There is provided a control method for a piezoelectric driving device including a vibrating body including a piezoelectric element for driving and configured to vibrate when a driving signal is applied to the piezoelectric element for driving, a section to be driven that is driven by the vibration of the vibrating body, and a driving-signal generating section configured to generate the driving signal using a pulse signal generated based on a target pulse duty ratio. When the target pulse duty ratio is smaller than a predetermined value, the driving signal generated by the driving-signal generating section is an intermittently generated periodic signal.

A vibration wave motor, includes a vibrator including an electro-mechanical energy conversion element and an elastic body, and a contact body, wherein the elastic body includes a flat plate portion on which the electro-mechanical energy conversion element is fixed, and a protruding portion, wherein the protruding portion includes a contact portion, a side wall portion, and a coupling portion that is configured to couple the contact portion and the side wall portion, and wherein a predetermined inequality is satisfied, where a thickness of the side wall portion in a direction orthogonal to the pressure direction is t1, and a distance in the pressure direction from a second surface of the flat plate portion to the coupling portion is h1, the second surface of the flat plate portion facing a first surface of the flat plate portion on which the electro-mechanical energy conversion element is fixed.

A drive control device 100, which controls driving of a vibration type actuator 200 including a vibrator 214 that includes a piezoelectric element 203, and a rotor 207, includes amplifier circuits 11 and 12 amplifying a power supply voltage to generate a drive voltage to be applied to the piezoelectric element 203, and a microcomputer unit 1. The microcomputer unit 1 performs a control to increase the amplitude of the drive voltage to perform acceleration from when the vibration type actuator 200 is started to when a target speed of the rotor 207 is reached, decrease the frequency of the drive voltage without changing the amplitude of the drive voltage when power supplied to the piezoelectric element 203 exceeds a first power limit P-Lim.sub.1, and increase the amplitude of the drive voltage when the power falls below a second power limit P-Lim.sub.2 during an operation of decreasing the frequency.

A method may include measuring an electrical parameter of an electromagnetic load having a moving mass during the absence of a driving signal actively driving the electromagnetic load, measuring a mechanical parameter of mechanical motion of a host device comprising the electromagnetic load, correlating a relationship between the mechanical parameter and the electrical parameter, and calibrating the electromagnetic load across a plurality of mechanical motion conditions based on the relationship.

A high-torque and high-precision ultrasonic motor with a self-protection function and an implementation mode of the high-torque and high-precision ultrasonic motor are provided. In the device, a gasket encloses an output shaft of an ultrasonic motor body. A harmonic reducer encloses a shell of the ultrasonic motor body. A motor shaft penetrates through the ultrasonic motor body. The end, close to the motor shaft, of the ultrasonic motor body is defined as a top end, and the bottom end of the motor shaft is sequentially enclosed with an encoder support and a high-precision encoder assembly. The gasket, the harmonic reducer, the encoder support and the high-precision encoder assembly are sequentially arranged from the ultrasonic motor body to the bottom end of the motor shaft. After the ultrasonic motor body decelerates and increases torque, the motor shaft outputs rotating speed and torque.

An optical element driving mechanism is provided. The optical element driving mechanism includes a fixed portion, a movable portion, a first driving assembly, and a positioning element. The movable portion is movably disposed on the fixed portion and comprises an optical element, wherein the optical element moves in the first direction. The first driving assembly is at least partially disposed on the fixed portion. The positioning element is rotatably disposed on the fixed portion or the movable portion, wherein when the first driving assembly is not activated, the positioning element is used to limit the position of the movable portion relative to the fixed portion to a limit position.

A composite motor having high-precision positioning, comprising: a housing (1), a rough positioning assembly, a hollow output shaft (2), a fine positioning assembly, a power switching apparatus and a controller (6). A stepper motor (3) in the rough positioning assembly is responsible for rough positioning of the composite motor, an annular travelling wave ultrasonic motor in the fine positioning assembly is responsible for tail end fine positioning of the composite motor, and the controller (6) implements power output switching between the annular travelling wave ultrasonic motor and the stepper motor (3). The composite motor effectively solves the problem that annular travelling wave ultrasonic motors which operate continuously for a long time have a short service life, and ensures high-precision positioning while also extending motor service life.

A method of controlling a piezoelectric driving apparatus including a vibration section that has a piezoelectric element and a transmission section that transmits vibration of the vibration section to a driven body, and, by energization of the piezoelectric element, vibrates the vibration section in a combination of longitudinal vibration and bending vibration to cause the transmission section to perform an elliptical motion and to move the driven body by the elliptical motion, the method of controlling the piezoelectric driving apparatus including switching, according to an external force received by the driven body, a drive algorithm of the piezoelectric driving apparatus between a first drive mode in which a separation amplitude, which is an amplitude of the longitudinal vibration, is changed while a feed amplitude, which is an amplitude of the bending vibration, is constant and a second drive mode in which both the feed amplitude and the separation amplitude are changed.

A controller is capable of reducing time required to stop a control target at a target stop position as a final stop position. The controller drives a vibration element including a piezoelectric element by an AC signal to thereby move a contact body, in contact with the vibration element, relative to the vibration element. The controller controls a pulse duty cycle of a signal converted to the AC signal based on a difference between a target stop position, which is a final stop position of the contact body, and a current position of the contact body, and an actual speed of the contact body.

Provided is a control apparatus of a vibration-type actuator for generating an elliptical motion of contact portions by a common alternating current including a frequency determining unit for setting a frequency of the alternating current. The frequency determining unit sets the frequency of the alternating current for changing an ellipticity of the elliptical motion, within a frequency range such that ellipticity changing frequency ranges set for the vibrators are overlapped, and the ellipticity changing frequency ranges are set for the vibrators as frequency ranges between an upper limit and a lower limit, such that the lower limit is a maximum resonant frequency at a time of changing the ellipticity, and the upper limit is larger than the lower limit and is a maximum frequency for the relative movement of the driving member.