Papers by Keyword: Voice Coil Motor (VCM)

Abstract: This paper presents design of micro stage performing 6 degree-of-freedom (DOF) motions, which actuated by voice coil motor (VCM). The VCMs generate forces to perform in-plane motions and out-of-plane motions. The stage is supported by springs for compensating mass of the moving part of the stage and the stiffness of the springs has been chosen to meet the moving range requirement and to have high resonant frequency at the same time. Moving magnet type has been selected against moving coil type due to few merits of the type. The size of the stage is 380 X 380 X 60 mm³ and the motions are measured by laser interferometer and gap sensors.

Abstract: The core component of profilometer is a stylus displacement measuring system, whose resolution reaches nanoscale. Since the stylus tip is very small, a variation on probing force has a great impact on the results of high-precision displacement measurements. In this paper, a special flat rectangular voice coil motor is designed to realize a constant probing force for the stylus displacement measuring system. Experimental results show the probing force can be adjusted from 5mg to 1000mg and the resolution can reach 5mg.

Abstract: This paper studies an efficient voice coil motor (VCM) in which permanent magnets (PMs) with Halbach array are mounted on the surface of its mover. This arrangement has the advantages of improving the force constant of the VCM significantly compared with non-Halbach array motor. Finite element analysis has been conducted to verify the feasibility and the strength of the design. Experiments finally prove the test results match the simulation results well and hence validate the proposed VCM has large force constant and high efficiency with the employed design.

Abstract: The traditional fatigue machine using stepping motor as driving device has the disadvantages of low efficiency, low frequency and producing heat terribly. This paper presents the development of a new type fatigue machine using voice coil motor which has the advantage of high frequency, high accuracy and easy to control as driving device in order to make up for these deficiencies of the traditional machine. The maximum frequency of fatigue machine can reach 200Hz, and the maximum stroke will reach 30mm. The machine can test the properties of anti-fatigue crack of metal and non-metallic materials and the fatigue lives of mechanical parts. It also can provide the force curve changing with time under different frequencies when carrying on tensile and compressive test on sample, which can greatly improve the accuracy and stability of measuring system

Abstract: Voice coil motor is an electromagnetic actuator widely used for motion generation. The main weakness of a voice coil motor is small force. In this paper a voice coil motor is mathematically modeled, analyzed and optimized to obtain high force. According to the optimized final designs, the performance of the voice coil motor is evaluated.

Abstract: A voice coil motor (VCM) is the module to realize auto-focus function in mobile devices such as smartphones and tablet PCs. The VCM has very complicated structure in a small dimension. There are many faults like large hysteresis, short movement range and improper starting current. However, VCM makers are struggling to point out the cause of faults. Break-down analysis is also difficult to apply because main VCM parts are tightly bonded together and easily deformable during disassembly processes. Therefore, we proposed the novel diagnosis method of VCM faults without breaking it. Our method expected to classify the causes of faults by analyzing vibration characteristics of VCMs. Frequency spectrum characteristics and fast Fourier transform (FFT) spectrum analysis are performed. Experimental results revealed that natural frequency shifts shown for NG samples compare to good ones and the fluctuation of magnitude over natural frequency range appeared. Also, sidebands are observed in adjacent of integer multiple harmonic peaks for NG sample. We can find clear vibration characteristic differences caused by VCM defects. Therefore, the causes of defects expected to be classified and corresponding actions can be done in the production line that lead to high productivity of high quality VCM.

Abstract: In this paper, a new control strategy is put forward, which is a single neuron PID control based on the quadratic performance index (QPI) learning algorithm. This single neuron PID control is self-learning and self-adjusting. Through the study of system performance, the weights of the neuron are adjusted by the QPI learning algorithm. The new strategy solves the contradiction between fast tracking performance and robustness in the positioning servo system. In addition, the mathematic model of voice coil motor is analyzed. In order to improve the fast response performance and disturbance suppression of the position loop, the Two-Degree-of-Freedom (TDOF) control is proposed. The simulation results show that disturbance rejection and dynamic performance of the VCM servo control system have been improved. Compared with the utilizing traditional PID system, this new control strategy has stronger self-adapting and robustness.

Abstract: The mechanical environment has an important influence on biological behavior of the human musculoskeletal system. Either in vivo or in vitro culture, the growth and development of the musculoskeletal tissue depend on the mechanical environment. Now we propose a new loading device which uses a voice coil motor as driving force to further optimize tissue engineering bioreactor. It can not only provide tissue engineering in vitro culture with different sizes and frequency of loading environments within the physiological range, but also detect the mechanical properties of the culture in building process. This device, which uses the voice coil motor as driving force and closed-loop encoder to control displacement, has the characteristics of low power loss, high acceleration and smooth loading, and can achieve a high-precision loading process with different ranges such as from high-speed to low-speed. The device can facilitate the load research in build process of the engineered musculoskeletal system.

Abstract: A Voice Coil Motor (VCM) for precise positioning with high output force was designed. The stability and heat dissipation of VCM were analyzed. The performance of VCM was also compared with that of the same type VCM produced by SMAC. Uniaxial ratcheting behavior of solder wire (Sn63/Pb37) was studied by uniaxial cyclic stress controlled tension deformation tests,to verify the VCM systematically.

Abstract: A two-degrees-of-freedom voice coil motor and its control system are proposed for linear and rotary motions with high speed. This VCM consists of two individual motion parts driven by two separated DSP embedded controllers. For servo control of the VCM, an improved PID control algorithm is adopted. The performance of the control algorithm is evaluated under actual environment. When the targets of position and angle are set at 5mm and 15°, the time response shows 48ms and 70.4ms settling time with 5μm and 3’ steady state error without overshoot. Settling time is reduced to 36% as compared to that of original PID controller.