Development Of Radar Display Control System Based On VxWorks And Qt

It is a basic requirement for a radar display and control system to process the data received in real time.By previous experience,to achieve the interface with the external data and to process the data through VxWorks is a very reasonable choice.And on this basis,the requirements for the display system of users must be met constantly,more friendly graphical interface must be developed,and in the meanwhile,the display function should be modularized.Thus the early management and the post-maintenace of the software project becomes easy,and the developing cycle of the interface is shortened.In the past,the design of graphical interface was usually developed by means of WindMx,a component of the VxWroks library.The effect of 2D display couldn't meet the requirement of current use.Even though the ZINC plug-in produced by WindRiver Company can be purchased to improve the effect,the process-oriented encoding mode limits the general applicability of the newly developed module.An advantage of Qt is that it can fill the holes exesiting in WindML.Under this background,this paper introduces a radar display control system which combines the embedded real time operationg system based on VxWorks and Qt technology.This system not only implements many functions,such as the transmitting and receiving of the radar data via the serial port/the network,the recording and playback of data,human-computer interactions,window display of videos,data processing and update of graphical interface,but also meets the real-time requirements of the system on the basic of similar multimedia display effect.Firstly,in this paper,the requirements of this radar display and control system is analyzed,the use-case model for the functional requirements of the system is structured.The performance,reliability,safety,maintenance and other non-functional requirements of the system and its design constraints are analyzed as well,and the specification of the requirements of the system is determined.Then the hardware and software architecture of system is designed.The system is divided into nine modules--network receiving module,network sending module,a serial port receiving module,the record module,playback module,data processing module,the screen refreshment module,control processing module,and video display module.11 tasks are designed,the watchdogs and other sub-tasks are created through the main task,and a multi-task paralleled working mode is formed under the drive by data and manipulation.Secondly,research on key technologies is carried out.(1)We propose VxWorks and Qt hybrid programming technology,solving the problem about the failure in the direct communication between Qt main thread and VxWorks through semaphores and message queue.A sub-thread is created in Qt,the interaction between VxWorks and the Qt sub-thread is completed through the semaphore and the shared memory mechanism,the interaction between the Qt sub-thread and the Qt main thread is completed through the signal slot mechanism.(2)We propose a strong real-time shared memory multitask coordinated operation mechanism.It reasonably assigns parallel task level,reduces redundant signals,and thus avoids deadlock,starvation and priority inversion.(3)We propose 62.5ms real-time display assurance technology.The time-sharing processing is conducted on the data according to the degree of its importance.The block processing is conducted on the screen update according to the scope of the displayed objects,so the problem that the multi frame data is for refreshment at the same time is avoided by constructing screen update mechanism and the tolerance mechanism reasonably.In this paper,through the program flow diagram,nine modules are designed in detail.The bootstrap file is generated by compiling the BLP project,the target code is compiled by compiling the DKM project,the VxWorks image containing a target code and a drive is compiled by compiling VIP project,and then the system is integrated into VxWorks and deployed to the established hardware platform.At last,a series of test cases is designed for the functional test of the system;the performance test of the system is conducted on the basis of the analysis of the test data and System Viewer;the system reliability test is conducted in the way of checking,static analysis and uninterrupted operation.At present,the system has passed all the tests and successfully installed in the domestic vehicle miniaturized radar vehicle.