• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.190-194
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• 2005

There is a great demand of micro-actuators for mobile information devices such as SFF optical drives and mobile camera phones. However, conventional magnetic coils of electromagnetic motors are a major obstacle for miniaturization because of their complicated structures and large power consumption. In this paper, a linear ultrasonic motor to actuate focusing lens of mobile devices is proposed. The new actuator uses a ring type bimorph piezoelectric material, and $d_{31}$ mode is adopted for applying linear motion. The interaction between inertia force and friction force makes linear motion by high-frequency saw signal input. The saw signal gives steady forces on the one direction by asymmetric inclination property of the signal itself on time domain. A commercial FEM (ANSYS) was used in this investigation for simulating structural analysis, identification of dynamic property, such as resultant displacement and coupled analysis with piezoelectric material. To evaluate the performance of the new design, a prototype was manufactured and experiments were carried out. Experimental results show the actuator motion of 1.52 mm/s at 10 kHz input signal in 5 V.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.251-256
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• 2006

There is a great demand of micro-actuators for mobile information devices such as SFF optical drives and mobile phone cameras. However, the magnetic coils used in conventional electromagnetic motors are a major obstacle for the miniaturization because of their complicated structures and large power consumption. In this paper, a linear ultrasonic motor to actuate focusing lens of mobile devices is proposed. The new actuator uses a ring type bimorph piezoelectric material, and $d_{31}$ mode is adopted for applying linear motion. The interaction between inertia force and friction force makes linear motion by high-frequency saw signal input. The saw signal gives steady forces on the one direction by asymmetric inclination property of the signal itself on time domain. A commercial FEM(ANSYS) was used in this investigation for simulating structural analysis, identification of dynamic property, such as resultant displacement and coupled analysis with piezoelectric material. To evaluate the performance of the new design, a prototype was manufactured and experiments were carried out. Experimental results show the actuator motion of 5.4 mm/s at 10V saw signal of 41 kHz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.661-666
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• 2000

Traveling wave on the structure can be generated by superposing two standing waves. Precise matching of the amplitudes and phase shift between two standing waves in time and space is the key to the success of generating a traveling wave. The principle of generating a traveling wave on the structure is utilized in the construction of linear and rotary type ultrasonic motors. This paper demonstrates experimentally generating a traveling wave on the simply supported beam.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.2
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• pp.165-171
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• 2005

The ultrasonic piezo motor is a new type motor that has an excellent performance and many useful features that electromagnetic motors do not have. But, it suffers from severe system non-linearities and parameter variations especially during speed control. Therefore, it is difficult to accomplish satisfactory control performance by using the conventional PID controller. In this paper, to achieve the precise control for linear type ultrasonic motor was analyzed as a function of response time and change with a driving time. Also, we propose controller that combines STEP controller and PD controller that have error of ${\mu}m$ about liner type ultrasonic motor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.484-489
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• 2003

In this paper, a single phase driven piezoelectric motor design was presented for linear motion Two metal/ceramic composite actuators, a piezoelectric ring which was bonded to a metal endcap from one side, were used as the active elements of this motor. The motor was composed of a piezoelectric ceramic, a metal ring which has 4 arms, and a guider. Motors with 30 [mm] and 35 [mm] diameter were studied by finite element analysis and experiments. As results, the maximum speed of motor was obtained at resonance frequency. When the applied voltage of the motor increased, the speed was increased. Also, bidirectional motion of the motor was achieved by combining two motors which have different resonance frequency. But the characteristics of bidirectional motion were not equaled, because of the problem of reproduction on the fabrication and the experiment. If present motor is used at the auto-zoom device of a camera, it will have much advantage. Because the direct linear motion can be achieved with a simple structure of motor and no gearbox of total system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.233-233
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• 2008

A piezoelectric ultrasonic linear motor shaped with 'Butterfly' wings has been developed for thin electronics such as cellular phone and PDA. The butterfly piezoelectric transducer is simply composed of an elastic plate, which includes a tip for energy transfer and two protrusions to fix it, and two piezoelectric ceramics. Contact materials, such as a brass, and steel and alumina can make it possible to improve dynamic properties of the motors over a wide range of tribological conditions. The dynamic properties of the motor have been intensively measured and analyzed according to the applied voltage wave forms at the various frequencies. The results of numerical study and experimental investigation will be used for the future optimization of the actuator and the realization of the advanced ultrasonic motor.

• Journal of Power Electronics
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• v.6 no.1
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• pp.38-44
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• 2006

In this paper, a speed sensorless control for an ultrasonic motor (USM) using a neural network (NN) is presented. In the proposed method, rotor speed is estimated by a three-layer NN which adapts nonlinearities associated with load torque and motor temperature into control. The intrinsic properties of a USM, such as high torque for low speeds, high static torque, compact size, etc., offer great advantages for industrial applications. However, the speed property of a USM has strong nonlinear properties associated with motor temperature and load torque, which make accurate speed control difficult. These properties are considered in designing a control method through the application of mathematical models. In these strategies, a detailed speed model of the USM is required which makes actual applications impractical. In the proposed method, a three-layer NN estimates the speed of the USM from the drive frequency, the root mean square value of input voltage and the surface temperature of the USM, where no mechanical speed sensor is needed. The NN speed based estimator enables inclusion of variations in driving conditions due to input signals of the NN involved during the driving state of the USM. The disuse of sensors offers many advantages on both the cost and maintenance front. Moreover, the model free sensorless control method offers practical controller construction within a small number of parameters. To validate the proposed speed sensorless control method for a USM, experiments have been executed under several conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.873-882
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• 2022

In this paper, we studied the voice recognition system kiosk for convenience, thinking that the kiosk widely used in modern society should compensate for the inconvenience of using by the visually impaired. Using ultrasonic sensor and PIR(Passive Infrared), it recognizes the visually impaired within the range of 80cm-40cm, introduces the kiosk through the MP3 module and induces them to come closer. Also, when the visually impaired within 40cm is recognized, the product description and order are guided through the MP3 module. A recording-based data voice recognition system and a kiosk that outputs desired items through servo motors were studied. A kiosk for the convenience of the visually impaired was manufactured through operation and optimization experiments of PIR, ultrasonic, voice recognition, and shock sensor for the manufactured voice recognition kiosk. Finally, it was confirmed that security can be strengthened by using shock sensors and emergency bells to enhance security.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1285-1288
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• 1997

The basic technology of virtual reality can be described as the cognition of the condition change in virtual world by stimulating the visual, auditory, kinesthetic and tactile sensation. Among these, the kinesthetic and tactile sensation is one of the most important things to recognize the interaction. In this paper, it is addressed the haptic device which help the human feel the sense of the operator, and is designed in modular type to expand for five fingers later. the haptic device is driven by tendon and ultrasonic motors located in the wrist part. Each joint is actuated by coupled tendons and adopts more actrator by one than the number of the joints, called 'N+1 type'. The haptic device adopts metamorphic 4-bar linkage structure and the length of linkages, shape and the location of joint displacement sensor are optimized through the analysis.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.449-453
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• 1997

이 논문은 초음파모터를 이용한 직접구동방식의 전완로봇 개발에 관해서 논하였다. 기어 감속 없이 느린 동작하에서 큰 힘을 제공하기 위해 진행파형 초음파모터를 액츄에이터로 사용하였다. 이 시스템에서는 환경과의 상호작용력에 의한 힘 피드백 제어는 사용하지 않고, 위치 정보만을 사용하였다. 크랭크 회전같은 접촉작업과 핑거의 협력작업에 대한 실험을 고찰하였다.