Project
Eagle — Cable-Driven Floating Robot
My master thesis project — a cable-driven parallel robot I designed from scratch and took from concept to field-tested prototype in 6 months. The core innovation is a novel 'Coupled Drive' mechanism that shares torque between actuators, a first in the field. Presented at Swiss Robotics Day 2021. Thesis grade: 6.0/6.0.
Coupled Drive Mechanism
The key invention: a Coupling Matrix (Q_c) that interconnects actuators and cables so each motor contributes to multiple cable tensions simultaneously. Conventional cable robots use one motor per cable — the coupled drive shares torque across actuators, slashing peak motor requirements and energy consumption. This was essential for a platform that had to fly over steep agricultural terrain while carrying a Kinova Gen2 robot arm, solar panel, and payload.
Topology Optimisation & FEA
Every gram matters on a flying platform. I applied topology optimisation across all structural subsystems — wings, rope drums, actuator brakes, body frame — achieving 40% mass reduction while maintaining full structural safety under flight loads. Each component was FEA-validated for the real operating conditions: cable tensions, payload inertia, wind disturbance, and the dynamic loads of a robot arm moving on a suspended platform.
Prototyping & Field Testing
Concept to flying prototype in 6 months. Subsystems manufactured via SLA, SLS, and CNC machining. Field tests demonstrated hovering, external load disturbance recovery, elevation control, and workspace scanning — proving the coupled drive works in practice, not just in theory. Presented the results at Swiss Robotics Day 2021.
6 mo
Concept to Field Test
40%
Mass Reduction
6.0/6.0
Thesis Grade
Challenges
- Conventional direct-drive actuators were far too heavy for an aerial platform. The entire project hinged on finding a way to share torque across motors — something nobody had done in cable robotics before.
- Rope friction across coupled drum mates made force control highly non-linear. The theoretical coupling matrix was clean; the physical reality was not.
- Every structural component had to be mass-optimised to its limit while carrying a robot arm, solar panel, and harvesting payload over uneven terrain.
Outcomes
- First demonstrated proof that actuator coupling works as a drive mechanism in cable-driven parallel robots — a novel contribution to the field.
- 40% mass reduction across all structural subsystems through topology optimisation, validated by FEA and physical load testing.
- Concept to field-tested prototype in 6 months. Swiss Robotics Day 2021. Thesis grade: 6.0/6.0.