Kamarulzaman Kamarudin

Performance Analysis of the Microsoft Kinect Sensor for 2D Simultaneous Localization and Mapping (SLAM) Techniques

This paper presents a performance analysis of two open-source, laser scanner-based Simultaneous Localization and Mapping (SLAM) techniques (i.e., Gmapping and Hector SLAM) using a Microsoft Kinect to replace the laser sensor. Furthermore, the paper proposes a new system integration approach whereby a Linux virtual machine is used to run the open source SLAM algorithms. The experiments were conducted in two different environments; a small room with no features and a typical office corridor with desks and chairs. Using the data logged from real-time experiments, each SLAM technique was simulated and tested with different parameter settings. The results show that the system is able to achieve real time SLAM operation. The system implementation offers a simple and reliable way to compare the performance of Windows-based SLAM algorithm with the algorithms typically implemented in a Robot Operating System (ROS). The results also indicate that certain modifications to the default laser scanner-based parameters are able to improve the map accuracy. However, the limited field of view and range of Kinects depth sensor often causes the map to be inaccurate, especially in featureless areas, therefore the Kinect sensor is not a direct replacement for a laser scanner, but rather offers a feasible alternative for 2D SLAM tasks.

Method to convert Kinect's 3D depth data to a 2D map for indoor SLAM

Mobile robotics has been strongly linked to localization and mapping especially for navigation purpose. A robot needs a sensor to see objects around it, avoid them and also map the surrounding area. The use of 1D and 2D proximity sensors such as ultrasonic sensor, sonar and laser range finder for area mapping is believed to be less effective since they do not provide information in Y or Z (horizontal and vertical) direction. The robot may miss an object due to its shape and position; thus increasing the risk of collision as well as inaccurate map. In this paper, a 3D visual device particularly Microsoft Kinect was used to perform area mapping. The 3D depth data from the devices depth sensor was retrieved and converted into 2D map using the presented method. A Graphical User Interface (GUI) was also implemented on the base station to depict the real-time map. It was found that the method applied has successfully mapped the potentially missing objects when using 1D or 2D sensor. The convincing results shown in this paper suggest that the Kinect is suitable for indoor SLAM application given that the devices limitations are solved.

Interference issues and mitigation method in WSN 2.4GHz ISM band: A survey

Current lifestyles promote the development and advancement in wireless technologies, especially in Wireless Sensor Networks (WSN) due to its several benefits. WSN offers a low cost, low data rate, flexible routing, longer lifetime, and low-energy consumption suitable for unmanned and long term monitoring. Among huge WSN applications, some key applications are smart houses, environmental monitoring, military applications, and other monitoring applications. As a result, ubiquitous increase in the number of wireless devices occupying the 2.4GHz frequency band. This causes a dense wireless connection followed by interference problem to WSN in the 2.4GHz frequency band. WSN is most affected by the interference issue because it has a lower data rate and transmission power compared to WLAN. Despite efforts made by researchers, to the authors knowledge, the interference issue is still a major problem in wireless networks. This paper aims to review the coexistence and interference issues of existing wireless technologies in the 2.4GHz Industrial, Scientific and Medical (ISM) band.

A real-time greenhouse monitoring system for mango with Wireless Sensor Network (WSN)

Harumanis or its scientific name as Mangifera indica is a popular mango in Malaysia due to its unique aroma and taste, despite its expensive price. The high demand for this mango and its potential in export has been the reason why this tropical fruit being a national agenda for the Malaysian government to classify it as the specialty fruit from Perlis (smallest state in Malaysia). As the sole university in Perlis, University of Malaysia Perlis (UniMAP) has taken the initiative to develop greenhouse specifically for Harumanis mango. To support this, a real-time greenhouse monitoring system has been proposed. The system was developed based on Wireless Sensor Networks technology which consists of three parts: sensing module, radio communication module and gateway module. This system is able to provide real time monitoring of the important factors in plant growth such as the carbon dioxide, temperature, humidity level in the greenhouse. The performance result shows that the temperature inside the greenhouse is slightly higher compared to the open field; which meets the crop requirements. At night, the greenhouse microclimate drops and equilibrates to the surrounding temperature and humidity. This condition ensures good flowering and fruiting of sweet and juicy mangoes.

Simulation and analysis of LEACH for wireless sensor networks in agriculture

The challenges in deploying robust wireless sensor networks WSNs in agricultural environments are limited power supply and variability of wireless propagation channel that restrict performance. Proposed protocols do not meet the challenges for realistic simulation and evaluation of WSN for agricultural applications. The design of LEACH protocol is, for the most part, efficient for many applications. It achieves energy efficiency through a clustering technique with TDMA based MAC layer algorithms and data aggregation method. Analysis performed shows that LEACH uses simple radio propagation and energy models that are unrealistic. This paper focuses on the performance analysis of LEACH protocol for agricultural environments.

Flexible and autonomous integrated system for characterizing metal oxide gas sensor response in dynamic environment

Characterization and calibration of gas sensor is a complex problem due to the dynamic behavior of gases and the limitations of current technology. This article reports a flexible, robust, and autonomous integrated system that is able to perform characterization on metal oxide-based gas sensors in dynamic environments. The system controls the concentration and flow of the relevant gases into the gas chamber and simultaneously measuring the sensor response. This feature allows the characterization of the sensor under continuous dynamic flow of gases similar to conditions on a robot or flow pipes. Several experiments have been performed on the system using hydrogen sulfide. The results provide information on the general characteristics of the sensor as well as its sensitivity. The noise levels were studied with different reference voltages. Overall, the results verify that the system is reliable and able to produce repeatable measurements.

Improving performance of 2D SLAM methods by complementing Kinect with laser scanner

The feasibility of using Kinect sensor for 2D Simultaneous Localization and Mapping (SLAM) application has been widely studied. Researchers concluded that the acquired maps are often inaccurate due to the limited field of view of the sensor. Therefore in this work, we complemented the Kinect with a laser scanner and proposed a method to merge the data from both sensors. Two SLAM algorithms (i.e Gmapping and Hector SLAM) were tested using the method, in different environments. The results show that the method is able to detect multi-sized objects and produce more accurate map as compared to when using single sensor (i.e Kinect only or laser scanner only). Finally, the performance of the Gmapping and Hector SLAM are compared particularly in terms of the computational complexity and the map accuracy.

Braitenberg swarm vehicles for odour plume tracking in laminar airflow

This paper presents an algorithm to trace an odour plume using swarm robots in laminar airflow. The algorithm proposed here aims to bridge the gap between single and multiple element systems by mimicking and enhancing biologically derived strategies for odor plume tracking. Simulations were carried out on Webots to verify the potential of the algorithm. A simple gas sensor model was introduced to mimic the response of a real metal oxide sensor in the simulation. A gas sensor model was introduced based on the response of metal oxide sensor (MOS) to closely mimic and provide real environment condition. Different weightage configurations of the gas sensor, kg and wind sensor, kw are compared to find its effects on the performance and behavior of the purposed algorithm. It was found that robots separated from the swarm can still perform the plume tracking task. Also, multiple entity systems show an increase in performance compared to single entity robots.

Odour and Hazardous Gas Monitoring System for Swiftlet Farming Using Wireless Sensor Network (wsn)

Odour and Hazardous Gas Monitoring System for Swiftlet Farming using Wireless Sensor Network (WSN) Syed M. Mamduh*, Ali Y. Md. Shakaff, Shaharil M. Saad, Kamarulzaman Kamarudin, Latifah M. Kamarudin, Ammar Zakaria, H. Kamarudin, A. M. M. Ezanuddin, Fathinul S.A. Sa’ad,, W.M. Nooriman, Abu H. Abdullah Center of Excellence for Advanced Sensor Technology (CEASTech), Universiti Malaysia Perlis (UniMAP), Pusat Pengajian Jejawi 2, Taman Muhibah, Jalan Jejawi-Permatang, 02600, Perlis, Malaysia ceastech@unimap.edu.my

Cross-sensitivity of metal oxide gas sensor to ambient temperature and humidity: Effects on gas distribution mapping

Metal oxide gas sensors have been widely used in robotics application to perform remote and mobile gas sensing. However, previous researches have indicated that this type of sensor technology is cross-sensitive to environmental temperature and humidity. This paper therefore investigates the effects of these two factors towards gas distribution mapping and gas source localization domains. A mobile robot equipped with TGS2600 gas sensor was deployed to build gas distribution maps of indoor environment, where the temperature and humidity varies. The results from the trials in environment with and without gas source indicated that there is a strong relation between the fluctuation of the mean and variance map with respect to the variations in the temperature and humidity maps.