SANDBOX

Solar UAV

Summary

The major problem with any micro Unmanned Aerial Vehicle(UAV) is that it can fly in air for a short period of time due to energy and weight constraints associated with an electrical propulsion system. Solar powered micro UAVs that store the excess charge for the night are an alternative solution, but with current battery technologies and their energy is to weight ratio, the energy is just barely sufficient for slow gliding through the night. As the batteries are heavy, a Solar powered micro UAV needs to have an extremely efficient and robust design.

With these constraints designing a solar UAV that can have perpetual flight (theoretically) is hard, except in certain favorable conditions. The main aim of the project is to develop a ‘Solar Endurance UAV’ The unmanned vehicle in its finished stage will be able to sustain continuous long flights with very few stops for maintenance.

The product will maximize its efficiency by utilizing wind updrafts to its advantage i.e. we will incorporate the concept of soaring into our product. Also, the auxiliary batteries attached onboard will be charged during the day by solar panels attached on the wings of the product.

It is our belief that the project can be used majorly for surveillance and can advance the industry towards energy efficiency in a significant way. The product can also be included in space exploration missions with minor modifications to its structure. Geological explorations of earth can be made easier since our product will be able to cover large areas of lands just on wind energy.

We would also be implementing a more effective and efficient MPPT (Maximum power point tracker) algorithm, which would reduce energy loss.

Technical Insights

Autopilot algorithms will be integrated into the product’s main control mechanism which will judge the wind speed around it and decide it’s path instantaneously. It improvises time-to-time and learns air patterns to decide the optimal path.

During take-off and landing precise control is required to ensure smooth transition to auto-pilot. Once safe take-off is ensured the auto-pilot takes over and starts analyzing wind patterns and stores data over time. This is used to map an optimal path of flight.

Design

The design of the product will consist of two major parts, Wing and Body. The wing will be designed similar to a soarer and will be made so that it can maximize use of winds and have a stable flight. An effort will be made to increase surface area of wings as much as possible to provide room for solar panels. The body of the aircraft will be spacious as it will be accommodating significant amount of the electronics and the batteries.

Electronics

The electronics will majorly involve a processing board for the auto-pilot algorithm and a power control for the input from the solar panels. Solar panels give an output depending on the intensity of sunlight hence such inconsistent energy input can damage the batteries. This will be managed by attaching a MPPT in between the solar panels and the batteries.

Target Customers

Our product, Solar-Powered endurance UAV, can have a plethora of civil, commercial and military application. Some of these include mobile surveillance and mapping, weather analysis, aerial photography and videography, rescue missions, pick-up and delivery services over long distances, mineral exploration, meteorological and archaeological research.

Project Development

The project is currently in pre-testing phase. We are preparing a prototype to collect test data on various parameters related to energy output of the solar panels. The data will be used to find the number of solar panels for a feasible output to charge the batteries. It will be used to find the correct combination of motor and batteries to used in the aircraft.

On completion of the testing designs will be developed for the aircraft. These designs will be constructed using different materials and the most optimum wing design will be used for the first model of the aircraft.

Role of Sandbox

We currently use the 3-D printer and the laser cutter in Sandbox. Also, most of the electronics components including the auto-pilot module and the processing board for the auto-pilot algorithm are provided by Sandbox. Sandbox has provided us with miscellaneous components like motors and batteries during the present phase of the project We also have access to sophisticated tools and machinery which has reduced the time required for manufacturing different components of the product.

The lab itself has provided a positive working environment which has acted as a catalyst for the project. A presence of proper equipment along with the experience from other projects in the lab has helped the project progress smoothly over time.

Sandbox lacks in materials processing equipment significantly. Machinery for processing carbon fiber and other such strong materials should be added to the lab. The presence of a wind tunnel would help out project significantly and will be a valuable addition to Sandbox.

The proposed glove-based model aims to add to the use of traditional input methods and make use of physical gestures to control a device using intuitive, natural movements. The key idea behind developing this prototype is to pave the way for completely new input devices. With sustained growth in Augmented Reality and Virtual Reality, such controllers will emerge as ideal wearable devices that can be used to communicate with computers, devices, robots and environments, both wirelessly and in a wired manner. In future, this kind of technology is ideal to interact with immersive 3D Virtual Reality environment, to model the movement of body parts in that environment. The glove can give a level of control that traditional input devices cannot rival.

Apart from controlling a computer, it can be used to control robotic devices like remote controlled cars, or most naturally, a robotic arm. Home devices like smart TV (certain extensions will allow control of older TV versions), lighting systems, and various electrical appliances in the house can be controlled using the controller with simple hand gestures.

Product details

The controller is a skeleton/glove which enables the wearer to control electronic devices like computers, robots, drones and IoT enabled home appliances. Designing the device is a challenge since it needs to comfortably fit the hand and at the same time be portable and lightweight.

The device consists of five flex sensors placed over each finger and a central 6/9 degree of freedom Inertial Measurement Unit (IMU)(MPU 6050/9150 breakout board ) modules attached to the dorsal surface of the hand . Each of these flex sensors are designed in a manner that their resistance increases on bending the sensor.

The change in current passing through it will be fed to a on-board microcontroller (Arduino nano/ Arduino pro mini). The board will read the raw values from the IMU and it will process the data into human-readable instantaneous state variables. These values will be sent wirelessly (over WiFi / Bluetooth) or by wire (as per requirement) to a Computer*.

The computing unit will process the data, interpret the gestures and accordingly perform the required tasks based on the current operating mode of the controller.

Impact and utility

The controller is an entirely new input method and is expected to soon be incorporated in almost all VR enabled devices. The main thrust behind developing the glove is to enable a more natural way of interacting with technology. In this manner, we will be able to better understand newer methods of controlling devices and appliances.

In the near future this technology could be used to control robotic devices remotely, eliminating every single remote controlled device to be replaced with a universal controller. It has potentially limitless application.

It can be used to control robots in a manufacturing line, where humans are not allowed to enter. It can be used to drive vehicles, control office and home electronics, it can be connected to media streaming devices to control media playback. And it can also be used to instruct intelligent robotic objects. Gesture recording is also possible and gestures can be user independent.

Target Customers

Since the product can control every aspect of technology, it can be used from the most basic forms like controlling a powerpoint presentation, by swiping left or right to change slides, or use it as a virtual laser pointer on screen to as advanced as controlling complex machinery and robotic elements like quadcopters or remotely controllable robots. It can interact with 3D drawings and objects in the virtual world and be used to play games in immersive environments.

It can be used for home automation, controlling smart devices. Complicated gestures can be used for extensive interaction with computers and VR controllers. In future iterations, we plan on using the product for integrating with 3D CAD software like Solidworks or Autodesk Fusion.

Project Development

The project began in September 2017. In the initial month, we discussed design, interfacing and programming decisions with regards to the glove. We elected to use the Arduino Nano for our processing needs as its 5 volt logic level was in alignment with the sensor’s voltage requirements and also for its robustness. We chose not to use the Teensy as it was too expensive for the prototyping phase .

Starting October, we formalized the pipeline for transmission and processing of the sensor data generated by the MPU 6050. A few simple programs were written which allowed the wearer to navigate a computer and move a cursor via glove control. We had established high reliability levels for data correctness given transmission rates and distances.

By November, we were able to estimate the pose of a hand purely from MPU readings as well as deftly maneuver a radio controlled rover. A simplistic housing for the components was developed which enabled us to collect sensor data so as to explore the possibility of gesture recognition. Four iterations of the housing were designed and 3D printed in the Sandbox. Models trained on the collected data indicated that offline gesture recognition was entirely possible. A flight simulator was also interfaced with the glove. Users who engaged with the rover and the simulator shared that glove control felt more natural and intuitive than traditional methods such as a radio controller or a keyboard and mouse setup.

We suffered a setback in December and January due to a delay in the delivery of new components such as flex sensors and the MPU 9150 which would provide richer, more confident sensor readings. We also experienced a malfunction in which one iteration of the glove was rendered defunct. In this period of time, we interfaced the glove with traditional video games such as Pong and Super Mario, developed a preliminary pipeline for online gesture recognition and made extensive use of the PCB printing machine so as to reduce the size and weight of the module.

Currently, the prototype must be tethered to a power source, communicates through line-of-sight over radio frequencies, and uses an MPU 6050 to collect acceleration and angular velocity readings. Ideally, a battery module must be incorporated into the glove. A wifi module should be used so that transmission is multi-directional and data can be sent to a central server, a facet that can be immensely useful while adapting the glove to the task of home automation. An upgrade to the MPU 9150 would lend greater reliability to the sensor data.

Role of Sandbox

We used the 3D printer for making the outer case for compact assembly. The consumables provided in SANDBOX were used for making circuits. CNC PCB milling machine was used to make PCBs for the third and fourth iterations. The CNC laser cutting machine was used to make parts of the chassis of the robot vehicle. Oscilloscopes were used to check various aspects of the circuitry. The mech workshop in Sandbox is a priceless addition to the facility that has all the tools to manufacture mechanical components.

Apart from the equipment provided, SANDBOX provides us a perfect working space to execute and implement the ideas. It provides an environment that helps us focus on our work. The financial aid provided by SANDBOX in terms of ordering project components is indispensable to our project. 3D printing makes assembly easy. Rapid prototyping has become easy and PCB printing can be done in a matter of few hours, at cheap prices.