{"id":163,"date":"2026-04-03T20:35:28","date_gmt":"2026-04-04T01:35:28","guid":{"rendered":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/?page_id=163"},"modified":"2026-11-14T01:28:28","modified_gmt":"2026-11-14T06:28:28","slug":"control-system","status":"publish","type":"page","link":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/system-implementation\/control-system\/","title":{"rendered":"Control Sub-system"},"content":{"rendered":"\n

Fall 2026 Updates<\/h3>\n\n\n\n

Repeatable Button Pressing:<\/strong><\/p>\n\n\n\n

Button pressing was reworked for repeatability: the arm motion was tuned (path smoothing and speed tuning), onboard tracking with position holding keeps the target fixed while the arm moves, and the final approach was slowed with a one-second pause at the pre-grasp pose. The robot has been tested pressing real elevator buttons.<\/p>\n\n\n\n

\"Repeatable<\/a>
Fig:<\/strong> Repeatable button pressing: motion tuning, tracking and holding, and a slower final approach.<\/figcaption><\/figure>\n\n\n\n

Arm planning was also optimized (offline measurements from five desktop runs):<\/p>\n\n\n\n

Metric<\/th>Before<\/th>After<\/th><\/tr><\/thead>
Total planning time<\/td>2194\u20132583 ms<\/td>682\u2013838 ms<\/td><\/tr>
IK calls per plan<\/td>22<\/td>11<\/td><\/tr>
Goal residual<\/td>186 \u00b5m<\/td>39 \u00b5m<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Open issue:<\/em> the robot still occasionally misses the button. Root-cause analysis is ongoing; the next step is to collect success rates while separating perception error from control error. An apparent wall motion of 11.95 mm peak-to-peak with a 3.01\u00b0 tilt was measured during pressing; timing, robot-model parameters and motor encoders remain hypotheses for its cause.<\/p>\n\n\n\n

\"The<\/a>
Fig:<\/strong> The G1 pressing a real elevator call button.<\/figcaption><\/figure>\n\n\n\n
\"The<\/a>
Fig:<\/strong> The G1 pressing an elevator button panel.<\/figcaption><\/figure>\n\n\n\n

Spring 2026<\/h3>\n\n\n\n

Arm Visual Servoing for Button Pressing:<\/strong><\/p>\n\n\n\n

We utilize Inverse-Dynamics to control the upper body (the arms). The system ensures a good precision and accuracy.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Fig: Robot Pressing a Button with Language Prompt.<\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Fig. Visual servo arm pipeline.<\/strong><\/p>\n\n\n\n

<\/p>\n\n\n\n

Door Opening Task: <\/strong><\/p>\n\n\n\n

We regard door opening as a whole-body loco-manipulation task and handle it using a trained joint-level control policy with Reinforcement Learning (RL). The simulation environment is built in IsaacSim. <\/p>\n\n\n\n

The policy is optimized to open slightly damped doors with a crash bar. It takes in proprioceptions (to capture humanoid’s state) and processed perceptions data (to capture door’s state) and outputs the desired joint positions of 29 joints. A PD controller is then implemente to eventually transfer the joint position to torques.<\/p>\n\n\n\n

To alleviate the sim2real gap, we further create the door model in simulator to match the real door.<\/p>\n\n\n\n

\n
\"\"<\/figure>\n<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Fig :<\/strong> Simulation Environment:<\/strong> The humanoid initializing in front of the modeled door.<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n","protected":false},"excerpt":{"rendered":"

Fall 2026 Updates Repeatable Button Pressing: Button pressing was reworked for repeatability: the arm motion was tuned (path smoothing and speed tuning), onboard tracking with position holding keeps the target fixed while the arm moves, and the final approach was slowed with a one-second pause at the pre-grasp pose. The robot has been tested pressing […]<\/p>\n","protected":false},"author":434,"featured_media":0,"parent":93,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-163","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/pages\/163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/users\/434"}],"replies":[{"embeddable":true,"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/comments?post=163"}],"version-history":[{"count":8,"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/pages\/163\/revisions"}],"predecessor-version":[{"id":352,"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/pages\/163\/revisions\/352"}],"up":[{"embeddable":true,"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/pages\/93"}],"wp:attachment":[{"href":"https:\/\/mrsdprojects.ri.cmu.edu\/2026teama\/wp-json\/wp\/v2\/media?parent=163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}