Abstract
In order to conduct high-precision measurement of the LIPS-300 ion thruster grid deformation in a vacuum, high-temperature, and plasma environment, a noncontact videometrics system using a telemicroscope was designed. Based on the captured image, the interactive partitioning edge detection method (IPEDM) was used to obtain stable and clear edges of multiple circular cooperative targets. Meanwhile, magnification factor calibration, rotation angle correction, and subpixel-level grid deformation measurement were performed with cooperative targets. The measurement results show that under the power of 750 W in the discharge chamber, the maximum thermal deformation of the screen grid is 1120 μm, and the gap between the screen grid and the accelerator grid is reduced by 420 μm. An accuracy assessment of the system shows that the grid deformation measurement accuracy is better than 12 μm, and the system satisfies the requirement of high-precision real-time measurements of the grid thermal deformation of the ion thruster under the discharge-chamber-running condition and the plasma-beam-extraction condition.
Highlights
The LIPS-300 is a high-power high-thrust gridded ion thruster which has been designed for the new generation of large-scale truss-type satellite platforms in China [1]
Based on the principle of videometrics [20,21], we propose an installation scheme of the cooperative targets that can measure the deformation of the three-grid ion optics, and improve the measurement accuracy by using subpixel positioning
If the X-axes of the camera coordinate system and the probe coordinate system are not projected parallel in the XY-plane due to the angle error caused by the installation of the camera or the ion thruster, the displacement direction of the cooperative target will not be perpendicular to the optical axis of the camera and the measurement result will contain errors
Summary
The LIPS-300 is a high-power high-thrust gridded ion thruster which has been designed for the new generation of large-scale truss-type satellite platforms in China [1]. Based on the improvement of the above problems, Soulas [13] measured the thermal deformation of the grid using a telemicroscope and bolted probes This measurement method could operate under the condition of the ion thruster with the plasma beam, and the grids’ thermal deformation and hot gap of the NASA Solar Electric Propulsion Technology Readiness (NSTAR) thruster 30 cm titanium ion optics were measured successfully. In order to further optimize the direct measurement method of grid thermal deformation and meet the actual measurement requirements of the LIPS-300 ion thruster, this paper improves the measurement method of Soulas and designs a set of grid thermal deformation measurements system using a telemicroscope. The high-precision real-time measurement of grid deformation is realized based on the software written by MATLAB (version 2017b)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
