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SRS OBJECT DATABASE

The package srs_object_database allow storing information about an object in a database postgresql. It provides also service to insert, update and retrieve this information.

Installing and Configuring Database

Data about objects, such as: mesh,grasp,surface points, images, is stored in file inside a file repository while the database keep track, for each object, of the data files associated with it.

Postgresql Database

The first step is to install postgresql database. General information on how to install and configure the database are described in Installing a PostgreSQL Server.

Database Creation

After the previous step is completed an empty database must be created using a script found inside the folder db_scripts of the package srs_object_database. The first time you need to create an empty database with the internal structure and data. To do this simply enter the db_scripts folder and run:

 . createDatabase.sh databaseName

NOTE: database name must not include capital letters.

This will create an empty database named databaseName. You can usethis script also to create additional database in case you want to do some test. Also if you want to create an empty database you can use the following script:

 . createemptyDb.sh databaseName

In general if you have already a user which is different from 'willow' and database should be assigned to this user, you can specify an additional parameter which is the name of the sql user to be used to create database. This second command can be used in all previous scripts and the one used to restore and delete database. For example to create a database with owner the user 'srs_user', which must be already created before executing the script.

 . createemptyDb.sh databaseName srs_user

Database Restore

Database can be restored to original data using the following script:

 . resetDatabase.sh databaseName

PS: warning this command will drop the previous database so your data will be lost!

Database Delete

Database can be deleted completely in some case:

 . deleteDatabase.sh databaseName

PS: warning this command will drop the previous database so your data will be lost!

File repository

After the database creation is required to create the fileRepository which can be retrieved in the git repository git file share repository. This share contains a root folder named ros_data_files Upload the laters version of the repository that will be syncronized with the latest data created by the script in the folder db_scripts.

Configuration of SRS object services

Environment configuration is passed to services through the launch file which run srs_object_database services. The file called srs_db.launch is stored in the folder launch of the srs_object_database.

<launch>

   <param name="instanceName" value="localhost" type="str"/>
   <param name="dbPort" value="5432" type="str"/>
   <param name="databaseName" value="srs_template_database" type="str" />
   <param name="userName" value="user" type="str" />
   <param name="pwd" value="pwd" type="str" />
   <param name="repoPath" value="/path_to_ros_fileshare/ros_data_files/" type="str"/>

   <node pkg="srs_object_database" name="get_model_server" type="get_model_server" output="screen"/>
   <node pkg="srs_object_database" name="get_model_mesh" type="get_model_mesh" output="screen"/>
   <node pkg="srs_object_database" name="get_model_surf" type="get_model_surf" output="screen"/>
   <node pkg="srs_object_database" name="get_model_urdf" type="get_model_urdf" output="screen"/>
   <node pkg="srs_object_database" name="get_model_pcl" type="get_model_pcl" output="screen"/>
   <node pkg="srs_object_database" name="get_model_grasp" type="get_model_grasp" output="screen"/>
   <node pkg="srs_object_database" name="get_model_img" type="get_model_img" output="screen"/>
   <node pkg="srs_object_database" name="insert_object_service" type="insert_object_service" output="screen"/>
   <node pkg="srs_object_database" name="dispacherService" type="dispacherService" output="screen" />


</launch>

The configuration is controlled by the param element inside the launch file.

Localhost set the ip addres of the postgreSQL server. For local installation use 'localhost'.

   <param name="instanceName" value="localhost" type="str"/>

dbPort set the port on which the database server is listening. Default for postgres is 5432

   <param name="dbPort" value="5432" type="str"/>

databaseName must be set to the name of database created before.

   <param name="databaseName" value="srs_template_database" type="str" />

username must be set to the user which own read and write right on the srs_database.

   <param name="userName" value="user" type="str" />

pwd must provide the password for the user specified at the previous point.

   <param name="pwd" value="willow" type="str" />

repoPath is used to set the root folder where the file repository is stored. Note that at the end / is added otherwise services will fail to return object data.

   <param name="repoPath" value="/path_to_ros_fileshare/ros_data_files/" type="str"/>

Once this parameters are correctly configured the services provided by srs_object_database are ready to be run.

example_node_name

Example description what the node is doing.

Services

insert_object_service (srs_object_database/InsertObject) dispacherService (srs_object_database/GetData) get_model_server (srs_object_database/GetObjecId) get_model_mesh (srs_object_database/GetMesh) get_model_img (srs_object_database/GetImg) get_model_pcl (srs_object_database/GetPcl) get_model_grasp (srs_object_database/GetGrasp) get_model_surf (srs_object_database/GetSurf) get_model_urdf (srs_object_database/GetUrdf)

Usage/Examples

In order to run all ros services for both insert and retrieval execut the launch file.

roslaunch srs_object_database srs_db.launch

clientTest

A simple client has been created to allow inserting and updating information on database. This service make use of service provided by srs_object_database and should be used only for the purpose of testing data. It is executed with rosrun. Is mandatory to execute the srs_object_database launch file to start all services before running the client.

 rosrun srs_object_database clientTest params

After running the client it will be possible to specify an action to take:

Choose between [i]nsert,[u]pdate,[r]etrieve functionality 

The selection of the action should be consequence of the input parameters.

how to search data with clientTest

clientTest can be used to retrieve data. To achieve this provide parameters as specified in this section and use r to specify that you want to retrieve data. The client calls the srs_object_database/GetObjecId service and by command line is possible to search in database for object id using the following combination of input:

Search all objects:

Providing all as parameter allows retrieve all object currently stored in the sql database.

 rosrun srs_object_database clientTest all

Search by object id:

It is possible to specify id as key search and provide a numeric object id to verify if an object with a give id is present in database and in case retrieve its infomation.

 rosrun srs_object_database clientTest id object_id

Search by object category: It is possible to search all object which have a specified class. Use class as first parameter and provide an object_class such as glass.

 rosrun srs_object_database clientTest class object_class

Search by object name: It is possible to search a specific object using its name. Use nameas first parameter and provide an object_name such as "milkBox1".

 rosrun srs_object_database clientTest class object_name

how to force retrieve of data with clientTest without user interaction

Adding the key 'retrieve' after the previous command will allow the client to direclty retrieve object data, the general data, without requiring additional user interaction.

 rosrun srs_object_database clientTest testInputInsert.txt update

how to retrieve data with clientTest

after an object as been retrieved the clienTest allow to return the data using the command line:

[ INFO] [1321287335.121522116]: Retrieved 0
[ INFO] [1321287335.121909683]: Enter number of menu option you wish:
[ INFO] [1321287335.122290084]: 1 Mesh
[ INFO] [1321287335.122558812]: 2 Point Cloud
[ INFO] [1321287335.122709195]: 3 Image
[ INFO] [1321287335.123171475]: 4 Grasp
[ INFO] [1321287335.123527822]: 5 Feature Points
[ INFO] [1321287335.124457739]: 6 Urdf
[ INFO] [1321287335.124734287]: 7 List selected objects id - tag - description - size
[ INFO] [1321287335.125110589]: 0 Exit

Selecting 3, for example, will allow to retrieve, if available, image of the current object retrieved by the search.

how to insert data with clientTest

Inserting new object is usefull to test functionality of other components which make use of database. clientTest provide such functionality in order to allow developer to test object information and services. A file with a list of property for a give object is provided and then the client retrieve the files with its data and load them in an appropriate way to be sent to InsertObject service.

The input file must be stored inside the Input folder available in the git repository git file share repository with the data files. The input file is

id
name 
category 
description 
x-size 
y-size 
z-size 
basic-shape 
graspable 
urdf
image
grasp
mesh
typeMesh 
pcl 
surf 
end

Each attribute will be insert in database in the respective table. For object such as: urdf,image,grasp,mesh,pcl or surf. It mush be provided the filename, with extenstion, of the file containing the data to be inserted. This file must be placed in the Input folder inside the file repository. Once the data will be inserted, a file will be created inside the appropiate folder of the file repository. One example is testInputInsert.txt which allow to insert a new object simply calling the clientTest:

 rosrun srs_object_database clientTest testInputInsert.txt

In the output you will be able to see which id is assigned to this new object.

how to force insertion of data with clientTest without user interaction

Adding the key 'insert' after the previous command will allow the client to direclty insert object and its data without requiring additional user interaction.

 rosrun srs_object_database clientTest testInputInsert.txt insert

how to update data with clientTest

Updating an object with the client work in the same way as the insert, the only difference is that when providing an input file you will change information so that the service will repleace old information with the new information or will insert additional information that previouvsly where not provided. It is mandatort that in the input file the id will not be empty, otherwise it will be interpreted as an insert, but you will provide the id of the object to be updated.

how to force update of data with clientTest without user interaction

Adding the key 'update' after the previous command will allow the client to direclty update object and its data without requiring additional user interaction.

 rosrun srs_object_database clientTest testInputInsert.txt update

general usage of srs_object_database services

The clienTest which is used for test purpose, build request for srs_object_database services. In run time scenario those are the services that other components should invoke.

Inserting/Updating Objects

To insert and update object data the service "InsertObject" should be used. Note that you should provide a type of mesh (usually iv.txt) and an Image type such as: icon,top-view,front-view.

# insert   create a new object
# update   update replacing old data or adding missing data

# the model id provide it only in case you want to update an already existing object
int32 model_id
...

# data inserted by service must be serialized in case of uint8

uint8[] pcl
uint8[] fpt
sensor_msgs/Image img
string image_type
uint8[] data_grasp
#mesh data and type extension ex dae, iv.txt
uint8[] data_mesh
string meshType
uint8[] urdf

---

# is/ids of objects inserted usefull to know which id the service has associated to # a new objet

int32 model_id

Getting Objects data

To retrieve data a dispacher service can be invoked. It has some boolean flag which must be put to 1 to indicate the data that should be retrieved if available for the provided objects ids.

...

bool mesh
bool pcl
bool surf
bool image
bool grasp
bool urdf
...

Getting objects id of objects

In order to get objects ids the getObjectId service must be invoked. It requires a type parameters which specify the search criteria as well as an item which is the value of the key provided for the search. It can be specified as type: all, to retrieve all objects id in database, name, to search a specific object based on its name, class, to search ids of object using their class.

# retrieves the object id for a class of items
# type of search. use item if want to search on item description such as glass
# use id if want to search data about a specific object and you know its id
string type
# the search key, could be an object description such as glass or an id i.e. 10000
string item
---

This service will return general information for the objects retrieved, such as name, description, size.

Calling a specific service

While using getData allow to retrieve more information at the same time, if the object id is know and only a specific service need to be called it is possible to just call the respective service. For instance if it is required to get only image information for a give object id, the service getImg can be directly called. In this specific case calling directly this service allow to use additional parameter such as the type of the image to be retrieved for the object id provided in the request message. It works like a filter to select, for instance, only icon image.

# retrieves the object id for a class of items

# is/ids of objects of which we will retrieve information
int32[] model_ids
# apply a filter on the search to get only a subset of image
# all or icon or top-view
string type

---

# the outcome of the end service
string return_response
# array of message containing image information retrieved
srs_object_database/img[] msg

Managing object category

The database allow management of knowledge category associated to an object. The category could be managed through services or clientTest with the following command line:

 rosrun srs_object_database clientTest category

The key 'category' tells the client to enter a submenu where it is possible to query database for the existing category, insert new category, search category associated with an object.


2020-01-18 13:13