TuLiP planning, May 2013

This page contains a draft description of the TuLiP toolbox.

Examples

This section contains a set of example that illustrate how the TuLiP code should be structured. This goes first so that we focus on the TuLiP interface and functionality and then figure out what is required to support it.

Load up an example stored in files and synthesize a controller

This example shows how to load up a problem that is specified in files and synthesize a controller. Save the controller to a file, but also generate a version that can be executed in Ptolemy.

Code

import tulip

# Load up the system and environment descriptions, plus specifications
system = tulip.ts.load("robot-discrete.tsf")
environment = tulip.sp.load("robot-env.spf")
specs = tulip.sp.load("robot-specs.spf")

# Synthesize a controller
controller = tulip.syn.jtlv(system, environment, specs)

# Save the controller in TuLiP and Ptolemy formats
tulip.ts.save("robot-control.tsf")
tulip.ptolemy.savefsm("robot-control.fsm")

Notes

1. The .tsf (transition system file) and .spf (specification file) formats are the default TuLiP file formats.
   • Alternatively, perhaps we have a single file format .tlp and then use tulip.load and tulip.save to read and write. The type of object would just be part of the file specification. --Richard Murray (talk) 15:07, 11 May 2013 (PDT)
2. The tf module contains data types and functions for representing different types of transition systems. Multiple transition systems are supported, including deterministic transition systems, Markov decision processes, Kripke structures, Rabin automata, etc.
3. The sp module contains data types and functions for representing specifications. Multiple temporal logics, including LTL, MTL, CTL, PCTL, TCTL, STL, etc are supported.
4. The syn module contains interfaces to various synthesis tools. Supported tools include JTLV, gr1c and PRISM. The input arguments must be compatible with the synthesis tool, but all arguments should be core TuLiP objects.
   • Would it make more sense to have a module for each program we support? So this line would become tulip.jtlv.syn? --Richard Murray (talk) 15:07, 11 May 2013 (PDT)
5. The ptolemy module contains functions for interfacing with Ptolemy.
   • Should we instead make an FMI interface and then use Ptolemy's FMI capability? --Richard Murray (talk) 15:09, 11 May 2013 (PDT)

Create an example from scratch

This example shows how to create a system and environment from scratch, then synthesize a controller. It is based on the robot-simple.py example that is distributed with TuLiP and used in the EECI short course.

Code

import tulip

#
# Create the system transition system corresponding to a 2x3 grid of cells
#
system = tulip.ts()
system.addstates({'c11', 'c12', 'c13', 'c21', 'c22', 'c23'})

# Allow transitions between adjacent cells
system.addtransition('c11', {'c12', 'c21'})
system.addtransition('c12', {'c11', 'c13', 'c22'})
system.addtransition('c13', {'c12', 'c31'}})
system.addtransition('c21', {'c12', 'c22'})
system.addtransition('c22', {'c21', 'c23', 'c12'})
system.addtransition('c23', {'c22', 'c13'}})

# Add labels to selected points
system.addlabel('home', 'c11')
system.addlabel('lot', 'c13 or c23')

#
# Create an environment that allows an obstacle to move around in the same state space
#
# We model the environment in a slightly different way, just to show functionality
#
environment = tulip.ts()

environment.addvar('obs', system.states)
envspec = tulip.spec(environment,
  ( obs = c11 -> next (obs = c12 or obs = c21) ) and
  ( obs = c12 -> next (obs = c11 or obs = c13 or obs = c22) ) and
  ( obs = c13 -> next (obs = c12 or obs = c31) ) and
  ( obs = c21 -> next (obs = c22 or obs = c12) ) and
  ( obs = c22 -> next (obs = c21 or obs = c23 or obs = c12) ) and
  ( obs = c23 -> next (obs = c22 or obs = c13) )
')

environment.addvar('park', {1, 0})
envspec = envspec + tulip.spec(environment, '[] <> !park')

#
# System specification
#
spec = tulip.spec({system,environment}, envspec + '-> 
  (always eventually home) and
  (always (park -> eventually lot)) and
  (always !(
    (obs = c11 and c11) or
    (obs = c12 and c12) or
    (obs = c13 and c13) or
    (obs = c21 and c21) or
    (obs = c22 and c22) or
    (obs = c23 and c23) ) )
')

# Synthesize the automaton
controller = tulip.syn.jtlv({system, environment}, spec)

# Simulate the system