Wireless sensor systems with energy harvesting capabilities for safety enhancement in agricultural vehicles

This paper presents an overview of a multi-sensor wireless system applied to agricultural vehicles. The data provided by the different kinds of ad-hoc developed wireless sensors can be used as starting point for the implementation of an automatic system for the active safety enhancement of the vehicles. In order to guarantee a lifetime comparable with the one of the implement or trailer where they are mounted, each sensor has his own energy harvesting system able to gather energy from the vibrations occurring in the environment where the sensor operates

A 868MHz CMOS RF-DC Power Converter With -17dBm Input Power Sensitivity and Efficiency Higher Than 40% Over 14dB Input Power Range

In this paper we present a novel CMOS RF-DC converter circuit, operating at 868MHz, for RFID and remote powering applications. The novel reconfigurable architecture of the converter allows the circuit to operate over a very wide input power range with very high efficiency compared with previous art works. Prototypes realized in STM 0.130ìm CMOS technology provide a regulated output voltage ~2V with a -17dBm input power sensitivity. The circuit efficiency, higher than 40% over a 14dB input power range, peaks at 60%

Wildflowers in urban design: an exploratory research of preference in Italian adults

Wildflowers are plants rich in diversity that can be used in many different ways; nevertheless they are not widely used in Italian urban settings. This exploratory study aims to verify preference for wildflowers. To this end, seventy-six adults answered a questionnaire developed to assess a series of wildflower pictures for preference (pictures depicted wildflowers in natural and urban environments, showing pro and cons of this cultivation), and a series of questions concerning wildflowers and their use (questions served as a control of preference ratings). To verify a secondary hypothesis - how preference for wildflowers may be affected by the way the issue is presented - the questionnaire was presented with or without the title explaining the nature of the study, and each question presented with or without a picture. Finally, it was verified whether an individual’s connection to Nature affects preference for wildflowers. Results showed our participants liked wildflowers (no differences between genders and ages emerged) and this correlated with participants’ connection to Nature. However questions concerning the actual use of wildflowers in urban settings still remain, e.g. concerning the fauna that comes with them, and people being more used to ornamental vegetation that challenges preference and use of wildflowers

Integrated RF-DC converter and PCB antenna for UHF wireless powering applications

In this work, a broadband differential RF-DC CMOS converter realized in CMOS 130 nm technology with a customized PCB antenna with inductive coupling feeding for RF energy scavenging is presented. Experimental results show that output DC voltage higher than 1V from 800MHz to 970MHz can be obtained with a load of 1kohm

Force Impact Effect in Contact-Mode Triboelectric Energy Harvesters: Characterization and Modeling

In this paper we investigate the effect of the contact force on the voltage generated by Contact-Mode Triboelectric Energy Harvesting Devices (CM-TEHD). The electrical energy harvested from mechanical shocks increases with the contact force. In order to investigate the role of the contact force in the triboelectric energy generation, we developed a physical model, which allows understanding the physical mechanisms of this process, while predicting the output voltage and power at given conditions. Prototypes of the CM-TEHD made of low-cost commercial silicone were fabricated using a very low cost process. The prototypes provide up to 5.5µW when subjected to repetitive impacts with a contact force of 65N

System With RF Power Delivery Capabilities for Active Safety Enhancement in Industrial Vehicles Using Interchangeable Implements

In this paper, an active system for safety enhancement in industrial and off-highway vehicles using interchangeable implements is presented. The system, applied to the real case study of automatic identification of implements connected to a telehandler, is developed by adopting a hardware–software codesign approach. It is comprised of two devices: the Illuminator-Gateway Device (IGD) and the End Device (ED). Differently from other similar solutions, the system embeds a complete radio frequency (RF) power delivery system that is compliant with the regulations in force in Europe and in North America to extend the battery lifetime of the ED. In particular, the IGD, positioned on the free end of the telescopic arm of the telehandler, supplies the RF energy required for the operations of the ED and acts as a gateway sending the data received from the ED to the other Electronic Control Units (ECUs) of the vehicle. The ED, instead, is mounted on the connected implement, collects the RF energy delivered by the IGD, and wirelessly sends the unique identifier, the key parameters, and the calculated effective working time of the implement. This information can be used by the main ECU of the vehicle for safety-related purposes and programmed maintenance. Experimental results show that the implemented RF power delivery system is able to gather up to 63% of the power required by the ED when it is on duty, thus significantly extending its battery lifetime

Reconfigurable RF Energy Harvester with Customized Differential PCB Antenna

In this work, a RF Energy harvester comprised of a differential RF-DC CMOS converter realized in ST130nm CMOS technology and a customized broadband PCB antenna with inductive coupling feeding is presented. Experimental results show that the system can work with different carrier frequencies and thanks to its reconfigurable architecture the proposed converter is able to provide a regulated output voltage of 2 V over a 14 dB of RF input power range. The conversion efficiency of the whole system peaks at 18% under normal outdoor working conditions

Active Safety System with RF Energy Harvesting Capabilities for Industrial Applications using Interchangeable Implements

In this paper a system for the remote powering of low power electronic devices is presented. The system has been applied to a real industrial application allowing to enhance active safety in industrial vehicles. It is comprised of two main devices: i) the End Device (ED) with an embedded Radio Frequency (RF) energy harvester; ii) the Illuminator-Gateway Device (IGD) with an embedded RF power transmitter. Thanks to the optimization of the customized dual band Planar Inverted Folded Antenna (PIFA) used, the ULP architecture of the ED, the hardware-software co-design approach used and the optimization of the ED firmware, the proposed system is able to provide up to the 63% of the power required by the ED when it is on duty

A WSN System Powered by Vibrations to Improve Safety of Machinery with Trailer

In this paper we present an energetically autonomous wireless sensor system designed to enhance safety in industrial machinery comprising a main vehicle with an attached trailer. The proposed system establishes a wireless link between the vehicle ECU and our sensors to provide motion dynamic data of trailer to the vehicle stability control algorithm. The wireless sensor devices we implemented comprise a 3-axial accelerometer and a 3-axial magnetometer to detect the trailer operating conditions. Such motion data are elaborated using an ultra-low power MCU, which communicates to vehicle\u2019 ECU using an IEEE 802.15.4 channel at 2.4GHz. To enable perpetual operation of the system, we developed a vibrational energy harvesting system, VIBester, capable to gather kinetic energy from trailer natural vibrations and convert such energy in electrical energy for the system power supply. The vibrational energy harvester adopts a piezoelectric (PZT) transducer to convert the kinetic energy and a custom AC/DC converter to supply the wireless sensor device

Investigation of trapping/detrapping mechanisms in Al2O3 electron/hole traps and their influence on TANOS memory operations

The purpose of this work is to investigate the physics of electron/hole trapping/detrapping mechanisms in Al2O3. Combining I-V and C-V measurements with a physical model we derive the energy levels of electron/hole traps and the location of electron/hole charge. The influence of electron/hole alumina traps on TANOS operations and reliability is investigated