Whole body vibration transmission reduction device

A method of reducing the transmission of a vibration having an excitation frequency to a seat occupant, the method comprising of the steps of:

• providing a vibration damping device comprising:
• a top plate;
• a bottom plate secured to a base;
• a linkage arm arrangement coupled to the top plate and the bottom plate;
• at least one resilient member coupled to the top plate and the bottom plate;
• a load sensor for determining a mass of a load on the top plate;
• at least one accelerometer;
• a damper coupled to the linkage arm arrangement and the top plate;
• and
• wherein the device comprises a natural frequency;
• adjusting stiffness of the device, wherein the stiffness of the device is based on at least one of the natural frequency, the mass of the load, and the excitation frequency;
• wherein the device comprises a natural frequency and wherein the stiffness of the device is based on at least one of the natural frequency, the mass of the load, and the excitation frequency;
• wherein the stiffness of the device is high below a cut-off frequency of the device, and the stiffness of the device is low above the cutoff frequency of the device;
• wherein the excitation frequency is associated with a base, and wherein the bottom plate is secured to the base, and the excitation frequency is transmitted to a seat, on the base, supporting an occupant;
• a controller for receiving parameter inputs from the load sensor, and the at least one accelerometer;
• at least one sensor for sensing an absolute value or a change in a physical quantity and generate a corresponding signal for input into the controller to provide a control signal to the damper, and
• wherein the controller determines at least one of a relative position of the seat with respect to the base based on at least an output from the at least one sensor and a relative velocity of the seat with respect to the base based on at least an output from the at least one sensor.

A seat comprising:

• a vibration damping device for reducing transmissibility of an excitation frequency comprising:
• a top plate;
• a bottom plate;
• a linkage arm arrangement coupled to the top plate and the bottom plate;
• at least one resilient member coupled to the top plate and the bottom plate;
• a load sensor for determining a mass of a load on the top plate;
• at least one accelerometer;
• and
• a damper coupled to the linkage arm arrangement and the top plate, wherein the damper is controllable to modify stiffness of the device;
• wherein the device comprises a natural frequency and wherein the stiffness of the device is based on at least one of the natural frequency, the mass of the load, and the excitation frequency;
• wherein the stiffness of the device is high below a cut-off frequency of the device, and the stiffness of the device is low above the cutoff frequency of the device;
• wherein the excitation frequency is associated with a base, and wherein the bottom plate is secured to the base, and the excitation frequency is transmitted to the seat, on the base, supporting an occupant;
• a controller for receiving parameter inputs from the load sensor, and the at least one accelerometer;
• at least one sensor for sensing an absolute value or a change in a physical quantity and generate a corresponding signal for input into the controller to provide a control signal to the damper, and
• wherein the controller determines at least one of a relative position of the seat with respect to the base based on at least an output from the at least one sensor and a relative velocity of the seat with respect to the base based on at least an output from the at least one sensor.