Warehouse Material Handling Research Articles

Lifting platform PWM control system design combining distance detection

Abstract The design of this system aims to achieve running speed control of a lifting platform based on pulse width modulation (PWM) technology, combined with weight and distance detection. The system consists of a microcontroller unit (MCU), pressure sensor, ultrasonic ranging, L298N motor drive, LCD1602 display, keys, and alarm modules. The system generates corresponding PWM signals based on the weight of load and distance between the platform and the starting point to control the speed of lifting the platform DC motor, ensuring the safety and stability of the lifting process. The system’s overall functionality has been verified through simulation by PROTEUS 8.15 and tested through physical circuit construction. This control system can achieve real-time and accurate lifting speed control of the platform, and has good performance and stability. The design is simple and can be applied to various occasions such as industrial production lines, warehouse material handling, and high-altitude operations, improving work efficiency and reducing the risk and burden of manual operations.

Redesign Production Layout Using Dedicated Storage Method: Case Study of PT.Solo Grafika Utama

PT. Solo Grafika Utama is one of the companies in the field of newspaper production. The newspaper industry has strict production characteristics. Therefore, it requires a good factory layout in order to create effectiveness and production efficiency. The warehouse layout in PT Solo Grafika Utama still deficient in the application of material handling in warehouses so that it often raises problems. The problem is that the product arrangement in the warehouse is not optimal because there are still products stored in an wrong place. This article aims to provide an effective and efficient proposal to improve warehouse layout in PT Solo Grafika Utama using the dedicated storage method. Dedicated Storage is chosen to improve warehouse arrangement and minimize the distance of product displacement. After the proposed improvement, a better warehouse layout is obtained. In the proposed layout can also minimize the product displacement distance of 23% from the initial distance. Thus it can be said that the proposed layout is better than the initial layout and can be proven to be able to facilitate the handling of materials in the warehouse so that it can make newspaper production more effective and efficient.

Dynamic Resource Reservation Based Collision and Deadlock Prevention for Multi-AGVs

Automated guided vehicles (AGVs) are widely used for material handling in warehouses and automated production lines due to their high efficiency and low cost. However, AGVs usually interact with each other because of the restricted capacity of the layout. Although many algorithms have been proposed to address the problem, most of them are inefficient for collision and deadlock avoidance in dynamic environments. This paper proposes a dynamic resource reservation (DRR) based method supporting time-efficient scheduling and collision avoidance of multiple AGVs. In this method, the layout is divided into square blocks with the same size that are abstracted as points in the undirected graph. In order to solve the collision and deadlock problem dynamically, the shared resource points of each vehicle are extracted from their guide paths in real time. Unlike the traditional approaches most of which adopt a static point occupation policy, DRR exploits dynamical reservations of shared resource points to change AGV movement states for avoiding collisions and deadlocks, resulting in better time efficiency. We jointly implement the algorithm on both central and local controllers. Extensive simulation results demonstrate the feasibility and efficiency of the proposed collision and deadlock prevention method.

Deadlock Detection and Avoidance Strategies for Automated Storage and Retrieval Systems

This paper focuses on real-time control of automated storage and retrieval systems (AS/RSs) serviced by a rail-guided vehicle system, a widely used solution for material handling in warehouses. The generic multiproduct AS/RS is modeled as a timed discrete event dynamical system, whose state provides the information on the current interactions between users and resources. Moreover, we address the real-time controller that governs resource allocations and scheduling choices by enabling and inhibiting the system events in order to avoid collisions and deadlocks. To this aim, we characterize deadlock in AS/RSs and define two deadlock resolution strategies: a deadlock avoidance and a deadlock detection/recovery policy. The proposed deadlock formulation and characterization have a general validity and can be applied to single unit resource allocation systems where a subset of users may be regarded as resources of other users. We compare the proposed control policies for a large-scale AS/RS presented in the related literature by several discrete event simulation tests.