Dissect a Robot
You have spent the last eight lessons learning the vocabulary and concepts behind every major subsystem of a robot. Now it is time to use them. In this lesson, you will choose a real robot — one that actually exists and has been deployed — and systematically dissect it: identify each of its five subsystems, understand why they were designed the way they were, and trace how they work together. This is exactly what robotics engineers do when they study competitors' designs or audit their own.
How to Dissect a Robot
A robot dissection follows five questions, one per subsystem. For sensors: What information does this robot need from its environment? What sensors collect that information, and what physical quantities do they detect? For the controller: What kind of computer runs this robot? Is it a microcontroller, a single-board computer, or a multi-computer architecture? For actuators: How does this robot move itself or manipulate objects? What motor types or other actuators enable that motion? For power: Where does this robot's energy come from? What batteries, capacity, or external power supply does it use, and what limits its operational time? For the frame: What shape is this robot and why? What materials is it built from, and how does its form reflect its function? After answering all five, you synthesize: how do the subsystems interact? Where are the most interesting engineering tradeoffs in this design?
The best robots to analyze are ones with publicly available technical information. Strong choices include: NASA's Perseverance Mars rover (NASA publishes engineering details), Boston Dynamics' Spot quadruped robot (good press coverage and technical papers), the da Vinci surgical robot (surgical journals and company materials), Amazon's Proteus warehouse robot, and classic FIRST Robotics competition robots (full technical documentation is open). Your school or local library may have access to robotics journals.
Full Robot Dissection
- Step 1: Choose your robot. Pick one real, deployed robot from this list or propose your own with teacher approval: (A) NASA Perseverance Mars rover, (B) Boston Dynamics Spot, (C) Intuitive Surgical da Vinci Xi, (D) Amazon Proteus warehouse robot, (E) DJI Phantom 4 Pro drone, (F) a FIRST Robotics Competition robot of your choice.
- Step 2: Research your robot. Find at least two reliable sources (manufacturer specs, engineering papers, NASA documentation, reputable tech journalism). Write down your sources.
- Step 3: Complete the Subsystem Map. For each of the five subsystems, fill in the details:
- SENSORS — List every sensor you can identify. For each, name the physical quantity it measures and why this robot needs that information.
- CONTROLLER — What computer(s) run this robot? Is the architecture real-time, general-purpose, or layered?
- ACTUATORS — List every actuator. What type is each (DC motor, servo, pneumatic, etc.)? What motion does each produce?
- POWER — What is the power source? What is the battery capacity or power rating? What limits operational time or range?
- FRAME — What is the overall shape and why? What materials? How does the geometry reflect the task environment?
- Step 4: Trace one complete sense-think-act cycle for your robot. Pick one specific task it performs (avoiding an obstacle, picking up an object, landing safely) and trace the exact path from sensor detection through controller decision to actuator response.
- Step 5: Identify the three most interesting engineering tradeoffs in this design. For each, explain what was gained and what was sacrificed.
- Step 6: If you could add one sensor, upgrade one actuator, or change one structural material, what would it be and why? What new capability would it unlock — and what new problems might it introduce?
What a Good Dissection Looks Like
A thorough dissection goes beyond naming parts. It explains relationships. Saying 'the rover has a camera' is naming. Saying 'the rover has seven cameras including hazard-avoidance stereo cameras that feed into an autonomous navigation algorithm running on a radiation-hardened computer, because the 24-minute radio delay to Earth makes remote driving too slow and dangerous' is dissecting. The difference is understanding why each part exists and how it connects to the robot's mission. The best dissections also engage with the engineering constraints. Perseverance weighs 1,025 kg but must survive the violent deceleration of Mars atmospheric entry. Its aluminum chassis uses a rocker-bogie suspension system that keeps all six wheels in contact with the ground regardless of rocky terrain without needing active suspension — an elegant passive mechanical solution that reduces the control complexity dramatically. That is the level of insight that a dissection can reveal.
After you complete your dissection, notice how deeply every design choice reflects the robot's deployment environment. Perseverance's arm joints are driven by brushless DC motors chosen for function in minus-80 degree Celsius temperatures. Spot's legs are designed around a dynamic running gait that handles stairs and snow. The da Vinci's instruments are wristed with 7 DOF in a tiny package designed to fit through a centimeter-wide incision. Every robot is a solution to a specific problem, and every part of it answers a specific constraint.
During your dissection you find that a Mars rover uses multiple independent computers: one for autonomous navigation and one for science instrument control. What architecture is this, and why might engineers design it this way?
You are dissecting a drone and notice it has no GPS sensor but does have a downward-facing camera and an optical flow sensor. What can you infer about this drone's design intent?