Research Of The Road-lineation Vehicle Positioning System Based On DSP

In recent years, the demands of highway maintenance have been enhanced with rapiddevelopment of superhighway in China. Road-lineation is one part of these demands. Roadtraffic markings, which are very important for road control and traffic leading, include lines,arrows, characters, vertical plane signs, protuberant signposts, contour signs, etc. In thepast, most lineation work was manual. Road-lineation instruments used today are higherefficiency, but still have many disadvantages such as poor automatic movement ability, badworking environment, high price and so on. Therefore, it is of great practical importance todevelop intelligent road-lineation system.This paper focuses on study on the intelligent road-lineation vehicle positioning system,which is based on ultrasonic ranging measurement. The system works by detecting the echoof ultrasonic wave from simulated guardrail or curbstone on road to positing theroad-lineation vehicle.LM1812 is adopted to transmit and receive ultrasonic, which can simplify the designprocess, reduce the interference and improve the stability of the system. As the majorcontrol section, TMS320LF2407, digital signal processor (DSP) controller designed by TI,is used to control the ultrasonic ranging system considered for its fast calculating abilityand distinguish motor control function. TMS320LF2407 is a controller just for motorcontrol, it has high-performance processing capabilities, optimized for digital motor andmotion control applications, provides non-intrusive real-time capabilities required to debugdigital control systems. A complete suite of code-generation tools from C compilers to theindustry-standard Code Composer Studio debugger supports this controller. Numerousthird-party developers offer not only device-level development tools but also system-leveldesign and development support. A serial communications interface (SCI) is integrated onall devices to provide asynchronous communication with other devices in the DSP system.After debugging and examining, the system can make performance as expected.Static and dynamic tests were conducted with wall, simulate guardrail and curbstone.Under the static conditions, with the data analysis, the range of the ultrasonic rangingsystem was found and the conditions, under which the system can correctly measure the distance between the vehicle and simulate guardrail and curbstone was identified. Dynamicexperiment showed that it is available to positing the truck by using the simulate guardrailas reference, but there are great disadvantages to locate the truck by using curbstone asreference.