System and method for adjustable suspension for non-road recreational vehicle

Abstract

There is provided a suspension system for a snowmobile having a track, the suspension system comprising: a front adjustable track damping portion operable according to a first damping characteristic of the front adjustable track damping portion; the rear adjustable track damping part can be operated according to the first damping characteristic of the rear adjustable track damping part; and an operator input operable to adjust an operating mode of the suspension system between a first configuration and a second configuration wherein, in response to the operator input being actuated to the first configuration, the front adjustable track damper first damping characteristic is increased and the rear adjustable track damper first damping characteristic is decreased, and wherein the operator input is actuated to the second configuration. In response to the operator input being actuated to the second configuration, the front adjustable track shock first damping characteristic is reduced and the rear adjustable track shock first damping characteristic is increased.

Description

[0001] This application is a divisional application of the Chinese application entitled “Systems and methods for adjustable suspension for off-road recreational vehicles”, filed on May 19, 2021, and application number 202180036366.2.

[0002] Background and Summary of the Invention

[0003] The present disclosure relates to improved suspensions for off-road recreational vehicles, and more particularly to systems and methods for damping control of shock absorbers for off-road recreational vehicles.

[0004] Currently, some off-road vehicles include adjustable shock absorbers. The corresponding adjustments include spring preload, high-speed and low-speed compression damping, and / or rebound damping. To make these adjustments, the vehicle is stopped and the operator makes adjustments at each shock absorber position on the vehicle. Adjustments typically require the use of tools. Some off-road vehicles also include adjustable electric shocks and sensors for active ride control systems. Exemplary systems are disclosed in U.S. Patent No. 9,010,768 and U.S. Published Patent Application No. 2016 / 0059660, both of which are assigned to the present assignee, and the entire disclosure of each patent is expressly incorporated herein by reference.

[0005] In an exemplary embodiment of the present disclosure, a suspension system is provided for a snowmobile having a track, the suspension system comprising: a front adjustable track shock operable according to a first front adjustable track shock damping characteristic; a rear adjustable track shock operable according to a first rear adjustable track shock damping characteristic; and an operator input operable to adjust an operating mode of the suspension system between a first configuration and a second configuration, wherein, in response to the operator input being actuated to the first configuration, the first front adjustable track shock damping characteristic is increased and the first rear adjustable track shock damping characteristic is decreased, and wherein, in response to the operator input being actuated to the second configuration, the first front adjustable track shock damping characteristic is decreased and the first rear adjustable track shock damping characteristic is increased.

[0006] In another exemplary embodiment of the present disclosure, a snowmobile is provided comprising: a plurality of ground-contacting members, including a left front ski, a right front ski, and a track assembly; a frame supported by the plurality of ground-contacting members; a seat supported by the frame; and wherein the track assembly includes a suspension system as described in the exemplary embodiments above.

[0007]

[0011] Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiments, which illustrate the best mode of carrying out the invention as presently understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0008]

[0011] The foregoing aspects of the present systems and methods, as well as many additional features, will become more readily appreciated and become better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings.

[0009] Figure 1 A left side view of an exemplary snowmobile is shown;

[0010] Figure 1A Shown Figure 1 A left front perspective view of an exemplary snowmobile illustrating the yaw axis, pitch axis, and roll axis of the snowmobile;

[0011] Figure 1B illustrates a right front perspective view of another exemplary snowmobile having another exemplary shock absorption arrangement relative to an endless track of the snowmobile;

[0012] Figure 1C Shown Figure 1B a left side view of an exemplary snowmobile;

[0013] Figure 2 Shown Figure 1 a right side view of an exemplary snowmobile;

[0014] Figure 3 Shown Figure 1 An exemplary snowmobile track suspension;

[0015] Figure 4 Shown Figure 1 A representative view of components of an exemplary snowmobile including a suspension having a plurality of continuous damping control shock absorbers, an operator interface, and a plurality of sensors integrated with a controller of the snowmobile;

[0016] Figure 5 Shown Figure 1 a partial left rear perspective view of an exemplary snowmobile;

[0017] Figure 6 Shown Figure 1 A representative view of components of an exemplary snowmobile including a suspension having a plurality of continuous damping control shock absorbers, an operator interface, and a plurality of sensors integrated with a controller of the snowmobile;

[0018] Figure 7 Shown Figure 1 a right front perspective view of an exemplary snowmobile illustrating a tunnel and pyramidal frame covering an endless track ground contact member;

[0019] Figure 8AShown Figure 6 A representative diagram of an exemplary shock absorption damping logic of an electronic controller;

[0020] Figure 8B Shown Figure 6 A representative diagram of another exemplary shock absorption damping logic of an electronic controller;

[0021] Figure 8C Shown Figure 6 A representative diagram of yet another exemplary shock absorption damping logic of an electronic controller;

[0022] Figures 9A to 9C Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for use as Figure 1 A portion of a suspension of a left front ski of an exemplary snowmobile provides a continuous damping control shock absorber;

[0023] 10A to 10C Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for use as Figure 1 A portion of a suspension of a right front ski of an exemplary snowmobile provides a continuous damping control shock absorber;

[0024] Figure 11A and Figure 11B Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for use as Figure 1 A portion of a suspension of an exemplary snowmobile endless track provides a continuous damping control shock absorber;

[0025] Figure 12A and Figure 12B Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for use as Figure 1 A portion of a suspension of an exemplary snowmobile endless track provides a continuous damping control shock absorber;

[0026] Figure 13 Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for detecting a g-out event or a chatter event;

[0027] Figure 14 Shown Figure 6 an exemplary processing sequence of the shock absorber damping logic of the electronic controller for detecting an exemplary braking event;

[0028] Figure 15 Shown Figure 6an exemplary processing sequence of the shock damping logic of the electronic controller for detecting an exemplary launch event;

[0029] 16A to 16C Shown Figure 6 an exemplary processing sequence of the shock damping logic of the electronic controller for detecting an exemplary anti-squat event;

[0030] 17A to 17D Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller for detecting an exemplary cornering event;

[0031] Figure 18 Shown Figure 6 an exemplary processing sequence of shock damping logic of an electronic controller for detecting an exemplary driver-actuatable suspension adjustment input event;

[0032] Figure 19A and Figure 19B Shown Figure 6 an exemplary processing sequence of the shock absorber damping logic of the electronic controller for detecting an exemplary launch mode event;

[0033] Figure 20 Shown Figure 6 an exemplary processing sequence of the shock damping logic of the electronic controller for detecting an exemplary one ski event;

[0034] Figure 21 Shown Figure 1 An exemplary snowmobile being airborne;

[0035] Figure 22 The pitching of the snowmobile 10 in deep snow is demonstrated without adjusting the damping characteristics of the adjustable shock absorbers;

[0036] Figure 23 The pitching of the snowmobile 10 in deep snow is shown with the damping characteristics of the adjustable shock absorbers adjusted;

[0037] Figure 24 Shown Figure 6 A representative diagram of an exemplary shock absorption damping logic of an electronic controller;

[0038] Figure 25 Shown Figure 6 An exemplary processing sequence of the shock absorption damping logic of the electronic controller;

[0039] Figure 26 A left front perspective view of a side-by-side off-road recreational vehicle is shown;

[0040] Figure 27 Shown Figure 26left side view of a side-by-side nonroad recreational vehicle;

[0041] Figure 28 Shown Figure 26 Right side view of a side-by-side nonroad recreational vehicle.

[0042] Figures 29A to 29C An exemplary arrangement of inputs of an exemplary operator interface is illustrated; and

[0043] Figure 30 Shown are example input screens for adjusting the gain of various damping profiles.

[0044] Corresponding reference numerals indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components according to the present disclosure, the drawings are not necessarily drawn to scale and certain features may be exaggerated in order to better illustrate and explain the disclosure. DETAILED DESCRIPTION

[0045] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the accompanying drawings, which will be described below. The embodiments disclosed below are not intended to be exhaustive or limited to the precise forms disclosed in the following detailed description. Rather, these embodiments are selected and described so that those skilled in the art can utilize their teachings.

[0046] Now refer to Figure 1 、 Figure 1A 、 Figures 2 to 4 and Figure 7 , an illustrative embodiment of a snowmobile 10 is shown. Snowmobile 10 includes a chassis or frame 12 having a front frame portion 12a and a rear frame portion 12b. A body assembly 14 generally surrounds at least the front frame portion 12a of frame 12. Front frame portion 12a is supported by a front ground-engaging member, illustratively a ski 16, while rear frame portion 12b is supported by a rear ground-engaging member, illustratively an endless track 18. The rider uses a steering assembly 20, which is activated by a steering linkage 17 (see FIG. 1 ), when operating snowmobile 10. Figure 7 ) is operatively coupled to at least the snowboard 16. A seat assembly 22 is generally provided rearward of the steering assembly 20 and is configured to support a rider.

[0047] The front skis 16 are operatively coupled to the left and right front suspension assemblies 24, and the endless track 18 cooperates with the rear suspension assembly 26. The power transmission assembly is generally positioned intermediate the front and rear suspension assemblies 24, 26 and provides power to the endless track 18 to move the snowmobile 10. More specifically, the power transmission assembly 30 includes an engine (see prime mover 110, see Figure 1C), transmission, and drive shaft. In one embodiment, the transmission includes a shiftable transmission and a continuously variable transmission ("CVT") 111 (see Figure 1C In an embodiment, the shiftable transmission includes a low forward gear, a high forward gear, a reverse gear, a neutral gear, and a park gear.

[0048] like Figure 3 As shown, the rear suspension assembly 26 includes a plurality of slide rails 32, a front track-adjustable shock 144 positioned within the interior of the endless track 18, a rear track-adjustable shock 146 positioned within the interior of the endless track 18, a plurality of torque arms 36 operably coupled to the front lower ends of the rear track-adjustable shocks 146, and a link assembly 38 operably coupled to the rear upper ends of the rear track-adjustable shocks 146. In one embodiment, the torque arms 36 can be constructed of forged aluminum, which can reduce the overall weight of the snowmobile 10. Additionally, the rear suspension assembly 26 can include a front track-adjustable shock 144 positioned forward of the rear track-adjustable shock 146 and operably coupled to the torque arms 36 and the slide rails 32.

[0049] The rear suspension assembly 26 also includes a plurality of rear guide wheels 42 rotatably coupled to the rear end of the slide rail 32, and a plurality of track support rollers 44 laterally adjacent the rear upper end of the rear track adjustable shock absorber 146. The rear guide wheels 42 and the track support rollers 44 are configured to maintain tension in the endless track 18. In addition, the position of the rear guide wheels 42 on the slide rail 32 can be adjusted to adjust the tension in the endless track 18. Figure 1 and Figure 2 As shown, the endless track 18 generally surrounds the rear suspension assembly 26 and is supported on at least the skids 32, rear guide wheels 42, and support rollers 44. The rear suspension assembly 26 is configured to cooperate with the endless track 18 when the snowmobile 10 is operating. In particular, the rear suspension assembly 26 is configured to move longitudinally and vertically during operation of the snowmobile 10 and to maintain tension in the endless track 18 through at least the rear guide wheels 42 throughout the movement of the rear suspension assembly 26.

[0050] Reference Figure 1B and Figure 1C , shows a snowmobile 10' having a different rear suspension 24' than the snowmobile 10. The rear suspension 24' positions the front track adjustable shock absorber 144 inside the interior of the endless track 18 and positions the rear track adjustable shock absorber 146 outside the interior of the endless track 18, specifically above the endless track 18. Figure 1AAs shown, the endless track 18 has a lateral width W. For each of the snowmobile 10 and the snowmobile 10', the front track adjustable shock 144 and the rear track adjustable shock 146 are positioned laterally within the rearward width W of the endless track 18. Throughout this disclosure, when discussing the damping characteristics of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146, the snowmobile 10 should be read as referring to both snowmobiles 10, 10'.

[0051] Right front adjustable shock absorber 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146 are adjustable shock absorbers whose damping characteristics are continuously controlled by electronic controller 100. In one embodiment, endless track 18 includes one adjustable shock absorber and standard shock absorbers, such as manually adjustable shock absorbers. In one embodiment, electronic controller 100 updates the damping characteristics of right front adjustable shock absorber 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146 during motion of snowmobile 10, 10'. The electronic controller 100 continuously controls the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 by updating the desired damping characteristics of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 at discrete time instances based on monitored sensor values, received operator inputs, and / or other inputs. An exemplary time interval is approximately 1 millisecond to approximately 5 milliseconds. For example, the electronic controller 100 updates the target for each of the right front adjustable shock absorber 140, f142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 approximately every 5 milliseconds and updates the current control loop approximately every millisecond.

[0052] In an embodiment, the damping characteristics of the front track-adjustable shock absorber 144 are controlled by the electronic controller 100, while the rear track-adjustable shock absorber 146 is manually adjustable independently of the electronic controller 100. In an embodiment, the damping characteristics of the rear track-adjustable shock absorber 146 are controlled by the electronic controller 100, while the front track-adjustable shock absorber 144 is manually adjustable independently of the electronic controller 100. In an embodiment, the arrangement and control of one or both of the front track-adjustable shock absorber 144 and the rear track-adjustable shock absorber 146 of the rear suspension 26 can be applied to a vehicle with a single front ski, such as a snowbike. A snowbike can have one or more shock absorbers associated with the front ski. These one or more shock absorbers can be adjustable shock absorbers controlled by the controller 100 in a manner similar to the right front adjustable shock absorber 140 and the left front adjustable shock absorber 142.

[0053] In an embodiment, the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 include solenoid valves mounted at the base of the shock absorber body or mounted inside the damping pistons of the respective right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146. The stiffness of the shock absorber is increased or decreased by introducing additional fluid into the interior of the shock absorber, removing fluid from the interior of the shock absorber, and / or increasing or decreasing the ease with which fluid can transfer from a first side of the shock absorber's damping piston to a second side of the shock absorber's damping piston. In another embodiment, the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 include magnetorheological fluid within the damping pistons of the respective right front adjustable shock absorbers 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146. The stiffness of the damping portion is increased or decreased by varying the magnetic field to which the magnetorheological fluid is subjected. Further details of an exemplary adjustable damping portion are provided in U.S. Published Patent Application No. 2016 / 0059660, filed on November 6, 2015, entitled “VEHICLE HAVING SUSPENSION WITH CONTINUOUS DAMPING CONTROL,” which is assigned to the present assignee and whose entire disclosure is expressly incorporated herein by reference. In one embodiment, the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 each include a first controllable proportional valve for adjusting compression damping and a second controllable proportional valve for adjusting rebound damping. In another embodiment, the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 each include a combined proportional valve for controlling both compression damping and rebound damping.

[0054] Further details of the frame 12, body assembly 14, endless track 18, front suspension assembly 24, rear suspension assembly 26, and drivetrain assembly for the snowmobile 10, 10' and other exemplary snowmobiles are disclosed in U.S. Patent Nos. 7,891,454, 8,590,654, 8,820,458, 8,944,204, 9,428,232, 9,540,072, 9,809,195, and 10,358,187, the entire disclosures of which are expressly incorporated herein by reference.

[0055] Reference Figure 4, the electronic controller 100 includes at least one processor 104 and at least one non-transitory computer-readable medium, namely, a memory 106. In an embodiment, the electronic controller 100 is a single unit that controls the operation of various systems of the snowmobile 10. In an embodiment, the electronic controller 100 is a distributed system composed of multiple controllers, each of which controls one or more systems of the snowmobile 10 and can communicate with each other via one or more wired and / or wireless networks. For example, the electronic controller 100 may include a suspension controller 200 (see Figure 6 ) and an engine controller 204 that controls the damping characteristics of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146, and the engine controller that controls the prime mover 110 of the snowmobile 10 (see Figure 4 ) operator.

[0056] The electronic controller 100 includes shock damping logic 150 that controls the damping characteristics of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146. The term "logic" as used herein includes software and / or firmware executed on one or more programmable processors, application specific integrated circuits, field programmable gate arrays, digital signal processors, hard-wired logic, or a combination thereof. Thus, depending on the embodiment, the various logics may be implemented in any suitable manner and will be maintained in accordance with the embodiments disclosed herein. A non-transitory machine-readable medium including logic may also be considered to be implemented in any tangible form of a computer-readable carrier, such as solid-state memory, magnetic disks, and optical disks, which contains an appropriate collection of computer instructions and data structures that cause a processor to perform the techniques described herein. The present disclosure contemplates other embodiments in which the electronic controller 100 is not microprocessor-based, but is instead configured to control the operation of the right front adjustable shock absorber 140 , the left front adjustable shock absorber 142 , the front track adjustable shock absorber 144 , and the rear track adjustable shock absorber 146 based on one or more hard-wired instruction sets.

[0057] return Figure 4 The electronic controller 100 provides electronic control and / or monitoring for various components of the snowmobile 10 (illustratively, a prime mover 110, a steering system 120, and a braking system 122). Exemplary prime movers include two-stroke internal combustion engines, four-stroke internal combustion engines, electric motors, and other suitable power devices. The prime mover 110 is operatively coupled to the endless track 18 via a transmission. Exemplary transmissions include shiftable transmissions, continuously variable transmissions, and combinations thereof. Figure 7, an exemplary steering system 120 is shown including a handlebar 124 attached to a steering column 126, which in turn is coupled to a steering linkage 128. The steering linkage 128 is coupled to the skis 16 to adjust the orientation of the skis 16 relative to the ground.

[0058] Furthermore, the electronic controller 100 is operatively coupled to a plurality of sensors 130 (see Figure 4 ), which monitor various parameters of the snowmobile 10 or the environment surrounding the snowmobile 10. Exemplary sensors 130 include a global positioning sensor (GPS) 131, an inertial measurement unit (“IMU”) 132, an engine speed sensor 133, a brake switch 134, a brake pressure sensor 135, a steering angle sensor 136, a transmission gear selection sensor 137, a throttle position sensor 138, a vehicle speed sensor 139, and an air pressure sensor 141.

[0059] The GPS sensor 131 provides the position of the snowmobile 10 on the surface of the earth. The IMU 132 includes a three-axis accelerometer and a three-axis gyroscope. Figure 1A The three-axis accelerometer provides acceleration data of the snowmobile 10 along axes 160, 162, and 164, and the three-axis gyroscope provides angular information about rotation about each of the axes 160, 162, and 164. Illustratively, the IMU 132 is supported on the chassis 150 of the snowmobile 10 (see FIG. Figure 7 ) to provide an indication of the acceleration forces of the vehicle during operation. In an embodiment, the IMU 132 is attached to a channel 154 of the chassis 150 that covers the track 18. In an embodiment, the IMU 132 is attached to an upper structural frame 156 of the chassis 150. In an embodiment, the IMU 132 is located within the interior of the upper structural frame 156 of the chassis 150. In an embodiment, the IMU 132 is aligned with the steering column 126 (see FIG. 1 ) of the snowmobile 10 within the interior of the upper structural frame 156 of the chassis 150. Figure 7 ) are positioned in a straight line in the vertical direction. In an embodiment, the IMU 132 is mounted near the frame 156, for example, on the front side of the fuel tank 114 (see Figure 1C ), or integrated into the wall of the fuel tank. In an embodiment, the IMU 132 is located longitudinally between the fuel tank and the prime mover 110 of the snowmobile 10. In an embodiment, the IMU 132 is located on the main axis 116 of the left ski 16 (see Figure 1C) and the rear end 118 of the fuel tank 114 supported by the plurality of ground-contacting members. In an embodiment, the IMU 132 is positioned along the longitudinal centerline plane of the snowmobile 10. In an embodiment, the IMU 132 is located at the center of gravity of the snowmobile 10. In an embodiment, the IMU 132 is offset from the center of gravity of the snowmobile 10, and the electronic controller 100 uses the readings of the three-axis gyroscope to determine the acceleration value of the snowmobile 10 at the center of gravity of the snowmobile 10. In an embodiment, the IMU is integrated into the electronic controller 100, such as into the suspension controller 200. In an embodiment, the IMU is spaced apart from the electronic controller 100. In an embodiment, the IMU 132 is isolated from the chassis 150 by an isolation mount, such as a rubber mount, to reduce the amount of engine vibration experienced by the IMU 132.

[0060] An engine speed sensor 133 monitors the engine's crankshaft speed. In an embodiment, the crankshaft speed is provided to the controller 100 by an engine control module ("ECU").

[0061] The brake switch 134 monitors the actuation of an operator brake input such as a foot actuated input or a hand actuated input. The steering angle sensor 136 monitors the rotation angle of the steering column 126 (see Figure 7 In an embodiment, the steering system 120 includes an electronic power steering unit. In an embodiment, the steering system does not include an electronic power steering unit. In embodiments without an electronic power steering unit, the steering angle sensor 136 is supported in front of the engine and below the exhaust port of the engine, or in the rear of the engine and above the throttle body of the engine.

[0062] A throttle position sensor 138 monitors actuation of a throttle input, such as a foot-actuated input or a hand-actuated input. A vehicle speed sensor 139 monitors the speed of the snowmobile 10 relative to the ground. In one example, the speed of the endless track 18 is monitored by the vehicle speed sensor 139 and serves as an indication of the speed of the snowmobile 10 relative to the ground. In an embodiment, the snowmobile 10 has a single vehicle speed sensor 139 that monitors the movement of the endless track 18.

[0063] Brake pressure sensor 135 is a transducer that measures operator applied pressure in the brake lines of the brake system.

[0064] The steering angle sensor 136 monitors the rotational movement of the steering column or monitors the movement of other parts of the steering system.

[0065] The transmission gear selection sensor 137 monitors input from the engine selection module for gear selection of the shiftable transmission and / or rotational direction of the crankshaft for forward and reverse directions.

[0066] Vehicle speed sensor 139 measures ground speed by monitoring the rotational speed of the track drive shaft or other measurement indicative of ground speed of a rotating component of the drive train.

[0067] An air pressure sensor 141 monitors one of ambient atmospheric pressure and / or manifold air pressure in the engine's air intake system.

[0068] The electronic controller 100 also communicates with an operator interface 180 (see FIG. 1 ) comprising at least one input device 182 and at least one output device 184. Figure 4 and Figure 5 ) interaction. Exemplary input devices 182 include joysticks, buttons, switches, soft keys, and other suitable input devices. Exemplary output devices 184 include lights, displays, audio devices, tactile devices, and other suitable output devices. In an embodiment, the operator interface 180 includes a display 190 such as a touch screen display, and the electronic controller 100 interprets various types of touches on the touch screen display as input and controls the content displayed on the touch screen display.

[0069] Reference Figure 5 , the operator interface 180 may include one or more switches 192, one or more inputs 194 supported by the handlebars 124, and one or more portions of an instrument panel 196 that may include a display 190. In an embodiment, referring to Figure 6 , an operator interface 180 includes a mode selection input 170, a driver-actuable suspension adjustment input 172, and a launch mode input 174. The mode selection input allows the operator to select between at least three settings for the snowmobile 10, each setting having a predefined base damping characteristic for the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146.

[0070] Exemplary modes selectable via mode selection input 170 include a comfort mode, a handling mode, and a rough trail mode. In comfort mode, the compression damping and rebound damping of each of right front adjustable shock absorber 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146 are lower than in rough trail mode. In one example, the compression damping and rebound damping are generally constant with vehicle speed and longitudinal acceleration. In rough trail mode, the compression damping of each of right front adjustable shock absorber 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146 is generally higher than in comfort and handling modes based on vehicle speed and longitudinal acceleration. Rebound damping in rough trail mode is maintained or reduced, and the corresponding shock absorber is more likely to extend and therefore has a longer damping length to absorb compression. In handling mode, each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 has lower compression damping than in the comfort mode and the rough handling mode based on vehicle speed and longitudinal acceleration, and higher rebound damping than in the comfort mode based on vehicle speed and longitudinal acceleration. The dynamic ride height of the snowmobile 10 is lowest in handling mode and highest in rough trail mode. In an embodiment, the selected mode provides base damping characteristics for each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146. These base damping characteristics are updated by the controller 200 based on the movement or predicted movement of the snowmobile 10. Exemplary updates of damping characteristics are provided herein. In an embodiment, the controller 200 proactively checks engine torque and / or throttle position for predicted longitudinal acceleration of the snowmobile 10 and adjusts compression and rebound damping to react to predicted motion, such as pitching or squatting, of the snowmobile 10. In an example, the snowmobile 10 is traveling at 80 MPH and the operator reduces the throttle to 0%. In response, the controller 200 increases compression damping of the right front adjustable shock 140 and the left front adjustable shock 142 to react to the front end pitching of the snowmobile 10, and increases rebound damping of the front track adjustable shock 144 and the rear track adjustable shock 146 to react to the rear end lifting.

[0071] In an embodiment, the longitudinal acceleration of the snowmobile 10 is measured based on one or more inputs (such as the IMU 132), estimated based on one or more inputs (such as monitored throttle position and / or monitored engine rpm), or predicted based on one or more inputs as described herein.

[0072] In an embodiment, an operator may provide a gain factor to one or more damping profiles. Figure 30 , shows an exemplary input screen 1200 for display 190. Input screen 1200 is a custom suspension mode screen. The operator selects the mode to be modified by selecting one of comfort mode input 1202, sport mode input 1204, and firm mode input 1206. Figure 30 Also shown are slider inputs, illustratively, base gain input 1210, brake gain input 1212, acceleration gain input 1214, and steering or cornering gain input 1216. Each of base gain input 1210, brake gain input 1212, acceleration gain input 1214, and steering column 126 has a corresponding slider 1220, 1222, 1224, and 1226. When a slider (e.g., base gain slider 1220 for base gain input 1210) is centered, no change is made to the standard base damping profile for the selected mode. Moving the corresponding slider to the left on input screen 1200 decreases the standard base damping profile for the selected mode, while moving the corresponding slider to the right on steering system 120 increases the standard base damping profile for the selected mode. In an embodiment, a first screen is provided for right front adjustable shock absorber 140 and left front adjustable shock absorber 142, and a second screen is provided for front track adjustable shock absorber 144 and rear track adjustable shock absorber 146.

[0073] In an embodiment, the input screen 1200 further includes inputs for selecting one passenger (driver only) or two passengers and for indicating the weight of cargo. In an embodiment, one or more damping profiles are automatically adjusted based on operator input, such as based on identification of the operator and their rider profile settings in the rider profile. The rider profile can be stored in the electronic controller of the snowmobile 10, a personal computing device (e.g., a mobile phone), a key fob, or retrieved from the cloud or a remote computing device.

[0074] Reference Figure 29A , an exemplary embodiment 1100 of the operator interface 180 is shown. Figure 29AA portion of the left handlebar 124 is shown, including a handle portion 1102 to be grasped by the operator's left hand and an input housing 1104. The handle portion 1102 includes a longitudinal axis 1103. On a front face 1108 of the input housing 1104, facing the seat 22, the input housing 1104 includes a plurality of actuatable inputs 1106A-C. Exemplary inputs include a light input, a heated grip input, and a control input for the display 190. Inputs 1106A-C can be any type of actuatable input, including buttons, membrane switches, rockers, and other suitable inputs. Additional inputs are provided on the top surface 1110 of the input housing 1104. In one embodiment, a mode selection input 170 (up and down buttons for cycling between modes) and a driver-actuatable suspension adjustment input 172 are provided on the top surface 1110 of the input housing 1104. Inputs 170 and 172 can be any type of actuatable input, including buttons, membrane switches, rockers, levers, triggers, and other suitable inputs. In an embodiment, input 172 is positioned within touching distance of a finger or thumb to the handle so that the input can be actuated without requiring the operator to remove their hand from the handle. In an embodiment, one or both of input 170 and input 172 can be positioned on front face 1108 and actuable therefrom.

[0075] Reference Figure 29B , an exemplary embodiment 1130 of the operator interface 180 is shown. Figure 29BA portion of the left handlebar 124 is shown, including a handle portion 1102 to be grasped by the operator's left hand and an input housing 1104. The handle portion 1102 includes a longitudinal axis 1103. On a front 1108 of the input housing 1104, facing the seat 22, the input housing 1104 includes a plurality of actuatable inputs 1106A-C. Exemplary inputs include a light input, a heated grip input, and a control input for the display 190. The inputs 1106A-C can be any type of actuatable input, including buttons, membrane switches, rockers, and other suitable inputs. Additional inputs are provided on the top surface 1110 of the input housing 1104. In an embodiment, a mode selection input 170 (up and down buttons for cycling between modes) is provided on the top surface 1110 of the input housing 1104. Additional inputs are provided on a rear surface 1134 of the input housing 1104, which is opposite the front surface 1108. In an embodiment, a driver-actuable suspension adjustment input 172 is provided on the rear face 1134 of the input housing 1104. Inputs 170 and 172 can be any type of actuatable input, including buttons, membrane switches, rockers, levers, triggers, and other suitable inputs. The driver-actuable suspension adjustment input 172 is pressed downward in the direction 1132 toward the front face 1108 to actuate the driver-actuable suspension adjustment input 172. In an embodiment, the input 172 is a lever or trigger that is pulled toward the operator when actuated or pushed away from the operator when actuated.

[0076] Reference Figure 29C , an exemplary embodiment 1150 of the operator interface 180 is shown. Figure 29CA portion of the left handlebar 124 is shown, including a handle portion 1102 to be grasped by the operator's left hand and an input housing 1104. The handle portion 1102 includes a longitudinal axis 1103. On a front face 1108 of the input housing 1104 facing the seat 22, the input housing 1104 includes a plurality of actuatable inputs 1106A-C. Exemplary inputs include a light input, a heated grip input, and a control input for the display 190. The inputs 1106A-C can be any type of actuatable input, including buttons, membrane switches, rockers, and other suitable inputs. Additional inputs are provided on the top surface 1110 of the input housing 1104. In an embodiment, a mode selection input 170 (up and down buttons for cycling between modes) is provided on the top surface 1110 of the input housing 1104. Additional inputs are provided on the handle side 1152 of the input housing 1104. In an embodiment, a driver-actuable suspension adjustment input 172 is provided on handle side 1152 of input housing 1104. Inputs 170 and 172 can be any type of actuatable input, including buttons, membrane switches, rockers, and other suitable inputs. The driver-actuable suspension adjustment input 172 is pressed down along 1103 in direction 1154 to actuate the driver-actuable suspension adjustment input 172. In an embodiment, the travel of input 172 in direction 1154 is approximately 0.25 inches. In an embodiment, input 172 includes tactile feedback to the operator's depression. In one example, input 172 and input housing 1104 cooperate to provide a "click" feel at the end of the travel of input 172 in direction 1154. In an embodiment, the operator interface surface of input 172 is half-moon shaped and can be actuated from either handle face 1152 or front face 1108.

[0077] Although Figures 29A to 29C An exemplary arrangement of driver-actuable suspension adjustment inputs 172 is shown, but other inputs may occupy corresponding positions. In an embodiment, a launch mode input 174 replaces the driver-actuable suspension adjustment input 172 .

[0078] In an embodiment, input 172 may be provided as one input of a multi-function input device. For example, the multi-function input device may provide a function of input 172 in response to a first actuation characteristic(s) (e.g., sequence), and provide another function (e.g., mode change) in response to a second actuation characteristic(s) (e.g., sequence).

[0079] The driver-actuable suspension adjustment input 172 allows the operator to request a maximum stiffness for one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146. Exemplary operation of the driver-actuable suspension adjustment input is discussed in U.S. Patent No. 10,406,884, assigned to the assignee of the present application, the entire disclosure of which is incorporated herein by reference. The electronic controller 100 controls the operation of the output device 184 and monitors the actuation of the input device 182. Figure 6 In an embodiment, the display 190 is operatively coupled to the electronic controller 100 (illustratively, the suspension controller 200 ) via a network (illustratively, a CAN network).

[0080] Reference Figure 8A The shock damping logic 150 includes one or more processing sequences 202 that control damping characteristics of one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146. In an embodiment, the shock damping logic 150 includes one or more functions that output a desired damping characteristic for each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on one or more inputs.

[0081] Reference Figure 8B The shock damping logic 150 includes one or more processing sequences 202 that control the damping characteristics of one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146, and one or more lookup tables 204 that provide the damping characteristics of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on one or more inputs.

[0082] Reference Figure 8CThe shock damping logic 150 includes one or more processing sequences 202 that control the damping characteristics of one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146, and one or more lookup tables 204 that provide the damping characteristics of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on one or more inputs. Exemplary lookup tables include an air time event table 210, a driver actuatable suspension adjustment input event table 212, a braking event table 214, an anti-dive event table 216, a ski-only event table 218, a braking cornering event table 220, a judder cornering event table 222, a g-out event table 224, a judder event table 226, a cornering event table 228, a base damping table 230, a launch mode event table 232, an anti-squat event table 234, and a predicted longitudinal acceleration and predicted vehicle pitch table 236. Figure 20 and Figure 24 The use of the lookup table 204 by the processing sequence 202 is illustrated in the exemplary processing sequence of FIG. In one embodiment, the electronic controller 200 generally executes the exemplary processing sequence continuously while monitoring operator inputs and sensor values. In one embodiment, the electronic controller 200 updates the damping characteristics of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 every approximately 1 millisecond to approximately 5 milliseconds. For example, the electronic controller 200 updates the targets for each of the right front adjustable shock absorber 140, f142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 approximately every 5 milliseconds and updates the current control loop approximately every 1 millisecond.

[0083] While executing the process sequence 202, the electronic controller 200 arbitrates which damping characteristics to use for the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 based on the sensed values ​​from the sensors 130 and the input from the operator interface 180. In an embodiment, with respect to compression damping, the arbitration by the electronic controller 200 may be prioritized as follows, with airborne detection compression damping having the highest priority, followed by the operator-actuatable suspension adjustment input 172 compression damping having the second highest priority, followed by cornering detection compression damping, followed by braking detection compression damping, and then the greatest of the mode-selected base compression damping and acceleration-based detection compression damping. In one example, where a predictive longitudinal acceleration and predictive vehicle pitch processing sequence is used, brake detection damping is taken into account along with the predicted acceleration and pitch, and thus the subsequent turn detection compression damping is the maximum of the mode-selected base compression damping and the detected compression damping based on the predicted longitudinal acceleration and the predicted vehicle pitch. In an embodiment, for rebound damping, arbitration by the electronic controller 200 may be prioritized as follows, with airborne detection rebound damping having the highest priority, including post-landing time, followed by turn detection rebound damping, then brake detection rebound damping, and then the maximum of the mode-selected base rebound damping and the detected rebound damping based on acceleration. In one example, where a predictive longitudinal acceleration and predictive vehicle pitch processing sequence is used, brake detection rebound damping is taken into account along with the predicted acceleration and pitch, and thus the subsequent turn detection rebound damping is the maximum of the mode-selected base rebound damping and the detected rebound damping based on the predicted longitudinal acceleration and the predicted vehicle pitch. The above are exemplary arbitration priorities, and different processing sequences may include different arbitration priorities based on the provided event detection table and the desired performance of the vehicle.

[0084] Reference Figure 24 The predicted longitudinal acceleration and predicted pitch table 236 includes damping characteristics for each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on one or both of the predicted longitudinal acceleration of the snowmobile 10 and the predicted pitch of the snowmobile 10. The shock damping logic 150 changes the damping characteristics of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on the predicted vehicle longitudinal acceleration 240 and / or the predicted vehicle pitch 242.

[0085] When considering both the predicted longitudinal acceleration 240 and the predicted vehicle pitch 242, the shock damping logic 150 can adjust the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 to accelerate the snowmobile 10, including minimizing vehicle squat during acceleration and minimizing vehicle pitch during deceleration. In one example, a predicted increase in longitudinal acceleration causes the shock damping logic 150 to change, such as increasing the compression damping of the front track adjustable shock 144 and the rear track adjustable shock 146 to reduce the chance of the skis 16 lifting off the snow, and to change (e.g., increase) the rebound damping of the right front adjustable shock 140 and the left front adjustable shock 142. Further, the rebound damping of the front track adjustable shock 144 can be increased. In another embodiment, when the predicted vehicle pitch indicates that the rear of the snowmobile 10 is predicted to drop and the predicted longitudinal acceleration is increasing, the shock damping logic 150 increases the compression damping of the right and left front adjustable shocks 140, 142 and decreases the rebound damping of the right and left front adjustable shocks 140, 142 to encourage the skis 16 to lift off the snow. In another embodiment, when the predicted longitudinal acceleration is decreasing and the predicted vehicle pitch indicates that the front of the snowmobile 10 is predicted to drop, the shock damping logic 150 increases the compression damping of the right and left front adjustable shocks 140, 142 to reduce the nodding of the front of the snowmobile 10 and changes (e.g., increases or decreases) the compression damping of the front track adjustable shocks 144 to increase the pressure of the tracks 18 on the snow and absorb bumps.

[0086] The predicted longitudinal acceleration 240 and predicted vehicle pitch 242 may also be applied to other off-road recreational vehicles, including side-by-side vehicles, such as Figures 26 to 28 . Vehicle 2000 includes a pair of front wheels 2002 and a pair of rear wheels 2004 supporting a frame 2006. Vehicle 2000 includes a driver's seat 2010 and a passenger seat 2012 arranged in a side-by-side arrangement. Each front wheel 2002 is coupled to the frame 2006 via a front suspension 2020 including shock absorbers 2022, 2024, which may be adjustable shock absorbers as described herein. Each rear wheel 2004 is coupled to the frame 2006 via a rear suspension 2030 including shock absorbers 2032, 2034, which may be adjustable shock absorbers as described herein. Further details regarding vehicle 2000 are provided in U.S. published patent application US2019 / 0210668, entitled “VEHICLE,” filed on January 10, 2019, the entire disclosure of which is expressly incorporated herein by reference.

[0087] Reference Figure 25, shows an exemplary processing sequence 250 of the suspension controller 200 for determining a predicted longitudinal acceleration 240 and a predicted vehicle pitch 242 of the snowmobile 10. As indicated by block 252, a predicted power for the prime mover 110 (e.g., an internal combustion engine) is determined. In one example, engine torque is provided from the vehicle's engine controller. The engine torque is multiplied by the measured engine speed measured by the engine speed sensor 133 to determine the engine's power output. In another example, throttle position is measured and a corresponding engine torque is provided by a lookup table. Similarly, the engine torque is multiplied by the engine speed to obtain the engine's power output. In an embodiment, the value is measured by the air pressure sensor 141, and the lookup table used to determine the engine torque is multidimensional and includes torque values ​​for different air pressures. In one example, the air pressure sensor 141 measures the air pressure associated with the air tank of the snowmobile 10. In another example, air pressure is measured indirectly by GPS sensor 131, which determines the location of snowmobile 10 and provides an ambient air pressure reading for that altitude based on a lookup table, either the actual ambient air pressure reading provided by a third-party service or a typical ambient air pressure reading based on a lookup table.

[0088] The determined engine power is then multiplied by the efficiency factor of the snowmobile 10 transmission to provide the output power for the drive train, as shown in block 254. In one example, the efficiency factor accounts for losses associated with the CVT transmission. The output power of the drive train is converted to forward propulsion force for the vehicle by dividing the output power of the drive train by the vehicle speed measured by the vehicle speed sensor 139, as shown in block 256.

[0089] The resultant or composite forward moving force is determined by subtracting the vehicle's coasting down force and the braking force from the forward moving force determined in block 256, as shown in block 258. The vehicle's coasting down force is determined from the measured vehicle speed as measured by the vehicle speed sensor 139 via a lookup table. The braking force is determined from the measured brake pressure as measured by the brake pressure sensor 135 via a lookup table of braking forces.

[0090] The predicted vehicle longitudinal acceleration is determined by dividing the resultant forward traction force by the mass of the vehicle, as shown in block 260. In one example, the standard mass of the vehicle is used.

[0091] The predicted vehicle longitudinal acceleration is compared to the traction limits and set equal to the corresponding traction limit (negative traction limit for deceleration of the snowmobile 10 and positive traction limit for acceleration of the snowmobile 10 ) if the predicted longitudinal acceleration exceeds the corresponding traction limit, as represented by block 262 .

[0092] In an embodiment, the predicted vehicle acceleration from block 262 is filtered to provide a smoother response, as shown in block 264. Filtering helps account for time differences between the determined engine output power and the acceleration of the snowmobile 10, and helps account for different sampling rates of the various sensors.

[0093] The filtered predicted vehicle longitudinal acceleration is used to determine the predicted pitch motion of the snowmobile 10. The direction of travel of the snowmobile 10 is determined, as shown in block 266. Once the direction of travel, forward or reverse, is known, the effects of acceleration or deceleration on the front and rear of the vehicle can be considered. In one example, a gear selection sensor 137 is provided as part of a shiftable transmission of the snowmobile 10 and provides an indication as to whether the shiftable transmission is in forward or reverse gear. In another example, the gear selection sensor detects that an electric reverse input (not shown) has been actuated. When the electric reverse input is actuated, the engine of the snowmobile 10 is shut down and then fired in the opposite direction to change the rotation of the engine's output shaft.

[0094] The predicted magnitude of the pitch motion is determined by taking the derivative of the filtered predicted vehicle longitudinal acceleration, as indicated by block 268. The predicted vehicle pitch motion value is filtered to provide a smoother result over time, as indicated by block 270. The shock damping logic 150 uses the predicted vehicle pitch motion 242 and / or the predicted vehicle longitudinal acceleration 240 to adjust the damping characteristics of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146, as indicated by block 272.

[0095] In an embodiment, the predicted vehicle longitudinal acceleration and the predicted vehicle pitch motion are used to change the base damping of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146, which can be set by the selected vehicle mode (Comfort, Handling, and Rough Road). The damping characteristic table for compression of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 and the damping characteristic table for rebound of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 can be two-dimensional (one input, one output damping characteristic), three-dimensional (two inputs, one output damping characteristic), or x-dimensional (x-1 inputs, one output damping characteristic).

[0096] In an embodiment, the base damping table is a two-dimensional mapping (two inputs, one output) of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 to each of the compression damping characteristic and the rebound characteristic. The two inputs are vehicle speed and predicted longitudinal vehicle acceleration, and depending on the table, the output is one of compression damping and rebound damping. In one example, vehicle speed is measured by the vehicle speed sensor 139, and the predicted longitudinal vehicle acceleration is determined by the processing sequence 250.

[0097] Reference Figure 8C Based on the predicted longitudinal vehicle acceleration and the predicted vehicle pitch motion, the predicted longitudinal acceleration and pitch motion table 236 provides damping characteristics for the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146. Assuming the snowmobile 10 is traveling forward, for a predicted constant longitudinal acceleration (no or minimal predicted pitch motion), the shock damping logic 150 increases the rebound damping characteristics of the right front adjustable shock 140 and the left front adjustable shock 142, and optionally decreases the compression damping characteristics of the right front adjustable shock 140 and the left front adjustable shock 142. For the predicted increase in vehicle pitch motion (rearward pitch), the shock damping logic 150 further increases the rebound damping characteristics of the right front adjustable shock absorber 140 and the left front adjustable shock absorber 142, and increases the compression damping characteristics of the front track adjustable shock absorber 144 and the rear track adjustable shock absorber 146 for the duration of the predicted vehicle pitch motion.

[0098] Assuming the snowmobile 10 is traveling forward, for a predicted constant longitudinal deceleration (no or minimal pitch), the shock damping logic 150 increases the rebound damping characteristics and decreases the compression damping characteristics of the right and left front adjustable shocks 140, 142, and optionally increases the rebound damping characteristics of the front and rear track adjustable shocks 144, 146. For a predicted decrease in vehicle longitudinal pitch motion (forward pitch), the shock damping logic 150 further increases the compression damping characteristics of the right and left front adjustable shocks 140, 142, and changes (e.g., increases) the rebound damping characteristics of the front and rear track adjustable shocks 144, and changes (e.g., increases) the rebound damping characteristics of the rear track adjustable shocks 146 for the duration of the predicted vehicle pitch motion. In response to the predicted increase in vehicle longitudinal pitch motion (backward pitch), the shock damping logic 150 changes (e.g., increases) the compression damping characteristics of the front track-adjustable shock absorber 144 and changes (e.g., increases) the compression damping characteristics of the rear track-adjustable shock absorber 146 for the duration of the predicted vehicle pitch motion. Furthermore, in response to the predicted increase in vehicle longitudinal pitch motion (backward pitch), the shock damping logic 150 changes (e.g., increases) the rebound damping characteristics of the rear track-adjustable shock absorber 146 for the duration of the predicted vehicle pitch motion. Additionally, in response to the predicted increase in vehicle longitudinal pitch motion (backward pitch), the shock damping logic 150 changes (e.g., increases) the rebound damping characteristics of the right front adjustable shock absorber 140 and the left front adjustable shock absorber 142 for the duration of the predicted vehicle pitch motion.

[0099] return Figure 8C The airborne timetable 210 includes damping characteristics for each of the right front adjustable shock 140 , the left front adjustable shock 142 , the front track adjustable shock 144 , and the rear track adjustable shock 146 based on the elapsed time that the snowmobile 10 has been airborne. Figure 21 An example of an airborne snowmobile 10 is shown in FIG. In an embodiment, airborne schedule 210 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression damping and rebound damping for one or more airborne detection time period ranges. For example, a first percentage for a first time range of airborne elapsed time detection and a second percentage for a second time range of airborne elapsed time detection.

[0100] In one embodiment, upon detection of an airborne condition, the compression damping characteristics of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 provide an increased damping percentage relative to the base damping table, and continue to increase as the detected airborne time continues to increase. After the airborne event ends, the increased compression damping is maintained to ensure that the additional compression damping is applied throughout the entire compression stroke of the corresponding shock. In one example, the increased compression damping is maintained for approximately 300 milliseconds. The increased compression damping is then gradually reduced back to the base damping level for normal operation of the snowmobile 10, or changed to another level if a different event (e.g., acceleration, braking, or cornering) is detected.

[0101] In one embodiment, upon detecting an airborne condition, the rebound damping characteristics of right front adjustable shock 140, left front adjustable shock 142, front track adjustable shock 144, and rear track adjustable shock 146 are minimized, for example, to zero, to promote extension of the shock absorbers. Once the snowmobile 10 lands, the rebound damping characteristics are increased to provide a smooth landing and reduce vehicle jerkiness. The amount of rebound increase depends on the airborne time (higher for longer airborne times). This provides a different response between small airborne events (such as whoops) and larger airborne events, allowing for different activation between whoops (medium-sized bumps on trails) and large jumps with longer airborne times. Rebound damping is maintained at a minimum level while the snowmobile 10 is airborne and is increased upon initial landing for a period of time generally equal to the first extension stroke of the corresponding shock absorber after compression. This advantageously allows for greater snow contact between the tracks and skis, increasing traction and stability.

[0102] In an embodiment, the IMU 132 is used to detect when the snowmobile 10 is airborne by monitoring the acceleration along the axis 164 (see Figure 1A Exemplary detection of airborne events is described in U.S. Published Patent Application No. 2016 / 0059660, filed on November 6, 2015, entitled “VEHICLE HAVING SUSPENSION WITH CONTINUOUS DAMPING CONTROL,” which is assigned to the present assignee and the entire disclosure of which is expressly incorporated herein by reference. Additional exemplary detection methods for airborne events are described in U.S. Patent No. 9,381,810, filed on June 3, 2011, entitled “ELECTRONIC THROTTLE CONTROL,” which is assigned to the present assignee and the entire disclosure of which is expressly incorporated herein by reference.

[0103] The driver-actuatable suspension adjustment input event table 212 includes damping characteristics for each of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 in response to actuation of the driver-actuatable suspension adjustment input event table 212 for the snowmobile 10. In an embodiment, the driver-actuatable suspension adjustment input event table 212 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression damping and rebound damping for actuation of the driver-actuatable suspension adjustment input event table 212. In an embodiment, actuation of the driver-actuatable suspension adjustment input event table 212 causes the compression damping of each of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 to be set to an increased level. In one example, compression damping is set to 100% for each of right front adjustable shock 140, left front adjustable shock 142, front track adjustable shock 144, and rear track adjustable shock 146. Driver-actuatable suspension adjustment input 172 can be actuatable by the operator to increase compression damping in order to absorb upcoming rough terrain that the operator sees.

[0104] In an embodiment, a second actuation of the driver-actuatable suspension adjustment input 172 within a given time period is interpreted by the electronic controller 100 as reducing the compression damping of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 to absorb chatter bumps (small bumps on the trail).

[0105] In an embodiment, a second actuation of the driver-actuatable suspension adjustment input 172 within a given time period is interpreted by the electronic controller 100 as maintaining the compression damping of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 until a third actuation of the driver-actuatable suspension adjustment input 172 is received or the driver mode (Comfort, Handling, Rough Road) is changed.

[0106] In an embodiment, continued actuation of the driver-actuatable suspension adjustment input 172 (e.g., keeping a button pressed) for a given time period is interpreted by the electronic controller 100 as maintaining the compression damping of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 until a subsequent actuation of the driver-actuatable suspension adjustment input 172 is received or the driver mode (Comfort, Handling, Rough Road) is changed.

[0107] In an embodiment, the driver-actuatable suspension adjustment input 172 is not a separate input, but rather is recognized as a characteristic of another driver input. In one example, a quick, partial actuation of a brake lever of a short duration detected by the brake switch 134 is interpreted by the controller 100 as an input from the driver-actuatable suspension adjustment input 172, while a longer and / or more complete actuation of the brake lever is interpreted by the controller 100 as an actuation of the brakes of the snowmobile 10.

[0108] The brake event table 214 includes the damping characteristics of each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on the actuation of the brake input of the snowmobile 10 as monitored by the brake switch 134 on the brake lever, or based on the pressure value (actual pressure reading or pressure switch) from the brake pressure sensor 135.

[0109] In an embodiment, when braking is detected while the snowmobile 10 is traveling forward, the compression damping characteristics of the right and left front adjustable shocks 140, 142 are increased to minimize forward pitching of the snowmobile 10 and bottoming out of the right and left front adjustable shocks 140, 142. For the front track adjustable shocks 144, the compression damping characteristics are decreased to increase the ability of the snowmobile 10 to absorb bumps in the trail and collect snow in front of the endless track 18 to help slow the snowmobile 10. For the rear track adjustable shocks 146, the compression damping is either maintained at its current level or decreased to keep more of the weight of the snowmobile 10 on the endless track 18.

[0110] In an embodiment, when braking is detected while the snowmobile 10 is traveling forward, the rebound damping characteristics of the right and left front adjustable shocks 140, 142 are either maintained or reduced to keep the right and left front adjustable shocks 140, 142 as extended as possible, thereby keeping the front of the snowmobile 10 high. For the front track adjustable shocks 144, the rebound damping characteristics are increased to collect snow in front of the endless track 18 to help slow the snowmobile 10 and keep the weight on the track. For the rear track adjustable shocks 146, the rebound damping is increased to reduce the pitching motion of the snowmobile 10 and keep more weight transferred to the rear of the snowmobile 10.

[0111] In an embodiment, a separate braking event table 214 is not provided because braking response is accounted for in the predictive vehicle pitch table 236 when looking at the predicted deceleration of the snowmobile 10 .

[0112] The anti-diving event table 216 includes damping characteristics for each of the right and left front adjustable shock absorbers 140, 142 based on the vehicle's deceleration rate from an accelerometer input or a vehicle speed input. In an embodiment, the anti-diving event table 216 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping based on actuation of the snowmobile 10's brake input as monitored by the brake switch 134 or based on a pressure value from the brake pressure sensor 135. In an embodiment, the compression damping characteristics of the right and left front adjustable shock absorbers 140, 142 are increased to minimize forward pitching of the snowmobile 10 and bottoming out of the right and left front adjustable shock absorbers 140, 142. For the front track adjustable shocks 144, the compression damping characteristic is reduced to increase the ability of the snowmobile 10 to absorb bumps in the trail and collect snow in front of the endless track 18 to help slow the snowmobile 10. For the rear track adjustable shocks 146, the compression damping is either maintained at the current level or reduced to keep more of the weight of the snowmobile 10 on the endless track 18.

[0113] In an embodiment, when braking is detected while the snowmobile 10 is traveling forward, the rebound damping characteristics of the right and left front adjustable shocks 140, 142 are either maintained or reduced to keep the right and left front adjustable shocks 140, 142 as extended as possible, thereby keeping the front of the snowmobile 10 high. For the front track adjustable shocks 144, the rebound damping characteristics are increased to collect snow in front of the endless track 18 to help slow the snowmobile 10 and keep the weight on the track. For the rear track adjustable shocks 146, the rebound damping is increased to reduce the pitching motion of the snowmobile 10 and keep more weight transferred to the rear of the snowmobile 10.

[0114] In an embodiment, the compression damping characteristics of the right front adjustable shock absorber 140 and the left front adjustable shock absorber 142 are increased beyond the level used for the braking event 214. Based on the level of applied brake pressure, the shock damping logic 150 selects between the braking event table 214 and the anti-diving event table 216, which is used for higher braking pressure levels. In one example, the anti-diving event table 216 is used during the initial time frame, and then the braking event table 214 is used thereafter as the vehicle speed has slowed.

[0115] In an embodiment, a separate anti-dive event table 216 is not provided. In an embodiment, braking and anti-dive responses are considered in the predictive vehicle pitch table 236 when looking at the predicted deceleration of the snowmobile 10 and the predicted forward pitch of the snowmobile 10. In an embodiment, braking and anti-dive responses are considered based on the degree of actuation of the brake level or based on the level or monitored brake pressure.

[0116] Single-ski event table 218 includes damping characteristics for each of right front adjustable shock 140, left front adjustable shock 142, front track adjustable shock 144, and rear track adjustable shock 146 based on the steering angle of the steering system and one or more outputs of IMU 132 (e.g., lateral acceleration, roll axis angle, and roll rate). In an embodiment, single-ski event table 218 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping based on the roll angle detected by IMU 132.

[0117] In an embodiment, if the snowmobile 10 rolls to the right, the compression damping of the left front adjustable shock absorber 142 is increased to counteract the roll, and the rebound damping of the right front adjustable shock absorber 140 is reduced to extend the right front adjustable shock absorber 140 to increase contact with the snow. If the snowmobile 10 rolls to the left, the compression damping of the right front adjustable shock absorber 140 is increased to counteract the roll, and the rebound damping of the left front adjustable shock absorber 142 is reduced to extend the left front adjustable shock absorber 142 to increase contact with the snow. In an embodiment, if the snowmobile 10 rolls to the right, the compression damping of the right shock absorber is increased and the rebound damping of the right shock absorber is reduced. In an embodiment, if the snowmobile 10 rolls to the left, the compression damping of the left shock absorber is increased and the rebound damping of the left shock absorber is reduced.

[0118] The G-out event table 224 includes damping characteristics for each of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 based on the pitch motion of the snowmobile 10. In an embodiment, the G-out event table 224 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping. In an embodiment, the compression damping characteristics of the right front adjustable shock 140, the left front adjustable shock 142, and the rear track adjustable shock 146 are increased.

[0119] Flutter event table 226 includes damping characteristics for each of right front adjustable shock absorber 140, left front adjustable shock absorber 142, front track adjustable shock absorber 144, and rear track adjustable shock absorber 146 based on the pitch motion of snowmobile 10. In an embodiment, flutter event table 226 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping. In an embodiment, compression and rebound damping are reduced for all shock absorbers. In an embodiment, flutter events are distinguished from bounding events based on frequency analysis of the IMU output.

[0120] Cornering event table 228 includes damping characteristics for each of right front adjustable shock 140, left front adjustable shock 142, and front track adjustable shock 144 based on the longitudinal acceleration of snowmobile 10 and based on at least one of steering angle sensor 136 for cornering or acceleration along axis 162 (lateral acceleration). In an embodiment, cornering event table 228 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping.

[0121] In an embodiment, when a turn is detected while the snowmobile 10 is traveling forward, the compression damping characteristic of the front outboard shock (fp140 if turning left, or the left front adjustable shock 142 if turning right) is increased to minimize roll of the snowmobile 10, and the compression damping characteristic of the front inboard shock (fp142 if turning left, or the right front adjustable shock 140 if turning right) is decreased to more smoothly absorb bumps in the trail. The level of increase and decrease depends on the longitudinal acceleration of the snowmobile 10 (the higher the speed, the greater the increase and decrease) to control the pitch motion of the snowmobile 10. Regardless of the direction of the turn, the compression damping characteristic of the front track adjustable shock 144 is decreased to increase ski traction for improved cornering, and the compression damping characteristic of the rear track adjustable shock 146 is updated to control longitudinal pitch motion and weight transfer throughout the cornering event. For example, at corner entry, the compression damping characteristics of the rear track adjustable shocks 146 may remain constant or decrease based on longitudinal acceleration, but at mid-corner or corner exit, when the throttle is applied, the compression damping characteristics of the rear track adjustable shocks 146 may increase to prevent the skis from lifting and losing traction at the front of the snowmobile 10.

[0122] In an embodiment, when a turn is detected while the snowmobile 10 is traveling forward, the rebound damping characteristic of the front inboard shock (fp 142 if turning left, or the right front adjustable shock 140 if turning right) is increased to reduce the roll of the snowmobile 10. The level of increase or decrease depends on the longitudinal acceleration of the snowmobile 10. In one example, the level of increase or decrease also depends on the lateral acceleration of the snowmobile 10. Regardless of the direction of the turn, the rebound damping characteristic of the front track adjustable shock 144 is increased to add ski traction for improved cornering, and the rebound damping characteristic of the rear track adjustable shock 146 is maintained or increased to control longitudinal pitch motion, keep the rear end down, and control body motion throughout the cornering event.

[0123] Braking cornering event table 220 includes damping characteristics for each of right front adjustable shock 140, left front adjustable shock 142, front track adjustable shock 144, and rear track adjustable shock 146 based on both cornering and braking of snowmobile 10. In an embodiment, shock damping logic 150 follows whichever of braking event table 214 and cornering event table 228 has a higher priority. In one example, a cornering event has a higher priority than a braking event.

[0124] Flutter turn event table 222 includes damping characteristics for each of right front adjustable shock 140, left front adjustable shock 142, front track adjustable shock 144, and rear track adjustable shock 146 based on both turn and lift detection of snowmobile 10. In one embodiment, lift events take precedence over turn events. Furthermore, steering angle can be used to modify lift damping values, thereby increasing damping for the outboard front and / or rear shock sections. In one embodiment, a separate flutter turn event table 222 is not provided; instead, shock damping logic 150 follows whichever of the lift time event table 210 and the turn event table 228 has a higher priority.

[0125] The base damping table 230 includes damping characteristics for each of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 when no one or more of the air time event table 210, the driver actuatable suspension adjustment input event table 212, the braking event table 214, the anti-dive event table 216, the snowboard event table 218, the braking cornering event table 220, the judder cornering event table 222, the g-out event table 224, the judder event table 226, the cornering event table 228, the launch mode event table 232, the anti-squat event table 234, and the predictive vehicle pitch table 236 are detected. In an embodiment, the base damping table 230 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping within one or more airborne detection time periods for a detected vehicle speed and / or throttle position. As mentioned herein, each selectable mode (Comfort, Handling, and Rough Road) has its own base damping table.

[0126] Launch mode event table 232 includes damping characteristics for each of front track-adjustable shock absorbers 144 and rear track-adjustable shock absorbers 146 based on actuation of launch mode input 174 or based on one or more sensor readings (e.g., vehicle speed is zero and throttle actuation is above a first level). In an embodiment, launch mode event table 232 specifies percentages of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping. In response to actuation of the launch mode input, different actions are taken based on the selected mode of snowmobile 10 (Comfort, Handling, Rough Trail) to achieve the desired high acceleration of snowmobile 10. For comfort mode and handling mode, it is desirable to keep skis 16 on the snow. To achieve this, the compression damping characteristics of the front track-adjustable shocks 144 are maintained or reduced, the rebound damping characteristics of the front track-adjustable shocks 144 are increased, the compression damping characteristics of the rear track-adjustable shocks 146 are increased, and the rebound damping characteristics of the rear track-adjustable shocks 146 are maintained or reduced. These changes both help keep the skis 16 on the snow and minimize rearward pitching motion. For rough trail mode, it may be desirable to lift the skis 16 off the snow. To achieve this, the compression damping characteristics of the front track-adjustable shocks 144 are increased, the rebound damping characteristics of the front track-adjustable shocks 144 are decreased, the compression damping characteristics of the rear track-adjustable shocks 146 are maintained or reduced, and the rebound damping characteristics of the rear track-adjustable shocks 146 are maintained or increased. These changes both help lift the skis 16 and help rearward pitching motion. Further, changes to the front and rear track adjustable shocks 144, 146 may be further modified to encourage the snowmobile 10 to lift the skis further off the ground to perform wheelie balancing when starting from a stop or low speed.

[0127] The anti-squat event table 234 includes damping characteristics for each of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shocks 144, and the rear track adjustable shocks 146 based on the longitudinal acceleration, pitch rate, and / or pitch angle of the snowmobile 10 measured by the IMU 132. In an embodiment, the anti-squat event table 234 specifies a percentage of the available damping range for compression damping only, rebound damping only, or both compression and rebound damping for one or more detection time period ranges. For a measured pitch angle, the shock damping logic 150 increases the rebound damping characteristics of the right front adjustable shock 140 and the left front adjustable shock 142, and increases the compression damping characteristics of the front track adjustable shocks 144 and the rear track adjustable shocks 146 for the duration of the predicted vehicle pitch motion.

[0128] Making the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 adjustable helps orient the snowmobile 10 in various environmental conditions. Figure 22 , shows snowmobile 10 in deep snow. When shocks 144 and 146 are not adjustable, the rear of snowmobile 10 sinks into the snow, up to the running boards of snowmobile 10. By sensing the rearward pitch of snowmobile 10 with IMU 132, the rebound damping characteristics of front and rear track-adjustable shocks 144, 146 can be automatically increased to promote extension of front and rear track-adjustable shocks 144, 146, and the compression damping characteristics of front and rear track-adjustable shocks 144, 146 can be reduced. This causes the rear end of the rear suspension to drop, allowing snowmobile 10 to more steadily remain in the snow.

[0129] Reference Figures 9A to 9C , Figure 6 An exemplary processing sequence 300 of the shock damping logic 150 of the electronic controller 200 is provided for the left front adjustable shock absorber 142. Figure 1 A portion of the suspension 24 of the left front ski 16 of the exemplary snowmobile 10 is shown. Figure 9A , the processing sequence 300 determines whether a loft event is detected, as shown in block 302 . Figure 15 An exemplary process 700 for detecting a lift-off event is shown in FIG. If a lift-off event is detected, the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value provided in the lift-off schedule 210 of the shock damping logic 150, as indicated by block 304, and the processing sequence 300 is completed, as indicated by block 306.

[0130] If a launch event is not detected, the shock damping logic 150 determines whether a driver-actuatable suspension adjustment input event is detected, as indicated by block 310. If a driver-actuatable suspension adjustment input event is detected, the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value provided in the driver-actuatable suspension adjustment input event table 212 of the shock damping logic 150, as indicated by block 312, and the processing sequence 300 is completed, as indicated by block 306.

[0131] If a driver-actuable suspension adjustment input event is not detected, the shock damping logic 150 determines whether a braking event is detected, as represented by block 314 . Figure 14An exemplary process 650 for detecting a braking event is shown in FIG. If a braking event is detected, the shock damping logic 150 determines whether the anti-diving time threshold has passed, as indicated by block 316. If the anti-diving threshold has not passed, the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value provided in the anti-diving table 216 of the shock damping logic 150, as indicated by block 318, and the processing sequence 300 is completed, as indicated by block 306.

[0132] If the anti-dump threshold has been passed, the damping characteristics of the left front adjustable shock absorber 142 are set based on the value of vehicle deceleration from the IMU 132 and based on the damping value provided in the braking event table 214 of the shock damping logic 150. The shock damping logic 150 then determines whether a cornering event has been detected, as indicated by block 322. If a cornering event has not been detected, the processing sequence 300 is complete, as indicated by block 306. If a cornering event has been detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the left side of the snowmobile 10, as indicated by block 324. If the vehicle acceleration is toward the left side, the left front adjustable shock absorber 142 is designated as the outboard shock absorber, as indicated by block 326, and the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value for the outboard shock absorber provided in the braking cornering event table 220, as indicated by block 328, and the processing sequence 300 is complete, as indicated by block 306. If the vehicle acceleration is not toward the left, the left front adjustable shock absorber 142 is designated as the inboard shock absorber, as indicated by block 330 , and the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value for the inboard shock absorber provided in the braking cornering event table, as indicated by block 328 , and the processing sequence 300 is completed, as indicated by block 306 .

[0133] If a braking event is not detected, the shock damping logic 150 determines whether a single snowboard event is detected, as represented by block 340 . Figure 20 An exemplary process 1000 for detecting a single ski event is shown in FIG. If a single ski event is detected, the shock damping logic 150 determines to set the damping characteristics of the left front adjustable shock 142 based on the damping value provided in the single ski event table 218 of the shock damping logic 150, as indicated by block 342, and the processing sequence 300 is complete, as indicated by block 306.

[0134] If a single snowboard event is not detected, the shock damping logic 150 determines whether a G-out event is detected, as represented by block 350 . Figure 13An exemplary process 600 for detecting a G-out event is shown in FIG. If a G-out event is detected, the shock damping logic 150 determines to set the damping characteristics of the left front adjustable shock absorber 142 based on the damping value provided in the G-out event table 224 of the shock damping logic 150, as indicated by block 352, and the processing sequence 300 is complete, as indicated by block 306.

[0135] If a G-out event is not detected, the vibration damping logic 150 determines whether a flutter event is detected, as represented by block 354 . Figure 13 An exemplary process 600 for detecting a judder event is shown in FIG. If a judder event is detected, the shock damping logic 150 determines to set the damping characteristics of the left front adjustable shock absorber 142 based on the damping values ​​provided in the judder event table 226 of the shock damping logic 150, as shown in block 356. The shock damping logic 150 then determines whether a cornering event is detected, as shown in block 358. If a cornering event is not detected, the processing sequence 300 is complete, as shown in block 306. If a cornering event is detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the left side of the snowmobile 10, as shown in block 364. If the vehicle acceleration is toward the left, the left front adjustable shock absorber 142 is designated as the outboard shock absorber portion, as indicated by block 366, and the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value for the outboard shock absorber portion provided in the chatter turn event table 222, as indicated by block 368, and the processing sequence 300 is completed, as indicated by block 306. If the vehicle acceleration is not toward the left, the left front adjustable shock absorber 142 is designated as the inboard shock absorber portion, as indicated by block 370, and the damping characteristics of the left front adjustable shock absorber 142 are set based on the damping value for the inboard shock absorber portion provided in the chatter turn event table 222, as indicated by block 368, and the processing sequence 300 is completed, as indicated by block 306.

[0136] If a flutter event is not detected, the shock damping logic 150 determines whether a cornering event is detected, as represented by block 376 . 17A to 17DAn exemplary process 800 for detecting a cornering event is shown in FIG. If a cornering event is detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the left side of the snowmobile 10, as indicated by block 378. If the vehicle acceleration is toward the left side, the left front adjustable shock 142 is designated as the outboard shock portion, as indicated by block 380, and the damping characteristics of the left front adjustable shock 142 are set based on the damping value for the outboard shock portion provided in the cornering event table 228, as indicated by block 382, ​​and the processing sequence 300 is completed, as indicated by block 306. If the vehicle acceleration is not toward the left side, the left front adjustable shock 142 is designated as the inboard shock portion, as indicated by block 384, and the damping characteristics of the left front adjustable shock 142 are set based on the damping value for the inboard shock portion provided in the cornering event table 228, as indicated by block 382, ​​and the processing sequence 300 is completed, as indicated by block 306. In an embodiment, the shock damping logic 150 also monitors the vehicle's acceleration / deceleration along axis 160, and this acceleration / deceleration value is an additional input to the cornering event table. By considering the vehicle's acceleration / deceleration along axis 160, the shock damping logic 150 can adjust the damping characteristics of the left front adjustable shock 142 differently for when the snowmobile 10 is entering a corner (decelerating) than when the snowmobile 10 is exiting a corner (accelerating).

[0137] If a cornering event is not detected, the shock damping logic 150 determines the damping characteristics of the left front adjustable shock absorber 142 based on the damping values ​​provided in the base damping table 230 , as indicated by block 390 , and the processing sequence 300 is complete, as indicated by block 306 .

[0138] Reference 10A to 10C , Figure 6 An exemplary processing sequence 400 of the shock absorption damping logic 150 of the electronic controller 200 is for the right front continuous damping control shock absorber 142, which is provided as Figure 1 A portion of the suspension 24 of the left front ski 16 of the exemplary snowmobile 10 is shown. Figure 9A , the processing sequence 400 determines whether a loft event is detected, as shown in block 402 . Figure 15 An exemplary process 700 for detecting a lift-off event is shown in FIG. If a lift-off event is detected, the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value provided in the lift-off schedule 210 of the shock damping logic 150, as shown in block 404, and the processing sequence 400 is completed, as shown in block 406.

[0139] If a launch event is not detected, the shock damping logic 150 determines whether a driver-actuatable suspension adjustment input event is detected, as indicated by block 410. If a driver-actuatable suspension adjustment input event is detected, the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value provided in the driver-actuatable suspension adjustment input event table 212 of the shock damping logic 150, as indicated by block 412, and the processing sequence 400 is complete, as indicated by block 406.

[0140] If a driver-actuable suspension adjustment input event is not detected, the shock damping logic 150 determines whether a braking event is detected, as represented by block 414 . Figure 14 An exemplary process 650 for detecting a braking event is shown in FIG. If a braking event is detected, the shock damping logic 150 determines whether an anti-diving time threshold has passed, as indicated by block 416. If the anti-event threshold has not passed, the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value provided in the anti-diving table 216 of the shock damping logic 150, as indicated by block 418, and the processing sequence 400 is completed, as indicated by block 406.

[0141] If the anti-dump time threshold has passed, the damping characteristics of the right front adjustable shock 140 are set based on the value of vehicle deceleration from the IMU 132 and based on the damping value provided in the braking event table 214 of the shock damping logic 150. The shock damping logic 150 then determines whether a cornering event has been detected, as indicated by block 422. If a cornering event has not been detected, the processing sequence 400 is complete, as indicated by block 406. If a cornering event has been detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the right side of the snowmobile 10, as indicated by block 424. If the vehicle acceleration is toward the right side, the right front adjustable shock 140 is designated as the outboard shock, as indicated by block 426, and the damping characteristics of the right front adjustable shock 140 are set based on the damping value for the outboard shock provided in the braking cornering event table 220, as indicated by block 428, and the processing sequence 400 is complete, as indicated by block 406. If the vehicle acceleration is not toward the left, the right front adjustable shock absorber 140 is designated as the inboard shock absorber, as indicated by block 430 , and the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value for the inboard shock absorber provided in the braking cornering event table, as indicated by block 428 , and the processing sequence 400 is completed, as indicated by block 406 .

[0142] If a braking event is not detected, the shock damping logic 150 determines whether a single snowboard event is detected, as represented by block 440 . Figure 20An exemplary process 1000 for detecting a single ski event is shown in FIG. If a single ski event is detected, the shock damping logic 150 determines to set the damping characteristics of the right front adjustable shock 140 based on the damping value provided in the single ski event table 218 of the shock damping logic 150, as shown in block 442, and the processing sequence 400 is complete, as shown in block 406.

[0143] If a single snowboard event is not detected, the shock damping logic 150 determines whether a G-out event is detected, as represented by block 450 . Figure 13 An exemplary process 600 for detecting a G-out event is shown in FIG. If a G-out event is detected, the shock damping logic 150 determines to set the damping characteristics of the right front adjustable shock absorber 140 based on the damping value provided in the G-out event table 224 of the shock damping logic 150, as indicated by block 452, and the processing sequence 400 is complete, as indicated by block 406.

[0144] If a G-out event is not detected, the vibration damping logic 150 determines whether a flutter event is detected, as represented by block 454 . Figure 13 An exemplary process 600 for detecting a judder event is shown in FIG. If a judder event is detected, the shock damping logic 150 determines to set the damping characteristics of the right front adjustable shock absorber 140 based on the damping values ​​provided in the judder event table 226 of the shock damping logic 150, as shown in block 456. The shock damping logic 150 then determines whether a cornering event is detected, as shown in block 458. If a cornering event is not detected, the processing sequence 400 is complete, as shown in block 406. If a cornering event is detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the right side of the snowmobile 10, as shown in block 464. If the vehicle acceleration is toward the right, the right front adjustable shock absorber 140 is designated as the outboard shock absorber portion, as indicated by block 466, and the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value for the outboard shock absorber portion provided in the chatter turn event table 222, as indicated by block 468, and the processing sequence 400 is completed, as indicated by block 406. If the vehicle acceleration is not toward the left, the right front adjustable shock absorber 140 is designated as the inboard shock absorber portion, as indicated by block 470, and the damping characteristics of the right front adjustable shock absorber 140 are set based on the damping value for the inboard shock absorber portion provided in the chatter turn event table 222, as indicated by block 468, and the processing sequence 400 is completed, as indicated by block 406.

[0145] If a flutter event is not detected, the shock damping logic 150 determines whether a cornering event is detected, as represented by block 476 . 17A to 17DAn exemplary process 800 for detecting a cornering event is shown in FIG. If a cornering event is detected, the shock damping logic 150 determines whether the vehicle acceleration is toward the right side of the snowmobile 10, as indicated by block 478. If the vehicle acceleration is toward the right side, the right front adjustable shock 140 is designated as the outboard shock portion, as indicated by block 480, and the damping characteristics of the right front adjustable shock 140 are set based on the damping value for the outboard shock portion provided in the cornering event table 228, as indicated by block 482, and the processing sequence 400 is completed, as indicated by block 406. If the vehicle acceleration is not toward the left side, the right front adjustable shock 140 is designated as the inboard shock portion, as indicated by block 484, and the damping characteristics of the right front adjustable shock 140 are set based on the damping value for the inboard shock portion provided in the cornering event table 228, as indicated by block 482, and the processing sequence 400 is completed, as indicated by block 406. In an embodiment, the shock damping logic 150 also monitors the vehicle's acceleration / deceleration along axis 160, and this acceleration / deceleration value is an additional input to the cornering event table. By taking into account the vehicle's acceleration / deceleration along axis 160, the shock damping logic 150 can adjust the damping characteristics of the right front adjustable shock 140 differently for when the snowmobile 10 is entering a corner (decelerating) than when the snowmobile 10 is exiting a corner (accelerating).

[0146] If a cornering event is not detected, the shock damping logic 150 determines the damping characteristics of the right front adjustable shock absorber 140 based on the damping values ​​provided in the base damping table 230 , as indicated by block 490 , and the processing sequence 400 is complete, as indicated by block 406 .

[0147] Reference Figure 11A and Figure 11B , Figure 6 An exemplary processing sequence 500 of the shock absorption damping logic 150 of the electronic controller 200 is provided for the first track continuous damping control shock absorber 144, which is provided as Figure 1 A portion of a suspension 26 of an exemplary snowmobile 10 is shown.

[0148] The damping logic 150 determines whether launch mode is enabled, as shown in block 502. Figure 19A and Figure 19B An exemplary process sequence 950 for determining whether launch mode is enabled is provided in FIG. If launch mode is enabled, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the launch mode event table 232, as indicated by block 504, and the process sequence 500 is complete, as indicated by block 506.

[0149] If launch mode is not detected, the shock damping logic 150 determines whether a lift-off event is detected, as indicated at block 510. If a lift-off event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the lift-off event table 210, as indicated at block 512, and the processing sequence 500 is complete, as indicated at block 506.

[0150] If a lift-off event is not detected, the shock damping logic 150 determines whether a driver-actuatable suspension adjustment input event is detected, as indicated at block 514. If a driver-actuatable suspension adjustment input event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the driver-actuatable suspension adjustment input event table 212, as indicated at block 516, and the processing sequence 500 is complete, as indicated at block 506.

[0151] If a driver-actuable suspension adjustment input event is not detected, the shock damping logic 150 determines whether a braking event is detected, as indicated by block 518. If a braking event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the braking event table 214, as indicated by block 520, and the processing sequence 500 is complete, as indicated by block 506.

[0152] If a braking event is not detected, the shock damping logic 150 determines whether a single ski event is detected, as indicated at block 522. If a single ski event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the single ski event table 218, as indicated at block 524, and the processing sequence 500 is complete, as indicated at block 506.

[0153] If a single snowboard event is not detected, the shock damping logic 150 determines whether a g-out event is detected, as indicated at block 526. If a g-out event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock 144 based on the damping values ​​provided in the g-out event table 224, as indicated at block 528, and the processing sequence 500 is complete, as indicated at block 506.

[0154] If a G-out event is not detected, the shock damping logic 150 determines whether a flutter event is detected, as indicated at block 530. If a flutter event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the flutter event table 226, as indicated at block 532, and the processing sequence 500 is complete, as indicated at block 506.

[0155] If a flutter event is not detected, the shock damping logic 150 determines whether an anti-squat event is detected, as indicated at block 534. If an anti-squat event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the anti-squat event table 234, as indicated at block 536, and the processing sequence 500 is complete, as indicated at block 506.

[0156] If no anti-squat event is detected, the shock damping logic 150 determines whether a cornering event is detected, as indicated at block 538. If a cornering event is detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock 144 based on the damping values ​​provided in the cornering event table 228, as indicated at block 540, and the processing sequence 500 completes, as indicated at block 506. In an embodiment, the shock damping logic 150 also monitors the vehicle acceleration / deceleration along the axis 160, and this acceleration / deceleration value is an additional input to the cornering event table. By considering the vehicle acceleration / deceleration along the axis 160, the shock damping logic 150 can adjust the damping characteristics of the front track adjustable shock 144 differently for when the snowmobile 10 is entering a corner (decelerating) than when the snowmobile 10 is exiting a corner (accelerating).

[0157] If a cornering event is not detected, the shock damping logic 150 determines the damping characteristics of the first track continuous damping control shock absorber 144 based on the damping values ​​provided in the base damping table 230 , as indicated by block 542 , and the processing sequence 500 is complete, as indicated by block 506 .

[0158] Reference Figure 12A and Figure 12B , Figure 6 The exemplary processing sequence 550 of the shock absorption damping logic 150 of the electronic controller 200 is for the second track continuous damping control shock absorber 146, which is provided as Figure 1 A portion of a suspension 26 of an exemplary snowmobile 10 is shown.

[0159] The shock damping logic 150 determines whether launch mode is enabled, as indicated in block 552. Figure 19A and Figure 19B An exemplary processing sequence for determining whether launch mode is enabled is provided in FIG. If launch mode is enabled, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the launch mode event table 232, as indicated by block 554, and the processing sequence 550 is completed, as indicated by block 556.

[0160] If launch mode is not detected, the shock damping logic 150 determines whether a lift-off event is detected, as indicated at block 558. If a lift-off event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the lift-off event table 210, as indicated at block 560, and the processing sequence 550 is complete, as indicated at block 556.

[0161] If a lift-off event is not detected, the shock damping logic 150 determines whether a driver-actuatable suspension adjustment input event is detected, as indicated by block 562. If a driver-actuatable suspension adjustment input event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the driver-actuatable suspension adjustment input event table 212, as indicated by block 564, and the processing sequence 550 is complete, as indicated by block 556.

[0162] If a driver-actuable suspension adjustment input event is not detected, the shock damping logic 150 determines whether a braking event is detected, as indicated by block 566. If a braking event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the braking event table 214, as indicated by block 568, and the processing sequence 550 is complete, as indicated by block 556.

[0163] If a braking event is not detected, the shock damping logic 150 determines whether a single ski event is detected, as indicated at block 570. If a single ski event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the single ski event table 218, as indicated at block 572, and the processing sequence 550 is complete, as indicated at block 556.

[0164] If a single snowboard event is not detected, the shock damping logic 150 determines whether a g-out event is detected, as indicated at block 574. If a g-out event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the g-out event table 224, as indicated at block 576, and the processing sequence 550 is complete, as indicated at block 556.

[0165] If a g-out event is not detected, the shock damping logic 150 determines whether a flutter event is detected, as indicated at block 578. If a flutter event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the flutter event table 226, as indicated at block 580, and the processing sequence 550 is complete, as indicated at block 556.

[0166] If a flutter event is not detected, the shock damping logic 150 determines whether an anti-squat event is detected, as indicated by block 582. If an anti-squat event is detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the anti-squat event table 234, as indicated by block 584, and the processing sequence 550 is complete, as indicated by block 556.

[0167] If an anti-squat event is not detected, the shock damping logic 150 determines the damping characteristics of the second track continuous damping control shock absorber 146 based on the damping values ​​provided in the base damping table 230 , as indicated by block 586 , and the processing sequence 550 is complete, as indicated by block 556 .

[0168] Reference Figure 13 , showing Figure 6 FIG6 illustrates an exemplary processing sequence 600 of the shock damping logic 150 of the electronic controller 200 for detecting a g-out event or a chatter event. The suspension controller 200 samples the pitch of the snowmobile 10 about the axis 162 from the IMU 132 over a time window, as shown at block 602. The sampled values ​​are input to a discrete Fourier transform ("DFT"), as shown at block 604, to provide a frequency map of the pitch variation of the snowmobile 10.

[0169] The magnitude of the low frequency value (e.g., from 0 Hz to 3 Hz) is compared to a low frequency threshold, as shown in block 606. If the magnitude of the low frequency value does not meet the low frequency threshold, then no event is detected and the low frequency portion of the processing sequence 600 ends, as shown in blocks 614 and 612. If the magnitude of the low frequency value meets the low frequency threshold, then the processing sequence 600 compares the pitch-up rate of the gyroscope input from the IMU 132 to another threshold, as shown in block 608. If the pitch-up rate does not meet the threshold, then no event is detected and the low frequency portion of the processing sequence 600 ends, as shown in blocks 614 and 612. If the pitch-up rate meets the threshold, then a g-out event is detected, as shown in block 610. As explained herein, detection of a g-out event results in selection of a damping characteristic for one or more of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 based on the g-out event table 224. Generally, the damping characteristic is an increased stiffness of the right front adjustable shock 140, the left front adjustable shock 142, and the rear track adjustable shock 146.

[0170] The magnitude of the high frequency value (e.g., from 3 Hz to 10 Hz) is compared to a high frequency threshold, as shown in block 616. If the magnitude of the high frequency value does not satisfy the high frequency threshold, then no event is detected, and the high frequency portion of the processing sequence 600 ends, as shown in blocks 614 and 612. If the magnitude of the high frequency value satisfies the high frequency threshold, then a flutter event is detected, as shown in block 618. As explained herein, detection of a flutter event results in the selection of damping characteristics for one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on the flutter event table 226.

[0171] Reference Figure 14 , showing Figure 6 An exemplary processing sequence 650 of the shock damping logic 150 of the electronic controller 200 is shown for detecting an exemplary braking event. The shock damping logic 150 determines whether the brake switch is activated, as indicated by block 652. In an embodiment, the switch is closed when the brake input is actuated. If the brake switch is not activated, no braking event is detected, as indicated by block 654, and the processing sequence 650 is complete. If the brake switch is activated, a braking event is detected, as indicated by block 656, and the processing sequence 650 is complete.

[0172] Figure 15 Shown Figure 6, an exemplary processing sequence 700 of the shock damping logic 150 of the electronic controller 200 for detecting an exemplary lift-off event. The shock damping logic 150 determines whether the acceleration of the snowmobile 10 along the axis 164, as detected by the IMU 132, is below a threshold, as indicated by block 702. If the detected acceleration is below the threshold, a lift-off event is detected, as indicated by block 704, and the processing sequence 700 is complete. If the detected acceleration is greater than the threshold, the shock damping logic 150 checks to see if the current state of the snowmobile 10 is lift-off event active for the snowmobile 10, meaning that the snowmobile 10 was recently determined to be in a lift-off event and is still in a lift-off event, as indicated by block 708. If the lift-off event is not active, no change is made, meaning that the snowmobile 10 is not currently found to be in a lift-off event, as indicated by block 710, and the processing sequence 700 is complete. If a lift-off event is active, the shock damping logic 150 determines whether the detected vertical acceleration exceeds a threshold value plus the hysteresis value of the IMU 132, as indicated by block 712. If not, no changes are made, meaning the snowmobile 10 remains in a lift-off event, as indicated by block 710, and the processing sequence 700 is completed, as indicated by block 706. If the detected vertical acceleration does exceed the threshold value plus the hysteresis value of the IMU 132, the shock damping logic 150 determines whether the time that has elapsed since the snowmobile 10 was determined to be in a lift-off event exceeds a timeout value, as indicated by block 714. If the time that has elapsed does not exceed the timeout value, no changes are made, meaning the snowmobile 10 remains in a lift-off event, as indicated by block 710, and the processing sequence 700 is completed, as indicated by block 706. If the elapsed time does exceed the timeout value, the status of the snowmobile 10 changes to no airborne event detected, as indicated by block 716 , and the processing sequence 700 is complete, as indicated by block 706 .

[0173] 16A to 16C Shown Figure 6An exemplary processing sequence 750 of the shock damping logic 150 of the electronic controller 200 is shown for detecting an exemplary anti-squat event. The shock damping logic 150 determines whether the rate of change of the throttle input detected by the throttle position sensor 138 exceeds an enable limit, as indicated by block 752. If so, the shock damping logic 150 determines that a throttle rate event has been detected, as indicated by block 754. If not, the shock damping logic 150 determines whether the rate of change of the throttle input is less than a disable limit, as indicated by block 756. If the rate of change of the throttle input is less than the disable limit, the shock damping logic 150 determines that a throttle rate event has not been detected, as indicated by block 758. If the rate of change of the throttle input is not less than the disable limit, the shock damping logic 150 determines whether the detected throttle position is less than the throttle limit, indicating that the operator has backed off the throttle, as indicated by block 760. If the detected throttle position is less than the throttle limit, the damping logic 150 determines that a throttle rate event has not been detected, as represented by block 758. If the detected throttle position is greater than the throttle limit, the damping logic 150 determines whether the time elapsed since the throttle rate event was detected exceeds a hold time threshold, as represented by block 762. If the time elapsed since the throttle rate event was detected does not exceed the hold time threshold, no change is made to whether a throttle rate event is active, as represented by block 764. If the time elapsed since the throttle rate event was detected does exceed the hold time threshold, the damping logic 150 determines that a throttle rate event has not been detected, as represented by block 758.

[0174] Go to Figure 16B , the shock damping logic 150 next determines whether the linear acceleration of the snowmobile 10 along the axis 160 exceeds a threshold, as indicated by block 766. If the linear acceleration of the snowmobile 10 along the axis 160 exceeds the threshold, an acceleration event is detected, as indicated by block 768. If the detected linear acceleration of the snowmobile 10 along the axis 160 does not exceed the threshold, the shock damping logic 150 determines whether the linear acceleration of the snowmobile 10 is less than the threshold minus the hysteresis of the IMU 132, as indicated by block 770. If so, no acceleration event is detected, as indicated by block 772. If not, no change is made to the current state of whether an acceleration event is active for the snowmobile 10, as indicated by block 774.

[0175] Go to Figure 16C, the shock damping logic 150 determines whether one of a throttle rate event or an acceleration event is active for the snowmobile 10, as indicated by block 780. If either is active, an anti-squat event is determined, as indicated by block 782, and the processing sequence 750 is completed, as indicated by block 790. If not, the shock damping logic 150 checks to verify that neither a throttle rate event nor an acceleration event is active, as indicated by block 784. If neither is active, the shock damping logic 150 disables the anti-squat event, as indicated by block 786, and the processing sequence 750 is completed, as indicated by block 790. If either a throttle rate event or an acceleration event is active, the squat state of the snowmobile 10 is not changed, as indicated by block 788, and the processing sequence 750 is completed, as indicated by block 790.

[0176] 17A to 17D Shown Figure 6 FIG2 illustrates an exemplary processing sequence 800 of the damping logic 150 of the electronic controller 200 for detecting an exemplary cornering event. The damping logic 150 determines whether the absolute value of the detected steering angle detected by the steering angle sensor 136 exceeds a threshold (a zero steering angle corresponds to the snowboard pointing straight ahead along the axis 160), as indicated by block 802. If the absolute value of the detected steering angle detected by the steering angle sensor 136 exceeds the threshold, a cornering event is detected, as indicated by block 804. If not, the absolute value of the detected steering angle detected by the steering angle sensor 136 is compared to the threshold minus a hysteresis value of the steering angle sensor 136, as indicated by block 806. If the absolute value of the detected steering angle detected by the steering angle sensor 136 is less than the threshold minus a hysteresis value of the steering angle sensor 136, the damping logic 150 determines that a cornering event has not been detected, as indicated by block 808. If the absolute value of the detected steering angle detected by the steering angle sensor 136 is not less than the threshold value minus the hysteresis value of the steering angle sensor 136 , the shock damping logic 150 does not change the steering event state of the snowmobile 10 , as represented by block 810 .

[0177] Go to Figure 17B, the shock damping logic 150 determines whether the lateral acceleration of the snowmobile 10 along the axis 162 exceeds a threshold, as indicated by block 812. If the lateral acceleration of the snowmobile 10 along the axis 162 exceeds the threshold, a turning event is detected, as indicated by block 814. If not, the absolute value of the detected lateral acceleration of the snowmobile 10 is compared to the threshold value minus the hysteresis value of the IMU 132, as indicated by block 816. If the absolute value of the detected lateral acceleration of the snowmobile 10 is less than the threshold value minus the hysteresis value of the IMU 132, the shock damping logic 150 determines that a turning event is not detected, as indicated by block 818. If the absolute value of the detected lateral acceleration of the snowmobile 10 is not less than the threshold value minus the hysteresis value of the IMU 132, the shock damping logic 150 does not change the turning event status of the snowmobile 10, as indicated by block 820.

[0178] Go to Figure 17C , the damping logic 150 determines whether the absolute value of the yaw rate and / or angle about the axis 164 exceeds a threshold, as indicated by block 830. If the absolute value of the yaw rate and / or angle about the axis 164 exceeds the threshold, a yaw event is detected, as indicated by block 832. If not, the absolute value of the yaw rate and / or angle about the axis 164 is compared to the threshold minus the hysteresis value of the IMU 132, as indicated by block 834. If the absolute value of the yaw rate and / or angle about the axis 164 is not less than the threshold minus the hysteresis value of the IMU 132, the damping logic 150 does not change the yaw state of the snowmobile 10, as indicated by block 836. If the absolute value of the yaw rate and / or angle about the axis 164 is less than the threshold minus the hysteresis value of the IMU 132, the damping logic 150 determines whether a turn event timeout period has elapsed, as indicated by block 838. If the turn timeout has not passed, the shock damping logic 150 does not change the yaw state of the snowmobile 10, as indicated at block 836. If the turn timeout has passed, a yaw event is detected, as indicated at block 840.

[0179] Go to Figure 17D, the damping logic 150 determines whether a yaw event or a turn event is detected during the processing sequence 800, as indicated by block 850. If one of a yaw event and a turn event is detected, a turn event is detected, the turn timeout timer is set to zero, as indicated by block 852, and the processing sequence 800 is completed, as indicated by block 854. If neither a yaw event nor a turn event is detected, the damping logic 150 determines whether neither a yaw event nor a turn event is detected, as indicated by block 856. If not, the turn event state is not changed, as indicated by block 858, and the processing sequence 800 exits, as indicated by block 854. If so, the damping logic 150 determines that a turn event is not detected, as indicated by block 860, and the processing sequence 800 exits, as indicated by block 854.

[0180] Figure 18 Shown Figure 6 An exemplary processing sequence 900 of the shock damping logic 150 of the electronic controller 200 is shown for detecting an exemplary driver-actuatable suspension adjustment input event. The shock damping logic 150 monitors whether the driver-actuatable suspension adjustment input 172 has been actuated, as indicated by block 902. If the driver-actuatable suspension adjustment input 172 has been actuated, a driver-actuatable suspension adjustment input event is detected, as indicated by block 904, and the processing sequence 900 is complete. If the driver-actuatable suspension adjustment input 172 has not been actuated, the shock damping logic 150 checks to see if the driver-actuatable suspension adjustment input timeout counter is active, and if so, checks to see if the driver-actuatable suspension adjustment input timeout has expired, as indicated by block 908. If the driver-actuatable suspension adjustment input timeout has expired, the shock damping logic 150 determines that a driver-actuatable suspension adjustment input event has not been detected, as indicated by block 910, and the processing sequence 900 is complete. If the driver actuatable suspension adjustment input timeout has not elapsed, the shock damping logic 150 maintains the current state of the driver actuatable suspension adjustment input event state, as represented by block 912 , and the processing sequence 900 is complete.

[0181] Figure 19A and Figure 19B Shown Figure 6 An exemplary processing sequence 950 of the shock absorber damping logic 150 of the electronic controller 200 for detecting an exemplary launch mode event is shown. Figure 19A, the damping logic 150 monitors to determine if the launch mode input 174 has been actuated, as indicated by block 952. If the launch mode input 174 has not been actuated, the launch mode event state is not changed, as indicated by block 954. If the launch mode input 174 has been actuated, the damping logic 150 determines if launch mode is currently active, as indicated by block 956. If launch mode is currently active, actuation of the launch mode input 174 disables launch mode, as indicated by block 958. If launch mode is not currently active, the damping logic 150 determines based on the vehicle speed sensor 139 whether the speed of the snowmobile 10 is zero, as indicated by block 960. If the vehicle speed is not zero, the launch mode state is not changed, as indicated by block 954. If the vehicle speed is zero, the damping logic 150 determines if the launch button 174 has timed out of actuation, as indicated by block 962. If not, the launch mode state is not changed, as indicated by block 954. If so, the shock damping logic 150 enables launch mode, as represented by block 964 .

[0182] Reference Figure 19B , the damping logic 150 determines whether launch mode is enabled, as indicated by block 966. If not, the launch mode state is not changed, as indicated by block 968. If launch mode is enabled, the damping logic 150 determines whether the vehicle speed is above a threshold based on the vehicle speed sensor 139, as indicated by block 970. If not, the launch mode state is not changed, as indicated by block 968. If the vehicle speed is above the threshold, the damping logic 150 determines whether the linear acceleration of the snowmobile 10 along the axis 160 is less than a threshold, as indicated by block 972. If not, the launch mode state is not changed, as indicated by block 968. If the linear acceleration of the snowmobile 10 along the axis 160 is less than the threshold, the damping logic 150 disables launch mode because the snowmobile 10 is traveling at a near constant speed, rather than rapidly accelerating, as indicated by block 974.

[0183] Figure 20 Shown Figure 6An exemplary processing sequence 1000 of the damping logic 150 of the electronic controller 200 is shown for detecting an exemplary single-ski event. The damping logic 150 monitors the roll rate and / or angle of the snowmobile 10 about the axis 160 based on the IMU 132 to see if it is greater than a low threshold, as indicated by block 1002. If so, the damping logic 150 checks to see if the monitored roll rate and / or angle is less than a high roll rate and / or angle threshold, as indicated by block 1004. If the vehicle roll rate and / or angle is within a range between the low and high thresholds, a single-ski event is detected, as indicated by block 1006, and the processing sequence 1000 is complete, as indicated by block 1008. Returning to block 1002, if the vehicle roll rate and / or angle is not greater than the low threshold, the damping logic 150 determines if the vehicle roll rate and / or angle is less than the low threshold minus the hysteresis of the IMU 132, as indicated by block 1010. If not, the shock damping logic 150 does not change the single ski event state, as indicated by block 1014. If so, the shock damping logic 150 determines that a single ski event has not been detected, as indicated by block 1012, and the processing sequence 1000 exits, as indicated by block 1008. Returning to block 1004, if the vehicle roll rate and / or angle is not less than the high threshold, the shock damping logic 150 determines that a single ski event has not been detected, as indicated by block 1012, and the processing sequence 1000 completes, as indicated by block 1008.

[0184] In an embodiment, power is provided to the front and / or rear adjustable track shocks 144, 146 via a wired connection routed through suspension components or laterally into the interior of the track. In an embodiment, communication signals are provided to and / or transmitted from the front and / or rear adjustable track shocks 144, 146 via a wired connection routed through suspension components or laterally into the interior of the track. In an embodiment, both communication signals and power are provided to and / or transmitted from the front and / or rear adjustable track shocks 144, 146 via a wired connection routed through suspension components or laterally into the interior of the track. In an embodiment, at least one of the front and / or rear adjustable track shocks 144, 146 includes a power source and / or wirelessly receives and transmits communication signals to / from the controller 100.

[0185] In an embodiment, the snowmobile 10 includes a demonstration mode to illustrate the functionality of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shocks 144, and the rear track adjustable shocks 146. In one embodiment, the snowmobile 10 includes a battery, and an operator input is provided to activate the auxiliary power source on the snowmobile 10. In this example, the operator can select different operating modes (Comfort, Handling, Rough Trail) and / or input adjustments to the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shocks 144, and the rear track adjustable shocks 146. In one example, the operator can select a left turn option and experience the changes in the damping characteristics of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shocks 144, and the rear track adjustable shocks 146 for a left turn. In another embodiment, the snowmobile 10 does not include a battery. In this example, a power connection is provided on the snowmobile 10 that allows an external power source to be plugged into the snowmobile 10 to power the snowmobile 10 for operation in the demonstration mode.

[0186] In an embodiment, during operation of the vehicle 10 or 10 ′, the damping characteristics of at least one of the front track-adjustable shock absorbers 144 and the rear track-adjustable shock absorbers 146 can be further adjusted to alter handling. In an example, the base damping profile, the predicted acceleration damping profile (longitudinal or lateral), the braking damping profile, and the cornering damping profile for a given mode (e.g., comfort or sport) include adjustments to the damping characteristics of at least one of the front track-adjustable shock absorbers 144 and the rear track-adjustable shock absorbers 146.

[0187] During normal straight-line driving (no perceptible cornering or acceleration changes), the base damping characteristics of the front track-adjustable shocks 144 may be different from, or the same as, the rear track-adjustable shocks 146. Changes in driving (e.g., cornering or acceleration changes) may result in adjustments to the base damping profile.

[0188] For example, in Comfort mode, during normal straight-line driving, the front track-adjustable shocks 144 have a first setting of compression damping (stiffer or equal) relative to the rear track-adjustable shocks 146. This setting biases the balance of the snowmobile 10, causing skis 16 to have less ski pressure against the ground and generally track less aggressively. The compression damping of the front track-adjustable shocks 144 remains soft enough not to sacrifice ride comfort. When the snowmobile 10 brakes, slows down, or turns, or anticipates doing so, the compression damping of the front track-adjustable shocks 144 increases relative to its previous setting. This adjustment prevents weight transfer to the skis 16 and reduces cornering forces on the snowmobile 10 at the expense of traction on the skis 16.

[0189] In another example, in sport mode, during normal driving, the front track-adjustable shocks 144 have a first setting of compression damping (softer or the same) relative to the rear track-adjustable shocks 146. This setting biases the balance of the snowmobile 10, causing the skis 16 to have greater ski pressure against the ground and generally track the skis 16 more aggressively. When the snowmobile 10 brakes, slows, or turns, or anticipates doing so, the compression damping of the front track-adjustable shocks 144 is reduced relative to its previous setting. This adjustment increases the weight transferred to the skis 16 and increases traction on the skis 16 at the expense of increased cornering effort.

[0190] In an embodiment, the electronic controller 100 monitors the output of the IMU 132 (a three-axis accelerometer and a three-axis gyroscope) to assess terrain and / or driver aggressiveness. Driver aggressiveness can be monitored by the longitudinal and lateral accelerations experienced by the vehicle 10. Further, throttle position, brake pressure, steering angle, and steering speed can provide indicators. The electronic controller 100 can monitor these factors and adjust the damping characteristics of one or more of the right front adjustable shock absorber 140, the left front adjustable shock absorber 142, the front track adjustable shock absorber 144, and the rear track adjustable shock absorber 146 based on these factors. Terrain type can be monitored by longitudinal acceleration, lateral acceleration, vertical acceleration, and all three angular rates of the IMU 132. In an embodiment, the outputs are analyzed to determine the frequency response of each. The frequency response can be determined using one or more bandpass filters, fast Fourier transforms, or other methods. For example, the roll angle frequency response can be monitored using a bandpass filter for frequencies within a first range (e.g., 8-15 Hz) to provide an indication of chatter. The frequency response monitored for one or more of these outputs is compared to stored ranges for different terrain types and used as a basis for adjusting the damping characteristics of one or more of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146.

[0191] In an embodiment, the electronic controller 100 also monitors the GPS sensor 131. A given location may indicate a first terrain type based on the frequency response of the IMU 132 on the first day (e.g., first snow), and a second terrain type based on the frequency response of the IMU 132 on the second day (e.g., hard snow). Based on these historical data for different terrain types and locations, the electronic controller may adjust the damping characteristics of one or more of the right front adjustable shock 140, the left front adjustable shock 142, the front track adjustable shock 144, and the rear track adjustable shock 146 to make the hard snow on the second day feel more like the first snow on the first day. This provides the snowmobile 10 with the ability to have the same feel at the same location on different days, even if the terrain characteristics have changed.

[0192] In an embodiment, the sensors 130 include sensors that monitor whether the rear suspension assembly 26 is in a coupled state or a decoupled state. Exemplary sensors are position sensors, angle sensors, pressure sensors, or contact sensors that monitor when the suspension arm contacts a coupling block of the rear suspension assembly 26. In an embodiment, the damping characteristics (compression and / or rebound) of the front track-adjustable shock absorber 144 and / or the rear track-adjustable shock absorber 146 are adjusted based on whether the rear suspension assembly 26 is in a coupled state or a decoupled state.

[0193] Although the embodiments of the present disclosure have been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the present disclosure. Therefore, this application is intended to cover any variations, uses, or modifications of the present invention made using the general principles of the present disclosure. Further, this application is intended to cover deviations from the present disclosure that fall within known or customary practices in the field to which the present invention belongs.

Claims

1. A suspension system for a snowmobile having tracks, the suspension system comprising: a front adjustable track shock absorber capable of operating according to a first damping characteristic of the front adjustable track shock absorber; a rear adjustable track shock absorber operable according to a first rear adjustable track shock absorber damping characteristic; and an operator input operable to adjust an operating mode of the suspension system between a first configuration and a second configuration, wherein, in response to the operator input being actuated to the first configuration, the first damping characteristic of the front adjustable track shock is increased and the first damping characteristic of the rear adjustable track shock is decreased, and Wherein, in response to the operator input being actuated to the second configuration, the first damping characteristic of the front adjustable track shock is decreased and the first damping characteristic of the rear adjustable track shock is increased.

2. The suspension system of claim 1, wherein: Each of the front and rear adjustable track shocks includes a solenoid valve operable to adjust respective front and rear adjustable track shock damping characteristics.

3. The suspension system of claim 1, wherein: Each of the front adjustable track shock damping characteristic and the rear adjustable track shock damping characteristic is a compression damping characteristic.

4. The suspension system of claim 1, wherein: The first damping characteristic of the front adjustable track shock absorber is a compression damping characteristic, and the first damping characteristic of the rear adjustable track shock absorber of the second adjustable track shock absorber is a compression damping characteristic.

5. The suspension system of claim 4, wherein: In the first configuration, the second damping characteristic of the front adjustable track shock is reduced, and the second damping characteristic of the rear adjustable track shock is increased.

6. The suspension system of claim 5, wherein: The second damping characteristic of the front adjustable track shock absorber is a rebound damping characteristic, and the second damping characteristic of the rear adjustable track shock absorber is a rebound damping characteristic.

7. The suspension system of claim 4, wherein: In the second configuration, the second damping characteristic of the front adjustable track shock is increased, and the second damping characteristic of the rear adjustable track shock is decreased.

8. The suspension system of claim 7, wherein: The second damping characteristic of the front adjustable track shock absorber is a rebound damping characteristic, and the second damping characteristic of the rear adjustable track shock absorber is a rebound damping characteristic.

9. A snowmobile comprising: a plurality of ground contact members, including a left front ski, a right front ski, and a track assembly; a frame supported by the plurality of ground-contacting members; a seat supported by the frame; as well as Wherein, the track assembly includes the suspension system as described in claim 1.

10. The snowmobile of claim 9, wherein: Each of the front adjustable track shock and the rear adjustable track shock is positioned within a track of the track assembly.

11. The snowmobile according to claim 10, wherein: The track assembly includes a plurality of suspension arms, and each of the front adjustable track shock and the rear adjustable track shock is coupled to a respective one of the plurality of suspension arms.

12. The snowmobile of claim 11 further comprising a left front shock absorber operatively coupled to the left front ski and a right front shock absorber operatively coupled to the right front ski.

13. The snowmobile of claim 12, wherein: The left front shock absorber is a left front adjustable shock absorber operable according to a left front shock absorber damping characteristic, and the right front shock absorber is a right front adjustable shock absorber operable according to a right front shock absorber damping characteristic.

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