Provided is a multi-flap standing wave type ultrasonic motor, including a rotor part, a stator part, a control circuit board, and a fixing attachment. The rotor part includes a flange, a rotor ring, and a shaft. The shaft and the flange are joined together by using a first screw and the flange and the rotor ring are joined together by using a second screw. The stator part includes a piezoelectric ceramics, an excitation ring, and flaps. The piezoelectric ceramics and the excitation ring are fixed with glue, the flaps and the excitation ring are connected through welding, and form an angle with the radial direction of the excitation ring. The stator part is sleeved on a support, is attached to a pressure plate and is connected, through an upright, to a locking plate, and to a substrate of the control circuit board to form a fixing attachment. The flaps are an elastomer and a preload provider. The inner diameter of the rotor ring is less than the outer diameter of the flaps. Adopted is a circular-distributed flap structure, an outer rotor design, an integrated design of motor and control, and a sensor, thereby simplifying the system structure. By adopting circular-distributed assembled flaps, the processing difficulty of the flaps is reduced.

A control method for a piezoelectric motor having a vibrating portion including a piezoelectric element and a transmitting portion transmitting vibration of the vibrating portion to a driven member, and synthesizing longitudinal vibration and flexural vibration by energization of the piezoelectric element to vibrate the vibrating portion and elliptically move the transmitting portion and moving the driven member by the elliptical motion, includes changing an orbit of the elliptical motion according to a load received by the transmitting portion.

An ultrasonic motor includes a vibration section having a piezoelectric element configured to generate vibration by receiving a drive voltage, a driven section, a convex section connected to the vibration section and configured to transmit vibration of the vibration section to the driven section, a drive circuit configured to generate the drive voltage, an encoder configured to detect a movement amount of the driven section, a storage section configured to store a specified voltage value, and a determination section configured to receive position information from the encoder when the driven section starts to move and a voltage value at the time of start up from the drive circuit and to determine that least one of the convex section or the driven section is worn out when the voltage value at the time of start up is larger than the specified voltage value.

Provided is a method for controlling an ultrasonic motor to reduce noise sounding during low-speed rotation in a surveying instrument adopting the ultrasonic motor for a rotary shaft, and a surveying instrument for the same. In a method for controlling an ultrasonic motor according to an aspect of the present invention, in a low-speed rotation range of an ultrasonic motor, a ratio of an acceleration period as a time of application of the drive signal in a control cycle is controlled, and a time to start the acceleration period is randomly shifted for each control cycle. In a method for controlling an ultrasonic motor according to another aspect, a time to start the acceleration period is regularly shifted for each control cycle. In a method for controlling an ultrasonic motor according to still another aspect, second-half acceleration control and first-half acceleration control are alternately repeated.

Provided is a method for controlling an ultrasonic motor provided at a rotary shaft of a surveying instrument to meet requirements for a rotation speed and a plurality of operation modes, and a surveying instrument for the same. In the present invention, the ultrasonic motor is controlled by a first signal having a square wave in a range of rotation speed of the rotary shaft from zero to a first speed, controlled by a second signal in which rises or falls of the square wave are sloped in a range from the first speed to a second speed, controlled by a third signal in which rises and falls of the square wave are sloped in a range from the second speed to a third speed, and controlled by a fourth signal in which the drive signal is continuously applied in a range higher than the third speed.

Information regarding a rotational speed is detected by utilizing a variation in the amplitude at a frequency corresponding to the number of a plurality of protrusions of a vibrating member generated in an S-phase signal detected from a vibration detection electrode of a vibration-type actuator.

Provided is a method for controlling an ultrasonic motor to reduce deterioration of automatic tracking performance, and a surveying instrument for the same. The present invention provides a method for controlling an ultrasonic motor in a surveying instrument including a rotary shaft, an ultrasonic motor that drives a rotary shaft, a tracking unit that includes a light emitting unit and a light receiving unit and tracks a target, and a clock signal oscillation unit that outputs a clock signal, wherein at the time of low-speed rotation of the ultrasonic motor, based on the clock signal, a ratio of an acceleration period in which a drive signal is applied and a deceleration period in which the drive signal is stopped in a drive cycle of the drive signal of the ultrasonic motor is set, and the light emitting unit is made to emit light in the deceleration period.

A drive device for a vibration actuator, which makes it possible to perform low-speed and stable driving and expand a dynamic range of driving speed. A first switching circuit and a second switching circuit apply a first drive signal and a second drive signal for exciting vibration, to an electromechanical energy conversion element of a vibrating body. A position detection sensor acquires information on a relative position between the vibrating body and a driven body in pressure contact with each other. An MPU switches the first and second drive signal to a third drive signal and a fourth drive signal, respectively, based on the acquired information, to thereby change a position at which a largest one of peaks of amplitude of vibration excited in the vibrating body is formed.

A control circuit of a piezoelectric driving device includes: a signal generation unit that inputs a state inspection signal to a plurality of piezoelectric elements connected to each other in parallel; and a state detection unit that detects a state of the plurality of piezoelectric elements based on a state detection signal generated from the plurality of piezoelectric elements in accordance with the state inspection signal.

A posture adjustment device for an optical sensor includes: a controller, a posture detector, and a posture adjustment structure. An optical sensor to be detected is fixed on the posture adjustment structure. The posture detector receives an emitted beam of the optical sensor to be detected, detects a posture of the optical sensor to be detected according to the emitted beam, and sends posture information to the controller. The controller controls, according to the posture information, the posture adjustment structure to adjust the posture of the optical sensor to be detected.