Robot Skill Hub by Superfast Robotics

Computed-torque PD control in headless procedural simulation

Computed-torque PD control in headless procedural simulation. Parameterized bounded JSON adapter; synthetic DIRECT simulation, no physical robot.

pybullet-torque-pd-skill | Record version: 1.0.0

Record JSON | Markdown recipe | Complete search index

Fetch and prepare

curl -fsSL https://hub.superfastrobotics.com/skills/pybullet-torque-pd-skill/skill.json
curl -fsSL https://hub.superfastrobotics.com/skills/pybullet-torque-pd-skill/README.md
python /PATH_TO_SKILL/scripts/rsh.py inspect pybullet-torque-pd-skill --json
python /PATH_TO_SKILL/scripts/rsh.py prepare pybullet-torque-pd-skill --project ./experiment --expected-source-commit 2c204c49e56ed15ec5fcfa71d199ab6d6570b3f5 --expected-record-version 1.0.0 --plan --json

Inspect the requirements, then remove --plan to prepare a project. Preparation verifies the archive SHA256 and preserves exact source pins. --install-deps explicitly installs dependencies. Run the returned simulation command separately.

Environment

Runtime
pybullet 3.2.7
Robot
synthetic-seven-axis-or-procedural-scene
Controller
json-contract-v1
Observation
explicit-json-input
OS / architecture
linux / x86_64
Python
>=3.10,<3.11

Compatibility status: hub_verified

All inputs and outputs follow interface v1. Simulation adapters query exact synthetic simulator state; no perception or physical sensor compatibility.

Requirements

No display. Matplotlib Agg for numerical imports; PyBullet DIRECT for simulation.

Packages: numpy==1.26.4, pybullet==3.2.7

Runtime dependency versions are pinned for the supported Python 3.10 x86_64 CPU environments and checked against execution receipts. Platform-specific wheel hashes are not represented as a universal artifact lock; prepare captures pip freeze.

External API keys: none.

Invocation

Executable interface

{
  "version": "1",
  "kind": "controller",
  "abstraction_level": 1,
  "execution_domain": "simulation",
  "language": "python",
  "input_transport": "json_file_or_inline",
  "output_transport": "json_stdout",
  "conventions": {
    "linear_unit": "m",
    "angular_unit": "rad",
    "time_unit": "s",
    "coordinate_frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
    "joint_order": "input_array_order",
    "quaternion_order": "not_used"
  },
  "input_schema": {
    "type": "object",
    "required": [
      "joint_angles",
      "target_joint_angles"
    ],
    "additionalProperties": false,
    "properties": {
      "joint_angles": {
        "type": "array",
        "minItems": 7,
        "maxItems": 7,
        "items": {
          "type": "number",
          "minimum": -3,
          "maximum": 3
        },
        "x-unit": "rad",
        "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
        "description": "joint_angles; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
      },
      "target_joint_angles": {
        "type": "array",
        "minItems": 7,
        "maxItems": 7,
        "items": {
          "type": "number",
          "minimum": -1,
          "maximum": 1
        },
        "x-unit": "rad",
        "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
        "description": "target_joint_angles; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
      }
    }
  },
  "output_schema": {
    "type": "object",
    "required": [
      "joint_angles_rad",
      "maximum_joint_error_rad"
    ],
    "additionalProperties": false,
    "properties": {
      "joint_angles_rad": {
        "type": "array",
        "minItems": 7,
        "maxItems": 7,
        "items": {
          "type": "number",
          "minimum": -100,
          "maximum": 100
        },
        "x-unit": "rad",
        "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
        "description": "joint_angles_rad; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
      },
      "maximum_joint_error_rad": {
        "type": "number",
        "minimum": 0,
        "maximum": 100,
        "x-unit": "rad",
        "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
        "description": "maximum_joint_error_rad; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
      }
    }
  },
  "preconditions": [
    "PyBullet DIRECT CPU simulation with procedural shapes and a synthetic seven-axis arm where applicable; no downloaded models.",
    "This is an adaptation of the referenced API example, not verification of its original robot model or hardware.",
    "Simulation steps are fixed and bounded; force/torque order is Fx,Fy,Fz,Mx,My,Mz in the joint sensor frame."
  ],
  "postconditions": [
    "All declared checks must pass and all outputs must be finite.",
    "Success applies only to this operation and model, not higher-level task completion."
  ],
  "failure_codes": [
    "invalid_input_or_environment",
    "execution_failed",
    "task_failed"
  ],
  "composition": {
    "depends_on": [],
    "automatic_frame_conversion": false,
    "automatic_hardware_execution": false
  },
  "output_selector": "outputs",
  "origin_reference_ids": [
    "pybullet-pdcontrol"
  ],
  "origin_relationship": "adapted_from; inspect declared model and inputs, not original robot compatibility"
}

Entrypoint: python run.py

{
  "argv": [
    "{python}",
    "{recipe_dir}/run.py",
    "--source-dir",
    "{source_dir}",
    "--example"
  ],
  "inputs": {
    "joint_angles": [
      0.1,
      -0.3,
      0.4,
      0.2,
      -0.2,
      0.1,
      0.1
    ],
    "target_joint_angles": [
      0.2,
      -0.2,
      0.3,
      0.1,
      -0.1,
      0.2,
      0
    ]
  },
  "outputs": {
    "format": "single JSON object on stdout",
    "payload_selector": "outputs",
    "schema": {
      "type": "object",
      "required": [
        "joint_angles_rad",
        "maximum_joint_error_rad"
      ],
      "additionalProperties": false,
      "properties": {
        "joint_angles_rad": {
          "type": "array",
          "minItems": 7,
          "maxItems": 7,
          "items": {
            "type": "number",
            "minimum": -100,
            "maximum": 100
          },
          "x-unit": "rad",
          "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
          "description": "joint_angles_rad; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
        },
        "maximum_joint_error_rad": {
          "type": "number",
          "minimum": 0,
          "maximum": 100,
          "x-unit": "rad",
          "x-frame": "right_handed_world_xyz; +z_up; procedural_arm_base=world_origin",
          "description": "maximum_joint_error_rad; units=rad; frame=right_handed_world_xyz; +z_up; procedural_arm_base=world_origin"
        }
      }
    }
  }
}

Success: Exit 0, status=task_complete, success=true, finite outputs satisfying interface.output_schema and all declared numerical/model checks. This is not a physical robot or general task-success claim.

Timeout: 30 seconds. Caller must terminate the separate adapter process after 30 seconds; adapters bound iterations/scene steps and close simulation clients.

Failure modes

Source and license

Repository
https://github.com/bulletphysics/bullet3
Authors
Erwin Coumans and Bullet Physics contributors
Commit
2c204c49e56ed15ec5fcfa71d199ab6d6570b3f5
Archive SHA256
f7c486f10b9f645d0577249d02855e076e8368babaa3d31ced6095e7162baee9
License
Zlib
Hub commit
39b06d7a6016edcea27e348e49ffd86f29ec1811

Evidence

Runtime: task_complete / task_complete

Three frozen positive cases passed against this exact adapter; see per-case receipts. This does not estimate general accuracy.

Reviewer: Hub maintainer runtime harness | 2026-10-19

Submitter reports and hub verification remain separate. Source review does not establish task success.