WO2017032785A1

WO2017032785A1 - Dampening lateral vehicle disturbances

Info

Publication number: WO2017032785A1
Application number: PCT/EP2016/069953
Authority: WO
Inventors: James Kelly
Original assignee: Jaguar Land Rover Limited
Priority date: 2015-08-24
Filing date: 2016-08-24
Publication date: 2017-03-02
Also published as: GB2541664A; GB201515009D0

Abstract

The method (100) comprises receiving information relating to the operation of the vehicle (step 102), which may comprise receiving one or more electrical signals representative of that information. The method (100) further comprises determining whether one or more predetermined conditions are met based on the received information (step 104), the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible. And when at least certain of the one or more predetermined conditions are met, the method (100) still further comprises automatically dampening a lateral disturbance to the vehicle by stiffening a portion of a steering assembly of the vehicle (step 106).

Description

DAMPENING LATERAL VEHICLE DISTURBANCES

TECHNICAL FIELD

The present disclosure relates to dampening lateral vehicle disturbances and particularly, but not exclusively, to dampening lateral vehicle disturbances by stiffening a portion of a steering assembly of the vehicle. Aspects of the invention relate to a method, to a non- transitory computer-readable storage medium, to a system, to a vehicle, and to an electronic controller.

BACKGROUND

When negotiating a rough terrain, for example, a potholed or rutted driving surface when travelling off-road, a vehicle may experience both longitudinal and lateral disturbances. Such disturbances may adversely affect the comfort of the vehicle occupants and the composure of the vehicle.

Techniques have been developed to address the longitudinal disturbances. These techniques include controlling the amount brake torque being applied by the braking subsystem of the vehicle, the amount of drive torque being applied by the powertrain subsystem of the vehicle, or a combination of both to dampen the longitudinal disturbances. More particularly, one or more vehicle-related parameters may be monitored to detect or predict the occurrence of a longitudinal disturbance and in dependence on that detection or prediction, the braking and/or powertrain subsystem may be controlled accordingly to dampen that disturbance.

While steps have been taken to dampen longitudinal disturbances, lateral disturbances have not been addressed. Accordingly, it is an aim of the present invention to dampen lateral disturbances experienced by a vehicle and the occupants thereof as the vehicle traverses relatively rough (e.g., potholed, rutted) terrain. SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a method, a non-transitory computer- readable storage medium, a system, a vehicle, and an electronic controller as claimed in the appended claims.

According to one aspect of the invention, there is provided a method for dampening lateral disturbances to a vehicle. In an embodiment, the method comprises determining whether one or more predetermined conditions exist under which a lateral disturbance to the vehicle are possible, and when it is determined that at least certain of the predetermined condition(s) exist, automatically dampening a lateral disturbance by stiffening at least a portion of a steering assembly of the vehicle.

According to another aspect of the invention, there is provided a method for dampening lateral disturbances to a vehicle. The method comprises: receiving information relating to the operation of the vehicle; determining whether one or more predetermined conditions are met based on the received information, the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible; and when at least certain of the one or more predetermined conditions are met, automatically dampening a lateral disturbance to the vehicle by stiffening a portion of a steering assembly of the vehicle.

According to yet another aspect of the invention, there is provided a non-transitory, computer-readable storage medium storing instructions thereon that when executed by one or more electronic processors causes the one or more processors to carry out the method(s) described herein. According to a further aspect of the invention, there is provided a system for dampening lateral disturbances to a vehicle. In an embodiment, the system comprises means for determining whether one or more predetermined conditions exist under which a lateral disturbance to the vehicle is possible, and means for commanding the stiffening of at least a portion of a steering assembly of the vehicle to dampen a lateral disturbance to the vehicle when it is determined that at least certain of the one or more conditions are met.

According to a still further aspect of the invention, there is provided a system for dampening lateral disturbances to a vehicle. In an embodiment, the system comprises means for receiving information relating to the operation of the vehicle; means for determining whether one or more predetermined conditions are met based on the received information, the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible; and means for automatically commanding the stiffening of a portion of a steering assembly of the vehicle to dampen a lateral disturbance to the vehicle.

In an embodiment, the receiving, determining, and commanding means of the system comprise: an electronic processor having an electrical input for receiving the information relating to the operation of the vehicle; and an electronic memory device electrically coupled to the electronic processor and having instructions stored therein. The electronic processor is configured to access the memory device and to execute the instructions stored therein such that it is configured to: determine whether one or more predetermined conditions are met based on the information represented by the one or more received electrical signals; and automatically command the stiffening of a portion of the steering assembly of the vehicle when at least certain of the one or more conditions are met.

According to yet another aspect of the invention, there is provided an electronic controller for a vehicle having a storage medium associated therewith storing instructions that when executed by the controller causes the dampening of a lateral disturbance to the vehicle in accordance with the method of: determining whether one or more predetermined conditions exist under which a lateral disturbance to the vehicle is possible, and when it is determined that at least certain of the predetermined condition(s) exist, automatically dampening a lateral disturbance by stiffening at least a portion of a steering assembly of the vehicle.

According to still a further aspect of the invention, there is provided an electronic controller for a vehicle having a storage medium associated therewith storing instructions that when executed by the controller causes the dampening of a lateral disturbance to the vehicle in accordance with the method of: receiving information relating to the operation of the vehicle; determining whether one or more predetermined conditions are met based on the received information, the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible; and when at least certain of the one or more predetermined conditions are met, automatically dampening a lateral disturbance to the vehicle by stiffening a portion of a steering assembly of the vehicle. According to yet another aspect of the invention for which protection is sought, there is provided a vehicle comprising a system or electronic controller described herein.

Optional features of the various aspects of the invention are set out below in the dependent claims.

At least some embodiments of the present invention have the advantage that as a vehicle traverses a relatively rough terrain, for example, a potholed or rutted driving surface, adjustments may be automatically made to the stiffness of the steering assembly of the vehicle resulting in the dampening of lateral disturbances to the vehicle, and therefore, the occupant(s) thereof. As a result, lateral disturbances to the vehicle may be reduced or at least mitigated, thereby increasing the comfort of the vehicle occupants and/or the composure of the vehicle.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description or drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the following figures in which:

FIG. 1 is a side view of an illustrative embodiment of a vehicle having a plurality of subsystems, a plurality of sensors, and an electronic controller;

FIG. 2 is a schematic and block diagram of an illustrative embodiment of a system for a vehicle such as, for example, the vehicle illustrated in FIG. 1 ;

FIG. 3 is a schematic view of an illustrative embodiment of a steering subsystem of a vehicle, such as, for example, the vehicle illustrated in FIGS. 1 and 2; FIG. 4 is a diagram of a steering wheel for use with a vehicle, such as the vehicle illustrated in FIGS. 1 and 2; and

FIG. 5 is a flow diagram depicting various steps of an illustrative embodiment of a method for dampening lateral disturbances to a vehicle such as, for example, the vehicle illustrated in FIGS. 1 and 2. DETAILED DESCRIPTION

The system and method described herein may be used to automatically dampen lateral disturbances to a vehicle resulting from the vehicle's negotiation of a relatively rough terrain. In an embodiment, the present system and method determine whether one or more predetermined conditions exist under which a lateral disturbance to the vehicle is possible, and when it is determined that at least certain of that or those conditions exist, the system and method automatically dampen the lateral disturbance by stiffening (or commanding the stiffening of) a portion of a steering assembly of the vehicle.

References herein to a block such as a function block are to be understood to include reference to software code for performing the function or action specified in which an output is provided responsive to one or more inputs. The code may be in the form of a software routine or function called by a main computer program, or may be code forming part of a flow of code not being a separate routine or function. Reference to function blocks is made for ease of explanation of the manner of operation of a control system according to an embodiment of the present invention. With reference to FIGS. 1 and 2, there are shown some of the components of a vehicle 10 with which the present system and method may be used. Although the following description is provided in the context of the particular vehicle or vehicle arrangement/configuration illustrated in FIGS. 1 and 2, it will be appreciated that this vehicle/vehicle arrangement is merely an example and that other vehicles and/or vehicle arrangements may certainly be used instead. For instance, in various embodiments, the method and system described herein may be used with any type of vehicle having an automatic, manual, or continuously variable transmission, including traditional vehicles, hybrid electric vehicles (HEVs), extended-range electric vehicles (EREVs), battery electrical vehicles (BEVs), passenger cars, sports utility vehicles (SUVs), cross-over vehicles, and trucks, to cite a few possibilities. According to an embodiment, vehicle 10 generally includes a plurality of vehicle systems or subsystems 12, a plurality of vehicle sensors 14, and a vehicle control means in the form of an electronic controller 16 (which, in a non-limiting embodiment such as that described below, comprises a vehicle control unit (VCU) (i.e., VCU 16)), among any number of other components, systems, and/or devices that may or may not be illustrated or otherwise described herein.

Subsystems 12 of vehicle 10 may be configured to perform or control various functions and operations relating to the vehicle and, as illustrated in FIG. 2, may include any number of subsystems, for example, one or more of a powertrain subsystem 12a, a brake subsystem 12b, a driveline subsystem 12c, a chassis management subsystem 12d, and/or a steering subsystem 12e, to cite a few examples.

For the purposes of this invention, unless otherwise provided herein, each of the powertrain, brake, driveline, and chassis management subsystems, and the functionality corresponding thereto, is known in the art. As such, detailed descriptions will not be provided; rather, the structure and function of each identified subsystem 12 will be readily apparent to those having ordinary skill in the art.

Steering subsystem 12e, and the functionality corresponding thereto, is also generally known in the art. To summarize, however, FIG. 3 depicts one illustrative embodiment of a steering subsystem that may find application with the present invention. In such an embodiment, steering system 12e includes a steering assembly 18 comprising a rotatable steering column 20 coupled at a proximal end to a driver steering input device in the form of a steering wheel 22. At an opposed, distal end, steering column 20 is coupled to a combination of linked components comprising two or more linked components, for example, shafts 24a, 24b that are coupled to each other by a joint 26a. Shaft 24a is also coupled to steering column 20 by a joint 26b. In the illustrated embodiment, steering assembly 18 further comprises a pinion 28 operatively coupled (i.e., indirectly coupled) to steering column 20 through the linked components, and a steering member in the form of a rack or rack bar 30 is co-operable and operatively coupled (i.e., directly coupled) with pinion 28. It will be appreciated that as a result of the aforedescribed configuration and arrangement of steering assembly 18, rotary motion of steering wheel 22, and thus steering column 20, causes linear motion of rack bar 30, and linear motion of rack bar 30 causes rotary motion of steering column 20 and steering wheel 22. Further, in the illustrated embodiment, rack bar 30 is coupled via first and second tie rod assemblies 32a, 32b of steering assembly 18 to first and second wheels 34a, 34b of vehicle 10, such that linear motion of rack bar 30 causes first and second wheels 34a, 34b to be steered. Wheels 34a, 34b may thus be steered by rotation of steering wheel 22, which leads to rotation of steering column 20, which in turn causes linear movement of rack bar 30 and the steering of wheels 34a, 34b.

In embodiment, steering of wheels 34a, 34b is assisted by an actuator in the form of an electric steering assistance motor 36. Steering assistance motor 36 may be operative coupled, either directly or indirectly (e.g., through one or more gears), to rack 30. In such an embodiment steering subsystem 12e comprises an Electric Power Assisted Steering (EPAS or EPS) system, or vehicle 10 at least includes an EPAS system that is used in conjunction with steering subsystem 12e.

In addition to the components described above, in at least some embodiments or implementations, steering subsystem 12e may further include one or more braking devices 37 each coupled to a component of steering assembly 18, for example, one of steering column 20 or one of the linked components (e.g., shafts 24a, 24b). In such an embodiment, the braking device(s) are configured to apply a torque or force to the component to which it is coupled that opposes or is counter to a torque or force applied to the steering assembly by, for example, the vehicle wheels as vehicle 10 traverses a rough terrain, for example, a potholed or rutted driving surface.

As will be described in greater detail below, in an embodiment, though certainly not the only embodiment, steering subsystem 12e may further include control means in the form of an electronic controller or electronic control unit (ECU) 38 that is configured and operable to perform, or to contribute to the performance of, various functions, including one or more steps of the method described below. For example, in an embodiment, electronic controller 38 may be configured to receive information from, for example, one or more of sensors 14 described below and to control the operation of steering assistance motor 36 and/or a braking device 37 coupled to a component of steering assembly 18 (if applicable), etc., in dependence on that received information in order to stiffen at least a portion of steering assembly 18 to dampen possible lateral disturbances to vehicle 10 as vehicle 10 traverses rough terrain. Alternatively, some or all of this functionality may be performed by one or more other components of vehicle 10 in conjunction with steering subsystem 12e (e.g., VCU 16 and/or an electronic controller of another vehicle subsystem 12).

While a general description of one particular embodiment of steering subsystem 12e has been provided, it will be appreciated by those having ordinary skill in the art that other types/embodiments of steering subsystems may be used instead, including steering subsystems that operate substantially differently than that described above. For example, the present invention may find application with steer-by-wire steering subsystems and/or steering subsystems that comprise or include hydraulic power assisted steering systems, to cite a few possibilities. Accordingly, the present invention is not intended to be limited to any particular type of steering subsystem, but rather any suitable steering subsystem may be utilized. In an embodiment, one or more of subsystems 12 may be under at least a certain degree of control by VCU 16 (a detailed description of which will be provided below). In such an embodiment, those subsystems 12 are electrically coupled to, and configured for communication with, VCU 16 to provide feedback to VCU 16 relating to operational or operating parameters of the vehicle, as well as to receive instructions or commands from VCU 16. Taking steering subsystem 12e as an example, steering subsystem 12e may be configured to gather various types of information relating to the operation of the vehicle, such as, for example, steering wheel angle values, steering torque values, etc., and to communicate that information to VCU 16. This information may be gathered from, for example, one or more of vehicle sensors 14 described below that are part of or separate from steering subsystem 12e. Steering subsystem 12e may also receive commands from VCU 16 to adjust certain operating parameters thereof when, for example, a change in conditions dictates such a change (e.g., when the terrain being traversed by vehicle 10 becomes sufficiently rough or changes to a particular type of terrain, when a particular terrain response mode is selected by the driver via a user interface device within the passenger cabin of the vehicle, etc.). These commands may be received by electronic controller 38 of steering subsystem 12e, or by one or more other components of steering subsystem 12e in an instance where, for example, steering subsystem 12e does not include a dedicated controller (e.g., motor 36 or a motor controller associated therewith). Alternatively, subsystem 12e may be configured to determine a change in conditions and to make the appropriate adjustments in dependence thereon without involvement on the part of VCU 16. In any event, while the description above has been with particular reference to steering subsystem 12e, it will be appreciated that the same principles apply to each such other subsystem 12 that is configured to exchange information/commands with VCU 16 or directly with one another. As briefly described above with respect to steering subsystem 12e, each subsystem 12 may include a dedicated control means in the form of one or more electronic controllers (e.g., one or more electronic control units (ECUs)) configured to receive and execute instructions or commands provided by VCU 16, and/or to perform or control certain functionality independent from VCU 16. In such an embodiment, each electronic controller may comprise any suitable ECU, and may include a variety of electronic processing devices, memory devices, input/output (I/O) devices, and/or other known components, and perform various control and/or communication related functions.

In an embodiment, each electronic controller comprises one or more electronic processors each having one or more inputs and one or more outputs, and one or more electronic memory devices. By way of illustration, FIG. 3 depicts controller 38 having an electronic processor 40 and an electronic memory device 42. The electronic processor(s) may include any type of suitable electronic processor (e.g., a programmable microprocessor or microcontroller, an application specific integrated circuit (ASIC), etc.) that is configured to execute appropriate programming instructions for software, firmware, programs, algorithms, scripts, etc., to perform various functions associated with the subsystem 12 with which it corresponds.

The electronic memory device(s) of each controller may include any type of suitable electronic memory means and may store a variety of information and data. This includes, for example and without limitation: software; firmware; programs; algorithms; scripts; and other electronic instructions and information (e.g., threshold values, vehicle-related information, data structures, etc.) that, for example, are required or used to perform or cause to be performed one or more functions associated with the subsystem 12 with which the controller corresponds. In some embodiments, rather than all of the aforementioned information/data being stored in a single memory device, multiple memory devices may be provided. In an embodiment, each subsystem 12 has its own dedicated controller that may be electronically connected to other vehicle devices, modules, subsystems (e.g., controllers thereof), and components (e.g., sensors) via suitable vehicle communications and can interact with them when or as required. Alternatively, two or more subsystems 12 may share a single controller, or one or more subsystems 12 may comprise or be directly controlled by the VCU 16 itself. In an embodiment wherein a subsystem 12 communicates with VCU 16 and/or other subsystems 12, such communication may be facilitated via any suitable wired or wireless connection, such as, for example, a controller area network (CAN) bus, a system management bus (SMBus), a proprietary communication link, or through some other arrangement known in the art.

For purposes of this invention, and notwithstanding the above, it is to be understood that the electronic controller(s) or ECU(s) described herein, including that or those described below, may each comprise a control unit or computational device having one or more electronic processors. It will be appreciated that vehicle 10 and/or a subsystem 12 thereof may comprise a single control unit or electronic controller or alternatively different functions of the controller(s) may be embodied in, or hosted in, different control units or controllers. As used herein, the term "control unit" will be understood to include both a single control unit or controller and a plurality of control units or controllers collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause said controller(s) or control unit(s) to implement the control techniques described herein (including the method(s) described below). The set of instructions may be embedded in one or more electronic processors, or alternatively, may be provided as software to be executed by one or more electronic processor(s) (e.g., software stored in a suitable electronic memory device). For example, a first controller may be implemented in software run on one or more electronic processors, and one or more other controllers may also be implemented in software run on or more electronic processors, optionally the same one or more processors as the first controller. It will be appreciated, however, that other arrangements are also useful, and therefore, the present invention is not intended to be limited to any particular arrangement. In any event, the set of instructions described above may be provided as a computer program product and/or embedded in a computer-readable storage medium (e.g., a non-transitory storage medium) that may comprise any suitable mechanism for storing information in a form readable by a machine or electronic processors/computational device, including, without limitation: a magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g., CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

It will be appreciated that the foregoing represents only some of the possibilities with respect to the particular subsystems that may be included in vehicle 10, as well as the arrangement of those subsystems with VCU 16. Accordingly, it will be further appreciated that embodiments of vehicle 10 that include other or additional subsystems and subsystem/VCU arrangements remain within the spirit and scope of the present invention.

Vehicle sensors 14 may comprise any number of different sensors, components, devices, modules, systems, etc. In an embodiment, some or all of sensors 14 may provide subsystems 12 and/or VCU 16 with information or input that can be used by the present method, and as such, may be electrically coupled (e.g., via wire(s) or wirelessly) to, and configured for communication with, VCU 16, one or more subsystems 12 (e.g., steering subsystem 12e, or some other suitable device of vehicle 10. Sensors 14 may be configured to monitor, sense, detect, measure, or otherwise determine a variety of parameters and/or information relating to vehicle 10 and the operation and configuration thereof, and may include, for example and without limitation, any one or more of: wheel speed sensor(s); ambient temperature sensor(s); atmospheric pressure sensor(s); tyre pressure sensor(s); gyro sensor(s) to detect yaw, roll, and pitch of the vehicle; vehicle speed sensor(s); longitudinal acceleration sensor(s); engine torque sensor(s); driveline torque sensor(s); throttle valve sensor(s); steering angle sensor(s); steering torque sensor(s); steering wheel speed sensor(s); wheel torque sensor(s) (e.g., for measuring torque applied to steering assembly by one or more of the vehicle wheel(s)); gradient sensor(s); lateral acceleration sensor(s); brake pedal position sensor(s); brake pedal pressure sensor(s); brake pressure sensor(s); accelerator pedal position sensor(s); air suspension sensor(s) (i.e., ride height sensors); wheel position sensor(s); wheel articulation sensor(s); vehicle body vibration sensor(s); water detection sensor(s) (for both proximity and depth of wading events); transfer case HI-LO ratio sensor(s); air intake path sensor(s); vehicle occupancy sensor(s); longitudinal, lateral, and vertical motion sensor(s); camera(s) or other imaging device(s) for detecting characteristics of the terrain proximate the vehicle; and ground sensing radar unit(s), among others known in the art.

The sensors identified above, as well as any other sensors not specifically identified above but that may provide information that can be used by the present method, may be embodied in hardware, software, firmware, or some combination thereof. Sensors 14 may directly sense, detect, or measure the conditions for which they are provided, or they may indirectly evaluate such conditions based on information provided by other sensors, components, devices, modules, systems, etc. Further, these sensors may be directly coupled to VCU 16 and/or to one or more of vehicle subsystems 12, indirectly coupled thereto via other electronic devices, vehicle communications bus, network, etc., or coupled in accordance with some other arrangement known in the art. Some or all of these sensors may be integrated within one or more of the vehicle subsystems 12 identified above, may be standalone components, or may be provided in accordance with some other arrangement. Finally, it is possible for any of the various sensor readings used in the present method to be provided by some other component, module, device, subsystem, etc. of vehicle 10 instead of being directly provided by an actual sensor element. For example, VCU 16 or a subsystem 12 may receive certain information from the ECU of a (or another) subsystem 12 rather than directly from a sensor 14. It should be appreciated that the foregoing scenarios represent only some of the possibilities, as vehicle 10 is not limited to any particular sensor(s) or sensor arrangement(s); rather any suitable embodiment may be used. As with the electronic controllers of subsystems 12 described above, VCU 16 may comprise control means in the form of one or more electronic controllers (e.g., one or more ECUs) configured to receive information and/or to perform or control certain functionality relating to the operation of the vehicle. Each electronic controller of VCU 16 may comprise any suitable ECU, and may include a variety of electronic processing devices, memory devices, input/output (I/O) devices, and/or other known components, and perform various control and/or communication related functions.

In an embodiment, VCU 16 comprises one or more electronic processors 44 each having one or more inputs and one or more outputs, and one or more electronic memory devices 46. As with the electronic processors described above, electronic processor(s) 44 may include any type of suitable electronic processor (e.g., a programmable microprocessor or microcontroller, an ASIC, etc.) that is configured to execute appropriate programming instructions for software, firmware, programs, algorithms, scripts, etc., to perform various functions of VCU 16.

Electronic memory device(s) 46 may include any type of suitable electronic memory means and may store a variety of information and data. This includes, for example and without limitation: software; firmware; programs; algorithms; scripts; sensor readings; look-up tables or other data structures; vehicle-related information; threshold values; and other electronic instructions that, for example, are required or used to perform or cause to be performed one or more functions of VCU 16, including, in at least some embodiments, one or more of the steps of the method described below.

In any event, VCU 16 may be electronically connected to other vehicle devices, modules, subsystems, and components (e.g., sensors) via suitable vehicle communications and can interact with them when or as required. In addition to the functionality that may be performed by VCU 16 described elsewhere herein, in an embodiment, VCU 16 may also be responsible for various functionality described above with respect to subsystems 12, especially when those subsystems are not also configured to do so. These are, of course, only some of the possible arrangements, functions, and capabilities of VCU 16, as other embodiments, implementations, or configurations could also be used. Depending on the particular embodiment, VCU 16 may be a stand-alone vehicle electronic module, may be incorporated or included within another vehicle electronic module (e.g., in one or more of the subsystems 12 identified above), or may be otherwise arranged and configured in a manner known in the art. Accordingly, VCU 16 is not limited to any one particular embodiment or arrangement. In addition to the components and systems described above, in an embodiment, vehicle 10 may further comprise one or more automatic vehicle speed control systems. For example and with continued reference to FIG. 2, in an embodiment, vehicle 10 may further comprise a cruise control system 48, also referred to as an "on-highway" or "on-road" cruise control system, and a low-speed progress (LSP) control system 50, which may be referred to an "off-highway" or "off-road" progress control system.

On-highway cruise control system 48, which may comprise any number of conventional cruise control systems known in the art, is operable to automatically maintain vehicle speed at a desired "set-speed" set by the user. Such systems are generally limited in their use in that the vehicle must be traveling above a certain minimum threshold speed (e.g., 30mph (approximately 50kph)) for the system to be operable. As such, these systems are particularly suited for use in highway driving, or at least driving wherein there is not a lot of repeated starting and stopping, and that permits the vehicle to travel at a relatively high speed. As is known in the art, on-highway cruise control system 48 may include a dedicated or standalone ECU configured to execute and perform the functionality of the system, or alternatively, the functionality of cruise control system 48 may be integrated into another subsystem 12 of vehicle 10 or VCU 16 (as is illustrated in FIG. 2).

Further, and as is known in the art and shown in FIG. 4, cruise control system 48 may include one or more user interface devices 52 that may be used by the user (e.g., driver) to interact with system 48 (e.g., the ECU thereof), and in certain embodiments, that allow the system to interact with the user. For example, these devices may allow a user to activate/deactivate system 48 and set and/or adjust the set-speed of the system, to cite a few possibilities. Each of these devices may take any number of forms, such as, for example and without limitation, one or more of: a pushbutton; a switch; a touch screen; a visual display; a speaker; a heads-up display; a keypad; a keyboard; or any other suitable device. Additionally, these devices may be located at any number of locations within the vehicle cabin and in relatively close proximity to the user (e.g., steering wheel, steering column, dashboard, center console, etc.). For instance, in the embodiment illustrated in FIG. 4, steering wheel 22 of vehicle 10 may be configured with a plurality user interface devices of cruise control system 48 in the form of pushbuttons. One such device may be a "set speed" button 52a that when manipulated in a particular manner may activate the operation of cruise control system 48 and also set the desired set-speed. Cruise control system 48 may further comprise one or more other user-selectable interface devices (e.g., buttons) to allow the user to increase or decrease the set-speed of the system. For example, a "+" button 52b may be provided to allow the user to increase the set-speed in discrete increments (e.g., 1 mph (or 1 kph)), and a "-" button 52c to allow the user to decrease the set-speed in the same or different discrete increments. Alternatively, the "+" and "-" buttons 52b, 52c may be integrated into a single user-selectable device. Additional user-selectable interface devices of system 48 may include, for example, a "cancel" button 52d to deactivate the system, as well as a "resume" button 52e to allow for the system to be re-activated following a temporary suspension of the system function, for example standard cruise control system go into a standby state where they do not control vehicle speed if the user brakes as detailed further below.

It should be appreciated that the foregoing scenarios represent only some of the possibilities of cruise control system 48 and the user interface devices thereof, as vehicle 10 is not limited to any particular cruise control system or user interface device or arrangement; rather, any suitable embodiments may be used.

LSP control system 50 provides a speed control system that enables, for example, the user of a vehicle equipped with such a system to select a very low target speed or set-speed at which the vehicle can progress without, for example, any pedal inputs being required by the user. This low-speed progress control function differs from that of cruise control system 48 in that unlike cruise control system 48, the vehicle need not be traveling at relatively high speeds (e.g., 30mph (approximately 50kph)) for the system to be operable (although system 50 may be configured to facilitate automated speed control at speeds from rest to around 30mph (approximately 50kph) or more, and therefore, is not limited to "low speed" operation). Furthermore, known on-highway cruise control systems are configured so that in the event the user presses or depresses the brake or the clutch pedals, for example, the on- road cruise control function is suspended and the vehicle reverts to a manual mode of operation requiring user pedal input to maintain vehicle speed and a dedicated operator input (e.g., a "resume" button) is needed to reactivate the cruise control in an active mode in which it controls vehicle speed. In addition, in at least certain cruise control systems, the detection of a wheel slip event, which may be initiated by a loss of traction, may also have the effect of cancelling the cruise control function. LSP control system 50 may also differ from such cruise control systems in that, in at least an embodiment, it is configured in such a way that the speed control function provided thereby may not be cancelled or deactivated in response to those events described above. In an embodiment, LSP control system 50 is particularly suited for use in off-road or off-highway driving.

In an embodiment, LSP control system 50 includes, among potentially other components, a control means in the form of an electronic controller 54, which, in an embodiment comprises an ECU (i.e., ECU 54) (shown, in the illustrated embodiment and for reasons described below, as comprising VCU 16), and one or more user input devices 56. ECU 54 may include any variety of electronic processing devices, memory or storage devices, input/output (I/O) devices, and any other known components, and may perform any number of functions of LSP control system 50, including those described below and embodied in the present method. To that end, ECU 54 may be configured to receive information from a variety of sources (e.g., vehicle sensors 14, vehicle subsystems 12, user input devices 56) and to evaluate, analyze, and/or process that information in an effort to control or monitor one or more operational aspects of vehicle 10, such as, for example: detecting steering commands initiated by a driver; automatically commanding and/or controlling the stiffness of one or more portions of steering subsystem 12e; automatically commanding and/or controlling a drive torque generated by the powertrain subsystem 12a and/or a retarding torque generated and applied to one or more wheels of vehicle 10 by, for example, brake subsystem 12b; determining the type and/or one or more characteristics of the terrain over which vehicle 10 is traveling; etc. Further, in an embodiment, ECU 54 is configured to carry out or perform one or more steps of the present method described in greater detail below. It should be appreciated that ECU 54 may be a standalone electronic module or may be integrated or incorporated into either another subsystem 12 of vehicle 10 or, for example, VCU 16. For purposes of illustration and clarity, the description below will be with respect to an embodiment wherein the functionality of ECU 54 is integrated or incorporated into VCU 16, such that, as illustrated in FIG. 2, VCU 16 comprises the ECU of LSP control system 50. Accordingly, in such an embodiment, VCU 16, and a memory device thereof or accessible thereby (e.g., memory device 46), in particular, stores various information, data (e.g., predefined set-speeds), sensor readings, look-up tables or other data structures, algorithms, software, acceleration/deceleration profile(s), and the like, required for performing the functionality of LSP control system 50, including that embodied in the method described below.

As with on-highway cruise control system 48 described above, LSP control system 50 further comprises one or more user interface devices 56 that may be used by a user to interact with the system 50, and in certain embodiments, to allow the system 50 to interact with the user. These devices may allow the user to, for example, activate/deactivate LSP control system 50, set and/or adjust the set-speed of the system, select a desired set-speed from a plurality of predefined set-speeds, switch between two or more predefined set-speeds, identify the particular type of terrain vehicle 10 is traversing, activate certain features relating to the operation of the vehicle (e.g., a lateral disturbance dampening feature), and otherwise interact with system 50 as may be described herein. These user interface devices may also allow for system 50 to provide certain notifications, alerts, messages, requests, etc. to the user including, but not limited to, those described herein below. Each of these devices may take any number of forms, such as, for example and without limitation, one or more of: a pushbutton; a switch; a touch screen; a visual display; a speaker; a heads-up display; a keypad; a keyboard; a selector knob or dial; a slider; or any other suitable device. Additionally, these devices may be located at any number of locations within the vehicle cabin and in relatively close proximity to the user (e.g., steering wheel, steering column, dashboard, etc.). In an embodiment, user interface devices 52, 56 of on-highway cruise control system 48 and LSP control system 50, respectively, are arranged adjacent to one another within vehicle 10, and, in an embodiment, on steering wheel 22 of vehicle 10. However, in other embodiments, such as, for example, that described herein, on-highway cruise control system 48 and LSP control system 50 may share some or all of the same user interface devices. In such an embodiment, an additional user-selectable device, such as a switch, pushbutton, or any other suitable device may be provided to switch between the two speed control systems. Accordingly, in the embodiment illustrated in FIG. 4, those user interface devices 52a-52e described above with respect to cruise control system 48 may also be used in the operation of LSP control system 50, and as such, may also be referred to as user interface devices 56a-56e when discussed in the context of system 50.

In addition to performing a speed control function, LSP control system 50 may be further configured to detect, sense, derive, or otherwise determine information relating to the terrain over which vehicle 10 is traveling (e.g., terrain type, surface type, terrain classification, terrain or surface roughness, etc.). In accordance with an embodiment, VCU 16 may be configured to perform this function and to do so in a number of ways. One such way is that described in UK Published Application No. GB2492748A published on 16 January 2013, the entire contents of which are incorporated herein by reference. More particularly, in an embodiment, information relating to a variety of different parameters associated with the vehicle are received or acquired from a plurality of vehicle sensors and/or various vehicle subsystems, including, for example, some or all of those sensors 14 and/or subsystems 12 described above. The received information is then evaluated and used to determine one or more terrain indicators, which may represent the type of terrain and, in certain instances, one or more characteristics thereof, such as, for example, the classification, roughness, etc. of the terrain.

More specifically, in an embodiment, the speed control system (e.g., VCU 16) may include an evaluation means in the form of an estimator module to which the information acquired or received from one or more sensors 14 and/or subsystems 12 (collectively referred to as "sensor/subsystem outputs" below) is provided. Within a first stage of the estimator module, various ones of the sensor/subsystem outputs are used to derive a number of terrain indicators. In the first stage, vehicle speed is derived from wheel speed sensors, wheel acceleration is derived from wheel speed sensors, the longitudinal force on the wheels is derived from a vehicle longitudinal acceleration sensor, and the torque at which wheel slip occurs (if wheel slip occurs) is derived from a powertrain torque signal provided by the powertrain subsystem and additionally or alternatively from a torque signal provided by the driveline subsystem (e.g., transmission), and from motion sensors to detect yaw, pitch and roll. Other calculations performed within the first stage of the estimator module include the wheel inertia torque (the torque associated with accelerating or decelerating the rotating wheels), "continuity of progress" (the assessment of whether the vehicle is repeatedly starting and stopping, for example as may be the case when the vehicle is traveling over rocky terrain), aerodynamic drag, and lateral vehicle acceleration.

The estimator module also includes a second stage in which the following terrain indicators are calculated: surface rolling resistance (based on the wheel inertia torque, the longitudinal force on the vehicle, aerodynamic drag, and the longitudinal force on the wheels), the steering force on the steering wheel (based on the lateral acceleration and the output from a steering wheel sensor and/or steering column sensor), the wheel longitudinal slip (based on the longitudinal force on the wheels, the wheel acceleration, stability control system (SCS) activity and a signal indicative of whether wheel slip has occurred), lateral friction (calculated from the measured lateral acceleration and the yaw versus the predicted lateral acceleration and yaw), and corrugation detection (high frequency, low amplitude vertical wheel excitement indicative of a washboard type surface). The SCS activity signal is derived from several outputs from the ECU of a brakes control system, which may contain a dynamic stability control (DSC) function, a terrain control (TC) function, anti-lock braking system (ABS), and hill descent control (HDC) algorithms, indicating DSC activity, TC activity, ABS activity, brake interventions on individual wheels, and powertrain torque reduction requests from the brakes control system ECU to the powertrain subsystem. All these indicate a slip event has occurred and the brakes control system ECU has taken action to control it. The estimator module also uses the outputs from wheel speed sensors and in a four wheel vehicle, compares outputs across each axle and from front to rear on each side, to determine a wheel speed variation and corrugation detection signal.

In an embodiment, and in addition to the estimator module, a road roughness module may also be included for calculating the terrain roughness based on air suspension sensors (the ride height or suspension articulation sensors) and wheel accelerometers. In such an embodiment, a terrain indicator signal in the form of a roughness output signal is output from the road roughness module.

In any event, the estimates for the wheel longitudinal slip and the lateral friction estimation are compared with one another within the estimator module as a plausibility check. Calculations for wheel speed variation and corrugation output, the surface rolling resistance estimation, the wheel longitudinal slip and the corrugation detection, together with the friction plausibility check, are then output from the estimator module and provide terrain indicator output signals, indicative of the nature of the terrain over which the vehicle is traveling, for further processing by VCU 16. For example, the terrain indicators may be used to determine which of a plurality of vehicle subsystem control modes (e.g., terrain modes) is most appropriate based on the indicators of the type of terrain over which the vehicle is traveling, and to then automatically control the appropriate subsystems 12 accordingly.

In another embodiment, rather than LSP control system 50 performing the above-described terrain sensing/detecting functionality, another component, module, or subsystem of vehicle 10, such as, for example VCU 16 (in the case where it does not perform the functionality of LSP control system 50), one of subsystems 12, or another suitable component may be appropriately configured to do so; and such other embodiments remain within the spirit and scope of the present invention.

It should be appreciated that the foregoing description of the arrangement, functionality, and capability of LSP control system 50 has been provided for purposes of example and illustration only and is not meant to be limiting in nature. Accordingly, LSP control system 50 is not intended to be limited to any particular embodiments or arrangements.

Again, the preceding description of vehicle 10 and the illustrations in FIGS. 1 -4 are only intended to illustrate one potential vehicle arrangement and to do so in a general way. Any number of other vehicle arrangements and architectures, including those that differ significantly from the one shown in FIGS. 1 -4, may be used instead.

Turning now to FIG. 5, there is shown an illustrative embodiment of a method 100 for dampening lateral disturbances to a vehicle as the vehicle traverses, for example, a relatively rough (e.g., potholed, rutted, etc.) driving surface. For purposes of illustration and clarity, method 100 will be primarily described in the context of vehicle 10 described above. It will be appreciated, however, that the application of the present methodology is not meant to be limited solely to such vehicle or vehicle arrangement/configuration, but rather method 100 may find application with any number of vehicles and/or vehicle arrangements/configurations (i.e., the steps of method 100 may be performed by subsystems or components of vehicle 10 other than that or those described below, or vehicle arrangements/configurations (e.g., steering systems) other than that or those described above). Additionally, it will be appreciated that unless otherwise noted, the performance of method 100 is not meant to be limited to any one particular order or sequence of steps or to any particular component(s) for performing the steps. In the embodiment illustrated in FIG. 5, method 100 comprises a step 102 of receiving information relating to the operation of vehicle 10. In an embodiment, this comprises receiving one or more electrical signals representative of the information relating to the operation of the vehicle. A variety of information may be received in step 102, including, for example and without limitation, one or a combination of: a force applied to steering assembly 18 of vehicle 10 by one or more of vehicle wheels (e.g., wheels 34a, 34b); a torque applied to one or more of the vehicle wheels as a result of vehicle 10 traversing the prevailing terrain; a lateral acceleration of vehicle 10; a terrain response ("TR") mode in which vehicle 10 is being operated; a speed of vehicle 10; a speed of one or more of the wheels of vehicle 10; an operational status of a speed control system (e.g., LSP control system 50) of vehicle 10 (i.e., whether LSP control system 50 is "active" or "on", or "inactive" or "off"); and an indication as to the type and/or characteristic(s) of the prevailing terrain and/or the terrain ahead of vehicle 10 in the intended direction of travel, to cite a few possibilities.

The particular component of vehicle 10 that receives the information (e.g., electrical signal(s) representing the information) in step 102 will be dependent upon the particular implementation. For example, in an illustrative embodiment, VCU 16 receives the information; while in another embodiment, steering subsystem 12e, and the electronic controller thereof, in particular, receives the information. In yet other embodiments, one or more subsystems 12 other than steering subsystem 12e may be configured to receive the information. Additionally, the particular component(s) of vehicle 10 from which the information (e.g., electrical signal(s)) are received in step 102 may also be dependent upon the implementation and the particular information being received. For example, the information may be received from one or more of vehicle sensors 14 (e.g., vehicle speed sensor(s), wheel speed sensor(s), wheel torque sensor(s), lateral acceleration sensor(s), camera(s), radar unit(s), etc.), one or more subsystems 12 of vehicle 10, VCU 16, and/or any other suitable component of vehicle 10. In any event, the information may be received directly from the corresponding vehicle component, or indirectly via, for example, a CAN bus, a SMBus, a proprietary communication link, or in another suitable manner.

It will be appreciated in view of the foregoing that the present invention is not limited to any particular component of vehicle 10 receiving the information in step 102, to a particular source of the received information, or to a particular manner or way in which the information is received or sent/communicated. Rather, the information may be received by and/or from any number of suitable components in a number of suitable ways.

Method 100 further includes a step 104 of determining whether one or more predetermined conditions are met based on the information received in step 102, the predetermined condition(s) representing conditions under which a lateral disturbance to the vehicle is possible. Exactly how it is determined whether the predetermined condition(s) are met will be at least in part dependent upon the particular condition(s) being evaluated. And a variety of conditions may be evaluated including, for example and without limitation, one or a combination of those described below.

One such condition is that the prevailing terrain, the terrain ahead of vehicle 10 in the intended direction of travel, or both has/have a particular characteristic and/or is/are a particular type of terrain (e.g., a relatively rough terrain, for example, a potholed or rutted driving surface). In an embodiment, determining whether or not this condition is met first requires that the type and/or characteristic(s) of interest of the prevailing terrain and/or the terrain ahead of the vehicle be determined. This determination can be performed in a number of ways. For example, the terrain type/characteristic may be determined automatically in the manner described above with respect to LSP control system 50. An additional or alternative way is in response to a user input representative of a particular terrain type/characteristic. More particularly, a vehicle occupant (e.g., driver) may provide this input using a suitably configured user interface device, for example, a user interface device of the speed control system (e.g., one of user input devices 56 of LSP control system 50 described above and shown in FIG. 4), or another user interface device located within the passenger cabin of the vehicle, for example, a knob, switch, pushbutton, touch screen display, or other suitable device that allows for the selection of a terrain type/characteristic from one or a plurality of different terrain types/characteristics. Yet another way in which the terrain type/characteristic(s) may be determined is by using the output(s) of one or more cameras and/or ground sensing radar units in conjunction with, for example, known (image) processing techniques for processing the data received from the camera(s) and/or radar unit(s). Accordingly, it will be appreciated that any number of techniques may be used to determine a terrain type and/or terrain characteristic(s), and therefore, the present invention is not intended to be limited to any particular technique(s) for doing so.

In any event, once the type and/or characteristic(s) of interest of the prevailing terrain and/or terrain ahead of the vehicle are determined, the determined terrain type/characteristic(s) is/are compared to or with one or more terrain characteristics and/or terrain types stored in, for example, a data structure (e.g., look-table) stored in a memory device of vehicle 10 (e.g., memory device 42 of controller 38 of steering subsystem 12e, memory device 46 of VCU 16, etc.). If it is determined that the prevailing terrain and/or terrain ahead of the vehicle matches one of the terrain type(s)/characteristic(s) in the data structure, as the case may be, then it can be further determined that the condition is met. Otherwise it can be determined that the condition is not met.

Another condition that may be evaluated in step 104 is that the value of each of one or more monitored vehicle-related parameters is above a respective predetermined, empirically- derived threshold; or that the value(s) of certain ones or a certain number of the monitored parameters is/are above a respective predetermined, empirically-derived threshold. Any number of vehicle-related parameters may be evaluated with respect to this particular condition, including, for example and without limitation, one or a combination of: a force applied to steering assembly 18 of vehicle 10 by one or more wheels of vehicle 10; a torque applied to one or more wheels of vehicle 10 as a result of the vehicle traversing the prevailing terrain; a speed of vehicle 10; and a lateral acceleration of vehicle 10.

Regardless of the particular vehicle-related parameters that are evaluated, determining whether or not this condition is met first requires that the value(s) of the one or more parameters being monitored be acquired. In an embodiment, the information received in step 102 may include one or more of those values. In other embodiments, the value(s) of interest may be acquired other than from the information received in step 102, and may be acquired from, for example, one or more of vehicle sensors 14 (e.g., vehicle speed sensor(s), wheel speed sensor(s), wheel torque sensor(s) (e.g., wheel torque sensor(s) located between one or more of the vehicle wheels and one or more components of steering subsystem 12e), lateral acceleration sensor(s), etc.), one or more subsystems 12 of vehicle 10, VCU 16, and/or any other suitable component of vehicle 10 (e.g., from a memory device of a component of vehicle 10). In any event, in an embodiment, the value(s) may be represented by electrical signal(s) that may be received directly from the appropriate vehicle component, or indirectly via, for example, a CAN bus, a SMBus, a proprietary communication link, or in another suitable manner. Accordingly, it will be appreciated that value(s) of the vehicle- related parameter(s) of interest may be acquired in a number of ways, including, but certainly not limited to, those described above.

Once the value(s) of the relevant vehicle-related parameter(s) of interest are acquired, each of the value(s) may be compared to a respective threshold value. For a given vehicle-related parameter, the threshold value may comprise an empirically-derived value that is stored in a memory device of vehicle 10 as part of, for example, the manufacture of vehicle 10. In an embodiment, the threshold may represent a value of the parameter at which a lateral disturbance to the vehicle typically occurs or at which a lateral disturbance is possible or likely to occur. In another embodiment, the threshold may represent a value of the parameter that is just below the value at which a lateral disturbance typically occurs or is likely to occur. In either instance, the component performing step 104 may be configured to access the memory device(s) in which the threshold value(s) for the relevant vehicle-related parameter(s) are stored, and to compare each parameter value to the threshold corresponding to that particular parameter. In an embodiment, if it is determined that the value(s) of any, or at least a certain number or certain ones of the monitored parameters, is/are above (or, in an embodiment, meets or is above) the threshold(s) to which the value(s) was/were compared, then it can be determined that the condition is met. In other embodiments, however, it is only determined that the condition is met when all of the parameter values are above (or, in an embodiment, meet or are above) the threshold values to which they were compared.

Still another condition that may be evaluated in step 104 is that the value of each of one or more monitored vehicle-related parameters is below a respective predetermined, empirically- derived threshold; or that one or more but less than all of the value(s) of the one or more monitored vehicle-related parameters is/are below a respective predetermined, empirically- derived threshold. In either instance, any number of vehicle-related parameters may be evaluated with respect to this particular condition, including, for example and without limitation, the speed of the vehicle and/or the wheel speed of one or more wheels of the vehicle. Regardless of the particular vehicle-related parameter(s) being evaluated, determining whether or not this condition is met first requires that the value(s) of the one or more parameters be acquired. In an embodiment, the information received in step 102 may include one or more of those values. In other embodiments, the value(s) of interest may be acquired other than from the information received in step 102, and may be acquired from, for example, one or more of vehicle sensors 14 (e.g., vehicle speed sensor(s), wheel speed sensor(s), etc.), one or more subsystems 12 of vehicle 10, VCU 16, and/or any other suitable component of vehicle 10. In any event, in an embodiment, the value(s) may be represented by electrical signal(s) that may be received directly from the appropriate vehicle component, or indirectly via, for example, a CAN bus, a SMBus, a proprietary communication link, or in another suitable manner. Accordingly, it will be appreciated that value(s) of the vehicle-related parameter(s) of interest may be acquired in a number of ways, including, but certainly not limited to, those described above.

Once the value(s) of the relevant vehicle-related parameter(s) of interest are acquired, each of the value(s) may be compared to a respective threshold value. For a given vehicle-related parameter, the threshold value may comprise an empirically-derived value that is stored in a memory device of vehicle 10 as part of, for example, the manufacture of vehicle 10, and that may represent the value of the parameter at which a lateral disturbance to the vehicle is possible. Accordingly, the component performing step 104 may be configured to access the memory device(s) in which the threshold value(s) for the relevant vehicle-related parameter(s) are stored, and to compare each parameter value to the threshold corresponding to that particular parameter. In an embodiment, if it determined that the value(s) of any, or at least a certain number or certain ones, of the monitored parameters is/are below (or, in an embodiment, meets or is below) the threshold(s) to which the value(s) was/were compared, then it can be determined that the condition is met. In other embodiments, however, it is only determined that the condition is met when all of the parameter values are below (or, in an embodiment, meet or are below) the threshold values to which they were compared.

Another condition that may be evaluated in step 104 is that the vehicle is being operated in a particular mode of operation. In an embodiment, the particular mode of operation may comprise a particular TR mode, a low speed progress control mode (e.g., LSP control system 50 is "active"), or both. Similar to the conditions described above, in an illustrative embodiment, determining whether or not this condition is met first requires determining the mode of operation in which the vehicle is being operated. In an embodiment, this determination can be made in response to a user input representative of a desired mode of operation (e.g., selection of a TR mode or the activation of LSP control system 50, for example). For instance, and as described above, a vehicle occupant (e.g., driver) may provide this input using a suitable configured user interface device, for example, a user interface device of the speed control system (e.g., one of user input devices 56 of LSP control system 50 described above and shown in FIG. 4), or another user interface device located within the passenger cabin of the vehicle, for example, a knob, switch, pushbutton, touch screen display, or other suitable device that allows for the selection of an operating mode from a plurality of different operating modes. In another embodiment, this determination can be made in dependence on a received electrical signal indicative of the current operating mode of the vehicle. In an embodiment, this signal may be automatically sent to the component performing step 104 (e.g., periodically sent), or may be sent in response to a request to do so or some other triggering event (e.g., a change in the operating mode).

In any event, once the mode of operation of the vehicle is determined, it may be compared to or with one or more operating modes stored in, for example, a data structure (e.g., look- table). If it is determined that the current operating mode matches one of the stored operating modes, then it can be further determined that the condition is met. Otherwise it can be determined that the condition is not met.

Yet still another condition that may be evaluated in step 104 is that a disturbance is detected in steering assembly 18 of vehicle 10. A disturbance in steering assembly 18 can be detected in a number of ways. One way, though certainly not the only way, is in dependence on the output of one or more sensor(s) (e.g., torque sensor(s)) located at one or more locations of steering assembly 18). More specifically, when the component that performs step 104 receives an output from that or those sensor(s) or detects a change (or at least a sufficient change) in the output of that or those sensor(s), the component can detect that there is a disturbance in steering assembly 18, and thus, that the condition is met. Otherwise it can be determined that the condition is not met.

Yet another condition that may be evaluated in step 104 is that a steering command has not been received. In an embodiment, this condition may be evaluated by determining whether an electrical signal indicative of a steering command has been received. This may comprise monitoring the output(s) of one or more sensors 14 (e.g., steering angle sensor(s), steering torque sensor(s), steering wheel speed sensor(s), etc.), and determining whether an electrical signal indicative of a steering command has been received from one of subsystems 12 of vehicle 10 (e.g., chassis management subsystem 12d, steering subsystem 12e, etc.), or from VCU 16. In an instance wherein sensor outputs are monitored, each of the sensors may be at locations in steering assembly 18 that allow the component performing step 104 to discern that the sensor output is in response to a driver or vehicle-initiated steering command as opposed to a force or torque applied to the steering system by the vehicle wheels. In other words, the sensors used to determine if a steering command has been received may be different from those used to measure the force/torque applied to the steering assembly by vehicle wheels.

While only a few conditions were described in detail above, it will be appreciated that conditions in addition to or in lieu of those described above may be evaluated and used in the same or similar manner as that described herein. Accordingly, the present invention is not limited to the use of any particular conditions.

The particular component of vehicle 10 that performs step 104 will be dependent upon the particular implementation. For example, in an illustrative embodiment, VCU 16 performs step 104; while in another embodiment, steering subsystem 12e, or another subsystem of vehicle 10, and the electronic controller thereof, in particular, may perform step 104. In yet another embodiment, step 104 may be performed by VCU 16 in conjunction with one of subsystems 12. Accordingly, the present invention is not intended to be limited to any particular component performing step 104.

As shown in FIG. 5, if it is determined in step 104 that the predetermined condition(s), or at least not certain ones or a certain number of the predetermined conditions, are not met, method 100 may loop back to a previous step, for example, step 102. If, on the other hand, it is determined that the predetermined condition(s) or at least certain ones or a certain number of the predetermined conditions are met, method 100 may proceed to a step 106 of automatically stiffening (or automatically commanding the stiffening of) a portion of steering assembly 18 of vehicle 10 to dampen (e.g., eliminate or at least mitigate) a lateral disturbance or possible lateral disturbance to vehicle 10. Step 106 may be performed in a number of ways depending, at least in part, on the particular type and/or arrangement or configuration of steering subsystem 12e of vehicle 10, and steering assembly 18 thereof, in particular. For example, in the embodiment of steering subsystem 12e described above and illustrated in FIG. 3 wherein steering assembly 18 includes steering assistance motor 36, motor 36 may be controlled to apply a force or torque to a portion of steering assembly 18 that results in the stiffening of at least a portion of assembly 18. This may comprise, for example, operating motor 36 in a direction opposite that in which it normally operates to provide steering assistance. By way of example, in an instance wherein one of the conditions evaluated in step 104 comprises a force applied to the steering assembly by one or more wheels of vehicle 10 being above a given threshold, motor 36 may be controlled to apply a counter force that acts against the force being applied by the vehicle wheels. The amount of force applied by motor 36 may be sufficient to at least partially counteract the force applied by the wheels, fully counteract the force applied by the wheels, or may be greater in magnitude than the force applied by the vehicle wheels.

In an embodiment, wherein steering subsystem 12e comprises one or more braking devices 37 each coupled to a component of steering assembly 18, step 106 may comprise actuating at least one of the one or more braking devices 37 to apply a torque/force to steering assembly 18 to partially or fully counteract or to prevent a force or torque applied by the wheel(s) of vehicle 10 to steering subsystem 12e.

In an embodiment wherein a steering assistance motor and/or braking device(s) are used to stiffen at least a portion of steering assembly 18, the amount of counter torque/force applied by the steering assistance motor and/or braking device(s) may be determined, for example, by looking up the amount of force applied to the steering assembly by the wheel(s) in an appropriately configured data structure (e.g., look-up table) stored in or on a memory device of vehicle 10, and obtaining an amount or magnitude of force/torque to apply from that data structure. In an embodiment wherein steering subsystem 12e comprises a hydraulic-based power assisted steering system, step 106 may comprise controlling (i.e., limiting or reducing) the flow of fluid in the steering subsystem using techniques known in the art. In an embodiment, the amount by which the fluid follow is adjusted or controlled may be determined by, for example, looking up the amount of force applied to the steering assembly by the wheel(s) in an appropriately configured data structure (e.g., look-up table) stored in or on a memory device of vehicle 10, and obtaining an amount by which to adjust the fluid flow from that data structure.

Regardless of the particular way in which the stiffening of at least a portion of steering assembly 18 is effected, in at least some embodiments, the degree to which the steering assembly is stiffened is dependent upon the speed of vehicle 10 (i.e., low vehicle speed results in little to no stiffening, and then the stiffness is ramped in as the speed increases). More particularly, step 106 may comprise monitoring the vehicle speed in a manner such as that described above and then either applying a counter force/torque (in embodiments wherein the steering assembly is stiffened utilizing a steering assistance motor or a braking device coupled to a steering assembly component) or adjusting the fluid flow (in embodiments wherein the steering system comprises a hydraulic power assisted steering system and the steering assembly is stiffened by adjusting the flow of fluid in the system) in accordance with the monitored speed. In such an embodiment, a multi-dimensional data structure (e.g., look-up table) may be utilized wherein vehicle speed and the magnitude of the torque/force applied to the steering assembly by the vehicle wheels may be "input" into the data structure and either an amount or magnitude of force/torque to apply or an amount by which to adjust the fluid flow may be obtained from the data structure as an "output."

In any event, it will be appreciated in view of the foregoing that the steering assembly of vehicle 10 may be stiffened in a number of different ways, including, but not limited to, those described above. As such, it will be further appreciated that the present invention is not intended to be limited to any particular way(s) of doing so.

As with steps 102 and 104 described above, the particular component of vehicle 10 that performs step 106 will be dependent, at least in part, on the particular implementation of vehicle and/or one or more subsystems thereof. For example, in an illustrative embodiment, VCU 16 performs step 106 in conjunction with steering subsystem 12e (e.g., VCU 16 may provide commands to the electronic controller of steering system 12e, or may directly control one or more components of steering subsystem 12e to stiffen the steering assembly thereof); while in another embodiment, steering subsystem 12e alone is configured to perform step 106 (i.e., without any involvement by VCU 16). Accordingly, the present invention is not intended to be limited to any particular component or components of vehicle 10 performing step 106.

In addition to the steps above, in some embodiments or implementations, method 100 may optionally include one or more additional steps. One such step, step 108, comprises cancelling or overriding the stiffening of the steering assembly in dependence on the receipt of a steering command. In an embodiment, step 108, which may be performed after step 106, comprises a first substep 1 10 of detecting a user (e.g., driver) or vehicle system- initiated steering command, and a second substep 1 12 of reducing the stiffness of the steering assembly in dependence on the detected steering command. Substep 1 10 may comprise the component of vehicle 10 performing method 100, and in an embodiment, step 106 thereof, in particular, receiving an electrical signal indicative of the steering command. This signal may be received from, for example, one or more vehicle sensors 14 (e.g., steering angle sensor(s), steering torque sensor(s), steering wheel speed sensor(s), etc.), one of subsystems 12 of vehicle 10 (e.g., chassis management subsystem 12d, steering subsystem 12e, etc.), or from VCU 16. As described above with respect to step 104, in an instance wherein sensor outputs are used to detect a steering command, each of those sensors may be at locations in steering assembly 18 that allow the component performing step 108 to discern that the sensor output is in response to and indicative of a driver or vehicle-initiated steering command as opposed to a force or torque applied to the steering system by the vehicle wheels. In other words, the sensors used to detect a steering command may be different from those used to measure the force/torque applied to the steering assembly by vehicle wheels.

Upon detecting the steering command, the component performing step 108 may then, in substep 1 12, reduce (or command the reduction in) the stiffness of steering assembly 18. The particular manner in which this is done will be dependent upon the particular implementation of steering system 12e, in an embodiment, however, the stiffness may be reduced by reducing or removing the counter torque/force being applied by the steering assistance motor 36 and/or one or more braking devices 37 coupled to a steering assembly component, and/or reducing or eliminating the limit on the flow of fluid in the steering subsystem 12e.

When it is subsequently determined that the steering command has ceased, method 100 may loop back to a previous step, for example, one of steps 102 (as shown in FIG. 5), 104, or 106. It will be appreciated that the particular component of vehicle 10 that performs step 108 and the substeps thereof will be dependent, at least in part, on the particular implementation of vehicle 10 and steering subsystem 12e. For example, in an illustrative embodiment, VCU 16 may perform step 108 in conjunction with steering subsystem 12e (e.g., VCU 16 may provide commands to the electronic controller of steering system 12e, or may directly control one or more components of steering subsystem 12e to reduce the stiffness of the steering assembly); while in another embodiment, steering subsystem 12e may be configured to perform step 108 alone (i.e., without any involvement by VCU 16). Accordingly, the present invention is not intended to be limited to any particular component or components of vehicle 10 performing step 108. In any event, it will be understood that step 108 provides for a user or vehicle override of the lateral disturbance dampening feature in order to allow the vehicle to be steered in a desired manner without having to overcome an elevated level or degree of steering assembly stiffness. It has been determined that by stiffening the steering assembly of a vehicle, or at least one or more portions thereof, as the vehicle traverses relatively rough terrain, lateral disturbances to the vehicle may be dampened. Accordingly, at least some embodiments of the present invention have the advantage that as a vehicle traverses a relatively rough terrain, adjustments may be automatically made to the stiffness of the steering assembly of the vehicle resulting in the dampening of lateral disturbances to the vehicle, and therefore, to the occupant(s) thereof. As a result, lateral disturbances to the vehicle may be at least mitigated, thereby increasing the comfort of the vehicle occupants and/or the composure of the vehicle.

It will be understood that the embodiments described above are given by way of example only and are not intended to limit the invention, the scope of which is defined in the appended claims. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. For example, the specific combination and order of steps is just one possibility, as the present method may include a combination of steps that has fewer, greater or different steps than that shown here. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

As used in this specification and claims, the terms "for example," "e.g.," "for instance," "such as," and "like," and the verbs "comprising," "having," "including," and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that that the listing is not to be considered as excluding other, additional components or items. Further, the terms "electrically connected" or "electrically coupled" and the variations thereof are intended to encompass both wireless electrical connections and electrical connections made via one or more wires, cables, or conductors (wired connections). Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.

Claims

1 . A method for dampening lateral disturbances to a vehicle, comprising:

receiving information relating to the operation of the vehicle;

determining whether one or more predetermined condition(s) are met based on the received information, the one or more predetermined condition(s) representing conditions under which a lateral disturbance to the vehicle is possible; and

when at least certain of the one or more predetermined condition(s) are met, automatically stiffening a portion of a steering assembly of the vehicle to dampen a lateral disturbance to the vehicle,

wherein the one or more predetermined condition(s) comprise(s) the vehicle being operated in a particular mode of operation and wherein the particular mode of operation comprises a particular terrain response mode, a low speed progress control mode, or both.

2. The method of claim 1 , wherein the one or more predetermined condition(s) comprise(s) one or both of the prevailing terrain and the terrain ahead of the vehicle in the direction of travel having a particular characteristic.

3. The method of claim 1 or 2, wherein the one or more predetermined condition(s) comprise(s) at least one of one or more monitored vehicle-related parameter(s) being above a respective predetermined threshold.

4. The method of claim 3, wherein the one or more monitored vehicle-related parameter(s) comprise(s) one or more of:

a force applied to the steering assembly of the vehicle by one or more wheels of the vehicle;

a torque applied to one or more wheels of the vehicle as a result of the vehicle traversing the prevailing terrain; and

a lateral acceleration of the vehicle.

5. The method of claim 4, wherein the one or more monitored vehicle parameter(s) comprise(s) the force applied to the steering assembly by one or more wheels of the vehicle, and further wherein the stiffening of the steering assembly comprises applying a counter force to the steering assembly to act against the force applied by the one or more wheels.

6. The method of claim 5, wherein applying a counter force comprises controlling at least one of an electric motor or a braking device to apply the counter force to the steering assembly.

7. The method of any one of the preceding claims, wherein the one or more predetermined condition(s) comprise(s) a detection of a disturbance in the steering assembly of the vehicle.

8. The method of any one of the preceding claims, wherein stiffening a portion of the steering assembly comprises monitoring the speed of the vehicle and stiffening the steering assembly in accordance with the vehicle speed.

9. The method of any one of the preceding claims, wherein the stiffening of the steering assembly comprises one or a combination of:

limiting a flow of fluid in the steering assembly;

actuating a braking device coupled to a component of the steering assembly; and controlling an electric motor to apply a force to the steering assembly.

10. The method of any one of the preceding claims, wherein following the stiffening of the steering assembly, the method comprises:

detecting a driver or vehicle system-initiated steering command; and

reducing the stiffness of the steering assembly in response to the detected steering command.

1 1 . The method of any one of the preceding claims, wherein receiving information relating to the operation of the vehicle comprises receiving one or more electrical signals representative of the information relating to the operation of the vehicle.

12. A non-transitory, computer-readable storage medium storing instructions thereon that when executed by one or more electronic processors causes the one or more electronic processors to carry out the method of any one of the preceding claims.

13. A system for dampening a lateral disturbance to a vehicle, the system comprising: means for receiving information relating to the operation of the vehicle; means for determining whether one or more predetermined condition(s) are met based on the received information, the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible; and

means for automatically commanding the stiffening of a portion of a steering assembly of the vehicle when at least certain of the one or more predetermined conditions are met to dampen a lateral disturbance to the vehicle.

14. The system of claim 13, wherein the receiving, determining, commanding means comprise:

an electronic processor having an electrical input for receiving the information relating to the operation of the vehicle; and

an electronic memory device electrically coupled to the electronic processor and having instructions stored therein,

wherein the processor is configured to access the memory device and execute the instructions stored therein such that it is configured to:

determine whether the one or more predetermined conditions are met based on the received information; and

automatically command the stiffening of the portion of the steering assembly of the vehicle when the at least certain of the one or more predetermined conditions are met.

15. The system of claim 13 or 14, wherein the one or more predetermined condition(s) comprise(s) one or both of the prevailing terrain and the terrain ahead of the vehicle in the direction of travel having a particular characteristic.

16. The system of any one of claims 13 to 15, wherein the one or more predetermined condition(s) comprise(s) one or more monitored vehicle-related parameters represented by the received information each being above a respective predetermined threshold.

17. The system of claim 16, wherein the one or more monitored vehicle-related parameter(s) comprise(s) one or a combination of:

a lateral acceleration of the vehicle.

18. The system of claim 17, wherein the one or more monitored vehicle parameter(s) comprise(s) the force applied to the steering assembly by one or more wheels of the vehicle, and further wherein commanding the stiffening of the steering assembly comprises commanding the application of a counter force to the steering assembly to act against the force applied by the one or more wheels.

19. The system of claim 18, wherein commanding the application of a counter force comprises commanding at least one of an electric motor or a braking device to apply the counter force to the steering assembly.

20. The system of any one of claims 13 to 19, wherein the one or more predetermined condition(s) comprise(s) the vehicle being operated in a particular mode of operation.

21 . The system of claim 20, wherein the particular mode of operation comprises a particular terrain response mode, a low speed progress control mode, or both.

22. The system of any one of claims 13 to 21 , wherein the one or more predetermined condition(s) comprise(s) a detection of a disturbance in the steering assembly of the vehicle.

23. The system of any one of claims 14 to 22, wherein the electronic processor is configured to monitor the speed of the vehicle and to command the stiffening of the steering assembly in accordance with the vehicle speed.

24. The system of any one of claims 13 to 23, wherein commanding the stiffening of the steering assembly comprises one or a combination of:

commanding a reduction in a flow of fluid in the steering assembly;

commanding an actuation of a braking device coupled to a component of the steering assembly; and

commanding an electric motor to apply a force to the steering assembly.

25. The system of any one of claims 14 to 24, wherein the electronic processor is configured to detect a driver or vehicle system-initiated steering command, and to command a reduction in the stiffness of the steering assembly in response to the detected steering command.

26. An electronic controller for a vehicle having a storage medium associated therewith storing instructions that when executed by the controller causes the dampening of a lateral disturbance to a vehicle in accordance with the method of:

receiving information relating to the operation of the vehicle;

5 determining whether one or more predetermined conditions are met based on the received information, the one or more predetermined conditions representing conditions under which a lateral disturbance to the vehicle is possible; and

when at least certain of the one or more predetermined conditions are met, automatically stiffening a portion of a steering assembly of the vehicle to dampen a lateral o disturbance to the vehicle.

27. A vehicle comprising the system according to any one of claims 13 to 25, or the electronic controller of claim 26. 5 28. A method, system, controller, or vehicle substantially as hereinbefore described with reference to the accompanying drawings.