#Methodology

The RAPP Knowrob wrapper ROS node is needed to expose specific services to the other ROS nodes and RPSs (similarly to the MySQL wrapper concept). In our implementation, the pure KnowRob ontology was enhanced after the insertion of extra classes derived from the OpenAAL ontology, as well as others needed to implement the desired RApps.

The services of the RAPP Knowrob wrapper are detailed below.

#ROS Services Each service is analyzed below.

Subclasses of

This service was created in order to return the subclasses of a specific ontology class. Apart from the basic functionality, one can perform recursive search in the ontology and not just in the classes’ immediate lower level connections.

Service URL: /rapp/rapp_knowrob_wrapper/subclasses_of

Service type: ```bash

Contains info about time and reference

Header header

The class whose subclasses we want

string ontology_class

True if the query is recursive

bool recursive

Container for the subclasses

string[] results

Possible error

string error

true if successful

bool success ```

Superclasses of

This service was created in order to return the superclasses of a specific ontology class. Apart from the basic functionality, one can perform recursive search in the ontology and not just in the classes’ immediate higher level connections.

Service URL: /rapp/rapp_knowrob_wrapper/superclasses_of

Service type: ```bash

Contains info about time and reference

Header header

The class whose superclasses we want

string ontology_class

True if the query is recursive

bool recursive

Container for the superclasses

string[] results

Possible error

string error

true if successful

bool success ```

Is sub-super-class of

This service was created in order to investigate two classes’ semantic relations. Apart from the basic functionality, one can perform recursive search in the ontology and not just in the classes’ immediate higher or lower level connections.

Service URL: /rapp/rapp_knowrob_wrapper/is_subsuperclass_of

Service type: ```bash

Contains info about time and reference

Header header

The parent class

string parent_class

The child class

string child_class

True if the query is recursive

bool recursive

True if the semantic condition applies

bool result

Possible error

string error

true if successful

bool success ```

Create instance

This service was created in order to create an instance related to a specific ontology class. One can also store a file and comments. This service is not public but it is employed from the RIC nodes. Ownership of the new instance is assigned to the provided user which is an instance of the class Person within the ontology. The assignment involves setting an ontology attribute. The username provided in the input is the username of the user in the MySQL database and not the name of the user’s instance in the ontology. The second is also stored within the MySQL database the service acquires it by querying the MySQL database (with the username as input) through the MySQL wrapper. In case no ontology instance name (alias) is defined a new one is created utilizing the Create ontology alias service described below and the Ontology and MySQL database are updated accordingly.

Service URL: /rapp/rapp_knowrob_wrapper/create_instance

Service type: ```bash

Contains info about time and reference

Header header

The user to whom the instance belongs

string username

The instance’s ontology class

string ontology_class

A file url (if needed)

string file_url

Comments (if needed)

string comments

A unique id

string instance_name

Possible error

string error

true if successful

bool success ```

Create ontology alias

This service was created in order to create an alias for a user within the ontology. A user ontology alias is basically an instance of the class Person that exists within the ontology. The user’s ontology alias is stored within the MySQL database in the respective column of the table User. This service accepts the MySQL username of the user and performs a check by querying the MySQL database in order to identify if an ontology alias has already been defined. If that is the case it simply returns that ontology alias. If not, it creates the ontology alias instance within the ontology, stores this information in the MySQL database and finally it returns the newly created user ontology alias. In the case that a new ontology alias is created both the ontology and the MySQL need to be updated. The service ensures that either both are updated in tandem or in case one fails no modifications take place in the other. This is critical to preserving proper synchronization between the MySQL database and the ontology.

Service URL: /rapp/rapp_knowrob_wrapper/create_ontology_alias

Service type: ```bash

Contains info about time and reference

Header header

The user to whom the instance belongs

string username

A unique id

string ontology_alias

Possible error

string error

true if successful

bool success ```

User instances of class

This service allows an ML algorithm to retrieve user-specific information in order to compute and extract personalized data. This service is not exposed via a HOP service, but is employed internally by other RIC nodes. It returns all the ontology instances that are assigned to the ontology alias of the provided user. The ontology alias is acquired again by querying the MySQL database.

Service URL: /rapp/rapp_knowrob_wrapper/user_instances_of_class

Service type: ```bash

Contains info about time and reference

Header header

The user whose instances must be returned

string username

The ontology class whose instances we desire

string ontology_class

The instances

String[] results

Possible error

string error

true if successful

bool success ```

Load / Dump ontology

Since the KnowRob ontology framework does not provide online storage functionality, the ontology (along with the new information) must be stored in predefined time slots. This way, if a system crash occurs, the stored data won’t be lost but can be retrieved using the Load ontology ROS service. Both of these services have a common representation.

Service URL: /rapp/rapp_knowrob_wrapper/load_ontology Service URL: /rapp/rapp_knowrob_wrapper/dump_ontology

Service type: ```bash

Contains info about time and reference

Header header

The file intended for loading or dumping the ontology

string file_url

Possible error

string error

true if successful

bool success ```

Create cognitive test

This service creates a new cognitive exercise test in the ontology as an instance. This service is not exposed via a HOP service, but is employed internally by the RAPP Cognitive exercise system node. It accepts as input that parameters of the test which include its type, subtype, difficulty, variation and file path and returns the name of the ontology instance created.

Service URL: /rapp/rapp_knowrob_wrapper/create_cognitve_tests

Service type: ```bash

Contains info about time and reference

Header header

The type of the test

string test_type

The sub type of the test

string test_subtype

The difficulty of the test

int32 test_difficulty

The variation id of the test

int32 test_variation

The file path where the test is located

string test_path

The created test name

string test_name

Possible error

string error

true if successful

bool success ```

Return cognitive tests of type

This service returns all cognitive tests of the given type that exist within the ontology. This service is not exposed via a HOP service, but is employed internally by the RAPP Cognitive exercise system node. It accepts as input the test type and returns the names of the tests and their parameters which include their subtypes, file paths, difficulties and variation ids.

Service URL: /rapp/rapp_knowrob_wrapper/cognitive_tests_of_type

Service type: ```bash

Contains info about time and reference

Header header

The type of the tests to be returned

string test_type

The names of the tests

string[] tests

The subtype of the tests

string[] subtype

The file paths of the tests

string[] file_paths

The difficulty of the tests

string[] difficulty

The variation of the tests

string[] variation

Possible error

string error

true if successful

bool success ```

Record user cognitive test performance

This service records the user’s (patient’s) performance on a given test at a given time. Performance is measured as integer value in the 0-100 range. This service is not exposed via a HOP service, but is employed internally by the RAPP Cognitive exercise system node.

Service URL: /rapp/rapp_knowrob_wrapper/record_user_cognitive_tests_performance

Service type: ```bash

Contains info about time and reference

Header header

The name of the test

string test

The type of the test

string test_type

The ontology alias of the patient who is taking the test

string patient_ontology_alias

The score the patient achieved in the test

int32 score

The timestamp at which the test was performed

int32 timestamp

The name of the cognitive test performance entry

string cognitive_test_performance_entry

Possible error

string error

true if successful

bool success ```

Return user cognitive test performance

This service returns all the tests of the requested type that a specific user (patient) has undertaken along with the scores achieved, the time at which they were performed and the difficulty and variation ids of the tests. This service is not exposed via a HOP service, but is employed internally by the RAPP Cognitive exercise system node.

Service URL: /rapp/rapp_knowrob_wrapper/user_performance_cognitve_tests

Service type: ```bash

Contains info about time and reference

Header header

The ontology alias of the patient

string ontology_alias

The type of the tests of interest

string test_type

The names of the tests

string[] tests

The scores of the tests

string[] scores

The difficulty of the tests

string[] difficulty

The variation ids of the tests

string[] variation

The timestamps at which the tests were performed

string[] timestamps

Possible error

string error

true if successful

bool success ```

Register image object to ontology

This service will register an image, annotated by the rapp_caffe_wrapper to the ontology.

Service URL: /rapp/rapp_knowrob_wrapper/register_image_object_to_ontology

Service type: ```bash

Contains info about time and reference

Header header #the user's ontology alias string user_ontology_alias #the ontology class of the to be registered object string object_ontology_class #the caffe class of the to be registered object string caffe_class #the path to the image representing the object string image_path #timestamp of the time of registration

int32 timestamp

The results of the query

#the name of the registered object entry string object_entry #possible error string error #trace information string[] trace #true if service call was successful bool success ```

Retract user ontology alias

This service will remove the ontology alias of a user from the ontology.

Service URL: /rapp/rapp_knowrob_wrapper/retract_user_ontology_alias

Service type: ```bash

Contains info about time and reference

Header header #the user ontology alias to be retracted

string ontology_alias

The results of the query

#possible error string error #trace information string[] trace #true if service call was successful bool success ```

Clear user cognitive test performance records

This service will remove all cognitive test performance records of a user from the ontology.

Service URL: /rapp/rapp_knowrob_wrapper/clear_user_cognitive_tests_performance_records

Service type: ```bash

Contains info about time and reference

Header header #the username of the user whose records will be cleared string username #specify clearing the records of this test type onle

string test_type

The results of the query

#possible error string error #trace information string[] trace #true if service call was successful bool success ```

#Launchers

Standard launcher

Launches the rapp_knowrob_wrapper node and can be launched using ``` roslaunch rapp_knowrob_wrapper knowrob_wrapper.launch ```

#HOP services

Ontology-SubClasses-Of

Service-Url

``` /hop/ontology_subclasses_of ```

Service request arguments

```js { query: '' } ```

• query (String): The query to the ontology database.

Service response

application/json response.

```javascript { results: [], error: '' } ```

• results (Array): Query results.
• error (String): Error message, if one occures.

```javascript { results: [ 'http://knowrob.org/kb/knowrob.owl#Oven', 'http://knowrob.org/kb/knowrob.owl#MicrowaveOven', 'http://knowrob.org/kb/knowrob.owl#RegularOven', 'http://knowrob.org/kb/knowrob.owl#ToasterOven'], error: '' } ```

Ontology-SuperClasses-Of

Service-Url

``` /hop/ontology_superclasses_of ```

Service request arguments

```js { query: '' } ```

• query (String): The query to the ontology database.

Service response

application/json response.

```javascript { results: [], error: '' } ```

• results (Array): Query results returned from ontology database.
• error (String): Error message, if one occures.

Ontology-Is-SubSuperClass-Of

Service-Url

``` /hop/ontology_is_subsuperclass_of ```

Service request arguments

```js { parent_class: '', child_class: '', recursive: false } ```

• parent_class (String): The parent class name.
• child_class (String) The child class name.
• recursive (Boolean): Defines if a recursive procedure will be used (true/false).

Service response

application/json response.

```javascript { result: true, error: '' } ```

• result (Boolena): Success index on ontology-is-subsuperclass-of query.
• error (String): Error message, if one occures.