## 4 Reconfiguration of the Bus Chassis Module  
The reconfiguration process is a novel method, as shown in Figure 7. It follows the steps set out below:  
1. Retrieve the module: Analyze the user needs and retrieve the appropriate modules that meet these requirements from the module database. 2. Check and reconfigure the module interface: The module interface is checked to determine if the two pre-connected modules satisfy the interface-type conditions. If the two module interface types are the same, it is necessary to reconfigure one of them. 3. Retrieving or constructing the digital expression model of the pre-connected module interfaces: The digital expression model of the plug interface includes the location matrix \(M\) and the relative characterization matrix \(Q\) of the connection section. The digital expression model of the socket interface includes the location matrix \(A\) and the acceptable range matrix \(B\). 4. Matching and reconfiguration of the position of the pre-connected structural components of the interface: The connection matching of the position of the interface structural components is evaluated by the parent and child relationship between the location matrix \(M\) of the plug interface and the location matrix \(A\) of the socket interface. Adjustable components are reconfigured to achieve connectivity for full overlap of the interface node network. 5. Construction and operation of the process matrix: Once the module is reconfigured during the connection-matching process, the reconfiguration process matrix \(Z\) is constructed. Then, the reconfiguring of the module, the position, or the section size of a component changes, and the change is written into the matrix \(Z\) in the form of coordinates, thus forming the reconstruction process matrix. The characterization matrix \(Q^{\prime}\) of the connection section of the plug interface and the acceptable range matrix \(B^{\prime}\) of the socket interface are solved thereafter. 6. Matching and reconfiguration of the connection section of the pre-connected structural components: Based on step (5), matching of the connection section of the interface structural components is evaluated by the parent and child relationship between the characterization matrix \(Q^{\prime}\) for the connection section of the plug interface and the acceptable range matrix \(B^{\prime}\) of the socket interface. Meanwhile, the connection section of the adjustable structural components is reconfigured to meet the requirements of the matching relationship. 7. Completion of the module reconfiguration: The connection-matching relationship of the module interface is checked, and then the pre-connected module is reconfigured based on the calculation results. The module can be fine-tuned according to the actual engineering needs, until the final design of the module is completed. Figure 7: Process of module reconfiguration based on the interface digital expression model. As mentioned in step (5), the reconfiguration process matrix \(Z\) of the module was constructed based on the results of the above-mentioned process. The characterization matrix \(Q^{\prime}\) of the connection section of the plug interface and the acceptable range matrix \(B^{\prime}\) of the socket interface are solved by the equation below:  
\[Q^{\prime}=(M+Z_{1})\times\underbrace{\big{(} \begin{array}{cccc}1&1&\cdots&1 \end{array} \big{)}}_{\big{(} \begin{array}{cccc}1&1&\cdots&1\end{array} \big{)}} +Q \tag{1}\]  
_Row matrix, a total of n elements, each element is 1_  
In Equation (1), \(Q^{\prime}\) is the characterization matrix of the connection section of the plug interface; \(M\) is the location matrix of the plug interface without reconfiguration; \(Z_{1}\) is the process matrix of the reconfiguration of the plug interface; and \(Q\) is the relative characterization matrix of the connection section of the plug interface.