Iris is a quadcopter which has a dead-cat configuration which basically means the frontal arms are wider apart from the back armswhich increases the FOV of the camera as the arms do not obstruct the footage.The flight controller is the infamous Pixhawk 2.4.8 which runs on PX4 firmware.
To improve the efficiency and flight time, it was later upgraded with 810 kv motors and 10 inch propellers. Iris has served the club as well as other activities well. The datasets for image detection in DRDO SASE’s UAV Fleet Challenge were obtained from Iris.
Of course, we had to improvise on a few things.The one I would like to mention is the frame of the quadcopter.
But we had to reconsider that because we had very little space inside the frame body to place everything properly
This was a good option and we would have almost gone with this design and 3D printed it- but *fortunately* the 3D printers in TL were not working at that time. I said fortunately, because otherwise we could not get this awesome frame-
Apart from improvisations, one thing focussed on by us was achieving a clean build. Space Management was a challenge and fun too. The most time consuming part was cutting wires and soldering them in places to achieve that clean build. Heat shrinks are extremely efficient and satisfying to use.
Autonomous aerial vehicles with different configurations exist to supply requirements for diverse applications. One such is the tailsitter, which gives a comparative advantage over VTOL quadcopters and fixed-wing planes.Small Unmanned Aerial Vehicle (UAV) development is an area with rapid growth, primarily due to its low-cost, smooth operation and a desire to reduce human risk. Furthermore, these aircraft can be used in several missions, like inspection of high-risk areas, search and rescue operations in the event of accidents, environmental monitoring and precision agriculture. However, aircraft based on rotary wings suffer a penalty in performance regarding the speed of operation, which reduces the area covered in a mission. A configuration that solves this problem is the tailsitter, a fixed-wing aircraft with VTOL capabilities. Besides, flying in both hover and cruise condition, having less mechanical complexity and reduced maintenance cost are significant benefits from the operational point of view for tailsitter aircraft. The main focus of this research is the development of a small tailsitter UAV. The proposed aircraft design differs from previously tailsitters due to its simplicity and independence regarding the infrastructure for vertical takeoff and landing while still maintaining the operational benefits over similar fixed-wing and copters.
Our paper attempts to present an uncomplicated design methodology for small autonomous battery-powered tailsitters. Subsystem parameter such as takeoff weight, power and energy consumption, and battery discharge models, would be investigated and their efficiency maximised. Feasible design space would be given by simulation with the mission and weight constraints, while the influences of wing loading and battery ratio would also be analysed. A case study would be carried out according to the design process, and then compared to previous designs to validate the results. The design methodology can be used to determine critical parameters and make necessary preparations for detailed design and vehicular realisation of small battery-powered tailsitters. We would be constructing a non-vectored tailsitter aircraft, i.e., a tailsitter with fixed-rotor orientation relative to the fuselage with a large surface for extended hover authority. A non-vectored tailsitter lends much ease in manoeuvrability with keeping the design uncomplicated.
This was a different field we were entering as a club and our major focus was to have an agile micro aerial vehiclewhich could redefine the flying experience. FPV Racer drones have existed for quite some time throughout the past demi-decade . The sport is evolving since then and now has an international platform like the Drone Racing League (DRL)MultiGP governs and sanctions drone racing events internationally, with over 16,000 members and over 500 chapters worldwide
The frame is 250 mm sized made from a carbon fibre composite. The flight controller board used is Omnibus F4 V3 pro which runs on a Betaflight firmware.
The ESCs run on DShot protocol. DShot is a new communication protocol between flight controller (FC) and ESC, substitute to Oneshot and Multishot. DShot stands for Digital Shot.Analog signals have potential issues with value accuracy because: Due to the possibly different speed of the oscillators (or clock) in ESC’s and FC, the length of the pulse might not be measured accurately, especially when we are talking about it’s down to the level of microseconds. Electrical noise (voltage spikes) can corrupt analog data – that’s why we sometimes see people suggest running higher motor update rate than PID loops helps flight performance. With digital protocol, there won’t be any of these problems. It’s exciting to know that ESC calibration will no longer be necessary. Because of the nature of digital signal, which is ones and zeros, it will also be much more resistant to electrical noise. Proper Space Management is very important in these micro builds, as you can see.
The Final Build actually weighs around 660 grams with a GoPro.
The ailerons were to be placed such that their centreline coincides with the centreline of each half-wing.The idea was that having the ailerons at the end would lead to excessive torque and thus more sensitivity, so we tried to reduce that. The percentage area of the ailerons with respect to the wings was decided to be around 7 percent, which is very close to the prescribed 10 percent by area for trainers. Thus, keeping in mind the sensitivity and connectivity, the length of each aileron obtained was 22 cm, and accordingly the width came out to be about 4.2 cm.
It was decided that the airfoil shape would be achieved by folding onto themselves, two seperate sheets of Depron with length 60 cm and width more than double the chord length, to make two seperate half wings that would later be joined to form one wing. Tape was applied on one side and a groove for folding was made on the other, with distance equal to 20 cm from one of the longer edges.
A small slot, of thickness 6 mm, was left between the two bars so that a rod made of carbon fibre could be inserted. This was to prevent bending of the wing in-flight and to provide structural integrity, as the actual wing is made of two separate halves. Glue was applied in the upper bar and near the end of the flat, lower part of the wing(after its edge was filed using sandpaper) to stick it to the curved, upper part of the wing as it was folded. The extra part of the upper depron protruding was used to cut out ailerons by making a bevel
Slots were cut at the base of the wing to attach servo motors for Ailerons. We had enough area to generate the required torque for roll, thus we did not further increase the sensitivity using the holes on control horns and Servos.
The design of the plane resembles a trainer plane with moderately sensitive control surfaces to battle unexpected conditions such as rogue winds.
To keep the build simple and accurate, it was decided that there was to be no taper or sweep, and thus the shape of the wing as viewed from the top was a rectangle. Aspect ratio is defined as the ratio of square of span length to the area of the wing, which in the case of rectangular wings is equal to the ratio of span length to chord length. To provide ease in maneuverability, the ailerons’ area is kept around 15% of the total wing area. According to design constraints, the maximum allowed span length was 120 cm. AR is kept as 6 because lower AR results in more drag and lower effective thrust. As thrust to weight ratio is already skewed. We decided to reduce any drag inducing factors in our design.
To provide ease in maneuverability, the ailerons’ area is kept around 15% of the total wing area. According to design constraints, the maximum allowed span length was 120 cm. AR is kept as 6 because lower AR results in more drag and lower effective thrust. As thrust to weight ratio is already skewed. We decided to reduce any drag inducing factors in our design.
Our plane’s estimated weight is around 800gms. Keeping that in mind, the plane’s wing loading is 33.33 gm/dm2 without payload. Which will be ideal for the competition. Ailerons are situated somewhat off centre and towards the end of the half wings. This was done to make the ailerons more sensitive for control as ailerons towards the ends creates more torque. Each aileron has a dimension of 35 x 5 cms and are situated 2.5cms towards the end from the centre of half wing.
We are attempting to build a quadcopter for the Techfest Drone Challenge. The aim is to build a 250mm Carbon Fibre frame with 2300kv brushless motors. The quadcopter should be capable of carrying a payload of 30 grams and dimensions 10cmx2cmx2cm. Our aim is to build a quad which weighs no more than 1kg (estimated weight 800g) and has dimensions no bigger than 400*400mm. Therefore, we are using a Quadcopter frame of 250mm (diagonal) and 6in props which will fit these dimensions. These motors require 3s-4s battery and draws 4A of current while hovering. We will power these motors with a 3s 3000mAh lipo battery. For controlling motor rpm, we will be using EMAX lightweight ESC’s with no Battery Eliminator Circuit (BEC). KK2.1.5 board will work as our flight controller taking inputs from receiver and giving output to the ESC’s as well as Runcam. As we have to power everything from a single lipo, power distribution board (PDB) with sufficient capacity will be used.
We will be transmitting the video from our FPV camera to our phone via
receiver connected on the handheld. Then, we’ll continuously scan the video
being played on our mobile using an app called “QR Code Reader by Sumy
Applications” which will run in the background and display the text as soon as
it detects a QR Code. The reason behind using this mechanism is that we
already have fpv equipment with us which can transmit to the mobile phone
and it is the easiest and simplest solution to scan the QR code, given the lower
weightage assigned in terms of total points for this task.
QR Scanning Method
We will be transmitting the video from our FPV camera to our phone via receiver connected on the handheld. Then, we’ll continuously scan the video being played on our mobile using an app called “QR Code Reader by Sumy Applications” which will run in the background and display the text as soon as it detects a QR Code. The reason behind using this mechanism is that we already have fpv equipment with us which can transmit to the mobile phone and it is the easiest and simplest solution to scan the QR code, given the lower weightage assigned in terms of total points for this task.