The embodiments described herein relate to retractable steering column assemblies and, more particularly, to a manually retractable steering column assembly for an autonomous vehicle.
As autonomously driven vehicles are developed, a number of opportunities will evolve related to comfort, entertainment and functionality for drivers. Steering wheels are commonly limited to standard driving positions due to the need for a driver to handle the steering wheel during operation of the vehicle. These limitations may be unnecessary during an autonomous driving mode of a vehicle. For example, a steering wheel may be retracted to a stowed position to enlarge the space available to a driver. Many vehicles with stowable columns during autonomous driving utilize power column actuators to move the column into the stowed position. However, manually adjusted columns do not have stow capability and do not have the ability to communicate a driving mode status to potential autonomous system(s).
According to one aspect of the disclosure, a manually retractable steering column assembly includes a retractable portion translatable upon exertion of a manual force applied by a driver. Also included is a stationary portion defining a slot path at least partially defined by a first end wall and a second end wall. Further included is a member operatively coupled to, and projecting outwardly from, the retractable portion. Yet further included is a gate operatively coupled to the stationary portion proximate the second end wall, the gate having an edge protruding into the slot path, the member extending through, and moveable within, the slot path during translation of the retractable portion, the first end wall and the edge of the gate defining a first translation range of the retractable portion available during a standard driving mode, the gate moveable to dispose the edge of the gate out of the slot path to allow a second translation range of the retractable portion available during an autonomous driving mode.
According to another aspect of the disclosure, a manually retractable steering column assembly includes a retractable portion translatable upon exertion of a manual force applied by a driver, the retractable portion restricted to a first translation range during a standard driving mode and translatable within a second translation range during an autonomous driving mode, the second translation range greater than the first translation range.
According to yet another aspect of the invention, a manually retractable steering column assembly for an autonomous vehicle includes a retractable portion translatable upon exertion of a manual force applied by a driver. Also included is a stationary portion defining a slot path at least partially defined by a first end wall and a second end wall. Further included is a member operatively coupled to, and projecting outwardly from, the retractable portion. Yet further included is a gate operatively coupled to the stationary portion proximate the second end wall, the gate restricting translation of the retractable portion to a first translation range during a standard driving mode, the gate moveable to allow a second translation range during an autonomous driving mode, the gate having a contoured recess for receiving the member in the autonomous driving mode, the member removable from the contoured recess to translate the retractable portion to the first translation range upon exertion of a force on the retractable portion toward the first end wall of the slot path.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
Referring now to the Figures, where the invention will be described with reference to specific embodiments, without limiting same, illustrated is a portion of a steering column assembly 10. The steering column assembly 10 facilitates translation of a steering wheel (not shown) and a steering shaft in a manually retractable manner. This is particularly beneficial in embodiments where the assembly 10 is employed in a passenger vehicle equipped with Advanced Driver Assist System(s) (ADAS) to allow the vehicle to be autonomously, or semi-autonomously, controlled using sensing, steering, and/or braking technology. When the ADAS is activated, the steering wheel is not required for vehicle control in some situations. Retraction of the steering wheel and steering shaft toward, and possibly into, the instrument panel (e.g., dash) greatly enhances user comfort by providing a driver with more space when compared to typical ranges of repositioning available to a driver. The additional space provided facilitates additional workspace area or leg room, for example.
The embodiments described herein provide a manually retractable steering column which allows the steering wheel to be retracted to a greater extent while the vehicle is in an autonomous, or semi-autonomous, driving mode. The operating conditions described herein for the steering wheel are standard driving mode and an autonomous driving mode.
In the standard driving mode, the steering column assembly 10 is extended to a location that disposes the steering wheel in a position that is comfortably reached by a driver in a manner that allows the driver to fully handle and control the steering wheel. Adjustment over a first range of extended positions is possible in the standard driving mode, as shown in
Extension and retraction of the steering column assembly 10 refers to translation of a retractable portion 16 of the steering column assembly 10. The retractable portion 16 includes one or more components that are translatable. For example, in addition to the aforementioned steering wheel and the steering shaft, a moveable portion 18, which may also be referred to as an upper jacket in some embodiments, is translatable relative to a stationary portion 20, which may be referred to as a lower jacket in some embodiments. In the autonomous driving mode, a second range of translation, or retraction, is available to the driver, with the second range of translation being greater than the first range that is available in the standard driving mode, as shown in
The steering column assembly includes a member 36 that is operatively coupled to the moveable portion 18, and projects outwardly from the moveable portion 18. The member 36 projects through a slot 24 (also referred to herein as a slot path) defined by the stationary portion 20 of the steering column assembly 10 and partially constrained therein. In particular, the slot 24 is at least partially defined by a slot wall 26 having a first end wall 28 and a second end wall 30. The slot 24 extends substantially axially with respect to the longitudinal direction of the steering column assembly 10. The member 36 may include any variety of shapes, and may be a pin that may be substantially cylindrical, for example.
A gate 40 is operatively coupled to the stationary portion 20 proximate the second end wall 30 of the slot 24. The gate 40 may be formed of any shape, but includes an edge 42 regardless of the particular geometry. In the standard driving mode, the gate 40 is positioned to dispose at least a portion of the edge 42 within the slot 24 to limit the telescoping travel of the moveable portion 18 of the steering column assembly 10 by impeding the travel within the slot 24 of the member 36 protruding from the moveable portion 18. Specifically, the first end wall 28 and the edge 42 of the gate 40 define the above-described first range of translation. The boundary labeled with numeral 44 defines the full range of motion of the member 36, and therefore the moveable portion 18, in some embodiments (
The gate 40 is moveable to remove the edge 42 from the slot 24 to avoid impeding the member 36 from additional translation. Upon removal of the edge 42 from the slot 24, the second range of translation is available to a driver. The second range of translation is only available when the vehicle is operated in the autonomous driving mode. Upon initiation of the autonomous driving mode, the gate 40 is moved to remove the edge 42 from the slot 24. This is carried out with an actuator 46 operatively coupled to the gate 40. The actuator 46 may be any suitable actuator, such as a solenoid or electric motor, for example. The actuator 46 is in operative communication with the ADAS 48 to determine if the vehicle is in the autonomous driving mode or the standard driving mode. The operative communication between the actuator 46 and the ADAS 48 may be wired or wireless. If the ADAS is activated (i.e., vehicle is in autonomous driving mode), the ADAS 48 provides a signal to the actuator 46 to impart movement of the gate 40 to remove the edge 42 from the slot 24. The ADAS may include a sensor or any other position detection structure to determine if the moveable portion 18 of the steering column assembly 10 is in a retracted condition (i.e., stowed position of steering column assembly 10).
Movement of the gate 40 may be carried out in several contemplated manners. For example, the actuator 46 may translate the gate 40 within a plane or may rotate the gate 40. Furthermore, a combination of translation and rotation may occur. Irrespective of the particular movement of the gate 40, the edge 42 is removed from the slot 24 to allow the member 36 to translate further along the slot 24.
The gate 40 also includes a contoured recess 50 that retains the member 36. In some embodiments, the contoured recess 50 includes an angled portion or portion with curvature that allows the vehicle operator to manually withdraw the steering column assembly from the stowed position to an extended position. The driver simply manually unclamps the steering column assembly 10 and exerts a manual force on the moveable portion 18 in a direction away from the instrument panel. In the stowed position, the member 36 is positioned within the contoured recess 50, but is removable upon exertion of the manual force based on the geometry of the angled portion. In particular, the angled portion or portion with curvature facilitates movement of the gate 40 during sliding of the member 36 therealong. Such motion allows the member 36 to be released from the contoured recess 50 of the gate 40 to place the member 36 in the portion of the slot 24 that restricts motion to the first range of translation. In an embodiment having this angled feature, the driver can disengage the ADAS by moving the steering column from the stowed position. In other embodiments, an angled feature is not present. Such embodiments require the ADAS system to activate the gate 40 via the actuator 46 before the column may be released from the stowed position.
The embodiments described herein facilitate conditional stowing of manually adjusted steering columns and enables ADAS with stowable columns in vehicles which do not package power adjustable columns.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.
Number | Name | Date | Kind |
---|---|---|---|
4138167 | Ernst et al. | Feb 1979 | A |
4315117 | Kokubo et al. | Feb 1982 | A |
4337967 | Yoshida et al. | Jul 1982 | A |
4503300 | Lane, Jr. | Mar 1985 | A |
4503504 | Suzumura et al. | Mar 1985 | A |
4561323 | Stromberg | Dec 1985 | A |
4691587 | Farrand et al. | Sep 1987 | A |
4836566 | Birsching | Jun 1989 | A |
4921066 | Conley | May 1990 | A |
4962570 | Hosaka et al. | Oct 1990 | A |
4967618 | Matsumoto et al. | Nov 1990 | A |
4976239 | Hosaka | Dec 1990 | A |
5240284 | Takada et al. | Aug 1993 | A |
5295712 | Omura | Mar 1994 | A |
5319803 | Allen | Jun 1994 | A |
5488555 | Asgari | Jan 1996 | A |
5618058 | Byon | Apr 1997 | A |
5668721 | Chandy | Sep 1997 | A |
5690362 | Peitsmeier et al. | Nov 1997 | A |
5765116 | Wilson-Jones et al. | Jun 1998 | A |
5893580 | Hoagland et al. | Apr 1999 | A |
5911789 | Keipert et al. | Jun 1999 | A |
6070686 | Pollmann | Jun 2000 | A |
6170862 | Hoagland et al. | Jan 2001 | B1 |
6227571 | Sheng | May 2001 | B1 |
6301534 | McDermott, Jr. | Oct 2001 | B1 |
6354622 | Ulbrich et al. | Mar 2002 | B1 |
6360149 | Kwon et al. | Mar 2002 | B1 |
6373472 | Palalau et al. | Apr 2002 | B1 |
6381526 | Higashi et al. | Apr 2002 | B1 |
6390505 | Wilson | May 2002 | B1 |
6578449 | Anspaugh et al. | Jun 2003 | B1 |
6612393 | Bohner et al. | Sep 2003 | B2 |
6819990 | Ichinose | Nov 2004 | B2 |
7021416 | Kapaan et al. | Apr 2006 | B2 |
7048305 | Muller | May 2006 | B2 |
7062365 | Fei | Jun 2006 | B1 |
7295904 | Kanevsky et al. | Nov 2007 | B2 |
7308964 | Hara et al. | Dec 2007 | B2 |
7428944 | Gerum | Sep 2008 | B2 |
7461863 | Muller | Dec 2008 | B2 |
7495584 | Sorensen | Feb 2009 | B1 |
7628244 | Chino et al. | Dec 2009 | B2 |
7719431 | Bolourchi | May 2010 | B2 |
7735405 | Parks | Jun 2010 | B2 |
7793980 | Fong | Sep 2010 | B2 |
7862079 | Fukawatase et al. | Jan 2011 | B2 |
7894951 | Norris et al. | Feb 2011 | B2 |
7909361 | Oblizajek et al. | Mar 2011 | B2 |
8002075 | Markfort | Aug 2011 | B2 |
8027767 | Klein et al. | Sep 2011 | B2 |
8055409 | Tsuchiya | Nov 2011 | B2 |
8069745 | Strieter et al. | Dec 2011 | B2 |
8079312 | Long | Dec 2011 | B2 |
8146945 | Born et al. | Apr 2012 | B2 |
8170725 | Chin et al. | May 2012 | B2 |
8260482 | Szybalski et al. | Sep 2012 | B1 |
8352110 | Szybalski et al. | Jan 2013 | B1 |
8479605 | Shavrnoch et al. | Jul 2013 | B2 |
8548667 | Kaufmann | Oct 2013 | B2 |
8606455 | Boehringer et al. | Dec 2013 | B2 |
8634980 | Urmson et al. | Jan 2014 | B1 |
8650982 | Matsuno et al. | Feb 2014 | B2 |
8670891 | Szybalski et al. | Mar 2014 | B1 |
8695750 | Hammond et al. | Apr 2014 | B1 |
8818608 | Cullinane et al. | Aug 2014 | B2 |
8825258 | Cullinane et al. | Sep 2014 | B2 |
8825261 | Szybalski et al. | Sep 2014 | B1 |
8843268 | Lathrop et al. | Sep 2014 | B2 |
8874301 | Rao et al. | Oct 2014 | B1 |
8880287 | Lee et al. | Nov 2014 | B2 |
8881861 | Tojo | Nov 2014 | B2 |
8899623 | Stadler et al. | Dec 2014 | B2 |
8909428 | Lombrozo | Dec 2014 | B1 |
8948993 | Schulman et al. | Feb 2015 | B2 |
8950543 | Heo et al. | Feb 2015 | B2 |
8994521 | Gazit | Mar 2015 | B2 |
9002563 | Green et al. | Apr 2015 | B2 |
9031729 | Lathrop et al. | May 2015 | B2 |
9032835 | Davies et al. | May 2015 | B2 |
9045078 | Tovar et al. | Jun 2015 | B2 |
9073574 | Cuddihy et al. | Jul 2015 | B2 |
9092093 | Jubner et al. | Jul 2015 | B2 |
9108584 | Rao et al. | Aug 2015 | B2 |
9134729 | Szybalski et al. | Sep 2015 | B1 |
9150200 | Urhahne | Oct 2015 | B2 |
9150224 | Yopp | Oct 2015 | B2 |
9164619 | Goodlein | Oct 2015 | B2 |
9174642 | Wimmer et al. | Nov 2015 | B2 |
9186994 | Okuyama et al. | Nov 2015 | B2 |
9193375 | Schramm et al. | Nov 2015 | B2 |
9199553 | Cuddihy et al. | Dec 2015 | B2 |
9227531 | Cuddihy et al. | Jan 2016 | B2 |
9233638 | Lisseman et al. | Jan 2016 | B2 |
9235111 | Davidsson et al. | Jan 2016 | B2 |
9235987 | Green et al. | Jan 2016 | B2 |
9238409 | Lathrop et al. | Jan 2016 | B2 |
9248743 | Enthaler et al. | Feb 2016 | B2 |
9260130 | Mizuno | Feb 2016 | B2 |
9290174 | Zagorski | Mar 2016 | B1 |
9290201 | Lombrozo | Mar 2016 | B1 |
9298184 | Bartels et al. | Mar 2016 | B2 |
9308857 | Lisseman et al. | Apr 2016 | B2 |
9308891 | Cudak et al. | Apr 2016 | B2 |
9333983 | Lathrop et al. | May 2016 | B2 |
9352752 | Cullinane et al. | May 2016 | B2 |
9360865 | Yopp | Jun 2016 | B2 |
20030046012 | Yamaguchi | Mar 2003 | A1 |
20030094330 | Boloorchi et al. | May 2003 | A1 |
20030227159 | Muller | Dec 2003 | A1 |
20040016588 | Vitale et al. | Jan 2004 | A1 |
20040046346 | Eki et al. | Mar 2004 | A1 |
20040099468 | Chernoff et al. | May 2004 | A1 |
20040129098 | Gayer et al. | Jul 2004 | A1 |
20040204808 | Satoh et al. | Oct 2004 | A1 |
20040262063 | Kaufmann et al. | Dec 2004 | A1 |
20050001445 | Ercolano | Jan 2005 | A1 |
20050081675 | Oshita et al. | Apr 2005 | A1 |
20050197746 | Pelchen et al. | Sep 2005 | A1 |
20050275205 | Ahnafield | Dec 2005 | A1 |
20060224287 | Izawa et al. | Oct 2006 | A1 |
20060244251 | Muller | Nov 2006 | A1 |
20070021889 | Tsuchiya | Jan 2007 | A1 |
20070029771 | Haglund et al. | Feb 2007 | A1 |
20070046003 | Mori et al. | Mar 2007 | A1 |
20070046013 | Bito | Mar 2007 | A1 |
20070241548 | Fong | Oct 2007 | A1 |
20070284867 | Cymbal et al. | Dec 2007 | A1 |
20080009986 | Lu et al. | Jan 2008 | A1 |
20080028884 | Monash | Feb 2008 | A1 |
20080238068 | Kumar et al. | Oct 2008 | A1 |
20090024278 | Kondo et al. | Jan 2009 | A1 |
20090256342 | Cymbal et al. | Oct 2009 | A1 |
20090276111 | Wang et al. | Nov 2009 | A1 |
20090292466 | McCarthy et al. | Nov 2009 | A1 |
20100152952 | Lee et al. | Jun 2010 | A1 |
20100222976 | Haug | Sep 2010 | A1 |
20100228417 | Lee et al. | Sep 2010 | A1 |
20100228438 | Buerkle | Sep 2010 | A1 |
20100280713 | Stahlin et al. | Nov 2010 | A1 |
20100286869 | Katch et al. | Nov 2010 | A1 |
20100288567 | Bonne | Nov 2010 | A1 |
20110098922 | Ibrahim | Apr 2011 | A1 |
20110153160 | Hesseling et al. | Jun 2011 | A1 |
20110167940 | Shavrnoch et al. | Jul 2011 | A1 |
20110187518 | Strumolo et al. | Aug 2011 | A1 |
20110266396 | Abildgaard et al. | Nov 2011 | A1 |
20110282550 | Tada et al. | Nov 2011 | A1 |
20120136540 | Miller | May 2012 | A1 |
20120205183 | Rombold | Aug 2012 | A1 |
20120209473 | Birsching et al. | Aug 2012 | A1 |
20120215377 | Takemura et al. | Aug 2012 | A1 |
20130002416 | Gazit | Jan 2013 | A1 |
20130087006 | Ohtsubo et al. | Apr 2013 | A1 |
20130158771 | Kaufmann | Jun 2013 | A1 |
20130218396 | Moshchuk et al. | Aug 2013 | A1 |
20130233117 | Read et al. | Sep 2013 | A1 |
20130325202 | Howard et al. | Dec 2013 | A1 |
20140028008 | Stadler et al. | Jan 2014 | A1 |
20140046542 | Kauffman et al. | Feb 2014 | A1 |
20140046547 | Kauffman et al. | Feb 2014 | A1 |
20140111324 | Lisseman et al. | Apr 2014 | A1 |
20140300479 | Wolter et al. | Oct 2014 | A1 |
20140309816 | Stefan et al. | Oct 2014 | A1 |
20150002404 | Hooton | Jan 2015 | A1 |
20150014086 | Eisenbarth | Jan 2015 | A1 |
20150032322 | Wimmer | Jan 2015 | A1 |
20150051780 | Hahne | Feb 2015 | A1 |
20150060185 | Feguri | Mar 2015 | A1 |
20150120142 | Park et al. | Apr 2015 | A1 |
20150210273 | Kaufmann et al. | Jul 2015 | A1 |
20150246673 | Tseng et al. | Sep 2015 | A1 |
20150251666 | Attard et al. | Sep 2015 | A1 |
20150283998 | Lind et al. | Oct 2015 | A1 |
20150324111 | Jubner et al. | Nov 2015 | A1 |
20150375769 | Abboud | Dec 2015 | A1 |
20160009332 | Sirbu | Jan 2016 | A1 |
20160075371 | Varunjikar et al. | Mar 2016 | A1 |
20160082867 | Sugioka et al. | Mar 2016 | A1 |
20160185387 | Kuoch | Jun 2016 | A1 |
20160200246 | Lisseman et al. | Jul 2016 | A1 |
20160200343 | Lisseman et al. | Jul 2016 | A1 |
20160200344 | Sugioka | Jul 2016 | A1 |
20160207538 | Urano et al. | Jul 2016 | A1 |
20160209841 | Yamaoka et al. | Jul 2016 | A1 |
20160229450 | Basting et al. | Aug 2016 | A1 |
20160231743 | Bendewald et al. | Aug 2016 | A1 |
20160244070 | Bendewald | Aug 2016 | A1 |
20160318540 | King | Nov 2016 | A1 |
20160318542 | Pattok et al. | Nov 2016 | A1 |
20160347347 | Lubischer | Dec 2016 | A1 |
20160347348 | Lubischer | Dec 2016 | A1 |
20160362084 | Martin et al. | Dec 2016 | A1 |
20160362117 | Kaufmann et al. | Dec 2016 | A1 |
20160362126 | Lubischer | Dec 2016 | A1 |
20160368522 | Lubischer | Dec 2016 | A1 |
20160375860 | Lubischer | Dec 2016 | A1 |
20160375923 | Schulz | Dec 2016 | A1 |
20160375925 | Lubischer et al. | Dec 2016 | A1 |
20160375926 | Lubischer et al. | Dec 2016 | A1 |
20160375927 | Schulz et al. | Dec 2016 | A1 |
20160375928 | Magnus | Dec 2016 | A1 |
20160375929 | Rouleau | Dec 2016 | A1 |
20160375931 | Lubischer | Dec 2016 | A1 |
20170029009 | Rouleau | Feb 2017 | A1 |
20170029018 | Lubischer | Feb 2017 | A1 |
20170113712 | Watz | Apr 2017 | A1 |
Number | Date | Country |
---|---|---|
1722030 | Jan 2006 | CN |
1736786 | Feb 2006 | CN |
101041355 | Sep 2007 | CN |
101596903 | Dec 2009 | CN |
102452391 | May 2012 | CN |
103419840 | Dec 2013 | CN |
19523214 | Jan 1997 | DE |
19923012 | Nov 2000 | DE |
10212782 | Oct 2003 | DE |
102005032528 | Jan 2007 | DE |
102005056438 | Jun 2007 | DE |
102006025254 | Dec 2007 | DE |
102010025197 | Dec 2011 | DE |
1559630 | Aug 2005 | EP |
1783719 | May 2007 | EP |
1932745 | Jun 2008 | EP |
2384946 | Nov 2011 | EP |
2426030 | Mar 2012 | EP |
2489577 | Aug 2012 | EP |
2604487 | Jun 2013 | EP |
1606149 | May 2014 | EP |
2862595 | May 2005 | FR |
3016327 | Jul 2015 | FR |
H05162652 | Jun 1993 | JP |
20100063433 | Jun 2010 | KR |
2006099483 | Sep 2006 | WO |
2010082394 | Jul 2010 | WO |
2010116518 | Oct 2010 | WO |
Entry |
---|
China Patent Application No. 201510204221.5 Second Office Action dated Mar. 10, 2017, 8 pages. |
CN Patent Application No. 201210599006.6 First Office Action dated Jan. 27, 2015, 9 pages. |
CN Patent Application No. 201210599006.6 Second Office Action dated Aug. 5, 2015, 5 pages. |
CN Patent Application No. 201310178012.9 First Office Action dated Apr. 13, 2015, 13 pages. |
CN Patent Application No. 201310178012.9 Second Office Action dated Dec. 28, 2015, 11 pages. |
CN Patent Application No. 201410089167 First Office Action and Search Report dated Feb. 3, 2016, 9 pages. |
EP Application No. 14156903.8 Extended European Search Report, dated Jan. 27, 2015, 10 pages. |
EP Application No. 14156903.8 Office Action dated Nov. 16, 2015, 4 pages. |
EP Application No. 14156903.8 Office Action dated May 31, 2016, 5 pages. |
EP Application No. 14156903.8 Partial European Search Report dated Sep. 23, 2014, 6 pages. |
EP Application No. 15152834.6 Extended European Search Report dated Oct. 8, 2015, 7 pages. |
European Application No. 12196665.9 Extended European Search Report dated Mar. 6, 2013, 7 pages. |
European Search Report for European Application No. 13159950.8; dated Jun. 6, 2013; 7 pages. |
European Search Report for related European Application No. 15152834.6, dated Oct. 8, 2015; 7 pages. |
Gillespie, Thomas D.; “Fundamentals of Vehicle Dynamics”; Society of Automotive Enginers, Inc.; published 1992; 294 pages. |
Kichun, et al.; “Development of Autonomous Car—Part II: A Case Study on the Implementation of an Autonomous Driving System Based on Distributed Architecture”; IEEE Transactions on Industrial Electronics, vol. 62, No. 8, Aug. 2015; 14 pages. |
Partial European Search Report for related European Patent Application No. 14156903.8, dated Sep. 23, 2014, 6 pages. |
Van Der Jagt, Pim; “Prediction of steering efforts during stationary or slow rolling parking maneuvers”; Jul. 2013, 20 pages. |
Varunjikar, Tejas; Design of Horizontal Curves With DownGrades Using Low-Order Vehicle Dynamics Models; A Theisis by T. Varunkikar; 2011; 141 pages. |