Crease Lab

Click a crease to select it.

FOLD file

FOLD is the plain-JSON format most origami tools share (Origami Simulator, Rabbit Ear, ORIPA exports). Import one to simulate it, or export this pattern.

Every gait on this bench is a sequence of a few primitives. Drive them by hand here. The gait pauses while you do.

Keeps the phase order and anchors of the gait above and searches every phase's timing, contraction and bend. Each candidate is crawled for three cycles in the simulator.

From simulation to robot

Servo plan

Servos hold positions, not forces, so the simulator's job is to say how far each cable pair must shorten in each phase of the gait.

Wiring

Parts

Generated from the current gait. Open it in the Arduino IDE, pick your board and upload.

Build steps

Use it from code

Everything on this page is exposed as window.CreaseLab (source in web/). Open the browser console to drive the simulator from your own learning loop.

const { CrawlerEnv } = CreaseLab;
const env = new CrawlerEnv({ cells: 4 }, { feet: 'anchors' });
let obs = env.reset();   // plate positions, cable levels, anchors
for (let t = 0; t < 400; t++) {
  // 4 cable levels in 0..1, then head and tail anchors (0/1)
  const action = t % 60 < 30 ? [1, 1, 1, 1, 1, 0] : [0, 0, 0, 0, 0, 1];
  const { obs: o, reward, done } = env.step(action); // reward = forward speed
  if (done) break;
}

const { OrigamiEnv } = CreaseLab;
const env = new OrigamiEnv('kresling', { phi: 30 },
  { target: 0.4 });          // aim for 40% stroke
let obs = env.reset();      // hinge angles + height + strain
for (let t = 0; t < 200; t++) {
  const action = [0.5];      // tendon force, 0..1
  const { obs: o, reward, done } = env.step(action);
  if (done) break;
}

CreaseLab.buildPattern(key, params)   // crease pattern
CreaseLab.buildMesh(pattern, stiffness) // -> Sim
sim.setFold(0.6); sim.step(500)      // drive creases
sim.maxStrain(); sim.energy()        // measurements
CreaseLab.makeProblem(key, params, 'compact', { fold: 0.6 })
new CreaseLab.CMAES(x0, 0.25)       // ask() / tell()
CreaseLab.toFOLD(pattern); CreaseLab.fromFOLD(json)
CreaseLab.evaluateGait(robotParams, CreaseLab.GAITS.inchworm)
CreaseLab.makeGaitProblem(robotParams, gait, 'speed')