Attached self-lifting scaffolds synchronous movements measuring method and device based on transmitted light of optoelectronic measurement

► In this study we research synchronous movement of attached self-lifting scaffolds. ► The transmission of light through opaque liquid in a connected pipe is proposed. ► An integrated infrared optoelectronic sensor was presented to measure liquid level. ► We model a dual-side measuring method. ► We conclude that movement differences can be limited within 30 mm. Attached self-lifting scaffolds (ASS) are widely used in high-rise building construction. Machine position load will be re-distributed with imbalance when ASS are moved asynchronously, causing structural members and mechanical parts to to overload and form incipient faults. In order to achieve synchronous movement of ASS, an integrated infrared optoelectronic sensor was devised to measure liquid level. A measuring instrument utilising the transmission of light through opaque liquid in a connected pipe is proposed based on the infrared optoelectronic sensor. A dual-side model of this method is presented in this paper as a possible solution to achieve synchronous movement of scaffolds. With the dual-side model algorithm, the lifting or dropping length difference (movement difference) can be computed by detecting the liquid level in the connected pipe, and synchronous movements of different machine positions can be maintained. The experimental results showed that a measurement accuracy of 1.0 mm can be obtained and movement differences can be limited to within 30 mm (as per Chinese construction specifications), this provides a predictive control to the movements of ASS and reduce the safety risk in high-rise building construction. Field application in a building construction indicated that the sensors are stable and suitable for the ASS system.