The four-rotor UAV is ubiquitous, but the Spherical UAV with only one rotor is not bad. Interested partners can learn about it.
The UAV can fly with only one blade, and it can fly smoothly~
The above UAV Ball Drone Project Mk II differs from our common multi-rotor UAV. It is a 7-inch circular single-rotor UAV with complete 3D design and printing. It achieves directional control by changing different airflow channels.
Material components used by round UAV:
1) For 3D printing parts.
2) Electronic governor (ESC), 32-bit, 35A. T-Motor F35A 3-6S BLHeli specially designed for FPV UAV competition_ 32。
3) Brushless motor, 2700kV.
4) Helical blade, 6 inches, 3 blades clockwise.
5) Remote receiver, FlySky FS-A8S.
6) Flight control, compatible with Betaflight, uses Diatone Mamba F405 MK2.
7) 4 micro servo motors, Emax ES9051.
8) LED light bar (optional), a WS2812B RGB LED is used here.
9) Lithium-polymer battery, 1300mAh (3-cell), small and lightweight, uses Tattu 11.1V battery with XT60 connector.
10) XT60 socket or any socket matching the battery
11) M3 hardware: 10mm screw (10), 12mm screw (4), nut (8) and 15mm gasket (4)
12) Cable tie
Solder iron and solder
Open source computing with Betaflight Configurator software
1. Prepare parts
All parts of 3D printing and sorting:
2. Add the steering gear to the lower ring
Install each server in the bracket of the lower ring so that its rotation axis is aligned with the center of the UAV.
3. Center the steering gear
The rotor position of each servo motor is aligned by sending a 1.5 millisecond pulse to each servo motor. You can use simple Arduino to call the servo library (arduino. cc/reference/en/libraries/servo). Once the server is centered, install the servo swing arm provided with the ES9051 servo motor.
4. Insert blade and bolt
The servo rocker arm is completely suitable for the accessories on the blade wing. With M3 × A set screw is made on the opposite side of the 12mm screw.
When all four wings are installed, the lower ring is ready and can be put aside.
5. Add motor on the upper ring
Install the brushless motor first. Add screws to the flight controller from below so that the flight controller can be pushed down onto the thread, and then use M3 circuit board gasket to fix the flight controller in place.
6. Connecting electronic equipment
ESC and R/C receivers are mounted on the top. According to the battery interface, “an XT60 plug can also be welded to the power supply of the ESC and two small cables for power supply of the flight controller. I connect (daisy chain) WS2812B lights on the inside of the UAV leg and use them to connect the servo power line. The signal line of the steering gear must extend to the flight control in the middle of the UAV.
Next, weld the LED light bar, motor and servo line to the flight controller. If the flight controller does not have any direct servo output, of course, these can be repositioned to the current motor connection through the “resource remapping” in Betaflight.
After all cables are welded to the flight controller, the battery holder can be screwed onto the gasket, and the assembly is completed!
7. Configure Betaflight firmware
The flight controller and software that almost everyone can access for free are used this time. There are many open source projects, but Betaflight is currently a competition for UAV firmware (github. com/betaflight/beta light). There are many tutorials and resources on the Internet, but there is no more explanation here. Anyone who has played drones should know Betaflight. What we need to know is: how to change from a four-wheel race UAV to a single-rotor UAV? this is it:
Flight control resource allocation: to control this single-rotor helicopter, we need one main motor and four steering engines to do the power and control part. Most flight controls can control 4 motors, some of which have steering gear control interfaces. What we need to do is to reconfigure the steering gear interface to the 4 motor output ports of BF. In the configuration using FURY F4 flight control ((github. com/beta flight/beta light/three/master/src/main/target/FURYF4), we can see which interface pins are available, and we can configure the LED output interface as the motor output interface. The PPM input is reconfigured as the output information interface of the motor.
CLI commands used:
8. Use servo PID to stabilize UAV
The steering gear used by this UAV can usually be used in the form of servo_ pwm_ The rate operates at a frequency of about 333 Hz (of course, it can also handle more steering engines). SERVO_ pwm_ The rate is set to 250Hz, which is equivalent to one quarter of the PID loop rate. It is understood that the algorithm in Betaflight can only update the command of the actuator with a small part of the rate, so it is meaningless to set a high PID rate manually.
After setting up the UAV, connecting all equipment and implementing the configuration, the test can be carried out. The UAV should behave as follows:
Transmitter rolls right – front and rear blades move right
Transmitter pitch forward – left and right blades move forward
Transmitter yaw right – front blade moves left, right blade moves forward, rear blade moves right, left blade moves backward