Suspension control method and suspension control system

A suspension control system comprising:

• a suspension mechanism provided between a sprung mass and an unsprung mass, and that including an elastic body and a variable damping force damper;
• and
• a control device configured to apply a target control force, which determined based on a damping coefficient of the variable damping force damper, to the variable damping force damper,
• the control device including
• a state estimation unit configured to calculate 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 and output a damping coefficient of the variable damping force damper based on the sprung mass speed that was calculated,
• a target control amount management unit configured to determine a target control force based on the damping coefficient that was outputted by the application control unit,
• a damping coefficient holding unit configured to temporarily hold the damping coefficient calculated based on the sprung mass speed, and
• under a first condition, determines the target control force based on a damping coefficient temporarily held in the damping coefficient holding unit, and in the case that the first condition is not met, determines a target control force based on a current damping coefficient outputted from the application control unit.