9 results about "Tolerance design" patented technology

The invention discloses a collision transmission mechanism serialized spare part tolerance design method considering a part degradation effect. The method comprises the following steps: establishing a linear degradation model of a critical dimension; carrying out tolerance accumulation analysis by adopting a dimensional tolerance accumulation method to obtain a dynamic distribution rule of the assembly precision target; calculating precision reliability based on the distribution; establishing a mapping model of the spare part size and the reliable service time, and determining an optimal tolerance zone center design value and the corresponding reliable service time; establishing a calculation model of the serialized spare part size and the total reliable service time of the mechanism, and formulating a multi-stage replacement strategy; and a genetic algorithm is adopted to carry out multi-objective optimization, and various tolerance schemes are solved and sorted by taking the processing cost, the replacement frequency and the total reliable service time as objectives. The spare part tolerance can be dynamically designed according to the actual degradation state of the part, the service life is effectively prolonged while the assembly precision is guaranteed, the accidental failure rate is reduced, and the optimal balance of cost and reliability is achieved.

The invention discloses a civil aircraft assembly tolerance optimization method based on an improved NSGA-II framework and a storage medium. The method comprises the following steps: constructing a comprehensive cost evaluation module, and establishing a multi-target cost function; establishing a tolerance optimization model, and defining a tolerance optimization function by taking a key tolerance design index as a constraint condition and combining a reliability requirement, machining feasibility and machining cost; based on a tolerance optimization module of an improved NSGA-II framework, generating a Pareto frontier solution set through non-dominated sorting and congestion degree calculation; a filial generation generator module combining a multi-head attention mechanism and a tournament algorithm is adopted, and the generation efficiency of a Pareto leading-edge solution set is optimized; process data support is provided through the assembly process database module, and it is ensured that the tolerance optimization range does not exceed the current executable process category; iterative optimization is carried out until the design index with the lowest total cost is met, and a final tolerance allocation scheme is output. According to the method, on the premise of meeting design indexes, the total cost index is reduced as much as possible, and the benefits of assembly production are improved.

The present invention provides a large-tolerance deployable double-point special-shaped positioning and guiding mechanism and a tolerance design method. The mechanism comprises two sets of deployable positioning and guiding mechanisms with parallel and symmetric structures and similar structures, both of which are composed of an active end and a passive end. The passive end includes a base and a guiding column, and is fixed on the outer platform of the cabin. The active end includes a deployable mechanism, a compression and release mechanism, a connecting rod, a positioning and guiding hole, and a visualization window, and is connected to a space payload. The guiding column corresponds to the guiding hole and is divided into a small column section, a large column section, and a transition section. The positioning and guiding mechanism is divided into a fixed and a floating fit, and the corresponding positioning and guiding holes are circular and waist-shaped respectively. The present invention saves space, has a large deployment stroke, controllable speed, improves the bending and torsion resistance capabilities of the space payload, makes it have the characteristics of large stiffness, reliable connection, etc., and has a large tolerance adaptation ability during guiding, can better realize the positioning and guiding function, and provides technical support for installing a large space payload at a set position outside the spacecraft cabin.

The invention belongs to the technical field of helicopter design, and particularly relates to a helicopter multi-constraint motion system tolerance design method. All parts in the helicopter engine compartment fairing sliding configuration form a multi-constraint motion system. The method comprises the steps that the tolerance design requirement of the multi-constraint motion system is determined; decomposing tolerance design requirements of the multi-constraint motion system according to three vector directions of X, Y and Z; evaluating tolerance reference candidate items of the multi-constraint motion system; determining a structural part of the main reducing joint as a tolerance reference of the multi-constraint motion system; determining a Z-direction surface reference of the multi-constraint motion system; determining a Y-direction line reference of the multi-constraint motion system; determining an X-direction point reference of the multi-constraint motion system; and establishing a multi-constraint motion system dimension chain model.

The invention relates to the technical field of mechanical design, in particular to a tolerance optimization distribution method based on a self-adaptive decision operator whale optimization algorithm, and aims to realize a multi-objective optimization function of planetary gear tolerance design. The tolerance manufacturing cost and the mass loss cost of a tooth thickness reduction amount error, an eccentric error, an axis flatness error, an axis position degree error and a bearing radial clearance error are taken as objective functions, and the tolerance value upper and lower limits and transmission error precision requirements of the error terms are taken as constraint conditions, so that a tolerance multi-objective optimization model of the planetary gear is established; and introducing a whale algorithm under an adaptive decision operator as an optimization algorithm, and solving the multi-objective optimization model to realize planetary gear tolerance optimization distribution of the error term. Experiments prove that the manufacturing cost model of each tolerance machining geometric feature is formulated, the accuracy of the target function is improved, and the global optimization efficiency and reliability of the multi-target coupling tolerance system are improved.

The application discloses a positioning accuracy reliability-based industrial robot tolerance design method and system, and the method comprises the following steps: performing differential transformation processing on a homogeneous transformation matrix of an industrial robot connecting rod coordinate system, and constructing a positioning accuracy limit state function; establishing an inner and outer test table for industrial robot tolerance design; calculating the failure probability of the positioning accuracy of the industrial robot according to the inner and outer test table and the positioning accuracy limit state function; and sorting the importance of the kinematic parameter tolerance according to a signal-to-noise ratio calculation formula and the positioning accuracy failure probability, and guiding the design of the kinematic parameter tolerance scheme of the industrial robot. Through the use of the application, the kinematic parameter tolerance of each component of the industrial robot can be tightened and loosened, and the positioning accuracy of the industrial robot can be effectively improved under the same production conditions. The application can be widely applied to the technical field of industrial robot tolerance design as a positioning accuracy reliability-based industrial robot tolerance design method and system.

The invention discloses a pass design method for mixed production of bar high-quality steel and common steel, which relates to the technical field of bar rolling process, and comprises the following steps: designing the base circle radius of the high-quality steel pass based on national standard positive tolerance, designing the base circle radius of the common steel pass based on negative tolerance, and controlling the difference between the base circle radiuses of the high-quality steel pass and the base circle radius of the common steel pass to be 0.15-0.25 mm; high-quality steel and common steel hole patterns are integrated in different rolling grooves of the same roller, the maximum groove matching number is dynamically adjusted according to the specification, and the rolling grooves are distributed according to the yield proportion; by adjusting the expansion radius, the roll gap precision and the outer fillet radius, the dimensional precision of the high-quality steel is improved to more than two groups from three groups in the national standard. Under the framework of a low-cost two-roller mill, high-precision rolling of high-quality steel and negative difference maximization production of common steel are both considered, the method is suitable for a round steel mixing production line with the diameter being 20-45 mm, and the technical problem that in a traditional process, collaborative optimization of precision and the yield is difficult is solved.

This invention proposes an example-based tolerance optimization method and system for locking and unlocking mechanisms, belonging to the field of intelligent firearms manufacturing. The method optimizes the tolerance design of the locking and unlocking mechanism by comprehensively considering processing costs and process capability indices while ensuring qualified assembly accuracy. Based on a tolerance example library of locking and unlocking mechanisms, the method constructs optimization objectives for product processing costs and quality losses through contribution analysis and calculation. It establishes an objective optimization model with process capability indices and tolerance accumulation as constraints, achieving a balance between processing costs and assembly quality losses. This invention can meet the design accuracy requirements of precision manufacturing, improve production efficiency, enhance part quality, and further reduce production costs.

The invention belongs to the technical field of commercial vehicle chassis design, and discloses a vehicle frame assembly dimensional tolerance design method, electronic equipment and a storage medium, and the method comprises the steps: S1, size problem identification: decoupling the size problem affecting the whole vehicle installation and quality problem, determining the whole vehicle key size related to the quality problem, and carrying out the recognition of the size problem; identifying the key size of the frame assembly from the listed key sizes of the whole vehicle; s2, design optimization of the size precision of the frame assembly: identifying the current situation of the key size precision of the frame assembly, setting a key size precision target of the frame assembly, and analyzing and optimizing the key size of the frame assembly to achieve the precision target; and S3, completing improvement and summarization. The invention designs a method for designing the dimensional tolerance of a frame assembly, which is used for solving the problems of assembly, performance and reliability caused by unreasonable traditional tolerance design, and improves the dimensional accuracy of a frame and the structural performance and quality of a whole vehicle by optimizing the design of a frame dimensional chain.