# Design, Fabrication, and Control Algorithm of Self-Reconfigurable Modular Intelligent Vehicles
###### Abstract  
Self-reconfigurable vehicles are able to transform into new formations on the basis of mutual communication and positioning so as to adapt to a new environment and new tasks. Compared with fixed-formation vehicles, reconfigurable vehicles feature multifunction and high reliability. First, a modular vehicle with a Mecanum wheel is designed, and a motion control method of a modular vehicle is derived through the establishment and analysis of its kinematics model. Afterwards, a visual positioning system based on AprilTag is designed, and the reconfiguration experiment of modular vehicles is completed in order to validate the feasibility of the proposed control method. A hardware control platform is built, which is able to realize the omnidirectional movement of the vehicle in the plane. The proposed modular vehicles with the corresponding control method successfully completes centralized perception, trajectory planning, and self-reconfiguration, which can be potentially applied in various scenarios, such as orientation guidance and logistics handling. modular; reconfiguration; motion control; multipoint communication +
Footnote †: journal: Applied
A modular reconfigurable vehicle system refers to a group of modular units with the same or different configurations assembled according to a series of unit groups, and it can change its original configuration through the reorganization and transformation of different units and actively adapt to different environments. The modular vehicle can be decomposed into general units for optimization and fabrication, which greatly reduces the difficulty of design, debugging, and maintenance. In 2002, the Japan Institute of Industrial Science and Technology designed a modular robot, M-TRAN III [3], as shown in Figure 2. Each subunit is composed of two U-shaped structures that can rotate around the rotating shaft. Each unit can rotate \(\pm\)90\({}^{\circ}\) under the action of the driving motor. Electromagnet coils are installed on each connecting surface to realize configuration reorganization and separation through the electromagnetic force generated between the two units. The Lausanne Federal Polytechnic University developed a self-reconfigurable modular robot, S-bot [4], as shown in Figure 3. The S-bot has an active gripper and a passive gripper for the interconnection between different units. Each unit is equipped with a differential track drive, intelligent sensing, and independent decision-making controller, which guarantees its movement in a complex environment. In 2010, the Beijing University of Aeronautics and Astronautics designed the Sambot modular robot [5], as shown in Figure 4. Each of its submodules integrates functions, such as driving, communication, power supply, and sensing, which guarantees independent decision making and mobility. Each Sambot unit has four active docking surfaces, which can independently reform the car configuration or bionic spider configuration, providing a multifunctional integrated platform. Experiments show that Sambot has the highest degree of freedom among the current self-reconfigurable robots. Figure 3: S-bot and swarm-bot self-reconfigurable modular vehicle. Figure 2: M-TRAN III modular robot. The self-reconfigurable crawler designed by the Shenyang Institute of Automation, Chinese Academy of Sciences [6], is shown in Figure 5. The original design intention is that when exploring in an unknown environment on the surface of extraterrestrial planets, the self-reconfigurable crawler can form into a large platform through reconfiguration. Each unit is capable of moving, docking, and communication. Through the cooperation of multiple independent units, the robustness of location environment detection can be greatly improved [7]. Swarmanoids are modular self-reconfigurable robots developed by [PERSON] at the Free University of Brussels, Belgium, in 2017 [8].