Ziang Ni

Automatic Facade Cleaning System – Major Project

My major project is an intelligent robot for high-rise façade cleaning and maintenance. It features a closed-loop water recycling system and a caterpillar-inspired motion structure, enhancing both cleaning efficiency and operational safety. Designed with sustainability in mind, it aligns with UK and EU water-saving and environmental principles while demonstrating a balance between innovation, safety, and responsible design.

Rendering of the robot attached to the glass façade.

Rendering of the turning motion at the building corner.

Main body of the machine and the components on top and a close view of transparent window installed in the rear half of the machine body, which facilitates real-time observation of the internal operation of the water tank and water circulation by the staff.

The end of the pipe is a sliding mechanic structure, as shown in the fiqure, which has four wheels driven by motors to achieve the rotation of the machine. The pipe will turn through a converter next to this sliding mechanism and then connect to the machine.

Product & Marketing Research

I conducted a market positioning analysis of the mainstream exterior wall cleaning equipment based on two dimensions: “cleaning efficiency” and “energy/water resource efficiency”.

The product targets an unmet gap in the market by integrating a complete water circulation system that significantly reduces total water consumption. This sustainable approach enhances resource efficiency while offering a new opportunity zone in building cleaning design.

1:1 Scale Engineering Drawing

A full-scale engineering drawing was created to represent the actual size of the product. Unlike conventional consumer products, this design features a significantly larger overall volume, and the full-scale drawing helps to better visualise its real dimensions, proportions, and spatial presence in context.

Traditional drafting tools were used to carefully transfer digital dimensions onto large-format paper, allowing the design to be experienced at its true physical scale. The process helped verify proportions, refine key structural relationships, and better visualise the overall presence of the product beyond screen-based modelling.

Ideation & Sketches

Research and exploring ideas of rope position & terrain adaptive structure.

Research and exploring ideas of crane structure & circular suction arrays.

Research and exploring ideas of rope rotating & axle alternating motion structure.

Research and exploring ideas of extension structure.

Research and exploring ideas of cleaning head.

Structure – An Exploded View

Water Recycling System

The cleaning system operates through an integrated water circulation mechanism that balances pressure, flow, and recovery efficiency. Clean water is distributed to the cleaning head and later reclaimed through a controlled return process; allowing partial reuse within a closed loop. The mechanism maintains equilibrium automatically, achieving both performance stability and significant water savings. The system reflects sustainable design thinking, aligning with UK and EU principles of water efficiency and responsible resource management.

Caterpillar-style Sliding Rail Mechanism

The robot advances through a caterpillar-inspired mechanism: the supporting legs of the upper suction unit retract first, allowing the entire upper section to slide forward along the rail. Once repositioned, it reattaches securely, followed by the movement of the lower unit. This alternating motion ensures continuous adhesion, stable progress, and enhanced safety on vertical surfaces.