CLASS kb_tools

See also

see also NODE kb_interface which is an application of the services offered by this class.

Header

basic tools for dealng with the ROSPLan knowledge base.

Essential tools for handling the informations inside the ROSPlan knowledge base in a more intuitive, convenient way.

Todo:

the class right now has a very limited support for the fluents.

Authors

Francesco Ganci

Version

v1.0.0

Defines

__H_KB_TOOLS__

DEBUG_MODE_ENABLED

SERVICE_QUERY

KB query (predicates only)

TIMEOUT_QUERY

SERVICE_QUERY_2

KB propositions query.

TIMEOUT_QUERY_2

SERVICE_KB_UPDATE

KB update (fluents and predicates)

TIMEOUT_KB_UPDATE

SERVICE_KB_GET_FLUENT

KB query (fluents only)

TIMEOUT_KB_GET_FLUENT

KB_ADD_KNOWLEDGE

KB_DEL_KNOWLEDGE

KB_ADD_GOAL

KB_DEL_GOAL

KB_KTYPE_FLUENT

KB_KTYPE_PREDICATE

class kb_tools

#include <kb_tools.h>

base interface with the ROS plan knowledge base

this interface can be considered a abstraction of the ROS plan knowledge base. the knowledge base is seen as a database containing predicates and fluents, which can be obtaine by GET methods, and set using SET methods.

Moreover, the class opens and manages all the services needed to perform such communication with the database, hence the node using this kind of functonality doesn’t need to manually open the required interfaces.

Subclassed by kb_interface

Public Functions

kb_tools()

class constructor

~kb_tools()

class destructor

bool ok()

check if the last action succeeded or not

Note

this function should be called every time you perform a call to any service.

void set_debug_mode(bool dbmode)

set the log verbosity level

with the debug mode disabled, the class will notify only the opening of the services; otherwise, each method contains a lot of printable messages.

Parameters

dbmode – if true, the class will print on the log/shell every operations the system will perform.

bool get_predicate(const std::string &pname, std::map<std::string, std::string> params)

get value of a predicate

Todo:

the method assumes that only one result is returned, which is true for fully defined queries, but what about partial queries?

Note

the boolean ‘false’ is returned also when the call fails, so remember to check the valdity of the value using ok

Parameters

• pname – the name of the predicate to get

• params – the map of the parameters of the predicate to check

Returns

• true if the predicate is true (and the call succeeded)

• false if the predicate is false OR if the service call failed, see ok

bool set_predicate(const std::string &pname, std::map<std::string, std::string> params, bool pvalue)

set the truth value of a predicate

Note

no need here to check the success of the call using ok: the return value is sufficient to understand what’s going on.

Parameters

• pname – the name of the predicate to get

• params – the map of the parameters of the predicate to check

• pvalue – the boolean value to set for that predicate

Returns

(bool) true if the operation has gone well, false otherwise.

bool set_goal(const std::string &pname, std::map<std::string, std::string> params, bool pvalue)

set the truth value of a goal predicate

Note

no need here to check the success of the call using ok: the return value is sufficient to understand what’s going on.

Parameters

• pname – the name of the goal predicate to get

• params – the map of the parameters of the goal predicate to check

• pvalue – the boolean value to set for that goal predicate

Returns

(bool) true if the operation has gone well, false otherwise.

Protected Functions

rosplan_knowledge_msgs::KnowledgeQueryService request_query(const std::string &pname, std::map<std::string, std::string> &params)

build a query message (predicates only)

the method returns a message ready for a simple predicate query. just give the name of the predicate you’re searching, and its parameters.

Parameters

• pname – (string) the name of the predicate

• params – (std::map<std::string, std::string>&) the map of parameters for the predicate

Returns

a copy of the message rosplan_knowledge_msgs::KnowledgeQueryService, with the .request field ready for the service request.

rosplan_knowledge_msgs::KnowledgeUpdateService request_update(const std::string pname, std::map<std::string, std::string> &params, bool value, bool is_goal = false)

build a update message for predicates

Parameters

• pname – (string) the name of the predicate

• params – (std::map<std::string, std::string>&) the map of parameters for the predicate

• value – (bool) the new value of the predicate

Returns

a copy of the message rosplan_knowledge_msgs::KnowledgeUpdateService, with the .request field ready for the service request.

std::map<std::string, std::string> keyvalue2map(const std::vector<diagnostic_msgs::KeyValue> &kv)

cast a KeyValue message into a simple map

this function is often useful, since the messages of the knowledge base use a lot the message type diagnostic_msgs::KeyValue.

Parameters

kv – the vector of messages diagnostic_msgs::KeyValue

Returns

a map from that vector

Protected Attributes

ros::NodeHandle nh

node handle reference

bool debug_mode

debug mode status,

See also

set_debug_mode

bool success

last action success or not,

See also

ok

Private Functions

void open_services()

open the services with the knowledge base

here is the list of the services opened by this function:

• SERVICE_QUERY : rosplan_knowledge_msgs::KnowledgeQueryService>

• SERVICE_KB_UPDATE : rosplan_knowledge_msgs::KnowledgeUpdateService

• ??? : ???

Private Members

ros::ServiceClient cl_query

predicates query client handle

ros::ServiceClient cl_query_2

another query client handle

ros::ServiceClient cl_kb_update

update clent handle

ros::ServiceClient cl_kb_get_fluent

fluents query client handle

Implementation

implementation of the class kb_tools

See also

kb_tools.h

Authors

Fracesco Ganci

Version

v1.0