So far, we had completed the suction mechanism, chassis to support this mechanism, and mechanism to control the vacuum status as well as the movement of the wheels.

Now, our goal was to integrate all the three components and build a synchronously functioning working model of an eco-friendly leaf collector as our final product.

It is worth mentioning here that the product that we have built as a part of this project is a scaled down version of the actual idea of the product. The actual leaf collector should be 3 times as large as our working model in order to collect the leaves efficiently from the streets.

The major challenges for us in this phase were:

To select the wheels of proper size and material that can withstand the combined weight of the suction mechanism along with the chassis and work appropriately.

To adjust the position of the four wheels to be attached to the chassis taking into consideration the center of mass of combined chassis and suction mechanism such that when we drive the leaf collector, it doesn’t topple.

To establish a sync between the electronic and mechanical components of the product.

CAD design for the final prototype

CAD Design Video.mp4

Link for CAD design (Fusion 360 Software) : https://a360.co/3tGMKly

Process for integrating the components

Specifications of the motors used for operating four wheels

Each motor is a 300 RPM dual shaft battery operated (BO) motor with a gearbox giving a good torque at lower voltages. Made up of shock and vibration resistance plastic, the motor has two shafts where either one of them can be used for connecting wheels. The operating voltage is in the range 3V-12V at which it offers a maximum speed of 300 RPM with a torque of 0.35 Kg-cm. It weighs around 30 grams and has dimensions of 70x20x24 mm³. The shaft length is 7mm.

Specifications of the wheels used

The wheels are made of plastic with a diameter of 7cm and thickness 2 cm. The wheels are equipped with a screw for fastening the motor shaft.

Attaching wheels and motors to the chassis

After fastening motors with wheels, we mounted the four wheels and motors equidistant from the assumed center of mass. Forming a square shape with an edge 23 cm in length (with center of mass coinciding with center of square), the distance of each motor from the assumed center of mass is 16.25cm. Keeping them equidistant from the center of mass will give us an advantage of equal weight distribution.

FINAL PRODUCT VIDEO

Final Product.mp4

ENR_FINAL PRODUCT.mov

Explanation of working of the final product

Movement of joystick in x-y plane

This movement controls the direction of the wheels. When the movement of the joystick is in forward or backward direction, an appropriate signal is received by the receiving controller, and therefore, the chassis along with the suction mechanism moves in those respective directions.

Movement of joystick in z direction

This movement controls the vacuum status in the suction mechanism. When the joystick is pushed in the z-direction, the controller transmits the signal to turn on the mechanism and enough vacuum is created for the suction of the dry leaves.

When the vacuum collector is on, the airflow direction inside the suction mechanism and the path that the dry leaves follow (From collection hose to the storage space) is as shown in the images below.

Shortcoming in the final product and its reasoning

However, we were not able to achieve the turning effects, i.e. the joystick movement was in the left or right direction, the transmitted input signals were received by the receiver but the wheels were not able to move in those respective directions. The reasons for that are as follows:

The payload on the wheels was quite heavy taking into consideration the wheel size and material. Therefore, due to high friction, the wheels were not able to turn in spite of the fact that the correct signals were received by the receiver. Moreover, the motors that we have used are not able to provide enough torque to replicate the turning effect received in the controller. In addition to that, we had attached the wheels in such a way that the payload was balanced and the whole mechanism would not topple off when in motion. However, in this arrangement, the four wheels were placed quite far apart which was also a hindrance in order to achieve the turning effect.

We could not purchase new wheels that are strong enough and bigger in size, or motors with higher torque because of the pandemic. If we had an access to these components with proper strength, we could achieve the turning effect in our product.

Explanation for left and right turns of motor

We used the idea of “rotating in place” for programming the left and right turning of our vehicle. The vehicle turns about its center of mass as the speed of the wheels on both sides are equal but velocity is in opposite directions. This mechanism can be used for turning the vehicle into any direction without changing its position.

Final Product (calc for website).pdf

Conclusion

The usefulness of our product to the customers is summarized in the points below:

Our product uses a single joystick to carry out various functionalities such as moving the product and turning the vacuum status on/ off. This has made using the product very straightforward and easy for all categories of customers. This fulfills the job to be done for government or private sanitation workers and society residents who found previously existing methods troublesome to carry out.

In comparison to the conventional methods this method is very efficient and accomplishes the job to be done for sanitation workers and society residents as they will have to devote less time and effort towards doing this job. Along with being efficient, this product is also cost effective, therefore the government and private agencies will now have to put less human power towards doing the job as well as have reduced cost in manufacturing and maintaining the product.

This product has minimal human intervention as it is joystick operated, making the job for sanitation workers and society residents effortless.

The entire product is operated using batteries and no fossil fuel is used in power generation which makes it environment-friendly. This will reduce the adverse health effects on the society residents and also provide a safe and comfortable working environment for the sanitation workers.

The previous methods of collection, disposal and processing of dry leaves lacked the above mentioned points. The reason is that burning of dry leaves was practiced in the first place. With our product removing these problems it will hopefully reduce the practice of burning, thus reducing pollution and its adverse effects on human, animals, and plants to a certain extent.

CAD design for the final prototype

Process for integrating the components

FINAL PRODUCT VIDEO

Explanation of working of the final product

Explanation for left and right turns of motor

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