A mobile robot is a machine can locomote and do the work of a person on its own. It is capable to move around its environment. It can work automatically or can be controlled by a computer or operator. Mobile Robots offer mobility, a certain level of autonomy and perception.
A mobile robot is a combination of various hardware and software components. Hardware components of mobile robots is composed of locomotion, sensing, reasoning and communication.
Locomotion is the study off how the robot moves around its environment. Sensing is the study of how the robot measures properties of itself and its environment. Reasoning focuses on how the robot maps the measurements into actions. Communication is the study of how the robot communicates with an outside operatör. Software components of mobile robots is planning in various aspects.
A mobile robot consists of a vehicle, host software, wireless communication, user interface, battery/charger.
Mobile robots are being used for various processes in warehouses&facilities. Some of the processes they are used for are material flow and transport; distribution, high-density storage&high speed sortation; production and manufacturing support system.
In this report, only unmanned ground mobile robots for warehousing&logistic management will be focused.
2.1 Automated Guided Vehicle, AGVs
AGV systems are material handling systems featuring automatically controlled, unmanned vehicles. They are typically used where high volumes of repetitive movements of material are required when there is little or no human decision making skill is required to perform the movement.
An AGV is directed by a pre-programmed guidance system that varies in complexity based on the function being performed. There are different types of navigation systems used for AGV.
Most common navigation systems for AGV are LGV and Fixed path systems.Laser guided AGVs rely on mounted laser scanners to function accurately. The scanners emit a laser onto a target, then reflects it back. Based on the amount of time it takes the reflection to return, the AGV can determine target distance. It orients itself in relation to its distance from the target. Fixed path systems use an embedded wire, magnetic tape or colored paint as a guide for very simple vehicle routes. The AGV is equipped with sensors and frequencies that respond to the wire or tape and allow it to follow a path. These simple systems can be quite accurate and reliable, although they do not allow for the flexibility that some applications may require.
AGVs use a wide range of navigations systems such as Free-range navigation systems; Camera guidance navigation systems; Optical guidance naigation systems and Inertial guidance navigation systems.
Early models of AGVs were guided using wires and tapes but today AGVs are mostly navigated by using lasers. These types of vehicles known as laser-guided vehicles(LGVs), that products are moved efficienty throughout the warehouse.
AGV replace the maually operated material handling vehicles such as forklift and the labor force who operate the vehicle. Therefore usage of AGV in plants reduceses the money spent on labor and operating&maintenance cost of material handling vehicles. AGV transport materials more effectively and efficiently compare to manual labor. Usage of AGV increases the production in factories and speeds up the logistics processes in facilities. Due to the need for initial infrastructure AGV may seem like an expensive investment but in the long run it is the best way to reduce costs as it eliminates manual labor. AGV creates a safe work environment and eliminates forklifts accidents. If an obstacle is in front of the AGV, It stops immediately. In conlusion, AGV provides safe, efficient, cost-effective movement of materials.