Throw Maneuver: Exact Trajectories for Invariant Target Hitting in Robotic Throwing
Sheng Cheng, Ziyin Han, Rong Wang, NAIRA HOVAKIMYAN
AI summary
Problem
Existing robotic throwing methods rely on a single precise release point, making target-hitting highly sensitive to inevitable release delays and mechanical uncertainties.
Approach
The authors derive exact ordinary differential equations that define a carrier trajectory where any object released at any moment along the path will invariantly reach the target, with analytical solutions for special cases.
Key results
- Exact ODE-based trajectory derivation with analytical solutions for special cases
- Simulation validation confirming invariant target-hit property across varying release times
- Outdoor quadrotor experiments showing superior accuracy and precision over baseline methods
- Demonstration of reliable sequential throwing despite hardware release delays
Why it matters
Enables reliable, delay-robust robotic throwing for real-world aerial applications like material transport and firefighting where timing precision is critical.
Abstract
Robots can throw objects to distant targets using gravity, with applications ranging from material transport to firefighting. Existing approaches typically adopt a singleton throw formulation, where the carrier must reach a specific position–velocity configuration at the moment of throw. This reliance on a single throw point makes target-hitting highly sen- sitive to release delays. To address this limitation, we introduce the throw maneuver: a carrier trajectory that guarantees target hitting for objects released at any time along the trajectory. By differentiating the governing projectile equations, we derive the throw maneuver in its exact representation as ordinary differential equations, with analytical solutions available in special cases. Simulation results verify its invariant target-hit property and show that throw maneuvers achieve longer avail- able throw time and ranges without target miss compared with a strong baseline throw method. Outdoor quadrotor experiments further demonstrate throw maneuver’s improved accuracy and precision under realistic flight conditions compared with several baseline throw methods.