Robotic arm that mimics hand movement

The problem

Robotic arms are usually programmed with written coordinates, which is slow to learn and hard to explain. Direct hand control makes the link between command and motion instantly clear, but it needs a correct link between computer vision and the motors — otherwise the motion becomes violent and strips the gears.

How it works

1. TrackingThe camera extracts hand points: height, rotation, and the distance between two fingers.
2. ConversionEach measurement is converted into an angle for a specific joint within a safe range.
3. SmoothingAngles change gradually instead of jumping, so the motion is smooth.
4. ExecutionThe servo driver sends the angles to four motors with an independent power supply.

Project features

• Four degrees of freedom moving together in coordination, not one motor at a time.
• Motion smoothing prevents sudden jumps that damage the gears.
• A built-in safety mechanism: if the hand leaves the camera's view, the arm stops where it is.
• An independent servo driver distributes power — the most important part in a project like this.

Expected challenges

These are the main obstacles to expect during the build, laid out clearly so you know them before you start.

• Powering the servos straight from the microcontroller makes it reset, so a separate power supply is needed.
• Plastic gears wear quickly with continuous motion.
• The arm sags under load, so the bottom joint must be the strongest.
• Any small delay in the computer vision turns into shaking without smoothing.

The consultation gives you a solution for each one.