Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack
In many cases, a pack of robots holds an advantage over a single robot such when an oversized or over-weighted load is to be carried. In such cases, a single robot will not do. Nevertheless, this may not be an easy task for a pack of robots as well, especially when the load needs to be lifted off th...
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| Format: | Article |
| Language: | English |
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IEEE
2023-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/10038682/ |
| _version_ | 1797894965301346304 |
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| author | Harel Cohen Shlomi Hacohen Nir Shvalb Oded Medina |
| author_facet | Harel Cohen Shlomi Hacohen Nir Shvalb Oded Medina |
| author_sort | Harel Cohen |
| collection | DOAJ |
| description | In many cases, a pack of robots holds an advantage over a single robot such when an oversized or over-weighted load is to be carried. In such cases, a single robot will not do. Nevertheless, this may not be an easy task for a pack of robots as well, especially when the load needs to be lifted off the ground making the cooperative task less tolerant of errors. The limited research on such a load can be attributed to the mechanical complexity of the problem. Notably, previous studies have not considered the spatial, decentralized, communication-free scenario. We, therefore, consider a robotic pack of six agents that assumes the task of spatially moving a load through a cluttered space. As it transports the load, the pack carefully avoids planar obstacles while maintaining its orientation. To do so, we model the whole system as a six Prismatic-Prismatic-Spherical-Spherical (6-PPSS) redundant mobile platform, having twelve degrees of freedom. This paper focuses on a decentralized control scheme where no mutual communication is needed. Each agent calculates its ego movements according to the height of its corresponding load-node; the surrounding obstacles, and; the goal’s relative position. To avoid numerical errors appearing in the vicinity of singular configurations, we calculate the platform’s forward kinematics in the model’s full configuration space. We then show how this rationale can be further extended to formulate a distributed control scheme for the motion planner. We demonstrate our algorithms in several simulated scenarios and in a set of real-world experiments using specially designed omnidirectional robot agents. We test the ability of the pack to maintain the load’s orientation just by measuring the load’s height at the holding node of each agent. Lastly, we measured the time required for the pack to assume a desired load orientation. Results indicated that even in the presence of a 10-degree tilt error, the load was able to be restabilized within a maximum of 15 seconds in simulated conditions and 20 seconds in real-life experiments. |
| first_indexed | 2024-04-10T07:18:57Z |
| format | Article |
| id | doaj.art-d45bf088375841c7bd51cf855d053f89 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-04-10T07:18:57Z |
| publishDate | 2023-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-d45bf088375841c7bd51cf855d053f892023-02-25T00:02:00ZengIEEEIEEE Access2169-35362023-01-0111165571656610.1109/ACCESS.2023.324304310038682Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic PackHarel Cohen0Shlomi Hacohen1https://orcid.org/0000-0002-6487-161XNir Shvalb2https://orcid.org/0000-0001-8246-3727Oded Medina3https://orcid.org/0000-0001-6590-0059Department of Mechanical Engineering, Ariel University, Ariel, IsraelDepartment of Mechanical Engineering, Ariel University, Ariel, IsraelDepartment of Mechanical Engineering, Ariel University, Ariel, IsraelDepartment of Mechanical Engineering, Ariel University, Ariel, IsraelIn many cases, a pack of robots holds an advantage over a single robot such when an oversized or over-weighted load is to be carried. In such cases, a single robot will not do. Nevertheless, this may not be an easy task for a pack of robots as well, especially when the load needs to be lifted off the ground making the cooperative task less tolerant of errors. The limited research on such a load can be attributed to the mechanical complexity of the problem. Notably, previous studies have not considered the spatial, decentralized, communication-free scenario. We, therefore, consider a robotic pack of six agents that assumes the task of spatially moving a load through a cluttered space. As it transports the load, the pack carefully avoids planar obstacles while maintaining its orientation. To do so, we model the whole system as a six Prismatic-Prismatic-Spherical-Spherical (6-PPSS) redundant mobile platform, having twelve degrees of freedom. This paper focuses on a decentralized control scheme where no mutual communication is needed. Each agent calculates its ego movements according to the height of its corresponding load-node; the surrounding obstacles, and; the goal’s relative position. To avoid numerical errors appearing in the vicinity of singular configurations, we calculate the platform’s forward kinematics in the model’s full configuration space. We then show how this rationale can be further extended to formulate a distributed control scheme for the motion planner. We demonstrate our algorithms in several simulated scenarios and in a set of real-world experiments using specially designed omnidirectional robot agents. We test the ability of the pack to maintain the load’s orientation just by measuring the load’s height at the holding node of each agent. Lastly, we measured the time required for the pack to assume a desired load orientation. Results indicated that even in the presence of a 10-degree tilt error, the load was able to be restabilized within a maximum of 15 seconds in simulated conditions and 20 seconds in real-life experiments.https://ieeexplore.ieee.org/document/10038682/Swarm roboticsparallel robotsmotion planningdecentralized control |
| spellingShingle | Harel Cohen Shlomi Hacohen Nir Shvalb Oded Medina Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack IEEE Access Swarm robotics parallel robots motion planning decentralized control |
| title | Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack |
| title_full | Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack |
| title_fullStr | Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack |
| title_full_unstemmed | Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack |
| title_short | Decentralized Motion Planning for Load Carrying and Manipulating by a Robotic Pack |
| title_sort | decentralized motion planning for load carrying and manipulating by a robotic pack |
| topic | Swarm robotics parallel robots motion planning decentralized control |
| url | https://ieeexplore.ieee.org/document/10038682/ |
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