Smart Automated Guided Vehicle for Flexible Manufacturing Systems

Abstract

In a Flexible Manufacturing System (FMS) the automation and the ability to restructure the manufacturing facility is essential. The material handling and storage system is as important as the workstation in an FMS. The development of an industrial, discretely working Smart Automated Guided Vehicle (SAGV) will be a stepping stone to make the FMS completely autonomous. The SAGV will solve the problem of existing material handling systems like conveyors and manual handling systems. The objective is to develop a compact unit load SAGV to increase efficiency and productivity in FMS.
The research paper was studied to take the knowledge of working of the Radio-Frequency Identification (RFID) tags and extended the concept to the line following SAGV to eliminate the errors in de-railing [1]. The material picks and place and transfer methodology were adopted. The basic issues of designing and installing a system of SAGV in a Flexible Manufacturing System (FMS) are examined in this work. The development, advantages and future trends of SAGVs are briefly reviewed [2]. The design, implementation, and experimental results of an RFID based wireless control of a distributed microcontroller-based SAGV to integrate a discretely working SAGV to a centralized monitoring network [3]. The benefits of a simulation model that compares several common fixed layouts with the shortest connection approach were studied through this. The avoidance of collisions plays an important role and paved the way for the SAGV [4].
To overcome the problems of conventional material handling systems and to improve the efficacy of manufacturing some important features are added to it along with the traditional navigation technology. In the SAGV, to follow the line in specified paths, an IR sensor is used, unlike the RFID technology. An important feature, a weight sensing system that runs SAGV only when a specified amount of weight is added to it, to eliminate errors in the timer-based systems. To include the Obstacle detection system is an important feature that avoids any objects in the path to provide a safe environment to the SAGV as well as its surroundings. To include auxiliary functions like Battery level monitoring, Sensor health, communication etc., is necessary for the discretely operating systems for providing safe and fully automatic systems and to reduce human dependency.
The plan is to design and manufacture the Chassis based on the space requirements to mount the Motor, Battery, Microcontroller, Infrared sensor, Ultrasonic Sensor, Load cell Etc. Infrared sensors enable SAGV to follow the black line. The high or low signal is given by the sensor based on the black or non-black surface respectively, and the microcontroller actuates the motor based on this input. Weight sensing is an important feature that makes the working of the automatic guided vehicle more efficient. The load cell detects the weight placed on the unit load type SAGV and this is further connected to the analog to digital converter (ADC) to feed the changes in the load placed on the SAGV. An ultrasonic sensor is used to detect obstruction in the path of the SAGV. The main purpose of this system is to avoid accidents or to prevent SAGVs from any damages. It measures the distance dynamically and feeds it to the microcontroller for the control of the actuation system. Then the actuation system works through a motor controller L293D is connected to the microprocessor, then two DC motors are connected to the motor controllers. The motor controller allows speed and direction control of the motors simultaneously using the concept of Pulse Width Modulation through the H bridge. Using these major subsystems, the plan is to achieve the objectives of the project. The list of components, part number and application are listed in table 1.

The idea behind this project is automation in an FMS environment. An analytical, simulation model needs to be developed for the SAGVs to overcome large computation times, congestion, deadlocks and delays in the system. Using SAGV increases workplace safety in addition to removing the human element, which is the root cause of many accidents. They can perform tasks that are hazardous to humans, such as handling hazardous substances, working in extreme temperatures, and moving heavy materials, thus being helpful. In general, mechatronic systems are environmentally friendly as they don’t require fossil fuels or their by-products like hydraulic oils in their operation depicts the industrial, research, societal and environmental motivations to take up the project.

Table 1. List of components and their application Components Part Number Applications in SAGV