Abdussalam Alajami

Mr. Abdussalam Alajami

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 August 2022 in Drones
Verified
Journal Article
Open access
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Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
GMGuillem Moreno
Guillem Moreno
Rafael PousRafael Pous
Rafael Pous
Unmanned aerial vehicles (UAVs) and radio frequency identification (RFID) technology are becoming very popular in the era of Industry 4.0, especially for retail, logistics, and warehouse management. However, the autonomous navigation for UAVs in indoor map-less environments while performing an inventory mission is, to this day, an open issue for researchers. This article examines the method of leveraging RFID technology with UAVs for the problem of the design of a fully autonomous UAV used for inventory in indoor spaces. This work also proposes a solution for increasing the performance of the autonomous exploration of inventory zones using a UAV in unexplored warehouse spaces. The main idea is to design an indoor UAV equipped with an onboard autonomous navigation system called RFID-based stigmergic and obstacle avoidance navigation system (RFID-SOAN). RFID-SOAN is composed of a computationally low cost obstacle avoidance (OA) algorithm and a stigmergy-based path planning and navigation algorithm. It uses the same RFID tags that retailers add to their products in a warehouse for navigation purposes by using them as digital pheromones or environmental clues. Using RFID-SOAN, the UAV computes its new path and direction of movement based on an RFID density-oriented attraction function, which estimates the optimal path through sensing the density of previously unread RFID tags in various directions relative to the pose of the UAV. We present the results of the tests of the proposed RFID-SOAN system in various scenarios. In these scenarios, we replicate different typical warehouse layouts with different tag densities, and we illustrate the performance of the RFID-SOAN by comparing it with a dead reckoning navigation technique while taking inventory. We prove by the experiments results that the proposed UAV manages to adequately estimate the amount of time it needs to read up-to 99.33% of the RFID tags on its path while exploring and navigating toward new zones of high populations of tags. We also illustrate how the UAV manages to cover only the areas where RFID tags exist, not the whole map, making it very efficient, compared to the traditional map/way-points-based navigation.

17 May 2021 in IEEE Transactions on Industrial Informatics
Verified
Journal Article
Closed access
VCVictor Casamayor-Pujol
Victor Casamayor-Pujol
BGBernat Gaston
Bernat Gaston
Sergio Lopez-SorianoSergio Lopez-Soriano
Sergio Lopez-Soriano
Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
Rafael PousRafael Pous
Rafael Pous
This article presents a simple solution to estimate the location of products in a retail store, using an autonomous ground robot with a radio frequency identification payload. The model used and explained in this article is designed to be as simple and versatile as possible, while achieving accurate location estimations when compared with other proposed models in the state of the art. In addition, the solution developed meets the business requirements of the retail industry, such as locating at stock keeping unit level, as opposed to item level, or expressing the location in terms of store fixtures (e.g., shelf and rack) as opposed to $(x,y)$ coordinates. The research results are obtained from experiments of the model in different environments, achieving accurate location estimations in a controlled laboratory environment. Moreover, for the first time, the model has been tested in a large retail store, where the results obtained met the requirements of the store owners.

23 February 2023 in Intelligent Service Robotics
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Journal Article
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Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
NPNil Palau
Nil Palau
SLSergio Lopez-Soriano
Sergio Lopez-Soriano
Rafael PousRafael Pous
Rafael Pous
The problem of estimating and tracking the location and orientation of a mobile robot by another in heterogeneous distributed multi-robots is studied in this paper. We propose a distributed multi-robot localization strategy (DMLS) that is Robotic Operating System (ROS) based. It consists of an algorithm that fuses data of diverse sensors from 2 heterogeneous robots that are not connected within their transform trees to localize and measure the relative position and orientation.The method exploits the robust detection of the Convolutional Neural Networks (CNN) and the accurate relative position measurements from the local costmap. The algorithm is composed of two parts: The localization part and the relative orientation measurement part. Localization is done by optimization and alignment calibration of the CNN output with the costmap in an individual robot. The relative orientation measurement is done by a collaborative multi-robot fusing of diverse sensor data to align and synchronize the transform frames of both robots in their costmaps. To illustrate the performance of this strategy, the proposed method is compared with a conventional object localization and orientation measuring method that uses computer vision and QR codes. The results show that this proposed method is robust and accurate while maintaining a degree of simplicity and efficiency in costs. The paper also presents various application experiments in laboratory and simulation environments. By using the proposed method, distributed multi-robots collaborate to achieve collective intelligence from individuals, which increases team performance.

5 September 2022 in IEEE Access
Verified
Journal Article
Open access
Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
GMGuillem Moreno
Guillem Moreno
Rafael PousRafael Pous
Rafael Pous
Simulation, robotics, and Radio Frequency Identification (RFID) technology have significant roles in the new industrial revolution, and their application are key aspects of making Industry 4.0 a reality. Developing efficient use cases in Industry 4.0 almost always requires accurate simulation tools to be used in the digital world. The problem of simulating RFID readers for robotics in environments where high populations of RFID tags exist is addressed in this paper. This paper will discuss the design of an RFID system plugin based on Robot Operating System (ROS) and Gazebo simulator and the probability-based model on which the plugin is based. To assess the performance of the proposed system model, the simulation results of the designed plugin are compared with experiments. We also prove that the proposed simulator is flexible enough to be used on any robot platform, including aerial and ground robots. We show initial results of the simulation of having an Unmanned Aerial Vehicle (UAV) and a Unmanned Ground Vehicle (UGV) equipped with an RFID reader, navigating in an environment in which RFID tags have been placed. The robots will be reading tags in different map layouts using RFID antennas, with different orientations. We compare the simulation and experimental results in terms of the total unique tag readings vs. time, for various map-layouts. Finally, we show how this plugin can be used in robotics research by using it to simulate a novel, RFID-based stigmergic navigation strategy. We illustrate, the accurate navigation of the UAV using the proposed plugin.

11 April 2025 in Sensors
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Journal Article
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Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
Rafael PousRafael Pous
Rafael Pous
In contemporary warehouse logistics, the demand for efficient and precise inventory management is increasingly critical, yet traditional Radio Frequency Identification (RFID)-based systems often falter due to static antenna configurations that limit tag detection efficacy in complex environments with diverse object arrangements. Addressing this challenge, we introduce an advanced RFID-based inventory robot that integrates a 3-degree-of-freedom (3DOF) manipulator with vision-assisted dynamic antenna positioning to optimize tag detection performance. This autonomous system leverages a pretrained You Only Look Once (YOLO) model to detect objects in real time, employing forward and inverse kinematics to dynamically orient the RFID antenna toward identified items. The manipulator subsequently executes a tailored circular scanning motion, ensuring comprehensive coverage of each object’s surface and maximizing RFID tag readability. To evaluate the system’s efficacy, we conducted a comparative analysis of three scanning strategies: (1) a conventional fixed antenna approach, (2) a predefined path strategy with preprogrammed manipulator movements, and (3) our proposed vision-assisted dynamic positioning method. Experimental results, derived from controlled laboratory tests and Gazebo-based simulations, unequivocally demonstrate the superiority of the dynamic positioning approach. This method achieved detection rates of up to 98.0% across varied shelf heights and spatial distributions, significantly outperforming the fixed antenna (21.6%) and predefined path (88.5%) strategies, particularly in multitiered and cluttered settings. Furthermore, the approach balances energy efficiency, consuming 22.1 Wh per mission—marginally higher than the fixed antenna (18.2 Wh) but 9.8% less than predefined paths (24.5 Wh). By overcoming the limitations of static and preprogrammed systems, our robot offers a scalable, adaptable solution poised to elevate warehouse automation in the era of Industry 4.0.

27 February 2026 in Sensors
Verified
Journal Article
Open access
PDF file
Abdussalam AlajamiAbdussalam Alajami
Abdussalam Alajami
Rafael PousRafael Pous
Rafael Pous
Efficient RFID spatial exploration in dynamic warehouse environments is challenging due to occlusions, sensing geometry constraints, and the weak coupling between information acquisition and navigation decisions. Many existing inventory robots treat RFID sensing as a passive data source during exploration, without explicitly optimizing sensing pose or prioritizing inventory-driven frontiers, which can result in incomplete coverage and redundant traversal. This paper presents ArmTenna, an articulated mobile robotic platform that formulates RFID inventory exploration as an active perception problem. The system integrates dual 4-DOF robotic arms carrying directional UHF RFID antennas and a 2-DOF neck-mounted RGB-D camera, enabling adaptive interrogation of candidate regions. We propose a multi-modal frontier exploration framework that combines newly detected EPC tags, average RSSI values, and vision-based product detections into a composite utility function for goal selection. By embedding articulated antenna control directly into the frontier evaluation loop, the robot tightly couples sensing geometry with exploration decisions. Experimental validation with 150 tagged items across three separated warehouse zones shows that ArmTenna achieves up to 97% map coverage, compared to 72% for a baseline platform, while reducing missed-tag regions. These results demonstrate that integrating active sensing pose control with multi-modal frontier evaluation provides an effective and scalable solution for RFID-driven warehouse inventory automation.