A project focused on simulating the forward and inverse kinematics of a SCARA robot using MATLAB & Simulink. The SCARA (Selective Compliance Articulated Robot Arm) is widely used in pick-and-place and precision assembly applications, making it an ideal test case for academic modeling, validation, and simulation.
- Year: 2025
- Industry: Mechanical Simulations
- Client: University Project
- Duration: 1 Month
To model, analyze, and validate the kinematic behavior of a SCARA robot, including its workspace, degrees of freedom, and motion trajectories using MATLAB & Simulink.
The SCARA robot model has 3 degrees of freedom (DOF):
- θ1 (Theta1): Base rotation joint (−145° to +145°)
- θ2 (Theta2): Elbow rotation joint (−145° to +145°)
- d3 (Prismatic Joint): Vertical displacement (−0.23 m to +0.07 m)
- θ4 (end-effector rotation) is ignored, as the model uses a suction-type end effector.
- Horizontal: Circular area defined by reach (L1 + L2).
- Vertical: Range from −0.23 m to +0.15 m.
The robot was modeled using SolidWorks → Simulink Multibody Integration.
- Link 1 (L1): 40 cm
- Link 2 (L2): 30 cm
- Prismatic Joint (d3): Range −0.23 m to +0.07 m
- Geometry & joints defined in CAD.
- Exported as XML via Export CAD to XML.
- Imported to Simulink using smimport.
| Link | aᵢ | αᵢ | dᵢ | θᵢ |
|---|---|---|---|---|
| 1 | L1 | 0 | 0 | θ1 |
| 2 | L2 | 0 | 0 | θ2 |
| 3 | 0 | 0 | −d3 | 0 |
| 4 | 0 | 0 | 0 | θ4 (ignored) |
-
Planar Position: X = L1·cos(θ1) + L2·cos(θ1 + θ2) Y = L1·sin(θ1) + L2·sin(θ1 + θ2)
-
Vertical Position: Z = -d3
- Compute reach radius: R = √(X² + Y²)
- Solve θ1, θ2 using trigonometric relations.
- Compute d3 directly from Z.
- Validate by feeding results back into forward kinematics.
Implemented both script-based computation and block-based simulation.
- Input joint values via script.
- End-effector position output in MATLAB console.
- Motion visualization in Simulink.
| Case | Joint Inputs (θ1, θ2, d3) | Status |
|---|---|---|
| 1 | (140°, 100°, 0.01 m) | ✅ Simulated successfully |
| 2 | (−145°, −145°, 0.015 m) | ✅ Simulated successfully |
| 3 | (130°, −135°, 0.07 m) |
- Verified forward & inverse kinematics through MATLAB-Simulink integration.
- Validated workspace boundaries for both planar and vertical reach.
- Implemented error handling for out-of-range configurations.
- Delivered a modular workflow for future robotic manipulator simulations.
This project provided practical insights into:
- Kinematic modeling of SCARA manipulators.
- Using DH parameters for forward/inverse analysis.
- Integrating CAD, MATLAB, and Simulink for robotic simulations.
- Validating theoretical equations with simulation-based testing.