Khairul Salleh Mohamed Sahari

Simulation Analysis of the Four Configurations of Solar Desiccant Cooling System Using Evaporative Cooling in Tropical Weather in Malaysia

A high demand for air conditioning systems exists in hot and humid regions because of the warm climate during the year. The high energy consumption of conventional air conditioning system is the reason for our investigation of the solar desiccant cooling system as an energy-efficient cooling system. Four model configurations were considered to determine the best configuration of a solar desiccant cooling system: one-stage ventilation, one-stage recirculation, two-stage ventilation, and two-stage recirculation. These models were stimulated for 8,760 hr of operation under hot and humid weather in Malaysia. Several parameters (i.e., coefficient of performance or COP, room temperature and humidity ratio, and the solar fraction of each system) were evaluated by detecting the temperature and humidity ratio of the different points of each configuration by TRNSYS simulation. The latent and sensible loads of the test room were 0.875 kW and 2.625 kW, respectively. By investigating the simulation results of the four systems, the ventilation modes were found to be higher than the recirculation modes in the one- and two-stage solar desiccant cooling systems. The isothermal dehumidification COP of the two-stage ventilation was higher than that of the two-stage recirculation. Hence, the two-stage ventilation mode desiccant cooling system in a hot and humid area has higher efficiency than the other configurations.

Development of in-pipe inspection robot: A review

This paper reviewed several previous papers on work that have been done on the development of in-pipe inspection robot for the last 20 years. By sorting the types of the inspection robots they can be divided into several groups according to their locomotion. Each prototype has its own advantages and disadvantages depending on its design requirements and purpose of inspection. The prototypes have been tested in several experiments in order to verify its functionality and efficiency of inspection task. Some of the researchers ran simulations to validate the kinematic and modeling the mechanism of their own prototype. Developing in-pipe inspection robot can overcome the issues of human factor in labour intensive or dangerous work and also to act in inaccessible environment during repair and maintaining inside the pipeline.

Modeling of heat and moisture transfer in building using RLF method

This study is concerned with effectiveness of building internal temperature and relative humidity by ventilation and infiltration flow rate. Building model is inevitable to study the feasibility of building ventilation, and how to affect on indoor air quality. The empirical method which used in building model is a residential load factor (RLF). RLF formed to calculate cooling/heating load depend upon indoor/outdoor temperature. The transparency, functionality of indoor/outdoor temperatures and simplicity of RLF make it suitable for use in this model. Furthermore the parameters of model can be calculated room by room and thats proper for variable air volume (VAV). Today a VAV system is universally accepted as means of achieving energy efficient and comfortable building environment. The model what we get verified with different method, by manual or software program calculation.

Clothes Manipulation by Robot Grippers with Roller Fingertips

Unfolding or spreading is a very important process in clothes handling in order to sort out whether an item is a shirt, skirt, pants, etc. Spreading of clothes basically involves holding two corners of the clothes next to each other. The problem is finding the two corners. Usage of tracing manipulation to find the second corner can solve this problem. However, there are also problems concerning tracing manipulation. One of the major problems is how to retrieve the fabric when it is in danger of slipping away from the gripper. The robot may be able to detect that the fabric is about to slip, but it is hard to retrieve or prevent it. If the robot tries to regrasp the fabric, it would probably slip away. If the robot tries to retrieve the fabric without regrasping it, it would most probably drag the fabric along instead of retrieving it. This is due to the fact that deformable objects are sensitive to contact forces. A simple solution to this problem is to design a special gripper that can trace the edge smoothly and can also perform fabric retrieval. This paper proposes a unique tracing method for towel spreading using two sensors-equipped grippers with a rolling mechanism at the fingertips. Tracing in the context of this paper involves tracing the towels edge, with the robot movement based on feedback from sensors. The gripper will allow more flexibility towards fabric manipulation. Experimental results have demonstrated the effectiveness of both the method and the grippers.

Indoor mapping using kinect and ROS

This research covers an endeavor by the author on the usage of automated vision and navigation framework; the research is conducted by utilizing a Kinect sensor requiring minimal effort framework for exploration purposes in the zone of robot route. For this framework, GMapping (a highly efficient Rao-Blackwellized particle filer to learn grid maps from laser range data) parameters have been optimized to improve the accuracy of the map generation and the laser scan. With the use of Robot Operating System (ROS), the open source GMapping bundle was utilized as a premise for a map era and Simultaneous Localization and Mapping (SLAM). Out of the many different map generation techniques, the tele-operation used is interactive marker, which controls the TurtleBot 2 movements via RVIZ (3D visualization tool for ROS). Test results completed with the multipurpose robot in a counterfeit and regular environment represents the preferences of the proposed strategy. From experiments, it is found that Kinect sensor produces a more accurate map compared to non-filtered laser range finder data, which is excellent since the price of a Kinect sensor is much cheaper than a laser range finder. An expansion of experimental results was likewise done to test the performance of the portable robot frontier exploring in an obscure environment while performing SLAM alongside the proposed technique.

Multiple sequence behavior recognition on humanoid robot using long short-term memory (LSTM)

Recurrent neural networks (RNN) are powerful sequence learners. However, RNN suffers from the problem of vanishing gradient point. This fact makes learning sequential task more than 10 time steps harder for RNN. Recurrent network with LSTM cells as hidden layers (LSTM-RNN) is a deep learning recurrent network architecture designed to address the vanishing gradient problem by incorporating memory cells (LSTM cells) in the hidden layer(s). This advantage puts it at one of the best sequence learners for time-series data such as cursive hand writings, protein structure prediction, speech recognition and many more task that require learning through long time lags [2][3][4], In this paper, we applied the concept of using recurrent networks with LSTM cells as hidden layer to learn the behaviours of a humanoid robot based on multiple sequences of joint data from 10 joints on the NAO robot. We show that the LSTM network is able to learn the patterns in the data and effectively classify the sequences into 6 different trained behaviors.

Improvement of the 2D SLAM system using Kinect sensor for indoor mapping

Simultaneous localization and mapping (SLAM) is an important system for making fully autonomous robot navigation system. A robot must have a good understanding of the environment for navigation. Mobile robot using fixed laser range finder can only detect obstacle on a particular plane level. This may lead to missing of important obstacles that are both above or below the laser scan level. This will cause the map generated to be inaccurate and collision may happen during autonomous navigation. The Microsoft Kinect sensor can replace a laser range finder in a mobile robot as a low cost alternative while providing 3D data. Using depth image data from Kinect, the obstacles between ground surface and 500mm high are projected to horizontal surface, and converted to laser scan data. This will include the entire obstacles that the robot might collide into. Simulations and experiments have been conducted to test out the method in SLAM process in an indoor environment. Both simulation and experimental results show that the proposed method is capable of getting more detailed map compared to the normal 2D map.

Continual improvement and assessment plan for Mechanical Engineering Programme in UNITEN

This paper describes the continuous quality improvement (CQI) process plan that was developed and implemented by the Department of Mechanical Engineering (DME), Universiti Tenaga Nasional (UNITEN), Malaysia for its Bachelor of Mechanical Engineering Programme. The plan is part of the Outcome-Based Education (OBE) system that is required by the Engineering Accreditation Council (EAC) of Malaysia. DME has implemented OBE approach in the programme for the past 3 years. Throughout the implementation process, the Department has developed ongoing assessment and CQI plan to measure the outcomes and improve the teaching and learning process. This plan, which was first implemented at the end of 2006, has generally shown a positive trend in the teaching and learning process in the programme. This paper also discusses the assessment tools that are used in the continuous quality improvement (CQI) plan. Assessment is one of the important parts in the CQI plan. Direct and indirect measurement methods are used to gather the data which are to be analysed to measure the outcome attainment. The attainment results are used to identify the areas that need to be improved. The assessment plan has been continuously improved to be more effective in measuring the achievement of the OBE implementation in the department.

Inspection robot for parallel entry boiler header pipe

This paper presents the development of inspection robot for parallel entry boiler header pipes with drastic change in diameter. The proposed robot consists of caterpillar based robot body, lifting mechanism and camera gimbal mechanism. These mechanisms are designed to adapt the sudden pipe diameter change from 89mm to 300mm. This robot applies differential drive locomotion system that provides turning ability plus forward and reverse movement. Lifting mechanism consists of linear transmission using leadscrew and scissors linkage mechanism. This enables the robot to retract when entering the parallel entry and expand in bigger pipe. Camera gimbal mechanism enables the robot to acquire 360° inner pipe surface image with its position. Experiments have been accomplished to investigate the functionality of these mechanisms. Results obtained shows that the robot has fulfilled its design requirements and achieved its objective.

Using Electromagnetism-like algorithm and genetic algorithm to optimize time of task scheduling for dual manipulators

A method based on Electromagnetism-Like algorithm (EM) and Genetic Algorithm (GA) is proposed to determine the time-optimal task scheduling for dual robot manipulators. GA is utilized to calculate the near-optimal task scheduling for the two robots. On top of that, the EM is recommended as a suitable alternative to obtain multiple solutions at each task points for both manipulators with less error. During the course of the tour, the dual robots move from point to point with less cycle time, while ensuring that no collision occurs between the two manipulators or between the dual manipulators and the static obstacles in the workspace. The movement and the configurations of the manipulators at the task points were visualized using a simulator developed via Visual Basic. Net. The method is verified using two simulators acting as examples for two identical four-link planar robots working in the environment, with square-shaped obstacles cluttered at different locations.