US 10,312,831 B2 · Method for controlling an ultrasound motor and corresponding control arrangement

Abstract

A method for controlling an ultrasonic motor. From a starting velocity or starting position of the driven element, the method includes adjusting the frequency of the electrical excitation voltage such that it is equal to or close to the mechanical resonance frequency of the ultrasonic actuator; changing the frequency of the electrical excitation voltage using the signal of the velocity sensor or the position sensor towards the anti-resonance frequency of the ultrasonic actuator until an end velocity or an end position of the driven element is reached; and controlling the end velocity or position of the driven element with a predetermined accuracy by means of antiphase frequency change. Also disclosed is a corresponding control arrangement for an ultrasonic motor having an ultrasonic actuator with at least two acoustic wave generators, a driven element and a generator via a frequency adjustment.

Claims17

Dependent claims

A method for controlling a velocity of movement or a position of a driven element of an ultrasonic motor from a first adjustment state which is defined by at least one of a starting velocity or a starting position of the driven element into a second adjustment state which is defined by one or both of the end velocity of the driven element or the end position of the driven element, the ultrasonic motor comprising an ultrasonic actuator with at least a first and a second acoustic wave generator, wherein one of the generators or both generators are subjected to an electrical excitation voltage, the method comprising the steps of:

starting from the first adjustment state of the driven element adjusting a frequency of the electrical excitation voltage such that it is equal to or close to a mechanical resonance frequency of the ultrasonic actuator;
changing the frequency of the electrical excitation voltage using the signal of at least one of the velocity sensor or the position sensor towards an anti-resonance frequency of the ultrasonic actuator until the second adjustment state is reached;
controlling the end velocity or the end position of the driven element with a predetermined accuracy by means of an antiphase frequency change.

A control arrangement for an ultrasonic motor, the ultrasonic motor comprising an ultrasonic actuator with at least a first and a second acoustic wave generator, a driven element and an independent generator for an electrical excitation voltage, wherein the independent generator for an electrical excitation voltage comprises a frequency adjustment, wherein an output of the independent generator is connected to a power amplifier and an input of the independent generator is connected to a controller for a movement velocity or for a position of the driven element,

wherein the control arrangement, when starting from a first adjustment state of the driven element, is configured to adjust the frequency of the electrical excitation voltage such that it is equal to or close to a mechanical resonance frequency of the ultrasonic actuator, and is further configured to thereupon change the frequency of the electrical excitation voltage using the signal of at least one of a velocity sensor or a position sensor towards an anti-resonance frequency of the ultrasonic actuator until a second adjustment state is reached;
wherein the first adjustment state is defined by at least one of a starting velocity or a starting position of the driven element and the second adjustment state is defined by at least one of an end velocity or an end position of the driven element.

Dependencies are inferred from the claim text.

Method for controlling an ultrasound motor and corresponding control arrangement

Life of this patent

Method for controlling an ultrasound motor and corresponding control arrangement

Life of this patent

Abstract

Claims17