In this paper, a telescope control method to reject ground-based disturb is proposed to enhance the tracking precision of telescope systems. Telescope systems usually suffer some uncertainouter disturbances, some disturbance come from the torque disturb such as friction orwind loads, some of the others may come from the platform. For astronomical telescope, especially relative large volume telescope, disturb from ground istransferred to the telescope via the pier foundation. And the main mount of disturb is the resonance frequency of pier foundation. The frequency is about 10Hz.A complete vibration test was carried out on a quantum satellite-ground communicationground telescope. Some conclusion is achieved. And a control method based on data fusion to rejecting ground-based disturbance is proposed. The test showed that the method could reduce the track error from 1.5 angular second to 0.28 angular second.
An efficient and low-latency pixel data transmission module for the adaptive optics wavefront processor is presented. A fiber-based custom real-time pixel data transfer protocol is developed, which has the characteristics of long transmission distance, low-latency, and low-protocol overhead. The hardware part of the suite has been verified on different circuit boards with different field-programmable gate arrays. Obtained results demonstrate that the transmission and protocol processing delay are only 413.5 ns, the transmission bandwidth is 3.125 Gbps, and the error rate is less than 10−12. Under the same conditions of 156.25 MHz clock frequencies and length of transmission line, compared with the serial front panel data port protocol adopted by the thirty meter telescope and the european southern observatory, the transmission delay is significantly reduced by 2.82 times and has a remarkably low logic occupancy rate through our solution. Also, the method has been applied in several actual projects.
Electro-optical stabilization and tracking system is critical and difficult issue in satellite laser communication. Moreover,
line-of-sight stabilized system is the kernel of implementing electro-optical stabilization and tracking system, which can
be used to isolate the vibration of the moving platform of the satellite and the disturbance of the space environment. In
this paper, we propose a new method, which using H∞ mix sensitivity based on generalized internal model controller
(GIMC), to design the control system of the electro-optical stabilized platform. It is well known that there is an intrinsic
conflict between performance and robustness in the standard feedback framework. Generalized internal model controller
is a new architecture which can separate the performance and robustness design in controller design. This architecture
has two parts: a high performance controller, say K0,which is designed by PI controller in this paper, and then a
robustification controller, say Q, which is designed to improve the ability of the anti disturbance by using H-infinity mix
sensitivity controller design method. In this paper, we also present the steps of controller design by using this method to
make it easier to use. Based on the proposed method, numerical simulation and experiment are both carried out for a
gyro stabilized platform of electro-optical tacking system. Both the numerical simulated and the experimental results
show that the electro-optical stabilized platform using the H-infinity mix sensitivity controller design method based on GIMC
is accurate and effective. Comparing with the same PI controller in standard feedback framework, the proposed method
can guarantee the high tracking performance as same as the PI controller and improve the external disturbance
restraining ability a lot. In conclusion, H-infinity mix sensitivity controller design method based on GIMC is a new approach
for gyro stabilized platform of electro-optical stabilization and tracking system and might be used easily in practical.
Line-of-sight stabilized system, which can be used to isolate the vibration of the moving bed and the disturbance of
environment, is the most important part of an electro-optical tracking system. The steady precision and robustness are the
key issues of recent researches. In this paper, a novel control approach so called 2-Port Internal Model Control (2-PIMC)
for line-of-sight stabilized system is proposed. By adding a parallel feedback control loop on the basis of Internal Model
Control (IMC), the 2-PIMC method can improve precision while it also has strong robustness as the IMC. The
robustness and the static error of 2-PIMC method were subsequently analyzed. Based on this novel method, Simulation
and experiment are both carried out for a gyro stabilized platform of electro-optical tracking system. The experiments
include a shaking table which can generate disturbance as the moving bed and a gyro stabilized platform which is
mounted on the shaking table. The experimental result indicated that the gyro stabilized platform using 2-PIMC method
is accurate and effective. Comparing with PI control, the following error and disturbance restraining error were both
greatly improved at low-frequency and mid-frequency by the 2-PIMC method proposed. The improvement of precision
is more than 10dB at 4Hz. In addition, the 2-PIMC method doesn't need any extra sensors for the platform and it's easy
for parameters regulation. It can be concluded that the2-PIMC method is a new approach for the high-performance gyro
stabilized platform and might have broad application prospect.
The objective of this research is to develop advanced control methods to improve the bandwidth and tracking precision
of the electro-optical fine tracking system using a fast steering mirror (FSM). FSM is the most important part in this
control system. The model of FSM is established at the beginning of this paper. Compared with the electro-optical fine
tracking system with ground based platform, the electro-optical fine tracking system with movement based platform
must be a wide bandwidth and a robustness system. An advanced control method based on internal model control law is
developed for electro-optical fine tracking system. The IMC is an advanced algorithm. Theoretically, it can eliminate
disturbance completely and make sure output equals to input even there is model error. Moreover, it separates process to
the system dynamic characteristic and the object perturbation. Compared with the PID controller, the controller is
simpler and the parameter regulation is more convenient and the system is more robust. In addition, we design an
improved structure based on classic IMC. The tracking error of the two-port control system is much better than which of
the classic IMC. The simulation results indicate that the electro-optical control system based on the internal model
control algorithm is very effective. It shows a better performance at the tracing precision and the disturbance suppresses.
Thus a new method is provided for the high-performance electro-optical fine tracking system.