Quanser QArm – Adaptive Robotic Control in Lab

This lab series used the Quanser QArm, a 4 degree-of-freedom (DoF) robotic arm designed for control systems and robotics education. Each lab introduced a new control method or sensor strategy. Over the quarter, we worked with forward and inverse kinematics, visual servoing, and lead-through teaching.

The QArm was programmed using Simulink and MATLAB. This made it a good platform for testing control logic and running simulations. One of the first labs focused on lead-through teaching. Instead of coding each joint position, we manually guided the arm through a full pick and place routine. The robot recorded the motion and could replay it with good accuracy. This reduced the complexity of solving inverse kinematics for every point in the cycle.

In another lab, we implemented visual servoing. A camera was mounted on the arm. Its task was to track the green side of a Rubik’s cube in real-time. We used MATLAB to detect the centroid of the green face and calculate position error. That error was used to update joint targets. The system adjusted as the cube moved to keep it centered in the camera frame. Performance was not perfect. For example, the robot passed through a singularity during testing. But overall, the visual tracking held well.

All motion plans were first modeled in Simulink. This helped catch errors and avoid hardware crashes. We used PID controllers for joint-level control and tested performance using built-in scope tools. These let us track joint angles and end-effector position error over time.

Each lab used a finite state machine to structure behavior. States controlled different steps in the task such as “search,” “move,” and “grasp.” Transitions were based on timers or sensor feedback. This method kept the system logic simple and easy to follow.

The QArm labs gave us hands-on experience with robotic systems. We worked with control flow, sensor integration, and real-time feedback. The platform was reliable and recoverable which helped us test ideas without major risk. These labs were a strong introduction to practical robotics.