At (or Near) Wholesale Prices: Happy Product - Sad Box >
Give Us A Call
615-373-1444

10am - 4pm CST
Results 1 to 2 of 2

Thread: Senior Telemaster Umanned Aircraft

  1. #1

    Senior Telemaster Umanned Aircraft

    The following is a document providing an overview of a Telemaster UAS I built for the University of North Dakota. We use this platform for various research projects within the university. I also have a giant telemaster converted to a twin engine (2 DLE-30 engines) with a pan-tilt video system and integrated autopilot.... but that's a new topic for another day :)


    System Overview
    The Telemaster UAS is versatile small UAS designed to carry compact payloads up to six pounds for a maximum of one hour. The aircraft and its components, all commercial off the shelf, were chosen for their availability, ease of use, price, and proven track record within the UAS and RC modeling community. The resulting unmanned aircraft exhibits trainer like flight characteristics with the ability to carry relatively heavy payloads with ease and efficiency. While this aircraft does require a runway for launch and recovery it can be as short as 100 feet. The entire system can easily be transported in the bed of a pickup truck. The simplicity and versatility of the system allows it to be adapted for different research projects and training events.
    ?
    [attachment=0:3m16iutm]IMAG0007.jpg[/attachment:3m16iutm]

    Airframe……………………………….…Senior Telemaster
    Wingspan..………………………………………………… 72 in.
    Length……………………………………..………………...68 in.
    Height……………………………………………..………… 17 in.
    Empty Weight…………………………………. 10 lbs 12 oz
    Max Payload…………………………………….………… 6 lbs
    Max Takeoff……………………………………..………. 23 lbs
    Cruise Speed………………………………..……… 20-40 kts
    Max Speed………………………………………..……… 50 kts
    Autopilot……………………………..…..MicroPilot 2028g
    Motor…………………………………………….. AXI 4130/16
    Propeller……………………………. APC 18x10 Thin Elec.
    Battery (main).…..…………. 4 FlightMax 5Ah 6S 15C
    Battery (backup)………….………… 1 TP 2.2Ah 3S 20C
    Transmitter……………………..………… JR 9503 2.4GHz
    GCS……………………………..…Laptop with HORIZONmp
    Data Link……………………....Microhard 2.4GHz 20km

    System Breakdown

    Airframe:
    The UAS is based on a Hobby Lobby Senior Telemaster. This airframe was chosen for its exceptional flight characteristics, payload capacity, and versatility. It is constructed from balsa, birch plywood, and covered in Oracover, an iron on plastic covering. The once rubber band on two piece wing was converted to one piece bolt on for added strength. The engine mount was modified to accept an electric motor instead of a conventional combustion engine. A new battery hatch was fabricated to hold 4 lithium polymer batteries opposed to a fuel tank. The servos were moved to the tail to provide an unobstructed payload bay. A second elevator servo was added for redundancy. The larger tires and tail wheel assembly raise the aircraft further off the ground to ensure payloads will have acceptable clearance during take-off and landing.

    Autopilot:
    The autopilot selected for the Telemaster is MicroPilot’s 2028g. The 2028g provides capabilities that meet or exceed the intended application within the Telemaster UAS. Its compact size and weight makes it easy to integrate into small airframes. The 2028g has an array of sensors including static pressure, dynamic pressure, 3 axis gyro, Y axis accelerometer, 1Hz GPS, AGL sensor, and magnetometer. The combination of these sensors allow for fully autonomous flight, including take-off and landing. The included HORIZONmp software allows the operator to adjust many different parameters within the autopilot; such as PID loops, gains, maximum airspeed, altitude, and distance, etc. HORIZONmp is also used to communicate and control the autopilot during operations. It features a moving map and full telemetry. The operator has the ability to modify missions and send commands to the aircraft during flight. Data logging occurs on the autopilot and is downloaded after every flight.

    Power Plant:
    Propulsion is provided by an AXI 4130/16 brushless motor. An electric motor was chosen for its ease of use and to prevent contamination for atmospheric sampling payloads. This particular motor, coupled with an APC 18x10 propeller and up to 4 FlightMax 6S 15C batteries, provides nearly twenty pounds of static thrust at full throttle. The relatively large propeller complements the aircraft’s slow cruise speed providing efficient cruise speeds for an endurance of up to one hour. Controlling the motors power is a Castle Creations 80amp ESC. It has many adjustable features such as low battery cutoff and thermal protection. It will also prevent accidental motor operation until it receives an idle throttle command, preventing any issues with turning the aircraft on with a high throttle setting.

    Electrical:
    The heart of the electrical system is 4 FlightMax 6S 5000mah 15C batteries connected in parallel. This provides over 22 volts to the ESC and motor. In order to power the autopilot, servos, and radio modem the power is passed through a regulator to provide a constant 5 volts. In case of a main pack failure there is a backup battery located in the tail of the aircraft. Power is instantly transferred to prevent the autopilot from rebooting. This battery is capable of powering the onboard electronics, except the motor, for a minimum of 3 hours. The backup battery is used during aircraft programming on the ground to prevent accidental motor run up.

    Ground Control Station:
    The GCS used for the Telemaster UAS is comprised of a laptop running HORIZONmp, radio modem, RC controller, and a generator. While the laptop is capable of running without a generator it is required to power the radio modem. If the generator is lost the operator still has full control over the aircraft via the RC controller, which is powered by a built in battery.

    Communications:
    The Telemaster UAS features 2 independent data links, both capable of controlling the aircraft. The first is provided by the JR 9503. This controller allows complete manual control over the aircraft including turning the autopilot on and off. The included receiver has multiple antennas to ensure a reliable data link regardless of orientation. It operates at 2.4GHz with a range of over one nautical mile line of sight. This system also features a built in failsafe. If the data link is lost it will automatically switch control to the autopilot, allowing the operator to control the aircraft using the second data link via the GCS. The second data link is to connect the laptop running HORIZONmp to the autopilot. This link is comprised of two 2.4GHz Microhard radio modems; one in the aircraft and one for the GCS. The modems were supplied and setup by MicroPilot to be used with their autopilots. These radio modems provide the necessary bandwidth and range for communicating with the aircraft. If this data link is lost the autopilot will automatically execute the Lost Com Procedure, which is described later in this document.
    ?
    Emergency Procedures

    LOST LINK PROCEDURE:
    Telemaster has two radio links, both capable of controlling the aircraft (computer to autopilot and RC link). There are two independent command channels to control the aircraft. The RC command channel allows manual control of the UA Telemaster. A separate radio modem connects the GCS to the aircraft. Either channel can be used to control the aircraft real time. Prior to flight, the PIC may tailor the lost link procedure for the area of operation. Altitude and landing pattern direction are pilot selectable prior to launch and will be chosen based on local obstructions or terrain features.

    1. RC Link Failure, GCS Link Operational
    In the event of a RC Link Failure, the autopilot will maintain or immediately assume control of the aircraft. The aircraft will continue to fly its preprogramed mission until the GSC operator commands the aircraft back to the recovery location. The standard procedure is for the GCS operator to command immediate landing due to the loss of redundant command links. In short, the aircraft is completely capable of being flown with the GCS and the PIC has complete control of the aircraft and is technically not “Lost Link”.

    2. RC Link Operational, GCS Link Failure
    In the event of a GCS Link Failure, while the autopilot is in command, the Lost Link Procedure will be automatically initiated after a ten second delay. The PIC may opt to take manual control of the aircraft via the RC Control link, or allow the aircraft to continue the Lost Link Procedure. The Lost Link Procedure will be to fly from present position to the Home location; which is the Launch and Recovery location. The aircraft will then orbit the Home location 5 times at the predetermined safe altitude and then perform an auto landing. In the event of a GCS Link failure while the aircraft was under manual control, the pilot’s manual control of the aircraft is unaffected. The PIC would continue to fly the aircraft to the landing site. Should the PIC transfer control back to the autopilot, the aircraft immediately performs the Lost Link Procedure.

    3. RC Link Failure, GCS Link Failure
    In the event of a RC Link Failure and GCS Link Failure the Lost Link Procedure will be initiated 10 seconds after the GCS Link Failure. (This is because the RC failure will cause transfer of control to the autopilot, and a GCS link failure with autopilot in control will trigger the Lost Link Procedure.) The Lost Link Procedure will be to fly from present position direct to the Home location; which is the Launch and Recovery location. The aircraft will then orbit the Home location 5 times at the predetermined safe altitude and then perform an auto landing.

    GPS FAILURE:
    In the event of a GPS Failure the autopilot will be unable to navigate the aircraft. The aircraft will be commanded into a 10 degree bank and zero throttle. This will cause a slow spiraling descent to the ground unless the PIC interrupts the procedure by switching to manual control. Standard procedure will be for the PIC to switch to manual control and return to the aircraft to the launch and recovery location for immediate landing.
    Manual flight may not be continued beyond what is required for landing. This is due to the possibility of losing RC Link and the inability for the autopilot to safely navigate the aircraft.
    The GPS connection should be replaced every 100 flights to prevent accidental decoupling in flight as per the manufacturer.

    MOTOR FAILURE:
    Motor failure, or loss of thrust, can be the result of different failures; electrical or mechanical. If this occurs the autopilot will detect the loss of thrust and make an immediate turn towards the launch and recovery location. Depending on altitude, distance, and wind the aircraft may or may not be able to glide home. In either case the PIC must take manual control and attempt to safely bring the plane to the ground avoiding hazardous obstacles; such as people, buildings, and vehicles. In the event the PIC determines a safe landing attempt cannot be made the aircraft may be forced into the ground for the sake of safety to persons and property.
    This failure can be triggered by low battery voltage. If this is the cause minimal power can be restored under manual control by bringing the throttle to zero then up to a low power setting. This process can be repeated if too high of a power setting is selected after the failure and motor power is lost again.
    Attached Thumbnails Attached Thumbnails IMAG0007.jpg  

  2. #2
    Hi cctaylor410 We are currently tuning PID gains for a Senior Telemaster at Carleton U, Ottawa,Canada.
    I was wondering if you ever got to autonomous flight and if we could maybe get a copy of your vrs file...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •