https://mulhamfetna.com/tags/control/ Recent content in Control on Mulham Fetna Hugo -- gohugo.io en contact@mulhamfetna.com (Mulham Fetna) contact@mulhamfetna.com (Mulham Fetna) © 2026 Mulham Fetna Wed, 16 Sep 2026 00:00:00 +0000 https://mulhamfetna.com/projects/ros2-tendon-driven-hand-mujoco-digital-twin-vision-teleoperation/tendon-physics-switch/ Wed, 16 Sep 2026 00:00:00 +0000 contact@mulhamfetna.com (Mulham Fetna) https://mulhamfetna.com/projects/ros2-tendon-driven-hand-mujoco-digital-twin-vision-teleoperation/tendon-physics-switch/ <div class="lead text-neutral-500 dark:text-neutral-400 !mb-9 text-xl"> The vision layer sends a carefully normalized, smooth 0-to-1 signal. The simulated finger turns it into two states: open and closed. This is the most important thing to understand about the twin — and every number below was measured on the model in the repository. </div> <h2 class="relative group">The measurement <div id="the-measurement" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#the-measurement" aria-label="Anchor">#</a> </span> </h2> <p>The same flexion was applied to all five motors, the model simulated for 3 s from rest, and the steady-state joint angles recorded — 41 flexion values from 0 to 1.</p> <div class="chart"> <canvas id="chart-21ff2680002d0af6f1365e2e937bcf1a"></canvas> <script type="text/javascript"> window.addEventListener("DOMContentLoaded", (event) => { const ctx = document.getElementById("chart-21ff2680002d0af6f1365e2e937bcf1a"); const chart = new Chart(ctx, { type: 'line', data: { labels: ['0.000','0.025','0.050','0.075','0.100','0.125','0.150','0.175','0.200','0.225','0.250','0.275','0.300','0.325','0.350','0.375','0.400','0.425','0.450','0.475','0.500','0.525','0.550','0.575','0.600','0.625','0.650','0.675','0.700','0.725','0.750','0.775','0.800','0.825','0.850','0.875','0.900','0.925','0.950','0.975','1.000'], datasets: [ { label: 'Index finger (mean of MCP, PIP, DIP)', data: [-3.3,-3.1,-2.9,-2.8,-2.6,-2.5,-2.3,-2.1,-2.0,-1.8,-1.7,-1.5,-1.3,-1.2,-1.0,-0.8,-0.7,-0.5,-0.3,-0.2,0.0,90.2,90.4,90.6,90.8,91.0,91.2,91.5,91.7,91.9,92.1,92.2,92.4,92.6,92.8,93.0,93.2,93.4,93.5,93.7,93.9], borderColor: '#2a78d6', backgroundColor: '#2a78d6', borderWidth: 2, pointRadius: 1.5, tension: 0 }, { label: 'Thumb CMC', data: [-2.9,-2.8,-2.6,-2.5,-2.4,-2.2,-2.1,-1.9,-1.8,-1.6,-1.5,-1.4,-1.2,-1.1,-0.9,-0.8,-0.6,-0.5,-0.3,-0.1,0.0,90.1,90.2,90.4,90.5,90.6,90.7,90.8,91.0,91.1,91.2,91.3,91.4,91.5,91.6,91.7,91.8,92.0,92.1,92.2,92.3], borderColor: '#1baf7a', backgroundColor: '#1baf7a', borderWidth: 2, pointRadius: 1.5, tension: 0 }, { label: 'Thumb IP', data: [-2.7,-2.6,-2.5,-2.3,-2.2,-2.0,-1.9,-1.8,-1.6,-1.5,-1.4,-1.2,-1.1,-0.9,-0.8,-0.7,-0.5,-0.4,-0.3,-0.1,0.0,41.2,44.3,45.1,45.5,45.6,45.7,45.8,45.8,45.9,45.9,45.9,45.9,45.9,45.9,46.0,46.0,46.0,46.0,46.0,46.0], borderColor: '#eb6834', backgroundColor: '#eb6834', borderWidth: 2, pointRadius: 1.5, tension: 0 } ] }, options: { plugins: { title: { display: true, text: 'Simulated joint bend vs flexion — flat, then a wall at 0.5' } }, scales: { x: { title: { display: true, text: 'flexion command (0.5 = 0 N)' } }, y: { min: -10, max: 100, title: { display: true, text: 'joint bend (°)' } } } } }); }); </script> </div> <table> <thead> <tr> <th>Flexion</th> <th>Force</th> <th>Index MCP / PIP / DIP</th> <th>Thumb CMC / MP / IP</th> </tr> </thead> <tbody> <tr> <td>0.000</td> <td>+50.0 N</td> <td>−3.3° / −3.2° / −3.3°</td> <td>−2.9° / −2.7° / −2.7°</td> </tr> <tr> <td>0.250</td> <td>+25.0 N</td> <td>−1.7° / −1.6° / −1.7°</td> <td>−1.5° / −1.3° / −1.4°</td> </tr> <tr> <td>0.500</td> <td>0.0 N</td> <td>0.0° / 0.0° / 0.0°</td> <td>0.0° / 0.0° / 0.0°</td> </tr> <tr> <td>0.625</td> <td>−12.5 N</td> <td>91.1° / 91.0° / 91.0°</td> <td>90.6° / 53.9° / 45.6°</td> </tr> <tr> <td>1.000</td> <td>−50.0 N</td> <td>94.0° / 93.8° / 93.9°</td> <td>92.3° / 54.2° / 46.0°</td> </tr> </tbody> </table> <p><em>Joint limits are 90°; values just above it are MuJoCo&rsquo;s soft limit being pressed.</em></p>