Phase error compensation methods for high-accuracy profile measurement

Digital fringe projection measurement technology has been widely used in computer vision and optical three-dimensional (3D) measurement. Considering the phase error caused by the gamma distortion and nonlinear error, the active gamma precorrection and phase error compensation methods based on the three-frequency with three-phase shifts are designed to reversely solve the initial phase and accurately compensate phase error. On the one hand, the gamma coefficient of the measurement system depends on precoding two groups of fringe sequences with different gamma coefficients to calculate the corresponded proportional coefficient of harmonic component. On the other hand, the phase error compensation method is designed to compensate the phase error and improve the accuracy and speed of phase calculation after gamma correction. Experiments show that the proposed precalibration gamma coefficient method can effectively reduce the sinusoidal error in nearly 80 percent which only needs fewer fringe patterns. Compared with the traditional three-frequency with four-phase shift method, the proposed method not only has higher phase accuracy and better noise resistance but also has good robustness and flexibility, which is not limited to the gamma distortion model.

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High accuracy profile measurement of a machined surface by the combined method

Measurement ◽

10.1016/s0263-2241(96)00066-8 ◽

1996 ◽

Vol 19 (1) ◽

pp. 55-64 ◽

Cited By ~ 60

Author(s):

Wei Gao ◽

Satoshi Kiyono

Keyword(s):

High Accuracy ◽

Profile Measurement ◽

Combined Method ◽

Machined Surface ◽

Accuracy Profile

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Initial Alignment Error and Navigation Error Compensation Methods for SINS/CNS Integration

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.390.490 ◽

2013 ◽

Vol 390 ◽

pp. 490-494 ◽

Cited By ~ 1

Author(s):

Jia Sheng Yang ◽

Yue Gang Wang

Keyword(s):

Error Compensation ◽

Phase Error ◽

Alignment Error ◽

Initial Alignment ◽

Theory Analysis ◽

Integration System ◽

Velocity Error ◽

Compensation Methods ◽

Navigation Error ◽

Simulation Results

To remove the navigation error accumulated in the boost phase of the missile’s SINS/CNS integration system, an error compensation algorithm is presented, which uses the saved IMU data and reverse attitude updating algorithm to remove the error caused by initial misalignments, and uses the off-line navigation computation to correct the boost phase error. The theory analysis show that the proposed algorithm’s performance is mainly dependent on the CNS precision , while the errors caused by gyro and accelerometer drift are tiny., the simulation results show that the proposed algorithm can reduce the velocity error to 0.012m/s and the position error to 1.12 meter, which leads to the navigation error compensated greatly.

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