- 标题
- 摘要
- 关键词
- 实验方案
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Arbitrarily accurate variable rotations on the Bloch sphere by composite pulse sequences
摘要： Composite pulse sequences, which produce arbitrary prede?ned rotations of a two-state system at an angle θ on the Bloch sphere, are presented. The composite sequences can contain arbitrarily many pulses and can compensate experimental errors in the pulse amplitude and duration to any desired order. A special attention is devoted to two classes of π/2 sequences—symmetric and asymmetric—the phases of which are given by simple formulas in terms of rational multiples of π for any number of constituent pulses. This allows one to construct arbitrarily accurate π/2 composite rotations. These π/2 composite sequences are used to construct three classes of arbitrarily long composite θ sequences by pairing two π/2 composite sequences, one of which is shifted by a phase π ? θ with respect to the other one.
关键词： Bloch sphere,quantum control,composite pulses,error compensation,pulse sequences
更新于2025-09-23 15:23:52
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A self-calibration method for error of photoelectric encoder based on gyro in rotational inertial navigation system
摘要： As a precision goniometer, photoelectric encoder plays an important role in rotational inertial navigation system (RINS). The encoder is used to measure the rotate angle of rotating mechanism for attitude calculation and feedback of motor control. However, the experiment shows that there are position-related errors in the encoder output, so calibration is necessary in high precision applications. This paper presents a calibration method designed by the characteristics of encoder errors and the structure of a tri-axis RINS. In RINS, the gyro sensitive axis can be coincided with the motor axis by gimbals rotation, and then the gyro and the photoelectric encoder measure the same angle, so the error can be calculated as the difference between the encoder output and the integral of gyro output. The error will be analyzed through Fourier method, then the error will be ?tted by least squares method and a harmonic model will be established. The veri?cation experiments demonstrate that the angle measurement error is reduced from ± 4000 to ± 200, and the attitude output error drops 7500. The calibration method is proved to be experimentally effective.
关键词： error compensation,gyro,rotational inertial navigation system,self-calibration,photoelectric encoder
更新于2025-09-23 15:21:01
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Volumetric error measurement and compensation of three-axis machine tools based on laser bidirectional sequential step diagonal measuring method
摘要： This paper proposes an approach to the measurement, modeling, and compensation of the volumetric errors for three-axis machine tools, using the laser bidirectional sequential step diagonal measurement. Disparate measuring tracks are specially arranged for forward and backward paths, and the conforming error decoupling method is demonstrated. By decoupling, all the geometric errors which can result in the volumetric errors are distinguished simultaneously, containing translational and angular errors. In comparison with traditional unidirectional measuring method, the proposed bidirectional method distinguishes more geometric errors (the angular errors) by measuring the same four body diagonals. Uncertainty analysis based on the Monte Carlo simulation was conducted, followed by experimental validation on a vertical machining center. The experiment result indicates that the diagonal systematic deviation of positioning is reduced by 90% after volumetric compensation.
关键词： Bidirectional laser sequential step diagonal measurement,Machine tool error compensation,Volumetric error
更新于2025-09-16 10:30:52
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[IEEE 2019 24th Microoptics Conference (MOC) - Toyama, Japan (2019.11.17-2019.11.20)] 2019 24th Microoptics Conference (MOC) - High-Speed Electro-Optics Based on Lithium Niobate Nanophotonics
摘要： The strapdown inertial navigation system (SINS) can be installed on a shearer and used for monitoring its position. However, under the complex environment of the mechanized mining face, the strong vibration of the shearer may cause large calculation error. First, the dynamic model of a double-drum shearer is built with a force analysis, and the spectrum characteristics of linear vibration and angular vibration for the fuselage are then obtained. Second, the coning error and sculling error compensation models of SINS for the shearer are derived based on vibration characteristics. Meanwhile, according to the factor of the uncompensated model, multi-sample compensation model, and different coal and rock traits and different vibration frequencies of the fuselage, the shearer SINS error compensation property under multiple parameters is researched and analyzed in simulation. Finally, simulations indicate that the SINS error compensation model with the three-sample algorithm and four-sample algorithm can improve the calculating accuracy of the shearer SINS. The coning and sculling errors can be compensated effectively by the shearer error compensation model under many vibration conditions, such as different coal and rock traits and different frequencies of the fuselage.
关键词： error compensation,dynamic model of shearer,vibration characteristic,accuracy analysis,Strapdown inertial navigation system (SINS)
更新于2025-09-16 10:30:52
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[IEEE 2018 4th International Conference on Computational Intelligence & Communication Technology (CICT) - Ghaziabad (2018.2.9-2018.2.10)] 2018 4th International Conference on Computational Intelligence & Communication Technology (CICT) - A Low Cost Polarized Navigation Sensor Design
摘要： In this paper, a low-cost bionic polarized light collection sensor is designed based on the sand ant navigation mechanism. The paper presents the basic theory and hardware implementation plan. At the same time, the algorithm and principle of polarization angle acquisition are introduced, which describe the calculation method in detail. At the end of the paper, the causes of the polarization angle error are analyzed and the error compensation method is given. The result of experiment shows that the sensor can collect the information of polarized light and the azimuth angle can be gotten effectively. Its error is about 2(cid:101)(cid:101)and cost is low.
关键词： error analysis,polarized light,error compensation,sensor design
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 14th International Conference on Automation Science and Engineering (CASE) - Munich, Germany (2018.8.20-2018.8.24)] 2018 IEEE 14th International Conference on Automation Science and Engineering (CASE) - CKF-based Fast Error Compensation Filter Design for IR-UWB Indoor Positioning System for Building Automation
摘要： Recently, impulse radio-ultra wideband is widely used for highly accurate location estimation of robots and objects in indoor space for building automation. For their accurate positioning, calibration must be performed after the positioning system is installed, and a compensation technique of the multipath signals should be performed in real-time. In this paper, a real-time calibration and error compensation method is proposed. A filter that estimates channel common error and channel-specific error sequentially is designed based on cubature Kalman filter and the fast and accurate estimation performance of this filter is verified experimentally.
关键词： indoor positioning,impulse radio-ultra wideband,calibration,cubature Kalman filter,error compensation
更新于2025-09-04 15:30:14