Integration Of Testability Design And Allocation Considering System Integration

Due to the rapid development of equipment and the requirement of actual combat,the traditional test mode has been unable to adapt to the development of high-tech equipment.The fault and test elements of high-tech equipment are more prominent in the system level.On the one hand,the fault mechanism and performance are more complex,especially the interaction between integrated fault and unit fault,which makes fault isolation more difficult.On the other hand,because the system has the characteristics of high correlation and high coupling,the ability of integrated testing in the system becomes more and more prominent,and the impact on fault detection and isolation is also growing.Facing complex systems,the existing testability technique usually doesn’t fully consider system-level faults and system integration factors,nor does it combine testability allocation with system-level testability solutions,resulting in unreasonable system-level testability design and allocation results.In order to solve the above problems,the paper mainly studies the following four aspects:(1)The existing problems of testability technique are analyzed when facing modern complex equipment and the integrated design and allocation scheme of testability is proposed.This paper analyzes the current testability design method and the characteristics of modern equipment,points out the shortcomings and unreasonableness of the current testability scheme design and index allocation in the face of modern complex equipment,puts forward a design idea and technical method for the integration of testability design and allocation,and points out main problems need to be solved in the integration of testability design and allocation.(2)The failure mechanism and integration testing mechanism of complex system are analyzed.Firstly,the paper analyzes the connotation and characteristics of the integrated system,and makes it clear that the integrated system mainly includes integration fault and integration testing.Then,the paper gives the connotation of integrated fault,analyzes the fault mechanism of three typical types of integrated faults: connection type,interference type and accumulation type,and analyzes the impact of integrated faults on testability design.Finally,the paper gives the definition of integration testing,clarifies the relationship among integration testing,unit testing and system-level testing,and analyzes the impact of integration testing on testability design.(3)An extended testability model based on integrated fault and integrated test is constructed.In order to meet the requirements of the integrated design idea and technical approach for the integration of testability design and allocation,the traditional testability model is extended and an extended testability model is constructed.The extended testability model considers many factors,such as unit self-test,integrated fault and integrated test.It can integrate testability index allocation and scheme design into an organic whole to meet the design requirements.Then,the prediction methods of fault detection rate and isolation rate based on extended correlation model are given.(4)A system-level test selection technology based on extended testability model is proposed.In this paper,the technical approach of system-level test selection is given,and the integrated test selection problem based on extended testability matrix is described.Aiming at the characteristics of the extended testability model,this paper improves the traditional artificial fish swarm algorithm and proposes a binary artificial fish swarm algorithm to select the integrated test.Compared with genetic algorithm,it has the characteristics of stability and fast convergence.(5)A testability allocation technology based on system level testability scheme is proposed.Aiming at the problem of disjointing index allocation and test scheme in traditional testability allocation,this paper studies the method of secondary iteration testability allocation considering unit mutual testing,combining the design idea and technical method of the integration of testability design and allocation.The index needs to be allocated twice in this method.The first allocation uses the arc-tangent function fault rate allocation algorithm proposed in this paper.The arc-tangent function fault rate allocation algorithm is proposed to overcome irrationality of index in the traditional allocation method.It is simple and practical.The second allocation is carried out when the testability scheme is designed to a certain extent,mainly according to the mutual testing between units to adjust the testability indicators.