Papers by Keyword: Error Analysis

Abstract: Based on the study of planetary differential roller screw, a planetary differential micro-displacement mechanism is designed for tool compensation. Axial stiffness is an important factor of over-all properties of planetary roller screw. The structure of planetary differential roller screw is similar to planetary roller screw. The axial stiffness was analyzed with Hertz contact theory and confirmed with the ANSYS. Finally, the theoretical values and simulation values were compared to verify the simplified model, and the error was analyzed. The results show that the relative error between simulation values and theoretical values are less than 5%. Therefore, the simplified model of the finite element is reasonable.

Abstract: To deal with the lack of accurate and efficient inspection methods in complex free-form surfaces, three-dimensional measurement method based on the optical measurement and computer image processing technology was proposed. It adopted laser scanning technology to get point clouds of free-form surface. Used rapid measurement software to inspect precision of point cloud& CAD model. What could be the cause of machining errors was analyzed. 3D deviation inspection of complex surfaces was applied by an artifact. Detected the machining error of an important section, and outputted test report. This research provides a convenient and swift method for the inspection of free-form surface and processing quality control.

Abstract: In this paper, a dual-axis tracking trough solar collector system is established, and used to measure and calibrate flow rate at different conditions by using the ultrasonic flow meter and mass flow meter, providing important reference for follow-up experimental study. With the changing of the medium’s temperature and the rotation speed variation of the pump, the two flow meters were used to work together to measure the accurate flow measurements, obtaining the measurement error of the mass flow meter. After that, the reason of error and methods used to reduce the error are analyzed.

Abstract: In this paper the processing scheme of the special grinding in rotational workpiece with complex generatrix is mainly studied. With the help of combining the linear fitting and circular arc fitting, the mathematics model is established and the impulse distribution is obtained. Meanwhile,its matching errors are analyzed.Consequently,it realizes the grinding processing with arbitrary complex curve.

Abstract: Releasing beacon balloons is an effective way for space TT&C ship to obtain accurate comparison data and an important resource for accuracy evaluation. However, it is hard for theodolite to keep track beacon balloon stably for a long time. Its function has not been realized because the time period of the effective data is so short that it can not satisfy the request of traditional accuracy evaluation test. Aiming at this problem, this paper suggests an assumption of accuracy evaluation based on dynamic time interval non-continuous variable data. Utilizing self–adaptive outlier detection method and fitting residual error method, this paper solves the puzzle of dealing with dynamic time interval data which can not be treated by existing method, and realizes the self-determination of space TT&C ship accuracy evaluation test.

Abstract: In this paper, we did the analysis of the gyro error using Allan variance method, static output data using a three-axis gyroscope of the global first integrated six-axis motion processing components MPU6050. Experimental result shows that it not only improves the estimation accuracy of gyro error, but also the amount of data required is greatly reduced.

Abstract: A ground test method of the heat exchanger in intake is proposed using simplified method. A theoretical analysis was carried out to investigate its influences on the performance of heat exchanger. The results show that the performance of heat exchanger keeps invariable with the density of gas if the temperature and mass flow rate remain the same. The error caused by substituting total pressure of free stream for inlet entrance was analyzed and the results show that for subsonic inlet the experimental error is relatively small and the experimental error increasing rapidly as flight Mach number exceed 1.2 and flight altitude has little impact on the experimental error while the error increasing slightly with flight altitude.

Abstract: Pulse chasing is an important means to achieve foundation-bistatic radar space synchronization. The principle and working process of achieving space synchronization by using pulse chasing is described which is based on a motion platform in bistatic radar; and the requirements on the receiving beam width is derived. How to cause the error of space synchronization with pulse chasing and its factors are analysed in detail, then the simulation on error of receiving beam width and beam pointing has been realized.

Abstract: The parallelism between an industrial camera and a servo motion direction is corrected with the help of image measurement to shadowed geometric contours. Then a nearly orthogonal angle between XY servo motion directions is obtained according to an inherent geometry relationship in contours. The installation error of a PCB in platform is compensated based on automatic multi-spot imaging finally. An experimental prototype was built while the PCB alignment was implemented on a lot of samples according to the method introduced above. It proves that the developed immediate alignment method as well as its specific embodiment fulfills the requirement of positioning accuracy in the initial design.

Abstract: A hydrodynamic experiment apparatus is constructed to accomplish the measurement of hydrodynamic force on three-dimensional. This paper firstly introduces the mechanical structure of the novel hydrodynamic experiment apparatus. Then, it introduces the mathematical modeling of the hydrodynamic experiment apparatus which is based on the relationship between measurement data and the force on experiment subject. Finally, the error source of the mechanical structure and load cells were analyzed and the error compensation model is established to improve the measurement accuracy.