On distributed mechatronics controller for omni-directional autonomous guided vehicles

Purpose – In this paper, two omni-directional mobile vehicles are designed and controlled implementing distributed mechatronics controllers. Omni-directionality is the ability of mobile vehicle to move instantaneously in any direction. It is achieved by implementing Mecanum wheels in one vehicle and conventional wheels in another vehicle. The control requirements for omni-directionality using the two above-mentioned methods are that each wheel must be independently driven, and that all the four wheels must be synchronized in order to achieve the desired motion of each vehicle. Design/methodology/approach – Distributed mechatronics controllers implementing Controller Area Network (CAN) modules are used to satisfy the control requirements of the vehicles. In distributed control architectures, failures in other parts of the control system can be compensated by other parts of the system. Three-layered control architecture is implemented for; time-critical tasks, event-based tasks, and task planning. Global variables and broadcast communication is used on CAN bus. Messages are accepted in individual distributed controller modules by subscription. Findings – Increase in the number of distributed modules increases the number of CAN bus messages required to achieve smooth working of the vehicles. This requires development of higher layer to manage the messages on the CAN bus. Research limitations/implications – The limitation of the research is that analysis of the distributed controllers that were developed is complex, and that there are no universally accepted tool for conducting the analysis. The other limitation is that the mathematical models of the mobile robot that have been developed need to be verified. Practical implications – In the design of omni-directional vehicles, reliability of the vehicle can be improved by modular design of mechanical system and electronic system of the wheel modules and the sensor modules. Originality/value – The paper tries to show the advantages of distributed controller for omni-directional vehicles. To the author's knowledge, that is a new concept

Distributed control architecture of an omni-directional autonomous guided vehicle

Omni-directionality is the ability of a mobile robot to move instantaneously in any direction. This paper describes the wheel and controller designs of a Mecanumwheeled, autonomous guided vehicle (AGV) for reconfigurable manufacturing systems. Mecanum wheels use slip developed between rollers and surface, surface and ground, to achieve omni-directionality. An advantage of omni-directional robotic platforms is that they are capable of performing tasks in congested environments such as those found in factory workshops, narrow aisles, warehouses, etc. Controller Area Network (CAN) is implemented as a distributed controller to control motion and navigation tasks of the developed robot. The design of the distributed controller is described and its performance analyzed. This increases the reliability and functionality of the mobile robot.Die artikel beskryf wiel - en beheerontwerpe van ‘n veelrigting mobiele robot. Die robot is ‘n selfstandigbeheerde voertuig vir gebruik by vervaardigingstelsels met veranderbare konfigurasie. Die ontwerp van die robot en bypassende beheerstelsel word beskryf en ontleed teen die agterground van bewegings– en navigeertake. Die betroubaarheid en funksionering van die sisteem word beoordeel

A modular design of a wall-climbing robot and its mechatronics controller

The modular design of a wall-climbing robot, implementing two articulated legs per module (biped robotic modules), is presented in this paper. Modular design improves a wall-climbing robot’s manoeuvrability and flexibility during surface changes or while walking on uneven surfaces. The design of the articulated legs uses four motors to control the posture of the vacuum cups, achieving the best possible contact with the surface. Each leg can contain more than five sensors for effective feedback control, and additional sensors such as gyros, CCD sensors, etc, can be fitted on a module, depending on the robot’s application. As the number of modules used in the design of the robot is increased, the number of activators and sensors increases exponentially. A distributed mechatronics controller of such systems is presented.AFRIKAANS: Modulêre ontwerp van 'n muurklim-robot met twee geskarnierde bene per module (twee-benige robotmodules) word in hierdie artikel weergegee. Modulêre ontwerp verbeter die muurklim-robot se beweeglikheid en aanpasbaarheid tydens veranderings in die loopvlak of terwyl dit loop op ongelyke oppervlaktes. Ontwerp van geskarnierde bene implementeer vier motors wat die oriëntasie van vakuumsuigdoppe beheer om die bes moontlike kontak met die loopvlak te handhaaf. Elke been kan meer as vyf sensors hê vir doeltreffende terugvoerbeheer, en bykomende sensors soos giroskope, CCD sensors, ens. kan by 'n module gevoeg word soos die toepassing van die robot dit mag vereis. Soos die aantal modules wat in die ontwerp van die robot gebruik word, toeneem, neem die aantal aktiveerders en sensors eksponensiëel toe. 'n Verdeelde megatroniese beheerder van sulke stelsels word aangebied