Study Of Experimental Testing And Evaluation Approaches On The Operation Performance Of Automobile Multi-Function Switches

The automobile multi-function switch (AMFS) is one of the important machinery-electronics assembles in automobile products. In view of the much higher technical requirements on a final automobile product as well as its important assembles such as the AMFS, manufacturers related to the AMFS consider it very urgent to evaluate correctly its technical performances so as to make sequential improvements on the product design and manufacturing. Besides, under the modern paradigms of manufacturing and management, a large percentage of automobile manufacturers have tuned their conventional production mode of making all by themselves to that of outsourcing such assembles as AMFSs. This kind of change also makes it much emphasized for both buyers and suppliers of AMFSs to make rapid and efficient evaluation on the product performance.Although in the literature some factors that may affect the operation performance evaluation of the AMFS have pointed out, the existing mechanisms of influences of the operation performance on the product's performance and the collective evaluation method of the product's performance have not been presented. Just due to this shortcoming of theoretical studies, it occurs that automobile manufactures have to check the performance of AMFS only by technicians'experiential feelings, which is resulted from the lack of technical standards and detecting procedures.In view of the two aspects as mentioned above, this dissertation has considered the AMFS as a human-machinery system and presented the mensurable evaluation model for detecting the operation performance of AMFS (OPAMFS). In particular, the main research contributions of this dissertation are as follows.1. The various factors that may affect OPAMFS have been systematically analyzed and classified into factor groups by the theory of factorial analysis. 2. On the basis of summarizing and developing current methods of evaluation weights, an approach to weight determination on the OPAMFS, i.e., the pairwise judgment matrix method improved by reducing the comparing reference-point influence, is presented. By this weight-determination method, the influence degree of factors on the OPAMFS is identified. The derived weight results show that the important factors that decisively affect the OPAMFS are the shifting force and its displacement. As a result, these two factors are selected as major objects of quantitative study in the next.3. To make correct measurements on AMFSs'technical parameters of force-characteristic and to find out the principles between various influence factors and the OPAMFS, a testing system is designed and established. The major functions of this system areas follows:Firstly,it can well make on-line checking on the operation forces that a driver uses in various shift positions.Secondly, it can well show the curve of displacement respective to operation forces. The testing system reflects the curve of displacement respective to operation forces in the real-time manner, and thus make the experiment process well controllable.Thirdly, it can make functions either in manual pattern or in automatic pattern. The manual pattern can make the testing system well imitate a driver's operation process of shifting a AMFS. On the other hand, in the automatic pattern the testing system is capable of ensuring the shifting operation in the same experiment conditions, which can well satisfy the need of comparing parameters differences of various kinds of AMFSsFourthly, it ensures that the operation speed of machinery hand is adjustable in the automatic pattern.4. Though testing and analyzing various parameters of AMFSs, influence relationships between all the parameters and the OPAMFS are identified respectively, based on which the final evaluation parameters of OPAMFS have been presented. The analysis results show that in the shifting duration of AMFS the distribution region of shifting force and that of the inflexion force and the dispersed states of the two forces, are remarkably correlated with OPAMFS. Based on the derived analysis results and the identified principles, the set of evaluation indices for OPAMFS have been concluded as shifting force distribution (SFD) region, dispersed states of SFD, and dispersed states of shifting force displacement.5. From the viewpoints of the real world application, two approaches to the evaluation of OPAMFS, i.e., that for production online testing and that for comparing and selecting products provided by different suppliers, are finally presented in the dissertation.The approach for production online testing (APOT) is devised to serve two kinds of production requirements of OPAMFS evaluation ranks, i.e., two ranks and multiple ranks. For the two-rank evaluation requirement, APOT can make a qualified or unqualified conclusion on a batch of AMFS products. The particular two-rank evaluation procedure of APOT are as follows: (1) taking the shifting force ( F_m ) as the evaluation parameter, and measuring the F_m values of a batch of AMFSs; (2) calculating the average shifting-force value of the AMFS batch; (3) using a controlling standard of shifting-force fluctuation, denoted byδF_m ,and the formulae of F_m -δF_mh/2≤F_m≤F_m+δF_mh/2 to make an evaluation conclusion on the production batch. If the formulae is satisfied for a product batch, the batch is then concluded as qualified; else, the batch of products is as unqualified. The multi-rank evaluation procedure of APOT is a development of the two-rank evaluation procedure, and it evaluates a product batch by such a rank system as good, general and poor quality.The approach for comparing and purchasing products provided by different AMFS suppliers is devised with the consideration of a buyer's purchasing process. The particular evaluation procedure are as follows: (1) selecting the same amount of products provided by different suppliers; (2) taking the distribution region of shifting force, denoted byΔF_m , and the distribution region of shifting-force displacement, denoted byΔS , as evaluation parameters, and measuring the values of shifting force ( F_mi) and its shifting duration ( t_i) equivalent toΔS ; (3)finding the values ofΔF_m andΔS_i for the set of selected products.(4) ranking the products provided by different suppliers according to the values ofΔF_m andΔS_i. Note that the smallerΔF_m andΔS_i are, the better is the product operation performance.