Patent Grant
10196994
A powertrain of a vehicle includes an engine, a torque converter, and a transmission coupled in series. If the engine is an internal-combustion engine, the engine contains cylinders that serve as combustion chambers that convert fuel to rotational kinetic energy. The torque converter transmits rotational motion from the engine to the transmission while allowing slippage between the engine and transmission, for example, while the engine is running and the vehicle is stopped. The transmission transmits the kinetic energy from the torque converter to a drive axle and ultimately to wheels of the vehicle, while applying a gear ratio allowing different tradeoffs between torque and rotational speed.
Noise, vibration, and harshness (NVH) constraints can limit the fuel economy possible for the powertrain. Deactivating cylinders of the engine can increase the efficiency of the engine, but running the engine with fewer cylinders can cause torque pulsations that are unpleasant for occupants of the vehicle. Likewise, reduced slippage in the torque converter can increase the efficiency of the powertrain, but reduced slippage also transmits more vibrational shocks from the engine to occupants. And finally, reducing the vehicle speeds at which gear shifts occur or gear ratios change can increase fuel economy but may also increase the noise and vibrations experienced by occupants.
With reference to the Figures, wherein like numerals indicate like parts throughout the several views, a vehicle 30 includes a transmission 36; a torque converter 38 coupled to the transmission 36; a controller 60 in communication with the transmission 36 and the torque converter 38; a driver seat 52, a passenger seat 53, and a back seat 54 coupled to the transmission 36; and sensors 64 configured to detect user occupancy of the seats 52, 53, 54. The sensors 64 are in communication with the controller 60. The controller 60 is programmed to receive data from the sensors 64, determine an occupancy status based on the occupancy data, set an engine operating parameter of one of the transmission 36 and the torque converter 38 based on the occupancy status, and control one or both of the transmission 36 and the torque converter 38 to operate according to the parameter.
Setting the engine operating parameter based on the occupancy status increases the efficiency of the vehicle 30 at the expense of increasing noise, vibration, and/or harshness (NVH) in situations in which the increased NVH is less likely to be experienced by occupants. If the vehicle 30 is autonomous, then the vehicle 30 may be unoccupied, or occupants may be seated only in the back seat 54 and not the driver or passenger seats 52, 53, or an occupant may be seated in the passenger seat 53 and not the driver seat 52. Occupants of the back seat 54 may be less exposed to NVH from an engine 34, torque converter 38, and transmission 36 than occupants of the driver or passenger seats 52, 53, and the occupants of the driver seat 52 and the passenger seat 53 may have different NVH exposures. Increased NVH has less downside in some of these occupancy statuses than others, so it becomes more acceptable to trade off NVH for greater efficiency of the vehicle 30.
The vehicle 30 may be an autonomous vehicle. In this context, “autonomous” means that each of vehicle 30 propulsion (e.g., a powertrain including an internal combustion engine), steering, and braking are controlled by the controller 60 without human intervention. The controller 60, sometimes referred to as the “virtual driver,” may be capable of operating the vehicle 30 independently of the intervention of a human driver, to a greater or a lesser degree, e.g., the vehicle 30 could be operated semi-autonomously, meaning that one or two of propulsion, steering, and braking are controlled by the controller 60 without human intervention. The controller 60 may be programmed to operate the engine 34, the torque converter 38, the transmission 36, a braking system, a steering system, and/or other vehicle systems. The controller 60 may have an autonomous mode, in which the controller 60 operates the vehicle 30, and semi-autonomous and/or manual modes, in which a human driver operates some or all of the subsystems of the vehicle 30 pertaining to propulsion, steering, and braking.
As shown in
The vehicle 30 includes a powertrain 32, which includes the engine 34; the torque converter 38, which is coupled to the engine 34, that is, directly or indirectly drivably connected to the engine 34; and the transmission 36, which is coupled to the torque converter 38. The powertrain 32 produces energy and converts the energy into rotational motion of wheels 44 that propel the vehicle 30.
The engine 34 may be an internal combustion engine, an electric engine, or a hybrid electric engine. In an internal combustion or hybrid engine, the engine 34 includes a plurality of cylinders 40.
The cylinders 40 operate as combustion chambers in which a chemical reaction of a fuel translates into kinetic energy of a piston (not shown) of the cylinder 40. The pistons of the cylinders 40 are coupled to the torque converter 38 such that linear movement of the pistons drives rotational motion of the torque converter 38. The cylinders 40 of the engine 34 fire in a predefined sequence.
The engine 34 may use all of the cylinders 40 to power the vehicle 30 or may use a set of active cylinders 40 including less than all the cylinders 40.
The torque converter 38 is coupled to the engine 34 and to the transmission 36. The torque converter 38 transmits rotational motion from the engine 34 to the transmission 36. The torque converter 38 decouples the motion of the engine 34 from the motion of the transmission 36, allowing the engine 34 to, for example, continue running while the vehicle 30 is stopped. When the vehicle 30 is moving, the torque converter 38 allows the engine speed to be higher than the input speed of the transmission 36. The difference in speed across the torque converter 38 from the engine speed to the input speed of the transmission 36 is called “slip.” The torque converter 38 has a lock-up clutch that can reduce or eliminate slip by establishing a mechanical connection through the lock-up clutch to connect the engine 34 and the transmission 36, thus allowing a variable slip. Using the lock-up clutch, the torque converter 38 can switch between an unlocked state with a positive rate of slip and a locked state with zero rate of slip. In the unlocked state, the torque converter 38 allows slippage between the engine 34 and the transmission 36, transmitting less rotation at higher torque from the engine 34 to the transmission 36. In the locked state, the torque converter 38 transmits all rotation from the engine 34 to the transmission 36, so the transmission 36 rotates at the same speed as the engine 34. The lock-up clutch may be intermediately engaged to allow partial slipping.
A lock-up schedule lists the conditions under which the torque converter 38 has different quantities of slip or is in the locked or the unlocked state. The conditions are based on variables describing the state of the engine 34 or the vehicle 30, such as accelerator pedal position, vehicle speed, the ratio of accelerator pedal position to vehicle speed, and other factors such as brake pedal position, engine speed, engine torque, engine temperature, transmission temperature, etc.
The transmission 36 is coupled to the torque converter 38, that is, directly or indirectly drivably connected to the torque converter 38. The transmission 36 transmits power generated by the engine 34 to a drive axle connected to wheels (not shown). The transmission 36 can change the gear ratio between input from the torque converter 38 and output to the drive axle. The transmission 36 may be any suitable type of transmission, including an automatic transmission with a set of defined gear ratios, called gears, or a continuously variable transmission. At higher gear ratios or lower gears, the transmission 36 transmits more torque at a higher engine speed to the drive axle, and at lower gear ratios or higher gears, the transmission 36 receives torque from the engine 34 at a slower engine speed for a given speed of the drive axle and transmits less torque to the drive axle.
A transmission schedule determines the gear ratio of the transmission 36 as a function of the vehicle speed and the position of an accelerator pedal or a throttle (not shown). For an automatic transmission 36, a transmission schedule indicates the conditions under which the transmission 36 will shift between two gears as a function of the vehicle speed and the pedal or throttle position. The throttle is an input device, such as a floor pedal, through which an occupant indicates a desired change in the vehicle acceleration or speed.
As shown in
A driver-identification sensor 64 may be in communication with the controller 60. The driver-identification sensor 64 may detect an RFID or other signature unique to different keys of the vehicle 30, an input by an occupant of the vehicle 30, biometric data of an occupant of the vehicle 30, or any other suitable indicator of identity for an occupant of the vehicle 30. The identity of an occupant of the vehicle 30 may be tied to a classification of that occupant, for example, as a chauffeur or as a non-chauffeur.
As further shown in
The controller 60 may transmit and receive signals through the communications network 66, such as a controller area network (CAN) bus, Ethernet, Local Interconnect Network (LIN), and/or by any other wired or wireless communications network.
Next, in a block 510, the controller 60 receives occupancy data from the sensors 64 and receives driver-identifying data from the driver-identification sensor 64 via the communications network 66.
Next, in a block 515, the controller 60 determines the occupancy status of the vehicle 30 based on received sensor data, including the occupancy data and the driver-identifying data. The controller 60 thus detects the occupancy status of the vehicle 30. The occupancy status may take on one of multiple statuses. There may be as few as two possible occupancy statuses, or there may be a unique occupancy status for each possible seating configuration. If the vehicle 30 is an SUV or minivan with eight seats, there may be as many as 28=256 occupancy statuses without using driver-identifying data.
For example, the occupancy status may be one of “occupied” and “unoccupied.” The occupancy status is occupied if the occupancy data indicates that at least one of the seats 52, 53, 54 is occupied. The occupancy status is unoccupied if the occupancy data indicates that all the seats 52, 53, 54 are unoccupied.
For another example, the occupancy status may be one of “front-seat-occupied,” “back-seat-only-occupied,” and “unoccupied.” The occupancy status is front-seat-occupied if the occupancy data indicates that at least one of the driver seat 52 and the passenger seat 53 is occupied. The occupancy status is back-seat-only-occupied if the occupancy data indicates that both the driver seat 52 and the passenger seat 53 are unoccupied and the back seat 54 is occupied. The occupancy status is unoccupied if the occupancy data indicates that the seats 52, 53, 54 are unoccupied.
For a third example, the occupancy status may be one of “driver-seat-occupied,” “passenger-seat-only-occupied,” “back-seat-only-occupied,” and “unoccupied.” The occupancy status is driver-seat-occupied if the occupancy data indicates that the driver seat 52 is occupied. The occupancy status is passenger-seat-only-occupied if the occupancy data indicates that the passenger seat 53 is occupied and the driver seat 52 is unoccupied. The occupancy status is back-seat-only-occupied if the occupancy data indicates that the driver and passenger seats 52, 53 are unoccupied and the back seat 54 is occupied. The occupancy status is unoccupied if the occupancy data indicates that the driver, passenger, and back seats 52, 53, 54 are unoccupied.
For a fourth example, the occupancy status may be one of “front-seat-occupied,” “chauffeur,” “back-seat-only-occupied,” and “unoccupied.” The occupancy status is front-seat-occupied if the occupancy data indicates that the driver seat 52 or the passenger seat 53 is occupied and the driver-identifying data indicates that an occupant of the driver or passenger seat 52, 53 is a non-chauffeur. The occupancy status is chauffeur if the occupancy data indicates that the driver seat 52 is occupied, the passenger seat 53 is unoccupied, and the driver-identifying data indicates that an occupant of the driver seat 52 is a chauffeur. The occupancy status is back-seat-only-occupied if the occupancy data indicates that the driver and passenger seats 52, 53 are unoccupied and the back seat 54 is occupied. The occupancy status is unoccupied if the occupancy data indicates that the seats 52, 53, 54 are unoccupied. The chauffeur and back-seat-only-occupied statuses may be treated as the same occupancy status or as different statuses.
In addition to these three examples, other occupancy statuses and/or combinations of occupancy statuses are possible.
Next, in a block 520, the controller 60 sets an engine operating parameter based on the occupancy status. The engine operating parameter may be a parameter of one of the transmission 36 or the torque converter 38.
For example, the parameter may be the transmission schedule. The controller 60 may store a different transmission schedule for each possible occupancy status. The transmission 36 operates with a lower gear ratio for a given vehicle speed for occupancy statuses with less stringent NVH requirements. For automatic transmissions, for example, that means that the transmission 36 shifts at lower vehicle speeds for occupancy statuses with less stringent NVH requirements. For example, as shown in
For another example, the parameter may be the lock-up schedule for the torque converter 38. The controller 60 may store a different lock-up schedule for each status that the occupancy status may take on. The torque converter 38 uses lower quantities of slip or more frequently enters the locked state for statuses with less stringent NVH requirements. For example, a lock-up schedule for the unoccupied status has quantities of slip no higher than, and under at least some vehicle conditions lower than, a lock-up schedule for the back-seat-only-occupied status; and the lock-up schedule for the back-seat-only-occupied status has rates of slip no higher than, and under at least some vehicle conditions lower than, a lock-up schedule for the front-seat-occupied status.
Next, in a block 525, the controller 60 controls one of the transmission 36 and the torque converter 38 to operate according to the parameter set as described above, that is, the transmission schedule and the lock-up schedule, respectively. The controller 60 may shift the transmission 36 according to the transmission schedule for the current occupancy status. The controller 60 may set the quantity of slip of the torque converter 38 according to a lock-up schedule for the current occupancy status. The process 500 ends following the block 525.
Next, in a block 610, the controller 60 receives occupancy data from the sensors 64 and receives driver-identifying data from the driver-identification sensor 64 via the communications network 66.
Next, in a block 615, the controller 60 determines the occupancy status of the vehicle 30 based on received sensor data, including the occupancy data and the driver-identifying data, as described above with respect to the block 515 of the process 500.
Next, in a block 620, the controller 60 sets the cylinder deactivation schedule based on the occupancy status. The controller 60 may store a different cylinder deactivation schedule for each possible occupancy status and thus select a set of active cylinders 40 from the plurality of cylinders 40 based on the occupancy status. Cylinder deactivation may occur more frequently for statuses with less stringent NVH requirements. For example, as shown in
Next, in a block 625, the controller activates a set of active cylinders 40 and deactivates a remainder of the plurality of cylinders 40 according to a cylinder deactivation schedule for the current occupancy status. The process 600 ends following the block 625.
To execute the exemplary processes 500 and 600, the controller 60 is programmed to receive occupancy data from the sensors 64, determine an occupancy status based on the occupancy data, set an engine operating parameter of one of the transmission 36 and the torque converter 38 based on the occupancy status, select a set of active cylinders 40 from the plurality of cylinders 40 based on the occupancy status, control one of the transmission 36 and the torque converter 38 to operate according to the parameter, and activate the set of active cylinders 40 and deactivate a remainder of the plurality of cylinders 40. The controller 60 may be further programmed to determine the occupancy status as occupied if the occupancy data indicates that at least one of the seats 52, 53, 54 are occupied and as unoccupied if the occupancy data indicates that the seats 52, 53, 54 are unoccupied. Alternatively or additionally, the controller 60 may be programmed to determine the occupancy status as driver-seat-occupied if the occupancy data indicates that the driver seat 52 is occupied, as passenger-seat-only-occupied if the occupancy data indicates that the passenger seat 53 is occupied, as back-seat-only-occupied if the occupancy data indicates that the driver and passenger seats 52, 53 are unoccupied and the back seat 54 is occupied, and as unoccupied if the occupancy data indicates that the seats 52, 53, 54 are unoccupied. Yet further alternatively or additionally, the controller 60 may be programmed to determine the occupancy status as front-seat-occupied if the occupancy data indicates that at least one of the driver and passenger seats 52, 53 is occupied and the driver-identifying data indicates that an occupant of the at least one of the driver and passenger seats 52, 53 is a non-chauffeur, as chauffeur if the occupancy data indicates that the driver seat 52 is occupied and the driver-identifying data indicates that an occupant of the driver seat 52 is a chauffeur, as back-seat-only-occupied if the occupancy data indicates that the front seat 52 is unoccupied and the back seat 54 is occupied, and as unoccupied if the occupancy data indicates that the seats 52, 53, 54 are unoccupied.
The disclosure has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6436005 | Bellinger | Aug 2002 | B1 |
| 6786191 | Foster | Sep 2004 | B2 |
| 6874383 | Sayman et al. | Apr 2005 | B2 |
| 7278391 | Wong et al. | Oct 2007 | B1 |
| 7499784 | Kresse | Mar 2009 | B2 |
| 7637842 | Tamai et al. | Dec 2009 | B2 |
| 7696710 | Byrne et al. | Apr 2010 | B2 |
| 7836866 | Luken et al. | Nov 2010 | B2 |
| 8050856 | Duty et al. | Nov 2011 | B2 |
| 8108132 | Reinke | Jan 2012 | B2 |
| 8660734 | Zhu et al. | Feb 2014 | B2 |
| 8755959 | Fassnacht | Jun 2014 | B2 |
| 8882636 | Pietron et al. | Nov 2014 | B2 |
| 8948955 | Zhu et al. | Feb 2015 | B2 |
| 9008854 | Breed | Apr 2015 | B2 |
| 9082239 | Ricci | Jul 2015 | B2 |
| 9086020 | Pirjaberi et al. | Jul 2015 | B2 |
| 9475361 | Arai et al. | Oct 2016 | B2 |
| 20040068998 | Ieda et al. | Apr 2004 | A1 |
| 20040079099 | Kumada et al. | Apr 2004 | A1 |
| 20050045322 | Yoshida et al. | Mar 2005 | A1 |
| 20050052080 | Maslov et al. | Mar 2005 | A1 |
| 20050121185 | Yonekura et al. | Jun 2005 | A1 |
| 20060000597 | Errington et al. | Jan 2006 | A1 |
| 20070038364 | Lee et al. | Feb 2007 | A1 |
| 20070112502 | Asano | May 2007 | A1 |
| 20070209789 | Oomura et al. | Sep 2007 | A1 |
| 20070235549 | Nakajima | Oct 2007 | A1 |
| 20070277544 | Honda et al. | Dec 2007 | A1 |
| 20080196954 | Soliman et al. | Aug 2008 | A1 |
| 20090030568 | Amano et al. | Jan 2009 | A1 |
| 20090031741 | Hara et al. | Feb 2009 | A1 |
| 20090139789 | Yang | Jun 2009 | A1 |
| 20100132388 | Oyobe et al. | Jun 2010 | A1 |
| 20100163220 | Nakajima | Jul 2010 | A1 |
| 20110112708 | Fassnacht | May 2011 | A1 |
| 20110172880 | Tamura | Jul 2011 | A1 |
| 20110208403 | Tsumiyama | Aug 2011 | A1 |
| 20110246021 | Prokhorov | Oct 2011 | A1 |
| 20120074238 | Morita et al. | Mar 2012 | A1 |
| 20120109438 | Akebono | May 2012 | A1 |
| 20130079978 | Uyeki | Mar 2013 | A1 |
| 20130092127 | Pirjaberi | Apr 2013 | A1 |
| 20140053804 | Rayl | Feb 2014 | A1 |
| 20140090624 | Verner | Apr 2014 | A1 |
| 20140244106 | Singer | Aug 2014 | A1 |
| 20150129192 | Boss et al. | May 2015 | A1 |
| 20150203106 | Zhao | Jul 2015 | A1 |
| 20150260117 | Shost et al. | Sep 2015 | A1 |
| 20150338858 | Bates et al. | Nov 2015 | A1 |
| 20150345958 | Graham | Dec 2015 | A1 |
| 20160059845 | Nefcy | Mar 2016 | A1 |
| 20160144689 | Miller et al. | May 2016 | A1 |
| 20160193895 | Aich et al. | Jul 2016 | A1 |
| 20160207375 | Gauthier et al. | Jul 2016 | A1 |
| 20160214596 | Glugla | Jul 2016 | A1 |
| 20160280160 | MacNeille et al. | Sep 2016 | A1 |
| 20160328976 | Jo | Nov 2016 | A1 |
| 20160339906 | Nefcy | Nov 2016 | A1 |
| 20160347149 | Rustoni | Dec 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 102337974 | Feb 2012 | CN |
| 205370771 | Jul 2016 | CN |
| Entry |
|---|
| UKIPO Search Report dated Aug. 24, 2017 for Application No. GB1707219.0 (5 pages). |
| Non-Final Office Action dated Jun. 19, 2017 for U.S. Appl. No. 15/155,552 (4 pages). |
| Wilcutts, Mark, et al, “Design and Benefits of Dynamic Skip Fire Strategies for Cylinder Deactivated Engines”, SAE International, Apr. 8, 2013 (11 pages). |
| Non-Final Office Action dated Jun. 14, 2018 for U.S. Appl. No. 15/181,491 (32 pages). |
| Non-Final Office Action dated Dec. 11, 2018 for U.S. Appl. No. 15214496 (28 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20170328292 A1 | Nov 2017 | US |
