, the control module 40 implements or otherwise executes the recirculating air purging process 300 during the transmission start-up process 200 to alternately pulsate different clutches among the clutches 53, 54, 55 in a sequence or order that can dynamically change over time, based on the relationship between corresponding weighting factors and the depletion times associated with the corresponding clutches 53, 54, 55. Additionally, in some embodiments, when the recirculating air purging process 300 is implemented or otherwise executed independently of the transmission start-up process 200, the subgroup of clutches 51, 52, 53, 54, 55 available for purging can vary according to the current gear ratio of the transmission 14 indicated by the gear selection device 26. For example, in some implementations, whenever the vehicle 10 is parked or in neutral, the recirculating air purging process 300 is initiated after an engine start event.

[0038] It should be understood that Figure 4The timing diagrams shown are simplified representations for illustrative purposes and are not restrictive. In practice, it should be noted that the command pressure and / or command duration associated with different pulses 402, 404, 406, 408, 410, 412, 414, 416 may vary between clutches 51, 52, 53, 54, 55 to reflect the differences between clutches 51, 52, 53, 54, 55, and may vary from one transmission 14 to another. In this regard, the clutches 51, 52, 53, 54, and 55 of the transmission 14 can be calibrated before being deployed in the vehicle 10 to determine the relationship between the applied pressure and the actuation amount of the corresponding clutches 51, 52, 53, 54, and 55. This can then be used to derive the command pressure and duration of the corresponding pulses 402, 404, 406, 408, 410, 412, 414, and 416 to achieve the desired actuation of the corresponding clutches 51, 52, 53, 54, and 55, while ensuring that the corresponding clutches 51, 52, 53, 54, and 55 do not engage during the transmission starting process 200 and / or the recirculating air purging process 300. Additionally, in some embodiments, the amount of time required for each respective clutch 51, 52, 53, 54, 55 to become depleted after actuation can also be calibrated or otherwise determined and used to determine when to restart the depletion timer associated with the respective clutch 51, 52, 53, 54, 55, while taking into account the variation in depletion rate between different instances of transmission 14, thereby allowing clutches 51, 52, 53, 54, 55 to become fully depleted before pulsating again in some way during the recirculating air purging process 300.

[0039] By cyclically disengaging the clutches of the multi-clutch transmission 14 to partially actuate the clutches, the clutches 51, 52, 53, 54, 55 of the multi-clutch transmission 14, and their associated pistons and / or other hydraulic actuators, can be purged, lubricated, and otherwise prepared for actuation prior to a shift event. One or more of clutches 51, 52, 53, 54, 55 are actuated and engaged within the transmission 14 to form a gear ratio, thereby reducing the likelihood of abnormal shift events (e.g., momentary neutral, momentary neutral, momentary neutral). Furthermore, due to temperature-related weighting factors and exhaustion timers, specific clutches among 51, 52, 53, 54, 55 that would otherwise be more likely to be problematic can be purged and lubricated with greater frequency or priority, thereby reducing the likelihood of that specific clutch exhibiting abnormal behavior during subsequent shift events.

[0040] While at least one exemplary specification has been presented in the foregoing detailed embodiments, it should be understood that numerous variations exist. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of this disclosure in any way. Rather, the foregoing detailed embodiments will provide those skilled in the art with a convenient roadmap for implementing one or more exemplary specifications. It should be understood that various changes can be made to the function and arrangement of elements without departing from the scope of this disclosure as set forth in the appended claims and their legal equivalents.

Claims

1. A method for operating a vehicle's transmission, the method comprising: Multiple weighting factors are obtained by the control module, wherein each of the multiple weighting factors is associated with a corresponding clutch among the multiple clutches of the transmission of the vehicle; For each of the plurality of clutches: The depletion time associated with the corresponding clutch is obtained by the control module; as well as The control module determines the corresponding priority metric associated with the corresponding clutch based at least in part on the depletion time associated with the corresponding clutch and the corresponding weighting factor associated with the corresponding clutch; The control module determines the highest priority clutch among the plurality of clutches based at least in part on a corresponding priority metric associated with the respective clutch among the plurality of clutches; as well as The control module operates one or more valves according to pulse commands to pulsate the highest priority clutch for a command period of time using command pressure.

2. The method of claim 1, further comprising, after operating the one or more valves to pulsate the highest priority clutch, resetting a timer for the exhaustion time associated with the highest priority clutch.

3. The method according to claim 2, further comprising: After resetting the timer for the exhaustion time associated with the highest priority clutch, the control module determines an updated highest priority clutch among the plurality of clutches based at least in part on a corresponding priority metric associated with the respective clutch among the plurality of clutches, wherein the updated highest priority clutch is different from the original highest priority clutch; and The control module operates one or more valves according to a second pulse command to pulsate the updated highest priority clutch for a second command time period after pulsating the highest priority clutch.

4. The method of claim 1, further comprising a plurality of clutches for identifying the disengagement of the vehicle's transmission based on the current gear ratio indicated by the gear selection device.

5. The method according to claim 4, wherein, When the current gear ratio corresponds to parking or neutral, the plurality of clutches include a plurality of rotary clutches of the transmission.

6. The method of claim 1, further comprising the control module operating the one or more valves according to a start pulse command to pulsate the brake clutch before pulsating the highest priority clutch.

7. The method according to claim 1, wherein, The method further includes obtaining a current temperature measurement from a temperature sensor associated with the transmission, wherein obtaining the plurality of weighting factors includes identifying a plurality of weighting factors corresponding to the current temperature measurement.

8. The method according to claim 1, wherein, Operating one or more valves according to the pulse command to pulsate the highest priority clutch includes actuating the piston associated with the highest priority clutch from a depleted state to an intermediate actuated state without engaging the highest priority clutch.

9. A vehicle comprising: The transmission includes multiple clutches; One or more valves, the one or more valves being operable to control the operation of the plurality of clutches; A data storage element, the data storage element including computer-readable instructions; as well as A processing apparatus for executing the computer-readable instructions, the computer-readable instructions controlling the processing apparatus to perform operations, the operations including: A plurality of weighting factors are obtained, wherein each of the plurality of weighting factors is associated with a corresponding clutch among the plurality of clutches; For each of the plurality of clutches, obtain the exhaust time associated with the respective clutch; For each of the plurality of clutches, a corresponding priority metric associated with the corresponding clutch is determined at least in part based on the exhaustion time associated with the corresponding clutch and the corresponding weighting factor associated with the corresponding clutch; The highest priority clutch among the plurality of clutches is determined at least in part based on a corresponding priority metric associated with a respective clutch among the plurality of clutches; and The valves are operated according to a pulse command to pulsate the highest priority clutch for a command period of time with command pressure.

10. The vehicle according to claim 9, wherein, The computer-readable instructions control the processing device to perform operations, which further include: After resetting the timer for the exhaustion time associated with the highest priority clutch among the plurality of clutches, an updated highest priority clutch among the plurality of clutches is determined at least in part based on a corresponding priority metric associated with the respective clutch among the plurality of clutches, wherein the updated highest priority clutch is different from the original highest priority clutch; and After the highest priority clutch is pulsated, the one or more valves are operated according to the second pulse command to pulsate the updated highest priority clutch for a second command time period with the second command pressure.

Images