A novel six degrees-of-freedom parallel manipulator for aircraft fuselage assemble and its trajectory planning

2022

Self Cite

Purpose Large gear components widely exist in the transmission system of helicopters, ships, etc. Due to the small assembly clearance of large gear components, using an automatic docking system based on position control will lead to forced assembly. The purpose of this paper is to reduce the assembly stress of large gear components by an active compliant docking technology based on distributed force sensors. Design/methodology/approach Firstly, aiming at the noise interference in three-dimensional force sensor (TDFS), Kalman filter and Savitzky–Golay filter are used to process the sensor’s output signal. Secondly, the active compliant docking control model is constructed according to the principle of impedance control. Thirdly, the contact force is calculated based on the Euler equation, and the impedance control parameters are tuned by the particle swarm optimization algorithm. Finally, an active compliant docking system of a large gear structure based on distributed force sensor is built in the laboratory to verify the proposed method. Findings The experimental results show that the contact force and contact torque gradually decrease in all directions and are always in the safe range during the docking process. The feasibility of this method in practical application is preliminarily demonstrated. Originality/value The distributed TDFSs are used to replace the traditional six-dimensional force sensor in the active compliant docking system of gear components, which solves the problem of the small bearing capacity of the conventional active compliant docking system. This method can also be used for the docking of other large components.

Section: Automatic Docking System For Large Gear Componentsmentioning

confidence: 99%

An active compliant docking method for large gear components based on distributed force sensor

Chu

2022

Self Cite

“…In the digital docking system, the three-dimensional NCL is usually used as the actuator to adjust the position and posture of ALC (Liu et al, 2019). The NCL is a kind of automatic mechatronics equipment, which can move in X/Y/Z direction according to the predetermined trajectory (Chu and Huang, 2020;Zhu et al, 2015). Multiple NCLs are connected with the brackets used to fix the ALC to form the n-prismatic-prismatic-prismatic-sphere (nPPPS) redundant actuated parallel posture adjustment mechanism (PAM) (Luo et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

A calibration method of redundant actuated parallel mechanism for posture adjustment

Chu

2021

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Purpose With the improvement of modern aircraft requirements for safety, long life and economy, higher quality aircraft assembly is needed. However, due to the manufacturing and assembly errors of the posture adjustment mechanism (PAM) used in the digital assembly of aircraft large component (ALC), the posture alignment accuracy of ALC is difficult to be guaranteed, and the posture adjustment stress is easy to be generated. Aiming at these problems, this paper aims to propose a calibration method of redundant actuated parallel mechanism (RAPM) for posture adjustment. Design/methodology/approach First, the kinematics model of the PAM is established, and the influence of the coupling relationship between the axes of the numerical control locators (NCL) is analyzed. Second, the calibration method based on force closed-loop feedback is used to calibrate each branch chain (BC) of the PAM, and the solution of kinematic parameters is optimized by Random Sample Consensus (RANSAC). Third, the uncertainty of kinematic calibration is analyzed by Monte Carlo method. Finally, a simulated posture adjustment system was built to calibrate the kinematics parameters of PAM, and the posture adjustment experiment was carried out according to the calibration results. Findings The experiment results show that the proposed calibration method can significantly improve the posture adjustment accuracy and greatly reduce the posture adjustment stress. Originality/value In this paper, a calibration method based on force feedback is proposed to avoid the deformation of NCL and bracket caused by redundant driving during the calibration process, and RANSAC method is used to reduce the influence of large random error on the calibration accuracy.

“…In the cell, the robot locates the rib into the spars with the aid of the Leica laser tracker system (Rooks, 2001). Comac has developed an automatic docking platform for the docking of wing and fuselage of large passenger aircraft (Zhu et al , 2015; Deng et al , 2018a, 2018b). In these applications, the sensors and on-line measuring equipment are used to get the measurement data of the control features.…”

Section: Introductionmentioning

confidence: 99%

A coordination modelling approach for assembly of multi-constrained objects based on measured skin model

Jiang

et al. 2019

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Purpose The purpose of this paper is to propose an assembly coordination modelling approach based on measured data for assembly quality control of multi-constrained objects in aircraft assembly. This approach aims to establish a high-precision digital mirror of physical assembly system in the virtual environment, with which the assembly process in the virtual environment can be performed synchronously with that in the physical world. Design/methodology/approach This paper presents a realistic geometrical representation model based on measured point cloud, as well as the multiple constraints modelling methods for local and global constraints with the proposed representation model. For the assembly target optimization, a novel optimization method based on the evaluation of multi-dimensional tolerance zone is proposed, where the particle swarm optimization and simulated annealing algorithm are combined to calculate the optimal solutions. Findings As shown in the validation results, the minimum easiness value for easiness model in global optimization is 3.01, while the best value for weighting model by adjusting weights for more than 10 times is 1.94. The results verify that the proposed coordination modelling approach is effective to the assembly of multi-constrained objects, and the optimization model has an obvious advantage over the traditional weighting method. Originality/value This paper provides a new idea for the fine control of assembly quality of non-ideal components by introducing the measured data into the on-line assembly process. Besides, a novel optimization method based on the evaluation of multi-dimensional tolerance zone is proposed, which overcomes the problem of traditional weighting model wherein the weightings are difficult to determine.