CN114923696B

CN114923696B - Unmanned aerial vehicle miniature turbojet engine measurement and control platform and measurement and control method

Info

Publication number: CN114923696B
Application number: CN202210322081.1A
Authority: CN
Inventors: 安斯奇; 遆政宪; 彭旭; 杨国龙; 齐元; 张启悦
Original assignee: Civil Aviation Flight University of China
Current assignee: Civil Aviation Flight University of China
Priority date: 2022-03-30
Filing date: 2022-03-30
Publication date: 2023-05-12
Anticipated expiration: 2042-03-30
Also published as: CN114923696A

Abstract

The invention provides a measurement and control platform and a measurement and control method of a miniature turbojet engine of an unmanned aerial vehicle, which comprises an engine test platform and a control terminal, wherein a tested engine is the miniature turbojet engine, and comprises an engine main body, a tail nozzle, an air inlet channel, an engine electronic control unit ECU, arduinomega2560 single-chip microcomputer controller and a plurality of sensor groups for measuring data of the tested engine and the external environment; the engine test bench is movable; an anti-overturning lateral support arm is arranged on one side, close to the tested engine, of the main equipment vehicle; and an explosion-proof acrylic plate is arranged at the upper part and the lateral direction of the tested engine. The control terminal comprises a computer host, a display and an instruction box. The invention can test and collect important performance parameters of the unmanned aerial vehicle micro turbojet engine during operation, and evaluate performance characteristics and power output indexes of the micro turbojet engine during operation under various working conditions.

Description

Unmanned aerial vehicle miniature turbojet engine measurement and control platform and measurement and control method

Technical Field

The invention belongs to the field of testing and controlling of micro turbojet engines, and particularly relates to a measurement and control platform and a measurement and control method of an unmanned aerial vehicle micro turbojet engine.

Background

As unmanned aerial vehicles are increasingly widely applied to military operations and economic society, the use environments and application scenes of unmanned aerial vehicles are more diversified. Thus, there is a growing need for the performance of unmanned power systems in various fields. Turbojet engines have the advantages of high thrust-weight ratio, high altitude high speed performance, compact structure and the like, and are commonly mounted on unmanned aerial vehicles with strong maneuverability, such as: BQM-34 fire bee unmanned plane developed by Tridain Ruian aircraft Co., USA, and a J-69-41A turbojet engine carried by the unmanned plane were delivered in 1951. Such unmanned aerial vehicles in the form of turbojets are often an excellent option for meeting high-load, high-speed flight performance requirements.

In 1983, also 45 th year after the birth of the first turbojet engine worldwide, the uk technical group developed a miniature aviation turbojet engine, but the miniature aviation turbojet engine has not been commercially popular because of the excessively high manufacturing and use costs and the small demand scale of the consumer market. Although a turbojet engine is an ideal unmanned aerial vehicle power device, the unmanned aerial vehicle has the defect of excessively high fuel consumption rate. Particularly, in terms of the cruising ability, the operation intensity and the fuel supply device of the unmanned aerial vehicle, the unmanned aerial vehicle is often limited in the working efficiency due to the higher fuel consumption rate of the turbojet engine. In the 80 s of the 19 th century, jerry Jackman and his research team developed the world's first miniature turbojet test stand. Thereafter, the development of foreign micro turbojet engines has become more mature. In China, the northwest industrial university was developed in nineties of the last century. In 2001, a 6cm diameter micro turbojet was developed by the university of aviation aerospace in south Beijing, supported by the national defense department of technology. In recent years, the Beijing aviation aerospace university establishes a microminiature aeroengine laboratory and a distributed energy laboratory, and breaks through in microminiature aviation turbojet engines. At present, the research level of the micro turbine engine in China is higher, and the micro turbine engine with the diameter of 5-20 cm and the thrust of 30-500N is mainly adopted.

The engine test stand plays an important role in developing a miniature turbojet engine. Successful research and development of the aero-engine test bed is closely related to the development of aero-engine research and development technology. The aeroengine test bed provides an extremely important test bed for the aeroengine in various stages of development, production, comprehensive performance test and evaluation and the like, and the test bed can realize: the popularization and application of the advanced technology of engine verification, the optimization of the manufacturing process, the assistance of engineers to complete tasks such as engine state monitoring and fault diagnosis and the like, so that when the turbojet engine is truly carried on the unmanned aerial vehicle, the unmanned aerial vehicle which is truly stable, reliable and excellent in performance can be provided for a user to be effectively ensured. Based on the working characteristics of the turbojet engine, effective parameter acquisition and test of the important performance of the turbojet engine carried by the unmanned aerial vehicle are necessary for exploring the cruising ability of the unmanned aerial vehicle carried by the turbojet engine, verifying the power performance of the unmanned aerial vehicle during flight.

Currently, there are a number of limitations to performing aero turbojet tests: firstly, a large-scale fixed aeroengine test bench has huge scale, has strict requirements on working environment and too high manufacturing cost, and is not suitable for testing a turbojet engine carried by an unmanned aerial vehicle; secondly, unmanned aerial vehicle users often need to consult technical data manuals from unmanned aerial vehicles or engine manufacturers, and the method does not have the capability of measuring the performance parameters of a single turbojet engine under all working conditions in real time and lacks timeliness; finally, the performance of the turbojet engine is externally tested by a third party organization, so that the test cost is too high when the batch performance test is carried out, and the turbojet engine has no economy, convenience, operability and demonstration.

Micro turbojet engines were tested on a test bench by the university of Qinghai automation line Li Yingjie, et al. The six-component force measuring balance is arranged on the rack, namely, the deformation sensor sheet measures X, Y force and moment in three directions of a Z axis to obtain force measuring signals, the throttle is controlled by the computer host, the thrust generated by the engine changes along with the opening of the throttle, and then the data such as the thrust of the turbojet engine in each rotating speed interval are obtained by processing the signals output by the rotating speed, the throttle and the force measuring sensor.

A micro turbojet engine test bed is built by Chinese civil aviation university Peng Hongbo and the like. The test stand hardware part comprises: turbojet engine, oil circuit system, controller, measurement and control system and rack for assembling these hardware parts; in software, on the one hand, data collected by the data acquisition system is processed by a computer, and on the other hand, starting and acceleration and deceleration of the engine are controlled. The LabVIEW programming is used in the host computer 20 to control the start of the turbojet engine, and the program is recorded in the singlechip to control acceleration and deceleration of the engine through control of the throttle lever.

However, firstly, when testing the engine, the above solution does not place suitable isolation protection equipment nearby, and does not take measures for preventing dangers caused by engine runaway in emergency situations possibly occurring in the test, and once accidents happen, injuries and damages can be caused to accessory personnel and surrounding environment. Secondly, the above-mentioned scheme only makes experiments in a single environment, and does not sufficiently consider the change of external environment, for example: the effect on engine performance is unknown when experiments are performed at different temperatures or under different air pressure conditions. Finally, the sensor adopted by the scheme is fewer in types, on one hand, the acquired data is caused, and the measurement precision can not be increased through an algorithm in processing so as to reduce errors caused by data fluctuation; on the other hand, by exploring the aspects of turbojet experiments too limited, the operation and response times of the engine from start-up to acceleration at various stages cannot be measured by comparison.

Disclosure of Invention

In order to solve the technical problems, the invention provides a measurement and control platform and a measurement and control method for an unmanned aerial vehicle micro turbojet engine, which can test and collect important performance parameters of the unmanned aerial vehicle micro turbojet engine during working, for example: the air mass flow, the rotating speed, the exhaust temperature, the thrust, the fuel consumption rate and the like at the inlet of the engine, and can evaluate the performance characteristics and the power output indexes of the micro turbojet engine in the running process of all working conditions, so as to provide a measuring and controlling device of a power system for an unmanned aerial vehicle carrying the micro turbojet engine, and assist an unmanned aerial vehicle manufacturer to provide a testing instrument for the design, research and development of the power system of the unmanned aerial vehicle and matching with the high-performance turbojet engine.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the unmanned aerial vehicle miniature turbojet engine measurement and control platform comprises an engine test platform and a control terminal, which are respectively arranged on a main equipment vehicle and an auxiliary equipment vehicle;

the engine test bench is formed by an antistatic workbench, and the tested engine is a miniature turbojet engine and is arranged on the antistatic workbench through a horizontal profile bracket; the tested engine comprises an engine main body, a tail spray pipe and an air inlet channel; a plurality of intake pressure collecting pipes are arranged in the circumferential direction of the air inlet channel; the tested engine is provided with an engine electronic control unit ECU, an Arduino mega2560 singlechip controller and a plurality of sensor groups for measuring data of the tested engine and external environment; a thrust indicating disc, a test box and an aviation socket are sequentially arranged on the antistatic workbench outwards from the tail nozzle; the bottom of the antistatic workbench is provided with a plurality of supporting legs, and the bottom of each supporting leg is provided with a pulley so that the engine test bench can move; the antistatic workbench is connected with a micro flowmeter and a fuel servo valve; the sensor groups comprise high-precision ultrasonic liquid level sensors, pull pressure sensors, micro differential pressure sensors, hall flow sensors, BOSCH BMP180 air temperature and air pressure monitoring modules and accelerometer electronic gyroscopes with MPU6050 modules; an anti-overturning lateral support arm is arranged on one side, close to the tested engine, of the main equipment vehicle; an explosion-proof acrylic plate is arranged at the upper part and the lateral direction of the tested engine;

The control terminal comprises a workbench, a computer host, a display and an instruction box are arranged on the workbench, and an outdoor power supply is arranged on a partition plate at the bottom of the workbench; the instruction box is internally provided with a starting rod and an accelerator rod.

Further, the micro flow meter and the fuel servo valve are simultaneously connected in series in a fuel pipeline, fuel flows into the tested engine from the fuel tank through the antistatic oil path hose, and flows through the fuel servo valve and the micro flow meter in sequence.

Further, the test box, the starting rod, the accelerator rod, the air inlet channel and the thrust indicating disc are manufactured through a 3D printing technology; the Arduino mega2560 singlechip controller and the engine electronic control unit ECU are integrated in the test box.

Further, the high-precision ultrasonic liquid level sensor is arranged in the fuel tank and is used for measuring the distance from the top of the fuel tank to the oil liquid so as to calculate the residual oil quantity in the fuel tank; the tension and pressure sensor is arranged at the bottom of the horizontal section bar bracket and is used for measuring the thrust of the tested engine during working; the micro differential pressure sensor is arranged at one end of the antistatic workbench, which is close to the air inlet channel, and is used for measuring the air pressure of the air inlet channel and converting the air pressure into air mass flow; the Hall flow sensor is connected in series in a fuel pipeline for providing fuel for the tested engine and is used for measuring the fuel flow; the BOSCH BMP180 air temperature and pressure monitoring module is arranged in the test box and connected with the Arduino mega2560 singlechip controller and is used for monitoring the atmospheric temperature and pressure; the accelerometer electronic gyroscope carrying the MPU6050 module is arranged and fixed on the horizontal section bar bracket and used for measuring triaxial vibration signals of the tested engine.

Further, the BOSCH BMP180 air temperature and pressure monitoring module is connected with the Arduino mega2560 singlechip controller through an IIC bus, and measured temperature and pressure data are displayed in an LCD display screen on the test box.

Further, the anti-overturning lateral supporting arm consists of an aluminum alloy supporting column and supporting beams, two metal clamping rings are arranged on each of two adjacent supporting legs in the longitudinal direction of the long side of the anti-static workbench, the two metal clamping rings are fixed and locked with one end of the anti-overturning lateral supporting arm, and the anti-overturning lateral supporting arm is foldable.

Further, the thickness of the explosion-proof acrylic plate is 30mm.

Further, the vertical direction of the air inlet channel is communicated with the micro differential pressure sensor by adopting a transparent hose, the micro differential pressure sensor is arranged on the outer side of the explosion-proof acrylic plate, is connected with the atmosphere and is not influenced by airflow around the tested engine, and dynamic pressure and static pressure signals measured by the micro differential pressure sensor are input to the Arduino mega2560 singlechip controller, so that the air mass flow at the air inlet channel is calculated.

The invention also provides a measurement and control method of the unmanned aerial vehicle miniature turbojet engine measurement and control platform, which comprises a manual operation mode and an automatic operation mode; the automatic operation mode is based on the manual operation mode, the throttle lever is manually operated according to the power requirement of the tested engine, and once the position of the throttle lever is determined, the tested engine automatically operates under the corresponding power.

Further, in the manual operation mode, the control of the tested engine is divided into three parts: starting, accelerating and decelerating and stopping; the control of the tested engine is realized by manually controlling the throttle lever; the angle sensor arranged in the instruction box is mechanically connected with the throttle lever on the instruction box, reads the position of the throttle lever for semicircular movement operation according to the linear position relation between the throttle lever and the angle sensor, converts the position signal into voltage data, and outputs a corresponding frequency signal to the stepping motor after the computer reads the voltage data, so that the stepping motor accurately controls the fuel gear pump at different rotating speeds, and further changes the fuel flow to control the tested engine; the throttle lever transmits PWM signals to the Arduino mega2560 single-chip microcomputer controller, the Arduino mega2560 single-chip microcomputer controller transmits data through a Thr-ch end in an engine electronic control unit ECU, and the engine electronic control unit ECU controls the rotating speed of the tested engine through an internal algorithm; the sensor groups transmit signals acquired by the tested engine in the test to the Arduino mega2560 singlechip controller; on one hand, the Arduino mega2560 singlechip controller transmits partial data to an LCD display screen and a thrust indication disc on the instruction box through serial port communication; on the other hand, the Arduino mega2560 singlechip controller uploads communication data of an ECU (electronic control unit) of the engine to a host computer, and the acquisition of test data is completed after signal processing;

In an automatic operation mode, starting and acceleration and deceleration of the tested engine are completed by executing pneumatic control logic by the starting rod, a starting control program is input into the engine electronic control unit ECU, and the starting rod and the throttle rod on the instruction box are executed according to the logic of the starting control program; after the test is finished, the effective data or the filtered data recorded by the sensor groups through the Arduino mega2560 singlechip controller are exported in a computer host; the Arduino mega2560 singlechip controller displays the calculated parameters on an LCD display screen or a display of a computer host through an IIC protocol; and finally, inputting and processing the dynamic data of the tested engine in each working stage and the clock of serial port data of a unified engine electronic control unit ECU and an Arduino mega2560 singlechip controller.

The beneficial effects are that:

1. the invention has good adaptability to different models of micro turbojet engines. The design size of the measurement and control platform can be well matched with various micro turbojet engines, and the purposes of batch test of various types and various numbers of micro turbojet engines and simultaneous control experiment and data acquisition are achieved. Therefore, the invention has the advantages of strong adaptability, better economy, convenience and high efficiency, and is suitable for being put into use in unmanned aerial vehicle manufacturers or turbojet power debugging workshops.

2. The measurement and control platform can directly transmit the acquired data to the simulation software of the computer host after processing. The experimental results of the micro turbojet engine can be directly uploaded to MATLAB software by an experimenter to obtain various data models such as a three-dimensional equivalent oil consumption model, a three-dimensional equivalent power model and a universal characteristic curve of the engine, so that the working characteristics of the micro turbojet engine under various working conditions can be conveniently explored, and the highest energy efficiency interval can be found.

3. The measurement and control platform has a flexible equipment combination mode. The tester can add power generation equipment, load, mechanical transmission gear sets, an electrical system and the like on the measurement and control table according to the requirements of design tests, expands the research breadth of an aircraft power system, provides technical support for the optimization design experiment of the high-energy-efficiency ratio unmanned aerial vehicle, and can even provide an exploration platform and a heuristic for the new energy power system of the innovative invention in the future. From the aspect of control program, test personnel can independently write the control program, and test data of the micro turbojet engine is drawn into a curve by utilizing MATLAB in the host computer 20 according to measurement and control requirements, so that various performances of the turbojet engine can be easily explored, including characteristics such as starting characteristics, steady-state running characteristics, thrust, exhaust temperature, fuel consumption and the like when the engine performance is changed by air temperature and air pressure.

4. The invention is used as a movable micro-turbine jet engine measurement and control platform, and can be arranged in different places according to the requirements of design tests to test the power parameters of the micro-turbine jet engine and master the performance index of the micro-turbine jet engine in a complex working environment. The micro turbojet measurement and control platform can also be used for demonstrating aviation science and technology or being put into teaching equipment for use, and particularly for experimental courses of a college aerospace power system.

5. According to the invention, the safety of test personnel is considered from various aspects at the beginning of design, the explosion-proof sub-force plate, the anti-overturning lateral support arm and the fire extinguishing equipment are additionally arranged, and control signals and feedback data are remotely transmitted to the computer host through the aerial cable, so that the test control platform is isolated from a monitoring control area, and the safety of a test is ensured to a great extent.

Drawings

FIG. 1 is a schematic diagram of a main equipment vehicle of the measurement and control station of the present invention.

FIG. 2 is a schematic diagram of a slave device of the test and control station of the present invention.

FIG. 3 is a schematic view of an anti-toppling side support arm of the present invention.

Fig. 4 is a schematic view of an explosion-proof acrylic plate according to the present invention.

FIG. 5 is a schematic view of an inlet and its components according to the present invention.

FIG. 6 is a schematic diagram of an electrical system of the test and control station of the present invention.

Fig. 7 is a schematic diagram of serial data communication and visualization of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

The measurement and control platform comprises an engine test platform and a control terminal, which are respectively arranged on a main equipment car and an auxiliary equipment car.

A schematic diagram of a host equipment vehicle is shown in fig. 1. The engine test bench is formed by an antistatic working bench 1. On the main equipment vehicle, the tested engine comprises an engine main body 5, a tail nozzle 8 and an air inlet channel 2. A plurality of intake pressure collecting pipes 4 are provided in the circumferential direction of the intake duct 2. Preferably, the tested engine is a JetCat P160-RXi-B micro turbojet engine, and is provided with an engine electronic control unit ECU, an Arduino mega2560 singlechip controller and a plurality of sensor groups for measuring data of the tested engine and the external environment. The tested engine main body is arranged on the antistatic workbench 1 through a horizontal section bar bracket. The anti-static workbench 1 is provided with a thrust indicating disc 17, a test box 10 and an aviation socket 9 in sequence from the tail nozzle 8 outwards. The bottom of the antistatic workbench 1 is provided with a plurality of supporting legs, and the bottom of each supporting leg is provided with a pulley 16 so that the engine test bench can move. The antistatic workbench 1 is connected with a micro flowmeter 11 and a fuel servo valve 12. The micro flow meter 11 and the fuel servo valve 12 are simultaneously connected in series in a fuel pipeline, fuel flows into the tested engine from the fuel tank 13 through an antistatic oil path hose, and sequentially flows through the fuel servo valve 12 and the micro flow meter 11. The antistatic workbench 1 is internally provided with a partition board, and a fuel tank 13, a direct current voltage stabilizer 14 and a fire extinguisher 15 are placed on the partition board. The plurality of sensor groups on the main equipment vehicle includes: (1) 2 KS103 high-precision ultrasonic liquid level sensors which are arranged in the fuel tank 13 and are used for measuring the distance from the top of the fuel tank 13 to the oil liquid so as to calculate the residual oil quantity in the fuel tank 13; (2) the pull pressure sensor 6 with the measuring range of 20kg and the model of GJBLS-I, namely an S-shaped pull pressure sensor, is used for measuring the thrust of the tested engine when working in cooperation with the HX711 analog signal conversion module; which is arranged at the bottom of the horizontal section bar bracket. (3) A HALO-FY-WGH type micro-differential pressure sensor 3 for measuring the air pressure of the intake duct 2 and converting the air pressure into air mass flow; which is arranged at one end of the antistatic workbench 1, which is close to the air inlet channel 2. (4) The MJ-HZ06K type Hall flow sensor, namely a micro flowmeter, is connected in series in a fuel pipeline for providing fuel for the tested engine and is used for measuring the fuel flow; (5) the BOSCH BMP180 temperature and pressure monitoring module is arranged in the test box 10 and connected with the Arduino mega2560 singlechip controller and is used for monitoring the atmospheric temperature and pressure; (6) and the accelerometer electronic gyroscope with the MPU6050 module is used for measuring triaxial vibration signals of the tested engine and is arranged and fixed on a horizontal profile bracket for supporting the tested engine.

The test cartridge 10 is formed by 3D printing, which is integrated. The test box 10 conceals the connection harness, the engine electronic control unit ECU and the Arduino mega2560 controller inside, so that the invention is more attractive and concise, and accords with the ergonomics. The measurement and control platform of the invention introduces the collected fuel data into a more accurate and more stable algorithm, and utilizes the transmission data of the Hall flow sensor for measuring the fuel flow in the fuel pipeline of the tested engine and the ultrasonic liquid level sensor in the fuel tank 13 to obtain the test data with smaller interference, quicker response and smaller fluctuation range.

The invention explores the starting characteristics of the microminiature turbojet engine, namely the starting performance of the engine under different atmospheric temperatures and pressures, so that the BOSCH BMP180 air temperature and air pressure monitoring module adopted by the invention has small volume, high precision and low energy consumption, and can monitor the atmospheric pressure and the atmospheric temperature simultaneously. The BOSCH BMP180 air temperature and pressure monitoring module is connected with the Arduino mega2560 singlechip controller through an IIC bus, and measured temperature and pressure data are displayed in an LCD display screen on the test box 10.

The accelerometer electronic gyroscope with the MPU6050 module can detect the triaxial vibration condition of the tested engine in the test process. The accelerometer electronic gyroscope can be used for monitoring vibration of the tested engine and abnormal vibration of the tested engine in the test process, so that test staff can take emergency stop measures more timely when the tested engine shakes due to faults.

As shown in fig. 2, the control terminal is disposed on the auxiliary equipment vehicle and comprises a workbench, a computer host 20, a display and an instruction box 22 are disposed on the workbench, and an outdoor power supply 21 is disposed on a partition plate at the bottom. The command box 22 is provided with a starting rod 18 and a throttle rod 19.

As shown in fig. 3, a side supporting arm for preventing overturning is arranged on one side of the main equipment vehicle, which is close to the tested engine. The anti-overturning lateral support arm consists of an aluminum alloy support column and a support beam, and is formed by welding according to a mechanical stability structure. Two metal snap rings are arranged on each of two adjacent longitudinal supporting legs on the long side of the antistatic workbench 1, and the two metal snap rings are fixed and locked with one end of the lateral supporting arm for preventing overturning. The anti-static workbench can effectively prevent the anti-static workbench 1 from overturning, and improves test safety while resisting the reaction force and overturning moment of the tested engine to air. Preferably, the anti-toppling lateral support arm is collapsible. When the anti-overturning lateral supporting arms are unfolded laterally, the grounding ends of the two supporting arms extend outwards for a certain distance, so that the whole anti-static workbench 1 has a longer overturning moment arm, and when a tested engine is running, the whole anti-static workbench 1 is not inclined even under the interference of external air flow; when the anti-overturning lateral supporting arms are folded, the clamping rings for fixing the two supporting arms can enable the supporting arms to be rotated and folded below the anti-static workbench 1, the volume of the anti-static workbench 1 is not additionally increased, and the anti-static workbench is convenient to move and carry along with a vehicle.

As shown in fig. 4, the present invention provides an explosion-proof acrylic plate at the upper and lateral sides of the tested engine, considering that the tested engine sucks in the foreign matters in the air during the high-speed operation, resulting in the internal damage of the engine or the structural damage of the engine during the high-speed operation, causing the internal fragments to fly out at an extremely high speed, which will cause safety accidents. Preferably, the thickness of the explosion-proof acrylic plate is 30mm.

The inlet and its assembly according to the invention, as shown in fig. 5, are schematically represented by two parts: the air inlet channel 2 and the micro differential pressure sensor 3. Through fluid mechanics principle and formula calculation, a SolidWorks software is used for drawing an air inlet model, then a 3D printing technology is used for manufacturing an air inlet connecting device which can be matched with the measured engine in size and an air inlet 2, and a convergent air inlet is obtained, the shape of the convergent air inlet is similar to that of a loudspeaker, wherein the inner diameter of the air inlet 2 is 68mm, and epoxy resin is coated on the outer edge of the convergent air inlet to improve the smoothness of the convergent air inlet. The vertical direction of the air inlet channel 2 is communicated with a micro differential pressure sensor 3 by using a transparent hose, and the micro differential pressure sensor 3 is arranged on the outer side of the explosion-proof acrylic plate, is connected with the atmosphere and is not influenced by the surrounding air flow of the tested engine. When the tested engine runs, dynamic pressure and static pressure signals measured by the micro differential pressure sensor 3 are input to the Arduino mega2560 singlechip controller, so that the air mass flow at the air inlet channel 2 can be calculated, turbulence at the air inlet channel opening can be prevented, the flow loss work is reduced, the air flow velocity in front of the air inlet channel is improved, the fuel can be combusted more fully, and the engine efficiency is improved.

The measurement and control platform also comprises a space cable, a shutoff switch, an electromagnetic shutoff valve and the like. The electromagnetic shutoff valve improves safety, once the tested engine fails, the electromagnetic shutoff valve can rapidly close an oil way of the measurement and control platform, and the fuel supply to the tested engine is stopped, so that the safety of equipment and test personnel is protected. The invention realizes the control of the main equipment vehicle at a longer distance through the aerial cable, integrates control signals and analyzes test data.

The invention adopts SolidWorks software design and drawing design, and adopts 3D printing technology to manufacture the components of the test box 10, a control rod assembly comprising a starting rod 18 and a throttle rod 19, the air inlet channel 2, the thrust indicating disc 17 and the like. And the test box 10 is internally integrated with an Arduino mega2560 singlechip controller, an engine electronic control unit ECU, an aviation socket and a total signal cable of a circuit. The command box 22 contains the start lever 18 and throttle lever 19, an LCD display screen and an emergency control switch.

The electrical system schematic diagram of the measurement and control platform is shown in fig. 6. The outdoor power supply 21 is a total power supply of the measurement and control platform, supplies power to the computer host 20 and the display on the auxiliary equipment vehicle, and also supplies power to the plurality of sensor groups on the main equipment vehicle through the transformer and the voltage stabilizing plate. The 5V voltage inside the command box 17 powers the signal transmission of the plurality of sensor groups. In order to ensure that a plurality of sensor groups are connected in parallel simultaneously, an expansion board is welded on the Arduino mega2560 singlechip controller so as to provide a sufficient expansion port for sensor access. The measurement and control platform adopts the Arduino mega2560 singlechip controller as a main controller, adopts a JetCat P160-RXi-B micro turbojet engine as a tested engine, adopts a V12 version ECU full digital electronic controller with the weight of 29 g as an engine electronic control unit to carry out terminal control, and realizes communication through a PowerBus bus cable.

The measurement and control platform comprises a manual operation mode and an automatic operation mode. The automatic operation mode is based on a manual operation mode, an operator manually operates the throttle lever 19 according to the power requirement of the tested engine in a test, and once the position of the throttle lever 19 is determined, the tested engine automatically operates under corresponding power. The measurement and control platform is in open loop control, and the control on the running condition of the tested engine cannot be separated from an artificial operation mode.

In the manual operation mode, the control of the tested engine is divided into three parts: starting, accelerating and decelerating and stopping. The control of the tested engine is realized by manually controlling the throttle lever 19. The angle sensor arranged in the instruction box 22 is mechanically connected with the throttle lever 19 on the instruction box 22, the angle sensor reads the position of the throttle lever 19 for semicircular movement operation according to the linear position relation between the throttle lever 19 and the throttle lever, then the position signal is converted into voltage data, and after the voltage data is read by a computer, a corresponding frequency signal is output to the stepping motor, so that the stepping motor accurately controls the fuel gear pump at different rotating speeds, and further the fuel flow is changed to control the tested engine. The throttle lever 19 transmits PWM signals to the Arduino mega2560 single-chip microcomputer controller, the Arduino mega2560 single-chip microcomputer controller transmits data through a Thr-ch end in an engine electronic control unit ECU, and the engine electronic control unit ECU controls the rotating speed of the tested engine through an internal algorithm. And the sensor groups transmit signals acquired by the tested engine in the test to the Arduino mega2560 singlechip controller. On one hand, the Arduino mega2560 singlechip controller transmits partial data to an LCD display screen and a thrust indicating disc 17 on the instruction box 22 through serial port communication; on the other hand, the Arduino mega2560 singlechip controller uploads communication data of the engine electronic control unit ECU to the computer host 20, and the acquisition of test data is completed after signal processing.

In an automatic mode of operation, the starting and acceleration/deceleration of the engine under test is accomplished by the starting lever 18 executing pneumatic control logic. In the test of the present invention, a start control program was inputted to the engine electronic control unit ECU, and the start lever 18 and the throttle lever 19 on the command box 22 were executed in accordance with the logic of the start control program. In the test process, the Arduino mega2560 singlechip controller is used as a measurement and control development system of the tested engine, so that the computer host 20 runs Arduino codes in an Arduino integrated development environment, and runs programs after being burnt to the Arduino mega2560 singlechip controller through a data line. After the test is finished, the effective data or the filtered data recorded by the sensor groups through the Arduino mega2560 singlechip controller are exported from the Arduino IDE in the computer host 20, and the visual serial port data communication is completed by using the VSPD virtual serial port of the computer host 20. The Arduino mega2560 single-chip controller displays the calculated parameters on the LCD display screen or the display of the host computer 20 through IIC protocol. And finally, inputting the dynamic data of the tested engine in each working stage and clocks of serial port data of a unified engine electronic control unit ECU and an Arduino mega2560 singlechip controller into MATLAB for processing. In MATLAB software, not only can a dynamic characteristic curve chart of the tested engine be drawn by using a drawing function, but also a guide command can be further input to start a MATLAB GUI development tool.

As shown in fig. 7, using MATLAB GUI for serial data communication and visualization includes: installing a virtual serial port, creating a serial port object, configuring serial port attributes, receiving data by the serial port and displaying the serial port data. The virtual parameter is utilized to start and transmit the electronic control unit ECU of the engine to return the following data: 1. the rotating speed of the tested engine; 2. the temperature of the engine to be tested; 3. oil pump voltage (V); 4. engine state parameters such as rotational speed, thrust, intake pressure, exhaust temperature EGT, fuel flow, mass air flow, fuel consumption, etc.; pwm input throttle position (%); 6. and the current (A) of the tested engine. The sending RFI instructs the electronic control unit ECU to send the following data: 1. current fuel flow (ml/min); 2. residual fuel (ml) in the fuel tank; 3. a set rotation speed; 4. battery actual voltage (V); 5. the running time(s) of the tested engine; 6. and the fuel quantity consumed by the operation of the tested engine.

The engine electronic control unit ECU is connected with the Arduino mega2560 single-chip microcomputer controller and is used for operating the starting rod 18, and the engine electronic control unit ECU transmits a rotating speed signal to the tested engine; meanwhile, the engine ECU integrates a temperature sensor, and the open-loop control of the fuel flow is realized according to the ambient temperature of the tested engine. Wherein, the rotation speed signal and throttle command of the tested engine are collected by the host computer 20.

The measurement and control platform not only can control the working state of the tested engine, calculates and outputs signals fed back by a plurality of sensor groups to the Arduino mega2560 singlechip controller, but also stores data of the tested engine during operation, and leads the data into the host computer 20, and is matched with computer modeling software to draw a curve of the relation between the starting time and the converted rotational speed of the tested engine at different atmospheric temperatures, a curve of the relation between the converted rotational speed and the converted thrust at different temperatures, a curve of the relation between the converted rotational speed and the turbine outlet temperature at different temperatures, a curve of the relation between the converted rotational speed and the oil supply quantity at different temperatures, a curve of the relation between the converted rotational speed and the air mass flow at different pressures, a curve of the relation between the starting time and the converted rotational speed at different pressures, a curve of the converted rotational speed and the converted thrust at different pressures, a curve of the converted rotational speed and the converted oil supply quantity at different pressures, a curve of the converted rotational speed and the converted mass flow of the air at different pressures, and the like.

The following are specific examples of tests performed by the test and control station of the present invention.

Example 1: the invention relates to a start test of a tested engine, which comprises the following steps:

1. preparation and installation prior to testing.

2. Starting the tested engine: firstly, the spark plug is preheated for about 5 seconds in a state that the starting motor is not operated, and the starting motor is started to drive the tested engine to accelerate to a constant rotating speed. Then, the oil pump starts to pump fuel oil into the tested engine, the spark plug starts to ignite, the combustion chamber starts to heat up to more than 120 ℃, then the fuel oil is ignited, the turbine of the tested engine starts to do work with the help of the starting motor, and when the work generated by the turbine is equal to the work consumed by the air compressor, the tested engine is at the minimum balance rotating speed. Finally, after the measured engine speed exceeds the minimum equilibrium speed, the turbine produces more work than the compressor consumes, and therefore the measured engine is in an accelerated state.

3. And the starting motor continues to work, so that the rotating speed of the tested engine is gradually increased until the stable rotating speed is reached. And when the rotating speed of the tested engine exceeds the rotating speed of the slow car, the starting motor is separated. When the detected engine speed approaches to the stable speed, the engine stays briefly at the speed, and then automatically decelerates to the slow vehicle speed. When the measured engine speed reaches a slow speed and the throttle lever 19 is in a slow position, i.e. a minimum position, the thrust control of the measured engine is handed over to the operator's hand of the starting lever 18. And after maintaining the rotation speed of the tested engine at the slow vehicle rotation speed for at least 30 seconds, ending the start acceleration test.

4. Repeating the test for a plurality of times, checking the data validity of the data stored in each test, eliminating invalid data, and cutting out the data of the tested engine in the starting stage. And unifying clocks of data in serial ports of the ECU and the Arduino mega2560 SCM controller, and drawing a time-conversion rotating speed relation chart at different temperatures, a conversion rotating speed-conversion thrust relation chart at different temperatures, a conversion rotating speed-turbine outlet temperature relation chart at different temperatures, a conversion rotating speed-oil supply quantity relation chart at different temperatures, a conversion rotating speed-air mass flow relation chart at different pressures, a time-conversion rotating speed relation chart at different pressures, a conversion rotating speed-conversion thrust relation chart at different pressures, a conversion rotating speed-turbine outlet temperature relation chart at different pressures, a conversion rotating speed-oil supply quantity relation chart at different pressures and a conversion rotating speed-air mass flow relation chart at different pressures by MATLAB.

Example 2: the steady state test of the tested engine comprises the following steps:

1. according to the measurement graph of the atmospheric temperature and the atmospheric pressure change along with time in summer, the conclusion of the atmospheric temperature and the atmospheric pressure change in 24h is obtained: the lowest temperature in the day is approximately sunrise time; the highest temperature is approximately at 2 pm; air pressure is inversely related to the ratio. In summary, the test time selected in this test was 4: 00. 14:00 and 22:00. as shown in table 1, three sets of test environment parameter tables are provided.

2. Starting the engine, recording current test environment parameters when the tested engine reaches the slow speed, and keeping the test environment parameters and the starting time of each group shown in the table 1 for 30S.

3. The rotational speed of the engine under test was increased by 10000 revolutions each, the stationary running time was 30S each, the highest rotational speed of the test was 110000rpm, and test data of each group was recorded.

4. And reducing the rotating speed of the tested engine from 110000rpm, wherein the rotating speed is reduced by 100000 revolutions each time, the steady operation time is 30S each time, and each group of test data is collected and stored when the rotating speed of the tested engine is reduced to the slow vehicle rotating speed.

5. And closing the tested engine, starting a built-in heat dissipation bypass fan motor of the engine to cool, and finishing and checking the experimental instrument after the temperature is reduced to about normal temperature, so that the experiment is finished.

6. And drawing an engine time-rotating speed diagram under different working conditions, an engine rotating speed-thrust relation diagram under different temperatures, an engine rotating speed-air mass flow relation diagram under different temperatures, an engine rotating speed-fuel flow relation diagram under different temperatures, an engine rotating speed-thrust relation diagram under different pressures, an engine rotating speed-air mass flow relation diagram under different pressures and an engine rotating speed-fuel flow relation diagram under different pressures by MATLAB.

And obtaining the fuel oil quantity condition of the tested engine through multiple tests. As shown in Table 2, the fuel amount of the tested engine is shown in the three test environments in example 2.

Table 1 test environmental parameter table

Experiment group number	First number	No. two	No. three
				Atmospheric temperature (. Degree. C.)	18	23	28
Atmospheric pressure (KPA)	9.6200	9.5790	9.5319

TABLE 2 Fuel consumption Condition Meter for engines under different test environments

Experiment group number	First number	No. two	No. three
				Residual fuel quantity (ml) before testing	2650.42	2550.40	1986.88
Residual fuel quantity (ml) after test run	1443.00	1419.78	873.33
				Fuel consumption (ml)	1207.42	1130.62	1013.55

The invention intuitively displays the power data of the tested engine in real time when the tested engine runs. And from the aspects of thrust, rotating speed, fuel economy and the like of the tested engine, the performance data of the tested engine before test flight are verified, and the development of the turbojet power system is optimized. The invention provides a movable measurement and control platform which meets the requirements of testers on testing a power system of a tested engine in various environments and can be applied to teaching of related professions of an aviation power system.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. The utility model provides an unmanned aerial vehicle miniature turbine jet engine observes and controls platform which characterized in that: the test bench comprises an engine test bench and a control terminal, which are respectively arranged on a main equipment car and an auxiliary equipment car;

the engine test bench is formed by an antistatic workbench, and the tested engine is a miniature turbojet engine and is arranged on the antistatic workbench through a horizontal profile bracket; the tested engine comprises an engine main body, a tail spray pipe and an air inlet channel; a plurality of intake pressure collecting pipes are arranged in the circumferential direction of the air inlet channel; the tested engine is provided with an engine electronic control unit ECU, an Arduino mega2560 singlechip controller and a plurality of sensor groups for measuring data of the tested engine and external environment; a thrust indicating disc, a test box and an aviation socket are sequentially arranged on the antistatic workbench outwards from the tail nozzle; the bottom of the antistatic workbench is provided with a plurality of supporting legs, and the bottom of each supporting leg is provided with a pulley so that the engine test bench can move; the antistatic workbench is connected with a micro flowmeter and a fuel servo valve; the sensor groups comprise a high-precision ultrasonic liquid level sensor, a pull pressure sensor, a micro differential pressure sensor, a Hall flow sensor, a BOSCH BMP180 air temperature and pressure monitoring module and an accelerometer electronic gyroscope with an MPU6050 module; an anti-overturning lateral support arm is arranged on one side, close to the tested engine main body, of the main equipment vehicle; an explosion-proof acrylic plate is arranged at the upper part and the lateral direction of the tested engine; the micro flowmeter is the Hall flow sensor;

The control terminal comprises a workbench, a computer host, a display and an instruction box are arranged on the workbench, and an outdoor power supply is arranged on a partition plate at the bottom of the workbench; a starting rod and an accelerator rod are arranged in the instruction box;

the high-precision ultrasonic liquid level sensor is arranged in the fuel tank and is used for measuring the distance from the top of the fuel tank to the oil liquid so as to calculate the residual oil quantity in the fuel tank; the tension and pressure sensor is arranged at the bottom of the horizontal section bar bracket and is used for measuring the thrust of the tested engine during working; the micro differential pressure sensor is arranged at one end of the antistatic workbench, which is close to the air inlet channel, and is used for measuring the air pressure of the air inlet channel and converting the air pressure into air mass flow; the Hall flow sensor is connected in series in a fuel pipeline for providing fuel for the tested engine and is used for measuring the fuel flow; the BOSCH BMP180 air temperature and pressure monitoring module is arranged in the test box and connected with the Arduino mega2560 singlechip controller and is used for monitoring the atmospheric temperature and pressure; the accelerometer electronic gyroscope carrying the MPU6050 module is arranged and fixed on the horizontal section bar bracket and is used for measuring a triaxial vibration signal of the tested engine;

The anti-overturning lateral support arm consists of an aluminum alloy support column and a support beam, two metal clamping rings are arranged on each of two adjacent support legs in the longitudinal direction of the long side of the anti-static workbench, the two metal clamping rings are fixed and locked with one end of the anti-overturning lateral support arm, and the anti-overturning lateral support arm is foldable.

2. The unmanned aerial vehicle microturbine jet engine measurement and control station of claim 1, wherein: the micro flow meter and the fuel servo valve are simultaneously connected in series in a fuel pipeline, fuel flows into the tested engine from the fuel tank through the antistatic oil path hose, and sequentially flows through the fuel servo valve and the micro flow meter.

3. The unmanned aerial vehicle microturbine jet engine measurement and control station of claim 1, wherein: manufacturing the test box, the starting rod, the accelerator rod, the air inlet channel and the thrust indicating disc through a 3D printing technology; the Arduino mega2560 singlechip controller and the engine electronic control unit ECU are integrated in the test box.

4. The unmanned aerial vehicle microturbine jet engine measurement and control station of claim 1, wherein: and the BOSCH BMP180 air temperature and pressure monitoring module is connected with the Arduino mega2560 singlechip controller through an IIC bus, and measured temperature and pressure data are displayed in an LCD display screen on the test box.

5. The unmanned aerial vehicle microturbine jet engine measurement and control station of claim 1, wherein: the thickness of the explosion-proof acrylic plate is 30mm.

6. The unmanned aerial vehicle microturbine jet engine measurement and control station of claim 1, wherein: the vertical direction of the air inlet channel is communicated with the micro differential pressure sensor through a transparent hose, the micro differential pressure sensor is arranged on the outer side of the explosion-proof acrylic plate, is connected with the atmosphere and is not influenced by airflow around the tested engine, and dynamic pressure and static pressure signals measured by the micro differential pressure sensor are input to the Arduino mega2560 singlechip controller, so that the air mass flow at the air inlet channel is calculated.

7. The method for measuring and controlling the micro turbojet engine measuring and controlling platform of the unmanned aerial vehicle according to any one of claims 1 to 6, wherein the method comprises the following steps: the method comprises a manual operation mode and an automatic operation mode; the automatic operation mode is based on the manual operation mode, the throttle lever is manually operated according to the power requirement of the tested engine, and once the position of the throttle lever is determined, the tested engine automatically operates under the corresponding power.

8. The measurement and control method of claim 7, wherein:

in the manual operation mode, the control of the tested engine is divided into three parts: starting, accelerating and decelerating and stopping; the control of the tested engine is realized by manually controlling the throttle lever; the angle sensor arranged in the instruction box is mechanically connected with the throttle lever on the instruction box, reads the position of the throttle lever for semicircular movement operation according to the linear position relation between the throttle lever and the angle sensor, converts the position signal into voltage data, and outputs a corresponding frequency signal to the stepping motor after the computer reads the voltage data, so that the stepping motor accurately controls the fuel gear pump at different rotating speeds, and further changes the fuel flow to control the tested engine; the throttle lever transmits PWM signals to the Arduino mega2560 single-chip microcomputer controller, the Arduino mega2560 single-chip microcomputer controller transmits data through a Thr-ch end in an engine electronic control unit ECU, and the engine electronic control unit ECU controls the rotating speed of the tested engine through an internal algorithm; the sensor groups transmit signals acquired by the tested engine in the test to the Arduino mega2560 singlechip controller; on one hand, the Arduino mega2560 singlechip controller transmits partial data to an LCD display screen and a thrust indication disc on the instruction box through serial port communication; on the other hand, the Arduino mega2560 singlechip controller uploads communication data of an ECU (electronic control unit) of the engine to a host computer, and the acquisition of test data is completed after signal processing;