CN111703267A

CN111703267A - Vehicle with suspension with continuous damping control

Info

Publication number: CN111703267A
Application number: CN202010483972.6A
Authority: CN
Inventors: 路易·J·布拉迪; 亚历克斯·R·朔伊雷尔; 史蒂文·R·弗兰克; 阿伦·J·尼斯
Original assignee: Polaris Industries Inc
Current assignee: Polaris Inc
Priority date: 2014-10-06
Filing date: 2015-10-06
Publication date: 2020-09-25
Anticipated expiration: 2035-10-06
Also published as: EP3204248A1; WO2016057555A1; AU2015328248B2; BR112017006909A2; CN106794736B; MX2017004100A; MX2021011905A; AU2015328248B9; AU2015328248A1; CN111703267B; CN106794736A; CA2963790A1

Abstract

A damping control system for a vehicle having a suspension between a plurality of ground engaging members and a frame includes at least one adjustable shock absorber having an adjustable damping characteristic. The system further comprises: a controller coupled to each adjustable shock absorber to adjust a damping characteristic of each adjustable shock absorber; and a user interface coupled to the controller and accessible to a driver of the vehicle. The user interface includes at least one user input to allow manual adjustment of the damping characteristics of the at least one adjustable shock absorber during operation of the vehicle. A vehicle sensor is also coupled to the controller to adjust a damping characteristic of the at least one adjustable shock absorber based on a vehicle condition determined from the sensor output signal.

Description

Vehicle with suspension with continuous damping control

This application is a divisional application of an application having an international application date of 2015, 10/6, and a chinese national application number of 201580053877.X (international application number of PCT/US2015/054296) and entitled "vehicle with suspension with continuous damping control".

Technical Field

The present disclosure relates to an improved suspension for a vehicle having continuous "on-going" damping control for the shock absorber.

Background

Currently, some off-road vehicles include adjustable shock absorbers. These adjustments include spring preload, high and low speed compression damping and/or high and low speed rebound damping. To make these adjustments, the vehicle is stopped and the operator makes the adjustment at each shock absorber position on the vehicle. Often, tools are required to make the adjustments. Some road motor vehicles also include adjustable electronic shock absorbers and sensors for active steering control systems. However, these systems are typically computer controlled and focus on vehicle stability rather than on ride comfort. The system of the present disclosure allows the operator to make real-time "on-the-fly" adjustments to the shock absorbers to obtain the most comfortable ride for a given terrain and load scenario.

Disclosure of Invention

Vehicles typically have springs (coils, reeds or air) at each wheel, rail or ski to support most of the load. The vehicle of the present disclosure also has electronic shock absorbers that control the dynamic motion of each wheel, snowboard, or rail. The electronic shock absorbers have valves that control the damping force of each shock absorber. The valve may control compression damping only, rebound damping only, or a combination of compression and rebound damping. The valve is connected to a controller having a user interface within reach of the driver to facilitate adjustment by the driver while operating the vehicle. In one embodiment, the controller increases or decreases the damping of the shock absorber based on user input received from an operator. In another embodiment, the controller has a number of preset damping modes for selection by the operator. The controller is also coupled to sensors on the suspension and chassis to provide an actively controlled damping system.

In an illustrative embodiment of the present disclosure, there is provided a damping control method for a vehicle having: a suspension between the plurality of wheels and the frame; a controller; a plurality of vehicle state sensors; and a user interface, the suspension including a plurality of adjustable shock absorbers including a right front shock absorber, a left front shock absorber, a right rear shock absorber, and a left rear shock absorber. The damping control method comprises the following steps: receiving, by the controller, a user input from a user interface to provide a user selected damping mode of operation for the plurality of adjustable shock absorbers during operation of the vehicle; receiving, by a controller, a plurality of inputs from a plurality of vehicle state sensors, the plurality of vehicle state sensors including a brake sensor, a throttle sensor, and a vehicle speed sensor; determining, by a controller, whether a vehicle brake is actuated based on an input from a brake sensor; determining, by a controller, a throttle position based on input from the throttle sensor; and determining, by the controller, a speed of the vehicle based on input from the vehicle speed sensor. The illustrative damping control method further comprises: operating the damping control in a braking state if the brake is actuated, wherein in the braking state the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode and a vehicle speed; operating damping control in a driving state if the brake is not actuated and a throttle position is less than a threshold Y, wherein in the driving state a controller adjusts damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode and a vehicle speed; operating the damping control in a driving state if the brake is not actuated, the throttle position is greater than a threshold value Y and the vehicle speed is greater than a threshold value Z; and operating the damping control in a sink state if the brake is not actuated, the throttle position is greater than a threshold Y, and the vehicle speed is less than a threshold Z, wherein in the sink state, the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user-selected mode, the vehicle speed, and the throttle opening.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of an exemplary embodiment exemplifying the best mode of carrying out the invention as presently perceived.

Drawings

The foregoing aspects and many of the attendant features of this system and method will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.

FIG. 1 is a block diagram showing components of a vehicle of the present disclosure having a suspension including a plurality of continuous damping control shock absorbers and a plurality of sensors integrated with the continuous damping controller;

FIG. 2 illustrates an exemplary user interface for controlling damping at front and rear axles of a vehicle;

FIG. 3 illustrates another exemplary embodiment of a user interface for continuous damping control of a shock absorber of a vehicle;

FIG. 4 illustrates yet another user interface for setting various operating modes of the continuous damping control as a function of terrain traversed by the vehicle;

FIG. 5 illustrates an adjustable damping shock absorber coupled to a vehicle suspension;

FIG. 6 is a flow chart illustrating vehicle platform logic for controlling various vehicle parameters in a plurality of different user selectable operating modes;

FIG. 7 is a block diagram illustrating a plurality of different state modifiers used as inputs in different control modes to modify the damping characteristics of an electronically tunable shock absorber or damper according to the present disclosure;

FIG. 8 is a flow chart illustrating a damping control method for controlling a vehicle operating in a plurality of vehicle states based on a plurality of sensor inputs, according to an embodiment of the present invention;

FIG. 9 is a flow chart illustrating another embodiment of a damping control method of the present disclosure;

FIG. 10 is a flow chart illustrating yet another damping control method of the present disclosure;

FIG. 11 is a cross-sectional view of a selectively decoupled stabilizer bar of the present disclosure under certain vehicle conditions;

fig. 12 shows the stabilizer bar of fig. 11 with the actuator in a locked position to prevent movement of the stabilizer bar's piston;

FIG. 13 is a cross-sectional view similar to FIG. 12, showing the actuator in an unlocked position decoupled from the piston of the stabilizer bar to allow movement of the piston relative to the cylinder; and

FIG. 14 shows the x-axis, y-axis, and z-axis of a vehicle such as an ATV.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components in accordance with the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain the present disclosure.

Detailed Description

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described below. The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize the teachings of the embodiments. Therefore, it should be understood that there is no intention to limit the scope of the present invention by these embodiments. The present invention includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the invention as would normally occur to one skilled in the art to which the invention relates.

Referring now to fig. 1, the present disclosure is directed to a vehicle 10 having a suspension between a plurality of ground engaging members 12 and a frame 14. The ground engaging members 12 include wheels, skis, rails, treads, etc. The suspension generally includes a spring 16 and a shock absorber 18 coupled between ground engaging member 12 and frame 14. The spring 16 may comprise, for example, a coil spring, a leaf spring, an air spring, or other gas spring. The air or gas spring 16 may be adjustable. See, for example, U.S. patent No.7,950,486, which is incorporated herein by reference. The spring 16 is typically coupled between the frame 14 and the ground engaging member 12 by an A-arm link 70 (see FIG. 5) or other type of link. An adjustable shock absorber 18 is also coupled between the ground engaging member 12 and the frame 14. In the illustrated embodiment, the spring 16 and the damper 18 are positioned adjacent each of the ground engaging members 12. In an ATV (all terrain vehicle), for example, four springs 16 and four adjustable shock absorbers 18 are provided adjacent each wheel 12. Some manufacturers provide adjustable springs 16 in the form of air springs or hydraulically preloaded rings. These adjustable springs 16 allow the operator to adjust ride height during travel (on the go). However, ride comfort is greater than the damping provided by free shock absorber 18.

In the illustrated embodiment, adjustable shock absorber 18 is an electronically controlled shock absorber for adjusting the damping characteristics of shock absorber 18. Controller 20 provides signals that adjust the damping of shock absorber 18 in a continuous or dynamic manner. Adjustable shock absorber 18 may be adjusted to provide different compression damping, rebound damping, or both compression and rebound damping.

In the illustrated embodiment of the present disclosure, the user interface 22 is provided in a location that is easily accessible to a driver operating the vehicle. Preferably, the user interface 22 is a separate user interface mounted on the dashboard adjacent to the driver's seat or integrated into a display within the vehicle. User interface 22 includes user inputs to allow a driver or passenger to manually adjust the damping of shock absorbers 18 during operation of the vehicle based on encountered road conditions. In another illustrated embodiment, user inputs are provided on the steering wheel, handlebar, or other steering control of the vehicle to facilitate actuation of the damping adjustment. A display 24 is also provided on the user interface 22 or adjacent to the user interface 22 or integrated into the dashboard display of the vehicle to display information relating to the setting of the shock absorber damping.

In the illustrated embodiment, the adjustable shock absorber 18 is a CDC (continuous damping control) type electrically controlled shock absorber available from ZF Sachs Automotive. See cauema nn, Peter; automatic shock absorbers: Features, Designs, Applications, ISBN 3-478-93230-0, Verl. moderne Industrie, Second Edition,2001, pages 53-63, which is incorporated herein by reference, are used to illustrate the basic operation of shock absorber 18 in the illustrated embodiment. It should be understood that this description is not limiting, and that there are other suitable types of shock absorbers that are commercially available from other manufacturers.

Controller 20 receives user inputs from user interface 22 and adjusts the damping characteristics of adjustable shock absorber 18 accordingly. As discussed below, the user may independently adjust front 18 and rear 18 shock absorbers to adjust the ride characteristics of the vehicle. In certain other embodiments, each of shock absorbers 18 is independently adjustable such that the damping characteristics of shock absorbers 18 can be varied from one side of the vehicle relative to the other side of the vehicle. Side-to-side adjustment is desirable during tight turns or other maneuvers where the different damping characteristics of shock absorbers 18 on opposite sides of the vehicle improve ride. The damping response of shock absorber 18 may vary within microseconds to provide damping of nearly instantaneous changes in potholes, depressions, or other driving conditions in the road.

There are also a plurality of sensors coupled to the controller 20. For example, a global change accelerometer 25 is coupled adjacent to each ground member 12. The accelerometer provides an output signal coupled to the controller 20. The accelerometer 25 provides output signals indicative of movement between the ground engaging member and the

suspension components

16, 18 as the vehicle traverses different terrain.

Additional sensors may include a vehicle speed sensor 26, a steering sensor 28, and a chassis accelerometer 30, all having output signals coupled to the controller 20. The accelerometer 30 is, for example, a three-axis accelerometer located on the chassis to provide an indication of the forces on the vehicle during operation. Additional sensors include a brake sensor 32, a throttle position sensor 34, a wheel speed sensor 36, and a gear selection sensor 38. Each of these sensors has an output signal coupled to the controller 20.

In the illustrated embodiment of the present disclosure, user interface 22 shown in FIG. 2 includes

manual user inputs

40 and 42 for adjusting the damping of front axle shock absorbers 18 and rear axle shock absorbers 18. The user interface 22 also includes a first display 44 and a second display 46 for displaying damping level settings for the front shock absorbers and the rear shock absorbers, respectively. In operation, a driver or passenger of the vehicle may adjust

user inputs

40 and 42 to provide more or less damping to shock absorbers 18 adjacent the front and rear axles of the vehicle. In the illustrated embodiment, the

user inputs

40 and 42 are rotatable knobs. The operator reduces the damping of shock absorber 18 adjacent the front axle of the vehicle by rotating knob 40 in a counterclockwise direction. This provides a softer ride for the front axle. By rotating knob 40 in a clockwise direction, the operator provides more damping on shock absorber 18 adjacent the front axle to provide a stiffer ride. The damping level of the front axle is displayed on the display 44. The level of damping may be indicated by any desired numerical range, such as, for example, 0 to 10, where 10 is the hardest and 0 is the softest.

The operator rotates knob 42 in a counterclockwise direction to decrease the damping of shock absorber 18 adjacent the rear axle. The operator rotates knob 42 in a clockwise direction to provide more damping to shock absorber 18 adjacent the rear axle of the vehicle. The setting of the damping level of the rear shock absorber 18 is displayed in the display window 46.

Another embodiment of the user interface 22 is shown in fig. 3. In this embodiment,

buttons

50 and 52 are provided for adjusting the damping level of shock absorber 18 positioned adjacent the front axle, and

buttons

54 and 56 are provided for adjusting the damping of shock absorber 18 positioned adjacent the rear axle. The operator increases the damping of shock absorber 18 positioned adjacent the front axle by pressing button 50 and decreases the damping of shock absorber 18 positioned adjacent the front axle by pressing button 52. The level of damping of shock absorbers 18 adjacent the front axle is displayed in display window 57. As discussed above, the input control switch may be positioned at any desired location on the vehicle. For example, in other illustrated embodiments, the user input is located on the steering wheel, handlebar, or other steering control of the vehicle to facilitate actuation of the damping adjustment.

Similarly, the operator presses the button 54 to increase the damping of the shock absorber positioned adjacent the rear axle. The operator presses the button 56 to reduce the damping reduction of the shock absorber positioned adjacent the rear axle. Display window 58 provides a visual indication of the level of damping of shock absorber 18 adjacent the rear axle. In other embodiments, different user inputs, such as a touch screen control, a slide control, or other input, may be used to adjust the damping levels of shock absorbers 18 adjacent the front axle and shock absorbers 18 adjacent the rear axle. In other embodiments, different user inputs, such as a touch screen control, a sliding control, or other input, may be used to simultaneously adjust the damping levels of all shock absorbers 18 near the four wheels.

Fig. 4 shows a further embodiment of the present disclosure in which the user interface 22 includes a rotatable knob 60 having a selection indicator 62. The knob 60 can be rotated as indicated by double-headed arrow 64 to align the indicator 62 with a particular driving condition mode. In the illustrated embodiment, five modes are disclosed, including a level road mode, a rough trail mode, a rock climbing mode, a trembling mode, and a jump/bounce mode. Depending on the driving conditions, the operator rotates the control knob 60 to select a particular driving mode. Controller 20 automatically adjusts the damping levels of adjustable shock absorbers 18 adjacent the front axle and adjustable shock absorbers 18 adjacent the rear axle of the vehicle based on the particular mode selected.

It should be understood that various other modes may be provided, including a sports mode, a field mode (trail mode), or other desired modes. In addition, different modes may be provided for the two-wheel drive, four-wheel drive, high configuration, and low configuration operation of the vehicle. Example modes of operation include:

● level road mode-a very stiff setting intended to minimize transient vehicle pitch and roll during hard acceleration, hard braking, and sharp turns.

● Normal field mode-similar to level road mode but with a somewhat softer setting to allow for the absorption of rocks, rootstocks and potholes, but still with good cornering, acceleration and braking performance.

● rock climbing mode-this is perhaps the softest setting, in which the vehicle is operated at a lower speed, allowing maximum wheel tracking. In one embodiment, the rock climbing pattern is associated with a vehicle speed sensor 26.

● high speed bumpy trail (jitter) -this setting is between the normal field mode and the rock climbing mode to allow high speed control but provide very comfortable ride (easy bottom out).

● jump and jump mode-this mode provides harder compression in the damper but less rebound to keep the tire on the ground as much as possible.

● are examples only, and those skilled in the art will appreciate that there may be many more modes depending on the desired/intended use of the vehicle.

In addition to the driving mode, damping control may be adjusted based on outputs from a plurality of sensors coupled with controller 20. For example, the setting of adjustable shock absorber 18 may be adjusted based on the vehicle speed from speed sensor 26 or the output from

accelerometers

25 and 30. In a slowly moving vehicle, the damping of adjustable shock absorber 18 is reduced to provide a softer mode for better ride. As vehicle speed increases, shock absorbers 18 are tuned to a stiffer damping setting. The damping of shock absorber 18 may be coupled to the output from steering sensor 28 and controlled by the output from steering sensor 28. For example, if the vehicle makes a sharp turn, the damping of shock absorbers 18 on the appropriate side of the vehicle may be momentarily adjusted to improve ride.

The continuous damping control of the present disclosure may be combined with an adjustable spring 16. The spring 16 may be a preload adjustment or a continuous dynamic adjustment based on a signal from the controller 20.

The output from the brake sensor 32 may also be monitored by the controller 20 and used to adjust the adjustable shock absorbers 18. For example, during emergency braking, the damping level of the adjustable shock absorber 18 adjacent the front axle may be adjusted to reduce "dive" of the vehicle. In the illustrated embodiment, the damper is adjusted to minimize pitch by: by determining the direction of travel of the vehicle, by sensing input from the gear selection sensor 38 and then adjusting the damping when the brake is detected to be applied by the brake sensor 32. In the illustrative example, for a forward-traveling vehicle, to improve the braking feel, the system increases the compression damping of shock absorbers 18 at the front of the vehicle and increases the rebound damping of shock absorbers 18 at the rear of the vehicle.

In another embodiment, controller 20 uses the output from the throttle position sensor to adjust adjustable shock absorber 18 to adjust or control vehicle roll-down that occurs when the rear of the vehicle drops or rolls down during acceleration. For example, controller 20 may enhance damping of shock absorbers 18 adjacent the rear axle during rapid acceleration of the vehicle. Another embodiment includes a driver selectable mode that controls both throttle map and damper settings of the vehicle. By associating the throttle map with the CDC damper calibration, the throttle (engine) characteristics and suspension settings are changed simultaneously as the driver changes operating modes.

In another embodiment, a position sensor is provided adjacent to the adjustable shock absorber 18. Controller 20 uses these position sensors to enhance damping of adjustable shock absorber 18 near the end of its travel. This provides progressive damping control for the shock absorber. In one illustrated embodiment, the position sensor of the adjustable shock absorber is an angle sensor located on the a-arm of the vehicle suspension. In another embodiment, the adjustable shock absorber includes a built-in position sensor to indicate when the shock absorber is near the end of its stroke.

In another illustrated embodiment, the system limits the range of adjustment of shock absorbers 18 based on the gear selection detected by gear selection sensor 38. For example, the damping adjustment range is greater when the gear selector is in the low range than when the gear selector is in the high range to keep the load in a range accepted by both the vehicle and the operator.

Fig. 5 shows adjustable shock absorber 18 mounted on an a-arm link 70, the a-arm link 70 having a first end coupled to frame 14 and a second end coupled to wheel 12. The adjustable shock absorber 18 includes a first end 72 pivotally coupled to the a-arm 70 and a second end (not shown) pivotally coupled to the frame 14. Damping control actuator 74 is coupled to controller 20 by a wire 76.

In the illustrated embodiment of the present disclosure, as shown in fig. 1, a battery 80 is coupled to the controller 20. To operate in the demonstration mode in the display room, the controller 20, user interface 22 and display 24 are activated using the ignition or wireless key of the vehicle to place the vehicle in the auxiliary mode. This allows adjustment of the adjustable shock absorber 18 without starting the vehicle. The operation of the continuous damping control feature of the present disclosure may thus be demonstrated to a customer in a display room that, because of the enclosed space, does not allow starting of the vehicle. This provides an effective tool for demonstrating how the continuous damping control of the present disclosure quickly adjusts the damping of the front and rear axles of the vehicle.

As described herein, the system of the present disclosure includes four levels or levels of operation. In the first level, adjustable shock absorber 18 is adjusted by manual input as described herein using only user interface 22. In the second level of operation, the system is semi-active and uses user input from user interface 22 in combination with the vehicle sensors described above to control adjustable shock absorber 18. In the third level of operation, an input accelerometer 25 and a chassis accelerometer 30 located adjacent to ground engaging member 12 are used with steering sensor 28 and a shock absorber stroke position sensor to provide additional input to controller 20 for use in adjusting adjustable shock absorber 18. In the fourth operating level, controller 20 cooperates with the stability control system to adjust shock absorbers 18 to provide enhanced stability control for vehicle 10.

In another illustrated embodiment, vehicle load information is provided to controller 20 and used to adjust adjustable shock absorber 18. For example, the number of passengers may be used or the amount of cargo may be entered to provide vehicle load information. Passenger or cargo sensors may also be provided for automatic input to the controller 20. Additionally, sensors on the vehicle may detect accessories on the front or rear of the vehicle that affect the handling of the vehicle. Upon sensing a heavy accessory on the front or rear of the vehicle, the controller 20 adjusts the adjustable shock absorber 18. For example, when a heavy accessory is placed on the front of the vehicle, the compression damping of the front shock absorber may be increased to help support the additional load.

In another illustrative embodiment of the present disclosure, a method for actively controlling damping of an electronically tunable shock absorber using both a user selectable mode and multiple sensor inputs to actively adjust a damping level is disclosed. A central controller is used to continuously read inputs from a plurality of vehicle sensors and send output signals to control the damping characteristics of the electronically tunable shock absorbers. Illustrative embodiments control damping of the plurality of electronically tunable shock absorbers based on one or more of the following control strategies:

● damping meter based on vehicle speed

● roll control: damping meter for steering angle and steering rate of vehicle

● jump control: detecting air time and adjusting damping accordingly

● Pitch control: braking, dive and dive

● use of lookup tables or multivariate equations based on sensor inputs

● acceleration sensing: selecting damping based on chassis acceleration frequency

● load sensing: increasing damping based on vehicle/case load

● oversteer/understeer detection

● factory default setting, switch on mode selection

● failsafe device defaults to being completely stable

● closing the solenoid valve after a fixed period of time to conserve power when idle

In the illustrated embodiment of the present disclosure, the user selectable mode provides damping control for the electronic shock absorber. In addition to the methods described above, the present disclosure includes modes that can be selected by a user through knobs, touch screens, buttons, or other user inputs. Illustrative user-selectable modes and corresponding sensors and controls include:

in addition to damping control, the following key items can be adjusted in various modes:

1. factory default mode

2. Soft/comfort mode

● vehicle speed

● turning

● soaring (Air born) — jumping

● eCTV: low RPM > stationary

● higher assisted EPS calibration

3. Automatic/sport mode

● Pitch control

● is connected to the brake switch

● throttle (CAN) position

● roll control

● lateral acceleration

● steering position (EPS sensor)

● vehicle speed

● "Auto" indicates the use of a damping table or algorithm containing all of these inputs

4. Stabilization/competition mode

● eCTV: higher junction

● aggressive accelerator pedal mapping

● Stable (lower speed Assist) EPS calibration

● damping with complete stability

5. Rock climbing mode

● increased ride height-spring preload

● rebound increase to cope with additional preload

● Soft stabilizer bar

● speed limitation

6. Desert/dune model

● Soft stabilizer bar

● velocity based damping

● damping more stable than "soft

7. Wild/turn mode

● low ride height

● harder stabilizer bar

● increase damping

● Stable EPS calibration

8. Working mode (Lock, completely stable)

● eCTV: smooth joining

● eCTV: depending on engine load, keep low RPM > stationary

● load sense damping and preloading

9. Economy mode

● low ride height

● Engine calibration

● eCTV calibration

In the illustrated embodiments of the present disclosure, the sensor input includes one or more of:

● damping mode selection

● vehicle speed

● 4WD mode

● ADC mode

● Shift mode-CVT and other Transmission types

● EPS mode

● ambient temperature

● steering angle

● chassis acceleration (transverse, longitudinal, vertical)

● steering wheel acceleration

● Gyroscope

● GPS location

● shock absorber position

● shock absorber temperature

● in-box load/distribution

● Engine sensor (rpm, temperature, CAN)

● Accelerator pedal

● brake input/pressure

● passenger sensor (weight or safety belt)

In the illustrated embodiment of the present disclosure, the damping control system is integrated with other vehicle systems as follows:

vehicle system integration

● EPS calibration

Unique calibration for each driver mode. Full assist work or comfort mode.

● automatic preload adjustment setting (electrically and/or hydraulically controlled)

O load leveling

Flat field/road mode is low, and rock climbing is high

Increasing rebound damping for higher preload

The traction mode increases with rear preload. Execution mode-front preload

Increase of

● vehicle speed limit

Using look-up tables or using algorithms to increase damping in conjunction with vehicle speed for control and

security

■ adjust the minimum damping level in all modes except "steady",

■ stable mode will be at maximum damping independent of vehicle speed

■ may be used in certain modes with lower ride height (preload) and vehicle speed

● eCTV calibration

Unique calibration for each driver mode related to electronic damping and preload. (comfort mode ═ low rpm, soft damping)

● Engine/Pedal map calibration

Unique calibration for each driver mode related to electronic damping and preload. (comfort mode ═ soft pedal mapping, soft damping)

● steer-by-wire

● load sensing

● Decoupled wheel speed for cornering

● 4 wheel steering

● active stabilizer bar adjustment

● traction control

● stability control

●ABS

● active brake bias

● preload control

FIG. 6 is a flow chart illustrating vehicle mode platform logic for the systems and methods of the present disclosure. In the illustrated embodiment, the user selects the user mode, as shown at block 100. The selector may be a knob, button, touch screen input, or other user input. The controller 20 uses a look-up table or algorithm to determine the preload adjustments for the adjustable springs at the front right, front left, rear right, and rear left of the vehicle to adjust the target ride height for the vehicle, as shown at block 102. The controller 20 receives ride height input and/or load sensor input, as indicated at block 104, such that the controller 20 adjusts the spring preload based on the vehicle load.

The controller 20 then determines whether the anti-roll bar or stabilizer bar should be connected or disconnected, as indicated at block 106. As discussed in detail below, the stabilizer bar may be connected or disconnected depending on the selected mode and sensor input.

The controller 20 also implements damping control logic as discussed below and shown at block 108. The controller 20 uses a damper configuration (profile) for the right front, left front, right rear and left rear adjustable shock absorbers as shown at block 110. As shown at block 112 and discussed in detail below, a plurality of sensor inputs are provided to the controller 20 to continuously control the damping characteristics of the adjustable shock absorber.

The controller 20 uses the stored map to perform calibration of the Electronic Power Steering (EPS) of the vehicle, as indicated at block 114. Finally, the controller 20 uses the map to calibrate the accelerator pedal position of the vehicle, as shown at block 116. The damping control method of the present disclosure uses a plurality of different state modifiers to control the damping characteristics of an electronically tunable shock absorber. An exemplary condition modifier includes parameters set by: the particular user mode selected as indicated at block 118, vehicle speed as indicated at block 120, and throttle opening as indicated at block 122. Additional condition modifiers include a drive mode sensor, such as a four-wheel drive sensor, as shown at block 124, a steering position sensor, as shown at block 126, and a steering rate sensor, as shown at block 128. The drive mode sensors 124 may include a locked front sensor, an unlocked front sensor, a locked rear sensor, an unlocked rear sensor, or a high-low transmission setting sensor. The state modifier also includes an x-axis acceleration sensor as shown at block 130, a y-axis acceleration sensor as shown at block 132, and a z-axis acceleration sensor as shown at block 134. The x, y and z axes for a vehicle such as an ATV are shown in fig. 14. Another illustrative state modifier is a yaw-rate sensor as shown at block 136. The various state modifiers shown in fig. 7 are labeled 1-10 and correspond to modifiers that affect the operation of the damping control logic under the various driving conditions shown in fig. 8-10.

In a passive method for controlling a plurality of electronic shock absorbers, the user selected mode is set with discrete damping levels at all corners of the vehicle. The front compression, back compression, and rebound can be independently adjusted based on the user selected mode of operation without using active control based on sensor input.

An exemplary method for active damping control for a plurality of electrical shock absorbers is shown in FIG. 8. The method of FIG. 8 uses a throttle sensor 138, a vehicle speed sensor 140, and a brake switch or brake pressure sensor 142 as logic inputs. As shown at block 144, controller 20 determines whether the brake is activated (on). If so, the controller 20 executes the damping control method in the braking state, as shown at block 146. In the braking state, front suspension compression (dive) due to longitudinal acceleration from the braking input is detected. In the braking state 146, the state modifier includes the user selected mode 118 and the vehicle speed 120 to adjust the damping control. In the vehicle state of fig. 8-10, the selected user mode modifier 118 determines a particular look-up table defining the damping characteristics of the adjustable shock absorbers at the front right, front left, rear right and rear left portions of the vehicle. In the braking state 146, compression damping of the front shock absorber and/or rebound damping on the rear shock absorber is provided based on the braking signal.

In the braking state 146, the controller 20 increases damping based on the increased vehicle speed. In addition, the controller 20 increases compression damping on the front shock absorbers and/or rebound damping on the rear shock absorbers based on the brake sensor signals. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at various corners based on the above inputs.

If the brake is not activated, as indicated at block 144, the controller 20 determines whether the throttle position is greater than the threshold Y, as indicated at block 148. If not, the controller 20 operates the vehicle in a travel state, as shown at block 150. In the driving state, the vehicle is usually operated in a straight line, in which the driving and handling performance of the vehicle at the time of steering and turning is not detected. In the driving state 150, the state modifier for controlling damping includes the user mode 118, the vehicle speed 120, and a drive mode sensor such as the four wheel drive sensor 124. In the driving state 150, the controller 20 increases the damping based on the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the throttle position is greater than the threshold Y at block 148, the controller 20 determines whether the vehicle speed is greater than the threshold Z at block 152. If so, the controller 20 operates the vehicle in a travel state at block 150 as described above. If the vehicle speed is less than the threshold Z at block 152, the controller 20 operates the vehicle in a submerged state as shown at block 154. In the sink state 154, the state modifier for controlling damping includes the user selected mode 118, the vehicle speed 120, and the throttle opening 122. During the sink state 154, compression damping on the rear shock absorbers and/or rebound damping on the front shock absorbers are increased based on the throttle sensor signal and the vehicle speed. Longitudinal acceleration from the throttle input causes the rear suspension to compress (sink).

In the sink state 154, the controller 20 increases damping based on the increased vehicle speed. Further, controller 20 increases compression damping on the rear shock absorbers and/or rebound damping on the front shock absorbers based on the throttle sensor signal and the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

Another embodiment of the present disclosure that includes different sensor input options is shown in fig. 9. In the embodiment of FIG. 9, a throttle sensor 138, a vehicle speed sensor 140, and a brake sensor 142 are used as inputs as discussed in FIG. 8. Additionally, a steering rate sensor 156 and a steering position sensor 158 also provide inputs to the controller 20. As shown at block 160, the controller 20 determines whether the absolute value of the steering position is greater than a threshold X or the absolute value of the steering rate is greater than a threshold B. If not, the controller 20 determines whether the brake is activated, as shown at block 162. If not, controller 20 determines whether the throttle position is greater than threshold Y, as indicated at block 164. If the throttle position is greater than the threshold Y at block 164, the controller 20 operates the vehicle in the drive state as shown at block 150 and described above. In the driving state 150, the controller 20 increases the damping based on the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the throttle position is greater than the threshold Y at block 164, the controller 20 determines if the vehicle speed is greater than the threshold Z, as indicated at block 166. If so, the controller 20 operates the vehicle in a driving state, as shown at block 150. At block 166, if the vehicle speed is less than the threshold Z, the controller 20 operates the vehicle in the sink state 154 discussed above with reference to fig. 8. In the sink state 154, the controller 20 increases damping based on the increased vehicle speed. The additional controller 20 increases compression damping on the rear shock absorbers and/or rebound damping on the front shock absorbers based on the throttle sensor signal and the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

At block 162, if the brakes are activated, the controller 20 operates the vehicle in the braking state 146 discussed above with reference to fig. 8. In the braking state 146, the controller 20 increases damping based on the increased vehicle speed. In addition, the controller 20 increases compression damping on the front shock absorbers and/or rebound damping on the rear shock absorbers based on the brake sensor signals. The user pattern modifier 118 selects a look-up table and/or algorithm defined with damping characteristics at the respective corners based on the above inputs.

At block 160, if the absolute value of the steering position is greater than the threshold X or the absolute value of the steering rate is greater than the threshold B, the controller 20 determines whether the brakes are activated, as shown at block 168. If so, the controller 20 operates the vehicle in a braking state as shown at block 170. In the braking state 170, the mode modifier for controlling damping includes the user input 118, the vehicle speed 120, and the steering rate 128.

In the braking state 170, the controller 20 increases damping based on the increased vehicle speed. Further, the controller 20 increases the compression damping on the outside front corner shock absorbers based on the inputs from the steering sensor, the brake sensor, and the vehicle speed sensor. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the brake is not activated at block 168, the controller 20 determines if the throttle position is greater than the threshold Y, as indicated at block 172. If not, the vehicle controller 20 operates the vehicle in the roll/turn state as shown at block 174. In the roll/turn state, the state modifier for controlling damping includes a user mode 118, a steering position 126, and a steering rate 128. In the roll/turn state, lateral acceleration caused by steering and turning inputs causes the occurrence of body roll.

In the roll/turn state 174, the controller 20 increases damping based on the increased vehicle speed. Further, when a turning event is detected via the steering sensor, the controller 20 increases the compression damping on the outboard corner shock absorber and/or the rebound damping on the inboard corner shock absorber. For a left turn, the outboard shock absorbers are the right front and rear shock absorbers, and the inboard shock absorbers are the left front and rear shock absorbers. For a right turn, the outboard shock absorbers are the front left and rear left shock absorbers and the inboard shock absorbers are the front right and rear right shock absorbers. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the throttle position is greater than the threshold Y at block 172, the controller 20 operates the vehicle in a submerged state as shown at block 176. In the sink state 176, the mode modifier used by the controller 20 to control the damping characteristics relates to the user mode 118, the vehicle speed 120, the throttle opening 122, the steering position 126, and the steering rate 128. Further, damping is increased based on the increased vehicle speed. In addition, the compression damping on the rear corner on the outside is increased based on the steering sensor, the throttle sensor, and the vehicle speed.

In the sink state 176, the controller 20 increases damping based on the increased vehicle speed. Further, the controller 20 increases the compression damping on the outboard rear corner shock absorbers based on inputs from the steering sensor, the throttle sensor, and the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

Fig. 10 illustrates yet another embodiment of the damping control method of the present disclosure including different sensor input options than the embodiments of fig. 8 and 9. In addition to the throttle sensor 138, the vehicle speed sensor 140, the brake sensor 142, the steering position sensor 158, and the steering rate sensor 156, the embodiment of FIG. 10 also uses a z-axis acceleration sensor 180 and an x-axis acceleration sensor 182 as inputs to the controller 20.

As shown at block 184, the controller 20 first determines whether the acceleration from the z-axis sensor 180 has been less than a threshold value C for a time greater than a threshold value N. If so, the controller 20 determines that the vehicle is in a jump and controls the vehicle in a jump/pitch state as shown at block 186 in which the suspension is allowed to sag and the tires lose contact with the ground. In the skip/pitch state 186, the controller 20 controls the damping characteristics using a state modifier that relates the user input 118, the vehicle speed 120, and the z-axis acceleration sensor 134.

In the skip/pitch state 186, the controller 20 increases damping based on the increased vehicle speed. Further, when an empty event (and the duration of the empty event) is detected via negative vertical acceleration detected by the z-axis acceleration sensor 134, the controller 20 increases the compression damping on the shock absorbers at all four corners. The controller 20 maintains the damping increase for a predetermined time after the jump event. If positive vertical acceleration is detected by the z-axis acceleration sensor 134 for a time longer than the threshold duration by an amount greater than the threshold (such as when in contact with the ground following an emptying event), while the greater acceleration causes the required duration threshold to decrease, the rebound damping of the rear and/or front shock absorbers may be increased for a time duration. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If an empty event is not detected at block 184, the controller 20 determines at block 188 whether the absolute value of the steering position is greater than a threshold value X or the absolute value of the steering rate is greater than a threshold value B. If not, the controller 20 determines at block 190 whether the brakes are activated and the x-axis acceleration is greater than a threshold A. If so, the controller 20 operates the vehicle in a braking state as shown at block 192.

In the braking state 192, a state modifier involving the user input 118, the vehicle speed 120, the x-axis accelerometer 130, and the y-axis accelerometer 132 is used as an input for damping control. In the braking state 192, the controller 20 increases damping based on the increased vehicle speed. Further, the controller 20 increases the compression damping on the outboard front corner shock absorbers based on inputs from the steering sensor 158, the brake sensor 142, the vehicle speed sensor 140, and/or the acceleration sensor 180. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the determination at block 190 is negative, the controller 20 determines whether the throttle position is greater than the threshold Y, as indicated at block 194. If not, the controller 20 operates the vehicle in a travel state as at block 196. In the driving state 196, the controller 20 controls the damping characteristics using a state modifier involving the user selected mode 118, the vehicle speed 120, a drive mode sensor such as the four wheel drive sensor 124, and the z-axis accelerometer 134. In the driving state 196, the controller 20 increases damping based on the vehicle speed. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the throttle position is greater than the threshold Y at block 194, the controller 20 determines if the vehicle speed is greater than the threshold Z, as indicated at block 198. If so, the controller 20 operates the vehicle in the travel state 196 as described above. If not, the controller 20 operates the vehicle in a submerged state as shown at block 200. In the sink state 200, the controller 20 uses state modifiers related to the user mode 118, vehicle speed 120, throttle opening 122, and y-axis accelerometer 132 for damping control. In the sink state 200, the controller 20 increases damping based on vehicle speed. Further, controller 20 increases compression damping on the rear shock absorbers and/or rebound damping on the front shock absorbers based on input from throttle sensor 138, vehicle speed sensor 140, and/or acceleration sensor 180. Additional adjustments are made based on duration and longitudinal acceleration. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the absolute value of the steering position is greater than the threshold X or the absolute value of the steering rate is greater than the threshold B at block 188, the controller 20 determines if the brakes are activated and the X-axis acceleration is greater than the threshold A, as shown at block 202. If so, the controller 20 operates the vehicle in a braking state as shown at block 204. In the braking state 204, the controller 20 adjusts the damping control characteristics of the electronically tunable shock absorbers using state modifiers related to the user mode 118, the vehicle speed 120, the steering position 126, the x-axis acceleration 130, and the y-axis acceleration 132. In the braking state 204, the controller 20 increases damping based on the increased vehicle speed. Further, the controller 20 increases the compression damping on the outboard front corner shock absorber based on inputs from the steering sensor 158, the brake sensor 142, the vehicle speed sensor 140, and/or the acceleration sensor 180. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If a negative determination is made at block 202, the controller 20 determines whether the throttle position is greater than the threshold Y, as indicated at block 206. If not, the controller 20 operates the vehicle in the roll/turn state as shown at block 208. In the roll/turn state 208, the controller 20 controls the damping characteristics of the adjustable shock absorbers using state modifiers related to the user mode 118, the steering position 126, the steering rate 128, the y-axis acceleration 132, and the yaw rate 136. In the roll/turn state 208, the controller 20 increases damping based on the increased vehicle speed. Further, when a steering event is detected via the steering sensor 156 and the accelerometer 182, the controller 20 increases the compression damping on the outboard corner shock absorber and/or the rebound damping on the inboard corner shock absorber. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

If the throttle position is greater than the threshold Y at block 206, the controller 20 operates the vehicle in a submerged state as shown at block 210. In the sink state 210, the controller 20 controls the damping characteristics of the adjustable shock absorbers using state modifiers related to the user mode 118, the vehicle speed 120, the throttle opening 122, the steering position 126, the steering rate 128, and the y-axis acceleration 132. In the sink state 210, the controller 20 increases damping based on vehicle speed. Further, the controller 20 increases the compression damping on the outboard rear corner shock absorbers based on inputs from the throttle sensor 138, the vehicle speed sensor 140, and/or the

acceleration sensor

180 or 182. The user pattern modifier 118 selects a look-up table and/or algorithm defining damping characteristics at each corner based on the above inputs.

Another embodiment of the present disclosure is shown in fig. 11-13. As part of the damping control system, the stabilizer bar linkage 220 is selectively locked or unlocked. The linkage 220 includes a movable piston 222 located within a cylinder 224. An end 226 of the piston 222 is illustratively coupled to a stabilizer bar of the vehicle. An end 228 of the cylinder 224 is illustratively coupled to a suspension arm or component of the vehicle. It should be understood that this connection may be reversed.

The locking mechanism 230 includes a movable solenoid 232, the movable solenoid 232 being biased in the direction of arrow 236 by a spring 234. The controller 20 selectively energizes the solenoid 232 to retract the removable solenoid 232 from the extended position shown in fig. 11 and 12 to the retracted position shown in fig. 13 in the direction of arrow 238. In the retracted position, the end of the solenoid 232 is disengaged from the window 240 of the movable piston 232 to allow free movement between the piston 222 and the cylinder 224. If the solenoid 232 is in the extended position shown in fig. 11 and 12 engaged with the window 240, the piston 222 is locked relative to the cylinder 224.

When the linkage 220 is unlocked, the telescopic movement of the piston 222 and cylinder 224 eliminates the function of a stabilizer bar while the solenoid 232 is disengaged as shown in fig. 6. When the controller 20 removes the signal from the solenoid 232, the solenoid plunger 232 moves into the window 240 to lock the plunger 222 relative to the cylinder 220. If the solenoid 232 loses power due to the spring 234, it also enters the locked position. In other words, the solenoid 232 is disabled in the locked position. It is not necessary to level the vehicle in order for the solenoid 232 to lock the piston 222.

Unlocking the stabilizer bar 220 during low speed operation can provide tracking benefits to the suspension system. Thus, the stabilizer bar 220 is unlocked in some low speed states. For higher speeds, the stabilizer bar 220 is locked. When the stabilizer bar 220 is unlocked, the controller 20 may also use Electronic Throttle Control (ETC) to limit the vehicle speed to a predetermined maximum speed.

While the embodiments of the disclosure have been described by way of exemplary designs, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

Claims

1. A damping control method for a vehicle, the vehicle comprising: a suspension between the plurality of wheels and the frame; a controller; a plurality of vehicle state sensors; and a user interface, the suspension including a plurality of adjustable shock absorbers including a right front shock absorber, a left front shock absorber, a right rear shock absorber, and a left rear shock absorber, the damping control method including:

receiving, by the controller, user input from the user interface to provide a user-selected damping mode of operation for the plurality of adjustable shock absorbers during operation of the vehicle;

receiving, by the controller, a plurality of inputs from the plurality of vehicle state sensors, the plurality of vehicle state sensors including a brake sensor, a throttle sensor, and a vehicle speed sensor;

determining, with the controller, whether a vehicle brake is actuated based on input from the brake sensor;

determining, with the controller, a throttle position based on input from the throttle sensor;

determining, with the controller, a speed of the vehicle based on input from the vehicle speed sensor;

operating the damping control in a braking state if the brake is actuated, wherein in the braking state the controller adjusts damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode and a vehicle speed;

operating the damping control in a driving state if the brake is not actuated and a throttle position is less than a threshold Y, wherein in the driving state the controller adjusts damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode and a vehicle speed;

operating the damping control in the driving state if the brake is not actuated, the throttle position is greater than the threshold value Y, and the vehicle speed is greater than a threshold value Z; and

operating the damping control in a sink state if the brakes are not actuated, the throttle position is greater than the threshold Y, and the vehicle speed is less than the threshold Z, wherein in the sink state the controller adjusts damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode, vehicle speed, and throttle opening.

2. The method of claim 1, wherein in the braking state, the controller increases compression damping on the front right and front left shock absorbers.

3. The method according to claim 1 or 2, wherein in the braking state, the controller increases rebound damping on the right and left rear shock absorbers.

4. The method according to any one of claims 1 to 3, wherein in the sink state, the controller increases compression damping on the right and left rear shock absorbers.

5. The method according to any one of claims 1 to 4, wherein in the sink state, the controller increases rebound damping on the front right and front left shock absorbers.

6. The method of any of claims 1 to 5, further comprising:

receiving input from additional vehicle state sensors including a steering rate sensor and a steering position sensor;

determining, with the controller, a steering rate based on input from the steering rate sensor;

determining, with the controller, a steering position based on input from the steering position sensor; and

if the brake is actuated and if the steering position is greater than a threshold X or the steering rate is greater than a threshold B, operating the damping control in a modified braking state in which the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode, vehicle speed and steering rate.

7. The method of claim 6, further comprising:

if the steering position is greater than a threshold X or the steering rate is greater than a threshold B, and if the brake is not actuated and the throttle position is less than the threshold Y, operating the damping control in a roll/turn state in which the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode, a steering position, and a steering rate.

8. The method of claim 7, wherein in the roll/turn state, the controller increases compression damping on an outboard shock absorber upon detecting a turning event via the steering sensor.

9. The method of claim 7, wherein in the roll/turn state, the controller increases rebound damping on an inboard shock absorber upon detection of a turning event via the steering sensor.

10. The method of claim 6, further comprising:

if the steering position is greater than a threshold X or the steering rate is greater than a threshold B, and if the brake is not actuated and the throttle position is greater than the threshold Y, operating the damping control in a modified sink state in which the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers based on state modifiers including a user selected mode, vehicle speed, throttle opening, steering position, and steering rate.

11. The method of claim 10, wherein in the modified sink state, the controller increases compression damping on an outer rear side shock absorber based on inputs from the steering sensor, the throttle sensor, and the vehicle speed sensor.

12. The method of any of claims 1 to 11, further comprising:

receiving, with the controller, input from additional vehicle state sensors including a steering rate sensor, a steering position sensor, an x-axis acceleration sensor, and a z-axis acceleration sensor;

determining, with the controller, a steering position based on input from the steering position sensor;

determining, with the controller, an x-axis acceleration based on input from the x-axis acceleration sensor;

determining, with the controller, a z-axis acceleration based on input from the z-axis acceleration sensor; and

operating the damping control based on the detected conditions, the controller adjusting damping characteristics of the plurality of adjustable shock absorbers based on a condition modifier including a steering rate, a steering position, an x-axis acceleration, and a z-axis acceleration.

13. The method of any of claims 1 to 12, further comprising:

receiving, with the controller, input from an additional vehicle state sensor comprising a z-axis acceleration sensor;

operating the damping control in a skip/pitch state in which the controller adjusts damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including a user selected mode, vehicle speed, and z-axis acceleration sensor if the z-axis acceleration has been less than a threshold C for a duration N.

14. The method of claim 13, wherein in the bounce/pitch state, the controller increases compression damping on the front right, front left, rear right, and rear left shock absorbers upon detection of an empty event via a negative vertical acceleration detected by the z-axis acceleration sensor.

15. The method of claim 14, wherein in the skip/pitch state, the controller maintains an increase in damping for a predetermined time after the end of the skip event.

16. The method of claim 13, wherein in the jump/pitch state, the controller increases rebound damping on the front right, front left, rear right, and rear left shock absorbers when the occurrence of contact with the ground is detected via detection of positive vertical acceleration by the z-axis acceleration sensor after an empty event.

17. The method of any of claims 1-6, wherein a plurality of springs and a plurality of shock absorbers are coupled between the frame and the ground engaging member through an A-arm link of the suspension.

18. The method of any of claims 1-17, wherein a plurality of springs and a plurality of shock absorbers are coupled between the frame and the ground engaging member through a trailing arm suspension.

19. The method of any of claims 1-18, wherein the user interface is integrated with a display on a dashboard of a vehicle.

20. The method of any of claims 1-19, wherein at least one user input of the user interface is located on one of a steering wheel, a handlebar, or a steering control of a vehicle to facilitate adjusting a damping characteristic of at least one of the adjustable shock absorbers by a driver of the vehicle.

21. The method of any one of claims 1 to 20, wherein the user input of the user interface comprises at least one of a touch screen control, a slide control, a rotatable knob, and a button to adjust the damping characteristics of the front and rear adjustable shock absorbers.

22. The method of any of claims 1 to 21, further comprising:

receiving, by the controller, an input from a drive mode sensor, and wherein the controller adjusts the damping characteristics of the plurality of adjustable shock absorbers further based on a state modifier that includes the drive mode sensor.

23. The method of any of claims 1 to 22, further comprising:

receiving, by the controller, input from a four wheel drive sensor; and determining, with the controller, whether the vehicle is in four-wheel drive based on input from the four-wheel drive sensor; and wherein in the driving state, the controller further adjusts the damping characteristics of the plurality of adjustable shock absorbers based on a state modifier including the four-wheel drive sensor.