E1 · Closed chain
10 minRun the full chain on the boxing motion. Before running it, on a fresh bench, the check shows the steps that are missing.
Done when: python3 kit/conferir_pipeline.py; echo "saída: $?" → 4 etapas ok and saída: 0.
Lesson 8 · 15 min
Project: a safe motion, end to end
Each lesson left you one piece: clip read, retargeting with no violations, motion tracking measured, safety check. What goes to a robot is the whole chain, in a single movement. In this lesson you run the four steps in sequence, check that they all pass and refer to the same file, and generate your own study plan.
Start the lesson
In this lesson you will
- 1Four safety rules read from the motion itself
- 2The four-step chain and the file that ties them all together
- 3The most common mistake: checking one motion and sending another
- 4Your plan with dates for the next steps
Goal: run the chain mocap → retargeting → motion tracking → safety on a single motion and prove that all four steps pass.
01The chain of a motion
Click each step. Each script writes a summary to ~/fth/movimentos/etapas/.
Click each block of the diagram to see what it does.
The chain only holds if steps 2, 3, and 4 talk about the same file and step 2 comes from the BVH in step 1.
02The four safety rules
checar_seguranca.py reads the retargeted motion, frame by frame, on the G1 from Menagerie.
Terminal · check the boxing clip
F=${FTH:-$HOME/fth}; cd $F/corpo-inteiro && . $F/.venv/bin/activate
python3 kit/checar_seguranca.py $F/movimentos/boxe_g1.npz; echo "saída: $?"Example from the repository
ok · limites de junta: 0 quadro×junta fora ok · velocidade de junta: máx 313°/s em left_elbow_joint (teto 400°/s) ok · pé não afunda no chão: site do pé desce até 3.8 cm (de pé: 3.3 cm) ok · área de trabalho: pelve se afasta até 0.22 m (raio 1.5 m) segurança: 4/4 regras saída: 0
The left elbow reaches 313°/s in a punch. With a cap of 150°/s (for example, for the first test near people), the same rule fails the movement: --teto-graus-s 150 gives segurança: 3/4 regras.
segurança: 3/4 regras
With the cap for the first test near people, the boxing movement fails on speed.
03The whole chain on a single motion
Runs the four steps in sequence on the same clip and checks. Each line shows the result of one step; the check says whether the chain closes.
Terminal · full chain
F=${FTH:-$HOME/fth}; cd $F/corpo-inteiro; B=$F/GMR/assets/xsens_bvh_test/251021_04_boxing_120Hz_cm_3DsMax.bvh
. $F/.venv/bin/activate && python3 kit/ler_clipe.py $B | tail -1
( . $F/.venv-gmr/bin/activate && python3 kit/retarget.py $B --fim 1200 --nome boxe_g1 | grep violações )
python3 kit/reproduzir.py $F/movimentos/boxe_g1.npz | grep "erro médio"
python3 kit/checar_seguranca.py $F/movimentos/boxe_g1.npz | tail -1
python3 kit/conferir_pipeline.py; echo "saída: $?"Example from the repository
linhas de movimento conferidas: 4249/4249 violações de limite (Menagerie, folga 0.5°): 0 erro médio de junta: 0.3° · pior junta: right_shoulder_roll_joint (1.9°) segurança: 4/4 regras ok · mocap (BVH lido): 4249 quadros a 120 Hz ok · retargeting: 1200 quadros, 0 violações de limite ok · rastreio no simulador: erro médio 0.3° (máx 2°), queda: não ok · checagem de segurança: 4/4 regras cadeia: um só movimento (boxe_g1.npz) 4 etapas ok saída: 0
Four steps ok and a single motion from start to finish.
segurança: 4/4 regras violações de limite (Menagerie, folga 0.5°): 0 erro médio de junta: 0.3° · pior junta: right_shoulder_roll_joint (2.7°) ok · mocap (BVH lido): 4249 quadros a 120 Hz ok · retargeting: 600 quadros, 0 violações de limite ok · rastreio no simulador: erro médio 0.3° (máx 2°), queda: não ok · checagem de segurança: 4/4 regras FALHA · cadeia: as etapas falam de arquivos diferentes (boxe_curto.npz, boxe_g1.npz) 3 de 4 etapas ok saída: 1
After the chain closed, someone redid the retargeting (now with 600 frames) and the tracking, but not the safety check. Each step passes on its own; the chain does not: safety was checked on one file and the one that would go to the robot is another.
violações de limite (Menagerie, folga 0.5°): 0 erro médio de junta: 1.5° · pior junta: right_ankle_pitch_joint (5.1°) ok · limites de junta: 0 quadro×junta fora FALHA · velocidade de junta: máx 635°/s em left_knee_joint (teto 400°/s) FALHA · pé não afunda no chão: site do pé desce até 1.4 cm (de pé: 3.3 cm) ok · área de trabalho: pelve se afasta até 0.05 m (raio 1.5 m) segurança: 2/4 regras cadeia: um só movimento (boxe_trecho2.npz) 3 de 4 etapas ok
Frames 1200 to 2400 pass retargeting and motion tracking, but the knee reaches 635°/s and the foot drops 1.9 cm below the standing pose (retargeting does not enforce ground contact). The chain closes on a single file and fails: that is the right result.
04A batch of motions going through the chain
Datasets like SONIC's have millions of frames: the chain runs as a queue. Run it, interrupt it halfway, and run it again.
a conferir/
na cadeia/
aprovados/
reprovados/
Browser simulation: nothing really runs here. Pass and fail match the kit (10/19/2026): the 1200–2400 segment fails the safety check.
05What you built in this course
Four main deliverables. Click a step to see the "done when".
Lessons 4–6Execution
motion tracking, teleop
3 exercises
Error, latency, and grip measured.
See the lessonBy the end of the courseA human motion brought to the simulated G1 with every step checked.
8 lessonsTap an exercise to see what to do and the "done when".
- 1/5
Layers
The workbench in ~/fth and the three layers counted: the base for all the practices.
- 2/5
Data
Human motion read, with the license considered, and brought to the G1 by GMR in its own environment.
- 3/5
Execution
Replay with and without the gantry, teleop with latency, and the G1 hand in the model.
- 4/5
Chain
High-level commands checked and the mocap → safety chain closed.
- 5/5
The whole course
Four deliverables in sequence. The next step is operating a real robot safely: FTH course 4.
Order matters: without the retargeting checked, tracking and safety measure the wrong motion.
06Generate your plan with dates
Pick the start date and how much time you have per week. The plan lists the practices for each lesson.
plano.md
07Practice
Close the chain and adjust the rules.
E2 · Your lab's ceiling
5 minRun the check with the 150°/s ceiling and write in one sentence which part of the boxing motion went over the ceiling.
Done when: python3 kit/checar_seguranca.py ~/fth/movimentos/boxe_g1.npz --teto-graus-s 150 | tail -1 → segurança: 3/4 regras.
E3 · A clip that fails
15 minTake the clip from frame 1200 to 2400 through the whole chain (retarget, play back, and check with the same file) and write which rules it breaks and why.
Done when: python3 kit/conferir_pipeline.py | tail -2 → cadeia: um só movimento (boxe_trecho2.npz) and 3 de 4 etapas ok.
08Lesson quiz
The explanation appears after your answer.
Question 1 of 3
Each step passed on its own, but the check says "cadeia quebrada". What happened?skill
Correct
If you redo the retargeting without redoing the check, safety is approved on one file while another one is ready to go to the robot. The check compares the file names from each step.Not that one
If you redo the retargeting without redoing the check, safety is approved on one file while another one is ready to go to the robot. The check compares the file names from each step.Review: The four safety rulesQuestion 2 of 3
Where does the 400°/s ceiling in the speed rule come from?
Correct
Without a manufacturer number in the training research, the course doesn't invent one: the ceiling is yours, written into the rule and adjustable with --teto-graus-s.Not that one
Without a manufacturer number in the training research, the course doesn't invent one: the ceiling is yours, written into the rule and adjustable with --teto-graus-s.Review: The chain of a motionQuestion 3 of 3
Why does this course's tracking criterion use the gantry, while a real project's shouldn't?
Correct
Without the tracking policy (lesson 4), the free-standing G1 falls. In a project with mjlab or SONIC, tracking is measured without a gantry; the gantry is kept for the first test on the real robot (course 4).Not that one
Without the tracking policy (lesson 4), the free-standing G1 falls. In a project with mjlab or SONIC, tracking is measured without a gantry; the gantry is kept for the first test on the real robot (course 4).Review: The chain of a motionQuiz complete
You got {a} of {n} right. If you get them all right, the lesson is marked as complete.Choose an option. The explanation appears after you try.
09In three sentences
ChainMocap, retargeting, tracking, and safety, always on the same file.
RulesLimit and speed read from the motion; ceilings that are yours, written down.
NextOperating the real robot safely is FTH course 4.