Level 1 — Mechanical Structure
The physical body of a robot
Mechanical structure defines how a robot exists in physical space. Every movement, load, vibration, and limitation originates from its mechanical design.
Good mechanics simplifies control and electronics. Poor mechanics cannot be fixed by software.
Robot configurations
Common mechanical configurations include:
- Wheeled robots — simple, efficient, high speed
- Tracked robots — high traction and stability
- Legged robots — complex, adaptable terrain interaction
- Manipulators — precise control of position and orientation
Degrees of freedom
Each independent axis of movement adds one degree of freedom (DOF). More degrees of freedom increase flexibility but also complexity.
- 2–3 DOF — simple mobile platforms
- 4–6 DOF — articulated manipulators
- 7+ DOF — redundant and adaptive systems
Transmission mechanisms
Mechanical transmission converts motor motion into usable movement:
- Gearboxes — torque increase and speed reduction
- Belt drives — vibration damping and flexibility
- Chain drives — high load capability
- Worm gears — high reduction and self-locking
Center of mass
The center of mass defines robot stability. Poor mass distribution leads to tipping, oscillations, and increased control effort.
Mechanical design should place heavy components as low and as close to the center as possible.
Structural rigidity
Rigidity affects precision and repeatability. Flexible structures introduce delays, resonance, and unpredictable behavior.
- Short load paths improve stiffness
- Closed frames resist torsion
- Material choice defines vibration response
Next: Level 2 — Actuators & Motion