24-07-2012, 02:29 PM
Tri-Copter Unmanned Aerial Vehicle
Tri-Copter .doc (Size: 145.5 KB / Downloads: 61)
Introduction: -
Tri-Copter is hybrid of twin motor aircraft and helicopter UAV. Unmanned aerial vehicles are aircrafts capable of flight without an on-board operator. Such vehicles can be controlled remotely by an operator on the ground, or autonomously via a Pre-programmed flight path. Although it seems similar to Quad-Rotor but its controlling makes all the difference, in
Quad-Rotor pitch/forward and backward is controlled by two motor in front and back and in Tri-Copter pitch/forward and backward is controlled by tail rotor which is connected to servo for tilting mechanism. The controlling is simpler then Quad-Rotor and it is cost effective as one motor and its speed controller is reduced
Unlike conventional helicopters in which only the main center rotor give the entire propulsion which is further connected to SWASH plate which having complex mechanism to control in all three direction, it require massive power to rotate the center rotor, on the other hand in Tri-Copter there is three rotor connected at the edge of three arms, hence in spite of rotating heavy center rotor it require very less power to rotate three small rotor. This UAV design showcases important control capabilities which allow for autonomous balancing of a system which is otherwise dynamically unstable. A Tri-Copter poses a more challenging control problem than a single-rotor or dual-rotor inline helicopter because the controls demands include accounting for subtle variations which exist between the motors and cause each motor to provide a slightly different level of lift. In order for the Tri-Copter craft to be stable, the three motors must all provide the same amount of lift, and it is the task of the control system to account for variations between motors by adjusting the power supplied to each one. In-spite controlling challenge it is noteworthy that in Tri-Copter direction is controlled by speed of same propulsion motors unlike in helicopter there is a tail rotor to control the direction tail rotor not help in propulsion. The hovering capability of Tri-Copter is superior then helicopter
The Tri-Copter add a new dimension in photography which was almost impossible or very tedious in earlier days and this is possible with recent advances in communications, solid state devices, and battery technology which have made unmanned air vehicles feasible and provide solution for many applications in the scientific, civil and military sectors. With the use of on board sensors this can provide precious information which was impossible in earlier days by conventional methods. These are creating new era of military war in which no losses of human lives, there will be war in between technology and inelegancy. In industries and research institute theses UAVs help in assisting workers and professors.
Objective:-
The main objective is to design and build a Tri-Copter. Our proposed design is for a
Lightweight nimble craft that can be operated both indoors and out. The project poses particular challenges in terms of weight reduction and controllability. Tri-Copter crafts generally support only a light payload, as they are required to carry the light weight of the power supply, a heavy battery, onboard. Thus, weight reduction of all components is essential in order to allow for sufficient lift force. The main goal is to have stable, autonomous hovers with active controls system taking dynamic information from sensors mounted on craft.
Working & Control:-
The entire craft frame is made of aluminum rod having balsa wood base at the center containing all electronic and power unit, four motor is mounted at the edge of arm
To balance rounter rotating eeffect of propaller the motor 1 and 2 are made to rotate in opposite direction and motor 3 in any direction
Elevation is controled by increasing or decreasing speed/thrust of all four motor
For Pitch/ forward and abckward controle servo is move up and down to change the thrust direction of motor 3
For roll controle/ left right inclanation speed of left or right motor is controled
To controle Yaw/left right movement another servo move the tail rotor left and right to change the thrust in left and right direction
Conclusion:-
Tri-Copter has much more superior feature then conventional UAVs and helicopter. The stable and constant hovering gives ability to take quality photographs, through stable hovering electronic sensor work more efficiently. Further complete autonomous version can be used extensively