Wireless & Powerless Laser Welding Monitoring System

For quality assurance in the manufacture of automotive parts, the integrity of the laser-beam welds joining steel parts must' be monitored. A considerable number of on-line inspection systems have been developed to improve weld quality. Traditional monitoring systems in industrial plants use through wired systems, using communication cables and sensors. These systems suffer from two main drawbacks: a) the sensor cables are easily damaged and this conflicts with the need for easy installation and retrofitting into industrial plants, b) the installation and maintenance of sensor cables is much more expensive than the cost of the sensors themselves. Integration of electronics, sensors and wireless communications has prompted monitoring practitioners to consider alternatives that reduce wiring costs, make connections not previously feasible, and retrofit more measurement points cost effectively as well. This paper presents a prototype sensing device to achieve wireless and powerless operation for implementing a monitoring laser welding system. The weld monitor is designed to be simple, low cost and able to withstand a harsh manufacturing environment.