An indigenously developed remote-controlled window cleaner that can transform the facade of external glass cleaning

For the past few decades, commercial facilities have followed the template of a towering, glass-fronted structure surrounded by similar buildings in a corporate park. While these modern monuments appear elegant, their glass facades are a real challenge to clean. Presently, most facility management companies employ semi-trained window cleaners who are suspended with harnesses from the roof, who manually scrub and clean the glass. This method is both dangerous and provides unsatisfactory results; Clean India Journal showcases Smart Robo Spider, an indigenously developed, remote-operated facade-cleaning machine that can revolutionise the nature of this critical cleaning task.

While facility management companies do provide harnesses and safety gear to the workers who risk their lives on a daily basis to physically scrub the glass facades of buildings while suspended from the roof, this equipment is not 100% safe. Because of mechanical failures and incorrect usage, some workers plummet to the ground from their high work-places, suffering grievous injuries and even losing their lives. Those who have not yet been involved in such an accident face a daily risk of joining their unfortunate colleagues.

Limitations of manual window cleaning

Apart from the risk of loss of life and limb, this method also yields unsatisfactory results. Manually scrubbing a facade is very time-consuming; every time a worker has cleaned one side of a building, he has to come back up to the roof and move down to another side. He has to use the same limited quantity of cleaning solution or water and the same dirty brush, which leaves fine marks on the glass that may not be visible from a distance but can be seen by the occupants of the building. By repeating this procedure again and again, the cleaning solution itself becomes thick and mucky, and the worker’s actions merely transfer this grime back onto the glass.

India’s extreme climatic conditions further complicate this work; with temperatures rising above 45 degrees in summer, and sinking to single-digits in winter, it is impossible for a worker to function with the same efficiency throughout the day. They need frequent rest, plenty of water breaks and are at increased risk of accidents in such weather.

Buildings with glass facades are cleaned while their occupants are at work inside them; it can be disconcerting for the latter to look up from their work and spot a ‘spiderman’ hanging in mid-air outside their offices. Window cleaning workers can observe all the goings-on in an office, making privacy a real concern.

Development of Smart Robo Spider

Baljit Singh, Vice-President – Operations, Brookfield Properties, has been part of this industry for two decades. He said, “From my office window, I see people hanging from ropes everyday. Anyone can work on a horizontal surface, but working against gravity is a challenge. I find glass facade-cleaning the most challenging cleaning job, and decided to find a solution that eliminates its risks and gives better results.”

Over one-and-a-half years, he tried various types of wipers and water jets, but did not find what he was looking for. He then got 1.2-metre-long rollers custommade, with bearings on both sides, and trawled Delhi markets before arriving upon the correct gear ratio. After a long search, he found the right gear and motor combination.

Singh’s next target was to find a way to make this window-cleaning process human-free.

He explored radio-frequency controlled remotes which can work from a 100-metre distance, and which can signal the required number of instructions to the machine. After trying various permutations and combinations, he finally built and tested a prototype.

Parts of the product

• Bristle roller: This gently scrubs the glass surface to remove dust particles, dirt and stains, without causing any damage to the surface of the glass facade. The bristles carry droplets of cleaning liquid sprayed on the roller by the sprayer.
• Small-nozzle sprayers: Used to spray the cleaning liquids on the glass surface of the building.
• Micro-fabric roller: This soft roller will wipe off the liquid and any remaining dirt.
• Wiper: To wipe off excess water and washing liquid.
• Reversing mechanism: Which enables the Smart Robo Spider to move upward and downward, forward and backward, and ensures adequate pressure on the glass surface for better scrubbing and cleaning.
• Wireless control station: A radio signal-based remote station to control the movement of the machine, operation of the glass cleaning apparatus, visual monitoring of the glass and supervision of surface cleaning by a highresolution PTZ camera.

The machine is currently retrofitted onto existing models of cradles, and weighs around 150kg. Along with its own cradle, it will weigh 200kg.

How the Smart Robo Spider works

The machine uses regular glass cleaning chemical solutions and clean water with low TDS. One set of nozzles sprays the former onto the bristles, while another sprays the latter. A wiper wipes off the excess, which is followed by a drying roller to finish the job.

The machine is remote controlled and has been tested on a building that is 70 metres high, but is designed for use on buildings of up to 100 metre height. The machine can be moved in various directions, and the remote can also be used to change the rotationsper- minute of the gears and the pressure exerted on the glass.

The machine is suspended from the roof of the building and does not require any modifications to existing glass facades. While spraying of chemicals and water on a particular section is done from bottom to top, cleaning and wiping are done from top to bottom, before moving on to the next section.

At present, it runs on electricity sourced from plug points on the roof the building. Future models will run on their own batteries. Hence, the machine can run continuously all day, with breaks required only to fix maintenance issues, if any.

Present status

The Smart Robo Spider has been successfully designed, fabricated and tested. Singh said, “I want this to be used at maximum possible sites. I am looking for an industrial partner to manufacture it on a large scale”.

By removing the human element from window cleaning and devising a way to consistently clean every section of glass with the same precision and results, the Smart Robo Spider streamlines the process of window cleaning. What’s more is that it is designed and developed entirely in India, and is well-suited to Indian cleaning requirements. In the near future, it is sure to lead the trend Baljit Singh of mechanised window cleaning.