Low cost Window Cleaning Robot: Challenges and much more!

So, after having a look at last post Sneak Peak, you might want to know quite a lot of things. And here, we will discuss everything but step wise.

Why window cleaning?

The  exteriors of many buildings are being constructed with Huge glass Panes  which give an immense aesthetic beauty, but cleaning the outer part of the building is a tough job. Generally, human labor clean the outer pane by clinging themselves to the high storied building which involves high life risk factor.

So, the motive of building this project was quite simple, it ensures safety of human labor, and also cuts the maintenance budget of commercial buildings. But since, we are still working on the model, it can be used for our home glass window panes.

Figure 1: Human labor cleaning exterior panes which has high risk factor

Attempt in making the robot:

The main challenge is to manage the weight of the body, our original idea was to fabricate the wheels of the robot in such a way that it could stick to the window. The wheel used was a pulley wheel with 4 cm width and 6 cm diameter, where we used flat suction cups of 2 cm diameter, which were fitted on the wheel, by drilling holes on the wheel. In this way, we had got around twenty four to thirty suction cups on a single wheel. So, the wheel with so many suction cups does stick on the window, but with the weight of the robot? Does it? Even if it takes the weight, will it stick along with vertical motion of robot?

This was a challenging task!

Before moving on, I would discuss the components that we have used to make the robot:

1.  LiPo 11.1 Volts Battery: For powering up the controller as well as for driving the motors.
2. DC Motor (10 RPM high torque 10 kg-cm)
3. Arduino Mega: Control action
4. Dual DC motor driver 20 Amperes
5. Miscellaneous: Cleaning material.

Weight of the entire robot:

Components of robot	Weight (grams)
Wheels (Four)	152 gms
Acrylic Chassis	250 gms
DC Motor (Two)	360 gms
LiPo Battery 11.1V	140 gms
Arduino Mega	40 gms
Cleaning Purpose	40 gms
Total	980 gms

Now, we made a four wheel robot with all wheels fabricated with suction cups. The body is shown in figure. As per our calculations, the suction wheels took the weight of the robot perfectly. The robot got stuck to the window with all the components.

Designing our body:

Figure 2: Acrylic cutting

Figure 3: Mounting wheels in between

Figure 4: Mounting DC Motor

Figure 5: Final Acrylic chassis

So, keeping our fingers crossed we tried moving the robot, kick starting the motors the wheels didn't stick to the window and our robot fell down, which was heart breaking. This was the first failure and challenge we faced! So, our idea with having suction wheels went in vain, because by the time the other suction cup would come in contact with the window it slipped from the window.

Umm.. So what, we didn't give up that easily! We came up with other idea of creating suction the other way. The sneak peak post had the laser cutting fabrication of our new body, which would be discussed in the next post.

Figure 6: Robot stuck on window without motion

So readers, along with the weight, motion of the robot is also a challenging task of the previous model. But in the new model, we are not fabricating the wheels, we are changing the entire body, and made it quite compact, where we narrowed down the size and weight of the robot.