ROS Plan KB queries -- cheatsheet

• see tutorial 06 KB
• see tutorial 07 KB
• see tutorial 08 KB
• see tutorial 09 KB

Index of Interface Names of the KB

topics:

/rosplan_knowledge_base/pddl_action_parameters
/rosplan_knowledge_base/status/update

services:

## === USEFUL SERVICES === ##
# clear the actual problem instance
/rosplan_knowledge_base/clear
# make more complex queries to the knowledge base
/rosplan_knowledge_base/query_state
# update with a single call
/rosplan_knowledge_base/update

## === DOMAIN SERVICES === ##
/rosplan_knowledge_base/domain/name
/rosplan_knowledge_base/domain/functions
/rosplan_knowledge_base/domain/operator_details
/rosplan_knowledge_base/domain/operators
/rosplan_knowledge_base/domain/predicate_details
/rosplan_knowledge_base/domain/predicates
/rosplan_knowledge_base/domain/types

## === PROBLEM SERVICES === ##
/rosplan_knowledge_base/state/functions
/rosplan_knowledge_base/state/goals
/rosplan_knowledge_base/state/instances
/rosplan_knowledge_base/state/metric
/rosplan_knowledge_base/state/propositions
/rosplan_knowledge_base/state/timed_knowledge

## === KB UPDATE SERVICES === ##
/rosplan_knowledge_base/update
/rosplan_knowledge_base/update_array
/rosplan_knowledge_base/update_constraints_oneof
/rosplan_knowledge_base/update_sensed_predicates

SRV GET -- /rosplan_knowledge_base/domain/name

Name of the domain.

srv type : rosplan_knowledge_msgs/GetDomainNameService

SRV GET -- /rosplan_knowledge_base/domain/types

Types inside the domain.

srv type : rosplan_knowledge_msgs/GetDomainTypeService

response of this kind: the domain contains two types boolobj and key, see only the field types which is an array of all the types. better to not use nested types because they are poorly supported by the framework.

here's an example:

types: 
  - boolobj
  - key
super_types: 
  - ''
  - ''

SRV GET -- /rosplan_knowledge_base/domain/predicates

domain file predicates.

srv type : rosplan_knowledge_msgs/GetDomainAttributeService

here are some informations you can find from this service response:

• res.items[i].name (str): the name of the predicate, one for each cell of the array
• res.items[i].typed_parameters[j].key is the name of the parameter of the predicate
• res.items[i].typed_parameters[j].value is the type of the parameter of the predicate

an example of response: two predicates, the first one has two parameters, the second one has only one parameter.

items: 
  - 
    name: robot_at
    typed_parameters: 
      - 
        key: v
        value: robot
      - 
        key: wp
        value: waypoint
  - 
    name: visited
    typed_parameters: 
      - 
        key: wp
        value: waypoint

SRV GET -- /rosplan_knowledge_base/domain/predicate_details

it could be helpful when you need infos about the structure of one predicate.

srv type : rosplan_knowledge_msgs/GetDomainPredicateDetailsService

SRV GET -- instances of a type

complete name : /rosplan_knowledge_base/state/instances

srv type : rosplan_knowledge_msgs/GetInstanceService

string type_name
---
string[] instances

it returns only the names of the objects belonging to these instances. There are some limitations to take into account during the design:

• a object can have only one type
• the type of the object can't change in runtime

this service could be applied only for retrieving the objects.

SRV GET -- values of predicated

this service enables to retrieve the values of the predicates.

complete name : /rosplan_knowledge_base/state/propositions

srv type : rosplan_knowledge_msgs/GetAttributeService

here's an example of the response:

attributes: 
  - 
    knowledge_type: 1
    initial_time: 
      secs: 1528284422
      nsecs: 168676390
    is_negative: False
    instance_type: ''
    instance_name: ''
    attribute_name: robot_at
    values: 
      - 
        key: v
        value: kenny
      - 
        key: wp
        value: wp0
    function_value: 0.0
    optimization: ''
    expr: 
      tokens: []
    ineq: 
      comparison_type: 0
      LHS: 
        tokens: []
      RHS: 
        tokens: []
      grounded: False

in particular,

• res.attributes[]..values[].key is the name of the parameter
• res.attributes[]..values[].value is the object instance, value of the argument

very important to note that this service returns only the predicates with a true value, which means that the false predicates aren't returned.

predicates by shell: if predicate_name: '', it returns the entire set of true predicates.

rosservice call /rosplan_knowledge_base/state/propositions "predicate_name: ''"

SRV GET -- values of fluents

complete name : /rosplan_knowledge_base/domain/functions

srv type : rosplan_knowledge_msgs/GetAttributeService

# PDDL problem generation; service(2/3):
# Get all facts (or functions) by predicate name (or function name).
# The results are passed as an array of KnowledgeItems
# The array of initial_time is used for TILs and TIFs not yet active
string predicate_name
---
rosplan_knowledge_msgs/KnowledgeItem[] attributes

In particular,

• res.attributes[].knowledge_name is always 2
• res.attributes[].attribute_name is the name of the fluent
• res.attributes[].function_value is the value of the fluent

the system returns both zero and non-zero fluents.

SRV GET -- goal

goal predicates:

# get every true knowledge item
rosservice call /rosplan_knowledge_base/state/goals "predicate_name: ''"

SRV SET -- clear

it deletes the problem instance.

complete name : /rosplan_knowledge_base/clear

srv type : empty

SRV SET -- load a new model from file

you should use here the problem_interface

complete name : /rosplan_problem_interface/problem_generation_server_params

srv type : rosplan_dispatch_msgs/ProblemService

# request a problem to be generated in the problem_path
string problem_path
bool problem_string_response
---
bool problem_generated
string problem_string

SRV SET -- update the knowledge base

complete name : /rosplan_knowledge_base/update

srv type : rosplan_knowledge_msgs/KnowledgeUpdateService

🔗 see the code for understanding the effects of the commands here.

🔗 here is the function which removes a knowledge item.

uint8 ADD_KNOWLEDGE=0      # make truue a predicate, add a functional
uint8 REMOVE_KNOWLEDGE=2   # make false one predicate

uint8 ADD_GOAL=1
uint8 REMOVE_GOAL=3

uint8 ADD_METRIC=4
uint8 REMOVE_METRIC=5

uint8 update_type
rosplan_knowledge_msgs/KnowledgeItem knowledge
---
bool success

see the infos about the interface KnowledgeItem for further infos about the type of knowledge you're adding to the system.

knowledge types :

uint8 INSTANCE=0
uint8 FACT=1
uint8 FUNCTION=2
uint8 EXPRESSION=3
uint8 INEQUALITY=4

SRV GET -- queries

recommended to use the queries when interrogating the knowledge base to not overcomplicate the procedures.

complete name : /rosplan_knowledge_base/query_state

srv type : rosplan_knowledge_msgs/KnowledgeQueryService

rosplan_knowledge_msgs/KnowledgeItem[] knowledge
---
bool all_true
bool[] results
rosplan_knowledge_msgs/KnowledgeItem[] false_knowledge

reading predicates : if you're sure that the predicate you're asking for is unique, use the field response.all_true; or also .response.results[] showing each truth value.

reading fluents : not working, unfortunately. See this simple test:

root@dbfbde77a543:~/ros_ws# rosservice call /rosplan_knowledge_base/query_state "knowledge:
- knowledge_type: 2
  initial_time: {secs: 0, nsecs: 0}
  is_negative: false
  instance_type: ''
  instance_name: ''
  attribute_name: 'f-non-zero'
  values:
  - {key: '', value: ''}
  function_value: 0.0
  optimization: ''
  expr:
    tokens:
    - expr_type: 0
      constant: 0.0
      function:
        name: ''
        typed_parameters:
        - {key: '', value: ''}
      op: 0
      special_type: 0
  ineq:
    comparison_type: 0
    LHS:
      tokens:
      - expr_type: 0
        constant: 0.0
        function:
          name: ''
          typed_parameters:
          - {key: '', value: ''}
        op: 0
        special_type: 0
    RHS:
      tokens:
      - expr_type: 0
        constant: 0.0
        function:
          name: ''
          typed_parameters:
          - {key: '', value: ''}
        op: 0
        special_type: 0
    grounded: false" 
all_true: False
results: [False]
false_knowledge: 
  - 
    knowledge_type: 2
    initial_time: 
      secs: 0
      nsecs:         0
    is_negative: False
    instance_type: ''
    instance_name: ''
    attribute_name: "f-non-zero"
    values: 
      - 
        key: ''
        value: ''
    function_value: 0.0
    optimization: ''
    expr: 
      tokens: 
        - 
          expr_type: 0
          constant: 0.0
          function: 
            name: ''
            typed_parameters: 
              - 
                key: ''
                value: ''
          op: 0
          special_type: 0
    ineq: 
      comparison_type: 0
      LHS: 
        tokens: 
          - 
            expr_type: 0
            constant: 0.0
            function: 
              name: ''
              typed_parameters: 
                - 
                  key: ''
                  value: ''
            op: 0
            special_type: 0
      RHS: 
        tokens: 
          - 
            expr_type: 0
            constant: 0.0
            function: 
              name: ''
              typed_parameters: 
                - 
                  key: ''
                  value: ''
            op: 0
            special_type: 0
      grounded: False
root@dbfbde77a543:~/ros_ws# rosservice call /rosplan_knowledge_base/state/functions "predicate_name: 'f-non-zero'" 
attributes: 
  - 
    knowledge_type: 2
    initial_time: 
      secs: 1657285126
      nsecs:  52188800
    is_negative: False
    instance_type: ''
    instance_name: ''
    attribute_name: "f-non-zero"
    values: []
    function_value: 6.0
    optimization: ''
    expr: 
      tokens: []
    ineq: 
      comparison_type: 0
      LHS: 
        tokens: []
      RHS: 
        tokens: []
      grounded: False
root@dbfbde77a543:~/ros_ws# 

Interfaces

• KB Services located at /root/ros_ws/src/ROSPlan/rosplan_knowledge_msgs/srv
• KB messages located at /root/ros_ws/src/ROSPlan/rosplan_knowledge_msgs/msg

SRV -- rosplan_knowledge_msgs/GetDomainNameService

empty request

# Fetching the Domain (0/3):
# Get the domain name.

---
string domain_name

SRV -- rosplan_knowledge_msgs/GetDomainTypeService

empty request

# Fetching the Domain (1/3):
# Get all types in the domain.

---
string[] types
string[] super_types

SRV -- rosplan_knowledge_msgs/GetDomainAttributeService

empty request

---
rosplan_knowledge_msgs/DomainFormula[] items
  string name
  diagnostic_msgs/KeyValue[] typed_parameters
    string key
    string value

MSG -- DomainFormula

# A message used to represent an atomic formula from the domain.
# typed_parameters matches label -> type
string name
diagnostic_msgs/KeyValue[] typed_parameters

SRV -- rosplan_knowledge_msgs/GetDomainPredicateDetailsService

string name
---
rosplan_knowledge_msgs/DomainFormula predicate
  string name
  diagnostic_msgs/KeyValue[] typed_parameters
    string key
    string value
bool is_sensed

MSG -- KnowledgeItem

see also diagnostic_msgs/KeyValue

# A knowledge item used to represent a piece of the state in ROSPlan

uint8 INSTANCE = 0
uint8 FACT = 1
uint8 FUNCTION = 2
uint8 EXPRESSION = 3
uint8 INEQUALITY = 4

uint8 knowledge_type

# time at which this knowledge becomes true
time initial_time

# knowledge is explicitly false
bool is_negative

#---------
# INSTANCE
#---------

# instance knowledge_type
string instance_type
string instance_name

#----------------------
# PREDICATE OR FUNCTION
#----------------------

# attribute knowledge_type
string attribute_name
diagnostic_msgs/KeyValue[] values

#---------
# FUNCTION
#---------

# function value
float64 function_value

#-----------
# EXPRESSION
#-----------

string optimization
rosplan_knowledge_msgs/ExprComposite expr

#-----------
# INEQUALITY
#-----------

rosplan_knowledge_msgs/DomainInequality ineq

structure of the message, as it appears on the rossrv show:

uint8 INSTANCE=0
uint8 FACT=1
uint8 FUNCTION=2
uint8 EXPRESSION=3
uint8 INEQUALITY=4
uint8 knowledge_type
time initial_time
bool is_negative
string instance_type
string instance_name
string attribute_name
diagnostic_msgs/KeyValue[] values
  string key
  string value
float64 function_value
string optimization
rosplan_knowledge_msgs/ExprComposite expr
  rosplan_knowledge_msgs/ExprBase[] tokens
    uint8 CONSTANT=0
    uint8 FUNCTION=1
    uint8 OPERATOR=2
    uint8 SPECIAL=3
    uint8 ADD=0
    uint8 SUB=1
    uint8 MUL=2
    uint8 DIV=3
    uint8 UMINUS=4
    uint8 HASHT=0
    uint8 TOTAL_TIME=1
    uint8 DURATION=2
    uint8 expr_type
    float64 constant
    rosplan_knowledge_msgs/DomainFormula function
      string name
      diagnostic_msgs/KeyValue[] typed_parameters
        string key
        string value
    uint8 op
    uint8 special_type
rosplan_knowledge_msgs/DomainInequality ineq
  uint8 GREATER=0
  uint8 GREATEREQ=1
  uint8 LESS=2
  uint8 LESSEQ=3
  uint8 EQUALS=4
  uint8 comparison_type
  rosplan_knowledge_msgs/ExprComposite LHS
    rosplan_knowledge_msgs/ExprBase[] tokens
      uint8 CONSTANT=0
      uint8 FUNCTION=1
      uint8 OPERATOR=2
      uint8 SPECIAL=3
      uint8 ADD=0
      uint8 SUB=1
      uint8 MUL=2
      uint8 DIV=3
      uint8 UMINUS=4
      uint8 HASHT=0
      uint8 TOTAL_TIME=1
      uint8 DURATION=2
      uint8 expr_type
      float64 constant
      rosplan_knowledge_msgs/DomainFormula function
        string name
        diagnostic_msgs/KeyValue[] typed_parameters
          string key
          string value
      uint8 op
      uint8 special_type
  rosplan_knowledge_msgs/ExprComposite RHS
    rosplan_knowledge_msgs/ExprBase[] tokens
      uint8 CONSTANT=0
      uint8 FUNCTION=1
      uint8 OPERATOR=2
      uint8 SPECIAL=3
      uint8 ADD=0
      uint8 SUB=1
      uint8 MUL=2
      uint8 DIV=3
      uint8 UMINUS=4
      uint8 HASHT=0
      uint8 TOTAL_TIME=1
      uint8 DURATION=2
      uint8 expr_type
      float64 constant
      rosplan_knowledge_msgs/DomainFormula function
        string name
        diagnostic_msgs/KeyValue[] typed_parameters
          string key
          string value
      uint8 op
      uint8 special_type
  bool grounded

rosplan_knowledge_msgs/GetAttributeService

# PDDL problem generation; service(2/3):
# Get all facts (or functions) by predicate name (or function name).
# The results are passed as an array of KnowledgeItems
# The array of initial_time is used for TILs and TIFs not yet active
string predicate_name
---
rosplan_knowledge_msgs/KnowledgeItem[] attributes