Method for exciting rotary ultrasonic motor

Abstract

The invention discloses a method for exciting a rotary ultrasonic motor and relates to the field of the ultrasonic motors. The method comprises the following steps of determining the number of piezoelectric slices in each group, the group number of the piezoelectric slices, the number of operating waves and a physical included angle between adjacent groups of piezoelectric slices when the total number of the piezoelectric slices is fixed; for the rotary ultrasonic motor which is uniformly provided with the piezoelectric slices, estimating a first exciting effect by using a first formula so as to obtain a first basic parameter combination for ensuring the first exciting effect to be maximized; for the rotary ultrasonic motor with the grouped piezoelectric slices, estimating a second exciting effect by a second formula and a third formula so as to obtain a second basic parameter combination for ensuring the second exciting effect to be maximized; calculating an excitation response generated by harmonic excitation; and if standing waves or backward waves do not exist near a working point, using the first basic parameter combination or the second basic parameter combination as a final scheme. The method helps to improve the operation stability and the efficiency of the ultrasonic motor.

Description

technical field [0001] The invention relates to the field of ultrasonic motors, in particular to an excitation method for a rotating ultrasonic motor. Background technique [0002] The rotary ultrasonic motor is a new mechatronic direct drive device with great vitality, which has many advantages that the magnetic field motor cannot match. In the past two decades, considerable progress has been made in the research on rotating ultrasonic motors, including the construction of new motors and the design of new driving principles. But its lifetime, efficiency and stability issues are still not well resolved. [0003] Traditional rotary ultrasonic motors are mostly driven by two phases. Existing studies have shown that if three-phase or even multi-phase excitation is used, traveling waves can still be excited on the stator [1]. However, literature [2] pointed out that since the disk vibrator only has two resonant modes, the three-phase excitation cannot produce a stable rotatio...

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Problems solved by technology

[0007] 2. The existing technology only gives the matching relationship between the number of piezoelectric sheets and the wave number, but has not studied the influence of the excitation mode on the dynamic characteristics. Usually, the relationship between the number of piezoelectric sheets and the wave number is based on experience. It cannot be used to guide the high-efficiency excitation design of ultrasonic motors;

[0008] 3. The existing technology usually only considers the role of the fundamental wave of the excitation, and does not consider the harmonic excitation and its related derivative problems

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