31-05-2012, 03:46 PM
EMBEDDED COMPUTING PLATFORM FOR LIDAR SYSTEM
[attachment=23722]
Abstract
The processing architecture of DIAL system is heterogeneous, complex and requires state of art firmware. They are based on variety of processors ranging from PIC microcontrollers, DSP processors, FPGA and PowerPC based embedded microcontroller etc accompanied with Embedded S/w. Thus this makes such system well suited to Hardware – Software Co-design techniques, which facilitates the simultaneous optimizing of the hardware and software architectures of the system to meet all the system requirements.
SYSTEM INTRODUCTION
Differential Absorption Lidar (DIAL) Systems are advantageously used these days to detect very small concentrations of trace gases in the atmosphere. There is a requirement to interrogate and search for the presence of any one or more of toxic agents and the absence of the remaining agents out of a large number (about 20 or so) of possible agents at distances up to 5 kilometers in the environment with the help of a ground-based multi-wavelength DIAL system, which is based on pulsed, tunable laser sources in the wavelength bands of 2-5 micron and 9.2-10.8 micron. The Laser beam from these sources is directed in the atmosphere in a predefined direction & scans the atmosphere to detect the toxic agents.
. SYSTEM ARCHITECTURE
The primary features of DIAL-C&PU (Controlling & Processing Unit) unit is to control the firing sequence of Laser Sources (9.2-10.8 micron and 2-5 micron), tuning of wavelength, processing of return signal and precision movement control of scanning mirror in azimuth and elevation plane. This must also provide some operator interface so that some external commands can be issued to the System. Once the system starts scanning, if it encounters the interested region it must be scanned precisely with both the laser sources working simultaneously till some Agent of Interest is encountered.
CHOICE OF HARDWARE
AND SOFTWARE PLATFORM
The Hardware architecture for such system is based on the configuration that it can act as LIDAR Embedded Controller and has the necessary on board resources for providing computation, real time controllability and I/O intensive functionalities / Interfacing.
Conclusions
The DIAL C&PU being developed is a complex task which involves a hardware and software co- design approach. The requirement specifications for such kind of application are required to be analysed in detail before selection of Hardware and Development tools. Since the development cycle for RTES normally follows iterative models, which caters to the addition of functionality with each build of the system (H/w and S/w). Therefore all the developments are required to be carried out considering future expansion and debugability. The scope of this paper is limited to design of Lidar Embedded Controller and its related S/w only. However the entire performance of DIAL C&PU system also depends on other subsystems involved.
[attachment=23722]
Abstract
The processing architecture of DIAL system is heterogeneous, complex and requires state of art firmware. They are based on variety of processors ranging from PIC microcontrollers, DSP processors, FPGA and PowerPC based embedded microcontroller etc accompanied with Embedded S/w. Thus this makes such system well suited to Hardware – Software Co-design techniques, which facilitates the simultaneous optimizing of the hardware and software architectures of the system to meet all the system requirements.
SYSTEM INTRODUCTION
Differential Absorption Lidar (DIAL) Systems are advantageously used these days to detect very small concentrations of trace gases in the atmosphere. There is a requirement to interrogate and search for the presence of any one or more of toxic agents and the absence of the remaining agents out of a large number (about 20 or so) of possible agents at distances up to 5 kilometers in the environment with the help of a ground-based multi-wavelength DIAL system, which is based on pulsed, tunable laser sources in the wavelength bands of 2-5 micron and 9.2-10.8 micron. The Laser beam from these sources is directed in the atmosphere in a predefined direction & scans the atmosphere to detect the toxic agents.
. SYSTEM ARCHITECTURE
The primary features of DIAL-C&PU (Controlling & Processing Unit) unit is to control the firing sequence of Laser Sources (9.2-10.8 micron and 2-5 micron), tuning of wavelength, processing of return signal and precision movement control of scanning mirror in azimuth and elevation plane. This must also provide some operator interface so that some external commands can be issued to the System. Once the system starts scanning, if it encounters the interested region it must be scanned precisely with both the laser sources working simultaneously till some Agent of Interest is encountered.
CHOICE OF HARDWARE
AND SOFTWARE PLATFORM
The Hardware architecture for such system is based on the configuration that it can act as LIDAR Embedded Controller and has the necessary on board resources for providing computation, real time controllability and I/O intensive functionalities / Interfacing.
Conclusions
The DIAL C&PU being developed is a complex task which involves a hardware and software co- design approach. The requirement specifications for such kind of application are required to be analysed in detail before selection of Hardware and Development tools. Since the development cycle for RTES normally follows iterative models, which caters to the addition of functionality with each build of the system (H/w and S/w). Therefore all the developments are required to be carried out considering future expansion and debugability. The scope of this paper is limited to design of Lidar Embedded Controller and its related S/w only. However the entire performance of DIAL C&PU system also depends on other subsystems involved.