Bipeds
A two-legged robot with no humanoid torso, arms or head — legs and a body, built to study walking rather than to work with its hands.
- bipedal robot
- two-legged robot
What it is
A biped walks on two articulated legs and stops there: no human-proportioned torso, no arms, no head. It has the same balance problem as a walking humanoid, since it walks dynamically rather than standing on a stable base, but it leaves out everything above the hips. That is the trade: nothing to manipulate with and nothing to catch a fall, in exchange for a lighter, cheaper, simpler machine built only to walk. The LimX TRON 1 is the type specimen: legs under a compute box, with interchangeable point feet, soles or powered wheels.
Also called a bipedal robot, two-legged robot or point-foot biped. In this taxonomy it sits under Legged robot beside quadrupeds and multi-legged robots. The test is two articulated legs on a body that fails the humanoid test — no torso plus two arms plus a head in human proportion. Add those and it becomes a Bipedal humanoid.
What they are used for
- Locomotion research — training and testing walking controllers with reinforcement learning, where swapping feet on one robot isolates the gait problem.
- Teaching — a two-legged balance platform for courses on dynamics and control, with matching simulator models.
- Sensor and payload carrier — a small walking base for cameras or a light arm where stairs matter but a full humanoid does not.
What to compare
| Attribute | Why it matters | In this catalogue |
|---|---|---|
mass |
Light enough for one person to carry and to right after a fall | 20 kg (LimX TRON 1) |
height |
Sets step height and where a payload sits | not yet in the catalogue |
wheel_feet |
Powered wheels on the feet trade stairs for speed on flat floors | yes: LimX TRON 1 |
payload |
Compute, sensors or a small arm on the body | 10 kg (LimX TRON 1) |
battery_runtime |
Walking time; short, as on all legged platforms | 120 min (LimX TRON 1) |
dof_total |
Leg joints only; low counts compared with humanoids | not yet in the catalogue |
has_arm |
An add-on arm stays in this category | yes: LimX TRON 1 |
sdk |
Open joint control and simulator models are the reason to buy one | python (1) |
In the catalogue
Research: LimX TRON 1
Edge cases
- Two legs with a torso, two arms and a head: a bipedal humanoid, not a biped.
- Wheel-feet bipeds (TRON 1 in wheel mode): still a biped;
wheel_feet: true. - Self-balancing two-wheelers with no leg joints: a wheeled ground robot.
- A biped with a bolted-on arm: still a biped;
has_arm: true.
Related
Legged robot · Quadruped · Multi-legged · Bipedal humanoid · Wheeled robot
Rule of membership
Two articulated legs; fails the humanoid test (no torso + two arms + head in human proportion).
Category rb-3-2 in the whatrobot taxonomy.