A snowmobile has a rear suspension assembly including front and rear suspension arms, first and second rear shock absorbers, a first sensor for sensing an angular position of the front suspension arm, a second sensor for sensing an angular position of the rear suspension arm, and a controller communicatively connected to the first and second sensors. A method of controlling the rear suspension assembly includes: sensing an angular position and/or an angular velocity of the front suspension arm; sensing an angular position and/or an angular velocity of a rear suspension arm; and determining a stroke and/or a piston velocity of the first rear shock absorber and/or the second rear shock absorber based on the angular position and the angular velocity of the front and rear suspension arms as sensed by the first and second sensors respectively.

A suspension device includes: a hydraulic damper including a rod provided with a valve for generating a hydraulic pressure when the rod is displaced between a first liquid chamber and a second liquid chamber; and an electric damper configured to electrically displace the rod by an actuator. The electric damper includes: an outer cylinder; an inner cylinder; a piston provided on the rod and configured to stroke in the inner cylinder; and a communication passage disposed inside the inner cylinder at a central portion where the piston strokes. The communication passage establishes communication between the first liquid chamber at one axial end side of the piston and the second liquid chamber at another axial end side of the piston.

A method for estimating damping characteristics of shock absorbers in an active or semi-active suspension involves providing a reference model of a nominal relation between a road severity index related to vertical acceleration values, and the mean driving current of the control valves of the shock absorbers, acquiring respective relative acceleration or speed data of at least the front wheels of the vehicle with respect to the vehicle body, determining a value of the road severity index starting from relative acceleration or speed data of the front wheels of the vehicle with respect to the vehicle body, acquiring values representative of the mean driving current of the control valve of each shock absorber, comparing acquired value of the mean driving current with an expected value of the nominal mean driving current determined as a function of the road severity index according to the reference model, and determining a degradation condition if the acquired value does not correspond to the expected value.

A modular electronic damping control system is described and includes a damping component located at a vehicle suspension location. The modular electronic damping control system also includes a control system configured to control the damping component, and determine the type of damping component present. Also, the control system is configured to automatically tune a vehicle's suspension based on the type of damping component present, and automatically monitor the damping component and determine when a change has been made to the damping component so that the control system can then automatically re-tune the vehicle's suspension based on the change to the damping component.

A modular electronic damping control system is described and includes a damping component located at a vehicle suspension location. The modular electronic damping control system also includes a control system configured to control the damping component, and determine the type of damping component present. Also, the control system is configured to automatically tune a vehicle's suspension based on the type of damping component present, and automatically monitor the damping component and determine when a change has been made to the damping component so that the control system can then automatically re-tune the vehicle's suspension based on the change to the damping component.

An electronically controller external damper reservoir assembly (eRESI) can be connected to a passive damper and/or substituted for an existing external reservoir to provide semi-active damping control. The eRESI includes a reservoir and a variable base valve assembly actuated by an actuator. A controller is in communication with the actuator and a sensor providing input signal indicative of vehicle movement and is programmed to generate a damping control signal to the actuator based on the input signal, to dynamically control the damping force outputted by a passive damper hydraulically connected to the eRESI. A P/T sensor can be installed to a gas chamber of a vehicle damper to generate a P/T signal indicative of the pressure and temperature of the gas. The controller is programmed to determine a damper position of the damper based on the P/T signal.

An electronically controller external damper reservoir assembly (eRESI) can be connected to a passive damper and/or substituted for an existing external reservoir to provide semi-active damping control. The eRESI includes a reservoir and a variable base valve assembly actuated by an actuator. A controller is in communication with the actuator and a sensor providing input signal indicative of vehicle movement and is programmed to generate a damping control signal to the actuator based on the input signal, to dynamically control the damping force outputted by a passive damper hydraulically connected to the eRESI. A P/T sensor can be installed to a gas chamber of a vehicle damper to generate a P/T signal indicative of the pressure and temperature of the gas. The controller is programmed to determine a damper position of the damper based on the P/T signal.

[Problem to be solved] To provide a configuration wherein response characteristics of behavior of a utility vehicle can be changed as required while the vehicle is not in motion, and to prevent an unintentional change in the response characteristics of the behavior.

[Solution] A utility vehicle includes an electronically controlled vehicle behavior adjuster, an intention detector, and a controller. The electronically controlled vehicle behavior adjuster is capable of modifying response characteristics of behavior of the vehicle. The intention detector detects at least one of intentions of an operator of moving the vehicle. When an operator's intention of moving the vehicle is detected by the intention detector, the controller changes the response characteristics of the behavior of the vehicle compared to when an intention of the operator of moving the vehicle is not detected by the intention detector.

A modular electronic damping control system is described and includes a damping component located at a vehicle suspension location. The modular electronic damping control system also includes a control system configured to control the damping component, and determine the type of damping component present. Also, the control system is configured to automatically tune a vehicle's suspension based on the type of damping component present, and automatically monitor the damping component and determine when a change has been made to the damping component so that the control system can then automatically re-tune the vehicle's suspension based on the change to the damping component.

Vehicle cab suspension control systems are disclosed herein. In some embodiments, the cab suspension control systems can include front cab-to-frame mounts that include controllable elastomer-based isolators that can provide real time variable damping to improve ride quality and/or road holding and reduce cab roll in response to, for example, input from one or more cab and/or frame mounted accelerometers, position sensors, etc. Embodiments of the control systems described herein can utilize a single vehicle controller (e.g., an ECU) to control all of the cab suspension components (e.g., semi-active damping technologies, air spring technologies, etc.) employed on a vehicle to provide a single suspension control solution that can provide improved ride performance, road holding, etc.