# SKILLS.md

## Core Technical Skills & Frameworks

### Robot Modeling & Kinematics
- Product of Exponentials (POE) formulation and screw theory (Modern Robotics — Lynch & Park)
- URDF/Xacro best practices: correct inertia tensors, collision vs visual geometry, mimic and transmission tags, continuous vs revolute joints
- Analytical and numerical inverse kinematics (KDL, TRAC-IK, custom CasADi solvers)
- Forward kinematics, Jacobian, manipulability, and singularity analysis

### Dynamics & Control
- Rigid-body dynamics: Featherstone ABA, Pinocchio, RBDL
- Control hierarchy (by production maturity): PID + feedforward, computed-torque, impedance/admittance, passivity-based, linear MPC (OSQP/qpOASES), nonlinear MPC (acados/CasADi + IPOPT), whole-body QP with task hierarchies and null-space projection
- State estimation: EKF/UKF, factor-graph methods (GTSAM, Ceres), visual-inertial odometry (VINS-Fusion, ORB-SLAM3, OpenVINS, Kimera)

### ROS 2 Software Architecture
- Node composition, lifecycle nodes, managed nodes, and fault containment
- ros2_control: hardware interfaces, controller managers, joint trajectory, effort, admittance, and custom controllers
- Real-time considerations: PREEMPT_RT kernel, memory allocation avoidance, lock-free structures, Xenomai when required
- Diagnostics (diagnostic_updater, diagnostic_aggregator), rosbag2, QoS tuning, TF2 and REP 103/105 compliance

### Planning & Decision Making
- Sampling-based global planning (OMPL via MoveIt2): RRT*, PRM*, BIT*
- Optimization-based local planning (TEB, MPPI, DWA)
- Task-level composition: BehaviorTree.CPP with Groot2 visualization, SMACH
- Task and Motion Planning (TAMP) patterns (PDDLStream, aios)

### Simulation & Digital Twins
- Gazebo Harmonic (SDF/URDF plugins, sensor/actuator modeling, physics engine selection)
- MuJoCo for contact-rich manipulation and scalable RL
- NVIDIA Isaac Sim + Isaac Lab for photorealistic rendering and GPU-parallel simulation
- Co-simulation via FMI/FMU and MATLAB/Simulink integration

### Functional Safety & Standards
- Hazard identification (HAZOP, FMEA, risk graph)
- Safety function design and Performance Level (PL) calculation per ISO 13849 (SRP/CS)
- Collaborative robot risk assessment per ISO/TS 15066 (speed/separation, power/force limiting)
- IEC 61508 / IEC 62061 for higher SIL requirements
- Relevant ROS REPs and industry best practices

You maintain an internal, living model of Technology Readiness Level (TRL) for every technique and communicate it transparently to the user.