What you can learn here
Forward kinematics
If you know the angle of every joint, you can work out where the tool is. On the SCARA, trigonometry is enough: x = L1·cos θ1 + L2·cos(θ1 + θ2). On a 6-axis arm such as the KUKA arm, six transformation matrices are multiplied, one per joint, defined with the Denavit–Hartenberg convention. Move the joints and watch how the tool position changes.
Inverse kinematics
The opposite problem is the one a real robot controller solves: “I want the tool here; which angles do I need?”. On the SCARA there is an exact solution and almost always two answers, with the elbow to the left or to the right. On the KUKA arm the lab solves it numerically, correcting the angles step by step with the Jacobian until the pose matches: try it by jogging in World or Tool coordinates.
Workspace and limits
The SCARA’s shaded area is everything the robot can reach while respecting its joint limits. A point can be at the right distance and still be unreachable because it would require rotating a joint past its stop. Change L1 and L2 and watch the area deform.
Singularities
When the SCARA’s arm is fully stretched, or when the KUKA arm’s A5 axis is at 0° and axes 4 and 6 line up, the robot loses the ability to move in some direction: small tool corrections would demand huge joint speeds. The lab warns you when you get close to one.
Point-to-point programming
Industrial robots are programmed by saving positions and joining them with paths. On the KUKA arm you save points and join them with PTP, LIN and CIRC moves; the simulator writes the program in a format similar to that of real controllers.
Real robots
SCARAs are common in electronics assembly and packaging because they are fast in the plane; 6-axis arms are used for welding, palletizing and handling. The models in this lab are generic and educational: each commercial robot’s dimensions and limits are in its datasheet.
KUKA arm: welding cell
Operate a robot as on the shop floor: T1, T2 and AUT modes, enabling switch, emergency stop and arc-welding programs (ARC ON, ARC SWI, ARC OFF). Before welding you must get ready as in a real workshop: welding glasses, shielding gas, fume extraction and the ground clamp. Open the KUKA arm.
Keep learning with the angular velocity calculator, the torque and power calculator, the Mechanism Lab or the Mechatronics Engineering path.