A drive device comprises a drive unit, a source, a filter unit, and a determining unit.

A driving mechanism is provided, including a fixed portion, a movable portion, a driving assembly and a connecting element. The movable portion may move relative to the fixed portion and is used for holding an optical module. The driving assembly moves the movable portion relative to the fixed portion. The connecting element is movably connected to the fixed portion and the movable portion.

A method for operating a drive unit having an active element with a resonator and an excitation structure for exciting oscillations in the resonator and thereby driving a passive element. The method includes driving the excitation structure with a driving signal, the driving signal being a periodic signal having driving pulses repeated with an excitation frequency. Depending on a control signal, modifying the driving signal, if the control signal is within a first range, by modifying the excitation frequency or modifying the shape of the driving pulses and, if the control signal is within a second range, repeatedly omitting driving pulses.

A device (100) for the excitation of a fiber (150) comprises a first piezo bender actuator (110) and a second piezo bender actuator (120). The device (100) also comprises a connection part (130) which is arranged between the first piezo bender actuator (110) and the second piezo bender actuator (120). The device (100) also comprises a movable fiber (150) which is mounted to the connection part (130).

A virtual resistive load feedback circuit for driving a piezoelectric actuator is provided that accounts for a hysteresis error and drift within the movement of the actuator. The circuit may include a voltage divider and charge divider. A voltage monitor signal corresponding to a voltage of a driver signal and a current monitor signal corresponding to a current provided to the amplifier are combined by an operational amplifier and include electrical characteristics of the actuator such that the circuit approximates a virtual load across the actuator. A feedback portion of the operational amplifier may include a resistor and capacitor connected in parallel to provide the voltage and charge divide functions. The use of the virtual resistive circuit allows for the piezoelectric actuator to be ground referenced, with no external components connected directly to the actuator while gaining the feedback effect to counter the hysteresis and drifts errors of the actuator.

To compensate for hysteresis in an actuator, a path between a first position and a second position can be selected, and a drive signal can be applied to an actuator element that includes a hysteresis-compensated portion to move an object along the selected path.

A control unit of a piezoelectric drive device calculates a maximum deceleration α applied to a driven part by the piezoelectric drive device using a friction force F2max between the piezoelectric drive device and the driven part and a mass m of the driven part, calculates a distance Ln to a target position from a present position of the driven part detected by a position sensor, calculates a reference velocity vth of the driven part using the maximum deceleration α and the distance Ln from the present position of the driven part to the target position, calculates a velocity vn of the driven part from a temporal change of the present position of the driven part detected by the position sensor, and performs control to apply a drive force from the piezoelectric drive device to the driven part when the present velocity vn of the driven part is lower than the reference velocity vth, and apply a brake force from the piezoelectric drive device to the driven part when the present velocity vn is equal to or higher than the reference velocity vth.

A stick-slip piezo motor. At least one voltage source is connected to a piezo motor. The piezo motor has at least one oscillating piezo element and at least one moving friction element connected to the oscillating piezo element. The moving friction element moves in a desired travel direction. A computer is programmed to control the voltage source to deliver voltage to the piezo motor at a predetermined frequency and amplitude to control the speed of the piezo motor. The computer is programmed to hold the frequency constant while varying the amplitude to adjust the speed of the piezo motor. In a preferred embodiment the computer is programmed to hold the frequency constant at an ultrasonic frequency. In another preferred embodiment the computer is programmed to hold the frequency constant at a value of 15 kHz or higher.

A positioning system can include a drive unit having an actuator element and a control system. The actuator element can include a piezoelectric material. The control system can be configured to select a path between a first position and a second position, identify at least one change of direction of the actuator element along the selected path, generate a hysteresis-compensated drive signal based at least in part on the change in direction, and apply the hysteresis-compensated drive signal to the actuator element to move an object along the path.

A driving assembly is provided, including a transmission element and a first driving source. The transmission element has a first connecting point. The first driving source outputs a first driving force to the transmission element. The first driving source is at least partially fixedly connected to the transmission element at the first connecting point.