Trajectory shaping guidance for impact angle control of planetary hopping robots

Area of Science:

• Robotics
• Planetary Exploration
• Control Systems

Background:

• Planetary hopping robots face challenges with uncontrolled in-flight and after-landing motions, causing position drift.
• Accurate landing and trajectory control are crucial for robotic exploration of extraterrestrial surfaces.

Purpose of the Study:

• To present a novel optimal trajectory-shaping control concept for planetary hopping robots.
• To address and mitigate position drift caused by uncontrolled motions during hopping maneuvers.
• To enhance landing accuracy by controlling the impact angle and handling initial angle errors.

Main Methods:

• Utilizing the Generalized Vector Explicit (GENEX) guidance for optimal trajectory generation and shaping.
• Implementing the control concept on a thruster-based hopping robot.
• Generating lateral acceleration through thruster orientation control.
• Conducting extensive simulations on various surfaces and conditions.

Main Results:

• The proposed GENEX guidance successfully shapes optimal trajectories and satisfies end-point constraints, including impact angle.
• The control concept significantly reduces position drift at landing.
• The system demonstrates the ability to handle errors in initial hopping angles.
• Simulations confirm the impact angle's effect on position drift and the approach's viability on horizontal and sloped surfaces.

Conclusions:

• The novel optimal trajectory-shaping control concept effectively enhances the performance of planetary hopping robots.
• GENEX guidance provides a robust method for controlling hopping robot trajectories and minimizing landing errors.
• The approach offers a viable solution for improving the accuracy and reliability of planetary surface exploration robots.