A PROJECT ON A GLOBAL PROBLEM SOLVER, TREE PLANTING DRONE

Title: A PROJECT ON A GLOBAL PROBLEM SOLVER, TREE PLANTING DRONE

OBJECTIVE: To design a hexacopter for tree plantation which aids in solving climate change problem, in SOLIDWORKS

MOTIVATION: This project was motivated by the environmental problem caused by increasing deforestation and the huge bushfire occurred in Amazon forest and Australia in 2019 & 2020. The concept was inspired by the video of a YouTuber, Mark Rober from the campaign ‘20 million trees’ with #TEAMTREES.

INTRODUCTION:

In this project, a massive drone, hexacopter is designed with the aim to plant billions of trees per year. The goal of this project is to help the earth in the restoration of its natural characteristics by reducing the carbon dioxide content in the atmosphere. For this project, SOLIDWORKS is used as the tool for the design and assembly of the complete drone. This huge drone helps in planting trees in the bare lands by the help of automation following the predetermined path and location. Using the seedpods instead of a sapling as in the traditional method, this drone can help to speed up the tree plantation process by more than 10 times and reducing the overall cost by a huge amount.

This drone has 6 30” propellers made up of carbon fiber for more strength and stability during the flight. It is 630 mm in height and 2352 mm in diameter with the propellers pointing outwards.

Video Link: https://youtu.be/pdauF0faRpU?si=eu_fIowOqirMPPja 

DESIGN METHODOLOGY:

Identification of Need:

We have advanced technology to a huge tree in seconds, machines to destroy forests in a day, missiles to destroy enemy hundreds of miles away, vehicles to fly miles away either in air, water, land, or space, and yet we don’t have such a technology to plant trees. Every innovation and every invention is targeting only the human comfort and prosperity of human because of the selfishness of humans. All the inventions lead to carbon footprint in one way or the other, every machine is easing the lifestyle of people but hurting the mother earth. This need has been realized by several scientists and engineers in the early ’20s and a couple of companies like Drone Seed, BiCarbon Engineering, AirSeed Technologies, etc. are working on it but to mitigate the problem and to restore our ecosystem, the need is more than what is available today. A machine available in one part of the world may not be sustainable for the other part of the world. It is better if we could design it on our own with our requirements, available materials reducing the cost and increasing the result. This need has led to the design of a massive hexacopter for planting trees in this project.

Definition of Problem:

“A problem well-stated is a problem half solved.”

- Charles Kettering

Every year 3.5-7 billion trees are cut down. This is causing more accumulation of CO2 in the atmosphere and hence worsening global warming and climate change. The need for trees for our home planet to restore is very high. The figures can be over a trillion. It is possible to burn millions of hectares of forest-like in Amazon and Australia but is not possible to grow them right away. Planting trees with the traditional method can never restore the damage that the human has done or that would be done by the time a tree grows enough. A drone is a way to go for solving this problem because of its capability and the rate of work.

Project Ideation:

The inspiration for this design was taken from the company ‘Drone seed’ and ‘AirSeed Technology’. In addition to that, the inspiration was taken from agricultural drones of a large scale. The ideation of the overall design was done on paper first and later it was designed in SOLIDWORKS after finalizing the design. The size and scale were assumed to be nearly equal to a commercially available agricultural drone. Individual parts of electronics were designed according to the dimension of the product description from their website and their placement was planned and sketched on paper for better flexibility. The design criteria for a drone was followed to include the required components and the ad-on by the demand of a hexacopter for the tree plantation purpose.

Part Design in SOLIDWORKS:

SOLIDWORKS is a widely used and very powerful tool to design any engineering component or a device. After the ideation and planning, the part design of each component is done is SOLIDWORKS. For the design of each component, the base sketch is created based on the ideation sketches. Electronic components were sketched taking their dimensions and the layout from the product description from their respective website. Sketched features and applied features are employed as per the need for the design of each component. Some parts were designed in the Assembly environment using the ‘in context features’ to make the workflow easier allowing to design of complex shapes of certain parts without interfering with the existing parts within the assembly. All the nut and bolts were imported directly from the SOLIDWORKS Toolbox in assembly mode. Material and appearance are applied to each part after the completion of the design of each part. Mass is overridden for the standard components of electronics from their product description.

Assembly Creation:

After all the major components of the hexacopter are designed in a part design environment, assembly is then created from the part files. In SOLIDWORKS, the feature which connects or joins two different components is called mate. The parts are imported into the Assembly environment and then required mates are applied to each individual part with respect to the connecting part. The first part inserted into the assembly is always fixed by default.

In this hexacopter, the base plate is fixed first for ease of assembly. All the components are assembled with respect to that. The repeated parts like the arms, motors, and propellers were assembled using the ‘copy with mates’ command in the assembly. An alternate way is to create a subassembly of repeated parts and use it in assembly. Within the assembly environment, the errors occurred by the interference of the parts are eliminated by editing the part within the assembly. In this case, interference of the base plate and support structure was eliminated by editing the part within the assembly.

In this hexacopter, several parts like the cover for the central part of the drone, support structure were created using the ‘in context features’ offered by SOLIDWORKS in the assembly environment. Also, all the nuts and bolts for fastening purposes were added directly from the SOLIDWORKS Toolbox on all the holes created earlier.

Fig: Assembly of all the components shown with the transparent cover

Rendering:

Rendering is to make photo-realistic images out of the 3D designs that we have created and assembled in the design process. To render the 3D models, we need to set up the correct scene, lighting, camera views, and apply decals if necessary.

Why is rendering Important?

Rendering helps to visualize the product and it allows us to see how it interacts with the environment. It is very essential for the presentation of the product among the potential customers ahead of the actual manufacturing. Also, aesthetics is a very important part of every product in the industry, so to see how the final result looks upon the various materials and appearances applied, plays a vital role. It also saves a lot of time and money avoiding the real-time testing of its appearance before the actual production. It can also be used for digital marketing purposes without actual production.

Rendering Tools:

• ‘Photoview 360’ is one of the add-ons of SOLIDWORKS which allows creating photorealistic rendering. It is integrated with the SOLIDWORKS software.
• ‘SOLIDWORKS Visualize’ is another powerful tool of SOLIDWORKS which comes as separate software and is able to render extremely high quality and photo-realistic images of the product.
• ‘Keyshot’ is an alternative to the rendering tools which can be utilized to render high definition images of the product.

However, for this project, only ‘Keyshot’ has been employed for the rendering purpose.

Rendering Process:

The rendering process includes the following steps:

1. Apply Material
2. Apply scene

• Apply lights

1. Apply decals
2. Adjust camera views
3. Adjust image quality and

• Render

After the rendering is complete, it is presented among the possible customers and also for digital marketing.

DESIGN CRITERIA:

In order to define the problem properly and to determine the design considerations, the following aspects and requirements were considered:

• Tree plantation
• Ease of transport
• Long Flight Time
• Larger load carrying capability
• Hexacopter configuration
• Stable design
• Autonomous flight based on a predetermined path

A normal drone has to meet all the basic requirements of the design and for this hexacopter, more design considerations are taken into account. It has to be able to carry a larger load with a stable design. It should also have longer flight time with ease of transport because the size becomes huge.

Based on the application chosen, i.e. tree plantation, few more requirements were considered as follows:

• Autonomous flight supporting components by predetermined path and location
• Live camera
• GPS module
• Stable with loads
• Ability to customize
• Protected components

Because of its massive size than a normal drone, it is more difficult to handle and transport compared to commercially available basic drones. For the ease of transport of this huge drone, the following aspects were considered.

• Optimal size
• Can be disassembled
• Foldable arms
• Broader landing gear
• Wheels on the landing gear
• Protected components

This drone is designed with the intention to keep flight time for at least 15 min. In order to increase the flight time of this hexacopter, the following things were considered:

• Minimum 30 min flight time
• Flexible for change and configuration
• Maintain good thrust ratio

Basic Parts of a drone:

A drone in general consists of the following parts:

• Frame
• Motors
• Propellers
• Batteries
• Flight controller
• ESC (Electronic Speed Controller)
• PDB (Power Distribution Board)
• Controller and receiver
• Camera and video transmitter

For the purpose of tree plantation, additional parts considered in this design includes the following:

• Landing gear separate from the frame
• Pressurized canister
• Container for seedpods
• GPS Module
• Additional support structure and clamps

Component Selection:

The major components that constitute a drone were selected as stated below:

Motor:

Taking into consideration the size of a normal agricultural drone and the load it has to carry, the motor Xrotor 8120 100KV was selected. The key feature is that it can create a thrust of 13Kgf. This can meet our demand on a higher scale.

Propeller:

The propeller compatible with the above motor is normally of size 30". For this drone, Foxtech Supreme C/F Propeller 3010T was selected according to compatibility. This propeller is made up of carbon fiber which is ideal for our purpose.

ESC (Electronic Speed Controller):

The speed controller for the above motor is the recommended ESC provided along with the motor. XRotor HV 80A FOC V3 is used for this purpose.

Flight Controller:

For this hexacopter, a common FlySky FS IA6B is used which is compatible with our hexacopter configuration and meets the requirements. 

PDB (Power Distribution Board):

In order to meet the power distribution requirements for 6 motors and the additional components, the power distribution board a normal 100A multirotor PDB is used.

 

Battery:

The battery is one of the key figures of the drone. For longer flights and to meet the power requirements for our drone, a 12S battery, Tattu Plus 22000mah is used. It is of 44.5V and has a discharge rate of 25C which is ideal for our requirement.

PART DESIGN IN SOLIDWORKS:

In this project, the part design of each component is carried out in SOLIDWORKS. All the individual parts are described below:

Base plate: - Bottom part:

This is a part of the frame which is designed to hold all the arms together. It also serves as the base for the electronic components which can be fitted in the area inside. The holes are created in predetermined and assumed locations of the other components. Carbon fiber is applied for this purpose because it has great strength to weight ratio.

Base Plate: - Upper Part:

This is the upper half of the base plate which holds the other components tightly together with the bottom part. The dimensions are almost the same but the location of some holes differs according to the placement of the components above or below it.

Arm:

This part is one of the major parts of the drone. It is designed to be separate from the central body part to make it flexible and able to disassemble. It is also made up of carbon fiber for greater strength.

Motor Seat:

A motor seat is designed to fit the 90.2mm diameter motor for this drone at the end of each arm. It also has a place to attach ESC right in front of the motor.

 

Motor:

The motor is designed taking the dimensions of the product description of the specified model. It is placed on the motor seat at the end of each arm in the assembly.

ESC:

The ESC is also designed with reference to the standard dimensions from the product description of the recommended motor. It is placed in front of each rotor. Few wire connections are represented by using the sweep feature of the SOLIDWORKS.

Propeller:

A propeller for CW direction and a propeller for CCW directions are designed separately taking the aerofoil cross-section into consideration. The dimension of 30” is applied by scaling after the smaller version is modeled. The carbon fiber material is applied to meet the design criteria. Features like loft using the splines are applied to create the aerofoil cross-section.

Battery:

The battery was also designed taking the dimensions from the product description of the model specified earlier. It is placed above the upper half of the base plate. It is placed at the center for weight balance.

Flight Controller:

The FlySky IA6B flight controller is designed as per the product dimensions available in the market and is placed above the upper base plate.

PDB:

The 100A power distribution board is designed with the dimension of a commercially available model. It has simple features like extrusion and holes.

Video transmitter:

Skyzone TS5823 video transmitter is designed along with the antenna taking the reference of dimensions from the product description.

 

 

Camera:

For this drone, the video camera, the DJI FPV camera is designed with the dimensions referring to the product description.

Camera Gimbal:

A customized gimbal is designed for the above camera using simple commands like extrude and extruded cut in SOLIDWORKS. It is placed on the front side of the drone.

GPS Module:

A simple neo GPS module is designed taking the reference dimensions from the product description. Also, a small stand is designed to place the GPS module at a certain height.

Container:

A custom container for the seedpods was designed using general features like extrude and extruded cut. It has an extra part as a container lid on the top from where the seedpods are loaded inside it.

 

Container Adapter:

A simple custom adapter for the container is designed which is made able to slide easily while inserting and taking it out. It is fastened with the support structure.

Arm Clamp:

Arm clamps were designed with reference to the size of the arm and its placement in the baseplate. There are three types of arm clamps: 1) arm clamp which allows snapping and folding 2) clamps for rigid arms 3) clamps at the end of foldable arms. ABS plastic is applied as the material for these clamps. Simple extrude, extruded cuts, chamfers are used in these parts.

1) arm clamp which allows snapping and folding

2) clamps for rigid arms:

3) clamps at the end of foldable arms

Support structure:

The support structure is designed in the assembly with ‘in context features’ to avoid interference with other parts and to optimize the shape and design if required. It is a multi-body part and has an upper and lower part which lies above and below the base plates accordingly.

Cover:

This is also designed with ‘in context features’ in the assembly mode of SOLIDWORKS. It also has the upper half and lower half as a plate but in different part files. The upper part is designed with a revolve feature while the lower plate is designed with shape optimization with reference to the other parts.

Clamps for landing gear:

These are a simple bearing type of clamps designed to fasten the landing gear with the support structure of the drone. It is fastened at the lower side of the support structure.

 

 

Landing Gear:

This is one of the essential and important parts of any drone. For this project, it is designed to be high and wide enough to make it stable when it lands. Simple sweep commands are used for the creation of this landing gear. Aluminum is applied to the material so that it can withstand the load and self-weight. It is provided with small wheels so it can be easy to transport on the ground and also it absorbs shocks while landing.

Nuts and Bolts:
All the nuts and bolts were customized and imported automatically from the SOLIDWORKS Toolbox.

FINISHED PART ASSEMBLED IMAGES:

Isometric view:

Top view:

Front view:

 

 

WORKING:

This project is aimed to address one of the global problems, climate change due to deforestation. It has to work at a faster rate and greater scale. For this purpose, it is made automatic to follow the path. It works in two phases:

Phase 1:

A separate drone scans the geography of the terrain and finds out the bare land where a tree has to be planted. A 3D map is created and a path is planned with the position for each seedpod to drop on.

(Source: world economic forum YTC)

Phase 2:

In phase 2, this hexacopter goes to the exact location following the predetermined path flying over 2-3 meters above the ground.  The pressurized canister provides the necessary propulsive force to drop the seedpods at each location. Each seedpod consists of germinal seeds that can grow into a huge tree later with all the required nutrients and biodegradable additives which dissolve upon reaching the ground and mixing with the moisture.

DESIGN CALCULATIONS:

Motor specifications: XRotor 8120 100KV
- KV value:100
- Outer Diameter: 90.2mm
- Weight: 645g
- Fitted blade:HW2911
Outlet: enamelled wire straight out
- Recommended Props: 30 inch

Battery specifications:

Model Name/Number	Tattu
Battery Capacity	22000 mah
Voltage	44.4 V
Weight	5050 gm
Battery Type	Lithium-Polymer
Dimensions	158 x 118 x 121mm

Load Carrying Capacity:

Thrust ratio taken: 2:1

Overall weight of the drone: 27.9 kg + 0.5 kg for additional electrical components = 28.4kg

Thrust per motor: 13 kgf (127.53N)

Total thrust = 13*6 = 78 kgf (765.18N)

Load it can bear with 2:1 thrust ratio = (78/2)-28.4 = 10.6 kg

Thus, it can carry 10.6 kg of seedpods and fly.

RENDERED IMAGES:

 

 

 

 

 

IMAGES SHOWING INTERNAL PARTS:

SIGNIFICANCE OF THIS PROJECT:

• This project has a large significance which benefits not only the human race but all the living organisms and the ecosystem on the planet.
• It can plant billions of trees per year with multiple drones operating at a time.
• It can help to restore the lost forests and bare lands within 5-10 years time according to the vegetation.
• It will help in the carbon sequestration process naturally.

FUTURE SCOPE:

This project has a huge potential for further work, design improvement, and innovation. 

• The scale can be increased in terms of its work.
• The production rate can be increased.
• Additive manufacturing can also be used to manufacture custom parts which cost high in the machining process or any traditional manufacturing process.
• A faster rate of tree plantation in the future
• Area for more research and development
• The overall size and the weight can be reduced with the excessive use of material science and design validation with simulation.
• There is a lot of space for design improvement and optimization. It can be redesigned to make it more cost-effective and more productive.
• The working of seedpod dropping with the help of a canister can be improvised with more details or with better mechanisms and technology.
• Some parts like the container adapter are designed as a solid model. It can be redesigned as a sheet metal component increasing the stiffness and keeping the mass reduced.

MAJOR TAKEAWAYS OF THIS PROJECT:

The major takeaways of this project are:

Design in an industrial approach:

Design is an iterative process and it involves many professionals such as designer, design engineer, simulation engineer, CAE engineer, etc. Being a design engineer, one must be able to communicate with all the professionals, understand their responsibilities, and understand the design process maintaining coordination with others. One must not only know the CAD tools but also an efficient way of using them as the industry needs. This project has sharpened all those aspects. Starting from the identification of need, the definition of the problem, and the whole design process, this project has helped to dive deeper into the mechanical design field.

Application of Parametric Modelling:

Parametric modeling is a modeling process where we can modify the design, features at any point in time. The different elements of the model, such as sketch entities, features can be assigned to a parameter which can be changed anytime. It is a very powerful tool as it saves all the parameters forever and it can also be employed to add or edit features within a part of a generative design environment, where the parameters are not available initially. 
In this project, most of the parts had to be redesigned or they required some parametric changes while being in the assembly to remove the interference between the parts. This was successfully achieved by the use of the powerful parametric modeling environment of SOLIDWORKS.

 

Use of Design Intent:

Design Intent is the prediction of how the design will behave in the future when certain changes are made or when certain features are applied. In an industry, a design engineer should be able to use the features in such a way that even if any modifications are needed at any time, it should be modifiable in no time.

One can keep the design intent by making the use of the following features:

End Conditions: While applying end conditions, care must be taken and it should be predicted in what way it will behave if any additional changes have to be made later. The end conditions should be applied in such a way that it will affect only the current part and not others. For example, in this extruded cut of the sprocket in the wheel, it is required to keep the end condition ‘up to next’ because if ‘through all’ is selected, it can cut other bodies present in the part too.

Feature Scope: Feature Scope appears in the property manager only in the case of multi-bodies. A certain feature can be applied to certain bodies and can be skipped to others by selecting manually from the feature scope. If it is left as default, it will affect all the bodies present in the part. For example, in the same wheel as the above example, the body selected in feature scope is only the sprocket. In this case, using ‘through all’ in the end condition will also keep the design intent.

Equations: Linking the sketch dimensions together, applying global variables will also help in a great way to keep our design intent. It will allow us to edit it at any point in time.

Mates: In the assembly, the mates should be applied thinking of any moving parts or fixed parts. Also, the placement and position of each component with reference to each other should be taken care of. In an assembly mode, the choice of external reference really matters because any design change in a component affects the whole design.

Excessive use of 'in context feature' and SOLIDWORKS Toolbox:

 For this project, the support structures, the cover, and the base plate of the cover, the GPS module stand, etc. were designed using the 'in context features' within the SolidWorks assembly. This allowed for the design of components with an optimized shape with reference to the other components removing the possible interference and for better design in the placement of holes and fastening bolts and nuts.

For the design of nut and bolts as per the hole size, component type, the SOLIDWORKS Toolbox was excessively used with ease. It allowed repeating the process in a short time making it very easy.

CONCLUSION:

The ideation, design, assembly, and rendering of a huge hexacopter is successfully designed in SOLIDWORKS. This project has brought us closer to meet sustainable goals.

The project can be summarized with the following points:

• Completion of ideation, design, assembly, and rendering of a hexacopter
• Helps in the restoration of the ecosystem of the earth
• Helps to meet the sustainable goals
• Project completed in an industrial Workflow
• Use of SOLIDWORKS in an industrial approach

REFERENCES:

[1] Drone Seed: https://www.droneseed.com/

[2] Airseed Technology: https://airseedtech.com/

[3] Drenda Systems: https://www.dendra.io/

[4] Amazon: https://www.amazon.in/