pyonics

A Python library for simulating and controlling pneumatic artificial muscles using Klamp't robotics library.

Quick Start

Install:

pip install pyonics

Create a controller:

import klampt
from pyonics import ExoController, MuscleEmulator

# Load configuration
config = {
    "has_robworld": True,
    "world_path": "data/world.xml",
    "core": "data/robot.rob",
    "attachments": "data/muscles.csv",
    "timestep": 0.01,
    "address": "127.0.0.1",
    "port": 5005
}

pcm = ExoController(config)

Create a dataframe of muscles that looks like the following:

name;link_a;link_b;transform_a;transform_b;label_a;label_b;turns;r_0;l_0;weave_length;max_pressure

right_inferior_latissimus;9;4;0,0,0;0,-1,0;superior;inferior;20;1;2;2;80000

import pandas as pd
from klampt.sim.simulation import SimpleSimulator

sim = SimpleSimulator(pcm.world)

muscleinfo_df = pd.read_csv(config['attachments'], sep=";")

for _, row in muscleinfo_df.iterrows():
    row = muscleinfo_df.iloc[x] 
    muscle = MuscleEmulator(row, pcm, sim)
    sim.addEmulator(pcm.robot, muscle)

Start simulation:

import asyncio

async def startup():
    await pcm.setup_osc_server()
    await pcm.server.enable_osc_logging()
    
    running = True
    while running:
        sim.simulate(0.01)
        await asyncio.sleep(0.01)
        
asyncio.run(startup())

Features

• Pneumatic muscle emulation
• Pressure-driven actuation
• Klamp't simulator integration
• OSC network control

Requirements

• Python 3.x
• Klamp't installed
• python-osc
• differint

Configuration Format

has_robworld: Boolean. Currently must be true.

world_path: Filepath to the world, in XML format.

core: Filepath to the robot, in .rob format.

attachments: Filepath to the muscle attachment CSV.

timestep: Control rate for the robot.

address: IP address. Currently only tested locally.

port: Networking port to receive on.

Muscle Attachment DataFrame Format

name: A name for the muscle.

link_a: The index of the first robot link to attach to.

link_b: The index of the second robot link to attach to.

transform_a: The local transform on link A to attach to.

transform_b: The local transform on link B to attach to.

label_a: For convenience. Functionality not yet implemented.

label_b: For convenience. Functionality not yet implemented.

turns: Number of turns in the weave.

r_0: Resting radius of the muscle.

l_0: Resting length of the muscle.

weave_length: Length of the weave surrounding the muscle.

pressure: Pressure of the muscle. Updated with muscle commands.

Acknowledgments

Thanks to Dr. Paul Savala, my research advisor, for support in developing this library.