Bipedal Robot
The bipedal robot is the final goal of this project. It reuses the QDD actuator hardware and CAN driver from the manipulator phase, extending them to a full 12-DOF biped (6 DOF per leg).
This section is a work in progress. It will be populated once the manipulator milestone is complete.
Planned Specification
| Property | Target |
|---|---|
| Height | ~900 mm standing |
| Mass | ~12 kg |
| DOF | 12 (6 per leg) |
| Actuators | 12× Robstride 00 |
| CAN buses | 2 (one per leg) |
| Battery | 6S LiPo, ~1 hour runtime |
| Target gait | Walking at 0.5–1.0 m/s |
Leg Joint Layout
Hip
● Joint 1 — hip abduction/adduction (frontal plane)
● Joint 2 — hip flexion/extension (sagittal plane)
● Joint 3 — hip rotation (transverse plane)
│
────── thigh (L1 = 280 mm) ──────
│
● Joint 4 — knee flexion/extension
│
────── shank (L2 = 260 mm) ──────
│
● Joint 5 — ankle pitch
● Joint 6 — ankle roll
│
[Foot]Development Roadmap
Manipulator milestone ← current focus
Validate actuators, CAN driver, kinematics, and control on a stationary 6-DOF arm.
Leg prototype
Build and characterise a single leg assembly. Verify joint limits, back-drivability, and touchdown force sensing.
Whole-body dynamics model
Implement a rigid-body dynamics model (e.g. via Pinocchio or a custom URDF parser) for both legs + torso.
Stance control
Implement QP-based whole-body control to hold a static standing posture with perturbation rejection.
Gait planning
Implement a footstep planner and swing-leg trajectory generator. Start with quasi-static walking.
Dynamic locomotion
Extend to dynamic gaits (trot, run) using model-predictive control (MPC) over the centroidal dynamics.
Key References
- MIT Mini Cheetah — B. Katz et al., A Low Cost Modular Actuator for Dynamic Robots, ICRA 2019
- Unitree Go1/Go2 — public hardware reference for similar QDD biped/quadruped design
- Whole-Body Control — O. Sentis & O. Khatib, Synthesis of Whole-Body Behaviors through Hierarchical Control, IJHR 2005
- Centroidal MPC — D. Kim et al., Highly Dynamic Quadruped Locomotion via Whole-Body Impulse Control, ICRA 2019