A system is provided for damping vertical oscillations of an elevator car stopped at an elevator landing. The system includes an elevator traction sheave that receives a torque, a sensor that provides a sensor signal indicative of the torque, a controller that provides a control signal based on the sensor signal, and a motor that applies the torque to the sheave. Oscillations in the torque correspond to the vertical oscillations of the car stopped at the landing during a first (e.g., position control) mode of operation. The motor drives the sensor signal towards a baseline value in response to receiving the control signal during a second (e.g., constant torque control) mode of operation in order to reduce the vertical oscillations of the car.

Systems and methods provide for the mitigation of vibrational forces acting on a horizontal stabilizer of an aircraft. According to one aspect, a damper is coupled to a front portion of a horizontal stabilizer to dampen vibrations in a first degree of freedom, with another damper coupled to a mounting point of the horizontal stabilizer to dampen vibrations in a second degree of freedom. The dampers may be passive, operating independently to mitigate vibrational forces, or active, applying a mitigating force to the horizontal stabilizer based on real-time or estimated vibration states.

A vibration suppression device that suppresses vibration of an operation unit in a mechanical system having a natural vibration mode including the operation unit, an actuator unit that operates the operation unit, and an elastic body that couples the operation unit and the actuator unit, the vibration suppression device including a generation means for generating a drive signal for driving the actuator unit, an estimation means for estimating a measurement amount related to the mechanical system, a correction means for correcting the drive signal generated by the generation means on the basis of the measurement amount estimated by the estimation means, and a change means for changing a gain used by the estimation means so that an influence of an increase in a modeling error becomes small in a period in which the modeling error of the mechanical system increases.

A three-loop inertial stabilization system with active jitter suppression and optical control to reduce line-of-sight (LOS) jitter based on platform induced motion in cantilevered gimbal systems. A first loop comprises at least one rate sensor, a Kalman state estimator, and a rate to angle module. A second loop comprises a mirror system, a focal plane and centroid processing module, an open-loop closed loop selector, a signal combiner and a loop integrator. A third loop comprises a fast steering mirror, offload module and at least one gimbal motor driver, wherein the three loops suppress the jitter of the cantilevered gimbal system.

A method for controlling the damping characteristic of a shock absorber of a vehicle, particularly for compensating the variation of the operating temperature of the shock absorber, in an active or semi-active suspension system. The compensation of the variation of the operating temperature of the shock absorber takes place by: estimating a mechanical power dissipated in heat by the shock absorber; estimating a thermal power exchanged by the shock absorber with the environment; evaluating the current operating temperature of the shock absorber as a function of the dissipated mechanical power and of the thermal power exchanged with the environment; and controlling the driving current of the control valve of the shock absorber according to a shock absorber reference model indicating a relationship between the damping force of the shock absorber, the operating temperature of the shock absorber and the driving current of the control valve.

An electrically driven actuator includes a vibration damping device; and an electrically driven unit operated by using electricity. The vibration damping device includes a vibration absorbing unit provided between a first support and a second support provided to face the first support, and expanding and contracting by using electricity, a measurement unit that measures vibrations of the second support, and a control unit that electrically controls the vibration absorbing unit to cancel the vibrations of the second support which are measured by the measurement unit. The electrically driven unit includes a housing provided on a fixed side, a shaft movable in an axial direction which is a direction toward a movable side opposite to the fixed side with respect to the housing, and a drive unit provided between the housing and the shaft, and driving the shaft with respect to the housing.

The invention relates to a device and to a method for controlling a test stand arrangement having a specimen and having a loading machine, which is connected to the specimen by a connecting shaft. An estimated value (T.sub.E,est) for for the internal torque (T.sub.E) of the specimen is determined and, from the estimated value (T.sub.E,est), while taking into account a natural frequency (f.sub.0) and a delay, a damping signal (T.sub.Damp) is determined and fed back into the control loop.

A main orifice plate assembly may be configured to transition a multi-actor damping system from a first damping actor configuration to a second damping actor configuration. The multi-actor damping system may be used in a shock strut assembly to alter a damping curve of the shuck strut assembly. The main orifice plate assembly may be a part of a main orifice assembly including an orbital cam. The main orifice plate may include a flow restrictor. The flow restrictor may be configured to retract or deploy in response to main orifice plate rotating about the orbital cam. The first damping actor configuration may correspond to a first damping curve. The second damping actor configuration may correspond to a second damping curve. The first damping curve being different than the second damping curve.

A method of operating a vibration control system (VCS) using a single actuator which operates to attenuate a system frequency of a system is provided. The method includes determining whether current vibrations at a non-system frequency exceed a predefined level, determining a system response to compensate for the current vibrations exceeding the predefined level and adjusting the force response of the single actuator to respond to a system frequency and the non-system frequency according to the determined system response toward compensating for the current vibrations.

A six-degree-of-freedom micro vibration suppression platform includes a basic platform, a load platform, six sets of single-degree-of-freedom active and passive composite vibration isolation devices that are exactly the same and a controller. Upper and lower ends of each set of single-degree-of-freedom active and passive composite vibration isolation devices are connected with the load platform and the basic platform, respectively. A control method includes: calculating a logical axis signal, calculating a logical axis control signal, calculating physical axis real-time control signals and a transfer step.