Dynamic Coupling and Indirect Control of Jointed Robots Rolling Atop A Moving Platform
Two-link robots roll atop moving platforms with fish-like undulatory locomotion...
In a new paper on arXiv, researchers Hamidreza Moradi and Scott David Kelly explore the dynamic coupling and indirect control of jointed robots rolling atop a moving platform. The system features an asymmetric two-link robot supported by wheels that roll and pivot freely but do not slip laterally. By actuating the joint between the links internally, the robot develops forward momentum through oscillations that generate undulatory locomotion, reminiscent of fishlike swimming. This design leverages passive wheel dynamics to convert joint motion into directed movement without direct propulsion.
When two such robots are placed on a common platform free to translate with its own inertial dynamics, their individual dynamics become coupled. This means each robot's locomotion influences the other, creating a complex interaction. The team developed a mathematical model and ran simulations to demonstrate this behavior. Additionally, they explored a scenario where a single robot with an unactuated joint rolls atop a controlled platform. By using the platform's acceleration as an input, they could dictate the robot's heading to track a chosen function of time. This control is sufficient to make the robot orbit a fixed point on the platform or move persistently in a desired direction, opening up new possibilities for robotic manipulation and coordinated movement.
- Asymmetric two-link robot generates forward momentum via joint oscillations, mimicking fishlike swimming.
- Two robots on a shared platform exhibit coupled dynamics, influencing each other's locomotion.
- Platform actuation alone can control a robot's heading, enabling orbiting or persistent directional movement.
Why It Matters
This research offers a novel method for controlling robots without onboard actuators, useful for swarm coordination and mobile platforms.