# Improvement of Hexacopter UAVs Attitude Parameters Employing Control and Decision Support Systems
## 3 Hexacopter Platform Architecture  
The proposed hexacopter is presented in two equipment variants (v1 and v2), with two different sets of avionics equipment. Variant 1 (v1) (Figure 1) illustrates the Tarot ZYX-M avionics kit composed of the following: Tarot ZYX-M flight controller (AP--autopilot), 5V/12V voltage distribution module, GPS antenna sensor, status LED and radio receiver Turnigy 9X 8C v2 sensor on eight channels, frequency 2.4 GHz. A Turnigy Multistar 4-cell LiPo battery in 4S1P configuration with a capacity of 6600 mAh was employed as the drone power source. The radio control is model Turnigy TGY 9X, mode 2 with nine transmission channels, which is paired with the Turnigy 9X 8C v2 radio receiver mounted on the drone. For this variant, no data transmission-reception equipment was endowed for telemetry and video signals from drone to the operator. This variant is employed only for the preliminary testing of the normal operational parameters, on the ground and during the flight of the hexacopter, without a detailed analysis of the flight outputs. Figure 2 depicts the second version of the hexacopter, composed of the flight controller AP Pixhawk 2.4.8 sensor, a PPM protocol encoder sensor that allows the encoding of eight  
Figure 1: Variant v1 of the hexacopter. (**a**) Equipment; (**b**) Radio control. signals using the pulse width modulation (PWM) protocol in a single signal employing the pulse position modulation (PPM) procedure; loudspeaker, for AP status beeps; fail-safe on/off switch for protection against accidental starting of the motors; data transmitter telemetry transmitter YRRC at the 433 MHz frequency and 1000 mW power for the transmission of telemetry data on the ground, paired with the signals telemetry on the ground receiver, model YRCC, which transmits the video signal on 32 channels at a 5.8 GHz frequency; 600 mW power, for video signal transmission from the GoPro Hero 4 model camera mounted on the three-axis rotation gimbal, Tarot T4-3D model; a 12-channel RadioLink R12 DS radio receiver; 2.4 GHz frequency for radio command reception from the transmitter built into the control box at the ground operator; GPS signal reception antenna; and the ReadytoSky model. Both variants were mounted on the same hexacopter frame structure, made of carbon fibre and consisting of two central plates of the frame between which six supported arms are fixed. At the arm ends, the motors and electronic speed controllers are mounted on six special supports. The landing gear is composed of two tubular structures mounted in the form of the letter T at a specific angle to the end plate of the frame. At the bottom of the lower plate, a bracket is mounted for fixing the battery. In the v1 variant, an additional support is mounted on the right arm of the landing gear for fixing the video transmitter. The carbon fibre provides the drone frame with elasticity, i.e., increased resistance to deformations, stresses, bending and a reduced structural mass of the platform. However, a drawback arises from the fact that carbon fibre attenuates the strength of the transmitted/received radio signal. That is why it is necessary to carefully choose the location of the radio/video signal transmission-reception equipment on the hexacopter or its proximity by mounting spacers. Figures 3-5 depict the described design details both focused on components and on the entire equipment assembly for variants v1 and v2 (with 4 SIP LiPo battery, 14.8 v, 12,000 mAh). Figure 3: Hexacopter variant v1. (**a**) Components; (**b**) Assembly. Figure 2: Variant v2 of the hexacopter. The block diagram of the hexacopter platform architecture is presented in Figure 6 illustrating the main components of the hexacopter, respectively the command-and-control ground station and the relationships between them. Hexacopter telemetry data are transmitted via a YRCC transmitter equipped with an antenna operating at 433 MHz. On the ground, an YRCC receiver is equipped with an antenna paired with the one placed on the hexacopter and at the same operating frequency.