Origami Lunar Rover

01 | Problem Statement | Origami Rover

• Packing Problem: Landers carry spare volume, so a rover that flat-packs into that space can ride along and unfold once on the surface.

• Design Approach: A Miura-fold origami chassis that folds flat and unfolds on its own, using tensioned cables to control the opening angle and stiffness.

• Goal: Design, build, and demonstrate a flat-foldable rover with onboard actuators, sensors, and power, using closed-loop feedback to control folding and drive cable tension.

02 | Analysis & Design Process | Cable Tensioner Design

• Function: A motorized cable tensioner that uses a spring to hold constant tension in the cable while also measuring cable force directly.

• Purpose: Keeps the cable tight to ensure smooth, repeatable motion without overloading the structure or motor. The part doubles as a control element and sensor.

• Current Focus: Sizing spring, arm length, and motor for desired torque, while refining the design of the motor shaft-sleeve interface for repeatable operation.

03 | Manufacturing & Testing | Rigidity Testing & Assembly

• Torque Limitation: Initial testing showed the motor was not strong enough to fully compress the spring, and follow-up calculations confirmed the design needed a higher-torque motor.

• Spring Modeling: Tests conducted on a custom testbed showed the spring constant wasn't actually constant, so I collected torque-angle data and fit cubic, quadratic, and linear models to find the best fit curve.

• Electronics & Testing: Used Arduino to estimate cable force from sensor readings, and identified sources of measurement error before implementing PID control to hit a target force.

Luke Stratakos | (408) 805-9676 | lastratakos@gmail.com | linkedin.com/in/luke-stratakos