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Astronauts will suffer the orientation transformation problem without external force condition in spaceflight mission. Based on the establishment of human body system dynamics equation, the recommended control methods are put forward to guide the astronauts to make their orientation changed. The movement process is simulated through use of ADAMS to confirm the feasibility of method. Finally, simulated weightlessness environment is developed to demonstrate the advantages of the recommended control method compared with other control methods. The results show that using the control methods developed in this paper will make astronauts spend less time and smaller joint torques in performing body rotation about single axis in simulated weightlessness. There has certain reference significance for astronauts to conduct orientation transformation in spaceflight.

In dual-axis contouring motion, contouring error is a more important performance index than tracking error. Considering direct drive XY table control accuracy, the influence of load disturbance and the velocity mismatch between X and Y axis are great. As a result, the position tracking iterative learning controller based on DOB controller is adopted at single axis, it can overcome the influence of the load disturbance, and ensure the robustness of the system; For the velocity mismatch between X and Y axis, a control strategy based on hybrid error iterative learning control (HILC) and the real-time contour error model was proposed. Simulation results show that the designed control system of XY table has strong robustness, high contour accuracy and simple structure.

The method to analysis the influence of error sources on the fiber optic gyroscope north seeker is presented in this paper. The influence of various error sources of the north seeker are investigated comprehensively. The simulation results indicate that the precision of gyroscope is the most important influence factor; the influence of the position rotation error and mounting error are greater than that of the inclination angle measurement error. Based on the analysis, the advisable scheme to improve the accuracy of the four-position north seeker is proposed. The experimental results met the accuracy requirement well, which proved that the compensation and error analysis method in this paper are effective and feasible.

Rotation direction of single-axis rotation SINS is researched in this paper. The two aspects: one-way, positive and negative rotation and clockwise, counterclockwise rotation are deeply analyzed respectively, and experimental verification is also taken. The results show that: FOG-based single-axis SINS should rotate with the positive and negative rotation way. It has a significant meaning to the engineering application of this technology.

To investigate the optical performance of vertical single-axis tracked solar panels with the tilt-angle of solar panels being seasonally adjusted (4T-V-A tracked solar panels, in short) as compared with fixed and full 2-axis tracked solar panels, a mathematical procedure to estimate the daily collectible radiation on fixed and tracked panels is suggested based on the monthly horizontal radiation. Calculation results showed that the optimal date on which tilt-angle adjustments were seasonally made was about 23 days from the equinoxes, the seasonal optimal tilt-angles of a 4T-V-A tracked solar panel for maximizing seasonal energy collection strongly depended on site latitudes, and the corresponding maximum annual collectible radiation on such tracked panel was about 97% of solar radiation annually collected by a dual-axis tracked panel, slightly higher than that on those tracking the sun about south-north axis inclined at a yearly fixed tilt-angle from the horizon. Empirical correlations for a quick estimation of seasonal optimal tilt-angle of vertical single-axis tracked solar panels were also proposed based on climatic data of 32 sites in China.

The basic working principle and the two-position north-seeking method based on single-axis FOG(fiber optic gyroscope) is researched in this paper. Improved north-seeking method was proposed to solve the problem in the two-position FOG north-seeking scheme. To Sample in three positions of 0º, 90ºand 180ºseparately and obtain the measurement values of angular rate in these three positions. Then according to the measurement values of angular rate in the first and the third positions to calculate the north-seeking angle, and using the positive and negative pulse outputs of the FOG in the second position to obtain the specific direction information of carrier. So that, accomplish the north-seeking in the range of 0～360° for single-axis FOG. The experiment results showed that the accuracy of the improved two-position north-seeking program based on single-axis FOG is 0.101 (1σ) within 4 minutes.

By utilizing the parallel axis theorem of moment of inertia and the graphic geometric transformation theory as well as the method of rotating and moving axis, the calculation formula of irregular objects’ centroid was derived. And on the basis of a single axis air bearing table which was used for measuring the moment of inertia of objects around a fixed axis, the complete instrument of measuring the irregular objects’ centroid was designed. The objects’ centroid and moment of inertia could be measured synchronously. Through the analysis of the influence on measuring accuracy caused by measuring factors’ errors, the method of improving the measuring accuracy of instrument was derived. The measuring instrument meets the requirement of measuring the irregular objects’ centroid precisely.

The main hindrance to the widespread of solar systems is the cost of the solar collectors. Researchers all over the world have been exploring different means of overcoming this limitation in order to make solar conversion more cost effective. This paper describes an experimental work on optimum seeking position of solar collectors using feedback control theory. Single axis tracking mode is employed together with sun seek sensor for automatic reset. The performance of the tracking collector compares favorably against a fixed collector.

Solar energy is increasingly becoming a significant component in the energy profiles of several tropical nations. This paper discusses trends in solar tracking technologies: analyzing the cost of acquisition, domains of application, maintenance costs and efficiency improvements. The paper concludes that hydraulic-based tracking systems are suitable for low capacity installations with low pay loads while polar axis tracking systems offer a performance nearly equal to that of two-axis tracking systems, at the cost of single axis trackers.

It summarized the basic principle and characteristics of the rotational molding technology. Based on the experiment of the single axis device the processing of rotational molding was studied and predigested. Especially the heat transfer during rotational molding was analysed and a detailed mathematic model was presented. The heating time of mold and the heating time of resin material was resolved. We also brought forward the solution of analysing the function of time, radius and distribution about melting process.