Ride control system

Abstract

The invention relates to control system and to vehicles and other subjects incorporating such, and to methods for operating the control system. Preferably, the invention relates to a ride control system for a vehicle having a suspension system, configured for controlling the position, orientation, and / or motion of a suspended portion of the vehicle relative to a base portion via a plurality of displacement cylinder units.

Description

RIDE CONTROL SYSTEMTECHNICAL FIELD

[0001] The invention relates to a control system and to vehicles and other subjects incorporating such. Particularly, but not exclusively, the invention relates to a ride control system for a vehicle having a suspension system, configured for controlling the position, orientation, and / or motion of a sprung portion of the vehicle.BACKGROUND

[0002] Vehicles, and other objects that incorporate suspension systems (such as machines and buildings), experience forces that can cause changes to the position, orientation, and / or motion of sprung parts relative to un-sprung parts. Such changes can lead to undesirable effects, particularly when rapid or extreme, including losses in performance or efficiency, and reductions in stability, predictability, comfort and safety.

[0003] Some efforts have been made to manage unwanted body motions through direct control of suspension system properties, such as damping and spring rate. However, this approach can interfere with the performance and function of the suspension systems, and may be limited in its ability to effectively deal with the changes experienced by a vehicle.

[0004] US2002109310A1 by LIM HOWARD TAK SU and US20140175763A1 by HYUNDAI MOTOR CO LTD each disclose vehicle stability systems. However, these systems interfere with an existing suspension system by regulating fluid or by limiting the range of coil springs, thus adding complexity.

[0005] US20180141399A1 and US9, 643,46661 by GM GLOBAL TECH OPERATIONS LLC both disclose a hydraulic actuator assemblyconfigured to receive a pressurized fluid from a pump. However, these systems need hydraulic sleeves to provide locking.OBJECT OF THE INVENTION

[0006] It is therefore an object of the present invention to provide a control system which overcomes or at least ameliorates some of the disadvantages described above, or which at least provides a public with a useful choice.SUMMARY OF THE INVENTION

[0007] In a first aspect, the invention broadly provides a ride control system for use on a vehicle having a suspended portion resiliently supported upon a base portion via a suspension system, the base portion comprising ground-engaging means, such as wheels, legs, feet or tracks, wherein the control system comprises: at least one, and preferably a plurality, of cylinder units each configured for cooperative coupling to a respective suspension unit of the suspension system, such that each cylinder unit is operable to control a respective distance between the base portion and the suspended portion of the vehicle; a controller configured to operate at least one of the plurality of cylinder units to control a relative position, orientation and / or motion of the suspended portion and the base portion of the vehicle.

[0008] In a further aspect of the invention, there is provided a ride control system for use on a vehicle having a suspended portion resiliently supported upon a base portion via a suspension system, the base portion comprising groundengaging means, such as wheels, legs, feet or tracks, wherein the control system comprises: a plurality of displacement cylinder units each configured for cooperative coupling to a respective passively and independently controlled suspension unit of the suspension system, such that each displacement cylinder unit is operable to control a respective distance between the base portion and the suspended portion of the vehicle; a controller configured to operate one or more of the plurality of displacement cylinder units to control a relative position, orientation and / or motion of the suspended portion and the base portion of the vehicle, wherein each displacement cylinder is a double acting, regenerative displacement cylinder unit configured to actively extend or retract.

[0009] The suspended portion and base portion of the vehicle may be referred to as sprung and un-sprung portions, respectively. The portions may be unitary, connected in a unitary manner, or separate.

[0010] The cylinder units may be referred to generally as linear actuators or as displacement cylinders. The cylinder units may be operated to extend, retract, or hold position.

[0011] For each cylinder unit, the respective distance may be a distance between a mounting point on the base portion and a corresponding mounting point on the suspended portion. In some examples, corresponding mounting points maybe connected via a cooperative assembly of a cylinder unit and a suspension unit, referred to as a cylinder suspension module.

[0012] The cylinder units may be arranged for distribution at or proximate four corners of the vehicle.

[0013] The suspension units may each comprise a coil spring and a shock, preferably arranged in a coil-over-shock configuration.

[0014] Preferably, each cylinder unit of the plurality of cylinder units is configured for securing to a respective suspension unit in an inline configuration, such that the operational axis of the cylinder unit is parallel to and aligned with the operational axis of the suspension unit. With this arrangement, the cylinder unit can operate in series with the suspension unit to effect control of position and movement in the same direction.

[0015] Alternatively, each cylinder unit may be configured for securing to a respective suspension unit in a parallel configuration, such that the operational axis of the cylinder unit is parallel to and laterally offset from the operational axis of the suspension unit. With this arrangement, the assembly of the two units can be more compact (i.e., in the elongate direction).

[0016] In some examples, each cylinder unit is configured for coupling to a respective suspension unit via a link or mechanism, such as a bell crank. The bell crank is one example of a pivotal link. With this arrangement, the operational axis of the cylinder unit can be different from that of the suspension unit, whilst still cooperating to effect control of position and movement in the same direction.

[0017] Each cylinder unit may be secured, directly or indirectly, to the base portion or suspended portion of the vehicle. The cylinder unit may be secured at one end to the base portion or suspended portion and at the other end to the suspension unit.

[0018] In a further aspect, the invention broadly provides a control system, such as for use on a vehicle, machine, building or the like having a suspended portion moveably supported upon a base portion, the base portion comprising ground-engaging means, wherein the control system comprises: a cylinder unit arranged for operative coupling between the suspended portion and the base portion of the vehicle, such that the cylinder unit is operable to control a distance between the base portion and the suspended portion; a controller configured to operate the cylinder unit to control a relative position, orientation and / or motion of the suspended portion and the base portion of the vehicle.

[0019] Preferably, the control system comprises a plurality of cylinder units each operable to control a respective distance between the base portion and the suspended portion. The respective distance may be a distance between mounting points on the suspended portion and base portion of the vehicle.

[0020] The vehicle, machine, building, etc in which the control system is for incorporation may be referred to as the subject. Preferably, the subject comprises a suspension system for resiliently supporting the suspended portion upon the base portion. Preferably, the cylinder unit is arranged to operatively couple to the suspension system to provide a cooperative assembly for movably and resiliently supporting the suspended portion upon the base portion. Preferably, the control system comprises a plurality of cylinder units each arranged to couple to a respective suspension unit of the suspension system of the subject.

[0021] In some examples, the cylinder unit is secured between mounting points on the suspended portion and the base portion of the subject, e.g. a vehicle, such that the suspended portion is supported upon the base portion substantially directly.

[0022] Preferably, each cylinder unit of the plurality of cylinder units is configured for securing to a respective suspension unit in an inline configuration, such that the operational axis of the cylinder unit is parallel to and aligned with the operational axis of the suspension unit.

[0023] Preferably, each cylinder unit comprises an end having a recessed portion for housing a portion of a shock of a respective suspension unit.

[0024] Preferably, each cylinder unit is configured for securing to a respective suspension unit in a parallel configuration, such that the operational axis of the cylinder unit is parallel to and laterally offset from the operational axis of the suspension unit.

[0025] Preferably, each cylinder unit is configured for coupling to a respective suspension unit via a link or mechanism, preferably a pivotal link such as a bell crank.

[0026] Preferably, the controller is configured to operate one or more cylinder units to extend or retract for at least partially offsetting compression or extension of one or more respective suspension units of the suspension system.

[0027] The control system may compensate for, counteract, or substantially cancel out the change in the relative position, orientation and / or motion betweenthe suspended portion and the base portion of the vehicle caused by compression or extension of the suspension system.

[0028] The control system may be configured to retract a cylinder unit of the plurality of cylinder units by a distance substantially equivalent to a distance moved by a respective mounting point on the base portion in a direction toward a respective mounting point on the suspended portion. The control system may be configured to extend a cylinder unit of the plurality of cylinder units by a distance substantially equivalent to a distance moved by the respective mounting point on the base portion in a direction away from the respective mounting point on the suspended portion. The distance moved may be a result of e.g., vehicle acceleration or deceleration, vehicle steering (i.e., a change in steering angle) or other manoeuvre.

[0029] The controller may be configured to operate the cylinder units based on information from sensors, such as a gyroscopic sensor, an accelerometer, a compass, a magnetometer, an Inertial Measurement Unit (IMU), a steering-angle sensor, a speedometer, a vehicle speed sensor, a brake pressure sensor, a throttle position sensor, a cylinder position sensor, a suspension position sensor, or a combination thereof. Other examples of sensors are provided below.

[0030] Preferably the controller is configured to operate one or more cylinder units for substantially maintaining the position of the suspended portion relative to the base portion of the vehicle, for substantially maintaining a target ride height of the vehicle. With this arrangement, the control system can maintain a substantially consistent ride height, in accordance with a desired ride height, or target ride height, of the vehicle, notwithstanding compression or extension of the suspension system such as caused by ground surface conditions or vehicular manoeuvres.

[0031] Preferably, the controller is configured to operate one or more cylinder units for maintaining a substantially horizontal orientation of the suspended portion. With this arrangement, the control system is adapted for levelling control.

[0032] The controller may receive an orientation value from at least one sensor relating to the orientation of the vehicle, wherein the orientation value relates to a current angle between the suspended portion of the vehicle and a horizontal plane. If the present angle is greater than a previous angle or deviating sufficiently from the horizontal plane, then the controller may send an outputsignal, such as to the power system, to extend or retract said cylinder unit to reduce the angle between the suspended portion of the vehicle and the horizontal plane.

[0033] Preferably, the controller is configured to identify a mode of motion of the suspended portion relative to the base portion of the vehicle based on information received from one or more sensors or instruments of the control system and / or vehicle, and to control the one or more cylinder units in accordance with the identification so as to cancel out or attenuate said motion.

[0034] Preferably, the controller is configured to identify a mode of motion based on information pertaining to:a linear movement or change in linear position of one or more suspension units;vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;vehicle speed;vehicle acceleration, and / or an acceleration of the suspended portion or base portion of the vehicle along or about one or more axes (such as the vertical axis);elevation of the suspended portion of the vehicle.

[0035] Preferably, the control system further comprises one or more of: one or more accelerometers for measuring acceleration of one or more portions of the vehicle about one or more axes;one or more inertial measurement units;one or more inclinometers for monitoring the elevation and / or orientation one or more portions of the vehicle;an instrument for monitoring vehicle speed;an instrument for monitoring steering angle;one or more sensors for measuring the linear positions of one or more suspension units;a brake pressure sensor;a throttle position sensor.

[0036] Preferably, the control system is configured to identify the mode of motion based on information (first information) received from a first set of sensors, and to identify or categorise a cause of the mode of motion based on information (second information) received from a second set of sensors.

[0037] The cause of the motion may be identified as external, such as due to ground surface conditions, or due to vehicular control, such as steering, accelerating or braking.

[0038] Preferably, the first set of sensors is adapted for monitoring motion, acceleration and / or force, and the second set of sensors is adapted for monitoring vehicular control.

[0039] The first set of sensors may include, for example, sensors for monitoring the length of the suspension units, sensors for monitoring ride height, accelerometers or the like for measuring acceleration or force along or about an axis (e.g., a longitudinal axis, vertical axis, or lateral axis of the vehicle).

[0040] Preferably, the controller is configured for identifying one or more of roll, pitch, yaw, heave or warp.

[0041] The controller may be configured to calculate a response to the identified motion based at least in part on one or more of: vehicle speed; vehicle steering angle; vehicle braking pressure or throttle position.

[0042] Preferably, the controller is configured to calculate a response based at least in part on a drive mode setting, preferably wherein the drive mode setting is selected from a set comprising of one or more of: road mode; track mode; A / T mode.

[0043] Preferably, the controller is configured to prioritise maintaining a substantially consistent ride hide of the vehicle in accordance with a selection of road mode.

[0044] The controller may be configured to prioritise producing a desirable orientation of the suspended portion in accordance with a selection of track mode.

[0045] The controller may receive an orientation value from a sensor relating to a first orientation of the suspended portion of the vehicle and a speed value from a sensor relating to the speed of the vehicle and a steering angle value from a sensor relating to the steering angle of the vehicle. The controller may send an output signal, such as to the power system, to control at least one of the cylinder units to hold, extend, or retract said cylinder unit to move the suspended portion of the vehicle to a second orientation, wherein the second orientation was calculated based on the speed value and the steering angle.

[0046] Preferably, the controller is configured to produce a desirable lean angle of the suspended portion during cornering, in accordance with a selection of track mode.

[0047] Preferably, the controller is configured to prioritise maintaining a substantially horizontal orientation of the suspended portion in accordance with a selection of A / T mode.

[0048] Preferably, in response to an identification of roll motion, the controller is configured to extend one or more cylinder units on one side of the vehicle and / or retract one or more cylinder units on the other side of the vehicle.

[0049] In the case of roll motion due to cornering, the controller may extend cylinder unit(s) on the outside of the corner and / or retract cylinder unit(s) on the inside of the corner.

[0050] Preferably, in response to an identification of pitch motion due to deceleration, the controller is configured to extend one or more cylinder units at the front of the vehicle, and / or in response to an identification of pitch motion due to acceleration, the controller is configured to extend one or more cylinder units at the rear of the vehicle.

[0051] Preferably, in response to an identification of pitch motion due to deceleration, the controller is configured to retract one or more cylinder units at the rear of the vehicle.

[0052] Preferably, in response to an identification of pitch motion due to acceleration, the controller is configured to retract one or more cylinder units at the front of the vehicle.

[0053] Preferably, the controller may both extend and / or retract the one or more cylinder units at the respective front and rear of the vehicle in response to the deceleration or acceleration.

[0054] The controller may also, or alternatively, control the cylinder units at the opposite end of the vehicle to perform the opposite operation.

[0055] Preferably, the controller is configured to operate the plurality of cylinder units to adjust the relative position between the suspended portion and the base portion of the vehicle, thereby adjusting a ride height of the vehicle.

[0056] Preferably, the controller is configured to adjust the ride height based on information pertaining to one or more of:vehicle speed;user input;drive mode;driving conditions and / or vehicle conditions.

[0057] Preferably, the controller is configured to lower the ride height based on an increase in vehicle speed.

[0058] The control system may receive information pertaining to vehicle speed from one or more sensors or instruments of the control system or vehicle. The control system may compare the information to a threshold and, in accordance with a determination that the threshold is met or surpassed, the control system may lower the ride height, such as by a predetermined amount.

[0059] The controller may receive a position value from a sensor relating to a first ride height of the suspended portion of the vehicle and a speed value from a sensor or instrument relating to the speed of the vehicle. The controller may send an output signal, such as to the power system, to control at least one of the cylinder units to hold, extend, or retract said cylinder unit to move the suspended portion of the vehicle to a second ride height, wherein the second ride height was calculated based on the speed value.

[0060] Preferably, each of the plurality of cylinder units is operably coupled to at least a portion of the suspension system.

[0061] Preferably, the suspension system comprises a plurality of suspension units and wherein each of the plurality cylinder units is operably coupled to a respective suspension unit.

[0062] A suspension unit may comprise a spring (e.g., a coil spring) and a shock damper, preferably arranged in a coil-over-shock configuration. The suspension unit may be mounted directly or indirectly to the base portion of the vehicle or the suspended portion.

[0063] Preferably, the control system further comprises a power system for actuating the cylinder units, wherein the controller is communicatively coupled to the power system for controlling the operation of the cylinder units.

[0064] Preferably, the cylinder units are, or comprise, hydraulic cylinders, and wherein power system is a hydraulic power system.

[0065] The power system may comprise: a hydraulic motor, a hydraulic pump, a hydraulic reservoir, and a plurality of control valves. The power system may comprise a plurality of hydraulic sub-systems, wherein each hydraulic subsystem comprises: a hydraulic motor, a hydraulic pump, a hydraulic reservoir, and a control valve.

[0066] In a further aspect, the invention broadly provides a cylinder suspension module for use in the control system of any preceding claim forresiliently supporting the suspended portion upon the base portion of the vehicle, the cylinder suspension module comprising: a cylinder unit cooperatively coupled to a suspension unit so as to control a functional length of the cylinder suspension module, thereby controlling a distance between the base portion and the suspended portion of the vehicle.

[0067] Preferably, the cylinder unit is coupled to the suspension unit in an inline configuration, such that the operational axis of the cylinder unit is parallel to and aligned with the operational axis of the suspension unit.

[0068] Preferably, the cylinder unit is coupled to the suspension unit in a parallel configuration, such that the operational axis of the cylinder unit is parallel to and laterally offset from the operational axis of the suspension unit.

[0069] Preferably, the cylinder unit is coupled to the suspension unit via a link or mechanism.

[0070] Preferably, the cylinder unit is coupled to the suspension unit via a bell crank.

[0071] Preferably, the suspension unit comprises a spring and a shock, preferably arranged in a coil-over shock configuration.

[0072] In a further aspect, the invention broadly provides a vehicle comprising the control system as defined in any of the statements above, or the cylinder suspension module as defined in any of the statements above.

[0073] In a further aspect, the invention broadly provides a machine or building, comprising the control system as defined in any of the statements above, or the cylinder suspension module as defined in any of the statements above.

[0074] In a further aspect, the invention broadly provides a method of controlling the position, orientation and / or motion of a suspended portion of a vehicle relative to a base portion of a vehicle via a ride control system, the method comprising: receiving input by the controller, such as from one or more sensors or instruments of the control system and / or vehicle; producing, by the controller, output based on the input to operate one or more of the plurality of cylinder units so as to control a relative position, orientation and / or motion of the suspended portion and the base portion of the vehicle.

[0075] The ride control system may be as defined above.

[0076] Preferably, the input contains or relates to information pertaining to one or more of:a linear movement or change in linear position of one or more suspension units;vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;vehicle speed;vehicle acceleration or acceleration of the suspended or base portion of the vehicle along or about one or more axes;elevation of the suspended portion of the vehicle.

[0077] Preferably, the method further comprises identifying, by the controller, a mode of motion of the suspended portion of the vehicle based on the input, and determining, by the controller, the output based on the identified mode of motion.

[0078] Preferably, the method comprises receiving input by the controller identifying a change in length of a suspension unit, such as caused by compression or droop, and producing by the controller an output to operate a cylinder unit associated with the suspension unit to counteract the identified change in length of the suspension unit.

[0079] In a further aspect, the invention provides a method of substantially maintaining a target ride height of a vehicle using the control system, the method comprising: receiving, by a controller, information pertaining to one or more of:a linear movement or change in linear position of one or more suspension units;vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;vehicle speed;acceleration;elevation of the suspended portion of the vehicle;identifying, by the controller based on said information, a mode of motion of the suspended portion of the vehicle;in response to identifying the mode of motion, operating, by the controller, one or more cylinder units to extend or retract so as to cancel out or attenuate said motion.

[0080] Preferably, the step of receiving the information comprises receiving first information (such as from a first set of sensors) for identifying the mode of motion and receiving second information (such as from a second set of sensors)for identifying a cause of the motion or for categorising the motion (such as external or vehicular control).

[0081] Preferably, the method further comprises identifying, by the controller, a drive mode of the vehicle, and determining the output based at least in part of the identified drive mode.

[0082] In a further aspect, the invention broadly provides a method of compensating for roll motion. In a further aspect, the invention broadly provides a method of compensating for pitch motion. In a further aspect, the invention broadly provides a method of compensating for heave motion. In a further aspect, the invention broadly provides a method of compensating for yaw motion. In a further aspect, the invention broadly provides a method of compensating for warp motion. In a further aspect, the invention broadly provides a method of performing a levelling adjustment of a vehicle. In a further aspect, the invention broadly provides a method of adjusting a target ride height of a vehicle.

[0083] Unless otherwise noted, one or more statements relating to one aspect may equally apply to another aspect(s).BRIEF DESCRIPTION OF THE DRAWINGS

[0084] The invention will now be described by way of example only and with reference to the drawings in which:

[0085] Figure 1 shows a vehicle incorporating a control system according to an example of the invention.

[0086] Figure 2A shows an exploded elevation view of a cylinder suspension module according to one example of the invention, for use in a control system of the invention.

[0087] Figure 2B shows a cross-section elevation view of the cylinder suspension module of Figure 2A.

[0088] Figure 3 shows a cross-section elevation view of a cylinder unit of a cylinder suspension module according to one example of the invention.

[0089] Figure 4 shows a cross-section elevation view of a cylinder suspension module according to one example of the invention.

[0090] Figures 5A-B and 6A-B show examples of clamps for securing a cylinder unit to a suspension unit according to the invention.

[0091] Figures 7A-B show an elevation view of a cylinder suspension module according to a further example of the invention.

[0092] Figure 8A shows a front elevation view of a vehicle incorporating a control system according to one example of the invention.

[0093] Figures 8B-C show a side elevation view of example assemblies for coupling between the base portion and the suspended portion of the vehicle according to the invention.

[0094] Figure 9A shows a plan view of a vehicle incorporating four cylinder units according to one example of the present invention.

[0095] Figure 9B shows a side elevation view of the vehicle of Figure 9A.

[0096] Figure 9C shows a side elevation view of the vehicle of Figure 9A-B performing a levelling adjustment according to one example of the invention.

[0097] Figure 9D shows a front elevation view of Figure 9C.

[0098] Figure 10A-C show front elevation views of a vehicle undertaking a cornering manoeuvre according to examples of the invention.

[0099] Figure 11 shows a schematic diagram of power subsystem for powering a cylinder unit of a cylinder suspension module according to one example of the invention.

[0100] Figures 12A-B show schematic diagrams of hydraulic valve units according to examples of the invention.

[0101] Figures 13A-B show schematic diagrams of a hydraulic system according to an example of the invention.

[0102] Figure 14 shows a schematic diagram of a vehicle incorporating a control system according to an example of the invention.DETAILED DESCRIPTION OF THE INVENTION

[0103] The present invention relates to a control system for use on a subject, such as a vehicle, machine, building, etc., having a suspended portion moveably supported on a base portion, wherein the control system is configured to control the relative position, orientation and / or motion between the suspended portion and the base portion or ground surface. The control system may in some contexts be referred to as a ride (or ride height) control system, or motion control system.

[0104] Figure 1 shows a generalised schematic of a control system employed on a vehicle 10. The vehicle comprises a base portion 11 and a suspended portion 12, wherein the suspended portion 12 is supported on the base portion 11 at a distance DI above the ground surface 5. The base portion 11 of the vehicle is shown to comprise wheels 13 (two visible) but may comprise any number ofwheels, legs, feet, tracks, or other ground-engaging means for bearing upon and moving across a surface. The base portion 11 may be a connected or unitary portion, or a distributed system of independent wheels, legs, feet, tracks, etc., that cooperate to support the suspended portion but are separately coupled thereto. Both are considered 'portions' in the context of the invention. The suspended portion may comprise a chassis, body, etc., of the vehicle and is the part that may, for example, carry vehicle occupants in some contexts. The suspended portion may be referred to as the body.

[0105] A longitudinal axis x of the vehicle refers to an axis along the fore-and-aft direction of the vehicle, extending through front and rear of the vehicle, preferably through the vehicle centre. A lateral (or transverse) axis z of the vehicle refers to an axis along the side-to-side direction of the vehicle, preferably through the vehicle centre. A vertical axis y of the vehicle refers to an axis along the up-down direct of the vehicle, preferably extending through the vehicle centre. The three axes are substantially perpendicular.

[0106] The control system comprises a controller 20, a power system 30, and one or more cylinder units 40 operable to extend and retract to control the distance between respective mounting points 14, 15 on the base 11 and suspended 12 portions of the vehicle. The cylinder unit 40 may be or comprise a linear actuator, such as a hydraulic cylinder, or an electrical linear actuator. The cylinder unit(s) 40 is powered by the power system 30 and controlled by the controller 20. The controller 20 may be communicatively coupled to the power system 30 to control the cylinder unit(s) 40 via the power system 30, or may control the cylinder unit(s) 40 directly.

[0107] In preferred examples, the cylinder units are arranged for integration with vehicles having suspension systems, preferably such that the functions of the suspension (compression, damping, rebound, etc.) are substantially unimpeded (e.g., with respect to the ranges of travel). The suspension systems may comprise springs, or assemblies of springs and shock dampers, on which the suspended (i.e., sprung) portion of the vehicle is resiliently supported, such that the suspended portion of the vehicle is able to move relative to the base (i.e., unsprung) portion of the vehicle in an energy absorbing manner. The suspension system of a vehicle typically comprises a suspension unit 50 associated with each wheel. The cylinder unit 40 is preferably integrated with, or coupled to, a suspension unit 50 of the vehicle, and the assembly of the two units may bereferred to as a cylinder suspension module 100. The invention is described mainly in this context, but this is not intended to be limiting; the control system may also be integrated with vehicles that do not have a suspension system.

[0108] The cylinder units 40, or cylinder suspension modules 100 as appropriate, each couple between respective mounting points on the base portion and suspended portion of the vehicle, such that the suspended portion 12 is at least partially supported on the base portion 11 via the cylinder units 40 (or cylinder suspension modules 100 comprising said units). It will be appreciated that the coupling between mounting points of the vehicle provided by the cylinder units may be an operative coupling and may therefore be direct or indirect. Additionally, the cylinder suspension modules are not necessarily disposed (i.e., physically located) entirely between those mounting points, though this is possible in some configurations (refer to the examples below). In the case of cylinder suspension modules, the suspended (sprung) portion of the vehicle is supported on the base (un-sprung) portion via one or more such cylinder suspension modules, wherein the suspension unit(s) provides suspension between the two mounting points, while the cylinder unit(s) is operable to control the distance between the two mounting points, preferably in a way that keeps the functions of the suspension system substantially unimpeded (e.g., with respect to the ranges of travel and other properties of the suspension, like spring rate).

[0109] The cylinder units 40 may be installed with suspension 50 as part of a cylinder suspension module 100 according to any of the examples described below in relation to Figures 2A-7B, or other arrangement described in this specification. The cylinder units 40, or cylinder suspension modules 100, may be coupled (directly or indirectly) to the wheels or other means of locomotion according to any of the examples described in relation to Figure 8A-C, or other arrangement described in this specification. The skilled person will understand how the general principles described here can be achieved with any of these arrangements.

[0110] It will be apparent that each cylinder unit 40 can be used to control the distance D2 (e.g., vertical separation) between the associated mounting points, thereby controlling the distance between the suspended portion 12 of the vehicle and the base portion 11 and, as a result, the distance DI between the suspended portion 12 of the vehicle and the ground surface 5, i.e., the ride height. The distance between the suspended portion 12 and the base portion 11 may bethe distance between any two points thereon, which may be different. The same is true for the distance DI with respect to the suspended portion of the vehicle. Typically, the ride height relates to the lowest part of the suspended portion (chassis or body) but for the purposes of the present invention the term is used more broadly with respect to the reference location on the suspended portion. The ride height may also be considered on a point-by-point (e.g., unit-by-unit) basis.

[0111] The cylinder units 40 may be controlled 'statically' - that is, having a substantially constant or predetermined effect, such as a persistent change to a nominal, or 'target', value - or 'dynamically' - that is, having a variable or responsive effect, such as in response to impulses or other inconstant external influences.

[0112] An example of 'static' control is an adjustment in the nominal (i.e., 'target') ride height of a vehicle. The cylinder units can be used to modify or adjust the target ride height by extending or retracting to increase or decrease the nominal distance DI between the suspended portion and the base portion of the vehicle, thereby increasing or decreasing the nominal distance D2 between the suspended portion and the ground surface. Nominal values (distances, ride height, etc) may be averages, or those values under predetermined conditions, while the actual values may fluctuate in response to impulses or other transient influences.

[0113] The target ride height may be adjusted by the controller based on, for example, user selection, drive mode, vehicle speed, vehicular conditions, surface conditions (e.g., gravel, road), loading, clearance (e.g., manoeuvring over obstacles), etc. In some circumstances, the ride height adjustment may be used to facilitate inspection or maintenance (i.e., raising the vehicle, akin to jacking). The cylinder units may also, or alternatively, be locked in an immobilising or motion-limiting position for e.g., theft prevention. The cylinder units may also be locked in position when not being actuated for stiffness.

[0114] Where there are multiple cylinder units, the controller may extend or retract the cylinder units in concert, or at least by the same amount, to apply the adjustment universally (e.g., to maintain the orientation of the suspended portion).

[0115] In some circumstances, it may be desirable for the cylinder units to be controlled unevenly to change the orientation of the suspended portion of the vehicle relative to the base portion or ground surface, such as for levelling (e.g., in response to a sloped surface) or to produce a desirable angle for aerodynamicor performance reasons. In one example, discussed in greater detail below in relation to Figure 9A-D, the controller extends and / or retracts the cylinder units on one side of the vehicle to level the suspended portion against an uneven or sloped ground surface. In such cases, the controller may extend or retract the cylinder units individually or in groups, to apply the adjustment locally.

[0116] The cylinder units may be controlled dynamically or actively to counteract (e.g., limit, reduce, attenuate, or cancel-out) transient or variable effects that might otherwise (at least momentarily) perturb the distance between the suspended portion and the base portion of the vehicle (and hence the ride height), or the relative orientation or motion therebetween. Such effects may be produced by, for example, uneven (e.g., rough or featured) surface conditions, or during dynamic situations like braking, accelerating, or cornering. This may be particularly relevant for vehicles having suspension systems, which compress, droop and rebound as the base and / or suspended portions of the vehicle are subjected to forces. In some circumstances, the cylinder units may be controlled dynamically to substantially maintain the target ride, or at least to counteract or reduce deviations from the target ride height, notwithstanding the aforementioned effects. In some circumstances, the cylinder units may be controlled dynamically to substantially maintain the orientation of the suspended portion of the vehicle (e.g., to substantially prevent, or at least reduce, pitch of the suspended portion during acceleration or braking, or roll of the suspended portion during cornering). In some circumstances, the cylinder units may be controlled dynamically to effectively cancel, or at least attenuate / reduce, relative motion between the suspended portion and the base portion. With this arrangement, the stability and performance of the vehicle can be improved, among other benefits discussed later. In some circumstances, the cylinder units are controlled to produce such dynamic changes in position, orientation or motion as may be desired. For example, the cylinder units may be operated such that the vehicle 'leans-in' when cornering, or to generate 'bounce' to aid in freeing a stuck vehicle.

[0117] The control functions can be provided at each cylinder unit location, either individually (i.e., at any location without affecting other locations), in multiples or groups (e.g., grouping transversely, longitudinally or diagonally), or all at once. The control can be automatic (e.g., instigated by the controller based on sensor feedback) or on-demand (e.g., by user selection).

[0118] The control is preferably undertaken based on information from sensors. In particular, the inventor has recognised that certain modes of motion associated with suspension systems have defined characteristics that can be identified by the controller based on feedback from system sensors. Identifiable modes of motion may include roll (e.g., during cornering), pitch (e.g., during braking or accelerating), warp, yaw, and heave. The identification of these known modes of motion can then enable the controller to compensate such motion, with a view to e.g., maintaining the target ride height, via appropriate actuation of the cylinder units. Other motion that does not have distinct characteristics or is not identified as a particular known mode of motion (e.g., random compression and rebound of the suspension units) may not be regulated by the controller (e.g., bypass filtered without a response from the system).

[0119] With this arrangement, the control system can avoid (i.e., cancel-out) or at least limit undesirable body motions caused by the known modes of motion for vehicles having suspension systems and may function to substantially maintain ride height during such modes of motion.

[0120] As discussed above, the existing suspension unit 50 of the vehicle is not actively controlled by the controller. Instead, the suspension unit 50 functions independently so that, for instance, it retains the full movement of the suspension unit 50. However, the suspension unit 40 may react, e.g. passively, to the actuation of the cylinder unit 40. In some arrangements, the controller exclusively controls the cylinder unit 40.

[0121] Examples of such control are discussed further below.

[0122] The above discussion, and much of that below, uses a vehicle as an exemplary context. Vehicle may include for example passenger or transport vehicles, but may also include vehicles for agriculture, commerce, leisure, lunar, military, motorsport, and other sports. In further examples, the control system may be arranged for use on a non-locomotive subject, such as a machine, structure, or building that comprises a base portion (e.g., a foundation of a building) and a suspended portion moveably supported thereon. In some situations, machinery or structures may include suspension systems between the suspended portions and base portions, akin to that of vehicles. The term 'ride height' should be interpreted accordingly as 'height-to-surface' or the like. In general, the invention may be employed on various subjects having one portion moveably coupled to another portion that bears upon the ground, including butnot limited to vehicles, machines, buildings, structures, or other bodies. The invention may be particularly advantageous where the suspended and / or base portions are subject to external effectors that influence their relative motion, position, and / or orientation, and may in some examples be arranged to reduce or cancel such external effectors, or at least provide a degree of control.Cylinder Unit & Cylinder Suspension Module

[0123] The control system comprises one or more (preferably a plurality of) cylinder units 40 each arranged to extend and / or retract to control a distance between respective points of the base portion 11 and suspended portion 12 of a vehicle 10, thereby enabling control of the position, orientation and / or motion of the suspended portion 12 relative to the base portion 11 and / or ground surface 5. Such control may involve maintaining and / or adjusting one or more cylinder units to maintain or adjust the position, orientation and / or motion as described previously. The cylinder unit 40 may be or comprise a linear actuator, such as a hydraulic cylinder, or an electrical linear actuator. The cylinder unit may be controlled by a controller 20 and powered by a power system 30 (discussed below).

[0124] The cylinder unit is preferably coupled to (e.g., integrated with) a suspension unit 50 of the vehicle in a cooperative manner and the cooperative assembly of the two units may be referred to as a cylinder suspension module 100. With this arrangement, the suspended portion 12 of the vehicle is supported on the base portion 11 via one or more such cylinder suspension modules 100, each defining a respective distance between the suspended portion 12 (e.g., a mounting point thereon) and the base portion 11 (e.g., a mounting point thereon). The cylinder suspension module 100 may be characterised by an operative, or functional, length, which depends on the length (i.e., linear position) of both the cylinder unit 40 and the suspension unit 50. The length is functional in the sense of being an effective length that influences the distance between the vehicle portions, which may be different from the actual length of the two units (such as where links or mechanisms are used). The control system can control the functional length of the module by controlling the extension or retraction of the cylinder unit. In this way, the suspension unit is able to provide suspension between the two portions, while the cylinder unit is operable to control the distance between the two portions (or points thereon), preferably such that the functionsof the suspension system are substantially unimpeded (e.g., with respect to the ranges of travel and / or spring rates).

[0125] The cylinder unit 40 and suspension unit 50 may be operatively coupled in various configurations, such as an inline configuration, a parallel configuration, or a non-parallel configuration via one or more intermediate components.

[0126] A first example of a cylinder suspension module 100 comprising of a cylinder unit 40 and a suspension unit 50 arranged in an inline configuration is shown in Figures 1A-B. The cylinder unit 40 and the suspension unit 50 are secured 'end-to-end' in series, such that the operational axis of the cylinder unit 40 is aligned (parallel to and in line) with that of the suspension unit 50. In this example, the cylinder unit 40 is secured to a mounting point 14 on the base portion 11 and the suspension unit 50 is secured to a mounting point 15 on the suspended portion 12, such that the cylinder unit 40 is located below the suspension unit 50. Hence, the cylinder unit 40 is coupled to the suspended portion 12 indirectly, via the suspension unit 50. This arrangement of the cylinder suspension module 100 may be referred to as a 'suspension-over' configuration, in which the cylinder unit 40 is secured to the base portion 11 of the vehicle and arranged below the suspension unit 50, itself secured to the suspended portion 12. This is just one example and in other examples the cylinder suspension module 100 may be in a 'suspension-under' configuration, in which the cylinder unit 40 is secured to the suspended portion 12 of the vehicle and arranged above the suspension unit 50, itself secured to the base portion 11.

[0127] The cylinder unit 40 is illustrated as a hydraulic cylinder having a cylinder body 41 and a cylinder rod 42 ("ram" or "piston"). The cylinder body may comprise a hydraulic extension inlet / outlet port 43 ("extension inlet / outlet") and a hydraulic retraction inlet / outlet port 44 ("retraction inlet / outlet") for hydraulically actuating the cylinder unit 102 to extend or retract the cylinder rod 42. In this example, the cylinder rod 42 is arranged for securing to a mounting point 14 on the base portion of the vehicle, such as via a corresponding mount 45 at the end of the cylinder rod 42, while the body of the cylinder is arranged for securing to the suspension unit, such as via an internal cavity or through-hole 46 of the cylinder body arranged for receiving a portion of the suspension unit (e.g., an end of a shock 52). The retraction of the cylinder unit 40 does not require any external force (including gravity) to retract the cylinder rod 42. The retraction may becontrolled solely by the hydraulic fluid. Notably, in some arrangements, the retraction is active.

[0128] The cylinder unit 40 may be a hollow cylinder (i.e., having an annular cylinder rod 42), as shown in Figure IB. This can provide a more compact configuration that, in the retracted position, houses at least a portion of the suspension unit (e.g., the end of the shock 52) within both the body and ram of the cylinder. In other examples, the cylinder unit 102 may not be a hollow cylinder. Figure 3 shows a second example of an inline cylinder suspension module 100 in which the cylinder unit 40 comprises a solid cylinder rod 42. Here, the body of the cylinder unit comprises a recess for receiving a portion of the suspension unit 50. Preferably, the recess comprises an inset female thread 47 arranged to mate with an external thread at the end of the suspension unit (e.g., shock 52), such that the suspension unit 50 can be fastened to the end 48 of the cylinder unit. The cylinder unit may otherwise be substantially the same as that of Figure 1, comprising extension and retraction inlet / outlets 4442 for hydraulic actuation and a mount 45 at the end of the cylinder rod 42 for connection to the base portion 11 (or suspended portion 12) of the vehicle 10.

[0129] Various alternative configurations for the cylinder unit, or modifications thereof, will be apparent to the skilled person. For example, the cylinder unit could be arranged such that the cylinder rod secures to the suspension unit, while the cylinder body secures to the base portion (or suspended portion). Any suitable cylinder unit and configuration thereof could be used in any of the examples discussed herein.

[0130] The cylinder unit 40 may be arranged to couple to a conventional suspension unit known to the skilled person. Preferably, the suspension unit 50 comprises a spring 51 (e.g., a coil spring) and a shock damper 52 (also referred to as "shock" or "damper") arranged in a coil-over-shock configuration (i.e., wherein the spring is arranged above the shock). A coil-under-shock arrangement, or other suspension configuration, is also possible.

[0131] One example of a coil-over-shock suspension unit is shown for reference in Figures 2A-B. Here, a coil spring 51 is disposed between two spring caps 53 54 retained between a top hat 55 and a spring seat 56 of a spring portion of the suspension unit 50. The spring seat 56 is supported and / or fixed by a lockring 57 (e.g., a nut, circlip, or other suitable fastener), which is fastened to the body of the shock 52. The shock 52 has a rod 58 that runs through the centreof the spring 51 and is secured (such as by a rod nut 59) to a mounting point on the suspended portion 113 of a vehicle. The top hat 55 may also be fastened to the suspended portion 113, such as with nuts 59. The bottom of the shock 52 is secured to the cylinder unit 102 by a lockring. This is merely one example and other arrangements will be apparent to the skilled person.

[0132] Figures 2A-3 are examples of cylinder suspension modules 100 having an inline configuration, where the cylinder unit 40 is arranged such that, when employed in the cylinder suspension module 100, the cylinder rod axis 101 is parallel to and aligned with the operational axis 102 of the suspension unit 50. The cylinder unit and suspension unit are coupled in series between the base 11 and suspended 12 portions of the vehicle 10, such that the distance between the mounting point on the base portion of the vehicle and the mounting point on the suspended portion is dependent upon the combined length of the suspension unit and the cylinder unit along the axis of the suspension unit. Hence, it will be appreciated that the cylinder unit can be used to control the distance between mounting points of the base and suspended portions. For example, the cylinder unit may be operated to vary the distance between the mounting points. The cylinder unit may also be operated to counteract changes in the length of the suspension unit so as to maintain a substantially constant distance between mounting points. Exemplary operations are discussed in more detail elsewhere.

[0133] The same general function may also be achieved by a parallel configuration, in which the cylinder unit is arranged with an operational axis parallel to, but not in line with, that of the suspension unit. By using a parallel configuration, the invention can further reduce the length of the cylinder suspension module, which may be more suitable where vertical space is limited.

[0134] Figure 4 shows a first example of a cylinder suspension module 100 having a parallel configuration. The cylinder unit 40 and the suspension unit 50 may be, individually, substantially the same as described above for Figures 2A-3. Similarly, the cylinder suspension module 100 is shown in a suspension-over configuration in which the suspension unit 50 is secured to the suspended portion 12 and the cylinder unit 40 secured to the base portion 11. However, this is just one example and the variations already discussed are equally applicable here.

[0135] Unlike the previous examples, the cylinder unit 40 is disposed beside the suspension axis 102 and secured thereto such that the cylinder axis 101 is transversely (i.e., laterally) offset relative to the suspension axis 102 of thesuspension unit 50. Specifically, the cylinder unit 40 is secured to the side of the shock 52 of the suspension unit 50 using a pair of vertically spaced clamps 103 (e.g., shaft collars, pipe clamps, etc.). Some examples of clamps are shown in Figures 5A-B and 6A-B. Figures 5A-B show a clamp 103 having a pair of threaded through-holes 104 each arranged to receive and engage a corresponding threaded portion of the cylinder body 41 or shock body 52, respectively. The body portions of the shock and cylinder may have male threads, and the through-holes of the clamp may have corresponding female threads. Locking rings 105 may be used to lock the threaded cylinder and shock body to the threaded clamp. Figure 6A-B show a split clamp 103 with two halves that secure together to define clamping holes 104 each arranged to receive and restrain the cylinder body 41 and the shock 52, respectively. The clamping holes 104 may be designed with an internal diameter substantially matching the external diameter of the body portion to be clamped. The two halves 103a, b of the split clamp may be secured together and tightened by fasteners, such as the three fasteners 106 shown. The forms of the clamps in Figures 5A-6B may be combined, such that a clamp has one side according to Figures 5A-B (e.g., to secure the cylinder body or shock body, for example) and the other side according to Figures 6A-B (e.g., to secure the other of the cylinder body or shock body, for example).

[0136] The cylinder suspension module 100 configured in a parallel configuration preferably comprises two clamps, spaced apart in the direction of the operational axes 101 102 of the cylinder 40 and shock as shown in Figure 4. However, any number of clamps may be used. Other means for securing the cylinder and suspension units in a parallel configuration will also be apparent to the skilled person.

[0137] Preferably, the cylinder unit 40 is mounted to the base portion 11 with a mount adapter 107, such that the mounting point 14 on the base portion 11 of the vehicle is substantially aligned with operational axis 102 of the suspension unit 50 (and the mounting point 15 on the suspended portion 12). In other words, the mount adapter 107 is configured to offset the cylinder axis 101 of the cylinder unit 40 from the operational axis 102 of the suspension unit 50, whilst maintaining the mounting points 14, 15 substantially inline. This can enable the cylinder unit to be installed on the suspension arm of the vehicle, for example.

[0138] In the examples shown so far, the cylinder unit 40 has been arranged with an operational axis substantially parallel to (either inline or offset) that of thesuspension unit, with the cylinder suspension module disposed between the base and suspended portions of the vehicle. The connection between the cylinder unit and the suspension unit, and between those units and the relevant portions of the vehicle, may be direct or indirect, in the sense of involving intermediate connecting components.

[0139] In some examples, the cylinder unit may be operably coupled to the suspension unit via a mechanism or linkage or the like, such that the cylinder unit can be arranged at an angle to suspension unit (i.e., with the operational axes non-parallel), and / or such that the cylinder module (or suspension unit) can be disposed at a location other than between the base and suspended portions of the vehicle. This may be described as a remote (or distributed, or indirect) configuration of the cylinder suspension module.

[0140] Figures 7A and 7B show examples of cylinder suspension modules 100 in which the cylinder unit 40 is coupled to the suspension unit 50 indirectly via a bell crank 108. The bell crank 108 operably couples the cylinder unit 40 to the suspension unit 50 so as to achieve substantially the same function as previously described whilst allowing the cylinder unit 40 to have a different operational axis (i.e., orientation) from the suspension unit, and / or be installed at a different location (e.g., secured atop the suspended portion as shown).

[0141] In Figure 7A, the cylinder unit is at one end secured to the first mounting point 15 on the suspended portion 12 of the vehicle 10, illustrated as via a pivotal connection, and at the other end to the bell crank via a pivotal connection 109. The suspension unit 50 is at one end secured to the mounting point 14 on the base portion 11 of the vehicle 10, illustrated as via a pivotal connection, and at the other end to the bell crank via a second pivotal connection 110. The bell crank is pivotally mounted to a second mounting point 16 on the suspended portion 12 and is rotatable thereabout in response to e.g., the extension or retraction of the cylinder unit to transfer said displacement to the suspension unit. Hence, the cylinder unit 40 is operably coupled to the suspension unit 50 via the bell crank 108, such that the base portion 11 of the vehicle 10 and the suspended portion 12 are coupled without the cylinder unit 40 necessarily being disposed therebetween (though such arrangements are possible). It will be appreciated that a bell crank 108 is just one example of achieving the desired function and other suitable links or mechanisms are envisaged.

[0142] In some configurations, the bell crank or other suitable link may be located (e.g., secured) at the base portion of the vehicle, and / or with the cylinder unit secured at the base portion of the vehicle. The cylinder unit may also be secured to the opposite portion of the vehicle to that of the linkage.

[0143] The cylinder unit and the suspension unit may be of any of those previously described, and the same modifications in form, type and configuration apply here. Figure 7A shows an example of a coil-over-shock suspension unit 50, as shown previously, while Figure 7B shows a coil-under-shock suspension unit 50 in which the spring 51 of the suspension unit 50 is arranged adjacent the base portion 11 of the vehicle.

[0144] The cylinder suspension module in the remote configuration can facilitate integration with some systems and may enable the suspension unit to operate with reduced interference.

[0145] Any of the examples of cylinder suspension units discussed may be employed in a system having a plurality of such modules, each comprising a cooperative pair of a cylinder unit and a suspension unit as shown. However, in other examples, the number of cylinder units may be different from the number of suspension units (i.e., the number of cylinder units may be more or less than the number of suspension units). For example, a cylinder suspension module may comprise a plurality of cylinder units cooperatively paired to single suspension unit, or one cylinder unit cooperatively paired with a plurality of suspension units. For a vehicle with, say, four suspension units (e.g., one at each wheel), the system may only comprise two cylinder units.

[0146] In some examples, the cylinder unit may not be coupled to any particular suspension unit, such that the cylinder units are installed substantially independently of the suspension units, or the cylinder unit may be integrated into a vehicle without a suspension unit. For example, the cylinder unit may be connected between the base portion of the vehicle and the suspended portion (e.g., connecting between mounting points thereof), while the suspension units of the system are mounted independently (e.g., separately between the suspended portion and base portion of the vehicle), or the suspension units may be absent entirely.

[0147] Figure 8A shows an example of vehicle 10 having cylinder suspension modules installed with various assemblies (two being visible). For simplicity, only the cylinder units 40 are shown, but the cylinder suspension modules may alsocomprise a suspension unit according to any of the previously described examples. Alternatively, the cylinder suspension units may be installed without suspension, as shown.

[0148] The vehicle 10 comprises a suspended portion 12 and a base portion 11, wherein the base portion comprises a plurality of wheels 13 (typically four for a personal vehicle). A cylinder unit 40 (or cylinder suspension module) may be installed at each wheel via an assembly to couple the wheel to the suspended portion of the vehicle. The wheels could equally be legs, feet or tracks.

[0149] A first assembly is shown on the right-hand side and a second assembly is shown on the left-hand side. This is merely for the purposes of explanation and in practice the two side may be the same.

[0150] The first arrangement is shown in greater detail in Figure 8B and comprises a pivot arm 111 moveably connecting a wheel of the base portion to the suspended portion, such that the wheel is moveable vertically relative to the suspended portion via rotation of the pivot arm (shown by the dashed lines). A cylinder unit 40 is connected to the pivot arm 111 at a distance from the pivot point 112 such that the extension or retraction of the cylinder unit 40 causes the pivot arm 111 to rotate about the pivot 112, thereby controlling the height of the suspended portion 12 of the vehicle 10 relative to the wheel and the ground surface 5.

[0151] The second arrangement is shown in greater detail in Figure 8C and comprises a bell crank 108 and pivot arm 111 moveably connecting a wheel of the base portion to the suspended portion, such that the wheel is moveable vertically relative to the suspended portion via rotation of the bell crank and pivot arm (shown by the dashed lines). Here, a cylinder unit 40 is connected to the pivot arm 111 via a bell crank 108 at a distance from the pivot point 16 of the bell crank. Extension or retraction of the cylinder unit 40 can drive the bell crank 108 to rotate about the pivot 16, which in turn rotates the pivot arm 111, thereby controlling the height of the suspended portion 12 of the vehicle 10 relative to the wheel 13 and also the ground surface 5. The bell crank can enable the cylinder unit to be positioned at a desirable location, according to some applications.

[0152] The arrangements shown in Figure 8 may increase the range of movement achievable for the wheel relative to the suspended portion, and thus the distance between the suspended portion and ground surface (i.e., ride height).

[0153] It will be appreciated that these are simplified examples and in practice assemblies connecting a suspended portion to the wheel may include other components besides those illustrated or described.

[0154] As will be appreciated, the fastening, joining, linking and other connecting means used between articles of the invention, or the suspended / base portions, as described or shown in any of the foregoing examples, may be of other suitable forms, including but not limited to, fasteners, welding, shanks, pins, friction fits, clamps, tapers, etc. The examples shown are intended to be illustrative.

[0155] In some examples, the cylinder unit may comprise of a hollow cylinder, a plunger cylinder, a piston cylinder, a single rod cylinder, a dual rod cylinder, a telescopic cylinder, or a combination thereof. The cylinders of the cylinder unit may comprise cushioning against hard impact of its parts when in use, such as through the use of a pad, foam, rubber, Belleville washers, and the like.

[0156] In some examples, the cylinder unit of a cylinder suspension module is installed such that the midpoint of its stroke relates to a nominal or preferred ride height of the suspended portion of the vehicle, such that the cylinder unit comprises adequate stroke length either side of the stroke midpoint to at least compensate for the operational movement of the suspension unit.Control

[0157] It will be apparent from the foregoing discussion that the cylinder units can be used to control the position, orientation and / or motion of the suspended portion of the vehicle relative to the base portion or ground surface, by extending or retracting to control the distance between mounting points on the base portion and suspended portion. Such control is preferably undertaken by a controller 20, which may comprise a central processing unit (CPU) or the like. The controller may be part of a control unit. Preferably, the controller is communicatively coupled to one or more sensors and / or instruments, for receiving information about the control system and / or vehicle so as to control the cylinder units based on said information (e.g., by sending appropriate command signals). Preferably, the controller 20 is communicatively coupled to the power system 30 in order to control the operation of the cylinder units.

[0158] The control system preferably includes a plurality of sensors for providing information pertaining to the position, orientation, and / or motion of the suspended portion and / or base portion of the vehicle. Sensors may be arranged to monitor one or more of: linear position or movement of cylinder units or suspension units, the position or movement of vehicle portions (e.g., via accelerometer(s), inclinometer(s), etc.), as well as information pertaining to the vehicle and vehicle controls, such as vehicle speed, braking, accelerating, steering, etc.

[0159] The controller 20 may receive information from the sensors and determine command signals to be sent to the power system (or directly to the cylinder units) to control the position, orientation, and / or motion of the suspended portion of the vehicle based on the information. For example, the controller may receive information from a sensor (such as a linear position sensor on the suspension unit, or inclinometer on the suspended portion) and determine, based on said information, that (i) a distance between the respective mounting point on the base portion and suspended portion is reducing (or has reduced) (ii) a distance between the respective mounting point on the base portion and suspended portion is increasing (or has increased) and in response command the power system to extend or retract the associated cylinder unit, respectively. The controller may compare feedback from the system sensors to the target ride height or other value. The controller may convert the feedback errors into command signals sent to the power system (e.g., hydraulic system). The controller may use both positive and negative feedback errors to determine the actual response input to the control system and can have more than one feedback loop with the aim being to reduce the feedback errors of the systems sensors (e.g., linear movement sensors) to zero.

[0160] Decisions made by the controller 20 may be dependent upon preprogrammed modes, such as 'road mode', 'track mode', 'A / T mode', which might influence the actions that the controller takes to control the cylinder units. Other modes may include 'Height Select UP' (e.g., for raising the target ride height), 'Height Select DOWN' (e.g., for lowering the target ride height), 'BOUNCE' (e.g., a repeated or oscillatory actions of the cylinders to, for example, free a stuck vehicle), 'OFF / RESET' and 'IGNITION ON / OFF' (e.g., to extend the cylinders from an immobilising retracted position, or to contract the cylinders into said position, respectively). The modes may be selected by an operator (e.g., driver).

[0161] In one example, the controller 20 is arranged to adjust the target ride height based on information received pertaining to vehicle speed. For example, the controller may act to lower the target ride height as speed increases (either continuously, or discretely based on one or more threshold values) to reduce drag and improve stability. The controller may be arranged to adjust the vehicle orientation based on information pertaining to vehicle speed for aerodynamic improvements. The same action(s) may also be taken in response to user selection (see e.g., 'Height Select' modes above).

[0162] In another example, the controller is arranged for a levelling adjustment.

[0163] Figures 9A-D show an example of a vehicle 10 employing four cylinder units 40a-d each associated with (e.g., coupled to, or otherwise installed at or proximate) a respective wheel 13a-d of the vehicle 10 and controlled for a levelling adjustment. As per Figures 8, the vehicle comprises a suspended portion 12 and base portion 11 comprising four wheels 13a-d. The cylinder units may be installed as shown, or as described in relation to Figure 8, or other arrangement herein described. The cylinder units may also be installed with suspension as part of a cylinder suspension module 100 according to any of the examples shown in Figures 2A-7B, or other arrangement described herein. For the sake of simplicity, Figures 9A-D show cylinder units without suspension units, but the skilled person will understand how the general principles described here can be achieved by the cylinder suspension modules.

[0164] Figure 9B shows the vehicle on a flat (i.e., level, horizontal) surface, in which each cylinder unit 40a-d has the same extension establishing a nominal ride height DI. Figures 9C-D show the vehicle on an uneven surface; in particular, the ground is terraced such that the ground surface 5 traversed by the wheels on the righthand side of the vehicle (as seen in Figure 9D) is lower in elevation than that of the lefthand side. The depressed side is also sloped. As a result, the vehicle may ordinarily slump toward the lowest wheel 13a, or even lose contact between a wheel and the lower surface, affecting ride, safety, and performance.

[0165] With the present system, the cylinder units can be adjusted to level the suspended portion 12 of the vehicle 10 whilst substantially maintaining the contact between the four wheels and the ground. In this example, the cylinder units 40b and 40d are extended relative to the cylinder units 40a and 40c (not shown) to offset the stepped height of the ground. The cylinder unit 40d isextended such that the distance D2 between the wheel 13d and the suspended portion is greater than the distance DI to offset the step. The cylinder unit 40b is extended such that the distance D3 between the wheel 13b and the suspended portion is greater than the distance DI and greater than that D2 of the cylinder unit 40d to offset the slope. As such, the suspended portion of the vehicle is kept level (i.e., horizontal). The vehicle 10 may be maintained at a nominal ride height DI in relation to the raised ground, as shown, or the cylinder units on the lefthand side may be retracted (e.g., to achieve a greater offset between the two sides).

[0166] The control system may comprise, or be communicatively coupled to, one or more sensors to feedback information about the system and / or vehicle to the controller for use in making such levelling adjustments. For example, the control system may comprise one or more inclinometers for measuring the angle of the suspended portion (e.g., relative to the vertical, or horizontal), or the elevation between different points thereof. The controller may adjust the cylinder units based on feedback from the inclinometer to maintain the suspended portion as substantially horizontal. The controller may be programmed with an out-of-level threshold and, if met or surpassed by a measurement of the inclinometer, may take action to increase safety, such as slowing the vehicle, or preventing the vehicle from moving further. The control system may comprise linear movement sensors for measuring the extension states of the cylinder units. The controller may for example determine that one or more cylinder units on a depressed surface is fully extended before retracting one or more cylinder units on a raised surface. The controller may prevent the vehicle from moving further into uneven ground when the cylinder units have reached a maximum operating range, or met a threshold.

[0167] In some examples, levelling may be prioritised during a particular vehicle mode, such as A / T mode.

[0168] In preferred examples, the controller is arranged to identify predetermined modes of motion based on sensor feedback and / or information about the vehicle (such as from vehicular instruments) and to control the cylinder units to at least partially counteract such motion, based on known or calculated characteristics of the motion. The controller is preferably also arranged to identify the cause of the motion, which may be a result of external influences (such as changes in ground surface conditions) or vehicular control (such as a driver-initiated manoeuvre). The controller may be configured to use information from afirst set of sensors to identify a mode of motion and to use information from a second set of sensors to identify the cause of the motion or at least differentiate between, for example, external influences and vehicular control, and to control the cylinder units accordingly. The first set of sensors may include sensors arranged for monitoring motion or force about a vehicular axis (e.g., longitudinal, lateral and / or vertical axes of the vehicle) and may include, for example, one or more of: inclinometer(s), accelerometer(s), gyroscope(s), magnetometer(s), sensor(s) for determining the suspension length (e.g., as compared to the length at the target ride height), sensor(s) for determining the cylinder length (e.g., as compared to the length at the target ride height), and sensor(s) for determining the ride height (e.g., chassis to surface). The second set of sensors may include sensors or instruments for monitoring the vehicle or vehicular control and may include, for example, one or more of: steering angle sensor(s), brake pressure sensor(s), throttle position sensor(s), and vehicle speed sensor(s). With this combined data, the controller can identify a mode of motion and differentiate between modes of motion caused by, e.g., changes in surface conditions, and those caused by vehicle control (e.g., driver inputs), which can then be used for improved compensation of the mode of motion or other desired control.

[0169] To identify a mode of motion, the controller may compare feedback from the system sensors (e.g., the first set of sensors) to target values, such as the target ride height, and identify the motion mode currently being experienced. The controller may then convert the feedback errors into command signals back to power system. The controller may use both positive and negative feedback errors to determine the actual response input to the control system and can have more than one feedback loop with the aim being to reduce the feedback errors of the systems linear movement sensors to zero. Known modes of motion may include one or more of roll, pitch, yaw, warp, heave, or other mode of motion having predictable or identifiable characteristics.

[0170] The following examples provide illustrative scenarios of such modes of motion in the context of a wheeled vehicle having suspension. The examples are merely illustrative of the broader concepts of the invention and are not intended to be limiting.

[0171] Roll motion

[0172] A first example scenario is shown in Figures 10A-C, in which a vehicle 10 traverses a banked corner. For simplicity, only the suspended portion 12 of the vehicle is shown, but the vehicle should be understood to comprise a base portion (e.g., comprising four wheels) and a control system according to the invention, as previously described. In this example, the vehicle 10 comprises a suspension system and, preferably, the cylinder units are integrated with suspension units as cylinder suspension modules as per any of the previous examples. Preferably the suspension units are associated with each wheel as 'four-corner suspension'.

[0173] During a turning manoeuvre, the body of the vehicle tends to tilt about the longitudinal axis of the vehicle thereby compressing the two suspension units on the outside of the corner 12a (the righthand side in the figures) and extending the two suspension units on the inside of the corner 12b. In particular, the vehicle tends to 'lean away' from the corner in a motion referred to as 'roll' or 'lean', which may degrade ride, safety, and performance.

[0174] Roll motion occurs about the longitudinal axis of the vehicle and hence the controller may identify roll motion by receiving feedback signals from system sensors, such as the first set of sensors, with information pertaining to e.g., one or more of: acceleration, force, motion associated with motion about the longitudinal axis of the vehicle, and linear movement of the suspension units. The controller may also receive information from the second set of sensors, with information pertaining to e.g., one or more of vehicle speed, steering angle, and, based on said information, the controller can determine that the characteristics are indicative of roll motion from a cornering manoeuvre. If, for example, the controller determines that the steering angle remains substantially neutral (i.e., no steering) then the controller may determine that the roll motion is due to an external influence (road surface conditions, for example) rather than a cornering manoeuvre. Accordingly, the controller can determine appropriate command responses to cope with the roll motion.

[0175] The control system may be operable to cope with this motion in various ways, as desired.

[0176] A first example is shown in Figure 10A, in which the control system operates to prioritise ride height DI across the vehicle. Such operation may be based on a drive mode, such as 'road mode'. In this example, the controller extends the cylinder units on the outside of the corner 12b (righthand side) to compensate for (i.e., 'take up') the shortening of the associated suspension units,due to centripetal force tilting the suspended portion toward the outside of the corner, such that the overall effective length of the module remains substantially unchanged. As such, the distance between mounting points on the suspended portion of the vehicle and the base portion of the vehicle is substantially maintained. On the inside of the corner, the cylinder units may be retracted to compensate for any lengthening of the associated suspension units. The cylinder units on one or both sides may be operated simultaneously.

[0177] Preferably, the control is provided based on sensor feedback as described above. For example, the control system may comprise, or be coupled to, a sensor for measuring the compression / extension of the suspension units, or the forces thereon. The controller may also, or alternatively, receive information about vehicle speed and / or steering angle and take such information into account when making the adjustments.

[0178] A second example is shown in Figure 10B, in which the control system operates to intentionally angle the suspended portion of the vehicle relative to the base portion (and ground surface) such that the vehicle 'leans in' to the corner, as illustrated by D4 on the inside of the corner 12b being smaller than DI on the outside of the corner 12a. This can provide improvements in cornering performance. Such operation may be based on a drive mode, such as 'track mode'. In this example, the control system may operate substantially as described above for Figure 10A, except that the cylinder units on the inside and / or outside are operated such that the inside distance D4 is less than the outside distance DI. As will be appreciated, the lean-in (i.e., 'lean gain') may be achieved by further retraction of the inside cylinders, further extension of the outside cylinders, or both.

[0179] The controller may calculate the lean gain to be applied based on information about the vehicle, such as vehicle speed and / or steering angle.

[0180] A third example is shown in Figure IOC, in which the control system operates to prioritise levelling. Such operation may be based on a drive mode, such as 'A / T mode'. In this example, the control system may operate the cylinder units on the inside and / or outside to counteract the compression / extension of the suspension due to cornering, or remaining stationery on the slope, as already described, as well as offsetting any slope or unevenness in the ground surface. In this example, the distance D6 is greater than the distance D5 to level the suspended portion of the vehicle against the bank of the ground surface.

[0181] Preferably, the control is provided based on sensor feedback such as described above. For example, the control system may comprise, or be coupled to, a sensor for measuring the compression / extension of the suspension units, or the forces thereon. The control system may comprise, or be coupled to, an inclinometer like that described above in respect of Figure 9. The controller 20 may also receive information about vehicle speed and / or steering.

[0182] In any of the examples above, the controller may receive sensor feedback and identify the type of motion as roll motion.

[0183] Pitch motion

[0184] Pitch motion involves a lean or roll of the vehicle about the lateral axis of the vehicle and may occur during vehicle acceleration or deceleration (e.g., braking). Considering, for example, a vehicle as described in Figure 10, it will be understood that a braking or decelerating manoeuvre tends to compress the two front suspension units and extend the two rear suspension units, tilting the body of the vehicle forward relative to the base portion (and ground surface). An accelerating manoeuvre would be expected to have the opposite effect.

[0185] Pitch motion occurs about the lateral axis of the vehicle and hence the controller may identify pitch motion by receiving feedback signals from the system sensors, such as the first set of sensors, with information pertaining to e.g., one or more of: acceleration, force, motion associated with motion about the longitudinal axis of the vehicle, and linear movement of the suspension units. The controller may also receive information from the second set of sensors, with information pertaining to e.g., one or more of vehicle speed, vehicle control (e.g., braking or acceleration) and, based on said information, the controller can determine that the characteristics are indicative of pitch motion from accelerating or decelerating. If, for example, the controller determines that there is no change in throttle position, and / or no braking pressure, then the controller may determine that the pitch motion is due to an external influence rather than a braking or accelerating manoeuvre. Accordingly, the controller can determine appropriate command responses to cope with the pitch motion.

[0186] The control system may be operable to cope with this motion in various ways, as desired. For example, the controller may respond to an identification of a deceleration-induced (e.g., braking) pitch motion by extending the two front cylinder units and retracting the two rear system units, preferablysuch that the target ride height is substantially maintained at each module. The opposite control may be employed to respond to an identification of an acceleration-induced pitch motion. The cylinder units may be controlled simultaneously.

[0187] Heave motion

[0188] Heave motion involves motion along the vertical axis of the vehicle and may occur as vehicle speed increases, due to effects including downforce and ground effect, or as a result of the ground surface (e.g., crests or troughs) causing the effect of weighting or unweighting. Considering, for example, a vehicle as described in Figure 10, it will be understood that a heave motion tends to compress or extend the four suspension units substantially equally, effectively raising or lowering the ride height, respectively.

[0189] Since heave motion involves motion along the vertical axis of the vehicle (i.e., vertical motion), the controller may identify upward or downward heave motion by receiving feedback signals from the system sensors, such as the first set of sensors, with information pertaining to e.g., one or more of: acceleration, force, motion associated with motion about the longitudinal axis of the vehicle, and linear movement of the suspension units. The controller may also receive information from the second set of sensors, with information pertaining to e.g., one or more of vehicle speed. Accordingly, the controller can determine appropriate command responses to cope with the heave motion.

[0190] The control system may be operable to cope with this motion in various ways, as desired.

[0191] For example, the controller may respond to an identification of a downward (compressive) heave motion by extending all four cylinder units simultaneously so as to substantially maintain the target ride height.

[0192] Yaw motion

[0193] Yaw motion involves motion about the vertical axis and may occur during or after manoeuvres, such as after sudden or intense steering, braking or acceleration.

[0194] As such, the controller may identify yaw motion by receiving feedback signals from the system sensors, such as the first set of sensors, with information pertaining to e.g., one or more of: acceleration, force, motion about the verticalaxis. Based on said information, the controller can determine that the characteristics are indicative of yaw motion. The controller may also receive information from a second set of sensors, with information pertaining to e.g., one or more of: vehicle speed, steering angle. Accordingly, the controller can determine appropriate command responses to cope with the yaw motion.

[0195] The control system may be operable to cope with this motion in various ways, as desired. For example, the controller may employ a front-to-total anti-roll moment distribution algorithm for yaw rate control to determine command signals for the appropriate cylinder units, so that the combined length of each module plus its corresponding system unit substantially equals the target ride height, thereby substantially maintaining a consistent ride height and reducing the yaw motion.

[0196] Warp motion

[0197] Warp motion may involve motion about both the longitudinal and lateral axes of the vehicle and may occur as a result of varying ground surface conditions. Considering, for example, a vehicle as described in Figure 10, it will be understood that a warp motion tends to either compress or extend the two diagonally opposed suspension units while extending or compressing the suspension units of the other diagonal in the opposite manner.

[0198] The controller may identify warp motion by receiving feedback signals from the system sensors, such as the first set of sensors, with information pertaining to e.g., one or more of: acceleration, force, motion associated with motion about the longitudinal and lateral axes of the vehicle, and linear movement of the suspension units. The controller may also receive information from the second set of sensors, with information pertaining to e.g., vehicle speed. Based on said information, the controller can determine that the characteristics are indicative of warp motion. Accordingly, the controller can determine appropriate command responses to cope with the warp motion.

[0199] The control system may be operable to cope with this motion in various ways, as desired. For example, the controller may respond to an identification of warp motion by (e.g., simultaneously) extending diagonally opposed cylinder units subject to compression and (e.g., simultaneously) retracting diagonally opposed cylinder units subject to extension, so as tosubstantially maintain the target ride height at each module location and reduce the vehicle warp motion.

[0200] The above examples are merely illustrative and the skilled person will appreciate how the general principles can be applied to other examples (e.g., other vehicles, suspension arrangements, or control system arrangements).

[0201] In general, the control system of the present invention can result in improvements in stability, handling, predictability (e.g., in steering and / or braking), ride comfort, safety, and fuel economy. The control system can provide a shorter braking distance, a better tyre contact patch and traction (e.g., due to not needing as much camber and the wheels being more perpendicular to the surface), and reduced drag and aerodynamic improvements. The control system can avoid the need for conventional anti-sway or roll control bar system and the like.Power System

[0202] The power system 30 is a means of actuating (e.g., extending or retracting) the cylinder unit(s) 40 of the invention. The control unit (controller) 20 may control the extension and retraction of the cylinder units via the power system 30.

[0203] The cylinder units 40 preferably comprise hydraulic cylinders and, accordingly, the power system 30 is preferably a hydraulic power system and is described as such in the examples that follow. However, the power system 30 could alternatively be an electrical power system arranged to provide electrical power to, for example, electrical linear actuators. Hydraulic power systems may comprise components such as hydraulic motors, hydraulic pumps, hydraulic reservoirs, control valves, hydraulic conduits, filters. Electric power systems may comprise components such as batteries, capacitors, battery management systems, electrical conduits, inverters, cooling units.

[0204] The power system may be a collection of power sub-systems, wherein each sub-system provides power to a respective cylinder unit.

[0205] Figure 11 shows an example of power subsystem being a hydraulic power sub-system (hydraulic sub-system) 300 for powering a cylinder unit 40 of a cylinder suspension module 100. The cylinder suspension module is shown as that of Figures 2 but could be any of the cylinder suspension modules 100, or independent cylinder units 40, discussed in this specification.

[0206] The illustrated hydraulic sub-system 300 comprises a directional control valve 302, motor 303, pump 304 and pressurised reservoir 305. The motor 303 is arranged to power the pump 304, which provides pressurised hydraulic fluid to the control valve 302, via pressure line 306, for subsequent delivery to the cylinder unit. The reservoir 305 provides hydraulic fluid to the pump 304 and receives return fluid from the control valve 302 (returned from the cylinder unit) via the return line 307. The reservoir may have a diaphragm, wherein the diaphragm has a diaphragm pressurisation gas fill port 308. Preferably, the pump is a fixed displacement pump.

[0207] The control valve 302 is operable to selectively connect the pump (via pressure line 306) to the extension inlet / outlet 43 of the cylinder, and the reservoir (via return line 307) to the retracting inlet / outlet 44 of the cylinder unit 40 in order to extend the cylinder rod 42. The control valve 302 is also operable to selectively connect the reservoir 305 (via return line 307) to the extension inlet / outlet 43 of the cylinder unit 40 and the pump 304 (via pressure line 306) to the retracting inlet / outlet 44 of the cylinder unit 40 in order to retract the cylinder rod 42. The control valve is operable to switch between the two connections.

[0208] In some examples, the cylinder suspension module 100 and hydraulic sub-system 300 may be integrated as a compact assembly or module. The hydraulic sub-system may employ micropumps to provide an assembly of minimal volume and ease of integration into a vehicle.

[0209] The hydraulic sub-system 300 may provide dedicated hydraulic control over the cylinder unit 40, such that in the case of multiple modules integrated into a vehicle 10, each cylinder suspension module 100 comprises independent hydraulic sub-systems. The hydraulic subsystems may be centrally controllable by a central control unit (controller) (not shown) connected to each hydraulic subsystem. This arrangement can provide a reduction in hydraulic tubing across a vehicle, enabling smaller hydraulic components (e.g., micropumps) that provide hydraulic power within each cylinder suspension module rather than a central hydraulic system that provides hydraulic power to all cylinder units across the vehicle.

[0210] The control valve 302 and the cylinder-side fluid lines, along with other associated componentry between the pump / reservoir and the cylinder unit, may together be referred to as a hydraulic valve unit (or simply "valve unit").

[0211] An example of a valve unit 309 of a hydraulic system for controlling a cylinder unit 40 is shown in more detail in Figure 12A. The cylinder unit 40 may be any of those described. The hydraulic valve unit provides the hydraulic system (or sub-system) with the ability to hold, extend, or retract the cylinder unit, preferably at the demand of a controller. As discussed above, in some arrangements, the controller exclusively controls the cylinder(s) 40. Therefore, the existing suspension system 50 is not controlled by the controller.

[0212] The hydraulic valve unit 309 comprises a directional control valve 302 ("DCV" or "control valve") arranged to selectively control connection to a pump line 306 (or "pressure line") from a pump of the hydraulic system and a reserve line 307 (or "return line") from the hydraulic system. The directional control valve 302 is preferably electronically controllable. The control valve may be controlled to switch between states to either 1) disconnect the extension and retraction inlet / outlets 43 44 from the pump and reserve lines 306, 307 (as illustrated in Figure 12A), 2) connect the extension inlet / outlet to the pump line 306 and the retraction inlet / outlet to the reserve line 307, or 3) connect the extension inlet / outlet to the reserve line 307 and the retraction inlet / outlet to the pump line 306; respectively, said states of the control valve 1) hold the position of the cylinder rod 42, 2) extend the cylinder rod 42, and 3) retract the cylinder rod 42.

[0213] The illustrated valve unit also comprises two holding valves 310 311, which may be pilot-operated check valves as shown. The holding valves each receive a pilot line 312 313, which when not pressurised triggers the holding valve to default to allow flow through in only one direction - that direction being toward the cylinder unit inlet / outlet 43 44. When the pilot line 312 313 of a holding valve 310 311 is pressurised, the holding valve allows flow in either direction. Pressure sensors 314 315 are preferably provided between each holding valve and the control valve to provide sensor feedback to the control unit.

[0214] Figure 12B shows another example of a hydraulic valve unit 309 of a hydraulic system for controlling a cylinder unit 40, wherein the valve unit comprises a regeneration system. In this example, the hydraulic valve unit comprises a primary control valve 302, an extending control valve 316, and a retracting control valve 317.

[0215] The primary control valve 302 is operable to switch between two states of 1) connecting the first port Pl of the extending control valve 316 to the pump line 306 and the second port P2 of the extending control valve 316 to thereserve line 307, and the first port P4 of the retracting control valve 317 to the pump line 306 and the second port P5 of the retracting control valve 317 to the reserve line 307, and 2) connecting the first port Pl of the extending control valve 316 to the reserve line 307 and the second port P2 of the extending control valve 316 to the pump line 306, and the first port P4 of the retracting control valve 317 to the reserve line 307 and the second port P5 of the retracting control valve 317 to the pump line 306.

[0216] The primary control valve 302 (or extending control valve) is connected to cylinder extension inlet / outlet 43 through the third port P3. The retracting control valve 317 is connected to the cylinder extension inlet / outlet 44 through the sixth port P6. Therefore, depending on the extension or retraction of the cylinder 40, the third port P3 alternates between a feed or return with the line to the cylinder 40. Likewise, in the alternative, depending on the extension or retraction of the cylinder 40, the sixth port P3 alternates between a return or feed.

[0217] Each extending / retracting control valve 316317 is operable to switch between two states: a spring-returned default state in which the corresponding cylinder inlet / outlet 43 44 is disconnected from the first port and connected to the second port, and a triggered state in which the corresponding cylinder inlet / outlet is connected to the first port and disconnected from the second port. As each cylinder 40 has such control valves 316, 317, at each location on vehicle, the height may be varied. This allows the plurality of the cylinders 40 to counter the roll motion of a vehicle (as well as other body modes of motion, including squat and lift, pitch, warp, and yaw).

[0218] Preferably, pressure sensors 314 315 are provided between each extending / retracting valve and the primary control valve to provide sensor feedback to the control unit. Preferably, the pump in this example is a variable displacement pump.

[0219] This combination of control between the primary control valve, extending control valve, and retracting control valve, can provide the ability to increase the speed of movement of the cylinder ram by using the higher-pressure fluid exiting a cylinder port to combine with the pump flow into the other cylinder port. This allows for a fast-reacting cylinder.

[0220] The control valves described herein may be solenoid valves.

[0221] Figures 13A-B show a further example of a hydraulic valve unit, multiple instances of which are implemented within a wider hydraulic system 300(may be referred to as a "hydraulic power system") according to one example of the invention. It will be appreciated that the hydraulic system 300 could implement any of the hydraulic valve unit configurations previously discussed.

[0222] The hydraulic system 300 is shown to comprise four hydraulic valve units 309a 309b 309c 309d that each control the hydraulic power to a corresponding cylinder unit 40a 40b 40c 40d. Each hydraulic valve unit is similar in function to the valve unit in Figure 12A, comprising a directional control valve 302, and a pilot operated check valve (holding valve) 311, but further comprises a pressure reducing valve 318 at the pump line 306 of the control valve and a pilot operated shuttle valve 319 connecting the extending / retracting inlet / outlets 4344 of the cylinder 40.

[0223] Hydraulically connected to each of the valve units are the pump 304 and reservoir 305 systems. Preferably the pump is a variable displacement pump. The pump, as illustrated, may be powered by a motor 303 and may have a filter 322 on the reservoir side. The reservoir 305 has high-pressure side 320 and a low-pressure side 321. The reservoir has a pressure reducing valve 318 on the high-pressure side, which reduces the pressure of received fluid from the pump. Additionally, the reservoir has a pressure relief valve 323 on the low-pressure side, which returns fluid to the low-pressure side of the reservoir.

[0224] Figure 13B shows the hydraulic units of the hydraulic valve units 309a 309b 309c 309d in various positions for controlling various corresponding positions of the cylinder units 40a 40b 40c 40d. Such positions are shown from left to right merely for the purposes of explanation, as described below.

[0225] Cylinder 40a is shown to have its cylinder rod 42 held at the midpoint position 324 of its stroke, relating to a nominal ride height. The cylinder 40a is locked from moving by the pilot operated check valve 311, which prevents flow from the extending outlet / inlet 43, by the pilot operated shuttle valve 319, and by the closed centre position of the directional control valve 302a, which prevents flow from the retracting inlet / outlet 44 of the cylinder. Cylinder 40b is shown to have its cylinder rod 42 in an extended position 325. The cylinder rod extends as a result of the left control position of the directional control valve 302b connecting the pump line to the pilot operated check valve 311, which allows free flow in that direction. Flow from the retracting inlet / outlet is also permitted through the pilot operated shuttle valve 319 until the pressure closely matches the pilot pressure signal from the pressure reducing valve, at which point the flow from the retractinginlet / outlet returns to the reservoir through 302b. Cylinder 40c is shown to have its cylinder rod 42 in a retracted position 326. The cylinder rod 42 retracts as a result of the right control position of the directional control valve 302c, which allows flow from the pump line to the retracting inlet / outlet 44 of the cylinder. The pilot operated check valve 311 has pilot pressure from the retracting inlet / outlet port so is open for return flow from the expanding inlet / outlet port of the cylinder, which has a flow path through the pilot operated shuttle valve 319 until the pressure closely matches the pilot pressure signal from the pressure reducing valve, at which point the flow from the expanding inlet / outlet returns to the reservoir through 302c. Cylinder 40d is shown to have its cylinder rod 42 held at the retracted position 327. The cylinder 40d is held at this position (with the associated length) as described above for cylinder 40a until the system signals for the control valve 302d to switch to a flow-permitting position.

[0226] While the above discussion has been directed toward controlling four cylinder units, this is merely one example. As already mentioned, other hydraulic systems may include a plurality of hydraulic cylinder units and the hydraulic valve units of Figures 12A or Figure 12B, or a combination thereof. Furthermore, the number of hydraulic valve units or other components, or the number of cylinder units that the hydraulic system controls, may differ from the examples shown.

[0227] In some configurations, the reservoir of a hydraulic system may be an intensifier. In some configurations, the hydraulic system may comprise a filter, a hydraulic fluid cooler, or other appropriate elements of a hydraulic system known to a skilled person.

[0228] Although the power system has been described as a hydraulic power system, this is just one example. Other examples may employ e.g., an electrical power system, in which the cylinder units are linear electric actuators that can be extended or retracted based on power and / or signals received from the electrical power system and / or control unit. Alternative linear actuators may be known to the skilled person. Said hydraulic power system and electrical power system may be referred to, generically, as "power systems", and may also comprise power subsystems such as a hydraulic sub-system or electrical power sub-system, as will be apparent in further sections of the description. The term "cylinder" used herein therefore refers to a displacement cylinder, also known as a piston cylinder or a rod cylinder, wherein actuation of the cylinder results in a displacement, i.e. via the extension or retraction of a rod or similar feature. Where an electric actuatoris used, the term piston rod (or cylinder rod) is also used where the piston may be replaced by a ball and screw.Motion Control System

[0229] Figure 14 shows an example of a control system employed on a vehicle 10 having a base portion 11, comprising four wheels 13, and a suspended portion 12 comprising a body. The suspended portion 12 is coupled to each wheel 13 of the base portion 11 via a corresponding cylinder suspension module 100 of the control system, where the cylinder suspension module 100 comprises a cylinder unit 40 comprising a hydraulic cylinder and a suspension unit 50 as described elsewhere. The control system also includes a control unit 200 comprising a controller 20, a sensor unit 21 comprising a plurality of sensors 21a-c, and a hydraulic system 300 for powering the hydraulic cylinders. The control unit 200 is communicatively coupled to the sensor unit and the hydraulic system to send and / or receive signals. Sensors 21a-c may include the sensors discussed previously, such as one or more of an inclinometer, a gyroscopic sensor, an accelerometer, a compass, a magnetometer, an Inertial Measurement Unit (IMU), a vehicle orientation sensor, a steering-angle sensor, a speedometer, a vehicle speed sensor, a brake pressure sensor, a throttle position sensor, a cylinder position sensor (such as a linear position sensor or stroke position sensor), a suspension position sensor (such as a linear position sensor or stroke position sensor) or other sensor for receiving inputs from an operator of the vehicle (such as any of those discussed previously). These sensors may be employed as two sets for identifying and then further characterising the mode of motion, as discussed previously. The hydraulic system 300 may be the hydraulic system described above, comprising a motor 303, a pump 304, a reservoir 305 operatively connected to valve units 309, each hydraulically connected to the cylinder units 40 as described elsewhere. The vehicle 10 may further comprise an electrical power system, such that the power unit comprises a battery, and / or battery management system, which may be electrically connected to the control unit and / or sensor unit and / or hydraulic system. Alternatively, the hydraulic system may be replaced by an electric power system (where the cylinders units are also electric).

[0230] The control system may comprise a plurality of sensor units, wherein each cylinder suspension module is accompanied by a sensor unit providing datacorresponding to that module, such that the control unit may actuate each cylinder unit of the module based on sensor data from a respective sensor unit.

[0231] The invention has been described with examples relevant to its current form, however, potential configurations will include any form that is within the scope of the appended claims. It will be apparent to those skilled in the art that various modifications can be made without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Furthermore, the invention has been described in terms of various examples, where each example serves as to illustrate how the invention may be applied; such examples are not exclusive to each other, and features described in context of a given example may apply to another example, unless clear to a skilled person that such an application is incompatible or otherwise contradictory.

Claims

CLAIMS:

1. A ride control system for use on a vehicle having a suspended portion resiliently supported upon a base portion via a suspension system, the base portion comprising ground-engaging means, such as wheels, legs, feet or tracks, wherein the control system comprises:a plurality of displacement cylinder units each configured for cooperative coupling to a respective passively and independently controlled suspension unit of the suspension system, such that each displacement cylinder unit is operable to control a respective distance between the base portion and the suspended portion of the vehicle;a controller configured to operate one or more of the plurality of displacement cylinder units to control a relative position, orientation and / or motion of the suspended portion and the base portion of the vehicle, wherein each displacement cylinder is a double acting, regenerative displacement cylinder unit configured to actively extend or retract.

2. The control system of claim 1, wherein each displacement cylinder unit of the plurality of displacement cylinder units is configured for securing to a respective suspension unit in an inline configuration, such that the operational axis of the displacement cylinder unit is parallel to and aligned with the operational axis of the suspension unit.

3. The control system of claim 2, wherein each displacement cylinder unit comprises an end having a recessed portion for housing a portion of a shock of a respective suspension unit.

4. The control system of claim 1, wherein each displacement cylinder unit is configured for securing to a respective suspension unit in a parallel configuration, such that the operational axis of the displacement cylinder unit is parallel to and laterally offset from the operational axis of the suspension unit.

5. The control system of any one of claims 1 to 4, wherein each displacement cylinder unit is configured for coupling to a respective suspension unit via a link or mechanism, preferably a pivotal link such as a bell crank.

6. The control system of any preceding claim, wherein the controller is configured to operate one or more displacement cylinder units to extend or retract for at least partially offsetting compression or extension of one or more respective suspension units of the suspension system.

7. The control system of any preceding claim, wherein the controller is configured to operate one or more displacement cylinder units for substantially maintaining the position of the suspended portion relative to the base portion of the vehicle, for substantially maintaining a target ride height of the vehicle.

8. The control system of any preceding claim, wherein the controller is configured to operate one or more displacement cylinder units for maintaining a substantially horizontal orientation of the suspended portion.

9. The control system of any preceding claim, wherein the controller is configured to identify a mode of motion of the suspended portion relative to the base portion of the vehicle based on information received from one or more sensors or instruments of the control system and / or vehicle, and to control the one or more displacement cylinder units in accordance with the identification so as to cancel out or attenuate said motion.

10. The control system of claim 9, wherein the controller is configured to identify a mode of motion based on information pertaining to one or more of:- a linear movement or change in linear position of one or more suspension units;- vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;- vehicle speed;- vehicle acceleration, and / or an acceleration of the suspended portion or base portion of the vehicle along or about one or more axes (such as a longitudinal axis, a lateral axis and / or a vertical axis);- elevation of the suspended portion of the vehicle.

11. The control system of claim 9 or claim 10, further comprising one or more of:- one or more accelerometers for measuring acceleration of one or more portions of the vehicle about one or more axes;- one or more inertial measurement units;- one or more inclinometers for monitoring the elevation and / or orientation one or more portions of the vehicle;- an instrument for monitoring vehicle speed;- an instrument for monitoring steering angle;- one or more sensors for measuring the linear positions of one or more suspension units;- a brake pressure sensor;- a throttle position sensor.

12. The control system of any one of claims 9 to 11, wherein the controller is configured to identify the mode of motion based on information received from a first set of sensors, and to identify or categorise a cause of the mode of motion (such as external or vehicular control) based on information received from a second set of sensors.

13. The control system of claim 12, wherein the first set of sensors is adapted for monitoring motion, acceleration and / or force, and wherein the second set of sensors is adapted for monitoring vehicular control (such as braking, throttle, steering).

14. The control system of any one of claims 9 to 13, wherein the controller is configured for identifying one or more of roll, pitch, yaw, heave or warp.

15. The control system of any one of claims 9 to 14, wherein the controller is configured to calculate a response based at least in part on a drive mode setting, preferably wherein the drive mode setting is selected from a set comprising of one or more of:road mode;track mode;A / T mode.

16. The control system of claim 15, wherein the controller is configured to prioritise maintaining a substantially consistent ride hide of the vehicle in accordance with a selection of road mode.

17. The control system of claim 15, wherein the controller is configured to produce a desirable lean angle of the suspended portion during cornering, in accordance with a selection of track mode.

18. The control system of claim 15, wherein the controller is configured to prioritise maintaining a substantially horizontal orientation of the suspended portion in accordance with a selection of A / T mode.

19. The control system of any preceding claim, wherein, in response to an identification of roll motion, the controller is configured to extend one or more displacement cylinder units on one side of the vehicle and / or retract one or more displacement cylinder units on the other side of the vehicle.

20. The control system of any preceding claim, wherein, in response to an identification of pitch motion due to deceleration, the controller is configured to extend one or more displacement cylinder units at the front of the vehicle and / or retract one or more displacement cylinder units at the rear of the vehicle and / or in response to an identification of pitch motion due to acceleration, the controller is configured to extend one or more displacement cylinder units at the rear of the vehicle and / or retract one or more displacement cylinder units at the front of the vehicle.

21. The control system of any preceding claim, wherein the controller is configured to operate the plurality of displacement cylinder units to adjust the relative position between the suspended portion and the base portion of the vehicle, thereby adjusting a ride height of the vehicle.

22. The control system of claim 21, wherein the controller is configured adjust the ride height based on information pertaining to one or more of:- vehicle speed;- user input;- drive mode;- driving conditions and / or vehicle conditions.

23. The control system of claim 22, wherein the controller is configured to lower the ride height based on an increase in vehicle speed.

24. The control system of any preceding claim, comprising the suspension system, wherein each of the plurality of displacement cylinder units is operably coupled to at least a portion of the suspension system.

25. The control system of claim 24, wherein the suspension system comprises a plurality of suspension units and wherein each of the plurality displacement cylinder units is operably coupled to a respective suspension unit.

26. The control system of any preceding claim, further comprising a power system for actuating the displacement cylinder units, wherein the controller is communicatively coupled to the power system for controlling the operation of the displacement cylinder units.

27. The control system of claim 26, wherein the displacement cylinder units are, or comprise, hydraulic cylinders, and wherein the power system is a hydraulic power system.

28. A cylinder suspension module for use in the control system of any preceding claim for resiliency supporting the suspended portion upon the base portion of the vehicle, the cylinder suspension module comprising:a displacement cylinder unit cooperatively coupled to a suspension unit so as to control a functional length of the cylinder suspension module, thereby controlling a distance between the base portion and the suspended portion of the vehicle.

29. The cylinder suspension module of claim 28, wherein the displacement cylinder unit is coupled to the suspension unit in an inline configuration, such that the operational axis of the displacement cylinder unit is parallel to and aligned with the operational axis of the suspension unit.

30. The cylinder suspension module of claim 28, wherein the displacement cylinder unit is coupled to the suspension unit in a parallel configuration, such that the operational axis of the displacement cylinder unit is parallel to and laterally offset from the operational axis of the suspension unit.

31. The cylinder suspension module of any one of claims 28 to claim 30, wherein the displacement cylinder unit is coupled to the suspension unit via a link or mechanism.

32. The cylinder suspension module of claim 31, wherein the displacement cylinder unit is coupled to the suspension unit via a bell crank.

33. The cylinder suspension module of any one of claims 28 to 32, wherein the suspension unit comprises a spring and a shock, preferably arranged in a coil-over shock configuration.

34. A vehicle comprising the control system of any one of claims 1 to 27, or the cylinder suspension module of any one or claims 28 to 33.

35. A machine or building, comprising the control system of any one or claims 1 to 27, or the cylinder suspension module of any one of claims 28 to 33.

36. A method of controlling the position, orientation and / or motion of a suspended portion of a vehicle relative to a base portion of a vehicle via a ride control system as defined in any one of claims 1 to 27, the method comprising:receiving input by the controller, such as from one or more sensors or instruments of the control system and / or vehicle;producing, by the controller, output based on the input to operate one or more of the plurality of displacement cylinder units so as to control a relativeposition, orientation and / or motion of the suspended portion and the base portion of the vehicle.

37. The method of claim 36, wherein the input contains or relates to information pertaining to one or more of:- a linear movement or change in linear position of one or more suspension units;- vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;- vehicle speed;- vehicle acceleration or acceleration of the suspended or base portion of the vehicle along or about one or more axes;- elevation of the suspended portion of the vehicle.

38. The method of claim 36 or claim 37, further comprising identifying, by the controller, a mode of motion of the suspended portion of the vehicle based on the input, and determining, by the controller, the output based on the identified mode of motion.

39. The method of any one of claims 36 to 38, comprising receiving input by the controller identifying a change in length of a suspension unit, such as caused by compression or droop, and producing by the controller an output to operate a displacement cylinder unit associated with the suspension unit to counteract the identified change in length of the suspension unit.

40. A method of substantially maintaining a target ride height of a vehicle using the control system of any one of the preceding claims, the method comprising:receiving, by a controller, information pertaining to one or more of:- a linear movement or change in linear position of one or more suspension units;- vehicle control, including one or more of: a steering angle, a brake pressure, a throttle position;- vehicle speed;- vehicle acceleration or acceleration of the suspended or base portion of the vehicle along or about one or more axes;- elevation of the suspended portion of the vehicle;identifying, by the controller based on said information, a mode of motion of the suspended portion of the vehicle;in response to identifying the mode of motion, operating, by the controller, one or more displacement cylinder units to actively extend or retract so as to cancel out or attenuate said motion.

41. The method of claim 40, wherein the step of receiving the information comprises receiving first information (such as from a first set of sensors) for identifying the mode of motion and receiving second information (such as from a second set of sensors) for identifying a cause of the motion or for categorising the motion (such as external or vehicular control).

42. The method of any one of claims 36 to 41, further comprising identifying, by the controller, a drive mode of the vehicle, and determining the output based at least in part of the identified drive mode.

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