Fixed steering wheel system

Abstract

A steering system for a vehicle includes an upper shaft having a first distal end adapted to support a steering wheel on the upper shaft; a lower shaft; and a slidable sleeve selectively movable between an engaged position and a disengaged position wherein, when in the engaged position, the slidable sleeve is adapted to connect the upper shaft to the lower shaft and functionally connect the steering wheel to the steering system; and when in the disengaged position, the slidable sleeve is adapted to disengage the upper shaft from the lower shaft, functionally disconnect the steering wheel from the steering system, and secure the upper shaft and the steering wheel in the rest position.

Description

Fixed steering wheel system Technical Field

[0001] This disclosure generally relates to a steering system for a vehicle, and more specifically, to a system adapted to selectively 1) connect a steering wheel to the steering system, or 2) disconnect the steering wheel from the steering system and lock the steering wheel in a centered position. Background Technology

[0002] During autonomous operation of a vehicle, a steering wheel may not be necessary because the vehicle is autonomously controlled by the steering system and, under certain conditions, no input from the driver within the vehicle is required. During autonomous operation, steering wheel movement corresponding to autonomous steering may not be desired. Furthermore, unrestricted free-wheel movement of the steering wheel disengaged during autonomous operation is undesirable.

[0003] Therefore, while current systems and methods achieve their intended purpose, there is still a need for new and improved systems and methods for connecting the steering wheel to the steering system for manual driving situations, and selectively disconnecting the steering wheel from the steering system and locking the steering wheel in a stationary position during autonomous operation of the vehicle. Summary of the Invention

[0004] According to several aspects of this disclosure, a steering system for a vehicle includes: an upper shaft having a first distal end adapted to support a steering wheel on the upper shaft; a lower shaft; and a slidable sleeve selectively movable between an engaged position and a disengaged position. When in the engaged position, the slidable sleeve is adapted to connect the upper shaft to the lower shaft, functionally connecting the steering wheel to the steering system; and when in the disengaged position, the slidable sleeve is adapted to separate the upper shaft from the lower shaft, functionally disconnecting the steering wheel from the steering system and fixing the upper shaft and steering wheel in a stationary position.

[0005] According to another aspect, the lower shaft includes a cylindrical spline collar, a distal end of the lower shaft inserted into the spline collar, an outer surface of the lower shaft and an inner surface of the cylindrical spline collar, the outer surface of the lower shaft and the inner surface of the cylindrical spline collar being splined together, so that the lower shaft and the spline collar rotate integrally; the upper shaft has a cylindrical second distal end, and the spline collar is positioned within the second distal end of the upper shaft; the slidable sleeve is cylindrical and extends around the second distal end of the upper shaft, the outer surface of the upper shaft and the inner surface of the slidable sleeve being splined together, so that the upper shaft and the slidable sleeve rotate integrally; the second distal end of the upper shaft includes a plurality of flexible fingers. When the sliding sleeve moves to the disengaged position, a gap exists between the inner surface of the flexible finger at the second distal end of the upper shaft and the outer surface of the splined collar, and the splined collar and lower shaft can rotate relative to the upper shaft and the sliding sleeve, functionally disconnecting the steering wheel from the steering system. When the sliding sleeve moves to the engaged position, the inclined inner surface of the sliding sleeve pushes against the outer surface of the flexible finger, forcing the inner surface of the flexible finger to engage with the outer surface of the splined collar. The splined collar and lower shaft frictionally engage with the upper shaft, causing the lower and upper shafts to rotate as a unit, functionally connecting the steering wheel to the steering system.

[0006] According to another aspect, the slidable sleeve includes a flexible inwardly projecting tab located near a first distal end of the slidable sleeve, and the outer surface of the flexible finger of the upper shaft includes a radial notch. When the slidable sleeve is moved to the engaged position, the flexible inwardly projecting tab engages with the radial notch formed in the outer surface of the flexible finger to hold the slidable sleeve in the engaged position.

[0007] According to another embodiment, the steering system includes a fixed sleeve. A sliding sleeve, a second distal end of the upper shaft, a splined collar, and a distal end of the lower shaft are enclosed within the sleeve. The sleeve includes a radially inwardly extending pin. The sliding sleeve includes an axial groove formed within the second distal end of the sliding sleeve. When the sliding sleeve is in the disengaged position, the pin adapts to engage the axial groove of the sliding sleeve, preventing rotation of the sliding sleeve relative to the upper shaft.

[0008] According to another aspect, the spline collar includes a tab extending radially outward from the distal end of the spline collar. The sliding sleeve includes an axial recess formed within a first distal end of the sliding sleeve. When the sliding sleeve is in the engaged position, the tab of the spline collar engages the axial recess of the sliding sleeve. The engagement of the tab of the spline collar with the axial recess of the sliding sleeve prevents rotation of the spline collar and the lower shaft relative to the sliding sleeve and the upper shaft.

[0009] According to another embodiment, when the sliding sleeve is in the engaged position, the pin is positioned immediately adjacent to the second distal end of the sliding sleeve; when the sliding sleeve is in the disengaged position, the tab is positioned immediately adjacent to the first distal end of the sliding sleeve. During the transition movement of the sliding sleeve between the engaged and disengaged positions, the pin of the sheath engages with the axial groove formed in the second distal end of the sliding sleeve, and simultaneously, the tab of the spline collar engages with the axial notch formed in the first distal end of the sliding sleeve.

[0010] According to another aspect, the system also includes a bushing. This bushing is axially positioned inwardly from the second distal end and the flexible fingers of the upper shaft between the inner surface of the upper shaft and the outer surface of the spline collar. The bushing is adapted to allow the spline collar to rotate relative to the upper shaft when the slidable sleeve is in the disengaged position.

[0011] According to another aspect, the system also includes an axial retaining feature. This axial retaining feature is located between the inner surface of the upper shaft and the outer surface of the spline collar, and is adapted to prevent axial movement of the upper shaft relative to the spline collar.

[0012] According to several aspects of this disclosure, a method for operating a steering system within a vehicle to provide selective disengagement of a steering wheel from the steering system is disclosed. The steering system includes an upper shaft having a first distal end adapted to support a steering wheel on the upper shaft; a lower shaft; and a slidable sleeve selectively movable between an engaged position and a disengaged position. When in the engaged position, the slidable sleeve is adapted to connect the upper shaft to the lower shaft, functionally connecting the steering wheel to the steering system; and when in the disengaged position, the slidable sleeve is adapted to disconnect the upper shaft from the lower shaft, functionally disengaging the steering wheel from the steering system, and fixing the upper shaft and steering wheel in a stationary position. The method includes: the system controller receiving a request from a user in the vehicle to disengage the steering wheel from the steering system via a human machine interface (HMI) that communicates with the system controller of the steering system; using the system controller to disable the shift actuator in the vehicle and prevent the transmission in the vehicle from shifting from parking gear; sending a message to the user in the vehicle via the HMI indicating that the steering wheel is disengaging from the steering system and that both hands should remain off the steering wheel; and using the controller to move the sliding sleeve to the disengaged position.

[0013] According to another aspect, after receiving a request from a user to disengage the steering wheel from the steering system via the HMI, the method includes: verifying the user's authorization using the system controller; verifying whether the steering system is operable using the system controller; verifying whether the vehicle's transmission is in a parking state using the system controller; when the user is not authorized, stopping the disengagement of the steering wheel from the steering system and sending a message to the user; when the steering system is not operable, stopping the disengagement of the steering wheel from the steering system and sending a message to the user; and when the vehicle's transmission is not in a parking state, stopping the disengagement of the steering wheel from the steering system and sending a message to the user.

[0014] According to another aspect, the method further includes: measuring the torque applied to the steering wheel via communication with a torque sensor using a system controller before moving the sliding sleeve to the disengaged position; stopping the disengagement of the steering wheel from the steering system when torque is applied to the steering wheel, enabling the transmission to shift from parking gear and send a message to the user; and centering the steering wheel using the system controller when no torque is applied to the steering wheel.

[0015] According to another aspect, the method further includes: using a system controller to verify whether the steering wheel is centered via communication with a position sensor; when the steering wheel is not centered, using the system controller to measure the torque applied to the steering wheel via communication with a torque sensor; and when torque is applied to the steering wheel, repeatedly sending a message to the user in the vehicle via an HMI indicating that the steering wheel is disengaging from the steering system and that both hands should remain off the steering wheel; when torque is not applied to the steering wheel, stopping the disengagement of the steering wheel from the steering system, enabling the transmission to shift from parking gear and sending a message to the user that the steering system is blocked; and when the steering wheel is centered, continuing to use the controller to move the sliding sleeve to the disengaged position.

[0016] According to another aspect, the method further includes: after moving the sliding sleeve to the disengagement position using the system controller, measuring the amount of time taken to move the sliding sleeve to the disengagement position using the system controller; if the time taken to move the sliding sleeve to the disengagement position exceeds a predetermined threshold, stopping the disengagement of the steering wheel from the steering system and sending a message to the user that the disengagement was unsuccessful and that the steering wheel is being re-engaged with the steering system; and if the time taken to move the sliding sleeve to the disengagement position does not exceed the predetermined threshold, sending a message to the user via the HMI that the steering wheel has disengaged from the steering system and the vehicle is limited to autonomous operation; and disabling the manual driving mode of the vehicle using the system controller.

[0017] According to another aspect, the method further includes: the system controller receiving a request from a user in the vehicle to engage the steering wheel with the steering system via a human-machine interface (HMI) that communicates with the system controller of the steering system; using the system controller to disable the shift actuator in the vehicle and prevent the transmission in the vehicle from shifting from parking gear; sending a message to the user in the vehicle via the HMI indicating that the steering wheel is disengaging from the steering system and to keep both hands away from the steering wheel; and using the controller to move the sliding sleeve to the engagement position.

[0018] According to another aspect, after receiving a request from a user to engage the steering wheel from the steering system via an HMI, the method includes: verifying the user's authorization using a system controller; verifying whether the steering system is operable using a system controller; verifying whether the vehicle's transmission is in a parking state using a system controller; disengaging the steering wheel from the steering system and sending a message to the user when the user is unauthorized; disengaging the steering wheel from the steering system and sending a message to the user when the steering system is inoperable; and disengaging the steering wheel from the steering system and sending a message to the user when the vehicle's transmission is not in a parking state.

[0019] According to another aspect, the method further includes: centering the steering system using a system controller before moving the sliding sleeve to the engagement position; verifying whether the steering system is centered using the system controller; sending a message of engagement failure to the user when the steering system is not centered, stopping the centering of the steering system, stopping the engagement of the steering wheel with the steering system, and shifting the transmission from parking gear; and continuing to move the sliding sleeve to the engagement position when the steering system is centered.

[0020] According to another aspect, the method further includes: using a system controller to measure the amount of time taken to move the sliding sleeve to the engagement position; using the system controller to measure the amount of force required to move the sliding sleeve to the engagement position via communication with a force sensor; using the system controller to move the sliding sleeve back to the disengaged position when the amount of time taken to move the sliding sleeve to the engagement position exceeds a predetermined threshold, or when the amount of force required to move the sliding sleeve to the engagement position exceeds a predetermined threshold; and displaying a message via an HMI indicating that the steering wheel is engaged and all driving modes are activated when the amount of time taken to move the sliding sleeve to the engagement position does not exceed a predetermined threshold, and when the amount of force required to move the sliding sleeve to the engagement position does not exceed a predetermined threshold; and enabling the transmission to shift from parking gear.

[0021] According to another aspect, when the time taken to move the sliding sleeve to the engagement position exceeds a predetermined threshold, or the force required to move the sliding sleeve to the engagement position exceeds a predetermined threshold, and the sliding sleeve has been moved back to the disengaged position, the method further includes: using a system controller to measure the time taken to move the sliding sleeve back to the disengaged position; using the system controller to measure the force required to move the sliding sleeve back to the disengaged position via communication with a force sensor; when the time required to move the sliding sleeve back to the disengaged position exceeds the predetermined threshold, or the force required to move the sliding sleeve back to the disengaged position exceeds the predetermined threshold, displaying a message that the vehicle is inoperable via an HMI; and when the time required to move the sliding sleeve back to the disengaged position does not exceed the predetermined threshold, and the force required to move the sliding sleeve back to the disengaged position does not exceed the predetermined threshold, displaying a message via an HMI that the steering system needs maintenance, the steering wheel has disengaged from the steering system, and the vehicle is restricted to autonomous operation.

[0022] Further areas of application will become apparent from the description provided herein. It should be understood that these descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0023] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way.

[0024] Figure 1 is a schematic diagram of a vehicle having a steering system according to an exemplary embodiment of the present disclosure;

[0025] Figure 2 is a cross-sectional side view of the steering system;

[0026] Figure 3 is an enlarged view of a portion of Figure 2, showing the sliding sleeve in the engaged position;

[0027] Figure 4 is an enlarged view similar to Figure 3, in which the sliding sleeve is in the disengaged position;

[0028] Figure 5 is a schematic diagram of the cross-section taken along line 5-5 in Figure 3;

[0029] Figure 6 is a perspective view of the lower shaft, spline collar, upper shaft, and sliding sleeve of the steering system, in which the sliding sleeve is in the disengaged position, exposing multiple flexible finger-like components of the upper shaft;

[0030] Figure 7 is a cross-sectional side view showing a gap between the flexible fingers of the upper shaft and the spline collar when the sliding sleeve is in the disengaged position.

[0031] Figure 8 is a perspective view of the lower shaft, spline collar, upper shaft, and sliding sleeve of the steering system, wherein the sliding sleeve is in the engagement position and applies force to the flexible fingers of the upper shaft;

[0032] Figure 9 is a cross-sectional side view showing the engagement of the inner surface of the flexible fingers of the upper shaft with the outer surface of the spline collar when the sliding sleeve is in the engaged position.

[0033] Figure 10A is an enlarged view of a portion of Figure 3, as shown in the circled area marked "10A" in Figure 3;

[0034] Figure 10B is an enlarged view of a portion of Figure 4, as shown in the circled area marked "10B" in Figure 4;

[0035] Figure 11A is an enlarged view of a portion of Figure 3, as shown in the circled area marked "11A" in Figure 3;

[0036] Figure 11B is an enlarged view of a portion of Figure 4, as shown in the circled area marked "11B" in Figure 4.

[0037] Figure 12 is a schematic block diagram of the steering system;

[0038] Figure 13A is a first part of a flowchart illustrating a method according to an exemplary embodiment of the present disclosure;

[0039] Figure 13B is a second portion of a flowchart illustrating a method according to an exemplary embodiment of the present disclosure; and

[0040] Figure 13C is a third part of a flowchart illustrating a method according to an exemplary embodiment of the present disclosure.

[0041] The accompanying drawings are not necessarily drawn to scale, and some features may be enlarged or minimized, for example, to show details of specific components. In some cases, well-known components, systems, materials, or methods have not been described in detail to avoid obscuring this disclosure. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but only as the basis for the claims and as a representative basis for teaching those skilled in the art to apply this disclosure in different ways. Detailed Implementation

[0042] The following description is merely exemplary in nature and is not intended to limit this disclosure, its application, or its uses. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing technical fields, background art, summary of the invention, or the following detailed description. It should be understood that throughout the drawings, corresponding reference numerals denote similar or corresponding parts and features. As used herein, the term "module" means any hardware, software, firmware, electronic control components, processing logic, and / or processor device, individually or in any combination, including but not limited to: application-specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated, or grouped), and memory executing one or more software or firmware programs, combinational logic circuits, and / or other suitable components providing the described functionality. Although the drawings shown herein depict examples with certain element arrangements, additional intermediate elements, devices, features, or components may be present in actual embodiments. It should also be understood that the drawings are merely illustrative and may not be drawn to scale.

[0043] As used herein, the term "vehicle" is not limited to automobiles. While this article primarily describes the technology in the context of automobiles, the technology is not limited to automobiles. These concepts can be applied to a variety of applications, such as aircraft, ships, other vehicles, and consumer electronics components.

[0044] The provision of exemplary embodiments is intended to make this disclosure thorough and to fully convey the scope to those skilled in the art. Numerous specific details, such as examples of specific compositions, components, apparatuses, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, that exemplary embodiments may be embodied in many different forms, and none of them should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known techniques are not described in detail.

[0045] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may also be intended to include the plural forms unless the context clearly indicates otherwise. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of stated features, elements, compositions, steps, integrals, operations, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising” should be understood as a non-limiting term used to describe and claim the various embodiments presented herein, in some respects it may be understood alternatively as a more restrictive and limiting term, such as “consisting of” or “substantially consisting of”. Therefore, for any given embodiment describing a composition, material, component, element, feature, integral, operation, and / or process step, this disclosure also specifically includes embodiments consisting of, or substantially consisting of, the compositions, materials, components, elements, features, integrals, operations, and / or process steps listed therein. In the case of “consisting of…”, alternative embodiments exclude any additional compositions, materials, components, elements, features, integrals, operations, and / or process steps, while in the case of “substantially consisting of…”, any additional compositions, materials, components, elements, features, integrals, operations, and / or process steps that substantially affect the essential and novel characteristics are excluded from such embodiments; however, any compositions, materials, components, elements, features, integrals, operations, and / or process steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0046] Any method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. It should also be understood that additional or alternative steps may be employed unless otherwise stated.

[0047] When a component, element, or layer is referred to as being “on,” “joined to,” “connected to,” or “coupled to” another component or layer, it may be directly on, directly joined to, directly connected to, or directly coupled to the other component, element, or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as being “directly on,” “directly joined to,” “directly connected to,” or “directly coupled to” another component or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items.

[0048] Although the terms first, second, third, etc., may be used herein to describe various steps, elements, components, regions, layers, and / or portions, these steps, elements, components, regions, layers, and / or portions should not be limited by these terms unless otherwise stated. These terms may be used only to distinguish one step, element, component, region, layer, or portion from another. Terms such as “first,” “second,” and other numerical terms, when used herein, do not imply sequence or order unless the context clearly indicates otherwise. Therefore, the first step, element, component, region, layer, or portion discussed below may be referred to as the second step, element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0049] For ease of description, this document uses spatial or temporal relative terms such as “before,” “after,” “inside,” “outside,” “below,” “below,” “lower,” “above,” “upper,” etc., to describe the relationship of an element or feature to one or more other elements or features shown in the figures. In addition to the orientations depicted in the figures, spatial or temporal relative terms may be intended to cover different orientations of the device or system during use or operation.

[0050] Throughout this disclosure, numerical values ​​represent approximate measurements or limitations on ranges to cover minor deviations from a given value, and embodiments having approximately the mentioned value, as well as embodiments having the exact mentioned value. Except for the working examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified in all cases by the term "approximately," regardless of whether "approximately" actually appears before the numerical value. "Approximately" implies that the stated numerical value allows for some slight imprecision (accuracy achieved by some method; approximately or fairly close to the value; almost). If the imprecision provided by "approximately" is not understood in the art to have that general meaning, then "approximately" as used herein at least indicates a variation that may arise from common methods of measuring and using such parameters. For example, "approximately" with respect to percentages includes a variation of + / - 5%, "approximately" with respect to temperature includes a variation of + / - 5 degrees, and "approximately" with respect to distance includes + / - 10%. Additionally, the disclosure of ranges includes disclosing all values ​​throughout the range and further subdivisions of the range, including endpoints and subranges given for that range.

[0051] In addition, the disclosure of a range includes disclosing all values ​​within the entire range and further subdivisions of the range, including endpoints and subranges given for that range.

[0052] Example embodiments will now be described more fully with reference to the accompanying drawings. According to an exemplary embodiment, FIG1 illustrates an automated driving vehicle 10 having an associated steering system 24. Generally, the steering system 24 works in conjunction with other systems within the vehicle 10 to control the steering of the vehicle 10. The vehicle 10 generally includes a chassis 12, a body 14, front wheels 16, and rear wheels 18. The body 14 is arranged on the chassis 12 and generally surrounds the components of the vehicle 10. The body 14 and the chassis 12 may together form a frame. The front wheels 16 and the rear wheels 18 are each rotatably coupled to the chassis 12 near a corresponding corner of the body 14.

[0053] Vehicle 10 is an autonomous vehicle and a steering system 24 is incorporated into the autonomous vehicle 10. The autonomous vehicle 10 is, for example, a vehicle capable of being automatically controlled to transport passengers from one location to another. Vehicle 10 is depicted as a passenger car in the illustrated embodiment, but it should be understood that any other vehicle may be used, including trucks, SUVs, RVs, etc. In an exemplary embodiment, vehicle 10 is equipped with a so-called SAE Level 4 or higher level of automation system. Level 4 means "high automation," referring to the driving mode-specific performance of the autonomous driving system in various aspects of dynamic driving tasks, even if the human driver does not properly respond to intervention requests. Vehicle 10 can operate fully autonomously, and vehicle 10 can also be manually operated, with a driver within vehicle 10 controlling vehicle 10.

[0054] As shown in the figure, the vehicle 10 generally includes a propulsion system 20, a transmission system 22, a steering system 24, a braking system 26, a sensor system 28, an actuator system 30, at least one data storage device 32, a vehicle controller 34, and a communication system 36. In embodiments where the vehicle 10 is an electric vehicle, the transmission system 22 may be absent. In various embodiments, the propulsion system 20 may include an internal combustion engine, an electric motor (e.g., a traction electric motor), and / or a fuel cell propulsion system. The transmission system 22 is configured to transmit power from the propulsion system 20 to the front wheels 16 and / or the rear wheels 18 of the vehicle according to a selectable gear ratio. According to various embodiments, the transmission system 22 may include a stepped automatic transmission, a continuously variable transmission (CVT), or other suitable transmission. The braking system 26 is configured to provide braking torque to the front wheels 16 and the rear wheels 18 of the vehicle. In various embodiments, the braking system 26 may include friction brakes, brake-by-wire brakes, regenerative braking systems (e.g., electric motors), and / or other suitable braking systems. The steering system 24 affects the position of the front wheels 16 and / or the rear wheels 18.

[0055] The sensor system 28 includes one or more sensing devices 40a-40n that sense observable conditions of the external and / or internal environments of the autonomous vehicle 10. The sensing devices 40a-40n may include, but are not limited to, radar, lidar, global positioning system, optical camera, thermal camera, ultrasonic sensor, and / or other sensors.

[0056] The actuator system 30 includes one or more actuator devices 42a-42n that control one or more features of the vehicle 10, such as, but not limited to, the propulsion system 20, the transmission system 22, the steering system 24, and the braking system 26.

[0057] The vehicle controller 34 includes at least one processor 44 and a computer-readable storage device or medium 46. The at least one data processor 44 can be any custom or commercially available processor, central processing unit (CPU), graphics processing unit (GPU), auxiliary processor among a plurality of processors associated with the vehicle controller 34, semiconductor-based microprocessor (in the form of a microchip or chipset), macroprocessor, any combination thereof, or any device generally used for executing instructions. The computer-readable storage device or medium 46 can include volatile and non-volatile storage devices such as read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is persistent or non-volatile memory that can be used to store various operational variables when at least one data processor 44 is powered off. The computer-readable storage device or medium 46 can be implemented using any of a variety of known storage devices, such as PROM, EPROM, EEPROM, flash memory, or any other electrical, magnetic, optical, or combined storage device capable of storing data, some of which represents executable instructions, used by the controller 34 when controlling the vehicle 10.

[0058] Although only one controller 34 is shown in Figure 1, embodiments of the vehicle 10 may include any number of controllers 34 that communicate via any suitable communication medium or combination of communication media and cooperate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals to automatically control the functions of the autonomous vehicle 10.

[0059] The vehicle controller 34 is a non-general-purpose electronic control device that includes a pre-programmed digital computer or processor, memory or non-transitory computer-readable medium for storing data such as control logic, software applications, instructions, computer code, data, lookup tables, etc., and a transceiver [or input / output port]. Computer-readable medium includes any type of media that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of memory. "Non-transitory" computer-readable medium does not include wired, wireless, optical, or other communication links that transmit transient electrical signals or other signals. Non-transitory computer-readable medium includes media that can permanently store data and media that can store data and subsequently be rewritten (e.g., rewritable optical discs or erasable storage devices). Computer code includes any type of program code, including source code, object code, and executable code.

[0060] Referring to Figure 2, the steering system 24 includes an upper shaft 50 having a first distal end 52 adapted to support a steering wheel 54 on the upper shaft 50; a lower shaft 56; and a sliding sleeve 58 that can be selectively moved between an engaged position and a disengaged position, as indicated by arrow 60.

[0061] Referring to Figure 3, when in the engaged position, the sliding sleeve 58 moves toward the second distal end 62 of the upper shaft 50, as indicated by arrow 64, and is adapted to connect the upper shaft 50 to the lower shaft 56, functionally connecting the steering wheel 54 to the steering system 24. Referring to Figure 4, when in the disengaged position, the sliding sleeve 58 moves toward the first distal end 52 of the upper shaft 50, as indicated by arrow 66, and is adapted to disconnect the upper shaft 50 from the lower shaft 56, functionally disconnecting the steering wheel 54 from the steering system 24 and fixing the upper shaft 50 and the steering wheel 54 in a stationary position.

[0062] Referring to Figures 2, 3, 4, 5, and 6, in an exemplary embodiment, the lower shaft 56 includes a cylindrical spline collar 68, a distal end 70 of the lower shaft 56 inserted into the spline collar 68, an outer surface 72 of the lower shaft 56, and an inner surface 74 of the cylindrical spline collar 68, which are splined together, allowing the lower shaft 56 and the spline collar 68 to rotate integrally. The second distal end 62 of the upper shaft 50 is cylindrical, and the spline collar 68 is positioned within the second distal end 62 of the upper shaft 50. The slidable sleeve 58 is cylindrical and extends around the second distal end 62 of the upper shaft 50. The outer surface 76 of the upper shaft 50 and the inner surface 78 of the slidable sleeve 58 are splined together, allowing the upper shaft 50 and the slidable sleeve 58 to rotate integrally. Referring to Figures 4 and 5, the distal end 70 of the lower shaft 56 is coaxially positioned within a cylindrical spline collar 68, which is coaxially positioned within a cylindrical second distal end 62 of the upper shaft 50, which is coaxially positioned within a cylindrical sliding sleeve 58.

[0063] Referring to Figure 6, the second distal end 62 of the upper shaft 50 includes a plurality of flexible fingers 80. Referring to Figure 7, when the sliding sleeve 58 is in the disengaged position, a gap 82 exists between the inner surface 84 of the flexible fingers 80 of the second distal end 62 of the upper shaft 50 and the outer surface 86 of the splined collar 68, and the splined collar 68 and the lower shaft 56 are rotatable relative to the upper shaft 50 and the sliding sleeve 58, functionally disconnecting the steering wheel 54 from the steering system 24.

[0064] Referring to Figures 8 and 9, as the sliding sleeve 58 moves toward the engagement position, as indicated by arrow 88, the inclined inner surface 90 of the sliding sleeve 58 pushes against the outer surface 92 of the flexible finger 80 (as indicated by arrow 94), forcing the inner surface 84 of the flexible finger 80 to engage with the outer surface 86 of the splined collar 68 (as indicated by arrow 96), wherein the splined collar 68 and the lower shaft 56 are frictionally engaged with the upper shaft 50, causing the lower shaft 56 and the upper shaft 50 to rotate as a unit, functionally connecting the steering wheel 54 to the steering system 24. In the non-bent position, the flexible finger 80 is naturally spaced from the outer surface 86 of the splined collar 68, thereby forming a gap 82 therebetween. The outer surface 92 of each flexible finger 80 is inclined corresponding to the inclined inner surface 90 of the sliding sleeve 58, such that when the sliding sleeve 58 moves toward the engagement position (as indicated by arrow 88), the sliding sleeve 58 pushes the flexible finger 80 (as indicated by arrow 94) and deflects the flexible finger 80 inward to contact the outer surface 86 of the spline collar 68. In an exemplary embodiment, the inner surface 84 of the flexible finger 80 and the outer surface 86 of the spline collar 68 have the following surface finish: when the inner surface 84 of the flexible finger 80 and the outer surface 86 of the spline collar 68 are pushed together, the frictional engagement between the inner surface 84 of the flexible finger 80 and the outer surface 86 of the spline collar 68 is sufficient to transfer the input load from the steering wheel 54 and the upper shaft 50 to the spline collar 68 and the lower shaft 56, effectively locking the upper shaft 50 to the lower shaft 56, and functionally connecting the steering wheel 54 to the steering system 24.

[0065] Referring to Figures 10A and 10B, in an exemplary embodiment, the slidable sleeve 58 includes a flexible inwardly projecting tab 98 located near a first distal end 100 of the slidable sleeve 58, and the outer surface 92 of the flexible finger 80 of the upper shaft 50 includes a radial notch 102, wherein, when the slidable sleeve 58 is moved to the engaged position, as shown in Figure 10A, the flexible inwardly projecting tab 98 engages the radial notch 102 formed in the outer surface 92 of the flexible finger 80 to hold the slidable sleeve 58 in the engaged position. When the steering system 24 is actuated to move the slidable sleeve 58 from the engaged position to the disengaged position, once sufficient force is applied to move the slidable sleeve 58, the flexible inwardly projecting tab 98 adapts to bend radially outward (as indicated by arrow 104), disengaging the flexible inwardly projecting tab 98 from the radial notch 102 of the flexible finger 80, allowing the slidable sleeve 58 to move from the engaged position to the disengaged position (as indicated by arrow 106). Under normal operating conditions, no external force will remove the flexible inward tab 98 from the radial notch 102, thus holding the slidable sleeve 58 in the engaged position until selectively and intentionally moved towards the disengaged position. A smaller force will tend to act on the slidable sleeve 58 to move it towards the disengaged position, which is proportional to the angle of the tapered surface. Because of the steep angle between the tapered surfaces of the slidable sleeve 58 and the upper shaft 50, the force is very small. The tab 98 is present to prevent a small force from causing the frictional engagement between the slidable sleeve 58 and the upper shaft 50 to disengage.

[0066] In an exemplary embodiment, the steering system 24 includes a fixed sleeve 108, a sliding sleeve 58, a second distal end 62 of an upper shaft 50, a spline collar 68, and a distal end 70 of a lower shaft 56 enclosing within the sleeve 108. The sleeve 108 includes a radially inwardly extending pin 110, and the sliding sleeve 58 includes an axial groove 112 formed within the second distal end 114 of the sliding sleeve 58. Referring to FIG11A, when the sliding sleeve 58 is in the engaged position, the pin 110 does not engage with the axial groove 112, allowing the upper shaft 50 and the sliding sleeve 58 to rotate according to input from the steering wheel 54. Referring to FIG11B, when the sliding sleeve 58 is in the disengaged position, the pin 110 adapts to engage the axial groove 112 of the sliding sleeve 58, preventing rotation of the sliding sleeve 58 and the upper shaft 50. Therefore, when the sliding sleeve 58 is moved to the disengaged position, the upper shaft 50 and the steering wheel 54 are locked in a stationary position. In an exemplary embodiment, the axial groove 112 is positioned such that when the pin 110 engages with the axial groove 112, the steering wheel 54 remains stationary in a centered position. To achieve this, the steering system 24 is adapted to center the steering system 24 and the steering wheel 54 before moving the sliding sleeve 58 to the disengaged position, while engaging the sliding sleeve 58, as will be discussed further below.

[0067] In another exemplary embodiment, referring again to Figures 10A and 10B, the spline collar 68 includes a tab 116 extending radially outward from the distal end 118 of the spline collar 68, and the slidable sleeve 58 includes an axial recess 120 formed within a first distal end 100 of the slidable sleeve 58, wherein, referring to Figure 10A, when the slidable sleeve 58 is in the engaged position, the tab 116 of the spline collar 68 engages the axial recess 120 of the slidable sleeve 58. The engagement of the tab 116 of the spline collar 68 with the axial recess 120 of the slidable sleeve 58 prevents the spline collar 68 and the lower shaft 56 from rotating relative to the slidable sleeve 58 and the upper shaft 50. Therefore, if the frictional engagement between the inner surface 84 of the flexible finger 80 of the upper shaft 50 and the outer surface 86 of the splined collar 68 slides, the engagement of the tab 116 of the splined collar 68 with the axial recess 120 of the sliding sleeve 58 prevents the sliding sleeve 58 and the upper shaft 50 from rotating relative to the splined collar 68 and the lower shaft 56, maintaining the connection between the steering wheel 54 and the steering system 24. Referring to FIG10B, when the sliding sleeve 58 is in the disengaged position, the tab 116 of the splined collar 68 disengages from the axial recess 120 formed in the first distal end 100 of the sliding sleeve 58, and thereby, the sliding sleeve 58 and the upper shaft 50 are rotatedly separated from the splined collar 68 and the lower shaft 56.

[0068] In an exemplary embodiment, when the slidable sleeve 58 is in the engaged position, the pin 110 is positioned adjacent to the second distal end 114 of the slidable sleeve and disengages from the axial groove 112 formed therein; while when the slidable sleeve 58 is in the disengaged position, the tab 116 of the spline collar 68 is positioned adjacent to the first distal end 100 of the slidable sleeve 58 and disengages from the axial recess 120 formed therein. Therefore, during the transition movement of the slidable sleeve 58 between the engaged and disengaged positions, the pin 110 of the sheath 108 engages with the axial groove 112 formed in the second distal end 114 of the slidable sleeve 58, and simultaneously, the tab 116 of the spline collar 68 engages with the axial recess 120 formed in the first distal end 100 of the slidable sleeve 58. As the slidable sleeve 58 moves from the engaged position to the disengaged position, the pin 110 engages the axial groove 112 before the tab 116 disengages from the axial recess 120, and when the slidable sleeve 58 reaches the fully disengaged position, the pin 110 is fully engaged within the axial groove 112 and the tab 116 disengages from the recess 120. Correspondingly, as the slidable sleeve moves from the disengaged position to the engaged position, the tab 116 engages the axial recess 120 before the pin 110 disengages from the axial groove 112, and when the slidable sleeve 58 reaches the fully engaged position, the tab 116 is fully engaged with the axial recess 120 and the pin 110 disengages from the axial groove 112.

[0069] Referring again to FIG4, in another exemplary embodiment, the steering system 24 further includes a bushing 122 axially positioned inwardly from the second distal end 62 of the upper shaft 50 and the flexible finger 80 between the inner surface 124 of the upper shaft 50 and the outer surface 86 of the spline collar 68. The bushing 122 is adapted to support the upper shaft 50 on the spline collar 68 and allow the spline collar 68 to rotate relative to the upper shaft 50 when the slidable sleeve 58 is in the disengaged position.

[0070] Referring again to FIG4, in another exemplary embodiment, the steering system 24 further includes an axial retaining feature 126 positioned between the inner surface 124 of the upper shaft 50 and the outer surface 86 of the spline collar 68, and adapted to prevent axial movement of the upper shaft 50 relative to the spline collar 68. As shown, the axial retaining feature 126 includes a ring simultaneously positioned within a radial groove formed in the inner surface 124 of the upper shaft 50 and within a radial groove formed in the outer surface 86 of the spline collar 68.

[0071] Referring to Figure 2, the steering system 24 also includes an actuator 128 adapted to actuate a link 130 that engages an outward-facing radial notch 132 formed within a sliding sleeve 58 to selectively move the sliding sleeve 58 back and forth between an engaged position and a disengaged position. The actuator may be motorized, such as a linear motor, or may be a manually operated lever. Those skilled in the art will understand that the actuator can be any suitable structure or device adapted to selectively move the sliding sleeve 58 back and forth.

[0072] Referring to Figure 12, the steering system 24 includes an occupant monitoring system 134 and a human-machine interface (HMI) 136. The occupant monitoring system 134 is adapted to capture images of the user in the vehicle 10 to help identify the user and, by the system controller 36, to determine user authorization for using the steering system 24 to engage or disengage the steering wheel 54. The HMI 136 is adapted to allow communication between the user and the system controller 36 and to display the status of operating messages to the user. The plurality of sensors 40a-40n includes at least a steering wheel torque sensor 138 adapted to measure the amount of torque applied to the steering wheel 54, and a steering wheel position sensor 140 adapted to determine the angular position of the steering wheel 54.

[0073] Referring to Figures 13A, 13B, and 13C, a method 200 for operating a steering system 24 within a vehicle 10 to provide selective disengagement of a steering wheel 54 from the steering system 24, according to an exemplary embodiment of the present disclosure, includes: starting at block 202, where a sliding sleeve 58 of the steering system is in an engaged position and the vehicle 10 is operating in manual operation mode; moving to block 204, where a system controller 36 receives a request from a user within the vehicle 10 to disengage the steering wheel 54 from the steering system 24 via a human-machine interface (HMI) 136 communicating with the system controller 36 of the steering system 24. This request may be associated with a user's request to switch to an autonomous operation mode of the vehicle 10, where engagement of the steering wheel 54 with the steering system 24 is not necessary and may not be desired.

[0074] Method 200 further includes: moving to block 206, disabling the shift actuator 142 within the vehicle 10 using the system controller 36, and preventing the transmission 22 within the vehicle 10 from shifting from parking gear. This ensures that the vehicle 10 does not shift from parking gear during transitions between manual and autonomous operating modes. Moving to block 208, method 200 includes: sending a message via HMI 136 to a user within the vehicle 10 indicating that the steering wheel 54 is disengaging from the steering system 24 and instructing the user to keep both hands off the steering wheel 54; and moving to block 210, moving the sliding sleeve 58 to the disengaged position using the system controller 36. Moving the sliding sleeve includes actuating actuator 128 by the system controller 36 to move the sliding sleeve 58 using the linkage 130.

[0075] In an exemplary embodiment, method 200 further includes: after receiving a request from a user via HMI 136 at block 204 to disengage the steering wheel 54 from the steering system 24, moving to block 212 to verify the user's authorization using system controller 36. System controller 36 uses data collected by occupant monitoring system 134 and data received from the user by HMI 136 to determine that the user is authorized to switch between manual operation mode and autonomous operation mode of vehicle 10.

[0076] If at box 212, the system controller 36 determines that the user is not authorized, then moves to box 214, where method 200 includes: aborting the disengagement of the steering wheel 54 from the steering system 24 and sending a message to the user that the user is not authorized to perform such an operation; then method 200 returns to box 202, where the vehicle 10 continues to be operated in manual mode.

[0077] If at box 212 the system controller 36 determines that the user is authorized, then the process moves to box 216, where method 200 includes: using the system controller 36 to verify that the steering system 24 is operable. The system controller 24 receives data from multiple sensors 40a-40n within the vehicle to determine that all aspects of the steering system 24 are functioning correctly.

[0078] If at box 216, the system controller 36 determines that the steering system 24 is inoperable, then moves to box 218, where method 200 includes: disengaging the steering wheel 54 from the steering system 24 and sending a message to the user that operation is unavailable, and then method 200 returns to box 202, where the vehicle 10 continues to be operated in manual mode.

[0079] If at box 216 the system controller 36 determines that the steering system 24 is operable, then move to box 220, and method 200 includes: using the system controller 36 to verify that the transmission 22 of the vehicle 10 is in park.

[0080] If, at box 220, the system controller 36 determines that the transmission 22 is not in park, the process moves to box 222, and method 200 includes: disengaging the steering wheel 54 from the steering system 36, sending a message to the user that the transmission 22 is not in park, and instructing the user to shift the transmission 22 into park. This message remains displayed until the system controller 36 determines, via communication with multiple sensors 40a-40n, that the transmission 22 is in park. Once the system controller 36 determines that the transmission 22 is in park, the method proceeds to box 206, where the shifter is disabled, to box 208, where a message is sent to the user, and to box 210, where the sliding sleeve 58 moves to the disengaged position.

[0081] In another exemplary embodiment, method 200 further includes: before moving the slidable sleeve 58 to the disengaged position, moving to block 223 to measure the torque applied to the steering wheel 54 via communication with the steering wheel torque sensor 138 using the system controller 36; and when the torque is applied to the steering wheel 54, moving to block 224 to stop the disengagement of the steering wheel 54 from the steering system 24; and moving to block 226 to enable the transmission 22 to shift from parking gear and send a message to the user, and returning to block 202, where the vehicle 10 continues to be operated in manual mode.

[0082] In an exemplary embodiment, if torque is detected at block 223, the system controller 36 returns to block 208 and continues displaying a message instructing the user to keep both hands away from the steering wheel 54. If the message is ignored for less than a predetermined time length at block 228, the method returns to block 208 and continues displaying the message. If the message is ignored for more than a predetermined time length at block 228, method 200 proceeds to blocks 224 and 226. If no torque is applied to the steering wheel 54 at block 223, method 200 includes moving to block 230 and centering the steering wheel 54 using the system controller 36. As previously stated, in order to switch back and forth between engagement and disengagement of the steering wheel 54 and the steering system 24, the steering system 24 and the steering wheel 54 must be in a centered position. Therefore, the steering system 24 and the steering wheel 54 must be centered before the sliding sleeve 58 is moved at block 210.

[0083] Moving to box 232, method 200 includes: verifying whether the steering wheel 54 is centered via communication with the steering wheel position sensor 140 using the system controller 36. If the steering wheel 54 is not centered at box 232, then moving to box 234, method 200 includes: measuring the torque applied to the steering wheel 54 via communication with the torque sensor 138 using the system controller 36. If torque is applied to the steering wheel 54 at box 234, method 200 returns to box 208 and repeatedly sends a message to the user inside the vehicle 10 via the HMI 136 indicating that the steering wheel 54 is disengaging from the steering system 24 and that both hands are off the steering wheel 54. If torque is not applied to the steering wheel 54 at box 234, method 200 includes: moving to box 236 to abort disengagement of the steering wheel 54 from the steering system 24; moving to box 238 to shift the transmission 22 from park; and moving to box 240 to send a message to the user that the steering system is blocked, and returning to box 202, wherein the vehicle 10 continues to be operated in manual mode. In another exemplary embodiment, the method includes moving to box 242 to prevent future requests to disengage the steering wheel 54.

[0084] If at frame 232, the system controller 36 determines that the steering wheel 54 is centered, then method 200 proceeds to frame 210, and the controller 36 moves the sliding sleeve 58 to the disengaged position.

[0085] Referring to Figure 13B, after the sliding sleeve 58 is moved to the disengaged position using the system controller 36 at box 210, method 200 further includes: moving to box 244 and using the system controller 36 to measure the amount of time taken to move the sliding sleeve 58 to the disengaged position. If at box 244 the amount of time taken to move the sliding sleeve 58 to the disengaged position exceeds a predetermined threshold, then moving to box 246, method 200 includes: stopping the disengagement of the steering wheel 54 from the steering system 24; moving to box 248 and sending a message to the user that the disengagement was unsuccessful and that the steering wheel 54 is being re-engaged to the steering system 24; and moving to box 250 and using the system controller 36 to move the sliding sleeve 58 back to the engaged position.

[0086] If the amount of time taken to move the slidable sleeve 58 to the disengaged position at box 244 does not exceed a predetermined threshold, then method 200 includes: moving to box 252 to send a message to the user via HMI 136 that the steering wheel 54 has been disengaged from the steering system 24 and the vehicle 10 is restricted to autonomous operation; and moving to box 254 to disable the manual driving mode of the vehicle 10 using system controller 36.

[0087] In another exemplary embodiment, at block 255, where the sliding sleeve 58 of the steering system 24 is in the disengaged position and the vehicle 10 is operating in autonomous mode; moving to block 256, the system controller 36 receives a request from a user within the vehicle 10 via a human-machine interface (HMI) 136 communicating with the system controller 36 of the steering system 24 to engage the steering wheel 54 with the steering system 24, enabling manual operation of the vehicle 10. This request may be associated with a user's request to switch to manual operation mode of the vehicle 10, where engagement of the steering wheel 54 with the steering system 24 is necessary.

[0088] Method 200 further includes moving to block 258 to disable the shift actuator 142 within the vehicle 10 using system controller 36, and preventing the transmission 22 within the vehicle 10 from shifting from parking gear. This ensures that the vehicle 10 does not shift from parking gear during transitions between manual and autonomous operating modes. Moving to block 260, method 200 includes: sending a message via HMI 136 to a user within the vehicle 10 indicating that the steering wheel 54 is engaged with the steering system 24 and instructing the user to keep both hands off the steering wheel 54; and moving to block 250 to move the sliding sleeve 58 to the engaged position using system controller 36. Moving the sliding sleeve includes actuating actuator 128 by system controller 36 to move linkage 130 to move the sliding sleeve 58.

[0089] In an exemplary embodiment, method 200 further includes: after receiving a request from a user to engage the steering wheel 54 from the steering system 24 via the HMI 136 at block 256, moving to block 262 to verify the user's authorization using the system controller 36. The system controller 36 uses data collected by the occupant monitoring system 134 and data received from the user by the HMI 136 to determine that the user is authorized to switch between manual operation mode and autonomous operation mode of the vehicle 10.

[0090] If at box 262, the system controller 36 determines that the user is not authorized, then moves to box 264, and method 200 includes: aborting the engagement of the steering wheel 54 with the steering system 24 and sending a message to the user that the user is not authorized to perform such an action, then method 200 returns to box 255 and continues to operate the vehicle 10 in autonomous mode.

[0091] If at box 262 the system controller 36 determines that the user is authorized, then the process moves to box 266, where method 200 includes: using the system controller 36 to verify that the steering system 24 is operable. The system controller 36 receives data from multiple sensors 40a-40n within the vehicle to determine that all aspects of the steering system 24 are functioning correctly.

[0092] If at box 266, the system controller 36 determines that the steering system 24 is inoperable, it moves to box 268, where method 200 includes: disengaging the steering wheel 54 from the steering system 24 and sending a message to the user that operation is unavailable. Method 200 then returns to box 255 and continues to operate the vehicle 10 in autonomous mode.

[0093] If at box 266 the system controller 36 determines that the steering system 24 is operable, then move to box 270, and method 200 includes: using the system controller 36 to verify that the transmission 22 of the vehicle 10 is in park.

[0094] If, at box 270, the system controller 36 determines that the transmission 22 is not in park, the process moves to box 272, where method 200 includes: disengaging the steering wheel 54 from the steering system 36 and sending a message to the user that the transmission 22 is not in park, and instructing the user to shift the transmission 22 into park. This message remains displayed until the system controller 36 determines, via communication with multiple sensors 40a-40n, that the transmission 22 is in park. Once the system controller 36 determines that the transmission 22 is in park, method 200 proceeds to box 258, where the shifter is disabled; proceeds to box 260, where a message is sent to the user; and proceeds to box 250, where the sliding sleeve 58 moves to the engaged position.

[0095] In another exemplary embodiment, method 200 includes moving to block 274 to center the steering wheel 54 using system controller 36. As previously stated, in order to switch back and forth between engagement and disengagement of the steering wheel 54 and the steering system 24, the steering system 24 and the steering wheel 54 must be in a centered position. Therefore, the steering system 24 and the steering wheel 54 must be centered before movement of the sliding sleeve 58 begins at block 250.

[0096] Moving to box 276, method 200 includes: using system controller 36 to verify whether steering wheel 54 is centered via communication with steering wheel position sensor 140. If steering wheel 54 is not centered at box 276, then moving to box 278 to disengage steering wheel 54 from steering system 24; moving to box 280 to disengage centering of steering wheel 54 and steering system 24; moving to box 282 to allow transmission 22 to shift from parking gear; and moving to box 284 to send a message to the user that the steering system is obstructed; and moving back to box 255 and continuing to operate vehicle 10 in autonomous mode.

[0097] If at frame 276 the system controller 36 determines that the steering wheel 54 is centered, then method 200 proceeds to frame 250, and the sliding sleeve 58 is moved to the engagement position using the controller 36.

[0098] Referring to Figure 13C, after the sliding sleeve 58 is moved to the engagement position at frame 250 using the system controller 36, method 200 further includes: moving to frame 286, measuring the amount of time taken to move the sliding sleeve 58 to the engagement position using the system controller 36, and measuring the magnitude of the force used by the system controller 36 to move the sliding sleeve 58 to the engagement position using the force sensor 144.

[0099] If, at block 286, the time taken to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, or the force required to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, then the process moves to block 288, and method 200 includes: using system controller 36 to move the slidable sleeve 58 back to the disengaged position. In an exemplary embodiment, if, at block 286, the time taken to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, or the force required to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, then at block 290, if engagement fails less than a predetermined number of attempts, method 200 includes: moving to block 292, sending a message via HMI 136 indicating engagement failure and a retry of engagement, wherein the method returns to block 250, where another attempt is made to move the slidable sleeve 58 to the engagement position. If, at box 290, the number of unsuccessful engagement attempts exceeds the predetermined number of attempts, then method 200 moves to box 288 and uses system controller 36 to move the sliding sleeve 58 back to the disengaged position.

[0100] If, at frame 286, the time taken to move the sliding sleeve 58 to the engaged position does not exceed a predetermined threshold, and the force required to move the sliding sleeve 58 to the engaged position does not exceed a predetermined threshold, then method 200 includes: moving to frame 294 to display a message via the HMI that the steering wheel 54 is engaged and all driving modes are enabled; moving to frame 296 to deactivate the reverse actuator 128, releasing the pushing pressure from the sliding sleeve 58 to reduce the magnitude of friction and force on the sliding sleeve 58 during operation of the vehicle 10; and moving to frame 298 to enable the transmission 22 to shift from parking gear. Method 200 then returns to frame 202, and the vehicle 10 is operated in manual mode with the sliding sleeve 58 engaged.

[0101] In another exemplary embodiment, if at block 286, the amount of time taken to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, or the magnitude of the force required to move the slidable sleeve 58 to the engagement position exceeds a predetermined threshold, and at block 288, the slidable sleeve 58 has been moved back to the disengaged position, the method 200 further includes: moving to block 300, measuring, using system controller 36, the amount of time taken to move the slidable sleeve 58 back to the disengaged position, and using system controller 36, via communication with force sensor 144, measuring, the magnitude of the force required to move the slidable sleeve 58 back to the disengaged position.

[0102] When the time taken to move the slidable sleeve 58 back to the disengaged position at box 300 exceeds a predetermined threshold, or the force required to move the slidable sleeve 58 back to the disengaged position exceeds a predetermined threshold, the process moves to box 302, and method 200 includes displaying a message that the vehicle 10 is inoperable via HMI 136.

[0103] If, at box 300, the time taken to move the slidable sleeve 58 back to the disengaged position does not exceed a predetermined threshold, and the force required to move the slidable sleeve 58 back to the disengaged position does not exceed a predetermined threshold, then method 200 includes: moving to box 304, displaying via HMI 136 a message that the steering system 24 requires maintenance, the steering wheel 54 is disengaged from the steering system 24, and the vehicle 10 is restricted to autonomous operation; method 200 returns to box 255 and the vehicle 10 is in autonomous operation.

[0104] The descriptions in this disclosure are merely exemplary in nature, and variations thereof that do not depart from the spirit and scope of this disclosure are intended to fall within its scope. Such variations should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. A steering system for a vehicle, comprising: An upper shaft having a first distal end adapted to support a steering wheel on the upper shaft; Lower shaft; And a sliding sleeve, selectively movable between an engaged position and a disengaged position, wherein: when in the engaged position, the sliding sleeve is adapted to connect the upper shaft to the lower shaft and functionally connect the steering wheel to the steering system; and when in the disengaged position, the sliding sleeve is adapted to: disconnect the upper shaft from the lower shaft and functionally disconnect the steering wheel from the steering system; and fix the upper shaft and the steering wheel in a stationary position.

2. The steering system according to claim 1, wherein: The lower shaft includes a cylindrical spline collar, a distal end of the lower shaft inserted into the spline collar, an outer surface of the lower shaft, and an inner surface of the cylindrical spline collar. The outer surface of the lower shaft and the inner surface of the cylindrical spline collar are splined together, so that the lower shaft and the spline collar rotate as a whole. The upper shaft has a cylindrical second distal end, and the spline collar is positioned within the second distal end of the upper shaft; the slidable sleeve is cylindrical and extends around the second distal end of the upper shaft, and the outer surface of the upper shaft and the inner surface of the slidable sleeve are splined together, allowing the upper shaft and the slidable sleeve to rotate integrally; the second distal end of the upper shaft includes a plurality of flexible fingers, wherein: when the slidable sleeve moves to the disengaged position, there is a gap between the inner surface of the flexible fingers at the second distal end of the upper shaft and the outer surface of the spline collar. The spline collar and the lower shaft are rotatable relative to the upper shaft and the slidable sleeve, functionally disconnecting the steering wheel from the steering system; and when the slidable sleeve moves to the engagement position, the inclined inner surface of the slidable sleeve pushes against the outer surface of the flexible finger, forcing the inner surface of the flexible finger to engage with the outer surface of the spline collar, wherein the spline collar and the lower shaft are frictionally engaged with the upper shaft, causing the lower shaft and the upper shaft to rotate as a unit, functionally connecting the steering wheel to the steering system.

3. The steering system according to claim 2, wherein, The slidable sleeve includes a flexible inward protrusion located near a first distal end of the slidable sleeve, and the outer surface of the flexible finger of the upper shaft includes a radial notch, wherein when the slidable sleeve moves to the engagement position, the flexible inward protrusion engages with the radial notch formed in the outer surface of the flexible finger to hold the slidable sleeve in the engagement position.

4. The steering system according to claim 3, wherein, The steering system includes a fixed sleeve, within which the slidable sleeve, the second distal end of the upper shaft, the spline collar, and the distal end of the lower shaft are enclosed. The sleeve includes a radially inwardly extending pin. The slidable sleeve includes an axial groove formed in the second distal end of the slidable sleeve, wherein, when the slidable sleeve is in the disengaged position, the pin adapts to engage the axial groove of the slidable sleeve to prevent the slidable sleeve from rotating with the upper shaft.

5. The steering system according to claim 4, wherein, The spline collar includes a tab extending radially outward from the distal end of the spline collar, and the slidable sleeve includes an axial recess formed within a first distal end of the slidable sleeve, wherein, when the slidable sleeve is in the engaged position, the tab of the spline collar engages the axial recess of the slidable sleeve, wherein the engagement of the tab of the spline collar with the axial recess of the slidable sleeve prevents the spline collar and the lower shaft from rotating relative to the slidable sleeve and the upper shaft.

6. The steering system according to claim 5, wherein: When the slidable sleeve is in the engaged position, the pin is positioned adjacent to the second distal end of the slidable sleeve; when the slidable sleeve is in the disengaged position, the tab is positioned adjacent to the first distal end of the slidable sleeve; and during the transition movement of the slidable sleeve between the engaged and disengaged positions, the pin of the sheath engages with the axial groove formed in the second distal end of the slidable sleeve, and simultaneously, the tab of the spline collar engages with the axial notch formed in the first distal end of the slidable sleeve.

7. The steering system of claim 6 further includes a bushing axially positioned inwardly from a second distal end of the upper shaft and the flexible finger between an inner surface of the upper shaft and an outer surface of the spline collar, the bushing being adapted to allow rotation of the spline collar relative to the upper shaft when the slidable sleeve is in the disengaged position.

8. The steering system of claim 7 further includes an axial retaining feature positioned between the inner surface of the upper shaft and the outer surface of the spline collar, and adapted to prevent axial movement of the upper shaft relative to the spline collar.

9. A method of operating a steering system within a vehicle to provide selective disengagement of a steering wheel from the steering system, the steering system comprising: An upper shaft having a first distal end adapted to support the steering wheel on the upper shaft; Lower shaft; A sliding sleeve is selectively movable between an engaged position and a disengaged position, wherein: when in the engaged position, the sliding sleeve is adapted to connect the upper shaft to the lower shaft, functionally connecting the steering wheel to the steering system; and when in the disengaged position, the sliding sleeve is adapted to disconnect the upper shaft from the lower shaft, functionally disengaging the steering wheel from the steering system, and fixing the upper shaft and the steering wheel in a stationary position; the method includes: a system controller receiving a request from a user within the vehicle to disengage the steering wheel from the steering system via a human-machine interface (HMI) communicating with a system controller of the steering system; using the system controller, disabling a shift actuator within the vehicle and preventing the transmission within the vehicle from shifting from parking gear; sending a message via the HMI to the user within the vehicle indicating that the steering wheel is disengaging from the steering system and that hands should remain off the steering wheel; and using the controller to move the sliding sleeve to the disengaged position.

10. The method according to claim 9, wherein, Upon receiving a request from the user to disengage the steering wheel from the steering system via the HMI, the method includes: verifying the user's authorization using the system controller; verifying the operability of the steering system using the system controller; verifying whether the vehicle's transmission is in a parking state using the system controller; suspending the disengagement of the steering wheel from the steering system and sending a message to the user when the user is unauthorized; suspending the disengagement of the steering wheel from the steering system and sending a message to the user when the steering system is inoperable; and suspending the disengagement of the steering wheel from the steering system and sending a message to the user when the vehicle's transmission is not in a parking state.

Images