@pamoja/sim

Noisy and replay sensors, a recording actuator, and a simulated robot that dead-reckons its pose. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

npm install @pamoja/sim
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This pulls in @pamoja/native, the compiled engine. npm install pamoja is the whole framework in one package.

Example

The test that runs in CI, spliced here as it ran.

From bindings/node/guides/sim.ts:

import { RecordingActuator, Replay, SimulatedRobot } from '@pamoja/sim'

async function main() {
  // The clear distance ahead, in metres, taken from an earlier survey run. A replay hands
  // it back one reading at a time, so the loop below sees the same input on every run: the
  // same rover code, driven by a recording rather than a range finder.
  const capture = [4, 3, 1.5, 0.5]
  const ahead = new Replay(capture)
  const throttle = new RecordingActuator()
  const rover = new SimulatedRobot(0.5) // each command advances the rover half a second

  const seen: number[] = []
  for (let step = 0; step < capture.length; step += 1) {
    const reading = (await ahead.read())!
    seen.push(reading)

    // Drive on while there is room ahead, otherwise stop and turn on the spot.
    const clear = reading > 1
    const speed = clear ? 1 : 0
    const turn = clear ? 0 : 1
    await throttle.apply(speed)
    await rover.apply({ vx: speed, vy: 0, omega: turn })
    console.log(`${reading} m ahead, so drive at ${speed} and turn at ${turn}`)
  }

  // The recording actuator kept every command, which is how a test says what the control
  // loop decided rather than only what it ended up doing.
  const commands = await throttle.commands()
  console.log(`commands  ${commands.join(', ')}`)

  // Three half-second commands at 1 m/s reach 1.5 m along x. The last one turns on the spot
  // at 1 rad/s for half a second, which moves the rover nowhere.
  const pose = await rover.pose()
  console.log(
    `pose      x ${pose.x.toFixed(1)} m, y ${pose.y.toFixed(1)} m,` +
      ` heading ${pose.theta.toFixed(1)} rad`,
  )

  return { seen, commands, pose }
}

main()
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The same capability in every language

Documentation

• @pamoja/sim reference, every class, function, and type this package exports.
• The Simulators guide, with the same example in Rust, Python, and C#.
• Every capability, and the install page.

License

MIT