RU2799748C2 - Small-sized on-board radio-electronic device for controlling the flight and navigation complex of an unmanned aerial vehicle - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: group of inventions relates to the development and production of small-sized on-board radio electronic devices for controlling the flight and navigation complex of an unmanned aerial vehicle (UAV). The first version of the device for controlling the flight and navigation complex of an aircraft-type UAV contains an autopilot, a flight control unit, an inertial navigation unit, a magnetic heading measurement unit - a magnetometer, a broadband data transmission unit, an intelligent power supply. The second version of the device for controlling the flight and navigation complex of a multi-rotor UAV contains a flight control unit for small UAVs (flight control unit), inertial navigation unit, magnetic heading measurement, broadband data transmission unit, intelligent power supply, valve motor speed controllers, combined into a device using two redundant CAN-type control buses.

EFFECT: group of inventions is aimed at improving the accuracy, reliability and efficiency of UAV operation.

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Description

The invention relates to the field of aircraft engineering and can be used in the development and production of a small-sized on-board radio-electronic device for controlling the robotic complex of an unmanned aerial vehicle.

Currently, unmanned technologies are progressing at a rapid pace, and interest in them from the society and the media is growing even faster [1-3]. Even today, UAVs are widely used to deliver humanitarian cargo to war-torn areas or natural disasters, to conduct large-scale reconnaissance, to conduct professional and amateur filming, to assist repair and construction teams, oversight services and other departments.

In the near future, the range of applications of new air technologies will expand due to unmanned passenger transportation and sports manned flights using UAVs. These assumptions are based on the emergence of new ideas and developments.

Reducing the cost and increasing the reliability of UAV operation is impossible without the development of a universal set of MBREO. The low weight and the possibility of repeated duplication of systems make it possible to develop UAVs with increased efficiency (increasing the payload weight by reducing the weight and power consumption of the MBREO kit), as well as developing small UAVs.

There are many different UAVs, but each of them must have [4]: autopilot; sensors; navigation system; link; energy source; propulsion system.

Known patent RU No. 2733453 C1, IPC B64C 39/02, G05D 1/00, G08G 5/00. "A method for automatic control of the movement of a robotic unmanned aerial vehicle in autonomous mode". Published 01.10.2020.

In the process of UAV movement, the state of the navigation field is assessed and, if necessary, types of interference are identified, when the navigation field is in the most dangerous state of energy suppression or changes under the influence of active spoofing, then the correction of the strapdown inertial navigation system is turned off from the navigation data of the receiver of satellite navigation systems and the correction from the barometric altimeter is turned on. The predicted maximum allowable time of autonomous flight is calculated, if the time to the given destination point of the flight task is less than the maximum allowable time of autonomous flight, then the UAV continues to move to the point with the given coordinates, otherwise the flight task is interrupted, the flight to the landing point is performed. It is possible to perform a flight task in autonomous mode in the absence of a remote control radio channel and a distorted or suppressed navigation field.

Disadvantages: the proposal to ensure success in the performance of a flight mission is reduced to disabling the correction of the strapdown inertial navigation system from the navigation data of the receiver of satellite navigation systems, limited to the inclusion of correction from the barometric altimeter. At the same time, flight safety is not ensured due to the large error in determining the location of the UAV, leading to its unintentional collisions with natural or artificial obstacles, or the earth's surface.

Known patent RU No. 2390815 C1, IPC G05D 1/00. "A method for controlling an unmanned aerial vehicle and a device for its implementation." Published May 27, 2010.

The closest analogue (prototype) of the proposed technical solution is patent US 8200605 B2, IPC G05D 1/0011, "Decision block for an autonomous platform". Published 06/12/2012.

This document discloses information about the decision block, its architecture, decision-making method, an autonomous platform that implements these functions (including for UAVs). The technical solution described in this patent coincides with the proposed technical solution in the following ways:

- recognition of spatial obstacles and objects;

- analysis of the state of the system;

- platform autonomy;

- development of control decisions, depending on the state of the environment and the system, aimed at achieving the goal of the task;

- adaptability to various aircraft.

The disadvantages of this technical solution are:

- lack of accounting and assessment of the degree of danger of the flight situation;

- the principles of minimizing the degree of danger of a flight situation are not defined;

- the possibilities of increasing the reliability of the functioning of the MBREO due to duplication of the control exchange channel are not considered;

- the function of connecting to a flight simulator was not implemented, which allows performing HIL modeling in all modes of operation of the MBREO, working out a flight task, checking the performance of maneuvers, and conducting training and training of maintenance personnel.

- the possibility of increasing the reliability of providing MBREO with power supply, as well as its savings, is not considered;

- the issue of ensuring high communication stability and noise immunity in the absence of line-of-sight has not been sufficiently worked out.

The objective of the present invention was to develop a device based on the use of small-sized on-board radio-electronic equipment (MBREO), which meets the requirements of increased accuracy, reliability, and ensures high efficiency of the UAV for its intended purpose.

MBREO consists of the following blocks, combined into a device using two control buses of the Control Area Network (CAN) type.

Block 1. Flight control unit (FCU). The control unit is designed to control all UAV systems at all stages of flight. BUP is a software and hardware complex that provides control of all UAV systems in all modes from takeoff to landing. During the flight, the autopilot provides for automatic stabilization of the UAV movement parameters, as well as stabilization of altitude and speed.

BUP includes modules:

- global satellite navigation system (GSSN);

- power stabilization;

- microcontroller;

- non-volatile data storage.

The flight control unit performs intelligent flight control of the UAV in accordance with the entered flight task or the operator's control commands. The BUP receives route, navigation, telemetry information about the state of the UAV and the ground control point. In accordance with the control algorithms being worked out, the module generates standard control electrical signals that are fed to the input of standard controllers for servo drives of UAV steering machines, controllers for controlling traction motors, on-board and control light indication, parachute system, etc.

The presence of two CAN buses allows you to connect two sets of external sensors to the module, and organize the redundancy of critical PCU nodes. The TCU program determines the presence and status of connected sensors and automatically selects the required sensor.

The unit implements a communication protocol with a control controller for engines with a heavy fuel injection system of the HFE series manufactured by 3W international. This allows you to control all modes of engine operation, as well as receive information about its condition (temperature, speed, fuel consumption, etc.).

The unit has a function of connecting to a flight simulator, which allows you to perform half-life simulation in all modes of operation of the control unit, work out the flight task, check the performance of maneuvers, and conduct training and training of maintenance personnel.

The BUP can be used both independently and in cooperation with other blocks of the MBREO. Embedded software (SW) algorithms support the control of aircraft, helicopter, multi-rotor UAVs, as well as aircraft with vertical takeoff and landing and with a jet propulsion system.

The control unit collects information from all sensors of the inertial navigation system, calculates the orientation and position of the aircraft in space and, in accordance with the given flight program, controls the actuators: control plane servos, valve motors, internal combustion engines, jet engines. The control unit has redundant power supplies, CAN control buses, and can also be used in redundancy mode to increase fault tolerance.

Block 2. Block of inertial navigation (BIN). BIN is designed to measure angular velocities, linear accelerations, geographic coordinates and use it as a course vertical when building UAVs of all types.

BIN includes modules:

- microelectronic mechanical sensors of angular velocity;

- microelectronic mechanical sensors of linear acceleration;

- microelectronic mechanical atmospheric pressure sensors;

- microcontroller.

The inertial navigation unit receives and processes the signals of the global satellite navigation systems GPS and GLONASS, registers and processes the current values of the linear and angular accelerations of the UAV, transmitting to the control unit complex information about the positioning and dynamics of the UAV in space.

The inertial navigation unit is a small-sized unit for measuring angular velocities, linear accelerations, and geographic coordinates with high reliability. Designed for use on small, medium and heavy UAVs. The small size of the body allows it to be placed close to the center of mass and perform vibration decoupling to improve measurement accuracy. The CAN bus allows reliable data transmission in harsh electromagnetic environments, firmware updates and unit status monitoring.

BIN is made in a metal dust- and moisture-proof case with a connector placed on it for connecting an on-board cable assembly and a GLONASS/GPS antenna.

The unit provides the output of navigation data, orientation angles, angular velocities and g-forces, GLONASS/GPS coordinates. It interacts with the BUP unit and is part of the onboard segment of the UAV ACS. Equipped with CAN interface and GPS module. The components of the ACS units are combined into an on-board information network via the CAN interface.

UAV peripheral control and measuring and executive equipment is connected to the modules.

Block 3. Magnetic heading measurement unit (MIMC) - magnetometer.

BIMC is designed to measure the magnetic field and calculate the magnetic heading of the UAV based on the obtained data. The block contains an array of 3-axis magnetoresistive sensors, the data from which are compared, averaged, validated for falling into the confidence interval, the influence of local distortions of the magnetic field is compensated, and brought to the horizon, taking into account the calculated position of the sensor using linear acceleration sensors.

BIMK includes modules:

- magnetoresistive sensors of the Earth's magnetic field strength;

- microelectronic mechanical sensors of angular velocity;

- microelectronic mechanical sensors of linear acceleration;

- microcontroller.

The BIMC is made in a metal dust- and moisture-proof case with a connector placed on it for connecting an onboard cable assembly and a GLONASS/GPS antenna.

The CAN bus improves the reliability of data exchange with the flight control unit.

The presence of several magnetoresistive sensors allows you to work when one of the sensors fails, and with good sensors to increase the accuracy of heading measurement.

Also, the SPO has a simplified two-stage calibration algorithm for UAVs, which increases the usability of the unit on medium and heavy UAVs.

Block 4. Broadband data transmission block (BPDTT). The BPDS is designed to organize a broadband data transmission channel between the UAV and the ground control station.

BPSH includes modules:

- radio module;

- digital modem;

- nutrition;

- antenna-feeder device.

The UBDS is designed to transmit digital data over a radio channel at a high speed, for example, for streaming Full HD video, over long distances (100 kilometers or more). The system is designed for use in unmanned aerial vehicles, as well as to provide communication with ground-based mobile objects in difficult terrain.

The salient features of the system are:

Long range and line-of-sight data rate, 100 km / 6 Mbps, using 19 dB ground antenna and 6 dB airborne antenna.

High communication stability and noise immunity in non-line-of-sight environments, such as 1 km / 2 Mbps.

The use of universal modems with the possibility of simultaneous operation in the modes of the receiver, transmitter and repeater.

It is possible to transfer any digital data, it is possible to widely configure traffic parameters in agreement with the customer.

Support for modern digital interfaces for working with peripheral devices (Ethernet, I2C, UART). In addition, it is possible to implement non-standard interfaces and data transfer protocols as agreed with the customer.

Small weight and dimensions (150 g, 100×80×25 mm).

The possibility of diversity reception from several modems.

Possibility of building a point-to-multipoint communication system.

Ability to automatically select the type of modulation and redundancy to maintain the maximum data rate depending on the signal-to-noise ratio.

The data transmission unit provides broadband data transmission over long distances, implementing the standard FastEhternet interface for any type of data. The low latency and high bandwidth of the channel makes it possible to use the channel for transmitting video data together with telemetry and telecontrol data from the BSHA. The applied modulation allows maintaining high noise immunity in adverse radio conditions. A wide range of supply voltages makes it possible to use the BPD on almost any small/medium/heavy UAV.

The small mass of the block allows the block to be used, including on small UAVs that have a serious limitation on the payload mass.

All external interfaces of the modem, except for microwave connectors, are routed to one 34-pin connector. Depending on requirements, either connectors without latch PLD-34, PLD-34R can be used; or IDCC34MR snap connectors.

Table 1 shows the main characteristics of the BLDS radio channel.

Block 5. Valve motor speed controllers (RSVD). RSVD are designed to control valve three-phase asynchronous brushless DC motors with permanent magnets.

RSVD includes modules:

- power switch driver;

- high-speed power switches;

- Hall sensors and interfaces;

- microcontroller.

Regulators have control algorithms BLDC 6 phase algorithm and FOC - vector control. The applied algorithms allow choosing the most efficient and economical engine control mode. The vector mode provides high control accuracy and high torque at near-zero speeds, constant control of the rotor position without Hall sensors, high reliability of synchronization of the electric field and rotor speed. Vector control allows the use of brushless motors in servo mode, controlling the position of the rotor with high precision.

Regulators have a braking mode with regeneration or free run.

High performance microcontroller with built-in floating point unit allows motors with a large number of magnetic poles to be controlled to achieve high rotational speeds without loss of control accuracy. Built-in heat sink and sealing with heat dissipating silicone sealant allows operation of regulators in a wide range of operating temperatures and humidity.

The main features of the RSVD are:

FOC vector control technology with touch and non-touch modes.

Auto detection of all motor parameters.

Embedded software based on the Chibos RTOS.

Current and voltage control on all motor phases.

Regenerative braking.

Support for DC motors.

GUI setup program.

Adaptive PWM frequency for accurate ADC measurement.

Phase build-up based on measured RPM.

Good starting torque even in sensorless mode.

Tachometer and odometer functions.

Control duty cycle, speed or current.

Reverse in any control mode.

Seamless four-quadrant control.

Consumed and recovered ampere-hours and watt-hours meters.

The controller is powered from the power battery or from a separate input.

Built-in power switch temperature sensor.

Input for connecting an external motor temperature sensor.

Input for connecting an external motor shaft position sensor (option).

Adjustable protection against:

Low input voltage;

High input voltage.

High current motor.

High current consumption.

High current regenerative braking - using separate limits for motor and input.

Fast ramping duty cycle.

High RPM using separate limits for each direction.

When the limit is reached, a soft braking strategy is used while the engine continues to run. If the current gets too high, the motor shuts down completely.

The rev limiter also uses a soft braking strategy.

The commutation works great even with a quick change in motor speed. This is because the flux integrates after the zero crossing instead of adding a delay based on the previous speed.

When the motor control is disabled and the motor is rotating, the controller continues to monitor the position of the motor and perform duty cycle calculation, allowing a soft start to be performed while the motor is spinning.

All measured and calculated parameters are available as telemetry on the control interfaces.

Block 6. Flight control unit for small UAVs (BUPM). BUPM is intended for building small-sized multi-rotor aircraft.

BUMP includes modules:

- microelectronic mechanical sensors of angular velocity;

- microelectronic mechanical sensors of linear acceleration;

- microelectronic mechanical atmospheric pressure sensors;

- microelectronic mechanical sensors of the Earth's magnetic field;

- non-volatile data storage;

- microcontroller.

CUPM is designed to receive and process information coming from sensors, an air signal receiving unit (UAS), an inertial navigation unit (BIN), control of actuating devices, information exchange with a ground control station, receiving signals from satellites of the GLONASS/GPS satellite global positioning system. The components of the ACS units are combined into an on-board information network via the CAN interface. UAV peripheral control and measuring and executive equipment is connected to the blocks.

The control unit has small dimensions, is built on a modular principle and allows you to use the advantages of the concept of block-modular construction of MBREO in small dimensions while maintaining high reliability, flexibility and functionality of older models.

The communication is based on the CAN bus, open source software that has been proven many times in practice and reduces the total cost of developing and owning UAVs. The block-modular principle makes it possible to place individual modules at the most structurally advantageous points of the UAV body.

The control unit allows you to quickly build a reliable, compact UAV with extensive functionality, easily expandable due to open source code and compatibility with a large number of existing PCU projects.

Block 7. Intelligent power supply (BPI). BPI is designed to provide power to all devices on-board radio-electronic equipment with consumption control and the ability to charge the on-board battery (ACB).

BPI includes modules:

- highly efficient voltage converters;

- switching solid-state keys;

- current sensors;

- microcontroller;

- voltage sensors.

The intelligent power supply unit (IPP) is designed for installation on UAVs and other mobile objects as part of ACS and provides power to all UAV systems and payloads. The power source is a rechargeable battery (ACB), a generator or external (aerodrome) power. When operating from a generator or external power supply, the unit provides a controlled battery charge. The power part of the unit is made in the form of two independent channels, which allows you to connect two batteries, thereby providing backup power for UAV systems. The block also implements the function of a controller of various sensors, such as: a voltage and current consumption sensor, temperature sensors, an engine speed sensor, etc. and control of aircraft systems.

The BPI is made in a metal dust- and moisture-proof case with connectors for connecting the onboard cable assembly and two connectors for connecting the battery. The unit is controlled via the CAN bus from the TCU.

The power supply unit is built taking into account the task of providing high-quality power to the on-board radio-electronic equipment, provides control of individual voltage sources, high efficiency, control of consumption and charging of the on-board battery by converting the generator voltage (if any), as well as control of all power consumption parameters, protection against short circuit, overheating, overcurrent consumption, overvoltage, two-way data exchange with the control unit via the CAN bus. At the same time, the block has compact dimensions, a built-in heat sink, low weight, and high efficiency of using the energy stored in the onboard battery.

MBREO blocks are installed on board the UAV. They must be provided with a heat sink. When choosing an installation location, it must be possible to connect to the appropriate signal cables and access to the microSD card slot for the possibility of removing it.

Due to the fact that the MBREO kit can be used constructively on various types of UAVs, namely aircraft, helicopter multirotor or tiltrotor types, the design of the blocks remains unchanged, only their equipment changes. So, for an aircraft-type UAV, as a rule, one power electric motor and one RSVD are required (Fig. 1).

For UAVs of multi-rotor or tilt-rotor types, several regulators of power electric motors (according to the number of power plants) will be required, and the block diagram of the avionics in this case will look somewhat different (Fig. 2). The difference will be only in the software used in the BUP. A typical layout diagram of a small-sized radio-electronic device for controlling the robotic complex of an unmanned aerial vehicle is shown in Fig. 3.

The claimed invention is illustrated by the drawings shown in Fig. 1-3.

On FIG. 1 shows a block diagram of the MBREO UAV aircraft type.

On FIG. 2 shows a block diagram of the MBREO UAV of a multi-rotor type.

On FIG. 3 shows a typical layout diagram of a small-sized radio-electronic device for controlling the robotic complex of an unmanned aerial vehicle.

On FIG. 3 shown:

1. Flight control unit

2. Block of inertial navigation

3. Air signal receiving unit

4. Typical connection cable

5. Broadband Antenna

6. Antenna of the receiver of the GLONASS/GPS satellite navigation system

The technical result is an increase in the accuracy, reliability and efficiency of UAV control.

Information sources

1. Navigation and traffic control. Proceedings of the XXI conference of young scientists "Navigation and traffic control" with international participation / Nauch. editor d.t.s. prof. O.A. Stepanov / Under the general. ed. Academician of the Russian Academy of Sciences V.G. Peshekhonov. - St. Petersburg: State Scientific Center of the Russian Federation JSC Concern Central Research Institute Elektropribor, 2019.

2. 924 State Center for Unmanned Aviation of the Ministry of Defense of the Russian Federation. Prospects for the development and use of complexes with unmanned aerial vehicles. Collection of articles and reports based on the materials of the annual scientific and practical conference Kolomna, 2016

3. Matthew Flint, Emmanuel Fernandez and Marios Policarpo. "Effective Bayesian methods for updating and storing uncertain search information for UAVs" // Department of Electrical Engineering and Informatics. University of Cincinnati, Cincinnati, Ohio 45221-0030, USA.

4. Haiyan Chao, Yong Kang Cao, and Yang Quan Chen Autopilots for Small Unmanned Aircraft: A Review// International Journal of Control, Automation and Systems (2010) 8(1):36-44 DOI 10.1007/sl2555-010-0105-z.

Claims (7)

1. A small-sized on-board radio-electronic device for controlling the flight and navigation complex of an unmanned aerial vehicle of an aircraft type, including an autopilot, sensors, a navigation system, a communication channel, an energy source, a propulsion system, characterized in that it includes: - a flight control unit (FCU), which is a software and hardware complex that provides control of all UAV systems in all modes from takeoff to landing, automatically stabilizes the UAV motion parameters, stabilizes altitude and speed, performs intelligent flight control of the UAV in accordance with the entered flight task or operator control commands, generates standard control electrical signals fed to the input of typical servo controllers of all UAV control systems, implements communication protocol with the engine control controller, the function of connecting to the flight simulator, which allows to perform HIL simulation in all operating modes TCU that implements firmware algorithms TCU that supports the control of aircraft, helicopter, multi-rotor UAVs, aircraft with vertical takeoff and landing and with a jet propulsion system, collecting information from all sensors of the inertial navigation system and the air signal receiving module (AIAM), calculating orientation and the position of the UAV in space and in accordance with a given flight program, which controls the actuators: servo drives of control planes, valve motors, internal combustion engines, jet engines; - an inertial navigation unit (BIN) designed to measure angular velocities, linear accelerations, geographic coordinates and use it as a vertical heading when building UAVs of all types, which receives and processes signals from global satellite navigation systems GPS and GLONASS, navigation data, orientation angles, angular velocities and g-forces, registers and processes the current values of linear and angular accelerations of the UAV, broadcasts to the TCU complex information about the positioning and dynamics of the UAV in space, equipped with a CAN interface and a GPS module. - magnetic heading measurement unit (MIMC) - a magnetometer designed to measure the magnetic field and calculate the magnetic course of the UAV based on the obtained data, containing an array of 3-axis magnetoresistive sensors, the data from which are compared, averaged, validated for falling into the confidence interval, with compensation for the influence of local distortions of the magnetic field, bringing to the horizon, taking into account the calculated position of the sensor using linear acceleration sensors, BIMC software, which has an algorithm for simplified two-stage calibration on B PLA; - a broadband data transmission unit (BDSh), designed to transmit digital data over a radio channel at a high speed, for example, for streaming Full HD video, communication range and data transfer rate in line-of-sight conditions, 100 km / 6 Mbps, using a 19 dB ground antenna and 6 dB airborne antenna, high communication stability and noise immunity in conditions of no line of sight, for example, 1 km / 2 Mbps; - intelligent power supply unit (IPU), designed to provide power to all devices of on-board radio-electronic equipment with consumption control and the ability to charge the on-board battery (AC), equipped with a power unit in the form of two independent channels, allowing you to connect two batteries, thereby providing backup power for UAV systems, realizing the function of a controller of various sensors, controlling aircraft systems, built taking into account the task of providing high-quality power to on-board radio-electronic equipment, providing control of individual voltage sources, high efficiency, control of consumption and charging the aircraft new battery by converting the generator voltage, as well as monitoring all parameters of energy consumption, protection against short circuits, overheating, overcurrent consumption, overvoltage, two-way data exchange with the control unit via the CAN bus. 2. A small-sized on-board radio-electronic device for controlling the flight and navigation complex of a multi-rotor unmanned aerial vehicle, consisting of: BIN, BIMK, BPDSh, RSVD, BPI, a flight control unit for small UAVs (BUPM), designed to build small-sized multi-rotor aircraft, receive and process information from sensors, BIN, BIMK, control actuators, information exchange with a ground station control ohm, receiving signals from satellites of the GLONASS/GPS satellite global positioning system, blocks of brushless motor speed controllers (RSVD), designed to control valve three-phase asynchronous brushless DC motors with permanent magnets, having algorithms - BLDC control controllers 6-phase algorithm, allowing you to choose the most efficient and economical motor control mode, FOC control algorithms - vector control, providing high control accuracy and high torque at near-zero speeds, constant monitoring of the rotor position without sensors Hall, high reliability of synchronization of the electric field and the speed of rotation of the rotor, allowing the use of brushless motors in the servo mode, highly accurately controlling the position of the rotor, combined into a device using two redundant CAN-type control buses, installed on board the UAV, provided with a heat sink, the ability to connect to the appropriate signal cables and access to the microSD card slot for the possibility of removing it.