Wireless RF Module Research Articles

Design of remote injury diagnosis system for Wushu competition based on wireless sensor network

INTRODUCTION: In this paper, a remote injury diagnosis system for Wushu competition based on wireless sensor network is designed to improve the safety of athletes in the process of Wushu competition. OBJECTIVES: Improve the safety of athletes during martial arts competitions. METHODS: The pulse sensor, temperature sensor and ECG sensor are set as the terminal nodes of the remote injury diagnosis system for Wushu competition. The physiological parameters of athletes in Wushu competition are collected by the sensor, and the collected parameters are transmitted to the wireless RF module. The wireless RF module uses the wireless sensor network to realize the wireless communication of various parameter data through the routing node and terminal node, and transmits the data to the remote diagnosis module. The remote diagnosis module uses the collected physiological parameters of athletes to realize the remote diagnosis of injury in Wushu competition through particle swarm optimization-support vector machine diagnosis model. RESULTS: The experimental results show that the designed system can remotely collect the physiological parameters of athletes in Wushu competition, and remotely diagnose the injury of Wushu competition according to the collected data, and the diagnosis accuracy is as high as 99%. CONCLUSION: It has good safety performance and is of practical significance.

Cooperative Navigation of UAVs in GNSS-Denied Area With Colored RSSI Measurements

In this article, we investigate how the proposed navigation mode “dead reckoning + relative ranging + heading constraint” can be used to cooperatively localize a UAV swarm when GNSS (Global Navigation Satellite System) is denied. By focusing on the relative ranging performance, the wireless RF modules mounted on the cost-efficient UAVs are used to provide communication, ranging and positioning at the same time; however, its positioning accuracy is usually degraded by the noise in the actual RSSI (Received Signal Strength Indicator) measurements. To solve this problem, we analyze the influence of antenna pattern inhomogeneity and channel variation, respectively. The former mainly determines an antenna radiation function related to the yaw angle and relative position between the two measuring UAVs. The latter uses overlapping Allan variance to analyze and identify the measurement noises from outfield tests, that is, quantization noise, flicker noise, random walk noise and Gaussian white noise, which to some extent bridges the difference between the theoretical model and the practical measurement of RSSI. We also evaluate the sub-swarm size that guarantees robustness of RSS-based localization. In this way, an improved extended Kalman filter is proposed to predict and correct the colored noise by adaptively integrating the current peer-to-peer radio ranging performance and its Allan variance. To prove the effectiveness of this approach, simulation results based on real environment datasets and practical noise modeling are demonstrated.

ESNAP: Enabling Sensor Network Automatic Positioning in IoT Lighting Systems

The configuration of sensor nodes in Internet-of-Things (IoT) systems is a time-consuming and labor-intensive process, often due to the lack of user interfaces in embedded sensor devices or the large number of nodes in a network. A crucial step in configuring an IoT node is mapping its identification (ID) to its physical location within the deployment area. This step is more pronounced in lighting systems, where both lighting control and sensing data need to be supported. In this article, we propose, eSNAP , an ID-location mapping method that enables the automatic configuration of wireless sensor nodes in connected lighting systems. Such mapping allows setting up and maintaining a secure and reliable IoT network with little human intervention, while providing valuable contextual information for the sensor data, which is critical in most IoT applications, including lighting. Our proposed method combines available digitized building planning/design information with theories of the Euclidean distance matrices and combinatorial optimization to enable the automatic configuration of IoT nodes. Furthermore, we leverage the channel and time diversities of the received signal measurements obtained by off-the-shelf wireless RF modules to enhance the positioning accuracy over time. We evaluate and validate the proposed method using state-of-the-art wireless mesh networking standards on two real-world setups: 1) a 30-node lab setup implemented using the Bluetooth mesh standard-compliant embedded platform and 2) a real-world connected lighting system based on ZigBee mesh in a corporate office building.

Design of the Lamp Wireless Household Control System

With the development of wireless communication technology, the demand for lighting is increasing by people in daily life. The design consists of STC89C52 microcontroller, NRF24L01 wireless RF module, ADC0809 analog to digital conversion module button, LCD1602 display components. The design control by the microcontroller chip STC89C52, then use two wireless modules were set NRF24L01 transmitter module and receiver module, the system through the data forwarding the data to the monitoring center control lighting, completion of sending and receiving signals. The system realizes the light switch control, and can be adjusted according to the brightness of the surrounding environment, while intelligent lighting settings set time period. This design has a modern, energy-saving, comfort advantages of wireless communication technology knowledge and research has important significance.

IFAC Workshop on Advances in Control and Automation Theory for Transportation Applications Guidance and Control of an Unmanned Holonomic Robot for Transport Applications

In this work, indoor guidance and control of an autonomous holonomic transport robot vehicle via wireless (ZigBee) communication modules is presented.The vehicle modified as a mini forklift is equipped with four mecanum wheels which are separately driven with geared DC- Motors. In this configuration it has the capability of moving omnidirectional and to work even in very narrow areas.For indoor guidance and control of the autonomous unmanned vehicle (AUV), a remote control system existing of ZigBee wireless RF Modules, a PC as main controller and Ardupilot Mega (APM) microcontroller kit is implemented.Stationary PC as main controller can guide the vehicle to follow a calculated path autonomously through bilateral data transmission between APM and PC. As control data the angular position (yaw angle) is detected through integrated IMU (Inertial Measuring Unit) of APM and as second control parameter linear position is measured by an encoder. Besides navigation a self developed algorithm is integrated to the system for possible obstacle avoidance and optimal path finding. A Sharp distance sensor is used to detect distance and obstacles in the environment.Through integrated IMU and GPS system of APM the vehicle can be used for both indoor and outdoor applications. The results of experimental testing showed the effectiveness of the proposed approach.

Speech-based formation control of the multi-robot system

The article presents multiple pattern formation control of the multi-robot system using A* searching algorithm, and avoids the collision points moving on the motion platform. We use speech recognition algorithm to decide the various pattern formations, and program mobile robots to present the movement scenario on the grid-based motion platform. We have been developed some pattern formations to be applied in game applications, such as long snake pattern formation, phalanx pattern formation, crane wing pattern formation, sword pattern formation, cone pattern formation and so on. The mobile robot contains a controller module, three IR sensor modules, a voice module, a wireless RF module, a compass module, and two DC servomotors. The controller of the mobile robot can acquire the detection signals from reflect IR sensor modules and the compass module, and decide the cross points of the aisle. The mobile robot receives the command from the supervised computer, and transmits the status of environment to the supervised computer via wireless RF interface. We develop the user interface of the multi-robot system to program motion paths for various pattern formation exchanges using the minimum displacement. Users can use speech to control the multiple mobile robots to execut pattern formation exchange. In the experimental results, users can speak the pattern formation. The speech recognition system receives the signal to decide the pattern formation. The multiple mobile robots can receive the pattern formation command from the supervised computer, and arrange the assigned pattern formation on the motion platform, and avoid other mobile robots.

Path planning of fire-escaping system for intelligent building

We present the path-planning techniques of the fire-escaping system for intelligent building, and use multiple mobile robots to present the experimental scenario. The fire-escaping system contains a supervised computer, an experimental platform, some fire-detection robots and some navigation robots. The mobile robot has the shape of a cylinder, and its diameter, height and weight are 10 cm, 15 cm and 1.5 kg, respectively. The mobile robot contains a controller module, two DC servomotors (including drivers), three IR sensor modules, a voice module and a wireless RF module. The controller of the mobile robot acquires the detection signals from reflective IR sensors through I/O pins and receives the command from the supervised computer via wireless RF interface. The fire-detection robot carries the flame sensor to detect fire sources moving on the grid-based experiment platform, and calculates the more safety escaping path using piecewise cubic Bezier curve on all probability escaping motion paths. Then the user interface uses A* searching algorithm to program escaping motion path to approach the Bezier curve on the grid-based platform. The navigation robot guides people moving to the safety area or exit door using the programmed escaping motion path. In the experimental results, the supervised computer programs the escaping paths using the proposed algorithms and presents movement scenario using the multiple smart mobile robots on the experimental platform. In the experimental scenario, the user interface transmits the motion command to the mobile robots moving on the grid-based platform, and locates the positions of fire sources by the fire-detection robots. The navigation robot guides people leaving the fire sources using the low-risk escaping motion path and moves to the exit door.

Design an Auto-Recharging System for Mobile Robots

The article develops an auto-charging system for mobile robots, and programs a new docking processing to enhance successful rate. The system contains a docking station and a mobile robot. The docking station contains a docking structure, a limit switch, a charger, two power detection modules and two wireless RF modules. The mobile robot contains a power detection module (voltage and current), an auto-switch, a wireless RF module, a charging connection structure and a laser range finder. The docking structure is designed with one active degree of freedom and two passive degrees of freedom. The power detection module is controlled by HOLTEK microchip. We calculate the power values using the redundant management method and statistical signal prediction method, and develop an auto-recharging processing using multiple sensors and laser range finder for mobile robots. The processing can enhances the successful rate to guide the mobile robot moving to the docking station. In the experimental results, the power of the mobile robot is under the threshold value. The mobile robot transmits the charging command to the docking station via wireless RF interface, and searches the landmark of the docking station using laser range finder (SICK). The laser range finder guides the mobile robot approach to the docking station. The mobile robot touches the docking station to trig the power detection device. The docking station supplies the power to the mobile robot by charger, and detects the current and voltage values of the charging processing. The charging current of the docking station is under the threshold value. The docking station turns off the charging current, and trigs the mobile robot leaving the docking station via wireless RF interface.

Image Recognition Method Applying in Formation Control of Mobile Robots

The article develops multi-pattern formation exchange using A* searching algorithm, and programs the shortest motion paths for mobile robots. The system contains an image recognition system, a motion platform, some wireless RF modules and five mobile robots. We use Otsu algorithm to recognize the variety 2D bar code to classify variety pattern, and control five mobile robots to execute formation exchange, and present the movement scenario on the motion platform. We have been developed some pattern formations according to game applications, such as hook pattern formation, T pattern formation, L pattern formation, rectangle pattern formation, sward pattern formation and so on, and develop the user interface of the multi-robot system to program motion paths for variety pattern formation exchange on the supervised computer. The supervised computer programs pattern formation exchange according to the image recognition results, and controls mobile robots moving on the motion platform via wireless RF interface. In the experimental results, mobile robots can receive the pattern formation command from the supervised computer, and change the original pattern formation to the assigned pattern formation on the motion platform, and avoid other mobile robots on real-time.

Design of wireless underground sensor network nodes for field information acquisition

With the research of the wireless sensor network technology, some wireless underground sensor network nodes and a sink node based on embedded technology and RF technology were designed innovatively. Wireless underground sensor network node consists of sensor, the processor, wireless RF module and power module; here, processor using MSP430 microcontroller, RF modules adopting nRF905 communication module and having 433/868/915 MHz 3 ISM channel. Moreover, the sink node is made up of RF transceiver module, the core control circuit, information processing, data storage, Liquid Crystal Displays (LCD) module and power supply. The nodes which acquired soil parameters information were regularly distributed in the monitoring area. The sink node collected the information of nodes that were sent in way of a single jumping or multiple hops and implemented fusion, analysis, processing, storage and display of information. For 50% sands, 35%silt, and 15% clay, a bulk density of 1.5 g/cm3 and a specific density of 2.6 /cm3, test is conducted for different soil moisture (5, 10, 15, 20 and 25%) in three different frequencies 433/868/915 MHz, result shows that radio signal path loss is the minimum in the low frequency and low moisture. Furthermore, the changes of node deployed depth (0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8 and 2 m) affected signal attenuation under 433 MHz, it is concluded as the best wireless underground sensor networks (WUSN) node buried depth for effective transmission. Key words: Wireless underground sensor networks (WUSN), sink node, MSP430, soil moisture, depth,information acquisition.

Path planning of a multiple mobile robot system

We present path-planning techniques for a multiple mobile robot system. The mobile robot has the shape of a cylinder, and its diameter, height, and weight are 8 cm, 15 cm, and 1.5 kg, respectively. The controller of the mobile robot is an MCS-51 chip, and it acquires detection signals from sensors through I/O pins. It receives commands from the supervising computer via a wireless RF interface, and transmits the status of the robots to the supervising computer via a wireless RF interface. The mobile robot system is a module-based system, and contains a controller module (including two DC motors and drivers), an obstacle detection module, a voice module, a wireless RF module, an encoder module, and a compass detection module. We propose an evaluation method to arrange the position of the multiple mobile robot system, and develop a path-planning interface on the supervising computer. In the experimental results, the mobile robots were able to receive commands from the supervising computer, and to move their next positions according to the proposed method.

건구동식 로봇 의수용 착용형 인터페이스

This paper proposes a wearable interface for a tendon-driven robotic hand prosthesis. The proposed interface is composed of a dataglove to measure finger and wrist joint angle, and a micro-control board with a wireless RF module. The interface is used for posture control of the robotic hand prosthesis. The measured joint angles by the dataglove are transferred to the main controller via the wireless module. The controller works for directly controlling the joint angle of the hand or for recognizing hand postures using a pattern recognition method such as LDA and k-NN. The recognized hand postures in this study are the paper, the rock, the scissors, the precision grasp, and the tip grasp. In experiments, we show the performances of the wearable interface including the pattern recognition method.

Engineering design and realisation of an automatic real time weather monitoring station using commercial CAD tools

The paper describes the design and realisation of a low cost automatic real time weather station project aimed at significantly enhancing the design, realisation, and testing skills of undergraduate engineering students through the use of industrial Computer Aided Design (CAD) tools. The station measures the following meteorological variables: temperature, humidity, rain, and wind speed and direction. It has a wireless RF module to relay data to a computer, which displays, saves, and archives weather data. During the course of this project, software tools are used to speed up the design process. As a result, such tools allow students to not only design but also to redesign. It is only by redesign and experimentation that students learn how design problems interact and how to trade off competing issues.