| With the continuous development of China’s manufacturing industry, the largescale equipment, in particular, the huge heavy-duty operating equipment has shown more and more obvious importance, such as the large forging manipulator in steel industry has obvious effect on improving the product quality and production efficiency. However, our country still has no core technologies with independent intellectual property rights of the huge heavy-duty operating equipment, therefore, the development of superior performance of the huge heavy-duty operating equipment has become an important issue, and how to test and calibrate the performance of the huge heavy-duty operating equipment such as the complicance performance is also a serious problem.In real forging field, a forging manipulator is indispensable to cooperate with a large forging press equipment, to complete various forging processes such as handling, feeding, flip and holding forgings. When the press is forging workpiece, the forging manipulator tongs will simultaneously clamp the workpiece, the mutual reaction load between the manipulator clamp and the forging blank, is very large and unknown, and an unsuitable compliance strategy of forging manipulator will lead to serious accidents, such as the capsizing of forging manipulator, the fracture of manipulator clamp, the nonconformity of forging blank and so on. Forging behavioral characteristics and properties and the force/position laws in the contact interface during the forging process is the main impact factors to the compliance performance of forging manipulator, therefore how to restore the rule of complex forging conditions by experimental equipment and method are the faced challenges to to test and calibrate the performance of the huge heavy-duty operating equipment such as the complicance performance. Based on the above challenges, the specific contents of this paper include:First, the typical behavioral characteristics and law of forging process is studied. Numerical simulation of the conventional forging process only considers the system itself, ignoring the operation machine intervention, the actual operation of the forging molding constraints exist, including vertical and horizontal operating machines conform to the constraint, so the large forging forming process, in addition to internal deformation forging itself- heat- microscopic evolution of multi-field coupling effects, forgings and machine operation also exists a complex interaction. In this paper, the typical high temperature forging forging process, based on thermal coupling rigid viscoplastic finite element method, the main constraint on the forging process mapping between the variable system parameters and operating equipment clamp load resistance at the interface were analyzed, obtained under different conditions conform to the constraints in forging manipulator clamp load characteristics at the contact interface, the establishment of forging working conditions equivalent impedance model, got the simulated characteristics of forging working conditions, thus providing a basis for the design of forging condition simulation device and restore the experimental conditions.Second, the configuration of forging simulator is proposed based on the global kinematic performance evaluation system. A two-DOF parallel mechanism equipment is presented based on the forging process, kinematic performance of parallel mechanism can be described as kinematic performance data collection in the work space, there is uneven distribution of global scope, trends fluctuation problems, while there are many kinematic evaluation indices of parallel mechanism, thus establishing a global system kinematics evaluation system that will benefit more comprehensive analysis equipment kinematic performance evaluation mechanism to optimize the equipment structure. Based on the positive / inverse kinematics model and the speed Jacobian matrix, containing, the performance evaluation system is established for the motion transmission capacity including the passing accuracy and movement sensitivity, combined with the proposed distribution of spatial data evaluation vector based on operations statistical methods, thus establishing a global kinematics evaluation system, and operational performance, dexterity, sensitivity error and other kinematic performance of the parallel mechanism has been optimized based on the evaluation system, to obtain the configuration optimization domain of the kinematic parameters.Third, performance optimization based on statics full-load bearing performance evaluation system is studied. The full load Jacobian matrix is proposed based on parallel mechanism rigid body static model and combined with parallel mechanism’s load,and the force bearing performance evaluation system of parallel mechanism is established based on the global distribution evaluation vector and the full load of system,to evaluate the force transfer capability from the inside to the outside of and the load carrying capacity within the external loads for the parallel mechanism system,then static bearing performance parameter optimization domain is obtained, and design and optimization methods for the force bearing capacity of parallel mechanism considering the full load distribution is formed.Fourth, stiffness evaluation and match method based on energy distribution for the forging simulator is proposed. Stiffness model of forging simulator is established based on the principle of virtual work and linear superposition principle, and then stiffness performance evaluation system is established based on the elastic potential energy distribution of system and stiffness matrix, and stiffness performance matching design and optimization method is formed considering the load distribution, potential energy uniform and the end of the stiffness, then optimization domain of stiffness parameters is got, ultimately kinematics, statics and stiffness coordination and optimization domain is obtained through multi-objective optimization. Establishment of stiffness matching design methods and evaluation system for the parallel mechanism system, has important significance for rapid design and estimating overall performance static stiffness.Fifth, forging simulator experiment platform and compliance verification is finished. Focusing on forging simulation and reduction technology, regarding the compliance performance of forging manipulator as the core, based on kinematics, statics, stiffness performance parameter matching and optimization results, forging simulation platform is constructed based on force/position control system and configuration monitoring technology, then the compliance performance of forging manipulator is tested, ultimately the compliance strategy of forging manipulator is got.In summary, based on the behavior characteristic model of the forging process, a two-DOF parallel mechanism to reduce the foging force/motion is proposed, and the global kinematic performance evaluation system is established which includes kinematic transmission ability and kinematic transfer accuracy/sensitivity indecies, force bearing performance evaluation method considering the overall inside and outside load of system is formed,and stiffness matching design guideline and the global stiffness evaluation index are formed based on the principle of uniform potential energy and end stiffness, then the matching design and optimization of the mechanism component stiffness, mechanism scale parameters, physical parameters of forging simulator is further conducted, ultimately the forging simulation platform is established which provides a support platform for compliance performance testing and calibration of heavy-duty forging manipulator and theoretical basis and method support for parallel mechanism design in force and motion simulation field. |
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