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This paper describes how major beam positioning stability challenges faced by ShenGuangIII (SGIII) facility were met and solved by support system designs. The facility must provide vibrational and thermal stability conditions for alignment-sensitive components. The positioning stability error budget is developed for the alignment-sensitive components to provide connections between mechanical designs and performances of the support systems when they are subjected to multiple input sources that can cause structural vibration and drift. The largest allocation for vibration sources is broadband ambient vibration that is specified as acceleration power spectral density (PSD) at top-of-foundation. The components are supported in the laser bay primarily by relatively large and massive hybrid support structures of reinforced concrete (RC) pedestals and steel frames or vessels and in the target bay/switchyard primarily by building and large steel space frames. The support systems are required to afford the fundamental frequencies as best as they could. Finite element models of key modules in the laser bay and the global target bay/switchyard structures have been used to guide the designs of the combined conventional materials and optical system structures. Finite element analyses of broadband ambient vibration have demonstrated that the designs satisfy the positioning error budget. SGIII construction was completed in 2015. Ambient vibration measurements were performed and demonstrated that the acceleration PSDs remaining within guidelines. The dedicated shots to flat gold-plated targets showed that SGIII met its design requirement of ±30 μm rms beam pointing to target.

This paper will present a summary of the ShenGuangIII facility target chamber. During the machining the sphericity tolerances were addressed in forming process and numerical control vertical lathe for the individual plates. Procedure was developed for weld groove and welding of individual plates. The two hemispheric shells of the target chamber were welded in China Erzhong Group Co., Ltd. and sent to a temporary enclosure near the target bay for welding together. A drilling machine that can be accurately positioned on the sphere shell was used to bore the holes for the ports. After construction, the target chamber was lifted and placed on the support pedestal. The adjustment system and the precision surveyors with laser trackers were used to accurately position the target chamber on the pedestal support. The helium spray probe was used for the leak testing of the vacuum target chamber. Leak testing and repair of discovered leaks were performed to insure the vacuum integrity of the target chamber. A complete survey of the port flanges and custom contour machining of spacer plates were completed to insure that the devices attached to these port flanges meet the alignment requirement. The target shooting experiment of the sixth bundles of ShenGuangIII facility has shown that the target chamber satisfied the stability and precision criteria.

This paper will present a summary of the target area structural design results of ShenGuangIII (SGIII), which includes target bay and switchyard support structures, target chamber, and beam transport system. The target area building is rectangular and includes a target bay and a switchyard. The outer wall of the target area building is based outside the vibration isolation trenches and separates the diurnal temperature loads and the wind loads that occur outside the target area building during the alignment process prior to a shot. The target bay and switchyard support structures are mainly comprised of the steel reinforced concrete building and the steel space frame. The target chamber is a welded sphere made of aluminum alloy 5052 and has an inner diameter of 6 m and a nominal wall thickness of 8 cm. The beam transport system brought the 48 laser beams to the final optics assemblies (FOAs) and includes 276 transport mirrors. Sources that influence stability are mainly ambient random vibration, ambient wind induced vibrations, diurnal temperature changes, and HVAC. A FEM is used to calculate the responses of the target area structure under broadband ambient random vibration. The position deviations of 48 beam lines are calculated and used to evaluate the stability of the target area structure. The analyses demonstrated that the positioning deviations of 48 beam lines satisfy the deviation budget requirements.

In ICF lasers, many independent laser beams are required to be positioned on target with a very high degree of accuracy during a shot. The target chamber provides a precision platform and datum reference for final optics assembly and target collimation and location system. The target chamber consists of shell with welded flanges, reinforced concrete pedestal, and lateral support structure. The field precision machining technology of target chamber in ICF lasers have been developed based on ShenGuangIII (SGIII). The same center of the target chamber is adopted in the process of design, fabrication, and alignment. The technologies of beam collimation and datum reference transformation are developed for the fabrication, positioning and adjustment of target chamber. A supporting and rotating mechanism and a special drilling machine are developed to bore the holes of ports. An adjustment mechanism is designed to accurately position the target chamber. In order to ensure the collimation requirements of the beam leading and focusing and the target positioning, custom-machined spacers are used to accurately correct the alignment error of the ports. Finally, this paper describes the chamber center, orientation, and centering alignment error measurements of SGIII. The measurements show the field precision machining of SGIII target chamber meet its design requirement. These information can be used on similar systems.

For the hot and difficult issues of trajectory automatic control based on single bucket hydraulic excavator, this paper introduce the control method of combining RBF neural network with traditional PID. By setting up the mathematical model of machine-electricity-hydraulic control system, using the MATLAB-Simulink simulation analysts to get the conclusion that based on RBF neural network PID control is superior to the conventional PID control. This control method can make the system have the adaptability, automatically adjust the control parameters, adapt to the changes in the charged process, improve the control performance and reliability and provide a theory basis to further realize the excavator trajectory intelligent control.

With PSL proportional multi-way valve as the research object, its AMESim model is established. The effect of such factors as damping hole blocking and oil leakage on the characteristics of a multi-way valve system is analyzed and compared.

Exact constraint design can control the interrelation of the components by ensuring the number of the constraints being equal to the number of the degrees of freedom needed. The kinematic mounts which is a point contact linkup structure are the representative structure of exact constraint. It has μm orientation accuracy and 20nm relocation accuracy with low cost. According to the conception and design rule of the kinematic mounts the paper introduces its material choice, stability estimation and accuracy analysis. Two kinds of kinematic mounts sample (upside down and side hang) are designed that can be applied in the large aperture mirrors of ICF (Inertially Confined Fusion, ICF) facility. Mirror mounts of the samples are modularized LRU (Line Replace Unit, LRU). It can provide accurate allocated and relocated accuracy by adopting the kinematic design. Theoretical analysis, accuracy test of relocation and mechanic test of the samples are processed. The sample's maximal angle error of the two samples are less than 2" (design request less than ±40") and its relocating angle error less than 2.3"; (the upside down Sample) and 6.2" (the Side-hang Sample).