Coordinated Pose Control of Mobile Manipulation with an Unstable Bikebot Platform

TL;DR

This paper introduces a novel coordinated pose control method for a stationary bikebot with manipulation capabilities, addressing stability and kinematic challenges for autonomous plant inspection.

Contribution

It presents a steering balance model, a balancing equilibrium manifold, and a control strategy for stable, coordinated manipulation on an unstable bikebot platform.

Findings

Achieved end-effector position accuracy of about 5 mm.

Achieved orientation accuracy of about 0.3 degrees.

Demonstrated feasibility for autonomous plant inspection.

Abstract

Bikebot manipulation has advantages of the single-track robot mobility and manipulation dexterity. We present a coordinated pose control of mobile manipulation with the stationary bikebot. The challenges of the bikebot manipulation include the limited steering balance capability of the unstable bikebot and kinematic redundancy of the manipulator. We first present the steering balance model to analyze and explore the maximum steering capability to balance the stationary platform. A balancing equilibrium manifold is then proposed to describe the necessary condition to fulfill the simultaneous platform balance and posture control of the end-effector. A coordinated planning and control design is presented to determine the balance-prioritized posture control under kinematic and dynamic constraints. Extensive experiments are conducted to demonstrate the mechatronic design for autonomous plant inspection in agricultural applications. The results confirm the feasibility to use the bikebot manipulation for a plant inspection with end-effector position and orientation errors about 5 mm and 0.3 degs, respectively.