Unmodulated Visible Light Positioning using the Iterated Extended Kalman Filter

Authors: Robin Amsters, Nobby Stevens

With the rise of solid-state lighting, wireless positioning based on visible light is becoming more appealing. However, current visible light positioning systems require additional hardware at the transmitter end in order to modulate the light intensity. A receiver demultiplexes the combined signal from multiple sources into its components, which are then used by the positioning algorithm. This paper investigates the possibility of using unmodulated visible light for mobile robot positioning. Less hardware is required, consequently, cost and complexity are much lower. Position estimation is achieved by modeling the received signal strength inside a room, which is used as input for an Iterated Extended Kalman filter. We show that the proposed approach can achieve decimeter level accuracy in a simulation environment. Even with imperfect calibration, the total positioning error usually remains below 0.5 m. Positioning errors due to the blocking of the receiver can be mitigated by employing an innovation magnitude bounds test. We also show that by employing multiple receivers, accuracy and robustness can be further improved.

Influence of Transmitter and Receiver Orientation on the Channel Gain for RSS Ranging-Based VLP

Authors:  Nobby Stevens, Heidi Steendam

In this work, a set of general expressions taking into account the impact of transmitter and receiver tilt invisible light positioning on the channel gain is elaborated. A rigorous approach involving Euler rotations results in a compact expression for the modified channel gain that can be interpreted graphically. The relative modification of this gain is numerically evaluated for a number of representative configurations. A first-order approximation in case of small tilt angles leads to a number of interesting conclusions that can be utilized directly when applying received signal strength visible light positioning.

Experimental Evaluation of the Precision of Received Signal Strength Based Visible Light Positioning

Authors: Willem Raes, David Plets, Lieven De Strycker, Nobby Stevens

In this work, the experimental evaluation of the distance estimation variance is executed for received signal strength based visible light positioning. It is shown that based on the signal to noise ratio at the matched filter output, an accurate determination of the precision is achieved. In order to suppressed ambient light which contains no information regarding the distance between the LED and the receiver, matched filtering with the dc-balanced part of the transmitted signal is required. As a consequence, the theoretical lower bound for the precision can not be achieved.

Stage III – Development of the methods and techniques of the hybrid VLC/IR-RF system – finalized

This activity will be focused on the detailed description of all the components that are part of the VLC/ IR-RF communication system, including development boards, sensors, LEDs and photodiodes.

Activity III.1 – Context analysis for sensors involved in the architecture of the communication system

In this subchapter, there will be provided a brief description of the VLC/ IR-RF hybrid communication architecture, whose primary purpose was detailed in the previous stage of the project, along with a complete set of sensors that were implemented within the laboratory test bench,

Activity III.2 – Development of the communication solution for low power devices

Within this activity, the attention will be focused on the technical presentation of the current test bench along with the results that were observed during the experiments. Moreover, to achieve the proposed goal and to obtain the most accurate results, professional measurement tools were chosen to analyze the performance of the VLC / IR-RF hybrid communication system. In this case, the information coming from the sensing modules was carried via the VLC communication protocols.

Activity III.3 – Methods for data processing

This activity will be focused on how to export the data coming from the VLC components that were presented in the previous activity. Therefore, three popular scenarios will be analyzed as follows:
-MQTT Client – Grafana – Arduino;
-LabVIEW Client – Arduino;
-Arduino Client – Firebase – Android.

Stage II – The VLC/IR-RF system definition – finalized

Activity II.1 – Use cases

Activity II.2 – The hybrid communication system design for small and medium enterprises

This activity aims to describe the primary use cases of the VLC technology. There will be studied in detail the main events that were performed in this field. In the end, the best optical communication systems will be described. Moreover, this stage aims to describe de used case proposed by BEIA Consult International which focuses on the introduction on the market of a new hybrid communication system.



A Novel Multi-Industrial Nano Control Unit based on Thermal Imaging that aims to develop a novel type uncooled of low-cost thermal vision camera sensor and offer it to the consumer and automotive markets.

Thermography sensor for ambient assisted living

The main objective of the team project is to gain an effective approach for different healthcare applications by combining smart home technology with healthcare technology based on thermography capable of monitoring vital signs and activities of daily living (adl)

The main objective is to gain an effective approach for different healthcare applications by combining smart home technology with healthcare technology based on thermography. The thermography is a free-contact technology that can detect emergency situations such falls and provide continuous monitoring of the elderly’s health status through the monitoring of vital signs (breathing, heart rate), activities of daily living (ADL) and detection of emergency situations (falls). The smart home sensors will be used to represent many different types of context information. These sensors together with thermography imaging will be used to find patterns in data that do not conform to the expected behaviour. In this context, anomaly detection will be used for detecting anomalies in daily activities and indoor location will provide fine-grained location-based services to the elderly. The identification of any changes in activities of daily living (ADLs) might be an indicator of cognitive or physical decline. There are motion tracking sensor systems to recognise human activity and vital signs for research purposes but there are not robust commercial products in the market that combine both functionalities with a unique sensor. The most mature market is motion detection, dominated by a few cutting-edge enterprises of advanced countries whose technology and know-how is based on mass-volume industrial sector and don’t focus in a specific application (Ambient assisted Living) and therefore have less effectiveness in the problem to solve. The thermography technology can provide different applications in a precise way by using only one sensor which gives it a competitive advantage. This proposal will enable combining the knowledge and expertise of Sensing & Control, NNFC and Vu:t in order to develop an infrastructure for delivering healthcare services that combines open IoT platforms and successful commercial IoT solutions. Sensing & Control Systems S.L. has developed an IoT Smart Home Platform which enables our life to be safer, easier, more comfortable, and energy efficient through the use of a wireless sensor network and a control unit for reducing energy cost. The project aims at four important milestones. The 1st one is to integrate NNFC’s uncooled type of microbolometer array thermography sensor technology into Sensing & Control’s Smart Home platform in order to notify motion tracking data and vital signs at a sudden event to the clinic or caregivers through processed proper algorithm and platform systems with precise sensor performance. With the help of high performance potential of NNFC’s microbolometer technology, it will be possible to increase the sensitivity of the microbolometers and distinction of pulmonary artery. The 2nd milestone is to develop high performance thermography technology by coupling NNFC’s amorphous silicon microbolometer with readout & control circuits for reducing noise, while increasing the sensitivity and resolution, thereby enabling a distinct contrast in thermography. This technology will achieve the very precise detection of vital signs with high performance. The 3rd milestone is to develop algorithms to fit it into a proper input of the Smart Home platform. The main items to be developed are: • motion tracking & recognition algorithms that detect situations that can lead to falls and other hazards, reducing the susceptibility to falls for older people who live in private homes. • algorithms about space, relative positions and poses, and adapting individual users’ preferences The 4th milestone is to develop algorithms based on artificial intelligence in order to detect and alert about potential anomalies and to adapt the home environment automatically. At the beginning of the project, the definition of the requirements and the design of the pilot will be agreed between all partners. The main objective of the pilot is to demonstrate that the solution developed can be deployed within different culture backgrounds.

2nd Workshop of EUREKA Project in Romania

Korean partners NNFC, Crepas and GeneTel attended the 2nd Workshop of EUREKA Project in Romania at BEIA in Bucharest 11-15 September 2018 and visited ICPE-CA.

On the first day of the meeting, there were discussions on the system developed by BEIA Consult. A state of the art analysis of the hybrid system emphasized that due to technical expertise, our company will contribute to the development, testing and successful implementation of large-scale VLC-IR / RF hybrid system communications.

CREPAS made a presentation on entitled “Hybrid VLC/IR-RF Communication for Smart Space Based on Multi-Functional Thermal Image Sensor Module” where they presented an overview of the hybrid communication system based on LED sources and an optical communication channel.

There were some discussions that involved small beacons that can provide information regarding the position.

GeneTel Systems made a presentation called Interworking Specification where a hybrid VLC/IR-RF low sensor node interworking and a network interface.