Suspension control method and suspension control system
AssigneeNissan Motor Co., Ltd.
InventorHironobu Kikuchi
Life of this patent
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Abstract
A control device applies a target control force to a variable damping force damper in a suspension mechanism based on a damping coefficient of the variable damping force damper to eliminate unsprung tramp sensations and feelings of hardness when the stroke speed decreases in a conventional skyhook control. The control device includes a state estimation unit for calculating the sprung mass speed of the sprung mass based on a value detected by several of a plurality of sensors, an application control unit for calculating and outputting a damping coefficient of the variable damping force damper based on the calculated sprung mass speed, and a target control amount management unit for determining the target control force based on the damping coefficient output by the application control unit.
Claims15
A suspension control method for controlling a suspension control system that includes a suspension mechanism provided between a sprung mass and an unsprung mass and including an elastic body and a variable damping force damper, the suspension control method comprising:
- calculating a sprung mass speed of the sprung mass based on a value detected by at least one sensor from among a plurality of sensors;
- calculating a current damping coefficient of the variable damping force damper based on the sprung mass speed;
- selecting a prior damping coefficient as a selected damping coefficient upon determining that a first condition is satisfied and selecting the current damping coefficient as the selected damping coefficient upon determining that the first condition is not satisfied;
- determining a target control force based on the selected damping coefficient;
- applying the target control force to the variable damping force damper;
- and
- temporarily holding the current damping coefficient as the prior damping coefficient to be used in a subsequent control cycle.
A suspension control system comprising:
- a suspension mechanism that is provided between a sprung mass and an unsprung mass and includes an elastic body and a variable damping force damper;
- and
- a control device configured to apply a target control force to the variable damping force damper, the target control force being based on a damping coefficient of the variable damping force damper,
- the control device including
- a state estimation unit configured to calculate a sprung mass speed of the sprung mass based on a value detected by at least one sensor from among a plurality of sensors,
- an application control unit configured to calculate a current damping coefficient of the variable damping force damper based on the sprung mass speed,
- a selection unit configured to select a prior damping coefficient as a selected damping coefficient upon determining that a first condition is satisfied, and select the current damping coefficient as the selected damping coefficient upon determining that the first condition is not satisfied,
- a target control amount management unit configured to determine a target control force based on the selected damping coefficient, and
- a damping coefficient holding unit configured to temporarily hold the current damping coefficient as the prior damping coefficient to be used in a subsequent control cycle.
Dependencies are inferred from the claim text.