Provided is a damper with which the energy efficiency for attenuating input vibration corresponding to the unsprung resonance frequency and the sprung resonance frequency can be improved. Also provided is a method for manufacturing this damper. In this damper the electrical resonance frequency, as specified by the inductance of an electromagnetic motor and the capacitance of a capacitor, is set within ±20% of the unsprung resonance frequency, thereby enabling the input vibration corresponding to the sprung resonance frequency as well as the input vibration corresponding to the unsprung resonance frequency to be reduced.

This motor shaft state detection method has: a rotation determination step for determining, using a detected current waveform of a motor, whether or not to be a non-rotational state in which the rotational speed of the motor is smaller than a predetermined speed; a current determination step for determining whether or not to be a supply state in which the absolute value of current supplied to the motor is larger than a predetermined reference value; and a determination step for, when it is determined to be the non-rotational state in the rotation determination step and it is determined to be the supply state in the current determination step, determining that the motor is in a shaft locked state.

An electrically powered suspension system includes: an electromagnetic actuator; an information acquisition unit configured to acquire time-series information related to stroke position of the electromagnetic actuator, information on stroke velocity, and an amount of change in stroke of the electromagnetic actuator and information on a stroke direction based on the time-series information; a damping force calculation unit configured to calculate target damping force based on the information on the stroke velocity; and a drive control unit configured to control driving of the electromagnetic actuator using target driving force obtained based on the target damping force. The damping force calculation unit calculates equivalent friction compensation force based on the amount of change in the stroke and the information on the stroke direction, and corrects the target damping force based on the calculated equivalent friction compensation force. The equivalent friction compensation force has elastic force component and dynamic friction force component.

A voltage converter of a high voltage driver generates a high voltage applied to an electrorheological damper. The voltage converter and the electrorheological damper are electrically connected together through a connecting portion. The connecting portion comprises an electrode pin that connects the voltage converter and an electrode cylinder of the electrorheological damper; a ground pin that connects an external cylinder of the electrorheological damper and ground, and a ground detection pin disposed separately from the ground pin and connected to the ground through the external cylinder and the ground pin. When the ground detection pin and the ground are disconnected, the voltage converter discontinues the voltage generation with or without a command (control signal) of a sub-controller.

To provide a solenoid, a solenoid valve, and a damper in which when the amount of current supplied to the solenoid is small, the thrust of the solenoid to bias an object in one direction can be made small, and at the same time, even when the solenoid is not energized, the object can be biased in the same direction as that of the thrust. The solenoid includes a coil, a first movable iron core and a second movable iron core that are attracted in a direction away from each other by energizing the coil, a coil spring that biases the first movable iron core toward the second movable iron core, and a leaf spring that restricts the approach of the first movable iron core and the second movable iron core.

A method of on-demand energy delivery to an active suspension system is disclosed. The suspension system includes an actuator body, a hydraulic pump, an electric motor, a plurality of sensors, an energy storage facility, and a controller. The method includes disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

A suspension control device which controls an operation of a suspension of a vehicle includes an operation-induced state quantity estimation portion which estimates an operation-induced state quantity caused by an operation of a vehicle, a road surface-induced state quantity estimation portion which estimates a road surface-induced state quantity caused by a road surface, an operation-induced state quantity conversion portion which converts the operation-induced state quantity into an operation-induced required damping force, a road surface-induced state quantity conversion portion which converts the road surface-induced state quantity into a road surface-induced required damping force, and a current value calculation portion which determines a current value to be applied to the suspension with reference to the operation-induced required damping force and the road surface-induced required damping force.

An inductive shock absorber for a motor vehicle is provided having a cylindrical damper tube and a damper rod. A related method for operating a shock absorber is also provided.

A control unit that controls control currents supplied to shock absorbers that generate damping forces according to the control currents determines coefficients of two functions that functionally identify an equivalent damping coefficient and an equivalent spring constant of each suspension based on relationships between the control current supplied to each shock absorber and the coefficients of the two functions that change according to the control current and a frequency of a relative vibration between a sprung and an unsprung of a vehicle, and calculates a relative displacement or a relative velocity between the sprung and the unsprung based on a vertical acceleration detected by a detection device and the two functions in which the coefficients are determined.

A method of on-demand energy delivery to an active suspension system is disclosed. The suspension system includes an actuator body, a hydraulic pump, an electric motor, a plurality of sensors, an energy storage facility, and a controller. The method includes disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.