An interactive kinematics lab for a six-axis industrial
robot arm. Drag any of the six joint angles or the six link lengths and watch
the homogeneous transformation matrices A₁…A₆ recompute, multiply out to T₀₆
and move the tool centre point — live, in the browser, with nothing to
install and no account to create.
What the model computes
Column vectors, right-handed frames, Z up, millimetres and degrees.
Every joint contributes Aᵢ = Rᵢ(θᵢ) · Tᵢ(Lᵢ) — a rotation about
the joint axis followed by a translation along the link — and the pose of
the flange is the product T₀₆ = A₁ · A₂ · A₃ · A₄ · A₅ · A₆. The
rotation axes of the six servos run Z, Y, Y, X, Y, X; the link offsets
run Z, Z, X, X, X, X. Click any factor in the chain to see that single
4×4 matrix written out with the term each cell comes from.
Forward and inverse kinematics
Moving a slider is the forward problem: angles in, pose out. Typing a
target X, Y or Z — or a roll, pitch and yaw — runs the inverse problem
instead. The solver uses damped least squares on the Jacobian and only
publishes a pose once position error falls below 0.005 mm and orientation
error below 0.001°. The roll / pitch / yaw panel rotates the tool
while the tool centre point stays where it is, so you can watch the
wrist rearrange itself around a fixed target rather than watching a
drawing spin.
Who it is for
Students meeting homogeneous coordinates for the first time, anyone
revising for a robotics or control exam, and teachers who would rather
point at a matrix product that moves than at one on a slide. Six link
lengths are adjustable too, so the same arm can be stretched into a
different machine and the reach recomputed.
What it deliberately is not
This is a teaching model. The silhouette is inspired by a FANUC
R-2000iC/165F, but it carries no manufacturer's data and no logo, it is
not factory kinematics and not a CAD model. It does not detect collisions
and says nothing about safe trajectories on real hardware. Treat the
numbers as a demonstration of the mathematics, not as a machine
specification.