CSPS topology_v 0.1

Overview

Streams are the central concept of CSPS library and are managed through the other central concept of modules. The CSPS topology translate the way streams are used to link modules and their related devices. This pages gives a presentation of topology edition standards as expected by the library.

Topology edition

Topology are given to CSPS library in a simple formated text file. First of all, devices engaged in the topology have to be given befor editing links between modules. Considering a camera device, the definition line waited by the parser is as follow :

device cam 
    model EYESIS4PI 
    tag eyesis4pi
    block 1024
end

The device keyword indicates device definition. The device type is then given, here with cam parameter. The model keyword precede camera model. To deal with ambiguities, devices are referenced with a tag. The next keyword are used to specify device parameters. In this example, the block keyword gives the block size used for data importation buffer.

For module link edition, initial streams are initiated through extraction modules. Those module are device specific and are called in the following form :

module cam-mod-DSIDE 
    eyesis4pi 
end

The module keyword indicates a module call. The called module name has to be given as next parameter. Then, the device tag of the considered device has to be given. Because this example shows extraction module call, input stream are implicitly known.

The stream modules have to consider input streams and a typical call is illustrated here :

module imu-mod-IFETI
    adis16375 
    mod-SGNDN 
    mod-IOISA
end

As extraction module call, the module name is given just after module keyword. Then a list of device tag is given according to module expectations. The modules names that initiated stream considered as input is then provided.

Topology example

An example of a simple CSPS topology is provided here. It considers three devices that are a camera, a GPS reciever and an IMU sensor. The topology example file content is given by :

device cam 
    model EYESIS4PI 
    tag eyesis4pi
    block 1024
end

device gps 
    model LS20031   
    tag ls20031   
    block 1024
end

device imu 
    model ADIS16375 
    tag adis16375 
    block 1024
    downsampling-frequency 60
    initial-conditions-x-rotation +0.0
    initial-conditions-y-rotation +0.0
    initial-conditions-z-rotation -1.57079632679489655800
    inertial-still-ranges-maximum 256
    inertial-still-ranges-minimal-length 32
    inertial-still-ranges-gyroscope-threshold 0.05
    inertial-still-ranges-acceleration-threshold 0.50
end

module cam-mod-DSIDE 
    eyesis4pi 
end

module gps-mod-DSIDE 
    ls20031 
end

module gps-mod-SGNQF 
    ls20031
    mod-DSIDE
end

module imu-mod-DSIDE 
    adis16375 
end

module imu-mod-SGSFR 
    adis16375
    mod-DSIDE
end

module imu-mod-SGNDN 
    adis16375 
    mod-SGSFR
end

module imu-mod-ISRAD
    adis16375 
    mod-SGSFR
end

module imu-mod-IOISA
    adis16375
    mod-DSIDE 
    mod-ISRAD 
end

module imu-mod-IFETI
    adis16375 
    mod-SGNDN 
    mod-IOISA
end

module imu-mod-AACEX 
    adis16375 
    mod-SGNDN
    mod-IFETI 
end

The devices are initially declared with their specific options. Then the extraction modules are called for the camera and the gps reciever. After that, the gps-mod-SGNQF GPS related module is called and is responsible of GPS measure filtering. Then the IMU is treated using all mentionned modules to achieve inertial frame integration and acceleration extraction.

Topology results

The following image gives a three dimensional illustration of the results provided by the example topology. The three major axis give the longitude direction (red), the latitude direction (green) and the altitude direction (blue). The earth-attached position are given in yellow when orientations are provided in red-green-blue colors :

On the previous image, an Eyesis4Pi camera device was mounted on a car. Two whole turns around a building located at Geneva where performed during this record.