Advancements in Ballbot Design and Control
MiaPURE ballbot showcases agility and load capacity with effective control systems.
― 3 min read
Table of Contents
This article discusses the design and control of a robot called a ballbot. The aim is to create a robot that can move quickly, has a small size, and can carry heavy loads while remaining stable. Two test platforms were built to help with the design and to test how the Control Systems work. One of these platforms is a full-size ballbot called MiaPURE, which is designed to mimic the movements of a human. The other platform is a smaller version that allows for quick tests.
Ballbot Design
Ballbots are robots that balance on a sphere, allowing them to move in any direction. The design of MiaPURE focuses on achieving three main goals: high agility, a small footprint, and the ability to carry heavy items. The size of MiaPURE is similar to an average office chair, making it easy to move around in tight spaces. The ballbot can carry up to 60 kilograms and can move at a speed of up to 2.3 meters per second.
Control System
The control system is what helps the ballbot balance and move effectively. A specific type of controller called LQR-PI was developed. This controller combines a linear quadratic regulator and a proportional-integral controller. It was designed to help the ballbot manage the heavy weight and friction it faces. The controller was first tested on the smaller test platform before being put into the full-sized ballbot.
Testing the Control System
The testing of the control system was crucial because it needed to handle the challenges faced by the ballbot, such as balancing and overcoming friction. In the tests, the ballbot was made to stop quickly from a certain speed. The LQR-PI controller was found to perform better than other controllers in keeping the ballbot stable and responsive.
Results from Testing
During the tests, MiaPURE showed different maximum speeds depending on which direction it was moving. It was able to move quickly while carrying a load, demonstrating its capabilities in real-world conditions. The braking test was also successful, with the ballbot able to stop in a short amount of time without losing balance.
Applications
MiaPURE can be used in various situations, such as delivering packages or helping people move around while riding on it. The robot can be controlled remotely or with natural movements, like leaning the body to steer. This makes it a versatile tool for many applications.
Challenges and Limitations
While the MiaPURE ballbot showed good performance, some challenges remain. For example, the robot struggled to move backward without losing its balance. This is due to its design, which makes it more stable when moving forward or sideways. Adjustments need to be made to improve its balance in all directions.
Future Work
To improve the ballbot, researchers will need to look at how the design affects its ability to stay steady while moving. Understanding how the different parts work together will help in making better designs in the future. The goal is to make sure the robot can move safely and efficiently in various environments.
Conclusion
In summary, the development of the MiaPURE ballbot has shown promising results for creating a mobile robot that can carry heavy loads and navigate tight spaces. The research demonstrated how effective the LQR-PI controller is at managing balance and movement. The potential for practical applications in everyday tasks is significant, making this technology exciting for the future. As improvements are made, the MiaPURE ballbot could become an essential tool in various fields, offering innovative solutions for mobility and transport challenges.
Title: Design and Control of a Ballbot Drivetrain with High Agility, Minimal Footprint, and High Payload
Abstract: This paper presents the design and control of a ballbot drivetrain that aims to achieve high agility, minimal footprint, and high payload capacity while maintaining dynamic stability. Two hardware platforms and analytical models were developed to test design and control methodologies. The full-scale ballbot prototype (MiaPURE) was constructed using off-the-shelf components and designed to have agility, footprint, and balance similar to that of a walking human. The planar inverted pendulum testbed (PIPTB) was developed as a reduced-order testbed for quick validation of system performance. We then proposed a simple yet robust LQR-PI controller to balance and maneuver the ballbot drivetrain with a heavy payload. This is crucial because the drivetrain is often subject to high stiction due to elastomeric components in the torque transmission system. This controller was first tested in the PIPTB to compare with traditional LQR and cascaded PI-PD controllers, and then implemented in the ballbot drivetrain. The MiaPURE drivetrain was able to carry a payload of 60 kg, achieve a maximum speed of 2.3 m/s, and come to a stop from a speed of 1.4 m/s in 2 seconds in a selected translation direction. Finally, we demonstrated the omnidirectional movement of the ballbot drivetrain in an indoor environment as a payload-carrying robot and a human-riding mobility device. Our experiments demonstrated the feasibility of using the ballbot drivetrain as a universal mobility platform with agile movements, minimal footprint, and high payload capacity using our proposed design and control methodologies.
Authors: Chenzhang Xiao, Mahshid Mansouri, David Lam, Joao Ramos, Elizabeth T. Hsiao-Wecksler
Last Update: 2023-04-06 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2304.02887
Source PDF: https://arxiv.org/pdf/2304.02887
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
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