Guys these are the update of our finding and some problem identified. An initial design requirement was also created so as to explore possible solution, this serves as a good guide to kick start the project.
Topic is divided into 6 section, this let you as a reader has a better understanding on our project. =)
- Section 1 - Design of Quadcopter
- Section 2 - Protective cage (possible material and problem identified)
- Section 3 - Terrestrial drive system, also acting as a protective cage
- Section 4 - Autonomous batteries changes
- Section 5 - Frame structure of the quadcopter
- Section 6 - Control system.
Propeller
- Assuming a propeller diameter and pitch
- Using Abbott or Bob Boucher's equations to find the power absorbed by propeller(Dickey, 2012)
- Manipulate the Momentum equations so that propeller speed can be found (Hepperle, 1996; Dickey, 2012)
- Ensure that the propeller tip speed does not reach the speed of sound
- Propeller speed and power compare against plotted graph data and check for efficient (Brandt and Selig, 2011; Selig and Ananda, 2011)
- Ensuring calculated speed is not at the propeller peak efficient
- 50% of peak efficient
Motor
- Kv is the RPM when 1 v is supplied
- Assuming there is no losses
- Power = rad/s * Nm
- Maximum power = 0.5 angular speed * 0.5 torque; 100% thrust
- 0.5 power; 50% thrust
- Hovering power = Kv*voltage/4
Building a Quadcopter
- Estimate the overall weight, propeller speed and diameter
- Using power equations from Abbott equation or Bob Boucher's electric motor handbook equation
- Relate it with propeller Momentum theory
- Using the propeller coefficients
- Choosing battery that can give a flight time of 15min
Section 2 - Protective cage (possible material and problem identified)
Possible Material
The aim of this protective crash cage don't just serve as a collision crash proof structure. The selection of material plays an important role in this project mainly because of the limitation of the flight time, additional weight incur will definitely reduces it's capability.
Research available on the web and journal paper suggested that material like carbon fiber has a ratio of high strength to low density but this possibility doesn't limit the exploration of our selection.
Any suggestion of possible material? (woods, Styrofoam, plastic (ABS, polycarbon and etc) feel free to give comment!!!!!!!!
Problem Identified
Quadcopter is designed to be robust to both indoor and outdoor environment, complex programming and sensor can be applied into our system, but this does not eliminate the possibility of Quadcopter crashing into any object. Thus, once Quadcopter get into an impact or collision; it's must has the ability to regain "self-recovery"
These are the possible principle solution from our research:
- Gyroscope Gimball copter design ( from EPFL)
- Gecko like feet/arm adopting suction effect to regain recovery
- Insect like beetle to lift themselves
- Center of gravity (G.O.G)
Figure 6 - Possible concept design
Figure 6 shows the possible concept design generated using "inverted ice cream". Interesting? Please leave a comment.
Requirement :
- Two roles, ability to maneuver on the ground and serve as a protective cage for the Quadcopter
- Ability to conserve 50% battery while maneuvering
- Absorb shock from a height of 2m
- Steer and reverse
Figure 7 - Skywalker Copter
Figure 7 shows a hobbies toys which has the above capabilities, but these are normally on single axis propeller.
Comment on this similar approach will be greatly appreciate =)
Section 4 - Autonomous batteries changes
Autonomous or automated batteries changer is a platform for quadcopter to replace it's empty batteries and ready for take off! sound cool huh? that was an idea or concept selected by one of our team mate.
We would like to share our the list of item needed
- Two batteries
- possible battery carriage weighting <150g
Figure 8 - Mechanical Platform without linear motion
Figure 9 - Docking Bay
Section 5 - Frame structure of the quadcopter
This section describe the main frame structure of the quadcopter, the X-configuration will be used. But we are open to any possible solution or ideas.
Figure 10 - X configuration
Figure 10 is the configuration selected, this configuration has an advantage to maneuver the copter around balancing it's axis, hopefully this will conserve energy used.
Section 6 - Control System
Control system is currently under further experimentation refer to first post for details. More updates will be available next week =)
That's all for the updated for this week, hey guys/ladies please do leave a comment on our post after reading, it is much appreciate!
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