A control apparatus capable of improving responsiveness in a minute movement of a vibration-type actuator that has a vibration body (a piezoelectric device and an elastic body) and a driven body that pressure contact with the vibration body. A driving unit moves the driven body by causing a thrust-up vibration in a pressurizing direction and a conveyance vibration in a perpendicular direction in the vibration body by applying alternating voltages to the piezoelectric device. A control unit feedback-controls a position of the driven body by using a first operational parameter that defines an amplitude ratio of the conveyance vibration to the thrust-up vibration and a second operational parameter that defines amplitudes of the conveyance vibration and amplitude of the thrust-up vibration. A correction unit corrects a control amount of the first or second operational parameter so as to increase as the amplitude ratio decreases.

A vibration type driving apparatus includes a first vibrator including an electro-mechanical energy conversion element and configured to be in pressure contact with a driven member, a second vibrator including an electro-mechanical energy conversion element and configured to be in pressure contact with the driven member, and a first electric element connected in series with the second vibrator. The first vibrator is connected to a driving circuit, the second vibrator and the first electric element are connected in parallel with the first vibrator, the second vibrator is connected to the driving circuit via the first electric element, and a resonance frequency f of the first vibrator and a resonance frequency f2 of the second vibrator satisfy a relationship f1<f2.

An electromechanical actuator comprises a volume comprising electromechanically active material, a set of electrodes and a single drive pad. The single drive pad protrudes in a direction parallel to the third axis. The volume of electromechanically active material has a first and second part volume situated at a first longitudinal side, along the first axis, and a third and fourth part volume are situated at a second opposite longitudinal side. The first and third part volumes are situated at a first transverse side and the second and fourth part volumes are situated oppositely. The set of electrodes is provided for allowing excitation of the part volumes independently of each other. A motor comprising such an actuator is also disclosed as well as methods for driving the actuator and motor.

A driving circuit for a vibration type actuator includes an inductor and a capacitor which are connected in series to an electric-mechanical energy conversion element, in which, in a case where a series resonance frequency based on the inductor and the capacitor is set as fs, and a resonance frequency in a vibration mode other than vibration used for driving of the vibrator is set as fu, 0.73.Math.fu<fs<1.2.Math.fu is satisfied.

A vibration wave actuator includes a vibrator, a driven element, and a magnet. The vibrator has at least an electro-mechanical energy conversion element and an elastic body to which the electro-mechanical energy conversion element is joined, the elastic body including a contact portion. The driven element is in pressure contact with the contact portion of the vibrator, and includes a magnetic substance. The magnet is arranged such that the vibrator is placed between the driven element and the magnet.

A vibrator including an electro-mechanical transducer and an elastic body that is fixed to the electro-mechanical transducer and that is provided with a projection, the projection having a hollow structure. The projection includes a contact portion having a first surface at a tip, the first surface being parallel to a first plane, a wall portion projecting towards an opposite side with respect to the electro-mechanical transducer, and a connection portion connecting the wall portion and the contact portion to each other. The connection portion having a spring property, and the contact portion includes a portion of which a cross-sectional area in a second plane that is parallel to the first plane increases as an increase of a distance between the portion and the first surface.

A value obtained by adding an output of a speed feedforward calculation unit that uses a speed calculated from a change over time in an instruction value to a stage downstream from a feedback calculation unit that uses a positional deviation is used as a control amount, and at least one of an elliptic ratio of elliptical motion and a driving direction is controlled.

A control apparatus of a vibration actuator performs control of the vibration actuator using a control amount calculated using both of a first deviation which is a difference between a command value and a relative position, and a gain changed in accordance with a second deviation which is a difference between a target position and the relative position, so as to reduce the gain in accordance with reduction of the second deviation.

When stopping a vibration type actuator at a final target stopping position, driving frequency and phase difference of AC signals input to a piezoelectric element are set in accordance with a first deviation obtained from a command position sequentially determined and a relative position of a vibrating member and driven element, and also pulse duty is adjusted in accordance with a second deviation obtained from a final target stopping position and the relative position.

Provided is an ultrasonic motor, comprising: a vibrator including a piezoelectric element and a contact surface to be brought into contact with a member to be driven, the vibrator driving the member to be driven by an ultrasonic vibration excited by the piezoelectric element; a holding part configured to hold the vibrator; a pressurization unit configured to apply a bias force for biasing the holding part toward the member to be driven so as to impress the contact surface against the member to be driven; and a fixing unit configured to support the pressurization unit, in which the holding part holds the vibrator on both sides of the contact surface in a driving direction of the member to be driven.