Wind farm failure prediction via Piezo Sensor

Engineers have developed a piezoelectric sensor that lets wind farm operators know when bearings are about to fail, a development that could prevent costly downtime.

The sensor, developed by Wenqu Chen, a mechanical engineering research student at Sheffield University, uses ultrasonic waves to measure the load transmitted through a bearing in a wind turbine.
A limiting factor with wind turbines is gearbox reliability, particularly in relation to bearings where manufacturers and operators have faced issues with reliability. Failures come from the fact that these are big bearings subject to quite unusual loading.They’re subject to high dynamic loading and they’re failing in ways that aren’t usually seen on more conventional bearings seen in trucks and cars and process machinery. The 2mm2 sensor has been validated in the lab and is currently being tested at the Barnesmore wind farm in Donegal, Ireland by Ricardo.

Prof Dwyer-Joyce, director of the Leonardo Centre for Tribology at the University said the patented sensor has been installed in the raceway of a transmission bearing, adding that the raceway compresses slightly as the ball and roller pass over it. "We pick up that compression and that compression depends on the load applied to the ball in the first place,” he said. “It’s that stress…which is going to control the life of the bearing."

The time of flight of the ultrasonic pulse from the sensor is affected by the stress level in the material, making the new method the first to directly measure the transmitted load through the rolling bearing components.

Current sector-related condition monitoring methods come in the form of acoustic emission signal, vibration sensing, or oil debris analysis that alert operators to damage after it has occurred, which puts the new sensor – and its size – at an advantage.

For full article click here: https://www.theengineer.co.uk/piezo-sensor-predicts-wind-farm-failure/ 

India to develop its FIRST anti-tank mine

Instead of procuring from US or Israel, country's defense forces will soon be self-reliant with the first indigenous off-route or anti-tank mines. These are improvised explosive devices (IEDs), which explode like a projectile while camouflaged and placed on a tripod stand.

The mine, unlike conventional mines, is not buried underground and needs no pressure when placed underneath a vehicle for activation. To be developed by the Terminal Ballistic Research Laboratory (TBRL), a Defense Research and Development Organization (DRDO) laboratory in Chandigarh, and the Central Scientific Instruments Organisation (CSIO), the mine is used in surfaces where underground burial is not possible. The project began six months ago and was reviewed by DRDO experts early this week. It is expected to be completed in another four years.

The incoming target combat vehicle shall be detected using seismic and acoustics sensors, which shall be made by the CSIO. The sensors fitted in these mines can detect seismic vibrations produced when vehicles such as tanks head towards ambush area. When acoustic and seismic sensors detect approach of a suitable target, the infra-red sensors (IR) in it are also activated. These IR sensors can send images of the target for attack. Consequently, after the target is confirmed, all these sensors trigger the warhead of the mine to project towards the target as it comes before it.

The TBRL plans to have a smart mine trap using these anti-tank mines. "Until the target does not approach, the off route mines can be kept on sleep mode, which can conserve the battery required for its operation," said Manjit Singh, director TBRL. He said, "We are working with CSIO on production of special seismic sensors, which can detect the potential target approaching us and also give a wake-up call to the operator as soon as the target approaches."

The anti-tank mine is portable and suitable for both offensive and defensive operations. The range of the off-route mine is 2 to 97 meters. The collaborators are working towards enhancing the range. The CSIO already has special sensors, being used in Delhi metro, to provide advanced earthquake warning system. "These sensors shall be improvised and worked upon for defense application," said CSIO director R K Sinha.

How it works

• The off-route mine is placed in the range 2-97 m from the target on a tripod stand
• It does not require any pressure of a vehicle for explosion
• These mines cannot be detected easily
• Its acoustic vibration (seismic) and infra-red sensors are triggered when a combat vehicle nears the trap, the mine is activated and shoots off a projectile.

Read the full article: http://timesofindia.indiatimes.com/city/chandigarh/India-to-develop-its-first-anti-tank-mine/articleshow/50214894.cms

Vibration technology based security system has been proposed by NIT-K to secure unmanned level crossings.

Recently, an MoU has been signed between Palakkad division - Southern Railway and ECE department, National Institute of Technology Karnataka, Surathkal on a system to provide advance warning at unmanned level crossings.

NIT department focused on vibration technology  and detailed the approach stating that motion of train generating vibration will be used in this system development where a sensitive vibration sensor/acoustic sensor will be installed on the track or sleeper near the level crossing which be constantly monitored for its output.  Further, the output of the vibration sensor will be monitored by the micro-controller device which will process the readings and infer the presence of the train, its type and velocity. 

This simple system that can detect the presence of the train after sensing the unambiguous presence of the train and can provide an audio-visual warning so that people, vehicles, people and livestock can move away from the location of the level crossing. The system will reset itself for next train detection.  

Read the full article: http://timesofindia.indiatimes.com/home/education/news/NIT-K-Surathkal-students-to-secure-unmanned-level-crossings/articleshow/49438115.cms