Fullscreen HTML5Med Res (??MB)HTML4

RPAs in Action: By Ross Tester Designing, building and using RPAs for business SILICON CHIP talks to (while we watch in awe!) two young men who are dedicated RPA hobbyists turned businessmen: they are setting up a company specialising in aerial cinematography for movies and TV using RPAs – one of the first in Australia to do so. O n page 22 we showed an RPA – in this case a large octocopter – taking photographs at the top of a 50m-high communications tower and relaying the images back to ground operators in real time. That particular octocopter – a huge thing compared to the Parrot we reviewed – is one of several belonging to Matt Chang and Peter Maruncic. They’ve formed a business called “Rotorworks” to use RPAs in film, TV and advertising production, giving producers and directors hitherto impossible-to-obtain aerial shots and angles, at dramatically lower cost than traditional methods. “Previously only a real helicopter could get the angles but could never approach to such intimate close-up distance that we can achieve with our octocopter,” said Matt. With 35+ years of RC aircraft experience, Matt is the Chief UAV controller who will be certified to fly the octocopter, while Peter with 25 years RC experience is the Aerial Video operator and UAV controller. Matt was one the first UAV Operators certified back in year 2000 with the pioneering use of RC blimps for aerial advertising. With multi-rotor technology now available and certifi28  Silicon Chip cation to operate commercially in Australia, they are in a unique position to shoot aerial angles that have never before been available to the cinematographer without significant investment in manpower and costs. “We can fly indoors or outdoors and we can get her moving up to about 60km/h or faster if required for high speed tracking shots.” “Importantly, we can shoot in high-risk locations in complete safety and zero risk to people, with almost zero set-up time. For example, it’s simple for us to hover off a cliff face, above a tree or under a bridge. We can also take off and land on a moving boat. Shots over water are another great aspect of what we can offer, even take off and landing on water if required.” Aircraft Matt and Pete currently have about seven multi rotor aircraft of all types that carry all types of cameras, from a tiny GoPro to large Epic. The smallest craft can fly through narrow doorways and windows if required, while still carrying a camera (albeit a small one)! siliconchip.com.au Invasion of the RPAs! While the smallest of these are virtually hobby machines, they are still capable of taking a small camera aloft. But the real work is done by the hexacopter (at rear) and the octocopter at front. The orange-coloured radial arms assist the operator in orienting the craft from a distance – they’re mounted facing forward (same direction as camera). The Octocopter Of most interest to us was their giant octocopter, an eight-rotor electric-power RPA developed specifically for cinematography. It uses very powerful brushless motors and is quiet compared to past technologies. An onboard computer stabilises the craft while movement is controlled from the ground. The octocopter can fly for 10-15 minutes at a time, depending on the manoeuvres required. Batteries can be swapped for near-continual flying if needed. Battery swap time is approximately three minutes. Onboard is a GPS which allows Matt to do a number of things to aid in filming: • GPS position hold: locks at any altitude and position above the earth. • GPS return home: with the press of a button, the octocopter will return home and land automatically; this is a great feature for safety. • GPS Circle waypoint: it can circle a point chosen anywhere on earth, all while the camera is pointing in towards a subject. • Follow Me: The octocopter can follow the controller automatically as they walk or drive at a speed of between three and ten metres per second. • Point-and-click-to-fly is also possible from a ground station. One click with the mouse on a Google map and the octocopter flies there. uses on the ground. If required, it can relay HD video to the ground but there is a weight penalty, which reduces endurance. Safety In terms of safety and insurance, they offer $10-$20 million Professional Indemnity Insurance from an Aircraft Insurance company. Flying is limited to dry conditions and wind less than 20 knots, with a height restriction of 400 feet, This could be a great opportunity for customers as they are one of the first companies that will be able to do this legally in Australia, as officially certified by CASA. Currently in the US there is no provision for any form of licence to use these aircraft so we feel very lucky that Australian laws permit this type of operation. Contact: Rotorworks (Matt Chang & Peter Maruncic) Phone: 0405 902 033 Website: www.rotorworks.com.au ‑ Cinematography In terms of cameras, the respective aircraft can carry anything from a GoPro, which weighs a couple of hundred grams, to a Red Epic which weighs 2kg plus lens. An even bigger machine could be built if a client wanted the craft to carry two Epics for 3D work. The camera gimbal uses high speed servos to level the camera platform and can control its roll, tilt and pan. There’s also an onboard computer that takes care of camera stabilisation which updates 800 times per second to provide rock-solid stabilisation. Continuous and unobstructed 360° filming is possible. Recording is done on-camera but there is also a live fullvideo pass-through transmission that the camera operator siliconchip.com.au Hover mode: the hexacopter remains completely still while the operator’s hands are off the controls. This aircraft has provision for a camera though none is fitted. August 2012  29 Matt and Peter tell us about their aircraft and systems. . . The small Quadcopter airframe we flew is called a Kinjal and is made from carbon plate and computer motherboard standoffs. The brains behind the act is what we call a Flight Controller or FC. The particular one demonstrated doing aerobatics is called Quadrino and is one of the many flavours of “MultiWii” based flight controllers currently available. The Wii in MultiWii stems from the original use of the gyro and accelerometer in the Nintendo Wii Motion Plus and Nunchucks. Those gyro and accelerometer boards are stripped out and hooked up to Arduino boards. MultiWii is one of many open source flight controller software projects and is based on the Arduino platform. Originally started in 2010 by RCGroups user “AlexinParis” the software development has a huge following and the RCGroups MultiWii thread currently runs at 27,500 posts. The Multiwii software supports a 3-axis accelerometer, 3 axis gyro, 3-axis magnetometer, barometer and a GPS. Various forks of the software support other extras such as LED lights and ultrasonic sensors. You can learn more about it here: www.rcgroups.com/forums/showthread.php?t=1261382 A large index of multi-copters and software developments can be found here: www.rcgroups.com/forums/showthread. php?t=1097355 In the world of ready-to-fly flight controllers there are a few that seem to have had commercial success: MikroKopter (MK), Hoverfly, DJI Innovations and the newcomer, ZeroUAV. MK is developed by Holger Buss who was one of the first to develop an affordable commercial solution good enough for aerial photography and video. We fly with a DJI Flight controller called Wookong which is easy to set up and flies well out of the box. It’s also expandable from the default GPS and attitude hold, through to multi-waypoint navigation systems with a ground station. All of the features are locked up onboard and after an on-line payment, DJI unlocks the extra features with a special serial code. The Newcomer ZeroUAV has really given DJI a run for its money as it is developed by an ex-employee of DJI. The ZeroUAV YS-X6 has some great features such as WiFi telemetry downlink to your iPhone or Android device; FollowMe allows the multi-copter to literally follow you by tracking your iPhone’s position and circle mode which circles a point on earth while pointing the camera at the centre point. With the introduction of these great features, DJI seems to have become more competitive and will introduce some exciting new features soon. It’s a good time to be in this hobby with such rapid development in all areas of the hobby. The DJI and ZeroUAV solutions have some very tricky ways of insulating the onboard circuitry from the airframe’s vibration by mounting the gyros and accelerometers onto a small metal and lead covered block. The take-apart guides are here: Wookong technical review – www.rcgroups.com/forums/showthread.php?t=1510587 ZeroUAV technical review – http://www.rcgroups.com/forums/ showthread.php?t=1676150 Our Wookong powered octocopter uses eight brushless motors powered by eight 40A ESCs (Electronic Speed Controllers). Thrust generated with our setup peaks at just over 10kg. The Motors run at 770 RPM per volt which equates to a realworld RPM of about 7500 when hovering. Our starting voltage is about 16.8V on a fully charged (4 cell) LiPo (lithium polymer) battery and we land when it’s about 13.2V. Any lower than that starts to deteriorate the batteries permanently. Our endurance with 30  Silicon Chip The small Kinjal quadcopter is capable of unbelievable aerobatics. 16Ah of battery capacity is about 12 minutes. The frame, made of carbon plate, was developed in-house and cut on a DIY 3-Axis CNC milling machine. The booms that secure the motors are aluminium and carbon fibre. We use very light weight carbon fibre propellers which can react quickly to keep the multi-copter balanced, as instructed by the flight controller. With all that payload potential we can lift a gyro-stabilised camera platform or gimbal. Our gimbal is made by Photohigher of NZ who have developed an amazing system to stabilise the camera platform. The controller board is attached to the camera tray and uses its accelerometers and gyros to maintain a level camera platform at a rate of 800Hz. When tuned, camera stabilisation is near instantaneous. There are only a few certified UAV operators in Australia who are legally permitted by CASA to operate commercially and shortly we will have earned our Operator’s Certificate too. It’s worth noting the amazing change in RC Hobbies with the recent growth of the famous Chinese based powerhouse of hobbies “Hobbyking.com”. Their RC products are all sourced direct from the manufacturers so have dramatically reduced in prices, and entry into the hobby is more affordable than ever before. For example, where batteries like we now use used to cost upwards SC of $150 each, they now cost in the realm of $15 to $40. The octocopter is made of lightweight materials but with batteries, camera and all the control gear it’s still a handful! siliconchip.com.au