Research Of A Mobile Virtual Instrument Platform Based On IOS

With the increasingly powerful performance and the portable feature of smart phones,the mode of virtual instrument measurement system has gradually changed from PC mode to mobile phone mode.A large number of virtual instrument APPs have sprung up on mobile application stores.However,these virtual instrument APPs have a drawback that they usually serve for a specific measuring function.If users want to achieve multiple measurement functions on a mobile phone,they can only install multiple virtual instrument APPs.There is a lack of a unified virtual instrument platform like LabView on mobile phones.To solve the problem,a mobile virtual instrument platform that support script language was developed on iOS system.It divided the commonly used virtual instrument measurement functions into several controls,and then assembled these controls into virtual instruments with a script language.By loading different virtual instrument scripts,different virtual instrument measurement applications can be generated on a mobile phone.The main work of this paper is as follows:First,based on KVO mechanism of iOS,a general architecture of iOS mobile virtual instrument platform based on virtual instrument controls and scripts was proposed.The assembly relationship of controls was described by a script,and the assembly of controls based on KVO mechanism was carried out in the platform according to the script.Then,a model of multi input and multi output interfaces was designed and implemented according to KVO mechanism.The assembly and communication between controls were realized by connecting these input and output interfaces.In addition,the display and user interaction methods of 2D controls and 3D controls were summarized,and the functions of three special functional controls namely bluetooth control,Wi-Fi control and formula control were realized.Finally,XML language was introduced to design a script for describing the assembly of controls,and DOM was used to realize the parsing and assembly of the virtual instrument script.In order to test the effect of this work,37 virtual experiments such as spectrum analysis in the course of engineering test were realized.In addition,an Arduino card was used as a signal acquisition card to realize 4 sensor measurement experiments such as heart rate measurement.In addition,a PID control experiment of a two wheeled balancing vehicle was realized through bluetooth connect.A vibration signal measurement acquisition was realized through the WiFi connection to Dongfang acquisition card.These experiments fully demonstrated the feasibility of iOS mobile virtual instrument platform developed in this paper.