The space robot is an important tool for space on-orbit service. According to the requirement of the maintenance of the cooperative and non-cooperative targets, a multi-function on-orbit servicing robot system based on fastchangeable end-tools is proposed by investigating and analyzing the current research status of space robots, and a variety of end-effector design schemes are proposed. The three-finger-three-petal end-effector, as the quick-changing device for endeffectors and end tools, not only has the function of mechanical interface capture and docking, but also has the function of power/signal transmission and the mechanical power transmission function. The steel cable-snared end effector has superior misalignments tolerance and soft capture performance. It is suitable for capturing cooperative target with cooperative mechanical interface and non-cooperative engine nozzles of target satellite. The three-finger end-effector with underactuated mechanism has excellent capability of shape adaptation for the target and soft capture function, so it can be used to capture non-cooperative targets such as space garbage with irregular spatial shape. Through the research of the multi-function onorbit servicing robot system and the methods of end-effector quick changing, as well as the capture principles of the endeffectors, the multi-function on-orbit servicing robot system with fast-changeable end-effector and end tool has promising application prospects.
The automation of manufacturing processes in aviation production is very difficult and subject to technological challenges and economical risks. Both safety and easy-to-use collaborative robotics solutions, where human operators and robots share their workspace, combine their advantages and work collaboratively, are becoming valid to address the challenging requirements for complex manufacturing with low cost, high efficiency, flexibility and automation. In this paper, the background of collaborative robots and four kinds of human-robot-collaboration are first presented. Then the Airbus and the BAE’s visions of the “Factory of the Future” are presented, highlighting how collaborative solutions are intended to increase quality and productivity. The main industrial application cases for aircraft assembly where collaborative robots are advantageous are also explained in detail. Moreover, a summary of human-robot collaboration technological challenges is provided, with specific focus on robot hardware design, force sensing and control, behavior design and autonomous learning of collaborative robots. It is expected that human-robot-collaboration for safe, efficient, flexible and intelligent operations is found in wide industrial applications of the future.
Based on the robot automatic grinding platform, the experimental study on the grinding process of zirconia coating was carried out in order to control the coating thickness and surface roughness properly and improve coating surface quality. Based on Preston removal equation, the material removal model was established. The effect of main parameters on the removal depth was studied by single factor experiments. The optimum process parameters and process steps were determined by orthogonal experiment and utilized on the zirconia coating of throat seal of aero-engine. The experimental results show that the removal depth of the material increases with the increasing of grinding force and speed of grinding tool, and decreases with the increasing of feed speed in a certain range. The grinding force has the more influence and the grinding angle has less influence on the removal depth. The force control method is adopted to achieve the quantitative and uniform removal, the coating thickness and surface quality are consistent, the processing efficiency is improved significantly, which verifies the practicability and advantages of the robot automatic grinding system.
In the existing automatic drilling and riveting system, 90% of the faults are caused by the stuck in the rivet feeding system. In order to improve the efficiency of automatic rivet feeding system and reduce failure, a new rivet feeding system based on industrial robot and visual servo was proposed. By installing industrial camera and grasping device at the end of the robot, the quality and location of rivets were detected via machine vision. Then, the robot was guided to grasp and transfer rivets of specific types. Thus, quality of rivets is ensured before delivering and the process of delivery is optimized. The system weighs 1.1t and covers an area of 1.57m2, which effectively saves the area and load of the rivet feeding system in the automatic drilling and riveting system. Experimental results illustrate that the system can detect rivets with a precision of 0.1mm and the feeding efficiency reaches six rivets per minute, which meets the performance requirements of automatic riveting and drilling system.
Shape detection is a vital part of aircraft assembly. Traditional measurement method based on analog delivering cannot meet the requirements of shape detection of large structures in aircraft assembly. It is difficult to detect largesize and complex structures with separate digital measurement equipment and methods. Therefore, this paper constructs an automatic scanning system consisting of industrial robot and laser tracker system, and studies the automatic detection methods for large-scale structures in aircraft assembly. According to the results of trajectory planning and simulation, the scanning system realizes measurement on large structures, and compares the measurement results with the theoretical digital model to analyze the error information of large structures and realize the detection of large structures.
The positioning method of the riveting hole of the aircraft panel is studied. A riveting hole positioning method based on local active contour model is proposed. Firstly, the rough positioning of the riveting hole is performed by global threshold segmentation based on grayscale histogram and shape method. Then a traversal circle with the rough positioning coordinates as the center of the circle is created, and the energy circle is constructed with the traversal circle as the constraint. The energy equation is established to solve the precise positioning position of the rivet hole with the smallest energy point in the traversing circle. Finally, the visual guiding riveting hole positioning experiment is carried out. The experimental measurement of the positioning error is less than 0.05mm, which meets the process requirements for automatic riveting of aircraft panel. Moreover, it has higher accuracy than the traditional regional active contour model and has certain feasibility.
Thermosetting polyimide is one of the most excellent heat resistant materials in organic material systems. The fiber reinforced thermosetting polyimide composites have been widely used in the field of aeronautics and astronautics. However, the further application of high toughness polyimide composites in many fields is limited due to the lack of toughness properties. Therefore, the development of high toughness polyimide composites has gradually become a hot research topic in recent years. In this article, the research status and development trend of toughening methods of thermoset polyimide composites are reviewed, including a series of methods such as the modification method based on molecular main chain structure, thermoplastic polymer blending thermosetting polyimide and thermoplastic polymer interlaminar toughening polyimide composites.
In order to solve the problem of precision fitting in numerical control machining of the skin seam, a method for extracting repair amount of the skin seam was proposed based on scan line point cloud. Firstly, the point cloud was processed in blocks and the boundary feature point of each scan line was extracted by the distance from the point to the fitting plane. Then, the feature points were denoised using chord height difference method and the middle point was selected as the initial point to sort on both sides. Finally, the skin seam docking model and laser scanning boundary were analyzed and the feature points were extended to the docking direction to compensate. Field experiments showed that this method could provide exact repair amount with an accuracy of 0.06mm, which could meet the needs of numerical control machining.
Considering the geometric features of the transition section in a bowed-twist cooling passage of the turbine blade, a correlation modeling method was presented. The transition section was obtaining by trimming the inner part of the blade body with the tool piece, and then conducted modeling of transition section, The G1 continuity requirements for the transfer section and the ribs are met. The principle of the method was deeply analyzed, and the automatic recognition algorithm of the rib edge was proposed. The key parameters and the constraint condition were extracted. Eventually, the parametric design module of the transfer section was developed based on UG Open API, which achieved transition section modeling.
The non-contact, high accuracy, fast speed and wide application are advantages of the structured light measurement technology. It is one of the most important directions in the field of 3D measurement. The paper compares three different forms of structured light. Three-dimensional measurement of the object is carried out based on the principle of triangulation. The single point cloud of the measured object is obtained by data acquisition. The rough and fine stitching of single point cloud data is accomplished by automatic stitching of marker points and stitching technology based on ICP principle. By aligning the stitched point cloud data with the theoretical model and creating the color map, we can get the error color map of the measured object. The actual state of the measured object is intuitively reflected. By using different equipment to measure the same part, the correctness of the results and the efficiency of measurement are verified. The measurement factor analysis can effectively improve measurement efficiency and reduce the influence of noise on measurement results.
Aiming at hyperboloid NOMEX honeycomb of comgposite materials, this article focused on the honeycomb CNC milling and detection technology by using machining and test tool. Using high speed milling process, though optimizing the processing programming strategy and selecting the suitable machining parameters, we could effectively solve the forming accuracy of the hyperboloid honeycomb core parts. This result showed that adopting processing and testing integrated tooling could effectively solve the problem of fixation of the weak rigidity honeycomb as well as improving the cell forming precision. After the online detection of the honeycomb core, we could use the technology of forming verification film by pre-assembling the cell part and the upper and lower skins, and the assembly tolerance between the upper and lower skins and the honeycomb part was less than 0.15mm, splicing tolerance between each separated cell was less than 0.2mm. There was no obvious difference segment in the splicing location. According to the result of verification film, honeycomb core could be fully restored to the current verification film, without tearing, damage and other defects in the forming surface of honeycomb core. It showed that its assembly accuracy meet the requirements.
Aiming at the high speed milling of the wing structure in the aviation field, a fixture design scheme with small interference, high flexibility, fast changing and high automation is proposed in this paper. The composition, principle and PLC control program of the fixture system is discussed in detail. In order to solve the problem that the waste of raw materials in the traditional folder and interference between machine tool and fixture in processing, adjustable positioning plate positioning, rotary clamping cylinder clamping, the use of sensor perception, PLC control achieve the electromagnetic valve orderly action and the workpiece reliable clamping in this paper. Correspondingly, the PLC control program is edited successfully. The fixture design can be used in the actual production of the aircraft structural components and the design of the automatic control fixture.
To promote the technology development and application in production of intelligent manufacturing, a system architecture is proposed. The Connotation, key development contents and technologies of intelligent manufacturing are sorted out. It is a good borrowing for the technology development and the practical application of intelligent manufacturing.
